Alzheimer's therapy: Blocking ApoE/ABeta binding

阿尔茨海默病治疗：阻断 ApoE/Aβ 结合

• 批准号: 6919192
• 负责人: MARTIN Joseph SADOWSKI
• 金额: $ 20.8万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-15 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6919192
• 关键词: Alzheimer' s disease; amyloid proteins; apolipoprotein E; behavior; behavior test; binding sites; brain disorder chemotherapy; cognition; drug adverse effect; genetically modified animals; histology; inhibitor /antagonist; intermolecular interaction; laboratory mouse; microscopy; neuroprotectants; nonhuman therapy evaluation; protein binding; protein isoforms; synthetic peptide

DESCRIPTION (provided by applicant): Inheritance of the apolipoprotein (apo) E4 isoform is a major risk factor for sporadic Alzheimer's disease (AD). ApoE, especially its E4 isoform, can act as a pathological chaperone of beta-amyloid (Abeta) promoting its conformational transformation from soluble Abeta into toxic Abeta aggregates which accumulate in the form of plaques or in vascular walls. It is known that the binding site of apoE on Abeta corresponds to residues 12-28. To block this binding, we synthesized a peptide, Abeta12-28P, which is homologous to residues 12-28 of Abeta but with the valine at residue 18 was substituted by a proline. This renders this peptide non-toxic and non-fibrillogenic. Abeta12-28P is blood-brain-barrier permeable (clearance=65+/-20 mu l serum/gr.brain) and its end-protected version has a serum half-life of 62.2+/- 18 min. We have gathered extensive preliminary data demonstrating that Abeta12-28P reduces Abeta toxicity and fibril formation both in vitro and in vivo. Transgenic (Tg) APP/PS1 AD mice treated for one month with Abeta12-28P demonstrated a reduction in Abeta load by 63.3% in the cortex and by 61.9% (p=0.0048) in the hippocampus (p=0.0047) comparing to age matched Tg mice which received placebo. No antibodies against Abeta were detected in the sera of treated mice; therefore, the observed therapeutic effect of this peptide cannot be attributed to an antibody clearance response. No toxicity was observed in treated animals. In this research proposal we plan to extend our preliminary work, determining if treatment with our lead compound blocking apoE/Abeta interaction is a viable therapeutic approach for reducing Abeta deposition in AD using different animal models including double Tg mice co-expressing APP and various isoforms of human apoE on a murine apoE knock-out background. Behavioral testing, histological and biochemical analysis of Abeta load will be end points of this study. Two-photon microscopy will be used to follow the treatment effect in Tg mice in vivo. We are also planning to identify the location and structure of the Abeta binding site on apoE which is crucial for the development additional compounds which may block the apoE/Abeta interaction.

描述(由申请人提供)：载脂蛋白(Apo)E4亚型的遗传是散发性阿尔茨海默病(AD)的主要危险因素。APOE，尤其是其E4亚型，可作为β-淀粉样蛋白(Abeta)的病理性伴侣，促进其从可溶性Abeta构象转化为聚集在斑块或血管壁上的有毒Abeta聚集体。已知载脂蛋白E在Abeta上的结合部位对应于12-28个残基。为了阻断这种结合，我们合成了一个多肽Abeta12-28P，它与Abeta12-28残基同源，但第18位的valine被Pro取代。这使得这种多肽无毒和无纤维原。阿贝塔12-28P是血脑屏障通透性的(清除=65+/-20mU L血清/大鼠脑)，其末端保护版本的血清半衰期为62.2+/-18min。我们已经收集了大量的初步数据，表明Abeta12-28P在体外和体内都减少了Abeta毒性和纤维形成。使用Abeta12-28p治疗1个月的转基因(TG)APP/PS1AD小鼠显示，与接受安慰剂治疗的年龄匹配的TG小鼠相比，皮层和海马区的Aβ负荷分别减少了63.3%和61.9%(p=0.0048)(p=0.0047)。在治疗小鼠的血清中没有检测到抗Abeta抗体；因此，这种多肽的观察疗效不能归因于抗体清除反应。在处理的动物中没有观察到毒性。在这项研究方案中，我们计划扩展我们的初步工作，确定用我们的先导化合物阻断apoE/Abeta相互作用是否是减少AD中Abeta沉积的可行治疗方法，使用不同的动物模型，包括双TG小鼠共表达APP和在小鼠apoE基因敲除背景下的不同亚型的人apoE。行为测试、组织学和生化分析将是本研究的终点。将使用双光子显微镜在体内跟踪TG小鼠的治疗效果。我们还计划确定载脂蛋白E上Abeta结合位点的位置和结构，这对开发可能阻止apoE/Abeta相互作用的额外化合物至关重要。