Targeting ApoE4 as a Therapeutic Strategy for Alzheimer's Disease

以 ApoE4 为靶点作为阿尔茨海默病的治疗策略

• 批准号: 8549072
• 负责人: ROBERT W. MAHLEY
• 金额: $ 81.86万
• 依托单位: J. DAVID GLADSTONE INSTITUTES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-30 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8549072
• 关键词: Accounting; Affect; Age; Age of Onset; Alzheimer' s Disease; Amyloid beta-Protein Precursor; Animal Model; Apolipoprotein E; Behavioral; Binding; Biological Assay; Biological Availability; Brain; Canis familiaris; Cardiovascular system; Cells; Cerebrospinal Fluid; Chemicals; Chemistry; Clinical; Clinical Research; Cognitive; Cognitive deficits; Community Healthcare; Data; Dependency; Development; Disease Progression; Documentation; Dose; Drug Formulations; Drug Kinetics; Event; Excretory function; Family; Fluorescence Resonance Energy Transfer; Functional disorder; Future; Goals; Grant; Health Care Costs; Human; Impaired cognition; Impairment; In Vitro; Individual; Investigational Drugs; Lead; Learning; Libraries; Measures; Mediating; Memory impairment; Metabolism; Microsomes; Mitochondria; Modeling; Molecular Conformation; Mus; Mutant Strains Mice; Nerve Degeneration; Neurites; Neurodegenerative Disorders; Neuron-Specific Enolase; Neurons; No-Observed-Adverse-Effect Level; Oral; Pathology; Patients; Penetration; Peptide Hydrolases; Pharmaceutical Chemistry; Pharmaceutical Preparations; Pharmacodynamics; Pharmacologic Substance; Property; Protein Isoforms; Proteins; Rattus; Research; Risk; Role; Safety; Senile Plaques; Series; Specificity; Structure; Structure-Activity Relationship; Synapses; Technology; Testing; Therapeutic; Toxic effect; Toxicology; Transgenic Mice; absorption; analog; apolipoprotein E-3; apolipoprotein E-4; base; design; drug metabolism; efficacy testing; genetic risk factor; high throughput screening; improved; in vivo; meetings; mitochondrial dysfunction; mouse model; neuropathology; neurotoxic; neurotoxicity; novel; pharmacophore; pre-clinical; preclinical study; prevent; programs; protein structure; public health relevance; respiratory; safety testing; small molecule

DESCRIPTION (provided by applicant): Apolipoprotein (apo) E4 is the major genetic risk factor for Alzheimer's disease (AD), and apoE4 carriers account for 65-80% of AD cases. ApoE4 increases the occurrence and lowers the age of onset of AD, and considerable evidence suggests that it has a fundamental role in the neurodegeneration and pathophysiology of AD. We showed that apoE4, because of its unique structural feature referred to as apoE4 domain interaction, is highly susceptible to proteolytic cleavage in neurons, generating neurotoxic fragments. The primary toxic fragment, apoE4(1-272), is found at much higher levels in the brain and cerebrospinal fluid of AD patients than non-demented individuals and in transgenic mice expressing human apoE4 in neurons. These transgenic mice have learning and memory impairments and neuropathology, including loss of synaptodendritic connections, which correlates with the onset of learning deficits. The toxicity induced by apoE4 and apoE4(1-272) is mediated by their inhibition of mitochondrial function, an initial event leading to neurodegeneration and cognitive impairment in AD. Thus, a number of studies have validated apoE4 as an excellent target for AD drugs. We discovered small molecules that bind apoE4 to modify the protein's structure to reduce domain interaction and proteolytic cleavage to prevent its toxicity. Our lead apoE4 structure corrector (apoE4SC), PY-101, protects neurons from apoE4-induced mitochondrial toxicity and reverses the impairment of neurite outgrowth in vitro. In vivo, PY-101 has good pharmacokinetics (PK) and brain bioavailability, blocks formation of toxic apoE4(1-272) in neuron-specific enolase (NSE)-apoE4 transgenic mouse brain, and protects against mitochondrial impairment in brain, an initial event in disease progression in AD. In this U01 grant, we propose to conduct the preclinical studies to evaluate the efficacy of PY-101 as a unique drug to treat AD. We will test PY-101 for efficacy in blocking cognitive impairment and neuropathology in the NSE-apoE4 and APP/apoE4 animal models of AD to validate PY-101 as a drug to treat AD. In addition, we will focus on optimizing the properties of apoE4SCs using our pharmacophore model based on the structure-activity relationship around PY-101. We will use this model to build a chemical optimization program around a novel chemical series to improve the potency of our prototypical apoE4SC while maintaining good PK and high brain penetration. Using the model, medicinal chemistry, and our high-throughput screening assays, we will optimize the efficacy and pharmaceutical properties of our apoE4SCs. To do this, small molecules will be screened against our primary GFP-apoE4-eDHFR FRET assay, which measures target engagement and the ability to disrupt apoE4 domain interaction to increase apoE4 stability. Optimized apoE4SCs will be subjected to stability, PK, and pharmacodynamic studies to select leads to test for efficacy in AD mouse models. The lead apoE4SC will be subjected to standard investigational new drug-enabling preclinical development with a goal of initiating clinical studies to test for safety and efficacy in treating D and proceeding to an IND.

