ApoE4-targeted therapeutics that normalize SirT1

使 SirT1 正常化的 ApoE4 靶向疗法

• 批准号: 9914435
• 负责人: Varghese John
• 金额: $ 29.79万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9914435
• 关键词: 19q13; Address; Affect; Affinity; Alleles; Alzheimer' s Disease; Alzheimer' s disease model; Alzheimer' s disease risk; American; Amyloid beta-Protein; Amyloid beta-Protein Precursor; Apolipoprotein E; Apoptosis; Binding; Biological Assay; Biological Markers; Brain; Caspase; Cell Line; Cell model; Cells; Chemicals; Clinical; Clinical Trials; Collaborations; Data; Development; Disease; Disease Progression; Dose; Drug Kinetics; Drug Targeting; Enhancers; Enzyme-Linked Immunosorbent Assay; Evaluation; Future; G-substrate; Genotype; Glycine decarboxylase; Goals; In Vitro; Individual; Inflammation Mediators; Knowledge; Late Onset Alzheimer Disease; Lead; Learning; Libraries; Light; Link; Longevity; Mediating; Mediator of activation protein; Memory; Memory Loss; Molecular; Neurites; Neurons; Oral; Pathway interactions; Patients; Permeability; Pharmaceutical Chemistry; Pharmaceutical Preparations; Phosphorylation; Plasma; Play; Preclinical Testing; Preventive; Process; Production; Property; Reporting; Research; Risk; Risk Factors; Role; SIRT1 gene; Sampling; Serum; Signal Transduction; Sirtuins; Site; Societies; Structure; Synapses; Testing; Therapeutic; Time; Toxic effect; Toxicity Tests; aging brain; amyloid pathology; amyloid precursor protein processing; analog; apolipoprotein E-3; apolipoprotein E-4; cost; design; disease phenotype; disorder risk; drug candidate; drug discovery; efficacy testing; gene product; genetic risk factor; genotyped patients; improved; in vivo evaluation; inhibitor/antagonist; insight; lead candidate; lead optimization; longevity gene; mild cognitive impairment; mouse model; nanomolar; nervous system disorder; neuron loss; neurotoxic; neurotoxicity; new therapeutic target; novel; overexpression; pre-clinical; programs; research clinical testing; screening; targeted treatment; tau Proteins; tau phosphorylation; tau-1; therapeutic candidate; therapeutic development; tool development; transgenic model of alzheimer disease; uptake

PROJECT / SUMMARY ABSTRACT Our studies link for the first time the major risk factor for Alzheimer's disease - ApoE4 - with major longevity determinants, the Sirtuins; and identify the first candidate therapeutics that target this new link. Alzheimer's disease (AD) currently afflicts more than 5.4 million people in the US at an estimated cost to society of greater than $200 billion per year. The currently approved drugs for AD provide only short-term symptomatic relief but do not alter disease progression. The dominant risk factor for Alzheimer's disease (AD) is the epsilon-4 (ε4) allele of apolipoprotein E (ApoE4), which is present in about two-thirds of AD patients. The ApoE4 allele (chromosomal locus 19q13) confers increased risk for sporadic and late-onset AD (LOAD). Despite over a decade of knowledge that the ApoE4 allele is somehow contributory to the disease process, the precise molecular mechanisms underlying ApoE4-associated AD risk remain unclear. Our studies shed light on a novel mechanism for ApoE4-mediated toxicity and revealed a key mediator − SirT1 − that is differentially affected by ApoE4 vs. ApoE3. Interestingly, while both ApoE3 and ApoE4 bind to APP, only ApoE4 associates with nanomolar affinity (Kd ~80nM), and only ApoE4 significantly: (a) reduces the ratio of sAPPα to Aβ; (b) reduces SirT1 expression, resulting in a marked reduction of SirT1 levels and in the ratio of neuroprotective SirT1 to neurotoxic SirT2; (c) triggers tau and APP phosphorylation; and (d) induces programmed cell death. In our initial screen of a clinical library we have identified a promising hit (A03) that is a repurposing candidate, is highly brain permeable, and reverses the reduction of SirT1 levels. As part of this proposal we plan to complete the preclinical testing of A03 and develop new chemical entity (NCE) analogs of A03 for further development. In addition, through screening and “hit-to-lead” optimization we plan to discover new lead candidates for further testing. The eventual goal of the proposal is to provide 1-2 candidates for non-GLP toxicity testing. Our data support the hypothesis that neuronal connectivity - influenced by the ratios of critical mediators including sAPPα:Aβ, SirT2:SirT1, APP:p-APP, and tau:p-tau - is programmatically altered by ApoE4. The collaboration with the Clinical Core and the Gylys lab is important in this project, as it would provide preliminary analysis of plasma and CSF samples from ApoE genotyped patients for levels of SirT1. Such data would be extremely useful for future development of ApoE4-targeted drug candidates to clinical testing and SirT1 as a potential plasma biomarker in MCI/AD. In addition, comparing SirT1 with other biomarkers in plasma/CSF that are affected by the sirtuin/NFkB signaling is planned and would help further elucidate the role of ApoE4 in AD. The overall primary objective of this project is to identify potent, orally active, brain permeable SirT1-enhancing lead candidates that are suitable for further preclinical IND development as the first ApoE4- targeted SirT1 therapeutics for AD and to development the tools necessary to ascertain target engagement and efficacy.

