Figure 12.

Serous cell secretion in response to protease activation of protease-activated receptor 2 (PAR-2) is blocked by pretreatment with Pseudomonas aeruginosa conditioned media (CM). A: representative volume (open squares) and Ca²⁺ (fura-2 340/380; gray circles) traces showing responses to trypsin, tryptase, 2-Furoyl-LIGRLO-NH₂ (2FLI), or carbachol (CCh) after exposure to P. aeruginosa PAO-1 CM. B: representative Ca²⁺ and volume traces during stimulation with 10 µM 2FLI after PAO-1 CM exposure + GB88. Representative Ca²⁺ and volume during stimulation with trypsin after pretreatment with heat-inactivated PAO-1 CM (C), PAO-1 CM treated with elastase inhibitor phosphoramidon (10 µM; D), or CM from PAO-JP2 (E). F: representative Ca²⁺ and volume traces during stimulation with 2FLI and trypsin after treatment with recombinant P. aeruginosa (P.a.) elastase (500 nM) ± phosphoramidon. G: representative Ca²⁺ and volume traces during acute exposure to recombinant P.a. elastase (1 μM) with subsequent stimulation with 1 μM trypsin or tryptase (left), 5 μM 2FLI (left), or 100 μM CCh. All experiments shown are representative of 3–5 independent experiments using cells from 3 to 5 patients.