1. CXCL8 histone H3 acetylation is dysfunctional in airway smooth muscle in asthma: regulation by BET
- Author
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Alison E. John, Alan J. Knox, Rachel L. Clifford, Lisa Mazengarb, Jamie K. Patel, Christopher E. Brightling, and Amanda L. Tatler
- Subjects
Transcription, Genetic ,Physiology ,Cell Cycle Proteins ,BET protein ,Histones ,bromodomain ,Transcriptional regulation ,p300-CBP Transcription Factors ,Promoter Regions, Genetic ,Cells, Cultured ,Histone Acetyltransferase p300 ,biology ,histone acetylation ,Nuclear Proteins ,RNA-Binding Proteins ,Acetylation ,Articles ,respiratory system ,airway smooth muscle ,3. Good health ,Chromatin ,DNA-Binding Proteins ,Histone ,DNA methylation ,Airway Remodeling ,RNA Polymerase II ,Protein Binding ,musculoskeletal diseases ,Pulmonary and Respiratory Medicine ,Myocytes, Smooth Muscle ,Primary Cell Culture ,Nerve Tissue Proteins ,Physiology (medical) ,CXCl8 ,Humans ,Interleukin 8 ,Histone H3 acetylation ,Inflammation ,CCAAT-Enhancer-Binding Protein-beta ,Interleukin-8 ,Transcription Factor RelA ,Muscle, Smooth ,Cell Biology ,asthma ,DNA Methylation ,respiratory tract diseases ,Cancer research ,biology.protein ,Transcription Factors - Abstract
Asthma is characterized by airway inflammation and remodeling and CXCL8 is a CXC chemokine that drives steroid-resistant neutrophilic airway inflammation. We have shown that airway smooth muscle (ASM) cells isolated from asthmatic individuals secrete more CXCL8 than cells from nonasthmatic individuals. Here we investigated chromatin modifications at the CXCL8 promoter in ASM cells from nonasthmatic and asthmatic donors to further understand how CXCL8 is dysregulated in asthma. ASM cells from asthmatic donors had increased histone H3 acetylation, specifically histone H3K18 acetylation, and increased binding of histone acetyltransferase p300 compared with nonasthmatic donors but no differences in CXCL8 DNA methylation. The acetylation reader proteins Brd3 and Brd4 were bound to the CXCL8 promoter and Brd inhibitors inhibited CXCL8 secretion from ASM cells by disrupting Brd4 and RNA polymerase II binding to the CXCL8 promoter. Our results show a novel dysregulation of CXCL8 transcriptional regulation in asthma characterized by a promoter complex that is abnormal in ASM cells isolated from asthmatic donors and can be modulated by Brd inhibitors. Brd inhibitors may provide a new therapeutic strategy for steroid-resistant inflammation.
- Published
- 2015