中文摘要：

目的探讨包含IQ序列的三磷酸鸟苷酶（GTP）激活蛋白1（IQGAP1）和细胞分裂周期42蛋白（Cdc42）在气道上皮细胞损伤修复不同阶段的作用。方法选用健康昆明种小鼠24只,5 mg/m3气态甲醛,染毒4 h/d,分别染毒3,7和60 d后处死,采用免疫组织化学染色、蛋白印迹（Western blot）检测和免疫荧光共聚焦成像方法,观察IQ-GAP1和Cdc42蛋白在染毒小鼠气道上皮细胞损伤修复过程中的表达和定位变化。结果IQGAP1在染毒3和7 d时表达明显增强（P〈0.01）,60 d时恢复至对照组水平;Cdc42蛋白在染毒3 d时表达明显减弱（P〈0.01）,7 d时表达有所恢复。对照组中IQGAP1主要定位于气道上皮细胞的胞膜处,而Cdc42蛋白弥散分布于气道上皮细胞（AECs）胞质中;3 d和7 d时共同定位于细胞极化前缘;60 d时其定位与对照组相似。结论Cdc42蛋白和IQGAP1在气道上皮细胞损伤修复过程中的表达及定位呈动态变化,提示其在这一过程中发挥着重要作用。

英文摘要：

Objective To investigate the roles of IQ motif containing GTPase activating protein 1 （IQGAP1） and cell division cycle 42 protein （Cdc42） in the repair of the injured airway epithelial cells （AECs） at different stages. Methods Twenty-four Kunming mice were randomly divided into four groups as following：3, 7, 60 - day formaldehyde （FA） inhalation group and the control group. The mice were exposed to gaseous FA of 5 mg/m^3 for 4h/day for 3, 7, and 60 days. The expressions and locaiizations of IQGAP1 and Cdc42 protein in the AECs were observed during the repair. Results IQGAP1 of the 3 - and 7 - day groups significantly increased （ P 〈 0.01 ）, but decreased at the 60th day. Cde42 protein obviously decreased after 3 - day inhalation of FA （P〈0.01）, but enhanced again at the end of 7th day. IQGAP1 localized around the plasma membrane and Cde42 protein mainly distributed uniformly in the cytoplasm of AECs. In 3 - and 7 - day treated groups they were eo - localized at the cell leading edge, and in 60 - day treated group their localizations were similar to the control. Conclusion During the injury and the repair after the injury, the expression and the localization of IQGAP1 and Cdc42 protein are dynamically changed in the AECs. They may play a key role in the repair process of airway epithelium injury.