补肺汤通过TGF-β/Smad3信号通路抑制小鼠肺纤维化的研究

Bufei Decoction Alleviates Pulmonary Fibrosis in Mice Through TGF-β/Smad3 Signaling Pathway

目的研究补肺汤对博来霉素诱导的肺纤维化小鼠的保护作用,并探讨其可能的作用机制。方法将50只C57BL/6小鼠随机分为正常对照组、模型对照组、补肺汤小剂量组、补肺汤大剂量组、吡非尼酮组,每组10只。除正常对照组外,其他各组均采用气管滴注博来霉素建立小鼠肺纤维化模型。造模后第3天,补肺汤小、大剂量组分别灌胃给予3,12 g·kg-1补肺汤,吡非尼酮组灌胃给予吡非尼酮300 mg·kg-1,正常对照组和模型对照组给予等体积0.9%氯化钠溶液。28 d后处死小鼠,测定血清羟脯氨酸(HYP)、透明质酸(HA)、层黏连蛋白(LN)的含量,并对各组肺组织摄像,并进行苏木精-伊红(HE)染色以及Masson染色以观察肺形态学和组织病理学的改变。蛋白免疫印迹法检测小鼠肺组织中转化生长因子-β(TGF-β)、p-Smad3、α-平滑肌动蛋白(α-SMA)、I型胶原蛋白(Collagen I)蛋白的表达变化。结果与正常对照组比较,模型对照组小鼠血清HYP、HA、LN水平显著升高(P<0.05),肺组织可见肺泡结构破坏,肺间质增生,有炎性细胞浸润和胶原纤维增生形成,其中TGF-β、p-Smad3、α-SMA、Collagen I蛋白表达水平显著上调(P<0.05)。与模型对照组比较,补肺汤小、大剂量组HYP、HA、LN水平显著降低(P<0.05),肺损伤和纤维化程度改善,肺组织中TGF-β、p-Smad3、α-SMA、Collagen I等蛋白的表达水平显著下调(P<0.05)。结论补肺汤通过抑制TGF-β/Smad3信号通路改善小鼠肺纤维化的病变进程。

Objective To investigate the protective effect of Bufei decoction on bleomycin induced pulmonary fibrosis in mice and its possible mechanism.Methods Fifty C57BL/6 mice were randomly divided into the normal control group,model control group,pirfenidone group,low-and high-dose Bufei decoction groups,and 10 mice in each group.Except for the normal control group,bleomycin was infused into the trachea to establish the pulmonary fibrosis model in mice.On day 3 after the modeling,the mice were treated with Bufei decoction(3 and 12 g·kg-1 by gavage)in low-and high-dose Bufei decoction group.Pirfenidone group were treated with 300 mg·kg-1 of pirfenidone.The normal control group and the model control group were treated with equal volume of 0.9%sodium chloride solution.On day 28,all of mice were sacrificed.The serum hydroxyproline(HYP),hyaluronic acid(HA),laminin(LN)levels were measured by commercial kits.The lung tissues of each group were photographed,hematoxylin eosin(HE)staining and Masson staining were performed to observe the changes of lung morphology.The protein expression of transforming growth factor-β(TGF-β),p-Smad3,α-smooth muscle actin(α-SMA),and collagen I were analyzed by Western blotting.Results Compared with normal control group,HYP,HA,and LN levels in model control group were significantly increased(P<0.05).Several morphological and pathological changes,including alveolar space collapse,emphysema,infiltration of inflammatory cells,and collagen deposition were observed.The expression of TGF-β,p-Smad3,α-SMA and collagen I were increased significantly(P<0.05).Compared with model control group,the levels of HYP,HA,and LN in low-and high-dose Bufei decoction groups were decreased significantly(P<0.05).Morphological and pathological changes were markedly attenuated.In addition,the protein expressions of TGF-β,p-Smad3,α-SMA,and Collagen I were decreased obviously(P<0.05).Conclusion Bufei decoction can effectively improve the pathological process of pulmonary fibrosis,and the mechanism may be related to the regulation of TGF-β/Smad3 signaling pathway.