Transcriptional Responses to Wildfire Pollution in Airway Epithelial Cells Identify Genetic Risk Factors and Mechanisms of Asthma Exacerbations

点击翻译按钮获取中文摘要

Project Summary/Abstract Increased levels of air pollution from wildfires are directly associated with asthma exacerbations but the mechanisms mediating this association are not understood. Furthermore, the severity of asthma symptoms that result from wildfire exposure vary considerably by individual. We seek to identify Transcriptional Regulatory Elements (TREs) that connect wildfire particulate exposures with genetic variants associated with asthma to identify susceptibility features and mechanisms that govern asthma exacerbations. We will employ wood smoke particle (WSP) exposure in primary airway epithelial cells cultured at air- liquid interface to model the interaction between the respiratory epithelium and fine particulates released by wildfires. We will assay chromatin accessibility and nascent transcription using next- generation sequencing techniques to identify TREs regulated by WSP. Then, using a permutation- based bioinformatic approach, we will intersect the genomic coordinates of these TREs with genomic susceptibility loci for asthma. We will then characterize the transcriptional function of single nucleotide polymorphisms (SNPs) that result from this intersection. We will test TRE function in the context of WSP exposure with and without the SNPs in plasmid-derived luciferase reporters and in genomic DNA, using the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) – Cas9 tool to introduce the variant alleles. Finally, to assay the physiologic significance of these TRE-SNP overlaps, we will test the role of the rs258760 SNP, which inhabits a TRE under regulation by WSP and controls expression of the glucocorticoid receptor, in mediating Interleukin-8 secretion by exposing airway epithelial cells from donors with the major and minor alleles to WSP and dexamethasone. This project will identify and characterize genomic features that connect air pollution with asthma exacerbations. These loci and the genes they regulate will serve as candidates for pharmacologic therapies to mitigate asthma symptoms associated with wildfire air pollution. Furthermore, this project develops a method to integrate multiple models of disease in a genomic context. This strategy may be used to propose novel treatments for asthma.