| 1. |
Yu Horiuchi, Masahiko Asami, Tomomi Ide, Kazuyuki Yahagi, Kota Komiyama, Hitomi Yuzawa, Jun Tanaka, Jiro Aoki, Shouji Matsushima, Takeshi Tohyama, Nobuyuki Enzan, Hiroyuki Tsutsui, Kengo Tanabe, Prevalence, Characteristics and Cardiovascular and Non-cardiovascular Outcomes in Patients with Heart Failure with Supra-normal Ejection Fraction; Insight from the JROADHF Study., European journal of heart failure, 10.1002/ejhf.2895, 2023.05, AIMS: We aimed to investigate the characteristics and prognosis of patients with heart failure with supra-normal ejection fraction (HFsnEF) compared to HF with normal EF (HFnEF). METHODS AND RESULTS: Among 11,573 patients enrolled in the nationwide registry of hospitalized patients with HF in Japan, 1,943 patients (16.8%) were classified as HFsnEF (left ventricular EF [LVEF] > 65%), 3,277 (28.3%) as HFnEF (50% ≤ LVEF ≤ 65%), 2,024 (17.5%) as HF with mildly reduced EF (40% ≤ EF |
| 2. |
Nobuyuki Enzan, Shouji Matsushima, Hidetaka Kaku, Takeshi Tohyama, Tomoyuki Nezu, Tae Higuchi, Yuta Nagatomi, Takeo Fujino, Toru Hashimoto, Tomomi Ide, Hiroyuki Tsutsui, Propensity-Matched Study of Early Cardiac Rehabilitation in Patients With Acute Decompensated Heart Failure., Circulation. Heart failure, 10.1161/CIRCHEARTFAILURE.122.010320, 16, 4, e010320, 2023.04, BACKGROUND: The impact of early implementation of cardiac rehabilitation (CR) in heart failure (HF) patients remains to be elucidated. This study sought to determine whether CR during HF hospitalization could improve prognostic outcomes in patients with acute decompensated HF. METHODS: We analyzed patients with HF enrolled in the JROADHF (Japanese Registry of Acute Decompensated Heart Failure) registry, a retrospective, multicenter, nationwide registry of patients hospitalized for acute decompensated HF. Eligible patients were divided into 2 groups according to CR during hospitalization. The primary outcome was a composite of cardiovascular death or rehospitalization due to cardiovascular event after discharge. The secondary outcomes were cardiovascular death and cardiovascular event rehospitalization. RESULTS: Out of 10 473 eligible patients, 3210 patients underwent CR. Propensity score matching yielded 2804 pairs. Mean age was 77±12 years and 3127 (55.8%) were male. During a mean follow-up of 2.8 years, the CR group had lower incidence rates of the composite outcome (291 versus 327 events per 1000 patient-years; rate ratio, 0.890 [95% CI, 0.830-0.954]; P=0.001) and rehospitalization due to cardiovascular event (262 versus 295 events per 1000 patient-years; rate ratio, 0.888 [95% CI, 0.825-0.956]; P=0.002) than the no CR group. In-hospital CR was associated with an improvement in Barthel index for activities of daily living (P=0.002). Patients with very low Barthel index at admission were benefited by CR in comparison with patients with independent Barthel index (very low; hazard ratio, 0.834 [95% CI, 0.742-0.938]: independent; hazard ratio, 0.985 [95% CI, 0.891-1.088]; P for interaction=0.035). CONCLUSIONS: CR implementation during hospitalization was associated with better long-term outcomes in patients with acute decompensated HF. These data support the need for a randomized, controlled, adequately powered trial to definitively test the role of early physical rehabilitation in hospitalized patients with HF.. |
| 3. |
Yu Sato, Akiomi Yoshihisa, Tomomi Ide, Takeshi Tohyama, Nobuyuki Enzan, Shouji Matsushima, Hiroyuki Tsutsui, Yasuchika Takeishi, Regional Variation in the Clinical Practice and Prognosis in Patients With Heart Failure With Reduced Ejection Fraction in Japan - A Report From the Japanese Registry of Acute Decompensated Heart Failure (JROADHF)., Circulation journal : official journal of the Japanese Circulation Society, 10.1253/circj.CJ-22-0774, 2023.04, BACKGROUND: The present study aimed to clarify the regional variations in clinical practice and the prognosis of patients with heart failure with reduced ejection fraction (HFrEF) in Japan using the Japanese Registry of Acute Decompensated Heart Failure (JROADHF).Methods and Results: We recruited data of hospitalized patients with HFrEF (n=4,329) from the JROADHF. The patients were divided into 6 groups based on the region of Japan where they were hospitalized: Hokkaido-Tohoku (n=504), Kanto (n=958), Chubu (n=779), Kinki (n=902), Chugoku-Shikoku (n=446), and Kyushu (n=740). We compared the patients' characteristics, including etiology of HF and prognosis after discharge. The age of the patients was lowest in the Kanto and Kinki regions. In contrast, there were no differences in the prevalence of comorbidities, levels of B-type natriuretic peptide, or left ventricular EF among the 6 groups. Post-discharge cardiospecific prognosis, specifically, the composite of cardiac death or HF hospitalization, cardiac death, and HF hospitalization, was comparable among the 6 regions. CONCLUSIONS: There were no differences in cardiospecific prognosis in patients with HFrEF among the 6 regions in Japan.. |
| 4. |
Nobuyuki Enzan, Shouji Matsushima, Soichiro Ikeda, Kosuke Okabe, Akihito Ishikita, Taishi Yamamoto, Masashi Sada, Ryo Miyake, Yoshitomo Tsutsui, Ryohei Nishimura, Takayuki Toyohara, Yuki Ikeda, Yoko Shojima, Hiroko Deguchi Miyamoto, Tomonori Tadokoro, Masataka Ikeda, Kohtaro Abe, Tomomi Ide, Shintaro Kinugawa, Hiroyuki Tsutsui, ZBP1 Protects Against mtDNA-Induced Myocardial Inflammation in Failing Hearts., Circulation research, 10.1161/CIRCRESAHA.122.322227, 132, 9, 1110-1126, 2023.04, BACKGROUND: Mitochondrial DNA (mtDNA)-induced myocardial inflammation is intimately involved in cardiac remodeling. ZBP1 (Z-DNA binding protein 1) is a pattern recognition receptor positively regulating inflammation in response to mtDNA in inflammatory cells, fibroblasts, and endothelial cells. However, the role of ZBP1 in myocardial inflammation and cardiac remodeling remains unclear. The aim of this study was to elucidate the role of ZBP1 in mtDNA-induced inflammation in cardiomyocytes and failing hearts. METHODS: mtDNA was administrated into isolated cardiomyocytes. Myocardial infarctionwas conducted in wild type and ZBP1 knockout mice. RESULTS: We here found that, unlike in macrophages, ZBP1 knockdown unexpectedly exacerbated mtDNA-induced inflammation such as increases in IL (interleukin)-1β and IL-6, accompanied by increases in RIPK3 (receptor interacting protein kinase 3), phosphorylated NF-κB (nuclear factor-κB), and NLRP3 (nucleotide-binding domain and leucine-rich-repeat family pyrin domain containing 3) in cardiomyocytes. RIPK3 knockdown canceled further increases in phosphorylated NF-κB, NLRP3, IL-1β, and IL-6 by ZBP1 knockdown in cardiomyocytes in response to mtDNA. Furthermore, NF-κB knockdown suppressed such increases in NLRP3, IL-1β, and IL-6 by ZBP1 knockdown in response to mtDNA. CpG-oligodeoxynucleotide, a Toll-like receptor 9 stimulator, increased RIPK3, IL-1β, and IL-6 and ZBP1 knockdown exacerbated them. Dloop, a component of mtDNA, but not Tert and B2m, components of nuclear DNA, was increased in cytosolic fraction from noninfarcted region of mouse hearts after myocardial infarction compared with control hearts. Consistent with this change, ZBP1, RIPK3, phosphorylated NF-κB, NLRP3, IL-1β, and IL-6 were increased in failing hearts. ZBP1 knockout mice exacerbated left ventricular dilatation and dysfunction after myocardial infarction, accompanied by further increases in RIPK3, phosphorylated NF-κB, NLRP3, IL-1β, and IL-6. In histological analysis, ZBP1 knockout increased interstitial fibrosis and myocardial apoptosis in failing hearts. CONCLUSIONS: Our study reveals unexpected protective roles of ZBP1 against cardiac remodeling as an endogenous suppressor of mtDNA-induced myocardial inflammation.. |
| 5. |
Nobuyuki Enzan, Shouji Matsushima, Hidetaka Kaku, Takeshi Tohyama, Takuya Nagata, Tomomi Ide, Hiroyuki Tsutsui, Beneficial Effects of Dipeptidyl Peptidase-4 Inhibitors on Heart Failure With Preserved Ejection Fraction and Diabetes., JACC. Asia, 10.1016/j.jacasi.2022.09.015, 3, 1, 93-104, 2023.02, BACKGROUND: Dipeptidyl peptidase-4 (DPP-4) inhibitors have been shown to exert pleiotropic effects on heart failure (HF) in animal experiments. OBJECTIVES: This study sought to investigate the impact of DPP-4 inhibitors on HF patients with diabetes mellitus (DM). METHODS: We analyzed hospitalized patients with HF and DM enrolled in the JROADHF (Japanese Registry Of Acute Decompensated Heart Failure) registry, a nationwide registry of acute decompensated HF. Primary exposure was the use of a DPP-4 inhibitor. The primary outcome was a composite of cardiovascular death or HF hospitalization during the median follow-up of 3.6 years according to left ventricular ejection fraction. RESULTS: Out of 2,999 eligible patients, 1,130 had heart failure with preserved ejection fraction (HFpEF), 572 had heart failure with midrange ejection fraction (HFmrEF), and 1,297 had heart failure with reduced ejection fraction (HFrEF). In each cohort, 444, 232, and 574 patients received a DPP-4 inhibitor, respectively. A multivariable Cox regression model showed that DPP-4 inhibitor use was associated with a lower composite of cardiovascular death or HF hospitalization in HFpEF (HR: 0.69; 95% CI: 0.55-0.87; P = 0.002) but not in HFmrEF and HFrEF. Restricted cubic spline analysis demonstrated that DPP-4 inhibitors were beneficial in patients with higher left ventricular ejection fraction. In HFpEF cohort, propensity score matching yielded 263 pairs. DPP-4 inhibitor use was associated with a lower incidence rate of the composite of cardiovascular death or HF hospitalization (19.2 vs 25.9 events per 100 patient-years; rate ratio: 0.74; 95% CI: 0.57-0.97; P = 0.027) in matched patients. CONCLUSIONS: DPP-4 inhibitor use was associated with better long-term outcomes in HFpEF patients with DM.. |
| 6. |
Yoshitomo Tsutsui, Shouji Matsushima, Nobuyuki Enzan, Eri Noda, Keisuke Shinohara, Toru Hashimoto, Tomomi Ide, Shintaro Kinugawa, Hiroyuki Tsutsui, Nationwide Temporal Trends in Clinical Characteristics and Treatment of Dilated Cardiomyopathy From 2003 to 2013 in Japan - A Report From Clinical Personal Records., Circulation journal : official journal of the Japanese Circulation Society, 10.1253/circj.CJ-22-0554, 87, 4, 500-507, 2023.02, BACKGROUND: Little is known about nationwide temporal trends in the clinical characteristics and treatment of dilated cardiomyopathy (DCM) in Japan.Methods and Results: We collected data regarding demographics, echocardiography, and treatment of DCM between 2003 to 2013 from Clinical Personal Records, a national registry organized by the Japanese Ministry of Health, Labour, and Welfare. Among the 40,794 DCM patients screened, 27,702 with left ventricular ejection fraction (LVEF) |
| 7. |
Takeshi Tohyama, Tomomi Ide, Masataka Ikeda, Takuya Nagata, Koshiro Tagawa, Masayuki Hirose, Kouta Funakoshi, Kazuo Sakamoto, Junji Kishimoto, Koji Todaka, Naoki Nakashima, Hiroyuki Tsutsui, Deep Learning of ECG for the Prediction of Postoperative Atrial Fibrillation., Circulation. Arrhythmia and electrophysiology, 10.1161/CIRCEP.122.011579, 16, 2, e011579, 2023.01. |
| 8. |
Ichiro Sakamoto, Kenichiro Yamamura, Ayako Ishikita, Kisho Ohtani, Shintaro Umemoto, Hidetaka Kaku, Yuzo Yamasaki, Kohtaro Abe, Tomomi Ide, Hiroyuki Tsutsui, Visibility of Pulmonary Valve and Pulmonary Regurgitation on Intracardiac Echocardiography in Adult Patients with Tetralogy of Fallot., Journal of cardiovascular development and disease, 10.3390/jcdd10010024, 10, 1, 2023.01, Pulmonary regurgitation (PR) is a risk factor for sudden cardiac death in adult patients with repaired tetralogy of Fallot (TOF). However, transthoracic echocardiography (TTE) cannot fully visualize the pulmonary valve (PV) and PR. We investigated whether intracardiac echocardiography (ICE) could visualize the PV and PR better than TTE. Thirty adult patients with TOF (mean age 33 ± 15 years) scheduled for cardiac catheterization underwent ICE. The visualization of PV and the severity of PR were classified into three grades. ICE depicted the PV better than TTE (ICE vs. TTE: not visualized, partially visualized, and fully visualized: n = 1 [3%], n = 13 [43%], and n = 16 [53%] vs. n = 14 [47%], n = 13 [43%], and n = 3 [10%], p |
| 9. |
Ko Abe, Masataka Ikeda, Tomomi Ide, Tomonori Tadokoro, Hiroko Deguchi Miyamoto, Shun Furusawa, Yoshitomo Tsutsui, Ryo Miyake, Kosei Ishimaru, Masatsugu Watanabe, Shouji Matsushima, Tomoko Koumura, Ken-Ichi Yamada, Hirotaka Imai, Hiroyuki Tsutsui, Doxorubicin causes ferroptosis and cardiotoxicity by intercalating into mitochondrial DNA and disrupting Alas1-dependent heme synthesis., Science signaling, 10.1126/scisignal.abn8017, 15, 758, eabn8017, 2022.11, Clinical use of doxorubicin (DOX) is limited because of its cardiotoxicity, referred to as DOX-induced cardiomyopathy (DIC). Mitochondria-dependent ferroptosis, which is triggered by iron overload and excessive lipid peroxidation, plays a pivotal role in the progression of DIC. Here, we showed that DOX accumulated in mitochondria by intercalating into mitochondrial DNA (mtDNA), inducing ferroptosis in an mtDNA content-dependent manner. In addition, DOX disrupted heme synthesis by decreasing the abundance of 5'-aminolevulinate synthase 1 (Alas1), the rate-limiting enzyme in this process, thereby impairing iron utilization, resulting in iron overload and ferroptosis in mitochondria in cultured cardiomyocytes. Alas1 overexpression prevented this outcome. Administration of 5-aminolevulinic acid (5-ALA), the product of Alas1, to cultured cardiomyocytes and mice suppressed iron overload and lipid peroxidation, thereby preventing DOX-induced ferroptosis and DIC. Our findings reveal that the accumulation of DOX and iron in mitochondria cooperatively induces ferroptosis in cardiomyocytes and suggest that 5-ALA can be used as a potential therapeutic agent for DIC.. |
| 10. |
Masataka Ikeda, Tomomi Ide, Shouji Matsushima, Soichiro Ikeda, Kosuke Okabe, Akihito Ishikita, Tomonori Tadokoro, Masashi Sada, Ko Abe, Midori Sato, Akiko Hanada, Shinobu Arai, Kisho Ohtani, Atsushi Nonami, Shinichi Mizuno, Sachio Morimoto, Shinichiro Motohashi, Koichi Akashi, Masaru Taniguchi, Hiroyuki Tsutsui, Immunomodulatory Cell Therapy Using αGalCer-Pulsed Dendritic Cells Ameliorates Heart Failure in a Murine Dilated Cardiomyopathy Model., Circulation. Heart failure, 10.1161/CIRCHEARTFAILURE.122.009366, 15, 12, e009366, 2022.10, BACKGROUND: Dilated cardiomyopathy (DCM) is a life-threatening disease, resulting in refractory heart failure. An immune disorder underlies the pathophysiology associated with heart failure progression. Invariant natural killer T (iNKT) cell activation is a prospective therapeutic strategy for ischemic heart disease. However, its efficacy in nonischemic cardiomyopathy, such as DCM, remains to be elucidated, and the feasible modality for iNKT cell activation in humans is yet to be validated. METHODS: Dendritic cells isolated from human volunteers were pulsed with α-galactosylceramide ex vivo, which were used as α-galactosylceramide-pulsed dendritic cells (αGCDCs). We treated DCM mice harboring mutated troponin TΔK210/ΔK210 with αGCDCs and evaluated the efficacy of iNKT cell activation on heart failure in DCM mice. Furthermore, we investigated the molecular basis underlying its therapeutic effects in these mice and analyzed primary cardiac cells under iNKT cell-secreted cytokines. RESULTS: The number of iNKT cells in the spleens of DCM mice was reduced compared with that in wild-type mice, whereas αGCDC treatment activated iNKT cells, prolonged survival of DCM mice, and prevented decline in the left ventricular ejection fraction for 4 weeks, accompanied by suppressed interstitial fibrosis. Mechanistically, αGCDC treatment suppressed TGF (transforming growth factor)-β signaling and expression of fibrotic genes and restored vasculature that was impaired in DCM hearts by upregulating angiopoietin 1 (Angpt1) expression. Consistently, IFNγ (interferon gamma) suppressed TGF-β-induced Smad2/3 signaling and the expression of fibrotic genes in cardiac fibroblasts and upregulated Angpt1 expression in cardiomyocytes via Stat1. CONCLUSIONS: Immunomodulatory cell therapy with αGCDCs is a novel therapeutic strategy for heart failure in DCM.. |
| 11. |
Chiharu Ishii, Noburo Takizawa, Takeyuki Akita, Masashi Mita, Tomomi Ide, Ryuichi Konno, Kenji Hamase, Off-line two-dimensional LC-MS/MS determination of tryptophan enantiomers in mammalian urine and alteration of their amounts in d-amino acid oxidase deficient mice., Journal of pharmaceutical and biomedical analysis, 10.1016/j.jpba.2022.114919, 219, 114919-114919, 2022.09, D-Tryptophan (D-Trp) is one of the minor D-enantiomers of amino acids discovered in microbes and mollusca. In the present study, a highly-selective 2D chiral LC-MS/MS method has been designed and developed focusing on the determination of Trp enantiomers to investigate the presence and regulation of free D-Trp in mammals. The developed system consisted of a reversed-phase separation for the first dimension, an enantioselective separation for the second dimension and also the detection using a triple quadrupole mass spectrometer for the third/fourth dimensions. Using the present method, urinary D-Trp in mammals, including healthy human volunteers and mice, were successfully determined. Although only l-Trp was observed in a mixed urine sample of healthy volunteers, small amounts of D-Trp were detected in the C57BL/6J mice (n = 5, %D=6.18 ± 0.47). In B6DAO- mice lacking the activity of d-amino acid oxidase (DAO), relatively high levels of D-Trp were observed (n = 6, %d=27.43 ± 3.26). The obtained %d values of Trp in the urine of the C57BL/6J mice and B6DAO- mice were confirmed using various enantioselective columns having different separation properties. These results indicate that the urinary D-Trp level is regulated by DAO in mammals, and further investigations, such as tissue distribution and physiological significance of the intrinsic D-Trp, are expected.. |
| 12. |
Hiroko Deguchi Miyamoto, Masataka Ikeda, Tomomi Ide, Tomonori Tadokoro, Shun Furusawa, Ko Abe, Kosei Ishimaru, Nobuyuki Enzan, Masashi Sada, Taishi Yamamoto, Shouji Matsushima, Tomoko Koumura, Ken-Ichi Yamada, Hirotaka Imai, Hiroyuki Tsutsui, Iron Overload via Heme Degradation in the Endoplasmic Reticulum Triggers Ferroptosis in Myocardial Ischemia-Reperfusion Injury., JACC. Basic to translational science, 10.1016/j.jacbts.2022.03.012, 7, 8, 800-819, 2022.08, Ischemia-reperfusion (I/R) injury is a promising therapeutic target to improve clinical outcomes after acute myocardial infarction. Ferroptosis, triggered by iron overload and excessive lipid peroxides, is reportedly involved in I/R injury. However, its significance and mechanistic basis remain unclear. Here, we show that glutathione peroxidase 4 (GPx4), a key endogenous suppressor of ferroptosis, determines the susceptibility to myocardial I/R injury. Importantly, ferroptosis is a major mode of cell death in I/R injury, distinct from mitochondrial permeability transition (MPT)-driven necrosis. This suggests that the use of therapeutics targeting both modes is an effective strategy to further reduce the infarct size and thereby ameliorate cardiac remodeling after I/R injury. Furthermore, we demonstrate that heme oxygenase 1 up-regulation in response to hypoxia and hypoxia/reoxygenation degrades heme and thereby induces iron overload and ferroptosis in the endoplasmic reticulum (ER) of cardiomyocytes. Collectively, ferroptosis triggered by GPx4 reduction and iron overload in the ER is distinct from MPT-driven necrosis in both in vivo phenotype and in vitro mechanism for I/R injury. The use of therapeutics targeting ferroptosis in conjunction with cyclosporine A can be a promising strategy for I/R injury.. |
| 13. |
Tomonori Tadokoro, Masataka Ikeda, Ko Abe, Tomomi Ide, Hiroko Deguchi Miyamoto, Shun Furusawa, Kosei Ishimaru, Masatsugu Watanabe, Akihito Ishikita, Shouji Matsushima, Tomoko Koumura, Ken-Ichi Yamada, Hirotaka Imai, Hiroyuki Tsutsui, Ethoxyquin is a competent radical-trapping antioxidant for preventing ferroptosis in doxorubicin cardiotoxicity., Journal of cardiovascular pharmacology, 10.1097/FJC.0000000000001328, 2022.07, ABSTRACT: Doxorubicin (DOX) is an effective anti-cancer agent for various malignancies. Nevertheless, it has a side effect of cardiotoxicity, referred to as doxorubicin-induced cardiomyopathy (DIC), that is associated with a poorer prognosis. This cardiotoxicity limits the clinical use of DOX as a therapeutic agent for malignancies. Recently, ferroptosis, a form of regulated cell death induced by the accumulation of lipid peroxides, has been recognized as a major pathophysiology of DIC. Ethoxyquin is a lipophilic antioxidant widely used for food preservation and thus may be a potential therapeutic drug for preventing DIC. However, the efficacy of ethoxyquin against ferroptosis and DIC remains to be fully elucidated. Here, we investigated the inhibitory action of ethoxyquin against GPx4-deficient ferroptosis and its therapeutic efficacy against DOX-induced cell death in cultured cardiomyocytes and cardiotoxicity in a murine model of DIC. In cultured cardiomyocytes, ethoxyquin treatment effectively prevented GPx4-deficient ferroptosis. Ethoxyquin also prevented DOX-induced cell death, accompanied by the suppression of malondialdehyde (MDA) and mitochondrial lipid peroxides, which were induced by DOX. Furthermore, ethoxyquin significantly prevented DOX-induced cell death without any suppression of caspase cleavages representing apoptosis. In DIC mice, ethoxyquin treatment ameliorated cardiac impairments, such as contractile dysfunction and myocardial atrophy, and lung congestion. Ethoxyquin also suppressed serum lactate dehydrogenase and creatine kinase activities, decreased the levels of lipid peroxides such as MDA and acrolein, inhibited cardiac fibrosis, and reduced TUNEL-positive cells in the hearts of DIC mice. Collectively, ethoxyquin is a competent antioxidant for preventing ferroptosis in DIC and can be its prospective therapeutic drug.. |
| 14. |
Mitsukuni Kimura, Toru Hashimoto, Eri Noda, Yusuke Ishikawa, Akihito Ishikita, Takeo Fujino, Shouji Matsushima, Tomomi Ide, Shintaro Kinugawa, Kazuhiro Nagaoka, Tomoki Ushijima, Akira Shiose, Hiroyuki Tsutsui, Fulminant necrotizing eosinophilic myocarditis after COVID-19 vaccination survived with mechanical circulatory support, ESC HEART FAILURE, 10.1002/ehf2.13962, 2022.05, A 69-year-old man was hospitalized for heart failure 7 days after coronavirus disease 2019 (COVID-19) mRNA vaccination. Electrocardiography showed ST-segment elevation and echocardiography demonstrated severe left ventricular dysfunction. Venoarterial extracorporeal membrane oxygenation and Impella 5.0 were instituted because of cardiogenic shock and ventricular fibrillation. Endomyocardial biopsy demonstrated necrotizing eosinophilic myocarditis (NEM). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) PCR test was negative. He had no infection or history of new drug exposure. NEM was likely related to COVID-19 vaccination. He was administered 10 mg/kg of prednisolone following methylprednisolone pulse treatment (1000 mg/day for 3 days). Left ventricular function recovered and he was weaned from mechanical circulatory support (MCS). Follow-up endomyocardial biopsy showed no inflammatory cell infiltration. This is the first report of biopsy-proven NEM after COVID-19 vaccination survived with MCS and immunosuppression therapy. It is a rare condition but early, accurate diagnosis and early aggressive intervention can rescue patients.. |
| 15. |
Yuta Nagatomi, Tomomi Ide, Tae Higuchi, Tomoyuki Nezu, Takeo Fujino, Takeshi Tohyama, Takuya Nagata, Taiki Higo, Toru Hashimoto, Shouji Matsushima, Keisuke Shinohara, Tomiko Yokoyama, Aika Eguchi, Ayumi Ogusu, Masataka Ikeda, Yusuke Ishikawa, Fumika Yamashita, Shintaro Kinugawa, Hiroyuki Tsutsui, Home-based cardiac rehabilitation using information and communication technology for heart failure patients with frailty, ESC HEART FAILURE, 10.1002/ehf2.13934, 2022.05, Aims Cardiac rehabilitation (CR) is an evidence-based, secondary preventive strategy that improves mortality and morbidity rates in patients with heart failure (HF). However, the implementation and continuation of CR remains unsatisfactory, particularly for outpatients with physical frailty. This study investigated the efficacy and safety of a comprehensive home-based cardiac rehabilitation (HBCR) programme that combines patient education, exercise guidance, and nutritional guidance using information and communication technology (ICT).Methods and results This study was a single-centre, open-label, randomized, controlled trial. Between April 2020 and November 2020, 30 outpatients with chronic HF (New York Heart Association II-III) and physical frailty were enrolled. The control group (n = 15) continued with standard care, while the HBCR group (n = 15) also received comprehensive, individualized CR, including ICT-based exercise and nutrition guidance using ICT via a Fitbit (R) device for 3 months. The CR team communicated with each patient in HBCR group once a week via the application messaging tool and planned the training frequency and intensity of training individually for the next week according to each patient's symptoms and recorded pulse data during exercise. Dietitians conducted a nutritional assessment and then provided individual nutritional advice using the picture-posting function of the application. The primary outcome was the change in the 6 min walking distance (6MWD). The participants' mean age was 63.7 +/- 10.1 years, 53% were male, and 87% had non-ischaemic heart disease. The observed change in the 6MWD was significantly greater in the HBCR group (52.1 +/- 43.9 m vs. -4.3 +/- 38.8 m; P |
| 16. |
Petar M. Seferovic, Hiroyuki Tsutsui, Dennis M. McNamara, Arsen D. Ristic, Cristina Basso, Biykem Bozkurt, Leslie T. Cooper, Gerasimos Filippatos, Tomomi Ide, Takayuki Inomata, Karin Klingel, Ales Linhart, Alexander R. Lyon, Mandeep R. Mehra, Marija Polovina, Ivan Milinkovic, Kazufumi Nakamura, Stefan D. Anker, Ivana Veljic, Tomohito Ohtani, Takahiro Okumura, Thomas Thum, Carsten Tschope, Giuseppe Rosano, Andrew J. S. Coats, Randall C. Starling, Heart Failure Association of the ESC, Heart Failure Society of America and Japanese Heart Failure Society Position statement on endomyocardial biopsy (vol 23, pg 854, 2021), EUROPEAN JOURNAL OF HEART FAILURE, 10.1002/ejhf.2474, 24, 4, 732-732, 2022.04. |
| 17. |
Masataka Ikeda, Tomomi Ide, Shun Furusawa, Kosei Ishimaru, Tomonori Tadokoro, Hiroko Deguchi Miyamoto, Soichiro Ikeda, Kosuke Okabe, Akihito Ishikita, Ko Abe, Shouji Matsushima, Hiroyuki Tsutsui, Heart Rate Reduction with Ivabradine Prevents Cardiac Rupture after Myocardial Infarction in Mice, CARDIOVASCULAR DRUGS AND THERAPY, 10.1007/s10557-020-07123-5, 36, 2, 257-262, 2022.04, Purpose Cardiac rupture is a fatal complication following myocardial infarction (MI). An increase in heart rate (HR) is reportedly an independent risk factor for cardiac rupture during acute MI. However, the role of HR reduction in cardiac rupture after MI remains to be fully elucidated. We aimed to evaluate the therapeutic efficacy of HR reduction with ivabradine (IVA) on post-MI cardiac rupture in mice.Methods We induced MI in mice by ligating the left anterior descending coronary artery. Subsequently, we subcutaneously implanted osmotic pumps filled with IVA solution or vehicle (Veh) in the surviving MI mice at 24 h postoperatively. We biochemically analyzed the myocardium on day 5, additionally observed the mice for 10 days, and analyzed the rates of cardiac rupture and non-cardiac rupture death, and survival after MI.Results HR was significantly lower in the IVA-treated mice, whereas blood pressure was comparable between the two groups. Compared to the Veh-treated mice, apoptosis was significantly reduced in the MI border zone in the IVA-treated mice. Although there were no differences in the infarct size of the surviving MI mice between the two groups, HR reduction with IVA significantly reduced cardiac rupture (rupture rate 26 and 8% in the Veh-treated and IVA-treated groups, respectively) and improved survival after MI.Conclusion Our findings suggest that HR reduction with IVA prevents cardiac rupture after MI. This may be particularly effective in MI patients with a high HR who are either unable to adequately tolerate beta-blockers or whose HR remains high despite receiving beta-blockers.. |
| 18. |
Nobuyuki Enzan, Shouji Matsushima, Tomomi Ide, Takeshi Tohyama, Kouta Funakoshi, Taiki Higo, Hiroyuki Tsutsui, The use of angiotensin II receptor blocker is associated with greater recovery of cardiac function than angiotensin-converting enzyme inhibitor in dilated cardiomyopathy, ESC HEART FAILURE, 10.1002/ehf2.13790, 9, 2, 1175-1185, 2022.04, Aims Angiotensin-converting enzyme inhibitors (ACEis) or angiotensin II receptor blockers (ARBs) have been shown to be associated with recovery of cardiac function in patients with dilated cardiomyopathy (DCM). The aim of this study was to assess comparative effectiveness of ACEis vs. ARBs on recovery of left ventricular ejection fraction (LVEF) among patients with DCM.Methods and results We analysed the clinical personal records of DCM, a national database of the Japanese Ministry of Health, Labour and Welfare, from 2003 to 2014. Patients with LVEF = 40% at 3 years of follow-up. Out of 4618 eligible patients, 2238 patients received ACEis and 2380 patients received ARBs. Propensity score matching yielded 1341 pairs. Mean age was 56.0 years, 2041 (76.1%) were male, median duration of heart failure was 1 year, and mean LVEF was 27.6%. The primary outcome was observed more frequently in ARB group than in ACEi group (59.8% vs. 54.1%; odds ratio 1.26; 95% confidence interval 1.08-1.47; P = 0.003). The per-protocol analysis showed similar results (62.0% vs. 54.0%; odds ratio 1.39; 95% confidence interval 1.17-1.66; P |
| 19. |
Akihito Ishikita, Shouji Matsushima, Soichiro Ikeda, Kosuke Okabe, Ryohei Nishimura, Tomonori Tadokoro, Nobuyuki Enzan, Taishi Yamamoto, Masashi Sada, Yoshitomo Tsutsui, Ryo Miyake, Masataka Ikeda, Tomomi Ide, Shintaro Kinugawa, Hiroyuki Tsutsui, GFAT2 mediates cardiac hypertrophy through HBP-O-GlcNAcylation-Akt pathway, ISCIENCE, 10.1016/j.isci.2021.103517, 24, 12, 2021.12, Molecular mechanisms mediating cardiac hypertrophy by glucose metabolism are incompletely understood. Hexosamine biosynthesis pathway (HBP), an accessory pathway of glycolysis, is known to be involved in the attachment of O-linked N-acetylglucosamine motif (O-GlcNAcylation) to proteins, a post-translational modification. We here demonstrate that glutamine-fructose-6-phosphate amidotransferase 2 (GFAT2), a critical HBP enzyme, is a major isoform of GFAT in the heart and is increased in response to several hypertrophic stimuli, including isoproterenol (ISO). Knockdown of GFAT2 suppresses ISO-induced cardiomyocyte hypertrophy, accompanied by suppression of Akt O-GlcNAcylation and activation. Knockdown of GFAT2 does not affect anti-hypertrophic effect by Akt inhibition. Administration of glucosamine, a substrate of HBP, induces protein O-GlcNAcylation, Akt activation, and cardiomyocyte hypertrophy. In mice, 6-diazo-5-oxo-L-norleucine, an inhibitor of GFAT, attenuates ISO-induced protein O-GlcNAcylation, Akt activation, and cardiac hypertrophy. Our results demonstrate that GFAT2 mediates cardiomyocyte hypertrophy by HBP-O-GlcNAcylation-Akt pathway and could be a critical therapeutic target of cardiac hypertrophy.. |
| 20. |
Hiroyuki Tsutsui, Tomomi Ide, Hiroshi Ito, Yasuki Kihara, Koichiro Kinugawa, Shintaro Kinugawa, Miyuki Makaya, Toyoaki Murohara, Koichi Node, Yoshihiko Saito, Yasushi Sakata, Wataru Shimizu, Kazuhiro Yamamoto, Yasuko Bando, Yu-ki Iwasaki, Yoshiharu Kinugasa, Isamu Mizote, Hitoshi Nakagawa, Shogo Oishi, Akiko Okada, Atsushi Tanaka, Takashi Akasaka, Minoru Ono, Takeshi Kimura, Shun Kosaka, Masami Kosuge, Shin-ichi Momomura, JCS/JHFS 2021 Guideline Focused Update on Diagnosis and Treatment of Acute and Chronic Heart Failure, CIRCULATION JOURNAL, 10.1253/circj.CJ-21-0431, 85, 12, 2252-2291, 2021.12. |
| 21. |
Hiroyuki Tsutsui, Tomomi Ide, Hiroshi Ito, Yasuki Kihara, Koichiro Kinugawa, Shintaro Kinugawa, Miyuki Makaya, Toyoaki Murohara, Koichi Node, Yoshihiko Saito, Yasushi Sakata, Wataru Shimizu, Kazuhiro Yamamoto, Yasuko Bando, Yu-Ki Iwasaki, Yoshiharu Kinugasa, Isamu Mizote, Hitoshi Nakagawa, Shogo Oishi, Akiko Okada, Atsushi Tanaka, Takashi Akasaka, Minoru Ono, Takeshi Kimura, Shun Kosaka, Masami Kosuge, Shin-Ichi Momomura, JCS/JHFS 2021 Guideline Focused Update on Diagnosis and Treatment of Acute and Chronic Heart Failure, JOURNAL OF CARDIAC FAILURE, 10.1016/j.cardfail.2021.04.023, 27, 12, 1404-1444, 2021.12. |
| 22. |
Benjamin Bates, Nobuyuki Enzan, Takeshi Tohyama, Poonam Gandhi, Shouji Matsushima, Hiroyuki Tsutsui, Tomomi Ide, Soko Setoguchi, A Paradox of Medical Cost and Outcomes: A Comparison of Acute Heart Failure Outcomes in the United States vs. Japan, CIRCULATION, 144, 2021.11, 0. |
| 23. |
Nobuyuki Enzan, Shouji Matsushima, Tomomi Ide, Hidetaka Kaku, Takeshi Tohyama, Kouta Funakoshi, Taiki Higo, Hiroyuki Tsutsui, Inpatient Cardiac Rehabilitation After Hospitalization for Acute Decompensated Heart Failure is Associated With Reduced Cardiovascular Events, CIRCULATION, 144, 2021.11, 0. |
| 24. |
Takeshi Tohyama, Tomomi Ide, Masataka Ikeda, Hidetaka Kaku, Nobuyuki Enzan, Shouji Matsushima, Kouta Funakoshi, Junji Kishimoto, Koji Todaka, Hiroyuki Tsutsui, Machine learning-based model for predicting 1 year mortality of hospitalized patients with heart failure, ESC HEART FAILURE, 10.1002/ehf2.13556, 8, 5, 4077-4085, 2021.10, Aims Individual risk stratification is a fundamental strategy in managing patients with heart failure (HF). Artificial intelligence, particularly machine learning (ML), can develop superior models for predicting the prognosis of HF patients, and administrative claim data (ACD) are suitable for ML analysis because ACD is a structured database. The objective of this study was to analyse ACD using an ML algorithm, predict the 1 year mortality of patients with HF, and finally develop an easy-to-use prediction model with high accuracy using the top predictors identified by the ML algorithm.Methods and results Machine learning-based prognostic prediction models were developed from the ACD on 10 175 HF patients from the Japanese Registry of Acute Decompensated Heart Failure with 17% mortality during 1 year follow-up. The top predictors for prognosis in HF were identified by the permutation feature importance technique, and an easy-to-use prediction model was developed based on these predictors. The c-statistics and Brier scores of the developed ML-based models were compared with those of conventional risk models: Seattle Heart Failure Model (SHFM) and Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC). A voting classifier algorithm (ACD-VC) achieved the highest c-statistics among the six ML algorithms. The permutation feature importance technique enabled identification of the top predictors such as Barthel index, age, body mass index, duration of hospitalization, last hospitalization, renal disease, and non-loop diuretics use (feature importance values were 0.054, 0.025, 0.010, 0.005, 0.005, 0.004, and 0.004, respectively). Upon combination of some of the predictors that can be assessed from a brief interview, the Simple Model by ARTificial intelligence for HF risk stratification (SMART-HF) was established as an easy-to-use prediction model. Compared with the conventional models, SMART-HF achieved a higher c-statistic {ACD-VC: 0.777 [95% confidence interval (CI) 0.751-0.803], SMART-HF: 0.765 [95% CI 0.739-0.791], SHFM: 0.713 [95% CI 0.684-0.742], MAGGIC: 0.726 [95% CI 0.698-0.753]} and better Brier scores (ACD-VC: 0.121, SMART-HF: 0.124, SHFM: 0.139, MAGGIC: 0.130).Conclusions The ML model based on ACD predicted the 1 year mortality of HF patients with high accuracy, and SMART-HF along with the ML model achieved superior performance to that of the conventional risk models. The SMART-HF model has the clear merit of easy operability even by non-healthcare providers with a user-friendly online interface (https://hfriskcalculator.herokuapp.com/). Risk models developed using SMART-HF may provide a novel modality for risk stratification of patients with HF.. |
| 25. |
Nobuyuki Enzan, Shouji Matsushima, Tomomi Ide, Hidetaka Kaku, Takeshi Tohyama, Kouta Funakoshi, Taiki Higo, Hiroyuki Tsutsui, Sex Differences in Time-Dependent Changes in B-Type Natriuretic Peptide in Hypertrophic Cardiomyopathy., Circulation reports, 10.1253/circrep.CR-21-0110, 3, 10, 594-603, 2021.10, Background: Female sex is reported to be associated with poor prognosis in hypertrophic cardiomyopathy (HCM). The plasma B-type natriuretic peptide (BNP) concentration is a prognostic predictor in HCM. However, the effect of sex on BNP concentrations remains unclear among HCM patients. Methods and Results: Patient records in the Clinical Personal Records of HCM national database of the Japanese Ministry of Health, Labour and Welfare from 2009 to 2014 were analyzed. Of 3,570 HCM patients, 611 in whom BNP concentrations were assessed at both baseline and the 2-year follow-up were included in this analysis. The mean age was 60.4 years and 254 (41.6%) patients were female. Median (interquartile range) BNP concentrations were higher in females than males at both baseline (320.3 [159.0-583.1] vs. 182.8 [86.1-363.9] pg/mL; P |
| 26. |
Tomomi Ide, Hidetaka Kaku, Shouji Matsushima, Takeshi Tohyama, Nobuyuki Enzan, Kouta Funakoshi, Yoko Sumita, Michikazu Nakai, Kunihiro Nishimura, Yoshihiro Miyamoto, Miyuki Tsuchihashi-Makaya, Masaru Hatano, Issei Komuro, Hiroyuki Tsutsui, Clinical Characteristics and Outcomes of Hospitalized Patients With Heart Failure From the Large-Scale Japanese Registry Of Acute Decompensated Heart Failure (JROADHF), CIRCULATION JOURNAL, 10.1253/circj.CJ-20-0947, 85, 9, 1438-+, 2021.09, Background: With aging population, the prevalence and incidence of heart failure (HF) have been increasing worldwide. However, the characteristics and outcomes of patients with HF in an era of aging are not well established in Japan.Methods and Results: The Japanese Registry Of Acute Decompensated Heart Failure (JROADHF), a retrospective, multicenter, nationwide registry, was designed to study the clinical characteristics and outcomes of patients hospitalized with HF throughout Japan in 2013. One hundred and twenty-eight hospitals were selected by cluster random sampling and 13,238 hospitalized patients with HF were identified by medical record review. Demographics, medical history, severity, treatment, and in-hospital and long-term outcome data were collected from the Diagnostic Procedure Combination and medical charts. Data were analyzed using univariate and multivariate logistic regression or Cox regression analysis. The mean age of registered patients was 78.0 +/- 12.5 years and 52.8% were male. Elderly patients (age >75 years) accounted for 68.9%, and HF with preserved ejection fraction (HFpEF) accounted for 45.1%. Median length of hospital stay was 18 days and in-hospital mortality was 7.7%. The median follow-up period was 4.3 years, and the incidence rates for cardiovascular death and rehospitalization for HF were 7.1 and 21.1 per 100 person-years, respectively.Conclusions: A contemporary nationwide registry demonstrated that hospitalized HF patients were very elderly, HFpEF was common, and their prognosis was still poor in Japan.. |
| 27. |
Masataka Ikeda, Tomomi Ide, Tomonori Tadokoro, Hiroko Deguchi Miyamoto, Soichiro Ikeda, Kosuke Okabe, Akihito Ishikita, Midori Sato, Ko Abe, Shun Furusawa, Kosei Ishimaru, Shouji Matsushima, Hiroyuki Tsutsui, Excessive Hypoxia-Inducible Factor-1 alpha Expression Induces Cardiac Rupture via p53-Dependent Apoptosis After Myocardial Infarction, JOURNAL OF THE AMERICAN HEART ASSOCIATION, 10.1161/JAHA.121.020895, 10, 17, 2021.09, BACKGROUND: Apoptosis plays a pivotal role in cardiac rupture after myocardial infarction (MI), and p53 is a key molecule in apoptosis during cardiac rupture. Hif-1 alpha (hypoxia-inducible factor-1 alpha), upregulated under hypoxia, is a known p53 inducer. However, the role of Hif-1 alpha in the regulatory mechanisms underlying p53 upregulation, apoptosis, and cardiac rupture after MI is unclear.METHODS AND RESULTS: We induced MI in mice by ligating the left anterior descending artery. Hif-1 alpha and p53 expressions were upregulated in the border zone at day 5 after MI, accompanied by apoptosis. In rat neonatal cardiomyocytes, treatment with cobalt chloride (500 mu mol/L), which mimics severe hypoxia by inhibiting PHD (prolyl hydroxylase domain-containing protein), increased Hif-1 alpha and p53, accompanied by myocyte death with caspase-3 cleavage. Silencing Hif-1 alpha or p53 inhibited caspase-3 cleavage, and completely prevented myocyte death under PHD inhibition. In cardiac-specific Hif-1 alpha hetero-knockout mice, expression of p53 and cleavage of caspase-3 and poly (ADP-ribose) polymerase were reduced, and apoptosis was suppressed on day 5. Furthermore, the cleavage of caspase-8 and IL-1 beta (interleukin-1 beta) was also suppressed in hetero knock-out mice, accompanied by reduced macrophage infiltration and matrix metalloproteinase/tissue inhibitor of metalloproteinase activation. Although there was no intergroup difference in infarct size, the cardiac rupture and survival rates were significantly improved in the hetero knockout mice until day 10 after MI.CONCLUSIONS: Hif-1 alpha plays a pivotal role in apoptosis, inflammation, and cardiac rupture after MI, in which p53 is a critical mediator, and may be a prospective therapeutic target for preventing cardiac rupture.. |
| 28. |
Hiroaki Kitaoka, Hiroyuki Tsutsui, Toru Kubo, Tomomi Ide, Taishiro Chikamori, Keiichi Fukuda, Noboru Fujino, Taiki Higo, Mitsuaki Isobe, Chizuko Kamiya, Seiya Kato, Yasuki Kihara, Koichiro Kinugawa, Shintaro Kinugawa, Shigetoyo Kogaki, Issei Komuro, Nobuhisa Hagiwara, Minoru Ono, Yuichiro Maekawa, Shigeru Makita, Yoshiro Matsui, Shouji Matsushima, Yasushi Sakata, Yoshiki Sawa, Wataru Shimizu, Kunihiko Teraoka, Miyuki Tsuchihashi-Makaya, Hatsue Ishibashi-Ueda, Masafumi Watanabe, Michihiro Yoshimura, Arata Fukusima, Satoshi Hida, Shungo Hikoso, Teruhiko Imamura, Hiroko Ishida, Makoto Kawai, Toshiro Kitagawa, Takashi Kohno, Satoshi Kurisu, Yoji Nagata, Makiko Nakamura, Hiroyuki Morita, Hitoshi Takano, Tsuyoshi Shiga, Yasuyoshi Takei, Shinsuke Yuasa, Teppei Yamamoto, Tetsu Watanabe, Takashi Akasaka, Yoshinori Doi, Takeshi Kimura, Masafumi Kitakaze, Masami Kosuge, Morimasa Takayama, Hitonobu Tomoike, JCS/JHFS 2018 Guideline on the Diagnosis and Treatment of Cardiomyopathies, CIRCULATION JOURNAL, 10.1253/circj.CJ-20-0910, 85, 9, 1590-1689, 2021.09. |
| 29. |
Petar M. Seferovic, Hiroyuki Tsutsui, Dennis M. Mcnamara, Arsen D. Ristic, Cristina Basso, Biykem Bozkurt, Leslie T. Cooper, Gerasimos Filippatos, Tomomi Ide, Takayuki Inomata, Karin Klingel, Ales Linhart, Alexander R. Lyon, Mandeep R. Mehra, Marija Polovina, Ivan Milinkovic, Kazufumi Nakamura, Stefan D. Anker, Ivana Veljic, Tomohito Ohtani, Takahiro Okumura, Thomas Thum, Carsten Tschoepe, Giuseppe Rosano, Andrew J. S. Coats, Randall C. Starling, Heart Failure Association, Heart Failure Society of America, and Japanese Heart Failure Society Position Statement on Endomyocardial Biopsy, JOURNAL OF CARDIAC FAILURE, 10.1016/j.cardfail.2021.04.010, 27, 7, 727-743, 2021.07, Endomyocardial biopsy (EMB) is an invasive procedure, globally most often used for the monitoring of heart transplant rejection. In addition, EMB can have an important complementary role to the clinical assessment in establishing the diagnosis of diverse cardiac disorders, including myocarditis, cardiomyopathies, drug-related cardiotoxicity, amyloidosis, other infiltrative and storage disorders, and cardiac tumors. Improvements in EMB equipment and the development of new techniques for the analysis of EMB samples has significantly improved the diagnostic precision of EMB. The present document is the result of the Trilateral Cooperation Project between the Heart Failure Association of the European Society of Cardiology, Heart Failure Society of America, and the Japanese Heart Failure Society. It represents an expert consensus aiming to provide a comprehensive, up-to-date perspective on EMB, with a focus on the following main issues: (1) an overview of the practical approach to EMB, (2) an update on indications for EMB, (3) a revised plan for heart transplant rejection surveillance, (4) the impact of multimodality imaging on EMB, and (5) the current clinical practice in the worldwide use of EMB.. |
