Brain endorphin targets of low dose alcohol

低剂量酒精的大脑内啡肽目标

• 批准号: 9265712
• 负责人: M. FOSTER OLIVE
• 金额: $ 36.79万
• 依托单位: ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-19 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9265712
• 关键词: Acute; Affinity; Alcohol abuse; Alcohol consumption; Alcohols; Attenuated; Blood; Brain; Consumption; Data; Dependency; Development; Dose; Endorphins; Ethanol; Female; Gated Ion Channel; Genes; Genetic Transcription; Goals; Hypothalamic structure; Impaired cognition; Intoxication; Legal; Ligands; Medical; Methods; Molecular; Molecular Target; Mus; Nature; Neurons; Nucleus Accumbens; Peptides; Pro-Opiomelanocortin; Procedures; Proteins; Rattus; Rewards; Self Administration; Societies; Specificity; Structure of nucleus infundibularis hypothalami; System; Testing; Transgenic Mice; Viral; alcohol effect; cell type; cost; desensitization; drinking; drug of abuse; endogenous opioids; enhanced green fluorescent protein; extracellular; male; neural circuit; neurochemistry; novel; promoter; protein function; public health relevance; research study; socioeconomics; transmission process; voltage

ABSTRACT The precise molecular targets of ethanol action in the brain have remained elusive for decades, primarily as a result of the transient and low-affinity nature of ethanol interactions with specific proteins or other cellular components. The endogenous opioid system has been implicated in the rewarding, reinforcing, motivational, and neurochemical effects of drugs of abuse, including ethanol. We have previously demonstrated that acute ethanol administration in rats significantly increases extracellular endorphin levels in the nucleus accumbens (NAc). We have also generated novel preliminary data indicating that immunoneutralization of -endorphin in the NAc shell subregion, but not the core, attenuates low dose ethanol self-administration. These findings suggest that endorphinergic transmission in the NAc shell contributes to the motivational effects of low dose ethanol. Finally, we utilized transgenic mice that express enhanced green fluorescent protein (EGFP) under the control of the promoter for the -endorphin precursor peptide pro-opiomelanocortin (POMC), to assess the potential activation of these neurons by low dose ethanol. We observed that in these POMC-EGFP mice, low dose ethanol consumption in the drinking-in-the-dark paradigm resulted in brain and blood ethanol levels <10 mM, and activated POMC-expressing neurons in the arcuate nucleus of the hypothalamus (ArcN). Collectively, these data indicate that brain POMC/endorphin systems are molecular targets of low dose ethanol. However, additional studies are needed to test our overarching hypothesis that ArcN POMC-expressing neurons are a target of low dose ethanol in the brain. To accomplish this, we have formulated the following inter-related yet independent Specific Aims. In Aim 1, we will further characterize the ability of low dose ethanol to activate ArcN POMC-expressing neurons. POMC-EGFP mice will be tested in the drinking-in-dark paradigm to determine the dose-dependency, specificity, and desensitization of ethanol-induced activation of ArcN POMC-expressing neurons. In Aim 2, we will determine the accumbal targets of ArcN POMC-expressing neurons activated by low dose ethanol. This will be accomplished by the use of Cre-dependent viral retrograde tracing methods in POMC- Cre mice. Finally, in Aim 3, we will determine the molecular adaptations in ArcN POMC-expressing neurons that occur following low dose ethanol consumption. This will be accomplished by utilizing POMC-Cre Ribotag mice to determine cell-type specific changes in RNA expression of biologically related genes induced by low dose ethanol consumption. To increase the translational impact of these studies, all proposed experiments will utilize both male and female subjects, and ethanol intake procedures that allow voluntary consumption as opposed to passive administration by an experimenter. Together, these studies will ultimately guide the development of pharmacological or other approaches for inactivating the effects of ethanol in the brain, which may ultimately reduce the medical, socioeconomic and legal costs of ethanol abuse to society.

摘要 几十年来，乙醇在大脑中作用的精确分子靶点仍然难以捉摸，主要是作为一种药物。 这是乙醇与特定蛋白质或其他细胞因子相互作用的瞬时和低亲和力性质的结果。 件.内源性阿片系统与奖赏、强化、动机、 和滥用药物的神经化学影响，包括乙醇。我们以前已经证明，急性 大鼠乙醇给药显著增加了延髓核中细胞外内啡肽水平 （NAc）。我们还产生了新的初步数据，表明β-内啡肽的免疫中和作用， NAc壳亚区而不是核减弱了低剂量乙醇的自我给药。这些发现 表明NAc壳内的内啡肽能传递有助于低剂量的激发效应 乙醇最后，我们利用了转基因小鼠，这些转基因小鼠表达增强型绿色荧光蛋白（EGFP）， 控制β-内啡肽前体肽前体阿黑皮素（POMC）的启动子，以评估 这些神经元被低剂量乙醇潜在激活。我们观察到，在这些POMC-EGFP小鼠中， 在黑暗中饮酒的剂量乙醇消耗导致脑和血液乙醇水平<10 mM，并激活下丘脑弓状核（ArcN）中的POMC表达神经元。总的来说， 这些数据表明脑POMC/内啡肽系统是低剂量乙醇的分子靶点。然而，在这方面， 需要更多的研究来验证我们的总体假设，即表达ArcN POMC的神经元是一个神经元。 低剂量乙醇的目标。为了实现这一目标，我们制定了以下相互关联的 独立的具体目标。在目标1中，我们将进一步表征低剂量乙醇激活ArcN的能力 POMC表达神经元。POMC-EGFP小鼠将在黑暗中饮水的范例中进行测试，以确定POMC-EGFP小鼠在黑暗中饮水的能力。 乙醇诱导的ArcN POMC表达激活的剂量依赖性、特异性和脱敏 神经元在目标2中，我们将确定低浓度的多巴胺激活的表达ArcN POMC的神经元的靶点。 剂量乙醇。这将通过在POMC中使用Cre依赖性病毒逆行追踪方法来实现。 Cre小鼠。最后，在目标3中，我们将确定表达ArcN POMC的神经元的分子适应， 发生在低剂量乙醇消耗之后。这将通过使用POMC-Cre Ribotag小鼠来实现 确定低剂量诱导的生物学相关基因RNA表达的细胞类型特异性变化 乙醇消费为了增加这些研究的转化影响，所有拟议的实验都将利用 男性和女性受试者，以及允许自愿消费的乙醇摄入程序， 实验者的被动给药。总之，这些研究将最终指导 药理学或其他方法来灭活乙醇在大脑中的作用，这可能最终 减少乙醇滥用给社会带来的医疗、社会经济和法律的成本。