若手道場

若手道場3

2021/9/30　13:00～14:00　ZOOM 若手道場 WD3-1 マウス脳内出血病態に対するNurr1リガンドの効果比較 Comparison of the effects of Nurr1 ligands on the pathology of intracerebral hemorrhage in mice ^○木下慶大¹, Ayaka Yosimizu¹, Shunsuke Kotani¹, Yuki Kurauchi¹, Takahiro Seki¹, Hiroshi Katsuki¹ 1.熊本大学, 2.Department of Chemico-pharmacological Sciences, Kumamoto university, 3.Global Center for Natural Resources Sciences, Kumamoto University ^○Keita Kinoshita¹, Ayaka Yosimizu¹, Shunsuke Kotani¹, Yuki Kurauchi¹, Takahiro Seki¹, Hiroshi Katsuki¹ 1.Department of Chemico-pharmacological Sciences, Graduate School of Pharmacy, Kumamoto University, 2.Department of Chemico-pharmacological Sciences, Kumamoto university, 3.Global Center for Natural Resources Sciences, Kumamoto University Intracerebral hemorrhage (ICH) is a severe type of stroke featured by hematoma formation in the brain parenchyma that leads to high mortality and neurological dysfunction. At present, there are no effective pharmacotherapies for ICH. Nurr1 is an orphan nuclear receptor implicated in the suppression of inflammatory responses in microglia and astrocytes as well as the maintenance and survival of dopaminergic neurons in the midbrain. We have previously reported that a Nurr1 ligand amodiaquine (AQ) suppressed inflammatory events and mitigated neurological deficits in an experimental ICH model in mice. Here, we addressed whether another Nurr1 ligand 1,1-bis(3-indolyl)-1-(4-chlorophenyl)methane (C-DIM12) exerts a therapeutic effect in the mouse model of ICH and compared its effect with that of AQ. ICH was induced by injection of collagenase type VII (0.035 U) into the right striatum of young male ICR mice. C-DIM12 (50 mg/kg) was orally administered at 3 h after ICH induction, and thereafter, every 24 h. Although AQ showed significant suppression on astrocytic activation and restrictive inhibition on neuronal death, C-DIM12 did not affect astrocytic activation but significantly inhibited neuronal death. On the other hand, C-DIM12 significantly suppressed microglial activation and mRNA expression encoding pro-inflammatory cytokines/chemokines induced by ICH, as with the case of AQ. Moreover, C-DIM12 and AQ suppressed oxidative stress derived from nitric oxide and axonal damage after ICH. Furthermore, these ligands significantly mitigated ICH-induced neurological deficits. These results are consistent with the idea that Nurr1 may become a novel target for ICH therapy, although individual ligands exhibit different pharmacological profiles on ICH pathologies.		2021/9/30　13:00～14:00　ZOOM 若手道場 WD3-2 慢性脳低灌流に伴う認知機能障害および白質傷害に対するTRPA1の保護的役割 The protective role of TRPA1 in chronic cerebral hypoperfusion-induced cognitive impairment and white matter injury. ^○抱将史, Hiroki Nakajima, Shota Tobori, Misa Morishima, Kazuki Nagayasu, Hisashi Shirakawa, Shuji Kaneko 京都大学大学院薬学研究科 ^○Masashi Kakae, Hiroki Nakajima, Shota Tobori, Misa Morishima, Kazuki Nagayasu, Hisashi Shirakawa, Shuji Kaneko Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University Chronic cerebral hypoperfusion (CCH), resulting in an inadequate blood supply to the brain, is manifested in a variety of central nervous system (CNS) diseases including neurodegenerative and mental disorders accompanied by cognitive impairment. CCH is associated with oxidative stress and induces demyelination, white matter injury. Transient receptor potential ankyrin 1 (TRPA1), an oxidative stress-sensitive and Ca²⁺-permeable non-selective cation channel, is recently found to be expressed in brain cells, although the role of TRPA1 in the CNS diseases such as CCH-induced dementia is controversial. In this study, we investigated the pathophysiological role of TRPA1 in CCH using a mouse bilateral common carotid artery stenosis (BCAS) with 0.18 mm-diameter microcoils. At 14 days after operation, BCAS-operated TRPA1-knockout (TRPA1-KO) mice showed cognitive impairment and decreased myelin density, whereas these dysfunctions were not observed in wild-type (WT) mice. By contrast, BCAS-operated mice showed cognitive impairment and decreased myelin density in both WT and TRPA1-KO mice at 28 days after operation. Moreover, the activation of glial cells was observed in BCAS-operated WT but not TRPA1-KO mice. In addition, increased expressions of neurotrophic factors in BCAS-operated WT mice were not observed in TRPA1-KO mice at 14 days after operation. Finally, daily intraperitoneal administration of cinnamaldehyde, a TRPA1 activator, ameliorated BCAS-induced cognitive impairment and the decrease in myelin density at 28 days after operation. These results suggest that TRPA1 plays a protective role in the development of CCH-induced cognitive impairment and white matter injury, and that TRPA1 may be a therapeutic target for CCH-related CNS diseases.

2021/9/30　13:00～14:00　ZOOM 若手道場 WD3-3 シングルセル解析はマウス脊髄におけるアストロサイトの不均一性と脊髄損傷後のその反応性の違いを明らかにする Single nucleus RNA-sequencing reveals astrocyte heterogeneity in the mouse spinal cord and their different contributions to reactive gliosis after spinal cord injury ^○中西勝之¹, Yasuhiro Kamata², Tsukasa Sanosaka¹, Kentaro Ago², Noriko Mizota¹, Masaya Nakamura², Jun Kohyama¹, Hideyuki Okano¹ 1.未記入, 2.Department of Orthopedic Surgery, Keio University School of Medicine ^○Katsuyuki Nakanishi¹, Yasuhiro Kamata², Tsukasa Sanosaka¹, Kentaro Ago², Noriko Mizota¹, Masaya Nakamura², Jun Kohyama¹, Hideyuki Okano¹ 1.Department of Physiology, Keio University School of Medicine, 2.Department of Orthopedic Surgery, Keio University School of Medicine Astrocyte has physiologically essential roles in the healthy CNS to support neurons by the modulation of synapse formation, blood-brain barrier formation, as well as metabolite transportation. In addition to essential roles in the healthy tissue, astrocyte responds to CNS insults and this reactive gliosis has a crucial role for immune response and regeneration in the damaged tissue. In the spinal cord injury (SCI), astrocytes form glial scar that can impair axonal regeneration and functional recovery. However, concepts about what astrocyte reactivity in comprises and what it does after SCI are still incomplete and sometimes controversial. To investigate reactive gliosis after SCI at a molecular level, we performed single-nucleus RNA sequencing on intact and injured mouse spinal cord. Here, we show astrocytes have transcriptionally distinct subtypes in the spinal cord and specific subtypes contribute to glial scar formation after SCI. Interestingly, in the two subtypes of astrocytes, reactive astrocyte marker genes (pan-reactive, A1-specific, and A2 specific), axonal growth modulating genes, and immune response genes are upregulated after SCI. Histological analysis also shows these subtypes have specific distribution patterns in the intact spinal cord and specific subtypes accumulate in the glial scar in the injured spinal cord. Cell-cell interaction (CCI) analysis suggests CCI between microglia and these two subtypes of astrocytes is increasing after SCI. Whereas, these two subtypes have different gene expression patterns in ion channel and transporter, suggesting two subtypes have different capacities to sustain homeostasis of neuronal environment.Our findings offer a novel concept of reactive gliosis after spinal cord injury.