Abstract 252: Endocardial Cushion-derived Cardiovascular Progenitor Cells
Introduction: Regenerative therapies utilizing cardiac progenitor cells (CPCs) derived from human embryonic stem cells (hESC) have the potential to regenerate damaged myocardium post-myocardial infarctions. Previous studies have identified multipotent progenitors localized in the endocardial cushions of the developing mouse heart. Recent data in mice have also shown that the loss of a single transcription factor, Scl, enabled robust cardiomyogenic potential in these progenitor cells. Further analyses have delineated that these progenitors can be identified by co-expression of CD31 and PDGFRα. Recapitulation of this phenotypic progenitor cell from hESCs may have potential for clinical regenerative therapies.
Hypothesis: We hypothesize that CD31+/PDGFRα+ cells sorted from wild type mouse and human fetal heart tissue possess nascent cardiomyogenic potential. In addition, we believe that close mimicry of the in vivo developmental process of cushion formation would generate a hESC-derived CPC expressing CD31 and PDGFRα.
Methods: CD31+/PDGFRα+ cells sorted from wild type mouse heart and human fetal heart are plated in cardiac differentiation medium. Through a stage-specific differentiation protocol, hESCs are first differentiated into mesodermal progenitor cells, which then are sorted for the endothelial marker CD31. Under cardiac culture conditions, these CD31+ cells express the CPC marker PDGFRα. The CD31+/PDGFRα+ cells are then isolated and characterized through quantitative PCR, immunostaining, and functional assays.
Results: Wild type mouse heart CD31+/PDGFRα+cells, when isolated at E14.5 and plated in cardiac differentiation medium, develop beating colonies. In addition, CD31+/PDGFRα+cells are present in human fetal hearts. Moreover, hESC-derived CD31+/PDGFRα+ cells, when cultured in cardiac medium, show increased expression of cardiomyogenic markers.
Conclusions: We conclude that endogenous hESC-derived CD31+/PDGFRα+ cells have cardiogenic potential through in vitro differentiation, exhibited by their expression of cardiomyocyte characteristics and ability to beat. These cells may represent putative endocardial cushion-derived CPCs.
- © 2013 by American Heart Association, Inc.