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感染个体表明认知缺陷增加，并经历了加速艾滋病的进展率。积累的证据表明，阿片类药物滥用本质上加剧了HIV-1的发病机理。我们发现，神经元死亡是长时间的突触扣，功能损失和树突状病理，这些时期被认为是可逆的。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，珠子，片段化，修剪）来增强HIV-1的神经病生成，同时促进添加性树突状脊柱丧失（可塑性）。这已在纹状体的中刺神经元（MSN）中进行了验证，并已通过显微镜进行了突触修剪。此外，在没有明显的神经元死亡的情况下，运动活性中的行为缺陷伴随着突触损失和树突病理学，这表明共生神经元损伤和突触连通性的降低是阿片类药物加重HIV-1相关神经学疾病的能力。尽管死亡本身是重要的，但神经元死亡之前事件的中断可能更具战略性治疗。该赠款将通过研究阿片类药物+/- HIV诱导的兴奋性毒性的基本生理机制来关注MSN的功能水平。假设TAT会诱导细胞稳态的变化和MSN的兴奋性，而阿片类药物通过涉及或介导的途径的复杂事件序列加剧了MSN的兴奋性。通过评估阿片类药物和HIV-1 TAT诱导的神经毒性对解离的皮质 - 纹状体细胞培养物的影响，提出了体外方法。通过评估动作电位以及钠，钾，AMPA，NMDA和钙（Ca2+）电流，将在电压和电流夹模式下以电压和电流夹模式进行全细胞斑块钳记录。通过应用药理学（或拮抗剂），遗传（或基因敲除小鼠）和沉默（沉默的NMDAR）策略来识别阿片类药物 + HIV蛋白质相互作用的机制来阐明或将阐明其作用。为了弄清阿片类药物是否加剧了TAT在纹状体中通过MSN或MSN上的兴奋性毒性作用，我们将使用两种类型的Cre-lox小鼠在体内进行实验。有条件地删除或在关键位置删除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（包括树突状病理学和棘突密度）以及行为缺陷（包括树突状病理学和棘突）。