重症急性胰腺炎中肠上皮自噬对肠道细菌移位的影响及其可能机制

发布时间：2018-04-28 05:04

  本文选题：胰腺炎 + 自噬　； 参考：《青岛大学》2017年硕士论文

【摘要】：目的:在重症急性胰腺炎(severe acute pancreatitis,SAP)中,肠源性感染是SAP患者后期感染的重要预后指标,细菌移位(bacterial translocation,BT)是肠源性感染的重要原因,在SAP早期便可引起全身炎症反应综合征(systemic inflammatory response syndrome,SIRS),进而导致多器官功能衰竭(multiple organ dysfunction syndrome,MODS)与脓毒血症,是SAP后期死亡的主要因素,而SAP肠粘膜屏障损伤发生BT的具体分子机制尚不明确。自噬参与多种疾病的病理生理过程,肠上皮自噬对于肠道稳态及肠道免疫发挥重要作用,有研究证实肠上皮自噬具有清除侵入机体肠道细菌的作用,并且近期体外研究表明,自噬增强肠上皮紧密连接(tight junction,TJ)蛋白的表达。但是肠上皮自噬对于SAP患者肠道BT影响尚不明确,我们旨在研究SAP中肠上皮自噬对于肠道BT与肠上皮TJ表达的影响。方法:根据2012年修订的亚特兰大急性胰腺炎分类定义标准,并给予急性胰腺炎患者急性生理与慢性健康评分(APACHE-Ⅱ)评分,选取发病24小时内入院APACHE-Ⅱ评分在8到12分之间的31位SAP患者。根据SAP患者外周血中,基于16SrDNA测序结果,确定患者外周血中细菌DNA的有无,将SAP患者分为细菌移位阳性组与细菌移位阴性组即BT(+)和BT(-),另选取健康的8人作为健康对照组(healthy control,HC),同时使用结肠镜获取SAP患者与健康对照组的结肠上皮粘膜组织;采用酶联免疫吸附法(ELISA)测定血清内毒素水平;采用免疫印迹技术(Western blot)检测肠上皮组织的紧密连接蛋白Zonula occluden-1(ZO-1)、claudins-2(CL-2)、occludin(OC)以及自噬标志蛋白微管相关蛋白1轻链3Ⅱ(LC3Ⅱ)的表达水平。结果:在纳入的31位SAP患者中,有14位患者外周血样本可检测到细菌DNA,阳性率为45.2%,BT(+)有14人和BT(-)有17人。经方差分析结果显示,血清内毒素在三组间差异具有统计学意义(F=6.981,P0.05),利用LSD-t检验比较结果显示,在SAP患者中BT(+)组中检测到血清内毒素水平显著高于BT(-)组和HC组(t=4.973,P0.05,t=8.661,P0.05);CL-2蛋白表达在三组间的差异具有统计学意义(F=8.641,P0.05),利用LSD-t进行组间比较结果显示,在BT(+)组患者中CL-2蛋白表达水平高于BT(-)组和HC组(t=6.875,P0.05,t=10.733,P0.05);BT(+)组患者的TJ蛋白ZO-1和OC均低于BT(-)组患者。此外,自噬相关蛋白LC3Ⅱ表达在三组间的差异具有统计学意义(F=11.574,P0.05),BT(-)患者肠上皮LC3Ⅱ表达高于BT(+)患者(t=4.765,P0.05,t=6.981,P0.05),且在SAP患者中CL-2与LC3Ⅱ表达呈负相关(r=-0.71,P0.05),相反的是,ZO-1和OC与LC3Ⅱ表达呈正相关(r=0.79,P0.05;r=0.88,P0.05)。结论:在SAP患者中肠上皮自噬是激活的,肠上皮自噬激活可能减少细菌移位的发生,其机制可能是肠上皮自噬影响肠上皮紧密连接作用,增强肠上皮TJ作用减少细菌移位的发生。
[Abstract]:Objective: in severe acute patients with severe acute pancreatitis (SAP), enterogenous infection is an important prognostic indicator of late infection in SAP patients, and bacterial translocation is an important cause of enterogenic infection. Systemic inflammatory response syndrome and multiple organ dysfunction syndrome (mods) and sepsis can be caused in early stage of SAP, which is the main cause of death in the later stage of SAP. However, the molecular mechanism of BT in SAP intestinal barrier injury is still unclear. Autophagy is involved in the pathophysiological process of many diseases. Intestinal epithelium autophagy plays an important role in intestinal homeostasis and intestinal immunity. Autophagy enhances the expression of tight junction TJ protein in intestinal epithelium. However, the effect of intestinal epithelial autophagy on intestinal BT in patients with SAP is not clear. We aim to study the effect of SAP midgut epithelium autophagy on the expression of BT and TJ in intestinal epithelium. Methods: according to the Atlanta acute pancreatitis classification standard revised in 2012, and the acute physiological and chronic health score (APACHE- 鈪，

本文编号：1813880