Elucidating the roles of AMPK isoforms in Alzheimer's Disease Pathogenesis

阐明 AMPK 亚型在阿尔茨海默病发病机制中的作用

• 批准号: 9468906
• 负责人: Helena Rose Zimmermann
• 金额: $ 4.4万
• 依托单位: WAKE FOREST UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-30 至 2019-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9468906
• 关键词: 5' -AMP-activated protein kinase; Alzheimer' s Disease; Alzheimer' s disease model; Amyloid beta-Protein; Amyloid deposition; Behavior; Behavioral; Biochemical; Brain; Cause of Death; Cell model; Cognition Disorders; Communities; Defect; Dementia; Development; Disease; Elderly; Electrophysiology (science); Epidemic; Event; Excision; Functional disorder; Genes; Genetic; Genetic Translation; Goals; Hippocampus (Brain); Homeostasis; Human; Impairment; Intervention; Knockout Mice; Learning; Light; Long-Term Potentiation; Memory; Memory Loss; Memory impairment; Methods; Molecular; Mus; Mutant Strains Mice; Mutation; Neurodegenerative Disorders; Neurons; Pathogenesis; Pathology; Patients; Phosphotransferases; Prevention; Preventive Intervention; Prosencephalon; Protein Biosynthesis; Protein Isoforms; Protein Kinase; Proteins; Proto-Oncogene Proteins c-akt; Publications; Regulation; Repression; Research; Role; Short-Term Memory; Signal Pathway; Signal Transduction; Synaptic plasticity; Technical Expertise; Testing; Time; Transgenic Mice; Treatment Efficacy; V717F; Work; aging population; brain health; brain tissue; diagnostic biomarker; excitatory neuron; experimental study; familial Alzheimer disease; human tissue; impaired capacity; improved; morris water maze; mouse model; mutant mouse model; new therapeutic target; novel; novel diagnostics; object recognition; rapid growth; sensor; spatial memory; synaptic failure; targeted biomarker; therapeutic target

Project Summary/Abstract Alzheimer’s disease (AD) is the most common form of dementia in the elderly, and may become a new epidemic in the 21st century in accordance with the rapid growth of the aging population. There is currently no known cure or treatment to stop the progression of AD. Moreover, the basic molecular mechanisms responsible for AD remain elusive. Two key events in AD pathophysiology are impaired capacity of de novo protein synthesis (mRNA translation) and disrupted cellular energy homeostasis. AMP-activated protein kinase (AMPK) acts as a central cellular energy sensor to maintain cellular energy homeostasis. Furthermore AMPK integrates several signaling pathways (including AKT, GSK3, mTORC1, and eEF2) controlling de novo protein synthesis, dysregulation of which is implicated in cognitive syndromes associated with neurodegenerative diseases including AD. Mammalian AMPK is a heterotrimeric protein with a catalytic α subunit and regulatory β/γ subunit. The α subunit of AMPK exists in two isoforms: α1 and α2, and their roles in AD are unknown. By investigating brain tissue from post mortem human AD patients and a transgenic mouse model of AD, I have found that levels of AMPKα1 are dramatically increased while levels of AMPKα2 are decreased. The central hypothesis of the current project is that disruption of AMPK isoform homeostasis represents a key molecular mechanism of AD pathophysiology. Thus, the objective of this project is to determine whether selective AMPK isoform inhibition (and subsequent altering of AMPK isoform homeostasis) alleviates AD-associated deficits in protein synthesis and memory formation. This project will utilize a novel mouse model in which Prkaa1 and Prkaa2 (genes that encode AMPK α1 and α2 subunits, respectively) were removed in excitatory neurons in forebrains and hippocampus late in development, to generate brain- and isoform-specific conditional AMPKα1 and α2 knockout mice (AMPKα1 cKO and AMPKα2 cKO). We have further crossed the heterozygous AMPKα1/2 cKO mice [AMPKα1(+/-) and AMPKα2(+/-)] with Tg19959 AD mouse model (containing two familial AD mutations: K670N and V717F) to generate Tg19959/AMPKα1(+/-) and Tg19959/AMPKα2(+/-) double mutant mice. Using behavioral, electrophysiological, and biochemical methods, the experiments here will 1) elucidate the effects of genetic repression of AMPK isoforms on AD-associated synaptic plasticity impairments; 2) determine the effects of AMPK isoform suppression in learning and memory deficits in AD model mice; and 3) establish whether specific AMPK isoform reduction improves AD pathology, including brain amyloid deposition and de novo protein synthesis impairments. The experimental findings derived from this project will help elucidate a novel mechanism for AD pathophysiology, shedding a light on potentially new diagnostic biomarkers and therapeutic targets.

项目摘要/摘要 阿尔茨海默氏病（AD）是最古老的痴呆症形式，可能成为一种新的 21世纪的流行病符合老龄化人口的迅速增长。目前没有 已知的治疗或治疗以阻止AD的进展。此外，基本的分子机制 负责广告仍然难以捉摸。 AD病理生理学中的两个关键事件是从头开始的受损能力 蛋白质合成（mRNA翻译）和细胞能量稳态破坏。 AMP激活的蛋白激酶 （AMPK）充当维持细胞能量稳态的中央细胞能传感器。此外，AMPK 集成了几个信号通路（包括AKT，GSK3，MTORC1和EEF2） 合成，与神经退行性相关的认知综合征中隐含的失调 包括广告在内的疾病。哺乳动物AMPK是具有催化α亚基和调节性的异三聚体蛋白 β/γ亚基。 AMPK的α亚基存在于两个同工型中：α1和α2，它们在AD中的作用尚不清楚。经过 研究Mortem人类AD患者的脑组织和AD的转基因小鼠模型，我有 发现AMPKα1的水平急剧增加，而AMPKα2水平降低。中央 当前项目的假设是AMPK同工稳态的破坏代表关键分子 AD病理生理的机制。这是该项目的目的是确定选择性AMPK是否 同工型抑制（随后改变AMPK同工稳态）减轻了与AD相关的缺陷 蛋白质合成和记忆形成。该项目将利用一种新颖的鼠标模型，其中Prkaa1和 PRKAA2（分别编码AMPKα1和α2亚基的基因）在兴奋性神经元中删除 前脑和海马在发育后期，以产生脑和同工型特异性条件AMPKα1 和α2基因敲除小鼠（AMPKα1CKO和AMPKα2CKO）。我们进一步越过杂合子 AMPKα1/2 CKO小鼠[AMPKα1（+/-）和AMPKα2（+/--）] tg19959 AD鼠标模型（包含两个家庭模型 AD突变：K670N和V717F）生成TG19959/AMPKα1（+/-）和TG19959/AMPKα2（+/-）Double 突变小鼠。使用行为，电生理和生化方法，这里的实验将1） 阐明AMPK同工型遗传表示对AD相关的合成可塑性障碍的影响； 2）确定AMPK同工型在学习中的影响，并在AD模型小鼠中定义记忆；和 3）确定特定的AMPK同工型还原是否可以改善AD病理，包括脑淀粉样蛋白 沉积和从头蛋白质合成障碍。该项目得出的实验发现将 帮助阐明一种新型的AD病理生理学机制，阐明了潜在的新诊断 生物标志物和治疗靶标。