ESRD时的微生物代谢性毒素酚类、吲哚导致肠道上皮细胞紧密连接损伤。ESRD的肠道菌群紊乱、结肠转运时间延长、饮食结构的变化是否会使这些肠道毒素的种类和量增多，增多的毒素是否会更进一步损伤肠上皮细胞的紧密连接，损伤的机制如何尚不清楚。本课题运用联用UPLC/MS 的代谢组学和蛋白质组学方法，揭示ESRD大鼠和患者粪便提取液代谢产物谱和蛋白谱的差异，获得ESRD大鼠和患者肠道毒素谱；将已知的和代表性毒素与肠上皮T84细胞共培养，检测紧密连结蛋白Occludin 、Claudins及ZO-1含量及位置的变化、上皮细胞层电阻的改变以确定其对上皮屏障的破坏；运用RNA干扰，信号通路抑制剂等方法检测p38 MAPKs通路，确定其在肠道毒素导致紧密连接蛋白破坏的主导作用，揭示毒素对上皮紧密连接破坏的分子机制；评估ESRD大鼠口服活性炭吸附剂对肠上皮通透性的影响，为临床减轻毒素对疾病的影响奠定理论基础。

The microbial metabolic toxins phenols and indole in ESRD lead to intestinal epithelial tight junction damage. In ESRD, These remain unclear whether the disordered intestinal flora, prolonged colonic transportation and the changed diet ingredient result in increased type and quantity of these intestinal toxins, and whether the increased toxin further damage tight junctions of intestinal epithelial cells. If any, the mechanisms of injury is unclear. LC/MS will be used for determination of metabolomics and proteomics, revealing difference of metabolite spectrum and protein profiles in fecal extract between ESRD rats and control rats, and in healthy people and ESRD patients, and obtaining representative toxin in the ESRD rats and patients; through the detection of the content and position change of tight junction protein: occludin, claudins, ZO-1 in cultured epithelial cells and the change of resistance of epithelial cell layer after expose epithelial cell layer to the known and representative toxin, the status of the epithelial barrier will be observed; using RNA interference, signaling pathway inhibitors, and other molecular biology method, P38 MAPK will be analyzed, revealing the molecular mechanisms of epithelial tight junctions damage after the toxin expose; the effect of orally active carbon on intestinal epithelial permeability in ESRD rats will be assessed, which lays a theoretical foundation for reducing the influence of toxin on the original disease.