Fig. 2.

Pseudomonas aeruginosa exoenzyme Y (ExoY) does not induce intracellular caspase-3/7 activation in pulmonary microvascular endothelial cells (PMVECs). PMVECs were treated with vehicle control or inoculated with PA103 or ExoY⁺. PMVECs were loaded with fluorescently labeled active caspase-3/7 substrate FAM-DEVD-FMK (FLICA; A), caspase-8 substrate FAM-LETD-FMK (B), or caspase-9 substrate FAM-LEHD-FMK (C), for the last 3 h of infection. Intracellular active caspase was assessed by flow cytometry 4 h (PA103) or 6 h [control (CTRL) and ExoY⁺] postinoculation. Each data point represents 1 experiment performed in duplicate. Data were analyzed by ordinary 1-way ANOVA with Bonferroni’s multiple-comparison test. ANOVA, P < 0.0001. *P < 0.0001. NS, not significantly different from control, n = 5.