Purification, Expansion and Characterization of Putative Murine Cardiac Progenitor Cells

Abstract

Ischemic heart disease kills more people than any other condition. Medical treatment for ischemic heart disease is currently limited by the heart’s lack of regeneration after injury. Recent reports have suggested the existence of cardiac progenitor cells in the adult normal and diseased mammalian heart. The origin of these cells is unclear. We implemented novel culturing conditions to isolate putative cardiac progenitor cells (pCPCs) from the adult murine heart atrium with the properties of cardiac regeneration. Putative adult cardiac progenitor cells were purified and expanded from adult murine hearts by expansion medium supplemented with 2% fetal calf serum, epidermal growth factor, platelet-derived growth factor and leukemia inhibitory factor. Under the culture condition of 5% O2 , these cells can be expanded beyond 42 days, expressed stem cell antigen (Sca-1) and cardiac-specific transcription factors. When treated with oxytocin in vitro, these cells express cardiac contractile proteins and when injected intramuscularly in the tibialis anterior muscle these cells give rise to cardiomyocyte-like cells. In contrast, transplantation of these pCPCs in uninjured heart did not result in cardiomyocyte differentiation suggesting that the heart environment is less permissive than the skeletal muscle of cardiogenesis. These results suggest that cells from the adult murine heart selected with this culture conditions and transplanted in the skeletal muscle have cardiogenic potential. Thus, this approach warrants further investigation for the therapeutic development of strategies for cardiac tissue engineering and myocardial regeneration.