Figure 3.

cAMP‐mediated inhibition of PMA‐induced NETosis. After human peripheral neutrophils were incubated without or with 50 nM PMA in the presence of the indicated concentrations of (A) cell‐permeable cAMP analogue, db₂cAMP, and (B) PKA inhibitor H89 with 1 μM PGE₂, 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 five independent experiments. **P < 0.01 compared with NETosis with PMA alone (A) and that with PMA plus PGE₂ (B).