2026-03-11T22:16:49Z https://asahikawa-med.repo.nii.ac.jp/oai

oai:asahikawa-med.repo.nii.ac.jp:02000332 2025-02-13T02:52:12Z 7:27:45

NG-2positive pericytes regulate homeostatic maintenance of slow-type skeletal muscle with rapid myonuclear turnover NG2陽性周皮細胞は迅速な筋核のターンオーバーを介して遅筋の恒常性維持に寄与している 竜川, 貴光 タツカワ, タカミツ Tatsukawa, Takamitsu open access Myogenesis Pericytes Skeletal muscle Slow-type muscle Stem cells PMID:37592340 Background: Skeletal muscle comprises almost 40% of the human body and is essential for movement, structural support and metabolic homeostasis. Size of multinuclear skeletal muscle is stably maintained under steady conditions with the sporadic fusion of newly produced myocytes to compensate for the muscular turnover caused by daily wear and tear. It is becoming clear that microvascular pericytes (PCs) exhibit myogenic activity. However, whether PCs act as myogenic stem cells for the homeostatic maintenance of skeletal muscles during adulthood remains uncertain. Methods: We utilized PC-fused myofibers using PC-specific lineage tracing mouse (NG2-CreERT/Rosa-tdTomato) to observe whether muscle resident PCs have myogenic potential during daily life. Genetic PC deletion mouse model (NG2-CreERT/DTA) was used to test whether PC differentiates to myofibers for maintenance of muscle structure and function under homeostatic condition. Results: Under steady breeding conditions, tdTomato-expressing PCs were infused into myofibers, and subsequently, PC-derived nuclei were incorporated into myofibers. Especially in type-I slow-type myofibers such as the soleus, tdTomato+ myofibers were already observed 3 days after PC labeling; their ratio reached a peak (approximately 80%) within 1 month and was maintained for more than 1 year. Consistently, the NG2+ PC-specific deletion induced muscular atrophy in a slow-type myofiber-specific manner under steady breeding conditions. The number of myonucleus per volume of each myofiber was constant during observation period. Conclusions: These findings demonstrate that the turnover of myonuclei in slow-type myofibers is relatively fast, with PCs acting as myogenic stem cells-the suppliers of new myonuclei under steady conditions-and play a vital role in the homeostatic maintenance of slow-type muscles. 2023-08-17 eng doctoral thesis VoR https://asahikawa-med.repo.nii.ac.jp/records/2000332 https://doi.org/10.1186/s13287-023-03433-1 1757-6512 Stem cell research and therapy 14 1 205 甲第597号 博士（医学） 2023-12-25 旭川医科大学 https://asahikawa-med.repo.nii.ac.jp/record/2000332/files/K597 Tatsukawa Takamitsu_TD.pdf application/pdf 5.5 MB 2025-02-13