ALBUMIN CONJUGATED DETOXIFICATION DEPOT FOR BETA AMYLOID PEPTIDES

用于 β 淀粉样肽的白蛋白缀合解毒库

• 批准号: 7480700
• 负责人: PAZHANI SUNDARAM
• 金额: $ 35.1万
• 依托单位: RECOMBINANT TECHNOLOGIES, LLC
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-01 至 2009-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7480700
• 关键词: A2-binding peptide; Address; Albumins; Alzheimer' s Disease; Alzheimer' s disease model; Amino Acids; Amyloid; Amyloid beta-Protein; Amyloid beta-Protein Precursor; Avidity; Binding; Biochemical; Biological Assay; Blood - brain barrier anatomy; Brain; Brain Injuries; Chemical Agents; Complex; Data; Deposition; Digestion; Drug Metabolic Detoxication; Elements; Excision; Gel; Genetic; Goals; Human; Hydrogels; Injection of therapeutic agent; Investigation; Lead; Lesion; Life; Lipids; Liquid substance; Liver; Measures; Monoclonal Antibodies; Mus; Neurons; Outcome; Pathogenesis; Pathway interactions; Patients; Peptide Hydrolases; Peptides; Phase; Plasma; Play; Process; Property; Proteins; Proteolytic Processing; Psyche structure; Public Health; Publishing; Research; Resistance; Retro-Inverso Peptide; Role; Science; Series; Serum Albumin; Specificity; System; Testing; Therapeutic; Therapeutic Agents; Toxic effect; Variant; Week; amyloid peptide; brain tissue; concept; crosslink; design; extracellular; mouse model; novel strategies; peptide A; subcutaneous

DESCRIPTION (provided by applicant): The hallmark of Alzheimer's disease (AD) is the presence in brain of plaques, which are complex extracellular lesions composed of a central deposition of 2-amyloid peptide. Genetic, neuropathological and biochemical evidence have shown that these deposits play an important role in the pathogenesis of AD. We have confirmed the hypothesis that Alzheimer's disease (AD) can be effectively treated using our proprietary chemical agent that can sequester the toxic 2-amyloid peptides A21-40 and A21-42 in the periphery. In a mouse model of AD (APPSWE-2576), 3 biweekly injections of our peptide-like compound resulted in a 50% lower plaque content in the brain, as evidenced by immunohiostological analysis. This data is further supported by a quantitative reduction in the amount of AB peptides in brain extracts from treated AD versus control mice. However, we have not yet addressed the issue of removal of the subcutaneous detoxification depots. In the proposed study, we will examine a mobile detoxification depot. In Phase 1, this new system will be optimized for the properties of strong and specific binding of toxic A2 peptides and clearance from the body of AD model mouse. In summary, the current study aims to 1. Develop a "sink " that has sufficient avidity and specificity to function as a binding element at the low concentration of A2 peptides and at the high levels of extraneous proteins and lipids in the body. 2. Develop a process that will result in degradation and/or elimination of toxic A2 peptides captured by this sink. Can albumin be used as the carrier to provide plaque reduction without any extra removal steps? The outcome of the proposed research is expected to result in a greater impact in the treatment of AD and is likely to lead to human application in subsequent investigations. PUBLIC HEALTH RELEVANCE: Alzheimer's disease is now known to be cause by an accumulation of a particular group of peptides (40 or 42 amino acids), known as beta-amyloid (A2 ) peptides, in the brain. These A2 peptides tend to aggregate into insoluble masses that appear as plaques in the brain. These plaques are toxic to nearby neurons, thereby destroying mental function. The aggregation process is induce by a pentapeptide sequence , KLVFF, within the A2 peptide. In our early studies, we synthesized "retro-inverso" (RI) forms of A2 peptides (composed of D-amino acids in the reverse sequence, ffvlk) as potential therapeutic agents designed to interfere with the aggregation process. RI peptides are resistant to peptidase digestion, and we found that they retain the natural KLVFF binding/aggregation properties. Furthermore, aggregates with RI peptides were found to reduce the toxicity of bound A2 peptides. We also observed that conjugates bearing multiple copies of the RI peptide increase the avidity of interaction with A2 peptides. Our current research is derived from a published observation that demonstrated a novel approach to AD therapy [DeMattos, et al.(2002) Brain to plasma - 2 amyloid efflux: a measure of brain amyloid burden in a mouse model of Alzheimer's disease. Science 295, 2264-2267]. Instead of interfering with the synthesis of A2 peptides or with the aggregation process, it might be possible to sequester (i.e. capture) A2 peptides and keep them in a non-aggregating form or even to remove them from the body. The rationale for this concept is that the A2 peptides can cross the blood-brain barrier. While DeMattos was successful using a monoclonal antibody against A2 peptides, this would not be suitable for a therapeutic agent that would have to be used for the remainder of the patient's life. Our RI peptides however, seemed to fit all the requirements for a sequestering agent. RI peptides bind A2 peptides specifically and virtually irreversibly, they reduce the toxicity of bound A2 peptides and they are stable (non-digestible). Using a binding assay to screen a series of RI peptides, we selected a lead candidate and tested it in a mouse model of AD. After 6 weeks, control (4 untreated mice) had extensive brain damage, whereas treated (3 mice) did not. Clearly, the RI peptide approach can potentially lead to an effective therapeutic product.

