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

项目总结 个体对乙醇的初始反应水平(LR)(他们天真的敏感性)是高度可遗传的，而LR 强烈预测终生易患上酒精依赖。因此，调节LR的基因是 重要的研究目标，但尽管进行了密集的调查，人们对这些目标仍然知之甚少。其中一个限制是 很难将我们所了解到的影响反应水平的基因应用到模式生物中 在人类基因关联研究中识别易感基因座。在这里，我们从以下几个方面开始解决这个问题 最初在人类研究中确定的候选基因，并通过使用遗传模型来定义生物学 这些基因可能调节LR并随后导致滥用责任的机制。最近，等位基因 SWI/SNF染色质重塑蛋白复合体成员的变异与 人类酒精依赖的诊断。这项提议的目的是阐明通过什么机制 这种复合体控制乙醇的反应，并且因为SWI/SNF复合体调节转录，所以 确定调节这些影响的下游基因。我们研究了其分子机制。 SWI/SNF通过遗传模式生物--线虫影响神经元对乙醇的反应 优雅女装。线虫是这些研究的极好的模型，因为在 人类和蠕虫神经系统的运作机制，并有丰富的遗传资源可用来 在实验中操纵蠕虫的神经系统功能。线虫的行为受到相关因素的影响 剂量的乙醇，以及改变蠕虫中乙醇反应的基因也会改变乙醇反应，包括 哺乳动物的饮酒行为。我们发现，改变SWI/SNF复合体的功能 线虫改变对乙醇的急性行为反应，表明SWI/SNF在修饰中的作用 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 急性酒精反应需要SWI/SNF复合体，这将牵涉到特定的神经递质 系统在这些功能中发挥作用。其次，我们将使用全基因组表达分析来识别 受分化神经元中SWI/SNF复合体的调节；这些细胞将成为急性 乙醇反应。最后，我们将使用遗传和行为分析来识别 负责对酒精的急性行为反应，并确定其生物学机制 它们调节乙醇的反应。总之，这些研究将提供对生物学的新见解 调节对乙醇的反应水平的过程，这是一种预测糖尿病发展的表型 酒精依赖。重要的是，这项工作还将为易感基因座提供新的候选基因 在人群中检查是否与酒精依赖的易感性有关。

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.