question: what is the role of GATA-4 in regeneration of the heart after myocardial infarction?
answer: GATA-4 is implicated in cardiogenic differentiation of cardiac c-kit+AT2+ cells that represent approximately 0.19% of total cardiac cells in infarcted heart. GATA-4 overexpression in mesenchymal stem cells increases both survival and angiogenic potential in ischemic myocardium and may therefore represent a novel and efficient therapeutic approach for postinfarct regenaration. In addition, interventions, such as hypergravity and 5-Aza treatment, induce expression of early muscle and cardiac markers like GATA-4 in BMSCs. A subpopulation of primitive cells from rat heart, expressing c-kit and myogenic transcriptional factors, GATA-4 and MEF 2C, exhibit a high in vitro proliferative potential. Progeny of these implanted cells have been shown to migrate along the infarcted scar, reconstitute regenerated cardiomyocytes with incorporation into host myocardium, and inhibit cardiac remodeling with decreased scar formation. In another study, TGF-beta has been shown to conduct the myogenic differentiation of stem cells by upregulating GATA-4 and NKx-2.5 expression and the intramyocardial implantation of TGF-beta-preprogrammed stem cells effectively assisted the myocardial regeneration. Furthermore, G-CSF treatment in postinfarcted murine hearts appears to be an effective approach for treating heart failure and also leads to induction of GATA-4 resulting in expression of various sarcomeric proteins.