Sites and Mechanisms of Ethanol Action in P2X receptors

P2X 受体中乙醇的作用位点和机制

• 批准号: 7434447
• 负责人: Daryl L Davies
• 金额: $ 31.23万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-15 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7434447
• 关键词: Address; Adenosine; Adenosine Triphosphate; Affect; Alcohol consumption; Alcohols; Amino Acids; Behavior; Behavioral; Brain; Cations; Cells; Characteristics; Cross-Over Studies; Development; Electrodes; Embryo; Ethanol; Experimental Designs; Facility Construction Funding Category; Family; Foundations; Future; Gated Ion Channel; Glutamates; Glycol; Goals; Hippocampus (Brain); Human; Hydrogen Bonding; Investigation; Ion Channel Gating; Kidney; Knock-in Mouse; Knockout Mice; Knowledge; Laboratories; Lead; Ligands; Link; Long-Term Potentiation; Measures; Mediating; Molecular; Molecular Target; Mutagenesis; Mutation; Neurons; Nicotinic Receptors; Nucleus Accumbens; P2X-receptor; Pain; Patch-Clamp Techniques; Pattern; Perception; Physiologic Thermoregulation; Physiological; Play; Preparation; Rattus; Recombinants; Reporting; Reverse Transcriptase Polymerase Chain Reaction; Role; Satiation; Segment Type; Sequence Alignment; Site; Spinal Ganglia; Staging; Synapses; System; Techniques; Testing; Ventilatory Depression; Work; Xenopus oocyte; alcohol behavior; alcohol effect; alcohol sensitivity; extracellular; gamma-Aminobutyric Acid; hydrophilicity; insight; molecular modeling; molecular site; mutant; patch clamp; receptor; receptor function; tripolyphosphate; voltage clamp

DESCRIPTION (provided by applicant): P2X receptors (P2XRs) constitute the most recently cloned superfamily of ligand-gated ion channels LGICs). P2XRs are fast acting, cation-permeable ion channels that are gated by synaptically released extracellular adenosine 5'-triphosphate (ATP) and are widely distributed in the CNS. Studies to date by our lab and others show that: 1) P2XRs mediate behaviors that are affected by ethanol; 2) P2XRs modulate activity in receptors systems believed to be targets mediating ethanol-induced behaviors; 3) Ethanol inhibits ATP-activated current in hippocampal and nucleus accumbens neurons; 4) Ethanol inhibits ATP-activation in wildtype P2XRs expressed in Xenopus oocytes and HEK 293 cells and 5) Sensitivity to ethanol of P2XRs is subunit dependent. These findings are consistent with the notion that ethanol-induced changes in P2XR function may directly or indirectly play a role in causing or modulating some ethanol behavioral effects. Definitive evidence must await development of selective P2XR antagonists and sufficient knowledge regarding the actions and molecular targets of ethanol in P2XRs. The current proposal addresses the latter by beginning to answer three key questions: 1) What recombinant P2XR subtypes are sensitive to ethanol? 2) What native P2XR subtypes are sensitive to ethanol? This will require comparing the pharmacological and electrophysiological characteristics of ethanol sensitive recombinant receptors expressed in Xenopus oocytes and HEK293 cells and native P2XRs in hippocampal and nucleus accumbens neurons and 3) What are the molecular sites/mechanisms of ethanol action in P2XRs? The proposed work likely will contribute foundation information that will lead to initial molecular models of sites of action for ethanol in P2XRs and will set the stage for future investigations that will use this knowledge to develop knock in and null mutant ("knock out") mice that can be used to test the roles that specific P2XRs play in mediating physiological and behavioral effects of ethanol.

描述（由申请人提供）：P2X受体（P2XRs）构成了最近克隆的配体门控离子通道lgic超家族。P2XRs是一种快速作用的阳离子渗透离子通道，由突触释放的细胞外腺苷5'-三磷酸（ATP）门控，广泛分布于中枢神经系统。迄今为止，我们和其他实验室的研究表明：1)P2XRs介导受乙醇影响的行为；2) P2XRs调节被认为是介导乙醇诱导行为靶点的受体系统的活性；3)乙醇抑制海马和伏隔核神经元atp激活电流；4)乙醇抑制爪蟾卵母细胞和HEK 293细胞中表达的野生型P2XRs的atp激活；5)P2XRs对乙醇的敏感性是亚基依赖性的。这些发现与乙醇诱导的P2XR功能变化可能直接或间接地在引起或调节某些乙醇行为效应中起作用的观点一致。明确的证据需要等待选择性P2XR拮抗剂的开发和对乙醇在P2XR中的作用和分子靶点的充分了解。目前的提案通过回答三个关键问题来解决后一个问题：1)哪些重组P2XR亚型对乙醇敏感？2)哪些原生P2XR亚型对乙醇敏感？这将需要比较非洲蟾卵母细胞和HEK293细胞中表达的乙醇敏感重组受体与海马和伏隔核神经元中的天然P2XRs的药理学和电生理特性。3)乙醇作用于P2XRs的分子位点/机制是什么？拟议的工作可能会提供基础信息，这将导致乙醇在P2XRs中的作用位点的初始分子模型，并将为未来的研究奠定基础，这些研究将利用这些知识开发敲入和零突变（“敲除”）小鼠，这些小鼠可用于测试特定的P2XRs在调节乙醇的生理和行为效应中所起的作用。