AB and ApoE in animal models of Alzheimer's disease

阿尔茨海默病动物模型中的 AB 和 ApoE

• 批准号: 6368893
• 负责人: ALEX E ROHER
• 金额: $ 33.74万
• 依托单位: BANNER SUN HEALTH RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6368893
• 关键词: Alzheimer's disease; aging; amyloid proteins; amyloidosis; apolipoprotein E; brain; disease /disorder model; genetically modified animals; genotype; high performance liquid chromatography; histochemistry /cytochemistry; immunologic assay /test; laboratory mouse; mass spectrometry; neuropathology; neurophysiology; pathologic process; phenotype; plasma; presenilin; protein metabolism; protein purification; protein sequence; protein structure function; transforming growth factors

Alzheimer disease (AD) is a dementia affecting over 20 million people worldwide. In the USA, AD represents the fourth greatest cause of death in the elderly. Genetic, chemical and morphological studies strongly suggest a seminal role for amyloid-beta (Abeta) peptides in the pathogenesis of AD. The successful creation of beta-amyloid precursor protein (betaAPP), presenilin 1 (PS1), apolipoprotein E (ApoE) and transforming growth factor-beta1 (TGF-beta1) transgenic (tg) mice has provided an opportunity to investigate the pathophysiology of Abeta amyloidogenesis. Tg mice are of paramount importance in the testing of AD therapeutic agents such as anti-Abeta aggregating compounds, secretase inhibitors and anti-Abeta vaccination. Despite the wide adoption of tg mice models in the search for effective AD treatments, a rigorous chemical characterization and quantification study of the Abeta produced by the genetically and phenotypically diverse tg mice strains has not been attempted. It is hypothesized that: 1) due to differences in lifespan, phylogenetic distance, functional organization and distress conditions of the brain significant quantitative and qualitative differences will be found in Abeta structure and metabolism between humans and mice; 2) failure in the clearance of Abeta from the brain to the blood in tg mice causes the progressive accumulation of both soluble and insoluble Abeta in the brain; 3) the partial loss of some of amino acid domains of ApoE, in an environment rich in proteolytic enzymes such as the AD brain, results in structural changes which would affect the affinity of ApoE for Abeta and the clearance of the complexes. The research plan will characterize the chemical structure and quantify Abeta peptides in the tg mice: APP23, 2576, PDAPP, PS1, TGF-beta1 and the double tg PS1/betaAPP and TGF-beta1/betaAPP. The ApoE associated to Abeta will be quantified and characterized in the tg mice brains. In addition, the effects of Abeta vaccination in the doubly PS1/betaAPP tg mice will be evaluated in terms of the soluble and insoluble Abeta40 and Abeta42 load. To achieve these goals the water-soluble and water-insoluble Abeta and ApoE peptides will be isolated from the tg mice by fast- and high- performance liquid column chromatographies from either brain homogenates or plasma. All purified molecules and derived enzymatic peptides will be chemically characterized by mass spectrometry, amino acid analysis and amino acid sequencing. Quantification of peptides will be performed by Western blot or by sensitive europium immunoassay. These significant characterizations and comparisons will provide important insights in evolutionary, physiological and pathological terms that will be useful for understanding AD and for the interpretation of mitigating treatments in tg mouse models.

阿尔茨海默病(AD)是一种痴呆症，在全球范围内影响着超过2000万人。在美国，阿尔茨海默病是老年人的第四大死因。遗传、化学和形态研究强烈表明淀粉样β蛋白(Abeta)多肽在AD的发病机制中起重要作用。β-淀粉样前体蛋白(β-APP)、早老素1(PS1)、载脂蛋白E(ApoE)和转化生长因子-β1(TGF-β1)转基因小鼠的成功建立，为研究Aβ淀粉样变的病理生理机制提供了可能。Tg小鼠在测试抗Abeta聚集物、分泌酶抑制剂和抗Abeta疫苗等AD治疗剂方面具有至关重要的作用。尽管TG小鼠模型被广泛采用来寻找有效的AD治疗方法，但还没有人尝试对遗传和表型多样化的TG小鼠品系产生的Abeta进行严格的化学表征和量化研究。假设：1)由于脑的寿命、系统发育距离、功能组织和脑的窘迫条件的不同，人和小鼠之间的Abeta结构和代谢将存在显著的数量和质量上的差异；2)TG小鼠Abeta从大脑到血液的清除失败导致可溶性和不溶性Abeta在大脑中逐渐积累；3)在AD大脑等富含蛋白水解酶的环境中，ApoE的一些氨基酸结构域的部分丢失会导致ApoE与Abeta的亲和力和复合体的清除受到影响。该研究计划将对TG小鼠体内的APP23、2576、PDAPP、PS1、转化生长因子-β1(TGPS1/βAPP)和转化生长因子-β1/βAPP(TGPS1/βAPP)和转化生长因子-β1/βAPP(TGPS1/βAPP)进行化学结构表征和定量。与Abeta相关的载脂蛋白E将在转基因小鼠的大脑中被量化和表征。此外，将根据可溶和不可溶的Abeta40和Abeta42载量来评估双重PS1/BetaAPP转基因小鼠的Abeta疫苗接种效果。为了实现这些目标，将通过快速高效的液柱层析从转基因小鼠的脑匀浆或血浆中分离出水溶和水不溶的Abeta和ApoE多肽。所有纯化的分子和衍生的酶解肽将通过质谱学、氨基酸分析和氨基酸序列分析进行化学表征。多肽的定量将通过Western印迹或灵敏的Eu免疫分析进行。这些重要的特征和比较将在进化、生理和病理方面提供重要的见解，这将有助于理解AD和解释在TG小鼠模型中的缓解治疗。