Skeletal muscle myofibers possess regenerative capacity in response to muscle injuries caused by excessive exercise. Muscle-resident stem cells, called muscle satellite cells (MuSCs), play a critical role in myofiber regeneration to maintain homeostasis in skeletal muscle. Mechanosensation and concomitant adaptation are presumed to be involved in myofber regeneration, but the molecular entity that converts the mechanical stimuli into biochemical signals for myofiber regeneration remains unknown. Here we identify PIEZO1, a Ca²⁺-permeable mechanosensitive cation channel that is activated by membrane tension, as a key determinant for muscle regeneration. Fluorometric Ca²⁺ imaging detected PIEZO1-dependent Ca²⁺ fluctuation in freshly isolated MuSCs. Myofiber regeneration after muscle injury was significantly delayed in MuSC-specific Piezo1-deficient mice, at least partly because of mitotic defects of undifferentiated MuSCs, such as the presence of chromosomal bridges and micronuclei. Moreover, pharmacological studies revealed that the cell division defects in Piezo1-deficient MuSCs could be restored by Rho activation. Collectively, PIEZO1 plays a role in muscle regeneration by controlling cell division of MuSCs in a Rho-dependent manner, suggesting that the mechanosensing machinery is central to the maintenance of muscle homeostasis. In this session, we will also present our preliminary results showing that a series of mechanosensitive ion channels could orchestrate muscle regeneration.