肿瘤坏死因子转换酶在炎性气道黏液高分泌中的作用

Effects of tumor necrosis factor-α converting enzyme on mucous hypersecretion in inflammatory airway

目的:探讨肿瘤坏死因子转换酶(TNF-αconverting enzyme,TACE)对炎症条件下气道上皮细胞形成黏液高分泌过程的影响。方法:通过不同剂量人中性粒细胞弹性蛋白酶(human neutrophil elastase,HNE)刺激人肺腺癌的气道上皮细胞A549,构建炎症条件下气道黏液高分泌模型,以TACE抑制剂-1(TNF-αconverting enzyme inhibitor-1,TAPI-1)进行干预,观察TACE、黏蛋白(mucin,MUC)5AC的表达。将A549细胞分为5组:对照组,HNE(15,25,50 nmol/L)组,TAPI-1组。RT-PCR检测各组TACE和MUC5AC m RNA的表达;Western印迹检测TACE蛋白的表达;酶联免疫吸附测定法(ELISA)观察MUC5AC蛋白的表达。结果:各剂量HNE处理后,TACE和MUC5AC的m RNA和蛋白表达均较对照组明显升高(P<0.01),且呈现剂量依赖性。而给予TAPI-1预处理后,与HNE刺激组比,各指标明显下调(P<0.01)。结论:TACE参与了黏液高分泌的细胞转导途径,并可促成炎性气道黏液高分泌的形成。

Objective: To investigate the effect of tumor necrosis factor-α converting enzyme(TACE) on mucous hypersecretion in inflammatory airway.Methods: Mucous hypersecretion model of human lung adenocarcinoma cells A549 was induced by human neutrophil elastase(HNE), and TNF-α converting enzyme inhibitor-1(TAPI-1), an inhibitor of TACE, was chosen for the inference study. The expression of MUC5 AC and TACE was examined. Th e cells were divided into 5 groups: a negative control group, HNE1(15 nmol/L) group, HNE2(25 nmol/L) group, HNE3(50 nmol/L) group and TAPI-1 group. RT-PCR was used to examine MUC5 AC and TACE m RNA expression. The protein expression of TACE and MUC5 AC was examined by Western blot and ELISA, respectively.Results: HNE induced the TACE and MUC5 AC mR NA and protein expression in a dose-dependent manner. Compared with the control group, the increases were all significantly increased in the three dosages of HNE group(P<0.01). The HNE-induced TACE and MUC5 AC m RNA and protein expression were dramatically attenuated in the presence of TAPI-1, an inhibitor of TACE(P<0.01).Conclusion: TACE participated cell signalling pathway of airway mucous hypersecretion, and could down regulation the level of inflammation airway mucous hypersecretion.