一般口演

一般口演3

2021/9/30　14:00～15:00　オンデマンド D会場 O3-1 アストロサイトABCA1欠損誘導性緑内障における神経炎症 Astrocytic ABCA1 deficiency causes neuroinflammation during pathogenesis of glaucoma ^○篠崎陽一¹, Alex Lung³, Kazuhiko Namekata⁴, Kenji Kashiwagi⁵, Nobuhiko Ohno^5,6, Eiji Shigetomi^1,2, Takahiro Segawa⁸, Takayuki Harada⁴, Shinichi Ohnuma³, Schuichi Koizumi^1,2 1.山梨大学大学院総合研究部医学域基礎医学系薬理学講座, 2.GLIA Center, Univ. Yamanashi, 3.Inst. Ophthalmol., UCL, 4.Vis. Res. Project, Tokyo Metr. Inst. Med. Sci., 5.Dept. Ophthalmol, Interdiscip. Grad. Sch. Med. Univ. Yamanashi, 6.Div. Ultrastruct. Res., Natl. Inst. Physiol. Sci., 7.Dept. Anat., Jichi Med. Univ. Tochigi, 8.Cent. Life Sci. Res., Univ. Yamanashi ^○Youichi Shinozaki¹, Alex Lung³, Kazuhiko Namekata⁴, Kenji Kashiwagi⁵, Nobuhiko Ohno^5,6, Eiji Shigetomi^1,2, Takahiro Segawa⁸, Takayuki Harada⁴, Shinichi Ohnuma³, Schuichi Koizumi^1,2 1.Dept. Neuropharmacol., Interdisp. Grad. Sch. Med., Univ. Yamanashi, 2.GLIA Center, Univ. Yamanashi, 3.Inst. Ophthalmol., UCL, 4.Vis. Res. Project, Tokyo Metr. Inst. Med. Sci., 5.Dept. Ophthalmol, Interdiscip. Grad. Sch. Med. Univ. Yamanashi, 6.Div. Ultrastruct. Res., Natl. Inst. Physiol. Sci., 7.Dept. Anat., Jichi Med. Univ. Tochigi, 8.Cent. Life Sci. Res., Univ. Yamanashi Glaucoma, leading cause of blindness worldwide, is characterized by progressive degeneration of retinal ganglion cells (RGCs). Although an elevated intraocular pressure (IOP) is one of major risk factors, many Japanese glaucoma patients show normal level of IOP (i.e. normal tension glaucoma, NTG). Genome wide association studies have shown that single nucleotide polymorphism of ATP-binding cassette transporter 1 (ABCA1) gene correlates with an elevated risk of glaucoma. In the last meeting, we reported that deficiency of Abca1 gene, especially in astrocytes, caused RGC degeneration and visual impairment without IOP changes. Although dysfunction of astrocytes was essential for NTG-like pathologies, molecular mechanisms remained unclear. Here, we report a part of pathological mechanisms analyzed by single-cell RNA sequencing of retina. We first performed bioinformatics analysis at whole cell level and found many retinal disase-related annotations (e.g. Retinal degeneration) in Disease of Functions Annotation. In the Ingenuity Canonical Pathways, “CXCR4 signalling” was identified one of the up-regulated pathways in RGCs and astrocytes in ABCA1 deficient (KO) mice. Immunohistochemical analysis revealed that CXCL12, a ligand for CXCR4, was up-regulated in the astrocyte-specific ABCA1KO mice. Because CXCL12 is well-known to regulate monocytes/macrophage chemotaxis, we then investigated the number of microglia/macrophage (MG/Mφ) cluster. Compared to WT, the number of MG/Mφ cells increased. The increased cells expressed in C1q (MG/Mφ marker) but not P2ry12 (MG marker), indicating infiltration of peripheral Mφ into the retina. Taken together, our data showed that lack of ABCA1 triggers Mφ infiltration and neuroinflammation, which would contribute to pathogenesis of NTG.		2021/9/30　14:00～15:00　オンデマンド D会場 O3-2 細胞内lysophosphatidylserine 量の増加によるミクログリア炎症反応の増悪作用 Increase in intracellular lysophosphatidylserine content exacerbates inflammatory response by cultured microglia. ^○南畑朋輝, Katsura Takano, Yoichi Nakamura, Mitsuaki Moriyama 大阪府立大学　統合生理学教室 ^○Tomoki Minamihata, Katsura Takano, Yoichi Nakamura, Mitsuaki Moriyama Laboratory of Integrative Physiology in Veterinary Sciences, Osaka Prefecture University Alpha/beta-hydrolase domain containing (ABHD) 12 gene, that encode lysophosphatidylserine (LysoPS) lipase, is the causative gene of an early onset and progressive neurodegenerative disease characterized by polyneuropathy, hearing loss, ataxia, retinitis pigmentosa and cataract (PHARC). ABHD12 is highly expressed in the central nervous system, especially in microglia and intracellularly localized to the endoplasmic reticulum. Moreover, PHARC model mice which lack ABHD12 gene show enhanced LysoPS amount and increased number of activated microglia in the brain. Therefore, we hypothesize that increase in intracellular LysoPS in microglia, caused by ABHD12 deficiency, induces the symptoms of PHARC by promoting neuroinflammation and neurodegeneration. However, the impacts of increase in intracellular LysoPS content on microglial function remain unclear. Thus, we explored the effects of increased LysoPS content on microglial inflammatory responses using an inhibitor of LysoPS lipase, ABHD12. We used mouse microglial cell line, BV-2 and partly primary microglia that were experimentally stimulated with lipopolysaccharide (LPS). Blockade of ABHD12 by DO-264 enhanced intracellular LysoPS content in LPS-treated BV-2 microglia. Inhibition of ABHD12 by DO-264 exacerbated LPS-induced phagocytosis both in BV-2 and primary microglia. Furthermore, ABHD12 blockade alone significantly increased phagocytic activity even without LPS stimulation in primary microglia. In contrast, treatment with DO-264 had no effects on the production of pro-inflammatory factors such as nitric oxide and cytokine in BV-2 microglia. These results suggest that increase in intracellular LysoPS content in microglia may promote phagocytosis of neuronal cells, which can lead to neurodegeneration.

