Glycopyrronium bromide inhibits lung inflammation and small airway remodeling induced by subchronic cigarette smoke exposure in mice

The effects of long-acting muscarinic receptor antagonists (LAMAs) have not been evaluated in a model with simultaneous lung inflammation and small airway remodeling induced by cigarette smoke (CS). We exposed the mice to CS for four weeks with daily treatment with a LAMA (glycopyrronium bromide, NVA237) or its vehicle. Human bronchial epithelial cells (PBECs) and lung fibroblasts were exposed to CS extract (CSE) or acetylcholine with or without NVA237 treatment. We found that NVA237, but not its vehicle, suppressed elevations in inflammatory score, epithelial thickness, and peribronchial collagen deposition in CS-exposed mice. NVA237 alleviated CS-induced increased levels of chemokines, inflammatory cells, and total protein in the bronchoalveolar lavage fluid. NVA237 suppressed acetylcholine- or CSE-induced elevations in IL-8 production in PBECs and elevations in proliferation and collagen production in lung fibroblasts. These phenomena were also prevented by a p44/42 MAPK inhibitor. In conclusion, NVA237 exerted a potent suppressive effect on lung inflammation and small airway remodeling induced by subchronic CS exposure.