Intrinsic and extrinsic mechanisms regulating satellite cell function.
Muscle stem cells, termed satellite cells, are crucial for skeletal muscle growth and regeneration. In healthy adult muscle, satellite cells are quiescent but poised for activation. During muscle regeneration, activated satellite cells transiently re-enter the cell cycle to proliferate and subsequently exit the cell cycle to differentiate or self-renew. Recent studies have demonstrated that satellite cells are heterogeneous and that subpopulations of satellite stem cells are able to perform asymmetric divisions to generate myogenic progenitors or symmetric divisions to expand the satellite cell pool. Thus, a complex balance between extrinsic cues and intrinsic regulatory mechanisms is needed to tightly control satellite cell cycle progression and cell fate determination. Defects in satellite cell regulation or in their niche, as observed in degenerative conditions such as aging, can impair muscle regeneration. Here, we review recent discoveries of the intrinsic and extrinsic factors that regulate satellite cell behaviour in regenerating and degenerating muscles.
Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6.
Nicolas A
NA
Dumont
Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6 Faculty of Medicine, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5.
Yu Xin
YX
Wang
Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6 Faculty of Medicine, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5 mrudnicki@ohri.ca.
Michael A
MA
Rudnicki
D000375:Aging / Q000502:physiology*; D000818:Animals; D002453:Cell Cycle / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage / Q000502:physiology*; D003463:Cues; D006801:Humans; D008954:Models, Biological; D024510:Muscle Development / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D012038:Regeneration / Q000502:physiology*; D032496:Satellite Cells, Skeletal Muscle / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology
Aging; Asymmetric division; Cell cycle regulation; Muscle stem cell; Myogenesis; Quiescence; Regeneration; Satellite cell; Self-renewal; Skeletal muscle