丙型肝炎病毒核心蛋白通过FOXO1/PGC-1α途径上调磷酸烯醇式丙酮酸羧基酶的转录

Hepatitis C virus core protein upregulates the transcription of PCK1 through FOXO1/PGC-1α pathway

摘要:

摘要:【目的】分析丙型肝炎病毒(HCV)核心蛋白( CORE)稳定表达对磷酸烯醇式丙酮酸羧基酶(PCK1)转录水平的影响，并分析HCV CORE 调控PCK1 转录的分子机制，为进一步阐明HCV 感染致2 型糖尿病机理的探讨提供新的思路。【方法】利用反转录病毒表达系统构建稳定表达HCV CORE 的Huh7-lunet-core 细胞系。采用Real-time PCR 和萤光素酶报告基因技术检测Huh7-lunet-core 细胞系中PCK1、FOXO1 以及PGC-1α 转录水平变化，并结合Western blot 分析FOXO1 的活性变化。【结果】HCV CORE 的稳定表达显著增强 PCK1 的转录水平，HCV CORE 不影响FOXO1 的转录和表达水平，但降低FOXO1 的磷酸化水平，激活了FOXO1 的转录活性，并增强PGC-1α 的mRNA 表达水平。【结论】HCV CORE 在Huh7-lunet 细胞中的稳定表达激活FOXO1 的转录活性，并与PGC-1α 协同作用，上调PCK1 的转录，从而导致肝糖异生过度发生，对HCV CORE 调控PCK1 转录的分子机制的揭示可能为HCV 感染相关的糖尿病的治疗提供新的靶点。

Abstract:

Abstract:［Objective］We analyzed the effect of the stable expressed Hepatitis C virus core protein on PCK1 mRNA expression level and the molecular mechanisms involved in Huh7-lunet cells．［Methods］A retroviral vector mediated mammalian cell expression cell line of the HCV core protein was constructed． The mRNA and protein levels of PCK1，FOXO1 and PGC-1α were analyzed by Real-time PCR and luciferase assay in Huh7-lunet-core cells． ［Results］ HCV CORE upregulated the mRNA levels of PCK1 significantly． Both the mRNA and protein levels of FOXO1 were not affected in Huh7-lunet-core cells，whereas a decreased phosphorylation status of FOXO1 was exhibited． Moreover，activation of FOXO1 by HCV CORE was detected． Further，the mRNA level of PGC-1α was found to be significantly elevated in Huh7-lunet-core cells．［Conclusion］Our results revealed for the first time that HCV core protein expression-mediated FOXO1 activation and the increased PGC-1α leaded to the elevation of PCK1 at the mRNA level，which suggesting the immoderate gluconeogenesis in HCV-infected hepatocytes． Our findings contributed to the understanding of the molecular mechanisms of HCV-related insulin resistance and provided potential new clues for the prevention and therapy of diabetes．