Post-infarct heart repair with granulocyte-colony stimulating factor: Is it a utopian goal?

See article by Misao et al. [16] (pages 455–465) in this issue. For many years, the regeneration of the myocardium in which cells have been lost as a result of myocardial infarction (MI) and other forms of cardiac pathology has been a utopian goal of cardiologists. Recent experimental studies and early-phase clinical trials supported the possibility of enhancing cardiac repair as an achievable therapeutic target. Yet, disappointing, negative results have been reported both in experimental and clinical studies [1–3]. There can be several reasons for negative results. Certainly, the fact that we do not know the exact physiology of stem cells is one of the reasons. We do not know yet the ideal cell type: bone marrow stem cells (BMSCs), cardiomyoplasty cardiomyocytes, skeletal myoblasts, and resident stem cells have been tested, and among BMSCs several cell lines (MSCs, EPCs, etc.) have been proposed [1–3]. We do not know the underlying mechanism of cellular regeneration (transdifferentiation, fusion, and/or paracrine effects). Finally, we do not know whether myocardial repair can be better achieved via cellular transplantation (intramyocardial, intracoronary, and/or systemic delivery) or mobilization of primitive BMSCs by cytokines. Each of these approaches may be adequate for specific patients. Undoubtedly, mobilization of BMSCs might offer a noninvasive therapeutic approach that is appealing for both physicians and patients. The bone marrow is a large reservoir of adult stem cells distal from the heart that can be enrolled for cell-mediated cardiac repair via regeneration of healthy myocardial tissue and recovery of cardiac function. These could be accomplished by neo-angiogenesis, cardiogenesis, and/or paracrine effects. In its … * Tel.: +39 011 6705430; fax: +39 011 9038639. Email address: pasquale.pagliaro{at}unito.it