FTY720 is an
immunosuppressive agent which has been approved to treat
multiple sclerosis (MS). The main object of the present study is to investigate whether
FTY720 has the potential to induce the formation of neutrophil extracellular traps (NETs) in vitro. Using
Sytox Green assay and fluorescence microscopy, our results showed that
FTY720 trigged the NET formation. In contrast to classic NET formation induced by
Phorbol 12-myristate 13-acetate (PMA), FTY720-induced NETs were detected earlier and independent of
NADPH oxidase (NOX) activity. Pharmacological inhibitor experiments indicated that autophagy was also required for the NET formation induced by
FTY720. Moreover, p38 and AKT inhibitor significantly suppressed the NET formation by
FTY720, whereas ERK inhibitor had no effect, suggesting that FTY720-induced NETs depended on the activation of p38 and AKT. We further found that citrullination of
histone H3 and
peptidylarginine deiminase 4 (PAD4) did not mediated FTY720-induced NET formation. Interestingly, necroptosis signaling activation was involved in the vital NET formation by
FTY720, however, plasma membrane
rupture resulting from necroptosis was not a major component of NET formation described here. Collectively, these findings indicated that
FTY720 could be a potential antibacterial drug to protect host against pathogen
infection.