Effect of Wenyang Zhenshuai Granules on autophagy and apoptosis of myocardial cells in septic rats via regulating miR-132-3p/UCP2 expression / 中国中药杂志

ABSTRACT

This study aimed to investigate the effect of Wenyang Zhenshuai Granules(WYZSG) on autophagy and apoptosis of myocardial cells in rats with sepsis via regulating the expression of microRNA-132-3p(miR-132-3p)/uncoupling protein 2(UCP2). Sixty SD rats were randomly divided into modeling group(n=50) and sham operation group(n=10). The sepsis rat model was constructed by cecal ligation and perforation in the modeling group. The successfully modeled rats were randomly divided into WYZSG low-, medium-and high-dose groups, model group and positive control group. Rats in the sham operation group underwent opening and cecum division but without perforation and ligation. Hematoxylin-eosin(HE) staining was used to observe the pathological changes of rat myocardial tissue. Myocardial cell apoptosis was detected by TdT-mediated dUTP nick end labeling(TUNEL) assay. Real-time quantitative polymerase chain reaction(RT-qPCR) was performed to detect the expression of miR-132-3p and the mRNA expressions of UCP2, microtubule-associated protein light chain 3(LC3-Ⅱ/LC3-Ⅰ), Beclin-1 and caspase-3 in rat myocardial tissue. The protein expressions of UCP2, LC3-Ⅱ/LC3-Ⅰ, Beclin-1 and caspase-3 in myocardial tissue were detected by Western blot. Dual luciferase reporter assay was used to verify the regulatory relationship between miR-132-3p and UCP2. The myocardial fibers of sepsis model rats were disordered, and there were obvious inflammatory cell infiltration as well as myocardial cell edema and necrosis. With the increase of the WYZSG dose, the histopathological changes of myocardium were improved to varying degrees. Compared with the conditions in the sham operation group, the survival rate and left ventricular ejection fraction(LVEF) of rats in the model group, positive control group and WYZSG low-, medium-and high-dose groups were decreased, and the myocardial injury score and apoptosis rate were increased. Compared with the model group, the positive control group and WYZSG low-, medium-and high-dose groups had elevated survival rate and LVEF, and lowered myocardial injury score and apoptosis rate. The expression of miR-132-3p and the mRNA and protein expressions of UCP2 in myocardial tissue in the model group, positive control group and WYZSG low-, medium-and high-dose groups were lower, while the mRNA and protein expressions of LC3-Ⅱ/LC3-Ⅰ, Beclin-1 and caspase-3 were higher than those in the sham operation group. Compared with model group, the positive control group and the WYZSG low-, medium-and high-dose groups had an up-regulation in the expression of miR-132-3p and the mRNA and protein expressions of UCP2, while a down-regulation in the mRNA and protein expressions of LC3-Ⅱ/LC3-Ⅰ, Beclin-1 and caspase-3. WYZSG inhibited excessive autophagy and apoptosis of myocardial cells in septic rats and improved myocardial injury, possibly by regulating the expression of miR-132-3p/UCP2.