Ethanol-Induced Hypomethylation Accelerates Hepatitis C Progression

乙醇诱导的低甲基化加速丙型肝炎进展

• 批准号: 8540051
• 负责人: NATALIA ALEKSANDR OSNA
• 金额: --
• 依托单位: OMAHA VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8540051
• 关键词: Adaptor Signaling Protein; Affect; Alcohol consumption; Alcoholic beverage heavy drinker; Alcoholism; Alcohols; American; Animal Model; Antiviral Agents; Betaine; Cell Line; Cessation of life; Cirrhosis; Clinical Trials; Combined Modality Therapy; DNA; Data; Defect; Development; Disease Progression; Elements; Epidemic; Ethanol; Exposure to; Genes; Goals; Hepatitis C; Hepatitis C virus; Hepatocyte; Host Defense; Human; Human Cell Line; IRF3 gene; Immune; Immunity; Impairment; In Vitro; Incidence; Interferon Activation; Interferon-alpha; Interferons; Laboratories; Lead; Link; Liver; Liver diseases; Measures; Mediating; Methylation; Modality; Modeling; Morbidity - disease rate; Mus; Natural Immunity; Nature; Outcome; Pathogenesis; Pathology; Pathway interactions; Patients; Peptide Hydrolases; Population; Protocols documentation; Qualifying; Reaction; Regulation; Research; Risk; Role; STAT1 gene; Signal Transduction; Staging; Testing; Veterans; Viral; Viral Load result; Viral Proteins; Viral load measurement; Virus Diseases; Virus Replication; Work; abstracting; alcohol effect; alcohol exposure; arm; base; chronic alcohol ingestion; cost; experience; feeding; hepatoma cell; improved; in vivo; in vivo Model; innovation; intrahepatic; liver injury; mortality; novel strategies; public health relevance; research study; virus pathogenesis

DESCRIPTION (provided by applicant): Abstract: Amongst the roughly 4 million Americans infected with the Hepatitis C Virus (HCV), chronic alcohol use has long been known to dramatically accelerate the progression of liver disease. Recent analysis has shown that long-term alcohol exposure increases the risk of death from HCV more than 8-fold over viral infection alone. Despite its importance as one of the strongest independent predictors of both cirrhosis and death, very little is known about the nature of the interaction between alcohol and HCV pathogenesis. Previous work from the laboratories collaborating on this application has shown that ethanol exposure impairs protein methylation in liver cells and reduces IFN-induced signaling along the JAK-STAT1 pathway (pathway that limits viral replication). Others have demonstrated that hypomethylation leads to activation of HCV NS3/4 protease, which may potentially block host innate antiviral immunity through NS3/4a-mediated cleavage of the adaptor protein, MAVS and that hypomethylation of STAT1 causes suppression of its attachment to DNA. This allows formulating our central hypothesis that ethanol exposure exacerbates HCV infection by impairing interferon signaling in HCV-infected and uninfected hepatocytes via dysregulation of methylation reactions. To test the hypothesis, we propose three Specific Aims to perform detailed examination of the effects of ethanol exposure/impaired methylation and HCV-infection on human innate hepatocyte immunity utilizing both in vitro and in vivo models. In Specific Aim 1, we will investigate the in vitro effects of ethanol on HCV replication and interferon signaling in HCV-infected/ expressing cell lines and human hepatocytes. In Specific Aim 2, we will study the in vivo effects of ethanol and impaired methylation on HCV load and interferon signaling in mice (scid-Alb/uPA) with chimeric human livers. In Specific Aim 3 we will assess whether the correction of ethanol- induced methylation defects by the pro-methylating agent, betaine, restores interferon signaling and improves HCV clearance in infected mice treated with IFN¿2b. The results of these studies will aid in the determination of the central role for ethanol-impaired methylation in IFN signaling for suppression of host defense, viral replication and pathogenesis. In addition, we will also obtain data in support of the use of pro-methylation agents in the treatment of HCV-infected patients with chronic alcohol use. These findings would ultimately lead to a vertical step in the field through direct extension to a clinical trial using this novel approach with the long-term goa of reducing the excessive morbidity and mortality that HCV infection causes in patients with chronic alcohol use.

描述（由申请人提供）： 摘要：在大约400万感染了丙型肝炎病毒（HCV）的美国人中，长期以来，慢性饮酒已被众所周知，可以极大地加速肝病的进展。最近的分析表明，长期的酒精暴露会增加HCV死亡的风险超过病毒感染的8倍以上。尽管它是肝硬化和死亡的强大独立预测指标之一，但对酒精与HCV发病机理之间相互作用的性质知之甚少。在此应用程序上合作的实验室的先前工作表明，乙醇暴露会损害肝细胞中的蛋白甲基化，并沿JAK-STAT1途径（限制病毒复制的途径）减少IFN诱导的信号传导。其他人则表明，降压甲基化会导致HCV NS3/4蛋白酶的激活，这可能会通过NS3/4A介导的衔接蛋白，MAVS和STAT1的甲基化导致其与DNA的附着抑制apopter蛋白，MAVS和甲基化的寄生型通过NS3/4A介导的裂解来阻止宿主先天抗病毒免疫学。这允许我们提出我们的中心假设，即乙醇暴露会通过甲基化反应的失调而损害HCV感染和未感染的HCV感染和未感染的肝细胞中的干扰信号来加剧HCV感染。为了检验该假设，我们提出了三个特定的目的，旨在详细研究乙醇暴露/受损的甲基化和HCV感染对利用体外和体内模型的人类先天肝细胞免疫学对人类先天肝细胞免疫学的影响。在特定目标1中，我们将研究乙醇对HCV感染/表达细胞系和人肝细胞中HCV复制和干扰素信号传导的体外作用。在特定的目标2中，我们将研究乙醇和甲基化受损对嵌合人类生命的小鼠（SCID-ALB/UPA）中HCV负荷和干扰素信号传导的体内影响。在特定的目标3中，我们将评估乙醇诱导的甲基化缺陷是否通过甲基化剂BETAINE，BETAINE，恢复干扰素信号传导并改善了用IFN€2B处理的感染小鼠的HCV清除率。这些研究的结果将有助于确定IFN信号传导中乙醇损伤甲基化的中心作用 用于抑制宿主防御，病毒复制和发病机理。此外，我们还将获得支持促甲基化剂在治疗HCV感染的慢性酒精饮酒患者中的数据。这些发现最终将通过这种新型方法直接扩展到临床试验，从而导致该领域的垂直步骤，该方法的长期果阿降低了慢性酒精饮酒患者HCV感染导致HCV感染的过量发病和死亡率。