HIV-Encephalitis: Mechanisms for CXCL 10 Induction in Astrocytes

HIV 脑炎：星形胶质细胞中 CXCL 10 诱导的机制

• 批准号: 7496230
• 负责人: Rachel Williams
• 金额: $ 2.66万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7496230
• 关键词: AIDS Dementia Complex; Acetylcysteine; Acquired Immunodeficiency Syndrome; Affect; Anti-Retroviral Agents; Antioxidants; Astrocytes; Behavioral; Biological Assay; Brain; CXCL10 gene; Cells; Cessation of life; Chemotactic Factors; Cognitive; Coma; Conditioned Culture Media; Dementia; Diagnosis; Disease; Electrophoretic Mobility Shift Assay; Enzyme-Linked Immunosorbent Assay; Epidemic; Functional disorder; Generations; Genetic Transcription; Goals; HIV; HIV Envelope Protein gp120; HIV encephalitis; HIV-1; Impairment; Individual; Infection; Infiltration; Inflammatory; Intervention; Lactate Dehydrogenase; Lactate Dehydrogenases; Left; Mediating; Mediator of activation protein; Methods; Molecular; Motor; Nerve Degeneration; Neuroglia; Neurons; Neuropathogenesis; Neurotoxins; Oxidative Stress; Pathologic; Pathway interactions; Patients; Pharmaceutical Preparations; Phosphorylation; Play; Production; Proteins; Public Health; Role; Seizures; Severities; Signal Pathway; Signal Transduction; TNF gene; Testing; Toxic effect; Viral; Viral Proteins; Western Blotting; antioxidant therapy; antiretroviral therapy; astrogliosis; brain tissue; cell type; chemokine; cytokine; immunocytochemistry; mRNA Expression; neuron loss; neuropsychiatry; neurotoxicity; prevent; response; transcription factor

DESCRIPTION (provided by applicant): Studies show that 60% of HIV-1 carriers have some form of neuropsychiatric impairment. HIV associated dementia (HAD), the most severe form of HIV-1 induced CNS impairment, is the main cause of dementia in people 60 or younger. HIV-Encephalitis (HIVE), the pathologic correlate of HAD, is characterized by widespread astrogliosis, cytokine/chemokine dysregulation, oxidative stress, and neuronal degeneration. Astrocytes, the most numerous cell type within the brain, provide an important reservoir for the generation of inflammatory mediators, in response to HIV-1 infiltration into the brain. One of the inflammatory mediators expressed by stimulated astrocytes is CXCL10, a neurotoxin and chemoattractant whose expression can be induced by HIV-1/viral proteins and the cytokines IFN-y and TNF-a. The long term goal of this study is to test the hypothesis that in HAD antioxidant therapy can reduce the neuronal loss by lowering the levels of CXCL10 in the brain. This will be accomplished in three aims: 1) Examine the potential cellular and molecular mechanism(s) by which HIV-1 synergizes with IFN-y & TNF-a to induce the expression of CXCL10 in astrocytes. 2) Study the role of oxidative stress in the synergistic induction of CXCL10 in astrocytes exposed to HIV-1/IFN-v/TNF-a. 3) Examine the efficacy of using the antioxidant, N-acetyl cysteine (MAC), as a therapy for abrogating CXCL10 release from HIV- 1/IFN-y/TNF-a stimulated astrocytes. Aims 1&2 will investigate MARK signaling pathways that activate NF-KB mediated transcription of CXCL10 in stimulated astrocytes. Methods: Western blot analysis to confirm the phosphorylation of MARK proteins, CXCL10 ELISA to determine pathways necessary for CXCL10 production, and electrophoretic mobility shift assay (EMSA) to determine NF-KB activity. Rationale: NF-KB, a known transcription factor for CXCL10, is affected by the signaling cascades caused by HIV-1/viral proteins, IFN-y/TNF- a, and oxidative stress. Aim 3 will utilize immunocytochemistry and lactate dehydrogenase (LDH) assays to determine whether NAC treatment of stimulated astrocytes can reduce CXCL10 mediated neuronal toxicity. Rationale: in HIVE there is increased neuronal death along with increased CXCL10 and oxidative stress. Therefore the CXCL10 released by stimulated astrocytes could play a central role in HAD neuropathogenesis, and antioxidant therapy may be a mechanism for preventing the neuronal loss associated with this disease. PUBLIC HEALTH RELEVANCE: Patients suffering from HAD have increased levels of CXCL10 and oxidative stress. Antioxidant therapy for HAD patients has the potential to reduce oxidative stress and the neurotoxicity caused by CXCI10. If this form of intervention is successful it could be used in conjunction with the currently available antiretroviral drugs, which are often ineffective in the CNS.

描述（由申请人提供）：研究表明，60％的HIV-1载体具有某种形式的神经精神障碍。 HIV相关痴呆（HAD）是HIV-1诱导的CNS损害最严重的形式，是60岁以下人群痴呆的主要原因。 HIV-脑膜炎（Hive）是HAD的病理相关性，其特征是星形胶质细胞增多症，细胞因子/趋化因子失调，氧化应激和神经元变性的特征。星形胶质细胞是大脑中最多的细胞类型，为炎症介质的产生提供了重要的储层，以响应HIV-1浸润到大脑中。由刺激的星形胶质细胞表达的炎症介质之一是CXCL10，一种神经毒素和化学吸收剂，可以通过HIV-1/病毒蛋白和细胞因子IFN-Y-Y和TNF-A诱导其表达。这项研究的长期目标是检验以下假设：抗氧化剂治疗可以通过降低大脑中的CXCL10水平来减少神经元丧失。这将在三个目标中完成：1）检查HIV-1与IFN-Y Y＆TNF-A协同诱导星形胶质细胞中CXCL10表达的潜在细胞和分子机制。 2）研究氧化应激在暴露于HIV-1/IFN-V/TNF-A的星形胶质细胞中CXCL10协同诱导中的作用。 3）检查使用抗氧化剂N-乙酰半胱氨酸（MAC）作为一种从HIV-1/IFN-Y/TNF-A刺激的星形胶质细胞中释放的CXCL10释放的疗法。 AIMS 1和2将研究标记信号通路，该途径激活刺激的星形胶质细胞中CXCL10的NF-KB介导的转录。方法：蛋白质印迹分析以确认标记蛋白，CXCL10 ELISA的磷酸化，以确定CXCL10产生所需的途径以及电泳迁移率转移测定法（EMSA）以确定NF-KB活性。理由：NF-KB是CXCL10的已知转录因子，受HIV-1/病毒蛋白，IFN-Y/TNF-A和氧化应激引起的信号传导级联反应的影响。 AIM 3将利用免疫细胞化学和乳酸脱氢酶（LDH）测定法来确定NAC治疗刺激的星形胶质细胞是否可以降低CXCL10介导的神经元毒性。理由：在Hive中，神经元死亡增加，CXCL10和氧化应激增加。因此，被刺激的星形胶质细胞释放的CXCL10可能在神经病发生中起核心作用，抗氧化剂治疗可能是预防与该疾病相关的神经元丧失的机制。 公共卫生相关性：患者的CXCL10和氧化应激水平增加。 HAT患者的抗氧化剂治疗有可能减少CXCI10引起的氧化应激和神经毒性。如果这种干预形式成功，则可以与当前可用的抗逆转录病毒药物一起使用，这些药物在中枢神经系统中通常无效。