Although the regenerative potential of adult skeletal muscle is maintained by satellite cells, other stem/progenitor cell populations also reside in skeletal muscle. These heterogeneous cellular pools with mesenchymal lineage potentially play important roles in tissue homeostasis, with reciprocal collaborations between these cells and satellite cells appearing critical for effective regeneration. However, in disease settings, these mesenchymal stem/progenitors adopt a more sinister role – likely providing a major source of fibrosis, fatty tissue and extracellular matrix protein deposition in dystrophic tissue. Development of therapies for muscle degeneration therefore requires complete understanding of the multiple cell types involved and their complex interactions.
Like most postnatal tissues, skeletal muscle plays host to a heterogeneous pool of tissue resident mesenchymal stem/progenitor cells. These progenitors play critical supporting roles in regeneration, collaborating with the host stem cell pool (satellite cells) to ensure effective repair. In disease, however, mesenchymal stem/progenitor cells adopt a more sinister role, sabotaging regeneration and providing a major source of fibrosis in dystrophic muscle.