Project 1: Epigenetic control of transcription dynamics in long-term alcohol neuroadaptation

酒精成瘾是一种毁灭性的状况，通过持久的生理和行为适应而永久存在。 这些适应的核心是脑神经元基因表达的长期重排。 上瘾的人然而，酒精消费产生这种重排的机制 并导致行为的持久变化仍然没有解决。表观遗传组蛋白修饰最近 作为基因表达的重要调节剂出现，并被认为代表了转录的一种形式。 直接印在染色体上的记忆。一些组蛋白修饰通过以下方式影响转录： 调节底层DNA的可接近性，而其他的已经被提议用作标记， 转录因子作为“组蛋白密码”，有助于指定基因的表达水平。虽然影响 一些表观遗传修饰对基因转录活性的影响是众所周知的，但对表观遗传修饰的影响却知之甚少。 这些修改的时间动态及其对启动和维持的相对贡献 酒精诱导的转录变化。本申请的目的是调查时间的作用 作为长期功能性酒精耐受的基础的表观遗传调节剂-成瘾性的关键组成部分 过程在苍蝇中，单次酒精镇静诱导耐受表型，持续超过10天。这 表型是神经适应药物的直接产物，也引起同样持久的戒断 症状核心假设是，急性接触酒精会导致一系列持久的变化， 组蛋白修饰导致大脑转录组的重编程。不同的修改 据信对酒精耐受的起始和/或持久性具有明显的作用。为了验证这一 假设，这一建议结合了彻底检查组蛋白修饰的权力， 果蝇遗传学，以确定和表征表观遗传调制器，有助于时间 对酒精的耐受性。酒精诱导的组蛋白修饰的全面调查将在 在接触过酒精的苍蝇身上进行实验。将评估不同的时间点，以采集 酒精耐受表型的整个跨度。与此同时，独立的组蛋白修饰的活性 酶将在苍蝇神经系统中进行操纵，以确定它们对这种动力学的贡献。 表型。最后，在特定候选基因座处的表观遗传标记的靶向去除将在一个实施例中进行。 试图恢复对酒精的耐受性。实现这些目标将有助于确定和评估 表观遗传组蛋白修饰对酒精耐受性神经适应的时间作用 并将有助于理解酒精消费如何使表达的变化永久化， 促进成瘾。靶向这些调控机制而不是单个基因将导致更多的 扭转与毒瘾相关的全球酒精影响的有效治疗策略。

Alcohol addiction is a devastating condition perpetuated by enduring physiological and behavioral adaptations. At the core of these adaptations is the long-term rearrangement of neuronal gene expression in the brain of the addicted individual. However, the mechanisms by which alcohol consumption produces this rearrangement and leads to lasting changes in behavior remains unresolved. Epigenetic histone modifications have recently emerged as important modulators of gene expression and are thought to represent a form of transcriptional memory that is directly imprinted on the chromosome. Some histone modifications affect transcription by modulating the accessibility of the underlying DNA while others have been proposed to serve as marks read by transcription factors as a 'histone code' that helps to specify the expression level of a gene. While the effects of some epigenetic modifications on the transcriptional activity of genes is well known, little is known about the temporal dynamics of these modifications and their relative contribution to the initiation and maintenance of alcohol-induced transcriptional changes. The objective of this application is to investigate the temporal role of epigenetic modulators underlying long-term functional alcohol tolerance —a key component of the addictive process. In flies, a single alcohol sedation induces a tolerance phenotype that lasts over 10 days. This phenotype is a direct product of neural adaptations to the drug that also give rise to equally lasting withdrawal symptoms. The central hypothesis is that acute exposure to alcohol causes a sequence of lasting changes in histone modifications that lead to the reprogramming of the brain transcriptome. Different modifications are believed to have distinct effects on the initiation and/or the perdurance of alcohol tolerance. To test this hypothesis, this proposal combines a thorough examination of histone modifications with the power of Drosophila genetics to identify and characterize the epigenetic modulators that contribute to the temporal dynamics of tolerance to alcohol. A comprehensive survey of alcohol-induced histone modifications will be performed on flies that have been exposed to alcohol. Different time-points will be assessed in order to capture the entire span of the alcohol-tolerance phenotype. In parallel, the activity of independent histone modification enzymes will be manipulated in the fly nervous system to determine their contribution to the dynamics of this phenotype. Finally, targeted removal of epigenetic marks at specific candidate gene loci will be performed in an attempt to revert the development of tolerance to alcohol. Achieving these goals will help identify and evaluate the temporal role of epigenetic histone modifications on the neural adaptations that underlie alcohol tolerance and will contribute to the understanding of how alcohol consumption perpetuates changes in expression that promote addiction. Targeting these regulatory mechanisms rather than individual genes will result in a more effective therapeutic strategy for reversing global alcohol effects relevant to drug addiction.