| 30. |
Nobuyuki Enzan, Shouji Matsushima, Tomomi Ide, Hidetaka Kaku, Takeshi Tohyama, Kouta Funakoshi, Taiki Higo, Hiroyuki Tsutsui, The Use of Angiotensin-Converting Enzyme Inhibitors or Angiotensin II Receptor Blockers Is Associated with the Recovered Ejection Fraction in Patients with Dilated Cardiomyopathy, INTERNATIONAL HEART JOURNAL, 10.1536/ihj.20-671, 62, 4, 801-810, 2021.07, Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin II receptor blockers (ARB) have been shown to prevent left ventricular remodeling and improve outcomes of patients with heart failure (HF). This study aimed to investigate whether the use of ACEi/ARB could be associated with HF with recovered ejection fraction (HFrecEF) in patients with dilated cardiomyopathy (DCM).We collected individual patient data regarding demographics, echocardiogram, and treatment in DCM between 2003 and 2014 from the clinical personal record, a national database of the Japanese Ministry of Health, Labour and Welfare. Patients with left ventricular ejection fraction (LVEF) = 40% at 3 years of follow-up.Out of 5,955 patients with DCM and LVEF |
| 31. |
Nobuyuki Enzan, Shouji Matsushima, Tomomi Ide, Hidetaka Kaku, Takeshi Tohyama, Kouta Funakoshi, Taiki Higo, Hiroyuki Tsutsui, Beta-Blocker Use Is Associated With Prevention of Left Ventricular Remodeling in Recovered Dilated Cardiomyopathy, JOURNAL OF THE AMERICAN HEART ASSOCIATION, 10.1161/JAHA.120.019240, 10, 12, 2021.06, BackgroundWithdrawal of optimal medical therapy has been reported to relapse cardiac dysfunction in patients with dilated cardiomyopathy (DCM) whose cardiac function had improved. However, it is unknown whether beta-blockers can prevent deterioration of cardiac function in those patients. We examined the effect of beta-blockers on left ventricular ejection fraction (LVEF) in recovered DCM.Methods and ResultsWe analyzed the clinical personal record of DCM, a national database of the Japanese Ministry of Health, Labor and Welfare, between 2003 and 2014. Recovered DCM was defined as a previously documented LVEF 10% at 2 years of follow-up. Of 5370 eligible patients, 4104 received beta-blockers. Propensity score matching yielded 1087 pairs. Mean age was 61.9 years, and 1619 (74.5%) were men. Mean LVEF was 49.3 +/- 8.2%, and median B-type natriuretic peptide was 46.6 (interquartile range, 18.0-118.1) pg/mL. The primary outcome was observed less frequently in the beta-blocker group than in the no-beta-blocker group (19.6% versus 24.0%; odds ratio [OR], 0.77; 95% CI, 0.63-0.95; P=0.013). Subgroup analysis demonstrated that female patients (women: OR, 0.54; 95% CI, 0.36-0.81; men: OR, 0.88; 95% CI, 0.69-1.12; P for interaction=0.040) were benefited by beta-blockers.ConclusionsBeta-blocker use could prevent deterioration of left ventricular systolic function in patients with recovered DCM.. |
| 32. |
Petar M. Seferovic, Hiroyuki Tsutsui, Dennis M. McNamara, Arsen D. Ristic, Cristina Basso, Biykem Bozkurt, Leslie T. Cooper, Gerasimos Filippatos, Tomomi Ide, Takayuki Inomata, Karin Klingel, Ales Linhart, Alexander R. Lyon, Mandeep R. Mehra, Marija Polovina, Ivan Milinkovic, Kazufumi Nakamura, Stefan D. Anker, Ivana Veljic, Tomohito Ohtani, Takahiro Okumura, Thomas Thum, Carsten Tschope, Giuseppe Rosano, Andrew J. S. Coats, Randall C. Starling, Heart Failure Association of the ESC, Heart Failure Society of America and Japanese Heart Failure Society Position statement on endomyocardial biopsy, EUROPEAN JOURNAL OF HEART FAILURE, 10.1002/ejhf.2190, 23, 6, 854-871, 2021.06, Endomyocardial biopsy (EMB) is an invasive procedure, globally most often used for the monitoring of heart transplant (HTx) rejection. In addition, EMB can have an important complementary role to the clinical assessment in establishing the diagnosis of diverse cardiac disorders, including myocarditis, cardiomyopathies, drug-related cardiotoxicity, amyloidosis, other infiltrative and storage disorders, and cardiac tumours. Improvements in EMB equipment and the development of new techniques for the analysis of EMB samples have significantly improved diagnostic precision of EMB. The present document is the result of the Trilateral Cooperation Project between the Heart Failure Association of the European Society of Cardiology, the Heart Failure Society of America, and the Japanese Heart Failure Society. It represents an expert consensus aiming to provide a comprehensive, up-to-date perspective on EMB, with a focus on the following main issues: (i) an overview of the practical approach to EMB, (ii) an update on indications for EMB, (iii) a revised plan for HTx rejection surveillance, (iv) the impact of multimodality imaging on EMB, and (v) the current clinical practice in the worldwide use of EMB.. |
| 33. |
Yuya Yoshida, Naoya Matsunaga, Takaharu Nakao, Kengo Hamamura, Hideaki Kondo, Tomomi Ide, Hiroyuki Tsutsui, Akito Tsuruta, Masayuki Kurogi, Michio Nakaya, Hitoshi Kurose, Satoru Koyanagi, Shigehiro Ohdo, Alteration of circadian machinery in monocytes underlies chronic kidney disease-associated cardiac inflammation and fibrosis, NATURE COMMUNICATIONS, 10.1038/s41467-021-23050-x, 12, 1, 2021.05, Dysfunction of the circadian clock has been implicated in the pathogenesis of cardiovascular disease. The CLOCK protein is a core molecular component of the circadian oscillator, so that mice with a mutated Clock gene (Clk/Clk) exhibit abnormal rhythms in numerous physiological processes. However, here we report that chronic kidney disease (CKD)-induced cardiac inflammation and fibrosis are attenuated in Clk/Clk mice even though they have high blood pressure and increased serum angiotensin II levels. A search for the underlying cause of the attenuation of heart disorder in Clk/Clk mice with 5/6 nephrectomy (5/6Nx) led to identification of the monocytic expression of G protein-coupled receptor 68 (GPR68) as a risk factor of CKD-induced inflammation and fibrosis of heart. 5/6Nx induces the expression of GPR68 in circulating monocytes via altered CLOCK activation by increasing serum levels of retinol and its binding protein (RBP4). The high-GPR68-expressing monocytes have increased potential for producing inflammatory cytokines, and their cardiac infiltration under CKD conditions exacerbates inflammation and fibrosis of heart. Serum retinol and RBP4 levels in CKD patients are also sufficient to induce the expression of GPR68 in human monocytes. Our present study reveals an uncovered role of monocytic clock genes in CKD-induced heart failure. Alteration of circadian rhythms is often observed in patients with chronic kidney disease (CKD). Here, the authors show that CKD-induced dysfunction of the circadian clock increases the expression of G protein-coupled receptor 68 in circulating monocytes and that their cardiac infiltration exacerbates inflammation and fibrosis of heart.. |
| 34. |
Tomomi Ide, Masamitsu Hayashida, Takeshi Ohgai, Current-perpendicular-to-plane giant magnetoresistance in Co/Cu multilayered nanocylinders electrodeposited into anodized aluminum oxide nanochannels with ultra-large aspect ratio, JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS, 10.1007/s10854-021-05667-2, 32, 8, 10089-10100, 2021.04, An anodized aluminum oxide (AAO) thick film with numerous nanochannels was synthesized by a cathodic exfoliation technique from a metallic aluminum rod. The nanochannel diameter D and length L were about 60 nm and 60 mu m, respectively. The aspect ratio L/D reached similar to 1000. A rectangular pulsed potential deposition technique was applied to electrochemically grow the multilayered nanocylinders with alternating Cu and Co thin layers in the AAO nanochannels. The Co/Cu bilayer thickness was decreased to around 7 nm at the minimum by controlling the pulsed potential and duty cycle during the electrodeposition process. An electrochemical in situ single contact process was demonstrated by monitoring the observed current until a Co/Cu multilayered nanocylinder reached the nanoporous Au film on the AAO thick film. The resistance of the Co/Cu multilayered nanocylinder was determined to range from 1 to 2 k Omega, which corresponded well with a theoretical estimation. Current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) of a Co/Cu multilayered nanocylinder with similar to 6000 bilayers (Cu = 2.4 nm, Co = 7.1 nm) reached up to 31.5% at room temperature. Valet-Fert model agreed well with the present study concerning the effect of Cu-layer thickness on CPP-GMR.. |
| 35. |
Keisuke Yamasaki, Jun Hata, Tomomi Ide, Takuya Nagata, Satoko Sakata, Daigo Yoshida, Takanori Honda, Yoichiro Hirakawa, Toshiaki Nakano, Takanari Kitazono, Hiroyuki Tsutsui, Toshiharu Ninomiya, Urinary N-terminal pro-B-type natriuretic peptide as a biomarker for cardiovascular events in a general Japanese population: the Hisayama Study, ENVIRONMENTAL HEALTH AND PREVENTIVE MEDICINE, 10.1186/s12199-021-00970-0, 26, 1, 2021.04, Background Epidemiological evidence has shown that serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations, a diagnostic biomarker for heart failure, are positively associated with cardiovascular risk. Since NT-proBNP in serum is excreted in urine, it is hypothesized that urinary NT-proBNP concentrations are correlated with serum concentrations and linked with cardiovascular risk in the general population. Methods A total of 3060 community-dwelling residents aged >= 40 years without history of cardiovascular disease (CVD) were followed up for a median of 8.3 years (2007-2015). Serum and urinary concentrations of NT-proBNP at baseline were compared. The hazard ratios (HRs) and their 95% confidence intervals (CIs) for the association between NT-proBNP concentrations and the risk of developing CVD were computed using the Cox proportional hazards model. Results The median values (interquartile ranges) of serum and urinary NT-proBNP concentrations at baseline were 56 (32-104) pg/mL and 20 (18-25) pg/mL, respectively. There was a strong quadratic correlation between the serum and urinary concentrations of NT-proBNP (coefficient of determination [R-2] = 0.72): urinary concentrations of 20, 27, and 43 pg/mL were equivalent to serum concentrations of 55, 125, and 300 pg/mL, respectively. During the follow-up period, 170 subjects developed CVD. The age- and sex-adjusted risk of CVD increased significantly with higher urinary NT-proBNP levels (P for trend = 43 pg/mL as compared to those with urinary NT-proBNP of |
| 36. |
Chin-Ling Hsieh, Takeyuki Akita, Masashi Mita, Tomomi Ide, Jen-Ai Lee, Kenji Hamase, Development of a selective three-dimensional HPLC system for enantiomer discriminated analysis of lactate and 3-hydroxybutyrate in human plasma and urine, JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS, 10.1016/j.jpba.2020.113871, 195, 2021.02, For the enantiomer discriminated determination of lactate (LA) and 3-hydroxybutyrate (3HB) in various complicated samples, a three-dimensional HPLC (3D-HPLC) system has been designed and developed by investigating the separation of the target analytes from unknown substances observed in the real target matrices. LA and 3HB were pre-column derivatized with 4-nitro-7-piperazino-2,1,3-benzoxadiazole for the sensitive fluorescence detection and introduced into the 3D-HPLC system composed of reversed-phase, mixed-mode and enantioselective separations. The present method was validated by calibration curves, precision and accuracy using standard solutions and human samples, and sufficient values were obtained. Using the method, the levels of D-LA, L-LA, D-3Hb and L-3Hb were determined, and their concentrations were 9.9, 1004.2, 79.7 and 2.1 mu M in the human plasma and 16.0, 86.6, 8.7 and 4.8 mu M in the human urine, respectively. The present 3D-HPLC system could selectively determine trace amounts of the target hydroxy acid enantiomers without disturbance of the intrinsic interfering substances in complicated matrices and the applications to various disease samples are expected. (C) 2021 Elsevier B.V. All rights reserved.. |
| 37. |
Nobuyuki Enzan, Shouji Matsushima, Tomomi Ide, Hidetaka Kaku, Takeshi Tohyama, Kouta Funakoshi, Taiki Higo, Hiroyuki Tsutsui, Clinical Characteristics and Contemporary Management of Patients With Cardiomyopathies in Japan - Report From a National Registry of Clinical Personal Records., Circulation reports, 10.1253/circrep.CR-21-0001, 3, 3, 142-152, 2021.02, Background: The clinical features of patients with cardiomyopathy, including dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), or restrictive cardiomyopathy (RCM), have not been recently elucidated in Japan. Methods and Results: We collected individual patient data regarding demographics, echocardiogram, and treatment in DCM from 2003 to 2014 and in HCM and RCM from 2009 to 2014 from the national registry of clinical personal records organized by the Japanese Ministry of Health, Labour and Welfare. In all, 44,136 patients were included in this registry: 40,537 with DCM, 3,553 with HCM, and 46 with RCM. The median age at diagnosis was older for DCM and HCM than RCM (54 and 55 vs. 42 years, respectively). Male patients accounted for 74.6%, 58.7%, and 60.9% of the DCM, HCM, and RCM groups, respectively. NYHA functional Class III-IV was found in 26.9%, 11.3%, and 58.1% of patients in the DCM, HCM, and RCM groups, respectively. In the DCM group, the rates of β-blocker and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker prescription were 69% and 76%, respectively. In regional subgroup analysis, the median age at diagnosis of DCM and HCM was younger in the Kanto region. A family history of HCM was less frequent in the Hokkaido/Tohoku region. Conclusions: The national registry of clinical personal records of cardiomyopathy could provide important information regarding the demographics, clinical characteristics, and management of cardiomyopathy throughout Japan.. |
| 38. |
Sui-Wen Hsiao, Chiharu Ishii, Aogu Furusho, Chin-Ling Hsieh, Yukiko Shimizu, Takeyuki Akita, Masashi Mita, Tadashi Okamura, Ryuichi Konno, Tomomi Ide, Ching-Kuo Lee, Kenji Hamase, Determination of phenylalanine enantiomers in the plasma and urine of mammals and D-amino acid oxidase deficient rodents using two-dimensional high-performance liquid chromatography, BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS, 10.1016/j.bbapap.2020.140540, 1869, 1, 2021.01, A two-dimensional (2D) HPLC system focusing on the determination of phenylalanine (Phe) enantiomers in mammalian physiological fluids has been developed. D-Phe is indicated to have potential values as a disease biomarker and therapeutic molecule in several neuronal and metabolic disorders, thus the regulation of D-Phe in mammals is a matter of interest. However, the precise determination of amino acid enantiomers is difficult in complex biological samples, and the development of an analytical method with practically acceptable sensitivity, selectivity and throughput is expected. In the present study, a 2D-HPLC system equipped with a reversed-phase column in the 1st dimension and an enantioselective column in the 2nd dimension has been designed, following the fluorescence derivatization of the target amino acid enantiomers with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F). The analytical method was validated using both plasma and urine samples, and successfully applied to human, rat and mouse fluids. Trace levels of D-Phe were determined in the plasma, and the %D values were around 0.1% for all species. In the urine, relatively large amounts of D-Phe were observed, and the %D values for humans, rats and mice were 3.99, 1.76 and 5.25%, respectively. The relationships between the enzymatic activity of D-amino acid oxidase (DAO) and the amounts of intrinsic D-Phe have also been clarified, and high D-Phe amounts were observed (around 0.3% in the plasma and around 50% in the urine) in the DAO deficient rats and mice.. |
| 39. |
Takuya Nagata, Jun Hata, Satoko Sakata, Emi Oishi, Takanori Honda, Yoshihiko Furuta, Tomoyuki Ohara, Daigo Yoshida, Yoichiro Hirakawa, Mao Shibata, Tomomi Ide, Takanari Kitazono, Hiroyuki Tsutsui, Toshiharu Ninomiya, Serum N-terminal pro-B-type natriuretic peptide as a predictor for future development of atrial fibrillation in a general population: the Hisayama Study, INTERNATIONAL JOURNAL OF CARDIOLOGY, 10.1016/j.ijcard.2020.06.018, 320, 90-96, 2020.12, Background: Biomarkers for predicting future development of atrial fibrillation (AF) have not been fully established in general populations. The aim of this study was to assess the predictive ability of serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) for the development of AF.Methods and results: A total of 3126 community-dwelling Japanese subjects aged >= 40 years without a history of AF in 2002 were followed up for a median of 10.2 years. Serum NT-proBNP levels at baseline were divided into four categories (= 300 pg/mL) according to the current guidelines and prior reports. The hazard ratios for the development of AF were estimated using a Cox proportional hazards model. During the follow-up period, 153 subjects developed new-onset AF. The age- and sex-adjusted cumulative incidence of AF increased significantly with higher serum NT-proBNP levels (p = 300 pg/mL: 8.51 [4.48-16.17]; p |
| 40. |
Yoshihiko Kodama, Yuichi Ishikawa, Ayako Kuraoka, Makoto Nakamura, Shinichiro Oda, Toshihide Nakano, Hideaki Kado, Ichiro Sakamoto, Kisho Ohtani, Tomomi Ide, Hiroyuki Tsutsui, Koichi Sagawa, Systemic-to-Pulmonary Collateral Flow Correlates with Clinical Condition Late After the Fontan Procedure, PEDIATRIC CARDIOLOGY, 10.1007/s00246-020-02450-8, 41, 8, 1800-1806, 2020.12, In the Fontan circulation, there is a substantial degree of systemic-to-pulmonary collateral flow (SPCF), which can be measured by cardiac magnetic resonance (CMR). However, the correlation between the degree of SPCF and long-term outcomes is not fully understood. We retrospectively studied 321 patients who underwent the Fontan procedure and CMR at a single center. Using CMR, we calculated SPCF as pulmonary blood flow - systemic blood flow. %SPCF was defined as SPCF divided by pulmonary blood flow. The mean age of patients at CMR was 14.3 +/- 7.5 years. The average %SPCF was 13.0% +/- 11.0%. With a multivariate analysis, %SPCF was significantly correlated with time (i.e., the longer the time period since the Fontan procedure, the lower the %SPCF) (p = 0.006), previous total anomalous pulmonary vein drainage (p = 0.007), a low pulmonary artery index (Nakata index) before the Fontan procedure (p = 0.04), and older age at the time of the Fontan procedure (p = 0.002). Regarding the findings after the Fontan procedure, %SPCF was significantly correlated with ventricular end-diastolic volume (p |
| 41. |
Hiroyuki Tsutsui, Tomomi Ide, Yasushi Kawasaki, Is High Heart Rate Always Harmful to Heart Failure Patients? - Reply -, CIRCULATION JOURNAL, 10.1253/circj.CJ-20-0590, 84, 9, 1674-1675, 2020.09. |
| 42. |
Shintaro Umemoto, Ichiro Sakamoto, Kohtaro Abe, Ayako Ishikita, Yuzo Yamasaki, Ken-ichi Hiasa, Tomomi Ide, Hiroyuki Tsutsui, Preoperative Threshold for Normalizing Right Ventricular Volume After Transcatheter Closure of Adult Atrial Septal Defect, CIRCULATION JOURNAL, 10.1253/circj.CJ-20-0136, 84, 8, 1312-+, 2020.08, Background: The latest guidelines recommend early intervention in adult atrial septal defect (ASD) patients with signs of right ventricular (RV) enlargement. However, the criteria of RV enlargement for optimal intervention remain unclear. We investigated the preoperative determinants for normalizing the RV volume after transcatheter closure of ASD in adults.Methods and Results: We retrospectively analyzed 52 ASD patients who underwent transcatheter closure. Cardiac magnetic resonance imaging (CMR) measured RV volume before and 1 year after the closure. The patients were divided into normalized (postoperative RV end-systolic volume index [RVESVI] |
| 43. |
Hiroko Deguchi, Masataka Ikeda, Tomomi Ide, Tomonori Tadokoro, Soichiro Ikeda, Kosuke Okabe, Akihito Ishikita, Keita Saku, Shouji Matsushima, Hiroyuki Tsutsui, Roxadustat Markedly Reduces Myocardial Ischemia Reperfusion Injury in Mice, CIRCULATION JOURNAL, 10.1253/circj.CJ-19-1039, 84, 6, 1028-1033, 2020.06, Background: Ischemic preconditioning (IPC) is an effective procedure to protect against ischemia/reperfusion (I/R) injury. Hypoxia-inducible factor-1 alpha (Hif-1 alpha) is a key molecule in IPC, and roxadustat (RXD), a first-in-class prolyl hydroxylase domain-containing protein inhibitor, has been recently developed to treat anemia in patients with chronic kidney disease. Thus, we investigated whether RXD pretreatment protects against I/R injury.Methods and Results: RXD pretreatment markedly reduced the infarct size and suppressed plasma creatinine kinase activity in a murine I/R model. Analysis of oxygen metabolism showed that RXD could produce ischemic tolerance by shifting metabolism from aerobic to anaerobic respiration.Conclusions: RXD pretreatment may be a novel strategy against I/R injury.. |
| 44. |
Tomonori Tadokoro, Masataka Ikeda, Tomomi Ide, Hiroko Deguchi, Soichiro Ikeda, Kosuke Okabe, Akihito Ishikita, Shouji Matsushima, Tomoko Koumura, Ken Ichi Yamada, Hirotaka Imai, Hiroyuki Tsutsui, Mitochondria-dependent ferroptosis plays a pivotal role in doxorubicin cardiotoxicity, JCI Insight, 10.1172/jci.insight.132747, 5, 9, 2020.05, Doxorubicin (DOX), a chemotherapeutic agent, induces a cardiotoxicity referred to as doxorubicin-induced cardiomyopathy (DIC). This cardiotoxicity often limits chemotherapy for malignancies and is associated with poor prognosis. However, the molecular mechanism underlying this cardiotoxicity is yet to be fully elucidated. Here, we show that DOX downregulated glutathione peroxidase 4 (GPx4) and induced excessive lipid peroxidation through DOX-Fe2+ complex in mitochondria, leading to mitochondria-dependent ferroptosis; we also show that mitochondria-dependent ferroptosis is a major cause of DOX cardiotoxicity. In DIC mice, the left ventricular ejection fraction was significantly impaired, and fibrosis and TUNEL+ cells were induced at day 14. Additionally, GPx4, an endogenous regulator of ferroptosis, was downregulated, accompanied by the accumulation of lipid peroxides, especially in mitochondria. These cardiac impairments were ameliorated in GPx4 Tg mice and exacerbated in GPx4 heterodeletion mice. In cultured cardiomyocytes, GPx4 overexpression or iron chelation targeting Fe2+ in mitochondria prevented DOX-induced ferroptosis, demonstrating that DOX triggered ferroptosis in mitochondria. Furthermore, concomitant inhibition of ferroptosis and apoptosis with ferrostatin-1 and zVAD-FMK fully prevented DOX-induced cardiomyocyte death. Our findings suggest that mitochondria-dependent ferroptosis plays a key role in progression of DIC and that ferroptosis is the major form of regulated cell death in DOX cardiotoxicity.. |
| 45. |
Hidetaka Kaku, Kouta Funakoshi, Tomomi Ide, Takeo Fujino, Shouji Matsushima, Kisho Ohtani, Taiki Higo, Michikazu Nakai, Yoko Sumita, Kunihiro Nishimura, Yoshihiro Miyamoto, Toshihisa Anzai, Hiroyuki Tsutsui, Impact of Hospital Practice Factors on Mortality in Patients Hospitalized for Heart Failure in Japan. -An Analysis of a Large Number of Health Records From a Nationwide Claims-Based Database, the JROAD-DPC-, CIRCULATION JOURNAL, 10.1253/circj.CJ-19-0759, 84, 5, 742-+, 2020.05, Background: An inverse relationship exists between hospital case volume and mortality in patients with heart failure (HF). However, hospital performance factors associated with mortality in HF patients have not been examined. We aimed to identify these using exploratory factor analysis and assess the relationship between these factors and 7-day, 30-day, and in-hospital mortality among HF patients in Japan.Methods and Results: We analyzed the records of 198,861 patients admitted to 683 certified hospitals of the Japanese Circulation Society between 2012 and 2014. Records were obtained from the nationwide database of the Japanese Registry Of All cardiac and vascular Diseases-Diagnostic Procedure Combination (JROAD-DPC). Using exploratory factor analysis, 90 hospital survey items were grouped into 5 factors, according to their collinearity: "Interventional cardiology", "Cardiovascular surgery", "Pediatric cardiology", "Electrophysiology" and "Cardiac rehabilitation". Multivariable logistic regression analysis was performed to determine the association between these factors and mortality. The 30-day mortality was 8.0%. Multivariable logistic regression analysis showed the "Pediatric cardiology" (odds ratio (OR) 0.677, 95% confidence interval [CI]: 0.628-0.729, P |
| 46. |
Tomonori Tadokoro, Masataka Ikeda, Tomomi Ide, Hiroko Deguchi, Soichiro Ikeda, Kosuke Okabe, Akihito Ishikita, Shouji Matsushima, Tomoko Koumura, Ken-ichi Yamada, Hirotaka Imai, Hiroyuki Tsutsui, Mitochondria-dependent ferroptosis plays a pivotal role in doxorubicin cardiotoxicity, JCI INSIGHT, 10.1172/jci.insight.132747, 5, 9, 2020.05, Doxorubicin (DOX), a chemotherapeutic agent, induces a cardiotoxicity referred to as doxorubicin-induced cardiomyopathy (DIC). This cardiotoxicity often limits chemotherapy for malignancies and is associated with poor prognosis. However, the molecular mechanism underlying this cardiotoxicity is yet to be fully elucidated. Here, we show that DOX downregulated glutathione peroxidase 4 (GPx4) and induced excessive lipid peroxidation through DOX-Fe2+ complex in mitochondria, leading to mitochondria-dependent ferroptosis; we also show that mitochondria-dependent ferroptosis is a major cause of DOX cardiotoxicity. In DIC mice, the left ventricular ejection fraction was significantly impaired, and fibrosis and TUNEL+ cells were induced at day 14. Additionally, GPx4, an endogenous regulator of ferroptosis, was downregulated, accompanied by the accumulation of lipid peroxides, especially in mitochondria. These cardiac impairments were ameliorated in GPx4 Tg mice and exacerbated in GPx4 heterodeletion mice. In cultured cardiomyocytes, GPx4 overexpression or iron chelation targeting Fe2+ in mitochondria prevented DOX-induced ferroptosis, demonstrating that DOX triggered ferroptosis in mitochondria. Furthermore, concomitant inhibition of ferroptosis and apoptosis with ferrostatin-1 and zVAD-FMK fully prevented DOX-induced cardiomyocyte death. Our findings suggest that mitochondria-dependent ferroptosis plays a key role in progression of DIC and that ferroptosis is the major form of regulated cell death in DOX cardiotoxicity.. |
| 47. |
Kosuke Okabe, Shouji Matsushima, Soichiro Ikeda, Masataka Ikeda, Akihito Ishikita, Tomonori Tadokoro, Nobuyuki Enzan, Taishi Yamamoto, Masashi Sada, Hiroko Deguchi, Keisuke Shinohara, Tomomi Ide, Hiroyuki Tsutsui, DPP (Dipeptidyl Peptidase)-4 Inhibitor Attenuates Ang II (Angiotensin II)-Induced Cardiac Hypertrophy via GLP (Glucagon-Like Peptide)-1-Dependent Suppression of Nox (Nicotinamide Adenine Dinucleotide Phosphate Oxidase) 4-HDAC (Histone Deacetylase) 4 Pathway, Hypertension (Dallas, Tex. : 1979), 10.1161/HYPERTENSIONAHA.119.14400, 75, 4, 991-1001, 2020.04, Nox4 (NADPH [Nicotinamide adenine dinucleotide phosphate] oxidase 4) is a major source of oxidative stress and is intimately involved in cardiac hypertrophy. DPP (Dipeptidyl peptidase)-4 inhibitor has been reported to regulate Nox4 expression in adipose tissues. However, its effects on Nox4 in cardiac hypertrophy are still unclear. We investigated whether DPP-4 inhibitor could ameliorate cardiac hypertrophy by regulating Nox4 and its downstream targets. Ang II (Angiotensin II; 1.44 mg/kg per day) or saline was continuously infused into C57BL/6J mice with or without teneligliptin (a DPP-4 inhibitor, 30 mg/kg per day) in the drinking water for 1 week. Teneligliptin significantly suppressed plasma DPP-4 activity without any significant changing aortic blood pressure or metabolic parameters such as blood glucose and insulin levels. It attenuated Ang II-induced increases in left ventricular wall thickness and the ratio of heart weight to body weight. It also significantly suppressed Ang II-induced increases in Nox4 mRNA, 4-hydroxy-2-nonenal, and phosphorylation of HDAC4 (histone deacetylase 4), a downstream target of Nox4 and a crucial suppressor of cardiac hypertrophy, in the heart. Exendin-3 (150 pmol/kg per minute), a GLP-1 (glucagon-like peptide 1) receptor antagonist, abrogated these inhibitory effects of teneligliptin on Nox4, 4-hydroxy-2-nonenal, phosphorylation of HDAC4, and cardiac hypertrophy. In cultured neonatal cardiomyocytes, exendin-4 (100 nmol/L, 24 hours), a GLP-1 receptor agonist, ameliorated Ang II-induced cardiomyocyte hypertrophy and decreased in Nox4, 4-hydroxy-2-nonenal, and phosphorylation of HDAC4. Furthermore, exendin-4 prevented Ang II-induced decrease in nuclear HDAC4 in cardiomyocytes. In conclusion, GLP-1 receptor stimulation by DPP-4 inhibitor can attenuate Ang II-induced cardiac hypertrophy by suppressing of the Nox4-HDAC4 axis in cardiomyocytes.. |
| 48. |
Kosuke Okabe, Shouji Matsushima, Soichiro Ikeda, Masataka Ikeda, Akihito Ishikita, Tomonori Tadokoro, Nobuyuki Enzan, Taishi Yamamoto, Masashi Sada, Hiroko Deguchi, Keisuke Shinohara, Tomomi Ide, Hiroyuki Tsutsui, DPP (Dipeptidyl Peptidase)-4 Inhibitor Attenuates Ang II (Angiotensin II)-Induced Cardiac Hypertrophy via GLP (Glucagon-Like Peptide)-1-Dependent Suppression of Nox (Nicotinamide Adenine Dinucleotide Phosphate Oxidase) 4-HDAC (Histone Deacetylase) 4 Pathway., Hypertension (Dallas, Tex. : 1979), 10.1161/HYPERTENSIONAHA.119.14400, 75, 4, 991-1001, 2020.04, Nox4 (NADPH [Nicotinamide adenine dinucleotide phosphate] oxidase 4) is a major source of oxidative stress and is intimately involved in cardiac hypertrophy. DPP (Dipeptidyl peptidase)-4 inhibitor has been reported to regulate Nox4 expression in adipose tissues. However, its effects on Nox4 in cardiac hypertrophy are still unclear. We investigated whether DPP-4 inhibitor could ameliorate cardiac hypertrophy by regulating Nox4 and its downstream targets. Ang II (Angiotensin II; 1.44 mg/kg per day) or saline was continuously infused into C57BL/6J mice with or without teneligliptin (a DPP-4 inhibitor, 30 mg/kg per day) in the drinking water for 1 week. Teneligliptin significantly suppressed plasma DPP-4 activity without any significant changing aortic blood pressure or metabolic parameters such as blood glucose and insulin levels. It attenuated Ang II-induced increases in left ventricular wall thickness and the ratio of heart weight to body weight. It also significantly suppressed Ang II-induced increases in Nox4 mRNA, 4-hydroxy-2-nonenal, and phosphorylation of HDAC4 (histone deacetylase 4), a downstream target of Nox4 and a crucial suppressor of cardiac hypertrophy, in the heart. Exendin-3 (150 pmol/kg per minute), a GLP-1 (glucagon-like peptide 1) receptor antagonist, abrogated these inhibitory effects of teneligliptin on Nox4, 4-hydroxy-2-nonenal, phosphorylation of HDAC4, and cardiac hypertrophy. In cultured neonatal cardiomyocytes, exendin-4 (100 nmol/L, 24 hours), a GLP-1 receptor agonist, ameliorated Ang II-induced cardiomyocyte hypertrophy and decreased in Nox4, 4-hydroxy-2-nonenal, and phosphorylation of HDAC4. Furthermore, exendin-4 prevented Ang II-induced decrease in nuclear HDAC4 in cardiomyocytes. In conclusion, GLP-1 receptor stimulation by DPP-4 inhibitor can attenuate Ang II-induced cardiac hypertrophy by suppressing of the Nox4-HDAC4 axis in cardiomyocytes.. |
| 49. |
Daisuke Yakabe, Shouji Matsushima, Saori Uchino, Kisho Ohtani, Tomomi Ide, Taiki Higo, Hiroyuki Tsutsui, Left ventricular noncompaction with multiple thrombi in apical aneurysm, Internal Medicine, 10.2169/internalmedicine.3489-19, 59, 3, 377-381, 2020.02, A 44-year-old man was admitted to our hospital due to heart failure. Transthoracic echocardiography demonstrated global hypokinesis with an ejection fraction of 25%, prominent trabeculation and deep intertrabecular recesses, and apical aneurysm with multiple thrombi (10×13 mm in the inferior wall, 15×8 mm in the anterior wall). Cardiac magnetic resonance imaging showed an increased ratio of noncompacted (NC) to compacted (C) myocardium (NC/C ratio >2.3) and apical aneurysm. Coronary angiography revealed no significant stenosis. He was therefore diagnosed with left ventricular noncompaction complicated by apical aneurysm. Four weeks after starting anticoagulation, the multiple apical thrombi disappeared without clinical signs of embolism.. |
| 50. |
Nobuyuki Enzan, Shouji Matsushima, Tomomi Ide, Hidetaka Kaku, Taiki Higo, Miyuki Tsuchihashi-Makaya, Hiroyuki Tsutsui, Spironolactone use is associated with improved outcomes in heart failure with mid-range ejection fraction, ESC Heart Failure, 10.1002/ehf2.12571, 7, 1, 339-347, 2020.02, Aims: Spironolactone has been shown to improve outcomes in patients with heart failure (HF) with reduced ejection fraction (EF). We investigated whether the discharge use of spironolactone could be associated with better long-term outcomes among patients with HF with mid-range EF (HFmrEF). Methods and results: We analysed HFmrEF (left ventricular EF 40–49%) patients enrolled in the Japanese Cardiac Registry of Heart Failure in Cardiology, which prospectively studied the clinical characteristics, treatments, and long-term outcomes of patients hospitalized due to HF. Patients were divided into two groups according to the use of spironolactone at discharge. The primary outcome was a composite of all-cause death or HF rehospitalization. A total of 457 patients had HFmrEF. The mean age was 69.3 years and 286 (62.6%) were male. Among them, spironolactone was prescribed at discharge in 158 patients (34.6%). Chronic kidney disease (7.6% vs. 16.8%, P = 0.007) was less prevalent and loop diuretics (89.2% vs. 70.2%, P |
| 51. |
Nobuyuki Enzan, Shouji Matsushima, Tomomi Ide, Hidetaka Kaku, Taiki Higo, Miyuki Tsuchihashi-Makaya, Hiroyuki Tsutsui, Spironolactone use is associated with improved outcomes in heart failure with mid-range ejection fraction, ESC HEART FAILURE, 10.1002/ehf2.12571, 7, 1, 336-344, 2020.02, Aims Spironolactone has been shown to improve outcomes in patients with heart failure (HF) with reduced ejection fraction (EF). We investigated whether the discharge use of spironolactone could be associated with better long-term outcomes among patients with HF with mid-range EF (HFmrEF). Methods and results We analysed HFmrEF (left ventricular EF 40-49%) patients enrolled in the Japanese Cardiac Registry of Heart Failure in Cardiology, which prospectively studied the clinical characteristics, treatments, and long-term outcomes of patients hospitalized due to HF. Patients were divided into two groups according to the use of spironolactone at discharge. The primary outcome was a composite of all-cause death or HF rehospitalization. A total of 457 patients had HFmrEF. The mean age was 69.3 years and 286 (62.6%) were male. Among them, spironolactone was prescribed at discharge in 158 patients (34.6%). Chronic kidney disease (7.6% vs. 16.8%, P = 0.007) was less prevalent and loop diuretics (89.2% vs. 70.2%, P |
| 52. |
Hidetaka Kaku, Kouta Funakoshi, Tomomi Ide, Takeo Fujino, Shouji Matsushima, Kisho Ohtani, Taiki Higo, Michikazu Nakai, Yoko Sumita, Kunihiro Nishimura, Yoshihiro Miyamoto, Toshihisa Anzai, Hiroyuki Tsutsui, Impact of hospital practice factors on mortality in patients hospitalized for heart failure in Japan ― an analysis of a large number of health records from a nationwide claims-based database, the JROAD-DPC ―, Circulation Journal, 10.1253/circj.CJ-19-0759, 84, 5, 742-753, 2020.01, Background: An inverse relationship exists between hospital case volume and mortality in patients with heart failure (HF). However, hospital performance factors associated with mortality in HF patients have not been examined. We aimed to identify these using exploratory factor analysis and assess the relationship between these factors and 7-day, 30-day, and in-hospital mortality among HF patients in Japan. Methods and Results: We analyzed the records of 198,861 patients admitted to 683 certified hospitals of the Japanese Circulation Society between 2012 and 2014. Records were obtained from the nationwide database of the Japanese Registry Of All cardiac and vascular Diseases-Diagnostic Procedure Combination (JROAD-DPC). Using exploratory factor analysis, 90 hospital survey items were grouped into 5 factors, according to their collinearity: “Interventional cardiology”, “Cardiovascular surgery”, “Pediatric cardiology”, “Electrophysiology” and “Cardiac rehabilitation”. Multivariable logistic regression analysis was performed to determine the association between these factors and mortality. The 30-day mortality was 8.0%. Multivariable logistic regression analysis showed the “Pediatric cardiology” (odds ratio (OR) 0.677, 95% confidence interval [CI]: 0.628–0.729, P |
| 53. |
Soichiro Ikeda, Shouji Matsushima, Kosuke Okabe, Masataka Ikeda, Akihito Ishikita, Tomonori Tadokoro, Nobuyuki Enzan, Taishi Yamamoto, Masashi Sada, Hiroko Deguchi, Sachio Morimoto, Tomomi Ide, Hiroyuki Tsutsui, Blockade of L-type Ca2+ channel attenuates doxorubicin-induced cardiomyopathy via suppression of CaMKII-NF-κB pathway, Scientific reports, 10.1038/s41598-019-46367-6, 9, 1, 2019.12, Ca2+/calmodulin-dependent protein kinase II (CaMKII) and nuclear factor-kappa B (NF-κB) play crucial roles in pathogenesis of doxorubicin (DOX)-induced cardiomyopathy. Their activities are regulated by intracellular Ca2+. We hypothesized that blockade of L-type Ca2+ channel (LTCC) could attenuate DOX-induced cardiomyopathy by regulating CaMKII and NF-κB. DOX activated CaMKII and NF-κB through their phosphorylation and increased cleaved caspase 3 in cardiomyocytes. Pharmacological blockade or gene knockdown of LTCC by nifedipine or small interfering RNA, respectively, suppressed DOX-induced phosphorylation of CaMKII and NF-κB and apoptosis in cardiomyocytes, accompanied by decreasing intracellular Ca2+ concentration. Autocamtide 2-related inhibitory peptide (AIP), a selective CaMKII inhibitor, inhibited DOX-induced phosphorylation of NF-κB and cardiomyocyte apoptosis. Inhibition of NF-κB activity by ammonium pyrrolidinedithiocarbamate (PDTC) suppressed DOX-induced cardiomyocyte apoptosis. DOX-treatment (18 mg/kg via intravenous 3 injections over 1 week) increased phosphorylation of CaMKII and NF-κB in mouse hearts. Nifedipine (10 mg/kg/day) significantly suppressed DOX-induced phosphorylation of CaMKII and NF-κB and cardiomyocyte injury and apoptosis in mouse hearts. Moreover, it attenuated DOX-induced left ventricular dysfunction and dilatation. Our findings suggest that blockade of LTCC attenuates DOX-induced cardiomyocyte apoptosis via suppressing intracellular Ca2+ elevation and activation of CaMKII-NF-κB pathway. LTCC blockers might be potential therapeutic agents against DOX-induced cardiomyopathy.. |
| 54. |
Yoshihiko Kodama, Ayako Kuraoka, Yuichi Ishikawa, Makoto Nakamura, Hiroya Ushinohama, Koichi Sagawa, Shintaro Umemoto, Toru Hashimoto, Ichiro Sakamoto, Kisho Ohtani, Tomomi Ide, Hiroyuki Tsutsui, Shiro Ishikawa, Outcome of patients with functional single ventricular heart after pacemaker implantation
What makes it poor, and what can we do?, Heart Rhythm, 10.1016/j.hrthm.2019.06.019, 16, 12, 1870-1874, 2019.12, Background: Pacemaker implantation in patients with single ventricle is associated with poor outcomes. Objective: The purpose of this study was to determine the reasons for the poor outcomes of pacemaker implantation. Methods: We performed a retrospective chart review of patients with single ventricle who had undergone permanent pacemaker implantation. Patients were categorized into 3 groups based on the site of pacing and the proportion of ventricular pacing (VP) as follows: (1) atrial pacing group with atrial pacing only (n = 11); (2) low VP group with low daily VP proportion ( |
| 55. |
Yoshihiko Kodama, Ayako Kuraoka, Yuichi Ishikawa, Makoto Nakamura, Hiroya Ushinohama, Koichi Sagawa, Shintaro Umemoto, Toru Hashimoto, Ichiro Sakamoto, Kisho Ohtani, Tomomi Ide, Hiroyuki Tsutsui, Shiro Ishikawa, Outcome of patients with functional single ventricular heart after pacemaker implantation: What makes it poor, and what can we do?, HEART RHYTHM, 10.1016/j.hrthm.2019.06.019, 16, 12, 1870-1874, 2019.12, BACKGROUND Pacemaker implantation in patients with single ventricle is associated with poor outcomes.OBJECTIVE The purpose of this study was to determine the reasons for the poor outcomes of pacemaker implantation.METHODS We performed a retrospective chart review of patients with single ventricle who had undergone permanent pacemaker implantation. Patients were categorized into 3 groups based on the site of pacing and the proportion of ventricular pacing (VP) as follows: (1) atrial pacing group with atrial pacing only (n = 11); (2) low VP group with low daily VP proportion (= 50%; n = 15). Pacing leads were placed at the epicardium in all patients.RESULTS No patients in the atrial pacing or low VP groups died, whereas the survival rate in the high VP group was 58.9% and 39.3% at 10 and 20 years, respectively, after pacemaker implantation. Among the post-Fontan patients, plasma brain natriuretic peptide (BNP) levels significantly increased with the proportion of VP: 11.7, 20.3, and 28.4 pg/mL in the atrial pacing, low VP, and high VP groups, respectively (P = 0.04). In the high VP group, the plasma BNP level was significantly lower in patients with an apical pacing lead than in those with a nonapical pacing lead (27.0 pg/mL vs 82.8 pg/mL, respectively; P = .03).CONCLUSION A higher proportion of VP was associated with poor outcome and higher plasma BNP levels, probably due to ventricular dyssynchrony. In epicardial ventricular pacing, apical pacing is better to avoid the increase in ventricular stress and plasma BNP level.. |
| 56. |
Fumio Terasaki, Arata Azuma, Toshihisa Anzai, Nobukazu Ishizaka, Yoshio Ishida, Mitsuaki Isobe, Takayuki Inomata, Hatsue Ishibashi-Ueda, Yoshinobu Eishi, Masafumi Kitakaze, Kengo Kusano, Yasushi Sakata, Noriharu Shijubo, Akihito Tsuchida, Hiroyuki Tsutsui, Takatomo Nakajima, Satoshi Nakatani, Taiko Horii, Yoshikazu Yazaki, Etsuro Yamaguchi, Tetsuo Yamaguchi, Tomomi Ide, Hideo Okamura, Yasuchika Kato, Masahiko Goya, Mamoru Sakakibara, Kyoko Soejima, Toshiyuki Nagai, Hiroshi Nakamura, Takashi Noda, Takuya Hasegawa, Hideaki Morita, Tohru Ohe, Yasuki Kihara, Yoshihiko Saito, Yukihiko Sugiyama, Shin-ichiro Morimoto, Akira Yamashina, JCS 2016 Guideline on Diagnosis and Treatment of Cardiac Sarcoidosis - Digest Version, CIRCULATION JOURNAL, 10.1253/circj.CJ-19-0508, 83, 11, 2329-2388, 2019.11. |
| 57. |
