PI3K/PKB 信号通路抑制剂渥曼青霉素预处理对重症急性胰腺炎大鼠肠屏障功能的影响。

Effect of PI3K/PKB signal pathway inhibitor wortmannin pretreatment on intestinal barrier function in severe acute pancreatitic rats.

机构信息

Department of Emergency, First Affiliated Hospital of Anhui Medical University, Hefei, China.

出版信息

Adv Clin Exp Med. 2019 Aug;28(8):1059-1066. doi: 10.17219/acem/99910.

DOI:10.17219/acem/99910

PMID:31414732

Abstract

BACKGROUND

It is well-known that severe acute pancreatitis (SAP) due to infection is mainly caused by intestinal bacterial translocation. The intestinal barrier is tasked with preventing intestinal pathogenic bacteria and toxins from reaching the parenteral tissues through the intestinal wall. Therefore, maintaining intestinal barrier function may be the key to preventing damage from acute pancreatitis (AP). The phosphatidylinositol 3-kinase/protein kinase B pathway (PI3K/PKB) plays a role in AP. However, the exact effect of PI3K/PKB on injury associated with SAP has not yet been found.

OBJECTIVES

The present study was aimed at investigating the impact of wortmannin (WT), a PI3K/PKB inhibitor, on intestinal barrier function in SAP rats.

MATERIAL AND METHODS

The rats were divided into 3 groups: 1) the Sham Surgery group (SS), whose duodenum and pancreas were flipped 3 times (n = 18); 2) the pancreatitis group (SAP), who were injected through retrograde pancreatic duct injection with 5% sodium taurocholate (n = 18); and 3) the WSAP intervention group (SAP+WT). Serum alpha-amylase levels, plasma endogenous endotoxin, hematoxylin-eosin (H&E) staining, intestinal mucosa electron microscopy, intestinal permeability, and expression of p-PKB (phosphorylated protein kinase B) were measured.

RESULTS

In our findings under an electron microscope, the SAP group presented cell edema and mitochondrial vacuolated degeneration, sparsely arranged microvilli, tight junction damage, and widening, while the WSAP group exhibited less change and lower pancreas scores (7.4 ±1.14, 10.2 ±1.48 and 12.0 ±1.58 for 3 h, 6 h and 12 h, respectively) (p < 0.05). Furthermore, the plasma endogenous endotoxin levels and Evans blue content of the WSAP group was significantly lower at all timepoints than in the SAP group (p < 0.05). Western blotting showed that p-PKB expression was lower in the WSAP group than in the SAP group (p < 0.05). Our study suggests that WT relieves intestinal permeability changes in SAP rats and may be dose-dependent.

CONCLUSIONS

The PI3K/PKB signal pathway may involve SAP-related intestinal injuries and WT may relieve SAP intestinal injuries through the PI3K/PKB pathway.

摘要

背景

众所周知，感染引起的重症急性胰腺炎（SAP）主要是由肠道细菌易位引起的。肠道屏障的任务是防止肠道中的致病细菌和毒素通过肠壁到达周围组织。因此，维持肠道屏障功能可能是预防胰腺炎（AP）损伤的关键。磷脂酰肌醇 3-激酶/蛋白激酶 B 途径（PI3K/PKB）在 AP 中发挥作用。然而，PI3K/PKB 对 SAP 相关损伤的确切影响尚未找到。

目的

本研究旨在探讨 PI3K/PKB 抑制剂渥曼青霉素（WT）对 SAP 大鼠肠道屏障功能的影响。

材料和方法

大鼠分为 3 组：1）假手术组（SS），十二指肠和胰腺翻转 3 次（n=18）；2）胰腺炎组（SAP），经逆行胰管注射 5%牛磺胆酸钠（n=18）；3）WSAP 干预组（SAP+WT）。测定血清α-淀粉酶水平、血浆内毒素、苏木精-伊红（H&E）染色、肠黏膜电镜、肠黏膜通透性及磷酸化蛋白激酶 B（p-PKB）表达。

结果

在电子显微镜下，SAP 组细胞水肿，线粒体空泡变性，微绒毛排列稀疏，紧密连接损伤，间隙增宽，WSAP 组改变较轻，胰腺评分较低（3 h、6 h 和 12 h 分别为 7.4±1.14、10.2±1.48 和 12.0±1.58）（p<0.05）。此外，WSAP 组各时间点血浆内毒素水平和伊文思蓝含量均明显低于 SAP 组（p<0.05）。Western blot 显示，WSAP 组 p-PKB 表达低于 SAP 组（p<0.05）。本研究表明，WT 可减轻 SAP 大鼠肠通透性改变，且可能呈剂量依赖性。