[Regenerative potential of mesodermal stem cells for the heart]

There has been increasing interest in recent years in the phenomenon of "regeneration," especially in the function of the bone marrow stromal cell system in the support of hematopoiesis. The stromal cell system has been proposed to consist of mesodermal stem cells that are capable of self-renewal and differentiation into a variety of mesodermal tissues, including bone, cartilage, tendon, fat, endothelium, skeletal muscle, and cardiomyocytes. These findings raise the possibility that bone marrow-derived cells may provide an alternative source of cardiomyocytes in patients with severe cardiac failure due to loss of muscle cells. Some studies have indicated that locally or systemically delivered mesodermal stem cells can generate de novo cardiomyocytes. Despite their potential clinical utility for cellular and gene therapy, the mechanism of differentiation in mesodermal stem cells and characterization of stem cells in terms of surface antigen expression remain to be resolved. Although some clinical trials have been initiated using crude bone marrow-derived stromal cells, we need more knowledge of stem cells to establish a standard protocol for cellular therapy.