Trophic actions of bone marrow-derived mesenchymal stromal cells for muscle repair/regeneration

Bone marrow-derived mesenchymal stromal cells (BM-MSCs) represent the leading candidate cell in tissue engineering and regenerative medicine. These cells can be easily isolated, expanded in vitro and are capable of providing significant functional benefits after implantation in the damaged muscle tissues. Despite their plasticity, the participation of BM-MSCs to new muscle fiber formation is controversial; in fact, emerging evidence indicates that their therapeutic effects occur without signs of long-term tissue engraftment and involve the paracrine secretion of cytokines and growth factors with multiple effects on the injured tissue, including modulation of inflammation and immune reaction, positive extracellular matrix (ECM) remodeling, angiogenesis and protection from apoptosis. Recently, a new role for BM-MSCs in the stimulation of muscle progenitor cells proliferation has been demonstrated, suggesting the potential ability of these cells to influence the fate of local stem cells and augment the endogenous mechanisms of repair/regeneration in the damaged tissues.