猪繁殖与呼吸综合征病毒激活mTORC1/HIF-1α通路诱导炎症的作用机制OA

[Objective]The study aims to explore the mechanism of hypoxia-inducible factor HIF-1α in porcine reproductive and respiratory syndrome virus(PRRSV)-induced inflammation in porcine alveolar macro-phages.[Method]HIF-1α mRNA and protein expression levels in PRRSV-infected porcine lungs and alveolar macrophages were assessed using Western Blot and real-time quantitative PCR(RT-qPCR).PRRSV-infected porcine alveolar macrophages were treated with BAY87-2243 or CoCl2,followed by detection of PRRSV M protein and mRNA expression,and ELISA quantification of interleukin-1β(IL-1β),interleukin-6(IL-6),and tumor necrosis factor alpha(TNF-α).TSC2 siRNA-transfected porcine alveolar macrophages were treated with Rapa(mTORC1 inhibitor)and KU0063794(mTOR inhibitor),and the regulatory mechanism of mTOR on HIF-1α in porcine alveolar macrophages was detected by Western Blot.After mTORC1 overexpression in porcine alveolar macrophages,the effects of PRRSV on the levels of HIF-1α and inflammatory cytokines were evaluated.[Result]PRRSV infection significantly elevated HIF-1α mRNA and protein levels in porcine lungs and alveolar macrophages.Compared with the PRRSV-infected group,the HIF-1α activation group(CoCl2 treatment)showed increased expression of PRRSV M protein and mRNA and significantly elevated levels of IL-1β,IL-6,and TNF-α(P<0.01).The HIF-1α inhibition group(BAY87-2243 treatment)exhibited de-creased expression of PRRSV M protein and mRNA and significantly reduced levels of IL-1β,IL-6,and TNF-α(P<0.01).PRRSV was found to enhance mTOR expression in alveolar macrophages,while mTOR inhibition decreased HIF-1α expression and significantly or extremely significantly reduced inflammatory cytokine levels.Upon re-elevating HIF-1α expression,the inflammatory cytokine levels significantly increased(P<0.05).mTOR mainly upregulated HIF-1α expression through mTORC1.Overexpression of mTORC1 leads to in-creased levels of PRRSV M protein and HIF-1α protein,enhancing inflammatory cytokine expression(P<0.05).[Conclusion]HIF-1α plays a pivotal role in regulating PRRSV-induced inflammatory responses of al-veolar macrophages,with its expression modulated by the mTORC1 signaling pathway.