Kisho Ohtani, Tomomi Ide, Ken ichi Hiasa, Ichiro Sakamoto, Nami Yamashita, Makoto Kubo, Hiroyuki Tsutsui, Cardioprotective effect of renin–angiotensin inhibitors and β-blockers in trastuzumab-related cardiotoxicity, Clinical Research in Cardiology, 10.1007/s00392-019-01448-4, 108, 10, 1128-1139, 2019.10, Background: Trastuzumab-related cardiotoxicity (TRC) has been considered as reversible. However, recent studies have raised concern against reversibility of left ventricular (LV) systolic dysfunction in breast cancer patients treated with trastuzumab. In addition, the efficacy of medical treatment for heart failure (HF) including renin–angiotensin inhibitors and β-blockers has not been defined in TRC. Methods and results: We retrospectively studied 160 patients with breast cancer receiving trastuzumab in the adjuvant (n = 129) as well as metastatic (n = 31) settings in our institution from 2006 to 2015. During the median follow-up of 3.5 years, 20 patients (15.5%) receiving adjuvant trastuzumab and 7 patients (22.6%) with metastatic breast cancer developed TRC with a mean decrease in LV ejection fraction (EF) of 19.8%. By the multivariate analysis, lower LVEF before trastuzumab (OR 1.30; 95% CI 1.16–1.48; P = 0.0001) independently predicted subsequent development of TRC. LV systolic dysfunction was reversible in 20 patients (74.1%) with a median time to recovery of 7 months, which was independently associated with lower dose of anthracyclines (OR 1.03; 95% CI 1.01–1.07, P = 0.020) and an introduction of renin–angiotensin inhibitors and β-blockers (OR 19.0; 95% CI 1.00–592.2, P = 0.034). Conclusions: Irreversible decline in LVEF occurred in patients who underwent trastuzumab in combination with anthracyclines with a relatively high frequency. The lower cumulative dose of anthracyclines and HF treatment including renin–angiotensin inhibitors and β-blockers were both independent predictors to enhance LV functional reversibility in patients with TRC.. |
| 58. |
Kisho Ohtani, Tomomi Ide, Ken-Ichi Hiasa, Ichiro Sakamoto, Nami Yamashita, Makoto Kubo, Hiroyuki Tsutsui, Cardioprotective effect of renin-angiotensin inhibitors and β-blockers in trastuzumab-related cardiotoxicity., Clinical research in cardiology : official journal of the German Cardiac Society, 10.1007/s00392-019-01448-4, 108, 10, 1128-1139, 2019.10, BACKGROUND: Trastuzumab-related cardiotoxicity (TRC) has been considered as reversible. However, recent studies have raised concern against reversibility of left ventricular (LV) systolic dysfunction in breast cancer patients treated with trastuzumab. In addition, the efficacy of medical treatment for heart failure (HF) including renin-angiotensin inhibitors and β-blockers has not been defined in TRC. METHODS AND RESULTS: We retrospectively studied 160 patients with breast cancer receiving trastuzumab in the adjuvant (n = 129) as well as metastatic (n = 31) settings in our institution from 2006 to 2015. During the median follow-up of 3.5 years, 20 patients (15.5%) receiving adjuvant trastuzumab and 7 patients (22.6%) with metastatic breast cancer developed TRC with a mean decrease in LV ejection fraction (EF) of 19.8%. By the multivariate analysis, lower LVEF before trastuzumab (OR 1.30; 95% CI 1.16-1.48; P = 0.0001) independently predicted subsequent development of TRC. LV systolic dysfunction was reversible in 20 patients (74.1%) with a median time to recovery of 7 months, which was independently associated with lower dose of anthracyclines (OR 1.03; 95% CI 1.01-1.07, P = 0.020) and an introduction of renin-angiotensin inhibitors and β-blockers (OR 19.0; 95% CI 1.00-592.2, P = 0.034). CONCLUSIONS: Irreversible decline in LVEF occurred in patients who underwent trastuzumab in combination with anthracyclines with a relatively high frequency. The lower cumulative dose of anthracyclines and HF treatment including renin-angiotensin inhibitors and β-blockers were both independent predictors to enhance LV functional reversibility in patients with TRC.. |
| 59. |
Takuya Nagata, Tomoyuki Ohara, Jun Hata, Satoko Sakata, Yoshihiko Furuta, Daigo Yoshida, Takanori Honda, Yoichiro Hirakawa, Tomomi Ide, Shigenobu Kanba, Takanari Kitazono, Hiroyuki Tsutsui, Toshiharu Ninomiya, NT-proBNP and Risk of Dementia in a General Japanese Elderly Population
The Hisayama Study, Journal of the American Heart Association, 10.1161/JAHA.118.011652, 8, 17, e011652, 2019.09, Background Epidemiological evidence implies a link between heart disease and dementia. However, few prospective studies have assessed the association between serum NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels and dementia. Methods and Results A total of 1635 community-dwelling Japanese elderly aged ≥60 years without dementia (57% women, mean age±SD 70.8±7.7 years) were followed up for 10 years. Serum NT-proBNP levels were divided into 4 categories (≤54, 55-124, 125-299, and ≥300 pg/mL). The hazard ratios were estimated using a Cox proportional hazards model. During the follow-up period, 377 subjects developed all-cause dementia, 247 Alzheimer disease, and 102 vascular dementia. The age- and sex-adjusted incidence of all-cause dementia was 31.5 per 1000 person-years and increased significantly with higher serum NT-proBNP levels, being 16.4, 32.0, 35.7, and 45.5, respectively (P for trend |
| 60. |
Takuya Nagata, Tomoyuki Ohara, Jun Hata, Satoko Sakata, Yoshihiko Furuta, Daigo Yoshida, Takanori Honda, Yoichiro Hirakawa, Tomomi Ide, Shigenobu Kanba, Takanari Kitazono, Hiroyuki Tsutsui, Toshiharu Ninomiya, NT-proBNP and Risk of Dementia in a General Japanese Elderly Population: The Hisayama Study, JOURNAL OF THE AMERICAN HEART ASSOCIATION, 10.1161/JAHA.118.011652, 8, 17, 2019.09, Background-Epidemiological evidence implies a link between heart disease and dementia. However, few prospective studies have assessed the association between serum NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels and dementia.Methods and Results-A total of 1635 community-dwelling Japanese elderly aged >= 60 years without dementia (57% women, mean age +/- SD 70.8 +/- 7.7 years) were followed up for 10 years. Serum NT-proBNP levels were divided into 4 categories (= 300 pg/mL). The hazard ratios were estimated using a Cox proportional hazards model. During the follow-up period, 377 subjects developed all-cause dementia, 247 Alzheimer disease, and 102 vascular dementia. The age- and sex-adjusted incidence of all-cause dementia was 31.5 per 1000 person-years and increased significantly with higher serum NT-proBNP levels, being 16.4, 32.0, 35.7, and 45.5, respectively (P for trend = 300 pg/mL had a significantly higher risk of all-cause dementia (hazard ratio 2.46, 95% CI 1.63-3.71) than those with serum NT-proBNP levels of |
| 61. |
Soichiro Ikeda, Shouji Matsushima, Kosuke Okabe, Masataka Ikeda, Akihito Ishikita, Tomonori Tadokoro, Nobuyuki Enzan, Taishi Yamamoto, Masashi Sada, Hiroko Deguchi, Sachio Morimoto, Tomomi Ide, Hiroyuki Tsutsui, Blockade of L-type Ca2+ channel attenuates doxorubicin-induced cardiomyopathy via suppression of CaMKII-NF-kappa B pathway, SCIENTIFIC REPORTS, 10.1038/s41598-019-46367-6, 9, 2019.07, Ca2+/calmodulin-dependent protein kinase II (CaMKII) and nuclear factor-kappa B (NF-kappa B) play crucial roles in pathogenesis of doxorubicin (DOX)-induced cardiomyopathy. Their activities are regulated by intracellular Ca2+. We hypothesized that blockade of L-type Ca2+ channel (LTCC) could attenuate DOX-induced cardiomyopathy by regulating CaMKII and NF-kappa B. DOX activated CaMKII and NF-kappa B through their phosphorylation and increased cleaved caspase 3 in cardiomyocytes. Pharmacological blockade or gene knockdown of LTCC by nifedipine or small interfering RNA, respectively, suppressed DOX-induced phosphorylation of CaMKII and NF-kappa B and apoptosis in cardiomyocytes, accompanied by decreasing intracellular Ca2+ concentration. Autocamtide 2-related inhibitory peptide (AIP), a selective CaMKII inhibitor, inhibited DOX-induced phosphorylation of NF-kappa B and cardiomyocyte apoptosis. Inhibition of NF-kappa B activity by ammonium pyrrolidinedithiocarbamate (PDTC) suppressed DOX-induced cardiomyocyte apoptosis. DOX-treatment (18 mg/kg via intravenous 3 injections over lweek) increased phosphorylation of CaMKII and NF-kappa B in mouse hearts. Nifedipine (10 mg/kg/day) significantly suppressed DOX-induced phosphorylation of CaMKII and NF-kappa B and cardiomyocyte injury and apoptosis in mouse hearts. Moreover, it attenuated DOX-induced left ventricular dysfunction and dilatation. Our findings suggest that blockade of LTCC attenuates DOX-induced cardiomyocyte apoptosis via suppressing intracellular Ca2+ elevation and activation of CaMKII-NF-kappa B pathway. LTCC blockers might be potential therapeutic agents against DOX-induced cardiomyopathy.. |
| 62. |
Kisho Ohtani, Takeo Fujino, Tomomi Ide, Kouta Funakoshi, Ichirou Sakamoto, Hiasa Ken-Ichi, Taiki Higo, Kenjiro Kamezaki, Koichi Akashi, Hiroyuki Tsutsui, Recovery from left ventricular dysfunction was associated with the early introduction of heart failure medical treatment in cancer patients with anthracycline-induced cardiotoxicity, Clinical Research in Cardiology, 10.1007/s00392-018-1386-0, 108, 6, 600-611, 2019.06, Background: Left ventricular (LV) dysfunction due to anthracycline-induced cardiotoxicity (AIC) has been believed to be irreversible. However, this has not been confirmed and standard medical treatment for heart failure (HF) including renin–angiotensin inhibitors and β-blockers may lead to its recovery. Methods and results: We thus retrospectively studied 350 cancer patients receiving anthracycline-based chemotherapy from 2001 to 2015 in our institution. Fifty-two patients (14.9%) developed AIC with a decrease in LV ejection fraction (LVEF) of 24.1% at a median time of 6 months [interquartile range (IQR) 4–22 months] after anthracycline therapy. By multivariate analysis, AIC was independently associated with cardiac comorbidities including ischemic heart disease, valvular heart disease, arrhythmia, and cardiomyopathy [odds ratio (OR) 6.00; 95% confidence interval (CI) 2.27–15.84, P = 0.00044), lower baseline LVEF (OR per 1% 1.09; 95% CI 1.04–1.14, P = 0.00034). During the median follow-up of 3.2 years, LV systolic dysfunction recovered among 33 patients (67.3%) with a median time of 4 months (IQR 2–6 months), which was independently associated with the introduction of standard medical treatment for HF (OR 9.39; 95% CI 2.27–52.9, P = 0.0014) by multivariate analysis. Conclusion: Early initiation of standard medical treatment for HF may lead to LV functional recovery in AIC.. |
| 63. |
Ming Li, Ken Ichi Hirano, Yoshihiko Ikeda, Masahiro Higashi, Chikako Hashimoto, Bo Zhang, Junji Kozawa, Koichiro Sugimura, Hideyuki Miyauchi, Akira Suzuki, Yasuhiro Hara, Atsuko Takagi, Yasuyuki Ikeda, Kazuhiro Kobayashi, Yoshiaki Futsukaichi, Nobuhiro Zaima, Satoshi Yamaguchi, Rojeet Shrestha, Hiroshi Nakamura, Katsuhiro Kawaguchi, Eiryu Sai, Shu Ping Hui, Yusuke Nakano, Akinori Sawamura, Tohru Inaba, Yasuhiko Sakata, Yoko Yasui, Yasuyuki Nagasawa, Shintaro Kinugawa, Kazunori Shimada, Sohsuke Yamada, Hiroyuki Hao, Daisaku Nakatani, Tomomi Ide, Tetsuya Amano, Hiroaki Naito, Hironori Nagasaka, Kunihisa Kobayashi, Triglyceride deposit cardiomyovasculopathy
A rare cardiovascular disorder, Orphanet Journal of Rare Diseases, 10.1186/s13023-019-1087-4, 14, 1, 2019.06, Triglyceride deposit cardiomyovasculopathy (TGCV) is a phenotype primarily reported in patients carrying genetic mutations in PNPLA2 encoding adipose triglyceride lipase (ATGL) which releases long chain fatty acid (LCFA) as a major energy source by the intracellular TG hydrolysis. These patients suffered from intractable heart failure requiring cardiac transplantation. Moreover, we identified TGCV patients without PNPLA2 mutations based on pathological and clinical studies. We provided the diagnostic criteria, in which TGCV with and without PNPLA2 mutations were designated as primary TGCV (P-TGCV) and idiopathic TGCV (I-TGCV), respectively. We hereby report clinical profiles of TGCV patients. Between 2014 and 2018, 7 P-TGCV and 18 I-TGCV Japanese patients have been registered in the International Registry. Patients with I-TGCV, of which etiologies and causes are not known yet, suffered from adult-onset severe heart disease, including heart failure and coronary artery disease, associated with a marked reduction in ATGL activity and myocardial washout rate of LCFA tracer, as similar to those with P-TGCV. The present first registry-based study showed that TGCV is an intractable, at least at the moment, and heterogeneous cardiovascular disorder.. |
| 64. |
Ming Li, Ken-ichi Hirano, Yoshihiko Ikeda, Masahiro Higashi, Chikako Hashimoto, Bo Zhang, Junji Kozawa, Koichiro Sugimura, Hideyuki Miyauchi, Akira Suzuki, Yasuhiro Hara, Atsuko Takagi, Yasuyuki Ikeda, Kazuhiro Kobayashi, Yoshiaki Futsukaichi, Nobuhiro Zaima, Satoshi Yamaguchi, Rojeet Shrestha, Hiroshi Nakamura, Katsuhiro Kawaguchi, Eiryu Sai, Shu-Ping Hui, Yusuke Nakano, Akinori Sawamura, Tohru Inaba, Yasuhiko Sakata, Yoko Yasui, Yasuyuki Nagasawa, Shintaro Kinugawa, Kazunori Shimada, Sohsuke Yamada, Hiroyuki Hao, Daisaku Nakatani, Tomomi Ide, Tetsuya Amano, Hiroaki Naito, Hironori Nagasaka, Kunihisa Kobayashi, Triglyceride deposit cardiomyovasculopathy: a rare cardiovascular disorder, ORPHANET JOURNAL OF RARE DISEASES, 10.1186/s13023-019-1087-4, 14, 2019.06, Triglyceride deposit cardiomyovasculopathy (TGCV) is a phenotype primarily reported in patients carrying genetic mutations in PNPLA2 encoding adipose triglyceride lipase (ATGL) which releases long chain fatty acid (LCFA) as a major energy source by the intracellular TG hydrolysis. These patients suffered from intractable heart failure requiring cardiac transplantation. Moreover, we identified TGCV patients without PNPLA2 mutations based on pathological and clinical studies. We provided the diagnostic criteria, in which TGCV with and without PNPLA2 mutations were designated as primary TGCV (P-TGCV) and idiopathic TGCV (I-TGCV), respectively. We hereby report clinical profiles of TGCV patients. Between 2014 and 2018, 7 P-TGCV and 18 I-TGCV Japanese patients have been registered in the International Registry. Patients with I-TGCV, of which etiologies and causes are not known yet, suffered from adult-onset severe heart disease, including heart failure and coronary artery disease, associated with a marked reduction in ATGL activity and myocardial washout rate of LCFA tracer, as similar to those with P-TGCV. The present first registry-based study showed that TGCV is an intractable, at least at the moment, and heterogeneous cardiovascular disorder.. |
| 65. |
Kisho Ohtani, Takeo Fujino, Tomomi Ide, Kouta Funakoshi, Ichirou Sakamoto, Ken-Ichi Hiasa, Taiki Higo, Kenjiro Kamezaki, Koichi Akashi, Hiroyuki Tsutsui, Recovery from left ventricular dysfunction was associated with the early introduction of heart failure medical treatment in cancer patients with anthracycline-induced cardiotoxicity., Clinical research in cardiology : official journal of the German Cardiac Society, 10.1007/s00392-018-1386-0, 108, 6, 600-611, 2019.06, BACKGROUND: Left ventricular (LV) dysfunction due to anthracycline-induced cardiotoxicity (AIC) has been believed to be irreversible. However, this has not been confirmed and standard medical treatment for heart failure (HF) including renin-angiotensin inhibitors and β-blockers may lead to its recovery. METHODS AND RESULTS: We thus retrospectively studied 350 cancer patients receiving anthracycline-based chemotherapy from 2001 to 2015 in our institution. Fifty-two patients (14.9%) developed AIC with a decrease in LV ejection fraction (LVEF) of 24.1% at a median time of 6 months [interquartile range (IQR) 4-22 months] after anthracycline therapy. By multivariate analysis, AIC was independently associated with cardiac comorbidities including ischemic heart disease, valvular heart disease, arrhythmia, and cardiomyopathy [odds ratio (OR) 6.00; 95% confidence interval (CI) 2.27-15.84, P = 0.00044), lower baseline LVEF (OR per 1% 1.09; 95% CI 1.04-1.14, P = 0.00034). During the median follow-up of 3.2 years, LV systolic dysfunction recovered among 33 patients (67.3%) with a median time of 4 months (IQR 2-6 months), which was independently associated with the introduction of standard medical treatment for HF (OR 9.39; 95% CI 2.27-52.9, P = 0.0014) by multivariate analysis. CONCLUSION: Early initiation of standard medical treatment for HF may lead to LV functional recovery in AIC.. |
| 66. |
Yasuki Nakada, Rika Kawakami, Shouji Matsushima, Tomomi Ide, Koshiro Kanaoka, Tomoya Ueda, Satomi Ishihara, Taku Nishida, Kenji Onoue, Tsunenari Soeda, Satoshi Okayama, Makoto Watanabe, Hiroyuki Okura, Miyuki Tsuchihashi-Makaya, Hiroyuki Tsutsui, Yoshihiko Saito, Simple Risk Score to Predict Survival in Acute Decompensated Heart Failure-A2B Score, CIRCULATION JOURNAL, 10.1253/circj.CJ-18-1116, 83, 5, 1019-+, 2019.05, Background: Prognosis after acute decompensated heart failure (ADHF) is poor. An appropriate risk score that would allow for improved care and treatment of ADHF patients after discharge, however, is lacking.Methods and Results: We used 2 HF cohorts, the NARA-HF study and JCARE-CARD, as derivation and validation cohorts, respectively. The primary endpoint was all-cause death during the 2-year follow-up, excluding in-hospital death. Age, hemoglobin (Hb), and brain natriuretic peptide (BNP) at discharge were identified as independent risk factors. We determined 3 categorizations on the basis of these parameters, termed A2B score: age (= 75 years, 2), anemia (Hb = 12 g/dL, 0) and BNP (= 500 pg/mL, 2). We divided patients into 4 groups according to A2B score (extremely low, 0; low, 1-2; medium, 3-4; high, 5-6). For the extremely low-risk group, the 2-year survival rate was 97.8%, compared with 84.5%, 66.1%, and 45.2% for the low-, medium-, and high-risk groups, respectively. Using the JCARE-CARD as a validation model, for the extremely low-risk group, the 2-year survival was 95.4%, compared with 90.2%, 75.0%, and 55.6% for the low-, medium-, and high-risk groups, respectively.Conclusions: The user-friendly A2B score is useful for estimating survival rate in ADHF patients at discharge.. |
| 67. |
Shouji Matsushima, Hidetaka Kaku, Nobuyuki Enzan, Tomomi Ide, Taiki Higo, Miyuki Tsuchihashi-Makaya, Hiroyuki Tsutsui, Electrocardiographic Left Ventricular Hypertrophy Is Independently Associated With Better Long-Term Outcomes in Dilated Cardiomyopathy Patients., Circulation reports, 10.1253/circrep.CR-19-0025, 1, 6, 248-254, 2019.05, Background: Electrocardiogram (ECG) findings of left ventricular hypertrophy (LVH; ECG-LVH) are observed in patients with dilated cardiomyopathy (DCM), but the prognostic importance is unclear. The present study assessed the impact of QRS voltage on long-term outcomes, including mortality and rehospitalization, in patients with DCM using a database of patients hospitalized for worsening heart failure (HF). Methods and Results: We analyzed a total of 261 patients with DCM in the Japanese Cardiac Registry of Heart Failure in Cardiology (JCARE-CARD), a prospective cohort studying the characteristics and treatments in a broad sample of HF patients. ECG-LVH were diagnosed according to the Sokolow-Lyon voltage criteria. A total of 81 patients (31.0%) had ECG-LVH. During a mean follow-up period of 1.8 years, patients with ECG-LVH had a lower rate of all-cause death (9.0% vs. 20.3%, P=0.029) and composite of all-cause death and rehospitalization due to worsening HF (26.9% vs. 45.9%, P=0.007) than those without it. After multivariable adjustment, ECG-LVH was an independent negative predictor for the risk of composite all-cause death and rehospitalization (hazard ratio, 0.358; 95% CI: 0.157-0.857, P=0.049). Conclusions: ECG-LVH were independently associated with better long-term outcome in patients with DCM.. |
| 68. |
Tomomi Ide, Kisho Ohtani, Taiki Higo, Makoto Tanaka, Yasushi Kawasaki, Hiroyuki Tsutsui, Ivabradine for the treatment of cardiovascular diseases, Circulation Journal, 10.1253/circj.CJ-18-1184, 83, 2, 252-260, 2019.02, Higher heart rate (HR) is independently related to worse outcomes in various cardiac diseases, including hypertension, coronary artery disease, and heart failure (HF). HR is determined by the pacemaker activity of cells within the sinoatrial node. The hyperpolarization- activated cyclic nucleotide-gated (HCN) 4 channel, one of 4 HCN isoforms, generates the If current and plays an important role in the regulation of pacemaker activity in the sinoatrial node. Ivabradine is a novel and only available HCN inhibitor, which can reduce HR and has been approved for stable angina and chronic HF in many countries other than Japan. In this review, we summarize the current knowledge of the HCN4 channel and ivabradine, including the function of HCN4 in cardiac pacemaking, the mechanism of action of If inhibition by ivabradine, and the pharmacological and clinical effects of ivabradine in cardiac diseases as HF, coronary artery disease, and atrial fibrillation.. |
| 69. |
Tomomi Ide, Kisho Ohtani, Taiki Higo, Makoto Tanaka, Yasushi Kawasaki, Hiroyuki Tsutsui, Ivabradine for the Treatment of Cardiovascular Diseases, CIRCULATION JOURNAL, 10.1253/circj.CJ-18-1184, 83, 2, 252-260, 2019.02, Higher heart rate (HR) is independently related to worse outcomes in various cardiac diseases, including hypertension, coronary artery disease, and heart failure (HF). HR is determined by the pacemaker activity of cells within the sinoatrial node. The hyperpolarization-activated cyclic nucleotide-gated (HCN) 4 channel, one of 4 HCN isoforms, generates the If current and plays an important role in the regulation of pacemaker activity in the sinoatrial node. Ivabradine is a novel and only available HCN inhibitor, which can reduce HR and has been approved for stable angina and chronic HF in many countries other than Japan. In this review, we summarize the current knowledge of the HCN4 channel and ivabradine, including the function of HCN4 in cardiac pacemaking, the mechanism of action of I-f inhibition by ivabradine, and the pharmacological and clinical effects of ivabradine in cardiac diseases as HF, coronary artery disease, and atrial fibrillation.. |
| 70. |
Yasuki Nakada, Rika Kawakami, Shoji Matsushima, Tomomi Ide, Koshiro Kanaoka, Tomoya Ueda, Satomi Ishihara, Taku Nishida, Kenji Onoue, Tsunenari Soeda, Satoshi Okayama, Makoto Watanabe, Hiroyuki Okura, Miyuki Tsuchihashi-Makaya, Hiroyuki Tsutsui, Yoshihiko Saito, Simple risk score to predict survival in acute decompensated heart failure
A2B score, Circulation Journal, 10.1253/circj.CJ-18-1116, 83, 5, 1019-1024, 2019.01, Background: Prognosis after acute decompensated heart failure (ADHF) is poor. An appropriate risk score that would allow for improved care and treatment of ADHF patients after discharge, however, is lacking. Methods and Results: We used 2 HF cohorts, the NARA-HF study and JCARE-CARD, as derivation and validation cohorts, respectively. The primary endpoint was all-cause death during the 2-year follow-up, excluding in-hospital death. Age, hemoglobin (Hb), and brain natriuretic peptide (BNP) at discharge were identified as independent risk factors. We determined 3 categorizations on the basis of these parameters, termed A2B score: age ( |
| 71. |
Fumio Terasaki, Arata Azuma, Toshihisa Anzai, Nobukazu Ishizaka, Yoshio Ishida, Mitsuaki Isobe, Takayuki Inomata, Hatsue Ishibashi-Ueda, Yoshinobu Eishi, Masafumi Kitakaze, Kengo Kusano, Yasushi Sakata, Noriharu Shijubo, Akihito Tsuchida, Hiroyuki Tsutsui, Takatomo Nakajima, Satoshi Nakatani, Taiko Horii, Yoshikazu Yazaki, Etsuro Yamaguchi, Tetsuo Yamaguchi, Tomomi Ide, Hideo Okamura, Yasuchika Kato, Masahiko Goya, Mamoru Sakakibara, Kyoko Soejima, Toshiyuki Nagai, Hiroshi Nakamura, Takashi Noda, Takuya Hasegawa, Hideaki Morita, Tohru Ohe, Yasuki Kihara, Yoshihiko Saito, Yukihiko Sugiyama, Shin ichiro Morimoto, Akira Yamashina, JCS 2016 guideline on diagnosis and treatment of cardiac sarcoidosis ― digest version ―, Circulation Journal, 10.1253/circj.CJ-19-0508, 83, 11, 2329-2388, 2019.01. |
| 72. |
Mari Sakamoto, Hiroki Fukuda, Jiyoong Kim, Tomomi Ide, Shintaro Kinugawa, Arata Fukushima, Hiroyuki Tsutsui, Akira Ishii, Shin Ito, Hiroshi Asanuma, Masanori Asakura, Takashi Washio, Masafumi Kitakaze, The impact of creating mathematical formula to predict cardiovascular events in patients with heart failure, Scientific reports, 10.1038/s41598-018-22347-0, 8, 1, 2018.12, Since our retrospective study has formed a mathematical formula, α = f(x
1
, .., x
252
), where α is the probability of cardiovascular events in patients with heart failure (HF) and x
1
is each clinical parameter, we prospectively tested the predictive capability and feasibility of the mathematical formula of cardiovascular events in HF patients. First of all, to create such a mathematical formula using limited number of the parameters to predict the cardiovascular events in HF patients, we retrospectively determined f(x) that formulates the relationship between the most influential 50 clinical parameters (x) among 252 parameters using 167 patients hospitalized due to acute HF; the nonlinear optimization could provide the formula of α = f(x
1
, .., x
50
) which fitted the probability of the actual cardiovascular events per day. Secondly, we prospectively examined the predictability of f(x) in other 213 patients using 50 clinical parameters in 3 hospitals, and we found that the Kaplan-Meier curves using actual and estimated occurrence probabilities of cardiovascular events were closely correlated. We conclude that we created a mathematical formula f(x) that precisely predicted the occurrence probability of future cardiovascular outcomes of HF patients per day. Mathematical modelling may predict the occurrence probability of cardiovascular events in HF patients.. |
| 73. |
Akiyuki Nishimura, Tsukasa Shimauchi, Tomohiro Tanaka, Kakeru Shimoda, Takashi Toyama, Naoyuki Kitajima, Tatsuya Ishikawa, Naoya Shindo, Takuro Numaga-Tomita, Satoshi Yasuda, Yoji Sato, Koichiro Kuwahara, Yoshito Kumagai, Takaaki Akaike, Tomomi Ide, Akio Ojida, Yasuo Mori, Motohiro Nishida, Hypoxia-induced interaction of filamin with Drp1 causes mitochondrial hyperfission-associated myocardial senescence, Science Signaling, 10.1126/scisignal.aat5185, 11, 556, 2018.11, Defective mitochondrial dynamics through aberrant interactions between mitochondria and actin cytoskeleton is increasingly recognized as a key determinant of cardiac fragility after myocardial infarction (MI). Dynamin-related protein 1 (Drp1), a mitochondrial fission-accelerating factor, is activated locally at the fission site through interactions with actin. Here, we report that the actin-binding protein filamin A acted as a guanine nucleotide exchange factor for Drp1 and mediated mitochondrial fission-associated myocardial senescence in mice after MI. In peri-infarct regions characterized by mitochondrial hyperfission and associated with myocardial senescence, filamin A colocalized with Drp1 around mitochondria. Hypoxic stress induced the interaction of filamin A with the GTPase domain of Drp1 and increased Drp1 activity in an actin-binding-dependent manner in rat cardiomyocytes. Expression of the A1545T filamin mutant, which potentiates actin aggregation, promoted mitochondrial hyperfission under normoxia. Furthermore, pharmacological perturbation of the Drp1-filamin A interaction by cilnidipine suppressed mitochondrial hyperfission-associated myocardial senescence and heart failure after MI. Together, these data demonstrate that Drp1 association with filamin and the actin cytoskeleton contributes to cardiac fragility after MI and suggests a potential repurposing of cilnidipine, as well as provides a starting point for innovative Drp1 inhibitor development.. |
| 74. |
Akiyuki Nishimura, Tsukasa Shimauchi, Tomohiro Tanaka, Kakeru Shimoda, Takashi Toyama, Naoyuki Kitajima, Tatsuya Ishikawa, Naoya Shindo, Takuro Numaga-Tomita, Satoshi Yasuda, Yoji Sato, Koichiro Kuwahara, Yoshito Kumagai, Takaaki Akaike, Tomomi Ide, Akio Ojida, Yasuo Mori, Motohiro Nishida, Hypoxia-induced interaction of filamin with Drp1 causes mitochondrial hyperfission-associated myocardial senescence, SCIENCE SIGNALING, 10.1126/scisignal.aat5185, 11, 556, 2018.11, Defective mitochondrial dynamics through aberrant interactions between mitochondria and actin cytoskeleton is increasingly recognized as a key determinant of cardiac fragility after myocardial infarction (MI). Dynamin-related protein 1 (Drp1), a mitochondrial fission-accelerating factor, is activated locally at the fission site through interactions with actin. Here, we report that the actin-binding protein filamin A acted as a guanine nucleotide exchange factor for Drp1 and mediated mitochondrial fission-associated myocardial senescence in mice after MI. In peri-infarct regions characterized by mitochondrial hyperfission and associated with myocardial senescence, filamin A colocalized with Drp1 around mitochondria. Hypoxic stress induced the interaction of filamin A with the GTPase domain of Drp1 and increased Drp1 activity in an actin-binding-dependent manner in rat cardiomyocytes. Expression of the A1545T filamin mutant, which potentiates actin aggregation, promoted mitochondrial hyperfission under normoxia. Furthermore, pharmacological perturbation of the Drp1-filamin A interaction by cilnidipine suppressed mitochondria! hyperfission-associated myocardial senescence and heart failure after MI. Together, these data demonstrate that Drp1 association with filamin and the actin cytoskeleton contributes to cardiac fragility after MI and suggests a potential repurposing of cilnidipine, as well as provides a starting point for innovative Drp1 inhibitor development.. |
| 75. |
Chiharu Ishii, Takeyuki Akita, Masashi Mita, Tomomi Ide, Kenji Hamase, Development of an online two-dimensional high-performance liquid chromatographic system in combination with tandem mass spectrometric detection for enantiomeric analysis of free amino acids in human physiological fluid, Journal of Chromatography A, 10.1016/j.chroma.2018.07.076, 1570, 91-98, 2018.10, An automated two-dimensional HPLC-MS/MS system was designed and developed for the highly selective determination of trace levels of D-amino acids. As the targets, frequently observed ones in mammalian physiological fluids, Ala, Asp, Glu, Leu, Pro and Ser, were selected because these D-amino acids are the potential biomarkers for the early and sensitive diagnoses of various diseases. The target analytes were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), then isolated by a reversed-phase column in the first dimension. The NBD-amino acid fractions were automatically collected into the multi-loop device, and introduced into the enantioselective column in the second dimension to separate the D- and L-forms followed by detection by an MS/MS. The obtained resolution values of the enantiomers were 1.87–5.17 and the calibration lines, precision and accuracy were practically sufficient. By using the present 2D HPLC-MS/MS system, trace levels of D-amino acids in complex biological matrices were determined without disturbance by the intrinsic interfering compounds, and successfully applied to the analysis of the human clinical samples (plasma and urine).. |
| 76. |
Chiharu Ishii, Takeyuki Akita, Masashi Mita, Tomomi Ide, Kenji Hamase, Development of an online two-dimensional high-performance liquid chromatographic system in combination with tandem mass spectrometric detection for enantiomeric analysis of free amino acids in human physiological fluid, JOURNAL OF CHROMATOGRAPHY A, 10.1016/j.chroma.2018.07.076, 1570, 91-98, 2018.10, An automated two-dimensional HPLC-MS/MS system was designed and developed for the highly selective determination of trace levels of D-amino acids. As the targets, frequently observed ones in mammalian physiological fluids, Ala, Asp, Glu, Leu, Pro and Ser, were selected because these D-amino acids are the potential biomarkers for the early and sensitive diagnoses of various diseases. The target analytes were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), then isolated by a reversed-phase column in the first dimension. The NBD-amino acid fractions were automatically collected into the multi loop device, and introduced into the enantioselective column in the second dimension to separate the D- and L-forms followed by detection by an MS/MS. The obtained resolution values of the enantiomers were 1.87-5.17 and the calibration lines, precision and accuracy were practically sufficient. By using the present 2D HPLC-MS/MS system, trace levels of D-amino acids in complex biological matrices were determined without disturbance by the intrinsic interfering compounds, and successfully applied to the analysis of the human clinical samples (plasma and urine). (C) 2018 Elsevier B.V. All rights reserved.. |
| 77. |
Hiroki Fukuda, Kazuhiro Shindo, Mari Sakamoto, Tomomi Ide, Shintaro Kinugawa, Arata Fukushima, Hiroyuki Tsutsui, Shin Ito, Akira Ishii, Takashi Washio, Masafumi Kitakaze, Elucidation of the Strongest Predictors of Cardiovascular Events in Patients with Heart Failure, EBioMedicine, 10.1016/j.ebiom.2018.06.001, 33, 185-195, 2018.07, Background: In previous retrospective studies, we identified the 50 most influential clinical predictors of cardiovascular outcomes in patients with heart failure (HF). The present study aimed to use the novel limitless-arity multiple-testing procedure to filter these 50 clinical factors and thus yield combinations of no more than four factors that could potentially predict the onset of cardiovascular events. A Kaplan–Meier analysis was used to investigate the importance of the combinations. Methods: In a multi-centre observational trial, we prospectively enrolled 213 patients with HF who were hospitalized because of exacerbation, discharged according to HF treatment guidelines and observed to monitor cardiovascular events. After the observation period, we stratified patients according to whether they experienced cardiovascular events (rehospitalisation or cardiovascular death). Findings: Among 77,562 combinations of fewer than five clinical parameters, we identified 151 combinations that could potentially explain the occurrence of cardiovascular events. Of these, 145 combinations included the use of inotropic agents, whereas the remaining 6 included the use of diuretics without bradycardia or tachycardia, suggesting that the high probability of cardiovascular events is exclusively determined by these two clinical factors. Importantly, Kaplan–Meier curves demonstrated that the use of inotropes or of diuretics without bradycardia or tachycardia were independent predictors of a markedly worse cardiovascular prognosis. Interpretation: Patients treated with either inotropic agents or diuretics without bradycardia or tachycardia were at a higher risk of cardiovascular events. The uses of these drugs, regardless of heart rate, are the strongest clinical predictors of cardiovascular events in patients with HF.. |
| 78. |
Hiroki Fukuda, Kazuhiro Shindo, Mari Sakamoto, Tomomi Ide, Shintaro Kinugawa, Arata Fukushima, Hiroyuki Tsutsui, Shin Ito, Akira Ishii, Takashi Washio, Masafumi Kitakaze, Elucidation of the Strongest Predictors of Cardiovascular Events in Patients with Heart Failure, EBIOMEDICINE, 10.1016/j.ebiom.2018.06.001, 33, 185-195, 2018.07, Background: In previous retrospective studies, we identified the 50 most influential clinical predictors of cardiovascular outcomes in patients with heart failure (HF). The present study aimed to use the novel limitless-arity multiple-testing procedure to filter these 50 clinical factors and thus yield combinations of no more than four factors that could potentially predict the onset of cardiovascular events. A Kaplan-Meier analysis was used to investigate the importance of the combinations.Methods: In a multi-centre observational trial, we prospectively enrolled 213 patients with HF who were hospitalized because of exacerbation, discharged according to HF treatment guidelines and observed to monitor cardiovascular events. After the observation period, we stratified patients according to whether they experienced cardiovascular events (rehospitalisation or cardiovascular death).Findings: Among 77,562 combinations of fewer than five clinical parameters, we identified 151 combinations that could potentially explain the occurrence of cardiovascular events. Of these, 145 combinations included the use of inotropic agents, whereas the remaining 6 included the use of diuretics without bradycardia or tachycardia, suggesting that the high probability of cardiovascular events is exclusively determined by these two clinical factors. Importantly, Kaplan-Meier curves demonstrated that the use of inotropes or of diuretics without bradycardia or tachycardia were independent predictors of a markedly worse cardiovascular prognosis.interpretation: Patients treated with either inotropic agents or diuretics without bradycardia or tachycardia were at a higher risk of cardiovascular events. The uses of these drugs, regardless of heart rate, are the strongest clinical predictors of cardiovascular events in patients with HF. (C) 2018 The Authors. Published by Elsevier B.V.. |
| 79. |
Chin Ling Hsieh, Reiko Koga, Aogu Furusho, Takeyuki Akita, Masashi Mita, Tomomi Ide, Jen Ai Lee, Kenji Hamase, Enantioselective and simultaneous determination of lactate and 3-hydroxybutyrate in human plasma and urine using a narrow-bore online two-dimensional high-performance liquid chromatography system, Journal of Separation Science, 10.1002/jssc.201701283, 41, 6, 1298-1306, 2018.03, For the enantioselective and simultaneous analysis of lactate and 3-hydroxybutyrate, a validated online two-dimensional high-performance liquid chromatography system using 4-nitro-7-piperazino-2,1,3-benzoxadiazole as a fluorescent derivatization reagent has been developed. For the reversed-phase separation in the first dimension, a Capcell Pak C18 ACR column (1.5 × 250 mm, particle size 3 μm) was used, and the target fractions were isolated by their hydrophobicity. In the second dimension, a polysaccharide-coated enantioselective column, Chiralpak AD-H (2.0 × 250 mm, 5 μm), was used. The system was validated by the calibration curve, intraday precision, interday precision, and accuracy using standards and real human samples, and satisfactory results were obtained. The present method was applied to human plasma and urine, and in the plasma, trace amounts of d-lactate (8.4 μM) and l-3-hydroxybutyrate (1.0 μM), besides high levels of l-lactate (860.9 μM) and d-3-hydroxybutyrate (59.4 μM), were successfully determined. In urine, trace levels of d-lactate (3.7 μM), d-3-hydroxybutyrate (2.3 μM), and l-3-hydroxybutyrate (3.3 μM) in addition to a relatively large amount of l-lactate (15.4 μM) were observed. The present online two-dimensional high-performance liquid chromatography system is useful for the simultaneous determination of all the lactate and 3-hydroxybutyrate enantiomers in human physiological fluids, and further clinical applications are ongoing.. |
| 80. |
Chin-Ling Hsieh, Reiko Koga, Aogu Furusho, Takeyuki Akita, Masashi Mita, Tomomi Ide, Jen-Ai Lee, Kenji Hamase, Enantioselective and simultaneous determination of lactate and 3-hydroxybutyrate in human plasma and urine using a narrow-bore online two-dimensional high-performance liquid chromatography system, JOURNAL OF SEPARATION SCIENCE, 10.1002/jssc.201701283, 41, 6, 1298-1306, 2018.03, For the enantioselective and simultaneous analysis of lactate and 3-hydroxybutyrate, a validated online two-dimensional high-performance liquid chromatography system using 4-nitro-7-piperazino-2,1,3-benzoxadiazole as a fluorescent derivatization reagent has been developed. For the reversed-phase separation in the first dimension, a Capcell Pak C18 ACR column (1.5 x 250 mm, particle size 3 mu m) was used, and the target fractions were isolated by their hydrophobicity. In the second dimension, a polysaccharide-coated enantioselective column, Chiralpak AD-H (2.0 x 250 mm, 5 mu m), was used. The system was validated by the calibration curve, intraday precision, interday precision, and accuracy using standards and real human samples, and satisfactory results were obtained. The present method was applied to human plasma and urine, and in the plasma, trace amounts of D-lactate (8.4 mu M) and L-3-hydroxybutyrate (1.0 mu M), besides high levels of L-lactate (860.9 mu M) and D3-hydroxybutyrate (59.4 mu M), were successfully determined. In urine, trace levels of D-lactate (3.7 mu M), D-3-hydroxybutyrate (2.3 mu M), and L-3-hydroxybutyrate (3.3 mu M) in addition to a relatively large amount of L-lactate (15.4 mu M) were observed. The present online two-dimensional high-performance liquid chromatography system is useful for the simultaneous determination of all the lactate and 3-hydroxybutyrate enantiomers in human physiological fluids, and further clinical applications are ongoing.. |
| 81. |
Takeo Fujino, Shujiro Inoue, Shunsuke Katsuki, Taiki Higo, Tomomi Ide, Yoshinao Oda, Hiroyuki Tsutsui, Fatal Cardiac Hemochromatosis in a Patient with Hereditary Spherocytosis, INTERNATIONAL HEART JOURNAL, 10.1536/ihj.17-160, 59, 2, 427-430, 2018.03, A 31-year-old man was admitted to our hospital with atrial tachycardia and cardiogenic shock. He had been diagnosed with hereditary spherocytosis (HS) during childhood, but he never received any red blood cell transfusions. Right ventricular endomyocardial biopsy revealed multiple myocardial hemosiderin deposits, and he was diagnosed with cardiac hemochromatosis. In addition to the iron deposition in the heart, the loss of myocyte and severe interstitial fibrosis were present. His cardiac function did not improve even after the cardioversion for atrial tachycardia, and he suffered from recurrent heart failure. Despite intensive medical treatment for heart failure and arrhythmias in combination with iron chelation therapy, he eventually died of progressive and refractory heart failure. Hemochromatosis is a systemic disorder characterized by the excessive deposition of iron in multiple organs. The occurrence of hemochromatosis in HS is extremely rare, and previous reports have shown that the coexistence of heterozygosity for the HFE gene mutation in HS patients causes excess iron storage. The prognosis is poor due to progressive congestive heart failure and refractory arrhythmias. Here we report a rare case of fatal cardiac hemochromatosis associated with HS. The possibility of cardiac hemochromatosis needs to be considered in cases of heart failure or arrhythmia in patients with HS.. |
| 82. |
Mari Sakamoto, Hiroki Fukuda, Jiyoong Kim, Tomomi Ide, Shintaro Kinugawa, Arata Fukushima, Hiroyuki Tsutsui, Akira Ishii, Shin Ito, Hiroshi Asanuma, Masanori Asakura, Takashi Washio, Masafumi Kitakaze, The impact of creating mathematical formula to predict cardiovascular events in patients with heart failure, SCIENTIFIC REPORTS, 10.1038/s41598-018-22347-0, 8, 2018.03, Since our retrospective study has formed a mathematical formula, a = f(x(1),., x(252)), where a is the probability of cardiovascular events in patients with heart failure (HF) and x(1) is each clinical parameter, we prospectively tested the predictive capability and feasibility of the mathematical formula of cardiovascular events in HF patients. First of all, to create such a mathematical formula using limited number of the parameters to predict the cardiovascular events in HF patients, we retrospectively determined f(x) that formulates the relationship between the most influential 50 clinical parameters ( x) among 252 parameters using 167 patients hospitalized due to acute HF; the nonlinear optimization could provide the formula of a = f(x(1),., x(50)) which fitted the probability of the actual cardiovascular events per day. Secondly, we prospectively examined the predictability of f(x) in other 213 patients using 50 clinical parameters in 3 hospitals, and we found that the Kaplan-Meier curves using actual and estimated occurrence probabilities of cardiovascular events were closely correlated. We conclude that we created a mathematical formula f(x) that precisely predicted the occurrence probability of future cardiovascular outcomes of HF patients per day. Mathematical modelling may predict the occurrence probability of cardiovascular events in HF patients.. |
| 83. |
