Adult Stem Cells for Myocardial Repair

Cell transplantation for myocardial repair has emerged as a promising therapy for patients with heart failure. Recent in vitro and in vivo animal studies have suggested the potential of different cell types to differentiate into tissues required for cardiac repair namely endothelial cells and cardiomyocytes. In this review, we will focus on the potential of adult stem cells obtained from adult muscle and adult bone marrow to regenerate cardiac tissue. There are a number of studies suggesting that autologous myoblast or satellite cells can contribute in vivo to improve cardiac contractility. In fact, several clinical studies have been initiated using autologous ex vivo expanded myoblast in patients with myocardial infarction. We will review the rationale for this approach. Although attractive, the use of muscle derived progenitors has been questioned as these cells may not have the potential to differentiate into cardiac tissues. Besides, initial studies have been associated with a high incidence of cardiac arrythmias. Bone marrow derived stem cells have also been explored in vitro and in animal models in the context of cardiac repair. The potential of adult bone marrow derived stem cells to differentiate into cardiomyocytes and endothelial cells will be summarized as well as the initial results of clinical trials using autologous bone marrow cells.