title: CCL20/CCR6 feedback exaggerates epidermal growth factor receptor-dependent MUC5AC mucin production in human airway epithelial (NCI-H292) cells.
abstract: Mucous hypersecretion is an important feature of obstructive airway diseases such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis. Multiple stimuli induce mucin production via activation of an epidermal growth factor receptor (EGFR) cascade, but the mechanisms that exaggerate mucin production in obstructive airway diseases remain unknown. In this study, we show that binding of CCL20, a G protein-coupled receptor (GPCR) ligand that is upregulated in the airways of subjects with obstructive airway diseases, to its unique GPCR CCR6 induces MUC5AC mucin production in human airway epithelial (NCI-H292) cells via metalloprotease TNF-α-converting enzyme (TACE)-dependent EGFR activation. We also show that EGFR activation by its potent ligand TGF-α induces reactivation of EGFR via binding of endogenously produced CCL20 to its receptor CCR6 in NCI-H292 cells but not in normal human bronchial epithelial (NHBE) cells, exaggerating mucin production in the NCI-H292 cells. In NCI-H292 cells, TGF-α stimulation induced two phases of EGFR phosphorylation (EGFR-P). The second EGFR-P was TACE-dependent and was responsible for most of the total mucin induced by TGF-α. Binding of endogenously produced CCL20 to CCR6 increased the second EGFR-P and subsequent mucin production induced by TGF-α. In NHBE cells, TGF-α-induced EGFR activation did not lead to significant CCL20 production or to EGFR rephosphorylation, and less mucin was produced. We conclude that NCI-H292 cells but not NHBE cells produce CCL20 in response to EGFR activation, which leads to a second phase of EGFR-P and subsequent exaggerated mucin production. These findings have potentially important therapeutic implications in obstructive airway diseases.
authors.affiliation: Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA 94143, USA. suil.kim@ucsf.edu
authors.forename: Suil
authors.initials: S
authors.lastname: Kim
authors.forename: Courtney
authors.initials: C
authors.lastname: Lewis
authors.forename: Jay A
authors.initials: JA
authors.lastname: Nadel
mesh_terms: D018277:Carcinoma, Mucoepidermoid / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D002450:Cell Communication / Q000276:immunology; D045744:Cell Line, Tumor; D054418:Chemokine CCL20 / Q000378:metabolism / Q000502:physiology*; D066246:ErbB Receptors / Q000378:metabolism / Q000502:physiology*; D025461:Feedback, Physiological / Q000502:physiology*; D006801:Humans; D008024:Ligands; D008175:Lung Neoplasms / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D055271:Mucin 5AC / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000378:metabolism; D010766:Phosphorylation / Q000276:immunology; D011485:Protein Binding / Q000276:immunology; D054399:Receptors, CCR6 / Q000378:metabolism / Q000502:physiology*; D020545:Respiratory Mucosa / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D016211:Transforming Growth Factor alpha / Q000378:metabolism / Q000502:physiology
chemical_list: C108355:CCL20 protein, human; C106311:CCR6 protein, human; D054418:Chemokine CCL20; D008024:Ligands; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D054399:Receptors, CCR6; D016211:Transforming Growth Factor alpha; D066246:ErbB Receptors