Takeo Fujino, Shujiro Inoue, Shunsuke Katsuki, Taiki Higo, Tomomi Ide, Yoshinao Oda, Hiroyuki Tsutsui, Fatal cardiac hemochromatosis in a patient with hereditary spherocytosis, International heart journal, 10.1536/ihj.17-160, 59, 2, 427-430, 2018.01, A 31-year-old man was admitted to our hospital with atrial tachycardia and cardiogenic shock. He had been diagnosed with hereditary spherocytosis (HS) during childhood, but he never received any red blood cell transfusions. Right ventricular endomyocardial biopsy revealed multiple myocardial hemosiderin deposits, and he was diagnosed with cardiac hemochromatosis. In addition to the iron deposition in the heart, the loss of myocyte and severe interstitial fibrosis were present. His cardiac function did not improve even after the cardioversion for atrial tachycardia, and he suffered from recurrent heart failure. Despite intensive medical treatment for heart failure and arrhythmias in combination with iron chelation therapy, he eventually died of progressive and refractory heart failure. Hemochromatosis is a systemic disorder characterized by the excessive deposition of iron in multiple organs. The occurrence of hemochromatosis in HS is extremely rare, and previous reports have shown that the coexistence of heterozygosity for the HFE gene mutation in HS patients causes excess iron storage. The prognosis is poor due to progressive congestive heart failure and refractory arrhythmias. Here we report a rare case of fatal cardiac hemochromatosis associated with HS. The possibility of cardiac hemochromatosis needs to be considered in cases of heart failure or arrhythmia in patients with HS.. |
| 84. |
Akiko Nishizaki, Kisho Ohtani, Yuji Maehata, Motohiro Esaki, Tomomi Ide, Refractory coronary artery spasm associated with tacrolimus, Coronary Artery Disease, 10.1097/MCA.0000000000000538, 29, 1, 83-85, 2018.01. |
| 85. |
Akiko Nishizaki, Kisho Ohtani, Yuji Maehata, Motohiro Esaki, Tomomi Ide, Refractory coronary artery spasm associated with tacrolimus, CORONARY ARTERY DISEASE, 10.1097/MCA.0000000000000538, 29, 1, 83-85, 2018.01. |
| 86. |
Takuya Nishikawa, Keita Saku, Koji Todaka, Yukimitsu Kuwabara, Shinobu Arai, Takuya Kishi, Tomomi Ide, Hiroyuki Tsutsui, Kenji Sunagawa, The challenge of magnetic vagal nerve stimulation for myocardial infarction -preliminary clinical trial, 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2017
2017 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Smarter Technology for a Healthier World, EMBC 2017 - Proceedings, 10.1109/EMBC.2017.8037812, 4321-4324, 2017.09, Numerous studies have shown in animal models that vagal nerve stimulation (VNS) strikingly reduces infarct size of acute myocardial infarction (AMI) and prevents heart failure. However, the lack of techniques to noninvasively stimulate the vagal nerve hinders VNS from clinical applications. Transcranial magnetic stimulation is noninvasive and capable of stimulating central neurons in patients. In this study, we examined whether the magnetic stimulation could noninvasively activate the cervical vagal nerve in healthy human. Sixteen healthy males and 4 females were enrolled in this study. We used Magstim Rapid2 with a 70-mm double coil in the right neck. We randomly assigned the subjects to 5 Hz or 20 Hz stimulation. We defined the maximum intensity of stimulation (MAX) which is the intensity just below the threshold of adverse effects. We defined HALF as a half of MAX. Protocols comprised 2 sets of MAX and 2 sets of HALF. Each stimulation continued for 3 minutes. We monitored heart rate (HR) and assessed the bradycardic response as an index of successful VNS. Nineteen subjects completed all protocols. They had no problematic adverse events during and/or after magnetic VNS. The magnetic VNS induced transient bradycardic responses in some subjects, whereas failed to induce sustained bradycardia in pooled data in any settings. Arterial pressure did not change either. Successful magnetic stimulation requires technical improvements including narrowing the magnetic focus and optimization of stimulation site. These improvements may enable us to apply magnetic VNS in the management of AMI.. |
| 87. |
Takuya Nishikawa, Keita Saku, Koji Todaka, Yukimitsu Kuwabara, Shinobu Arai, Takuya Kishi, Tomomi Ide, Hiroyuki Tsutsui, Kenji Sunagawa, The challenge of magnetic vagal nerve stimulation for myocardial infarction -preliminary clinical trial, Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS, 10.1109/EMBC.2017.8037812, 14, 4321-4324, 2017.09, Numerous studies have shown in animal models that vagal nerve stimulation (VNS) strikingly reduces infarct size of acute myocardial infarction (AMI) and prevents heart failure. However, the lack of techniques to noninvasively stimulate the vagal nerve hinders VNS from clinical applications. Transcranial magnetic stimulation is noninvasive and capable of stimulating central neurons in patients. In this study, we examined whether the magnetic stimulation could noninvasively activate the cervical vagal nerve in healthy human. Sixteen healthy males and 4 females were enrolled in this study. We used Magstim Rapid2 with a 70-mm double coil in the right neck. We randomly assigned the subjects to 5 Hz or 20 Hz stimulation. We defined the maximum intensity of stimulation (MAX) which is the intensity just below the threshold of adverse effects. We defined HALF as a half of MAX. Protocols comprised 2 sets of MAX and 2 sets of HALF. Each stimulation continued for 3 minutes. We monitored heart rate (HR) and assessed the bradycardic response as an index of successful VNS. Nineteen subjects completed all protocols. They had no problematic adverse events during and/or after magnetic VNS. The magnetic VNS induced transient bradycardic responses in some subjects, whereas failed to induce sustained bradycardia in pooled data in any settings. Arterial pressure did not change either. Successful magnetic stimulation requires technical improvements including narrowing the magnetic focus and optimization of stimulation site. These improvements may enable us to apply magnetic VNS in the management of AMI.. |
| 88. |
Yoshiko Kuribayashi, Kisho Ohtani, Tsunenori Saito, Tomomi Ide, Electron microscopy gain a glimpse into the pathogenesis of cardiac sarcoidosis, European Heart Journal Cardiovascular Imaging, 10.1093/ehjci/jex152, 18, 8, 2017.08. |
| 89. |
Tsukasa Shimauchi, Takuro Numaga-Tomita, Tomoya Ito, Akiyuki Nishimura, Ryosuke Matsukane, Sayaka Oda, Sumio Hoka, Tomomi Ide, Norimichi Koitabashi, Koji Uchida, Hideki Sumimoto, Yasuo Mori, Motohiro Nishida, TRPC3-Nox2 complex mediates doxorubicin-induced myocardial atrophy, JCI insight, 10.1172/jci.insight.93358, 2, 15, 2017.08, Myocardial atrophy is a wasting of cardiac muscle due to hemodynamic unloading. Doxorubicin is a highly effective anticancer agent but also induces myocardial atrophy through a largely unknown mechanism. Here, we demonstrate that inhibiting transient receptor potential canonical 3 (TRPC3) channels abolishes doxorubicin-induced myocardial atrophy in mice. Doxorubicin increased production of ROS in rodent cardiomyocytes through hypoxic stress-mediated upregulation of NADPH oxidase 2 (Nox2), which formed a stable complex with TRPC3. Cardiomyocyte-specific expression of TRPC3 C-terminal minipeptide inhibited TRPC3-Nox2 coupling and suppressed doxorubicin-induced reduction of myocardial cell size and left ventricular (LV) dysfunction, along with its upregulation of Nox2 and oxidative stress, without reducing hypoxic stress. Voluntary exercise, an effective treatment to prevent doxorubicin-induced cardiotoxicity, also downregulated the TRPC3-Nox2 complex and promoted volume load-induced LV compliance, as demonstrated in TRPC3-deficient hearts. These results illustrate the impact of TRPC3 on LV compliance and flexibility and, focusing on the TRPC3-Nox2 complex, provide a strategy for prevention of doxorubicin-induced cardiomyopathy.. |
| 90. |
Kana Fujii, Keita Saku, Takuya Kishi, Yasuhiro Oga, Takeshi Tohyama, Takuya Nishikawa, Takafumi Sakamoto, Masataka Ikeda, Tomomi Ide, Hiroyuki Tsutsui, Kenji Sunagawa, Carotid Body Denervation Markedly Improves Survival in Rats With Hypertensive Heart Failure, AMERICAN JOURNAL OF HYPERTENSION, 10.1093/ajh/hpx062, 30, 8, 791-798, 2017.08, BACKGROUNDHypertension is a major cause of heart failure. Excessive sympathoexcitation in patients with heart failure leads to poor prognosis. Since carotid body denervation (CBD) has been shown to reduce sympathetic nerve activity in animal models of hypertension and heart failure, we examined if bilateral CBD attenuates the progression of hypertensive heart failure and improves survival.METHODSWe randomly allocated Dahl salt-sensitive rats fed a high-salt diet from 6 weeks of age into CBD (n = 31) and sham-operation (SHAM; n = 50) groups, and conducted CBD or SHAM at 7 weeks of age. We examined the time course of 24-hour urinary norepinephrine (uNE) excretion, blood pressure (BP) and the percent fractional shortening assessed by echocardiography, and estimated the pressure-natriuresis relationship at 14 weeks of age. Finally, we assessed hemodynamics, histological findings, and survival at 16 weeks of age.RESULTSCompared to SHAM, CBD significantly reduced 24-hour uNE at 12, 14, and 16 weeks of age, shifted the pressure-natriuresis relationship leftward without changing its slope, and attenuated the increase in BP. CBD preserved percent fractional shortening (34.2 +/- 1.2 vs. 29.1 +/- 1.3%, P |
| 91. |
Yoshiko Kuribayashi, Kisho Ohtani, Tsunenori Saito, Tomomi Ide, Electron microscopy gain a glimpse into the pathogenesis of cardiac sarcoidosis, EUROPEAN HEART JOURNAL-CARDIOVASCULAR IMAGING, 10.1093/ehjci/jex152, 18, 8, 944-944, 2017.08. |
| 92. |
Tsukasa Shimauchi, Takuro Numaga-Tomita, Tomoya Ito, Akiyuki Nishimura, Ryosuke Matsukane, Sayaka Oda, Sumio Hoka, Tomomi Ide, Norimichi Koitabashi, Koji Uchida, Hideki Sumimoto, Yasuo Mori, Motohiro Nishida, TRPC3-Nox2 complex mediates doxorubicin-induced myocardial atrophy, JCI INSIGHT, 10.1172/jci.insight.93358, 2, 15, 2017.08, Myocardial atrophy is a wasting of cardiac muscle due to hemodynamic unloading. Doxorubicin is a highly effective anticancer agent but also induces myocardial atrophy through a largely unknown mechanism. Here, we demonstrate that inhibiting transient receptor potential canonical 3 (TRPC3) channels abolishes doxorubicin-induced myocardial atrophy in mice. Doxorubicin increased production of ROS in rodent cardiomyocytes through hypoxic stress-mediated upregulation of NADPH oxidase 2 (Nox2), which formed a stable complex with TRPC3. Cardiomyocyte-specific expression of TRPC3 C-terminal minipeptide inhibited TRPC3-Nox2 coupling and suppressed doxorubicin-induced reduction of myocardial cell size and left ventricular (LV) dysfunction, along with its upregulation of Nox2 and oxidative stress, without reducing hypoxic stress. Voluntary exercise, an effective treatment to prevent doxorubicin-induced cardiotoxicity, also downregulated the TRPC3-Nox2 complex and promoted volume load-induced LV compliance, as demonstrated in TRPC3-deficient hearts. These results illustrate the impact of TRPC3 on LV compliance and flexibility and, focusing on the TRPC3-Nox2 complex, provide a strategy for prevention of doxorubicin-induced cardiomyopathy.. |
| 93. |
Takuya Nishikawa, Keita Saku, Koji Todaka, Yukimitsu Kuwabara, Shinobu Arai, Takuya Kishi, Tomomi Ide, Hiroyuki Tsutsui, Kenji Sunagawa, The challenge of magnetic vagal nerve stimulation for myocardial infarction -preliminary clinical trial, Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings, 10.1109/EMBC.2017.8037812, 2017, 4321-4324, 2017.07, Numerous studies have shown in animal models that vagal nerve stimulation (VNS) strikingly reduces infarct size of acute myocardial infarction (AMI) and prevents heart failure. However, the lack of techniques to noninvasively stimulate the vagal nerve hinders VNS from clinical applications. Transcranial magnetic stimulation is noninvasive and capable of stimulating central neurons in patients. In this study, we examined whether the magnetic stimulation could noninvasively activate the cervical vagal nerve in healthy human. Sixteen healthy males and 4 females were enrolled in this study. We used Magstim Rapid2 with a 70-mm double coil in the right neck. We randomly assigned the subjects to 5 Hz or 20 Hz stimulation. We defined the maximum intensity of stimulation (MAX) which is the intensity just below the threshold of adverse effects. We defined HALF as a half of MAX. Protocols comprised 2 sets of MAX and 2 sets of HALF. Each stimulation continued for 3 minutes. We monitored heart rate (HR) and assessed the bradycardic response as an index of successful VNS. Nineteen subjects completed all protocols. They had no problematic adverse events during and/or after magnetic VNS. The magnetic VNS induced transient bradycardic responses in some subjects, whereas failed to induce sustained bradycardia in pooled data in any settings. Arterial pressure did not change either. Successful magnetic stimulation requires technical improvements including narrowing the magnetic focus and optimization of stimulation site. These improvements may enable us to apply magnetic VNS in the management of AMI.. |
| 94. |
Michinobu Nagao, Yuzo Yamasaki, Satoshi Kawanami, Takeshi Kamitani, Koji Sagiyama, Taiki Higo, Tomomi Ide, Atsushi Takemura, Umiko Ishizaki, Kenji Fukushima, Yuji Watanabe, Hiroshi Honda, Quantification of myocardial oxygenation in heart failure using blood-oxygen-level-dependent T2* magnetic resonance imaging
Comparison with cardiopulmonary exercise test, Magnetic Resonance Imaging, 10.1016/j.mri.2017.02.005, 39, 138-143, 2017.06, Purpose Quantification of myocardial oxygenation (MO) in heart failure (HF) has been less than satisfactory. This has necessitated the use of invasive techniques to measure MO directly or to determine the oxygen demand during exercise using the cardiopulmonary exercise (CPX) test. We propose a new quantification method for MO using blood-oxygen-level-dependent (BOLD) myocardial T2* magnetic resonance imaging (M-T2* MRI), and investigate its correlation with CPX results. Methods Thirty patients with refractory HF who underwent cardiac MRI and CPX test for heart transplantation, and 24 healthy, age-matched volunteers as controls were enrolled. M-T2* imaging was performed using a 3-Tesla and multi-echo gradient-echo sequence. M-T2* was calculated by fitting the signal intensity data for the mid-left ventricular septum to a decay curve. M-T2* was measured under room-air (T2*-air) and after inhalation of oxygen for 10 min at a flow rate of 10 L/min (T2*-oxy). MO was defined as the difference between the two values (ΔT2*). Changes in M-T2* at the two conditions and ΔT2* between the two groups were compared. Correlation between ΔT2* and CPX results was analyzed using the Pearson coefficient. Results T2*-oxy was significantly greater than T2*-air in patients with HF (29.9 ± 7.3 ms vs. 26.7 ± 6.0 ms, p 2, r = − 0.46, p 2 pulse, r = − 0.54, p |
| 95. |
Michinobu Nagao, Yuzo Yamasaki, Satoshi Kawanami, Takeshi Kamitani, Koji Sagiyama, Taiki Higo, Tomomi Ide, Atsushi Takemura, Umiko Ishizaki, Kenji Fukushima, Yuji Watanabe, Hiroshi Honda, Quantification of myocardial oxygenation in heart failure using blood-oxygen-level-dependent T2*magnetic resonance imaging: Comparison with cardiopulmonary exercise test, MAGNETIC RESONANCE IMAGING, 10.1016/j.mri.2017.02.005, 39, 138-143, 2017.06, Purpose: Quantification of myocardial oxygenation (MO) in heart failure (HF) has been less than satisfactory. This has necessitated the use of invasive techniques to measure MO directly or to determine the oxygen demand during exercise using the cardiopulmonary exercise (CPX) test. We propose a new quantification method for MO using blood-oxygen-level-dependent (BOLD) myocardial T2* magnetic resonance imaging (M-T2* MRI), and investigate its correlation with CPX results.Methods: Thirty patients with refractory HF who underwent cardiac MRI and CPX test for heart transplantation, and 24 healthy, age-matched volunteers as controls were enrolled. M-T2* imaging was performed using a 3-Tesla and multi-echo gradient-echo sequence. M-T2* was calculated by fitting the signal intensity data for the mid-left ventricular septum to a decay curve. M-T2* was measured under room-air (T2*-air) and after inhalation of oxygen for 10 min at a flow rate of 10 L/min (T2*-oxy). MO was defined as the difference between the two values (AT2*). Changes in M-T2* at the two conditions and AT2* between the two groups were compared. Correlation between AT2* and CPX results was analyzed using the Pearson coefficient.Results: T2*-oxy was significantly greater than T2*-air in patients with HF (29.9 +/- 7.3 ms vs. 26.7 +/- 6.0 ms, p |
| 96. |
Kana Fujii, Keita Saku, Takuya Kishi, Yasuhiro Oga, Takeshi Tohyama, Takuya Nishikawa, takafumi sakamoto, Masataka Ikeda, Tomomi Ide, Hiroyuki Tsutsui, Kenji Sunagawa, Carotid body denervation markedly improves survival in rats with hypertensive heart failure, American Journal of Hypertension, 10.1093/ajh/hpx062, 30, 8, 791-798, 2017.01, BACKGROUND Hypertension is a major cause of heart failure. Excessive sympathoexcitation in patients with heart failure leads to poor prognosis. Since carotid body denervation (CBD) has been shown to reduce sympathetic nerve activity in animal models of hypertension and heart failure, we examined if bilateral CBD attenuates the progression of hypertensive heart failure and improves survival. METHODS We randomly allocated Dahl salt-sensitive rats fed a high-salt diet from 6 weeks of age into CBD (n = 31) and sham-operation (SHAM; n = 50) groups, and conducted CBD or SHAM at 7 weeks of age. We examined the time course of 24-hour urinary norepinephrine (uNE) excretion, blood pressure (BP) and the percent fractional shortening assessed by echocardiography, and estimated the pressure-natriuresis relationship at 14 weeks of age. Finally, we assessed hemodynamics, histological findings, and survival at 16 weeks of age. RESULTS Compared to SHAM, CBD significantly reduced 24-hour uNE at 12, 14, and 16 weeks of age, shifted the pressure-natriuresis relationship leftward without changing its slope, and attenuated the increase in BP. CBD preserved percent fractional shortening (34.2 ± 1.2 vs. 29.1 ± 1.3%, P |
| 97. |
Shinobu Arai, Masataka Ikeda, Tomomi Ide, Yuka Matsuo, Takeo Fujino, Katsuya Hirano, Kenji Sunagawa, Hiroyuki Tsutsui, Functional loss of DHRS7C induces intracellular ca2+ overload and myotube enlargement in C2C12 cells via calpain activation, American Journal of Physiology - Cell Physiology, 10.1152/ajpcell.00090.2016, 312, 1, C29-C39, 2017.01, Dehydrogenase/reductase member 7C (DHRS7C) is a newly identified NAD/NADHdependent dehydrogenase that is expressed in cardiac and skeletal muscle and localized in the endoplasmic/sarcoplasmic reticulum (ER/ SR). However, its functional role in muscle cells remains to be fully elucidated. Here, we investigated the role of DHRS7C by analyzing mouse C2C12 myoblasts deficient in DHRS7C (DHRS7C-KO cells), overexpressing wild-type DHRS7C (DHRS7C-WT cells), or expressing mutant DHRS7C [DHRS7C-Y191F or DHRS7C-K195Q cells, harboring point mutations in the NAD/NADH-dependent dehydrogenase catalytic core domain (YXXXK)]. DHRS7C expression was induced as C2C12 myoblasts differentiated into mature myotubes, whereas DHRS7C-KO myotubes exhibited enlarged cellular morphology after differentiation. Notably, both DHRS7C-Y191F and DHRS7C-K195Q cells also showed similar enlarged cellular morphology, suggesting that the NAD/NADH-dependent dehydrogenase catalytic core domain is pivotal for DHRS7C function. In DHRS7CKO, DHRS7C-Y191F, and DHRS7C-K195Q cells, the resting level of cytosolic Ca2+ and total amount of Ca2+ storage in the ER/SR were significantly higher than those in control C2C12 and DHRS7C-WT cells after differentiation. Additionally, Ca2+ release from the ER/SR induced by thapsigargin and 4-chloro-m-cresol was augmented in these cells and calpain, a calcium-dependent protease, was significantly activated in DHRS7C-KO, DHRS7C-Y191F, and DHRS7C-K195Q myotubes, consistent with the higher resting level of cytosolic Ca2+ concentration and enlarged morphology after differentiation. Furthermore, treatment with a calpain inhibitor abolished the enlarged cellular morphology. Taken together, our findings suggested that DHRS7C maintains intracellular Ca2+ homeostasis involving the ER/SR and that functional loss of DHRS7C leads to Ca2+ overload in the cytosol and ER/SR, resulting in enlarged cellular morphology via calpain activation.. |
| 98. |
Takahiro Arimura, Keita Saku, Takamori Kakino, Takuya Nishikawa, Takeshi Tohyama, takafumi sakamoto, Kazuo Sakamoto, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Intravenous electrical vagal nerve stimulation prior to coronary reperfusion in a canine ischemia-reperfusion model markedly reduces infarct size and prevents subsequent heart failure, International Journal of Cardiology, 10.1016/j.ijcard.2016.10.074, 227, 704-710, 2017.01, Background Reducing myocardial damage is a prerequisite to prevent chronic heart failure after acute myocardial infarction (AMI). Although vagal nerve stimulation (VNS) has been repeatedly demonstrated to have potent anti-infarct effect, technical difficulties have precluded its clinical application. We developed a novel therapeutic strategy of intravenous VNS (iVNS) and examined whether iVNS administered prior to coronary reperfusion in a canine AMI model reduces infarct size and prevents heart failure. Methods and results In 35 mongrel dogs, we induced ischemia by ligating the left anterior descending coronary artery and then reperfused 3 h later (I/R). We transvenously placed a catheter electrode in the superior vena cava and adjusted the stimulation intensity to a level that induced bradycardia but maintained stable hemodynamics (continuous, 5.1 ± 2.1 V, 10 Hz). We administered iVNS from onset (iVNS-0, n = 7) or 90 min after onset (iVNS-90, n = 7) of ischemia until one hour after reperfusion. Four weeks after ischemia–reperfusion, iVNS markedly reduced infarct size (iVNS-0: 2.4 ± 2.1%, p |
| 99. |
Takamori Kakino, Keita Saku, takafumi sakamoto, Kazuo Sakamoto, Takuya Akashi, Masataka Ikeda, Tomomi Ide, Takuya Kishi, Hiroyuki Tsutsui, Kenji Sunagawa, Prediction of hemodynamics under left ventricular assist device, American Journal of Physiology - Heart and Circulatory Physiology, 10.1152/ajpheart.00617.2016, 312, 1, H80-H88, 2017.01, Left ventricular assist device (LVAD) saves lives in patients with severe left ventricular (LV) failure. However, predicting how much LVAD boosts total cardiac output (CO) remains difficult. This study aimed to develop a framework to quantitatively predict the impact of LVAD on hemodynamics. We adopted the circulatory equilibrium framework and incorporated LVAD into the integrated CO curve to derive the circulatory equilibrium. In anesthetized dogs, we ligated left coronary arteries to create LV failure and inserted a centrifugal pump as LVAD. Using CO and right (PRA) and left atrial pressure (PLA) measured before LVAD support, we predetermined the stressed volume (V) and logarithmic slope of right heart CO curve (SR). Next, we initiated LVAD at maximum level and then decreased LVAD flow stepwise while monitoring hemodynamic changes. We predicted LVAD-induced CO and PRA for given PLA from the predetermined SR and V and compared with those measured experimentally. The predicted CO [r2 = 0.907, SE of estimate (SEE) = 5.59 ml·min-1·kg-1, P 2 = 0.967, SEE = 0.307 mmHg, P |
| 100. |
Shinobu Arai, Masataka Ikeda, Tomomi Ide, Yuka Matsuo, Takeo Fujino, Katsuya Hirano, Kenji Sunagawa, Hiroyuki Tsutsui, Functional loss of DHRS7C induces intracellular Ca2+ overload and myotube enlargement in C2C12 cells via calpain activation, AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY, 10.1152/ajpcell.00090.2016, 312, 1, C29-C39, 2017.01, Dehydrogenase/reductase member 7C (DHRS7C) is a newly identified NAD/NADHdependent dehydrogenase that is expressed in cardiac and skeletal muscle and localized in the endoplasmic/sarcoplasmic reticulum (ER/SR). However, its functional role in muscle cells remains to be fully elucidated. Here, we investigated the role of DHRS7C by analyzing mouse C2C12 myoblasts deficient in DHRS7C (DHRS7C-KO cells), overexpressing wild-type DHRS7C (DHRS7C-WT cells), or expressing mutant DHRS7C [ DHRS7C-Y191F or DHRS7C-K195Q cells, harboring point mutations in the NAD/NADH-dependent dehydrogenase catalytic core domain (YXXXK)]. DHRS7C expression was induced as C2C12 myoblasts differentiated into mature myotubes, whereas DHRS7C-KO myotubes exhibited enlarged cellular morphology after differentiation. Notably, both DHRS7C-Y191F and DHRS7C-K195Q cells also showed similar enlarged cellular morphology, suggesting that the NAD/NADH-dependent dehydrogenase catalytic core domain is pivotal for DHRS7C function. In DHRS7CKO, DHRS7C-Y191F, and DHRS7C-K195Q cells, the resting level of cytosolic Ca2+ and total amount of Ca2+ storage in the ER/SR were significantly higher than those in control C2C12 and DHRS7C-WT cells after differentiation. Additionally, Ca2+ release from the ER/SR induced by thapsigargin and 4-chloro-m-cresol was augmented in these cells and calpain, a calcium-dependent protease, was significantly activated in DHRS7C-KO, DHRS7C-Y191F, and DHRS7C-K195Q myotubes, consistent with the higher resting level of cytosolic Ca2+ concentration and enlarged morphology after differentiation. Furthermore, treatment with a calpain inhibitor abolished the enlarged cellular morphology. Taken together, our findings suggested that DHRS7C maintains intracellular Ca2+ homeostasis involving the ER/SR and that functional loss of DHRS7C leads to Ca2+ overload in the cytosol and ER/SR, resulting in enlarged cellular morphology via calpain activation.. |
| 101. |
Takahiro Arimura, Keita Saku, Takamori Kakino, Takuya Nishikawa, Takeshi Tohyama, Takafumi Sakamoto, Kazuo Sakamoto, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Intravenous electrical vagal nerve stimulation prior to coronary reperfusion in a canine ischemia-reperfusion model markedly reduces infarct size and prevents subsequent heart failure, INTERNATIONAL JOURNAL OF CARDIOLOGY, 10.1016/j.ijcard.2016.10.074, 227, 704-710, 2017.01, Background: Reducing myocardial damage is a prerequisite to prevent chronic heart failure after acute myocardial infarction (AMI). Although vagal nerve stimulation (VNS) has been repeatedly demonstrated to have potent anti-infarct effect, technical difficulties have precluded its clinical application. We developed a novel therapeutic strategy of intravenous VNS (iVNS) and examined whether iVNS administered prior to coronary reperfusion in a canine AMI model reduces infarct size and prevents heart failure.Methods and results: In 35 mongrel dogs, we induced ischemia by ligating the left anterior descending coronary artery and then reperfused 3 h later (I/R) We transvenously placed a catheter electrode in the superior vena cava and adjusted the stimulation intensity to a level that induced bradycardia but maintained stable hemodynamics (continuous, 5.1 +/- 2.1 V. 10 Hz). We administered iVNS from onset (iVNS-0, n = 7) Of 90 min after onset (iVNS-90, n 7) of ischemia until one hour after reperfusion. Four weeks after ischemia-reperfusion, iVNS markedly reduced infarct size (iVNS-0: 24 +/- 2.1%, p |
| 102. |
Takamori Kakino, Keita Saku, Takafumi Sakamoto, Kazuo Sakamoto, Takuya Akashi, Masataka Ikeda, Tomomi Ide, Takuya Kishi, Hiroyuki Tsutsui, Kenji Sunagawa, Prediction of hemodynamics under left ventricular assist device, AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, 10.1152/ajpheart.00617.2016, 312, 1, H80-H88, 2017.01, Left ventricular assist device (LVAD) saves lives in patients with severe left ventricular (LV) failure. However, predicting how much LVAD boosts total cardiac output (CO) remains difficult. This study aimed to develop a framework to quantitatively predict the impact of LVAD on hemodynamics. We adopted the circulatory equilibrium framework and incorporated LVAD into the integrated CO curve to derive the circulatory equilibrium. In anesthetized dogs, we ligated left coronary arteries to create LV failure and inserted a centrifugal pump as LVAD. Using CO and right (P-RA) and left atrial pressure (P-LA) measured before LVAD support, we predetermined the stressed volume (V) and logarithmic slope of right heart CO curve (S-R). Next, we initiated LVAD at maximum level and then decreased LVAD flow stepwise while monitoring hemodynamic changes. We predicted LVAD-induced CO and PRA for given PLA from the predetermined SR and V and compared with those measured experimentally. The predicted CO [r(2) = 0.907, SE of estimate (SEE) = 5.59 ml . min(-1) . kg(-1), P |
| 103. |
Takuro Numaga-Tomita, Naoyuki Kitajima, Takuya Kuroda, Akiyuki Nishimura, Kei Miyano, Satoshi Yasuda, Koichiro Kuwahara, Yoji Sato, Tomomi Ide, Lutz Birnbaumer, Hideki Sumimoto, Yasuo Mori, Motohiro Nishida, TRPC3-GEF-H1 axis mediates pressure overload-induced cardiac fibrosis, Scientific reports, 10.1038/srep39383, 6, 2016.12, Structural cardiac remodeling, accompanying cytoskeletal reorganization of cardiac cells, is a major clinical outcome of diastolic heart failure. A highly local Ca 2+ influx across the plasma membrane has been suggested to code signals to induce Rho GTPase-mediated fibrosis, but it is obscure how the heart specifically decodes the local Ca 2+ influx as a cytoskeletal reorganizing signal under the conditions of the rhythmic Ca 2+ handling required for pump function. We found that an inhibition of transient receptor potential canonical 3 (TRPC3) channel activity exhibited resistance to Rho-mediated maladaptive fibrosis in pressure-overloaded mouse hearts. Proteomic analysis revealed that microtubule-Associated Rho guanine nucleotide exchange factor, GEF-H1, participates in TRPC3-mediated RhoA activation induced by mechanical stress in cardiomyocytes and transforming growth factor (TGF) β stimulation in cardiac fibroblasts. We previously revealed that TRPC3 functionally interacts with microtubule-Associated NADPH oxidase (Nox) 2, and inhibition of Nox2 attenuated mechanical stretch-induced GEF-H1 activation in cardiomyocytes. Finally, pharmacological TRPC3 inhibition significantly suppressed fibrotic responses in human cardiomyocytes and cardiac fibroblasts. These results strongly suggest that microtubule-localized TRPC3-GEF-H1 axis mediates fibrotic responses commonly in cardiac myocytes and fibroblasts induced by physico-chemical stimulation.. |
| 104. |
Takuro Numaga-Tomita, Naoyuki Kitajima, Takuya Kuroda, Akiyuki Nishimura, Kei Miyano, Satoshi Yasuda, Koichiro Kuwahara, Yoji Sato, Tomomi Ide, Lutz Birnbaumer, Hideki Sumimoto, Yasuo Mori, Motohiro Nishida, TRPC3-GEF-H1 axis mediates pressure overload-induced cardiac fibrosis, SCIENTIFIC REPORTS, 10.1038/srep39383, 6, 2016.12, Structural cardiac remodeling, accompanying cytoskeletal reorganization of cardiac cells, is a major clinical outcome of diastolic heart failure. A highly local Ca2+ influx across the plasma membrane has been suggested to code signals to induce Rho GTPase-mediated fibrosis, but it is obscure how the heart specifically decodes the local Ca2+ influx as a cytoskeletal reorganizing signal under the conditions of the rhythmic Ca2+ handling required for pump function. We found that an inhibition of transient receptor potential canonical 3 (TRPC3) channel activity exhibited resistance to Rho-mediated maladaptive fibrosis in pressure-overloaded mouse hearts. Proteomic analysis revealed that microtubule-associated Rho guanine nucleotide exchange factor, GEF-H1, participates in TRPC3-mediated RhoA activation induced by mechanical stress in cardiomyocytes and transforming growth factor (TGF)beta stimulation in cardiac fibroblasts. We previously revealed that TRPC3 functionally interacts with microtubuleassociated NADPH oxidase (Nox) 2, and inhibition of Nox2 attenuated mechanical stretch-induced GEF-H1 activation in cardiomyocytes. Finally, pharmacological TRPC3 inhibition significantly suppressed fibrotic responses in human cardiomyocytes and cardiac fibroblasts. These results strongly suggest that microtubule-localized TRPC3-GEF-H1 axis mediates fibrotic responses commonly in cardiac myocytes and fibroblasts induced by physico-chemical stimulation.. |
| 105. |
Sugako Oka, Julio Leon, Sakumi Kunihiko, Tomomi Ide, Dongchon Kang, Frank M. LaFerla, Yusaku Nakabeppu, Human mitochondrial transcriptional factor A breaks the mitochondria-mediated vicious cycle in Alzheimer's disease, Scientific reports, 10.1038/srep37889, 6, 2016.11, In the mitochondria-mediated vicious cycle of Alzheimer's disease (AD), intracellular amyloid β (Aβ) induces mitochondrial dysfunction and reactive oxygen species, which further accelerate Aβ accumulation. This vicious cycle is thought to play a pivotal role in the development of AD, although the molecular mechanism remains unclear. Here, we examined the effects of human mitochondrial transcriptional factor A (hTFAM) on the pathology of a mouse model of AD (3xTg-AD), because TFAM is known to protect mitochondria from oxidative stress through maintenance of mitochondrial DNA (mtDNA). Expression of hTFAM significantly improved cognitive function, reducing accumulation of both 8-oxoguanine, an oxidized form of guanine, in mtDNA and intracellular Aβ in 3xTg-AD mice and increasing expression of transthyretin, known to inhibit Aβ aggregation. Next, we found that AD model neurons derived from human induced pluripotent stem cells carrying a mutant PSEN1 (P117L) gene, exhibited mitochondrial dysfunction, accumulation of 8-oxoguanine and single-strand breaks in mtDNA, and impaired neuritogenesis with a decreased expression of transthyretin, which is known to be downregulated by oxidative stress. Extracellular treatment with recombinant hTFAM effectively suppressed these deleterious outcomes. Moreover, the treatment increased expression of transthyretin, accompanied by reduction of intracellular Aβ. These results provide new insights into potential novel therapeutic targets.. |
| 106. |
Naoyuki Kitajima, Takuro Numaga-Tomita, Masahiko Watanabe, Takuya Kuroda, Akiyuki Nishimura, Kei Miyano, Satoshi Yasuda, Koichiro Kuwahara, Yoji Sato, Tomomi Ide, Lutz Birnbaumer, Hideki Sumimoto, Yasuo Mori, Motohiro Nishida, TRPC3 positively regulates reactive oxygen species driving maladaptive cardiac remodeling, Scientific reports, 10.1038/srep37001, 6, 2016.11, Reactive oxygen species (ROS) produced by NADPH oxidase 2 (Nox2) function as key mediators of mechanotransduction during both physiological adaptation to mechanical load and maladaptive remodeling of the heart. This is despite low levels of cardiac Nox2 expression. The mechanism underlying the transition from adaptation to maladaptation remains obscure, however. We demonstrate that transient receptor potential canonical 3 (TRPC3), a Ca 2+-permeable channel, acts as a positive regulator of ROS (PRROS) in cardiomyocytes, and specifically regulates pressure overload-induced maladaptive cardiac remodeling in mice. TRPC3 physically interacts with Nox2 at specific C-terminal sites, thereby protecting Nox2 from proteasome-dependent degradation and amplifying Ca 2+-dependent Nox2 activation through TRPC3-mediated background Ca 2+ entry. Nox2 also stabilizes TRPC3 proteins to enhance TRPC3 channel activity. Expression of TRPC3 C-terminal polypeptide abolished TRPC3-regulated ROS production by disrupting TRPC3-Nox2 interaction, without affecting TRPC3-mediated Ca 2+ influx. The novel TRPC3 function as a PRROS provides a mechanistic explanation for how diastolic Ca 2+ influx specifically encodes signals to induce ROS-mediated maladaptive remodeling and offers new therapeutic possibilities.. |
| 107. |
Naoyuki Kitajima, Takuro Numaga-Tomita, Masahiko Watanabe, Takuya Kuroda, Akiyuki Nishimura, Kei Miyano, Satoshi Yasuda, Koichiro Kuwahara, Yoji Sato, Tomomi Ide, Lutz Birnbaumer, Hideki Sumimoto, Yasuo Mori, Motohiro Nishida, TRPC3 positively regulates reactive oxygen species driving maladaptive cardiac remodeling, SCIENTIFIC REPORTS, 10.1038/srep37001, 6, 2016.11, Reactive oxygen species (ROS) produced by NADPH oxidase 2 (Nox2) function as key mediators of mechanotransduction during both physiological adaptation to mechanical load and maladaptive remodeling of the heart. This is despite low levels of cardiac Nox2 expression. The mechanism underlying the transition from adaptation to maladaptation remains obscure, however. We demonstrate that transient receptor potential canonical 3 (TRPC3), a Ca2+-permeable channel, acts as a positive regulator of ROS (PRROS) in cardiomyocytes, and specifically regulates pressure overload-induced maladaptive cardiac remodeling in mice. TRPC3 physically interacts with Nox2 at specific C-terminal sites, thereby protecting Nox2 from proteasome-dependent degradation and amplifying Ca2+-dependent Nox2 activation through TRPC3-mediated background Ca2+ entry. Nox2 also stabilizes TRPC3 proteins to enhance TRPC3 channel activity. Expression of TRPC3 C-terminal polypeptide abolished TRPC3-regulated ROS production by disrupting TRPC3-Nox2 interaction, without affecting TRPC3-mediated Ca2+ influx. The novel TRPC3 function as a PRROS provides a mechanistic explanation for how diastolic Ca2+ influx specifically encodes signals to induce ROS-mediated maladaptive remodeling and offers new therapeutic possibilities.. |
| 108. |
Takahiro Inoue, Masataka Ikeda, Tomomi Ide, Takeo Fujino, Yuka Matsuo, Shinobu Arai, Keita Saku, Kenji Sunagawa, Twinkle overexpression prevents cardiac rupture after myocardial infarction by alleviating impaired mitochondrial biogenesis, American Journal of Physiology - Heart and Circulatory Physiology, 10.1152/ajpheart.00044.2016, 311, 3, H509-H519, 2016.09, Cardiac rupture is a fatal complication after myocardial infarction (MI). However, the detailed mechanism underlying cardiac rupture after MI remains to be fully elucidated. In this study, we investigated the role of mitochondrial DNA (mtDNA) and mitochondria in the pathophysiology of cardiac rupture by analyzing Twinkle helicase overexpression mice (TW mice). Twinkle overexpression increased mtDNA copy number approximately twofold and ameliorated ischemic cardiomyopathy at day 28 after MI. Notably, Twinkle overexpression markedly prevented cardiac rupture and improved post-MI survival, accompanied by the suppression of MMP-2 and MMP-9 in the MI border area at day 5 after MI when cardiac rupture frequently occurs. Additionally, these cardioprotective effects of Twinkle overexpression were abolished in transgenic mice overexpressing mutant Twinkle with an in-frame duplication of amino acids 353–365, which resulted in no increases in mtDNA copy number. Furthermore, although apoptosis and oxidative stress were induced and mitochondria were damaged in the border area, these injuries were improved in TW mice. Further analysis revealed that mitochondrial biogenesis, including mtDNA copy number, transcription, and translation, was severely impaired in the border area at day 5. In contrast, Twinkle overexpression maintained mtDNA copy number and restored the impaired transcription and translation of mtDNA in the border area. These results demonstrated that Twinkle overexpression alleviated impaired mitochondrial biogenesis in the border area through maintained mtDNA copy number and thereby prevented cardiac rupture accompanied by the reduction of apoptosis and oxidative stress, and suppression of MMP activity.. |
| 109. |
Takahiro Inoue, Masataka Ikeda, Tomomi Ide, Takeo Fujino, Yuka Matsuo, Shinobu Arai, Keita Saku, Kenji Sunagawa, Twinkle overexpression prevents cardiac rupture after myocardial infarction by alleviating impaired mitochondrial biogenesis, AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, 10.1152/ajpheart.00044.2016, 311, 3, H509-H519, 2016.09, Cardiac rupture is a fatal complication after myocardial infarction (MI). However, the detailed mechanism underlying cardiac rupture after MI remains to be fully elucidated. In this study, we investigated the role of mitochondrial DNA (mtDNA) and mitochondria in the pathophysiology of cardiac rupture by analyzing Twinkle helicase overexpression mice (TW mice). Twinkle overexpression increased mtDNA copy number approximately twofold and ameliorated ischemic cardiomyopathy at day 28 after MI. Notably, Twinkle overexpression markedly prevented cardiac rupture and improved post-MI survival, accompanied by the suppression of MMP-2 and MMP-9 in the MI border area at day 5 after MI when cardiac rupture frequently occurs. Additionally, these cardioprotective effects of Twinkle overexpression were abolished in transgenic mice overexpressing mutant Twinkle with an in-frame duplication of amino acids 353-365, which resulted in no increases in mtDNA copy number. Furthermore, although apoptosis and oxidative stress were induced and mitochondria were damaged in the border area, these injuries were improved in TW mice. Further analysis revealed that mitochondrial biogenesis, including mtDNA copy number, transcription, and translation, was severely impaired in the border area at day 5. In contrast, Twinkle overexpression maintained mtDNA copy number and restored the impaired transcription and translation of mtDNA in the border area. These results demonstrated that Twinkle overexpression alleviated impaired mitochondrial biogenesis in the border area through maintained mtDNA copy number and thereby prevented cardiac rupture accompanied by the reduction of apoptosis and oxidative stress, and suppression of MMP activity.. |
| 110. |
Akiko Nishizaki, Kazuo Sakamoto, Keita Saku, Kazuya Hosokawa, takafumi sakamoto, Yasuhiro Oga, Takuya Akashi, Yoshinori Murayama, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Optimal Titration Is Important to Maximize the Beneficial Effects of Vagal Nerve Stimulation in Chronic Heart Failure, Journal of Cardiac Failure, 10.1016/j.cardfail.2016.04.021, 22, 8, 631-638, 2016.08, Background Although vagal nerve stimulation (VNS) benefits patients with chronic heart failure (CHF), the optimal dose of VNS remains unknown. In clinical trials, adverse symptoms limited up-titration. In this study, we evaluated the impact of various voltages of VNS which were titrated below symptom threshold on cardiac function and CHF parameters in rat myocardial infarction (MI) models. Methods and Results We randomly allocated MI rats to vagal (VNS; n = 41) and sham (Sham; n = 16) stimulation groups. We stimulated the right vagal nerve with 20 Hz at 3 different voltages for 4 weeks. We defined Max as the highest voltage that did not evoke any symptom, Half as one-half of Max, and Quarter as one-fourth of Max. All 3 VNS groups significantly reduced biventricular weight compared with Sham (P |
| 111. |
Akiko Nishizaki, Kazuo Sakamoto, Keita Saku, Kazuya Hosokawa, Takafumi Sakamoto, Yasuhiro Oga, Takuya Akashi, Yoshinori Murayama, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Optimal Titration Is Important to Maximize the Beneficial Effects of Vagal Nerve Stimulation in Chronic Heart Failure, JOURNAL OF CARDIAC FAILURE, 10.1016/j.cardfail.2016.04.021, 22, 8, 631-638, 2016.08, Background: Although vagal nerve stimulation (VNS) benefits patients with chronic heart failure (CHF)., the optimal dose of VNS remains unknown. In clinical trials, adverse symptoms limited up-titration. In this study, we evaluated the impact of various voltages of VNS which were titrated below symptom threshold on cardiac function and CHF parameters in rat myocardial infarction (MI) models.Methods and Results: We randomly allocated MI rats to vagal (VNS; n = 41) and sham (Sham; n = 16) stimulation groups. We stimulated the right vagal nerve with 20 Hz at 3 different voltages for 4 weeks. We defined Max as the highest voltage that did not evoke any symptom, Half as one-half of Max, and Quarter as one-fourth of Max. All 3 VNS groups significantly reduced biventricular weight compared With Sham (P <.05 in contrast only half decreased left ventricular end-diastolic pressure mm hg sham: p and increased lv ejection fraction maximum the number of large vagal nerve fibers was reduced with max counts indicating significant neural damage by vns.conclusion: optimal titration vns would maximize benefits for chf minimize adverse effects.. id="gencho_ronbuns10190343" class="qir_handle_link"> |
