Towards Treatment of Alzheimer’s Disease by Targeting Pathogenic Tau and Beta-Amyloid Structures

项目摘要 目的1通过基于结构的药物设计解决痴呆症药物的匮乏问题。这种方法，所以 在治疗癌症和艾滋病毒-艾滋病方面卓有成效，由于进展，阿尔茨海默氏症(AD)正在打开大门 在衍射和低温电子显微镜中。Tau蛋白的聚集与痴呆症的发病密切相关。 基于原子结构，设计了9种tau聚集抑制剂。目标1建议 从牛磺酸中提取的tau原纤维尖端上其中一种抑制剂的原子结构测定 一名阿尔茨海默病患者的尸检结果。通过与纤维尖端结合，我们设计的抑制剂阻止了新的 在连接的细胞中有tau纤维。这种原子结构将揭示如何增加亲和力和特异性 抑制物的作用。目标1还将专注于发现tau上的身份和结合位点 推动其聚集的分子因素。这些结构将使小分子的设计成为可能 以及掩蔽结合部位的多肽，从而干扰因子结合，从而产生 预防阿尔茨海默病的药物。同样的方法将使翻译后结合位点可视化 Tau的修饰，包括磷酸化，为药物设计提供了相关的策略。 目标2建议填补关于tau和beta的小聚集体结构的知识真空。 淀粉样蛋白，称为寡聚体。对其他低聚物的大量研究提供了证据，表明齐聚物比 在重量(但不是摩尔)上比相同蛋白质的纤维具有细胞毒性。而且，在某种程度上 令人费解的是，不同纤维形成蛋白的低聚物在结构上有相似之处，即特定的 抗体(A11)识别它们，但不识别它们对应的纤维。低聚物的瞬变性质 已经击败了之前学习它们的原子结构的尝试，但幸运的是，我们在 Kayed和Raskatov实验室已经找到了稳定tau和β-淀粉样蛋白寡聚体的方法， 分别，足够长的时间，使我们的网格适合于低温EM结构确定。初步 显微照片令人鼓舞。 Aim 3建议在我们的合作者加州大学洛杉矶分校的实验室里培养的“迷你大脑”中测试AD药物 诺维奇教授。这些有机化合物的大小约为BB，但显示出结构和电学性质 真正的人脑。它们是由人类细胞制成的，显示细胞类型和电信号 人脑的信息传递。初步研究表明，这些迷你大脑可以感染tau 病理学，现在我们的各种候选药物干扰传播和 聚集的tau的伤害将在他们身上进行测试。如果成功，这种方法可以提供一条新的途径 在人体试验之前测试阿尔茨海默氏症药物。

Project Summary Aim 1 addresses the dearth of drugs for dementia, by structure-based drug design. This approach, so fruitful for treating cancer and HIV-AIDS, is opening for Alzheimer’s Disease (AD) because of advances in diffraction and cryoEM. Aggregation of protein tau is strongly correlated with the onset of dementia. Based on atomic structures, 9 inhibitors of tau aggregation have been designed. Aim 1 proposes determination of the atomic structure of one of these inhibitors on the tip of tau fibrils extracted from the autopsied brain of an AD patient. By binding to fibril tips, our designed inhibitors halt “seeding” of new tau fibrils in connected cells. This atomic structure will reveal how to increase the affinity and specificity of the inhibitor. Aim 1 will also focus on the discovery of the identity and binding sites on tau of molecular factors that drive its aggregation. These structures will enable design of small molecules and peptides that mask the binding site, thereby interfering with factor binding, and hence producing prophylactic drugs for AD. The same approach will visualize binding sites of post-translational modifications of tau, including phosphorylation, offering a related strategy for drug design. Aim 2 proposes to fill the vacuum of knowledge of the structures of small aggregates of tau and beta- amyloid, known as oligomers. Numerous studies of others provide evidence that oligomers are more cytotoxic on a weight basis (but not a mole basis) than fibrils of the same protein. And, somewhat mysteriously, oligomers of different fibril-forming proteins share structural similarities in that a particular antibody (A11) recognizes them, but not their corresponding fibrils. The transient nature of oligomers has defeated previous attempts to learn their atomic structures, but fortunately our collaborators in the Kayed and Raskatov labs have found methods to stabilize oligomers of tau and beta-amyloid, respectively, long enough for us to make grids suitable for cryoEM structure determination. Preliminary micrographs are encouraging. Aim 3 proposes tests of AD drugs in “mini-brains” which are grown in the lab of our collaborator UCLA Prof. Novitch. These organoids are about the size of a BB yet display structure and electrical properties of actual human brains. They are made from human cells and display the cell types and electrical messaging of human brains. Preliminary work shows these mini-brains can be infected with tau pathology, and now the ability of our various drug candidates to interfere with the spreading and damage of aggregated tau will be tested in them. If successful, this approach can provide a new avenue for testing Alzheimer’s drugs prior to human trials.