Exogenous H2s Attenuates The Myocardial Fibrosis In Hyperhomocysteinemia-induced Rats By Down-regulating The Activity Of TGF-?1/Smad3 Signaling Pathway

Objective:This study aimed to observe the effects of exogenous hydrogen suifide?H₂S?on myocardial fibrosis induced by hyperhomocysteinemia?HHcy?via regulating the activity of TGF-?1/Smad3 signaling pathway.Methods:After a week of adjustable feeding,40 male Sprague-Dawley rats were randomly assigned into Control group,HHcy group,HHcy+H₂S group and H₂S group?n=10?.HHcy group and HHcy+H₂S group were induced by adding L-methionine?10g/l?into the drinking water consecutive ten weeks to set up the model of HHcy.After ten weeks,the level of HHcy was detected and the concentration of Hcy no less than 15mmol/l was deemed as HHcy.NaHS?56umol/kg/d,intraperitoneal injection,lasting four weeks?,which was used as an exogenous H₂S,was used in these rats in HHcy+H₂S group and H₂S group.These rats in Control group and HHcy group were injected with the equal volume of normal saline.After fourteen weeks,LVDd,LVSd,LVPWd,LVFS were detected by M ultrasound.Then the rats were weighted?body weight,BW?and killed.The heart of the rats was removed and weighted?heart weight,HW?,The heart weight index?HW/BW,mg/g?was calculated.Collagen deposition was measured by masson staining.The expression of Collagen? was detected by immunohistochemical staining.The expression of CSE,MMPs/TIMPs Collagen?,Bcl-2,Caspase3/9,Bax,NF-?Bp65,IL-6,TGF-?1/Smad3 were detected by western blotting.RT-qPCR was used to detect Col1?2 and Col3?1.Results:Compared with the Control group,the concentration of Hcy in the HHcy group and the HHcy+H₂S group was significantly increased?P<0.05?,while there was no significant difference between the Control group and the H₂S group?P>0.05?.Compared with the Control group,HW/BW were significantly increased in the HHcy group?P<0.05?.Relative to the HHcy group,HW/BW of rats in the HHcy+H₂S group were significantly decreased?P<0.05?,while the differences in BW and HW were not statistically significant?P>0.05?.2.The results of M ultrasound showed decrease of cardiac function,compared with the Control group,the values of LVSd and LVDd significantly increased and the value of LVFS significantly decreased in the HHcy group?P<0.05?;In contrast to the HHcy group,the values of LVSd and LVDd significantly decreased and the value of LVFS significantly increased in the HHcy+H₂S group?P<0.05?.3.Compared with the Control group,for rats in the HHcy group,the blue dye collagen fiber was obviously increased?P<0.05?;Compared with the HHcy group,the blue dye collagen fiber was obviously reduced in the HHcy+H₂S group?P<0.05?.4.The results of immunohistochemistry staining revealed that the expression of collagen?was remarkably increased in the HHcy group?P<0.05?,relative to the Control group;Compared with the HHcy group,the expression of Collagen?was remarkably decreased in the HHcy+H₂S group?P<0.05?.5.Western blotting results showed:compared to Control group,the expression of Collagen?,MMP13,TIMP1,Caspase3,Caspase9,Bax,TGF-?1?Smad3?NF-?Bp65 and IL-6in myocardial tissue was increased significantly?P<0.05?,while that of CSE,MMP1,Bcl-2 decreased significantly?P<0.05?for rats in HHcy group;Relative to HHcy group,the expression of Collagen?,MMP13,TIMP1,Caspase3,Caspase9,Bax,TGF-?1,Smad3,NF-?Bp65 and IL-6 was significantly decreased?P<0.05?,while that of CSE,MMP1,Bcl-2 was significantly increased?P<0.05?for rats in HHcy+H₂S group.7.The results of RT-qPCR analysis revealed that the expression level of Col1?2 and Col3?1 in HHcy group were significantly elevated than Control group?P?0.05?.However,compared with HHcy group,the expression level of Col1?2 and Col3?1 were remarkably reduced?P?0.05?in HHcy+H₂S group.Conclusion:H₂S can reduce myocardial fibrosis in hyperhomocysteinemia-induced rats,which may be related with down-regulation of TGF-?1/Smad3 signaling pathway to inhibite apoptosis and reduce inflammatory reaction.