| 112. |
Ryo Miyake, Takeo Fujino, Kotaro Abe, Kazuya Hosokawa, Kisho Ohtani, Hiroko Morisaki, Osamu Yamada, Taiki Higo, Tomomi Ide, Pulmonary arterial hypertension associated with hereditary hemorrhagic telangiectasia successfully treated with sildenafil, International Journal of Cardiology, 10.1016/j.ijcard.2016.03.211, 214, 275-276, 2016.07. |
| 113. |
Ryo Miyake, Takeo Fujino, Kohtaro Abe, Kazuya Hosokawa, Kisho Ohtani, Hiroko Morisaki, Osamu Yamada, Taiki Higo, Tomomi Ide, Pulmonary arterial hypertension associated with hereditary hemorrhagic telangiectasia successfully treated with sildenafil, INTERNATIONAL JOURNAL OF CARDIOLOGY, 10.1016/j.ijcard.2016.03.211, 214, 276-277, 2016.07. |
| 114. |
Masataka Ikeda, Yasuhiro Sezutsu, takafumi sakamoto, Tomomi Ide, Electron microscopy reveals morphosis of multi-layered mitochondria in the myocardium of a patient with mitochondrial cardiomyopathy, European heart journal, 10.1093/eurheartj/ehv764, 37, 17, 2016.05. |
| 115. |
Masataka Ikeda, Yasuhiro Sezutsu, Takafumi Sakamoto, Tomomi Ide, Electron microscopy reveals morphosis of multi-layered mitochondria in the myocardium of a patient with mitochondrial cardiomyopathy, EUROPEAN HEART JOURNAL, 10.1093/eurheartj/ehv764, 37, 17, 1372-1372, 2016.05. |
| 116. |
Keita Saku, Takamori Kakino, Takahiro Arimura, takafumi sakamoto, Takuya Nishikawa, Kazuo Sakamoto, Masataka Ikeda, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Total mechanical unloading minimizes metabolic demand of left ventricle and dramatically reduces infarct size in myocardial infarction, PloS one, 10.1371/journal.pone.0152911, 11, 4, 2016.04, Background: Left ventricular assist device (LVAD) mechanically unloads the left ventricle (LV). Theoretical analysis indicates that partial LVAD support (p-LVAD), where LV remains ejecting, reduces LV preload while increases afterload resulting from the elevation of total cardiac output and mean aortic pressure, and consequently does not markedly decrease myocardial oxygen consumption (MVO2). In contrast, total LVAD support (t-LVAD), where LV no longer ejects, markedly decreases LV preload volume and afterload pressure, thereby strikingly reduces MVO2. Since an imbalance in oxygen supply and demand is the fundamental pathophysiology of myocardial infarction (MI), we hypothesized that t-LVAD minimizes MVO2 and reduces infarct size in MI. The purpose of this study was to evaluate the differential impact of the support level of LVAD on MVO2 and infarct size in a canine model of ischemia-reperfusion. Methods: In 5 normal mongrel dogs, we examined the impact of LVAD on MVO2 at 3 support levels: Control (no LVAD support), p-LVAD and t-LVAD. In another 16 dogs, ischemia was induced by occluding major branches of the left anterior descending coronary artery (90 min) followed by reperfusion (300 min). We activated LVAD from the beginning of ischemia until 300 min of reperfusion, and compared the infarct size among 3 different levels of LVAD support. Results: t-LVAD markedly reduced MVO2 (% reduction against Control: -56 ± 9%, p |
| 117. |
Keita Saku, Takamori Kakino, Takahiro Arimura, Takafumi Sakamoto, Takuya Nishikawa, Kazuo Sakamoto, Masataka Ikeda, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Total Mechanical Unloading Minimizes Metabolic Demand of Left Ventricle and Dramatically Reduces Infarct Size in Myocardial Infarction, PLOS ONE, 10.1371/journal.pone.0152911, 11, 4, 2016.04, BackgroundLeft ventricular assist device (LVAD) mechanically unloads the left ventricle (LV). Theoretical analysis indicates that partial LVAD support (p-LVAD), where LV remains ejecting, reduces LV preload while increases afterload resulting from the elevation of total cardiac output and mean aortic pressure, and consequently does not markedly decrease myocardial oxygen consumption (MVO2). In contrast, total LVAD support (t-LVAD), where LV no longer ejects, markedly decreases LV preload volume and afterload pressure, thereby strikingly reduces MVO2. Since an imbalance in oxygen supply and demand is the fundamental pathophysiology ofmyocardial infarction (MI), we hypothesized that t-LVADminimizes MVO2 and reduces infarct size in MI. The purpose of this study was to evaluate the differential impact of the support level of LVAD on MVO2 and infarct size in a caninemodel of ischemia-reperfusion.MethodsIn 5 normal mongrel dogs, we examined the impact of LVAD on MVO2 at 3 support levels: Control (no LVAD support), p-LVAD and t-LVAD. In another 16 dogs, ischemia was induced by occluding major branches of the left anterior descending coronary artery (90 min) followed by reperfusion (300 min). We activated LVAD from the beginning of ischemia until 300 min of reperfusion, and compared the infarct size among 3 different levels of LVAD support.Resultst-LVAD markedly reduced MVO2 (% reduction against Control: -56 +/- 9%, p |
| 118. |
Tomoki Ushijima, Yoshihisa Tanoue, Tomomi Ide, Shinji Okano, Yoshinao Oda, Ryuji Tominaga, Disuse Atrophy of the Aortic Valve After Left Ventricular Assist Device Implantation, Annals of Thoracic Surgery, 10.1016/j.athoracsur.2015.03.047, 101, 2, 742-744, 2016.02, A 31-year-old woman underwent implantation of a DuraHeart left ventricular assist device as bridge to transplantation. Aortic insufficiency was not observed before implantation but developed after implantation and became severe approximately 2 years later. Macroscopically, the aortic valve excised during heart transplantation showed no morphologic alteration. Microscopically, the collagen fibers in the fibrosa layer and the elastic fibers in the ventricularis layer of the valve leaflets were reduced in number, with irregular arrangement. These characteristics can be explained by a disuse atrophic change, and may lead to a better understanding of the mechanism underlying the development of aortic insufficiency.. |
| 119. |
Tomoki Ushijima, Yoshihisa Tanoue, Tomomi Ide, Shinji Okano, Yoshinao Oda, Ryuji Tominaga, Disuse Atrophy of the Aortic Valve After Left Ventricular Assist Device Implantation, ANNALS OF THORACIC SURGERY, 10.1016/j.athoracsur.2015.03.047, 101, 2, 742-744, 2016.02, A 31-year-old woman underwent implantation of a DuraHeart left ventricular assist device as bridge to transplantation. Aortic insufficiency was not observed before implantation but developed after implantation and became severe approximately 2 years later. Macroscopically, the aortic valve excised during heart transplantation showed no morphologic alteration. Microscopically, the collagen fibers in the fibrosa layer and the elastic fibers in the ventricularis layer of the valve leaflets were reduced in number, with irregular arrangement. These characteristics can be explained by a disuse atrophic change, and may lead to a better understanding of the mechanism underlying the development of aortic insufficiency. (C) 2016 by The Society of Thoracic Surgeons. |
| 120. |
Kazuo Sakamoto, Kazuya Hosokawa, Keita Saku, takafumi sakamoto, Tomoyuki Tobushi, Yasuhiro Oga, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Baroreflex failure increases the risk of pulmonary edema in conscious rats with normal left ventricular function, American Journal of Physiology - Heart and Circulatory Physiology, 10.1152/ajpheart.00610.2015, 310, 2, H199-H205, 2016.01, In heart failure with preserved ejection fraction (HFpEF), the complex pathogenesis hinders development of effective therapies. Since HFpEF and arteriosclerosis share common risk factors, it is conceivable that stiffened arterial wall in HFpEF impairs baroreflex function. Previous investigations have indicated that the baroreflex regulates intravascular stressed volume and arterial resistance in addition to cardiac contractility and heart rate. We hypothesized that baroreflex dysfunction impairs regulation of left atrial pressure (LAP) and increases the risk of pulmonary edema in freely moving rats. In 15-wk Sprague-Dawley male rats, we conducted sinoaortic denervation (SAD, n = 6) or sham surgery (Sham, n = 9), and telemetrically monitored ambulatory arterial pressure (AP) and LAP. We compared the mean and SD (lability) of AP and LAP between SAD and Sham under normal-salt diet (NS) or high-salt diet (HS). SAD did not increase mean AP but significantly increased AP lability under both NS (P = 0.001) and HS (P = 0.001). SAD did not change mean LAP but significantly increased LAP lability under both NS (SAD: 2.57 ± 0.43 vs. Sham: 1.73 ± 0.30 mmHg, P = 0.01) and HS (4.13 ± 1.18 vs. 2.45 ± 0.33 mmHg, P = 0.02). SAD markedly increased the frequency of high LAP, and SAD with HS prolonged the duration of LAP > 18 mmHg by nearly 20-fold compared with Sham (SAD ± HS: 2,831 ± 2,366 vs. Sham ± HS: 148 ± 248 s, P = 0.01). We conclude that baroreflex failure impairs volume tolerance and together with salt loading increases the risk of pulmonary edema even in the absence of left ventricular dysfunction. Baroreflex failure may contribute in part to the pathogenesis of HFpEF.. |
| 121. |
Takeo Fujino, Taiki Higo, Yoshihisa Tanoue, Tomomi Ide, FDG-PET/CT for driveline infection in a patient with implantable left ventricular assist device, European Heart Journal Cardiovascular Imaging, 10.1093/ehjci/jev234, 17, 1, 2016.01. |
| 122. |
Akiyuki Nishimura, Caroline Sunggip, Hidetoshi Saitoh, Tsukasa Shimauchi, Takuro Numaga-Tomita, Katsuya Hirano, Tomomi Ide, Jean Marie Boeynaems, Hitoshi Kurose, Tsuda Makoto, Bernard Robaye, Kazuhide Inoue, Motohiro Nishida, Purinergic P2Y6 receptors heterodimerize with angiotensin AT1 receptors to promote angiotensin II-induced hypertension, Science Signaling, 10.1126/scisignal.aac9187, 9, 411, 2016.01, The angiotensin (Ang) type 1 receptor (AT1R) promotes functional and structural integrity of the arterial wall to contribute to vascular homeostasis, but this receptor also promotes hypertension. In our investigation of how Ang II signals are converted by the AT1R from physiological to pathological outputs, we found that the purinergic P2Y6 receptor (P2Y6R), an inflammation-inducible G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptor (GPCR), promoted Ang II-induced hypertension in mice. In mice, deletion of P2Y6R attenuated Ang II-induced increase in blood pressure, vascular remodeling, oxidative stress, and endothelial dysfunction. AT1R and P2Y6R formed stable heterodimers, which enhanced G protein-dependent vascular hypertrophy but reduced b-arrestin-dependent AT1R internalization. Pharmacological disruption of AT1R-P2Y6R heterodimers by the P2Y6R antagonist MRS2578 suppressed Ang II-induced hypertension in mice. Furthermore, P2Y6R abundance increased with age in vascularsmoothmuscle cells. The increased abundance of P2Y6R converted AT1R-stimulated signaling in vascular smooth muscle cells from β-arrestin-dependent proliferation to G protein- dependent hypertrophy. These results suggest that increased formation of AT1R-P2Y6R heterodimers with age may increase the likelihood of hypertension induced by Ang II.. |
| 123. |
Kazuo Sakamoto, Kazuya Hosokawa, Keita Saku, Takafumi Sakamoto, Tomoyuki Tobushi, Yasuhiro Oga, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Baroreflex failure increases the risk of pulmonary edema in conscious rats with normal left ventricular function, AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, 10.1152/ajpheart.00610.2015, 310, 2, H199-H205, 2016.01, In heart failure with preserved ejection fraction (HFpEF), the complex pathogenesis hinders development of effective therapies. Since HFpEF and arteriosclerosis share common risk factors, it is conceivable that stiffened arterial wall in HFpEF impairs baroreflex function. Previous investigations have indicated that the baroreflex regulates intravascular stressed volume and arterial resistance in addition to cardiac contractility and heart rate. We hypothesized that baroreflex dysfunction impairs regulation of left atrial pressure (LAP) and increases the risk of pulmonary edema in freely moving rats. In 15-wk Sprague-Dawley male rats, we conducted sinoaortic denervation (SAD, n = 6) or sham surgery (Sham, n = 9), and telemetrically monitored ambulatory arterial pressure (AP) and LAP. We compared the mean and SD (lability) of AP and LAP between SAD and Sham under normal-salt diet (NS) or high-salt diet (HS). SAD did not increase mean AP but significantly increased AP lability under both NS (P = 0.001) and HS (P = 0.001). SAD did not change mean LAP but significantly increased LAP lability under both NS (SAD: 2.57 +/- 0.43 vs. Sham: 1.73 +/- 0.30 mmHg, P = 0.01) and HS (4.13 +/- 1.18 vs. 2.45 +/- 0.33 mmHg, P = 0.02). SAD markedly increased the frequency of high LAP, and SAD with HS prolonged the duration of LAP > 18 mmHg by nearly 20-fold compared with Sham (SAD + HS: 2,831 +/- 2,366 vs. Sham + HS: 148 +/- 248 s, P = 0.01). We conclude that baroreflex failure impairs volume tolerance and together with salt loading increases the risk of pulmonary edema even in the absence of left ventricular dysfunction. Baroreflex failure may contribute in part to the pathogenesis of HFpEF.. |
| 124. |
Takeo Fujino, Taiki Higo, Yoshihisa Tanoue, Tomomi Ide, FDG-PET/CT for driveline infection in a patient with implantable left ventricular assist device, EUROPEAN HEART JOURNAL-CARDIOVASCULAR IMAGING, 10.1093/ehjci/jev234, 17, 1, 23-23, 2016.01. |
| 125. |
Akiyuki Nishimura, Caroline Sunggip, Hidetoshi Tozaki-Saitoh, Tsukasa Shimauchi, Takuro Numaga-Tomita, Katsuya Hirano, Tomomi Ide, Jean-Marie Boeynaems, Hitoshi Kurose, Makoto Tsuda, Bernard Robaye, Kazuhide Inoue, Motohiro Nishida, Purinergic P2Y(6) receptors heterodimerize with angiotensin AT1 receptors to promote angiotensin II-induced hypertension, SCIENCE SIGNALING, 10.1126/scisignal.aac9187, 9, 411, 2016.01, The angiotensin (Ang) type 1 receptor (AT1R) promotes functional and structural integrity of the arterial wall to contribute to vascular homeostasis, but this receptor also promotes hypertension. In our investigation of how Ang II signals are converted by the AT1R from physiological to pathological outputs, we found that the purinergic P2Y(6) receptor (P2Y(6)R), an inflammation-inducible G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptor (GPCR), promoted Ang II-induced hypertension in mice. In mice, deletion of P2Y(6)R attenuated Ang II-induced increase in blood pressure, vascular remodeling, oxidative stress, and endothelial dysfunction. AT1R and P2Y(6)R formed stable heterodimers, which enhanced G protein-dependent vascular hypertrophy but reduced beta-arrestin-dependent AT1R internalization. Pharmacological disruption of AT1R-P2Y(6)R heterodimers by the P2Y(6)R antagonist MRS2578 suppressed Ang II-induced hypertension in mice. Furthermore, P2Y(6)R abundance increased with age in vascularsmoothmuscle cells. The increased abundance of P2Y(6)R converted AT1R-stimulated signaling in vascular smooth muscle cells from beta-arrestin-dependent proliferation to G protein-dependent hypertrophy. These results suggest that increased formation of AT1R-P2Y(6)R heterodimers with age may increase the likelihood of hypertension induced by Ang II.. |
| 126. |
Shu Ling Liu, Tsubasa Oyama, Yurika Miyoshi, Shiow Yunn Sheu, Masashi Mita, Tomomi Ide, Wolfgang Lindner, Kenji Hamase, Jen Ai Lee, Establishment of a two-dimensional chiral HPLC system for the simultaneous detection of lactate and 3-hydroxybutyrate enantiomers in human clinical samples, Journal of Pharmaceutical and Biomedical Analysis, 10.1016/j.jpba.2015.05.036, 116, 80-85, 2015.12, A two-dimensional chiral high-performance liquid chromatography system was established for simultaneous detection of lactate (LA) and 3-hydroxybutyrate (3HB) enantiomers in human clinical samples. d-LA is increased upon kidney damage but 3HB protected against kidney injury. Therefore, determining the concentrations of d,. l-LA and d,. l-3HB simultaneously would be useful for evaluating pathological conditions. LA and 3HB were pre-column-derivatized with the fluorescent reagent 4-(. N-chloroformylmethyl-. N-methylamino)-7-nitro-2,1,3-benzoxadiazole (NBD-COCl) at 60. °C for 15. min and separated in the first dimension with a capillary monolithic octadecylsilane column. The mobile phase consisted of 13% acetonitrile and 0.05% tirfluoroacetic acid in water. Chiralpak QD-AX and KSAACSP-001S enantioselective columns were used in the second dimension to separate LA and 3HB enantiomers, respectively. Mobile phases were mixed solutions of methanol and acetonitrile containing formic acid. The separation factors were 1.14 and 1.08, respectively. The detection limit of LA and 3HB enantiomers was 10. fmol/injection. This method was applied to human clinical samples; intra- and inter-day relative standard deviations of LA and 3HB enantiomers were, respectively, 1.04-3.25% and 1.61-5.12% in plasma, 9.19-11.2% and 4.60-5.89% in urine, and 7.12-8.90% and 2.86-6.97% in saliva. This novel analytical method is a powerful tool for investigating variations in LA and 3HB enantiomers under disease conditions.. |
| 127. |
Shu-Ling Liu, Tsubasa Oyama, Yurika Miyoshi, Shiow-Yunn Sheu, Masashi Mita, Tomomi Ide, Wolfgang Lindner, Kenji Hamase, Jen-Ai Lee, Establishment of a two-dimensional chiral HPLC system for the simultaneous detection of lactate and 3-hydroxybutyrate enantiomers in human clinical samples, JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS, 10.1016/j.jpba.2015.05.036, 116, 80-85, 2015.12, A two-dimensional chiral high-performance liquid chromatography system was established for simultaneous detection of lactate (LA) and 3-hydroxybutyrate (3HB) enantiomers in human clinical samples. ID-LA is increased upon kidney damage but 3HB protected against kidney injury. Therefore, determining the concentrations of D,L-LA and D,L-3HB simultaneously would be useful for evaluating pathological conditions. LA and 3HB were pre-column-derivatized with the fluorescent reagent 4-(N-chloroformylmethyl-N-methylamino)-7-nitro-2,1,3-benzoxadiazole (NBD-COCl) at 60 degrees C for 15 min and separated in the first dimension with a capillary monolithic octadecylsilane column. The mobile phase consisted of 13% acetonitrile and 0.05% tirfluoroacetic acid in water. Chiralpak QD-AX and KSAACSP-001S enantioselective columns were used in the second dimension to separate LA and 3HB enantiomers, respectively. Mobile phases were mixed solutions of methanol and acetonitrile containing formic acid. The separation factors were 1.14 and 1.08, respectively. The detection limit of LA and 3HB enantiomers was 10 fmol/injection. This method was applied to human clinical samples; intra- and inter-day relative standard deviations of LA and 3HB enantiomers were, respectively, 1.04-3.25% and 1.61-5.12% in plasma, 9.19-11.2% and 4.60-5.89% in urine, and 7.12-8.90% and 2.86-6.97% in saliva. This novel analytical method is a powerful tool for investigating variations in LA and 3HB enantiomers under disease conditions. (C) 2015 Elsevier B.V. All rights reserved.. |
| 128. |
Masataka Ikeda, Ide Tomomi, Takeo Fujino, Yuka Matsuo, Shinobu Arai, Keita Saku, Takamori Kakino, Yasuhiro Oga, Akiko Nishizaki, Kenji Sunagawa, The Akt-mTOR axis is a pivotal regulator of eccentric hypertrophy during volume overload, SCIENTIFIC REPORTS, 10.1038/srep15881, 5, 2015.10. |
| 129. |
Masataka Ikeda, Tomomi Ide, Takeo Fujino, Kenji Sunagawa, The Akt-mTOR Axis is a Pivotal Regulator of Eccentric Hypertrophy during Volume Overload, JOURNAL OF CARDIAC FAILURE, 10.1016/j.cardfail.2015.08.018, 21, 10, S147-S147, 2015.10. |
| 130. |
Krish Chandrasekaran, Muragundla Anjaneyulu, Tatsuya Inoue, Joungil Choi, Avinash Rao Sagi, Chen Chen, Ide Tomomi, James W. Russell, Mitochondrial transcription factor A regulation of mitochondrial degeneration in experimental diabetic neuropathy, AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM, 10.1152/ajpendo.00620.2014, 309, 2, E132-E141, 2015.07. |
| 131. |
Tomomi Ide, Role of mitochondria and reactive oxygen species in heart failure, Japanese Journal of Clinical Chemistry, 44, 3, 191-197, 2015.07. |
| 132. |
Kazuo Sakamoto, Keita Saku, Takuya Kishi, Takamori Kakino, Atsushi Tanaka, Takafumi Sakamoto, Tomomi Ide, Kenji Sunagawa, Prediction of the impact of venoarterial extracorporeal membrane oxygenation on hemodynamics, AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, 10.1152/ajpheart.00603.2014, 308, 8, H921-H930, 2015.04, Although venoarterial extracorporeal membrane oxygenation (ECMO) was developed to rescue patients with cardiogenic shock, the impact of ECMO on hemodynamics is often unpredictable and can lead to hemodynamic collapse. In this study, we developed a framework in which we incorporated ECMO into the extended Guyton's model of circulatory equilibrium and predicted hemodynamic changes in response to ECMO. We first determined the cardiac output (CO) curves of left and right heart (to generate the integrated CO curve) without ECMO in eight normal and seven dogs with left ventricular dysfunction. Using the CO curves obtained and standard parameters for the venous return surface, we predicted the circulatory equilibrium under various levels of ECMO support. The predicted total flow (native left heart flow plus ECMO flow), right atrial pressure (P-RA), and left atrial pressure (PLA) matched well with those measured [total flow: coefficient of determination (r(2)) = 0.99, standard error of estimate (SEE) = 5.8 ml.min(-1).kg(-1), P-RA: r(2) = 0.95, SEE = 0.23 mmHg, P-LA: r(2) = 0.99, SEE = 0.59 mmHg]. Lastly, we estimated the CO curves under ECMO support from minute changes in hemodynamics induced by change in ECMO. From the CO curves estimated, we predicted the circulatory equilibrium. The predicted total flow (r(2) = 0.93, SEE = 0.5 ml.min(-1).kg(-1)), P-RA (r(2) = 0.99, SEE = 0.54 mmHg), and P-LA (r(2) = 0.95, SEE = 0.89 mmHg) matched reasonably well with those measured. A numerical simulation indicated that ECMO support may cause pulmonary edema, if right ventricular function is compromised. We conclude that the proposed framework may enhance the benefit and reduce the risk of ECMO support in patients with critical hemodynamic conditions.. |
| 133. |
Masataka Ikeda, Ide Tomomi, Shinobu Arai, Keita Saku, Takamori Kakino, Henna Tyynismaa, Toshihide Yamasaki, Ken-ichi Yamada, Dongchon Kang, Anu Suomalainen, Kenji Sunagawa, Overexpression of TFAM or Twinkle Increases mtDNA Copy Number and Facilitates Cardioprotection Associated with Limited Mitochondrial Oxidative Stress, PLOS ONE, 10.1371/journal.pone.0119687, 10, 3, 2015.03. |
| 134. |
Masataka Ikeda, Tomomi Ide, Takeo Fujino, Shinobu Arai, Keita Saku, Takamori Kakino, Henna Tyynismaa, Toshihide Yamasaki, Ken-ichi Yamada, Dongchon Kang, Anu Suomalainen, Kenji Sunagawa, Overexpression of TFAM or Twinkle Increases mtDNA Copy Number and Facilitates Cardioprotection Associated with Limited Mitochondrial Oxidative Stress, PLOS ONE, 10.1371/journal.pone.0119687, 10, 3, 2015.03, BackgroundMitochondrial DNA (mtDNA) copy number decreases in animal and human heart failure (HF), yet its role in cardiomyocytes remains to be elucidated. Thus, we investigated the cardioprotective function of increased mtDNA copy number resulting from the overexpression of human transcription factor A of mitochondria (TFAM) or Twinkle helicase in volume overload (VO)-induced HF.Methods and ResultsTwo strains of transgenic (TG) mice, one overexpressing TFAM and the other overexpressing Twinkle helicase, exhibit an approximately 2-fold equivalent increase in mtDNA copy number in heart. These TG mice display similar attenuations in eccentric hypertrophy and improved cardiac function compared to wild-type (WT) mice without any deterioration of mitochondrial enzymatic activities in response to VO, which was accompanied by a reduction in matrix-metalloproteinase (MMP) activity and reactive oxygen species after 8 weeks of VO. Moreover, acute VO-induced MMP-2 and MMP-9 upregulation was also suppressed at 24 h in both TG mice. In isolated rat cardiomyocytes, mitochondrial reactive oxygen species (mitoROS) upregulated MMP-2 and MMP-9 expression, and human TFAM (hTFAM) overexpression suppressed mitoROS and their upregulation. Additionally, mitoROS were equally suppressed in H9c2 rat cardiomyoblasts that overexpress hTFAM or rat Twinkle, both of which exhibit increased mtDNA copy number. Furthermore, mitoROS and mitochondrial protein oxidation from both TG mice were suppressed compared to WT mice.ConclusionsThe overexpression of TFAM or Twinkle results in increased mtDNA copy number and facilitates cardioprotection associated with limited mitochondrial oxidative stress. Our findings suggest that increasing mtDNA copy number could be a useful therapeutic strategy to target mitoROS in HF.. |
| 135. |
takafumi sakamoto, Takamori Kakino, Kazuo Sakamoto, Tomoyuki Tobushi, Atsushi Tanaka, Keita Saku, Kazuya Hosokawa, Ken Onitsuka, Yoshinori Murayama, Takaki Tsutsumi, Tomomi Ide, Kenji Sunagawa, Changes in vascular properties, not ventricular properties, predominantly contribute to baroreflex regulation of arterial pressure, American Journal of Physiology - Heart and Circulatory Physiology, 10.1152/ajpheart.00552.2014, 308, 1, H49-H58, 2015.01, Baroreflex modulates both the ventricular and vascular properties and stabilizes arterial pressure (AP). However, how changes in those mechanical properties quantitatively impact the dynamic AP regulation remains unknown. We developed a framework of circulatory equilibrium, in which both venous return and cardiac output are expressed as functions of left ventricular (LV) end-systolic elastance (Ees), heart rate (HR), systemic vascular resistance (R), and stressed blood volume (V). We investigated the contribution of each mechanical property using the framework of circulatory equilibrium. In six anesthetized dogs, we vascularly isolated carotid sinuses and randomly changed carotid sinus pressure (CSP), while measuring the LV Ees, aortic flow, right and left atrial pressure, and AP for at least 60 min. We estimated transfer functions from CSP to Ees, HR, R, and V in each dog. We then predicted these parameters in response to changes in CSP from the transfer functions using a data set not used for identifying transfer functions and predicted changes in AP using the equilibrium framework. Predicted APs matched reasonably well with those measured (r2= 0.85–0.96, P es and HR (ventricular properties) accounted for 14 ± 4 and 4 ± 2%, respectively, whereas R and V (vascular properties) accounted for 32 ± 4 and 39 ± 4%, respectively, of baroreflex-induced AP regulation. We concluded that baroreflex-induced dynamic AP changes can be accurately predicted by the transfer functions from CSP to mechanical properties using our framework of circulatory equilibrium. Changes in the vascular properties, not the ventricular properties, predominantly determine baroreflex-induced AP regulation.. |
| 136. |
Kazuo Sakamoto, Keita Saku, Takuya Kishi, Takamori Kakino, Atsushi Tanaka, takafumi sakamoto, Tomomi Ide, Kenji Sunagawa, Prediction of the impact of venoarterial extracorporeal membrane oxygenation on hemodynamics, American Journal of Physiology - Heart and Circulatory Physiology, 10.1152/ajpheart.00603.2014, 308, 8, H921-H930, 2015.01, Although venoarterial extracorporeal membrane oxygenation (ECMO) was developed to rescue patients with cardiogenic shock, the impact of ECMO on hemodynamics is often unpredictable and can lead to hemodynamic collapse. In this study, we developed a framework in which we incorporated ECMO into the extended Guyton's model of circulatory equilibrium and predicted hemodynamic changes in response to ECMO. We first determined the cardiac output (CO) curves of left and right heart (to generate the integrated CO curve) without ECMO in eight normal and seven dogs with left ventricular dysfunction. Using the CO curves obtained and standard parameters for the venous return surface, we predicted the circulatory equilibrium under various levels of ECMO support. The predicted total flow (native left heart flow plus ECMO flow), right atrial pressure (PRA), and left atrial pressure (PLA) matched well with those measured [total flow: coefficient of determination (r2) = 0.99, standard error of estimate (SEE) = 5.8 ml•min−1•kg−1, PRA: r2 = 0.95, SEE = 0.23 mmHg, PLA: r2 = 0.99, SEE = 0.59 mmHg]. Lastly, we estimated the CO curves under ECMO support from minute changes in hemodynamics induced by change in ECMO. From the CO curves estimated, we predicted the circulatory equilibrium. The predicted total flow (r2 = 0.93, SEE = 0.5 ml•min−1•kg−1), PRA (r2 = 0.99, SEE = 0.54 mmHg), and PLA (r2 = 0.95, SEE = 0.89 mmHg) matched reasonably well with those measured. A numerical simulation indicated that ECMO support may cause pulmonary edema, if right ventricular function is compromised. We conclude that the proposed framework may enhance the benefit and reduce the risk of ECMO support in patients with critical hemodynamic conditions.. |
| 137. |
Takafumi Sakamoto, Takamori Kakino, Kazuo Sakamoto, Tomoyuki Tobushi, Atsushi Tanaka, Keita Saku, Kazuya Hosokawa, Ken Onitsuka, Yoshinori Murayama, Takaki Tsutsumi, Tomomi Ide, Kenji Sunagawa, Changes in vascular properties, not ventricular properties, predominantly contribute to baroreflex regulation of arterial pressure, AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, 10.1152/ajpheart.00552.2014, 308, 1, H49-H58, 2015.01, Baroreflex modulates both the ventricular and vascular properties and stabilizes arterial pressure (AP). However, how changes in those mechanical properties quantitatively impact the dynamic AP regulation remains unknown. We developed a framework of circulatory equilibrium, in which both venous return and cardiac output are expressed as functions of left ventricular (LV) end-systolic elastance (E-es), heart rate (HR), systemic vascular resistance (R), and stressed blood volume (V). We investigated the contribution of each mechanical property using the framework of circulatory equilibrium. In six anesthetized dogs, we vascularly isolated carotid sinuses and randomly changed carotid sinus pressure (CSP), while measuring the LV E-es, aortic flow, right and left atrial pressure, and AP for at least 60 min. We estimated transfer functions from CSP to E-es, HR, R, and V in each dog. We then predicted these parameters in response to changes in CSP from the transfer functions using a data set not used for identifying transfer functions and predicted changes in AP using the equilibrium framework. Predicted APs matched reasonably well with those measured (r(2) = 0.85-0.96, P |
| 138. |
Keita Saku, Takuya Kishi, Kazuo Sakamoto, Kazuya Hosokawa, Takafumi Sakamoto, Yoshinori Murayama, Takamori Kakino, Masataka Ikeda, Ide Tomomi, Kenji Sunagawa, Afferent vagal nerve stimulation resets baroreflex neural arc and inhibits sympathetic nerve activity, Vol.2, Iss 9 e12136, 2014.09. |
| 139. |
Keita Saku, Akiko Nishizaki, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Stimulus frequency differences in respiratory inhibition is negligible to optimize vagal nerve stimulation (VNS) for heart failure, BME = Bio medical engineering / henshu, Nihon ME Gakkai, 10.11239/jsmbe.52.O-84, 52, O-84-O-85, 2014.08, Although VNS benefits for heart failure, up titrations are limited in 72 % of human subject because of respiratory side effects. Since vagal nerves are connected to the respiratory center in brainstem, VNS is possible to change respiratory rhythms. In this study, we investigated how the frequency differences in VNS impact on respiration. In Sprague-Dawley rats (N=4), we changed the stimulus frequencies (5, 10, 20, and 50 Hz) and amplitude of VNS (0-8 V). In low frequencies (5 and 10 Hz), VNS slightly inhibited respiration with stimulus amplitudes. Maximum inhibition of minute ventilation was -18.4 ± 0.1 % in 5 Hz and -47.1 ± 2.7 % in 10 Hz. While in high frequencies (20 and 50 Hz), VNS induced apnea above 2-4 V. In conclusion, high stimulus frequency induced remarkable respiratory inhibition and apnea. It is negligible effect to titrate VNS.. |
| 140. |
Keita Saku, Akiko Nishizaki, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Stimulus frequency differences in respiratory inhibition is negligible to optimize vagal nerve stimulation (VNS) for heart failure, Transactions of Japanese Society for Medical and Biological Engineering, 10.11239/jsmbe.52.O-84, 52, 84-O-85, 2014.08, Although VNS benefits for heart failure, up titrations are limited in 72 % of human subject because of respiratory side effects. Since vagal nerves are connected to the respiratory center in brainstem, VNS is possible to change respiratory rhythms. In this study, we investigated how the frequency differences in VNS impact on respiration. In Sprague-Dawley rats (N=4), we changed the stimulus frequencies (5, 10, 20, and 50 Hz) and amplitude of VNS (0-8 V). In low frequencies (5 and 10 Hz), VNS slightly inhibited respiration with stimulus amplitudes. Maximum inhibition of minute ventilation was -18.4 ± 0.1 % in 5 Hz and -47.1 ± 2.7 % in 10 Hz. While in high frequencies (20 and 50 Hz), VNS induced apnea above 2-4 V. In conclusion, high stimulus frequency induced remarkable respiratory inhibition and apnea. It is negligible effect to titrate VNS.. |
| 141. |
Takahiro Arimura, Keita Saku, Takamori Kakino, Takuya Akashi, Takako Takehara, Akiko Nishizaki, Yasuhiro Oga, Masataka Ikeda, Kana Fujii, Tomomi Ide, Takuya Kishi, Kenji Sunagawa, Total left ventricular unloading markedly reduces the pressure-volume area, thereby oxygen consumption, Transactions of Japanese Society for Medical and Biological Engineering, 10.11239/jsmbe.52.O-548, 52, 548-O-549, 2014.08, Left ventricular assist device (LVAD) unloads LV and exerts better outcome in both acute coronary syndrome and severe heart failure. In this study, we investigate how the degree of LVAD support impacts on the hemodynamics and oxygen consumption of left ventricle. Methods/Results: We used 5 dogs and changed LVAD support at 3 levels, no support, Partial (LV remains ejecting) and Total (total LVAD dependent circulation). Mean aortic pressure were not different among 3 groups, while peak systolic pressure of LV reduced in Total (108±8.6 vs 102±3.3 vs 42±11mmHg, p<
0.05). The pressure-volume area (PVA) indicating oxygen consumption of LV significantly reduced in Partial, while markedly reduced in Total (2040±632 vs 1787±547 vs 487±160 ml·mmHg, p<
0.05). Conclusions: Total unloading minimizes oxygen consumption of left ventricle. Appropriate unloading minimizes oxygen consumption and enables us to maximize the beneficial effect of LVAD in heart disease.. |
| 142. |
船越 公太, 細川 和也, 岸 拓弥, 井手 友美, 砂川 賢二, Striking Volume Intolerance Is Induced by Mimicking Arterial Baroreflex Failure in Normal Left Ventricular Function, JOURNAL OF CARDIAC FAILURE, 10.1016/j.cardfail.2013.11.007, 20, 1, 53-59, 2014.01. |
| 143. |
Keita Saku, Takuya Kishi, Kazuo Sakamoto, Kazuya Hosokawa, takafumi sakamoto, Yoshinori Murayama, Takamori Kakino, Masataka Ikeda, Tomomi Ide, Kenji Sunagawa, Afferent vagal nerve stimulation resets baroreflex neural arc and inhibits sympathetic nerve activity, Physiological Reports, 10.14814/phy2.12136, 2, 9, 2014.01, It has been established that vagal nerve stimulation (VNS) benefits patients and/or animals with heart failure. However, the impact of VNS on sympathetic nerve activity (SNA) remains unknown. In this study, we investigated how vagal afferent stimulation (AVNS) impacts baroreflex control of SNA. In 12 anesthetized Sprague–Dawley rats, we controlled the pressure in isolated bilateral carotid sinuses (CSP), and measured splanchnic SNA and arterial pressure (AP). Under a constant CSP, increasing the voltage of AVNS dose dependently decreased SNA and AP. The averaged maximal inhibition of SNA was -28.0 ± 10.3%. To evaluate the dynamic impacts of AVNS on SNA, we performed random AVNS using binary white noise sequences, and identified the transfer function from AVNS to SNA and that from SNA to AP. We also identified transfer functions of the native baroreflex from CSP to SNA (neural arc) and from SNA to AP (peripheral arc). The transfer function from AVNS to SNA strikingly resembled the baroreflex neural arc and the transfer functions of SNA to AP were indistinguishable whether we perturbed ANVS or CSP, indicating that they likely share common central and peripheral neural mechanisms. To examine the impact of AVNS on baroreflex, we changed CSP stepwise and measured SNA and AP responses with or without AVNS. AVNS resets the sigmoidal neural arc downward, but did not affect the linear peripheral arc. In conclusion, AVNS resets the baroreflex neural arc and induces sympathoinhibition in the same manner as the control of SNA and AP by the native baroreflex.. |
| 144. |
Takahiro Arimura, Keita Saku, Takamori Kakino, Takuya Akashi, Takako Takehara, Akiko Nishizaki, Yasuhiro Oga, Masataka Ikeda, Kana Fujii, Tomomi Ide, Takuya Kishi, Kenji Sunagawa, Total left ventricular unloading markedly reduces the pressure-volume area, thereby oxygen consumption, BME = Bio medical engineering / henshu, Nihon ME Gakkai, 10.11239/jsmbe.52.O-548, 52, O-548-O-549, 2014.01, Left ventricular assist device (LVAD) unloads LV and exerts better outcome in both acute coronary syndrome and severe heart failure. In this study, we investigate how the degree of LVAD support impacts on the hemodynamics and oxygen consumption of left ventricle. Methods/Results: We used 5 dogs and changed LVAD support at 3 levels, no support, Partial (LV remains ejecting) and Total (total LVAD dependent circulation). Mean aortic pressure were not different among 3 groups, while peak systolic pressure of LV reduced in Total (108±8.6 vs 102±3.3 vs 42±11mmHg, p |
| 145. |
Kana Fujii, Takahiro Arimura, Keita Saku, Takamori Kakino, Takuya Akashi, Tomomi Ide, Takuya Kishi, Kenji Sunagawa, Transvenous vagal nerve stimulation (VNS) in acute myocardial infarction (AMI) reduces the infarct size and improves long term cardiac function, BME = Bio medical engineering / henshu, Nihon ME Gakkai, 10.11239/jsmbe.52.O-86, 52, O-86-O-87, 2014.01, VNS is known to have an anti-infarct effect. However, the technical difficulty associated with VNS precludes its application under clinical settings of AMI. We developed a novel technique where we stimulate the vagal nerves transvenously, and evaluated how the VNS affects the infarction size and cardiac function in the long term. We ligated the left anterior descending coronary artery for 3 hours, then reperfused. For transvenous VNS, we performed the field electrical stimulation at the superior vena cava. One month after the ischemia-reperfusion, we compared the infarct size and cardiac function with/without VNS. Transvenous VNS significantly decreased the infarction size by more than 80% (1.1±1.2 vs. 7.8±1.2cm2, p |
| 146. |
Kouta Funakoshi, Kazuya Hosokawa, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Striking Volume Intolerance Is Induced by Mimicking Arterial Baroreflex Failure in Normal Left Ventricular Function, JOURNAL OF CARDIAC FAILURE, 10.1016/j.cardfail.2013.11.007, 20, 1, 53-59, 2014.01, Background: Patients with heart failure and preserved ejection fraction (HFpEF) are supersensitive to volume overload, and a striking increase in left atrial pressure (LAP) often occurs transiently and is rapidly resolved by intravascular volume reduction. The arterial baroreflex is a powerful regulator of intravascular stressed blood volume. We examined whether arterial baroreflex failure (FAIL) mimicked by constant carotid sinus pressure (CSP) causes a striking increase in LAP and systemic arterial pressure (AP) by volume loading in rats with normal left ventricular (LV) function.Methods and Results: In anesthetized Sprague-Dawley rats, we isolated bilateral carotid sinuses and controlled CSP by a servo-controlled piston pump. We mimicked the normal arterial baroreflex by matching CSP to instantaneous AP and FALL by maintaining CSP at a constant value regardless of AP. We infused dextran stepwise (infused volume [Vi]) until LAP reached 15 mm Hg and obtained the LAP-Vi relationship. We estimated the critical Vi as the Vi at which LAP reached 20 mm Hg. In FAIL, critical Vi decreased markedly from 19.4 +/- 1.6 mL/kg to 15.6 +/- 1.6 mL/kg (P |
| 147. |
Ken Onitsuka, Tomomi Ide, Shinobu Arai, Yuko Hata, Yoshinori Murayama, Kazuya Hosokawa, Takafumi Sakamoto, Tomoyuki Tobushi, Kazuo Sakamoto, Takeo Fujino, Kenji Sunagawa, Cardiac phase-targeted dynamic load on left ventricle differentially regulates phase-sensitive gene expressions and pathway activation, Journal of Molecular and Cellular Cardiology, 10.1016/j.yjmcc.2013.08.008, 64, 30-38, 2013.11, The heart has remarkable capacity to adapt to mechanical load and to dramatically change its phenotype. The mechanism underlying such diverse phenotypic adaptations remains unknown. Since systolic overload induces wall thickening, while diastolic overload induces chamber enlargement, we hypothesized that cardiac phase-sensitive mechanisms govern the adaptation. We inserted a balloon into the left ventricle (LV) of a Langendorff perfused rat heart, and controlled LV volume (LVV) using a high performance servo-pump. We created isolated phasic systolic overload (SO) by isovolumic contraction (peak LV pressure >
170mmHg) at unstressed diastolic LVV [end-diastolic pressure (EDP)=0mmHg]. We also created pure phasic diastolic overload (DO) by increasing diastolic LVV until EDP >
40mmHg and unloading completely in systole. After 3hours under each condition, the myocardium was analyzed using DNA microarray. Gene expressions under SO and DO conditions were compared against unloaded control condition using gene ontology and pathway analysis (n=4 each). SO upregulated proliferation-related genes, whereas DO upregulated fibrosis-related genes (P<
10-5). Both SO and DO upregulated genes related functionally to cardiac hypertrophy, although the gene profiles were totally different. Upstream regulators confirmed by Western blot indicated that SO activated extracellular signal-regulated kinase 1/2, c-Jun NH2-terminal kinase, and Ca2+/calmodulin-dependent protein kinase II (3.2-, 2.0-, and 4.7-fold versus control, P<
0.05, n=5), whereas DO activated p38 (2.9-fold, P<
0.01), which was consistent with the downstream gene expressions. In conclusion, pure isolated systolic and diastolic overload permits elucidation of cardiac phase-sensitive gene regulation. The genomic responses indicate that mechanisms governing the cardiac phase-sensitive adaptations are different. © 2013 Elsevier Ltd.. |
| 148. |
Kiyohiro Ogawa, Yoshitaka Hirooka, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Partially Silencing Brain Toll-Like Receptor 4 Prevents in Part Left Ventricular Remodeling with Sympathoinhibition in Rats with Myocardial Infarction-Induced Heart Failure, PLOS ONE, 10.1371/journal.pone.0069053, 8, 7, e69053, 2013.07, Background: Left ventricular (LV) remodeling and activation of sympathetic nervous system (SNS) are cardinal features of heart failure. We previously demonstrated that enhanced central sympathetic outflow is associated with brain toll-like receptor 4 (TLR4) probably mediated by brain angiotensin II type 1 receptor in mice with myocardial infarction (MI)-induced heart failure. The purpose of the present study was to examine whether silencing brain TLR4 could prevent LV remodeling with sympathoinhibition in MI-induced heart failure.
Methodology/Principal Findings: MI-induced heart failure model rats were created by ligation of left coronary artery. The expression level of TLR4 in brainstem was significantly higher in MI-induced heart failure treated with intracerebroventricular (ICV) injection of hGAPDH-SiRNA than in sham. TLR4 in brainstem was significantly lower in MI-induced heart failure treated with ICV injection of TLR4-SiRNA than in that treated with ICV injection of hGAPDH-SiRNA. Lung weight, urinary norepinephrine excretion, and LV end-diastolic pressure were significantly lower and LV dimension was significantly smaller in MI-induced heart failure treated with TLR4-SiRNA than in that treated with hGAPDH-SiRNA for 2 weeks.
