Skeletal muscle satellite cell (MuSC)

Skeletal muscle satellite cells are mononucleated stem cells located between the basement membrane and plasma membrane of mature skeletal muscle fibers, serving as the primary source of new myonuclei for muscle maintenance, growth, repair, and remodeling.[1][5] These quiescent cells remain inactive under homeostatic conditions but activate in response to injury, exercise, or disease, re-entering the cell cycle to proliferate, differentiate into myoblasts, and fuse with existing fibers or form new ones, while a subset self-renews to replenish the stem cell pool.[1][3][5] Key markers like PAX7 are constitutively expressed, defining their identity, with heterogeneity revealed by subpopulations such as CAV1+ cells showing resistance to activation and stem-like properties.[2][4] In aging or inactivity, accumulated cellular waste and DNA damage impair their function, contributing to reduced regenerative capacity and senescence, whereas regular exercise promotes their activation to mitigate this.[1][13] Although not a conventional molecular drug target like receptors or enzymes, research explores modulating their behavior, such as via HIF2a inhibitors to enhance replication under hypoxia for faster healing.[7]

Other names

myosatellite cellsatellite cellmuscle satellite cellmyogenic satellite cell