Regulation of responses to alcohol by the SWI/SNF chromatin remodeling complex

项目摘要 个体对乙醇的初始反应水平（LR）（他们的幼稚敏感性）是高度遗传的，LR 强烈预测终身负债发展酒精依赖。因此，调节LR的基因是 这些是重要的研究目标，但尽管进行了深入的研究，对它们的了解仍然很少。一个限制是 很难将我们对影响模式生物反应水平的基因的了解应用于 在人类基因关联研究中识别易感位点。在这里，我们解决这个问题的开始， 候选基因最初是在人类研究中确定的，并通过使用遗传模型来定义生物学特征。 这些基因可能调控LR和随后的滥用倾向的机制。最近，等位基因 SWI/SNF染色质重塑蛋白复合物成员的变异与 诊断人类酒精依赖。本提案的目的是阐明 该复合物控制乙醇反应，并且由于SWI/SNF复合物调节转录， 确定介导这些效应的下游基因。我们研究的是 SWI/SNF影响神经元对乙醇的反应，使用遗传模式生物，小杆线虫 优雅C.秀丽线虫是这些研究的一个很好的模型，因为在线虫之间存在着惊人的保守性。 人类和蠕虫的神经系统功能，有丰富的遗传资源， 实验性地操纵蠕虫的神经系统功能。C.优雅的行为是受相关的 剂量的乙醇，而改变蠕虫乙醇反应的基因也会改变乙醇反应，包括 哺乳动物的饮水行为我们已经发现，改变SWI/SNF复合物的功能， C. elegans改变了对乙醇的急性行为反应，表明SWI/SNF在修饰 乙醇的作用是保守的。我们将确定特定的神经元和神经回路， SWI/SNF复合物是急性乙醇反应所必需的，这将涉及特定的神经递质 这些功能中的系统。第二，我们将使用全基因组表达分析来识别基因， 由SWI/SNF复合物在分化的神经元中调节;这些将是急性炎症介质的候选者。 乙醇反应。最后，我们将使用遗传和行为分析来识别基因， 负责对乙醇的急性行为反应，并确定生物学机制， 它们调节乙醇反应。总之，这些研究将为生物学提供新的见解。 调节对乙醇的反应水平的过程，这是一种可预测 酒精依赖重要的是，这项工作还将提供新的候选基因的责任位点，可以 在人群中检查与酒精依赖倾向的关系。

PROJECT SUMMARY An individual's initial level of response (LR) to ethanol (their naïve sensitivity) is highly heritable, and LR strongly predicts lifetime liability to develop alcohol dependence. The genes that regulate LR are therefore important targets for study, but despite intense investigation, they remain poorly understood. One limitation is that it has been difficult to apply what we learn about the genes affecting level of response in model organisms to identifying liability loci in human gene association studies. Here, we solve this problem by beginning with candidate genes initially identified in human studies and by using a genetic model to define the biological mechanisms by which these genes are likely to regulate LR and, subsequently, abuse liability. Recently, allelic variation in members of the SWI/SNF chromatin-remodeling protein complex has been associated with a diagnosis of alcohol dependence in humans. The goal of this proposal is to elucidate the mechanism by which this complex controls ethanol responses, and, because the SWI/SNF complex regulates transcription, to determine the downstream genes that mediate these effects. We study the molecular mechanisms by which SWI/SNF influences the neuronal response to ethanol using the genetic model organism, Caenorhabditis elegans. C. elegans is an excellent model for these studies, because there is striking conservation between the machinery of nervous system function in humans and worms, and there are rich genetic resources available to experimentally manipulate nervous system function in worms. C. elegans behavior is affected by relevant doses of ethanol, and genes that modify ethanol responses in worms also modify ethanol responses, including drinking behavior, in mammals. We have found that altering the function of the SWI/SNF complex in C. elegans alters acute behavioral responses to ethanol, demonstrating that the role of SWI/SNF in modifying the effects of ethanol is conserved. We will determine the specific neurons and neural circuits in which the SWI/SNF complex is required for acute ethanol responses, which will implicate specific neurotransmitter systems in these functions. Second, we will use whole genome expression analysis to identify genes that are regulated by the SWI/SNF complex in differentiated neurons; these will be candidates for mediators of acute ethanol responses. Finally, we will use genetic and behavioral analysis to identify the genes that are responsible for the acute behavioral response to ethanol, and determine the biological mechanisms by which they regulate ethanol responses. Together, these studies will provide novel insight into the biological processes that regulate the level of response to ethanol, a phenotype that is predictive of the development of alcohol dependence. Importantly, this work will also provide new candidate genes for liability loci that can be examined in human populations for association with liability to develop alcohol dependence.