Intramyocardial injection of heart-derived extracellular matrix combined with cardiosphere-derived cells improves myocardial structure and function in rats with acute myocardial infarction

This study aimed to investigate the cardioprotective effects of intramyocardial injection of heart derived extracellular matrix (ECM) and cardiosphere-derived cells (CDCs) in a rat model of myocardial infarction (MI). ECM and CDCs were collected from the rat heart, and the proliferation, apoptosis and morphology of CDCs maintained on ECM were characterized in vitro. MI model was established in rats (n=24) and intramyocardially injected (106/150 μl). When delivered into infarcted rat hearts, ECM solution proceeded with CDCs showed best cardiac structural and functional benefits, CDCs differentiation, retention and survival benefits as compared to ECM, CDC and vehicle alone at 3 weeks after acute myocardial infarction. There were similar benefits between ECM and CDC groups. Heart-derived ECM may promote CDCs to differentiate toward endothelial cells, cardiomyocytes and smooth muscle cells both in vitro and in vivo, increase the proliferation in vitro, improve the survival in vitro and suppress the apoptosis of CDCs in vivo. Intramyocardial transplantation of CDCs+ECM significantly improves the cardiac structure and function as compared to CDC or ECM alone in MI rats.