炎症性肠病肠黏膜屏障损伤机制

Intestinal barrier injury in inflammatory bowel disease

肠黏膜屏障是指将肠腔内细菌、抗原等物质与肠黏膜固有层免疫细胞隔离开,避免固有层免疫细胞激活的肠黏膜结构,主要由肠黏膜基底膜、上皮细胞层及其表面的黏液层所构成.炎症性肠病(inflammatoryboweldisease,IBD)肠黏膜屏障损伤的机制为:IBD发病时,肠黏膜所产生的大量炎症细胞因子、炎症介质等损伤肠上皮细胞,诱导上皮细胞凋亡;影响上皮细胞紧密连接蛋白的表达及分布,破坏上皮细胞间紧密连接;抑制黏蛋白的产生,破坏上皮细胞表面的黏液层,造成肠黏膜屏障障碍.

Intestinal mucosal barrier, which mainly contains epithalial cells and mucus layer, keeps physiological function of immune cells in intestine. During the process of inflammatory bowel disease （IBD）, mucosal integrity and barrier function are broken, which leads to translocation of luminal contents such as bacterial antigens, thus inducing expression of proinflammatory cytokines and triggering immune response. Meanwhile, the produced proinflammatory cytokines influence epithelial and mucosal barrier function by inducing apoptosis of intestinal epithelia, altering the expression and cellular distribution of tight junction proteins, and reducing the production of mucus.