Transporter Mechanism of Amphetamine Sensitization

描述（由申请方提供）：本提案将首次提供苯丙胺（AMPH）致敏小鼠中苯丙胺（AMPH）诱导的多巴胺转运蛋白（DAT）和5-羟色胺转运蛋白（SERT）运输的表征和理解。在人类和实验室动物中反复使用AMPH会导致行为和神经化学敏感化，这可能是药物的激励突出性的基础，例如，“吸毒”了解药物对致敏动物的影响具有重要的临床意义，因为人类药物成瘾者通常已经对药物致敏，反复服用药物。由于AMPH通过与表面DAT结合来发挥其作用，DAT运输对于DAT底物（AMPH和多巴胺）作用的强度和持续时间很重要。DAT运输主要由DAT底物（例如AMPH）和D2 R激动剂（例如喹吡罗）诱导。AMPH也是SERT的底物，SERT在AMPH的增强和敏化中起重要作用。SERT运输受底物调节。在反复AMPH诱导的DAT和SERT运输的改变将影响多巴胺能和多巴胺能信号，这可能有助于AMPH敏化或耐受反复暴露后的细胞机制。这个建议将扩展我目前的非NIH资助的赠款，以分析三个具体的目标：1）在AMPH致敏与盐水处理的小鼠中表征AMPH和喹吡罗诱导的DAT内化和再循环，并确定PKC 2是否起作用; 2）确定重复AMPH是否会改变SERT运输并增强5-羟色胺流出，以及PKC 2是否起作用;和3）确定重复的AMPH是否改变了突触融合蛋白1A与DAT和SERT的结合。这将是第一项研究，调查DAT和SERT贩运在AMPH致敏状态的啮齿动物，并可能揭示不同阶段的药物反应在人类药物暴露和戒断期间。这项研究具有广泛的应用，因为DAT和/或SERT涉及许多其他神经精神疾病，如精神分裂症，双相情感障碍和抑郁症，这些疾病通常与药物滥用共病。1 公共卫生相关性：人类药物渴求和滥用是通过重复安非他明治疗诱导啮齿动物的安非他明致敏来模拟的。了解多巴胺转运体和5-羟色胺转运体在苯丙胺致敏动物模型中的转运，将为药物成瘾者药物致敏状态下的多巴胺能和5-羟色胺能信号转导提供相关信息，并为潜在的药物干预提供新的细胞途径。多巴胺和5-羟色胺运输中发现的变化也与精神分裂症、双相情感障碍和抑郁症有关，这些疾病通常与药物滥用共病。

DESCRIPTION (provided by applicant): This proposal will provide for the first time characterization and understanding of amphetamine (AMPH)- induced dopamine transporter (DAT) and serotonin transporter (SERT) trafficking in the AMPH sensitized mouse. Repeated AMPH in humans and laboratory animals leads to a behavioral and neurochemical sensitization which may underlie the incentive salience of drugs, e.g., "drug wanting". Understanding the effect of drugs on a sensitized animal is of significant clinical relevance given that human drug addicts, often already sensitized to drugs, repeatedly take drugs. Since AMPH exerts its effect by binding to surface DAT, DAT trafficking is important for the strength and duration of DAT substrate (AMPH and dopamine) action. DAT trafficking is primarily induced by DAT substrate (e.g. AMPH) and D2R agonist (e.g. quinpirole). AMPH is also a substrate for SERT, and SERT is importantly involved in AMPH reinforcement and sensitization. SERT trafficking is regulated by substrates. An alteration in repeated AMPH-induced DAT and SERT trafficking will affect dopaminergic and serotonergic signaling, which may contribute to the cellular mechanisms of AMPH sensitization or tolerance upon repeated AMPH exposure. This proposal will expand upon my present non-NIH funded grant to analyze three specific aims: 1) characterize AMPH- and quinpirole-induced DAT internalization and recycling in AMPH sensitized vs. saline- treated mice and determine whether PKC2 plays a role; 2) determine if repeated AMPH will alter SERT trafficking and enhance serotonin efflux, and whether or not PKC2 plays a role; and 3) determine if repeated AMPH alters syntaxin 1A association with DAT and SERT. This will be the first study to investigate DAT and SERT trafficking in AMPH sensitized state in rodents, and may shed light on different phases of drug responses in humans upon drug exposure and during withdrawal. This study has a broad application because DAT and/or SERT are implicated in many other neuropsychiatric diseases such as schizophrenia, bipolar disorder and depression, which are commonly comorbid with drug abuse. 1 PUBLIC HEALTH RELEVANCE: Human drug craving and abuse is modeled by amphetamine sensitization in rodents induced by repeated amphetamine treatment. Understanding the trafficking of dopamine transporter and serotonin transporter in the animal model of amphetamine sensitization will provide pertinent information about the dopaminergic and serotonergic signaling in the state of drug sensitization in drug addicts, and provide a new cellular avenue for potential drug intervention. The changes found in dopamine and serotonin trafficking will also be relevant to schizophrenia bipolar disorder and depression, which are often comorbid with substance abuse.