HMGB1对急性坏死性胰腺炎大鼠肠上皮细胞紧密连接相关蛋白表达的影响

摘要

目的:观察急性坏死性胰腺炎(ANP)大鼠肠黏膜中高迁移率族蛋白B1 (HMGB1)的表达对肠黏膜上皮细胞紧密连接功能的影响.方法:24只Wistar大鼠随机分为正常对照组、ANP组和丙酮酸乙酯(EP)处理组,分别于建模后24 h取材.测定血浆淀粉酶(AMY)、血浆D-乳酸、肠黏膜髓过氧化物酶(MPO)水平变化；应用Western blot法检测ANP大鼠肠黏膜中HMGB1和occludin蛋白水平的变化.结果:在建模后24 h,大鼠AMY、D-乳酸与肠黏膜MPO水平ANP组明显高于正常对照组和EP处理组(P＜0.05),但EP处理组仍高于正常对照组(P＜ 0.05);ANP组大鼠肠黏膜HMGB1表达水平明显高于正常对照组和EP处理组(P＜0.05),EP处理组高于正常对照组(P＜0.05)；而肠黏膜上皮细胞紧密连接蛋白occludin的表达ANP组较正常对照组和EP处理组下降(P＜0.05),EP处理组低于正常对照组(P＜0.05).结论:ANP大鼠肠黏膜中HMGB1表达增高,可通过降低occludin蛋白表达,增加肠黏膜屏障通透性.EP能显著抑制HMGB1表达,使occludin蛋白表达升高,对ANP肠黏膜损伤有明显保护作用.%Objective: To investigate the effect of high mobility group box-1 protein (HMGB1) on the expression of intestinal epithelial tight junction protein in murine acute necrotizing pancreatitis(ANP). Methods:Twenty-four male health adult wistar rats were divided randomly into groups: control group, ANP group, and EP treatment group. Specimens were taken at 24h after operation respectively. The concentration of plasma amylase(AMY), plasma D-lactate and the activity of myeloperoxidase(MPO) in the intestinal tissue were determined. The expression of HMGB1 and oc-cludin protein in intestinal mucosa was detected by western blot. Results: In comparison with the control group, levels of plasma D-lactate and MPO in ANP group increased markedly at 24h after operation(P＜0.05). The levels of D-lactate and MPO were markedly lowered in EP treatment group 24 h after ANP model was set up(P＜ 0.05). The expression of HMGB1 in ANP group increased significantly compared with control group. However, the expression of occludin in ANP group was significantly lower than control group(P＜ 0.05). Compared with ANP group, the expression of HMGB1 was lower and the expression of occiudin was higher in EP treatment group(P＜ 0.05). Conclusion: The up-regulation of HMGB1 could down-regulate the expression of occludin in intestinal tissues of ANP rats, and thus mediate an increase in penetrability of intestinal mucosal barrier. EP can inhibit the expression of HMGB1 and up-regulate the expression of occluding protein in intestinal tissues of ANP rats, and protect intestine from injury induced by ANP.