Endocannabinoid-mediated neuroprotection in models of neuroAIDS in vivo

项目总结/摘要 几种神经退行性疾病，包括帕金森氏病和阿尔茨海默氏病，显示出在神经系统中的改变。 endocannabinoid（eCB）系统的功能。在联合抗逆转录病毒疗法（cART）时代， 人类免疫缺陷病毒1型（HIV-1）现在被认为是一种慢性疾病， 一种专门针对大脑的成分，导致艾滋病毒相关的神经认知功能障碍的高患病率。 疾病（手）。eCB系统作为治疗神经退行性疾病的靶点引起了人们的兴趣。 由于CB的潜在神经保护、抗炎和神经营养特性，然而，在这方面， 由于eCB被分解代谢酶快速降解，因此不太可能在体内进行治疗性使用。主要 负责降解两种主要eCB，花生四烯酸（AEA）和2-arochinonoylglycerol（2- AG）分别为：脂肪酸酰胺水解酶（FAAH）和单酰基甘油脂肪酶（MAGL）。一类新的 已经开发出这些酶的选择性抑制剂，其显示出神经保护和抗炎作用。 在神经退行性疾病的临床前动物模型中的作用。这些新的药理学工具允许 选择性升高eCB信号传导，这使得能够研究特定eCB的生理作用， 并揭示了这种精确调节的治疗潜力。本研究的目的是解开 eCB信号在神经保护中对HIV-1蛋白毒性的作用，导致行为改变， 手的后果。为了实现这一目标，我们计划使用达特和gp 120转基因（tg）小鼠，以及- 建立的neuroAIDS模型，这将使我们能够确定：1）eCB对 前额叶皮层（PFC）依赖的行为在体内，使用分解代谢酶抑制; 2）机制 eCB在PFC离体中的潜在保护作用;以及3）慢性eCB分解代谢酶的作用 在体内使用正电子发射断层扫描（PET）成像的神经炎症抑制剂。我们假设 在HIV-1蛋白tg小鼠模型中，eCB分解代谢酶抑制剂将显示出保护作用， 行为、功能和结构通过CB 1 R/CB 2 R介导的机制。在特定目标1中，达特tg小鼠将被 接受操作性条件处理Go/No-Go任务培训，并检测eCB酶抑制剂的保护性 对Tat诱导的认知功能干扰的影响，包括行为抑制的减少， 增加冲动。此外，相同的动物将接受PFC锥体的电生理学研究， 神经元离体培养以确定eCB酶抑制剂对突触电流的影响。在具体目标2中， 将进行行为、功能和形态学成像研究，以确定eCB是否具有神经保护作用 通过离体CB 1 R/CB 2 R介导的机制在达特中的毒性。在Specific Aim 3中，无创纵向PET 在达特和gp 120 tg小鼠中进行的成像研究将研究eCB酶抑制剂对活性 使用示踪剂[18F]-PBR 111观察炎症过程。了解eCB系统在神经系统中的作用 艾滋病可能会发现新的治疗目标，手和其他疾病的认知缺陷发生。

Project Summary/Abstract Several neurodegenerative disorders, including Parkinson’s and Alzheimer’s diseases, display alterations in the function of the endocannabinoid (eCB) system. In the era of combined antiretroviral therapy (cART), human immunodeficiency virus type 1 (HIV-1) is now considered a chronic disease with an inflammatory component that specifically targets the brain and causes a high prevalence of HIV-associated neurocognitive disorders (HAND). The eCB system has attracted interest as a target for treatment of neurodegenerative disorders, due to the potential neuroprotective, anti-inflammatory, & neurotrophic properties of CBs. However, therapeutic use of eCBs in vivo is unlikely due to their rapid degradation by catabolic enzymes. The main enzymes responsible for degradation of two major eCBs, anandamide (AEA) and 2-arochinonoylglycerol (2- AG), are respectively: fatty acid amide hydrolase (FAAH), and monoacylglycerol lipase (MAGL). A new class of selective inhibitors of those enzymes has been developed that show neuroprotective and anti-inflammatory effects in preclinical animal models of neurodegenerative diseases. These new pharmacological tools allow for selective elevation of eCB signaling, which enables investigation of physiological actions of particular eCBs as well as reveal therapeutic potential of such precise modulation. The aim of the present study is to unravel the role of the eCB signaling in neuroprotection against HIV-1 protein toxicity that results in behavioral changes as a consequence of HAND. To achieve this goal, we plan to use Tat and gp120 transgenic (tg) mice, as well- established models of neuroAIDS, that will allow us to determine: 1) the neuroprotective effects of eCBs on prefrontal cortex (PFC)-dependent behavior in vivo, with use of catabolic enzyme inhibition; 2) the mechanisms underlying protective effects of eCBs in PFC ex vivo; and 3) the effects of chronic eCB catabolic enzyme inhibitors on neuroinflammation using positron emission tomography (PET) imaging in vivo. We hypothesize that in the HIV-1 protein tg mouse models, eCB catabolic enzyme inhibitors will show protective effects on behavior, function, and structure via a CB1R/CB2R-mediated mechanism. In Specific Aim 1, Tat tg mice will be trained on the operant conditioning Go/No-Go task and eCB enzyme inhibitors will be tested for protective effects against Tat-induced interference in cognitive function, including a decrease of behavioral inhibition and increased impulsivity. Moreover, the same animals will undergo electrophysiology studies on PFC pyramidal neurons ex vivo to establish the effects of eCB enzyme inhibitors on synaptic currents. In Specific Aim 2, we will conduct behavioral, functional, and morphological imaging studies to determine if eCBs are neuroprotective in Tat toxicity via a CB1R/CB2R-mediated mechanism ex vivo. In Specific Aim 3, non-invasive longitudinal PET imaging studies in Tat and gp120 tg mice will investigate the effects of eCB enzyme inhibitors on active inflammatory processes using the tracer [18F]-PBR111. Understanding the role of the eCB system in neuro- AIDS may uncover novel therapeutic targets for HAND and other diseases in which cognitive deficits occur.