过刊浏览

小凹蛋白-1通过激活p38 MAPK抑制巨噬细胞内质网应激凋亡

岳雯, 姚树桐, 周晓, 司艳红, 桑慧, 王家富, 商战平^*

泰山医学院病理生理学教研室，泰安 271000；山东医学高等专科学校，临沂 276002

摘要

本文旨在探讨小凹蛋白-1 (caveolin-1, Cav-1)对巨噬细胞内质网应激凋亡途径的调控作用及机制。用毒胡萝卜素(thapsigargin, TG)诱导RAW264.7细胞内质网应激后，Western blot法检测Cav-1的表达变化。用小凹(caveolae)结构破坏剂filipin(III)预处理RAW264.7细胞，用Annexin V-FITC/PI双染和激光共聚焦显微镜观察RAW264.7细胞的凋亡情况，最后使用Western blot法检测凋亡相关蛋白——丝裂原激活蛋白激酶(mitogen-activated protein kinase, MAPK)家族成员p38的磷酸化及C/EBP同源蛋白(C/EBP homologous protein, CHOP)表达水平。结果显示，TG作用RAW264.7细胞可使Cav-1的表达呈山峰状改变，TG作用早期Cav-1的表达升高，其中1 μmol/L TG作用RAW264.7细胞24 h可使Cav-1的表达较对照组明显升高(P < 0.05)，随着TG作用浓度和时间的增加，Cav-1的表达降低。Filipin(III) (2.5 μg/mL)预处理RAW264.7细胞(30 min)可阻断TG诱导的Cav-1表达上调(P < 0.05)，同时，流式细胞仪检测结果显示filipin(III)使TG诱导的细胞凋亡率升高(P < 0.05)，激光共聚焦显微镜下可见明显凋亡形态变化，Western blot结果显示Filipin(III)使TG诱导的p-p38减少(P < 0.05)，而CHOP的表达无明显改变(P > 0.05)。以上结果提示，Cav-1可抑制巨噬细胞的内质网应激凋亡途径，其机制可能与激活p38 MAPK通路有关。

关键词： 小凹蛋白-1; 内质网应激; p38 MAPK; CHOP; 凋亡; 巨噬细胞

分类号：R332；R363.2；R329.2

[Inhibitory effect of caveolin-1 on endoplasmic reticulum stress-induced apoptosis in macrophages via p38 MAPK pathway.] [Article in Chinese]

YUE Wen, YAO Shu-Tong, ZHOU Xiao, SI Yan-Hong, SANG Hui, WANG Jia-Fu, SHANG Zhan-Ping^*

Pathophysiology Department, Taishan Medical College, Taian 271000, China； Pathophysiology Department, Shandong Medical College, Linyi 276002, China

Abstract

Endoplasmic reticulum (ER) stress occurs in macrophage-rich areas of advanced atherosclerotic lesions and contributes to macrophage apoptosis and subsequent plaque necrosis. The purpose of the present study was to investigate the effects of caveolin-1 (Cav-1) on ER stress-induced apoptosis in cultured macrophages and the underlying mechanisms. RAW264.7 cells were incubated with thapsigargin (TG) to establish ER stress model. And Cav-1 expression was detected by Western blot. After being pretreated with filipin(III), a caveolae inhibitor, RAW264.7 cells were assayed with flow cytometry and confocal laser scanning microscopy to detect cell apoptosis. Moreover, p38 mitogen-activated protein kinase (MAPK) phosphorylation and C/EBP homologous protein (CHOP) expression were detected with Western blot. The results showed that Cav-1 expression was markedly increased at early stage of TG treatment (P < 0.05) and then decreased with prolonged or high dose TG treatments. The increasing of Cav-1 expression induced by TG in RAW264.7 cells was abolished under inhibition of caveolae by filipin(III) (P < 0.05). The effect of TG on apoptosis of RAW264.7 cells was further augmented after pretreatment with filipin(III) (P < 0.05). Western blotting showed that MAPK phosphorylation induced by TG was inhibited by filipin(III) in RAW264.7 cells (P < 0.05), whereas CHOP remained unchanged (P > 0.05). These results suggest that Cav-1 may play a critical role in suppressing ER stress-induced macrophages apoptosis in vitro, and one of the mechanisms may be correlated with the activation of p38 MAPK prosurvival pathway.

Key words: caveolin-1; endoplasmic reticulum stress; p38 MAPK; CHOP; apoptosis; Macrophage

收稿日期：2011-09-23　　录用日期：2011-12-27

通讯作者：商战平　　E-mail: zhpshang@tsmc.edu.cn

引用本文：

岳雯, 姚树桐, 周晓, 司艳红, 桑慧, 王家富, 商战平. 小凹蛋白-1通过激活p38 MAPK抑制巨噬细胞内质网应激凋亡[J]. 生理学报 2012; 64 (2): 149-154.

YUE Wen, YAO Shu-Tong, ZHOU Xiao, SI Yan-Hong, SANG Hui, WANG Jia-Fu, SHANG Zhan-Ping. [Inhibitory effect of caveolin-1 on endoplasmic reticulum stress-induced apoptosis in macrophages via p38 MAPK pathway.] [Article in Chinese]. Acta Physiol Sin 2012; 64 (2): 149-154 (in Chinese with English abstract).