骨格筋の細胞融合による電位依存性カルシウム放出機構の制御

• Published in: 日本薬理学会年会要旨集 p. 4-B-O13-3
• Main Authors: 山口, 君空, 赤羽, 悟美, 大島, 大輔, 冨田, 太一郎, 三上, 義礼
• Format: Journal Article
• Language: Japanese
• Published: 公益社団法人 日本薬理学会 2022
• Subjects: calcium; muscle cell; skeletal muscle
• ISSN: 2435-4953
• DOI: 10.1254/jpssuppl.96.0_4-B-O13-3

One of the most dynamic processes during skeletal myogenesis is cell-cell fusion, which promotes skeletal myoblast to form a large multi-nucleated myofiber equipped with EC-coupling machinery. Recently discovered transmembrane protein Myomixer (Mymx) executes cell-cell fusion, although the physiological significance of Mymx-mediated fusion on myogenic cell differentiation remains largely unknown. The current study focuses on the intracellular Ca2+ signaling mechanism to understand the physiological importance of Mymx mediated cell fusion in regulating voltage-induced Ca2+release in the developing skeletal muscle cells. C2C12 cells were used as an in vitro myogenesis model of skeletal muscle cells. We investigated intracellular Ca2+ release upon electric field stimulation applied to differentiated Mymx-KO cells and Mymx-rescued cells. We found that the efficiency of Ca2+ response was dependent on the Mymx gene expression. Importantly, expression levels of MyoD and myogenin were almost unaltered by the gene rescue of Mymx, suggesting that the Mymx-dependent Ca2+ response is regulated independently of these transcription factors. In conclusion, we found a novel regulatory linkage between Mymx expression and the voltage-induced Ca2+ release essential for EC coupling.