ATP-Binding Cassette Transporter-2 Regulates Amyloid Precursor Protein Dynamics

ATP 结合盒转运蛋白 2 调节淀粉样蛋白前体蛋白动力学

• 批准号: 7739032
• 负责人: WARREN DAVIS
• 金额: $ 16.57万
• 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: 2009-09-30 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7739032
• 关键词: Alzheimer' s Disease; Alzheimer' s disease model; Amyloid beta-Protein Precursor; Brain; Cells; Cholesterol; Cholesterol Homeostasis; Crossbreeding; Enzymes; Etiology; Generations; Genes; Goals; Homeostasis; Human; In Vitro; Investigation; Knock-out; Knockout Mice; Knowledge; Link; Lysosomes; Mediating; Membrane; Membrane Microdomains; Metabolism; Microarray Analysis; Mus; Mutation; Neuroglia; Neurons; Pathway interactions; Peptides; Prevention; Process; Production; Protein Dynamics; Proteins; Proteolytic Processing; Regulation; Role; Tg2576; Transgenic Mice; Transgenic Organisms; Ursidae Family; amyloid precursor protein processing; base; cholesterol trafficking; clinically relevant; human TAP2 protein; in vivo; late endosome; mind control; mouse model; mutant; novel; promoter; public health relevance; secretase; therapeutic development

DESCRIPTION (provided by applicant): Project Summary: The long-term goals of this project focus on establishing the ATP-binding cassette transporter-2 (ABCA2) as a novel regulator of proteolytic processing of the amyloid precursor protein (APR). Amyloidogenic processing of APP results in the generation of A-beta peptide cleavage products that are implicated in the etiology of Alzheimer's disease (AD). The complete elucidation of the mechanisms that regulate APP processing and Ap production has not been realized. One mechanism that regulates APP processing is the cholesterol trafficking-dependent localization of APP and key enzymes that mediate its proteolytic cleavage in membrane compartments. ABCA2 may function to modulate intracellular cholesterol trafficking of exogenous llpoprotein-derived cholesterol from late-endosomes/lysosomes to membrane compartments. We identified ABCA2 as a regulator of APP processing and A-beta production in vitro. We determined that cellular APP holoprotein levels and A-beta secretion were increased in non-neuronal HEK293 cells that stably co-expressed ABCA2 and APP bearing the APP "Swedish" mutation. We also detected increased expression of a number of genes associated with AD using microarray analysis in HEK293 cells that stably expressed ABCA2. Although evidence suggests that ABCA2 may be a key regulator of APP metabolism, perhaps by regulation of intracellular cholesterol trafficking and distribution, we have not examined the effects of ABCA2 function in either neuronal cells or in the brains of transgenic mice expressing mutant forms of APP. Our recent production of ABCA2 knockout mice and ABCA2 transgenic mice under the control of the brain-specific Thy-1 promoter will permit the investigation of this novel function of the ABCA2 transporter in regulating APP processing and A-beta production in vivo in transgenic mouse models of AD. Our preliminary results have led us to the novel hypothesis that ABCA2 acts to regulate APP processing and A-beta production through modulation of intracellular cholesterol trafficking-dependent localization of APP and key processing enzymes in membrane compartments. Public Health Relevance: These studies may provide novel and mechanistic links between cholesterol metabolism and APP processing that could be of direct clinical relevance. In depth knowledge of the mechanisms of action of the ABCA2 transporter on regulation of APP processing may provide a basis for the development of therapeutic strategies in prevention and treatment of AD.

描述（由申请人提供）： 项目摘要：该项目的长期目标侧重于建立 ATP 结合盒转运蛋白 2 (ABCA2) 作为淀粉样前体蛋白 (APR) 蛋白水解过程的新型调节剂。 APP 的淀粉样蛋白形成过程会导致 A-β 肽裂解产物的产生，这些产物与阿尔茨海默病 (AD) 的病因学有关。尚未完全阐明调节 APP 加工和 Ap 生产的机制。调节 APP 加工的一种机制是 APP 的胆固醇运输依赖性定位以及介导其在膜区室中蛋白水解裂解的关键酶。 ABCA2 可能起到调节外源脂蛋白衍生胆固醇从晚期内体/溶酶体到膜区室的细胞内胆固醇运输的作用。我们确定 ABCA2 是体外 APP 加工和 A-β 产生的调节剂。我们确定，在稳定共表达 ABCA2 和带有 APP“Swedish”突变的 APP 的非神经元 HEK293 细胞中，细胞 APP 全蛋白水平和 A-β 分泌增加。我们还在稳定表达 ABCA2 的 HEK293 细胞中使用微阵列分析检测到许多与 AD 相关的基因表达增加。尽管有证据表明 ABCA2 可能是 APP 代谢的关键调节因子，可能是通过调节细胞内胆固醇运输和分布来实现的，但我们尚未研究 ABCA2 功能对神经元细胞或表达突变形式 APP 的转基因小鼠大脑的影响。我们最近在大脑特异性 Thy-1 启动子控制下生产了 ABCA2 敲除小鼠和 ABCA2 转基因小鼠，这将允许在 AD 转基因小鼠模型中研究 ABCA2 转运蛋白在体内调节 APP 加工和 A-β 产生的新功能。我们的初步结果使我们得出了一个新的假设，即 ABCA2 通过调节细胞内胆固醇运输依赖性 APP 和膜区室中关键加工酶的定位来调节 APP 加工和 A-β 产生。 公共卫生相关性：这些研究可能提供胆固醇代谢和 APP 处理之间新颖的机制联系，可能具有直接的临床相关性。深入了解 ABCA2 转运蛋白对 APP 加工调节的作用机制可能为制定预防和治疗 AD 的治疗策略提供基础。