|Ryo Yamasaki||Last modified date：2022.06.13|
Associate Professor / Neurology / Neurological Institute / Faculty of Medical Sciences
Unauthorized reprint of the contents of this database is prohibited.
|Ryo Yamasaki||Last modified date：2022.06.13|
|1.||Ryo Yamasaki, Wataru Shiraishi, Yu Hashimoto, Senri Kou, Noriko Isobe, C-C chemokine receptor 2+ macrophages in nerves ameliorate motor neuron disease model mice, 63rd Annual meeting of the Japanese Society of Neurology, 2022.04, [Objective]Macrophages expressing C-C chemokine receptor type (2 CCR2)infiltrate into the neural tissues of amyotrophic lateral sclerosis(ALS)patients. We reported an association between intrathecal upregulation of C-C chemokine ligand 2(CCL2) and disease severity in ALS. We investigated the roles of CCR2+ macrophages in ALS using mutant Cu/Zn superoxide dismutase 1G93A(mSOD1)-transgenic(Tg) mice.[Methods]CCR2-deficient mice and mSOD1-Tg mice were bred to obtain CCR2-deficient mSOD1-Tg mice. We compared mSOD1-Tg mice with or without CCR2 clinically, immunohistochemically, and immunocytochemically.[Results] In mSOD1-Tg mice, mSOD1 protein accumulated in the sciatic nerve earlier than in the spinal cord. Before disease onset, CCR2+ macrophages harboring mSOD1 infiltrated the sciatic nerve much earlier than in the lumbar cord. The life span of CCR2-deficient mSOD1-Tg mice was shorter than that of CCR2-positive(control) mSOD1-Tg mice(164.0 ± 1.48 days vs. 170.4 ± 2.06 days, p = 0.0047). CCR2- deficient mSOD1-Tg mice had a marked increase in deposited mSOD1 in the sciatic nerve compared with CCR2-positive mice, together with a decreased infiltration of CCR2+ macrophages. Flow cytometric analysis revealed immature macrophages' infiltration in the CCR2-deficient mSOD1-Tg mice sciatic nerve.[Conclusions] CCR2+ macrophages recruited into the peripheral nerves exert neuroprotective functions in mSOD1 ALS. Clearance of mSOD1 from the peripheral nerve by CCR2+ macrophages is a hitherto-underestimated host protective mechanism..|
|2.||Ryo Yamasaki, Treatment selection according to the pathophysiology of autoantibody-positive CIDP
-Based on the new guidelines for EAN / PNS 2021-, Joint Meeting for JSNI and ISNI 2021, 2021.10, We previously found that the serum of patients with combined central and peripheral demyelination (CCPD) had a high rate of antibodies against the paranode of Ranvier's protein, neurofascin 155 (NF155) (Kawamura et al., 2013). In the process, it was suggested that there might be many antibody-positive individuals in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), so we investigated a method for qualitatively and quantitatively measuring anti-NF155 antibodies. When the sera of CIDP patients were analyzed using the flow cytometry method, IgG4 anti-NF155 antibody was positive in 9 of 48 cases (18.8%). These patients had characteristic clinical features such as juvenile-onset, distal predominance, tremor, swelling of the root, and elevated CSF protein (> 100 mg/dl). In addition, high-dose intravenous immunoglobulin therapy (IVIg), which should be effective for CIDP, was not effective, and treatment with steroids was effective (Ogata et al., 2015). When we measured the cytokine profile in the patient's cerebrospinal fluid, not only Th1 / macrophage-related cytokines known to have high CIDP levels but also Th2-related cytokines were elevated. In addition, HLA gene analysis showed a surprising result that HLA-DR15 was positive in all cases (Ogata et al., 2020). From these results, we speculated that the Th2-related mechanism is important as the disease mechanism of anti-NF155 antibody-positive CIDP patients in addition to the conventional Th1-related autoimmune response.
