紧密连接蛋白occludin在三硝基苯磺酸诱导大鼠结肠炎肠黏膜屏障中的作用研究

目的探讨紧密连接蛋白occludin在三硝基苯磺酸（trinitro-benzen-sulfonic acid,TNBS）诱导大鼠结肠炎肠黏膜屏障中的作用。方法建立大鼠结肠炎模型。SD大鼠18只,按随机数字表法分为TNBS诱导大鼠结肠炎模型组（n=10）和正常对照组（n=8）,进行疾病活动指数（DAI）和组织学损伤评分,用ELISA法测定结肠组织肿瘤坏死因子-α（TNF-α）、白介素-10（IL-10）和血清内毒素,采用免疫组织学染色检测紧密连接（tight junction,TJ）相关蛋白occludin的分布。结果TNBS诱导大鼠结肠炎后,和正常组比较,TJ结构遭到破坏,TJ相关蛋白的表达亦减少,结肠组织TNF-α水平升高、IL-10水平降低和血清内毒素水平升高（P〈0.05）。结论TNBS诱导大鼠结肠炎肠黏膜上皮细胞TJ相关蛋白occludin表达下降,肠黏膜上皮屏障的完整性被破坏,导致肠黏膜屏障功能低下,促发炎症反应。

The study on the role of occludin in intestinal mucosal barrier of rats with trinitro-benzen-sulfonic acid induced colitis

Objective To investigate the effect of occluding in intestinal mucosal barrier in rats with trinitro-benzen-sulfonic acid （TNBS） induced colitis. Methods Acute colitis in rats was induced by TNBS. Eighteen Sprague-Dawley rats were randomized into the control group （n = 8） and TNBS Group （n = 10）. Diarrhea and bloody stool as well as colonic histology were observed. Tumor necrosis factor-α （TNF-α） and interleukin-10 （IL-10） in colonic tissue and serum endotoxin were determined with ELISA. The expression of occluding was detected by histochemistry. Results In TNBS Group,the tight junction was disrupted and the expression of occludin was decreased. TNF-α and serum endotoxin were significantly increased and serum IL-10 were remarkably reduced （P 0.05）. Conclusion The decreased expression of occludin in rats with TNBS induced colitis results in the disruption of intestinal mucosal barrier,leading to the initiation of inflammatory response.