Remote Ischemic Postconditioning Ameliorates the Mesenchymal Stem Cells Engraftment in Reperfused Myocardium

OBJECTIVES Remote Ischemic postconditioning (RIPoC) is a cardioprotective strategy for alleviating the reperfusion injury. We hypothesized that RIPoC or ischemic postconditioning (IPoC) could protect the engrafted mesenchymal stem cells (MSCs) in reperfusion myocardium. METHODS Female Sprague-Dawley rats were subject to 30 minutes of occlusion of left anterior descending (LAD). Ischemia reperfusion (IR) received reperfusion without interruption after ischemia. RIPoC received 3 cycles of 30 seconds reperfusion and re-occlusion on the limb at the onset of reperfusion. IPoC received 3 cycles of 30 seconds reperfusion and re-occlusion on the LAD at the same time. Male MSCs were intramyocardially administered after ischemia. RESULTS Compared with that in IR group, ischemic myocardium in RIPoC+IPoC group, RIPoC group and IPoC group were found to have higher anti-oxidative stress and mitochondrial function level, lower lipid peroxidation and inflammational injury level, higher level of stromal cell derived factor-1 alpha and vascular endothelium growth factor gene expression at 3 days later. By immunohistochemical examination and quantitative polymerase chain reaction, more engrafted MSCs, better cardiac function and less cardiac fibrosis in RIPoC+IPoC group, RIPoC group and IPoC group were detected at 3 weeks after delivery. There were no significant differences between RIPoC and RIPoC+IPoC group. CONCLUSIONS Combination therapy using intramyocardial MSCs transplantation with RIPoC enhanced transplantation efficiency and cardiac function, and reduced cardiac fibrosis. These beneficial effects were mainly attributed to hospitable milieu for engrafted cells. IPoC could not render additional effect on MSCs engraftment elicited by RIPoC.