The role of inflammatory factors in skeletal muscle injury

Injured skeletal muscle produces a series of inflammatory cytokines that activate the immune system. The pro-inflammatory factors in the lesions cause muscle loss most by activating the ubiquitin-proteasome degradation pathway and enhancing autophagy-lysosome degradation pathway. Also it can affect the repair and remodeling of muscle tissue by inhibiting the proliferation and differentiation of myogenic cells. However, the inflammation after injury is not all harmful. Destruction of tissue by phagocytic cells infiltrated by early inflammation will change the microenvironment. That is beneficial for muscle regeneration. The hallmark event of the muscle regeneration is that the macrophage transforms their phenotype. In that phase, immune cells produce cytokines with anti-inflammatory properties. These cytokines could promote muscle regeneration by down-regulating the expression of pro-inflammatory factors and affecting stem cell proliferation and differentiation.