Endothelial cells facilitate cell-based cardiac repair: progress and challenge.

About 1 billion cardiomyocytes are lost in heart disease such as myocardial infarction; the regeneration capacity of cardiomyocytes is extremely low and the heart is unable to fix this damage naturally. In the past 20 years, multiple cells, such as skeletal myoblasts, bone marrow-derived cells, cardiac progenitor cells and pluripotent stem cells have been utilized to test the efficacy on heart repair, but these cells show different kinds of drawbacks. Recent studies have revealed that concomitant transplantation of endothelial cells and stem cells can significantly improve the efficacy of cell based heart repair. In this review, we describe the progress on these studies with an emphasis on endothelial cell facilitated stem cell therapy. We also summarize the beneficial mechanisms of endothelial cells in cardiac repair and point out the potential challenges for endothelial cell-facilitated-cell therapy to be adopted for clinical application.