Figure 2.

PGE₂ inhibited PMA‐induced NETosis. After human peripheral neutrophils were incubated without or with 50 nM PMA in the presence of the indicated concentrations of (A) PGE₂, (B) EP₂ antagonist PF‐04418948 or EP₄ antagonist L‐161982 with 1 μM PGE₂, (C) EP₂ agonist butaprost and (D) EP₄ agonist CAY10598, cells undergoing NETosis were stained with cell‐impermeable DNA stain sytox orange. NETosis was visually measured in more than 300 cells in five randomly selected fields by confocal microscopy. Data shown are expressed as mean ± SEM of cells undergoing NETosis as a percentage of those stimulated with PMA alone in six (A) or five (B–D) independent experiments. *P < 0.05 and **P < 0.01 compared with NETosis with PMA alone for (A), (C) and (D) or that with PMA plus PGE₂ for (B).