Ets homologous factor (EHF) has critical roles in epithelial dysfunction in airway disease

Sara L Fossum,Michael J Mutolo,Antonio Tugores,Sujana Ghosh,Scott H Randell,Lisa C Jones,Shih-Hsing Leir,Ann Harris

doi:10.1074/jbc.m117.775304

Abstract

The airway epithelium forms a barrier between the internal and external environments. Epithelial dysfunction is critical in the pathology of many respiratory diseases, including cystic fibrosis. Ets homologous factor (EHF) is a key member of the transcription factor network that regulates gene expression in the airway epithelium in response to endogenous and exogenous stimuli. EHF, which has altered expression in inflammatory states, maps to the 5' end of an intergenic region on Chr11p13 that is implicated as a modifier of cystic fibrosis airway disease. Here we determine the functions of EHF in primary human bronchial epithelial (HBE) cells and relevant airway cell lines. Using EHF ChIP followed by deep sequencing (ChIP-seq) and RNA sequencing after EHF depletion, we show that EHF targets in HBE cells are enriched for genes involved in inflammation and wound repair. Furthermore, changes in gene expression impact cell phenotype because EHF depletion alters epithelial secretion of a neutrophil chemokine and slows wound closure in HBE cells. EHF activates expression of the SAM pointed domain-containing ETS transcription factor, which contributes to goblet cell hyperplasia. Our data reveal a critical role for EHF in regulating epithelial function in lung disease.

Highlights

The airway epithelium forms a barrier between the internal and external environments
Using Ets homologous factor (EHF) ChIP followed by deep sequencing (ChIP-seq) and RNA sequencing after EHF depletion, we show that EHF targets in human bronchial epithelial (HBE) cells are enriched for genes involved in inflammation and wound repair
The Cis-regulatory Element Annotation System (CEAS) software [33] was used to annotate peaks based on genomic location (Fig. 1A) and determined that EHF sites were enriched at promoters (Ϫ1 kb relative to the transcription start site) and 5Ј UTRs of genes (Fig. 1B)

Summary

Edited by Joel Gottesfeld

The airway epithelium forms a barrier between the internal and external environments. The airway epithelium plays a critical role in lung function in both normal and pathological states It forms an active barrier between the external and internal environments, responding to a wide range of stimuli. Modulation of gene expression underlies the response of the lung epithelium to the environment, both in normal and disease states, so it is critical to understand the causative mechanisms. Pivotal to these processes is the transcription factor (TF) network that regulates development, normal function, and response to disease in res-. We hypothesize that EHF regulates genes involved in cellular processes that impact the severity of epithelial pathology in airway disease, including inflammation and wound repair. Of particular relevance to CF are the release of neutrophil chemokines and wound repair

Results

EHF regulates genes involved in lung pathology

Discussion

Cell culture

Wound repair assay

Western blot