红景天苷通过抑制TLR4/NF-κB通路改善缺氧训练复合应激大鼠肠黏膜免疫状态

Salidroside improves intestinal mucosal immune status of rats under compound stress of hypoxia and training via inhibiting TLR4/NF-κB signaling pathway

目的探讨红景天苷对缺氧训练复合应激(HTCS)大鼠肠黏膜免疫状态的改善作用与机制。方法将SD大鼠随机分为3组,HTCS模型组未接受干预,安慰剂组和红景天苷组分别接受腹腔注射生理盐水、红景天苷,然后进行HTCS建模。取大鼠回肠组织,采用HE染色及Chiu评分法评估肠组织损伤程度,ELISA检测血清D二胺氧化酶(DAO)、D-乳酸(DLA)、内毒素(END)等肠通透性指标和肠组织分泌型免疫球蛋白A(sIgA);流式细胞术检测肠组织T淋巴细胞亚群;PCR及Western blot法检测闭锁小带蛋白1(ZO-1)、密封蛋白3(claudin-3)、闭合蛋白(occludin)紧密连接相关分子表达,Western blot法检测Toll样受体4/核因子κB(TLR4/NF-κB)信号活化状况。结果与模型组及安慰剂组相比,红景天苷组大鼠肠黏膜损伤减轻且Chiu法评分降低;血清DAO、DLA、END等肠通透性指标水平降低;CD4^(+)T细胞比例、CD4^(+)/CD8^(+)比值和sIgA水平升高,但CD8^(+)T细胞比例水平降低;ZO-1、claudin-3、occludin的mRNA和蛋白水平表达升高,TLR4/NF-κB信号活化受到显著抑制。结论红景天苷可能通过抑制TLR4/NF-κB信号通路保护HTCS大鼠肠屏障并改善肠黏膜免疫状态。

Objective To investigate the effect of salidroside on intestinal mucosal immune status in rats under compound stress of hypoxia and training(HTCS)and the mechanism.Methods SD rats were randomly divided into HTCS model group(model),placebo group(placebo)and salidroside group(salidro).Model group received no intervention,and placebo and salidro group received intraperitoneal injection of normal saline and salidroside,respectively.Then,ileum tissue of rats were collected and the intestinal damage was assayed by HE staining and Chiu scores.Intestinal permeability indices,including serum D-diamine oxidase(DAO),D-lactic acid(DLA)and endotoxin(END)and secretory immunoglobulin A(slgA)of intestinal tissue were detected by ELISA.T lymphocyte subsets of intestinal tssue were detected by flow cytometry.Expression of tight junction molecules,including ZO-1,Claudin-3,occluding,were detected by PCR and western blot.Activation of TLR4/NF-κB signaling pathway was detected by Western blot analysis.Results Compared with model group and placebo group,salidro group had the decreased intestinal mucosal injury and low Chiu score,and the level of intestinal permeability indices including serum DAO,DLA and END fell off.CD4^(+)T cell percentage,CD4^(+)/CD8^(+)ratio and slgA level were went up,while CD8^(+)T cell percentage was went down.mRNA and the level of protein expressions of ZO-1,claudin-3 and occludin increased,while activation of TLR4/NF-κB signaling pathway was inhibited.Conclusion Salidrosidecan alleviate the intestinal barrier injury and improve intestinal mucosal immune status of rats under compound stress of hypoxia and training via inhibiting TLR4/NF-κB signalling pathway.