Mechanisms and effects of GABAbR dephosphorylation during ischemic excitotoxicity

描述(申请人提供)：亨廷顿病(HD)是一种神经退行性疾病，以衰弱的运动、认知和情绪症状为特征。它是由亨廷顿(Huntingtin，HTT)基因中显性遗传的CAG三联体重复扩增引起的，通过突变的HTT蛋白的毒性获得功能和干扰野生型HTT的关键功能而导致HD病理。这项建议旨在更好地阐明野生型人类HTT基因的表达是如何由与自闭症有关的人类特有的长非编码RNA(LncRNA)调控的，强调其在大脑中的潜在重要性。初步数据表明，lncRNA在人脑中的表达模式与HTT mRNA的区域浓缩模式相似，并且它在表达这两种人类基因的转基因小鼠中增加了人HTT的表达。细胞培养分析将研究htt基因中的内含子转座元件是否必要且充分地使其受到lncRNA的调节，并鉴定由lncRNA招募以增加htt转录的染色质重塑过程。然后将人类的lncRNA和htt基因在转基因小鼠中表达，以重建基因调控系统。在这些小鼠身上的实验将检验lncRNA表达对分子、细胞和行为过程的影响，这些过程由野生型HTT增强，而在HD模型中受到损害。具体地说，将在Morris水迷宫中检测神经元基因转录、细胞凋亡、小泡运动、焦虑样行为和认知功能。阐明这种控制野生型HTT表达的新的、原始人特有的机制将提供更深入的了解HD病理影响的正常功能，从而可能推动改进治疗的发展。

DESCRIPTION (provided by applicant): Huntington's disease (HD) is a neurodegenerative disorder marked by debilitating motor, cognitive, and emotional symptoms. It is caused by a dominantly inherited CAG triplet repeat expansion in the Huntingtin (HTT) gene, which gives rise to HD pathology both via toxic gains of function of the mutant HTT protein and interference with the critical functions of wild-type HTT. This proposal seeks to better elucidate how the expression of the wild-type human HTT gene is regulated by a hominid-specific long noncoding RNA (lncRNA) that has been linked to autism, highlighting its potential importance in the brain. Preliminary data indicate that the lncRNA is expressed in the human brain in a similar regional enrichment pattern as HTT mRNA, and that it increases human HTT expression in transgenic mice expressing both human genes. Cell culture assays will investigate whether an intronic transposable element in the HTT gene is necessary and sufficient to confer its regulation by the lncRNA, and to identify the chromatin remodeling processes that are recruited by the lncRNA to increase HTT transcription. The human lncRNA and HTT genes will then be expressed in transgenic mice to reconstitute the genetic regulatory system. Experiments in these mice will examine the effects of lncRNA expression on molecular, cellular, and behavioral processes that are enhanced by wild-type HTT and impaired in HD models. Specifically, neuronal gene transcription, apoptosis, vesicle motility, anxiety-like behaviors, and cognitive function in the Morris water maze will be assayed. Illuminating this novel, hominid-specific mechanism controlling the expression of wild-type HTT will provide a more thorough understanding of the normal functions that HD pathology impinges upon, and may thereby advance the development of improved therapies.