HIV-1 protein neurotoxicity and ethanol pre-conditioning

HIV-1蛋白神经毒性和乙醇预处理

• 批准号: 6752910
• 负责人: MICHAEL A. COLLINS
• 金额: $ 29.6万
• 依托单位: LOYOLA UNIVERSITY CHICAGO
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6752910
• 关键词: AIDS dementia complex; HIV envelope protein gp120; HIV infections; alcoholic beverage consumption; apoptosis; arachidonate; biological signal transduction; brain; chemokine; chemokine receptor; ethanol; gene induction /repression; genetically modified animals; glutamates; heat shock proteins; human immunodeficiency virus 1; intermolecular interaction; laboratory mouse; laboratory rat; neuroprotectants; neurotoxins; protein structure function; superoxides; tissue /cell culture; transcription factor; virus protein

DESCRIPTION (provided by applicant): Cognitive decline due to extensive neurodegeneration occurs in unabated AIDS. HIV-1 productively infects brain microglia and invasive macrophages, shedding proteins in particular, gp120 and Tat--that promote glial-dependent neurotoxicity. While the proteins apparently use diverse neurotoxic mechanisms, chemokine receptor (CR)-based signaling and excitotoxic-apoptotic-oxidative stress cascades may be common to both. Consistent with efforts to clarify neurotoxic mechanisms, we are exploring the interactions of alcohol (ethanol) with the proteins; chronic abuse can worsen AIDS dementia, but the effects of moderate consumption are unclear. Our studies with rat organotypic hippocampal-cortical slice cultures show that moderate ethanol pre-conditioning (MEP, 20-30 mM) for >4 days prevents the neurotoxic effects of gp120 or Tat. That MEP increases a heat shock protein (HSP70) while suppressing early induction by gp120 of intracellular Ca ++,glial-derived apoptotic mediators(glutamate (Glu), arachidonic acid (AA), superoxide (O2")), and IL-10 (a cytokine that induces CRs), as well as CR density on chemokine-stimulated astroglia, suggests key roles for glia. We hypothesize that, as with gp120, MEP similarly suppresses Tat's induction of glial-regulated Glu, AA and 02, and that MEP neuroprotects against both retroviral proteins by promoting CR downregulation, induction of neuroprotective HSPs, and anti-apoptotic signal transduction. These hypotheses will be examined in four aims with rat brain slice cultures and human brain cell lines. Aim I will assess whether Tat, and gp120 with human cells, increases Glu, AA, O2 and other mediators, and in which cells, as well as the effects of MEP on these mediators and neurodegeneration/apoptosis. Aim II will investigate MEP potentiation of CR down-regulation during gp120 or Tat exposure, and the role of receptor phosphorylation. Aim III will ascertain whether HSP induction is critical to MEP neuroprotection, using Western blotting, antibodies, and slice cultures from HSP70 transgenic mice. Aim IV will examine whether MEP promotes activation of survival signal transduction kinases (PI3-kinase/Akt) in concert with reduction in pro-apoptotic (p38/JNK) pathways, and in which cells, and whether HSPs and CR reductions are upstream or downstream of these changes. The studies could shed light on the unexplored area of ethanol pre-conditioning as it relates to HSPs and CR receptor/anti-apoptotic signal transduction, while providing further insights into neuroprotective strategies that might eventually be therapeutically beneficial in AIDS dementia or other neurological diseases involving protein-mediated neurotoxicity.

描述（由申请人提供）：认知能力下降由于广泛的神经退行性变发生在有增无减的艾滋病中。HIV-1有效地感染脑小胶质细胞和侵袭性巨噬细胞，特别是释放蛋白gp120和Tat，促进胶质依赖性神经毒性。虽然这些蛋白明显具有不同的神经毒性机制，但基于趋化因子受体（CR）的信号传导和兴奋毒性-凋亡-氧化应激级联反应可能是两者共同的。与澄清神经毒性机制的努力一致，我们正在探索酒精（乙醇）与蛋白质的相互作用；长期滥用会加重艾滋病性痴呆，但适度消费的影响尚不清楚。我们对大鼠器官型海马皮层切片培养的研究表明，中度乙醇预处理（MEP, 20-30 mM） 40天可防止gp120或Tat的神经毒性作用。MEP增加热休克蛋白（HSP70），同时抑制gp120对细胞内Ca ++、胶质细胞来源的凋亡介质（谷氨酸（Glu）、花生四烯酸（AA）、超氧化物（O2"））和IL-10（一种诱导CR的细胞因子）的早期诱导，以及趋化因子刺激的星形胶质细胞上的CR密度，表明了胶质细胞的关键作用。我们假设，与gp120一样，MEP类似地抑制Tat诱导胶质细胞调节的Glu、AA和02，并且MEP通过促进CR下调、诱导神经保护性热休克蛋白和抗凋亡信号转导来保护这两种逆转录病毒蛋白。这些假设将在四个目标上用大鼠脑切片培养和人类脑细胞细胞系进行检验。目的I将评估Tat和gp120与人类细胞是否增加Glu、AA、O2等介质，以及在哪些细胞中增加，以及MEP对这些介质和神经变性/凋亡的影响。目的II将研究gp120或Tat暴露时MEP对CR下调的增强作用，以及受体磷酸化的作用。Aim III将使用Western blotting、抗体和HSP70转基因小鼠的切片培养来确定热休克蛋白诱导是否对MEP神经保护至关重要。目的IV将研究MEP是否促进生存信号转导激酶（pi3激酶/Akt）的激活，同时减少促凋亡（p38/JNK）通路，以及在哪些细胞中，以及HSPs和CR的减少是这些变化的上游还是下游。这些研究可以揭示乙醇预处理的未知领域，因为它与热休克蛋白和CR受体/抗凋亡信号转导有关，同时为神经保护策略提供进一步的见解，这些策略可能最终在治疗艾滋病痴呆或其他涉及蛋白质介导的神经毒性的神经系统疾病方面有益。