Mucosal bromodomain-containing protein 4 mediates aeroallergen-induced inflammation and remodeling

• Published in: Journal of allergy and clinical immunology Vol. 143; no. 4; pp. 1380 - 1394.e9
• Main Authors: Tian, Bing, Hosoki, Koa, Liu, Zhiqing, Yang, Jun, Zhao, Yingxin, Sun, Hong, Zhou, Jia, Rytting, Erik, Kaphalia, Lata, Calhoun, William J., Sur, Sanjiv, Brasier, Allan R.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2019; Elsevier Limited
• Subjects: aeroallergen; airway remodeling; Airway Remodeling - immunology; Allergens; Allergies; Animals; Antigens; Asthma; Asthma - immunology; Asthma - metabolism; Asthma - pathology; Biopsy; Bromodomain-containing protein 4; Cats; Cell Cycle Proteins - metabolism; Chromatin; Collagen; Dander; Dander - immunology; DNA-directed RNA polymerase; epigenetics; Epithelial cells; Epithelial-Mesenchymal Transition - immunology; Experiments; Extracellular matrix; Fibrosis; Gene expression; Histone acetyltransferase; histone acetyltransferase activity; Human subjects; Humans; Hypersensitivity - immunology; Hypersensitivity - metabolism; Hypersensitivity - pathology; Immunofluorescence; Immunoglobulin E; Inflammation; Inflammation - immunology; Inflammation - metabolism; Inflammation - pathology; Kinases; Laboratories; Lungs; Mesenchyme; Mice; Mice, Inbred C57BL; Morbidity; Mucosa; myofibroblast; NF-κB protein; nuclear factor κB; Nuclear Proteins - metabolism; Peptides; Polymerase chain reaction; Proteins; RelA protein; Respiratory function; Respiratory Mucosa - immunology; Respiratory Mucosa - metabolism; Respiratory Mucosa - pathology; Respiratory tract; Respiratory tract diseases; RNA polymerase; Signal transduction; Transcription Factors - metabolism; BD; IKKi; nuclear factor κB; PAS; H3K122Ac; PLA; myofibroblast; CDE; COL1A; RNA Pol II; epigenetics; aeroallergen; SRM; histone acetyltransferase activity; NF-κB; α-SMA; UTMB; shRNA; TLR; WT; BRD4; Bromodomain-containing protein 4; IFCM; MS; rCDE; airway remodeling; BALF; qRT-PCR; FN1; IKK; BMS; DAPI; EMT; ECM; MMP; hSAEC; ROS; HAT; VIM
• ISSN: 0091-6749; 1097-6825; 1097-6825
• DOI: 10.1016/j.jaci.2018.09.029

Frequent exacerbations of allergic asthma lead to airway remodeling and a decrease in pulmonary function, producing morbidity. Cat dander is an aeroallergen associated with asthma risk. We sought to elucidate the mechanism of cat dander–induced inflammation-remodeling. We identified remodeling in mucosal samples from allergic asthma by using quantitative RT-PCR. We developed a model of aeroallergen-induced experimental asthma using repetitive cat dander extract exposure. We measured airway inflammation using immunofluorescence, leukocyte recruitment, and quantitative RT-PCR. Airway remodeling was measured by using histology, collagen content, myofibroblast numbers, and selected reaction monitoring. Inducible nuclear factor κB (NF-κB)–BRD4 interaction was measured by using a proximity ligation assay in situ. Enhanced mesenchymal signatures are observed in bronchial biopsy specimens from patients with allergic asthma. Cat dander induces innate inflammation through NF-κB signaling, followed by production of a profibrogenic mesenchymal transition in primary human small airway epithelial cells. The IκB kinase–NF-κB signaling pathway is required for mucosal inflammation-coupled airway remodeling and myofibroblast expansion in the mouse model of aeroallergen exposure. Cat dander induces NF-κB/RelA to complex with and activate BRD4, resulting in modifying the chromatin environment of inflammatory and fibrogenic genes through its atypical histone acetyltransferase activity. A novel small-molecule BRD4 inhibitor (ZL0454) disrupts BRD4 binding to the NF-κB–RNA polymerase II complex and inhibits its histone acetyltransferase activity. ZL0454 prevents epithelial mesenchymal transition, myofibroblast expansion, IgE sensitization, and fibrosis in airways of naive mice exposed to cat dander. NF-κB–inducible BRD4 activity mediates cat dander–induced inflammation and remodeling. Therapeutic modulation of the NF-κB–BRD4 pathway affects allergen-induced inflammation, epithelial cell-state changes, extracellular matrix production, and expansion of the subepithelial myofibroblast population. [Display omitted]