Background
Previous work suggests that apoptosis is dysfunctional in cystic fibrosis (CF) airways with conflicting
Conclusions
Overall, these results suggest that CF airway epithelial cells are more sensitive to apoptosis via increased levels of Fas and subsequent activation of the Fas death receptor pathway, which may be associated with dysfunctional CFTR.
Methods
Apoptosis and associated caspase activity were analysed in non-CF and CF tracheal and bronchial epithelial cell lines.
Results
Basal levels of apoptosis and activity of caspase-3 and caspase-8 were significantly increased in CF epithelial cells compared to controls, suggesting involvement of extrinsic apoptosis signalling, which is mediated by the activation of death receptors, such as Fas (CD95). Increased levels of Fas were observed in CF epithelial cells and bronchial brushings from CF patients compared to non-CF controls. Neutralisation of Fas significantly inhibited caspase-3 activity in CF epithelial cells compared to untreated cells. In addition, activation of Fas significantly increased caspase-3 activity and apoptosis in CF epithelial cells compared to control cells. Conclusions: Overall, these results suggest that CF airway epithelial cells are more sensitive to apoptosis via increased levels of Fas and subsequent activation of the Fas death receptor pathway, which may be associated with dysfunctional CFTR.