HSP27在脑心肌炎病毒体外增殖中的多重调控作用

Multiple regulatory effects of HSP27 on the proliferation of encephalomyocarditis virus in vitro

摘要:

【目的】探究热休克蛋白27(heat shock protein 27,HSP27)在脑心肌炎病毒(encephalomyocarditis virus,EMCV)体外增殖过程中对多种信号通路的调控作用，为明确其他宿主因子体外调控EMCV增殖的机制研究奠定基础，并为进一步揭示EMCV致病的分子机制提供有力证据。【方法】利用实时荧光定量PCR(real-time quantitative PCR,RT-qPCR)、免疫印迹、间接免疫荧光和核质分离等方法检测干扰或过表达HSP27对EMCV感染引起的细胞自噬、翻译起始因子2α(eukaryotic translation initiation factor 2α subunit 1,EIF2S1)-应激特异性转录因子4(activating transcription factor 4,ATF4)信号通路及髓样分化因子(myeloid differentiation factor 88,MyD88)/核转录因子κB(nuclear transcription factor kappa B,NF-κB)信号通路的影响。【结果】干扰宿主细胞中HSP27的表达可促进自噬及EIF2S1-ATF4信号通路，抑制EMCV诱导的MyD88/NF-κB信号通路的活化。相反，过表达HSP27不仅能有效降低EMCV诱导的自噬及EIF2S1-ATF4信号通路，还能促进MyD88/NF-κB信号通路分子的表达、p65的核移位和炎症相关因子的转录表达。【结论】HSP27既可以通过抑制EIF2S1-ATF4信号通路来负调控EMCV诱导的自噬，还可以正向调控EMCV触发的MyD88/NF-κB信号通路，表明HSP27在EMCV感染中具有多重调控作用。

Abstract:

[Objective] We explored the regulatory effects of heat shock protein 27 (HSP27) on various signaling pathways during the proliferation of encephalomyocarditis virus (EMCV) in vitro, aiming to lay a foundation for deciphering the mechanism of other host factors in regulating EMCV proliferation in vitro and provide evidence for comprehensively revealing the pathogenic mechanism of EMCV. [Methods] Real-time quantitative PCR (RT-qPCR), Western blotting, indirect immunofluorescence, and nucleocytoplasmic separation were employed to evaluate the effects of the knockdown and overexpression of HSP27 on the EMCV infection-induced autophagy, eukaryotic translation initiation factor 2α subunit 1 (EIF2S1)-activating transcription factor 4 (ATF4) signaling pathway, and myeloid differentiation factor 88 (MyD88)/nuclear transcription factor kappa B (NF-κB) signaling pathway.[Results] Interfering with the expression of HSP27 in host cells promoted autophagy and activated EIF2S1-ATF4 signaling pathway, and inhibited EMCV-induced activation of MyD88/NF-κB signaling pathway. On the contrary, overexpression of HSP27 not only reduced EMCV-induced autophagy and inhibited EIF2S1-ATF4 signaling pathway, but also up-regulated the expression of the proteins in MyD88/NF-κB signaling pathway and promoted the nuclear translocation of p65 and the transcription of inflammation-related cytokines.[Conclusion] HSP27 can not only negatively regulate EMCV-induced autophagy by inhibiting the EIF2S1-ATF4 signaling pathway, but also positively regulate the EMCV-triggered MyD88/NF-κB signaling pathway, playing multiple regulatory roles in EMCV infection.