Conclusions: Partially silencing brain TLR4 by ICV injection of TLR4-SiRNA for 2 weeks could in part prevent LV remodeling with sympathoinhibition in rats with MI-induced heart failure. Brain TLR4 has a potential to be a target of the treatment for MI-induced heart failure.. |
| 149. |
Atsushi Tanaka, Tomomi Ide, Takeo Fujino, Ken Onitsuka, Masataka Ikeda, Takako Takehara, Yuko Hata, Emil Ylikallio, Henna Tyynismaa, Anu Suomalainen, Kenji Sunagawa, The Overexpression of Twinkle Helicase Ameliorates the Progression of Cardiac Fibrosis and Heart Failure in Pressure Overload Model in Mice, PLOS ONE, 10.1371/journal.pone.0067642, 8, 6, 2013.06, Myocardial mitochondrial DNA (mtDNA) copy number decreases in heart failure. In post-myocardial infarction mice, increasing mtDNA copy number by overexpressing mitochondrial transcription factor attenuates mtDNA deficiency and ameliorates pathological remodeling thereby markedly improving survival. However, the functional significance of increased mtDNA copy number in hypertensive heart disease remains unknown. We addressed this question using transgenic mice that overexpress Twinkle helicase (Twinkle; Tg), the mtDNA helicase, and examined whether Twinkle overexpression protects the heart from left ventricular (LV) remodeling and failure after pressure overload created by transverse aortic constriction (TAC). Twinkle overexpression increased mtDNA copy number by 2.2 +/- 0.1-fold. Heart weight, LV diastolic volume and wall thickness were comparable between Tg and wild type littermates (WT) at 28 days after TAC operation. LV end-diastolic pressure increased in WT after TAC (8.6 +/- 2.8 mmHg), and this increase was attenuated in Tg (4.6 +/- 2.6 mmHg). Impaired LV fractional shortening after TAC operation was also suppressed in Tg, as measured by echocardiography (WT: 16.2 +/- 7.2% vs Tg: 20.7 +/- 6.2%). These LV functional improvements were accompanied by a decrease in interstitial fibrosis (WT: 10.6 +/- 1.1% vs Tg: 3.0 +/- 0.6%). In in vitro studies, overexpressing Twinkle using an adenovirus vector in cultured cardiac fibroblasts significantly suppressed mRNA of collagen 1a, collagen 3a and connective tissue growth factor, and angiotensin II-induced transforming growth factor beta 1 expression. The findings suggest that Twinkle overexpression prevents LV function deterioration. In conclusion, Twinkle overexpression increases mtDNA copy number and ameliorates the progression of LV fibrosis and heart failure in a mouse pressure overload model. Increasing mtDNA copy number by Twinkle overexpression could be a novel therapeutic strategy for hypertensive heart disease.. |
| 150. |
Toshiro Saito, mayumi hirano, Ide Tomomi, Katsuya Hirano, Pivotal Role of Rho-Associated Kinase 2 in Generating the Intrinsic Circadian Rhythm of Vascular Contractility, CIRCULATION, 10.1161/CIRCULATIONAHA.112.135608, 127, 1, 104-+, 2013.01. |
| 151. |
Nakaya Michio, Satsuki Chikura, Kenji Watari, Natsumi Mizuno, Koji Mochinaga, Supachoke Mangmool, Koyanagi Satoru, Shigehiro Ohdo, Yoji Sato, Tomomi Ide, Motohiro Nishida, Hitoshi Kurose, Induction of cardiac fibrosis by β-blocker in G protein-independent and G protein-coupled receptor kinase 5/β-arrestin2-dependent signaling pathways, Journal of Biological Chemistry, 10.1074/jbc.M112.357871, 287, 42, 35669-35677, 2012.10, G-protein coupled receptors (GPCRs) have long been known as receptors that activate G protein-dependent cellular signaling pathways. In addition to the G protein-dependent pathways, recent reports have revealed that several ligands called "biased ligands" elicit G protein-independent and β-arrestin-dependent signaling through GPCRs (biased agonism). Several β-blockers are known as biased ligands. All β-blockers inhibit the binding of agonists to the β-adrenergic receptors. In addition to β-blocking action, some β-blockers are reported to induce cellular responses through G protein-independent and β-arrestin-dependent signaling pathways. However, the physiological significance induced by the β-arrestin-dependent pathway remains much to be clarified in vivo. Here, we demonstrate that metoprolol, a β1-adrenergic receptor-selective blocker, could induce cardiac fibrosis through a G protein-independent and β-arrestin2-dependent pathway. Metoprolol, a β-blocker, increased the expression of fibrotic genes responsible for cardiac fibrosis in cardiomyocytes. Furthermore, metoprolol induced the interaction between β1- adrenergic receptor and β-arrestin2, but not β-arrestin1. The interaction between β1-adrenergic receptor and β-arrestin2 by metoprolol was impaired in the G protein-coupled receptor kinase 5 (GRK5)- knockdown cells. Metoprolol-induced cardiac fibrosis led to cardiac dysfunction. However, the metoprolol-induced fibrosis and cardiac dysfunction were not evoked in β-arrestin2- or GRK5-knock-out mice. Thus, metoprolol is a biased ligand that selectively activates a G protein-independent and GRK5/β-arrestin2-dependent pathway, and induces cardiac fibrosis. This study demonstrates the physiological importance of biased agonism, and suggests that G protein-independent and β-arrestindependent signaling is a reason for the diversity of the effectiveness of β-blockers.. |
| 152. |
Michio Nakaya, Satsuki Chikura, Kenji Watari, Natsumi Mizuno, Koji Mochinaga, Supachoke Mangmool, Satoru Koyanagi, Shigehiro Ohdo, Yoji Sato, Tomomi Ide, Motohiro Nishida, Hitoshi Kurose, Induction of Cardiac Fibrosis by beta-Blocker in G Proteinin-dependent and G Protein-coupled Receptor Kinase 5/beta-Arrestin2-dependent Signaling Pathways, JOURNAL OF BIOLOGICAL CHEMISTRY, 10.1074/jbc.M112.357871, 287, 42, 35669-35677, 2012.10, G-protein coupled receptors (GPCRs) have long been known as receptors that activate G protein-dependent cellular signaling pathways. In addition to the G protein-dependent pathways, recent reports have revealed that several ligands called "biased ligands" elicit G protein-independent and beta-arrestin-dependent signaling through GPCRs (biased agonism). Several beta-blockers are known as biased ligands. All beta-blockers inhibit the binding of agonists to the beta-adrenergic receptors. In addition to beta-blocking action, some beta-blockers are reported to induce cellular responses through G protein-independent and beta-arrestin-dependent signaling pathways. However, the physiological significance induced by the beta-arrestin-dependent pathway remains much to be clarified in vivo. Here, we demonstrate that metoprolol, a beta(1)-adrenergic receptor-selective blocker, could induce cardiac fibrosis through a G protein-independent and beta-arrestin2-dependent pathway. Metoprolol, a beta-blocker, increased the expression of fibrotic genes responsible for cardiac fibrosis in cardiomyocytes. Furthermore, metoprolol induced the interaction between beta(1)-adrenergic receptor and beta-arrestin2, but not beta-arrestin1. The interaction between beta(1)-adrenergic receptor and beta-arrestin2 by metoprolol was impaired in the G protein-coupled receptor kinase 5 (GRK5)knockdown cells. Metoprolol-induced cardiac fibrosis led to cardiac dysfunction. However, the metoprolol-induced fibrosis and cardiac dysfunction were not evoked in beta-arrestin2- or GRK5-knock-out mice. Thus, metoprolol is a biased ligand that selectively activates a G protein-independent and GRK5/beta-arrestin2-dependent pathway, and induces cardiac fibrosis. This study demonstrates the physiological importance of biased agonism, and suggests that G protein-independent and beta-arrestin-dependent signaling is a reason for the diversity of the effectiveness of beta-blockers.. |
| 153. |
細川和也, 井手 友美, 戸伏倫之, 坂本和生, 鬼塚 健, 坂本隆文, 藤野剛雄, 朔啓太, 砂川賢二, Bionic Baroreceptor Corrects Postural Hypotension in Rats With Impaired Baroreceptor, CIRCULATION, 10.1161/CIRCULATIONAHA.112.108357, 126, 10, 1278-1285, 2012.09. |
| 154. |
Kazuya Hosokawa, Tomomi Ide, Tomoyuki Tobushi, Kazuo Sakamoto, Ken Onitsuka, Takafumi Sakamoto, Takeo Fujino, Keita Saku, Kenji Sunagawa, Bionic Baroreceptor Corrects Postural Hypotension in Rats With Impaired Baroreceptor, CIRCULATION, 10.1161/CIRCULATIONAHA.112.108357, 126, 10, 1278-1285, 2012.09, Background-Impairment of the arterial baroreflex causes orthostatic hypotension. Arterial baroreceptor sensitivity degrades with age. Thus, an impaired baroreceptor plays a pivotal role in orthostatic hypotension in most elderly patients. There is no effective treatment for orthostatic hypotension. The aims of this investigation were to develop a bionic baroreceptor (BBR) and to verify whether it corrects postural hypotension.Methods and Results-The BBR consists of a pressure sensor, a regulator, and a neurostimulator. In 35 Sprague-Dawley rats, we vascularly and neurally isolated the baroreceptor regions and attached electrodes to the aortic depressor nerve for stimulation. To mimic impaired baroreceptors, we maintained intracarotid sinus pressure at 60 mm Hg during activation of the BBR. Native baroreflex was reproduced by matching intracarotid sinus pressure to the instantaneous pulsatile aortic pressure. The encoding rule for translating intracarotid sinus pressure into stimulation of the aortic depressor nerve was identified by a white noise technique and applied to the regulator. The open-loop arterial pressure response to intracarotid sinus pressure (n = 7) and upright tilt-induced changes in arterial pressure (n = 7) were compared between native baroreceptor and BBR conditions. The intracarotid sinus pressure-arterial pressure relationships were comparable. Compared with the absence of baroreflex, the BBR corrected tilt-induced hypotension as effectively as under native baroreceptor conditions (native, -39 +/- 5 mm Hg; BBR, -41 +/- 5 mm Hg; absence, -63 +/- 5 mm Hg; P |
| 155. |
藤野 剛雄, 井手 友美, 吉田 昌義, 鬼塚 健, 田中 敬士, 秦 優子, 西田 基宏, Recombinant mitochondrial transcription factor A protein inhibits nuclear factor of activated T cells signaling and attenuates pathological hypertrophy of cardiac myocytes, MITOCHONDRION, 10.1016/j.mito.2012.06.002, 12, 4, 449-458, 2012.07. |
| 156. |
Takeo Fujino, Tomomi Ide, Masayoshi Yoshida, Ken Onitsuka, Atsushi Tanaka, Yuko Hata, Motohiro Nishida, Takako Takehara, Takaaki Kanemaru, Naoyuki Kitajima, Shinya Takazaki, Hitoshi Kurose, Dongchon Kang, Kenji Sunagawa, Recombinant mitochondrial transcription factor A protein inhibits nuclear factor of activated T cells signaling and attenuates pathological hypertrophy of cardiac myocytes, MITOCHONDRION, 10.1016/j.mito.2012.06.002, 12, 4, 449-458, 2012.07, The overexpression of mitochondrial transcription factor A (TFAM) attenuates the decrease in mtDNA copy number after myocardial infarction, ameliorates pathological hypertrophy, and markedly improves survival. However, non-transgenic strategy to increase mtDNA for the treatment of pathological hypertrophy remains unknown. We produced recombinant human TFAM protein (rhTFAM). rhTFAM rapidly entered into mitochondria of cultured cardiac myocytes. rhTFAM increased mtDNA and abolished the activation of nuclear factor of activated T cells (NFAT), which is well known to activate pathological hypertrophy. rhTFAM attenuated subsequent morphological hypertrophy of myocytes as well. rhTFAM would be an attractive molecule in attenuating cardiac pathological hypertrophy. (C) 2012 Elsevier B.V. and Mitochondria Research Society. All rights reserved.. |
| 157. |
Morimoto N, Miyazaki K, Kurata T, Ikeda Y, Matsuura T, Kang D, Ide T, Abe K., Effect of mitochondrial transcription factor a overexpression on motor neurons in amyotrophic lateral sclerosis model mice., 90, 6, 1200-1208, 2012.06. |
| 158. |
Nobutoshi Morimoto, Kazunori Miyazaki, Tomoko Kurata, Yoshio Ikeda, Tohru Matsuura, Dongchon Kang, Tomomi Ide, Koji Abe, Effect of mitochondrial transcription factor a overexpression on motor neurons in amyotrophic lateral sclerosis model mice, Journal of Neuroscience Research, 10.1002/jnr.23000, 90, 6, 1200-1208, 2012.06, Increasing evidence indicates that oxidative stress is an important mechanism underlying motor neuron (MN) degeneration in amyotrophic lateral sclerosis (ALS). Mitochondrial DNA (mtDNA) is highly susceptible to oxidative damage and has little potential for repair, although mitochondrial transcription factor A (TFAM) plays essential roles in maintaining mitochondrial DNA by reducing oxidative stress, promoting mtDNA transcription, and regulating mtDNA copy number. To analyze a possible therapeutic effect of TFAM on ALS pathology, double transgenic mice overexpressing G93A mutant SOD1 (G93ASOD1) and human TFAM (hTFAM) were newly generated in the present study. Rotarod scores were better in G93ASOD1/hTFAM double-Tg mice than G93ASOD1 single-Tg mice at an early symptomatic stage, 15 and 16 weeks of age, with a 10% extension of the onset age in double-Tg mice. The number of surviving MNs was 30% greater in double-Tg mice with end-stage disease, at 19 weeks, with remarkable reductions in the amount of the oxidative stress marker 8-OHdG and the apoptotic marker cleaved caspase 3 and with preserved COX1 expression. Double-immunofluorescence study showed that hTFAM was expressed specifically in MNs and microglia in the spinal cords of double-Tg mice. The present study suggests that overexpression of TFAM has a potential to reduce oxidative stress in MN and delay onset of the disease in ALS model mice.. |
| 159. |
Nobutoshi Morimoto, Kazunori Miyazaki, Tomoko Kurata, Yoshio Ikeda, Tohru Matsuura, Dongchon Kang, Tomomi Ide, Koji Abe, Effect of mitochondrial transcription factor a overexpression on motor neurons in amyotrophic lateral sclerosis model mice, JOURNAL OF NEUROSCIENCE RESEARCH, 10.1002/jnr.23000, 90, 6, 1200-1208, 2012.06, Increasing evidence indicates that oxidative stress is an important mechanism underlying motor neuron (MN) degeneration in amyotrophic lateral sclerosis (ALS). Mitochondrial DNA (mtDNA) is highly susceptible to oxidative damage and has little potential for repair, although mitochondrial transcription factor A (TFAM) plays essential roles in maintaining mitochondrial DNA by reducing oxidative stress, promoting mtDNA transcription, and regulating mtDNA copy number. To analyze a possible therapeutic effect of TFAM on ALS pathology, double transgenic mice overexpressing G93A mutant SOD1 (G93ASOD1) and human TFAM (hTFAM) were newly generated in the present study. Rotarod scores were better in G93ASOD1/hTFAM double-Tg mice than G93ASOD1 single-Tg mice at an early symptomatic stage, 15 and 16 weeks of age, with a 10% extension of the onset age in double-Tg mice. The number of surviving MNs was 30% greater in double-Tg mice with end-stage disease, at 19 weeks, with remarkable reductions in the amount of the oxidative stress marker 8-OHdG and the apoptotic marker cleaved caspase 3 and with preserved COX1 expression. Double-immunofluorescence study showed that hTFAM was expressed specifically in MNs and microglia in the spinal cords of double-Tg mice. The present study suggests that overexpression of TFAM has a potential to reduce oxidative stress in MN and delay onset of the disease in ALS model mice. (c) 2012 Wiley Priodicals, Inc.. |
| 160. |
Masao Takemoto, Yasushi Mukai, Shuujirou Inoue, Tetsuya Matoba, Mari Nishizaka, Tomomi Ide, Akiko Chishaki, Kenji Sunagawa, Usefulness of non-contact mapping for radiofrequency catheter ablation of inappropriate sinus tachycardia
New procedural strategy and long-term clinical outcome, Internal Medicine, 10.2169/internalmedicine.51.5882, 51, 4, 357-362, 2012.02, Objectives The present study evaluated the clinical benefits of a new therapeutic method of radiofrequency catheter ablation (RFCA) using an EnSite system for inappropriate sinus tachycardia (IST). Materials and Methods Six patients with debilitating IST underwent RFCA using EnSite. Using the betaadrenergic blocker and agonist, the heart rate was controlled between 70 to 150 bpm before and after the RFCA. The areas of the breakout sites (BOSs) were clearly distinguished between those from the normal Pwave zones during rates of less than 100 bpm and those from more upper rate sites during rates of more than 100 bpm using the EnSite system, in accordance with the appearance of tall P-waves (tall P-wave zone) in the IST patients. This was selected as the target for ablation. Results After the RFCA, the BOSs observed during heart rates of more than 100 bpm moved completely from the tall P-wave zone to the normal P-wave zone in the IST patients. The total number of heart beats and average heart beat on the 24-h Holter monitoring decreased statistically from that before the RFCA to that after, and no adverse heart rate responses was observed after the RFCA. Before the RFCA, the brain natriuretic peptide was elevated, New York Heart Association functional class was worse, and there was an impaired exercise tolerance observed with exercise electrocardiogram testing. The RFCA for the IST significantly improved those parameters. Conclusion This new therapeutic method for IST using EnSite is effective and produces clinical benefits.. |
| 161. |
Mayumi Yamato, Takeshi Shiba, Tomomi Ide, Naoko Seri, Wataru Kudo, Makoto Ando, Ken-Ichi Yamada, Shintaro Kinugawa, Hiroyuki Tsutsui, High-fat diet-induced obesity and insulin resistance were ameliorated via enhanced fecal bile acid excretion in tumor necrosis factor-alpha receptor knockout mice, Molecular and cellular biochemistry, 10.1007/s11010-011-1010-3, 359, 1-2, 161-167, 2012.01, Tumor necrosis factor-α (TNF-α) is one of the main mediators of inflammatory response activated by fatty acids in obesity, and this signaling through TNF-α receptor (TNFR) is responsible for obesity-associated insulin resistance. Recently, TNF-α has shown to affect lipid metabolism including the regulation of lipase activity and bile acid synthesis. However, there is scanty in vivo evidence for the involvement of TNF-α in this process, and the mechanistic role of TNFR remains unclear. In this study, TNFR2 knockout mice (R2KO) and wild-type (WT) mice were fed commercial normal diet (ND) or high-fat diet (HFD) for 8 weeks. In R2KO/HFD mice, the increase in body weight and the accumulation of fat were significantly ameliorated compared with WT/HFD mice in association with the decrease in plasma total cholesterol (137.7 ± 3.1 vs. 98.6 ± 3.1 mg/dL, P |
| 162. |
Tomomi Ide, Kenji Sunagawa, [Chronic heart failure
progress in diagnosis and treatment. Topics: III. Progress in prevention, control and treatment; 1. Prevention for chronic heart failure]., Nihon Naika Gakkai zasshi. The Journal of the Japanese Society of Internal Medicine, 101, 2, 369-374, 2012.01. |
| 163. |
Mayumi Yamato, Takeshi Shiba, Tomomi Ide, Naoko Seri, Wataru Kudo, Makoto Ando, Ken-ichi Yamada, Shintaro Kinugawa, Hiroyuki Tsutsui, High-fat diet-induced obesity and insulin resistance were ameliorated via enhanced fecal bile acid excretion in tumor necrosis factor-alpha receptor knockout mice, MOLECULAR AND CELLULAR BIOCHEMISTRY, 10.1007/s11010-011-1010-3, 359, 1-2, 161-167, 2012.01, Tumor necrosis factor-alpha (TNF-alpha) is one of the main mediators of inflammatory response activated by fatty acids in obesity, and this signaling through TNF-alpha receptor (TNFR) is responsible for obesity-associated insulin resistance. Recently, TNF-alpha has shown to affect lipid metabolism including the regulation of lipase activity and bile acid synthesis. However, there is scanty in vivo evidence for the involvement of TNF-alpha in this process, and the mechanistic role of TNFR remains unclear. In this study, TNFR2 knockout mice (R2KO) and wild-type (WT) mice were fed commercial normal diet (ND) or high-fat diet (HFD) for 8 weeks. In R2KO/HFD mice, the increase in body weight and the accumulation of fat were significantly ameliorated compared with WT/HFD mice in association with the decrease in plasma total cholesterol (137.7 +/- A 3.1 vs. 98.6 +/- A 3.1 mg/dL, P |
| 164. |
Kazuya Hosokawa, Kouta Funakoshi, Atsushi Tanaka, takafumi sakamoto, Ken Onitsuka, Kazuo Sakamoto, Tomoyuki Tobushi, Takeo Fujino, Keita Saku, Yoshinori Murayama, Tomomi Ide, Kenji Sunagawa, Artificial baroreflex system restores volume tolerance in the absence of native baroreflex, 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS 2011
33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS 2011, 10.1109/IEMBS.2011.6090157, 697-699, 2011.12, The arterial baroreflex stabilizes arterial pressure by modulating the mechanical properties of cardiovascular system. We previously demonstrated that the baroreflex impairment makes the circulatory system extremely sensitive to volume overload and predisposes to pulmonary edema irrespective of left ventricular systolic function. To overcome the volume intolerance, we developed an artificial baroreflex system by directly stimulating the carotid sinus nerves in response to changes in arterial pressure. The artificial baroreflex system precisely reproduced the native arterial pressure response and restored physiological volume buffering function. We conclude that the artificial baroreflex system would be an attractive tool in preventing pulmonary edema in patients with impaired baroreflex function.. |
| 165. |
Kazuya Hosokawa, Kouta Funakoshi, Atsushi Tanaka, takafumi sakamoto, Ken Onitsuka, Kazuo Sakamoto, Tomoyuki Tobushi, Takeo Fujino, Keita Saku, Yoshinori Murayama, Tomomi Ide, Kenji Sunagawa, Artificial baroreflex system restores volume tolerance in the absence of native baroreflex, 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS 2011
33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS 2011, 10.1109/IEMBS.2011.6090157, 697-699, 2011.12, The arterial baroreflex stabilizes arterial pressure by modulating the mechanical properties of cardiovascular system. We previously demonstrated that the baroreflex impairment makes the circulatory system extremely sensitive to volume overload and predisposes to pulmonary edema irrespective of left ventricular systolic function. To overcome the volume intolerance, we developed an artificial baroreflex system by directly stimulating the carotid sinus nerves in response to changes in arterial pressure. The artificial baroreflex system precisely reproduced the native arterial pressure response and restored physiological volume buffering function. We conclude that the artificial baroreflex system would be an attractive tool in preventing pulmonary edema in patients with impaired baroreflex function.. |
| 166. |
Takeo Fujino, Tomomi Ide, Masayoshi Yoshida, Ken Onitsuka, Atsushi Tanaka, Yuko Hata, Takako Takehara, Kazuya Hosokawa, Takafumi Sakamoto, Motohiro Nishida, Kenji Sunagawa, Recombinant Mitochondrial Transcriptional Factor A Protein Attenuates Pathological Remodeling in Cardiac Myocytes, CIRCULATION, 124, 21, 2011.11. |
| 167. |
Yamato M, Shiba T, Ide T, Honda Y, Yamada K, Tsutsui H., Nifedipine treatment reduces brain damage after transient focal ischemia, possibly through its antioxidative effects., Hypertension Research, 34, 7, 840-845, 2011.07. |
| 168. |
Mayumi Yamato, Takeshi Shiba, Tomomi Ide, Youhei Honda, Ken-Ichi Yamada, Hiroyuki Tsutsui, Nifedipine treatment reduces brain damage after transient focal ischemia, possibly through its antioxidative effects, Hypertension Research, 10.1038/hr.2011.51, 34, 7, 840-845, 2011.07, Stroke is a major cause of mortality and morbidity in hypertensive patients. This study investigated the effects of nifedipine, an L-type voltage-gated Ca 2+ channel blocker, on ischemic lesion volume after focal cerebral ischemia and reperfusion in rats. Rats were subjected to 1 h of transient middle cerebral artery occlusion (MCAO). At 2 days after MCAO, the rats were randomized into two groups that were fed either a normal control diet (n=10) or a nifedipine (0.001%) containing diet (n=11) for 2 weeks. Nifedipine treatment significantly reduced ischemic lesion volume (116.5±10.8 vs. 80.0±8.2 mm 3, P-1 tissue, P-1 protein, P-1 protein, P |
| 169. |
Mayumi Yamato, Takeshi Shiba, Tomomi Ide, Youhei Honda, Ken-ichi Yamada, Hiroyuki Tsutsui, Nifedipine treatment reduces brain damage after transient focal ischemia, possibly through its antioxidative effects, HYPERTENSION RESEARCH, 10.1038/hr.2011.51, 34, 7, 840-845, 2011.07, Stroke is a major cause of mortality and morbidity in hypertensive patients. This study investigated the effects of nifedipine, an L-type voltage-gated Ca(2+) channel blocker, on ischemic lesion volume after focal cerebral ischemia and reperfusion in rats. Rats were subjected to 1 h of transient middle cerebral artery occlusion (MCAO). At 2 days after MCAO, the rats were randomized into two groups that were fed either a normal control diet (n = 10) or a nifedipine (0.001%) containing diet (n = 11) for 2 weeks. Nifedipine treatment significantly reduced ischemic lesion volume (116.5 +/- 10.8 vs. 80.0 +/- 8.2 mm(3), P |
| 170. |
Yikallio E. Ylikallio E, Page JL, Xu X, Lampinen M, Bepler G, Ide T, Tyynismaa H, Weiss RS, Suomalainen A, Ribonucleotide reductase is not limiting for mitochondrial DNA copy number in mice., Nucleic Acids Res, 38, 8208-8218, 2011.05. |
| 171. |
Kitajima N, Watanabe K, Morimoto S, Sato Y, Kiyonaka S, Hoshijima M, Ikeda Y, Nakaya M, Ide T, Mori Y, Kurose H, Nishida M., TRPC3-mediated Ca2+ influx contributes to Rac1-mediated production of reactive oxygen species in MLP-deficient mouse hearts., Biochem Biophys Res Commun, 409, 1, 108-113, 2011.05. |
| 172. |
Naoyuki Kitajima, Kunihiro Watanabe, Sachio Morimoto, Yoji Sato, Shigeki Kiyonaka, Masahiko Hoshijima, Yasuhiro Ikeda, Nakaya Michio, Tomomi Ide, Yasuo Mori, Hitoshi Kurose, Motohiro Nishida, TRPC3-mediated Ca2+ influx contributes to Rac1-mediated production of reactive oxygen species in MLP-deficient mouse hearts, Biochemical and Biophysical Research Communications, 10.1016/j.bbrc.2011.04.124, 409, 1, 108-113, 2011.05, Dilated cardiomyopathy (DCM) is a myocardial disorder that is characterized by dilation and dysfunction of the left ventricle (LV). Accumulating evidence has implicated aberrant Ca2+ signaling and oxidative stress in the progression of DCM, but the molecular details are unknown. In the present study, we report that inhibition of the transient receptor potential canonical 3 (TRPC3) channels partially prevents LV dilation and dysfunction in muscle LIM protein-deficient (MLP (-/-)) mice, a murine model of DCM. The expression level of TRPC3 and the activity of Ca2+/calmodulin-dependent kinase II (CaMKII) were increased in MLP (-/-) mouse hearts. Acitivity of Rac1, a small GTP-binding protein that participates in NADPH oxidase (Nox) activation, and the production of reactive oxygen species (ROS) were also increased in MLP (-/-) mouse hearts. Treatment with pyrazole-3, a TRPC3 selective inhibitor, strongly suppressed the increased activities of CaMKII and Rac1, as well as ROS production. In contrast, activation of TRPC3 by 1-oleoyl-2-acetyl-sn-glycerol (OAG), or by mechanical stretch, induced ROS production in rat neonatal cardiomyocytes. These results suggest that up-regulation of TRPC3 is responsible for the increase in CaMKII activity and the Nox-mediated ROS production in MLP (-/-) mouse cardiomyocytes, and that inhibition of TRPC3 is an effective therapeutic strategy to prevent the progression of DCM.. |
| 173. |
Naoyuki Kitajima, Kunihiro Watanabe, Sachio Morimoto, Yoji Sato, Shigeki Kiyonaka, Masahiko Hoshijima, Yasuhiro Ikeda, Michio Nakaya, Tomomi Ide, Yasuo Mori, Hitoshi Kurose, Motohiro Nishida, TRPC3-mediated Ca2+ influx contributes to Rac1-mediated production of reactive oxygen species in MLP-deficient mouse hearts, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 10.1016/j.bbrc.2011.04.124, 409, 1, 108-113, 2011.05, Dilated cardiomyopathy (DCM) is a myocardial disorder that is characterized by dilation and dysfunction of the left ventricle (LV). Accumulating evidence has implicated aberrant Ca2+ signaling and oxidative stress in the progression of DCM, but the molecular details are unknown. In the present study, we report that inhibition of the transient receptor potential canonical 3 (TRPC3) channels partially prevents LV dilation and dysfunction in muscle LIM protein-deficient (MLP (-/-)) mice, a murine model of DCM. The expression level of TRPC3 and the activity of Ca2+/calmodulin-dependent kinase II (CaMKII) were increased in MLP (-/-) mouse hearts. Acitivity of Rac1, a small GTP-binding protein that participates in NADPH oxidase (Nox) activation, and the production of reactive oxygen species (ROS) were also increased in MLP (-/-) mouse hearts. Treatment with pyrazole-3, a TRPC3 selective inhibitor, strongly suppressed the increased activities of CaMKII and Rac1, as well as ROS production. In contrast, activation of TRPC3 by 1-oleoyl-2-acetyl-sn-glycerol (OAG), or by mechanical stretch, induced ROS production in rat neonatal cardiomyocytes. These results suggest that up-regulation of TRPC3 is responsible for the increase in CaMKII activity and the Nox-mediated ROS production in MLP (-/-) mouse cardiomyocytes, and that inhibition of TRPC3 is an effective therapeutic strategy to prevent the progression of DCM. (C) 2011 Elsevier Inc. All rights reserved.. |
| 174. |
Nishida M, Ogushi M, Suda R, Toyotaka M, Saiki S, Kitajima N, Nakaya M, Kim KM, Ide T, Sato Y, Inoue K, Kurose H., Heterologous down-regulation of angiotensin type 1 receptors by purinergic P2Y2 receptor stimulation through S-nitrosylation of NF-kappaB., Proc Natl Acad Sci U S A., 108, 16, 6662-6667, 2011.04. |
| 175. |
Motohiro Nishida, Mariko Ogushi, Reiko Suda, Miyuki Toyotaka, Shota Saiki, Naoyuki Kitajima, Nakaya Michio, Kyeong Man Kim, Tomomi Ide, Yoji Sato, Kazuhide Inoue, Hitoshi Kurose, Heterologous down-regulation of angiotensin type 1 receptors by purinergic P2Y2 receptor stimulation through S-nitrosylation of NF-κB, Proceedings of the National Academy of Sciences of the United States of America, 10.1073/pnas.1017640108, 108, 16, 6662-6667, 2011.04, Cross-talk between G protein-coupled receptor (GPCR) signaling pathways serves to fine tune cellular responsiveness by neurohumoral factors. Accumulating evidence has implicated nitric oxide (NO)-based signaling downstream of GPCRs, but the molecular details are unknown. Here, we show that adenosine triphosphate (ATP) decreases angiotensin type 1 receptor (AT 1R) density through NO-mediated S-nitrosylation of nuclear factor κB (NF-κB) in rat cardiac .broblasts. Stimulation of purinergic P2Y2 receptor by ATP increased expression of inducible NO synthase (iNOS) through activation of nuclear factor of activated T cells, NFATc1 and NFATc3. The ATP-induced iNOS interacted with p65 subunit of NF-κB in the cytosol through .avin-binding domain, which was indispensable for the locally generated NO-mediated S-nitrosylation of p65 at Cys38. β-Arrestins anchored the formation of p65/ IκBα/β-arrestins/iNOS quaternary complex. The S-nitrosylated p65 resulted in decreases in NF-κB transcriptional activity and AT1R density. In pressure-overloaded mouse hearts, ATP released from cardiomyocytes led to decrease in AT 1R density through iNOS-mediated S-nitrosylation of p65. These results show a unique regulatory mechanism of heterologous regulation of GPCRs in which cysteine modi.cation of transcriptional factor rather than protein phosphorylation plays essential roles.. |
| 176. |
Motohiro Nishida, Mariko Ogushi, Reiko Suda, Miyuki Toyotaka, Shota Saiki, Naoyuki Kitajima, Michio Nakaya, Kyeong-Man Kim, Tomomi Ide, Yoji Sato, Kazuhide Inoue, Hitoshi Kurose, Heterologous down-regulation of angiotensin type 1 receptors by purinergic P2Y(2) receptor stimulation through S-nitrosylation of NF-kappa B, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 10.1073/pnas.1017640108, 108, 16, 6662-6667, 2011.04, Cross-talk between G protein-coupled receptor (GPCR) signaling pathways serves to fine tune cellular responsiveness by neurohumoral factors. Accumulating evidence has implicated nitric oxide (NO)-based signaling downstream of GPCRs, but the molecular details are unknown. Here, we show that adenosine triphosphate (ATP) decreases angiotensin type 1 receptor (AT(1)R) density through NO-mediated S-nitrosylation of nuclear factor kappa B (NF-kappa B) in rat cardiac fibroblasts. Stimulation of purinergic P2Y(2) receptor by ATP increased expression of inducible NO synthase (iNOS) through activation of nuclear factor of activated T cells, NFATc1 and NFATc3. The ATP-induced iNOS interacted with p65 subunit of NF-kappa B in the cytosol through flavin-binding domain, which was indispensable for the locally generated NO-mediated S-nitrosylation of p65 at Cys38. beta-Arrestins anchored the formation of p65/I kappa B alpha/beta-arrestins/iNOS quaternary complex. The S-nitrosylated p65 resulted in decreases in NF-kappa B transcriptional activity and AT(1)R density. In pressure-overloaded mouse hearts, ATP released from cardiomyocytes led to decrease in AT(1)R density through iNOS-mediated S-nitrosylation of p65. These results show a unique regulatory mechanism of heterologous regulation of GPCRs in which cysteine modification of transcriptional factor rather than protein phosphorylation plays essential roles.. |
| 177. |
Emil Ylikallio, Jennifer L. Page, Xia Xu, Milla Lampinen, Gerold Bepler, Tomomi Ide, Henna Tyynismaa, Robert S. Weiss, Anu Suomalainen, Ribonucleotide reductase is not limiting for mitochondrial DNA copy number in mice, Nucleic acids research, 10.1093/nar/gkq735, 38, 22, 8208-8218, 2010.12, Ribonucleotide reductase (RNR) is the rate-limiting enzyme in deoxyribonucleoside triphosphate (dNTP) biosynthesis, with important roles in nuclear genome maintenance. RNR is also essential for maintenance of mitochondrial DNA (mtDNA) in mammals. The mechanisms regulating mtDNA copy number in mammals are only being discovered. In budding yeast, RNR overexpression resulted in increased mtDNA levels, and rescued the disease phenotypes caused by a mutant mtDNA polymerase. This raised the question of whether mtDNA copy number increase by RNR induction could be a strategy for treating diseases with mtDNA mutations. We show here that high-level overexpression of RNR subunits (Rrm1, Rrm2 and p53R2; separately or in different combinations) in mice does not result in mtDNA copy number elevation. Instead, simultaneous expression of two RNR subunits leads to imbalanced dNTP pools and progressive mtDNA depletion in the skeletal muscle, without mtDNA mutagenesis. We also show that endogenous RNR transcripts are downregulated in response to large increases of mtDNA in mice, which is indicative of nuclear-mitochondrial crosstalk with regard to mtDNA copy number. Our results establish that RNR is not limiting for mtDNA copy number in mice, and provide new evidence for the importance of balanced dNTP pools in mtDNA maintenance in postmitotic tissues.. |
| 178. |
Emil Ylikallio, Jennifer L. Page, Xia Xu, Milla Lampinen, Gerold Bepler, Tomomi Ide, Henna Tyynismaa, Robert S. Weiss, Anu Suomalainen, Ribonucleotide reductase is not limiting for mitochondrial DNA copy number in mice, NUCLEIC ACIDS RESEARCH, 10.1093/nar/gkq735, 38, 22, 8208-8218, 2010.12, Ribonucleotide reductase (RNR) is the rate-limiting enzyme in deoxyribonucleoside triphosphate (dNTP) biosynthesis, with important roles in nuclear genome maintenance. RNR is also essential for maintenance of mitochondrial DNA (mtDNA) in mammals. The mechanisms regulating mtDNA copy number in mammals are only being discovered. In budding yeast, RNR overexpression resulted in increased mtDNA levels, and rescued the disease phenotypes caused by a mutant mtDNA polymerase. This raised the question of whether mtDNA copy number increase by RNR induction could be a strategy for treating diseases with mtDNA mutations. We show here that high-level overexpression of RNR subunits (Rrm1, Rrm2 and p53R2; separately or in different combinations) in mice does not result in mtDNA copy number elevation. Instead, simultaneous expression of two RNR subunits leads to imbalanced dNTP pools and progressive mtDNA depletion in the skeletal muscle, without mtDNA mutagenesis. We also show that endogenous RNR transcripts are downregulated in response to large increases of mtDNA in mice, which is indicative of nuclear-mitochondrial crosstalk with regard to mtDNA copy number. Our results establish that RNR is not limiting for mtDNA copy number in mice, and provide new evidence for the importance of balanced dNTP pools in mtDNA maintenance in postmitotic tissues.. |
| 179. |
Yuan Yuan Wang, Sachio Morimoto, Cheng Kun Du, Qun Wei Lu, Dong Yun Zhan, Takaki Tsutsumi, Tomomi Ide, Yosikazu Miwa, Fumi Takahashi, Toshiyuki Sasaguri, Up-regulation of type 2 iodothyronine deiodinase in dilated cardiomyopathy, Cardiovascular research, 10.1093/cvr/cvq133, 87, 4, 636-646, 2010.09, Aims Thyroid hormone (TH) has prominent effects on the heart, and hyperthyroidism is occasionally found to be a cause of dilated cardiomyopathy (DCM). We aim to explore the potential role of TH in the pathogenesis of DCM. Methods and results The pathophysiological role of TH in the heart was investigated using a knock-in mouse model of inherited DCM with a deletion mutation ΔK210 in the cardiac troponin T gene. Serum tri-iodothyronine (T3) levels showed no significant difference between wild-type (WT) and DCM mice, whereas cardiac T3 levels in DCM mice were significantly higher than those in WT mice. Type 2 iodothyronine deiodinase (Dio2), which produces T3 from thyroxin, was up-regulated in the DCM mice hearts. The cAMP levels were increased in DCM mice hearts, suggesting that transcriptional up-regulation of Dio2 gene is mediated through the evolutionarily conserved cAMP-response element site in its promoter. Propylthiouracil (PTU), an anti-thyroid drug, prevented the hypertrophic remodelling of the heart in DCM mice and improved their cardiac function and life expectancy. Akt and p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation increased in the DCM mice hearts and PTU treatment significantly reduced the phosphorylation levels, strongly suggesting that Dio2 up-regulation is involved in cardiac remodelling in DCM through activating the TH-signalling pathways involving Akt and p38 MAPK. Dio2 gene expression was also markedly up-regulated in the mice hearts developing similar eccentric hypertrophy after myocardial infarction. Conclusion Local hyperthyroidism via transcriptional up-regulation of the Dio2 gene may be an important underlying mechanism for the hypertrophic cardiac remodelling in DCM.. |
| 180. |
Yuan-Yuan Wang, Sachio Morimoto, Cheng-Kun Du, Qun-Wei Lu, Dong-Yun Zhan, Takaki Tsutsumi, Tomomi Ide, Yosikazu Miwa, Fumi Takahashi-Yanaga, Toshiyuki Sasaguri, Up-regulation of type 2 iodothyronine deiodinase in dilated cardiomyopathy, CARDIOVASCULAR RESEARCH, 10.1093/cvr/cvq133, 87, 4, 636-646, 2010.09, Thyroid hormone (TH) has prominent effects on the heart, and hyperthyroidism is occasionally found to be a cause of dilated cardiomyopathy (DCM). We aim to explore the potential role of TH in the pathogenesis of DCM.The pathophysiological role of TH in the heart was investigated using a knock-in mouse model of inherited DCM with a deletion mutation delta K210 in the cardiac troponin T gene. Serum tri-iodothyronine (T(3)) levels showed no significant difference between wild-type (WT) and DCM mice, whereas cardiac T(3) levels in DCM mice were significantly higher than those in WT mice. Type 2 iodothyronine deiodinase (Dio2), which produces T(3) from thyroxin, was up-regulated in the DCM mice hearts. The cAMP levels were increased in DCM mice hearts, suggesting that transcriptional up-regulation of Dio2 gene is mediated through the evolutionarily conserved cAMP-response element site in its promoter. Propylthiouracil (PTU), an anti-thyroid drug, prevented the hypertrophic remodelling of the heart in DCM mice and improved their cardiac function and life expectancy. Akt and p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation increased in the DCM mice hearts and PTU treatment significantly reduced the phosphorylation levels, strongly suggesting that Dio2 up-regulation is involved in cardiac remodelling in DCM through activating the TH-signalling pathways involving Akt and p38 MAPK. Dio2 gene expression was also markedly up-regulated in the mice hearts developing similar eccentric hypertrophy after myocardial infarction.Local hyperthyroidism via transcriptional up-regulation of the Dio2 gene may be an important underlying mechanism for the hypertrophic cardiac remodelling in DCM.. |
| 181. |
Masaaki Hokari, Satoshi Kuroda, Shintaro Kinugawa, Tomomi Ide, Hiroyuki Tsutsui, Yoshinobu Iwasaki, Overexpression of mitochondrial transcription factor A (TFAM) ameliorates delayed neuronal death due to transient forebrain ischemia in mice, Neuropathology, 10.1111/j.1440-1789.2009.01086.x, 30, 4, 401-407, 2010.08, Mitochondrial transcription factor A (TFAM) is an important regulator to maintain mitochondrial DNA copy number. However, no studies have denoted its roles in cerebral ischemia. Therefore, this study was aimed to assess whether the forced overexpression of TFAM ameliorates delayed neuronal death following transient forebrain ischemia. We have established human TFAM-transgenic (Tg) mice. Wild type (WT) and TFAM-Tg mice were subjected to 20-min bilateral common carotid artery occlusion (BCCAO). Immunostaining against cytochrome c was performed to estimate its release from mitochondria at 24 h after 20-min BCCAO. Histological analysis was performed to evaluate the effect of TFAM overexpression on delayed neuronal death at 72 h after 20-min BCCAO. The number of cytochrome c-positive neurons in the hippocampal CA1 sector was significantly smaller in TFAM-Tg mice than in WT mice (P = 0.005). The percentage of viable neurons in the hippocampal CA1 sector was significantly higher in TFAM-Tg mice than in WT mice (P |
| 182. |
Masaaki Hokari, Satoshi Kuroda, Shintaro Kinugawa, Tomomi Ide, Hiroyuki Tsutsui, Yoshinobu Iwasaki, Overexpression of mitochondrial transcription factor A (TFAM) ameliorates delayed neuronal death due to transient forebrain ischemia in mice, NEUROPATHOLOGY, 10.1111/j.1440-1789.2009.01086.x, 30, 4, 401-407, 2010.08, Mitochondrial transcription factor A (TFAM) is an important regulator to maintain mitochondrial DNA copy number. However, no studies have denoted its roles in cerebral ischemia. Therefore, this study was aimed to assess whether the forced overexpression of TFAM ameliorates delayed neuronal death following transient forebrain ischemia. We have established human TFAM-transgenic (Tg) mice. Wild type (WT) and TFAM-Tg mice were subjected to 20-min bilateral common carotid artery occlusion (BCCAO). Immunostaining against cytochrome c was performed to estimate its release from mitochondria at 24 h after 20-min BCCAO. Histological analysis was performed to evaluate the effect of TFAM overexpression on delayed neuronal death at 72 h after 20-min BCCAO. The number of cytochrome c-positive neurons in the hippocampal CA1 sector was significantly smaller in TFAM-Tg mice than in WT mice (P = 0.005). The percentage of viable neurons in the hippocampal CA1 sector was significantly higher in TFAM-Tg mice than in WT mice (P |
| 183. |
Yikallio E, Tyyismaa H, Tsutsui H, Ide T, Suomalainen A, High mitochondrial DNA copy number has detrimental effects in mice, Hum Mol Genom, 13, 2695-2705, 2010.07. |
| 184. |
Emil Ylikallio, Henna Tyynismaa, Hiroyuki Tsutsui, Tomomi Ide, Anu Suomalainen, High mitochondrial DNA copy number has detrimental effects in mice, HUMAN MOLECULAR GENETICS, 10.1093/hmg/ddq163, 19, 13, 2695-2705, 2010.07, Mitochondrial DNA (mtDNA) is an essential multicopy genome, compacted into protein-DNA clusters called nucleoids. Maintaining an adequate mtDNA copy number is crucial for cellular viability. Loss of mtDNA results in severe human syndromes, whereas increased mtDNA copy number has been suggested to improve survival from myocardial infarction in mice and to be a promising therapeutic strategy for mitochondrial disease. The mechanisms that regulate mtDNA amount and organization are, however, not fully understood. Of the proteins required for mtDNA existence, only the mitochondrial helicase Twinkle and mitochondrial transcription factor A (TFAM) have been shown to increase mtDNA copy number in vivo, when expressed in physiological levels. Here we studied how Twinkle and TFAM affect mtDNA synthesis and nucleoid structure in mice. Using in vivo BrdU labeling, we show that Twinkle specifically regulates de novo mtDNA synthesis. Remarkably, high mtDNA copy number in mice is accompanied by nucleoid enlargement, which in turn correlates with defective transcription, age-related accumulation of mtDNA deletions and respiratory chain (RC) deficiency. Simultaneous overexpression of Twinkle and TFAM in bitransgenic mice has an additive effect on mtDNA copy number, increasing it up to 6-fold in skeletal muscle. Bitransgenic mice also exhibit further enlargement of nucleoids and aggravation of the RC defect. In conclusion, we show that Twinkle acts as a regulator of mtDNA replication initiation, and provide evidence that high mtDNA copy number and alteration of nucleoid architecture may be detrimental to mitochondrial function.. |
| 185. |
Nishioka T, Onishi K, Shimojo N, Nagano Y, Matsusaka H, Ikeuchi M, Ide T, Tsutsui H, Hiroe M, Yoshida T, Imanaka-Yoshida K , Tenascin-C may aggravate left ventricular remodeling and function after myocardial infarction in mice., Am J Physiology-Heart and Circulatory Physiology. 2, 298, H1072-1078, 2010.05. |
| 186. |
Nishida M, Watanabe K, Sato Y, Nakaya M, Kitajima N, Ide T, Inoue R, Kurose H. , Phosphorylation of TRPC6 channels at Thr69 is required for anti-hypertrophic effects of phosphodiesterase 5 inhibition., J Biol Choem 285:13244-13253 (2010), Am J Physiology-Heart and Circulatory Physiology. 2, 285, 13244-13253, 2010.05. |
| 187. |
Emil Ylikallio, Henna Tyynismaa, Hiroyuki Tsutsui, Tomomi Ide, Anu Suomalainen, High mitochondrial DNA copy number has detrimental effects in mice, Human Molecular Genetics, 10.1093/hmg/ddq163, 19, 13, 2695-2705, 2010.04, Mitochondrial DNA (mtDNA) is an essential multicopy genome, compacted into protein-DNA clusters called nucleoids. Maintaining an adequate mtDNA copy number is crucial for cellular viability. Loss of mtDNA results in severe human syndromes, whereas increased mtDNA copy number has been suggested to improve survival from myocardial infarction in mice and to be a promising therapeutic strategy for mitochondrial disease. The mechanisms that regulate mtDNA amount and organization are, however, not fully understood. Of the proteins required for mtDNA existence, only the mitochondrial helicase Twinkle and mitochondrial transcription factor A (TFAM) have been shown to increase mtDNA copy number in vivo, when expressed in physiological levels. Here we studied how Twinkle and TFAM affect mtDNA synthesis and nucleoid structure in mice. Using in vivo BrdU labeling, we show that Twinkle specifically regulates de novo mtDNA synthesis. Remarkably, high mtDNA copy number in mice is accompanied by nucleoid enlargement, which in turn correlates with defective transcription, age-related accumulation of mtDNA deletions and respiratory chain (RC) deficiency. Simultaneous overexpression of Twinkle and TFAM in bitransgenic mice has an additive effect on mtDNA copy number, increasing it up to 6-fold in skeletal muscle. Bitransgenic mice also exhibit further enlargement of nucleoids and aggravation of the RC defect. In conclusion, we show that Twinkle acts as a regulator of mtDNA replication initiation, and provide evidence that high mtDNA copy number and alteration of nucleoid architecture may be detrimental to mitochondrial function.. |
| 188. |
