Study on role of miR-208b-3p in dexmedetomidine alleviating rat myocardial ischemia-reperfusion injury / 重庆医学

ABSTRACT

Objective To investigate the role of miR-208b-3p in dexmedetomidine(DEX) alleviating rat myocardial ischemia reperfusion injury(MIRI).Methods Eighty adult male Wister rats were divided into the sham operation(Sham) group,I/R group,DEX group and miR-208b-3p+ DEX group.In the Sham group,a 6-0 silk suture was only placed without ligation,and other 3 groups were treated by I/R model.Before ischemia reperfusion,the DEX group received a loading dose of DEX(5 μg/kg) via the femoral vein followed by a continuous infusion of 5 μg · kg-1 · h-1 for 1 h.In the miR-208b-3p+ DEX group,rats received intramuscular injection of miR-208b-3p analogue at 24 h before ischemia reperfusion.The cardiac function indexes were monitored at 120 min after reperfusion,including heart rate(HR),left ventricular systolic blood pressure(LVSP),left ventricular end diastolic pressure(LVEDP) and left ventricular rate maximum(dp/dtmax).The serum levels of cTn-Ⅰ and CK-MB were detected and the apoptosis rate(AI) was measured by in situ apoptosis assay.The levels of oxidative stress related indicators were detected and Western blot was used to detect the level of myocardial apoptosis protein.Results Compared with the Sham group,the cardiac function in the I/R group was decreased,but the levels of CTn-Ⅰ,CK-MB,AI,MDA,Bax and Caspase-3 were increased(P＜0.05);compared with the I/R group,the above indexes in the DEX group were improved(P＜0.05);compared with the DEX group,the above indexes in the miR-208b-3p+DEX group were deteriorated(P＜0.05).Conclusion Overexpression of miR-208b-3p can eliminate the protective effect of DEX on MIRI.