Impact of vascular apoE in aging and AD

项目总结(APOE U19：项目4) 而载脂蛋白E(ApoE)的主要功能是介导脂质转运，而apoE基因型(apo2， APOE3和APOE4)显著影响认知功能和阿尔茨海默病(AD)的发病机制 通过多条途径。载脂蛋白E不仅与淀粉样蛋白β(Aβ)的病理有关，而且与脑血管疾病有关 功能包括血脑屏障完整性和脑血流量。鉴于脑血管疾病 ApoE在老年人的认知能力下降中起重要作用，并且在血管中大量表达 大脑中的壁细胞(平滑肌细胞和周细胞)以及星形胶质细胞和小胶质细胞，总的目标是 项目4的目的是定义血管壁细胞中的载脂蛋白E基因如何影响分子机制和 衰老和阿尔茨海默病期间脑血管调节障碍和认知功能下降的发展途径。在……里面 目的1、利用表达人载脂蛋白2、载脂蛋白3或载脂蛋白4基因的新型小鼠模型 血管壁细胞特异性Sm22α启动子驱动的Cre切除loxP侧翼截止盒 血管壁细胞特异性表达载脂蛋白E亚型对血管内皮生长因子的影响 衰老过程中的脑血管功能和脑认知。在目标2中，我们将定义apoE亚型的影响 血管壁细胞缺失对老年性脑血管功能障碍和认知功能减退的影响 APOE基因敲除小鼠，其中小鼠的APOE基因被APOE2、APOE3或APOE4基因所取代。通过 与SM22α-Cre小鼠杂交，我们将特异性地删除血管壁细胞中的个别载脂蛋白E亚型。在AIM 3，我们将研究在条件性小鼠模型中，载脂蛋白E亚型的血管特异性表达或缺失 培育血管壁细胞特异性载脂蛋白E亚型表达或敲除对AD相关表型的影响 淀粉样变性模型小鼠APP敲门小鼠(AppNL-F/NL-F)。使用这些独特的鼠标模型，我们将 全面研究血管壁细胞载脂蛋白E亚型对脑血管功能、胶质细胞的影响 不同年龄段的表型、神经炎症、神经变性、脑认知和淀粉样蛋白病理。在……里面 特别是，将从生化和结构角度对小鼠模型的载脂蛋白E特性进行分析 造型核心(核心B)。小鼠的载脂蛋白E含量、氧化和/或糖基化以及其他AD相关液体 生物标志物将通过生物标志物核心(D核心)进行测量。而小鼠的神经病理学将是 研究神经病理学核心(核心C)，这是一种包括蛋白质组学、代谢组学、 脂质组学和单细胞RNA测序将通过多组体核心(核心F)和 生物信息学、生物统计学和数据管理核心(核心G)，以描述这些基因的分子表型 老鼠模型。总而言之，我们的创新研究应该会填补我们对载脂蛋白E如何 脑血管亚型通过影响衰老和阿尔茨海默病的细胞功能和脑稳态 与核心B-G的协同作用以及项目2和项目3的比较小鼠模型研究。

PROJECT SUMMARY (APOE U19: Project 4) While the major function of apolipoprotein E (apoE) is to mediate the lipid transport, APOE genotype (APOE2, APOE3 and APOE4) significantly influences cognitive function and Alzheimer’s disease (AD) pathogenesis through multiple pathways. APOE is associated with not only amyloid-β (Aβ) pathology but also cerebrovascular function including blood-brain barrier integrity and cerebral blood flow. Given that cerebrovascular disturbance substantially contributes to cognitive decline in the elderly and that apoE is abundantly expressed in vascular mural cells (smooth muscle cells and pericytes) as well as astrocytes and microglia in the brain, the overall goal of Project 4 is to define how APOE genotype in vascular mural cells impacts the molecular mechanisms and pathways in the development of cerebrovascular dysregulations and cognitive decline during aging and AD. In Aim 1, we will utilize novel mouse models, in which human APOE2, APOE3, or APOE4 gene is expressed upon an excision of a loxp-flanked STOP cassette by vascular mural cell specific sm22α promoter driven Cre expression to determine the effects of vascular mural cell-specific expression of apoE isoforms on cerebrovascular function and brain cognition during aging. In Aim 2, we will define the impact of apoE isoform deletion in vascular mural cells on age-related cerebrovascular dysfunction and cognitive decline using novel APOE knock-in mice, in which murine Apoe is replaced with floxed APOE2, APOE3, or APOE4 gene. By crossing with sm22α-Cre mice, we will specifically delete individual apoE isoforms in vascular mural cells. In Aim 3, we will examine how vascular-specific expression or deletion of apoE isoforms in conditional mouse models affects AD-related phenotypes by breeding the vascular mural cell-specific apoE isoform expressing or knockout mice with amyloid model APP knockin mice (AppNL-F/NL-F). Using those unique mouse models, we will comprehensively investigate how apoE isoforms in vascular mural cells impact cerebrovascular function, glial phenotypes, neuroinflammation, neurodegeneration, brain cognition and amyloid pathology at different ages. In particular, the apoE properties in the mouse models will be analyzed by the Biochemistry and Structural Modeling Core (Core B). ApoE amounts, oxidation and/or glycation in the mice as well as other AD-rerated fluid biomarkers will be measured through the Biomarker Core (Core D). While neuropathology in the mice will be investigated in Neuropathology Core (Core C), a multi-Omics approach including proteomics, metabolomics, lipidomics and single cell RNA sequencing will be carried out through the Multi-Omics Core (Core F) and Bioinformatics, Biostatistics, and Data Management Core (Core G) to profile molecular phenotypes in these mouse models. Together, our innovative study should fill a critical void in our understanding of how apoE isoforms in cerebrovasculature impact cellular functions and brain homeostasis during aging and AD through synergistic interaction with Core B-G and comparative mouse model studies by Project 2 and Project 3.