TARGETING THE HISTONE DEMETHYLASE JMJD2B/KDM4B AS A NOVEL THERAPEUTIC APPROACH IN IL-13-MEDIATED FIBROSIS IN AIRWAY FIBROBLASTS OF SEVERE ASTHMATICS

Abstract

TYPE: Abstract TOPIC: Allergy and Airway PURPOSE: Asthma is a heterogeneous disorder characterized by chronic inflammation and remodeling of the airways. Asthma responses are driven mainly by type 2 immune responses, where IL-13 plays a key role in asthma pathogenesis. We previously identified JMJD2B as an IL-13-regulated epigenetic modifier in asthmatic airway fibroblasts. Therefore, this study aimed to target JMJD2B to potentially alleviate IL-13-mediated fibrosis in asthma. METHODS: Bronchial fibroblasts isolated from asthmatic and healthy individuals were stimulated with IL-13 and treated with JIB-04, a pan-selective inhibitor of histone demethylase(s). Gene and protein expression of extracellular matrix markers were assessed using qRT-PCR, western blotting and matrix metalloproteinases (MMPs) activity assay. Chromatin immunoprecipitation (ChIP) assay was used to determine the bindig of JMJD2B to promoter region of Tissue inhibitors of matrix metalloproteinases (TIMPs). RESULTS: Here we show that JIB-04 inhibited JMJD2B activity by reducing the demethylation of its downstream target, H3K36me3, in asthmatic fibroblasts. Inhibition of JMJD2B significantly affected the viability of the bronchial fibroblasts at 48 hours. JMJD2B inhibition was further associated with the downregulation of extracellular matrix (ECM) proteins such as MMP-2, MMP-9, collagen-1, and fibronectin, and upregulation of TIMP-2, at both the gene and protein levels. This was accompanied by inhibition of IL-13 mediated MMPs activity. JIB-04 further prevented the association of JMJD2B on TIMP-2 promoter region. CONCLUSIONS: Our results demonstrate the potential of JMJD2B inhibition in attenuating IL-13-mediated fibrosis in asthma. CLINICAL IMPLICATIONS: Therapeutic targeting of JMJD2B using JIB-04 is a promising candidate to alleviate IL-13-mediated responses in chronic disorders such as asthma. DISCLOSURE: Nothing to declare. KEYWORD: Asthma