Preventing Tau uptake by novel inhibitors of tau binding to LRP1

项目总结 一些神经退行性疾病，如阿尔茨海默病(AD)，其特点是扩散和 蛋白tau的聚集。Tau聚集体或神经原纤维缠结(NFT)在整个大脑中积聚 并导致痴呆症。目前还没有有效的治疗方法来治疗肥胖症。这些方法 已经考虑过，例如tau抗体和反义寡核苷酸，直接针对tau。复杂性 然而，tau细胞生物学的研究使这种方法具有挑战性。一种全新的方法是利用 在tau扩散路径上。NFT的传播与疾病的进展相关，并可能是一种媒介 对于观察到的神经毒性。最近，我们发现了一种细胞受体，LRP1(低密度脂蛋白 受体相关蛋白1)，调节tau的传播途径。LRP1基因敲除可阻止tau扩散 在人类iPS神经元和小鼠脑中，表明tau-LRP1相互作用可能是一个重要的 疾病干预的切入点。因此，这个项目的主要目标是识别小分子 阻止tau与LRP1结合的化学探针，假设这些分子将服务于 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 并建立了一种tr-fret高通量筛选(HTS)方法来鉴定 可以破坏这种相互作用的化合物。我们已经将化验优化为1536孔格式，并进行了 中试筛选出5000种性能优良的化合物，Z‘~0.7，命中率~0.4%。20个国家的分析 从这个屏幕上点击的初级、人工制品和正交性分析确定了几种化合物 剂量反应的效力。为了充分开展这项工作，我们提出了三个目标。在目标1中，我们将使用tr-fret 以筛选420,000个化学库，同时进行44亿的亲和筛选- 利用DELOpen平台(无锡AppTec)的成员DNA编码库。在目标2中，我们将缩小命中范围 选择使用正交和新的生化图谱分析，以确定作用机制。最后，在 目的3我们将用先进的生物物理和基于细胞的分析方法来验证HITS。我们希望我们的多管齐下 该方法将确定具有不同作用机制的多个化学系列。随后的命中扩展 我们将努力生产具有适合测试我们假设的小分子LRP1-tau的化学探针 抑制剂可以防止tau的摄取和扩散。在未来的研究中，我们打算发展这些对药物的调查 防止tau在tauopy病中扩散，如AD。随着关键路径测试漏斗的到位，我们预计我们 可以快速获得和评估选择性的体外药物，探索它们的活性，并最终将它们的适合性作为 在动物模型和最终患者中进行Hit-to-Lead研究和未来体内评估的起点。

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.