記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Clinical and Translational Science  

This study aimed to evaluate the diagnostic utility of urinary exosomal microRNAs (miRNAs) in subclinical rejection following kidney transplantation by comparing miRNA expression profiles in urinary exosomes between patients with no evidence of rejection and patients with subclinical T-cell-mediated rejection (sc-TCMR), as confirmed by protocol kidney biopsies performed 3 months after transplantation. To elucidate these differences, a comprehensive miRNA expression analysis was conducted using microarray profiling. Consequently, 38 urinary exosomal miRNAs were detected, among which three were upregulated and five were downregulated in patients with sc-TCMR. To further evaluate the diagnostic value of these miRNAs, quantitative real-time PCR analysis was performed using urinary exosomes collected at the time of protocol biopsy from 70 kidney transplant recipients. This analysis confirmed that miR-5100 and miR-7975 were differentially expressed in patients with sc-TCMR at the time of the 12-month protocol biopsy. Importantly, miR-7975 demonstrated the ability to distinguish among three groups—no evidence of rejection, borderline changes, and sc-TCMR—with high diagnostic accuracy, as indicated by an area under the receiver operating characteristic curve of 0.825. In vitro, exposure of proximal tubular epithelial cells to transforming growth factor-beta 1 resulted in a reduction in miR-7975 expression within urinary exosomes, implicating these cells as a potential source of exosomal miR-7975. Collectively, these findings suggest that urinary exosomal miR-7975 may serve as a promising noninvasive biomarker for diagnosing and monitoring sc-TCMR, offering valuable insights for future research and clinical applications.

DOI： 10.1111/cts.70572

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PubMed

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Biological Chemistry  

5-Fluorouracil (5-FU) is a commonly used chemotherapeutic agent for breast cancer. Its efficacy relies on the function of p53, and mutations in p53 contribute to the development of resistance during 5-FU chemotherapy. Here, we report that microcurrent stimulation (MCS) of a p53-mutant breast cancer cell line induces p53-mediated cell death. Although MDA-MB-231 and MDA-MB-468 cells, both human breast cancer cell lines, are less sensitive to 5-FU due to p53 mutations, MCS (300 μA for 30 min) induced apoptosis in these cells and improved the antitumor effect of 5-FU in tumor-bearing mice. MCS-induced apoptosis was mediated by an increase in intracellular Cu²⁺ ions and reactive oxygen species, along with the concurrent transcriptional enhancement of pro-apoptotic genes by p53. Furthermore, MCS induced apoptosis in MDA-MB-231 cells that had developed resistance to 5-FU and inhibited tumor growth in tumor-bearing mice with reduced 5-FU sensitivity. These findings suggest that an approach involving MCS could serve as a foundation for developing breast cancer treatment strategies to overcome p53 mutations.

DOI： 10.1016/j.jbc.2025.110414

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PubMed

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Biochemical and Biophysical Research Communications  

Among the various RNA modifications, adenosine-to-inosine RNA editing, catalyzed by adenosine deaminase acting on RNA (ADAR) family, ADAR1 and ADAR2, is the most common nucleotide conversion in mammalian cells. The pathological relevance of ADAR expression has been highlighted in recent human genetic studies. Low expression of the ADAR2 gene is correlated with a poor prognosis in breast cancer patients, but the underlying mechanism remains enigmatic. In this study, we constructed Adar2-knockdown (Adar2-KD) murine breast cancer 4T1 cells and observed their reduced susceptibility to chemotherapeutic drug doxorubicin. Downregulation of ADAR2 induced the expression of P-glycoprotein (P-gp), leading to a reduction in the intracellular accumulation of doxorubicin. The upregulation of P-gp occurred at the post-transcriptional level due to the decreased miR-195a-3p function. The search for the underlying cause of the induction of P-gp expression in Adar2-KD 4T1 cells led to the identification of circular RNA (circRNA) circHif1a as a sponge for miR-195a-3p. The enhanced expression of circHif1a inhibited miR-195a-3p function, resulting in the upregulation of P-gp expression. These results suggest that ADAR2 acts as a suppressor of circHif1a biogenesis and then allows miR-195a-3p to interfere with P-gp translation. Our findings may help to improve drug efficacy by clarifying the mechanism of chemoresistance in breast cancer.

