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）：阿尔茨海默氏病（AD）的标志是大脑中存在斑块，斑块是由2-淀粉样肽的中央沉积组成的复杂的细胞外病变。遗传、神经病理学和生化证据表明这些沉积物在 AD 的发病机制中发挥着重要作用。我们已经证实了这样的假设：使用我们的专有化学剂可以有效治疗阿尔茨海默病 (AD)，该化学剂可以将有毒的 2-淀粉样肽 A21-40 和 A21-42 隔离在外周。免疫组织学分析证明，在 AD 小鼠模型 (APPSWE-2576) 中，每两周注射 3 次我们的肽样化合物，可使大脑中的斑块含量降低 50%。与对照小鼠相比，接受治疗的 AD 小鼠脑提取物中 AB 肽含量的定量减少进一步支持了该数据。然而，我们还没有解决皮下排毒库移除的问题。在拟议的研究中，我们将检查一个移动解毒站。在第一阶段，这个新系统将针对毒性 A2 肽的强效和特异性结合以及从 AD 模型小鼠体内清除的特性进行优化。总之，本研究的目的是： 1. 开发一种具有足够亲和力和特异性的“水槽”，在体内低浓度的 A2 肽和高水平的外来蛋白质和脂质下充当结合元件。 2. 开发一种工艺，能够降解和/或消除该接收器捕获的有毒 A2 肽。是否可以使用白蛋白作为载体来减少牙菌斑而不需要任何额外的去除步骤？ 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应用于人类。公共健康相关性：目前已知阿尔茨海默氏病是由大脑中一组特定肽（40 或 42 个氨基酸）（称为 β-淀粉样 (A2) 肽）的积累引起的。这些 A2 肽往往会聚集成不溶性物质，在大脑中表现为斑块。这些斑块对附近的神经元有毒，从而破坏精神功能。聚集过程是由 A2 肽内的五肽序列 KLVFF 诱导的。在我们的早期研究中，我们合成了“逆向反转”(RI) 形式的 A2 肽（由反向序列的 D-氨基酸组成，ffvlk）作为潜在的治疗剂，旨在干扰聚集过程。 RI 肽能够抵抗肽酶消化，我们发现它们保留了天然的 KLVFF 结合/聚集特性。此外，发现与 RI 肽的聚集体可以降低结合的 A2 肽的毒性。我们还观察到带有多个 RI 肽拷贝的缀合物增加了与 A2 肽相互作用的亲合力。 我们目前的研究源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) 脑到血浆 - 2 淀粉样蛋白流出：阿尔茨海默病小鼠模型中大脑淀粉样蛋白负荷的测量。科学 295, 2264-2267]。与其干扰 A2 肽的合成或聚集过程，不如隔离（即捕获）A2 肽并使其保持非聚集形式，甚至将其从体内去除。这个概念的基本原理是 A2 肽可以穿过血脑屏障。虽然 DeMattos 成功地使用了针对 A2 肽的单克隆抗体，但这并不适合必须在患者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，它们降低了结合的 A2 肽的毒性，并且它们是稳定的（不可消化）。我们使用结合测定法筛选一系列 RI 肽，选择了一个主要候选物并在 AD 小鼠模型中进行了测试。 6 周后，对照组（4 只未治疗的小鼠）出现了广泛的脑损伤，而治疗组（3 只小鼠）则没有。显然，RI 肽方法有可能产生有效的治疗产品。