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Molecular chaperon HSP regulates apoptosis signaling

分子伴侣 HSP 调节细胞凋亡信号

基本信息

批准号：
16591863
负责人：
KYAKUMOTO Seiko
金额：
$ 2.3万
依托单位：
Iwate Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16591863/
关键词：
HSP90 geldanamycin Fas apootosis FLIP caspase 熱ショックタンパク質 HSP

项目摘要

In this study, the involvement of heat shock protein 90 in the anti-Fas antibody (CH-11)-induced apoptosis in HSG cells was investigated using geldanamycin (GDM), the specific inhibitor of HSP90. GDM itself caused the apoptosis in HSG cells, and moreover, it enhanced CH-11-induced apoptosis. RT-PCR and Westernblotting revealed that the expression of HSP90 was up-regulated by GDM, suggesting that the immediate complementation of HSP90 occurs after the functional inhibition of HSP90 by GDM. Further, the transfection of HSP90 protein into HSG cells significantly inhibited the enhancement of CH-11-induced apoptosis by GDM. Immunoprecipitation-Westernblotting analysis revealed FLIP, Caspase 8 and RIP as target proteins of HSP90. FLIP mRNA level was significantly decreased by GDM treatment. From these results, it was revealed that HSP90 negatively regulates Fas-induced apoptosis through its chaperoning effect on FLIP, the dominant-negative Caspase 8. Furthermore, we examined the transcription activation from the heat shock element-harboring luciferase reporter gene that was transfected into HSG cells. Treatment of the transfected cells with GDM, as well as heat shock treatment, increased the luciferase activity as compared with the untreated cells. This result suggested that GDM increases the expression of HSP90 through the dissociation of heat shock factor from HSPs and its following activation, translocation into nuclei, and then transcription activation of HSP90 gene.

在这项研究中，参与热休克蛋白90在抗Fas抗体（CH-11）诱导的HSG细胞凋亡使用格尔德霉素（GDM），热休克蛋白90的特异性抑制剂。GDM本身可引起HSG细胞凋亡，并增强CH-11诱导的细胞凋亡。RT-PCR和Westernblotting结果显示，GDM可上调HSP 90的表达，提示GDM对HSP 90的功能性抑制后，HSP 90的表达立即发生互补。此外，HSP 90蛋白转染HSG细胞显著抑制GDM对CH-11诱导的细胞凋亡的增强作用。免疫沉淀-Westernblotting分析显示FLIP、Caspase 8和RIP为HSP 90的靶蛋白。FLIP mRNA水平显著降低GDM治疗。从这些结果中，它被揭示，热休克蛋白90负调控Fas诱导的细胞凋亡，通过其伴侣效应FLIP，显性负半胱天冬酶8。此外，我们研究了从热休克元件携带的荧光素酶报告基因转染到HSG细胞的转录激活。与未处理的细胞相比，用GDM处理转染的细胞以及热休克处理增加了荧光素酶活性。结果提示，GDM通过热休克因子从HSPs上解离并激活，转位到细胞核，进而激活HSP 90基因的转录，从而促进HSP 90的表达。