热休克蛋白90抑制剂17-AAG对乙型肝炎病毒复制的抑制作用

17-AAG,an inhibitor of heat shock protein 90,down-regulates hepatitis B virus replication

目的探讨热休克蛋白90(HSP90)是否参与肝细胞转化生长因子(TGF)β信号通路的活化,以及HSP90对乙型肝炎病毒(HBV)复制的影响。方法 HSP90抑制剂17-AAG作用HepG2细胞,提取细胞总RNA,实时定量RT-PCR检测TGFβ下游信号分子PAI-1的表达。HepG2细胞用17-AAG预处理2 h,同时用TGFβ或TβR抑制剂SB431542作用后,将HBV复制型质粒HBV1.3转染细胞,第4 d提取HBV核心颗粒,Southern Blot检测HBV复制中间体,ELISA检测上清HBsAg的表达。结果 17-AAG能够下调HepG2细胞PAI-1的表达,HepG2细胞内HBV复制中间体表达水平明显降低,HBsAg的表达亦受到抑制,但上调或阻断TGFβ信号通路对HBV复制影响不明显。结论 HSP90参与肝细胞内TGFβ信号通路的活化,其抑制剂17-AAG能够抑制HBV的复制与蛋白表达,但该抑制作用与TGFβ信号通路活化无关。

Objective To investigate the potential involvement of the heat shock protein 90（HSP90） in transforming growth factor-beta（TGFβ） signaling activation in hepatocytes,and to observe the effect of the HSP90 inhibitor,17-AAG,on hepatitis B virus（HBV） replication.Methods HepG2 cells were treated with 17-AAG and total RNA was extracted to measure PAI-1（SERPINE1） expression by real-time RT-PCR.Meanwhile,HepG2 cells were also transfected with the HBV1.3 HBV replicative plasmid after two hours of pretreatment with 17-AAG and TGFβ or SB431542.At day 4 post-transfection,HBV core particles were extracted and HBV replicative intermediates were detected by Southern blotting analysis.HBV surface antigen（HBsAg） was measured by ELISA.Results 17-AAG down-regulated mRNA expression of PAI-1 in HepG2 cells.HBV replication and HBsAg expression were inhibited upon 17-AAG treatment.However,activation of the TGFβ signaling pathway had no effect on HBV replication.Conclusion HSP90 is involved in the TGFβ signaling pathway during HBV infection.The HSP90 inhibitor,17-AAG,can inhibit HBV replication and HBsAg expression through a TGFβ-independent signaling mechanism.