2021/9/30　14:00～15:00　オンデマンド D会場 O3-3 CD38の阻害及びNRの補充は脳内NAD+を増加させ神経炎症を抑制する Inhibition of CD38 and supplementation of nicotinamide riboside ameliorate lipopolysaccharide-induced microglial and astrocytic neuroinflammation by increasing NAD+ ^○服部剛志, Jureepon Roboon, Hiroshi Ishii, Mika Takarada-Iemata, Thi Nguyen, Osamu Hori 金沢大学医薬保健研究域医学系神経解剖学講座 ^○Tsuyoshi Hattori, Jureepon Roboon, Hiroshi Ishii, Mika Takarada-Iemata, Thi Nguyen, Osamu Hori Department of Neuroanatomy, Graduate School of Medical Science, Kanazawa University Insufficient control of neuroinflammation leads to enhanced or prolonged pathology in various neurological conditions including multiple sclerosis and Alzheimer’s disease. Nicotinamide adenine dinucleotide (NAD+) plays critical roles in cellular energy metabolism and calcium homeostasis. To clarify whether CD38 directly affects neuroinflammation through regulating brain NAD+ level, we investigated the effect of CD38 deletion and inhibition and supplementation of NAD+ on lipopolysaccharide (LPS)-induced neuroinflammation in mice. First, intracerebroventricular injection of LPS significantly increased CD38 expression especially in the hippocampus. Deletion of CD38 decreased LPS-induced inflammatory responses and glial activation. Pre-administration of apigenin, a flavonoid with CD38 inhibitory activity, or nicotinamide riboside (NR), an NAD+ precursor, increased NAD+ level, and significantly suppressed induction of cytokines and chemokines, glial activation and subsequent neurodegeneration after LPS administration. In cell culture, LPS-induced inflammatory responses were suppressed by treatment of primary astrocytes or microglia with apigenin, NAD+, NR or 78c, the latter a specific CD38 inhibitor. Finally, all these compounds suppressed NF-kB signaling pathway in microglia. These results suggest that CD38-mediated neuroinflammation is linked to NAD+ consumption and that boosting NAD+ by CD38 inhibition and NR supplementation directly suppress neuroinflammation in the brain.		2021/9/30　14:00～15:00　オンデマンド D会場 O3-4 免疫依存性神経変性病態における疾患関連ミクログリアの役割 Disease-associated microglia as a pathogenic hub in immune cell-mediated neurodegeneration ^○大木伸司, Ben Raveney, Fumio Takahashi, Takashi Yamamura, Chenyang Zhang Department of Immunology, National Institute of Neuroscience, NCNP ^○Shinji Oki, Ben Raveney, Fumio Takahashi, Takashi Yamamura, Chenyang Zhang Department of Immunology, National Institute of Neuroscience, NCNP The pathogenic process of neurodegeneration is entangled with little mechanistic view obtained to date. Although cell autonomous neurodegeneration has been highlighted for a long while, non-cell autonomous cues have recently got into the limelight. Microglia are one of such pathogenic players under neurodegeneration and one of representative phenotypic changes acquired during neurodegenerative processes is the activation of type I interferon (IFN-I) responses and upregulation of MHC class II molecules. Whereas the roles of MHC class II are not described yet, hyper responses of IFN-I are commonly associated with pathogenesis of authentic neurodegenerative diseases such as Alzheimer’s diseases (AD) and amyotrophic lateral sclerosis (ALS) We have recently demonstrated that helper T cells expressing Eomes (Eomes+ Th cells) are intrinsically involved in neurodegenerative processes comorbid in a progressive subtype of multiple sclerosis (MS) and its animal model. As both IFN-I and MHC class II are important regulators of immune responses, we evaluated intrinsic involvement of microglia for immune cell-mediated neurodegeneration. Now we revealed that primed microglia under the chronic inflammation of the central nervous system (CNS) secreted IFN-I that boosted generation of Eomes+ Th cells with intracellular retention of cytolytic granzyme B. Furthermore, Eomes+ Th cells are quickly activated upon encounter with primed microglia that present putative CNS antigens on their MHC class II molecules, which is enough to secrete neurotoxic granzyme B in brain parenchyma. Collectively, our data clearly demonstrate a critical involvement of microglia as a pathogenic hub in immune-cell mediated neurodegeneration.