HIV Neural Apoptosis: Mechanisms, Pathways & Protection

HIV 神经细胞凋亡：机制、途径

• 批准号: 8118784
• 负责人: Dennis Larry Kolson
• 金额: $ 39.49万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8118784
• 关键词: AIDS Dementia Complex; Antioxidants; Apoptosis; Apoptotic; Appearance; Astrocytes; Brain; Brain region; Calpain; Cessation of life; Excitatory Neurotoxins; Failure; Functional disorder; Funding; Glutamates; HIV; HIV Infections; HIV-1; Hippocampus (Brain); Human; Immunologic Deficiency Syndromes; In Vitro; Individual; Infection; Link; Macaca; Mediating; Mitochondria; Modeling; Monkeys; N-Methyl-D-Aspartate Receptors; NR1 gene; NR2B NMDA receptor; Nerve Degeneration; Neuroglia; Neurons; Oxidative Stress; Pathway interactions; Pattern; Phosphorylation; Phosphorylation Site; Platelet Activating Factor; Play; Population; Predisposition; Production; Proteins; Publishing; Quinolinic Acid; Rattus; Reactive Oxygen Species; Receptor Activation; Rodent; Role; SIV; Site; Stress; Synapses; Testing; Virus; activating transcription factor; age related; base; biological adaptation to stress; brain tissue; calpain inhibitor; density; design; drug development; excitotoxicity; inhibitor/antagonist; killings; macrophage; monocyte; neuroprotection; neurotoxicity; receptor function; relating to nervous system; response; response marker; sensor; src-Family Kinases

DESCRIPTION (provided by applicant): Neuronal damage in HIV-infected brain resulting in HIV-associated dementia (HAD) is thought to occur in part through oxidative stress-associated N-methyl-D-aspartate receptor (NMDAR) excitation initiated by HIV infection of brain macrophages. Brain regions enriched in NMDAR expressing the NR2A and NR2B subunits, such as the hippocampus, are particularly vulnerable to HIV. HIV proteins as well as glutamate, quinolinic acid (QUIN), platelet activating factor (PAF) and reactive oxygen species (ROS) released from activated glia can act as direct or indirect triggers for HIV-induced NMDAR-mediated excitotoxicity. In our initial funding period, we used our NT2.N neurotoxicity model to show that HIV-1-infected monocyte-derived macrophages (HIV/MDM) trigger the NMDAR-activated intrinsic (mitochondrial) apoptosis pathway. Furthermore, our recent study using our primary rodent hippocampal culture model demonstrates that HIV/MDM release excitotoxins that kill neurons by NMDAR-mediated calpain activation, and that hippocampal vulnerability is determined by NR2A and NR2B subunit expression. Our hypothesis is that HIV/MDM-induced NMDAR activation, altered NR subunit phosphorylation & localization are associated with macrophage stress responses and determine hippocampal neuronal vulnerability to HIV induced damage. Our studies of HIV/MDM neurotoxicity and the roles of NMDAR and the macrophage integrated stress response (ISR) have shown that i) hippocampal neuronal vulnerability is age-dependent and is determined by NR2A and NR2B expression patterns; ii) HIV/MDM rapidly induce neuronal calpain and cdk5 activation, altered NR2B phosphorylatioh & cleavage, and calpain- and cdk5-dependent death; iii) HIV replication in MDM induces the macrophage integrated stress response (ISR); and iv) the ISR is activated in macaque brain and human brain in individuals infected with immunodeficiency virus. To better define how HIV infection of macrophages triggers neurodegeneration cascades and to identify new targets for neuroprotection we will: 1) Define the pathways of calpain-induced NMDAR-mediated neurotoxicity induced by HIV/MDM and the functional roles for NR2 subunits; 2) Determine whether specific phosphorylation and synaptic localization of NMDAR modulate HIV/MDM neurotoxicity and whether similar NR phosphorylation patterns are expressed in HAD; and 3) Determine the role of the macrophage Integrated Stress Response (ISR) in HIV/MDM-induced neurotoxicity. These studies offer appealing targets at multiple steps in the neurodegeneration cascade initiated by HIV infection that can potentially be exploited for identfication of currently available drugs and for the development of new neuroprotective strategies that can be effective against HIV-induced neurodegeneration. Project Narrative: This project investigates the mechanisms by which HIV-1 infection of macrophages induces neurodegeneration, using an in vitro infection model and pathological analyses of HIV-infected human brain and simian immunodeficiency virus (SIV)-infected macaque/monkey brain tissues. Our hypothesis, based on our preliminary studies, is that such infection alters the macrophage integrated stress response (ISR), leading to excitotoxin production and neuronal NMDA receptor activation by mechanisms that determine why selective neuronal populations are damaged in HIV-1 infection. We are attempting to validate our in vitro observations in human brain tissue and in the SIV macaque model so that neuroprotection studies can eventually be rationally designed for testing in the macaque model.

