Small molecule inhibitors of hyperphosphorylated tau aggregation and cytotoxicity for the development of Alzheimer’s therapeutics

项目总结 阿尔茨海默病(AD)的神经退行性变越来越被认为是由阿司匹林的毒性引起的 过度磷酸化的tau聚集体，是脑内神经原纤维缠结(NFT)的主要成分 AD患者。绝大多数AD药物的开发工作都集中在抑制或清除Aβ斑块上。 到目前为止，这些努力在临床试验中都失败了。与β斑块相反，后者与疾病进展的相关性很差 研究AD临床症状、NFTs认知功能障碍的时空分布。越来越多的证据 提示过度磷酸化的tau蛋白的前聚集体对神经元是有毒的，并且可能起着关键作用。 阿尔茨海默病的神经退行性变。 多亏了一种名为PIMAX的产生磷酸化蛋白质的技术，这个项目将是第一个 筛选抑制过度磷酸化tau(hyper-p-tau)聚集的药物。到目前为止，超p-tau 没有足够的数量来筛选化合物文库。以前的项目筛选化合物 用于结合未磷酸化的tau，或tau的两个半胱氨酸基，或tau仅与1至3个磷酸盐结合。 作为我们的PIMAX生成的高-p-tau药物靶点，我们将使用tau亚型1N4R在多达16个氨基酸上磷酸化 残留物。在AD患者的大脑中，tau 1N4R过度磷酸化，这16个残基中有8个被用来 公元前的死后大脑。因此，由于我们独特的过度磷酸化目标，这个项目不会重复 以前的药物项目针对tau，取而代之的是发现tau抑制剂的开创性新方法 Tau聚集成神经毒性纤维。我们的初步数据显示，我们的新型小分子(JF 化合物)可以抑制高-p-tau 1N4R的聚集。我们迄今为止最有效的抑制剂，JF-19-73，剂量- 在体外依赖地拮抗高-p-tau 1N4R的寡聚体形成和神经元细胞毒性，提示 它对神经保护的潜力。JF-19-73比白藜芦醇更有效地抑制高p-tau 1NR4 聚合。JF化合物具有经典的药物属性(Lipinski等人的Rules Of Five)，表现出阳性 能够穿越血脑屏障的预测性分数，对细胞无毒。 目标1将优化JF化学的溶解性(例如，降低ClogP)，抑制形成细胞毒性高- P-tau 1N4R寡聚纤维，以及体外细胞保护作用。目标2将测试最有效的超p-tau聚集 在体外抑制ADME的性质，并为未来的临床前研究鉴定JF先导化合物，包括 动物实验和PK/PD实验。总体影响：阿尔茨海默病的神经退行性变越来越被接受为 过度磷酸化的tau聚集体的毒性。这个项目将使我们能够进入领先的发展阶段 使用针对过度磷酸化tau的优化JF衍生品进行编程-tau的形式实际上在 阿尔茨海默病患者的死后脑。这个项目是独一无二的，因为它是基于克服长期存在的 Tau药理学中的关键障碍-缺乏足够数量的过度磷酸化tau以满足高通量 放映。

PROJECT SUMMARY Neurodegeneration in Alzheimer's disease (AD) is increasingly accepted to result from the toxicity of hyperphosphorylated tau aggregates, the major constituent of the neurofibrillary tangles (NFTs) in the brains of AD patients. The vast majority of AD drug development efforts have focused on inhibiting or clearing Aβ plaques. So far, these efforts have failed in clinical trials. In contrast to Aβ plaques, which poorly correlate with progression of clinical AD symptoms, the spatiotemporal distribution of NFTs cognitive impairment. Mounting evidence suggests that pre-tangle aggregates of hyperphosphorylated tau are toxic to neurons, and likely play a key role in AD neurodegeneration. Thanks to a technology for generating phosphorylated proteins called PIMAX, this project will be the first to screen drugs for inhibition of aggregation of hyperphosphorylated tau (hyper-p-tau). Until now, hyper-p-tau in sufficient quantities to screen a compound library has been unavailable. Previous projects screened compounds for binding either unphosphorylated tau, or tau's two cysteine groups, or tau with only 1 to 3 phosphates. As our PIMAX-generated hyper-p-tau drug target, we will use tau isoform 1N4R phosphorylated on up to 16 aa residues. In brains of AD patients, tau 1N4R is hyperphosphorylated, and 8 of these 16 residues are used to stage AD postmortem brains. Thus, due to our unique hyperphosphorylated target, this project does not duplicate previous drug projects targeting tau, and is instead a groundbreaking new approach to discovering inhibitors of tau aggregation into neurotoxic fibrils. Our preliminary data shows that our novel small molecules (JF compounds) can inhibit aggregation of hyper-p-tau 1N4R. Our most potent inhibitor to date, JF-19-73, dose- dependently antagonizes oligomer formation and neuronal cytotoxicity of hyper-p-tau 1N4R in vitro, suggesting its potential for neuroprotection. JF-19-73 is more potent than resveratrol in inhibiting hyper-p-tau 1NR4 aggregation. JF compounds have classic drug attributes (Rules of Five by Lipinski et al.), exhibit positive predictive scores to traverse the blood-brain barrier, and are non-toxic to cells. Aim 1 will optimize JF chemistry for solubility (e.g. reduction of ClogP), inhibition of formation of cytotoxic hyper- p-tau 1N4R oligomeric fibrils, and cytoprotection in vitro. Aim 2 will test the most potent hyper-p-tau aggregation inhibitors for ADME properties in vitro and identify JF lead compounds for future preclinical studies including animal and PK/PD studies. Overall Impact: Neurodegeneration in AD is increasingly accepted to result from the toxicity of hyperphosphorylated tau aggregates. This project will enable us to move into a lead development program with optimized JF derivatives that target hyperphosphorylated tau — the form of tau actually found in postmortem brains of AD patients. This project is unique because it is based on overcoming a longstanding critical barrier in tau pharmacology — lack of hyperphosphorylated tau in sufficient quantities for high throughput screening.