MMPs and Synaptic Injury with HIV/METH

描述（由申请人提供）：突触损伤已被描述为HIV痴呆（HIVD）和冰毒使用。例如，树突损伤已经在HIV脑炎（HIVE）中得到了很好的描述，使用甲基苯丙胺的HIV脑炎（HIVE）患者比使用HIVE的非甲基苯丙胺的患者表现出更大的突触蛋白免疫反应性丧失。基质金属蛋白酶（MMPs）是锌依赖性酶，其水平可能与HIVE相关而显著升高。此外，HIV蛋白和甲基苯丙胺均可增加培养的神经元和神经胶质细胞的MMP释放。尽管对MMPs在脑外的作用进行了充分的研究，但对CNS中的MMPs的研究通常仅限于它们对血脑屏障蛋白质的影响。然而，特别令人感兴趣的是MMPs靶向对突触结构和功能至关重要的蛋白质的潜力。通常使用非神经系统的体外研究表明，MMPs的靶分子包括syndecans、cadherins和SIRP-1a。有趣的是，已知这些分子中的每一个都在突触粘附中发挥作用。此外，正如下面所示，我们有初步的数据表明，选择的MMPs目标分子在突触功能中起主导作用。其中一个分子是NMDA型谷氨酸受体的NR1亚基。因此，目前的申请将概述计划来测试MMPs是HIV蛋白和冰毒发生的突触损伤的关键介质的假设。在存在或不存在特异性MMP抑制剂的情况下，解离和切片培养物将用HIV蛋白和甲基安非他明处理，然后评估MMP介导的突触损伤的证据。将检查MMP水平，选择突触粘附分子和NMDA受体亚基，以及神经元死亡。突触结构也将通过共聚焦和电子显微镜进行评估。在平行研究中，甲基安非他明处理过表达HIV-1 Tat或gp120的小鼠将用广谱MMP抑制剂或载体对照治疗，并对中枢神经系统组织进行类似的评估。本R21申请中提出的研究结果应确定HIV蛋白/甲基安非他明处理的培养物和动物中MMPs是否升高。更重要的是，拟议的研究应确定MMPs是否可能在甲基苯丙胺使用和HIV感染时发生的突触损伤中发挥作用，以及是否应考虑使用一般或选择性MMP拮抗剂治疗特定患者。

DESCRIPTION (provided by applicant): Synaptic damage has been described with both HIV dementia (HIVD) and METH use. For example, dendritic injury has been well described in HIV encephalitis (HIVE), and METH using patients with HIV encephalitis (HIVE) show greater loss of synaptic protein immunoreactivity than do HIVE non-METH users. Matrix metalloproteinases (MMPs) are zinc dependent enzymes whose levels may be substantially elevated in association with HIVE. Further both HIV proteins and methamphetamine have been shown to increase MMP release from cultured neurons and glia. Though well studied for their effects outside of the brain, studies of MMPs in the CNS have generally been limited to their effects on proteins of the blood brain barrier. Of particular interest, however, is the potential for MMPs to target proteins critical to synaptic structure and function. In vitro studies, often using non-neural systems, have shown that MMPs target molecules including syndecans, cadherins, and SIRP-1a. Of interest, each of these molecules is known to play a role in synaptic adhesion. Moreover, as will be shown to follow, we have preliminary data which suggests that select MMPs target molecules that play a predominant role in synaptic function. One such molecule is the NR1 subunit of the NMDA type glutamate receptor. The present application will therefore outline plans to test the hypothesis that MMPs are critical mediators of synaptic injury occurring with HIV proteins and METH. Dissociated and slice cultures will be treated with HIV proteins and METH, in the presence or absence of specific MMP inhibitors, and then evaluated for evidence of MMP mediated synaptic injury. MMP levels, select synaptic adhesion molecules, and NMDA receptor subunits will be examined, as will be neuronal death. Synaptic structure will also be evaluated by confocal and electron microscopy. In parallel studies, METH treated mice that over express HIV-1 Tat or gp120 will be treated with a broad spectrum MMP inhibitor, or vehicle control, and CNS tissues will be similarly evaluated. The results of the studies proposed in this R21 application should determine whether MMPs are elevated in HIV protein/METH treated cultures and animals. More importantly, the proposed studies should determine whether MMPs likely play a role in synaptic injury occurring with METH use and HIV infection, and whether general or selective MMP antagonists should be considered for the treatment of specific patients.