Project 1: Differential Roles of ApoE Isoforms in Neural Network Dysfunction of Alzheimer's Disease

项目 1：ApoE 同工型在阿尔茨海默病神经网络功能障碍中的不同作用

基本信息

批准号：
10670337
负责人：
YADONG HUANG
金额：
$ 94.27万
依托单位：
J. DAVID GLADSTONE INSTITUTES
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-08-15 至 2026-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10670337
关键词：
Abeta synthesis Affect Age Age of Onset Alleles Alzheimer&apos s Disease Alzheimer&apos s disease model Alzheimer&apos s disease risk Amyloid beta-Protein Apolipoprotein E Astrocytes Behavioral Brain region Cell Culture Techniques Cells Clinical Research Cognition Collaborations Dose Enterobacteria phage P1 Cre recombinase Etiology Frontotemporal Dementia Genes Genetic Hippocampus Human Individual Knock-in Knowledge LoxP-flanked allele Microglia Molecular Mus Nature Network-based Neurofibrillary Tangles Neurons Pathogenesis Pathologic Pathology Pathway interactions Population Study Program Research Project Grants Protein Isoforms Role Virulence Factors age related apolipoprotein E-4 cell type genetic risk factor insight mouse model mutant network dysfunction neural network neurofibrillary tangle formation novel prevent single nucleus RNA-sequencing tau Proteins therapeutic target therapy development transcriptomics

项目摘要

PROJECT 1 – SUMMARY The complexity and multifactorial nature of Alzheimer’s disease (AD) pose unique challenges for mechanistic studies and developing therapies. Although the three major pathogenic factors of AD—amyloid-beta peptides, tau, and apolipoprotein E4 (apoE4)—have been extensively studied as independent entities in AD pathogenesis, efforts to target individual AD-related pathways, such as Ab production or clearance, have largely failed in human trials. Emerging evidence strongly suggests that AD is a consequence of age-dependent neural network dysfunction in brain regions that mostly affect cognition, likely through the interactive effects of multiple pathogenic factors. Thus, there is a pressing need to identify novel mechanisms and therapeutic targets, at a neural network level and in the context of interactions between multiple pathogenic factors—the focus of this proposal. APOE4, which encodes one of the three major isoforms of apoE in humans, is the major genetic risk factor for AD and lowers the age of onset in a gene dose-dependent manner. In most clinical studies, APOE4 carriers account for 60–75% of AD cases, highlighting the importance of APOE4 in AD pathogenesis. On the other hand, many clinical and population studies show that APOE2, encoding the rarest apoE isoform, is a strongly protective genetic factor in AD. A pathological hallmark of AD is the formation of neurofibrillary tangles (NFTs) consisting of hyperphosphorylated, insoluble tau, containing both 3R and 4R tau isoforms. In cell cultures and mouse models, apoE isoforms have tau-dependent differential effects, and tau has apoE isoform-dependent effects, suggesting interactive roles in AD pathogenesis. However, almost all of these studies of apoE isoforms and tau drew conclusions based either on mouse tau, which is present almost exclusively as 4R tau, or on mutant human tau, which is associated with frontotemporal dementia but not AD. In Project 1, we propose to determine cell- type-specific, differential roles of apoE isoforms in age-dependent neural network dysfunction and behavioral deficits, in the context of wildtype (WT) human tau (both 3R and 4R tau isoforms), in novel mouse models of AD. In Aim 1, we will determine differential roles of apoE isoforms in neural network dysfunction and behavioral deficits, using apoE-isoform-floxed knock-in (APOEfE2/fE2 [fE2], APOEfE3/fE3 [fE3], and APOEfE4/fE4 [fE4]) mice expressing WT human tau (MAPT knock-in or TAUWT) at different ages. In Aim 2, we will determine cell-type- specific, differential roles of apoE isoforms in neural network dysfunction and behavioral deficits, using fE2/TAUWT, fE3/TAUWT, and fE4/TAUWT mice expressing cell-type-specific Cre recombinase (neuron-specific Cresyn1, astrocyte-specific CreGFAP, and microglia-specific CreCx3cr1) in order to delete the APOE allele in a cell- type-specific manner. The studies in this project, together with those of the three other projects of this program project grant, will yield new insights into the multifactorial pathogenesis of AD and may identify neural network- based targets for apoE isoform–dependent and cell type-specific therapies to treat or prevent AD.

项目 1 – 摘要阿尔茨海默病 (AD) 的复杂性和多因素性质给机械治疗带来了独特的挑战尽管AD的三大致病因素——淀粉样蛋白-β肽， tau 和载脂蛋白 E4 (apoE4)——作为 AD 发病机制中的独立实体已被广泛研究，针对个体 AD 相关途径（例如抗体产生或清除）的研究在人类中基本上失败了新出现的证据强烈表明 AD 是年龄依赖性神经网络的结果。主要影响认知的大脑区域功能障碍，可能是通过多种因素的相互作用产生的因此，迫切需要确定新的机制和治疗靶点。神经网络水平以及多种致病因素之间相互作用的背景——本研究的重点提议。 APOE4 编码人类 apoE 的三种主要亚型之一，是以下疾病的主要遗传风险因素：在大多数临床研究中，APOE4 携带者可以以基因剂量依赖的方式降低 AD 的发病年龄。占 AD 病例的 60-75%，凸显了 APOE4 在 AD 发病机制中的重要性。许多临床和人群研究表明，APOE2 编码最稀有的 apoE 亚型，是一种强保护性药物。 AD 的一个病理特征是神经原纤维缠结 (NFT) 的形成。细胞培养物和小鼠中含有 3R 和 4R tau 亚型的高度磷酸化、不溶性 tau 蛋白。模型，apoE亚型具有tau依赖性差异效应，并且tau具有apoE亚型依赖性效应，然而，几乎所有这些研究都涉及 apoE 亚型和 tau 蛋白。根据小鼠 tau（几乎完全以 4R tau 形式存在）或突变人类得出结论 tau，与额颞叶痴呆有关，但与 AD 无关。在项目 1 中，我们建议确定细胞- apoE亚型在年龄依赖性神经网络功能障碍和行为中的类型特异性、差异性作用在新型 AD 小鼠模型中，野生型 (WT) 人类 tau（3R 和 4R tau 亚型）存在缺陷。在目标 1 中，我们将确定 apoE 亚型在神经网络功能障碍和行为中的不同作用缺陷，使用 apoE-isoform-floxed 敲入（APOEfE2/fE2 [fE2]、APOEfE3/fE3 [fE3] 和 APOEfE4/fE4 [fE4]）小鼠在不同年龄表达 WT 人类 tau（MAPT 敲入或 TAUWT）在目标 2 中，我们将确定细胞类型。 apoE 亚型在神经网络功能障碍和行为缺陷中的特定、不同作用，使用 fE2/TAUWT、fE3/TAUWT 和 fE4/TAUWT 小鼠表达细胞类型特异性 Cre 重组酶（神经元特异性 Cresyn1、星形胶质细胞特异性 CreGFAP 和小胶质细胞特异性 CreCx3cr1），以删除细胞中的 APOE 等位基因 - 该项目以及该计划其他三个项目的研究。项目资助，将对 AD 的多因素发病机制产生新的见解，并可能识别神经网络 - 基于 apoE 同工型依赖性和细胞类型特异性疗法的靶点来治疗或预防 AD。