Now, the widely used CIDP diagnostic guidelines (EFNS / PNS (2010)) have recently been revised by the European Academy of Neurology / Peripheral Nerve Society (EAN / PNS (2021)) joint task force. The main changes are as follows: (1) "Atypical CIDP" has been renamed to "CIDP variant", and previously known as "MADSAM (Lewis-Sumner)", "Distal-Symmetric (DADS)", "Pure motor CIDP", "Pure sensory CIDP", were re-classified as "Multifocal CIDP", "Distal CIDP", "Motor CIDP", "Sensory CIDP", and "Focal CIDP" respectively. (2) The electrical diagnosis level has been changed from the conventional three levels of definite, probable, and possible CIDP to two levels of CIDP and possible CIDP. (3) Autoimmune nodopathy (cases positive for autoantibodies against CNTN1, NF155, Caspr1, NF140 / 186) was isolated from CIDP. (4) Introduced a sensory nerve conduction test as an electrical diagnostic standard. (5) Initial treatment/maintenance therapy for each disease type was recommended. We would like to provide an opportunity for discussion on the clinical application of the new guidelines.
|3.||Ryo Yamasaki, Glial gap junctions control chronic CNS inflammation in the multiple sclerosis lesions - Insights from disease model animal, The 33rd Annual Meeting of the Japanese Society of Neuroimmunology, 2021.10, Gap junctions in the vertebrate are composed of connexin (Cx) hexamer. In the central nervous system lesions of patients with secondary progressive multiple sclerosis (SPMS), Cx47 of oligodendrocyte is widely diminished, while Cx43 of astroglia is abnormally expressed. (Masaki, 2015). Cx forms a gap junction between oligodendrocytes and astroglia and is responsible for energy supply and homeostasis. Focusing on this point, we established the world's first SPMS model by establishing a Cx47-inducible conditional knockout (Cx47icKO) mouse that specifically ablates Cx47 after administration of tamoxifen and immunizing it with MOG35-55 peptide (Zhao, Yamasaki, et al., 2020). As a result, not only did EAE become more severe from the acute phase, but it also recurred in the chronic phase and gradually became more severe. In the chronic lesions, marked activation of microglia and astroglia and progression of demyelination were observed. Since these glial cells exhibited abnormal inflammatory activation that is not typically seen, the imbalance of gap junction proteins can cause the brain environment to become inflammatory and promote inflammatory demyelination. On the contrary, when Cx43-inducible conditional knockout (Cx43icKO), which specifically ablates Cx43 after tamoxifen administration, was created and EAE was induced, the symptoms were alleviated. It was strongly suggested that this symptom relief was associated with a decrease in CSF cytokine levels due to the suppression of glial inflammation (Une et al., 2021). From the results of these animal experiments, the abnormal promotion of glial inflammation due to the relative overexpression of astroglial Cx43 seemed to be a common mechanism for amplifying intracerebral inflammation. Chronic glial inflammation, which has been pointed out as an essential pathological mechanism of SPMS, is caused by an imbalance of glial connexin in the brain, and inflammation control by modifying connexin function is considered to be important as a new therapeutic target..|
|4.||Ryo Yamasaki, Wataru Shiraishi, Yu Hashimoto, Yuko Kobayakawa, Jun-ichi Kira, C-C chemokine receptor 2+ macrophages in nerves ameliorate motor neuron disease, PACTALS, 2021.09, Macrophages expressing C-C chemokine receptor type 2 (CCR2) infiltrate into the neural tissues of amyotrophic lateral sclerosis (ALS) patients. We reported an association between intrathecal upregulation of C-C chemokine ligand 2 (CCL2) and disease severity in ALS. We investigated the roles of CCR2+ macrophages in ALS using mutant Cu/Zn superoxide dismutase-1 G93A (mSOD1)-transgenic (Tg) mice. We generated SOD1G93A / CCR2 red fluorescence protein (RFP) / wild type (WT) / CX3CR1 green fluorescence protein (GFP) / WT-Tg mice heterozygously expressing CCR2-RFP and CX3CR1-GFP, and SOD1G93A / CCR2RFP/RFP-Tg mice, which developed a CCR2-deficient phenotype, and compared their clinical courses and pathology. In mSOD1-Tg mice, mSOD1 accumulated in the sciatic nerve earlier than in the spinal cord. Before disease onset, CCR2+ macrophages harboring mSOD1 infiltrated the sciatic nerve much earlier than in the lumbar cord. CCR2- deficient mSOD-Tg mice showed an earlier onset of disease and axonal derangement in the sciatic nerve compared with CCR2-positive mSOD1-Tg mice. CCR2-deficient mSOD1-Tg mice had a marked increase in deposited mSOD1 in the sciatic nerve compared with CCR2-positive mice together with a decreased infiltration of CCR2+ macrophages. These findings suggest CCR2+ macrophages recruited into the peripheral nerves exert neuroprotective functions in mSOD1 ALS. Clearance of mSOD1 from the peripheral nerve by CCR2+ macrophages is a hitherto-underestimated host protective mechanism..|
＠Jun-ichi Kira, Glial assembly via gap junction controls CNS disorders: insights from disease model mice
, 2021 asian oceanian congress of neurology, 2021.04.
