Drivers of Pathological Tau Aggregation

项目总结 倒立疗法发展的瓶颈是缺乏有效的倒立疗法模型，无论是小鼠、细胞还是体外。 这反映在目前的现实中，通过冷冻-EM从尸检中解决了自闭症特有的纤维结构 患者的脑组织从未在患者外复制过，也就是说，没有在小鼠、细胞或体外复制。当病人- 衍生的脊椎病原纤维提供了关键的目标，它们本身并不是可行的治疗靶点。为 例如，用于诊断和跟踪阿尔茨海默病的正电子发射断层扫描(PET)配体的开发 (AD)或皮质基底性变性(CBD)疾病的进展依赖于筛选与CBD结合的小分子。 AD-表型纤维--目前还没有人知道如何构建这种结构。还有更多的因素需要考虑 复制tau聚集的病理途径，但复制疾病表型tau纤维是最小的 和必要的要求，而且到目前为止还是治疗发展的工具。主要的知识差距是 这项提议旨在关闭在体外复制牛磺酸特异性纤维的机制和工具(目标1)， 以及启动细胞内tau错误折叠的关键细胞和分子因素对疾病表型的影响 并促进聚合(目标2)。如果我们能成功复制任何一种表型tau折叠，甚至 折叠的tau结构的一部分，例如具有播种能力的CBD或AD的微型发夹折叠，它将具有 对正在进行的治疗开发产生直接影响，例如对开发特异型PET配体， 抗体和小分子药物。该团队将使用一套创新的结构生物学工具，包括 脉冲双电子-电子共振(DEER)、透射电子显微镜和低温电子显微镜，以及要重点研究的计算工具 捕获tau蛋白从其固有的无序到 部分折叠和完全收敛的纤丝态。该团队将同时使用创新的细胞生物学工具和 了解专门的tau受体和转运蛋白可以通过以下方式促进tau的播种 内体逃逸和对tau局部环境疏水性增强的认识是一个强有力的因素 以启动错误折叠、聚合和繁殖。在发现合格种子的定义属性的同时 利用该方案中开发的种子实现形状繁殖将是一项突破，与此无关 如果成功，我们将开发实验和计算工具来评估种子形状 是否发生了传播，或者是否传播了全部、部分或不传播任何形状。有工具来评估 形状传播机制将改变游戏规则。在关闭上述项目方面缺乏进展 知识差距不是由于世界各地的顶尖实验室缺乏投资，而是由于缺陷 现有的概念和工具。韩和科西克以及谢伊将依靠他们各自的融合 使用创新的工具解决指压疗法研究中长期存在的问题，并进行协调一致的努力。

PROJECT SUMMARY The bottleneck for tauopathy therapy development is the lack of validated tauopathy models, mouse, cell or in vitro. This is reflected in the current reality that tauopathy-specific fibril structures solved by cryo-EM from post mortem patient brain tissue have never been replicated outside a patient, i.e. not in a mouse, cell or in vitro. While the patient- derived tauopathy fibrils offer critical goal posts, they are not in and of themselves viable therapeutic targets. For example, the development of Positron Emission Tomography (PET) ligands to diagnose and track Alzheimer’s disease (AD) or corticobasal degeneration (CBD) disease progression relies on screening small molecule binding to CBD- or AD-phenotypic fibrils—the very construct that nobody knows how to build yet. There are many more factors to consider for replicating the pathological pathway of tau aggregation, but replicating disease phenotypic tau fibrils is a minimal and necessary requirement, and so far an unattained tool for therapy development. The major knowledge gap that this proposal aims to close is the mechanism and tools to replicate tauopathy specific fibrils in vitro (Aim 1), and the key cellular and molecular factors that initiate misfolding of tau in cell to disease phenotypic shapes and facilitate aggregation (Aim 2). If we can successfully replicate any one tauopathy-phenotypic tau fold, or even a part of a folded tau structure, such as a mini-hairpin fold of CBD or AD with seeding competency, it will have an immediate impact on ongoing therapy developments, such as on the development of tauopathy-specific PET ligands, antibodies and small molecule drugs. This team will employ an innovative set of structural biology tools encompassing pulsed double electron-electron resonance (DEER), TEM and cryo-EM, as well as computational tools to focus on capturing the full folding and aggregation pathway of the tau protein ensemble from its intrinsically disordered to partially folded and fully converged fibril states. This team will concurrently use innovative cell biological tools with a strong premise of the knowledge of a dedicated tau receptor and transporter that can enhance tau seeding by endosomal escape and the knowledge that enhanced hydrophobicity of the local environment of tau is a potent factor to initiate misfolding, aggregation and propagation. While discovering the defining property of a competent seed and achieving shape propagation with seeds developed in this proposal will be a breakthrough, independent of this success, we will have developed experimental and computational tools to evaluate whether seeded shape propagation has occurred, or whether all, part, or none of the shape propagates. To have the tools to evaluate the mechanism of shape propagation will be a game changer. The lack of progress in closing the above-described knowledge gap is not due to a lack of investment by top notch laboratories around the world, but due to shortcomings of existing concepts and tools. Han and Kosik, together with Shea, will rely on the convergence of their respective fields and investing concerted effort using innovative tools to address long-standing questions in tauopathy research.