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

 描述（由申请人提供）：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（如TRiC）的功能网络，其负责正常蛋白质的正确折叠以及受损和遗传异常蛋白质的重新折叠或启动破坏。来自模型系统的令人信服的证据支持这样的观点，即蛋白质稳态网络可以被调节以改善由负责神经退行性疾病的毒性蛋白质种类所呈现的细胞挑战的结果。然而，迄今为止，还没有基于任何原理（包括伴侣蛋白网络的调节）开发出用于任何神经退行性疾病的有效治疗干预。这项建议的重点是开展一项综合调查计划，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稳态的相互作用。 该网络与通过减少生产和/或提高清除率来减少这些物质积累的转化方法有关。在这样做时，该应用程序解决了拦截即将到来的神经退行性疾病流行病的关键社会目标。我们选择了典型的神经退行性疾病亨廷顿病和TRiC伴侣蛋白网络作为我们计划的重点，这是基于我们团队的强有力的数据，即TRiC复合物组分对模型系统中突变HTT诱导的表型提供了明确的有益作用。在这个项目中，我们提出了3个综合项目和2个支持核心，以研究mHTT-TRiC伴侣蛋白相互作用，并确定选择TRiC相关成分如何促进或减少mHTT驱动的发病机制。指导该提议的假设是TRiC在调节毒性形式的扩增重复HTT蛋白的积累中起关键作用，因此增加TRiC和TRiC衍生蛋白的活性将消除和/或逆转mHT相关的发病机制。我们提出了以下四个总体具体目标：目标1：表征在体外和离体条件下以及在HD模型细胞和神经元中TRiC试剂与异常形式的mHTT之间的相互作用。目的2：研究现有和新型TRiC试剂对mHTT物质的产生和积累以及细胞蛋白质稳态的影响。目的3：系统评价TRiC试剂对细胞培养中神经元功能和存活的影响。目标4：通过定量测量神经元结构、功能和病理学，系统评价和比较TRiC试剂治疗对HD小鼠模型的影响。我们的计划将为基于TRiC的其他神经退行性疾病（包括AD，PD，ALS或FTD）治疗策略的研究扩展提供一个框架。虽然我们的提案将集中在基于TRiC的治疗方法上，但我们的分析可能指向与TRiC合作调节mHTT效应的伴侣分子的参与，并为HD和相关疾病的其他新方法开辟了可能性。

 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.