＃白石 渉, C-C chemokine receptor 2+ macrophages in nerves ameliorate motor neuron disease model mice, 第126回日本解剖学会総会・全国学術集会 / 第98回日本生理学会大会 合同大会, 2021.03, Macrophages expressing C-C chemokine receptor type 2 (CCR2) infiltrate into the neural tissues of amyotrophic lateral sclerosis (ALS) patients. We reported an association between intrathecal upregulation of C-C chemokine ligand 2 (CCL2) and disease severity in ALS. We investigated the roles of CCR2+ macrophages in ALS using mutant Cu/Zn superoxide dismutase 1G93A (mSOD1)-transgenic (Tg) mice.
In mSOD1-Tg mice, mSOD1 accumulated in the sciatic nerve earlier than in the spinal cord. Before disease onset, CCR2+ macrophages harboring mSOD1 infiltrated the sciatic nerve much earlier than in the lumbar cord. CCR2- deficient mSOD-Tg mice showed an earlier onset of disease and axonal derangement in the sciatic nerve compared with CCR2-positive mSOD1-Tg mice. CCR2-deficient mSOD1-Tg mice had a marked increase in deposited mSOD1 in the sciatic nerve compared with CCR2-positive mice together with a decreased infiltration of CCR2+ macrophages. These findings suggest CCR2+ macrophages recruited into the peripheral nerves exert neuroprotective functions in mSOD1 ALS. Clearance of mSOD1 from the peripheral nerve by CCR2+ macrophages is a hitherto-underestimated host protective mechanism..
|7.||Ryo Yamasaki Yinan Zhao Marion Wijering Mei Fang Hayato Une Guangrui Li Hiroo Yamaguchi Jun-ichi Kira, Glial assembly via gap junction controls CNS disorders: insights from disease model mice, 第63回 日本神経化学会大会, 2020.09, Connexins, which comprise gap junctions via homotypic/heterotypic oligomerization, act as channels to connect opposing cells, mainly in solid organs such as the skin, liver, heart, and central/peripheral nervous system. Connexins are synthesized and inserted into the cell membrane as hemichannels. Opening of hemichannels, which depends on the intra- or extracellular environment, allows various bioactive molecules to enter into or be released from the host cells. Recent pathological studies on human demyelinating diseases have revealed alterations of connexin expression patterns in demyelinating lesions. To elucidate the molecular mechanisms of connexins in the pathomechanisms of inflammatory demyelination, we induced experimental autoimmune encephalomyelitis (EAE) in connexin 30 (Cx30)-deficient mice, oligodendroglia-specific Cx47-ablated mice, and astroglia-specific Cx43-ablated mice. We found that both astroglial-Cx30-deficient mice and Cx43-ablated mice showed amelioration of the clinical course of EAE, while oligodendroglial-Cx47-ablated mice showed aggravation. These findings indicate the distinct role of connexins expressed in different cell types and the substantial contribution of connexin-mediated pathology to demyelinating disorders. The imbalance in connexin expression, which is caused by the inflammatory environment, results in an increase in hemichannels in glial cells. The release of pro-inflammatory molecules induced by the increase in hemichannels on activated glial cells is a crucial mechanism of demyelinating disorders..|
