Determining the role of AR transcriptional function in SBMA

许多神经退行性疾病，包括阿尔茨海默病，帕金森病和 多聚谷氨酰胺疾病是由多种遗传和/或基因突变引起的蛋白质错误折叠和积累引起的。 环境原因。脊髓延髓肌萎缩症（SBMA）是一种成人发病，遗传性， 一种由雄激素受体（AR）内多聚谷氨酰胺扩增引起的神经肌肉疾病， 与多聚谷氨酰胺扩增引起的其他神经退行性疾病相关，包括亨廷顿病 疾病和几种脊髓小脑共济失调。虽然导致神经元 功能障碍和死亡是未知的，这些疾病的转基因小鼠和细胞模型的评价 对疾病的发病机理有了深入的了解。SBMA不同于其他聚谷氨酰胺 这些疾病的发病和进展依赖于AR雄激素配体。我们的细胞和老鼠 SBMA模型再现了在1999 - 2000年的研究中观察到的雄激素和多聚谷氨酰胺依赖的核AR聚集。 患者，以及随之而来的毒性，使这些模型非常有用的分析， AR毒性上游事件的机制基础。我们小组和其他人以前的研究 揭示了AR的核定位、N/C相互作用、磷酸化和乙酰化都是 需要它的聚集和毒性。通过遗传或药理学抑制这些步骤中的每一个 操纵防止突变体AR聚集以及其毒性。值得注意的是，抑制这些步骤中的每一个 也阻止AR转录活性，突出了理解SBMA的中心问题 AR转录活性在疾病中的作用的发病机制。虽然早期对果蝇的研究 SBMA模型支持这种作用，但哺乳动物系统中的研究表明并非如此。回答这个 这个重要的问题对于开发有效的治疗方法至关重要。我们在此申请中建议， 通过使用新的细胞，我们回答了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，我们提出的研究将进一步揭示AR转录活性在细胞凋亡中的作用。 疾病的发病机制，并提供了强大的见解SBMA的理想治疗方向。实现 为了实现这些目标，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， 体内，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的模型;以及3）使用这些模型通过以下途径识别常见的致病途径： 突变AR相互作用蛋白的转录谱和定量分析。我们预计 这些研究结果将使我们对SBMA的分子发病机制有新的认识 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.