Expression and mechanism of miR-214 in rat myocardial ischemic postconditioning

Objective To observe the expression of miR-214 in rat acute myocardial ischemia/ reperfusion injury and ischemic postconditioning, to investigate the probable mechanism of miR-214 on the protection of ischemic postconditioning. Methods 30 SD rats were randomized into sham operation group, ischemia/ reperfusion group and ischemic postconditioning group. The hemodynamic values and myocardial functions were measured via a cannula inserted into the right common carotid artery. The infarct size as measured by TTC staining and the area at risk was assessed by evans blue staining. Real time PCR was used to assess the expression of miR-214 and predicted target gene HIF1AN in the area at risk at the end of reperfusion. Results Postconditioning in in vivo rats improved the hemodynamic values of LVSP, LVEDP and ±dp/dtmax, and reduced the infarct size; the expression of miR-214 in ischemia/reperfusion group was lower compared with sham operation group,and was higher in ischemic postconditioning than that in ischemia/ reperfusion group;Meanwhile, HIF1AN mRNA level in ischemia/reperfusion group was higher compared with sham operation group, and was lower in ischemic postconditioning than that in ischemia/ reperfusion group. Concluision Postconditioning could obviously decrease the reperfusion injury by improving heart function and decreasing the infarct size in in vivo rat. The expression of miR-214 in ischemia/ reperfusion group was dramaticlly depressed, postconditioning could increase the expressiom of miR-214, and the upregulation of miR-214 may play a role in the protection of postconditioning.