Zhao Lan-Juan, Wang Wen, Wang Wen-Bo, Ren Hao, Qi Zhong-Tian
Department of Microbiology, Shanghai Key Laboratory of Medical Biodefence, Second Military Medical University, Shanghai 200433, China.
Department of Microbiology, Shanghai Key Laboratory of Medical Biodefence, Second Military Medical University, Shanghai 200433, China.
Cytokine. 2015 Mar;72(1):17-24. doi: 10.1016/j.cyto.2014.11.031. Epub 2014 Dec 23.
Interferon alpha (IFN-α) is the key component of the therapy for hepatitis C virus (HCV) infection. IFN-α exerts anti-HCV activity by targeting certain signaling pathways. Using infectious HCV culture system in human hepatoma Huh7.5.1 cells, we analyzed functional relevance of extracellular signal-regulated kinase (ERK) pathway for IFN-α-mediated anti-HCV activity. IFN-α treatment resulted in activation of ERK pathway by increasing phosphorylation of c-Raf, MEK, and ERK1/2 in Huh7.5.1 cells, whereas HCV impaired such activation. IFN-α-dependent ERK1/2 phosphorylation was blocked by MEK inhibitor U0126. Pharmacological inhibition of ERK1/2 by U0126 or siRNA-mediated knockdown of ERK1/2 resulted in suppressive effects on HCV RNA levels and expression of HCV nonstructural protein 3 and envelope protein 2, establishing an important role for ERK pathway in HCV replication. Moreover, induction of a set of antiviral genes by IFN-α was enhanced in HCV-infected Huh7.5.1 cells due to the ERK1/2 knockdown, suggesting that impairment of ERK signaling may potentiate HCV inhibition by IFN-α. These results demonstrate that ERK pathway is involved in IFN-α-mediated antiviral activity against HCV.
干扰素α（IFN-α）是丙型肝炎病毒（HCV）感染治疗的关键组成部分。IFN-α通过靶向某些信号通路发挥抗HCV活性。利用人肝癌Huh7.5.1细胞中的感染性HCV培养系统，我们分析了细胞外信号调节激酶（ERK）通路对IFN-α介导的抗HCV活性的功能相关性。IFN-α处理通过增加Huh7.5.1细胞中c-Raf、MEK和ERK1/2的磷酸化导致ERK通路激活，而HCV损害这种激活。MEK抑制剂U0126阻断了IFN-α依赖性ERK1/2磷酸化。U0126对ERK1/2的药理学抑制或siRNA介导的ERK1/2敲低导致对HCV RNA水平以及HCV非结构蛋白3和包膜蛋白2表达的抑制作用，确立了ERK通路在HCV复制中的重要作用。此外，由于ERK1/2敲低，IFN-α诱导的一组抗病毒基因在HCV感染的Huh7.5.1细胞中增强，表明ERK信号的损害可能增强IFN-α对HCV的抑制作用。这些结果表明ERK通路参与IFN-α介导的抗HCV抗病毒活性。
