Genetic and Epigenetic Analysis of Alcohol Self-Administration in Monkeys

描述（由申请人提供）：本提案研究了遗传变异和表观遗传修饰对灵长类动物HPA轴调节和过度饮酒的影响。这些研究将利用恒河猴乙醇自我给药模型，这将使纵向研究设计能够检查乙醇摄入前后12个月的基因组DNA甲基化，准确测量乙醇摄入量和内分泌水平，并获得血液和脑组织样本，以比较两种组织中的表观遗传变化。我们将使用全基因组方法来测量慢性乙醇消耗前后组织中的CpG甲基化水平。我们将测试甲基化水平的变化是否与基因表达的相应变化相关。我们还将测试血液中甲基化模式的变化是否与大脑中的变化平行。同样利用下一代测序技术的高效率，我们将在大量动物中对HPA轴和单胺信号通路的神经递质基因进行测序。我们将测试常见变异和内分泌功能障碍之间的关联，并将评估潜在的加性效应和多个信号通路中“风险”等位基因之间的相互作用。我们还将探讨特定等位基因或单倍型与慢性饮酒后甲基化变化（等位基因特异性甲基化）之间是否存在关联。总之，这些方法将为评估导致过度饮酒的累积遗传脆弱性提供全面的基础。由于非人类灵长类动物的密切进化关系，这些研究将与人类酒精中毒具有高度的翻译相关性，可能1）识别与酒精相关的基因表观遗传修饰，2）确定临床可及组织（血液）中表观遗传修饰与大脑中表观遗传修饰的相关性，3）为酒精使用障碍的未来治疗提出新的靶点。

DESCRIPTION (provided by applicant): This proposal investigates the implication of both genetic variation and epigenetic modification on HPA axis regulation and excessive alcohol consumption in primates. These studies will draw upon the rhesus macaque ethanol self-administration model, which will enable a longitudinal study design examining genomic DNA methylation before and after 12 months of ethanol consumption, accurate measure of ethanol intake and endocrine levels, and access to both blood and brain tissue samples for the comparison of epigenetic changes in both tissues. We will use whole-genome approaches to measure CpG methylation levels in the tissues before and after chronic ethanol consumption. We will test whether changes in methylation levels are associated with corresponding changes in gene expression. We will also test whether changes in methylation patterns in the blood parallel those found in the brain. Also taking advantage of the high efficiency of next generation sequencing technology, we will sequence neurotransmitter genes from the HPA axis and monoamine signaling pathways in a large cohort of animals. We will test the association between common variants and endocrine dysfunction, and will evaluate potential additive effects and interactions between "risk" alleles in multiple signaling pathways. We will also explore whether there is an association between specific alleles or haplotypes and changes in methylation following chronic alcohol consumption (allele-specific methylation). Together, these approaches will provide a comprehensive basis for evaluating the cumulative genetic vulnerabilities that contribute to excessive alcohol use. Owing to the close evolutionary relationship of non-human primates, these studies will have a high-degree of translational relevance to human alcoholism, potentially 1) identifying alcohol-linked epigenetic modification of genes, 2) determining the relevance of epigenetic modifications in a clinically accessible tissue (blood) to those in the brain and 3) suggesting novel targets for the future treatment of alcohol use disorders.