RECEPTOR GENE TRANSCRIPTION IN HUNTINGTONS DISEASE

描述：(逐字摘自申请者的摘要)最近亨廷顿的 疾病(HD)和其他三联体重复疾病被发现是由 突变基因中CAG密码子重复序列长度的扩展和 转基因这些突变的小鼠被创造出来。有害的、生化的 这种类型的突变的后果尚不清楚。有没有线索显示 因此，突变的生化效应可能是研究这种有毒物质的重要线索。 突变的后果。我们发现多巴胺D1和 D2、腺苷A2a和代谢型谷氨酸受体2的mRNA表达 三个品系的转基因小鼠HD基因外显子1的表达增加 多聚谷氨酰胺。观察到的受体mRNA的变化表明， 截短的HD蛋白改变基因转录。几乎没有其他生化变化 已在HD转基因小鼠中发现。因此，这是为数不多的线索之一 我们可以用来确定该病的病理机制。而受体 变化本身可能不会导致疾病，我们的数据强烈表明 受体的变化反映了一个关键的、有害的过程，可能包括 基因表达失调。此外，我们所发生的变化的幅度 发现(在症状前期小鼠中下降高达90%)提供了强大的读数 可用于机械学和治疗学研究。我们将确定 用信使核糖核酸水平测定这些变化的概括性和有效性 并鉴定了这些受体和对照受体的蛋白表达 HD转基因大脑皮层、纹状体、海马和小脑的神经元类型 和产仔对照小鼠以及死后症状前和 使用我们在过去15年中开发的技术来控制人脑； 双标记同位素和非同位素原位杂交，免疫印迹， 配体结合分析和免疫细胞化学。我们还将确定 这些变化与神经元核内发育的关系 包裹体。(Nii)在这些小鼠和人类HD中都看到了， 无论它们是否发生在转导突变HD基因的培养细胞中 在人类中，受体变化与CAG重复数相关的程度， 小鼠和培养的细胞。

DESCRIPTION: (Verbatim from the Applicant's Abstract) Recently Huntington's disease (HD) and other triplet repeat disorders were found to be caused by expansions in the length of CAG codon repeat stretches in the mutated genes and mice transgenic for these mutations were created. The deleterious, biochemical consequences of this type of mutation remain unknown. Any clues to the biochemical effects of the mutation may, therefore, be vital clues to the toxic consequences of the mutation. We have found striking changes in dopamine D1 and D2, adenosine A2a and metabotropic glutamate type 2 receptor mRNA expression in three strains of mice transgenic for exon 1 of the HD gene with increased polyglutamines. The observed changes in receptor mRNA suggest that the truncated HD protein alters gene transcription. Few other biochemical changes have been found in HD transgenic mice. As such, it is one of the very few clues we can use to determine the pathologic mechanism of the disease. While receptor changes may themselves not cause disease, our data strongly suggest that receptor changes reflect a crucial, deleterious process which may include dysregulation of gene expression. Further, the magnitude of the change we have found (up to 90% decrease in presymptomatic mice) provides a strong readout that can be used in mechanistic and therapeutic studies. We will determine the generalizability and validity of these changes by measuring the levels of mRNA and protein expression for these receptors and control receptors in identified neuronal types of cortex, striatum, hippocampus and cerebellum in HD transgenic and littermate control mice as well as post-mortem presymptomatic HD and control human brains using techniques we have developed over the last 15 years; double label isotopic and nonisotopic in situ hybridization, immunoblotting, ligand binding assays and immuno-cytochemistry. We also will determine the relationship of the changes to the development of the neuronal intranuclear inclusions. (NII) that have been seen in both these mice and in human HD, whether they occur in cultured cells transfected with the mutant HD gene and the degree to which receptor changes correlate with CAG repeat number in human, mouse and cultured cells.