Preventing Tau uptake by novel inhibitors of tau binding to LRP1

项目摘要 几种神经退行性疾病，如阿尔茨海默病（AD），其特征在于扩散和 蛋白质tau的聚集。Tau聚集体或神经元缠结（NFT）在整个大脑中积累 导致老年痴呆症。目前对于tau蛋白病没有有效的治疗。这些方法， 已经考虑过，如tau抗体和反义寡核苷酸，直接靶向tau。的复杂性 然而，tau细胞生物学的研究使得这种方法具有挑战性。一个全新的方法是利用 tau蛋白扩散途径的一部分NFT的扩散与疾病进展相关，可能是一种介导因素 观察到的神经毒性。最近，我们发现了一种细胞受体，LRP 1（低密度脂蛋白 受体相关蛋白1），调节tau扩散途径。LRP 1的敲除防止tau扩散 在人类iPS神经元和小鼠大脑中，这表明tau-LRP 1相互作用可能是一个重要的机制。 疾病干预的切入点。因此，本项目的主要目标是识别小分子 阻止tau蛋白与LRP 1结合的化学探针，假设这些分子 作为新疗法的关键起点。在初步工作中，我们已经确定了主要的相互作用 并开发了TR-FRET高通量筛选（HTS）测定来鉴定 能破坏这种相互作用的化合物。我们已经将测定优化为1536孔格式，并进行了 中试筛选了5，000种性能优异的化合物，Z '~ 0.7，命中率~ 0.4%。分析20 在初级、人工和正交试验中，来自该筛选的命中鉴定了几种化合物， 剂量反应的效力。为了充分开展这项工作，我们提出三个目标。在目标1中，我们将使用TR-FRET 分析以筛选420，000个化学文库，并且并行地进行44亿个化学文库的亲和筛选。 利用DELopen平台（WuXi AppTec）的成员DNA编码文库。在目标2中，我们将缩小我们的打击范围 选择使用正交和新的生化分析测定，以确定作用机制。最后在 目标3：我们将使用先进的生物物理和基于细胞的检测来验证命中。我们希望我们的多管齐下 这一方法将确定具有不同作用机制的多种化学系列。后续命中扩展 我们将努力生产具有适合于测试我们的假设的性质的化学探针，小分子LRP 1-tau 抑制剂可以阻止tau摄取和扩散。在未来的研究中，我们打算将这些探针开发成药物， 防止tau蛋白病如AD中的tau蛋白扩散。由于关键路径测试漏斗已经到位，我们预计， 可以快速获得和评估体外选择性命中，探索它们的活性，并最终探索它们作为 这是电极导线碰撞研究的起点，也是未来在动物模型和最终患者中进行体内评价的起点。

PROJECT SUMMARY Several neurodegenerative diseases, such as Alzheimer's disease (AD), are characterized by the spread and aggregation of the protein tau. Tau aggregates or neurofibrillary tangles (NFTs) accumulate throughout the brain of patients and lead to dementia. No effective treatments currently exist for tauopathies. Those approaches that have been considered, such as tau antibodies and antisense oligonucleotides, directly target tau. The complexity of tau cell biology, however, makes this approach challenging. A completely novel approach is to take advantage of the tau spreading pathway. The spread of NFTs correlate with disease progression and is a likely mediator for the observed neurotoxicity. Recently, we identified a cellular receptor, LRP1 (Low-density lipoprotein Receptor-related Protein 1), that regulates the tau spread pathway. Knockdown of LRP1 prevents tau spread in human iPS neurons and the mouse brain, suggesting that the tau-LRP1 interaction could be an important entry point for disease intervention. Therefore, the main objective of this project is to identify small-molecule chemical probes that prevent the binding of tau to LRP1, with the hypothesis that these molecules would serve as key starting points for novel therapeutics. In preliminary work, we have identified the primary interaction surface for tau on LRP1 and have developed a TR-FRET high-throughput screening (HTS) assay to identify compounds that can disrupt this interaction. We have optimized the assay to 1536-well format and conducted a pilot screen of 5,000 compounds with excellent performance, Z'~0.7 and a hit rate of ~0.4%. Analysis of the 20 hits from this screen in primary, artifact, and orthogonal assays identified several compounds with modest potency in dose response. To fully develop this work, we propose three aims. In Aim 1, we will use the TR-FRET assay to screen a 420,000 chemical library and, in parallel, conduct an affinity screen of a 4.4-billion- member DNA encoded library leveraging the DELopen platform (WuXi AppTec). In Aim 2, we will narrow our hit selection using orthogonal and novel biochemical profiling assays to determine mechanism of action. Finally, in Aim 3 we will validate hits with advanced biophysical and cell-based assays. We expect our multi-pronged approach will identify multiple chemical series with different mechanisms of action. Subsequent hit expansion efforts will produce chemical probes with properties suitable to test our hypothesis that small molecule LRP1-tau inhibitors can prevent tau uptake and spread. In future studies we intend to develop these probes into drugs that prevent tau spreading in tauopathies such as AD. As the critical path testing funnel is in place, we anticipate we can rapidly obtain and evaluate selective in vitro hits, explore their activity, and ultimately their suitability as starting points for hit-to-lead studies and for future in vivo evaluation in animal models and eventually patients.