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

• 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
• 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' s Disease; Alzheimer' 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

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（由申请人提供）：目前研究表明，阿尔茨海默病（Alzheimer's disease， AD）患者的动脉粥样硬化程度比无AD的年龄匹配的对照组更为严重，并建立了AD患者脑动脉粥样硬化程度与AD典型神经病理特征之间的正相关关系。然而，胆固醇代谢影响阿尔茨海默病发病的机制仍不确定。CL外排和HDL生成由ABCA1膜转运蛋白介导，ABCA1膜转运蛋白受肝X核受体（LXR）的转录控制。ABCA1突变导致严重的高密度脂蛋白缺乏，如低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。核心假设是ABCA1影响ABeta的形成/沉积和清除。我们的研究（目前正在出版中）由NIA R21和R03奖资助，表明APP23小鼠中ABCA1缺乏导致可溶性apoE急剧减少，ABeta在大脑中的沉积增加。我们还证明，在体内应用合成LXR配体T0901317 （TO）可增加中枢神经系统中ABCA1的表达，并减少大脑中ABeta物种的数量。我们发现来自TD患者的原代细胞产生和分泌更多的β，并且它们对LXR合成配体的反应是不同的，并且取决于ABCA1突变的类型。重要的是，其中一种主要的ABCA1突变细胞系，其点突变导致N935S氨基酸替代，是在一名患有痴呆症的TD患者身上建立的，该患者大脑中有大量淀粉样蛋白沉积，但没有心血管病理。因此，ABCA1的特异性突变会不同程度地干扰其对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了患者的临床表型。这项NIA试点资助的目标是开发和表征表达ABCA1N935S突变的小鼠品系。目的1。创造表达突变ABCA1N935S的基因工程小鼠。该小鼠系将通过“敲入”方法在小鼠ES细胞的ABCA1位点引入N935S突变来创建。这些ABCA1S/S小鼠将普遍表达ABCA1N935S，突变基因将保持在内源性ABCA1转录控制下，突变蛋白将取代野生型ABCA1。目标2。对ABCA1N935S敲入小鼠进行表征。我们将通过测定血浆CL和脂蛋白来分析ABCA1N935s在体内的表达及其作为胆固醇转运体的功能。突变的ABCA1N93ss对脑脂蛋白、内源性APR加工和体内ABeta生成的影响将被确定为进一步详细生化研究的初步步骤。