中文摘要：

目的探讨栓链因子复合物亚基Sec3对中性粒细胞弹性蛋白酶（NE）诱导的气道上皮细胞黏蛋白（MUC）分泌的影响。方法体外培养人气道上皮细胞16HBE，随机分为8组：空白对照组、表皮生长因子受体（EGFR）磷酸化抑制剂AG1487组、Sec3 siRNA组、阴性siRNA对照组、NE组、NE＋AG1478、NE＋Sec3 siRNA组、NE＋阴性siRNA组。采用Westernblot法检测Sec3蛋白及pEGFR的相对含量；EusA、RT-PCR法分析细胞培养上清液中MUCSAC的相对含量及细胞中MUCSACmRNA水平。结果Sec3siRNA转染显著降低Sec3蛋白表达，提示转染成功，且加入NE对转染效果无干扰。单纯NE刺激组上清液中MUC5Ac含量，细胞中MUC5AC mRNA、pEGFR水平显著高于空白对照组（P〈0．01），AG1487可明显抑制上述刺激作用；转染Sec3siRNA可阻断MUCSAC分泌（P〈0．01），但并不影响其转录水平表达（P〉0．05）。结论在NE诱导的人气道上皮黏液高分泌过程中，栓链因子复合物亚基Sec3对黏蛋白出胞有重要的介导作用。

英文摘要：

Objective To explore the effects of the exocyst complex subunit Sec3 on the secretion of mucin （MUC） 5AC induced by neutrophil elastase （NE） in human airway epithelial ceils. Methods The 16HBE airway epithelial cells were cultured and divided into 8 groups ： blank control group, epidermal growth factor receptor （EGFR） phosphorylated inhibitor （AG1487） group, Sec3 siRNA group, negative siRNA control group, NE group, NE＋ AG1478 group, NE ＋ Sec3 siRNA group, and NE＋ negative siRNA group. The levels of Sec3 protein and phosphorylated EGFR （pEGFR） were detected by Western blot. The level of MUCSAC protein in the supernatants was detected by enzyme-linked immunosorbent assay （ELISA） and the expression of MUC5AC mRNA in cultured cells by RT-PCR. Results The level of Sec3 protein was significantly decreased after the transfeetion of Sec3 siRNA, indicating the success of transfection. NE had no effects on the outcomes of transfection. The levels of MUC5AC protein and pEGFR protein, and the mRNA expression level of MUC5AC were significantly increased in the NE group when compared with the blank control group （P~0.01） ,which could be suppressed by AG1487. The Sec3 siRNA could significantly inhibit the secretion of MUC5AC （P〈0.01） but failed to affect the transcription process （P〈0.05）. Conclusion The exocyst complex subunit See3 plays a critical role in mucin exocytosis in the NE-induced MUC5AC hypersecretion in human airway epithelial cells.