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

描述（由申请人提供）：用于阿尔茨海默病药物筛选的高重复率Tau寡聚体测定项目概述：对于阿尔茨海默病的疾病修饰药物存在大量且快速增长的未满足需求。目前，全球有1800万例AD病例;到2025年，这一数字预计将增加到3400万例。目前，仅存在5种轻度有效的AD治疗药物，但没有一种治疗潜在的神经退行性过程。Tau正成为疾病修饰药物（DMD）开发的更突出的靶标，因为其在神经变性中的作用正变得更好理解。tau蛋白MAPT基因的突变是痴呆的原因，tau病理学与AD进展密切相关。与此同时，基于淀粉样蛋白假说的治疗的晚期临床失败提出了仅靶向A2的问题。已经出现了强有力的证据，表明tau寡聚体在AD和超过20种其他神经退行性疾病的疾病发病机制中发挥直接作用（Brunden et al. 2008; Davidowitz et al. 2008）。为了发现靶向tau寡聚化的药物，开发了选择抑制tau自身相互作用的化合物的方法，并选择使用AlphaScreen检测技术的测定法用于进一步开发高通量筛选（Chatterjee等人，2008）。此外，使用由Sierks博士（ASU）开发的噬菌体展示-原子力显微镜方法来分离将在基于细胞的筛选测定中采用的特异性结合tau寡聚体的抗体片段（scFv）。拟议方案的具体目标如下：“将tau寡聚体测定转换为HTS形式“将测定转移至密歇根高通量筛选中心（MHTSC），用于高度优化的化合物文库的自动化和筛选（100，000种化合物）并进行药物化学分析以模拟药效团并选择其他化学型进行筛选”在基于细胞的测定中使用tau寡聚体特异性抗体片段选择化合物所提出的II期计划的预期结果是选择至少三种或更多种靶向tau寡聚体的先导候选化合物，其将在III期计划期间开发并在AD和tau蛋白病的动物模型中进行评估。为了获得这一结果，将对高通量测定进行优化，并转移到密歇根州高通量筛选中心，在那里将在Robert Kilkuskie Hits博士的指导下筛选约100，000种化合物的Select Set文库，并将对结构药效团模型进行验证。毒性化合物将使用神经细胞毒性试验消除。将以高灵敏度和特异性选择三种或更多种scFv，其将用于使用基于体外细胞的测定来鉴定抑制tau自缔合的化合物。除了实现主要目标外，抗体片段还支持该公司的其他计划，包括tau生物标志物开发计划和tau免疫计划。然而，该计划的主要目标是推进tau寡聚体药物发现平台，以确定活性抑制剂作为IND使能研究的主要候选药物。关键词阿尔茨海默病，tau蛋白病，神经退行性疾病，药物发现，tau寡聚体，噬菌体展示，抗体片段，单链抗体，高通量筛选 公共卫生相关性：该计划的重点是开发一种针对tau寡聚体的高通量筛选方法，用于阿尔茨海默病（AD）的药物发现。该项目的灵感来自于观察到tau寡聚体的积累已被证明与AD和tau蛋白病小鼠模型中的神经元损失和记忆障碍密切相关。OLIGOMERIX开发了用于筛选抑制细胞毒性tau寡聚体形成的化合物的体外试验。该计划旨在1.）将tau寡聚体测定转化为HTS形式; 2.）将检测转移到密歇根高通量筛选中心（MHTSC），以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; 3.）使用tau寡聚体特异性抗体片段和基于细胞的筛选来选择化合物，以确定未来动物研究和临床前开发的主要候选物。

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.