Effect of HIV protease inhibitor on alcohol induced ER stress and liver injury.

描述（由申请方提供）：HIV蛋白酶抑制剂（HIV PI）用于高活性抗逆转录病毒治疗（HAART）。然而，HIV PI通常与肝损伤的发展有关。HIV蛋白酶抑制剂诱导的肝损伤机制尚不清楚.新出现的证据表明，HIV PI诱导内质网（ER）应激反应，已显示其在肝功能障碍（包括坏死性炎症、肝细胞死亡和脂肪肝）中起重要作用。我们以前观察到，酒精消费，这是一个公认的辅助因素的易感性感染和进展的艾滋病毒，诱导高同型半胱氨酸血症和ER应激反应的肝脏。很大比例的HIV感染患者滥用酒精，并且认为酒精和HIV PI的影响之间的相互作用有助于严重的肝脂肪变性和损伤是合乎逻辑的。我们推测HIV PI和酒精对内质网应激和脂质代谢产生增强作用，从而导致肝损伤。我们建议探讨HIV PI诱导的ER应激反应在原代小鼠和人肝细胞，并在体内研究其相互作用与酒精的致病作用，在动物喂酒精。我们的具体目标是：（1）在慢性配对和酒精喂养的小鼠中，比较由单一或组合HIV PI治疗在体内诱导的ER应激和肝损伤，并通过在原代小鼠和人肝细胞中检查HIV PI诱导的ER应激反应和通过监测血浆和肝细胞培养基中HIV PI的生物利用度来评估累加或协同效应;（2）在存在或不存在模拟人类抗逆转录病毒治疗的单一或组合HIV PI的情况下，证实口服高甲硫氨酸低叶酸饮食的小鼠的ER应激反应;（三）通过监测原代小鼠和人细胞质中钙的释放，研究HIV PI和酒精对ER应激反应的协同机制通过检测给予HIV PI的肝细胞中蛋白酶体活性和葡萄糖转运蛋白的表达和活性;（4）分离非实质细胞（肝星状细胞，枯否细胞和内皮细胞）和分化HIV PI或酒精诱导的ER应激反应在这些细胞类型;（5）在体外和体内确定保护性分子伴侣（例如4-苯基丁酸酯）在HIV PI诱导的ER应激和肝损伤中的有效性。该项目将提供对HIV蛋白酶抑制剂肝毒性的更好理解，并提供更好的策略来改善对HIV感染患者的护理。

DESCRIPTION (provided by applicant): HIV protease inhibitors (HIV PIs) are used in the highly ctive antiretroviral therapy (HAART). However, HIV PIs are often associated with development of liver damages. The mechanisms of the HIV protease inhibitor- induced liver injury are poorly defined. Emerging evidence indicates that the HIV PIs induce endoplasmic reticulum (ER) stress response which has been shown to play an essential role in liver dysfunction including necroinflammation, hepatic cell death and fatty liver. We previously observed that alcohol consumption, which is a well-recognized co-factor in susceptibility to the infection and progression of HIV, induced hyperhomocysteinemia and ER stress response in the liver. A significant proportion of HIV infected patients abuse alcohol and it is logical to consider that an interplay between the effects of alcohol and HIV PIs contributes to severe hepatic steatosis and injury. We hypothesize that HIV PI and alcohol exert a potentiated effect on ER stress and lipid metabolism which worsens liver injury. We propose to explore the HIV PI-induced ER stress response in both primary mouse and human hepatocytes and to investigate in vivo its interactions with pathogenic effects of alcohol in animals fed alcohol. Our specific aims are: (1) to compare ER stress and hepatic injury induced by single or combined HIV PI treatments in vivo in chronic pair- and alcohol-fed mice, and to assess additive or synergistic effects by examining HIV PI-induced ER stress response in vitro in both primary mouse and human hepatocytes and by monitoring bioavailability of HIV PIs in plasma and culture medium of hepatocytes; (2) to confirm ER stress response in mice fed orally a high methionine low folate diet in the presence or absence of single or combined HIV PIs that mimic the antiretroviral therapy in human; (3) to study synergistic mechanisms of ER stress response by HIV PIs and by alcohol through monitoring calcium releasing into the cytosol in primary mouse and human hepatocytes and through examining proteasome activities and expression and activities of glucose transporters in hepatocytes administered HIV PIs; (4) to isolate non-parenchymal cells (hepatic stellate cells, Kupffer cells, and endothelial cells) and differentiate HIV PI- or alcohol-induced ER stress response in these cell types; (5) to determine in vitro and in vivo the effectiveness of protective molecular chaperones (e.g. 4-phenylbutyrate ) in HIV PI- induced ER stress and liver injury. This project will provide a better understanding of the hepatotoxicity of HIV protease inhibitors and better strategies to improve care for HIV-infected patients.