title: Proinflammatory cytokine secretion is suppressed by TMEM16A or CFTR channel activity in human cystic fibrosis bronchial epithelia.
abstract: Cystic fibrosis (CF) is caused by the functional expression defect of the CF transmembrane conductance regulator (CFTR) chloride channel at the apical plasma membrane. Impaired bacterial clearance and hyperactive innate immune response are hallmarks of the CF lung disease, yet the existence of and mechanism accounting for the innate immune defect that occurs before infection remain controversial. Inducible expression of either CFTR or the calcium-activated chloride channel TMEM16A attenuated the proinflammatory cytokines interleukin-6 (IL-6), IL-8, and CXCL1/2 in two human respiratory epithelial models under air-liquid but not liquid-liquid interface culture. Expression of wild-type but not the inactive G551D-CFTR indicates that secretion of the chemoattractant IL-8 is inversely proportional to CFTR channel activity in cftr(∆F508/∆F508) immortalized and primary human bronchial epithelia. Similarly, direct but not P2Y receptor-mediated activation of TMEM16A attenuates IL-8 secretion in respiratory epithelia. Thus augmented proinflammatory cytokine secretion caused by defective anion transport at the apical membrane may contribute to the excessive and persistent lung inflammation in CF and perhaps in other respiratory diseases associated with documented down-regulation of CFTR (e.g., chronic obstructive pulmonary disease). Direct pharmacological activation of TMEM16A offers a potential therapeutic strategy to reduce the inflammation of CF airway epithelia.
authors.affiliation: Department of Physiology and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montréal, QC H3G 1Y6, Canada.
authors.forename: Guido
authors.initials: G
authors.lastname: Veit
authors.forename: Florian
authors.initials: F
authors.lastname: Bossard
authors.forename: Julie
authors.initials: J
authors.lastname: Goepp
authors.forename: A S
authors.initials: AS
authors.lastname: Verkman
authors.forename: Luis J V
authors.initials: LJ
authors.lastname: Galietta
authors.forename: John W
authors.initials: JW
authors.lastname: Hanrahan
authors.forename: Gergely L
authors.initials: GL
authors.lastname: Lukacs
mesh_terms: D000388:Air; D000075369:Anoctamin-1; D001980:Bronchi / Q000473:pathology; D002452:Cell Count; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity; D018118:Chloride Channels / Q000378:metabolism*; D003550:Cystic Fibrosis / Q000503:physiopathology*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D004848:Epithelium / Q000276:immunology / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007113:Immunity, Innate; D018836:Inflammation Mediators / Q000378:metabolism*; D015640:Ion Channel Gating; D008954:Models, Biological; D009363:Neoplasm Proteins / Q000378:metabolism*; D021381:Protein Transport; D034741:RNA, Small Interfering / Q000378:metabolism; D058470:Receptors, Purinergic P2Y / Q000378:metabolism
chemical_list: C476213:ANO1 protein, human; D000075369:Anoctamin-1; D018118:Chloride Channels; D016207:Cytokines; D018836:Inflammation Mediators; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; D058470:Receptors, Purinergic P2Y; D019005:Cystic Fibrosis Transmembrane Conductance Regulator