The Role of Stem Cells in Skeletal and Cardiac Muscle Repair

Abstract

In postnatal muscle, skeletal muscle precursors (myoblasts) can be derived from satellite cells (reserve cells located on the surface of mature myofibers) or from cells lying beyond the myofiber, e.g., interstitial connective tissue or bone marrow. Both of these classes of cells may have stem cell properties. In addition, the heretical idea that post-mitotic myonuclei lying within mature myofibers might be able to re-form myoblasts or stem cells is examined and related to recent observations for similar post-mitotic cardiomyocytes. In adult hearts (which previously were not considered capable of repair), the role of replicating endogenous cardiomyocytes and the recruitment of other (stem) cells into cardiomyocytes for new cardiac muscle formation has recently attracted much attention. The relative contribution of these various sources of precursor cells in postnatal muscles and the factors that may enhance stem cell participation in the formation of new skeletal and cardiac muscle in vivo are the focus of this review. We concluded that, although many endogenous cell types can be converted to skeletal muscle, the contribution of non-myogenic cells to the formation of new postnatal skeletal muscle in vivo appears to be negligible. Whether the recruitment of such cells to the myogenic lineage can be significantly enhanced by specific inducers and the appropriate microenvironment is a current topic of intense interest. However, dermal fibroblasts appear promising as a realistic alternative source of exogenous myoblasts for transplantation purposes. For heart muscle, experiments showing the participation of bone marrow-derived stem cells and endothelial cells in the repair of damaged cardiac muscle are encouraging.

Hepatocyte Growth Factor in Mouse Soleus Muscle Increases with Reloading after Unloading

“…Satellite cells display c-Met in all states of activation, proliferation and differentiation 27) and c-Met can be used as a molecular marker for these cells. The satellite cell is known as a quiescent muscle progenitor cell, and injury leads to cell activation 50) . After reloading, the majority of satellite cells were PCNA-positive, indicating that cells had entered the cell cycle.…”

Absence of p21CIP Rescues Myogenic Progenitor Cell Proliferative and Regenerative Capacity in Foxk1 Null Mice

“…In recent years, cellular augmentation therapy has been pursued using alternative adult stem cell populations, including myogenic stem (progenitor) cells, to repopulate the failing heart and myopathic skeletal muscle (23,24). The studies utilizing the transfer of myogenic progenitor cells for the treatment of debilitating myopathies and congestive heart failure have unfortunately yielded disappointing results.…”

Menstrual Blood-derived Cells Confer Human Dystrophin Expression in the Murine Model of Duchenne Muscular Dystrophy via Cell Fusion and Myogenic Transdifferentiation

“…Myoblasts represent the natural first choice in cellular therapeutics for skeletal muscle because of their intrinsic myogenic commitment (Grounds et al, 2002). However, myoblasts recovered from muscular biopsies are poorly expandable in vitro and rapidly undergo senescence (Cossu and Mavilio, 2000).…”