Oxidative damage and proteasome activity: Role of opioid in HIV-HCV infection

描述(申请人提供)：在注射吸毒者中，人类免疫缺陷病毒和丙型肝炎病毒是最常通过血液传播的两种病原体。在美国，大约25%的艾滋病毒感染者也感染了丙型肝炎病毒，而通过注射吸毒感染艾滋病毒的人中，丙型肝炎病毒的感染率接近90%。虽然丙型肝炎病毒在HIV疾病进展中的作用尚不清楚，但与HIV感染合并感染已与慢性丙型肝炎加速发展为肝硬变和终末期肝病有关。在HIV-1感染者中，导致肝病进展更快和丙型肝炎病毒血症增加的机制还不完全清楚。病毒感染迅速触发细胞内信号事件，导致细胞内天然的抗病毒状态，天然免疫受损可能为病毒持续感染创造有利的微环境。大多数与丙型肝炎病毒感染相关的肝损伤是由先天性和获得性免疫反应介导的。吗啡是海洛因的主要代谢物，是最常见的阿片类药物，它优先激活类阿片受体。长期使用和滥用吗啡会损害宿主的先天免疫反应，包括产生趋化因子和促炎细胞因子、吞噬和中性粒细胞迁移，从而增加对细菌和病毒感染的易感性。吗啡通过下调干扰素-1介导的天然免疫，促进丙型肝炎病毒在肝细胞中的复制。趋化因子和促炎细胞因子是免疫反应和炎症过程的重要介质。更具体地说，促炎症细胞因子肿瘤坏死因子-1在多种病理生理状态下的肝细胞损伤和细胞死亡中发挥着不可或缺的作用，这些病理生理状态包括毒素肝损伤、缺血/再灌注和肝炎病毒。此外，实验在小鼠和海洛因滥用者身上显示的肝病和肝毒性的系统表现中，有太多是由吗啡诱导的氧化损伤造成的。MOR的激活可引发活性氧(ROS)生成增加和细胞凋亡。利用最近建立的体外丙型肝炎病毒感染系统，我们将检验这一假说，即阿片类药物通过1)增加细胞因子和趋化因子的产生以及2)诱导反应性氧化物种(ROS)和一氧化氮(NO)来扰乱肝细胞对丙型肝炎病毒和艾滋病毒的反应而导致丙型肝炎病毒疾病的进展。公共卫生相关性：这项建议中的研究将集中于分析阿片类药物和艾滋病毒在多大程度上增加人肝细胞中丙型肝炎病毒感染的易感性，特别是对促炎细胞因子肿瘤坏死因子-1的敏感性，我们将研究阿片类药物和艾滋病毒影响丙型肝炎病毒感染肝细胞中病毒复制和毒性的机制。

DESCRIPTION (provided by applicant): Among injection drug users (IDUs), human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are the two blood-borne pathogens most commonly transmitted. About 25% of HIV infected persons in the United States are also infected with Hepatitis C virus (HCV) while the incidence of HCV infection among persons who acquired HIV from injection drug use approaches 90%. Although the role of HCV in progression of HIV disease remains unclear, co-infection with HIV infection has been associated with accelerated progression of chronic hepatitis C towards cirrhosis and end stage liver disease. The mechanisms responsible for more rapid progression of hepatic disease and increased HCV viremia in individuals co-infected with HIV-1 are not fully understood. Viral infection rapidly triggers intracellular signaling events, leading to an innate cellular antiviral state, and damage to the innate immunity may generate a favorable microenvironment for persistent viral infection. Most liver damage associated with HCV infection is mediated by innate and acquired immune responses. Morphine, the major metabolite of heroin, is the most common opiate drug and preferentially activates <-opioid receptors (MOR). Chronic morphine use and abuse has been shown to impair host innate immune responses, including the production of chemokines and pro-inflammatory cytokines, phagocytosis, and neutrophil migration, which can lead to increased susceptibility to bacterial and viral infections. Morphine, through down- regulation of IFN-1 mediated innate immunity, favors HCV replication in hepatic cells. Chemokines and pro- inflammatory cytokines are important mediators of the immune response and the inflammatory process. More specifically, the pro-inflammatory cytokine, tumor necrosis factor-1 (TNF-1) plays an integral role in hepatocyte injury and cell death in a number of pathophysiological states such as liver injury from toxins, ischemia/ reperfusion, and hepatitis virus. In addition, morphine-induced oxidative damage has been hypothesized to contribute too many of the systemic manifestations of liver disease and hepatotoxicity experimentally shown in mice and in heroin abusers. Activation of MOR can trigger increased production of reactive oxygen species (ROS) and apoptosis. Using a recently established in vitro HCV infection system, we will test the hypothesis that opioids contributes to HCV disease progression by disrupting the response of hepatocytes to HCV and HIV through 1) increase production of cytokines and chemokines and 2) induction of reactive oxidative species(ROS) and nitric oxide (NO). PUBLIC HEALTH RELEVANCE: Studies in this proposal will focus on assaying the extent by which opioids and HIV enhances the susceptibility of HCV infection in human hepatocytes in particular, to proinflammatory cytokine tumor necrosis factor-alpha (TNF-1) and we will investigate the mechanisms by which opiates and HIV affect viral replication and toxicity in HCV infected hepatocytes.