|8.||山﨑 亮, A genetically engineered mouse approach to elucidate molecular mechanisms of demyelinating diseases
, 第61回日本神経学会学術大会, 2020.08, Connexins (Cxs) are gap-junction proteins that are organized as a hexagonal cylinder with a central pore. In the central nervous system, Cx30 and 43 are expressed on astroglia while Cx32 and 47 are expressed on oligodendroglia. In acute and chronic multiple sclerosis (MS) lesions, oligodendroglial Cx47 is extensively and persistently lost. In order to elucidate roles of glial Cxs in inflammatory demyelination, we generated Plp-CreERT; Cx47 fl/fl mice, which showed oligodendroglia-specific Cx47 deletion (Cx47 icKO upon tamoxifen administration. Control Cx47 flox (fl)/fl mice were also treated by tamoxifen. Fourteen days after tamoxifen treatment, experimental autoimmune encephalomyelitis (EAE) was induced by myelin oligodendrocyte glycoprotein peptide (MOG35-55) immunization. Cx47 icKO mice demonstrated exacerbation of acute and chronic EAE with increased relapse rates and more pronounced demyelination than Cx47 fl/fl littermates. CD3+ T cells, especially Th17 cells, and macrophages more abundantly infiltrated the spinal cord in Cx47 icKO mice compared with Cx47 fl/fl mice, while MOG35-55-specific proliferation and pro-inflammatory cytokine production of splenocytes were unaltered. Microarray analysis of isolated microglia revealed stronger microglial activation toward pro-inflammatory and injury-response phenotypes in Cx47 icKO mice compared with Cx47 fl/fl mice at the acute to chronic phases. Immunohistochemically, NOS2+ and MHC class II+ microglia were more abundant in Cx47 icKO mice than Cx47 fl/fl mice. While both mice showed up-regulation of A1-specific, A2-specific, and pan-reactive astroglial genes at the acute phase, only Cx47 icKO mice showed persistent upregulation of A1-specific genes at the chronic phase. These findings suggest that oligodendroglia-specific Cx47 ablation induces severe inflammation upon autoimmune demyelination, underlining a critical role for Cx47 in regulating neuroinflammation. .
|9.||Ryo Yamasaki, Wataru Shiraishi, and Jun-ichi Kira, CCR2 Positive Immune Cells Play Protective Roles in ALS Mouse Model, Society for Neuroscience 2018 (SFN2018), 2018.11.|
|10.||Ryo Yamasaki, Takayuki Fujii, Kyoko Iinuma,Daisuke Tsuchimoto, Mizuho Kido, Shinichi Aishima, Yusaku Nakabeppu, Jun-ichi Kira , Plexin D1 as a novel autoantibody in patients with neuropathic pain: from bench to bedside, 10th meeting for Korean Encephalitis and Neuroinflammation Society, Fall 2018, 2018.10.|
|11.||Ryo Yamasaki MD, PhD, Yinan Zhao MD, Marion Wijering BS, Mei Fang MD, Guangrui Li MD, PhD, Hayato Une MD,
Hiroo Yamaguchi MD, PhD, Jun-ichi Kira MD, PhD., Elucidation of the effects of gap junction protein connexin on the pathogenesis of multiple sclerosis model mice and development of new therapeutic options by functional modification
ギャップ結合蛋白コネキシンが多発性硬化症モデルマウスの病態に及ぼす影響の解析, 第61回日本神経化学学会, 2018.09.
