High throughput tau oligomer assay for drug screening for Alzheimer's disease

项目概述：阿尔茨海默病的疾病修饰药物有大量且快速增长的未满足需求。目前全球有1800万AD病例；到2025年，这一数字预计将增加到3400万。目前，只有5种轻度有效的阿尔茨海默病症状治疗药物存在，但没有一种治疗潜在的神经退行性过程。随着Tau蛋白在神经退行性疾病中的作用被越来越多地了解，它正成为疾病修饰药物（dmd）开发的一个更突出的靶标。tau蛋白MAPT基因的突变是痴呆的诱因，tau病理与AD的进展密切相关。与此同时，基于淀粉样蛋白假说的晚期临床治疗失败提出了仅针对A2的问题。强有力的证据表明，tau寡聚物在阿尔茨海默病和其他20多种神经退行性疾病的发病机制中起着直接作用（Brunden et al. 2008; Davidowitz et al. 2008）。为了发现靶向tau寡聚化的药物，研究人员开发了一种方法来选择抑制tau蛋白自相互作用的化合物，并选择了一种使用alphasgreen检测技术的检测方法来进一步开发高通量筛选（Chatterjee et al. 2008）。此外，Sierks博士（ASU）开发的噬菌体展示-原子力显微镜方法用于分离特异性结合tau寡聚物的抗体片段（scFvs），这些抗体片段将用于基于细胞的筛选试验。拟议计划的具体目标如下：“将tau寡聚物分析转换为HTS格式”将分析转移到密歇根高通量筛选中心（MHTSC）进行自动化和筛选高度优化的化合物库（100,000种化合物），并进行药物化学分析以模拟药效团并选择额外的化学型进行筛选“在基于细胞的分析中使用tau寡聚物特异性抗体片段选择化合物拟议的II期计划的预期结果是选择at至少三种或更多靶向tau寡聚物的先导候选化合物将在III期项目中开发，并在AD和tau病变的动物模型中进行评估。为了获得这一结果，高通量分析将被优化并转移到密歇根高通量筛选中心，在那里他们的大约10万种化合物的Select Set库将在Robert Kilkuskie博士的指导下进行筛选，Hits将被验证，并将开发一个结构药团模型。使用神经细胞毒性试验将消除有毒化合物。将以高灵敏度和特异性选择三种或更多的scFvs，这些scFvs将用于体外细胞检测来识别抑制tau自结合的化合物。抗体片段除了实现主要目标外，还支持公司的其他项目，包括其tau生物标志物开发项目和tau免疫治疗项目。然而，该项目的主要目标是推进tau寡聚物药物发现平台，以确定活性抑制剂作为IND启用研究的主要候选物。关键词阿尔茨海默病，tau病变，神经退行性疾病，药物发现，tau寡聚物，噬菌体展示，抗体片段，scFv，高通量筛选

DESCRIPTION (provided by applicant): High Throughput Tau Oligomer Assay for Drug Screening for Alzheimer's Disease Project Summary: There is a large and rapidly growing unmet need for disease modifying drugs for Alzheimer's disease. Currently there are 18 million cases of AD worldwide; by 2025 this number is expected to increase to 34 million. Presently, only 5 mildly effective AD symptom-treating drugs exist, but none that treat the underlying neurodegenerative processes. Tau is becoming a more prominent target for the development of disease- modifying drugs (DMDs), as its role in neurodegeneration is becoming better understood. Mutations in the gene for tau protein MAPT are causative of dementia and tau pathology correlates well with AD progression. At the same time, late stage clinical failures for therapeutics based on the amyloid hypothesis have raised questions on solely targeting A2. Strong evidence has emerged implicating tau oligomers as playing a direct role in disease pathogenesis for AD and over 20 other neurodegenerative diseases (Brunden et al. 2008; Davidowitz et al. 2008). To discover drugs targeting tau oligomerization methods were developed to select compounds inhibiting tau self-interaction, and an assay using AlphaScreen detection technology was selected for further development for high throughput screening (Chatterjee et al. 2008). In addition, the phage display- atomic force microscopy method developed by Dr. Sierks (ASU) was used to isolate antibody fragments (scFvs) specifically binding to tau oligomers that will be adopted in the cell based screening assays. The specific aims of the proposed program are as follows: " Convert the tau oligomer assay to HTS format " Transfer Assay to the Michigan High Throughput Screening Center (MHTSC) for automation and screening of a highly optimized compound library (100,000 compounds) and carry out medicinal chemistry analysis to model the pharmacophore and select additional chemotypes for screening " Select compounds using tau oligomer specific antibody fragments in cell based assays The anticipated outcome of the proposed Phase II program is the selection of at least three or more lead candidate compounds targeting tau oligomers that will be developed during the Phase III program and evaluated in animal models of AD and tauopathies. To attain this result, the high throughput assay will be optimized and transferred to the Michigan High Throughput Screening Center where their Select Set library of approximately 100,000 compounds will be screened under the direction Dr. Robert Kilkuskie Hits will be validated and a structural pharmacaophore model will be developed. Toxic compounds will be eliminated using a neurocytotoxicity assay. Three or more scFvs will be selected with high sensitivity and specificity that will be used to identify compounds inhibiting tau self-association using in vitro cell based assays. Antibody fragments, in addition to enabling the primary goal, are supportive of the company's other programs including its tau biomarker development program and its tau immunotherapeutic program. However, the primary goal of the program is to advance the tau oligomer drug discovery platform to identify active inhibitors as lead candidates for IND enabling studies. Key Words Alzheimer's disease, tauopathy, neurodegenerative disease, drug discovery, tau oligomer, phage display, antibody fragment, scFv, high throughput screening PUBLIC HEALTH RELEVANCE: The proposed program focuses on developing a high throughput screening assay targeting tau oligomers for drug discovery for Alzheimer's disease (AD). This project was inspired by observations that accumulation of tau oligomers has been shown to correlate well with neuronal loss and memory impairment in AD and in tauopathy mouse models. OLIGOMERIX has developed in vitro assays for screening compounds that inhibit the formation of cytotoxic tau oligomers. This program aims to 1.) .Convert the tau oligomer assay to HTS format; 2.) Transfer Assay to the Michigan High Throughput Screening Center (MHTSC) for automation and screening of a highly optimized compound library (100,000 compounds) and carry out medicinal chemistry analysis to model the pharmacophore; 3.) Select compounds using tau oligomer specific antibody fragments and cell based screening to identify lead candidates for future animal studies and pre-clinical development.