Towards Mechanistic Explanations of Striatal Disorders

描述(由申请人提供)：本申请的主要目标是确定与正常和病理条件下纹状体功能相关的机制。纹状体是几种神经退行性疾病的主要功能障碍区域，如亨廷顿病和帕金森病，也与运动障碍和精神障碍有关。目前，这些疾病的治疗策略不是根治的，而是旨在减轻症状。因此，更好地了解促进纹状体功能的机制和途径是至关重要的。我们研究的逻辑是，在纹状体表达受限的mRNA分子可能编码优先与该区域特定生理过程相关的蛋白质。在具体目标1中，我们将使用系统化、自动化的mRNA显示技术TOGA(总基因表达分析)来鉴定和分离所有在纹状体中特异或丰富表达的已知基因。然后，我们将创建一个包含所有已知和新发现的纹状体富集物的cDNA微阵列芯片(100)。这将为我们提供一种DNA工具来分析各种病理条件下所有纹状体明显基因的表达状态。在本应用程序中，我们将重点介绍亨廷顿病(HD)的病理(尽管其他/未来的研究将调查其他纹状体疾病)。HD是一种遗传性神经退行性疾病，以进行性运动、精神和认知障碍为特征。在特定的目标2中，我们将通过从转基因HD小鼠的脑中筛选带有RNA的纹状体富集型DNA芯片来识别与HD相关的基因。这些小鼠表达人类HD基因的第一外显子，携带一个极其扩大的CAG重复序列。最后，我们将测试这一假设，即HD基因产物Huntingtin与纹状体中丰富的蛋白质相互作用，从而导致在这种疾病中观察到的组织特异性退变模式。我们将同时筛选所有富含纹状体的蛋白，以寻找与正常形式和突变形式的亨廷顿蛋白的特定相互作用。这将通过创建包含每个纹状体富含基因的GST融合蛋白的蛋白质微阵列芯片，然后用生物素化标记的亨廷顿蛋白进行探测来实现。这些研究中确定的分子可能成为新疗法的靶点，这些疗法将预防或减缓亨廷顿病的症状和进展，并很可能导致治愈这种和其他毁灭性的神经退行性疾病。这些潜在的药物靶点的一个重要优势是，它们只在受限制的表达部位纹状体起作用。

DESCRIPTION (provided by applicant): The broad goals of this application are to identify mechanisms associated with the functions of the striatum under normal and pathological conditions. The striatum is the primary region of dysfunction in several neurodegenerative disorders, such as Huntington's and Parkinson's diseases, and is also associated with movement disorders and psychiatric disturbances. Presently, treatment strategies for these disorders are not curative, but rather are aimed at reducing symptoms. Hence, a better understanding of the mechanisms and pathways that contribute to striatal function is essential. The logic that has motivated our studies is that mRNA molecules with restricted expression in the striatum are likely to encode proteins that are preferentially associated with particular physiological processes of this region. In Specific Aim 1, we will identify and isolate all known genes with specific or enriched expression in the striatum using the systematic, automated mRNA display technology TOGA (Total Gene expression Analysis). We will then create a cDNA microarray chip containing all known and newly discovered striatal-enriched species ( 100). This will provide us with a DNA tool for analyzing the expression status of all striatal-evident genes under various pathological conditions. In this application, we will focus on the pathology of Huntington's disease (HD), (although additional/future studies will investigate other striatum disorders). HD is an inherited, neurodegenerative disorder characterized by progressive motor, psychiatric, and cognitive disturbances. In Specific Aim 2, we will identify genes associated with HD by screening the striatal-enriched DNA chip with RNA from the brains of transgenic HD mice. These mice express exon 1 of the human HD gene carrying an extremely expanded CAG repeat. Finally, we will test the hypothesis that the HD gene product, huntingtin, interacts with proteins that are enriched in the striatum, hence, giving rise to the tissue-specific degenerative patterns observed in this disease. We will screen all striatum-enriched proteins simultaneously for specific interactions with both normal and mutated forms of the huntingtin. This will be achieved by creating a protein microarray chip containing GST-fusion proteins of each striatal-enriched gene and then probing with biotinylated-labeled huntingtin. The molecules identified in these studies could targets for novel therapies that would prevent or slow the onset of symptoms as well as the progression of Huntington's disease, and very well may lead to cures for this and other devastating neurodegenerative disorders. An important advantage of these potential pharmaceutical targets is that they would act only at the restricted site of expression, the striatum.