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: 7720846
• 负责人: WARREN DAVIS
• 金额: $ 21.46万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7720846
• 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; Cholesterol; Computer Retrieval of Information on Scientific Projects Database; Depth; Development; 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; Numbers; Pathway interactions; Peptide Fragments; Presenile Alzheimer Dementia; Prevention; Production; Protein Overexpression; Proteins; Regulation; Reporting; Research; Research Personnel; Resources; Role; Single Nucleotide Polymorphism Map; Source; Therapeutic; United States National Institutes of Health; amyloid precursor protein processing; apolipoprotein E-4; base; cholesterol trafficking; genetic risk factor; in vivo; protein expression; protein metabolism

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.

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 该项目的长期目标集中在确定负责处理淀粉样前体蛋白(APP)的机制。APP的淀粉样变性处理会导致Abeta多肽片段的产生，这些片段参与阿尔茨海默病(AD)的病因。调控APP处理的机制尚未完全阐明。我们对大脑中表达的ATP结合盒转运体进行了筛选，以了解它们对APP新陈代谢的影响。我们目前的结果表明，ATP结合盒转运体(ABCA2)是APP加工和Abeta产生的调节因子。单核苷酸多态(SNP)定位的遗传学证据表明，ABCA2中存在一个与早发性AD显著相关的同义突变。我们确定ABCA2在携带APP瑞典突变(APPsw)的HEK293细胞中过表达增加了细胞APP全蛋白水平和Abeta分泌。利用基因芯片分析稳定转染ABCA2的HEK293细胞的基因表达谱，我们检测到与AD相关的一些基因水平升高。最近生产的ABCA2基因敲除小鼠将使我们能够明确地确定ABCA2转运蛋白在体内调节APP加工和Abeta产生的功能。 这项拨款申请的一个中心假设是，ABCA2在神经细胞中发挥作用，调节APP的处理和Abeta的产生，从而在维持APP代谢的淀粉样变途径和非淀粉样变途径之间的动态平衡方面发挥关键作用。深入了解ABCA2转运蛋白在体内调节APP过程的作用机制，将为开发治疗策略以减少AD防治中的Aβ负担提供重要的基础。这一假设将通过追求以下具体目标进行调查： 具体目的1.确定ABCA2在调节神经细胞APP加工和Abeta产生中的作用。由于我们之前已经证明ABCA2调节非神经性HEK293细胞中APP全蛋白水平和Abeta分泌，我们建议研究ABCA2可能调节神经细胞中APP加工和Abeta产生的具体假设。 具体目的2：通过神经细胞中的载脂蛋白E/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的强烈遗传风险因素，是低密度脂蛋白受体相关蛋白的配体，在那里它介导高密度脂蛋白衍生的胆固醇的酯化。LRP还调节应用程序的处理和Abeta的生成。由于我们报道ABCA2可能通过胆固醇转运调节N2a神经母细胞瘤细胞中LRP的表达，我们提出了ABCA2可能通过ApoE/LRP在神经细胞中调节APP加工和Abeta产生的具体假设。