| Abstract: | Objective To investigate the effect and mechanism of miR-208a on myocardial injury induced by myocardial ischemia reperfusion by regulating the expression of QKI5 in rats. Methods Thirty-two male SD rats were randomly divided into sham group, I/R group, I/R+anta-miR-NC group and I/R+anta-miR-208a group. The rat model of myocardial I/R was established, and the LVEF, LVFS and SV were detected in each group. The levels of CK-MB, cTnI, IL-1β, IL-6, TNF-αwere measured by ELISA. HE staining was used to observe the pathological changes of myocardial tissue in each group, and TUNEL staining was used to detect myocardial cell apoptosis.RT-PCR was used to detect the expression of miR-208a and QKI5 mRNA in myocardial tissue, and Western blot was used to detect the realative expression levels of QKI5 protein and Caspase-3 in myocardial tissue. Results Compared with the Sham group, the levels of LVEF, LVFS, SV in the I/R group were decreased, while the apoptosis rate of cardiomyocytes was increased, and the levels of CK-MB, cTnI, IL-1β, IL-6, TNF-α in serum and the expressions of miR-208a and Caspase-3 in the myocardial tissue were increased, and the expressions of QKI5 were decreased （P < 0.05）. Compared with the I/R+anta-miR-NC group, the levels of LVEF, LVFS, SV in the I/R+anta-miR-208a group were increased, while the apoptosis rate of cardiomyocytes was decreased, and the levels of CK-MB, cTnI, IL-1β, IL-6, TNF-α in serum and the expressions of miR-208a and Caspase-3 in the myocardial tissue were decreased, and the expressions of QKI5 were increased （P < 0.05）. Correlation analysis found that the expression of miR-208a and QKI5 had negative correlation in the I/R rats. Conclusion Inhibition of miR-208a may alleviate the inflammatory response to exert myocardial protective function in myocardial ischemia-reperfusion injury by regulating the expression of QKI5. |
