权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Implicating novel microglial mechanisms of late-onset Alzheimer's disease with variant-to-gene mapping methods

用变异到基因作图方法揭示晚发性阿尔茨海默病的新小胶质细胞机制

基本信息

批准号：
10312478
负责人：
ELIZABETH Anne BURTON
金额：
$ 4.6万
依托单位：
UNIVERSITY OF PENNSYLVANIA
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：
2021-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10312478
关键词：
3-Dimensional ATAC-seq Address Adult Affect Alleles Alzheimer&apos s disease brain Alzheimer&apos s disease pathology Alzheimer&apos s disease patient Alzheimer&apos s disease risk American Amyloid beta-Protein Area Biological Assay Brain CRISPR/Cas technology Cause of Death Cell Line Cell model Cells ChIP-seq Characteristics Chromatin Chromosome Mapping Cleaved cell Clustered Regularly Interspaced Short Palindromic Repeats Code Data Development Disease Disease Progression Distal Economic Burden Elderly Enhancers Epigenetic Process Feedback Gene Expression Gene Targeting Genes Genetic Genetic Transcription Genome Haplotypes Healthcare Systems Heritability Human Immune In Vitro Individual Inflammation Inflammatory Inflammatory Response Ingestion Innate Immune Response Interferon Type II Knock-out Late Onset Alzheimer Disease Lead Link Location Luciferases Maps Measures Methods Microglia Molecular Nerve Degeneration Neuraxis Neurodegenerative Disorders Neurofibrillary Tangles Neurons Output Pathogenesis Pathway interactions Phagocytes Phagocytosis Phenotype Play Population Production Proteins Quantitative Trait Loci Regulator Genes Regulatory Element Role Senile Plaques Sentinel Single Nucleotide Polymorphism Site Tissues Untranslated RNA Ursidae Family Validation Variant abeta deposition causal variant cell type cytokine effective therapy epigenetic marker extracellular gene interaction genome wide association study genome-wide genomic locus human old age (65+)induced pluripotent stem cell insight interest macrophage misfolded protein neurodegenerative dementia novel novel therapeutics prevent promoter response targeted treatment therapeutic development therapeutic gene transcriptome transcriptome sequencing

项目摘要

ABSTRACT Late-onset Alzheimer’s disease (LOAD) is the most common neurodegenerative disease among the elderly population, affecting nearly 6 million US adults over the age of 65. Despite being the 6th leading cause of death in the US, there are still no effective therapies that can slow or halt disease progression. The prevailing molecular feature that differentiates LOAD from other types of neurodegenerative dementia is the extracellular aggregation of inappropriately cleaved amyloid-b protein plaques (Ab1-42) in the brain. In response to Ab1-42 production, microglia, the resident macrophages of the central nervous system (CNS) activate and migrate to the site of plaque accumulation, and then break down and phagocytose the plaques, while also secreting pro-inflammatory cytokines to stimulate the innate immune response. Persistent production of these cytokines reduces microglial ability to clear Ab1-42 in a negative feedback loop, and results increased formation of interfibrillary tangles in the neurons that exacerbates neurodegeneration. Large genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) that associate with LOAD and reside near genes with known rare coding variants that affect microglial function, further emphasizing the importance of microglia in LOAD pathology. However, while GWAS has successfully identified numerous genetic loci associated with LOAD, it cannot directly identify the causal SNP implicated by these loci, as a GWAS sentinel SNP is representative of an entire haplotype of SNPs. Additionally, the majority of these GWAS SNPs lie within non-coding regions of the genome, and may not necessarily implicate the nearest gene as causal. Instead, these SNPs likely regulate the expression of LOAD-associated genes by modulating the activity of distal regulatory elements, such as enhancers, which in turn regulate LOAD gene expression. Therefore, I hypothesize that LOAD GWAS SNPs contribute to the dysregulated inflammation and phagocytosis in the brains of LOAD patients by altering the regulatory activity of microglial enhancers and the expression of their linked effector genes. In Aim 1, I will utilize a “variant-to-gene mapping” approach to identify putatively causal LOAD GWAS SNPs in the microglia by identifying SNPs that lie within open chromatin, are enriched in marks of active enhancers, and function as expression quantitative trait loci in microglial cell models. I will validate the activity of these enhancers through luciferase assays in the microglial cell models, and I will also identify the likely effector genes whose expression are modulated by these enhancers through our lab’s promoter-focused Capture-C assay. In Aim 2, I will functionally validate the phenotype conferred by LOAD-associated microglial enhancers by knocking out these enhancers in microglial cell models using CRISPR, and then assessing how these knockouts impact global gene expression, inflammation, and phagocytosis. Taken together, these aims will provide insight into microglial genetic mechanisms of LOAD, and may lead to the development of new therapies that can cure or prevent the disease.

摘要