Motohiro Nishida, Kenta Watanabe, Yoji Sato, Nakaya Michio, Naoyuki Kitajima, Tomomi Ide, Ryuji Inoue, Hitoshi Kurose, Phosphorylation of TRPC6 channels at Thr69 is required for anti-hypertrophic effects of phosphodiesterase 5 inhibition, Journal of Biological Chemistry, 10.1074/jbc.M109.074104, 285, 17, 13244-13253, 2010.04, Activation of Ca2+ signaling induced by receptor stimulation and mechanical stress plays a critical role in the development of cardiac hypertrophy. A canonical transient receptor potential protein subfamily member, TRPC6, which is activated by diacylglycerol and mechanical stretch, works as an upstream regulator of the Ca2+ signaling pathway. Although activation of protein kinase G (PKG) inhibits TRPC6 channel activity and cardiac hypertrophy, respectively, it is unclear whether PKG suppresses cardiac hypertrophy through inhibition of TRPC6. Here, we show that inhibition of cGMP-selective PDE5 (phosphodiesterase 5) suppresses endothelin-1-, diacylglycerol analog-, and mechanical stretch-induced hypertrophy through inhibition of Ca2+ influx in rat neonatal cardiomyocytes. Inhibition of PDE5 suppressed the increase in frequency of Ca2+ spikes induced by agonists or mechanical stretch. However, PDE5 inhibition did not suppress the hypertrophic responses induced by high KCl or the activation of protein kinase C, suggesting that PDE5 inhibition suppresses Ca2+ influx itself or molecule(s) upstream of Ca2+ influx. PKG activated by PDE5 inhibition phosphorylated TRPC6 proteins at Thr69 and prevented TRPC6-mediated Ca2+ influx. Substitution of Ala for Thr69 in TRPC6 abolished the anti-hypertrophic effects of PDE5 inhibition. In addition, chronic PDE5 inhibition by oral sildenafil treatment actually induced TRPC6 phosphorylation in mouse hearts. Knockdown of RGS2 (regulator of G protein signaling 2) and RGS4, both of which are activated by PKG to reduce Gαq-mediated signaling, did not affect the suppression of receptor-activated Ca2+ influx by PDE5 inhibition. These results suggest that phosphorylation and functional suppression of TRPC6 underlie prevention of pathological hypertrophy by PDE5 inhibition.. |
| 189. |
Motohiro Nishida, Kenta Watanabe, Yoji Sato, Michio Nakaya, Naoyuki Kitajima, Tomomi Ide, Ryuji Inoue, Hitoshi Kurose, Phosphorylation of TRPC6 Channels at Thr(69) Is Required for Anti-hypertrophic Effects of Phosphodiesterase 5 Inhibition, JOURNAL OF BIOLOGICAL CHEMISTRY, 10.1074/jbc.M109.074104, 285, 17, 13244-13253, 2010.04, Activation of Ca2+ signaling induced by receptor stimulation and mechanical stress plays a critical role in the development of cardiac hypertrophy. A canonical transient receptor potential protein subfamily member, TRPC6, which is activated by diacylglycerol and mechanical stretch, works as an upstream regulator of the Ca2+ signaling pathway. Although activation of protein kinase G (PKG) inhibits TRPC6 channel activity and cardiac hypertrophy, respectively, it is unclear whether PKG suppresses cardiac hypertrophy through inhibition of TRPC6. Here, we show that inhibition of cGMP-selective PDE5 (phosphodiesterase 5) suppresses endothelin-1-,diacylglycerol analog-, and mechanical stretch-induced hypertrophy through inhibition of Ca2+ influx in rat neonatal cardiomyocytes. Inhibition of PDE5 suppressed the increase in frequency of Ca2+ spikes induced by agonists or mechanical stretch. However, PDE5 inhibition did not suppress the hypertrophic responses induced by high KCl or the activation of protein kinase C, suggesting that PDE5 inhibition suppresses Ca2+ influx itself or molecule(s) upstream of Ca2+ influx. PKG activated by PDE5 inhibition phosphorylated TRPC6 proteins at Thr(69) and prevented TRPC6-mediated Ca2+ influx. Substitution of Ala for Thr(69) in TRPC6 abolished the anti-hypertrophic effects of PDE5 inhibition. In addition, chronic PDE5 inhibition by oral sildenafil treatment actually induced TRPC6 phosphorylation in mouse hearts. Knockdown of RGS2 (regulator of G protein signaling 2) and RGS4, both of which are activated by PKG to reduce G alpha(q)-mediated signaling, did not affect the suppression of receptor-activated Ca2+ influx by PDE5 inhibition. These results suggest that phosphorylation and functional suppression of TRPC6 underlie prevention of pathological hypertrophy by PDE5 inhibition.. |
| 190. |
Tomohiro Nishioka, Katsuya Onishi, Naoshi Shimojo, Yuka Nagano, Hidenori Matsusaka, Masaki Ikeuchi, Tomomi Ide, Hiroyuki Tsutsui, Michiaki Hiroe, Toshimichi Yoshida, Kyoko Imanaka-Yoshida, Tenascin-C may aggravate left ventricular remodeling and function after myocardial infarction in mice, American Journal of Physiology - Heart and Circulatory Physiology, 10.1152/ajpheart.00255.2009, 298, 3, 2010.03, Tenascin-C (TN-C) is an extracellular matrix glycoprotein with high bioactivity. It is expressed at low levels in normal adult heart, but upregulated under pathological conditions, such as myocardial infarction (MI). Recently, we (Ref. 34) reported that MI patients with high serum levels of TN-C have a greater incidence of maladaptive cardiac remodeling and a worse prognosis. We hypothesized that TN-C may aggravate left ventricular remodeling. To examine the effects of TN-C, MI was induced by ligating coronary arteries of TN-C knockout (KO) mice under anesthesia and comparing them with sibling wild-type (WT) mice. In WT+MI mice, TN-C expression was upregulated at day 1, peaked at day 5, downregulated and disappeared by day 28, and the molecule was localized in the border zone between intact myocardium and infarct lesions. The morphometrically determined infarct size and survival rate on day 28 were comparable between the WT+MI and KO+MI groups. Echocardiography and hemodynamic analyses demonstrated left ventricular end-diastolic diameter, myocardial stiffness, and left ventricular end-diastolic pressure to be significantly increased in both WT+MI and KO+MI mice compared with sham-operated mice. However, end-diastolic pressure and dimension and myocardial stiffness of KO+MI were lower than those of the WT+MI mice. Histological examination revealed normal tissue healing, but interstitial fibrosis in the residual myocardium in peri-infarcted areas was significantly less pronounced in KO+MI mice than in WT+MI mice. TN-C may thus accelerate adverse ventricular remodeling, cardiac failure, and fibrosis in the residual myocardium after MI.. |
| 191. |
Tomohiro Nishioka, Katsuya Onishi, Naoshi Shimojo, Yuka Nagano, Hidenori Matsusaka, Masaki Ikeuchi, Tomomi Ide, Hiroyuki Tsutsui, Michiaki Hiroe, Toshimichi Yoshida, Kyoko Imanaka-Yoshida, Tenascin-C may aggravate left ventricular remodeling and function after myocardial infarction in mice, AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, 10.1152/ajpheart.00255.2009, 298, 3, H1072-H1078, 2010.03, Nishioka T, Onishi K, Shimojo N, Nagano Y, Matsusaka H, Ikeuchi M, Ide T, Tsutsui H, Hiroe M, Yoshida T, Imanaka-Yoshida K. Tenascin-C may aggravate left ventricular remodeling and function after myocardial infarction in mice. Am J Physiol Heart Circ Physiol 298: H1072-H1078, 2010. First published January 15, 2010; doi:10.1152/ajpheart.00255.2009.-Tenascin-C (TN-C) is an extracellular matrix glycoprotein with high bioactivity. It is expressed at low levels in normal adult heart, but upregulated under pathological conditions, such as myocardial infarction (MI). Recently, we (Ref. 34) reported that MI patients with high serum levels of TN-C have a greater incidence of maladaptive cardiac remodeling and a worse prognosis. We hypothesized that TN-C may aggravate left ventricular remodeling. To examine the effects of TN-C, MI was induced by ligating coronary arteries of TN-C knockout (KO) mice under anesthesia and comparing them with sibling wild-type (WT) mice. In WT + MI mice, TN-C expression was upregulated at day 1, peaked at day 5, downregulated and disappeared by day 28, and the molecule was localized in the border zone between intact myocardium and infarct lesions. The morphometrically determined infarct size and survival rate on day 28 were comparable between the WT + MI and KO + MI groups. Echocardiography and hemodynamic analyses demonstrated left ventricular end-diastolic diameter, myocardial stiffness, and left ventricular end-diastolic pressure to be significantly increased in both WT + MI and KO + MI mice compared with sham-operated mice. However, end-diastolic pressure and dimension and myocardial stiffness of KO + MI were lower than those of the WT + MI mice. Histological examination revealed normal tissue healing, but interstitial fibrosis in the residual myocardium in peri-infarcted areas was significantly less pronounced in KO + MI mice than in WT + MI mice. TN-C may thus accelerate adverse ventricular remodeling, cardiac failure, and fibrosis in the residual myocardium after MI.. |
| 192. |
Dong Yun Zhan, Sachio Morimoto, Cheng Kun Du, Yuan Yuan Wang, Qun Wei Lu, Atsushi Tanaka, Tomomi Ide, Yoshikazu Miwa, Fumi Takahashi, Toshiyuki Sasaguri, Therapeutic effect of β-adrenoceptor blockers using a mouse model of dilated cardiomyopathy with a troponin mutation, Cardiovascular research, 10.1093/cvr/cvp168, 84, 1, 64-71, 2009.10, AimsExtensive clinical studies have demonstrated that β-adrenoceptor blocking agents (β-blockers) are beneficial in the treatment of chronic heart failure, which is due to various aetiologies, including idiopathic dilated cardiomyopathy (DCM) and ischaemic heart disease. However, little is known about the therapeutic efficacy of β-blockers in the treatment of the inherited form of DCM, of which causative mutations have recently been identified in various genes, including those encoding cardiac sarcomeric proteins. Using a mouse model of inherited DCM with a troponin mutation, we aim to study the treatment benefits of β-blockers.Methods and resultsThree different types of β-blockers, carvedilol, metoprolol, and atenolol, were orally administered to a knock-in mouse model of inherited DCM with a deletion mutation ΔK210 in the cardiac troponin T gene (TNNT2). Therapeutic effects were examined on the basis of survival and myocardial remodelling. The lipophilic β1-selective β-blocker metoprolol was found to prevent cardiac dysfunction and remodelling and extend the survival of knock-in mice. Conversely, both the non-selective β-blocker carvedilol and the hydrophilic β1-selective β-blocker atenolol had no beneficial effects on survival and myocardial remodelling in this mouse model of inherited DCM.ConclusionThe highly lipophilic β1-selective β-blocker metoprolol, known to prevent ventricular fibrillation via central nervous system-mediated vagal activation, may be especially beneficial to DCM patients showing a family history of frequent sudden cardiac death, such as those with a deletion mutation ΔK210 in the TNNT2 gene.. |
| 193. |
Dong-Yun Zhan, Sachio Morimoto, Cheng-Kun Du, Yuan-Yuan Wang, Qun-Wei Lu, Atsushi Tanaka, Tomomi Ide, Yoshikazu Miwa, Fumi Takahashi-Yanaga, Toshiyuki Sasaguri, Therapeutic effect of beta-adrenoceptor blockers using a mouse model of dilated cardiomyopathy with a troponin mutation, CARDIOVASCULAR RESEARCH, 10.1093/cvr/cvp168, 84, 1, 64-71, 2009.10, Extensive clinical studies have demonstrated that beta-adrenoceptor blocking agents (beta-blockers) are beneficial in the treatment of chronic heart failure, which is due to various aetiologies, including idiopathic dilated cardiomyopathy (DCM) and ischaemic heart disease. However, little is known about the therapeutic efficacy of beta-blockers in the treatment of the inherited form of DCM, of which causative mutations have recently been identified in various genes, including those encoding cardiac sarcomeric proteins. Using a mouse model of inherited DCM with a troponin mutation, we aim to study the treatment benefits of beta-blockers.Three different types of beta-blockers, carvedilol, metoprolol, and atenolol, were orally administered to a knock-in mouse model of inherited DCM with a deletion mutation delta K210 in the cardiac troponin T gene (TNNT2). Therapeutic effects were examined on the basis of survival and myocardial remodelling. The lipophilic beta(1)-selective beta-blocker metoprolol was found to prevent cardiac dysfunction and remodelling and extend the survival of knock-in mice. Conversely, both the non-selective beta-blocker carvedilol and the hydrophilic beta(1)-selective beta-blocker atenolol had no beneficial effects on survival and myocardial remodelling in this mouse model of inherited DCM.The highly lipophilic beta(1)-selective beta-blocker metoprolol, known to prevent ventricular fibrillation via central nervous system-mediated vagal activation, may be especially beneficial to DCM patients showing a family history of frequent sudden cardiac death, such as those with a deletion mutation delta K210 in the TNNT2 gene.. |
| 194. |
Sanae Hamaguchi, Miyuki Tsuchihashi-Makaya, Shintaro Kinugawa, Takashi Yokota, Tomomi Ide, Akira Takeshita, Hiroyuki Tsutsui, Chronic kidney disease as an independent risk for long-term adverse outcomes in patients hospitalized with heart failure in Japan - Report from the Japanese Cardiac Registry of Heart Failure in Cardiology (JCARE-CARD), Circulation Journal, 10.1253/circj.CJ-09-0062, 73, 8, 1442-1447, 2009.08, Background: Previous studies have demonstrated that renal dysfunction is common in patients with heart failure (HF), but it is not known whether chronic kidney disease (CKD) is associated with increased risks of long-term adverse outcomes in unselected HF patients encountered in current routine clinical practice in Japan. Methods and Results: The Japanese Cardiac Registry of Heart Failure in Cardiology (JCARE-CARD) prospectively studied a broad sample of patients hospitalized with worsening HF and their outcomes with an average of 2.4 years of follow-up. The study cohort (n=2,013) were classified into 3 groups by estimated glomerular filtration rate (eGFR): ≥60 (n=579), 30-59 (n=1,025), and -1·1.73 m-2 or patients with dialysis (n=409); 1,372 patients (70.3%) had an eGFR -1·1.73 m-2 and 62 patients were treated with dialysis. The multivariable adjusted risk for all-cause death or rehospitalization increased with reduced eGFR; an adjusted hazard ratio (HR) 1.520 (95% confidence interval (CI) 1.186-1.949) for eGFR 30-59 ml·min-1·1.73 m-2 (P=0.001) and HR 2.566 (95%CI 1.885-3.492) for eGFR -1·1.73 m-2 or patients with dialysis (P |
| 195. |
Jaakko L.O. Pohjoismäki, Steffi Goffart, Henna Tyynismaa, Smaranda Willcox, Tomomi Ide, Dongchon Kang, Anu Suomalainen, Pekka J. Karhunen, Jack D. Griffith, Ian J. Holt, Howard T. Jacobs, Human heart mitochondrial DNA is organized in complex catenated networks containing abundant four-way junctions and replication forks, Journal of Biological Chemistry, 10.1074/jbc.M109.016600, 284, 32, 21446-21457, 2009.08, Analysis of human heart mitochondrial DNA (mtDNA) by electron microscopy and agarose gel electrophoresis revealed a complete absence of the θ-type replication intermediates seen abundantly in mtDNA from all other tissues. Instead only Y- and X-junctional forms were detected after restriction digestion. Uncut heart mtDNA was organized in tangled complexes of up to 20 or more genome equivalents, which could be resolved to genomic monomers, dimers, and linear fragments by treatment with the decatenating enzyme topoisomerase IV plus the cruciform-cutting T7 endonuclease I. Human and mouse brain also contained a population of such mtDNA forms, which were absent, however, from mouse, rabbit, or pig heart. Overexpression in transgenic mice of two proteins involved in mtDNA replication, namely human mitochondrial transcription factor A or the mouse Twinkle DNA helicase, generated abundant four-way junctions in mtDNA of heart, brain, and skeletal muscle. The organization of mtDNA of human heart as well as of mouse and human brain in complex junctional networks replicating via a presumed non-θ mechanism is unprecedented in mammals.. |
| 196. |
Sanae Hamaguchi, Miyuki Tsuchihashi-Makaya, Shintaro Kinugawa, Takashi Yokota, Tomomi Ide, Akira Takeshita, Hiroyuki Tsutsui, Chronic Kidney Disease as an Independent Risk for Long-Term Adverse Outcomes in Patients Hospitalized With Heart Failure in Japan - Report From the Japanese Cardiac Registry of Heart Failure in Cardiology (JCARE-CARD) -, CIRCULATION JOURNAL, 10.1253/circj.CJ-09-0062, 73, 8, 1442-1447, 2009.08, Background: Previous studies have demonstrated that renal dysfunction is common in patients with heart failure (HF), but it is not known whether chronic kidney disease (CKD) is associated with increased risks of long-term adverse outcomes in unselected HF patients encountered in current routine clinical practice in Japan. Methods and Results: The Japanese Cardiac Registry of Heart Failure in Cardiology (JCARE-CARD) prospectively studied a broad sample of patients hospitalized with worsening HF and their outcomes with an average of 2.4 years of follow-up. The study cohort (n=2,013) were classified into 3 groups by estimated glomerular filtration rate (eGFR): >= 60 (n=579), 30-59 (n=1,025), and |
| 197. |
Pohjoismäki JL, Goffart S, Tyynismaa H, Willcox S, Ide T, Kang D, Suomalainen A, Karhunen PJ, Griffith JD, Holt IJ, Jacobs HT., Human heart mitochondrial DNA is organized in complex catenated networks containing abundant four-way junctions and replication forks., J Biol Chem. , 284, 32, 21446-21457, 2009.06. |
| 198. |
Inoue T, Ide T, Yamato M, Yoshida M, Tsutsumi T, Andou M, Utsumi H, Tsutsui H, Sunagawa K. , Time-dependent changes of myocardial and systemic oxidative stress are dissociated after myocardial infarction. Free Radical Res 43: 37-46 (2009), Free Radical Res., 43, 37-46, 2009.05. |
| 199. |
Takahiro Inoue, Tomomi Ide, Mayumi Yamato, Masayoshi Yoshida, Takaki Tsutsumi, Makoto Andou, Hideo Utsumi, Hiroyuki Tsutsui, Kenji Sunagawa, Time-dependent changes of myocardial and systemic oxidative stress are dissociated after myocardial infarction, Free Radical Research, 10.1080/10715760802534820, 43, 1, 37-46, 2009.04, Reactive oxygen species (ROS) is increased in myocardium after myocardial infarction (MI), which may play a causal role in cardiac remodelling. However, there is scant direct and longitudinal evidence that systemic oxidative stress is enhanced accompanying an increase of ROS in myocardium. The authors conducted a comprehensive investigation of ROS markers by simultaneously sampling urine, blood and myocardium and in vivo ESR for the heart at different stages of post-MI cardiac remodelling in mouse with permanent occlusion of left coronary artery. Systemic oxidative markers increased at early days after MI and were normalized later. In contrast, TBARS and 4-hexanoyl-Lys staining were increased in non-infarct myocardium at day 28. The enhancement of ESR signal decay of methoxycarbonyl-PROXYL measured at the chest was associated with the progression of left ventricle dilatation and dysfunction. This study provided the direct evidence that redox alteration and production of ROS occurred in myocardium during the progression of cardiac remodelling and failure; however, ROS marker levels in blood and urine do not reflect the production of ROS from failing myocardium.. |
| 200. |
Inoue T, Ide T, Yamato M, Yoshida M, Tsutsumi T, Andou M, Utsumi H, Tsutsui H, Sunagawa K, Time-dependent changes of myocardial and systemic oxidative stress are dissociated after myocardial infarction, Free radical research, 2009.01. |
| 201. |
Motohiro Nishida, Yoji Sato, Aya Uemura, Yusuke Narita, Hidetoshi Saitoh, Nakaya Michio, Tomomi Ide, Kazuhiro Suzuki, Kazuhide Inoue, Taku Nagao, Hitoshi Kurose, P2Y6 receptor-Gα12/13 signalling in cardiomyocytes triggers pressure overload-induced cardiac fibrosis, EMBO Journal, 10.1038/emboj.2008.237, 27, 23, 3104-3115, 2008.12, Cardiac fibrosis, characterized by excessive deposition of extracellular matrix proteins, is one of the causes of heart failure, and it contributes to the impairment of cardiac function. Fibrosis of various tissues, including the heart, is believed to be regulated by the signalling pathway of angiotensin II (Ang II) and transforming growth factor (TGF)-β. Transgenic expression of inhibitory polypeptides of the heterotrimeric G12 family G protein (Gα12/13) in cardiomyocytes suppressed pressure overload-induced fibrosis without affecting hypertrophy. The expression of fibrogenic genes (TGF-β, connective tissue growth factor, and periostin) and Ang-converting enzyme (ACE) was suppressed by the functional inhibition of Gα12/13. The expression of these fibrogenic genes through Gα12/13 by mechanical stretch was initiated by ATP and UDP released from cardiac myocytes through pannexin hemichannels. Inhibition of G-protein-coupled P2Y6 receptors suppressed the expression of ACE, fibrogenic genes, and cardiac fibrosis. These results indicate that activation of Gα12/13 in cardiomyocytes by the extracellular nucleotides-stimulated P2Y6 receptor triggers fibrosis in pressure overload-induced cardiac fibrosis, which works as an upstream mediator of the signalling pathway between Ang II and TGF-β.. |
| 202. |
Motohiro Nishida, Yoji Sato, Aya Uemura, Yusuke Narita, Hidetoshi Tozaki-Saitoh, Michio Nakaya, Tomomi Ide, Kazuhiro Suzuki, Kazuhide Inoue, Taku Nagao, Hitoshi Kurose, P2Y(6) receptor-G alpha(12/13) signalling in cardiomyocytes triggers pressure overload-induced cardiac fibrosis, EMBO JOURNAL, 10.1038/emboj.2008.237, 27, 23, 3104-3115, 2008.12, Cardiac fibrosis, characterized by excessive deposition of extracellular matrix proteins, is one of the causes of heart failure, and it contributes to the impairment of cardiac function. Fibrosis of various tissues, including the heart, is believed to be regulated by the signalling pathway of angiotensin II (Ang II) and transforming growth factor (TGF)-beta. Transgenic expression of inhibitory polypeptides of the heterotrimeric G12 family G protein (G alpha(12/13)) in cardiomyocytes suppressed pressure overload-induced fibrosis without affecting hypertrophy. The expression of fibrogenic genes (TGF-beta, connective tissue growth factor, and periostin) and Ang-converting enzyme (ACE) was suppressed by the functional inhibition of G alpha(12/13). The expression of these fibrogenic genes through G alpha(12/13) by mechanical stretch was initiated by ATP and UDP released from cardiac myocytes through pannexin hemichannels. Inhibition of G-protein-coupled P2Y6 receptors suppressed the expression of ACE, fibrogenic genes, and cardiac fibrosis. These results indicate that activation of G alpha(12/13) in cardiomyocytes by the extracellular nucleotides-stimulated P2Y(6) receptor triggers fibrosis in pressure overload-induced cardiac fibrosis, which works as an upstream mediator of the signalling pathway between Ang II and TGF-beta.. |
| 203. |
Nozoe M, Hirooka Y, Koga Y, Araki S, Konno S, Kishi T, Ide T, Sunagawa K, Mitochondria-derived reactive oxygen species mediate sympathoexcitation induced by angiotensin II in the rostral ventrolateral medulla., Journal of Hypertension, 26; 2176-84, 2008.11. |
| 204. |
Masatsugu Nozoe, Yoshitaka Hirooka, Yasuaki Koga, Shuichiro Araki, Satomi Konno, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Mitochondria-derived reactive oxygen species mediate sympathoexcitation induced by angiotensin II in the rostral ventrolateral medulla, Journal of hypertension, 10.1097/HJH.0b013e32830dd5d3, 26, 11, 2176-2184, 2008.11, OBJECTIVES: Reactive oxygen species (ROS) in the central nervous system are thought to contribute to sympathoexcitation in cardiovascular diseases such as hypertension and heart failure. Nicotinamide adenine dinucleotide phosphate oxidase is a major source of ROS in the central nervous system, which acts as a key mediator (mediators) of angiotensin II (AngII). It is not clear, however, whether mitochondria-derived ROS in the central nervous system also participate in sympathoexcitation. METHODS: In an in-vivo study, we investigated whether the AngII-elicited pressor response in the rostral ventrolateral medulla, which controls sympathetic nerve activity, is attenuated by adenovirus-mediated gene transfer of a mitochondria-derived antioxidant (Mn-SOD). In an in-vitro study, using differentiated PC-12 cells with characteristics similar to those of sympathetic neurons, we examined whether AngII increases mitochondrial ROS production. RESULTS: Overexpression of Mn-SOD attenuated the AngII-induced pressor response and also suppressed AngII-induced ROS production, as evaluated by microdialysis in the rostral ventrolateral medulla. Using reduced MitoTracker red, we showed that AngII increased mitochondrial ROS production in differentiated PC-12 cells in vitro. Overexpression of Mn-SOD and rotenone, a mitochondrial respiratory complex I inhibitor, suppressed AngII-induced ROS production. Depletion of extracellular Ca with ethylene glycol bis-N,N,N′,N′-tetraacetate (EGTA) and administration of p-trifluoromethoxycarbonylcyanide phenylhydrazone, which prevents further Ca uptake into the mitochondria, blocked AngII-elicited mitochondrial ROS production. CONCLUSION: These results indicate that AngII increases the intracellular Ca concentration and that the increase in mitochondrial Ca uptake leads to mitochondrial ROS production.. |
| 205. |
Masatsugu Nozoe, Yoshitaka Hirooka, Yasuaki Koga, Shuichiro Araki, Satomi Konno, Takuya Kishi, Tomomi Ide, Kenji Sunagawa, Mitochondria-derived reactive oxygen species mediate sympathoexcitation induced by angiotensin II in the rostral ventrolateral medulla, JOURNAL OF HYPERTENSION, 10.1097/HJH.0b013e32830dd5d3, 26, 11, 2176-2184, 2008.11, Objectives Reactive oxygen species (ROS) in the central nervous system are thought to contribute to sympathoexcitation in cardiovascular diseases such as hypertension and heart failure. Nicotinamide adenine dinucleotide phosphate oxidase is a major source of ROS in the central nervous system, which acts as a key mediator (mediators) of angiotensin II (AngII). It is not clear, however, whether mitochondria- derived ROS in the central nervous system also participate in sympathoexcitation.Methods In an in-vivo study, we investigated whether the AngII-elicited pressor response in the rostral ventrolateral medulla, which controls sympathetic nerve activity, is attenuated by adenovirus-mediated gene transfer of a mitochondria- derived antioxidant (Mn-SOD). In an in-vitro study, using differentiated PC-12 cells with characteristics similar to those of sympathetic neurons, we examined whether AngII increases mitochondrial ROS production.Results Overexpression of Mn-SOD attenuated the AngII-induced pressor response and also suppressed AngII-induced ROS production, as evaluated by microdialysis in the rostral ventrolateral medulla. Using reduced MitoTracker red, we showed that AngII increased mitochondrial ROS production in differentiated PC-12 cells in vitro. Overexpression of Mn-SOD and rotenone, a mitochondrial respiratory complex I inhibitor, suppressed AngII-induced ROS production. Depletion of extracellular Ca2+ with ethylene glycol bis-N, N, N', N'-tetraacetate (EGTA) and administration of p-trifluoromethoxycarbonylcyanide phenylhydrazone, which prevents further Ca2+ uptake into the mitochondria, blocked AngII-elicited mitochondrial ROS production.Conclusion These results indicate that AngII increases the intracellular Ca2+ concentration and that the increase in mitochondrial Ca2+ uptake leads to mitochondrial ROS production. J Hypertens 26: 2176-2184 (c) 2008 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.. |
| 206. |
Takaki Tsutsumi, Tomomi Ide, Mayumi Yamato, Makoto Andou, Takeshi Shiba, Hideo Utsumi, Kenji Sunagawa, Effect of anaesthesia-induced alterations in haemodynamics on in vivo kinetics of nitroxyl probes in electron spin resonance spectroscopy, Free Radical Research, 10.1080/10715760801986542, 42, 4, 305-311, 2008.09, Although the advent of in vivo electron spin resonance (ESR) spectroscopy has allowed analysis of the redox status of living animals, whether the haemodynamic condition affects the signal decay rate remains unknown. Three kinds of haemodynamic conditions were generated by changing the anaesthetic dosage in mice. Haemodynamics was analysed (n = 6 each) and in vivo ESR was performed to measure the signal decay rates of three nitroxyl spin probes (carbamoyl-, carboxy- and methoxycarbonyl-PROXYL) at the chest and head regions (n = 6 for each condition and probe). Haemodynamic analysis revealed negative inotropic and chronotropic effects on the cardiovascular system depending on the depth of anaesthesia. Although signal decay rates differed among three probes, they were not affected by heart rate alteration. In this study we report the haemodynamics-independent signal decay rate of nitoxyl probes.. |
| 207. |
Hayashi Y, Yoshida M, Yamato M, Ide T, Wu Z, Ochi-Shindou M, Kanki T, Kang D, Sunagawa K, Tsutsui H, Nakanishi H, Reverse of age-dependent memory impairment and mitochondrial DNA damage in microglia by an overexpression of human mitochondrial transcription factor a in mice, Journal of Neuroscience, 28: 8624-34, 2008.08. |
| 208. |
Yoshinori Hayashi, Masayoshi Yoshida, Mayumi Yamato, Tomomi Ide, Hiro Take, Mayumi Ochi-Shindou, Tomotake Kanki, Dongchon Kang, Kenji Sunagawa, Hiroyuki Tsutsui, Hiroshi Nakanishi, Reverse of age-dependent memory impairment and mitochondrial DNA damage in microglia by an overexpression of human mitochondrial transcription factor A in mice, Journal of Neuroscience, 10.1523/JNEUROSCI.1957-08.2008, 28, 34, 8624-8634, 2008.08, Mitochondrial DNA (mtDNA) is highly susceptible to injury induced by reactive oxygen species (ROS). During aging, mutations of mtDNA accumulate to induce dysfunction of the respiratory chain, resulting in the enhanced ROS production. Therefore, age-dependent memory impairment may result from oxidative stress derived from the respiratory chain. Mitochondrial transcription factor A (TFAM) is now known to have roles not only in the replication of mtDNA but also its maintenance. We herein report that an overexpression of TFAM in HeLa cells significantly inhibited rotenone-induced mitochondrial ROS generation and the subsequent NF-κB (nuclear factor-κB) nuclear translocation. Furthermore, TFAM transgenic (TG) mice exhibited a prominent amelioration of an age-dependent accumulation of lipid peroxidation products and a decline in the activities of complexes I and IV in the brain. In the aged TG mice, deficits of the motor learning memory, the working memory, and the hippocampal long-term potentiation (LTP) were also significantly improved. The expression level of interleukin-1β (IL-1β) and mtDNA damages, which were predominantly found in microglia, significantly decreased in the aged TG mice. The IL-1β amount markedly increased in the brain of the TG mice after treatment with lipopolysaccharide (LPS), whereas its mean amount was significantly lower than that of the LPS-treated aged wild-type mice. At the same time, an increased mtDNA damage in microglia and an impaired hippocampal LTP were also observed in the LPS-treated aged TG mice. Together, an overexpression of TFAM is therefore considered to ameliorate age-dependent impairment of the brain functions through the prevention of oxidative stress and mitochondrial dysfunctions in microglia.. |
| 209. |
Yoshinori Hayashi, Masayoshi Yoshida, Mayumi Yamato, Tomomi Ide, Zhou Wu, Mayumi Ochi-Shindou, Tomotake Kanki, Dongchon Kang, Kenji Sunagawa, Hiroyuki Tsutsui, Hiroshi Nakanishi, Reverse of age-dependent memory impairment and mitochondrial DNA damage in microglia by an overexpression of human mitochondrial transcription factor A in mice, JOURNAL OF NEUROSCIENCE, 10.1523/JNEUROSCI.1957-08.2008, 28, 34, 8624-8634, 2008.08, Mitochondrial DNA (mtDNA) is highly susceptible to injury induced by reactive oxygen species (ROS). During aging, mutations of mtDNA accumulate to induce dysfunction of the respiratory chain, resulting in the enhanced ROS production. Therefore, age-dependent memory impairment may result from oxidative stress derived from the respiratory chain. Mitochondrial transcription factor A (TFAM) is now known to have roles not only in the replication of mtDNA but also its maintenance. We herein report that an overexpression of TFAM in HeLa cells significantly inhibited rotenone-induced mitochondrial ROS generation and the subsequent NF-kappa B (nuclear factor-kappa B) nuclear translocation. Furthermore, TFAM transgenic (TG) mice exhibited a prominent amelioration of an age-dependent accumulation of lipid peroxidation products and a decline in the activities of complexes I and IV in the brain. In the aged TG mice, deficits of the motor learning memory, the working memory, and the hippocampal long-term potentiation (LTP) were also significantly improved. The expression level of interleukin-1 beta(IL-1 beta) and mtDNA damages, which were predominantly found in microglia, significantly decreased in the aged TG mice. The IL-1 beta amount markedly increased in the brain of the TG mice after treatment with lipopolysaccharide (LPS), whereas its mean amount was significantly lower than that of the LPS-treated aged wild-type mice. At the same time, an increased mtDNA damage in microglia and an impaired hippocampal LTP were also observed in the LPS-treated aged TG mice. Together, an overexpression of TFAM is therefore considered to ameliorate age-dependent impairment of the brain functions through the prevention of oxidative stress and mitochondrial dysfunctions in microglia.. |
| 210. |
Fatty acids increase the circulating levels of oxidative stress factors in mice with diet-induced obesity via redox changes of albumin. |
| 211. |
Tsutsumi T., Ide T., Yamato M., Andou M., Shiba T., Utsumi H., Sunagawa K, Effect of anaesthesia-induced alterations in haemodynamics on in vivo kinetics of nitroxyl probes in electron spin resonance spectroscopy., Free Radic Res., 305-311, 2008.04. |
| 212. |
Tsutsumi T, Ide T, Yamato M, Kudou W, Andou M, Hirooka Y, Utsumi H, Tsutsui H, Sunagawa K, Modulation of the myocardial redox state by vagal nerve stimulation after experimental myocardial infarction., Cardiovasc Res., 713-721, 2008.03. |
| 213. |
Takaki Tsutsumi, Tomomi Ide, Mayumi Yamato, Wataru Kudou, Makoto Andou, Yoshitaka Hirooka, Hideo Utsumi, Hiroyuki Tsutsui, Kenji Sunagawa, Modulation of the myocardial redox state by vagal nerve stimulation after experimental myocardial infarction, Cardiovascular research, 10.1093/cvr/cvm092, 77, 4, 713-721, 2008.03, Aims: Redox alteration plays a major role in the pathogenesis of heart failure (HF). Since vagal nerve stimulation (VNS) is known to improve survival and attenuate cardiac remodelling, we hypothesized that VNS may modulate the myocardial redox state. Methods and results: Using a chronic HF mouse model, we applied VNS for 15 min and measured myocardial redox status using in vivo electron spin resonance spectroscopy. Signal decay rate of the nitroxyl probe, an index of redox status, was enhanced in HF compared with sham (0.16 ± 0.01 vs. 0.13 ± 0.01 min-1, P -1, P ω-Nitro-L- arginine methyl ester treatment and fixed-rate atrial pacing showed a trend to suppress the VNS effects, suggesting the involvement of nitric oxide-based signalling and myocardial oxygen consumption. Moreover, VNS decreased the myocardial norepinephrine (NE) level (0.25 ± 0.07 vs. 0.60 ± 0.12 ng/mL, P |
| 214. |
Takaki Tsutsumi, Tomomi Ide, Mayumi Yamato, Wataru Kudou, Makoto Andou, Yoshitaka Hirooka, Hideo Utsumi, Hiroyuki Tsutsui, Kenji Sunagawa, Modulation of the myocardial redox state by vagal nerve stimulation after experimental myocardial infarction, CARDIOVASCULAR RESEARCH, 10.1093/cvr/cvm092, 77, 4, 713-721, 2008.03, Aims Redox alteration plays a major role in the pathogenesis of heart failure (HF). Since vagal nerve stimulation (VNS) is known to improve survival and attenuate cardiac remodelling, we hypothesized that VNS may modulate the myocardial redox state.Methods and results Using a chronic HF mouse model, we applied VNS for 15 min and measured myocardial redox status using in vivo electron spin resonance spectroscopy. Signal decay rate of the nitroxyl probe, an index of redox status, was enhanced in HF compared with sham (0.16 +/- 0.01 vs. 0.13 +/- 0.01 min(-1), P |
| 215. |
Mayumi Yamato, Takeshi Shiba, Masayoshi Yoshida, Tomomi Ide, Naoko Seri, Wataru Kudou, Shintaro Kinugawa, Hiroyuki Tsutsui, Fatty acids increase the circulating levels of oxidative stress factors in mice with diet-induced obesity via redox changes of albumin, FEBS Journal, 10.1111/j.1742-4658.2007.05914.x, 274, 15, 3855-3863, 2007.08, Plasma concentrations of free fatty acids are increased in metabolic syndrome, and the increased fatty acids may cause cellular damage via the induction of oxidative stress. The present study was designed to determine whether the increase in fatty acids can modify the free sulfhydryl group in position 34 of albumin (Cys34) and enhance the redox-cycling activity of the copper-albumin complex in high-fat diet-induced obese mice. The mice were fed with commercial normal diet or high-fat diet and water ad libitum for 3 months. The high-fat diet-fed mice developed obesity, hyperlipemia, and hyperglycemia. The plasma fatty acid/albumin ratio also significantly increased in high-fat diet-fed mice. The increased fatty acid/albumin ratio was associated with conformational changes in albumin and the oxidation of sulfhydryl groups. Moreover, an ascorbic acid radical, an index of redox-cycling activity of the copper-albumin complex, was detected only in the plasma from obese mice, whereas the plasma concentrations of ascorbic acid were not altered. Plasma thiobarbituric acid reactive substances were significantly increased in the high-fat diet group. These results indicate that the increased plasma fatty acids in the high-fat diet group resulted in the activated redox cycling of the copper-albumin complex and excessive lipid peroxidation.. |
| 216. |
Mayumi Yamato, Takeshi Shiba, Masayoshi Yoshida, Tomomi Ide, Naoko Seri, Wataru Kudou, Shintaro Kinugawa, Hiroyuki Tsutsui, Fatty acids increase the circulating levels of oxidative stress factors in mice with diet-induced obesity via redox changes of albumin, FEBS JOURNAL, 10.1111/j.1742-4658.2007.05914.x, 274, 15, 3855-3863, 2007.08, Plasma concentrations of free fatty acids are increased in metabolic syndrome, and the increased fatty acids may cause cellular damage via the induction of oxidative stress. The present study was designed to determine whether the increase in fatty acids can modify the free sulfhydryl group in position 34 of albumin (Cys34) and enhance the redox-cycling activity of the copper-albumin complex in high-fat diet-induced obese mice. The mice were fed with commercial normal diet or high-fat diet. and water ad libitum for 3 months. The high-fat diet-fed mice developed obesity, hyperlipemia, and hyperglycemia. The plasma fatty acid/albumin ratio also significantly increased in high-fat diet-fed mice. The increased fatty acid/albumin ratio was associated with conformational changes in albumin and the oxidation of sulfhydryl groups. Moreover, an ascorbic acid radical, an index of redox-cycling activity of the copper-albumin complex, was detected only in the plasma from obese mice, whereas the plasma concentrations of ascorbic acid were not altered. Plasma thiobarbituric acid reactive substances were significantly increased in the high-fat diet group. These results indicate that the increased plasma fatty acids in the high-fat diet group resulted in the activated redox cycling of the copper albumin complex and excessive lipid peroxidation.. |
| 217. |
Yoshiya Monden, Toru Kubota, Takahiro Inoue, Takaki Tsutsumi, Shunichi Kawano, Tomomi Ide, Hiroyuki Tsutsui, Kenji Sunagawa, Tumor necrosis factor-α is toxic via receptor 1 and protective via receptor 2 in a murine model of myocardial infarction, American Journal of Physiology - Heart and Circulatory Physiology, 10.1152/ajpheart.00166.2007, 293, 1, 2007.07, Tumor necrosis factor (TNF)-α induced in damaged myocardium has been considered to be cardiotoxic. TNF-α initiates its biological effects by binding two distinct receptors: R1 (p55) and R2 (p75). Although TNF-α has been shown to be cardiotoxic via R1-mediated pathways, little is known about the roles of R2-mediated pathways in myocardial infarction (MI). We created MI in R1 knockout (R1KO), R2KO, and wild-type (WT) mice by ligating the left coronary artery. Functional, histological, and biochemical analyses were performed 4 wk after ligation. Although infarct size was not different among WT, R1KO, and R2KO mice, post-MI survival was significantly improved in R1KO but not R2KO mice. R1KO significantly ameliorated contractile dysfunction after MI, whereas R2KO significantly exaggerated ventricular dilatation and dysfunction. Myocyte hypertrophy and interstitial fibrosis in noninfarct myocardium was exacerbated in R2KO but not in R1KO mice. Expression of R1, which was not affected by MI and was nullified in R1KO mice, was significantly upregulated in R2KO mice. In contrast, expression of R2, which was significantly upregulated by MI and was nullified in R2KO mice, was unaffected in R1KO mice. Meanwhile, TNF-α expression, which was significantly upregulated in noninfarct myocardium after MI, was not affected by R1KO or R2KO. However, transcript levels of IL-6, IL-1β, transforming growth factor-β, and monocyte chemotactic protein-1, which were significantly upregulated after MI, were significantly downregulated in R1KO mice. In contrast, transcript levels of IL-6 and IL-1β were significantly further upregulated in R2KO mice. TNF-α is toxic via R1 and protective via R2 in a murine model of MI. Selective blockade of R1 may be a candidate therapeutic intervention for MI.. |
| 218. |
Yoshiya Monden, Toru Kubota, Takahiro Inoue, Takaki Tsutsumi, Shunichi Kawano, Tomomi Ide, Hiroyuki Tsutsui, Kenji Sunagawa, Tumor necrosis factor-alpha is toxic via receptor 1 and protective via receptor 2 in a murine model of myocardial infarction, AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, 10.1152/ajpheart.00166.2007, 293, 1, H743-H753, 2007.07, Tumor necrosis factor (TNF)-alpha induced in damaged myocardium has been considered to be cardiotoxic. TNF-alpha initiates its biological effects by binding two distinct receptors: R1 (p55) and R2 (p75). Although TNF-alpha has been shown to be cardiotoxic via R1-mediated pathways, little is known about the roles of R2-mediated pathways in myocardial infarction (MI). We created MI in R1 knockout (R1KO), R2KO, and wild-type (WT) mice by ligating the left coronary artery. Functional, histological, and biochemical analyses were performed 4 wk after ligation. Although infarct size was not different among WT, R1KO, and R2KO mice, post-MI survival was significantly improved in R1KO but not R2KO mice. R1KO significantly ameliorated contractile dysfunction after MI, whereas R2KO significantly exaggerated ventricular dilatation and dysfunction. Myocyte hypertrophy and interstitial fibrosis in noninfarct myocardium was exacerbated in R2KO but not in R1KO mice. Expression of R1, which was not affected by MI and was nullified in R1KO mice, was significantly upregulated in R2KO mice. In contrast, expression of R2, which was significantly upregulated by MI and was nullified in R2KO mice, was unaffected in R1KO mice. Meanwhile, TNF-alpha expression, which was significantly upregulated in noninfarct myocardium after MI, was not affected by R1KO or R2KO. However, transcript levels of IL-6, IL-1 beta, transforming growth factor-beta, and monocyte chemotactic protein-1, which were significantly upregulated after MI, were significantly downregulated in R1KO mice. In contrast, transcript levels of IL-6 and IL-1 beta were significantly further upregulated in R2KO mice. TNF-alpha is toxic via R1 and protective via R2 in a murine model of MI. Selective blockade of R1 may be a candidate therapeutic intervention for MI.. |
| 219. |
Tsutsui H, Matsushima S, Kinugawa S, Ide T, Inoue N, Ohta Y, Yokota T Hamaguchi S, Sunagawa K, Angiotensin II type 1 receptor blocker attenuates myocardial remodeling and preserves diastolic function in diabetic heart., Hypertension Res, 439-449, 2007.05. |
| 220. |
Tsutsui H, Matsushima S, Kinugawa S, Ide T, Inoue N, Ohta Y, Yokota T, Hamaguchi S, Sunagawa K., Angiotensin II type 1 receptor blocker attenuates myocardial remodeling and preserves diastolic function in diabetic heart., 30(5):439-49., 2007.05. |
| 221. |
Hiroyuki Tsutsui, Shoji Matsushima, Shintaro Kinugawa, Tomomi Ide, Naoki Inoue, Yukihiro Ohta, Takashi Yokota, Sanae Hamaguchi, Kenji Sunagawa, Angiotensin II type 1 receptor blocker attenuates myocardial remodelling and preserves diastolic function in diabetic heart, Hypertension Research, 10.1291/hypres.30.439, 30, 5, 439-449, 2007.05, Blockade of the renin-angiotensin system reduces cardiovascular morbidity and mortality in diabetic patients. Angiotensin II (Ang II) plays an important role in the structural and functional abnormalities of the diabetic heart. We investigated whether or not Ang II type 1 receptor blocker (ARB) could attenuate left ventricular (LV) remodeling in male mice with diabetes mellitus (DM) induced by the injection of streptozotocin (200 mg/kg, i.p.). Diabetic mice were treated with candesartan (1 mg/kg/day; DM+Candesartan, n=7) or vehicle (DM+Vehicle, n=7) for 8 weeks. Heart rate and aortic blood pressure were comparable between the groups. Normal systolic function was preserved in diabetic mice. In contrast diastolic function was impaired in DM+Vehicle and was improved in DM+Candesartan, as assessed by the deceleration time of the peak velocity of transmitral diastolic flow (40.3±0.3 vs. 37.3±0.5 ms, p |
| 222. |
Hiroyuki Tsutsui, Shouji Matsushima, Shintaro Kinugawa, Tomomi Ide, Naoki Inoue, Yukihiro Ohta, Takashi Yokota, Sanae Hamaguchi, Kenji Sunagawa, Angiotensin II type 1 receptor blocker attenuates myocardial remodeling and preserves diastolic function in diabetic heart, HYPERTENSION RESEARCH, 10.1291/hypres.30.439, 30, 5, 439-449, 2007.05, Blockade of the renin-angiotensin system reduces cardiovascular morbidity and mortality in diabetic patients. Angiotensin II (Ang II) plays an important role in the structural and functional abnormalities of the diabetic heart. We investigated whether or not Ang II type 1 receptor blocker (ARB) could attenuate left ventricular (LV) remodeling in male mice with diabetes mellitus (DM) induced by the injection of streptozotocin (200 mg/kg, i.p.). Diabetic mice were treated with candesartan (1 mg/kg/day; DM+Candesartan, n=7) or vehicle (DM+Vehicle, n=7) for 8 weeks. Heart rate and aortic blood pressure were comparable between the groups. Normal systolic function was preserved in diabetic mice. In contrast, diastolic function was impaired in DM+Vehicle and was improved in DM+Candesartan, as assessed by the deceleration time of the peak velocity of transmitral diastolic flow (40.3 +/- 0.3 vs. 37.3 +/- 0.5 ms, p |
| 223. |
