Cocaine & HIV: Role of PDGF/PDGF-Receptor Axis in Blood Brain Barrier Disruption

摘要 静脉注射毒品使用和艾滋病毒感染是两个相互关联的全球健康危机，因为共用针头是众所周知的 艾滋病毒的传播方式。而HIV-1感染是25-44岁美国人的主要死亡原因 旧的注射毒品使用现在约占美国每年报告的所有新增艾滋病病例的三分之一。 经常被艾滋病毒感染者滥用的可卡因被认为会加重艾滋病毒相关的痴呆症 (HAD)通过未知机制。大脑是娱乐毒品和HIV-1病毒的靶器官。 血脑屏障(BBB)破坏是HIV进入中枢神经系统的主要途径。这些机制由 单核细胞和/或T细胞如何穿过血脑屏障进入中枢神经系统实质仍是一个谜。BBB是 对维持中枢神经系统内环境平衡和调节神经微环境至关重要。 这项提案将调查可卡因和艾滋病毒共同引发血脑屏障的具体机制。 颠覆。我们假设HIV蛋白和可卡因可以相加或协同的方式相互作用，从而 直接放大导致其毒性血管效应的细胞和分子过程，例如，干扰 血脑屏障和感染的单核细胞向中枢神经系统移行增加。这一假设的基本原理是 基于初步研究显示，脑组织中一种血管生成的PDGF-BB表达上调 感染人类免疫缺陷病毒脑炎的猕猴和感染艾滋病毒或艾滋病病毒的单核细胞 暴露在可卡因中。反过来，我们的新发现也证明了可卡因介导的干扰 内皮单层涉及PDGF-β受体的磷酸化。因此，这项提案将调查 一种新的概念认为，PDGF/PDGF-R轴可能是可卡因/HIV介导的血脑屏障破坏的缺失环节。 使用体外和互补的HIV神经退行性变小鼠模型，我们将测试 假设有三个具体目的：SA1的研究将重点放在研究分子机制上 参与HIV蛋白和/或可卡因对单核细胞中PDGF表达的上调。SA2将专注于 PDGF参与可卡因引起的人脑通透性改变的机制探讨 微血管内皮细胞。最后，SA3将使用活体方法来检验抑制细胞周期的假说。 PDGF-β受体抑制剂Gleevac对PDGF/PDGF-R轴的作用将导致血脑屏障的消除 可卡因对HIV转基因大鼠和TAT转基因小鼠的破坏。

Abstract IV drug use and HIV infections are two linked global health crises since needle sharing is a well-recognized mode of HIV transmission. While HIV-1 infection is the leading cause of death among Americans 25-44 years old, injection drug use now accounts for about one-third of all new US AIDS cases reported each year. Cocaine, often abused by HIV-infected patients, has been suggested to worsen HIV-associated dementia (HAD) via unknown mechanisms. The brain is a target organ for both, the recreational drugs and HIV-1. Disruption of the blood brain barrier (BBB) is the main route of HIV entry into the CNS. The mechanisms by which the monocytes and/or T cells cross the BBB into the CNS parenchyma still remain an enigma. BBB is critical for the maintenance of CNS homeostasis and for the regulation of the neural microenvironment. This proposal will investigate specific mechanisms by which cocaine and HIV co-operate to induce BBB disruption. We hypothesize that HIV proteins & cocaine can interact in an additive or synergistic manner to directly amplify cellular & molecular processes contributing to their toxic vascular effects such as, disruption of the BBB and increased transmigration of infected monocytes into the CNS. The rationale of this hypothesis is based on preliminary studies showing up-regulation of a vascular permeant PDGF-BB in the brains of macaques with Simian-human immunodeficiency virus encephalitis and in monocytes infected with HIV or exposed to cocaine. Reciprocally, our new findings also demonstrate that cocaine-mediated disruption of endothelial monolayer involves phosphorylation of the PDGF-beta receptor. This proposal will thus investigate a novel concept that PDGF/PDGF-R axis could be the missing link in cocaine/HIV-mediated disruption of BBB. Using a combination of in vitro and complementary murine models of HIV neurodegeneration, we will test the hypothesis in three specific aims: SA1 of the study will be focused on investigating the molecular mechanisms involved in upregulation of PDGF in monocytes exposed to HIV proteins and/or cocaine. SA2 will be focused on exploring the mechanisms involved in PDGF & cocaine-induced permeability changes in human brain microvascular endothelial cells. Finally, SA3 will use in vivo approach to test the hypothesis that inhibition of the PDGF/PDGF-R axis by the PDGF-beta receptor inhibitor gleevac, will result in abrogation of BBB disruption in HIV-transgenic rats and Tat transgenic mice exposed to cocaine.