Investigating the role of cathepsin S in the pathogenesis of cystic fibrosis-like lung disease

Elevated levels of the cysteine protease cathepsin S (cat S) are found in cystic fibrosis (CF) lung secretions, however, the role of cat S in CF lung disease is unclear. Cat S is capable of maintaining its activity at a neutral pH allowing it to remain active outside of the cell. Consequently, cat S has the capacity to promote remodelling of the extracellular matrix via its potent elastolytic activity. In addition, cat S can cleave and inactivate key antimicrobials in the CF airways. On the basis of findings to date, we hypothesise that active cat S contributes to the pathogenesis of CF lung disease and represents a viable therapeutic target for the treatment of chronic lung disease. The βENaC transgenic…