Exocyst复合物关键亚基Sec3蛋白在气道黏液高分泌中的作用研究

目的 探讨Exocyst复合物关键亚基Sec3蛋白在气道黏液高分泌形成过程中的作用.方法 将60只大鼠随机分成3组:正常对照组,烟雾暴露组、烟雾暴露+人中性粒细胞弹性蛋白酶(HNE)组.烟雾暴露组大鼠采用烟雾暴露法建立慢性支气管炎症病理性改变,HNE攻击形成气道黏液高分泌大鼠模型.取肺组织支气管上皮,观察气道上皮杯状细...

The role of the key subunit Sec3 protein of the Exocyst complex in airway mucus hypersecretion

Objective To investigate the role of Exocyst subunit Sec3 in the airway mucus hypersecretion.Methods Sixty rats were randomly divided into 3 groups:normal control group,smoke exposure group,smoke exposure+human neutrophil elastase(HNE)group.Rats in the smoke exposure group used smoke exposure to establish pathological changes of chronic bronchial inflammation,and HNE attacked to form a rat model of airway mucus hypersecretion.The bronchial epithelium of lung tissue was taken to observe the goblet cells and mucus secretion in the airway epithelium.The expression of SEC3 and airway epithelial 5AC(MUC5AC)were determined.Human bronchial epithelioid cells(16HBE)were treated with HNE.Then the effect of HNE on the expression of Sec3,p-Sec3 and MUC5AC protein in 16HBE were analyzed.Sh-Sec3 was transfected into HNE-treated 16HBE,and the transfection efficiency was analyzed,then the effect of Sec3 on the hypersecretion of MUC5AC in 16HBE induced by HNE was discussed.Co-immunoprecipitation was used to identify the interaction between Sec3 and MUC5AC.Results Compared with normal control group,the remaining two groups had a significant increase in airway epithelial goblet cells proliferation and mucus secretion as well as in expression levels of Sec3 and MUC5AC proteins,and all the changes were more significant in smoke exposure+HNE group than in smoke exposure group(P<0.05).Compared with 16HBE group,the relative expression of Sec3,p-Sec3 and MUC5AC protein of 16HBE+HNE grop in creased with a time-dependent manner(P<0.05);Compared with 16HBE+HNE group and empty plasmid transfection group,the relative expression of Sec3 protein and mRNA and MUC5AC protein in the sh-Sec3 group were significantly reduced(P<0.05);Sec3 protein and MUC5AC antibody could co-precipitate each other,and this interaction was significantly enhanced under HNE stimulation.Conclusion Sec3 participates in the process of airway mucus hypersecretion,and interacts with MUC5AC both in vivo and in vitro,thus mediating the HNE-induced hypersecretion of MUC5AC.