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bioRxiv · 10.64898/2026.05.19.726396

Biomechanical regulation of Ca2+ dynamics during muscle stem cell activation

Hirano, K.·Ishikawa, Y.·Motohashi, N.·Kobata, Y.·Watanabe, H.·Sasaki, M.·Yokoyama, T.·Yamada, Y.·Takakura, K.·Murakami, A.·Tsuchiya, M.·Ono, Y.·Nonomura, K.·Aoki, Y.·Hara, Y.
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Abstract

Muscle satellite cells (MuSCs) are muscle-resident stem cells that are responsible for myofiber regeneration. Although the importance of calcium ions (Ca2+) in muscle physiology has been well established, the mechanism by which Ca2+ mobilization governs MuSC function remains poorly understood. In this study, we aimed to systematically characterize Ca2+ dynamics in MuSCs and to define the mechanisms regulating these signals during muscle regeneration. By employing modified protocols for mouse MuSC isolation and Ca2+ measurement, we observed spontaneous Ca2+ fluctuations in MuSCs isolated from regenerating muscle after cardiotoxin-induced myofiber injury. Our detailed analysis using chemical Ca2+ indicators and a genetically encoded Ca2+ indicator revealed that the frequency and amplitude of Ca2+ fluctuations increased significantly during the activated and proliferative stages of MuSCs in muscle regeneration. This effect was more pronounced in MuSCs isolated from dystrophic and aged mice. Mechanistically, these Ca2+ fluctuations were at least partially mediated by mechanosensitive ion channels, including PIEZO1 and TRPM7, which promote MuSC migration. Collectively, our findings demonstrate that Ca2+ fluctuations through mechanosensitive ion channels act as a key regulator of MuSC activation during muscle regeneration and may provide new insights into the role of Ca2+ influx in muscle biology and the pathogenesis of muscle diseases.

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Hirano, K., Ishikawa, Y., Motohashi, N., Kobata, Y., Watanabe, H., Sasaki, M., Yokoyama, T., Yamada, Y., Takakura, K., Murakami, A., Tsuchiya, M., Ono, Y., Nonomura, K., Aoki, Y., Hara, Y.. 2026-05-21. Biomechanical regulation of Ca2+ dynamics during muscle stem cell activation. https://doi.org/10.64898/2026.05.19.726396

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