The histone demethylase KDM6B links obstructive sleep apnea to idiopathic pulmonary fibrosis

Abstract

Obstructive sleep apnea (OSA) is increasingly recognized for its link to idiopathic pulmonary fibrosis (IPF), though the underlying mechanisms remain poorly understood. Histone lysine demethylase 6B (KDM6B) may either prevent or promote organ fibrosis, but its specific role in IPF is yet to be clarified. This study aimed to investigate the function and mechanisms of KDM6B in IPF and the exacerbating effects of OSA. We assessed KDM6B levels in lung tissues from IPF patients, IPF mouse models, and a dual-hit model combining OSA-associated intermittent hypoxia (IH) with bleomycin (BLM) or TGF-β1. We evaluated pulmonary fibrosis, myofibroblast activation, and oxidative stress. KDM6B levels were elevated in lung tissues from IPF patients and BLM-treated mice, as well as in TGF-β1-stimulated myofibroblasts. Importantly, IH significantly worsened BLM-induced pulmonary fibrosis and TGF-β1-induced myofibroblast activation, further amplifying KDM6B expression both in vivo and in vitro. Inhibition of KDM6B reduced pulmonary fibrosis and decreased fibroblast activation and migration in IPF and dual-hit models. Mechanistically, KDM6B inhibition led to decreased NOX4 expression and reduced oxidative stress. KDM6B plays a critical role in promoting pulmonary fibrosis and mediating the exacerbating effects of OSA on this condition. Our findings identify KDM6B as a novel potential therapeutic target for IPF.

Keywords: NADPH oxidase 4 (NOX4); idiopathic pulmonary fibrosis (IPF); intermittent hypoxia (IH); lysine demethylase 6B (KDM6B); obstructive sleep apnea (OSA); oxidative stress.