Progenitor cells from atria, ventricle and peripheral blood of the same patients exhibit functional differences associated with cardiac repair.

AIM: Deciding the best cell type for cardiac regeneration remains a big challenge. No studies have directly compared the functional efficacy of cardiac progenitor cells (CPCs) with extra-cardiac stem cells isolated from the same patient.

METHODS AND RESULTS: We compared the functional characteristics of endothelial progenitor cells (EPCs), right atrial (RAA) CPCs and left ventricular (LV) CPCs isolated from the same patients (n=14). Within the same heart, RAA and LV CPCs exhibited marked differences in surface marker expression, with RAA CPCs exhibiting better expansion potential and migration properties. When subjected to hypoxia and serum starvation to simulate in vivo ischemic environment, RAA and LV CPCs exhibited similar pattern of resistance to apoptotic cell death under ischemia. Interestingly, EPCs exhibited highest resistance to apoptotic cell death, however, they also showed the lowest proliferation under hypoxia. RT-profiler array showed comparable gene expression pattern in RAA and LV CPCs, while they were differentially expressed in EPCs. Further, treating human umbilical vein endothelial cells with conditioned medium (CM) from LV showed maximum angiogenic potential, while cardiomyocytes treated with CM from RAA showed greatest survival under hypoxic conditions.

CONCLUSIONS: Results from this study provide the first evidence that progenitor cells from different regions exhibit functional differences within the same patient.