Opiate drug abuse & HIV-induced excitotoxicity in striatal neurons

阿片类药物滥用

• 批准号: 8586520
• 负责人: Sylvia Fitting
• 金额: $ 11.02万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-12-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8586520
• 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; Complex; Corpus striatum structure; DRD2 gene; Defect; Dendrites; Dendritic Spines; Doctor of Philosophy; Drug abuse; Electrons; Engineering; Event; Functional disorder; Genetic; Glutamates; Grant; HIV; HIV-1; Homeostasis; Image; In Vitro; Individual; Injury; Interruption; Ion Channel; Ions; Knockout Mice; Knowledge; 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; public health relevance; receptor; research study; skills; synergism; voltage

DESCRIPTION (provided by applicant): 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 wil 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.

描述（由申请人提供）：注射阿片类药物的HIV-1感染者表现出认知缺陷增加，并加速进展为艾滋病。越来越多的证据表明，阿片类药物滥用本质上加剧了艾滋病毒-1的发病机制。我们已经发现，神经元死亡之前，突触淘汰，功能丧失，和树突病理假定是可逆的一个延长的时间。重要的是，阿片类药物滥用通过协同增加树突病理学（静脉曲张形成，串珠，碎片化，修剪），同时促进附加树突棘损失（可塑性），从而增强HIV-1的神经发病机制。这已经在纹状体的中型多刺神经元（MSN）中得到证实，并且突触修剪已经在电子显微镜下得到证实。此外，在没有明显神经元死亡的情况下，运动活动中的行为缺陷伴随着突触损失和树突病理学，这表明亚致死性神经元损伤和突触连接减少是阿片类药物加重HIV-1相关神经系统疾病（HAND）的能力的基础。虽然死亡本身是重要的，但在神经元死亡之前中断事件可能在治疗上更具策略性。该基金将通过研究阿片类药物+/-HIV诱导的兴奋性毒性的潜在生理机制，重点研究MSN的功能水平。据推测，达特诱导细胞内稳态和MSN的兴奋性的变化，阿片类药物通过涉及OR介导的途径的复杂事件序列加剧了这种变化。通过评估阿片类药物和HIV-1 Tat诱导的神经毒性在分离的皮质-纹状体细胞培养物中的作用，提出了体外方法。全细胞膜片钳记录将通过评估动作电位以及钠、钾、AMPA、NMDA和钙（Ca 2+）电流以电压钳和电流钳模式进行。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）策略来阐明，以确定阿片类药物+ HIV蛋白相互作用的机制。为了弄清楚阿片类药物是否通过OR加重达特在纹状体中对MSN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。在关键位点上删除OR将定义阿片类药物加剧纹状体中神经元兴奋性（动作电位、离子通道活性、离子成像、线粒体膜电位）、损伤（包括树突病理学和棘密度）和行为缺陷（运动活性）的靶点和相关机制。