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: 7591697
• 负责人: Rachel Williams
• 金额: $ 0.52万
• 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 2009-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7591697
• 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; Inflammation Mediators; Inflammatory; Intervention; Lactate Dehydrogenase; Left; Mediating; Methods; Molecular; Motor; Nerve Degeneration; Neuroglia; Neurons; Neuropathogenesis; Neurotoxins; Oxidative Stress; Pathologic; Pathway interactions; Patients; Pharmaceutical Preparations; Phosphorylation; Play; Production; Proteins; 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; public health relevance; 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(申请人提供)：研究表明，60%的HIV-1携带者有某种形式的神经精神障碍。HIV相关性痴呆(HAD)是HIV-1引起的中枢神经系统损害的最严重形式，是60岁或60岁以下人群痴呆的主要原因。人类免疫缺陷病毒脑炎(HIV-Encephalitis，HIVE)是HAD的病理相关疾病，以广泛的星形胶质细胞增生、细胞因子/趋化因子失调、氧化应激和神经元变性为特征。星形胶质细胞是大脑中数量最多的细胞类型，为响应HIV-1病毒渗透到大脑中而产生炎症介质提供了重要的储备库。刺激星形胶质细胞表达的炎症介质之一是CXCL10，它是一种神经毒素和趋化物质，可在HIV-1/病毒蛋白和细胞因子干扰素-γ和肿瘤坏死因子-α的诱导下表达。这项研究的长期目标是验证这样的假设，即在HAD中，抗氧化剂治疗可以通过降低大脑中CXCL10的水平来减少神经元损失。这将通过三个目标完成：1)研究HIV-1与干扰素-γ和肿瘤坏死因子-α协同诱导星形胶质细胞表达CXCL10的潜在细胞和分子机制(S)。2)研究氧化应激在HIV-1/干扰素-v/肿瘤坏死因子-a协同诱导星形胶质细胞CXCL10表达中的作用。3)检测抗氧化剂N-乙酰半胱氨酸(MAC)对HIV-1/IFN-γ/TNF-a刺激的星形胶质细胞释放CXCL10的抑制作用。AIMS 1和2将研究在刺激的星形胶质细胞中激活核因子-KB介导的CXCL10转录的Mark信号通路。方法：Western印迹分析确认MARK蛋白的磷酸化，CXCL10-EL ISA检测CXCL10产生途径，凝胶迁移率改变分析(EMSA)检测核因子-KB活性。原理：已知的CXCL10转录因子NF-KB受HIV-1/病毒蛋白、干扰素-γ/肿瘤坏死因子-α和氧化应激引起的信号级联反应的影响。目的3利用免疫细胞化学和乳酸脱氢酶(LDH)检测来确定NAC处理刺激的星形胶质细胞是否能降低CXCL10介导的神经元毒性。理论基础：在蜂巢中，神经元死亡增加，CXCL10和氧化应激增加。因此，受刺激的星形胶质细胞释放的CXCL10可能在HAD的神经发病机制中起中心作用，抗氧化治疗可能是预防与该病相关的神经元丢失的机制之一。 公共卫生相关性：患有HAD的患者CXCL10水平和氧化应激水平升高。HAD患者的抗氧化剂治疗有可能减少氧化应激和CXCI10引起的神经毒性。如果这种形式的干预成功，它可以与目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往往无效。