项目/摘要摘要 我们的研究首次将阿尔茨海默病的主要危险因素 - ApoE4 - 与主要的 长寿的决定因素，Sirtuins；并确定针对这一新联系的第一个候选疗法。 目前，美国有超过 540 万人患有阿尔茨海默病 (AD)，估计造成的损失 每年社会价值超过2000亿美元。目前批准的 AD 药物仅提供短期疗效 缓解症状但不改变疾病进展。阿尔茨海默病 (AD) 的主要危险因素 是载脂蛋白 E (ApoE4) 的 epsilon-4 (ε4) 等位基因，大约三分之二的 AD 患者中存在该基因。这 ApoE4 等位基因（染色体位点 19q13）会增加散发性和迟发性 AD (LOAD) 的风险。 尽管十多年来人们都知道 ApoE4 等位基因在某种程度上对疾病过程有贡献，但 ApoE4 相关 AD 风险的确切分子机制仍不清楚。我们的研究揭示了 ApoE4 介导的毒性的新机制，并揭示了一个关键介质 - SirT1 - 具有差异性 受 ApoE4 与 ApoE3 的影响。有趣的是，虽然 ApoE3 和 ApoE4 都与 APP 结合，但只有 ApoE4 结合 具有纳摩尔亲和力 (Kd ~80nM)，且仅 ApoE4 显着： (a) 降低 sAPPα 与 Aβ 的比率； (二) 降低 SirT1 表达，导致 SirT1 水平和神经保护作用比例显着降低 SirT1 至神经毒性 SirT2； (c) 触发 tau 和 APP 磷酸化； (d)诱导程序性细胞死亡。 在我们对临床库的初步筛选中，我们发现了一个有希望的热门产品 (A03)，它是一个重新利用的候选者， 具有高度的脑渗透性，可逆转 SirT1 水平的降低。作为该提案的一部分，我们计划 完成A03的临床前测试并开发A03的新化学实体（NCE）类似物以进一步 发展。此外，通过筛选和“hit-to-lead”优化，我们计划发现新的先导化合物 进一步测试的候选人。该提案的最终目标是为非GLP提供1-2名候选人 毒性测试。我们的数据支持这样的假设：神经元连接性受到关键比率的影响 介体包括 sAPPα:Aβ、SirT2:SirT1、APP:p-APP 和 tau:p-tau - 由 ApoE4 以编程方式改变。 与临床核心和 Gylys 实验室的合作在该项目中非常重要，因为它将提供 对 ApoE 基因分型患者的血浆和脑脊液样本中 SirT1 水平进行初步分析。这样的数据 对于未来 ApoE4 靶向候选药物的临床测试和开发非常有用 SirT1 作为 MCI/AD 的潜在血浆生物标志物。此外，将 SirT1 与其他生物标志物进行比较 计划对受 Sirtuin/NFkB 信号影响的血浆/CSF 进行研究，这将有助于进一步阐明其作用 AD 中的 ApoE4。该项目的总体主要目标是确定有效的、口服活性的、脑可渗透的 SirT1 增强先导候选药物适合进一步临床前 IND 开发，作为第一个 ApoE4- 针对 AD 的 SirT1 靶向疗法并开发确定靶点参与所需的工具 和功效。