Opiate drug abuse & HIV-induced excitotoxicity in striatal neurons

阿片类药物滥用

基本信息

批准号：
9064737
负责人：
Sylvia Fitting
金额：
$ 24.65万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-01-01 至 2018-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9064737
关键词：
AMPA Receptors Acquired Immunodeficiency Syndrome Action Potentials Affect Behavioral Breeding CTOP Calcium Cell Culture Techniques Cells Cessation of life Coculture Techniques Cognitive deficits Complex Corpus striatum structure DRD2 gene Defect Dendrites Dendritic Spines Doctor of Philosophy Drug abuse Electrons Electrophysiology (science)Engineering Event Functional disorder Genetic Glutamates Grant HIV HIV-1 Homeostasis Image In Vitro Individual Injury Interruption Ion Channel Ions Knockout Mice Knowledge LoxP-flanked allele Mediating Membrane Membrane Potentials Mentors Mitochondria Molecular Morphine Motor Activity Mus N-Methyl-D-Aspartate Receptors N-Methylaspartate Neurocognitive Deficit Neuronal Injury Neurons Neuropathogenesis Opiates Opioid Opioid Receptor Outcome Measure Pathogenesis Pathology Pathway interactions Pharmaceutical Preparations Phase Physiological Potassium Property Proteins Research Role Site Sodium Sorting - Cell Movement Synapses Techniques Testing Therapeutic Training Varicosity Vertebral column base biophysical properties cell type cellular imaging connective tissue-activating peptide density drug abuser electrical property excitotoxicity functional loss in vivo mitochondrial membrane mouse Cre recombinase naltrindole nervous system disorder neuron loss neuronal excitability neurotoxicity norbinaltorphimine opioid abuse patch clamp prevent receptor research study skills synergism voltage

项目摘要

Project Summary HIV-1 infected individuals who are injecting opioid drugs show increased cognitive defects and undergo an accelerated rate of progression to AIDS. Accumulating evidence suggests that opioid drug abuse intrinsically exacerbates the pathogenesis of HIV-1. We have found that neuronal death is preceded by a prolonged period of synaptic culling, functional losses, and dendritic pathology that are presumed reversible. Importantly, opioid abuse potentiates the neuropathogenesis of HIV-1 by synergistically increasing dendritic pathology (varicosity formation, beading, fragmentation, pruning), while promoting additive dendritic spine losses (plasticity). This has been verified in medium spiny neurons (MSN) of the striatum and synaptic pruning has been confirmed electron microscopically. Moreover, behavioral defects in locomotor activity are accompanied by synaptic losses and dendritic pathology in the absence of demonstrable neuron death, suggesting that sublethal neuronal injury and reduced synaptic connectivity underlie the ability of opioids to aggravate HIV-1-associated neurological disorders (HAND). While death per se is significant, the interruption of events preceding neuron death may be more strategic therapeutically. This grant will focus on the functional level of MSN by investigating the underlying physiological mechanisms of opioid ± HIV-induced excitotoxicity. It is hypothesized that Tat induces changes in the cellular homeostasis and excitability of MSN, that are exacerbated by opioid drugs through a complex sequence of events involving OR-mediated pathways. In vitro approaches are being proposed by assessing the effects of opioid drug and HIV-1 Tat-induced neurotoxicity in dissociated cortical- striatal cell cultures. Whole-cell patch-clamp recordings will be conducted in voltage- and current-clamp mode by assessing action potentials as well as sodium, potassium, AMPA, NMDA, and calcium (Ca2+) currents. The role of OR will be elucidated by applying pharmacological (OR antagonists), genetic (OR knockout mice) and silencing (silencing NMDAR) strategies to identify mechanisms underlying opioid + HIV protein interaction. To sort out whether opioids exacerbate the excitotoxic effects of Tat in the striatum via OR on MSN we will conduct experiments in vivo using two types of Cre-lox mice. Conditionally deleting OR at key sites will define the targets and associated mechanisms by which opioids exacerbate neuronal excitability (action potentials, ion channel activity, ion imaging, mitochondrial membrane potential), injury (including dendritic pathology and spine density), and behavioral defects (locomotor activity) in the striatum.

项目概要注射阿片类药物的 HIV-1 感染者表现出更多的认知缺陷并经历越来越多的证据表明阿片类药物滥用本质上加速了艾滋病的进展。我们发现神经元死亡之前会经历很长一段时间。突触剔除、功能丧失和树突病理学被认为是可逆的，重要的是，阿片类药物。滥用可通过协同增加树突病理学（静脉曲张）来增强 HIV-1 的神经发病机制形成、串珠、破碎、修剪），同时促进额外的树突棘损失（可塑性）。已在纹状体的中型多棘神经元（MSN）中得到验证，并且突触修剪已得到证实此外，运动活动的行为缺陷还伴随着突触。在没有明显神经元死亡的情况下损失和树突病理学，表明亚致死神经元损伤和突触连接减少是阿片类药物加重 HIV-1 相关性的基础神经系统疾病（HAND）虽然死亡本身很重要，但神经元之前的事件中断。死亡可能更具战略性的治疗作用。这笔资助将重点关注 MSN 的功能层面。研究阿片类药物±HIV引起的兴奋性毒性的潜在生理机制。 Tat 会引起细胞稳态和 MSN 兴奋性的变化，阿片类药物会加剧这种变化通过一系列复杂的事件，涉及 OR 介导的途径。通过评估阿片类药物和 HIV-1 Tat 诱导的分离皮质神经毒性的影响而提出纹状体细胞培养物将在电压和电流钳模式下进行全细胞膜片钳记录。通过评估动作电位以及钠、钾、AMPA、NMDA 和钙 (Ca2+) 电流。 OR 的作用将通过应用药理学（OR 拮抗剂）、遗传（OR 敲除小鼠）和沉默（沉默 NMDAR）策略以确定阿片类药物 + HIV 蛋白相互作用的潜在机制。通过 MSN 上的 OR 弄清楚阿片类药物是否会加剧纹状体中 Tat 的兴奋性毒性作用，我们将使用两种类型的 Cre-lox 小鼠进行体内实验，有条件地删除关键位点的 OR 将定义。阿片类药物加剧神经元兴奋性的目标和相关机制（动作电位、离子通道活性、离子成像、线粒体膜电位）、损伤（包括树突病理学和脊柱密度）和纹状体的行为缺陷（运动活动）。