Small Molecule Screen for Novel Regulators of Chaperone Expression

描述(申请人提供)：在亨廷顿病、阿尔茨海默病、帕金森病和肌萎缩侧索硬化症(ALS)的各种模型系统中，分子伴侣的高表达已被证明可以抑制蛋白质的错误折叠/聚集和毒性。与这些疾病相关的相应蛋白质的突变导致错误折叠的物种的出现，这些物种采用了替代的构象。这些观察导致了这样的假设，即突变的Huntingtin、tau、α-突触核蛋白和超氧化物歧化酶(SOD1)的一个共同特征是出现交替的折叠状态，这些状态自结合并形成有毒物种和蛋白质聚集体。分子伴侣因其识别和隔离受损和错误折叠物种的独特特性，为治疗学提供了有趣的靶点。因此，伴侣可能在蛋白质稳态中发挥核心作用，以防止长期错误折叠物种的有害后果，随着时间的推移，这种错误折叠会导致细胞发育不良和病理，就像神经退行性疾病和其他与蛋白质错误折叠相关的疾病所发生的那样。然而，由于伴侣在体内作为网络发挥作用，因此越来越明显的是，单独表达单个伴侣要么无效，要么远低于多个伴侣的协同表达以实现最大的网络功能。我们提出了三个具体的目标：目的1.建立热休克反应的小分子调节因子的初步筛选；目的2.鉴定HS基因表达和伴侣水平诱导的细胞毒性和动力学；以及目的3.在表达突变的Huntingtin和SOD1的细胞的二次检测中测试热休克反应的小分子调节因子。虽然我们的实验将只检查新型小分子伴侣蛋白表达调节器对神经退行性疾病模型系统的影响，但我们预计我们的结果可能会很好地扩展到与细胞质中错误折叠的蛋白质流量相关的其他病理。

DESCRIPTION (provided by applicant): Elevated expression of molecular chaperones has been shown to suppress protein misfolding/aggregation and toxicity in various model systems of Huntington's disease, Alzheimer's disease, Parkinson's disease, and Amyotrophic Lateral Sclerosis (ALS). Mutations in the respective proteins associated with these diseases results in the appearance of misfolded species that adopt alternate conformations. These observations have led to the proposal that a common feature of mutant huntingtin, tau, alpha-synuclein, and superoxide dismutase (SOD1) is the appearance of alternate folded states that self-associate and form toxic species and protein aggregates. Molecular chaperones offer intriguing targets for therapeutics because of their unique characteristic to recognize and sequester damaged and misfolded species. Consequently, chaperones may have a central role in protein homeostasis to prevent the deleterious consequences of chronic misfolded species, that, over time results in cell dysgenesis and pathologies as occurs in neurodegenerative diseases and other diseases associated with protein misfolding. However, because chaperones function in vivo as networks, it has also become increasingly evident that the expression of individual chaperones alone is either ineffective or much less effective than the coordinated expression of multiple chaperones to achieve maximal network functionality. We propose three Specific Aims: Aim 1. To establish a robust primary screen for small molecule regulators of the heat shock response; Aim 2. To characterize the candidates for cytotoxicity and kinetics of induction of HS gene expression and chaperone levels; and Aim 3. To test small molecule regulators of the heat shock response in secondary assays of cells expressing mutant huntingtin and SOD1. Although our experiments will only examine the consequences of novel small molecule regulators of chaperone expression on model systems of neurodegenerative disease, we anticipate that our results may well extend to other pathologies associated with the flux of misfolded proteins in the cytoplasm.