Yoshiya Monden, Toru Kubota, Takaki Tsutsumi, Takahiro Inoue, Shunichi Kawano, Natsumi Kawamura, Tomomi Ide, Kensuke Egashira, Hiroyuki Tsutsui, Kenji Sunagawa, Soluble TNF receptors prevent apoptosis in infiltrating cells and promote ventricular rupture and remodeling after myocardial infarction, Cardiovascular research, 10.1016/j.cardiores.2006.12.016, 73, 4, 794-805, 2007.03, Objective: Tumor necrosis factor (TNF)-α induced in damaged myocardium has been considered to be cardiotoxic. However, the negative results of RENEWAL and ATTACH prompt us to reconsider the role of TNF-α in cardiovascular diseases. The present study aimed to evaluate the effects of soluble TNF receptor treatment on myocardial infarction (MI). Methods: An adenovirus encoding a 55-kDa TNF receptor-IgG fusion protein (AdTNFR1) was used to neutralize TNF-α, and an adenovirus encoding LacZ (AdLacZ) served as control. In the pre-MI treatment protocol, mice were given an intravenous injection of AdTNFR1 or AdLacZ 1 week before left coronary artery ligation to induce MI. In the post-MI treatment protocol, mice were treated with AdTNFR1 or AdLacZ 1 week after left coronary ligation. Results: Treatment with AdTNFR1 neutralized bioactivity of TNF-α that was activated after MI and prevented apoptosis of infiltrating cells in infarct myocardium. However, pre-MI treatment with AdTNFR1 promoted ventricular rupture by reducing fibrosis with further activation of matrix metalloproteinase (MMP)-9. Post-MI treatment with AdTNFR1 exacerbated ventricular dysfunction and remodeling, with enhanced fibrosis of non-infarct myocardium with further MMP-2 activation. Conclusions: Both pre- and post-MI treatments with AdTNFR1 were deleterious in a mouse MI model. Thus, TNF-α may play not only toxic but also protective roles in MI.. |
| 224. |
Yoshiya Monden, Toru Kubota, Takaki Tsutsumi, Takahiro Inoue, Shunichi Kawano, Natsumi Kawamura, Tomomi Ide, Kensuke Egashira, Hiroyuki Tsutsui, Kenji Sunagawa, Soluble TNF receptors prevent apoptosis in infiltrating cells and promote ventricular rupture and remodeling after myocardial infarction, CARDIOVASCULAR RESEARCH, 10.1016/j.cardiores.2006.12.016, 73, 4, 794-805, 2007.03, Objective: Tumor necrosis factor (TNF)-alpha induced in damaged myocardium has been considered to be cardiotoxic. However, the negative results of RENEWAL and ATTACH prompt us to reconsider the role of TNF-alpha in cardiovascular diseases. The present study aimed to evaluate the effects of soluble TNF receptor treatment on myocardial infarction (MI).Methods: An adenovirus encoding a 55-kDa TNF receptor-IgG fusion protein (AdTNFR1) was used to neutralize TNF-alpha, and an adenovirus encoding LacZ (AdLacZ) served as control. In the pre-MI treatment protocol, mice were given an intravenous injection of AdTNFR1 or AdLacZ 1 week before left coronary artery ligation to induce MI. In the post-MI treatment protocol, mice were treated with AdTNFR1 or AdLacZ I week after left coronary ligation.Results: Treatment with AdTNFR1 neutralized bioactivity of TNF-alpha that was activated after MI and prevented apoptosis of infiltrating cells in infarct myocardium. However, pre-MI treatment with AdTNFR1 promoted ventricular rupture by reducing fibrosis with further activation of matrix metalloproteinase (MMP)-9. Post-MI treatment with AdTNFR1 exacerbated ventricular dysfunction and remodeling, with enhanced fibrosis of non-infarct myocardium with further MMP-2 activation.Conclusions: Both pre- and post-MI treatments with AdTNFR1 were deleterious in a mouse MI model. Thus, TNF-alpha may play not only toxic but also protective roles in MI. (c) 2006 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.. |
| 225. |
Tomomi Ide, Kenji Sunagawa, Diuretics--character, mechanisms, indications, side effects, Nippon rinsho. Japanese journal of clinical medicine, 65 Suppl 5, 34-38, 2007.01. |
| 226. |
Tomomi Ide, Kenji Sunagawa, ROS and disorder of mitochondrial DNA, Nippon rinsho. Japanese journal of clinical medicine, 65 Suppl 4, 238-242, 2007.01. |
| 227. |
Overexpression of glutathione peroxidase attenuates myocardial remodeling and preserves diastolic function in diabetic heart.. |
| 228. |
Shoji Matsushima, Shintaro Kinugawa, Tomomi Ide, Hidenori Matsusaka, Naoki Inoue, Yukihiro Ohta, Takashi Yokota, Kenji Sunagawa, Hiroyuki Tsutsui, Overexpression of glutathione peroxidase attenuates myocardial remodeling and preserves diastolic function in diabetic heart, American Journal of Physiology - Heart and Circulatory Physiology, 10.1152/ajpheart.00427.2006, 291, 5, 2006.11, Oxidative stress plays an important role in the structural and functional abnormalities of diabetic heart. Glutathione peroxidase (GSHPx) is a critical antioxidant enzyme that removes H2O2 in both the cytosol and mitochondia. We hypothesized that the overexpression of GSHPx gene could attenuate left ventricular (LV) remodeling in diabetes mellitus (DM). We induced DM by injection of streptozotocin (160 mg/kg ip) in male GSHPx transgenic mice (TG+DM) and nontransgenic wildtype littermates (WT+DM). GSHPx activity was higher in the hearts of TG mice compared with WT mice, with no significant changes in other antioxidant enzymes. LV thiobarbituric acid-reactive substances measured in TG+DM at 8 wk were significantly lower than those in WT+DM (58 ± 3 vs. 71 ± 5 nmol/g, P |
| 229. |
Shouji Matsushima, Shintaro Kinugawa, Tomomi Ide, Hidenori Matsusaka, Naoki Inoue, Yukihiro Ohta, Takashi Yokota, Kenji Sunagawa, Hiroyuki Tsutsui, Overexpression of glutathione peroxidase attenuates myocardial remodeling and preserves diastolic function in diabetic heart, AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, 10.1152/ajpheart.00427.2006, 291, 5, H2237-H2245, 2006.11, Oxidative stress plays an important role in the structural and functional abnormalities of diabetic heart. Glutathione peroxidase (GSHPx) is a critical antioxidant enzyme that removes H2O2 in both the cytosol and mitochondia. We hypothesized that the overexpression of GSHPx gene could attenuate left ventricular (LV) remodeling in diabetes mellitus (DM). We induced DM by injection of streptozotocin (160 mg/kg ip) in male GSHPx transgenic mice (TG + DM) and nontransgenic wildtype littermates (WT + DM). GSHPx activity was higher in the hearts of TG mice compared with WT mice, with no significant changes in other antioxidant enzymes. LV thiobarbituric acid-reactive substances measured in TG + DM at 8 wk were significantly lower than those in WT + DM (58 +/- 3 vs. 71 +/- 5 nmol/g, P |
| 230. |
Tomomi Ide, Mayumi Yamato, Masayoshi Yoshida, Hideo Utsumi, Ikeuchi Masaki, [Tsutsumi] Takaki, Takahiro Inoue, Takeshi Shiba, Hiroyuki Tsutsui, Kenji Sunagawa, Non-invasive analysis of oxidative stress in myocardial remodeling and failure in mice using in vivo electron spin resonance (ESR) spectroscopy, CIRCULATION, 114, 18, 95-95, 2006.10. |
| 231. |
Tsutsui H, Ide T, Kinugawa S., Mitochondrial oxidative stress, DNA damage, and heart failure, Antioxid Redox Signal. , 8(9-10):1737-44., 2006.09. |
| 232. |
Hidenori Matsusaka, Shintaro Kinugawa, Tomomi Ide, Shoji Matsushima, Tetsuya Shiomi, Toru Kubota, Kenji Sunagawa, Hiroyuki Tsutsui, Angiotensin II type 1 receptor blocker attenuates exacerbated left ventricular remodeling and failure in diabetes-associated myocardial infarction, Journal of Cardiovascular Pharmacology, 10.1097/01.fjc.0000245405.41317.60, 48, 3, 95-102, 2006.09, Diabetes mellitus adversely affects the outcomes in patients with myocardial infarction (MI), due in part to the exacerbation of left ventricular (LV) remodeling. Although angiotensin II type 1 receptor blocker (ARB) has been demonstrated to be effective in the treatment of heart failure, information about the potential benefits of ARB on advanced LV failure associated with diabetes is lacking. To induce diabetes, male mice were injected intraperitoneally with streptozotocin (200 mg/kg). At 2 weeks, anterior MI was created by ligating the left coronary artery. These animals received treatment with olmesartan (0.1 mg/kg/day; n = 50) or vehicle (n = 51) for 4 weeks. Diabetes worsened the survival and exaggerated echocardiographic LV dilatation and dysfunction in MI. Treatment of diabetic MI mice with olmesartan significantly improved the survival rate (42% versus 27%, P |
| 233. |
Hiroyuki Tsutsui, Tomomi Ide, Shintaro Kinugawa, Mitochondrial oxidative stress, DNA damage, and heart failure, Antioxidants and Redox Signaling, 10.1089/ars.2006.8.1737, 8, 9-10, 1737-1744, 2006.09, Recent experimental and clinical studies have suggested that oxidative stress is enhanced in heart failure. The production of oxygen radicals is increased in the failing heart, whereas antioxidant enzyme activities are preserved as normal. Mitochondrial electron transport is an enzymatic source of oxygen radical generation and also a target of oxidant-induced damage. Chronic increases in oxygen radical production in the mitochondria can lead to a catastrophic cycle of mitochondrial DNA (mtDNA) damage as well as functional decline, further oxygen radical generation, and cellular injury. Reactive oxygen species induce myocyte hypertrophy, apoptosis, and interstitial fibrosis by activating matrix metalloproteinases. These cellular events play an important role in the development and progression of maladaptive cardiac remodeling and failure. Therefore, mitochondrial oxidative stress and mtDNA damage are good therapeutic targets. Overexpression of mitochondrial transcription factor A (TFAM) could ameliorate the decline in mtDNA copy number and preserve it at a normal level in failing hearts. Consistent with alterations in mtDNA, the decrease in oxidative capacities was also prevented. Therefore, the activation of TFAM expression could ameliorate the pathophysiologic processes seen in myocardial failure. Inhihition of mitochondrial oxidative stress and mtDNA damage could be novel and potentially very effective treatment strategies for heart failure.. |
| 234. |
Hidenori Matsusaka, Shintaro Kinugawa, Tomomi Ide, Shouji Matsushima, Tetsuya Shiomi, Toru Kubota, Kenji Sunagawa, Hiroyuki Tsutsui, Angiotensin II type 1 receptor blocker attenuates exacerbated left ventricular remodeling and failure in diabetes-associated myocardial infarction, JOURNAL OF CARDIOVASCULAR PHARMACOLOGY, 10.1097/01.fjc.0000245405.41317.60, 48, 3, 95-102, 2006.09, Diabetes mellitus adversely affects the outcomes in patients with myocardial infarction (MI), due in part to the exacerbation of left ventricular (LV) remodeling. Although angiotensin 11 type I receptor blocker (ARB) has been demonstrated to be effective in the treatment of heart failure, information about the potential benefits of ARB on advanced LV failure associated with diabetes is lacking. To induce diabetes, male mice were injected intraperitoneally with streptozotocin (200 mg/kg). At 2 weeks, anterior MI was created by ligating the left coronary artery. These animals received treatment with olmesartan (0.1 mg/kg/day; n = 50) or vehicle (n 51) for 4 weeks. Diabetes worsened the survival and exaggerated echocardiographic LV dilatation and dysfunction in MI. Treatment of diabetic MI mice with olmesartan significantly improved the survival rate (42% versus 27%, P |
| 235. |
Hiroyuki Tsutsui, Tomomi Ide, Shintaro Kinugawai, Mitochondrial oxidative stress, DNA damage, and heart failure, ANTIOXIDANTS & REDOX SIGNALING, 10.1089/ars.2006.8.1737, 8, 9-10, 1737-1744, 2006.09, Recent experimental and clinical studies have suggested that oxidative stress is enhanced in heart failure. The production of oxygen radicals is increased in the failing heart, whereas antioxidant enzyme activities are preserved as normal. Mitochondrial electron transport is an enzymatic source of oxygen radical generation and also a target of oxidant-induced damage. Chronic increases in oxygen radical production in the mitochondria can lead to a catastrophic cycle of mitochondrial DNA (mtDNA) damage as well as functional decline, further oxygen radical generation, and cellular injury. Reactive oxygen species induce myocyte hypertrophy, apoptosis, and interstitial fibrosis by activating matrix metalloproteinases. These cellular events play an important role in the development and progression of maladaptive cardiac remodeling and failure. Therefore, mitochondrial oxidative stress and mtDNA damage are good therapeutic targets. Overexpression of mitochondrial transcription factor A (TFAM) could ameliorate the decline in mtDNA copy number and preserve it at a normal level in failing hearts. Consistent with alterations in mtDNA, the decrease in oxidative capacities was also prevented. Therefore, the activation of TFAM expression could ameliorate the pathophysiologic processes seen in myocardial failure. Inhibition of mitochondrial oxidative stress and mtDNA damage could be novel and potentially very effective treatment strategies for heart failure.. |
| 236. |
Matsusaka H, Ide T, Matsushima S, Ikeuchi M, Kubota T, Sunagawa K, Kinugawa S, Tsutsui H., Targeted deletion of p53 prevents cardiac rupture after myocardial infarction in mice., Cardiovasc Res. , 70(3):457-65. , 2006.06. |
| 237. |
Hidenori Matsusaka, Tomomi Ide, Shoji Matsushima, Masaki Ikeuchi, Toru Kubota, Kenji Sunagawa, Shintaro Kinugawa, Hiroyuki Tsutsui, Targeted deletion of p53 prevents cardiac rupture after myocardial infarction in mice, Cardiovascular research, 10.1016/j.cardiores.2006.02.001, 70, 3, 457-465, 2006.06, Objective: Apoptosis may play an important role in cardiac remodeling after myocardial infarction (MI). p53 is a well-known proapoptotic factor. However, its pathophysiological significance in these conditions remains unclear. We thus examined the effects of target deletion of the p53 gene on post-MI hearts. Methods: Anterior MI was created in male heterozygous p53-deficient (p53+/-; n = 28) mice and sibling wild-type (p53+/+; n = 29) mice by ligating the left coronary artery. Results: By day 7, p53+/- mice had significantly better survival rate than p53+/+ mice (89% vs. 69%, P +/- mice had a significantly lower incidence of left ventricular (LV) rupture (7% vs. 28%, P +/- and p53+/+ mice with MI. However, the p53+/- mice had a significantly thicker infarct wall. The number of TUNEL-positive cells in the infarct area was significantly lower in p53+/- mice than in p53+/+ mice (423 ± 86 vs. 1330 ± 275/105 cells, P |
| 238. |
Hidenori Matsusaka, Tomomi Ide, Shouji Matsushima, Masaki Ikeuchi, Toru Kubota, Kenji Sunagawa, Shintaro Kinugawa, Hiroyuki Tsutsui, Targeted deletion of p53 prevents cardiac rapture after myocardial infarction in mice, CARDIOVASCULAR RESEARCH, 10.1016/j.cardiores.2006.02.001, 70, 3, 457-465, 2006.06, Objective: Apoptosis may play an important role in cardiac remodeling after myocardial infarction (MI). p53 is a well-known proapoptotic factor. However, its pathophysiological significance in these conditions remains unclear. We thus examined the effects of target deletion of the p53 gene on post-MI hearts.Methods: Anterior MI was created in male heterozygous p53-deficient (p53(+/-); n=28) mice and sibling wild-type (P53(+/-); n = 29) mice by ligating the left coronary artery.Results: By day 7, p53(+/-) mice had significantly better survival rate than p53(+/+) mice (89% vs. 69%, P |
| 239. |
Matsushima S, Ide T, Yamato M, Matsusaka H, Hattori F, Ikeuchi M, Kubota T, Sunagawa K, Hasegawa Y, Kurihara T, Oikawa S, Kinugawa S, Tsutsui H., Overexpression of mitochondrial peroxiredoxin-3 prevents left ventricular remodeling and failure after myocardial infarction in mice., Circulation, 113(14):1779-86., 2006.04. |
| 240. |
Targeted deletion of matrix metalloproteinase 2 ameliorates myocardial remodeling in mice with chronic pressure overload.. |
| 241. |
Shoji Matsushima, Tomomi Ide, Mayumi Yamato, Hidenori Matsusaka, Fumiyuki Hattori, Masaki Ikeuchi, Toru Kubota, Kenji Sunagawa, Yasuhiro Hasegawa, Tatsuya Kurihara, Shinzo Oikawa, Shintaro Kinugawa, Hiroyuki Tsutsui, Overexpression of mitochondrial peroxiredoxin-3 prevents left ventricular remodeling and failure after myocardial infarction in mice, Circulation, 10.1161/CIRCULATIONAHA.105.582239, 113, 14, 1779-1786, 2006.04, BACKGROUND - Mitochondrial oxidative stress and damage play major roles in the development and progression of left ventricular (LV) remodeling and failure after myocardial infarction (MI). We hypothesized that overexpression of the mitochondrial antioxidant, peroxiredoxin-3 (Prx-3), could attenuate this deleterious process. METHODS AND RESULTS - We created MI in 12- to 16-week-old, male Prx-3-transgenic mice (TG+MI, n=37) and nontransgenic wild-type mice (WT+MI, n=39) by ligating the left coronary artery. Prx-3 protein levels were 1.8 times higher in the hearts from TG than WT mice, with no significant changes in other antioxidant enzymes. At 4 weeks after MI, LV thiobarbituric acid-reactive substances in the mitochondria were significantly lower in TG+MI than in WT+MI mice (mean±SEM, 1.5±0.2 vs 2.2±0.2 nmol/mg protein; n=8 each, P |
| 242. |
Hidenori Matsusaka, Tomomi Ide, Shoji Matsushima, Masaki Ikeuchi, Toru Kubota, Kenji Sunagawa, Shintaro Kinugawa, Hiroyuki Tsutsui, Targeted deletion of matrix metalloproteinase 2 ameliorates myocardial remodeling in mice with chronic pressure overload, Hypertension, 10.1161/01.HYP.0000208840.30778.00, 47, 4, 711-717, 2006.04, Matrix metalloproteinases (MMPs) play an important role in the extracellular matrix remodeling. Experimental and clinical studies have demonstrated that MMP 2 and 9 are upregulated in the dilated failing hearts and involved in the development and progression of myocardial remodeling. However, little is known about the role of MMPs in mediating adverse myocardial remodeling in response to chronic pressure overload (PO). We, thus, hypothesized that selective disruption of the MMP 2 gene could ameliorate PO-induced cardiac hypertrophy and dysfunction in mice. PO hypertrophy was induced by transverse aortic constriction (TAC) in male MMP 2 knockout (KO) mice (n=10) and sibling wild-type (WT) mice (n=9). At 6 weeks, myocardial MMP 2 zymographic activity was 2.4-fold increased in WT+TAC, and this increase was not observed in KO+TAC, with no significant alterations in other MMPs (MMP 1, 3, 8, and 9) or tissue inhibitors of MMPs (1, 2, 3, and 4). TAC resulted in a significant increase in left ventricular (LV) weight and LV end-diastolic pressure (EDP) with preserved systolic function. KO+TAC mice exerted significantly lower LV weight/body weight (4.2±0.2 versus 5.0±0.2 mg/g; P2; P |
| 243. |
Tomomi Ide, Seeking for the endogenous ligands for PPARγ, Journal of Clinical Biochemistry and Nutrition, 10.3164/jcbn.37.39, 37, 2, 39-44, 2005.12, Peroxisome proliferators-activated receptors gamma (PPARγ) is an isoform of PPARs which are members of the nuclear receptor superfamily and are considered as key sensors of lipid and glucose homeostasis. This ligand-activated transcription factor has been intensively studied for more than a decade and the bona fide endogenous ligand remains unknown. 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ 2) is of great interest because it affects gene transcription by binding and activating PPARγ and by covalent addition to transcription factors and signaling molecules. However, the actual concentration of 15d-PGJ2 is several orders of magnitude below the levels required to induce many of the biological reaction attributed to this molecule. This short review will focus on 15d-PGJ2 as a ligand of PPARγ and on other candidates of the endogenous ligand for the receptor.. |
| 244. |
Matsusaka H, Ikeuchi M, Matsushima S, Ide T, Kubota T, Feldman AM, Takeshita A, Sunagawa K, Tsutsui H., Selective disruption of MMP-2 gene exacerbates myocardial inflammation and dysfunction in mice with cytokine-induced cardiomyopathy., Am J Physiol Heart Circ Physiol. , 10.1152/ajpheart.00216.2005, 289, 5, H1858-H1864, 289(5):H1858-64. , 2005.11. |
| 245. |
Ikeuchi M, Matsusaka H, Kang D, Matsushima S, Ide T, Kubota T, Fujiwara T, Hamasaki N, Takeshita A, Sunagawa K, Tsutsui H., Overexpression of mitochondrial transcription factor a ameliorates mitochondrial deficiencies and cardiac failure after myocardial infarction., Circulation., 10.1161/CIRCULATIONAHA.104.524835, 112, 5, 683-690, 112(5):683-90. , 2005.08. |
| 246. |
Ide T, Bell-Parikh LC, Lawson JA, McNamara P, Reilly M, FitzGerald GA., Biosynthesis of 15-deoxy-delta12,14-PGJ2 and the ligation of PPARgamma., J Clin Invest. , 112(6):945-55., 2003.09. |
| 247. |
L. Chastine Bell-Parikh, Tomomi Ide, John A. Lawson, Peter McNamara, Muredach Reilly, Garret A. FitzGerald, Biosynthesis of 15-deoxy-Δ12,14-PGJ2 and the ligation of PPARγ, Journal of Clinical Investigation, 10.1172/JCI200318012, 112, 6, 945-955, 2003.09, 15-deoxy-Δ12,14-PGJ2 (15d-PGJ2) has been identified as an endogenous ligand for PPARγ, inducing adipogenesis in vitro. Additional roles for this molecule in the propagation and resolution of inflammation, ligation of NF-κB, and mediation of apoptosis have been proposed. However, quantitative, physiochemical evidence for the formation of 15d-PGJ2 in vivo is lacking. We report that 15d-PGJ2 is detectable using liquid chromatography-mass spectrometry-mass spectrometry at low picomolar concentrations in the medium of 3T3-L1 preadipocytes. However, despite induction of COX-2, production of PGs, including 15d-PGJ2, does not increase during adipocyte differentiation, a process unaltered by COX inhibition. 15d-PGJ2 is detectable as a minor product of COX-2 in human urine. However, its biosynthesis is unaltered during or after COX activation in vivo by LPS. Furthermore, the biosynthesis of 15d-PGJ2 is not augmented in the joint fluid of patients with arthritis, nor is its urinary excretion increased in patients with diabetes or obesity. 15d-PGJ 2 is not the endogenous mediator of PPARγ-dependent adipocyte activation and is unaltered in clinical settings in which PPARγ activation has been implicated.. |
| 248. |
Ide T, Egan K, Bell-Parikh LC, FitzGerald GA., Activation of nuclear receptors by prostaglandins., Thromb Res. , 110(5-6):311-5., 2003.06. |
| 249. |
Tomomi Ide, Karine Egan, L. Chastine Bell-Parikh, Garret A. FitzGerald, Activation of nuclear receptors by prostaglandins, Thrombosis Research, 10.1016/S0049-3848(03)00418-3, 110, 5-6, 311-315, 2003.06, Deletion of membrane receptors for prostaglandins has revealed their importance in diverse biological systems. Some evidence has accrued to support the contention that they may also ligate nuclear receptors, particularly peroxisomal proliferator activator receptors (PPARs). This is most pronounced in the case of 15-deoxy PGJ2, a cyclopentanone derivative of PGJ 2 as a ligand for PPARγ. However, while this compound can ligate the PPAR, the quantities formed in vivo suggest that this is an unlikely endogenous ligand. Furthermore, biosynthesis is unaltered in murine atherosclerosis and other inflammatory and metabolic disorders where activation of this PPAR has been implicated. The suggestion that prostaglandins serve as endogenous ligands for nuclear receptors is presently configured on the use of synthetic compounds and immunoreactive quantitation of dubious validity. The application of quantitatively precise and sensitive physicochemical methodology will enhance experiments designed to address this hypothesis.. |
| 250. |
Oxidative stress mediates tumor necrosis factor-alpha-induced mitochondrial DNA damage and dysfunction in cardiac myocytes.. |
| 251. |
Machida Y, Kubota T, Kawamura N, Funakoshi H, Ide T, Utsumi H, Li YY, Feldman AM, Tsutsui H, Shimokawa H, Takeshita A., Overexpression of tumor necrosis factor-alpha increases production of hydroxyl radical in murine myocardium., Am J Physiol Heart Circ Physiol., 10.1152/ajpheart.00581.2002, 284, 2, H449-H455, 284(2):H449-55. , 2003.02. |
| 252. |
Yoji Machida, Toru Kubota, Natsumi Kawamura, Hajime Funakoshi, Tomomi Ide, Hideo Utsumi, Yun You Li, Arthur M. Feldman, Hiroyuki Tsutsui, Hiroaki Shimokawa, Akira Takeshita, Overexpression of tumor necrosis factor-α increases production of hydroxyl radical in murine myocardium, American Journal of Physiology - Heart and Circulatory Physiology, 284, 2 53-2, 2003.02, Transgenic (TG) mice with cardiac-specific overexpression of tumor necrosis factor-α develop congestive heart failure with myocardial inflammation. The purpose of this study was to investigate the effects of tumor necrosis factor-α on reactive oxygen species (ROS) in this mouse model of cardiomyopathy. Myocardial production of hydroxyl radical detected by electron spin resonance spectroscopy was significantly increased in TG. Myocardial expression of Mn-SOD was significantly decreased in TG, whereas that of Cu,Zn-SOD was unaltered. Myocardial expression of catalase was unchanged, whereas that of glutathione peroxidase was significantly increased, in TG. Histological analysis revealed that macrophages and CD4-positive lymphocytes were increased in TG myocardium. To investigate whether these infiltrating inflammatory cells were the source of ROS, we treated TG mice with cyclophosphamide for 7 days. Although cyclophosphamide significantly suppressed the infiltration of inflammatory cells, it did not diminish the production of hydroxyl radical in TG myocardium. Damaged myocytes, but not infiltrating inflammatory cells, may be the source of ROS in TG.. |
| 253. |
Hiroyuki Tsutsui, Tomomi Ide, Akira Takeshita, Noriko Ohashi, Physiological variations of isoprostanes
A step forward? Response to letter to the editor [3], Arteriosclerosis, Thrombosis, and Vascular Biology, 22, 7, 1240-1241, 2002.07. |
| 254. |
Ide T, Tsutsui H, Ohashi N, Hayashidani S, Suematsu N, Tsuchihashi M, Tamai H, Takeshita A., Greater oxidative stress in healthy young men compared with premenopausal women., Arterioscler Thromb Vasc Biol. , 10.1161/hq0302.104515, 22, 3, 438-442, 22(3):438-42., 2002.03. |
| 255. |
Hayashidani S, Tsutsui H, Shiomi T, Suematsu N, Kinugawa S, Ide T, Wen J, Takeshita A., Fluvastatin, a 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitor, attenuates left ventricular remodeling and failure after experimental myocardial infarction., Circulation. , 10.1161/hc0702.104164, 105, 7, 868-873, 2002 Feb 19;105(7):868-73., 2002.02. |
| 256. |
Tsutsui H, Ide T, Shiomi T, Kang D, Hayashidani S, Suematsu N, Wen J, Utsumi H, Hamasaki N, Takeshita A., 8-oxo-dGTPase, which prevents oxidative stress-induced DNA damage, increases in the mitochondria from failing hearts., Circulation, 10.1161/hc4901.101347, 104, 24, 2883-2885, 104:2883-5., 2001.12. |
| 257. |
Nakamura R, Egashira K, Arimura K, Machida Y, Ide T, Tsutsui H, Shimokawa H, Takeshita A., Increased inactivation of nitric oxide is involved in impaired coronary flow reserve in heart failure., Am J Physiol Heart Circ Physiol. 2001 Dec;281(6):H2619-25., 281, 6, H2619-H2625, 281(6):H2619-25., 2001.12. |
| 258. |
R. Y.O. Nakamura, Kensuke Egashira, Kenichi Arimura, Youji Machida, Tomomi Ide, Hiroyuki Tsutsui, Hiroaki Shimokawa, Akira Takeshita, Increased inactivation of nitric oxide is involved in impaired coronary flow reserve in heart failure, American Journal of Physiology - Heart and Circulatory Physiology, 281, 6 50-6, 2001.12, Recent evidence suggests that increased inactivation of endothelium-derived nitric oxide (NO) by oxygen free radical (OFR) formation is involved in the pathogenesis of endothelial dysfunction in heart failure (HF). However, it is unclear whether increased OFR limits coronary flow reserve in HF. To test this hypothesis, we examined the effects of antioxidant therapy on coronary flow reserve in a canine model of tachycardia-induced HF. The flow reserve (percent increase in coronary blood flow) to adenosine or to 20-s ischemia was less and OFR formation (electron-spin resonance spectroscopy) in myocardial tissues was greater in HF dogs than in controls. Immunohistochemical staining of 4-hydroxy-2-nonenal, an OFR-induced lipid peroxide, was detected in coronary microvessels of HF dogs. Intracoronary infusion of a cell-permeable OFR scavenger, tiron, suppressed OFR formation and improved the vasodilating capacity to adenosine or brief ischemia in HF dogs but not in controls. A NO synthesis inhibitor, NG-monomethyl-Larginine (L-NMMA), diminished the beneficial effects of tiron in HF dogs. Vasodilation to sodium nitroprusside was similar between control and HF dogs, and no change in its response was noted with tiron or tiron + L-NMMA in either group. In summary, antioxidant treatment with tiron improved coronary flow reserve by increasing NO bioactivity in HF dogs. Thus increased OFR formation may impair coronary flow reserve in HF by reducing NO bioactivity.. |
| 259. |
Enhanced generation of reactive oxygen species in the limb skeletal muscles from a murine infarct model of heart failure.. |
| 260. |
Hiroyuki Tsutsui, Tomomi Ide, Shunji Hayashidani, Nobuhiro Suematsu, Tetsuya Shiomi, Jing Wen, Kei Ichiro Nakamura, Kazuhiro Ichikawa, Hideo Utsumi, Akira Takeshita, Enhanced generation of reactive oxygen species in the limb skeletal muscles from a murine infarct model of heart failure, Circulation, 10.1161/01.CIR.104.2.134, 104, 2, 134-136, 2001.07, Background - The generation of reactive oxygen species (ROS) is enhanced in the failing myocardium. We hypothesized that ROS were also increased in the limb skeletal muscles in heart failure. Methods and Results - Myocardial infarction (MI) was created in mice by ligating the left coronary artery. After 4 weeks, the left ventricle was dilated and contractility was diminished by echocardiography. Left ventricular end-diastolic pressure was elevated after MI in association with an increase in lung weight/body weight and the presence of pleural effusion. The generation of ROS in the limb muscles, including the soleus and gastrocnemius muscles, which were excised after MI, was measured by electron spin resonance spectroscopy with 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl (hydroxy-TEMPO). Overall, generation was increased, but it was attenuated in the presence of dimethylthiourea or 4,5-dihydroxy-1,2-benzenedisulfonic disodium salt in the reaction mixture, indicating increased generation of hydroxyl radicals originating from superoxide anion. Thiobarbituric acid-reactive substance formation was also increased in muscles after MI. Mitochondrial complex I and III activities were both decreased after MI, which may have caused the functional uncoupling of the respiratory chain and ROS production. Antioxidant enzyme activities, including superoxide dismutase, catalase, and glutathione peroxidase, were comparable between groups. Conclusions - Skeletal muscle in post-MI heart failure expressed an increased amount of ROS in association with ROS-mediated lipid peroxidation. This supports the hypothesis that oxidative stress may cause (at least in part) skeletal muscle dysfunction in heart failure.. |
| 261. |
Tsutsui H, Ide T, Hayashidani S, Kinugawa S, Suematsu N, Utsumi H, Takeshita A., Effects of ACE inhibition on left ventricular failure and oxidative stress in Dahl salt-sensitive rats.
, J Cardiovasc Pharmacol., 10.1097/00005344-200106000-00010, 37, 6, 725-733, 37(6):725-33., 2001.06. |
| 262. |
Kenichi Akimura, Kensuke Egashira, Ryo Nakamura, Tomomi Ide, Hiroyuki Tsutsui, Hiroaki Shimokawa, Akira Takeshita, Increased inactivation of nitric oxide is involved in coronary endothelial dysfunction in heart failure, American Journal of Physiology - Heart and Circulatory Physiology, 280, 1 49-1, 2001.06, Recent evidence suggests the possibility that enhanced inactivation of endothelium-derived nitric oxide (NO) by oxygen free radical (OFR) may cause endothelial dysfunction in heart failure (HF). To test this hypothesis, we examined the effect of antioxidant therapy on endothelium-dependent vasodilation of the coronary circulation in a canine model of tachycardia-induced HF. Endothelium-dependent vasodilation was less than that in controls, and OFR formation in coronary arterial and myocardial tissues was greater in HF dogs than those in controls. The immunohistochemical staining of 4-hydroxy-2-nonenal, OFR-induced lipid peroxides was detected in coronary microvessels of HF dogs. Intracoronary infusion of the cell-permeable OFR scavenger Tiron inhibited OFR formation and improved endothelium-dependent vasodilation in HF dogs but not in controls. The NO synthesis inhibitor NG-monomethyl-L-arginine (L-NMMA) diminished the beneficial effect of Tiron in HF dogs. Endothelium-independent vasodilation was similar between control and HF dogs, and no change in its response was noted by Tiron or Tiron plus L-NMMA in either group. In summary, antioxidant treatment with Tiron improved coronary vascular endothelium-dependent vasodilation by increasing NO activity in tachycardia-induced HF. Thus coronary endothelial dysfunction in HF may be, at least in part, due to increased inactivation of NO by OFR.. |
| 263. |
Tomomi Ide, Hiroyuki Tsutsui, Shunji Hayashidani, Dongchon Kang, Nobuhiro Suematsu, Kei Ichiro Nakamura, Hideo Utsumi, Naotaka Hamasaki, Akira Takeshita, Mitochondrial DNA damage and dysfunction associated with oxidative stress in failing hearts after myocardial infarction, Circulation research, 10.1161/01.RES.88.5.529, 88, 5, 529-535, 2001.03, Mitochondria are one of the enzymatic sources of reactive oxygen species (ROS) and could also be a major target for ROS-mediated damage. We hypothesized that ROS may induce mitochondrial DNA (mtDNA) damage, which leads to defects of mtDNA-encoded gene expression and respiratory chain complex enzymes and thus may contribute to the progression of left ventricular (LV) remodeling and failure after myocardial infarction (MI). In a murine model of MI and remodeling created by the left anterior descending coronary artery ligation for 4 weeks, the LV was dilated and contractility was diminished. Hydroxyl radicals, which originated from the superoxide anion, and lipid peroxide formation in the mitochondria were both increased in the noninfarcted LV from MI mice. The mtDNA copy number relative to the nuclear gene (18S rRNA) preferentially decreased by 44% in MI by a Southern blot analysis, associated with a parallel decrease (30% to 50% of sham) in the mtDNA-encoded gene transcripts, including the subunits of complex I (ND1, 2, 3, 4, 4L, and 5), complex III (cytochrome b), complex IV (cytochrome c oxidase), and rRNA (12S and 16S). Consistent with these molecular changes, the enzymatic activity of complexes I, III, and IV decreased in MI, whereas, in contrast, complex II and citrate synthase, encoded only by nuclear DNA, both remained at normal levels. An intimate link among ROS, mtDNA damage, and defects in the electron transport function, which may lead to an additional generation of ROS, might play an important role in the development and progression of LV remodeling and failure.. |
| 264. |
Tsutsui H, Kinugawa S, Ide T, Hayashidani S, Suematsu N, Satoh S, Nakamura R, Egashira K, Takeshita A., Positive inotropic effects of calcium sensitizers on normal and failing cardiac myocytes., JOURNAL OF CARDIOVASCULAR PHARMACOLOGY, 10.1097/00005344-200101000-00003, 37, 1, 16-24, 37(1):16-24., 2001.01. |
| 265. |
Hiroyuki Tsutsui, Tomomi Ide, Shunji Hayashidani, Nobuhiro Suematsu, Hideo Utsumi, Ryo Nakamura, Kensuke Egashira, Akira Takeshita, Greater susceptibility of failing cardiac myocytes to oxygen free radical-mediated injury, Cardiovascular research, 10.1016/S0008-6363(00)00197-8, 49, 1, 103-109, 2001.01, Objective: Oxygen-derived free radicals can produce myocardial cellular damage, which might contribute to the ischemia-reperfusion injury and to heart failure (HF). However, the effects of oxygen radicals on myocyte structure have not been examined in the failing heart. Methods: We examined the susceptibility of intact cardiac myocytes isolated from control (n=16) and rapid pacing (240 bpm, 4 wks)-induced HF (n=8) dog hearts to an exogenous hydroxyl radical (·OH), generated from H2O2 and Fe3+-nitrilotriacetate. The production of ·OH was monitored by electron spin resonance with 5,5'-dimethyl-1-pyroline-N-oxide (DMPO) as a spin trap. Results: The magnitude of DMPO-OH signals was not attenuated in the presence of either control or HF myocytes. ·OH induced a time-dependent decrease in myocyte length (i.e. hypercontracture). The time to the onset of hypercontracture and that to the submaximal hypercontracture after exposure was significantly shortened in HF. Activities of superoxide dismutase, catalase, and glutathione peroxidase was not decreased in HF. Conclusions: HF myocytes were more susceptible to oxidative stress-induced cellular injury, which was not due to decreased antioxidant defense, but to the intrinsic properties of cells. (C) 2001 Elsevier Science B.V.. |
| 266. |
Shintaro Kinugawa, Hiroyuki Tsutsui, Shunji Hayashidani, Tomomi Ide, Nobuhiro Suematsu, Shinji Satoh, Hideo Utsumi, Akira Takeshita, Treatment with dimethylthiourea prevents left ventricular remodeling and failure after experimental myocardial infarction in mice
Role of oxidative stress, Circulation research, 10.1161/01.RES.87.5.392, 87, 5, 392-398, 2000.09, Oxidative stress might play an important role in the progression of left ventricular (LV) remodeling and failure that occur after myocardial infarction (MI). We determined whether reactive oxygen species (ROS) are increased in the LV remodeling and failure in experimental MI with the use of electron spin resonance spectroscopy and whether the long-term administration of dimethylthiourea (DMTU), hydroxyl radical (.OH) scavenger, could attenuate these changes. We studied 3 groups of mice: sham-operated (sham), MI, and MI animals that received DMTU (MI+DMTU). Drugs were administered to the animals daily via intraperitoneal injection for 4 weeks. (.OH) was increased in the noninfarcted myocardium from MI animals, which was abolished in MI+DMTU. Fractional shortening was depressed by 65%, LV chamber diameter was increased by 53%, and the thickness of noninfarcted myocardium was increased by 37% in MI. MI+DMTU animals had significantly better LV contractile function and smaller increases in LV chamber size and hypertrophy than MI animals. Changes in myocyte cross-sectional area determined with LV mid-free wall specimens were concordant with the wall thickness data. Collagen volume fraction of the noninfarcted myocardium showed significant increases in the MI, which were also attenuated with DMTU. Myocardial matrix metalloproteinase-2 activity, measured with gelatin zymography, was increased with MI after 7 and 28 days, which was attenuated in MI+DMTU. Thus, the attenuation of increased myocardial ROS and metalloproteinase activity with DMTU may contribute, at least in part, to its beneficial effects on LV remodeling and failure. Therapies designed to interfere with oxidative stress might be beneficial to prevent myocardial failure.. |
| 267. |
Tomomi Ide, Hiroyuki Tsutsui, Shintaro Kinugawa, Nobuhiro Suematsu, Shunji Hayashidani, Kazuhiro Ichikawa, Hideo Utsumi, Youji Machida, Kensuke Egashira, Akira Takeshita, Direct evidence for increased hydroxyl radicals originating from superoxide in the failing myocardium, Circulation research, 10.1161/01.RES.86.2.152, 86, 2, 152-157, 2000.01, Experimental and clinical studies have suggested an increased production of reactive oxygen species (ROS) in the failing myocardium. The present study aimed to obtain direct evidence for increased ROS and to determine the contribution of superoxide anion (·O2-), H2O2, and hydroxy radical (·OH) in failing myocardial tissue. Heart failure was produced in adult mongrel dogs by rapid ventricular pacing at 240 bpm for 4 weeks. To assess the production of ROS directly, freeze-clamped myocardial tissue homogenates were reacted with the nitroxide radical, 4-hydroxy-2,2,6,6,-tetramethyl- piperidine-N-oxyl, and its spin signals were detected by electron spin resonance spectroscopy. The rate of electron spin resonance signal decay, proportional to ·OH level, was significantly increased in heart failure, which was inhibited by the addition of dimethylthiourea (·OH scavenger) into the reaction mixture. Increased ·OH in the failing heart was abolished to the same extent in the presence of desferrioxamine (iron chelator), catalase (H2O2 scavenger), and 4,5-dihydroxy-1,3-benzene disulfonic acid (Tiron; LaMotte) (·O2- scavenger), indicating that ·OH originated from H2O2 and ·O2-. Further, ·O2- produced in normal myocardium in the presence of antimycin A (mitochondrial complex III inhibitor) could reproduce the increase of H2O2 and ·OH seen in the failing tissue. There was a significant positive relation between myocardial ROS level and left ventricular contractile dysfunction. In conclusion, in the failing myocardium, ·OH was produced as a reactive product of ·O2- and H2O2, which might play an important role in left ventricular failure.. |
| 268. |
Shintaro Kinugawa, Hiroyuki Tsutsui, Shinji Satoh, Masaru Takahashi, Tomomi Ide, Keiko Igarashi-Saito, Ken ichi Arimura, Kensuke Egashira, Akira Takeshita, Role of Ca2+ availability to myofilaments and their sensitivity to Ca2+ in myocyte contractile dysfunction in heart failure, Cardiovascular research, 10.1016/S0008-6363(99)00205-9, 44, 2, 398-406, 1999.11, Objective: Contractile function is depressed at the isolated myocyte level in heart failure (HF), which could result from the decreased availability of intracellular calcium ([Ca2+]i) to the myofibrils and/or the depressed sensitivity of myofilaments to [Ca2+]i. However, the cellular basis of contractile dysfunction remains unestablished. Methods: We isolated left ventricular myocytes from dogs with rapid pacing-induced HF. Cell shortening and [Ca2+]i transients were measured by indo-1 fluorescence and the myofilament Ca2+ sensitivity was analyzed by the shortening-[Ca2+]i relation in intact myocytes as well as by the pCa-tension relation in skinned cells. Results: Peak cell shortening magnitude was depressed in HF, associated with a parallel decrease of [Ca2+]i transient amplitude. There was a significant positive correlation between these two variables (r=0.71, P2+, determined by both intact and skinned myocytes, was comparable between control and HF. Further, there was no significant difference in Ca2+ sensitivity between control and HF even at shorter (1.8 μm) or longer (2.2 μm) sarcomere length. Conclusions: Using both intact and skinned cellular preparations, a potential defect in myocyte contractile function in HF was a reduction in Ca2+ availability to the myofilaments, rather than the inherent defects in myofilament sensitivity to Ca2+. Copyright (C) 1999 Elsevier Science B.V.. |
| 269. |
Ide T, Tsutsui H, Kinugawa S, Utsumi H, Takeshita A., Amiodarone protects cardiac myocytes against oxidative injury by its free radical scavenging action., Circulation. , 100, 7, 690-692, 17;100(7):690-2., 1999.08. |
| 270. |
Tomomi Ide, Hiroyuki Tsutsui, Shintaro Kinugawa, Hideo Utsumi, Akira Takeshita, Amiodarone protects cardiac myocytes against oxidative injury by its free radical scavenging action, Circulation, 100, 7, 690-692, 1999.08, Background-Oxidative stress plays an important role in the pathophysiology of ischemic heart disease and heart failure, and antioxidants might be beneficial in the treatment of these patients. This study was performed to determine the scavenging effects of amiodarone on oxygen free radicals and its protective effects against oxygen radical-mediated injury in cardiac myocytes. Methods and Results-The formation of the radical spin adduct with hydroxy radical (·OH) in the presence of H2O2 (10 mmol/L) and Fe3+-nitrilotriacetate (20 μmol/L) was monitored by electron paramagnetic resonance spectroscopy combined with a spin trapping agent, 5,5-dimethyl pyrroline-N-oxide (DMPO). Amiodarone decreased the intensity of the DMPO-OH signals in a dose-dependent manner (0.1 to 100 μmol/L), whereas other antiarrhythmia drugs such as disopyramide and atenolol had no such effects. Furthermore, amiodarone (10 μmol/L) protected intact adult canine cardiac myocytes against ·OH-mediated myocyte injury, as assessed by the degree of morphological change from rod shape to the irreversible hypercontracture state during the exposure of cells to H2O2 and Fe3+ in vitro. Conclusions-Amiodarone can protect cardiac myocytes against oxidative stress- mediated injury by directly scavenging oxygen free radicals. Antioxidant action of amiodarone might potentially contribute to the beneficial effects of this drug in the treatment of patients with ischemic heart disease and congestive heart failure.. |
| 271. |
Tomomi Ide, Hiroyuki Tsutsui, Shintaro Kinugawa, Hideo Utsumi, Dongchon Kang, Nobutaka Hattori, Koji Uchida, Ken Ichi Arimura, Kensuke Egashira, Akira Takeshita, Mitochondrial electron transport complex I is a potential source of oxygen free radicals in the failing myocardium, Circulation research, 10.1161/01.RES.85.4.357, 85, 4, 357-363, 1999.08, Oxidative stress in the myocardium may play an important role in the pathogenesis of congestive heart failure (HF). However, the cellular sources and mechanisms for the enhanced generation of reactive oxygen species (ROS) in the failing myocardium remain unknown. The amount of thiobarbituric acid reactive substances increased in the canine HF hearts subjected to rapid ventricular pacing for 4 weeks, and immunohistochemical staining of 4- hydroxy-2-nonenal ROS-induced lipid peroxides was detected in cardiac myocytes but not in interstitial cells of HF animals. The generation of superoxide anion was directly assessed in the submitochondrial fractions by use of electron spin resonance spectroscopy with spin trapping agent, 5,5'- dimethyl-1-pyrroline-N-oxide, in the presence of NADH and succinate as a substrate for NADH-ubiquinone oxidoreductase (complex I) and succinate- ubiquinone oxidoreductase (complex II), respectively. Superoxide production was increased 2.8-fold (P-1· mg-1 protein, P |
| 272. |
Shintaro Kinugawa, Hiroyuki Tsutsui, Tomomi Ide, Ryo Nakamura, Ken ichi Arimura, Kensuke Egashira, Akira Takeshita, Positive inotropic effect of insulin-like growth factor-1 on normal and failing cardiac myocytes, Cardiovascular research, 10.1016/S0008-6363(99)00058-9, 43, 1, 157-164, 1999.01, Objective: The acute administration of growth hormone (GH) or insulin- like growth factor-1 (IGF-1) improves cardiac performance, possibly contributing to the beneficial effects of GH therapy on heart failure (HF). GH can induce the production of IGF-1 and thus the actions of GH may be mediated through its IGF-1 induction. However, these effects have not yet been demonstrated in failing hearts and the cellular basis of GH or IGF-1- induced inotropic effects remains unknown. We examined the direct effects of GH and IGF-1 on the contractile function and intracellular calcium ([Ca2+](i)) homeostasis in normal and failing myocytes. Methods: To determine whether GH and IGF-1 have a direct effect on myocardial contractility and whether the GH/IGF-1-induced effect was the results of changes in Ca2+ activation, cell shortening and [Ca2+](i) transient were simultaneously measured in the left ventricular myocyte preparations, isolated from normal and rapid pacing-induced HF dogs. Results: Basal shortening of HF myocytes was reduced by 64% (p-3 IU/ml) had no effect on either cell shortening or [Ca2+](i) transients. In normal myocytes, IGF-1 exerted a positive inotropic effect in a time- and dose-dependent manner (25-500 ng/ml), associated with a parallel increase of [Ca2+](i) transient amplitude. IGF- 1 increased the shortening magnitude in normal (121±5% increase from baseline, p2+](i) transient amplitude in normal and HF cells by 124±4 and 125±7%, respectively. The percent increase of cell shortening and [Ca2+](i) transient amplitude was comparable between normal and HF myocytes. Furthermore, IGF-1 did not shift the trajectory of the relaxation phase in the phase-plane plots of cell length vs. [Ca2+](i), indicating that it did not change myofilament Ca2+ sensitivity. Conclusions: In both normal and HF conditions, IGF-1 exerted an acute direct positive inotropic effect in adult cardiac myocytes by increasing the availability of [Ca2+](i) to the myofilaments, possibly explaining the beneficial effect of GH on HF.. |
| 273. |
Ide T, Tsutsui H, Hayashidani S, Kang D, Suematsu N, Nakamura K, Utsumi H, Hamasaki N, Takeshita A., Mitochondrial DNA damage and dysfunction associated with oxidative stress in failing hearts after myocardial infarction., 88(5):529-35.. |