描述（由申请人提供）：艾滋病毒感染的大脑中的神经元损伤，导致与HIV相关的痴呆（HAT）的神经元损害被认为部分通过氧化应激相关的N-甲基-D-天冬氨酸受体（NMDAR）激发，由大脑巨噬细胞的HIV感染引起。富含NMDAR的大脑区域表达NR2A和NR2B亚基，例如海马，特别容易受到HIV的影响。 HIV蛋白以及谷氨酸，喹啉酸（Quin），血小板激活因子（PAF）和反应性氧（ROS）从活化的神经胶质物中释放出来，可以作为HIV诱导的NMDAR诱导的NMDAR介导的兴奋性的直接或间接触发。在最初的资金期间，我们使用NT2.n神经毒性模型表明，HIV-1感染的单核细胞衍生的巨噬细胞（HIV/MDM）触发了NMDAR激活的内在（线粒体）凋亡途径。此外，我们最近使用原发性啮齿动物海马培养模型的研究表明，HIV/MDM释放通过NMDAR介导的钙蛋白钙蛋白酶激活杀死神经元的兴奋毒素，而海马毛发由NR2A和NR2B亚基表达确定。 我们的假设是，HIV/MDM诱导的NMDAR激活，NR亚基磷酸化和定位改变与巨噬细胞应力反应有关，并确定海马神经元易受HIV引起的损伤。 我们对HIV/MDM神经毒性以及NMDAR和巨噬细胞综合应激反应（ISR）的作用的研究表明，i）海马神经元脆弱性是年龄依赖性的，并由NR2A和NR2B表达模式确定； ii）HIV/MDM迅速诱导神经元的钙蛋白酶和CDK5激活，改变NR2B磷酸里磷酸和裂解，以及CALPAIN-和CDK5依赖性死亡； iii）MDM中的HIV复制诱导巨噬细胞综合应力反应（ISR）； iv）ISR在感染免疫缺陷病毒的个体的猕猴脑和人脑中被激活。为了更好地定义巨噬细胞的HIV感染如何触发神经退行性的级联并确定神经保护的新靶标，我们将：1）定义HIV/MDM诱导的Calpain诱导的NMDAR诱导的NMDAR介导的神经毒性的途径； 2）确定NMDAR调节HIV/MDM神经毒性的特定磷酸化和突触定位是否以及是否表达了类似的NR磷酸化模式； 3）确定巨噬细胞综合应力反应（ISR）在HIV/MDM诱导的神经毒性中的作用。这些研究在HIV感染引发的神经变性级联反应的多个步骤中提供了吸引力的目标，该级联可能被利用以鉴定当前可用的药物，并开发出可能有效抗HIV诱导的神经变性的新神经保护策略。项目叙述：该项目研究了使用体外感染模型和HIV感染的人脑和邻胺免疫缺陷病毒（SIV）感染的猕猴/猴子脑组织的HIV-1感染巨噬细胞诱导神经退行性的机制。基于我们的初步研究，我们的假设是，这种感染改变了巨噬细胞的综合应激反应（ISR），从而通过确定选择性神经元群体在HIV-1感染中损害选择性神经元群体而导致兴奋毒素的产生和神经元NMDA受体激活。我们试图在人脑组织和SIV猕猴模型中验证我们的体外观察结果，以便最终可以在猕猴模型中合理设计神经保护研究。