C4HSL and Wt Pseudomonas aeruginosa -conditioned medium stimulate an increase in mucociliary transport. (A) Representative images of one field of view showing streaks representing particle transport by a Wt mouse septal ALI culture before stimulation (left) and after 3 min stimulation with 100 μM C4HSL (right). (B) Graph showing mean ± SEM (n = ALI 3–5 cultures each) of normalized changes in particle transport after addition of PBS alone (reflecting the mechanical force of pipetting alone, 1.08 ± 0.12), C4HSL (2.25 ± 0.29), C4HSL + U73122 (1.21 ± 0.2), C4HSL + L-NAME (1.11 ± 0.15), C4HSL + cPTIO (1.21 ± 0.08), 12.5 % LB alone (1.15 ± 0.10), 12.5% PAO1 CM (2.21 ± 0.25), PAO1 CM + U73122 (1.21 ± 0.20), PAO-JP2 CM (1.25 ± 0.12), and Sad36 CM (1.98 ± 0.05). Symbols denote significance vs. appropriate control condition (PBS or LB alone) determined via 1-way ANOVA with Dunnett’s post-test; *P <0.05, **P <0.01.