摘要
目的探讨转录信号传导子和激活子3(Stat3)信号传导通路在肠上皮屏障功能改变中的分子机制。方法使用H2O2处理培养的HT29细胞,采用跨上皮电阻(TEER)法、Transwell法检测肠上皮单层细胞的完整性和通透性;采用固定化蛋白印迹(Westernblot)法检测凋亡相关蛋白及pStat3的表达。结果不同浓度H2O2刺激HT29单层细胞1h后,pStat3的表达随着H2O2浓度的增高而增加;以500μmol/L浓度的H2O2刺激HT29细胞,30min后pStat3的表达开始增高,2h表达下降;酪氨酸激酶抑制剂AG490可导致pStat3蛋白表达降低,显著降低bax蛋白表达增加(P<0.05)和bcl2蛋白表达减少的程度(P<0.05),改善氧化应激对单层细胞完整性及通透性的影响。结论氧化应激时,通过激活Stat3信号传导通路,破坏了单层肠上皮的完整性,提高了其通透性。
Objective To investigate the molecular mechanism of Stat3 signal pathway in the changes of the barrier of intestinal epithelial cells monolayer under oxidative stress. Methods HT-29 cells were cultured in vitro and treated with H2O2, to simulate the intestinal epithelial cells injured by ROS, The transepithelial electrical resistance and transwell were used to evaluate the integrity and the permeability of the intestinal epithelial cells monolayer respectively. The expression of p-Stat3 and apoptosis associated proteins was detected by Western Blot. Results Treatment of HT-29 cells for 1 h with different concentrations of H202 could increase the expression of p-Stat3 in a dose dependent manner. Moreover, after HT-29 cells were treated with H202 for 30 min in a dose of 500 μmol/L, the expression of p-Stat3 was increased, but it was decreased 2 h later. AG490 could inhibit the activation of Star3 （ P 〈 0.05）, reduce the expression ratio of bcl-2/bax （P 〈 0,05 ） and then protect intestinal mucosal barrier from oxidative stress induced dysfunction. Conclusion In oxidative stress, the activation of Star3 signaling pathway may down-regulate the ratio of bcl-2/bax expression, increase the apoptosis of HT-29 cells, furthermore, impair the integrity of intestinal epithelium cells and increase the permeability of monolayer.
出处
《中华实验外科杂志》
CAS
CSCD
北大核心
2005年第10期1183-1185,共3页
Chinese Journal of Experimental Surgery
基金
国家自然科学基金资助项目(30271269)
