Muscle Stem Cell Microenvironment and Functions in Muscle Regeneration

Muscle stem cells (MuSCs) are the key to muscle regeneration. The activation and maintenance of MuSCs require the precise regulation of their microenvironments. Myofibers and other cells including endothelial cells, fibroblasts, and immune cell populations constitute the cell components of the MuSC niche. The communication between these cell populations and MuSCs play an essential role in muscle repair. Furthermore, the physical and chemical stimulations around MuSCs also affect the cell behaviors of MuSCs. Extracellular matrix (ECM) and the factors stored in it generate a repair-promoting niche for efficient muscle regeneration. Understanding the mechanism of muscle stem cell regulation is the basis of clinically optimizing muscle repair. In this review, we discuss recent findings about the microenvironments of MuSCs and their functions in muscle regeneration, which would shed light on new targets and strategies for muscle injury treatment.