Background: Endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs) have different biological properties, but their potential for synergy in the treatment of injured myocardium has not been studied extensively.
Aim: To determine if outcome could be improved by simultaneously transplanting MSCs and EPCs into a rat model of isoproterenol (ISO)-induced injured myocardium.
Methods: Four weeks after ISO injection, 50 rats were separated randomly into five groups (n=10 per group) and allocated to receive a saline injection (control group), 200 microL medium alone, 200 microL medium plus 2x10(6) EPCs, 200 microL medium plus 2x10(6) MSCs, or 200 microL medium plus a combination of 1x10(6) EPCs and 1x10(6) MSCs. Echocardiography and invasive catheterization were performed to evaluate dynamic changes in cardiac performance, 12 weeks after treatment administration.
Results: Transplanted cells were detected in myocardial tissue by fluorescence in situ hybridization, indicating either differentiation or integration into cardiac tissue cells. The group of rats that received both EPCs and MSCs had an increased level of angiogenic growth factors expression, less collagen deposition, fewer apoptotic cells and an improved regional myocardial blood flow compared with the other groups; these effects resulted in greater enhancement of cardiac function in that group.
Conclusion: Transplantation of EPCs combined with MSCs may represent a novel and efficient therapeutic strategy for enhancing regional myocardial blood flow and improving cardiac function in injured myocardium.