描述（由申请人提供）：阿尔茨海默病（AD）的标志是脑中存在斑块，斑块是由2-淀粉样肽的中心沉积组成的复杂细胞外病变。遗传学、神经病理学和生物化学证据表明，这些沉积物在AD的发病机制中起重要作用。我们已经证实了这一假设，即阿尔茨海默病（AD）可以有效地治疗使用我们的专有化学剂，可以螯合有毒的2-淀粉样肽A21-40和A21-42在周边。在AD的小鼠模型（APPSWE-2576）中，我们的肽样化合物每两周注射3次，导致脑中斑块含量降低50%，如免疫组织学分析所证明的。该数据进一步得到了治疗AD小鼠与对照小鼠脑提取物中AB肽量定量减少的支持。然而，我们尚未解决去除皮下解毒库的问题。在建议的研究中，我们会研究一个移动的戒毒站。在第1阶段，将针对毒性A2肽的强和特异性结合以及从AD模型小鼠体内清除的特性对该新系统进行优化。综上所述，本研究的目的是1。开发一种具有足够亲合力和特异性的“汇“，以在体内低浓度A2肽和高水平外源蛋白质和脂质时作为结合元件发挥作用。2.开发一种过程，将导致降解和/或消除有毒的A2肽捕获这个水槽。白蛋白是否可以作为载体来减少斑块，而无需任何额外的清除步骤？ 拟议研究的结果预计将对AD的治疗产生更大的影响，并可能在后续研究中用于人类。公共卫生关系：现在已知阿尔茨海默病是由大脑中一组特定的肽（40或42个氨基酸）（称为β-淀粉样蛋白（A2）肽）的积累引起的。这些A2肽倾向于聚集成不溶性物质，在脑中表现为斑块。这些斑块对附近的神经元有毒，从而破坏精神功能。聚集过程由A2肽内的五肽序列KLVFF诱导。在我们早期的研究中，我们合成了A2肽的“逆向-反向”（RI）形式（由反向序列中的D-氨基酸组成，ffvlk）作为潜在的治疗剂，旨在干扰聚集过程。RI肽对肽酶消化具有抗性，并且我们发现它们保留了天然的KLVFF结合/聚集特性。此外，发现具有RI肽的聚集体降低结合的A2肽的毒性。我们还观察到，携带RI肽的多个拷贝的缀合物增加了与A2肽相互作用的亲合力。 我们目前的研究来自一项已发表的观察结果，该观察结果证明了AD治疗的一种新方法[DeMattos，et al.（2002）脑至血浆-2淀粉样蛋白流出：阿尔茨海默病小鼠模型中脑淀粉样蛋白负荷的测量。Science 295，2264-2267]。代替干扰A2肽的合成或聚集过程，有可能螯合（即捕获）A2肽并将它们保持在非聚集形式或甚至将它们从体内除去。这个概念的基本原理是A2肽可以穿过血脑屏障。虽然DeMattos成功地使用了抗A2肽的单克隆抗体，但这不适合于必须在患者的余生中使用的治疗剂。然而，我们的RI肽似乎符合螯合剂的所有要求。RI肽特异性地且几乎不可逆地结合A2肽，它们降低结合的A2肽的毒性并且它们是稳定的（不可消化的）。使用结合试验来筛选一系列RI肽，我们选择了一个先导候选物，并在AD小鼠模型中对其进行了测试。6周后，对照组（4只未处理的小鼠）有广泛的脑损伤，而处理组（3只小鼠）没有。显然，RI肽方法可以潜在地导致有效的治疗产品。