CXCL8 and chronic obstructive pulmonary disease: To investigate whether mitochondrial dysfunction also reduces the responsiveness to corticosteroids, as has been observed in COPD and for CXCL8 production in airway epithelial cells upon exposure to oxidative stress32, we studied the suppressive effect of the ICS budesonide on CXCL8 secretion in wild-type A549 and A549 Rho-0 cells.