黄芪注射液对肺纤维化小鼠肺组织上皮-间质转分化的影响

Effect of Astragalus injection on epithelial mesenchymal transition of lung tiusse in mice with pulmonary fibrosis

目的观察黄芪注射液对肺纤维化小鼠肺组织上皮-间质转分化(EMT)的影响,研究其对肺泡上皮细胞EMT过程的干预作用及可能机制。方法将30只实验小鼠随机平均为纤维化组、黄芪组、PBS对照组。纤维化组小鼠气管内灌注博莱霉素3 mg/kg;PBS对照组小鼠于气管灌注等量PBS;黄芪组小鼠给予气管灌注博莱霉素3 mg/kg,并且于实验造模后10 d腹腔注射黄芪注射液5 m L/kg,连续给药2周。实验第24天处死小鼠,肺组织切片行Masson染色观察肺组织病理改变,碱裂解法检测肺组织中羟脯氨酸(HYP)含量,ELISA法检测小鼠血清肿瘤坏死因子α(TNF-α)和转化生长因子-β1(TGF-β1)水平,Western blot法检测肺组织中上皮细胞标志物E-cadherin和间质细胞标志物α平滑肌肌动蛋白(α-SMA)的蛋白表达量。结果与纤维化组比较,黄芪组小鼠肺组织肺纤维化病理损伤明显减轻,胶原沉积减少;黄芪组小鼠肺组织中HYP含量和α-SMA蛋白表达量均明显低于纤维化组(P均<0.05),E-cadherin蛋白表达量明显高于纤维化组(P<0.05);黄芪组血清TNF-α和TGF-β1水平均明显低于纤维化组(P均<0.05)。结论黄芪注射液能下调TNF-α和TGF-β1表达,抑制肺泡上皮细胞EMT现象,从而改善博来霉素诱导的小鼠肺纤维化病理改变。

Objective It is to observe the effect of Astragalus injection on epithelial-mesenchymal transition（ EMT） of lung tissue in mice with pulmonary fibrosis,and to study the intervention effect on EMT in alveolar epithelial cells and its mechanism. Methods Thirty mice were randomly divided into fibrosis group,Astragalus group and PBS control group. The fibrosis group was treated with bleomycin（ 3 mg/kg） by endotracheally injection,PBS control group was treated with PBS at the same volume by endotracheally injection,Astragalus group was treated with Astragalus injection（ intraperitoneal injection 5m L/kg） plus bleomycin intratracheal administration. After 24 days,all the mice were killed,the lung tissue was examined pathologically with Masson staining to observe pathological changes. The content of Hydroxyproline（ HYP） in lung tissue was detected by alkaline lysis method,the serum concentrations of TNF-α and TGF-β1were detected by ELISA,and protein expression of α-SMA and E-cadherin in lung tissue was detected by Western blot method. Results Compared with fibrosis group,the pathological injury of lung fibrosis in lung tissue were significantly relieved and collagen deposition were decreased in Astragalus group; the contents of HYP and α-SMA protein in lung tissue and the levels of serum TNF-α and TGF-β1were lower while the expression of E-cadherin protein in lung tissue was significantly higher in Astragalus group than those in fibrosis group（ P〈0. 05）. Conclusion Astragalus injection can down-regulate the expression of TNF-αand TGF-β1,inhibit the EMT phenomenon of alveolar epithelial cells,and thus to improve the BLM-induced lung fibrosis in mice.