APOE orchestrated ''molecular signatures'' in aging brain and AD - the contribution of APOE2

APOE 在衰老大脑和 AD 中精心策划了“分子特征”——APOE2 的贡献

基本信息

批准号：
9555298
负责人：
RADOSVETA KOLDAMOVA
金额：
$ 44.06万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-15 至 2018-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9555298
关键词：
ATP-Binding Cassette Transporters Abeta clearance Adrenal Glands Age Aging Alleles Alzheimer&apos s Disease Amyloid beta-Protein Astrocytes Binding Biological Assay Biological Models Biology Brain Cell physiology Cholesterol Chromosomes, Human, Pair 19 Chylomicrons Clinical Research Code Cognitive deficits Data Disease Experimental Designs Frequencies Gene Cluster Gene Proteins Genes Genetic Transcription Genotype Goals High Density Lipoproteins Homeostasis Human Human Pathology Immunologic Receptors Impaired cognition In Vitro Individual Inflammation Inflammatory Response Intercellular Fluid Intervention Knowledge LDL-Receptor Related Protein 1 Lipid Binding Lipids Lipoproteins Low-Density Lipoproteins Mammalian Cell Mass Spectrum Analysis Mediating Microglia Mitochondria Molecular Molecular Profiling Molecular Target Mus Nanotechnology Nerve Degeneration Neuroglia Neurons Nuclear Receptors Pathogenesis Patients Phagocytosis Phenotype Phospholipids Physiology Plasma Population Process Protein Isoforms RXR Receptor Signaling Reporting Research Risk Risk Factors Role Sampling Shotguns System TREM2 gene TYROBP gene Testing Transgenic Mice Up-Regulation Very low density lipoprotein age related aging brain apolipoprotein E-3 apolipoprotein E-4 base brain parenchyma cell type chylomicron remnant comparative dectin 1 genetic risk factor genetic variant genome wide association study high risk immune function in vivo in vivo Model lipid metabolism nanoparticle new therapeutic target next generation sequencing non-demented particle prevent receptor binding receptor function transcription factor transcriptome transcriptomics

项目摘要

APOE (Apolipoprotein E) is part of APOE/APOC gene cluster on chromosome 19 and codes for 3 protein isoforms – APOE2, APOE3 and APOE4. APOE transports cholesterol and phospholipids in the periphery and brain. APOE isoforms differ in their lipid and receptor binding capacity and their role is associated with clearance of LDL, VLDL and chylomicrons. The inheritance of APOE4 allele increases and APOE2 decreases the risk for late onset AD (LOAD), but the mechanism is poorly understood. While APOE is involved in critical cellular functions such as oxidative processes, inflammation, glial cell and neuronal homeostasis, none of those can be dissociated from isoform specific binding, transport and delivery of cholesterol and phospholipids to different cell types. Recent reports suggest there might be a differential APOE-isoform specific effect on microglia mediated phagocytosis and function of immune receptors expressed in brain. Our preliminary data demonstrate APOE isoforms influence expression of immune receptors Dectin-1/Clec7a, Siglec1, Siglech, Oscar - involved in inflammatory response and phagocytosis. A strong support to an interconnected role for APOE and immune receptor mediated phagocytosis are our results of Multi-Dimensional Mass Spectrometry Shotgun Lipidomics of brain samples from AD patients, where we find significant differences in phospholipid molecular speciation in major phospholipid classes. We hypothesize the APOE isoform-specific effects on phagocytosis are driven by the different phospholipid composition of APOE lipid particles and/or by the differential effect of APOE isoforms on microglial transcriptome. We are proposing 3 Specific Aims to test the hypothesis: Aim 1. Establish isoform- dependent effect of APOEε2 allele on brain parenchymal and mitochondrial lipidome and transcriptome in AD patients and non-demented controls. The goal is to integrate lipid and transcriptional profiles and to reveal APOE allele controlled phenotypes and lipid molecular species for additional functional assays in SA3. Aim 2. Determine isoform- and age-dependent effect of APOE genotype on brain lipidome and transcriptome in mice expressing human APOE2, APOE3 or APOE4 isoforms. We will determine phospholipid content of native APOE in Astrocyte Conditioned media, lipid particles in brain interstitial fluid (ISF) and differences in brain parenchyma and mitochondrial lipidomes between mice expressing APOE2, APOE3 or APOE4 isoforms at 2 different ages. Aim 3. To test the effect of APOE-containing nanoparticles on Aβ phagocytosis in vitro and in vivo. The goals are to apply the knowledge about differences in lipid compositions of AD and mouse brains and to test the effect of phospholipid molecular species on microglia mediated Aβ phagocytosis and clearance of Aβ oligomeric species in in vitro and in vivo experimental systems.

APOE（载脂蛋白E）是染色体19上APOE/APOC基因簇的一部分，并编码3蛋白同工型 - APOE2，APOE3和APOE4。 APOE在外围运输胆固醇和磷脂脑。 APOE同工型的脂质和受体结合能力不同，其作用与清除有关 LDL，VLDL和乳糜微粒的作品。 APOE4等位基因的继承增加，APOE2降低了风险发作AD（负载）迟到，但该机制知之甚少。而APOE参与关键细胞诸如氧化过程，感染，神经胶质细胞和神经元体内平衡等功能，这些功能都不能与同工型特异性结合，胆固醇和磷脂的转运和递送到不同细胞类型。最近的报告表明，可能对小胶质细胞介导的特异性影响有差异大脑中表达的免疫接收器的吞噬作用和功能。我们的初步数据证明了APOE 同工型影响免疫受体Dectin -1/clec7a，Siglec1，Siglech，Oscar-参与参与炎症反应和吞噬作用。对APOE和免疫的互连作用的强烈支持受体介导的吞噬作用是我们的多维质谱shot弹枪脂质组的结果 AD患者的大脑样本，我们发现在磷脂分子规格上存在显着差异主要的磷脂类别。我们假设APOE同工型特异性对吞噬作用的影响是由 ApoE脂质颗粒的不同磷脂组成和/或通过APOE同工型的差异效应在小胶质细胞转录组上。我们提出了3个特定目标来检验假设：目标1。建立同工型 - APOEε2等位基因对AD中脑实质和线粒体脂质组和转录组的依赖性作用患者和非痴呆对照。目的是整合脂质和转录曲线并揭示 APOE等位基因控制的表型和脂质分子物种用于SA3中的其他功能测定。目标2。确定APOE基因型对脑脂肪组和转录组中的同工型和年龄依赖性效应表达人APOE2，APOE3或APOE4同工型的小鼠。我们将确定星形胶质细胞培养基中的天然APOE，脑间质流体（ISF）中的脂质颗粒和大脑差异表达APOE2，APOE3或APOE4同工型在2的小鼠之间的实质和线粒体脂质分子不同的年龄。目标3。测试含APOE的纳米颗粒对体外Aβ吞噬作用的影响和体内。目标是应用有关AD和鼠标脂质组成差异的知识大脑并测试磷脂分子物种对小胶质细胞介导的Aβ吞噬作用和在体外和体内实验系统中Aβ低聚物种的清除。