慢性机械压力诱导气道上皮黏蛋白5AC的表达

目的 探讨慢性机械压力能否诱导气道上皮黏蛋白(mucin,MUC)5AC表达及通过的相关信号通路.方法 培养大鼠气道上皮细胞建立气液相界面(air liquid interface,ALI),通过对Transwell培养板上的气道上皮细胞每天施加10、20、30 cmH2O水平的气体压力1 h并持续7 d来模拟慢性机械压力作用,并以表皮生长因子受体(epidermal growth factor receptor,EGFR)特异性抑制剂AG1478、细胞外信号调节激酶(extracellular signal regulated kinase, ERK)激酶抑制剂PD98059分别作为干预因素处理细胞.将细胞分为空白对照组、单纯压力组、AG1478+30 cmH2O压力组、PD98059+30 cmH2O 压力组,单纯压力组分为10、20、30 cmH2O 3个压力水平. RT-PCR检测MUC5AC mRNA 表达水平, ELISA法检测MUC5AC蛋白含量, Western blot 检测磷酸化ERK(p-ERK)、磷酸化c-Jun 氨基末端激酶(phosphorylated c-Jun N-terminal kinase,p-JNK)和磷酸化P38(p-P38)水平.结果 与空白对照组比较,单纯压力组MUC5AC蛋白及mRNA表达水平随压力水平的升高而升高(P<0.05),呈压力依赖性,同时伴随p-ERK蛋白含量增加(P<0.05),但p-JNK和p-P38含量没有明显变化(P>0.05).30 cmH2O压力水平MUC5AC蛋白及mRNA表达水平[(0.65±0.09)、(0.62±0.04)]明显高于空白对照组[(0.28±0.04)、(0.20±0.05),P<0.01],p-ERK蛋白含量(0.68±0.05)较空白对照组(0.27±0.07)显著增加(P<0.01).应用AG1478和PD98059分别预处理后,MUC5AC蛋白、mRNA表达水平及p-ERK蛋白水平在AG1478+30 cmH2O 压力组分别为(0.39±0.08)、(0.40±0.06)、(0.25±0.04),PD98059+30 cmH2O压力组分别为(0.36±0.09)、(0.38±0.13)、(0.26±0.11),与单纯压力组30 cmH2O水平比较均显著降低(P<0.05).结论 慢性机械压力能诱导气道上皮MUC5AC表达增加,这一作用可能通过机械压力压缩侧面胞间隙来实现,而EGFR及ERK信号通路参与其中.

Chronic mechanical stress induces mucin 5AC protein expression in rat airway epithelial cells in vitro

Objective To study the effect of chronic mechanical stress on mucin(MUC)5AC expre-ssion in airway epithelial cells of rats and its possible signaling pathway.Methods Airway epithelial cells from rats were cultured on transwell membrane at an air-liquid interface,stimulated by chronic mechanical stress from air pressure and pre-treated with EGFR kinase inhibitor AG1478 and specific inhibitor of the ERK pathway PD-98059,respectively.The cells were divided into negative control group,stress treatment group,AG1...