Evodiamine Prevents Cardiac Fibrosis By Regulating Endothelial-to-mesenchymal Transition

Background:Cardiac fibrosis characterized by the extensive accumulation of extracellular matrix(ECM)disrupts normal myocardial structures and contributes to many cardiac pathological conditions,such as myocardial infarction,hypertrophic cardiomyopathy,post-viral dilated cardiomyopathy and heart failure.However,the current therapies for cardiac fibrosis are not as effective as expected due to the limited knowledge on the molecular mechanisms involved in regulating the cardiac fibrosis.In recent years,evodiamine has been proven to suppress atherosclerosis in hyperlipidaemic mice and protect the myocardium against injury induced by ischemia-reperfusion.However,whether evodiamine can inhibit cardiac fibrosis remains unclear.The aim of our study is to investigate the possible effect and mechanism of evodiamine on cardiac fibrosis induced by ISO,providing a novel pharmacotherapeutic strategy for the precaution and treatment of cardiac fibrosis.Objective:This study aims to investigate the possible effect and mechanism involved in the function of evodiamine on isoproterenol(ISO)-induced cardiac fibrosis and endothelial-to-mesenchymal transition(EndMT).Methods:Male C57BL/6 mice were randomly divided into 4 groups for treatment:control;cardiac fibrosis(ISO);low-and high-dose evodiamine.ISO was injected subcutaneously in mice to induce cardiac fibrosis models.In the therapeutic groups,different concentrations of evodiamine were intragastrically injected at the same time as ISO injection.After the 14-day treatment,mice were performed echocardiography,then mouse hearts were quickly excised and weighed to calculate heart weight/body weight(HW/BW),heart weight/tibia length(HW/TL)ratios.Sections of the hearts were stained,while total protein and RNA were extracted.Western blot and PCR(Real Time-PCR)were performed to evaluate the extent of cardiac fibrosis and hypertrophy.The extent of EndMT was evaluated by the expression levels of CD31,CD34,a-smooth muscle actin(?-SMA)and vimentin by immunohistochemistry,immune-fluorescence staining and western blot analysis.The phosphorated proteins and total proteins involved in TGF-?/Smad,Erk and Akt signal pathways were evaluated.Results:After 14 days,HW/BW and HW/TL revealed no significant difference between the treatment groups and ISO group,however,heart weight decreased in the ISO/evodiamine-treated groups.Evodiamine prevented ISO-induced cardiac fibrosis according to the results of pathological staining and expression levels of hypertrophy and fibrotic markers.Evodiamine also prevented EndMT as evidenced by increased the expression levels of CD31,CD34 and decreased expression levels of a-SMA and vimentin,increased the microvascular density(MVD)in ISO/evodiamine-treated mice heart.Furthermore,ISO-induced activation of TGF-?/Smad,Erk and Akt signals was also blunted by evodiamine.Conclusions:Therefore,evodiamine may prevent ISO-induced cardiac fibrosis by regulating EndMT which is probably mediated by the blockage of above pathways.