Isoform-specific roles of AMPK in synaptic failure and memory deficit in Alzheimer's Disease

项目摘要/摘要 与阿尔茨海默病(AD)相关的基本分子机制仍然是一个关键的知识缺口 这阻碍了有效的治疗靶点和诊断/预后生物标记物的确定。海流 提案将通过研究与AMP激活相关的信号通路的作用来解决这一差距 蛋白激酶(AMPK)在AD中的异构体。AMPK作为中枢细胞能量感受器维持能量 动态平衡。此外，AMPK是整合多种信号通路的纽带，参与从头蛋白的形成。 合成(mRNA翻译)。重要的是，能量平衡的破坏和从头开始的损伤 蛋白质合成与神经退行性疾病相关的认知综合征有关，包括 广告。AMPK的激酶催化亚基在脑中以两种亚型存在：α1和α2，它们在突触中的作用 可塑性和记忆力是未知的。我们生成了特定于大脑和异构体的条件性AMPKα1和α2 基因敲除小鼠(AMPKα1 CKO和AMPKα2 CKO)，并进行行为、电生理、成像和 生化测试，以确定同工型的特殊表型。在我们初步数据的推动下，我们的中央 假说认为AMPK亚型动态平衡的破坏是 AD相关的突触可塑性损害和记忆缺陷。制定了三个具体目标，以 检验这一假设。目的1确定AMPK在海马区突触可塑性中的异构体特异性作用 和记忆的形成。AIM 2旨在确定AMPK亚型对突触失败的特异性调节 Tg19959 AD模型小鼠记忆功能障碍。AIM 3旨在阐明AMPK亚型特异性 Tg19959 AD小鼠模型对新生蛋白合成及脑Aβ病理的影响该项目 使用神经科学和AD领域的多种最新方法进行深入分析，包括小鼠 遗传学、突触电生理学、共聚焦成像和行为测试。此外，新的方法可以 将结合质谱学/蛋白质组学方法测量从头合成蛋白质 揭示阿尔茨海默病脑内因信号转导异常而合成失调的蛋白质的特性 破坏AMPK亚型的动态平衡。这种多学科的方法将使我们能够确定详细的 阿尔茨海默病发病机制中AMPK信号异常的细胞/分子机制 对AD和其他痴呆综合征的新治疗靶点和诊断生物标记物的见解。

Project Summary/Abstract The basic molecular mechanisms associated with Alzheimer’s disease (AD) remain a critical knowledge gap that prevents identification of effective therapeutic targets and diagnostic/prognostic biomarkers. The current proposal will address this gap by studying the role of signaling pathways associated with AMP-activated protein kinase (AMPK) isoforms in AD. AMPK functions as a central cellular energy sensor to maintain energy homeostasis. Moreover, AMPK is a nexus to incorporate multiple signaling pathways for de novo protein synthesis (mRNA translation). Importantly, both disruptions in energy homeostasis and impairments in de novo protein synthesis are implicated in cognitive syndromes associated with neurodegenerative diseases, including AD. The kinase catalytic subunit of AMPK exists in two isoforms in brain: α1 and α2, and their roles in synaptic plasticity and memory are unknown. We generated brain- and isoform-specific conditional AMPKα1 and α2 knockout mice (AMPKα1 cKO and AMPKα2 cKO), and performed behavioral, electrophysiology, imaging, and biochemical tests to characterize isoform-specific phenotypes. Driven by our preliminary data, our central hypothesis is that disruption of AMPK isoform homeostasis represents a key molecular mechanism underlying AD-associated impairments of synaptic plasticity and memory defects. Three specific aims are formulated to test the hypothesis. Aim 1 seeks to identify isoform-specific roles of AMPK in hippocampal synaptic plasticity and memory formation. Aim 2 is designed to determine AMPK isoform-specific regulation of synaptic failure and memory impairment in Tg19959 AD mouse model. Aim 3 is designed to elucidate AMPK isoform-specific effects on de novo protein synthesis and brain Aβ pathology in Tg19959 AD mouse model. The project proposes in-depth analyses using multiple state-of-art methods in neuroscience and AD, including mouse genetics, synaptic electrophysiology, confocal imaging, and behavioral tests. Moreover, novel methods to measure de novo protein synthesis combined with mass spectrometry/proteomics approach will be applied to reveal identities of proteins in AD brains whose synthesis is dysregulated because of abnormal signaling due to disruption of AMPK isoform homeostasis. This multidisciplinary approach will enable us to identify detailed cellular/molecular mechanisms associated with aberrant AMPK signaling in AD pathogenesis, providing insights into novel therapeutic targets and diagnostic biomarkers for AD and other dementia syndromes.