Effects of Ethanol on Proteasome-HCV Core Protein Interactions

乙醇对蛋白酶体-HCV 核心蛋白相互作用的影响

• 批准号: 7783877
• 负责人: NATALIA ALEKSANDR OSNA
• 金额: $ 15.59万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-10 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7783877
• 关键词: Affect; Alcohol abuse; Alcohol consumption; Alcohols; Antigen Presentation; Cells; Chronic; Chronic Hepatitis C; Clinical; Complex; Core Protein; Cytokine Signaling; Cytotoxic T-Lymphocytes; Disease; Enzymes; Ethanol; Ethanol Metabolism; Event; Future; Generations; Hepatitis C; Hepatitis C virus; Hepatocyte; Hydrolysis; Immune response; Immune system; Infection; Injury; Investigation; Knowledge; Language; Link; Liver; MHC Class I Genes; Oxidative Stress; Patients; Peptides; Population; Process; Proteasome Binding; Proteins; Proteolysis; Regulation; Research; Risk; Signal Transduction; Structural Protein; Testing; Therapeutic; Transgenic Mice; Viral Antigens; Viral Proteins; Viremia; Virulence; adaptive immunity; alcohol effect; alcohol exposure; drinking; feeding; hepatitis C virus nucleocapsid protein; improved; multicatalytic endopeptidase complex; problem drinker; protein degradation; vaccine development; virus core; virus pathogenesis

DESCRIPTION (provided by applicant): In HCV infection, about 70% of patients develop persistent viremia and chronic course of infection. Alcohol abuse strongly accelerates the progression of HCV infection. One of HCV structural proteins, known as core protein, induces oxidative stress in liver cells, and this is further potentiated by ethanol. Oxidative stress modulates the functions of many enzymes, including the multi-catalytic protein-degrading enzyme, the proteasome. This enzyme degrades oxidatively modified proteins, signal transduction factors and processes peptides for antigen presentation. We hypothesize that HCV core protein enhances proteasome activity by directly interacting with the enzyme and indirectly, by inducing low levels of oxidative stress. However, in ethanol-exposed liver cells, proteasome activation by core protein is blocked by ethanol metabolism, which suppresses proteasome activity. Potentially, these changes in proteasome activity may affect protein degradation and generation of peptides for antigen presentation. To test this hypothesis, we propose two Specific Aims. Aim 1 will ascertain the mechanism(s) of proteasome activation by HCV core protein and determine whether ethanol metabolism blocks proteasome activation by core protein. Aim 2 will determine whether HCV core protein affects proteasome activity and overall intracellular proteolysis in HCV core-expressing cells and in core-expressing control and ethanol-fed transgenic mice. The results derived from this study will help clarify the mechanism of alcohol-potentiated HCV progression, providing a link between altered proteasome function and processing of HCV peptides for presentation by infected liver cells. This investigation will also provide the framework for future HCV pathogenetic studies, namely, proteasome-dependent regulation of cytokine signaling and MHC class I-resticted presentation of HCV antigens to cytotoxic T-lymphocytes. Both transduction of cytokine signals and antigen presentation can be suppressed by ethanol metabolism. Lay Language Summary: The proposed study will expand our knowledge in the mechanisms of how hepatitis C viral protein and ethanol regulate the enzyme, which degrades proteins. The results of this investigation will partially explain why the immune system is less able to clear HCV in alcoholic compared to in non-drinking patients. We envision that this research will potentially have therapeutic applications, helping to improve chronic hepatitis C treatment and vaccine development

描述（由申请人提供）：在HCV感染中，约有70％的患者发展出持续性病毒血症和慢性感染过程。酒精滥用强烈加速了HCV感染的进展。 HCV结构蛋白之一，称为核心蛋白，诱导肝细胞中的氧化应激，这被乙醇进一步增强。氧化应激调节许多酶的功能，包括多催化蛋白降解酶，蛋白酶体。这种酶会降解氧化修饰的蛋白质，信号转导因子和抗原表现肽的过程。我们假设HCV核心蛋白通过直接与酶相互作用并间接地通过诱导低水平的氧化应激来增强蛋白酶体活性。但是，在暴露于乙醇的肝细胞中，核心蛋白的蛋白酶体激活被乙醇代谢阻止，从而抑制蛋白酶体活性。潜在地，蛋白酶体活性的这些变化可能会影响蛋白质降解和肽的产生以进行抗原表现。为了检验这一假设，我们提出了两个具体目标。 AIM 1将通过HCV核心蛋白来确定蛋白酶体激活的机制，并确定乙醇代谢是否阻止了核心蛋白的蛋白酶体激活。 AIM 2将确定HCV核心蛋白是否会影响HCV核心表达细胞的蛋白酶体活性和整体细胞内蛋白水解以及表达核心的控制和乙醇喂养的转基因小鼠。从这项研究中得出的结果将有助于阐明酒精训练的HCV进展的机制，从而在改变的蛋白酶体功能与HCV肽的加工之间有联系，以通过感染的肝细胞表现出来。这项研究还将为未来的HCV致病研究提供框架，即蛋白酶体依赖性调节细胞因子信号传导和MHC I类HCV抗原对细胞毒性T淋巴细胞的呈现。乙醇代谢都可以抑制细胞因子信号的转导和抗原表现。外行语言摘要：拟议的研究将扩大我们的知识，即丙型肝炎病毒蛋白和乙醇如何调节酶的酶，从而降解蛋白质。这项研究的结果将部分解释为什么与非饮食患者相比，免疫系统无法清除酒精中毒的HCV。我们设想这项研究将有可能具有治疗性应用，有助于改善慢性丙型肝炎治疗和疫苗开发

项目成果

Impaired methylation as a novel mechanism for proteasome suppression in liver cells.

甲基化受损是肝细胞中蛋白酶体抑制的新机制。

• DOI: 10.1016/j.bbrc.2009.12.074
• 发表时间: 2010
• 期刊: Biochemical and biophysical research communications
• 影响因子: 3.1
• 作者: Osna,NataliaA;White,RondaL;DonohueJr,TerrenceM;Beard,MichaelR;Tuma,DeanJ;Kharbanda,KusumK
• 通讯作者: Kharbanda,KusumK