肿瘤坏死因子α诱导ATF6、IRE1介导的未折叠蛋白反应  

TNFα induces ATF6-and IRE1-mediated unfolded protein response

作　　者：薛欣[1] 赵京元[2] 张永祥[1] 

机构地区：[1]中国中医科学院中医基础理论研究所实验中心免疫室,北京100700 [2]北京市航天中心医院骨科

出　　处：《毒理学杂志》2008年第6期431-434,共4页Journal of Toxicology

基　　金：人事部留学人员科技活动项目择优资助经费(2007LHR01);中国中医科学院基本科研业务费自主选题项目(ZZ2006015)

摘　　要：目的研究肿瘤坏死因子α(TNFα)对小鼠纤维母细胞(L929)中葡萄糖调节蛋白78(glucose regulatedprotein78,GRP78)、X盒结合蛋白1(X box binding protein 1,XBP-1)表达的影响,探讨TNFα信号传导通路与内质网应激的相关性。方法体外培养L929细胞,分别用TNFα、Tunicamycin作用0、24、、68、和10 h,以Western Blot、Northern Blot检测内质网应激的标志分子:GRP78蛋白的表达,以及非折叠蛋白反应中的关键分子:XBP-1蛋白及mRNA水平表达;用RT-PCR结合Pst1酶切法检测XBP-1 mRNA的剪接作用。结果TNFα作用于L929细胞即可以引起GRP78蛋白、XBP-1蛋白及XBP-1mRNA表达的升高,又可以诱导XBP-1mRNA的剪接作用;且这些分子表达的升高及mRNA的剪接作用均发生在TNFα作用的早期(开始于TNFα作用的2 h,4 h达到高峰,6 h后逐渐减弱)。结论TNFα作用于L929细胞可以诱导内质网应激,由此引起的活化转录因子6(activating transcription factor 6,ATF6)、ER转膜蛋白激酶1(inositol-requiring enzyme 1,IRE1)介导的未折叠蛋白反应对细胞具有促生存作用。Objective To investigate the association of TNFα signal pathway with endoplasmic reticulum stress （ER Stress）, the expression of glucose regulated protein78 （GRP78）and X box binding protein 1 （XBP-1） were examined in tumor necrosis factor α （TNFα）-treated L929 cells. Methods L929 cells were stimulated with TNFα and Tunicamycin for 0 - 10 h. The expression of ER chaperone GRP78 protein,XBP-I protein and XBP-1 mRNA were detected by Western blotting and Northern blotting. The splicing of XBP-1 mRNA were analyzed by RT-PCR with Pstl digestion. Results TNFα up-regulated the expression of GRP78 protein and increased the expression of XBP-1 in protein and mRNA levels. TNFα further induced the splicing of XBP-1 mRNA. All these changes happened in the early phage of TNFα stimulation （ it began at 2 h, peaked at 4 h and decreased gradually after 6 h） . Conclusion TNFzt induced the ER stress in L929 cells and subsequently initiated the unfolded protein response mediated by ATF6 and IRE1, which contributes to protection of cell from TNFα stimulation.

关 键 词：肿瘤坏死因子Α 内质网应激 GRP78 XBP-1 

分 类 号：R392.11[医药卫生—免疫学]