Elucidating the biophysics of pre-fibrillar, toxic tau oligomers: from amino acid motifs to neuronal dysfunction

阐明前原纤维有毒 tau 寡聚体的生物物理学：从氨基酸基序到神经元功能障碍

基本信息

批准号：
10461322
负责人：
Jonathan N Sachs
金额：
$ 52.44万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-30 至 2023-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10461322
关键词：
AMPA Receptors Affect Alzheimer&apos s Disease Alzheimer&apos s disease related dementia Amino Acid Motifs Amino Acid Sequence Binding Biochemical Biological Assay Biophysics Biosensor Brain CASP2 gene Catalogs Cell model Cells Cognitive Cognitive deficits Complex Cryoelectron Microscopy Data Dendritic Spines Disease Distress Electrostatics Enzymes Event Feedback Fluorescence Fluorescence Resonance Energy Transfer Goals Human Image Investigation Label Lead Length Medicine Molecular Structure Monitor Morphologic artifacts Mus Nature Neurobiology Neurofibrillary Tangles Neuronal Dysfunction Neurons Paper Pathologic Pathology Phosphorylation Post-Translational Protein Processing Proteins Reagent Research Research Personnel Resolution Structure Tauopathies Technology Testing Therapeutic Toxic effect Translating Work alpha synuclein base biophysical analysis comorbidity design dopaminergic neuron experimental study induced pluripotent stem cell inhibitor/antagonist mutant neuron loss non-Native novel novel strategies orientation selectivity paired helical filament prevent protein protein interaction small molecule small molecule inhibitor tau Proteins tau aggregation tau interaction tau mutation tau phosphorylation therapeutic target tool virtual

项目摘要

Abstract One of the most pressing questions in the study of Alzheimer’s disease (AD) and related dementias (ADRD) is how alterations in the amino-acid sequence of tau, along with post-translational modifications (PTMs) such as phosphorylation and cleavage, lead the protein to misfold and disrupt normal neuronal function. While much has been learned over decades of rigorous and focused research, there are currently no disease modifying therapies to treat AD or related tauopathies. Recently, the field has begun a complicated but promising shift from targeting large tau fibrils (e.g. PHFs and NFTs) to disrupting smaller, non-fibrillar tau oligomers. While late-stage tau fibrils have been studied extensively—including a flurry of recent high-resolution cryo- EM structures—there are few tools to study early-stage oligomers, especially in cells. As a result, almost nothing is known about 1) early misfolding events that produce toxic, non-fibrillar tau oligomers; nor 2) how these oligomers co-opt protein machinery to cause cellular distress. To begin to fill this void, our 2019 Alzheimer’s & Dementia paper established a set of high-resolution, lifetime-FRET based biosensors that monitor full-length tau oligomers in cells. Here, we present compelling preliminary data showing that these biosensors can delineate which folding motifs in the fibril structures, as well as PTMs, most affect early-stage tau oligomers. These biosensors have also enabled us to study two distinct pathological tau interactions in cells. First, co- Investigators Karen Ashe and Kathryn Nelson’s 2016 Nature Medicine paper showed that cleavage of tau by caspase-2 (Casp2) causes tau to mislocalize to dendritic spines, shut down AMPA receptors and promote cognitive defects in mice. We show intriguing evidence to suggest a complex feedback loop between cleavage, oligomerization and toxicity. Second, tau and alpha-Synuclein (aSyn) have well-known co-morbidity in multiple Alzheimer’s Disease related dementias, but the biophysics of their interaction in early-stage misfolding is poorly understood. We provide preliminary evidence of a preferred binding orientation between tau and aSyn, suggesting a stable and hence targetable binding motif. The two major goals of this proposal are to: 1) determine which structural motifs revealed in the available tau fibril structures, and which PTMs, contribute most to early-stage oligomerization in cells, and to pathology; and 2) to characterize and inhibit two pathogenic tau interactions: tau/Casp2 and tau/aSyn. In Aim 1, we analyze the recently available fibril structures and ask: how can these structures be used to unravel otherwise elusive structural details of non-fibrillar tau oligomers? Additionally, to deepen the impact of our investigations, and with the help of co-Investigator Shauna Yuan, we will develop new lines of iPSC-derived human cortical dopaminergic neurons expressing our biosensors. Then, in Aims 2 and 3, we study the biophysical interplay between tau oligomerization and toxicity of tau/Casp2 and tau/aSyn respectively. In each case, we will also perform high- throughput small-molecule screens to identify potent inhibitors of these two pathological, oligomeric assemblies.

抽象的阿尔茨海默氏病（AD）和相关痴呆症（ADRD）中最紧迫的问题之一是tau的氨基酸序列的改变以及翻译后修饰（PTM）尽管有很多磷酸化和裂解，但导致蛋白质折叠和破坏诺尔呋喃的呋喃呋喃的呋喃呋喃的呋喃呋喃子呋喃的呋喃呋喃呋喃子呋喃的呋喃子呋喃已经学到了数十年来的严格和专注的研究，目前有点头疗法为了治疗广告或相关的tauopathies，该领域已经开始大的tau原纤维（例如PHF和NFTS）破坏了较小的非纤维tau低聚物。后期tau beense beense beense the最近的高分辨率冷冻 - EM结构 - 研究阶段的低聚物，尤其是在细胞中，几乎没有任何工具。大约是1）产生有毒的非纤维tau低聚物的早期错误事件；寡聚物的蛋白质机制会引起细胞障碍。痴呆症纸建立了一组高分辨率的基于寿命的生物传感器，可监视全长tauuuu 细胞中的低聚物。在原纤维结构中以及PTM中折叠基序最多影响早期的Tau Olimers。这些生物传感器还使我们能够研究细胞中的两个不同的病理tau相互作用。调查人员Karen Ashe Ashe Ashe Kathryn Nelson的2016年自然医学论文表明，Tau的裂解 caspase-2（CASP2）导致tau误倒在树突状旋转，关闭AMPA受体并促进小鼠的认知缺陷。寡聚和毒性。阿尔茨海默氏病与痴呆有关的痴呆症，但是它们在早期错误折叠中相互作用的生物物理学很差理解。提示可供应，因此可以靶向结合基序。该提议的两个专业是：1）确定可用的tauuu中揭示了哪些结构图案原纤维结构和PTMS在细胞和病理学中对早期寡聚的贡献最大。 2）表征和抑制两种致病性tau相互作用：tau/casp2和tau/asyn。最近可用的原纤维结构，并询问：这些结构如何被解开否则难以捉摸非纤维tau低聚物的结构细节，以加深我们的研究的影响在共同投资者Shauna Yuan的帮助下，我们将开发IPSC衍生的人皮质多巴胺能的新线条然后，在AIM 2和3中表达我们的生物传感器。 tau/casp2和tau/asynzpective的寡聚和毒性。吞吐量的小分子筛选，以识别这两个病理性的寡聚组件的有效吸入者。