Huntington's Disease and the Striatum

此新修订的R01应用程序基于成功实现以前的R21版本的目标 例如，创建了亨廷顿病的“纹状体特异性”转基因小鼠模型。在……里面 Brief，这个小鼠模型，展示了中等刺状核包涵体，运动障碍，以及 转录失调。亨廷顿病(HD)是一种常染色体显性遗传性疾病 由编码亨廷顿蛋白(HTT)的IT15基因突变所致。这种突变由一个 以Gag重复序列(亨廷顿病)为特征的扩展聚谷氨酰胺(PolyQ)区域 协作研究小组，1993)，并且这种蛋白质在整个神经系统中表达 和外围设备。关于HD的病理生理学仍有许多问题，并回答了这些问题 问题对于指导治疗方法至关重要。与这项提议相关的这些问题 包括：1)突变型亨廷顿蛋白在纹状体神经元中的表达足以导致MSN功能障碍， 包括转录失调。纹状体特异的转录机制是什么？ 监管失调？2)纹状体脑源性神经营养因子(BDNF)功能丧失 成人突触后TrkB受体缺失会加剧小鼠模型中的HD表型？ 利用这种新的小鼠模型和基因表达所需的DMA序列的知识 在纹状体，我们将研究转录失调的机制，重点是 DARPP-32的乙酰化状态及其与纹状体特异性调控区的相互作用 基因，采用凝胶移位、超移位、染色质免疫沉淀等方法。使用基因工程技术 纹状体TrkB受体缺失的小鼠，我们将使用行为、形态和 分子检测确定BDNF/TrkB功能丧失是否加重HD 表型。纹状体特异转录调控的知识也将与其他 在转录失调中起作用的基底节疾病。 二、

This new, revised R01 application is based on the success in achieving the goals of a previous R21 award, i.e. the creation of a "striatal-specific" transgenic mouse model of Huntington's disease. In brief, this mouse model, demonstrates medium spiny nuclear inclusions, a motor disorder, and transcriptional dysregulation. Huntington's disease (HD) is an autosomal dominant disorder caused by a mutation in the IT15 gene encoding the protein huntingtin (htt). The mutation consists of an expanded polyglutamine (polyQ) region characterized by GAG repeats (The Huntington's Disease Collaborative Research Group, 1993), and the protein is expressed throughout the nervous system and periphery. Many questions remain as to the pathopnysiology of HD, and answering these questions is crucial to directing therapeutic approaches. Relevant to this proposal, these questions include: 1) Expression of mutant huntingtin in striatal neurons sufficient to produce MSN dysfunction, including transcriptional dysregulation. What are striatal-specific mechanisms of transcriptional dysregulation? And 2) Does loss of striatal brain-derived neurotrophic factor (BDNF) function via deletion of post-synaptic trkB receptors in the adult exacerbate an HD phenotype in a mouse model? Using this new mouse model and the knowledge of the DMA sequence required for gene expression in the striatum, we will investigate the mechanism of transcriptional dysregulation with a focus on acetylation status and protein interaction with striatal-specific regulatory regions of the DARPP-32 gene, using gel-shift, super-shift, and chromatin immunoprecipitation. Using genetically engineered mice with a deletion of the trkB receptor in the striatum, we will use behavioral, morphologic and molecular assays to determine whether or not BDNF/trkB loss of function exacerbates the HD phenotype. Knowledge of striatal-specific transcriptional regulation will also be highly relevant to other diseases of the basal ganglia in which transcriptional dysregulation plays a role. II.