硫化氢对博来霉素致肺纤维化大鼠TGF-β1介导上皮间充质转化过程影响

Effect of hydrogen sulfide on TGF-β1mediated epithelial-mesench ymal transformation in bleomycin-induced pulmonary fibrosis rats

目的观察硫化氢(H_(2)S)对转化生长因子-β1(TGF-β1)及上皮间充质转化(EMT)过程中E-钙黏素(E-cad)、波形蛋白(VIM)、α-平滑肌蛋白(α-SMA)表达影响,探讨H_(2)S抗纤维化机制。方法健康雄性SD大鼠60只,随机分为对照组、博来霉素组、NaHS+博来霉素组、泼尼松+博来霉素组,15只/组。于造模第7、14和28天处死各组大鼠5只,HE和Masson染色,观察肺泡炎和肺纤维化改变程度;免疫组化和逆转录-聚合酶链反应法测定各组肺组织中TGF-β1、E-Cad、VIM及α-SMA蛋白和mRNA的表达水平。结果①HE和Masson染色结果示对照组大鼠肺组织纤维化程度最低,博来霉素组程度最重,NaHS+博来霉素组和泼尼松+博来霉素组肺组织也有肺泡炎和纤维化改变,但程度均较博来霉素组减轻。②博来霉素组、NaHS+博来霉素组、泼尼松+博来霉素组各时间点TGF-β1、VIM、α-SMA的mRNA和蛋白表达水平较对照组均有升高(P<0.05),但NaHS+博来霉素组、泼尼松+博来霉素组各时间点三者表达水平较博来霉素组组均有降低(P<0.05),以NaHS+博来霉素组第28天下降最多。③博来霉素组、NaHS+博来霉素组、泼尼松+博来霉素组各时间点E-Cad的mRNA和蛋白表达水与对照相比均有降低(P<0.05),但NaHS+博来霉素组、泼尼松+博来霉素组各时间点E-Cad表达水平较博来霉素组组均有升高(P<0.05),以NaHS+博来霉素组28 d升高最多。结论H_(2)S可有效减轻大鼠肺纤维化程度,其机制可能与下调TGF-β1、降低VIM和α-SMA表达、增强E-cad表达、减少EMT过程发生有关。

Objective To observe the effect of hydrogen sulfide(H_(2)S)on the expression of transforming growth factor-β1(TGF-β1),E-cadherin(E-CAD),Vimentin(VIM),alpha-smooth muscle actin(α-SMA)during epithelial-mesenchymal transformation(EMT),and to explore the anti-fibrosis mechanism of it.Methods Sixty rats(male SD)were randomly divided into control group,bleomycin group,NaHS+bleomycin group and prednisolone+bleomycin group,15 rats per group.5 rats of each group were sacrificed at random in 7th,14th and 28th day.The degree of alveolitis and pulmonary fibrosis was observed.The expression of protein and mRNA of TGF-β1,E-cad,VIM,α-SMA were determined by Immunohistochemi stry and RT-PCR.Results①HE and Masson staining showed that the lung tissue of fibrosis had the lowest degree in control group.and the most severe in bleomycin group.The lung tissue of NaHS+bleomycin group and prednisolone+bleomycin group also had alveolitis and fibrosis changes,but the degree Were significantly less than bleomycin group.②The mRNA and protein expression levels of TGF-β1,VIM andα-SMA in bleomycin group,NaHS+bleomycin group and prednisolone+bleomycin group were all higher than that in control group at 7th,14th and 28th day(P<0.05),while the expression levels of them in NaHS+bleomycin group and prednisolone+bleomycin group were all lower than that in bleomycin groupat each time(P<0.05),which was significant at 28th day in NaHS+bleomycin.③The mRNA and protein expression levels of E-Cad in bleomycin group,NaHS+bleomycin group and prednisolone+bleomycin group were all lower than that in control group at 7th,14th and 28th day(P<0.05),but the expression levels of E-Cad inNaHS+bleomycin group and prednisolone+bleomycin group were higher than that in bleomycin group at each time(P<0.05),which was significant at 28th day in NaHS+bleomycin.Conclusion H_(2)S can reduce the degree of pulmonary fibrosis in rats,its mechanism may be related to the down-regulation of TGF-β1and the inhibition of the EMT,which can enhance the expression of E-cad and reduce the expression of TGF-β1,VIM andα-SMA.