Study On The Mechanism Of Kangxian Yixin Decoction Against Myocardial Fibrosis In Rats With Dilated Cardiomyopathy Based On The Regulation Of β-cateninPPARγ Signal Pathway By SIRT3

Objective:In this study,the rat model of dilated cardiomyopathy was made by drinking furazolidone aqueous solution,and the cell model was established by transdifferentiation of cardiac fibroblasts induced by AngⅡ.Based on the regulation of SIRT3/β-catenin/PPARγsignal pathway,the effect of Kangxian Yixin Decoction on myocardial fibrosis in dilated cardiomyopathy was investigated.Methods:1.Effect of Kangxian Yixin Decoction on myocardial fibrosis in rats with dilated cardiomyopathy:the rat model of dilated cardiomyopathy was made by using furazolidone aqueous solution of Wistar rats.The cardiac function of rats was detected by echocardiography after modeling to determine whether the model was successful or not.The successful rats were randomly divided into model group,Kangxian Yixin Decoction low,middle and high dose groups and captopril group.The model group was given intragastric administration of the same volume of normal saline as the treatment group,and the normal group was fed routinely without drug intervention.After drug treatment,the cardiac function of rats was detected by echocardiography again,and the heart samples were taken.The pathological changes of myocardial tissue were observed by HE staining and Masson staining,the gene and protein expression levels of fibrosis related indexes and SIRT3 were detected by RT-PCR and Western blot.2.The relationship between the inhibition of cardiac fibroblast transdifferentiationbyKangxianYixinDecoctionand SIRT3/β-catenin/PPARγsignal pathway:cardiac fibroblasts isolated from newborn SD rat heart were cultured in vitro,the c ell purity was identified by immunofluorescence,the optimal concentration of AngⅡ-induced cell transdifferentiation was detected by RT-PCR,the success of cell transdifferentiation induced by AngⅡwas detected by immunofluorescence,and the optimum concentration of Kangxian Yixin Decoction was detected by CCK-8.RT-PCR and Western blot were used to detect the expression of genes and proteins related to fibrosis and SIRT3/β-catenin/PPARγpathway.3.The relationship between the inhibitory effect of Kangxian Yixin Decoction on myocardial fibrosis in rats with dilated cardiomyopathy and SIRT3/β-catenin/PPARγsignal pathway:the gene and protein expression levels ofβ-catenin and PPARγin rat myocardium were detected by RT-PCR and Western blot.Results:1.Kangxian Yixin Decoction significantly decreased LVEDD,LVESD,and increased LVEF and LVFS,to improve cardiac function in rats with dilated cardiomyopathy.2.Kangxian Yixin Decoction significantly inhibited myocardial pathological damage and myocardial interstitial collagen fibe r proliferation in rats with dilated cardiomyopathy.3.Kangxian Yixin Decoction can effectively reduce the expression of myocardial fibrosis related factorsα-SMA,collagenⅠ,TGF-β1 protein and gene.4.When the concentration of Kangxian Yixin Decoction was 0.25mg/m L,the survival rate of cardiac fibroblasts was the highest.5.When the concentration of AngⅡwas 10^-7 mol/L,the transdifferentiation of cardiac fibroblasts was the best.6.Kangxian Yixin Decoction significantly increased the gene and protein expression of SIRT3 and PPARγand decreased the expression ofβ-catenin gene and protein in Cardiac myofibroblasts.7.Kangxian Yixin Decoction significantly increased the gene and protein expression of SIRT3 and PPARγand decreased the expression ofβ-catenin gene and protein in myocardium of rats with dilated cardiomyopathy.Conclusion:1.Kangxian Yixin Decoction can effectively improve the cardiac function of DCM rats,inhibit myocardial pathological damage and abnormal proliferation of collagen fibers,and inhibit myocardial fibrosis,which may be related to the activation of SIRT3 and PPARγand inhibition ofβ-catenin expression.2.Kangxian Yixin Decoction can inhibit the transdifferentiation of CFs by activating SIRT3 and PPARγand inhibiting the expression ofβ-catenin,thus inhibiting the process of myocardial fibrosis.