The Cystic Fibrosis Transmembrane Conductance Regulator Potentiator Ivacaftor Augments Mucociliary Clearance Abrogating Cystic Fibrosis Transmembrane Conductance Regulator Inhibition by Cigarette Smoke

• Published in: American journal of respiratory cell and molecular biology Vol. 56; no. 1; pp. 99 - 108
• Main Authors: Raju, S Vamsee, Lin, Vivian Y, Liu, Limbo, McNicholas, Carmel M, Karki, Suman, Sloane, Peter A, Tang, Liping, Jackson, Patricia L, Wang, Wei, Wilson, Landon, Macon, Kevin J, Mazur, Marina, Kappes, John C, DeLucas, Lawrence J, Barnes, Stephen, Kirk, Kevin, Tearney, Guillermo J, Rowe, Steven M
• Format: Journal Article
• Language: English
• Published: United States American Thoracic Society 01.01.2017
• Subjects: Acrolein - pharmacology; Amino Acid Sequence; Aminophenols - pharmacology; Bronchi - pathology; Bronchitis; Cells, Cultured; Chronic obstructive pulmonary disease; Cigarettes; Cilia - drug effects; Cilia - metabolism; Cystic fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator - antagonists & inhibitors; Cystic Fibrosis Transmembrane Conductance Regulator - chemistry; Cystic Fibrosis Transmembrane Conductance Regulator - metabolism; Epithelial Cells - drug effects; Epithelial Cells - metabolism; Genotype & phenotype; Humans; Ion Channel Gating - drug effects; Kinases; Mucociliary Clearance - drug effects; Mucous Membrane - pathology; Original Research; Proteins; Quinolones - pharmacology; Smoking - adverse effects; Software; Studies; Tomography; Tomography, Optical Coherence; Trachea - pathology; United States > US; cystic fibrosis transmembrane conductance regulator potentiator; cigarette smoke; ivacaftor; optical coherence tomography; mucociliary transport
• ISSN: 1044-1549; 1535-4989
• DOI: 10.1165/rcmb.2016-0226oc

Acquired cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction may contribute to chronic obstructive pulmonary disease pathogenesis and is a potential therapeutic target. We sought to determine the acute effects of cigarette smoke on ion transport and the mucociliary transport apparatus, their mechanistic basis, and whether deleterious effects could be reversed with the CFTR potentiator ivacaftor (VX-770). Primary human bronchial epithelial (HBE) cells and human bronchi were exposed to cigarette smoke extract (CSE) and/or ivacaftor. CFTR function and expression were measured in Ussing chambers and by surface biotinylation. CSE-derived acrolein modifications on CFTR were determined by mass spectroscopic analysis of purified protein, and the functional microanatomy of the airway epithelia was measured by 1-μm resolution optical coherence tomography. CSE reduced CFTR-dependent current in HBE cells (P < 0.05) and human bronchi (P < 0.05) within minutes of exposure. The mechanism involved CSE-induced reduction of CFTR gating, decreasing CFTR open-channel probability by approximately 75% immediately after exposure (P < 0.05), whereas surface CFTR expression was partially reduced with chronic exposure, but was stable acutely. CSE treatment of purified CFTR resulted in acrolein modifications on lysine and cysteine residues that likely disrupt CFTR gating. In primary HBE cells, CSE reduced airway surface liquid depth (P < 0.05) and ciliary beat frequency (P < 0.05) within 60 minutes that was restored by coadministration with ivacaftor (P < 0.005). Cigarette smoking transmits acute reductions in CFTR activity, adversely affecting the airway surface. These effects are reversible by a CFTR potentiator in vitro, representing a potential therapeutic strategy in patients with chronic obstructive pulmonary disease with chronic bronchitis.