HIV opiate interactions in white matter pathology

项目负责人/主要研究者（最后一名、第一名、中间名）：豪瑟、库尔特F. &克纳普，帕梅拉E. HIV相关的神经认知障碍（HAND）仍然是一个严重的临床问题， cART和滥用阿片类药物的艾滋病毒感染者患HAND的风险更大。阿片类药物可以直接通过 神经胶质细胞上的μ-阿片受体（莫尔）放大继发性神经毒性作用。这一概念是， 尽管白色物质缺乏，但少突胶质细胞（OLs）增加了HIV的神经功能缺陷， 在感染后早期发生。重要的是，我们的实验工作表明，OL容易受到病毒感染， 蛋白质或艾滋病毒感染。将转基因小鼠与HIV-1达特±吗啡共暴露7天， 表现出细胞结构/超微结构异常，caspase-3和TUNEL表达升高，后者 表明OL死亡（69;图1）。OL是唯一的响应急性达特而原位死亡的CNS细胞类型， 吗啡共暴露在体外，达特杀死发育中的OL，而成熟的OL反而显示髓鞘的损失 这两种结果都与Ca 2+和GluR介导的机制有关（84）。此外，OL损坏 血管/血脑屏障损伤，将有助于髓磷脂苍白一贯注意到在成像研究。 我们的中心假设是HIV-1达特与阿片类药物相互作用直接损伤表达MOR的OL。 由于未成熟的OLs表达莫尔，并且优先易受HIV/达特的攻击，我们预测髓鞘修复 进程尤其脆弱。在此，我们提出了一个全面的形态和功能， 评估急性和慢性（≤3个月）HIV/达特引起的OL和髓鞘损伤的时程，以及 吗啡共暴露阿片剂暴露是间歇性的，以更好地模拟注射吸毒者的暴露 （注射吸毒者）感染艾滋病毒。研究在两性中进行，因为髓鞘形成受到性类固醇的影响。的 中心假设在3个相关目标中得到检验。目标1全面描述阿片类药物相关OL， 使用HIV-1达特模型原位观察髓磷脂损伤。使用电生理学评估功能; 通过组织学、高分辨率DT-MRI和纤维束成像/连通性评估白色物质束和OL， 体视学和电子显微镜。通过血脑屏障渗漏评估的血管变化是 组织学监测并与脱髓鞘区域相关。在目标2中，从OL中删除莫尔以进行测试 阿片类药物相互作用是否通过对体内OL的直接作用发生;吗啡± HIV、达特 和gp 120对表达MOR的人OL的作用。Aim 3测试结构和功能 吗啡戒断后恢复。这些全面的研究回答了关于OL/髓鞘的关键问题 艾滋病毒/达特和鸦片制剂联合作用后的脆弱性和康复潜力。 OMB编号0925-0001/0002（2016年3月修订版，批准至2018年10月31日）

Program Director/Principal Investigator (Last, First, Middle): Hauser, Kurt F. & Knapp, Pamela E. HIV-associated neurocognitive disorder (HAND) remains a serious clinical problem even in patients receiving cART, and HIV-infected persons who abuse opiates are at greater risk for HAND. Opiates can act directly via µ-opiate receptors (MOR) on glia to amplify secondary neurotoxic effects. The concept that damage to oligodendroglia (OLs) adds to neurologic deficits in HIV is largely unexplored, even though white matter deficits occur quite early after infection. Importantly, our experimental work shows that OLs are vulnerable to viral protein or HIV exposure. A 7 d co-exposure of transgenic mice to HIV-1 Tat ± morphine damages OLs, which exhibit cytoarchitectural/ultrastructural anomalies, and elevated caspase-3 and TUNEL expression, the latter indicating OL death (69; Fig 1). OLs are the only CNS cell type that die in situ in response to acute Tat and morphine coexposure. In vitro, Tat kills developing OLs, while mature OLs instead show a loss of myelin membrane; both outcomes are related to Ca2+- and GluR-mediated mechanisms (84). OL damage, in addition to vascular/blood brain barrier damage, would contribute to myelin pallor consistently noted in imaging studies. Our central hypothesis is that HIV-1 Tat interacts with opiates to directly injure MOR-expressing OLs. Since immature OLs express MOR and are preferentially vulnerable to HIV/Tat, we predict that myelin repair processes are especially vulnerable. Herein, we propose a comprehensive morphological and functional assessment of the time course of OL and myelin damage caused by acute and chronic (≤3 month) HIV/Tat and morphine coexposure. Opiate exposure is intermittent to better model the exposure of injection drug users (IDUs) who contract HIV. Studies are done in both sexes, as myelination is influenced by sex steroids. The central hypothesis is tested in 3 related aims. Aim 1 develops a thorough picture of opiate-related OL and myelin damage in situ using an HIV-1 Tat model. Function is assessed using electrophysiology; damage to white matter tracts and OLs is assessed by histology, high resolution DT-MRI and tractography/connectivity, stereology, and electron microscopy. Vascular changes as assessed by blood-brain barrier leakiness are monitored histologically and correlated with areas of demyelination. In Aim 2, MOR is deleted from OLs to test whether opiate interactions occur via direct actions on OLs in vivo; the direct effects of morphine ± HIV, Tat and gp120 on MOR-expressing, human OLs are compared in vitro. Aim 3 tests structural and functional recovery after morphine is withdrawn. These comprehensive studies answer critical questions about OL/myelin vulnerability and the potential for their recovery after combined HIV/Tat and opiate insults. OMB No. 0925-0001/0002 (Rev. 03/16 Approved Through 10/31/2018) Page Continuation Format Page