Epicardial Progenitors in the Embryonic and Adult Heart

Abstract

Over the last decade, our knowledge of the function(s) of the epicardium in vertebrate heart development and repair has increased considerably. In development, the epicardium is required for proper heart formation by regulating myocardial compaction and contributing major cardiovascular cell types. In the adult heart, the idea of a dormant epicardium has been challenged by the observation that it can reacquire embryonic properties after heart injury and may contribute to tissue repair and regeneration. This has elevated the status of the adult epicardium to a resident source of regenerative cells with potential to restore cardiac structure and function after injury. Yet, many questions remain to be answered, in particular whether the observations arising from studies on model organisms are applicable to the human (diseased) heart. Here, we review the key established and emerging findings regarding epicardium formation, heterogeneity, and its therapeutic potential in heart repair. Moreover, we draw attention to studies focusing on the human epicardium, highlighting new tools that are being developed to promote further insight into the epicardium and its regenerative potential.