The role of beta-secretase 1 (BACE1) in modulating excitatory synaptic and circuit function and behavior

β-分泌酶 1 (BACE1) 在调节兴奋性突触和回路功能和行为中的作用

• 批准号: 10607846
• 负责人: ANNIE Y YAO
• 金额: $ 4.32万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-22 至 2027-02-21
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10607846
• 关键词: Address; Adult; Adverse effects; Alzheimer' s Disease; Alzheimer' s disease model; Alzheimer' s disease pathology; Alzheimer' s disease patient; Alzheimer' s disease therapeutic; Alzheimer' s disease therapy; Amyloid beta-Protein; Behavior; Behavioral; Behavioral Assay; Biochemical; Brain; Cause of Death; Cells; Cessation of life; Clinical Skills; Clinical Trials; Cognition; Cognitive deficits; Communication; Data; Defect; Dementia; Development; Development Plans; Disease; Disease Progression; Electrophysiology (science); Enzymes; Equilibrium; Excitatory Synapse; Failure; Future; Generations; Genetic; Health; Hippocampus; Human; Impaired cognition; Impairment; Ion Channel; Knockout Mice; Knowledge; Learning; Membrane; Membrane Potentials; Memory; Memory Loss; Memory impairment; Mentors; Methods; Mus; Mutant Strains Mice; Neurodegenerative Disorders; Neurons; Pathologic; Patients; Peptide Hydrolases; Phase; Phenotype; Physicians; Physiological; Physiology; Play; Potassium; Property; Prosencephalon; Publishing; Regulation; Research; Rest; Rodent; Rodent Model; Role; Scientist; Seizures; Senile Plaques; Sodium; Synapses; Synaptic Transmission; Synaptic plasticity; Technical Expertise; Techniques; Testing; Therapeutic; Training; Transgenic Organisms; abeta accumulation; abeta oligomer; age related neurodegeneration; behavioral study; beta-site APP cleaving enzyme 1; career; cell type; cognitive function; designer receptors exclusively activated by designer drugs; doctoral student; drug development; epileptiform; excitatory neuron; experience; extracellular; genetic approach; genetic manipulation; hippocampal pyramidal neuron; in vivo; inhibitor; insight; mutant; neuronal circuitry; neuronal excitability; neurophysiology; neurotoxicity; novel; patch clamp; presynaptic; prevent; skills; synaptic function; therapeutic target; voltage

PROJECT SUMMARY Alzheimer’s Disease (AD), the most common cause of dementia, is a debilitating disease that leads to progressive memory loss, cognitive impairment, and ultimately death. Pathological hallmarks of AD include extracellular amyloid beta (Aβ) plaques. β-secretase-1 (β-site APP cleaving enzyme 1, BACE1) is the rate- limiting enzyme of toxic Aβ generation. Transgenic BACE1 KO mouse models of AD led to suppression of AD pathology, which suggests that inhibiting BACE1 may be a rational strategy for AD treatment. However, human clinical trials have shown that BACE1 inhibitors are inefficacious, even worsening cognitive function, among AD patients. This benchtop-to-bedside translational failure is due to our incomplete understanding of BACE1’s physiological function. In particular, the mechanisms underlying neuronal and synaptic impairments in BACE1 deficiency or inhibition is poorly understood. In this proposal, we will address this knowledge gap by testing the hypothesis that BACE1 modulates intrinsic and synaptic neurophysiological properties in a cell-type- and circuit- specific manner in the hippocampus, a major substrate of memory storage derailed by AD. My preliminary data of whole-cell patch clamp of hippocampal pyramidal neurons (PNs) show that selective BACE1 deletion in excitatory neurons leads to neuronal hyperexcitability, suggesting that BACE1 deletion disrupts intrinsic neuronal function in a cell-autonomous manner. Given my preliminary findings, I hypothesize that BACE1 modulates excitability and synaptic transmission in hippocampal PNs by the regulation of ion channels – the identities of which have yet to be fully elucidated. In Aim 1, I will comprehensively determine the ionic basis underlying the hyperexcitability phenotype in my Excitatory-BACE1-KO mice (mice in which BACE1 is selectively deleted in excitatory PNs), and characterize the synaptic transmission and plasticity deficits in Excitatory-BACE1-KO, through patch clamp electrophysiology methods. In Aim 2, I will delineate behavioral deficits Excitatory-BACE1- KO neurons, and rescue hypothesized cognitive deficits in mutant mice by normalizing PN hyperexcitability through a chemogenetic approach. The findings from this study will provide insight into neuronal and synaptic physiology, mechanisms of learning/memory and behavior, and future AD therapeutic strategies. Importantly, completion of this project will help me master current concepts and state-of-the-art techniques in patch clamp electrophysiology, behavior studies, and in vivo genetic perturbation and increase my scientific communication skills through extensive opportunities to present and publish my studies. As an MD/PhD student at UConn Health, I will have access to mentors and experts that will not only directly facilitate my mastery of the necessary technical skills, but I will also have opportunities to continue honing my clinical skills and gain specialized experience during and after my research phase. Fulfilling my training and development plan will be a crucial step toward my future career as a physician-scientist studying the mechanisms underlying neurodegenerative disease in patients.

