MMPs and Synaptic Injury with HIV/METH

描述(由申请人提供)：突触损伤已被描述为艾滋病毒痴呆(HIVD)和冰毒使用。例如，树突状细胞损伤在艾滋病毒脑炎(HIVE)中已有很好的描述，使用冰毒的艾滋病毒脑炎(HIVE)患者显示出比不使用HIVE的患者更大的突触蛋白免疫反应丧失。基质金属蛋白酶(MMPs)是锌依赖的酶，其水平可显著升高与蜂窝有关。此外，HIV蛋白和甲基苯丙胺都被证明可以增加培养的神经元和神经胶质细胞释放的基质金属蛋白酶。尽管人们对MMPs在脑外的作用进行了广泛的研究，但对中枢神经系统中MMPs的研究通常仅限于它们对血脑屏障蛋白的影响。然而，特别令人感兴趣的是，MMPs有可能靶向对突触结构和功能至关重要的蛋白质。通常使用非神经系统的体外研究表明，MMPs的靶向分子包括突触素、钙粘附素和SIRP-1a。有趣的是，众所周知，这些分子中的每一个都在突触粘连中发挥作用。此外，如下所示，我们有初步数据表明，选择在突触功能中发挥主要作用的MMPs靶分子。其中一个这样的分子是NMDA型谷氨酸受体的NR1亚单位。因此，本申请将概述测试MMPs是HIV蛋白和冰毒引起的突触损伤的关键媒介这一假设的计划。分离培养和切片培养将在存在或不存在特定的基质金属蛋白酶抑制剂的情况下用HIV蛋白和冰毒进行处理，然后评估基质金属蛋白酶介导的突触损伤的证据。将检测基质金属蛋白酶水平、选择突触黏附分子和NMDA受体亚单位，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。在平行的研究中，过量表达HIV-1 TAT或gp120的冰毒处理小鼠将接受广谱基质金属蛋白酶抑制剂或赋形剂对照治疗，中枢神经系统组织也将进行类似的评估。R21应用中提出的研究结果应该确定在HIV蛋白/冰毒处理的培养物和动物中MMPs是否升高。更重要的是，建议的研究应该确定MMPs是否可能在冰毒使用和HIV感染引起的突触损伤中发挥作用，以及是否应该考虑使用一般的或选择性的MMPa拮抗剂来治疗特定的患者。

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.