DOI： 10.1016/j.bbrc.2024.150289

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PubMed

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Translational Research  

Chronic kidney disease (CKD) induces cardiac inflammation and fibrosis and reduces survival. We previously demonstrated that G protein-coupled receptor 68 (GPR68) promotes cardiac inflammation and fibrosis in mice with 5/6 nephrectomy (5/6Nx) and patients with CKD. However, no method of GPR68 inhibition has been found that has potential for therapeutic application. Here, we report that Cephalotaxus harringtonia var. nana extract and homoharringtonine ameliorate cardiac inflammation and fibrosis under CKD by suppressing GPR68 function. Reagents that inhibit the function of GPR68 were explored by high-throughput screening using a medicinal plant extract library (8,008 species), and we identified an extract from Cephalotaxus harringtonia var. nana as a GPR68 inhibitor that suppresses inflammatory cytokine production in a GPR68 expression-dependent manner. Consumption of the extract inhibited inflammatory cytokine expression and cardiac fibrosis and improved the decreased survival attributable to 5/6Nx. Additionally, homoharringtonine, a cephalotaxane compound characteristic of C. harringtonia, inhibited inflammatory cytokine production. Homoharringtonine administration in drinking water alleviated cardiac fibrosis and improved heart failure and survival in 5/6Nx mice. A previously unknown effect of C. harringtonia extract and homoharringtonine was revealed in which GPR68-dependent inflammation and cardiac dysfunction were suppressed. Utilizing these compounds could represent a new strategy for treating GPR68-associated diseases, including CKD.

DOI： 10.1016/j.trsl.2024.02.004

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PubMed

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：International Journal of Molecular Sciences  

Prostaglandins are bioactive compounds, and the activation of their receptors affects the expression of clock genes. However, the prostaglandin F receptor (Ptgfr) has no known relationship with biological rhythms. Here, we first measured the locomotor period lengths of Ptgfr-KO (B6.129-Ptgfr^tm1Sna) mice and found that they were longer under constant dark conditions (DD) than those of wild-type (C57BL/6J) mice. We then investigated the clock gene patterns within the suprachiasmatic nucleus in Ptgfr-KO mice under DD and observed a decrease in the expression of the clock gene cryptochrome 1 (Cry1), which is related to the circadian cycle. Moreover, the expression of Cry1, Cry2, and Period2 (Per2) mRNA were significantly altered in the mouse liver in Ptgfr-KO mice under DD. In the wild-type mouse, the plasma prostaglandin F<inf>2α</inf> (PGF<inf>2α</inf>) levels showed a circadian rhythm under a 12 h cycle of light–dark conditions. In addition, in vitro experiments showed that the addition of PTGFR agonists altered the amplitude of Per2::luc activity, and this alteration differed with the timing of the agonist addition. These results lead us to hypothesize that the plasma rhythm of PGF<inf>2α</inf> is important for driving clock genes, thus suggesting the involvement of PGF<inf>2α</inf>- and Ptgfr-targeting drugs in the biological clock cycle.

DOI： 10.3390/ijms25031841

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PubMed

記述言語：日本語  

記述言語：日本語   会議種別：口頭発表（一般）  

<p>【目的】乳がんは女性の年間罹患者数が最も多いがん種であり、現代においても未だに罹患数・死亡者数は増加の一途を辿っている。この大きな原因は既存の治療薬に対して高い抵抗性を有するトリプルネガティブ乳がん (Triple Negative Breast Cancer; TNBC) の存在であり、TNBCに対する有効な治療法の開発が望まれている。一方、創傷治癒や疼痛緩和に頻用される外部デバイスを用いた微弱電流刺激は様々な細胞内シグナル応答に影響を与えることが示唆されている。しかしその詳しい機序やがん細胞への影響は未解明な点が多く、がん治療への応用はなされていない。そこで本研究は微弱電流刺激 (Microcurrent stimulation; MCS)がTNBCに与える影響を解析するとともに、マイクロ電流刺激を用いた新規TNBC治療法の確立を目指した。【方法】担癌モデルマウス作製には5週齢BALB/c雌性ヌードマウスを用い、MCSにはES-530およびPALS Electrodeを用いた。mRNA発現量はリアルタイムRT-PCR法、タンパク発現量はWestern Blotにより測定した。また、アポトーシス細胞数の測定にはFACSを用いた。【結果・考察】ヒト正常乳腺細胞および乳癌細胞株に対してMCSを行い、細胞生存率への影響を評価した。その結果、乳癌細胞株においてのみMCSによって生存率が低下した。この原因を探索したところ、MCSが癌細胞特異的に、細胞内金属イオン濃度の増加に伴うアポトーシスを誘導することが示唆された。また、ヒトTNBC細胞株MDA-MB-231は化学療法に対する抵抗性を有し、特に5-FU感受性が低いことが報告されている。そこでMDA-MB-231に対してMCSを行ったところ、5-FU抵抗性が改善し、通常5-FUが殺細胞効果を示さない濃度においてもアポトーシスを誘導することが明らかになった。さらに、MDA-MB-231を移植した担癌モデルマウスを作製し、MCSと5-FU投与を行った結果、それぞれ単独処置では有意な抗腫瘍効果は認められなかったにもかかわらず、両処置の併用によって極めて高い抗腫瘍効果を示すことが明らかになった。【結論】以上の結果から、MCSがヒトTNBC細胞で癌細胞選択的なアポトーシス誘導効果を有すること、および5-FU感受性を改善し、5-FUの抗腫瘍効果を増強することが明らかとなった。今後、これらの技術を応用し、既存治療に変わる、または既存治療による負担を軽減し得る新たなTNBC治療の創出へと応用したい。</p>

DOI： 10.50993/jsptsuppl.43.0_3-c-p-130

CiNii Research

記述言語：日本語