|12.||Ryo Yamasaki MD, PhD, Yinan Zhao MD, Marion Wijering BS, Hiroo Yamaguchi MD, PhD, Jun-ichi Kira MD, PhD., A novel secondary progressive multiple sclerosis model by oligodendroglia-specific inducible conditional knockout of connexin 47, International Society of Neuroimmunology Congress 2018, 2018.08.|
|13.||Ryo Yamasaki, Revisiting glia; as a mother and guardian of central nervous system, 第59回日本神経学会学術大会, 2018.05.|
|14.||Ryo Yamasaki, Mei Fang, Yinan Zhao, Hayato Une, Hiroo Yamaguchi, Jun-ichi Kira, Astroglial and oligodendroglial connexins differentially modulate acute and chronic experimental autoimmune encephalomyelitis, The 22nd Annual Meeting of the Japan Glia, 2017.12.|
|15.||Ryo Yamasaki MD, PhD, Yinan Zhao, MD, Hiroo Yamaguchi MD, PhD, Jun-ichi Kira MD, PhD., Oligodendroglia-specific Connexin 47 deletion induced relapse-remitting EAE model mice, 10th PACTRIMS Ho Chi Minh City, Vietｎam, 2017.11.|
|16.||Ryo Yamasaki, Hiroo Yamaguchi, Takuya Matsushita, Takayuki Fujii, Akio Hiwatashi, Jun-ichi Kira, Early strong intrathecal inflammation in cerebellar type multiple system atrophy (MSA-C) based on cerebrospinal fluid cytokine and chemokine profiles, XXIII World Congress of Neurology（WCN2017）, 2017.09.|
|17.||山﨑 亮, Astroglial (Cx30, Cx43) and oligodendroglial (Cx47) connexins modulate acute and chronic experimental autoimmune encephalomyelitis (EAE)
, 第4回 MSサマーカレッジ, 2017.08.
|18.||山﨑 亮, Allergic inflammation affects to CNS innate immunity and glial inflammation., Basic Research Forum, 2016.12.|
|19.||山﨑 亮, Mei Fang, Hiroo Yamaguchi, Jun-ichi Kira, Functional analysis of Cx30 in experimental autoimmune encephalomyelitis, 141st Annual meeting of the american neurological association, 2016.10, Objective: Connexins are known to compose gap junctions by a pair of hemichannels connected in a head to head configuration. Each hemichannel is composed by hexameric cluster of connexins. There are 20 members of connexins known as connexin family in mice, and are expressed on each cell surface in different fashion. Connexin 30 (Cx30) is mainly expressed on the surface of oligodendroglia and astrocyte in central nervous system (CNS), but little is known about the functional relevance in neuroinflammatory diseases. To elucidate the role of Cx30 in the pathogenesis of neuroinflammatory disease, we induced experimental autoimmune encephalomyelitis (EAE) on Cx30 knock-out (Cx30-KO) mice and analyzed the clinical and neuropathological findings with wild-type control.
Methods: C57BL/6J and Cx30-KO mice > 12 weeks of age were used in this study (N > 3 in each group). EAE was induced by immunization of mice with MOG35-55 peptide emulsified in CFA at a dose of 200 μg per mouse, followed by the administration of pertussis toxin (500 ng per mouse) on days 0 and 2. Mice were sacrificed and brain, spinal cord, spleen, and optic nerve were harvested for immunohistochemical analyses at the acute and chronic phases of EAE. Mice with EAE were scored as follows: 0, no disease; 1, limp tail; 2, abnormal gait and hind limb weakness (shaking); 2.5, paralysis of one hind limb; 3, paralysis of two hind limb; 3.5, ascending paralysis (able to move around); 4, tetraplegia; and 5, moribund (death). At the onset and chronic stage of EAE, mononuclear cells were isolated and analyzed by flow cytometry to check the distinct characteristics of cellular populations in inflamed CNS lesions.
Results: Initial screening of immunohistological difference revealed basic activation of microglial cells in naïve Cx30-KO mice without any behavioral phenotype. Clinical signs of EAE were ameliorated in the Cx30-KO mice than in the control group mainly during the chronic phase of disease course. Immunohistochemical analyses of the fourth lumbar segment, brain and optic nerve revealed increased number of microglia in the Cx30-KO mice. Flow cytometric analysis also confirmed the findings. In contrast, there were no significant change in astroglial or oligodendroglial phenotype.
