Cigarette Smoke-Induced Acquired Dysfunction of Cystic Fibrosis Transmembrane Conductance Regulator in the Pathogenesis of Chronic Obstructive Pulmonary Disease

Figure 1

Model of airway surface dehydration (mucus hyperconcentration) in chronic obstructive pulmonary disease (COPD). The healthy airway surface (left panel) is covered with a thin film of mucus able to entrap inhaled insults that are constantly removed from the lungs by mucociliary clearance. The proper function of this innate airway defense mechanism largely relies on the function of CFTR, ENaC, and other alternative Cl⁻ channels. In the COPD airway (right panel), the dysfunction of CFTR-mediated chloride channel leads net absorption of sodium leads to dehydration of airway surfaces, decreases ASL volume, and impairs mucus stasis and clearance.