p38MAPK调控PDIA3介导的内质网途径细胞凋亡抑制在瑞芬太尼预处理抗肠缺血再灌注损伤中的作用

Intestinal ischemia/reperfusion (I/R) is one of the main causes contributing to multiple organ failure during perioperative period. We had already revealed remifentanil preconditioning(RPC) protected intestine against intestinal I/R injury by inhibiting the apoptosis, but the exact mechanism remains an enigma. Our previous study had documented for the first time that the expression of protein disulfide isomerase A3 (PDIA3) was decreased after intestinal I/R, and we also found RPC could increase the expression of PDIA3, which suggested PDIA3 may be the key enzyme of RPC against intestinal I/R injury. Lots of studies had found that RPC played a protective role in the organic I/R through p38MAPK signaling pathway, and it had been suggested that p38MAPK could regulate the expression of PDIA3. In addition, it was not clear whether PDIA3, the endoplasmic reticulum signaling pathway protein with an anti-apoptotic effect, was involved in intestinal protection of RPC by inhibiting the endoplasmic reticulum(ER) pathway apoptosis. Hence, the intestinal I/R injury model of rats and PDIA3 gene knockout mice combining with the IEC oxygen and glucose deprivation/ reperfusion model was used to explore the role of p38MAPK regulated inhibition of ER pathway apoptosis induced by PDIA3 in the RPC against intestinal I/R injury. Finally, our study attempts to provide new targets and scientific evidence for the prevention and treatment of intestinal injury after intestinal I/R.

肠缺血再灌注（I/R）是围术期患者发生多脏器功能衰竭的主要原因之一，申请者前期研究已证实瑞芬太尼预处理（RPC）可抑制细胞凋亡发挥抗肠I/R损伤的作用，但具体机制尚需进一步澄清。我们通过蛋白组学技术首次报道肠I/R可下调蛋白二硫化物异构酶A3(PDIA3)在肠的表达，同时预实验发现RPC能上调其表达，提示PDIA3可能是RPC肠保护作用的关键酶。大量研究表明p38MAPK信号通路参与RPC的器官保护作用，且已有研究提示其可调控PDIA3的表达。此外，PDIA3作为一具有抗凋亡作用的内质网信号通路蛋白，其是否通过抑制内质网途径细胞凋亡参与RPC的肠保护作用尚不清楚。据此，本课题拟通过大鼠及PDIA3基因敲除小鼠的肠I/R损伤模型，结合IEC氧糖剥夺/复灌模型，证实p38MAPK调控PDIA3介导的内质网途径细胞凋亡抑制在RPC抗肠I/R损伤中的作用，为肠I/R损伤的防治提供新靶点和科学依据。

本项目从p38MAPK调控蛋白二硫化物异构酶A3（PDIA3）介导的抗氧化应激和抗内质网应激角度探讨了肠缺血再灌注（I/R）后肠损伤和瑞芬太尼肠保护的新机制，为防治肠I/R损伤提供重要的可供干预的蛋白分子靶点（PDIA3），有利于临床开发防治肠I/R损伤的药物。取得的学术成果如下：.（1）应用小鼠肠I/R模型，证实瑞芬太尼具有抗肠I/R肠损伤的作用，其肠保护机制与抗氧化应激和抗内质网应激有关。.（2）应用条件基因敲除技术，证实瑞芬太尼通过上调PDIA3表达发挥肠保护作用。.（3）使用p38MAPK特异性抑制剂SB203580能阻断瑞芬太尼的肠保护作用，同时能够下调PDIA3的表达，证实瑞芬太尼是通过激活p38MAPK进而上调PDIA3表达发挥肠保护作用。