The role of Stat3 in the changes of the barrier of intestinal epithelial cells monolayer under oxidative stress

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 H_2O_2,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 H_2O_2 could increase the expression of p-Stat3 in a dose dependent manner.Moreover,after HT-29 cells were treated with H2O2 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 Stat3 (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 Stat3 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.