ABCA1 knock-in mouse model to study molecular pathology of Alzheimer's Disease

ABCA1敲入小鼠模型研究阿尔茨海默病的分子病理学

基本信息

批准号：
7268704
负责人：
ILIYA LEFTEROV
金额：
$ 6.15万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-08-01 至 2008-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7268704
关键词：
AP40 ATP-Binding Cassette Transporters Affect Age Agreement Alzheimer&apos s Disease Alzheimer&apos s disease model Amino Acid Substitution Amino Acids Amyloid Amyloid beta-Protein Amyloid deposition Animals Apolipoprotein E Atherosclerosis Award Binding Biochemical Biological Blood Vessels Brain Cardiovascular Pathology Cell Line Cells Cerebral Arterial Diseases Cholesterol Cholesterol Homeostasis Clinical Research Code Data Dementia Deposition Development Foam Cells Funding Future Gene Targeting Generations Genes Genetically Engineered Mouse Goals Grant High Density Lipoproteins Knock-in Mouse Late Onset Alzheimer Disease Ligands Link Lipoproteins Liver Measures Mediating Membrane Transport Proteins Microscopic Mining Molecular Mus Mutate Mutation Neurons Neuropathy Nuclear Nuclear Receptors Nucleic Acid Regulatory Sequences Partner in relationship Pathogenesis Pathology Patients Phenotype Plasma Point Mutation Process Proteins Research Response Elements Role Splenomegaly T 0901317 Tangier Disease Technology Testing Therapeutic Transcript Transcriptional Regulation Transgenic Organisms abeta deposition amyloid precursor protein processing cholesterol transporters clinical phenotype embryonic stem cell in vivo lipoprotein cholesterol molecular pathology mouse model mutant novel therapeutics promoter recombinase response tool transcription factor

项目摘要

DESCRIPTION (provided by applicant): Studies have now revealed that Alzheimer's disease (AD) patients have more severe atherosclerosis than age-matched controls without AD, and established a positive correlation between the degree of atherosclerotic disease of cerebral arteries in AD patients and neuropathological features typical for AD. However, mechanisms by which cholesterol (CL) metabolism influences AD pathogenesis remain uncertain. CL efflux and generation of HDL are mediated by ABCA1 membrane transporter which is transcriptionally controlled by Liver X nuclear Receptors (LXR). ABCA1 mutations cause severe HDL deficiencies, like hypoalphalipoproteinemia and Tangier Disease (TD). A major goal of our research is to reveal the role of ABCA1 in the molecular pathogenesis of AD and thus to explore and to test new therapeutic strategies. The central hypothesis is that ABCA1 affects ABeta formation/deposition and clearance. In support are our studies (currently in press) funded by NIA R21 and R03 awards, showing that ABCA1 deficiency in APP23 mice leads to a dramatic decrease of soluble apoE and an increased deposition of ABeta in the brain. We have also demonstrated that application of the synthetic LXR ligand T0901317 (TO) in vivo increases the expression of ABCA1 in CNS and decreases the amounts of ABeta species in the brain. We found that primary cells from TD patients generate and secrete more ABeta and that their response to LXR synthetic ligands is different and depend on the type of ABCA1 mutation. Importantly, one of the primary ABCA1 mutant cell lines with a point mutation causing N935S amino acid substitution was established from a TD patient with dementia and abundant amyloid deposits in the brain, but without cardiovascular pathology. Thus, specific mutations in ABCA1 differentially disturb its regulatory role on beta-amyloid deposition and atherosclerosis, and therefore we hypothesize that ABCA1 mutations determine the clinical phenotype observed in patients by at least partly different mechanisms. The goal of this NIA pilot grant is to develop and characterize a mouse line that expresses mutated ABCA1N935S. Aim 1. To create genetically engineered mice that express mutated ABCA1N935S. This mouse line will be created by utilizing a "Knock-in" approach to introduce an N935S mutation in the ABCA1 locus in mouse ES cells. These ABCA1S/S mice will ubiquitously express ABCA1N935S, the mutated gene will remain under the endogenous ABCA1 transcriptional control and the mutant protein will replace wild type ABCA1. Aim 2. To characterize ABCA1N935S knock-in mice. We will analyze in vivo the expression of ABCA1N935s and its function as a cholesterol transporter by measuring plasma CL and lipoproteins. The effect of the mutated ABCA1N93ss on brain lipoproteins and endogenous APR processing and ABeta generation in vivo will be determined as a preliminary step to substantiate future detailed biochemical studies.

描述（申请人提供）：目前研究表明，阿尔茨海默病（AD）患者的动脉粥样硬化程度较同龄非阿尔茨海默病对照者更为严重，并建立了AD患者脑动脉粥样硬化程度与神经病理特征之间的正相关关系。典型的AD。然而，胆固醇（CL）代谢影响 AD 发病机制的机制仍不确定。 CL 流出和 HDL 生成由 ABCA1 膜转运蛋白介导，该转运蛋白受肝 X 核受体 (LXR) 转录控制。 ABCA1 突变会导致严重的 HDL 缺乏，例如低 α 脂蛋白血症和丹吉尔病 (TD)。我们研究的一个主要目标是揭示 ABCA1 在 AD 分子发病机制中的作用，从而探索和测试新的治疗策略。中心假设是 ABCA1 影响 Aβ 形成/沉积和清除。支持我们的研究（目前正在印刷中）由 NIA R21 和 R03 奖项资助，表明 APP23 小鼠中 ABCA1 缺陷导致可溶性 apoE 急剧减少和大脑中 Aβ 沉积增加。我们还证明，在体内应用合成的 LXR 配体 T0901317 (TO) 会增加 CNS 中 ABCA1 的表达，并减少大脑中 Aβ 种类的数量。我们发现 TD 患者的原代细胞产生并分泌更多的 ABeta，并且它们对 LXR 合成配体的反应不同，并且取决于 ABCA1 突变的类型。重要的是，一种具有导致 N935S 氨基酸取代的点突变的主要 ABCA1 突变细胞系是从患有痴呆症且大脑中有大量淀粉样蛋白沉积但没有心血管病理的 TD 患者建立的。因此，ABCA1 的特定突变会不同程度地扰乱其对 β-淀粉样蛋白沉积和动脉粥样硬化的调节作用，因此我们假设 ABCA1 突变至少通过部分不同的机制决定在患者中观察到的临床表型。 NIA 试点资助的目标是开发和表征表达突变 ABCA1N935S 的小鼠品系。目标 1. 创造表达突变 ABCA1N935S 的基因工程小鼠。该小鼠系将通过利用“敲入”方法在小鼠 ES 细胞的 ABCA1 基因座中引入 N935S 突变来创建。这些ABCA1S/S小鼠将普遍表达ABCA1N935S，突变基因将保留在内源性ABCA1转录控制之下，并且突变蛋白将取代野生型ABCA1。目标 2. 表征 ABCA1N935S 敲入小鼠。我们将通过测量血浆 CL 和脂蛋白来分析 ABCA1N935 的体内表达及其作为胆固醇转运蛋白的功能。突变的 ABCA1N93ss 对脑脂蛋白、内源性 APR 加工和体内 Aβ 生成的影响将作为证实未来详细生化研究的初步步骤。