Epicardial GATA factors regulate early coronary vascular plexus formation

During early development, GATA factors have been shown to be important for key events of coronary vasculogenesis, including formation of the epicardium. Myocardial GATA factors are required for coronary vascular (CV) formation; however, the role of epicardial localized GATAs in this process has not been addressed. The current study was conducted to investigate the molecular mechanisms by which the epicardium controls coronary vasculogenesis, focusing on the role of epicardial GATAs in establishing the endothelial plexus during early coronary vasculogenesis. To address the role of epicardial GATAs, we ablated GATA4 and GATA6 transcription factors specifically from the mouse epicardium and found that the number of endothelial cells in the sub-epicardium was drastically reduced, and concomitant coronary vascular plexus formation was significantly compromised. Here we present evidence for a novel role for epicardial GATA factors in controlling plexus formation by recruiting endothelial cells to the sub-epicardium.