Conclusion: Microglial activation appears to be the key factor in the Cx30-KO mice EAE with alleviation of chronic disease scores. Unexpectedly, microglia were already activated in naïve CNS, indicating protective phenotypic change of microglia in Cx30-KO mice..
|20.||山﨑 亮, 方 梅, 藤井 敬之, 李 広瑞, 吉良 潤一, Atopic model mice express more severe signs at the chronic phase of EAE, 第57回日本神経学会学術大会, 2016.05.|
|21.||山﨑 亮, Wang Bing, Fang Mei, 藤井 敬之, 城戸 瑞穂, 吉良 潤一, A mouse model of atopic diathesis displaying tactile allodynia with glial inflammation in the spinal cord, XII European Meeting on Glial Cells in Health and Disease Bilbao, 2015.06.|
|22.||山﨑 亮, 山口 浩雄, 樋渡 昭雄, 松下 拓也, 吉良 潤一, Cerebrospinal fluid cytokine levels in multiple system atrophy patients, 第５６回日本神経学会, 2015.05.|
|23.||山﨑 亮, 吉良 潤一, Combined Central and Peripheral Demyelination (CCPD): clinical features and immune mechanisms, East Asia Neurology Forum 2015, 2015.04.|
|24.||山﨑 亮, 河村 信利, 米川 智, 松下 拓也, 村井 弘之, 吉良 潤一, Anti-neurofascin antibody in patients with combined central and peripheral demyelination, ECTRIMS, 2013.10.|
|25.||山﨑 亮, 松下 拓也, 村井 弘之, 吉良 潤一, 河村 信利, Anti-neurofascin antibody in patients with combined central and peripheral demyelination, ECTRIMS, 2013.10, Background: Growing reports indicated that some multiple sclerosis (MS) patients have peripheral demyelinations and also some of the chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients have demyelinating lesions in the central nervous system (CNS). These combined central and peripheral demyelinations (CCPD) patients have unique characteristics in clinical signs, medical examinations and responses in treatment, but it is still controversial if these patients are distinct from MS or CIDP.
Objectives: We aimed to identify the target antigens for CCPD and to characterize clinical course of CCPD patients.
Methods: We screened target antigens by immunohistochemistry and immunoblotting using peripheral nerve tissues to identify target antigens recognized by serum antibodies from selected CCPD and CIDP cases. We then measured the level of antibody to the relevant antigen in 7 CCPD patients, 16 CIDP patients, 20 MS patients, 20 patients with Guillain-Barré syndrome (GBS), 21 patients with other neuropathies (ON), and 23 healthy controls (HC) by ELISA and cell-based assays using HEK293 cells. We have also reviewed the clinical data of CCPD patients.
Results: At the initial screening, sera from two CCPD patients showed cross-like binding to sciatic nerve sections at fixed intervals, with nearly perfect co-localization with pan-neurofascin immunostaining at the node and paranode. ELISA with recombinant neurofascin revealed significantly higher mean optical density values in the CCPD group than in other disease groups and HC. Anti-neurofascin antibody positivity rates were 86% in CCPD patients, 10% in MS patients, 25% in CIDP patients, 15% in GBS patients, and 0% in ON patients and HC. The cell-based assay detected serum anti-neurofascin antibody in 5/7 CCPD patients; all others were negative. CSF samples from three CCPD patients examined were all positive. In anti-neurofascin antibody-positive CCPD patients, including those with a limited response to corticosteroids, intravenous immunoglobulin or plasma exchange alleviated the symptoms.
Conclusion: Anti-neurofascin antibody is frequently present in CCPD patients. Recognition of this antibody may be important, because antibody-positive CCPD patients respond well to intravenous immunoglobulin or plasma exchange.
|26.||The impaired neuroprotective function of microglia in the mutant superoxide dismutase 1 transgenic mice.|
|27.||The impaired neuroprotective function of microglia in the mutant SOD1 transgenic mice.|