Macrophages fine tune satellite cell fate in dystrophic skeletal muscle of mdx mice

Author summary

Satellite cells (SCs) are muscle stem cells that remain quiescent during homeostasis and are activated in response to acute muscle damage or in chronic degenerative conditions such as Duchenne Muscular Dystrophy. The activity of SCs is supported by specialized cells which either reside in the muscle or are recruited in regenerating skeletal muscles, such as for instance macrophages (M Phi s). By using a dystrophic mouse model of transient M Phi depletion, we describe a shift in identity of muscle stem cells dependent on the crosstalk between M Phi s and SCs. Indeed M Phi depletion determines adipogenic conversion of SCs and exhaustion of the SC pool leading to an exacerbated dystrophic phenotype. The reported data could also provide new insights into therapeutic approaches targeting inflammation in dystrophic muscles.