Multipotent islet-1 cardiovascular progenitors in development and disease.

During the past several years, advances at the intersection of cardiovascular development and heart stem cell biology have begun to reshape our view of the fundamental logic that drives the formation of discrete tissue components in the mammalian heart. Although many of the critical genes that control cardiac myogenesis have been identified, our understanding of how a highly diverse and specialized subset of heart cell lineages arises from mesodermal precursors and is subsequently assembled into distinct muscle chambers, coronary arterial tree and large vessels, valvular tissue, and conduction system/pacemaker cells remains at a relatively primitive stage. Recent studies have uncovered a diverse group of closely related heart progenitors that are central in controlling and coordinating these complex steps of cardiogenesis. Understanding the pathways that control their formation, renewal, and subsequent conversion to specific differentiated progeny forms the underpinning for unraveling the pathways for congenital heart disease and has direct relevance to cardiovascular regenerative medicine. This current brief review highlights the discovery and delineation of the role of Islet-1 cardiovascular progenitors in the generation of diverse heart cell lineages and how the implications of these findings are revising our classification and thinking about congenital heart disease in general.