Pharmacological modulation of synapses and cognition during HIV-1 neurotoxicity

HIV-1神经毒性过程中突触和认知的药理学调节

• 批准号: 8536498
• 负责人: Stanley A Thayer
• 金额: $ 22.8万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-15 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8536498
• 关键词: AIDS neuropathy; Acquired Immunodeficiency Syndrome; Affect; Agonist; Animal Model; Animals; Antiemetics; Appetite Stimulants; Behavior; Biological Assay; Bipolar Disorder; CNR1 gene; CNR2 gene; Cannabinoids; Cell Death; Cells; Cognition; Cognitive; DLG4 gene; Detection; Disease; Drug usage; Exhibits; Exposure to; Foundations; Green Fluorescent Proteins; HIV Envelope Protein gp120; HIV Infections; HIV-1; Image; Imaging technology; Impaired cognition; Impairment; In Vitro; Lithium; Mediating; Microglia; Modeling; Monitor; Morphology; Mus; N-Methyl-D-Aspartate Receptors; Neurocognitive; Neurodegenerative Disorders; Neurologic; Neurons; Neurotoxins; Patients; Performance; Pharmaceutical Preparations; Process; Proteins; Recovery; Scaffolding Protein; Site; Structure; Synapses; Technology; Testing; Toxin; Transgenic Mice; arachidonyl-2-chloroethylamide; base; behavior test; cannabinoid receptor; cognitive change; cognitive function; cognitive recovery; density; drug development; drug of abuse; env Gene Products; ifenprodil; improved; improved functioning; in vivo; insight; mouse model; neurotoxicity; postsynaptic; prevent; promoter; public health relevance; release factor; research study; synaptogenesis; tat Protein

DESCRIPTION (provided by applicant): Changes in dendritic morphology such as dendritic pruning precede cell death in many neurodegenerative disorders, including HIV-1-associated neurocognitive disorders (HAND). Dendritic degeneration correlates with cognitive decline in HAND. A confocal imaging-based assay was developed to detect intact postsynaptic densities (PSDs) based on detection of clusters of the scaffolding protein PSD95 fused to green fluorescent protein (PSD95-GFP). In neuronal cultures, PSD95-GFP puncta were lost following exposure to factors released by HIV-1 infected cells including the HIV-1 proteins Tat and gp120. PSD loss induced by HIV-1 neurotoxins is reversible. This proposal will relate the loss and recovery of synapses to cognitive function in mouse models of neuroAIDS. In vivo multiphoton imaging will track PSD95-GFP puncta during expression of HIV-1 proteins and behavioral tests will monitor cognitive function. The first aim is to relate HIV-1 protein induced synapse loss and recovery to cognitive performance. Treatment with ifenprodil, an antagonist selective for NR2B-containing NMDA receptors, induced the recovery of synapses lost following in vitro exposure to the HIV-1 protein Tat. What remains unclear is whether synapses recover in vivo and if they do, whether cognitive function improves. Transgenic mice that express Tat under the control of an inducible promoter exhibit synaptic degeneration and cognitive decline following induction. The hypothesis that ifenprodil will evoke recovery of synapses lost in Tat-expressing animals and that synaptic recovery will correlate with improved cognitive function will be tested. Anticipated results may provide proof of the principle that drug-induced changes in synaptic number predict changes in cognitive function. The second aim is to determine the effects of cannabinoids, drugs given to AIDS patients clinically and widely used illicitly, on the synaptic and cognitive changes induced by HIV-1 proteins. Synapse loss and recovery is a dynamic process influenced by cannabinoids in vitro. The effects of cannabinoids on cognitive function in HIV-1 models are unknown. Agonists selective for cannabinoid receptor subtypes will be tested in transgenic mice expressing the HIV-1 proteins gp120 or Tat. The CB2 agonist JWH-133 is predicted to improve cognition in gp120- expressing mice. In contrast, the CB1 agonist arachidonyl-2'-chloroethylamide (ACEA) is predicted to impair ifenprodil-induced synapse recovery and limit cognitive improvement in Tat-expressing mice. If cannabinoids impair synaptic and cognitive recovery, this result would caution against recreational use of cannabinoids or their use as antiemetics and appetite stimulants in patients with HAND. In vivo multiphoton imaging has potentially broad applications for relating the effects of drugs on synaptic structure to their effects on behavior. This project will provide a foundation to guide th development of drugs to improve function in HAND patients and will identify sites where drugs of abuse might interact with the formation and loss of synapses.

描述（由申请人提供）：在许多神经退行性疾病（包括 HIV-1 相关神经认知障碍（HAND））中，树突形态的变化（例如树突修剪）先于细胞死亡。树突变性与 HAND 认知能力下降相关。开发了一种基于共聚焦成像的测定法，通过检测与绿色荧光蛋白融合的支架蛋白 PSD95 (PSD95-GFP) 簇来检测完整的突触后密度 (PSD)。在神经元培养物中，PSD95-GFP 斑点在暴露于 HIV-1 感染细胞释放的因子（包括 HIV-1 蛋白 Tat 和 gp120）后丢失。 HIV-1 神经毒素引起的 PSD 损失是可逆的。该提案将在神经艾滋病小鼠模型中将突触的丧失和恢复与认知功能联系起来。体内多光子成像将在 HIV-1 蛋白表达过程中追踪 PSD95-GFP 斑点，行为测试将监测认知功能。第一个目标是将 HIV-1 蛋白诱导的突触丧失和恢复与认知能力联系起来。艾芬地尔（一种针对含有 NR2B 的 NMDA 受体的选择性拮抗剂）治疗可诱导体外暴露于 HIV-1 蛋白 Tat 后丢失的突触恢复。目前尚不清楚突触是否在体内恢复，如果恢复，认知功能是否会改善。在诱导型启动子控制下表达 Tat 的转基因小鼠在诱导后表现出突触变性和认知能力下降。艾芬地尔将引起表达 Tat 的动物中丢失的突触恢复以及突触恢复与认知功能改善相关的假设将得到测试。预期结果可能会证明药物诱导的突触数量变化可以预测认知功能的变化这一原理。第二个目的是确定大麻素（临床上为艾滋病患者提供并广泛非法使用的药物）对 HIV-1 蛋白诱导的突触和认知变化的影响。突触丢失和恢复是体外受大麻素影响的动态过程。大麻素对 HIV-1 模型认知功能的影响尚不清楚。针对大麻素受体亚型的选择性激动剂将在表达 HIV-1 蛋白 gp120 或 Tat 的转基因小鼠中进行测试。 CB2 激动剂 JWH-133 预计可改善 gp120 表达小鼠的认知能力。相比之下，CB1 激动剂花生四烯酰-2'-氯乙酰胺 (ACEA) 预计会损害艾芬地尔诱导的突触恢复并限制表达 Tat 的小鼠的认知改善。如果大麻素损害突触和认知恢复，这一结果将警告 HAND 患者不要娱乐性使用大麻素或将其用作止吐剂和食欲兴奋剂。体内多光子成像在将药物对突触结构的影响与其对行为的影响联系起来方面具有潜在的广泛应用。该项目将为指导药物开发以改善手部疾病患者的功能奠定基础，并将确定滥用药物可能与突触形成和丧失相互作用的位点。