Hsp90抑制TNFα诱导的细胞凋亡及线粒体细胞色素c的释放

Hsp90 Inhibits TNFα-induced Apoptosis and the Release of Cytochrome c from Mitochondria

目的应用热休克蛋白90(Hsp90)过表达系统探讨Hsp90是否抑制肿瘤坏死因子α(TNFα)诱导的细胞凋亡及线粒体细胞色素c的释放。方法采用电穿孔技术建立稳定过表达Hsp90的细胞克隆,应用激光共聚焦显微镜和流式细胞仪观察TNFα和放线菌酮(CHX)诱导的细胞凋亡。应用W estern b lotting方法检测细胞色素c的变化。结果相差显微镜观察Hsp90过表达细胞与对照细胞相比悬浮细胞较少(分别为18%和41%),PBS冲洗后剩余黏附细胞较多。应用共聚焦显微镜进行TUNEL测定结果显示大部分对照细胞发生凋亡,相对较少的Hsp90细胞发生凋亡。W estern b lotting检测Hsp90细胞中细胞色素c的表达与对照组相比明显减少。结论Hsp90过表达抑制TNFα诱导的细胞凋亡及线粒体细胞色素c释放,提示其在凋亡信号传导通路线粒体水平发挥抑制作用。

Objective We use Hsp90 overexpression system to investigate the effect of Hsp90 on TNFα-induced apoptosis and the release of cytochrome c from mitochondria. Methods Electroporation was used to establish stable ltsp90 overexpression clones, laser confocal microscopy and flowcytometry were used to observe apoptosis induced by TNFα and Western blotting to monitor the change of cytochrome c. Results Phase contrast photomicrographs showed less suspending cells in Hsp90 overexpression system（ 18% ） than in control （41%） and with more residual adherent cells in Hsp90 overexpression system. Confocal microscopic analysis showed a smaller proportion of cell apoptosis in Hsp90 overexpression system than in control. Western blotting showed less expression of cytochrome c in Hsp90 overexpression system than in control. Conclusion Hsp90 overexpression inhibits TNFα-induced apoptosis and the release of cytochrome c from mitchondria, indicating that the inhibition of cell apoptosis may occur at the mitochondria level within apoptotic signal transduction pathways.