轮状病毒通过STAT3磷酸化对肠道炎症的影响及机制研究

Effect and mechanism of rotavirus on intestinal inflammation through STAT3 phosphorylation

目的探讨轮状病毒(RV)感染BALB/c乳鼠后是否通过肠内白细胞介素-22(IL-22)水平变化,促使信号传导转录激活因子3(STAT3)磷酸化,调节肠道炎症反应,为RV的致病机制和有效防治提供理论依据。方法以RV灌胃感染7日龄BALB/c乳鼠,实验分为5组,分别为正常对照组、PBS对照组、RV感染组、RV+STAT3抑制剂组、STAT3抑制剂组。五组分别在感染后的1、2、3、4、5、6、7、8、9、10 d各处死5只乳鼠并收集肠组织标本。酶联免疫吸附试验(ELISA)检测肠黏膜匀浆液IL-22含量的变化情况,免疫印迹法(Western blot)检测各组不同时间点STAT3、pSTAT3和RegⅢ-γ蛋白水平的表达变化。结果 RV感染后肠组织表现出明显的炎症反应,并且肠道内IL-22水平随感染时间延长逐渐上升,在感染第4天达最大值,pSTAT3和RegⅢ-γ蛋白水平呈现出与IL-22类似的变化趋势,而STAT3蛋白水平呈现出相反的变化趋势,在感染后第4天表达水平最低。结论 RV感染机体后可活化IL-22/pSAT3/RegⅢ-γ信号通路,调节肠道炎症的发生与发展。

Objective To study whether rotavirus(RV) can promote the phosphorylation of signal transduction activator 3(STAT3),induce intestinal epithelial cells to secrete antimicrobial peptide RegⅢ-γ, and regulate intestinal inflammation after infection of BALB/c suckling mice.Methods 7-day-old SPF grade BALB/c suckling mice were administrated with RV by gavage.The experiment was divided into five groups:normal control group,PBS control group,RV infection group,RV + STAT3 inhibitor group and STAT3 inhibitor group.Five suckling mice were killed at 1,2,3,4,5,6,7,8,9 and 10 days after infection,respectively.Enzyme linked immunosorbent assay(ELISA) was used to detect the change of IL-22 content in intestinal homogenate,Western blot was used to detect the expression of STAT3,pSTAT3 and RegⅢ-γ protein at different time points in each group.Results After RV infection,the intestinal tissue showed obvious inflammatory reaction,and the level of IL-22 increased gradually with the infection time which reached the maximum value on the fourth day of infection.The protein levels of pSTAT3 and RegⅢ-γ showed the similar change trend with IL-22,while the protein level of STAT3 showed the opposite trend,and the expression level was the lowest on the fourth day after infection.Conclusion RV can activate IL-22/pSTAT3/RegⅢ-γ signaling pathway and regulate the development of intestinal inflammation.