Airway Epithelium Dysfunction in Cystic Fibrosis and COPD

Figure 4

Effects of cigarette smoke on CFTR and pathophysiology of airway disease in COPD. Cigarette smoke components (e.g., acrolein and cadmium) can decrease expression and function of the CFTR protein by decreasing CFTR mRNA and protein levels, accelerated CFTR internalization, and decreased channel opening probability (P_o). Increased levels of neutrophil elastase in COPD may worsen CFTR dysfunction by degrading CFTR and upregulating ENaC expression. Loss of CFTR function results in ASL dehydration and acidification, mucus hypersecretion, and mucus plugging leading to reduced mucociliary clearance, chronic inflammation, impaired innate immunity, and infection.