Exogenous hydrogen sulfide alleviates hyperhomocysteinemia-induced myocardial fibrosis in rats by regulating TGF-β1/Smad7 signaling pathway

Abstract:

Objective：To observe the effect of exogenous hydrogen suifide（H2S） on myocardial fibrosis and expression of transforming growth factor-β1（TGF-β1） and Smad7 in hyperhomocysteinemia（HHcy）-induced rats. Methods：A total of 40 adult male SD rats were randomly assigned into 4 groups（n=10）：the control group（Control），the model group（HHcy），the H2S-intervention model group（HHcy+H2S） and the H2S-intervention normal group（H2S）. L-methionine（10 g/L） was added into the drinking water for consecutive ten weeks to establish the model. After successful modeling，sodium hydrosulfide（NaHS） was intraperitoneally injected into the rats in the HHcy+H2S group and the H2S group for consecutive four weeks. Masson staining method was used to observe the deposition of myocardial collagen，immunohistochemical staining was used to detect the expression of Collagen Ⅲ and Western blotting was used to determine the expression of CBS，TGF-β1 and Smad7. Results：Compared with the control group，cardiomyocytes were arranged in disorder，the collagen deposition was significantly increased，the expression of collagen Ⅲ was significantly increased（P=0.000），the expression of TGF-β1 was increased apparently（P=0.004），and CBS（P=0.006） and Smad7（P=0.001） proteins were obviously down-regulated in the HHcy group. Compared with the HHcy group，cardiomyocytes were arranged in a relatively order man－ner，the collagen deposition was comparatively reduced，the ex－pression of collagen Ⅲ was relatively decreased（P=0.003），the expression of TGF-β1 was down-regulated distinctly（P=0.006），and CBS（P=0.005） and Smad7（P=0.000） proteins were increased in the HHcy+H2S group. Conclusion：H2S may improve myocar－dial fibrosis in hyperhomocysteinemia-induced rats and its mechanism may be related to the regulation of TGF-β1/Smad7 signaling pathway.