描述（申请人提供）：载脂蛋白（apo）E4是阿尔茨海默病（AD）的主要遗传危险因素，apoE4携带者占AD病例的65-80%。 ApoE4 会增加 AD 的发生率并降低发病年龄，大量证据表明它在 AD 的神经变性和病理生理学中具有重要作用。我们发现，apoE4 由于其独特的结构特征（称为 apoE4 结构域相互作用），非常容易受到神经元中蛋白水解裂解的影响，从而产生神经毒性片段。主要毒性片段 apoE4(1-272) 在 AD 患者的大脑和脑脊液中的含量比非痴呆个体和在神经元中表达人 apoE4 的转基因小鼠中高得多。这些转基因小鼠具有学习和记忆障碍以及神经病理学，包括突触树突连接的丧失，这与学习缺陷的发生相关。 apoE4 和 apoE4(1-272) 诱导的毒性是通过抑制线粒体功能介导的，这是导致 AD 中神经变性和认知障碍的初始事件。因此，许多研究已证实 apoE4 是 AD 药物的绝佳靶点。我们发现了结合 apoE4 的小分子，可以改变蛋白质的结构，从而减少结构域相互作用和蛋白水解切割，从而防止其毒性。我们的主要 apoE4 结构校正剂 (apoE4SC) PY-101 可保护神经元免受 apoE4 诱导的线粒体毒性，并在体外逆转神经突生长的损害。在体内，PY-101 具有良好的药代动力学 (PK) 和脑生物利用度，可阻止神经元特异性烯醇化酶 (NSE)-apoE4 转基因小鼠脑中有毒 apoE4(1-272) 的形成，并防止脑中线粒体损伤（AD 疾病进展的初始事件）。在这笔 U01 资助中，我们建议进行临床前研究，以评估 PY-101 作为治疗 AD 的独特药物的疗效。我们将在 AD 的 NSE-apoE4 和 APP/apoE4 动物模型中测试 PY-101 阻断认知障碍和神经病理学的功效，以验证 PY-101 作为治疗 AD 的药物。此外，我们将重点使用基于 PY-101 结构-活性关系的药效团模型来优化 apoE4SC 的特性。我们将使用该模型围绕新型化学系列构建化学优化程序，以提高原型 apoE4SC 的效力，同时保持良好的 PK 和高脑渗透性。利用模型、药物化学和我们的高通量筛选分析，我们将优化 apoE4SC 的功效和药物特性。为此，我们将针对我们的主要 GFP-apoE4-eDHFR FRET 测定筛选小分子，该测定测量靶标接合以及破坏 apoE4 结构域相互作用以提高 apoE4 稳定性的能力。优化的 apoE4SC 将接受稳定性、PK 和药效学研究，以选择在 AD 小鼠模型中测试功效的先导化合物。主要的 apoE4SC 将接受标准的研究性新药临床前开发，目标是启动临床研究，测试治疗 D 的安全性和有效性，并进入 IND。