Intracardiac injection of matrigel induces stem cell recruitment and improves cardiac functions in a rat myocardial infarction model

Abstract

Background: Matrigel promotes angiogenesis in the myocardium from ischemic injury and prevents remodeling of the myocardium. We assessed the therapeutic efficacy of intracardiac Matrigel injection and matrigel-mediated stem cell homing in a rat myocardial infarction (MI) model. Methods and Results: Following MI, Matrigel (250μl) or PBS was delivered by intracardiac injection. Compared to myocardial infarction control group (MI-PBS), Matrigel significantly improved left ventricular function (n=11, P<0.05) assessed by pressure-volume loops after 4 weeks. There is no significant difference in infarct size between MI-M (21.48±1.49%, n=10) and MI-PBS hearts (20.98±1.25%, n=10). The infarct wall thickness of left ventricular (LWT) is significantly higher (P<0.01) in MI-M (0.72±0.02mm, n=10) compared with MI-PBS (0.62±0.02mm, n=10). MI-Matrigel (MI-M) hearts exhibited higher capillary density (border 130.8±4.7 vs.115.4 ± 6.0, P<0.05; vessels per HPF (400×), n=6) than MI-PBS hearts. c-Kit+ stem cells (38.3±5.3 vs. 25.7±1.5 c-Kit+ cells per HPF(630×), n=5, P<0.05) and CD34+ cells (13.0±1.51 vs. 5.6±0.68 CD34+ cells per HPF (630×), n=5, P<0.01) were significantly more numerous in MI-Matrigel than in MI-PBS in the infarcted hearts (n=5, P<0.05). Conclusions: Intracardiac Matrigel injection restores myocardial functions following MI, which may attribute to the improved recruitment of CD34+ and c-Kit+ stem cells.