Project 3 - Post-transcriptional regulation of tau in aging and AD

项目 3 - 衰老和 AD 中 tau 蛋白的转录后调控

• 批准号: 8848716
• 负责人: John Fonda Crary
• 金额: $ 16.86万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8848716
• 关键词: 3' Untranslated Regions; Address; Affect; Aging; Alzheimer' s Disease; Autopsy; Behavior; Binding; Biochemical; Bioinformatics; Biological Markers; Brain region; Cell Culture Techniques; Complement; Consensus; Data; Development; Disease Progression; Down-Regulation; Drosophila genus; Drug Targeting; Event; Gene Expression; Generations; Genetic Programming; Glycogen Synthase Kinase 3; Human; In Vitro; Knowledge; Late Onset Alzheimer Disease; Lateral; Lead; Link; Longevity; Mammalian Cell; Measurement; Measures; Messenger RNA; MicroRNAs; Modeling; Molecular; Molecular Profiling; Nerve Degeneration; Neurofibrillary Tangles; Neurons; Pathogenesis; Pathway interactions; Phosphorylation; Phosphotransferases; Play; Post-Transcriptional Regulation; Post-Translational Protein Processing; Regulation; Regulator Genes; Reporter; Repression; Research; Role; Staging; Testing; Therapeutic; Toxic effect; Transcript; Transgenic Organisms; Untranslated RNA; Untranslated Regions; Work; base; brain tissue; cognitive function; disease phenotype; entorhinal cortex; gene repression; glycogen synthase kinase 3 beta; hyperphosphorylated tau; in vivo; innovation; miRNA expression profiling; neuron loss; neurotoxicity; novel; overexpression; research study; tau Proteins; tau expression; tau phosphorylation; transcriptome sequencing

PROJECT 3 SUMMARY Understanding the earliest events in Alzheimer disease (AD) has the potential to lead to therapeutic strategies that slow and/or halt disease progression. Addressing AD at its earliest stages is critical as it might be too late to regain cognitive function once neuronal loss has occurred. Development of neurofibrillary tangles (NFT) in the entorhinal cortex (EC) is among the earliest pathological events in AD, but what underlies this regional vul- nerability remains a mystery. NFT are abnormal aggregates of the microtubule-associated protein tau that be- come hyperphosphorylated and aggregated following abnormal kinase activity. Several post-translational modi- fications have been proposed to contribute to tau toxicity, with hyperphosphorylation thought to play a pivotal role. Recently, it has become widely recognized that late-onset AD is associated with abnormalities in mi- croRNAs (miRNAs), small non-coding RNAs that are powerful regulators of gene expression. MiRNAs bind to and silence target mRNAs on the post-transcriptional level. Each miRNA can bind many target transcripts, providing an additional level of regulation that complements canonical transcriptional pathways. While a con- sensus is beginning to emerge that certain miRNAs are consistently altered in AD, the functional significance if these findings remain unclear. The overall objective of this application is to characterize miRNA regulation of the expression of tau and glycogen synthase kinase 3 b (GSK3b), a kinase implicated in tau phosphorylation and leading candidate drug target in AD. This will be accomplished by performing miRNA profiling studies in human autopsy brain tissue and then modeling candidate pathogenic changes with in vitro mammalian neu- ronal cultures and transgenic Drosophila. Our central hypothesis is that down-regulation of miRNAs leads to de-repression of a genetic program that increases expression of genes that drive tau toxicity. To test our hy- pothesis, we propose the following specific aims: 1) to characterize changes in miRNA expression early in AD progression, with a focus on the lateral entorhinal cortex, a region affected early in AD, 2) to characterize miR- NA regulation of the expression of tau and GSK3b, and 3) to demonstrate that miRNAs modulate tau neurotox- icity. This project is significant because it will lead to a better understanding of a genetic program that regulates the expression of genes that we hypothesize contribute the generation of toxic forms of hyperphosphorylated tau and the progression of AD. This proposal is innovative because looking at miRNA regulation has forced a re-assessment of gene expression that will provide a new perspective on the pathogenesis of AD as well as a new framework and new models to investigate mechanisms of tau regulation and toxicity. Together, these ex- periments will help us address the critical need of understanding the earliest events in AD and help pave the way towards new strategies to address AD with miRNA-based biomarkers and therapeutics.

项目 3 摘要 了解阿尔茨海默病 (AD) 的最早事件有可能制定治疗策略 减缓和/或阻止疾病进展。在最早阶段解决 AD 问题至关重要，因为可能为时已晚 一旦发生神经元损失，即可恢复认知功能。神经原纤维缠结（NFT）的发展 内嗅皮质 (EC) 是 AD 中最早的病理事件之一，但这种区域性损伤的基础是什么？ 稳定性仍然是一个谜。 NFT 是微管相关蛋白 tau 的异常聚集体， 激酶活性异常后发生过度磷酸化和聚集。几种翻译后修饰 已提出tau蛋白的磷酸化会导致tau蛋白毒性，其中过度磷酸化被认为发挥着关键作用 角色。最近，人们广泛认识到迟发性 AD 与 MI 异常相关。 croRNA (miRNA) 是一种小型非编码 RNA，是基因表达的强大调节因子。 miRNA 结合 并在转录后水平沉默靶标 mRNA。每个miRNA可以结合许多目标转录物， 提供额外水平的调节来补充规范转录途径。虽然一个骗子 人们开始认识到某些 miRNA 在 AD 中持续发生改变，如果 这些发现仍不清楚。本应用的总体目标是表征 miRNA 调控 tau 和糖原合酶激酶 3 b (GSK3b) 的表达，糖原合酶激酶 3b 是一种参与 tau 磷酸化的激酶 AD 的主要候选药物靶点。这将通过在以下环境中进行 miRNA 分析研究来完成 人体尸检脑组织，然后用体外哺乳动物神经元模拟候选致病变化 ronal培养物和转基因果蝇。我们的中心假设是 miRNA 的下调会导致 去抑制一个基因程序，该程序会增加驱动 tau 毒性的基因的表达。为了测试我们的hy- 假设，我们提出以下具体目标：1）表征 AD 早期 miRNA 表达的变化 进展，重点关注外侧内嗅皮层，这是 AD 早期受影响的区域，2) 来表征 miR- NA 调节 tau 和 GSK3b 的表达，以及 3) 证明 miRNA 调节 tau 神经毒素 冰城。这个项目意义重大，因为它将导致人们更好地理解调节基因的基因程序 我们假设基因的表达有助于产生过度磷酸化的有毒形式 tau 蛋白与 AD 的进展。这个提议是创新的，因为对 miRNA 调控的研究迫使人们 基因表达的重新评估将为 AD 的发病机制提供新的视角 研究 tau 调节和毒性机制的新框架和新模型。这些前任一起 实验将帮助我们满足理解公元最早事件的迫切需要，并帮助铺平道路 寻找利用基于 miRNA 的生物标志物和疗法来解决 AD 的新策略。