From Structure to Therapy: The TRiC Chaperonin Network in Huntington's Disease

 描述(申请人提供)：针对蛋白质错误折叠和受损清除的主要细胞防御系统是伴侣蛋白质的功能网络，如TIRE，它既负责正常蛋白质的正确折叠，也负责尝试重新折叠或启动受损和遗传异常蛋白质的破坏。来自模型系统的令人信服的证据支持这样的观点，即蛋白质平衡网络可以被调节以改善导致神经退行性疾病的有毒蛋白质物种提出的细胞挑战的结果。然而，到目前为止，还没有开发出基于任何原理的针对任何神经退行性疾病的有效治疗干预措施，包括调节伴侣网络。这一建议的重点是执行一个综合调查计划，其目标是建立一个强有力的框架，在这个框架中，基础科学了解有毒物种的结构及其与蛋白质平衡的相互作用。 该网络与通过减少产量和(或)加强清除来减少这些物种积累的转换方法相联系。通过这样做，该应用程序解决了关键的社会目标，即拦截即将到来的神经退行性疾病的流行。我们选择了典型的神经退行性疾病亨廷顿病和TERE伴侣蛋白网络作为我们计划的重点，基于我们团队的强有力的数据，TICE复杂成分在模型系统中对突变的HTT诱导的表型提供了明显的有益影响。在这个项目中，我们提出了3个集成项目和2个支持核心，以研究mHTT分子伴侣蛋白的相互作用，并确定选择与mHTT相关的成分如何促进或减少mHTT驱动的发病机制。指导这一提议的假设是，TRIC在调节扩展的重复HTT蛋白的毒性形式的积累方面发挥关键作用，因此增加TRIC及其衍生蛋白的活性将消除和/或逆转mHTT相关的发病机制。我们提出了以下四个总的特异性目标：目标1：在体外和体外条件下，以及在HD模型细胞和神经元中，表征TIRE试剂与mHTT异常形式之间的相互作用。目的：研究现有的和新的TIRE试剂对mHTT物种的产生和积累以及细胞蛋白平衡的影响。目的：系统评价TIRE试剂对细胞培养中神经元功能和存活的影响。目的：通过对神经细胞结构、功能和病理的定量检测，系统评价和比较TIRE试剂治疗对HD小鼠模型的影响。我们的计划将为其他神经退行性疾病，包括AD，PD，ALS或FTD的基于TIC的治疗策略的扩展研究提供一个框架。虽然我们的提案将重点放在基于TRIC的疗法上，但我们的分析可能会指出，与TRIC合作的伴侣参与了mHTT效应的调节，并开启了治疗HD和相关疾病的新方法的可能性。

 DESCRIPTION (provided by applicant): The primary cellular defense system against protein misfolding and impaired clearance is the functional network of chaperone proteins, such as TRiC, which are both responsible for the proper folding of normal proteins and the attempt to refold or initiate destruction of damaged and genetically abnormal proteins. Compelling evidence from model systems supports the view that the proteostasis network can be modulated to improve the outcome of the cellular challenges presented by the toxic protein species responsible for neurodegenerative disease. However, to date, no effective therapeutic intervention for any neurodegenerative disease has been developed based on any principle including modulation of the chaperone network. This proposal is focused on carrying out an integrated program of investigation whose goal is to create a strong framework in which basic science understanding of the structure of toxic species and their interaction with the proteostasis network is linked to translational approaches to reduce the accumulation of these species through reduced production and/or enhanced clearance. In so doing, the application addresses the critical societal goal of intercepting the oncoming epidemic of neurodegenerative disorders. We have chosen the paradigmatic neurodegenerative disease Huntington's disease and the TRiC chaperonin network as the focus of our program, based on strong data by our team that TRiC complex components provide clear beneficial effects on mutant HTT-induced phenotypes in model systems. In this Program Project we propose 3 integrated Projects and 2 supporting Cores to investigate mHTT-TRiC chaperonin interactions and determine how select TRiC related components contribute to or reduce mHTT-driven pathogenesis. The hypothesis that guides the proposal is that TRiC plays a critical role in regulating the accumulation of toxic form of the expanded repeat HTT protein and hence increasing the activity of TRiC and TRiC-derived proteins will abrogate and/or reverse mHTT-linked pathogenesis. We propose the following four overall Specific Aims: Aim 1: To characterize the interactions between TRiC reagents and aberrant forms of mHTT under in vitro and ex vivo conditions as well as in HD model cells and neurons. Aim 2: To investigate the impact of existing and novel TRiC reagents on the production and accumulation of mHTT species and cellular proteostasis. Aim 3: To systematically evaluate the impact of TRiC reagents on neuronal function and survival in cell culture. Aim 4: To systematically evaluate and compare the impact of TRiC reagent therapy in mouse models of HD through quantitative measures of neuronal structure, function and pathology. Our program will provide a framework for the extension of the study of TRiC based therapeutic strategies for other neurodegenerative disorders, including AD, PD, ALS or FTD. While our proposal will focus on TRiC-based therapeutics, our assays may point to the participation of chaperones that partner with TRiC in regulating mHTT effects and open the possibility of additional novel approaches to HD and related disorders.