ATP-BINDING CASSETTEE TRANSPORTER-2 (ABCA2) REGULATION OF BETA APP PROCESSING

ATP 结合盒转运蛋白 2 (ABCA2) Beta APP 处理的调节

• 批准号: 7959965
• 负责人: WARREN DAVIS
• 金额: $ 14.6万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7959965
• 关键词: ATP-Binding Cassette Transporters; Abeta synthesis; Alleles; Alzheimer' s Disease; Amyloid beta-Protein; Amyloid beta-Protein Precursor; Apolipoprotein E; Applications Grants; Binding; Brain; Cells; Centers of Research Excellence; Cholesterol; Computer Retrieval of Information on Scientific Projects Database; Esterification; Etiology; Funding; Gene Expression; Generations; Genes; Genetic; Goals; Grant; Homeostasis; Institution; Knockout Mice; Knowledge; LDL-Receptor Related Protein 1; Ligands; Lipoprotein Receptor; Mediating; Microarray Analysis; Molecular Profiling; Mutation; Neuroblastoma; Neurons; Pathway interactions; Peptide Fragments; Presenile Alzheimer Dementia; Prevention; Production; Proteins; Regulation; Reporting; Research; Research Personnel; Resources; Role; Single Nucleotide Polymorphism Map; Source; United States National Institutes of Health; amyloid precursor protein processing; apolipoprotein E-4; base; cholesterol trafficking; genetic risk factor; in vivo; overexpression; protein expression; protein metabolism; therapeutic development

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The long-term goals of this project focus on defining mechanisms responsible for processing of the amyloid precursor protein (APP). Amyloidogenic processing of APP results in the generation of Abeta peptide fragments that are involved in the etiology of Alzheimer's disease (AD). The complete elucidation of the mechanisms that regulate APP processing has not been realized. We undertook a screen of ATP-binding cassette transporters expressed in the brain for their effects on APP metabolism. Our current results suggest that the ATP-binding cassette transporter (ABCA2) is a regulator of APP processing and Abeta production. Genetic evidence by single nucleotide polymorphism (SNP) mapping identified a single synonymous mutation in ABCA2 that is significantly associated with early-onset AD. We determined that ABCA2 overexpression in HEK293 cells bearing the APP Swedish mutation (APPsw) increased cellular APP holoprotein levels and Abeta secretion. Using microarray analysis of gene expression profiles in HEK293 cells stably transfected with ABCA2, we detected elevated levels of a number of genes associated with AD. The recent production of an ABCA2 knockout mouse will permit the unequivocal determination of the function of the ABCA2 transporter in regulating APP processing and Abeta production in vivo. A central hypothesis of this grant application is that ABCA2 functions in neuronal cells to regulate APP processing and Abeta production and thereby serves a critical role in maintaining homeostasis between amyloidogenic and non-amyloidogenic pathways of APP metabolism. In depth knowledge of the mechanisms of action of the ABCA2 transporter in vivo on regulation of APP processing will provide a critical basis for the development of therapeutic strategies to reduce Abeta burden in prevention and treatment of AD. This hypothesis will be investigating by pursuing the following the following specific aims: Specific Aim 1. Determine the role of ABCA2 in regulating APP processing and Abeta production in neuronal cells. Since we have previously demonstrated that ABCA2 regulates cellular APP holoprotein levels and Abetasecretion in non-neuronal HEK293 cells, we propose to investigate the specific hypothesis that ABCA2 may regulate APP processing and Abeta production in neuronal cells. Specific Aim 2: Determine the role of ABCA2 in APP processing and Abeta production through ApoE/low-density lipoprotein receptor-related protein (LRP) in neuronal cells. The ApoE4 allele is a strong genetic risk factor for AD and is a ligand for the low-density lipoprotein receptor-related protein, where it mediates esterification of HDL-derived cholesterol. LRP also mediates APP processing and Abeta generation. Since we report that ABCA2 regulates LRP expression in N2a neuroblastoma cells, perhaps by cholesterol trafficking, we propose the specific hypothesis that ABCA2 may regulate APP processing and Abeta generation through ApoE/LRP in neuronal cells.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目和 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 该项目的长期目标侧重于定义负责淀粉样前体蛋白（APP）加工的机制。 APP 的淀粉样蛋白形成过程会导致 Abeta 肽片段的产生，这些片段参与阿尔茨海默病 (AD) 的病因学。尚未完全阐明调节 APP 处理的机制。 我们对大脑中表达的 ATP 结合盒转运蛋白进行了筛选，以了解它们对 APP 代谢的影响。 我们目前的结果表明 ATP 结合盒转运蛋白 (ABCA2) 是 APP 加工和 Abeta 产生的调节者。通过单核苷酸多态性 (SNP) 作图的遗传证据确定了 ABCA2 中的单个同义突变，该突变与早发性 AD 显着相关。 我们确定携带APP瑞典突变（APPsw）的HEK293细胞中ABCA2过度表达增加了细胞APP全蛋白水平和Abeta分泌。 通过对稳定转染 ABCA2 的 HEK293 细胞中的基因表达谱进行微阵列分析，我们检测到许多与 AD 相关的基因水平升高。 最近生产的 ABCA2 敲除小鼠将能够明确确定 ABCA2 转运蛋白在体内调节 APP 加工和 Abeta 产生中的功能。 该资助申请的一个中心假设是 ABCA2 在神经元细胞中发挥作用，调节 APP 加工和 Abeta 产生，从而在维持 APP 代谢的淀粉样蛋白生成和非淀粉样蛋白生成途径之间的稳态中发挥关键作用。深入了解体内 ABCA2 转运蛋白对 APP 加工调节的作用机制，将为制定减少 AD 预防和治疗中 Abeta 负担的治疗策略提供重要基础。 该假设将通过追求以下具体目标进行调查： 具体目标 1. 确定 ABCA2 在调节神经元细胞中 APP 加工和 Abeta 产生中的作用。由于我们之前已经证明 ABCA2 调节非神经元 HEK293 细胞中的细胞 APP 全蛋白水平和 Abeta 分泌，因此我们建议研究 ABCA2 可能调节神经元细胞中 APP 加工和 Abeta 产生的具体假设。 具体目标 2：通过神经元细胞中的 ApoE/低密度脂蛋白受体相关蛋白 (LRP) 确定 ABCA2 在 APP 加工和 Abeta 产生中的作用。 ApoE4 等位基因是 AD 的一个强遗传风险因素，并且是低密度脂蛋白受体相关蛋白的配体，它介导 HDL 衍生胆固醇的酯化。 LRP 还介导 APP 处理和 Abeta 生成。 由于我们报道 ABCA2 可能通过胆固醇运输调节 N2a 神经母细胞瘤细胞中的 LRP 表达，因此我们提出了这样一个具体假设：ABCA2 可能通过神经元细胞中的 ApoE/LRP 调节 APP 加工和 Abeta 生成。