Effect Of Kangxian Yixin Dection On Myocardial Fibrosis In Rats With Dilated Cardiomyopathy Via RhoA/ROCK1 Signaling Pathway

Purposes:Kangxian Yixin Dection(KYD)is an effective prescription for the clinical treatment of dilated cardiomyopathy(DCM).Early basic research found that this prescription has the effect of inhibiting myocardial fibrosis,but its specific mechanism of action is still unclear.Studies have shown that RhoA/ROCK1 signaling pathway has a certain role in myocardial fibrosis,so this study intends to observe the potential mechanism of KYD inhibition of myocardial fibrosis by replicating the DCM rat model and myocardial fibroblast model.Method:1.With reference to the literature and the previous research method of this disease,a DCM rat model was constructed by furazolidone solution.After 10 weeks,according to the results of cardiac echocardiography,the successful rats were randomly divided into the model group,the high,medium,and low-dose groups of KYD and the captopril group,and a normal control group was set up.Relevant indicators were detected after continuous gastric administration for 4 weeks。2.Echocardiographic examination measures cardiac function indexes such as left ventricular end-diastolic diameter(LVEDD),ejection fraction(EF)and short-axis shortening rate(FS)in each group.3.HE staining was used to detect the pathological changes of myocardial tissue,Masson staining was used to detect the collagen deposition in myocardial tissue,and immunohistochemistry was used to detect the expression of a-SMA protein in myocardial tissue.4.Real-time PCR and Western blot were used to detect the expression levels of CTGF,a-SMA,COI-1 and the key molecules in the RhoA/ROCK1 signaling pathway.5.Myocardial fibroblasts(CFs)were extracted and cultured from neonatalrat,by AngⅡ was used to replicate the model of myocardial fibroblasts,and were divided into five groups according to the intervention by KYD or Fasudil,the normal group,the model group,KYD group,Fasudil group,and the KYD and Fasudil group.The expression of myocardial fibrosis factor and key molecules of RhoA/ROCK1 signaling pathway was detected by Real-time PCR and Western blot.Results:1.After 4 weeks of intervention,the left ventricular cardiac function of each group of rats was detected by ultrasound.Compared with the normal group,the LVEDD and LVESD of the model group increased(p(27)0.01)and the EF and FS decreased(p(27)0.01).Compared with the model group,the high and medium-dose KYD can reduce LVEDD and LVESD(p(27)0.05)and improve EF and FS(p(27)0.05),while the effects of the low-dose group was not significant(p(29)0.05).2.Pathological staining data showed that compared with normal group rats,In the model group,myocardial cells in the myocardial tissue were enlarged,disordered,necrotic,myoglobin arranged disorderly,collagen increased and deposited,and a-SMA expression was obvious increased.However,myocardial cell edema was reduced in myocardial tissues given by KYD treatment,and myoglobin was better than before,but the low-dose group did not improve significantly,and there was still a large amount of collagen deposition.3.The expression levels of key molecular proteins of RhoA /ROCK1 signaling pathway and myocardial fibrosis proteins in myocardial tis sue by Western blot,compared with normal group rats,RhoA/ROCK1 key molecular proteins and myocardial fibrosis-related proteins in model group(P(27)0.01).However,the high and medium-dose groups of KYD had different degrees of reduction(P(27)0.01,P(27)0.05),and the improvement was not significant in the low-dose group(P(29)0.05).4.The expression level of RhoA,ROCK1,MLC,and CTGF m RNA in myocardial tissue by Real-time PCR,the expression of RhoA,ROCK1,MLC,and CTGF m RNA in myocardial tissue of model group rats were significantly increased compared to normal group(P(27)0.01).But,the KYD high and medium dose groups had a down-regulation effect(P(27)0.01,P(27)0.05),while the low dose group showed no significant improvement(P(29)0.05).5.In the model of myocardial fibroblasts induced by Ang II,KYD can inhibit the expression of CTGF,a-SMA,COI-1 in the CFs model,KYD and fasudil have similar effects to inhibit the expression of RhoA,ROCK1,p-MLC(P(27)0.01,P(27)0.05).Conclosion:1.There is overexpression of RhoA/ROCK1 signaling pathway during myocardial fibrosis in DCM model rats.2.KYD can improve cardiac function and the pathological changes of myocardial fibrosis in DCM model rats.3.KYD can inhibit the transformation of myocardial fibroblasts.4.KYD may inhibit the effect of myocardial fibers by down-regulating RhoA/ROCK1 signaling pathway.