项目总结 阿尔茨海默病(AD)是导致痴呆症的最常见原因，是一种使人衰弱的疾病，会导致 进行性记忆丧失，认知障碍，最终死亡。阿尔茨海默病的病理特征包括 细胞外淀粉样β蛋白(Aβ)斑块。β-分泌酶-1(β-Site APP裂解酶1，BACE1)是指- 产生毒性Aβ的限制酶。转基因BACE1KO小鼠AD模型对AD的抑制作用 这表明抑制BACE1可能是治疗AD的一种合理策略。然而，人类 临床试验表明，在阿尔茨海默病患者中，BACE1抑制剂无效，甚至恶化认知功能 病人。这种从桌上到床边的翻译失败是因为我们对北京一号线的S了解不够全面 生理功能。特别是，BACE1中神经元和突触损伤的潜在机制 对缺乏或抑制知之甚少。在本提案中，我们将通过测试 假设BACE1调节细胞类型和回路中的固有和突触神经生理特性- 特定的方式在海马体，一个主要的底物的记忆存储脱轨AD。我的初步数据 海马锥体神经元(PNS)全细胞膜片钳的研究表明，BACE1选择性缺失在 兴奋性神经元导致神经元超兴奋性，提示BACE1缺失扰乱了固有神经元 以细胞自主的方式运作。根据我的初步发现，我假设BACE1调节 离子通道调节的海马三叉神经节兴奋性和突触传递 这些都还没有完全阐明。在目标1中，我将全面确定 我的兴奋性-BACE1-KO小鼠(其中BACE1选择性缺失的小鼠)的超兴奋性表型 兴奋性PNS)，并对兴奋性BACE1-KO的突触传递和可塑性缺陷进行了表征， 通过膜片钳电生理学方法。在目标2中，我将描述行为缺陷兴奋性-BACE1- KO神经元，并通过正常化PN超兴奋性来挽救突变小鼠假想的认知缺陷 通过化学遗传学的方法。这项研究的发现将提供对神经元和突触的洞察 生理，学习/记忆和行为的机制，以及未来的AD治疗策略。重要的是 这个项目的完成将帮助我掌握膜片钳的当前概念和最先进的技术 电生理学、行为研究和体内遗传干扰，增加了我的科学交流 通过广泛的机会展示和发表我的研究成果。作为康涅狄格州大学健康学院的一名医学博士/博士研究生， 我将有机会接触到导师和专家，他们不仅会直接帮助我掌握必要的技术 技能，但我也将有机会继续磨练我的临床技能并获得专业经验 在我的研究阶段期间和之后。完成我的培训和发展计划将是迈向我 未来的职业生涯是一名内科科学家，研究神经退行性疾病的潜在机制 病人。