Enhancing microglia-dependent plaque clearance in the Alzheimer disease brain by targeting Ifi27l2a expression

通过靶向 Ifi27l2a 表达增强阿尔茨海默病大脑中小胶质细胞依赖性斑块清除

基本信息

批准号：
10214069
负责人：
GAB SEOK KIM
金额：
$ 42.9万
依托单位：
UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
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：
2021-05-15 至 2023-10-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10214069
关键词：
Abeta clearance Age Aging Alzheimer&apos s Disease Alzheimer&apos s disease brain Alzheimer&apos s disease pathology Amyloid Amyloid beta-Protein Blood Vessels Brain Cell Line Cerebral Amyloid Angiopathy Data Dementia Deposition Development Diagnosis Disease Down-Regulation Equilibrium Exposure to Flow Cytometry Gene Expression Profile Genes Genetic Transcription Gliosis Human Impairment Inflammatory Interferon-alpha Interferons Ischemic Stroke Label Latex Bead Light Literature Measures Mediating Messenger RNA MicroRNAs Microglia Modeling Mus Neurodegenerative Disorders Neurons Ontology Pathologic Pathology Pathway interactions Patients Phagocytes Phagocytosis Phenotype Population Probability Process Proteins Regulation Role Sampling Senile Plaques Small Interfering RNA Stimulus Testing Tg2576 Thalamic structure Up-Regulation abeta deposition age related aged brain parenchyma effectiveness testing in silico in vivo knock-down mRNA Expression mouse model neuropathology new therapeutic target novel novel strategies overexpression predictive modeling promoter protein expression response single cell analysis single-cell RNA sequencing small hairpin RNA uptake

项目摘要

Abstract Alzheimer’s disease (AD) and cerebral amyloid angiopathy (CAA) are devastating aging-associated neurodegenerative diseases which involve pathological deposition of amyloid-beta (Aβ) in the brain parenchyma and around the leptomeningeal vasculature. Aβ uptake in microglia (MG) is strikingly reduced with age, which may contribute to reduced amyloid clearance and increased plaque accumulation. Recently, a novel subset of MG with a distinct gene expression signature (“disease- associated microglia”; DAM) have emerged as a critical player in phagocytosis of Aβ in AD. Using unbiased analysis of single-cell RNA sequencing (scRNAseq), we discovered that Interferon alpha- inducible protein 27-like protein 2A (Ifi27l2a) is the most highly upregulated gene in MG following ischemic stroke, with a greater increase in aging. Using this finding as a launch point, we then examined if similar upregulation occurred in conditions of AD and CAA. We subsequently found that Ifi27l2a mRNA expression is significantly elevated in the brain of symptomatic TgSwDI mice – a mouse model which develops both vascular and parenchymal Aβ deposits. In human brain samples, we found significantly elevated Ifi27l2a protein expression in MG in sections from patients with confirmed CAA and AD pathology versus non-disease age-matched controls. We also found upregulation of Ifi27l2a in a human microglial cell line (HMC3) following inflammatory challenge. Our scRNAseq analysis of the MG population showed a positive correlation between Ifi27l2a expression and inflammatory genes and a negative correlation with phagocytic (and DAM-identifying) genes. In light of our new findings regarding the role of Ifi27l2a in MG/DAM phenotype and the known role of MG in Aβ clearance, we now propose to explore the novel role of Ifi27l2a in regulating MG phagocytic function and Aβ clearance using a mouse model which demonstrates both vascular and parenchymal amyloid plaque formation (TgSwDI). We will test our model in which elevated Ifi27l2a expression in MG promotes reduced phagocytic capacity and thus impaired clearance of Aβ. In aim 1, we will examine potential mechanisms of post-transcriptional Ifi27l2a regulation. We will use primary MG (cultured from aged mouse brain) and a human MG cell line to determine the contribution of two in silico predicted microRNAs on Ifi27l2a level and on resulting phagocytic function. In aim 2, we will demonstrate the in vivo role of Ifi27l2a in regulating MG/DAM phagocytic phenotype and determine the potential for Ifi27l2a down-regulation to promote enhanced clearance of vascular and parenchymal Aβ plaques. For these studies, we will use TgSwDI mice at a stage where Aβ vascular deposits and parenchymal plaques are evident. If successful, these studies would provide the basis for new approaches for enhancing clearance of Aβ aggregates in the brain.

抽象的阿尔茨海默氏病（AD）和脑淀粉样血管病（CAA）是毁灭性的衰老相关的神经退行性疾病涉及淀粉样蛋白β（Aβ）在大脑中的病理沉积实质和瘦脑血管周围。小胶质细胞（MG）中的Aβ摄取非常引人注目随着年龄的增长而减小，这可能导致淀粉样蛋白清除率降低并增加斑块积累。最近，一个具有独特基因表达特征的MG的新型Mg（“疾病 - 相关的小胶质细胞”; DAM）已成为AD中Aβ吞噬作用的关键参与者。使用AD。对单细胞RNA测序（SCRNASEQ）的无偏分析，我们发现干扰素α- 诱导蛋白27类蛋白2a（IFI27L2A）是Mg中最大更新的基因缺血性中风，衰老增加。然后，我们将此发现作为发射点，然后检查了如果在AD和CAA的条件下发生了类似的上调。随后我们发现IFI27L2A mRNA 在有症状的TGSWDI小鼠的大脑中，表达显着升高 - 一种小鼠模型开发血管和副Aβ沉积物。在人脑样品中，我们发现升高的IFI27L2A蛋白在MG中的CAA和AD患者的切片中升高病理学与非疾病年龄匹配的对照。我们还发现人类IFI27L2A的上调炎症挑战后的小胶质细胞系（HMC3）。我们对MG的SCRNASEQ分析人群在IFI27L2A表达与炎症基因与A之间显示出正相关与吞噬细胞（和大坝识别）基因的负相关。鉴于我们关于有关的新发现 IFI27L2A在MG/DAM表型中的作用以及MG在Aβ清除率中的已知作用，我们现在建议探索IFI27L2A在调节Mg吞噬功能和使用小鼠Aβ清除率中的新作用模型显示了血管和副淀粉样菌斑形成（TGSWDI）。我们将测试我们的模型，其中升高的IFI27L2A表达在MG中促进吞噬能力降低因此，Aβ的清除率受损。在AIM 1中，我们将检查转录后的潜在机制 IFI27L2A调节。我们将使用初级MG（从老化的小鼠脑培养）和人类MG细胞系确定两者在硅中的贡献预测的microRNA对IFI27L2A水平以及结果吞噬功能。在AIM 2中，我们将展示IFI27L2A在调节MG/DAM中的体内作用吞噬表型，并确定IFI27L2A下调的潜力以促进增强血管和副Aβ斑块的清除。对于这些研究，我们将在A处使用TGSWDI小鼠证明了Aβ血管沉积和副斑块的阶段。如果成功，这些研究将为增强大脑中Aβ骨料清除的新方法提供基础。