中文摘要：

目的探讨p38丝裂原激活蛋白激酶（P38）信号通路参与高渗应激诱导黏蛋白5AC（MUC5AC）高表达的作用机制。方法利用545、695、855、1055和1280mOsm／L高渗氯化钠溶液培养人气道上皮NCl-H202细胞。同时以1280mOsm／L高渗氯化钠为刺激因素，以P38特异性抑制剂SB203580、c-jun氨基末端激酶（JNK）特异性抑制剂SP600125及细胞外信号调节蛋白激酶（ERK）特异性抑制剂U0126为干预因素，采用RT-PCR技术及ELISA观察培养细胞MUC5AC转录水平和MUC5AC蛋白水平改变。采用Western blotting法检测1280mOsm／L高渗氯化钠培养上清液中细胞匀浆磷酸化P38（P—P38）、磷酸化JNK（p-JNK）及磷酸化ERK（p—ERK）蛋白水平。结果分别以545、695、855、1055和1280mOsm／L高渗氯化钠刺激后，培养细胞中MUC5ACmRNA及蛋白含量显著高于对照组（P〈0．01），且呈现出与渗透浓度相关的趋势。SB203580显著下调1280mOsm／L高渗氯化钠所致的p-P38含量升高，同时显著下调MUC5ACmRNA及蛋白含量（P〈0．05）；SP600125则明显下调p-JNK的含量，并下调MUC5ACmRNA转录及蛋白含量（P〈0．05），但作用弱于SB203580；1280mOsm／L高渗氯化钠对ERK的含量无影响（P〉0．05），U0126对MUC5ACmRNA转录及蛋白含量也无明显影响（P〉0．05）。结论高渗应激可呈浓度依赖性地从转录水平诱导气道上皮细胞呈现黏液高分泌状态，且P38信号通路起主要作用。

英文摘要：

Objective To explore the mechanism of signal cascades in hyperosmolarity-induced mucous hypersecretion. Methods NCl-H292 airway epithelial cells were cultured in 545, 695, 855, 1 055 and 1 280 mOsm/L hypertonic saline solution. At the same time, 1 280 mOsm/L hypertonic saline was uesd as a stimulus to P38 inhibitor SB203580, c-jun N-terminal kinase （JNK） inhibitor SP600125 and extracellular signal-regulated protein kinase （ERK）-specific inhibitor U0126 were uesd as the intervention factors. The transcription levels of MUCSAC and MUCSAC protein levels in the cultured cells were observed with RT-PCR technology and ELISA. The cell homogenate phosphorylated P38 （p-P38）, phosphorylated JNK （p-JNK） and phosphorylated ERK （p-ERK） protein level in 1 280 mOsm/L hypertonic saline supernatant were determined by Western blotting. Results After the stimulation by 545,695, 855, 1 055 and 1 280 mOsm/L hypertonic saline respectively, the expression of MUC5AC mRNA and protein contents in cultured cells were significantly higher than those of control group （P〈0.01）, which were associated with the exposure doses. SB203580 significantly reduced the increase of p-P38 levels induced by 1 280 mOsm/L hypertonie saline , while significantly reduced the expression of MUC5AC mRNA and protein content （P〈0.05）; SP600125 markedly reduced the levels of p- JNK, transcription of MUC5AC mRNA and protein content （P〈0.05）, but its effects were weaker than SB203580; 1 280 mOsm/L hypertonic saline had no effect on ERK levels （P〉0.05）, U0126 had no significant effects on MUC5AC mRNA transcription and protein content also （P〉O.05）. Conclusion Hypertonic stress can induce the airway epithelial cells to develop a high mucus secretion with the concentration-dependent manner in the level of transcription, P38 signal pathway plays a major role.