Epigenetics underlies long-term risk of relapse during abstinence

描述(由申请人提供)：遗传和环境因素在酒精中毒等复杂疾病的发展中都起着至关重要的作用。不幸的是，在确定戒酒过程中改变的潜在分子机制以帮助开发维持清醒的新疗法方面进展甚微。我们提出了一种基因、分子、药理学和行为相结合的策略来确定戒酒一段时间后改变的途径。慢性酒精滥用会导致脑结构、可塑性和基因表达的神经适应，但这些表达差异在戒酒者中的稳定性存在争议。我们之前曾报道过，在一段确定的戒酒期内，前额叶皮质(PFC)的通路发生了变化，PFC是与酗酒者认知功能障碍和损害相关的大脑区域。为了表征遗传贡献，分析了选择性育种产生的对酒精反应差异很大的动物模型--戒断癫痫抵抗(WSR)和易戒断癫痫(WSP)系的性别。在持续禁欲期间，转录反应与戒断表型相关，而与性别无关。生物信息学分析表明，在WSR和WSP小鼠之间发生变化的主要途径中，最具二型性的是‘乙酰化’和‘组蛋白脱乙酰酶复合体’。数据显示，禁欲期间存在复杂的表型特异性调节，这表明在低反应WSR小鼠中存在广泛的表观遗传重编程，但在暴露于相同浓度乙醇的高反应WSP小鼠中不存在。我们将通过整合来自高通量靶向技术的数据，包括表达谱分析、DNaseI-seq和ChIP-seq，在我们建立的依赖诱导复发饮酒模型中确认参与使用药物干预调节复发的途径，从而在三个特定目标中识别低反应动物模型中的表型特异性调控机制。我们假设，有针对性的表观遗传机制在禁欲期间保持表达差异，这些差异增加了对酒精内表型反应低的患者复发的风险。这些研究具有很高的影响力，因为与酗酒有关的发病率/死亡率、普通人群中酒精使用障碍的高发生率以及这些疾病对人类健康的巨大影响。此外，神经适应性改变和表达模式的改变也可能在戒酒过程中持续的神经毒性和脑损伤中发挥作用，从而对学习和记忆功能产生不利影响，从而在成瘾的下行循环和酒精中毒的自我维持性质中发挥作用。因此，成功完成这些目标将有助于我们理解复发风险的潜在机制(S)，并通过识别新的药物疗法，提高我们为针对低反应内表型的酒精滥用提供治疗的能力，或加强对现有治疗方法的翻译应用，这些治疗方法具有以前未知的效用。

DESCRIPTION (provided by applicant): Both genetic and environmental contributions have crucial roles in the development of a complex disease such as alcoholism. Unfortunately, little progress has been made in identifying the underlying molecular mechanisms altered during abstinence to aid development of novel therapeutics for the maintenance of sobriety. We propose a combined genetic, molecular, pharmacological and behavioral strategy to identify pathways that are altered after a period of abstinence. Neuroadaptations in brain structure, plasticity and gene expression occur with chronic alcohol abuse, but the stability of these expression differences in the abstinent alcoholic is controversial. We have previously reported identification of pathways altered in prefrontal cortex (PFC), a brain region associated with cognitive dysfunction and damage in alcoholics, during a defined period of abstinence. To characterize genetic contributions, both sexes of an animal model with widely divergent responses to alcohol derived by selective breeding, the Withdrawal Seizure-Resistant (WSR) and Withdrawal Seizure-Prone (WSP) lines, were analyzed. During a sustained period of abstinence, the transcriptional response correlated with withdrawal phenotype rather than sex. Bioinformatic analysis showed that among the major pathways altered that were the most dimorphic between WSR and WSP mice were 'acetylation' and 'histone deacetylase complex'. Data shows a complex phenotype-specific regulation during abstinence indicating widespread epigenetic reprogramming in the low response WSR but not the high response WSP mice exposed to the same ethanol concentrations. We will identify phenotype-specific regulatory mechanisms in the low response animal model in three specific aims by integrating data from high-throughput targeting technologies including expression profiling, DNaseI-seq and ChIP-seq, with confirmation of involvement of pathways to modulate relapse using pharmacological intervention in our established dependence-induced relapse drinking model. We hypothesize that targetable epigenetic mechanisms maintain expression differences during abstinence and that these differences increase the risk of relapse in the low response to alcohol endophenotype. These studies have high impact because of the morbidity/mortality associated with alcohol abuse, the high incidence of alcohol use disorders in the general population, and the tremendous impact these maladies have on human health. In addition, neuroadaptive changes and altered expression patterns may also play a role in persistent neurotoxicity and brain damage during abstinence with detrimental consequences for learning and memory functions, to play a role in the down-ward cycle of addiction and the self-sustaining nature of alcoholism. Thus, successful completion of these aims will aid in our understanding of the mechanism(s) underlying the risk for relapse and advance our ability to provide therapy for alcohol abuse targeted to the low response endophenotype, through identification of novel pharmacotherapies or to enhance translational applications for currently available therapeutics with previously unrecognized utility.