MOR and CCR5 interactive signaling mediates opiate and HIV-driven synaptodendritic injury

注射吸毒增加感染艾滋病毒的可能性，阿片类药物加速艾滋病毒-1的进展 通过免疫抑制和直接的中枢神经系统作用感染。阿片受体广泛表达于 免疫细胞、神经胶质细胞和阿片类药物可以调节趋化因子信号。CCR5在HIV中发挥关键作用 感染作为CCR5偏好菌株进入的共同受体。CCR5的总体水平和小胶质细胞/中枢神经系统 巨噬细胞与HIV神经系统疾病的严重程度相关。具有纯合子的个体 Ccr5Δ32突变能抵抗感染，ccr5拮抗剂马拉韦罗(Mvc)用于临床抑制hiv。 进入。上一个资助期使用非感染性范例的结果表明，CCR5也可能促进 除了它在加强艾滋病毒感染方面的作用外，它还与艾滋病毒相关的神经病理学有关。例如，通过以下方式封锁CCR5 MVC增加突触可塑性，逆转TAT诱导的抗痛、耐受和吗啡减少 并提高经TAT处理的纹状体神经元的存活率。CCR5过度激活可能是一个关键因素 阿片类药物放大HIV神经致病能力的因素，以及MOR之间的异源相互作用 而CCR5很可能是许多中枢神经系统赤字的根源。在艾滋病毒方面，CCR5和MOR的相互作用是 由于CCR5和CCR5的不同胶质/神经元分布，可能在中枢神经系统区域之间存在根本不同 MOR、它们的配体和效应器耦合。对这项提议至关重要的是，MVC在一年内拯救了TAT导致的赤字 涉及海马区功能的空间学习/记忆任务(Barnes迷宫)，以及海马区损伤 与手部患者的学习/记忆障碍有关，与CART无关。来探索这样的假设 异常的CCR5-MOR相互作用是HIV诱导的海马区缺陷的基础，我们将系统地询问 在艾滋病毒/TAT和阿片类药物暴露方面的这些相互作用。HIV-1TAT的体内和体外研究 转基因小鼠还得到了使用暴露于TAT、gp120和HIV的人类神经元的体外研究的补充。 三个相互关联的目标在雄性和雌性小鼠身上测试假说。AIM 1测试CCR5对动力学的影响 使用行为功能评估(空间和空间)，研究HIV-1/TAT和MOR在海马区的相互作用 非空间任务)和神经生理学(体外切片中的LTP和膜特性)。AIM 2测试如何 CCR5激活或阻断(基因、MVC)使用TAT、gp120和HIV改变HIV-1/TAT和MOR相互作用 在小鼠或人类海马神经元和神经胶质细胞的共培养中。神经元功能障碍(光学生理学)， [Ca~(2+)]i稳态、突触树突起损伤和死亡，以及潜在的炎症和信号转导 探索了涉及的途径(BioPlex/MSD复合)。AIM 3研究了异源相互作用 MOR和CCR5，评估[~3H]纳洛酮或[~3H]马拉韦罗刺激的受体动力学和活性 [35S]GTPγS海马切片放射自显影及膜的量效结合曲线 来自大脑和培养的神经元/神经胶质细胞。TrkB和p75NTR在调节药理学测试结果中的作用； 通过改变proBDNF/mBDNF平衡(tPA以增加proBDNF裂解)在所有AIMS中评估的保护作用。

Injection drug use increases the probability of contracting HIV, and opioids accelerate the progression of HIV-1 infection through immune suppression and direct CNS actions. Opioid receptors are widely expressed on immune cells and glia, and opioids can modulate chemokine signaling. CCR5 plays a critical role in HIV infection as a co-receptor for entry of CCR5-preferring strains. CCR5 levels in general, and in microglia/CNS macrophages, have been correlated with severity of HIV neurologic disease. Individuals homozygous for the CCR5Δ32 mutation resist infection, and the CCR5 antagonist maraviroc (MVC) is used clinically to inhibit HIV entry. Results from the last funding period using non-infective paradigms reveal that CCR5 may also promote HIV-related neuropathology apart from its role in enhancing HIV infection. For example, blockade of CCR5 with MVC increases synaptic plasticity, reverses Tat-induced reductions in antinocicetion, tolerance, and morphine dependence, and enhances survival of Tat-treated striatal neurons. CCR5 overactivation may be a pivotal factor in the ability of opiates to amplify HIV neuropathogenesis, and heterologous interactions between MOR and CCR5 likely underlie many CNS deficits in HAND. CCR5 and MOR interactions in the context of HIV are likely fundamentally different among CNS regions due to distinct glial/neuronal distributions of CCR5 and MOR, their ligands, and effector coupling. Critical to this proposal, MVC rescued Tat-induced deficits in a spatial learning/memory task involving hippocampal function (Barnes maze), and hippocampal damage is involved in learning/memory deficits in HAND patients, irrespective of cART. To explore the hypothesis that aberrant CCR5-MOR interactions underlie HIV-induced hippocampal deficits, we will systematically interrogate those interactions in the context of HIV/Tat and opiate exposure. In vivo and ex vivo studies in HIV-1 Tat transgenic mice are complemented by in vitro studies using human neurons exposed to Tat, gp120, and HIV. Three interrelated Aims test hypotheses in male and female mice. Aim 1 tests CCR5 impact on the dynamics of HIV-1/Tat and MOR interactions in the hippocampus, using functional assessments of behavior (spatial and non-spatial tasks) and neurophysiology (LTP and membrane properties in ex vivo slices). Aim 2 tests how CCR5 activation or blockade (genetic, MVC) alters HIV-1/Tat and MOR interactions, using Tat, gp120, and HIV in murine or human co-cultures of hippocampal neurons and glia. Neuron dysfunction (optical physiology), [Ca2+]i homeostasis, synaptodendritic injury, and death, as well as underlying inflammation and signaling pathways involved (bioplex/MSD multiplex) are explored. Aim 3 examines heterologous interactions between MOR and CCR5, assessing receptor dynamics and activity by [3H]naloxone or [3H]maraviroc-stimulated [35S]GTPγS autoradiography in hippocampal sections, and concentration-effect binding curves in membranes from brain and cultured neurons/glia. TrkB and p75NTR roles in regulating outcomes tested pharmacologically; protection by altering the proBDNF/mBDNF balance (tPA to increase proBDNF cleavage) assessed in all Aims.