Determining the role of AR transcriptional function in SBMA

许多神经退行性疾病，包括阿尔茨海默氏症、帕金森氏病和 多发性谷氨酰胺病，由多种遗传和/或基因引起的蛋白质错误折叠和堆积引起 环境原因。脊髓和延髓肌萎缩症(SBMA)是一种成人起病的遗传性疾病。 由雄激素受体(AR)内的多聚谷氨酰胺膨胀引起的神经肌肉疾病；它是 与聚谷氨酰胺扩张引起的其他神经退行性疾病有关，包括亨廷顿氏症 疾病和几个脊髓小脑性共济失调。尽管通向神经元的确切路径 功能障碍和死亡尚不清楚，这些疾病的转基因小鼠和细胞模型的评估 已经对疾病的发病机制产生了机械论的见解。SBMA与其他聚谷氨酰胺不同 疾病的发生和发展依赖于AR雄激素配体。我们的细胞和老鼠 SBMA模型复制了雄激素和多谷氨酰胺依赖的核AR聚集 患者，以及由此产生的毒性，使这些模型对分析 AR毒性上游事件的机制基础。我们小组和其他人之前的研究 结果表明，AR的核定位、N/C相互作用、磷酸化和乙酰化都是 它的聚集和毒性所需的。通过遗传学或药理学方法抑制上述每一步 操纵可防止突变的AR聚集及其毒性。值得注意的是，抑制这些步骤中的每一步 也可以防止AR转录活性，突显了理解SBMA的一个中心问题 AR转录活性在疾病发病机制中的作用。虽然早期对果蝇的研究 SBMA的模型支持这种作用，但对哺乳动物系统的研究表明并非如此。回答这个问题 这一重要问题对开发有效的治疗方法至关重要。我们建议通过这份申请来 通过使用新的细胞，回答AR转录活性在SBMA中的作用这一中心问题 和动物模型，并使用这些模型来研究介导疾病的分子途径。 我们预测，我们提议的研究将揭示AR转录活动在 疾病的发病机制，并为SBMA的理想治疗方向提供强有力的见解。要实现 在这些目标中，我们提出了三个具体目标：1)确定AR DNA结合在疾病中的作用 活体，使用新的SBMA基因敲入小鼠模型；2)评估DNA结合在细胞中的作用 SBMA模型；以及3)使用这些模型来识别常见的致病途径 突变AR相互作用蛋白的转录图谱和定量分析。我们预料到 这些研究结果将使我们对SBMA的分子发病机制有一个新的认识。 并加强我们对SBMA新疗法的开发。

Many neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease and the polyglutamine diseases, result from protein misfolding and accumulation due to a variety of genetic and/or environmental causes. Spinal and bulbar muscular atrophy (SBMA) is an adult-onset, inherited neuromuscular disease that is caused by polyglutamine expansion within the androgen receptor (AR); it is related to other neurodegenerative diseases caused by polyglutamine expansion, including Huntington's disease and several spinocerebellar ataxias. Although the precise pathway leading to neuronal dysfunction and death is unknown, the evaluation of transgenic mouse and cell models of these diseases has yielded mechanistic insights to disease pathogenesis. SBMA stands apart from other polyglutamine diseases in that its onset and progression are dependent on AR androgenic ligands. Our cell and mouse models of SBMA reproduce the androgen- and polyglutamine-dependent nuclear AR aggregation seen in patients, as well as its consequent toxicity, making these models highly useful for the analysis of the mechanistic basis for upstream events involved in AR toxicity. Previous studies from our group and others revealed that the nuclear localization, N/C interaction, phosphorylation and acetylation of the AR are all required for its aggregation and toxicity. Inhibiting each of these steps through genetic or pharmacological manipulation prevents mutant AR aggregation as well as its toxicity. Notably, inhibition of each of these steps also prevents AR transcriptional activity, highlighting a central question in the understanding of SBMA pathogenesis of the role of AR transcriptional activity in disease. While earlier studies in a Drosophila model of SBMA supported such a role, studies in mammalian systems suggest otherwise. Answering this important question is critical to the development of effective therapies. We propose with this application to answer this central question of the role of AR transcriptional activity in SBMA, through the use of novel cell and animal models, and to use these models to investigate the molecular pathways that mediate disease. We predict that our proposed studies will reveal further details about the role of AR transcriptional activity in disease pathogenesis and provide robust insights into ideal therapeutic directions in SBMA. To achieve these goals, we propose three specific aims: 1) To determine the role of AR DNA binding in disease, in vivo, using novel, genetic knock-in mouse models of SBMA; 2) To evaluate the role of DNA binding in cell models of SBMA; and 3) To use these models to identify common pathogenic pathways through transcriptional profiling and quantitative analysis of mutant AR-interacting proteins. We anticipate that results from these studies will lead us to a new understanding of the molecular pathogenesis of SBMA and enhance our development of new therapies for SBMA.