Resveratrol Attenuates Pressure Overload-induced Cardiac Fibrosis

Background:Cardiac remodeling is a major risk factor for heart failure and sudden death.Myocardial fibrosis is one of the hallmarks of cardiac remodeling and is characterized by excessive deposition of extracellular matrix leading to systolic and diastolic dysfunction.Resveratrol?RES?is a natural polyphenolic compound with anti-inflammatory and anti-oxidant effects.Recent studies have shown that resveratrol has a protective effect on cardiovascular diseases,but its detailed regulatory mechanism remains unclear.Object:To elucidate the role and molecular mechanism of RES in pressure overload-induced myocardial fibrosis,and provide a new option for treating myocardial remodeling.Method:1.Animal model:The mouse model of myocardial fibrosis was established by pressure overload induced by transverse aortic constriction?TAC?for 2 weeks.2.Animal grouping and treatment:Male C57BL/6 mice were randomly allocated as follows?n=10 per group?:?1?Prevention experiments?4 groups?:sham,TAC,TAC+RES?5 mg/kg/day?and TAC+RES?50 mg/kg/Day?.?2?The reversal experiments?3 groups?:sham,TAC,and TAC+RES?50 mg/kg/day?.?3?Experiments for PTEN inhibition?3 groups?:TAC,TAC+RES?50 mg/kg/day?,and TAC+RES+PTEN inhibitor?VO-OHPIC,10 mg/kg/day?.3.The main experimental techniques:2 weeks or 4 weeks after TAC surgery,the dynamic changes of cardiac function in mice were evaluated by echocardiography.The recruitment of inflammatory cells in myocardial interstitial was detected by H&E staining,and cardiac fibrosis was detected by Masson trichrome staining.The infiltration of macrophages and activation of myofibroblasts were detected by immunohistochemical staining.The mRNA expression of markers of myocardial inflammation,oxidative stress and fibrotic markers were examined by real-time quantitative PCR analysis.The protein levels of myocardial fibrosis and inflammation related signaling mediators were detected by Western blot analysis.Result:1.RES treatment?2 weeks?significantly improved TAC-induced systolic and diastolic dysfunction?as indicated by decreased EF%and FS%as well as increased mitral E/A ratio?;inhibited myocardial interstitial and perivascular fibrosis?as reflected by decreased fibrotic area,hydroxyproline level,collagen expression and activation of?-SMA⁺myofibroblasts?;decreased myocardial inflammation[as indicated by recruitment of inflammatory cells,inflammatory cytokines?TNF-?,IL-1?and IL-6?],oxidative stress[as reflected by DHE staining and the gene expression levels of NADPH enzymes(Nox1,Nox2,Nox4 and p22^phox)].2.RES treatment for 2 weeks significantly reversed TAC-induced cardiac dysfunction and myocardial fibrosis.3.RES treatment markedly attenuated PTEN degradation and activation of fibrotic and inflammatory signaling pathways?AKT/TGF-?/Smad2/3 and IKK?/?/NF-?B?.4.Treatment of PTEN inhibitor?VO-OHPIC?blocked the protective effects of RES on cardiac dysfunction and myocardial fibrosis.Conclusion:This study provides new experimental evidence for the protective effect of RES on myocardial fibrosis.Mechanistically,RES inhibits PTEN degradation which blocks activation of fibrotic and inflammatory signaling pathways thereby leading to inhibition of cardiac fibrosis.Our findings suggest that RES is a potential therapeutic agent for preventing and treating myocardial fibrosis.