TLR4 介导的细胞凋亡在 Cerulein 诱导的急性胰腺炎中的作用。

Toll-like receptor 4-mediated apoptosis of pancreatic cells in cerulein-induced acute pancreatitis in mice.

机构信息

Institute of Digestive Surgery, West China Hospital, Sichuan University, Chengdu 610041, China.

出版信息

Hepatobiliary Pancreat Dis Int. 2010 Dec;9(6):645-50.

Abstract

BACKGROUND

Toll-like receptor 4 (TLR4) plays an important role in the occurrence and development of acute pancreatitis (AP). Apoptosis of pancreatic cells is closely related to the severity of AP. TLR4 is known to induce apoptosis in some cell types and therefore it is of importance to investigate potential associations between TLR4 activity and apoptosis in the setting of AP.

METHODS

A total of 50 wild-type (C57BL/10J) and TLR4-deficient (C57BL/10ScNJ) mice were divided into three groups: 2-hour, 4-hour, and control groups. Each group was divided into two equal subgroups: TLR4-wild-type mice and TLR4-deficient mice. AP was experimentally induced by 7 intraperitoneal injections of 50 μg/kg cerulein at hourly intervals. Control mice received 7 injections of equal volumes of saline. The severity of pancreatic injury during AP was assessed by serum amylase concentration and histopathology. The level of apoptosis of pancreatic cells in response to AP was evaluated by calculating the apoptotic index (AI) and comparing the expression levels of cytochrome C and Fas-associated protein with death domain (FADD) between TLR4-wild-type and TLR4-deficient mice at 2 time points.

RESULTS

The AI was found to be significantly lower in the pancreas of TLR4-deficient mice with AP compared to TLR4-wild-type mice at two hours after the last treatment injection. Enzyme-linked immunosorbent assay and real-time reverse transcription-polymerase chain reaction also revealed significantly lower expression of cytochrome C and FADD in the pancreas of TLR4-deficient mice than in TLR4-wild-type animals at the same time point. Serum amylase concentration and morphological severity of AP in pancreatic tissue were found to be similar in the two strains of mice at both time points.

CONCLUSION

We postulate that TLR4 can mediate apoptosis of pancreatic cells during the early stages of AP, via the activation of both intrinsic and extrinsic apoptotic signaling pathways.

摘要

背景

Toll 样受体 4（TLR4）在急性胰腺炎（AP）的发生和发展中起重要作用。胰腺细胞的凋亡与 AP 的严重程度密切相关。TLR4 已知可诱导某些细胞类型的凋亡，因此研究 AP 中 TLR4 活性与凋亡之间的潜在关联非常重要。

方法

共 50 只野生型（C57BL/10J）和 TLR4 缺陷型（C57BL/10ScNJ）小鼠分为三组：2 小时组、4 小时组和对照组。每组分为两组：TLR4 野生型小鼠和 TLR4 缺陷型小鼠。AP 通过 7 次腹腔注射 50μg/kg 亮抑蛋白酶原每隔 1 小时进行一次实验诱导。对照组小鼠接受 7 次等体积生理盐水注射。通过血清淀粉酶浓度和组织病理学评估 AP 期间胰腺损伤的严重程度。通过计算凋亡指数（AI）并比较 TLR4 野生型和 TLR4 缺陷型小鼠在 2 个时间点之间细胞色素 C 和 Fas 相关死亡结构域蛋白（FADD）的表达水平，评估胰腺细胞对 AP 的凋亡反应。

结果

与 TLR4 野生型小鼠相比，AP 后 2 小时 TLR4 缺陷型小鼠的胰腺 AI 明显降低。酶联免疫吸附试验和实时逆转录聚合酶链反应还显示，同一时间点 TLR4 缺陷型小鼠胰腺中细胞色素 C 和 FADD 的表达明显低于 TLR4 野生型动物。两种品系小鼠在两个时间点的血清淀粉酶浓度和胰腺组织 AP 的形态严重程度相似。