阻断MEK1上调支气管上皮细胞谷氨酰半胱氨酸合成酶的表达

Blocking MEKI signal transduction pathway increases the synthesis of γ-glutamylcysteine synthetase in the bronchial epithelial cell

目的探讨MEK1信号通路与支气管上皮细胞（16-HBE）谷氨酰半胱氨酸合成酶（1-GCS）表达的关系。方法应用MEK1抑制剂PD9805950μmol／L分别孵育16-HBE2、8、16及24h。用Western印迹方法和荧光定量PCR检测细胞γ-GCS重链蛋白和mRNA的表达。用显色方法检测细胞内谷胱甘肽（GSH）的含量。用Western印迹方法检测细胞c-jun的水平。结果经PD98059孵育4、8、16及24h后，γ-GCS重链蛋白和mRNA的表达和细胞内GSH的含量较对照组均增加。各时间段c-jun表达较各对照组减少。结论在支气管上皮细胞中MEKI抑制剂PD98059对16-HBE的γ-GCS和GSH有明显的上调作用。阻断激活蛋白-1（AP-1）途径不能减少γ-GCS和GSH的合成。

Objective To explore the relation between the MEKI signal transduction pathway and the synthesis of-y-glutamylcysteine synthetase（γ-GCS） in the bronchial epithelial cell（ 16-HBE）. Methods 16-HBE cells were incubated with the PD98059（50 μmol/L） for 2,8,16 and 24 hours. The expression of γ-GCS mRNA and protein was measured by Western blotting and real-time PCR. Cellular GSH level was detected by staining method. C-jun was examined by Western blotting. Results After the incubation with the PD98059 for 4,8,16 and 24 hours, the expression of γ-GCS, γ-GCS mRNA and GSH increased, but the expression of c-jun decreased as compared to the control group. Conclusions PD98059, inhibitor of MEKI, can increase the synthesis of γ-GCS and GSH in the 16-HBE. Blocking AP-1 could not decrease the synthesis of γ-GCS and GSH.