Uncovering APOE4 Matrisome endophenotypes using human iPSC-based models

使用基于人类 iPSC 的模型揭示 APOE4 基质体内表型

基本信息

批准号：
10670492
负责人：
Julia TCW
金额：
$ 50万
依托单位：
BOSTON UNIVERSITY MEDICAL CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-15 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10670492
关键词：
3-Dimensional Alleles Alzheimer&apos s Disease Alzheimer&apos s disease brain Alzheimer&apos s disease model Alzheimer&apos s disease patient Alzheimer&apos s disease risk Alzheimer&apos s disease therapeutic Alzheimer&apos s disease therapy Apolipoprotein E Astrocytes Biological Assay Biological Models Brain CRISPR/Cas technology Cells Chemotaxis Complement Complex Data Defect Dementia Development Disease Disease associated microglia Drug Screening Drug usage Etiology Gene Family Genes Genetic Diseases Genotype Glycoproteins Glycosaminoglycans Goals Human Human Genetics Knowledge Libraries Ligands Mediating Microglia Modality Modeling Molecular Neurofibrillary Tangles Neuroglia Neurons Neurosciences PLCG2 gene Pharmaceutical Preparations Pharmacology Phenotype Play Population Research Research Project Grants Risk Role Signal Transduction Single Nucleotide Polymorphism Synapses TREM2 gene TYROBP gene Testing Therapeutic abeta accumulation age related brain cell brain endothelial cell cell type disorder risk drug candidate drug development drug discovery drug use screening endophenotype experience experimental study functional genomics genetic risk factor genome wide association study glial activation glycosaminoglycan receptor induced pluripotent stem cell innovation lipid metabolism multi-electrode arrays neuroinflammation novel novel therapeutics receptor risk variant sialic acid binding Ig-like lectin sialic acid receptor single-cell RNA sequencing stem cell model three dimensional cell culture three-dimensional modeling transcriptome transcriptomics

项目摘要

PROJECT SUMMARY Alzheimer disease (AD), the most prevalent age-related dementia, is characterized by widespread β-amyloid accumulation, neurofibrillary tangles, neuroinflammation, and frank neuronal and synaptic loss. Recent AD GWAS studies have uncovered several risk single nucleotide polymorphisms (SNPs) within genes predominantly expressed in glia. Notably, the Apolipoprotein E (APOE) ε4 allele is the strongest genetic risk factor for AD; APOE ɛ4/ɛ4 (APOE 44) increases AD risk by 15-fold compared to APOE ɛ3/ɛ3 (APOE 33) and is predominantly expressed in astrocytes, but also upregulated in the recently identified disease-associated microglia phenotype. Although the relationship between APOE4 and AD risk is well-established, the mechanisms underlying this effect in particular human brain cell types are not entirely clear. To comprehensively assess the effect of human APOE4 on human brain cell types, we characterized the APOE4 genotype-phenotype relationship in four brain cell types: microglia, astrocytes, brain microvascular endothelial cells and mixed cortical cultures derived from human induced pluripotent stem cells (iPSCs). Global transcriptome analyses reveal that APOE4 drives enhanced Matrisome gene sets associated with chemotaxis, glial activation and lipid metabolism in astrocytes from iPSCs- derived mixed cortical cultures, and this signature is confirmed in AD brain cell-type deconvoluted transcriptome data–a phenotype from astrocytes when co-cultured with neurons. We hypothesize that matrisome signals derived from APOE4 astrocytes induce defects in neuronal activity and microglia function. We also hypothesize that interactions of Siglec receptor-sialic acid containing glycosaminoglycan ligands by CD33 risk genotype and APOE4 glia promote plaque formation and neuroinflammation. To test these hypotheses, human “brain-in-a- dish” model systems, composed of neurons, astrocytes and microglia derived from isogenic iPSCs will be utilized. In aim 1, we will perform single cell transcriptomic analysis to confirm matrisome signals in 2D and 3D models and determine how altered matrisome signaling by APOE4 impacts neuronal activity and microglia phenotype at baseline and in the context of AD neuropathological features. In aim 2, we will determine the molecular mechanism of synergistic effects of APOE4 and Siglec receptor CD33 risk in a single cell transcriptomic level, and its effects on plaque formation and neuroinflammation. In aim 3, we will identify compounds to reverse altered astrocyte matrisome signaling phenotypes using drug screening platforms. The goal of this project is to assess functional consequences of APOE4 driven matrisome endophenotypes and understand the mechanism of glycoprotein receptor risk crosstalk with APOE4 matrisome signals. Further this proposed research project sets out to uncover potential therapeutic drugs to tackle APOE4 driven matrisome endophenotypes found in APOE4 carrier AD patients.

项目概要阿尔茨海默病 (AD) 是最常见的与年龄相关的痴呆症，其特征是广泛存在 β-淀粉样蛋白累积、神经原纤维缠结、神经炎症以及明显的神经元和突触损失。 GWAS 研究发现了基因中的几种风险单核苷酸多态性 (SNP) 值得注意的是，载脂蛋白 E (APOE) ε4 等位基因是 AD 最强的遗传风险因素。与 APOE ɛ3/ɛ3 (APOE 33) 相比，APOE ɛ4/ɛ4 (APOE 44) 使 AD 风险增加 15 倍，并且占主导地位在星形胶质细胞中表达，但在最近发现的与疾病相关的小胶质细胞表型中也上调。尽管 APOE4 与 AD 风险之间的关系已明确，但这种效应背后的机制尤其是人类脑细胞类型尚不完全清楚，无法全面评估人类APOE4的效果。关于人类脑细胞类型，我们表征了四种脑细胞类型中的 APOE4 基因型-表型关系：小胶质细胞、星形胶质细胞、脑微血管内皮细胞和源自人类的混合皮质培养物诱导多能干细胞 (iPSC) 全局转录组分析表明 APOE4 驱动能力增强。与 iPSC 星形胶质细胞趋化性、神经胶质活化和脂质代谢相关的基质体基因组衍生的混合皮质培养物，这一特征在 AD 脑细胞型解卷积转录组中得到证实数据——星形胶质细胞与神经元共培养时的表型。我们还发现，源自 APOE4 星形胶质细胞会导致神经元活动和小胶质细胞功能缺陷。 Siglec 受体-含有糖胺聚糖配体的唾液酸与 CD33 风险基因型的相互作用 APOE4 神经胶质细胞促进斑块形成和神经炎症。由同基因 iPSC 衍生的神经元、星形胶质细胞和小胶质细胞组成的“菜”模型系统将在目标 1 中，我们将进行单细胞转录组分析以确认 2D 和 3D 基质体信号。模型并确定 APOE4 的基质体信号传导如何影响神经活动和小胶质细胞在目标 2 中，我们将确定基线和 AD 神经病理学特征的表型。 APOE4与Siglec受体CD33在单细胞中协同作用的分子机制在目标 3 中，我们将确定转录组水平及其对斑块形成和神经炎症的影响。使用药物筛选平台逆转改变的星形胶质细胞基质信号传导表型的化合物。该项目的目标是评估 APOE4 驱动的基质体内表型的功能后果和了解糖蛋白受体风险与 APOE4 基质体信号串扰的机制。拟议的研究项目旨在发现潜在的治疗药物来解决 APOE4 驱动的基质体 APOE4 携带 AD 患者中发现的内表型。