基于PTEN/AKT/mTOR通路探讨补心泻肺方改善慢性心力衰竭小鼠心肌纤维化的作用机制OA

Objective To investigate the effect and molecular mechanism of Buxin Xiefei Formula(BXXF)in improving myocardial fibrosis in mice with chronic heart failure(CHF)based on the PTEN/AKT/mTOR pathway.Methods A CHF model was established in C57/BL6J mice by intraperitoneal injection of isoproterenol hydrochloride(5 mg·kg-1,twice daily for 14 days).The mice were randomly divided into a control group,model group,low-dose BXXF(2.9 g·kg-1),medium-dose BXXF(5.8 g·kg-1),and high-dose BXXF group(11.6 g·kg-1),and a perindopril group(0.41 mg·kg-1).The BXXF groups and perindopril group were administered the corresponding drugs by gavage,while the control and model groups received an equal volume of saline for 4 weeks.Cardiac function was assessed using small-animal echocardiography to measure left ventricular ejection fraction(LVEF),left ventricular fractional shortening(LVFS),left ventricular end-diastolic volume(LVEDV),left ventricular end-systolic volume(LVESV),left ventricular end-diastolic diameter(LVEDD),and left ventricular end-systolic diameter(LVESD).Pathological changes in cardiac tissue were observed by HE staining,while myocardial fibrosis was evaluated by Masson staining.The mRNA expression levels of α-SMA,Collagen Ⅰ,and Collagen Ⅲ in cardiac tissue were detected by qRT-PCR,and the protein expression levels of α-SMA,Collagen Ⅰ,Collagen Ⅲ,PTEN,p-AKT,p-mTOR,AKT,and mTOR were measured by Western Blot.Results(1)Compared with the control group,the model group showed significantly decreased LVEF and LVFS values(P<0.01)and significantly increased LVEDD,LVESD,LVEDV,and LVESV values(P<0.01).HE staining revealed unclear myocardial cell boundaries,cell swelling,and local inflammatory cell infiltration in the model group.Masson staining indicated myocardial collagen deposition.The mRNA and protein expression levels of α-SMA,Collagen Ⅰ,and Collagen Ⅲ in cardiac tissue were significantly increased(P<0.01).PTEN protein expression was significantly elevated(P<0.01),while the p-AKT/AKT and p-mTOR/mTOR ratios were significantly decreased(P<0.01).(2)Compared with the model group,the low-,medium-,and high-dose BXXF groups exhibited significantly increased LVEF and LVFS(P<0.01)and significantly decreased LVEDD,LVESD,LVEDV,and LVESV(P<0.01).Pathological damage and fibrosis in cardiac tissue were markedly improved.The mRNA and protein expression levels of α-SMA,Collagen Ⅰ,and Collagen Ⅲ were significantly decreased(P<0.01).PTEN protein expression was significantly reduced(P<0.01),while the p-AKT/AKT and p-mTOR/mTOR ratios were significantly increased(P<0.01).Conclusion BXXF effectively improves cardiac function and inhibits ventricular remodeling in mice with CHF,and its mechanism may be associated with the regulation of PTEN/AKT/mTOR signaling pathway-mediated myocardial fibrosis.