FMLP-Induced IL-8 release is dependent on NADPH oxidase in human neutrophils

N-formyl-methionyl-leucyl-phenylalanine (fmlp) and platelet-activating factor (paf) induce similar intracellular signalling profiles; but only fmlp induces interleukin-8 (il-8) release and nicotinamide adenine dinucleotide phosphate reduced (nadph) oxidase activity in neutrophils. because the role of ros on il-8 release in neutrophils is until now controversial,we assessed if nadph oxidase is involved in the il-8 secretions and pi3k/akt,mapk,and nf-b pathways activity induced by fmlp. neutrophils were obtained from healthy volunteers. il-8 was measured by elisa,il-8 mrna by qpcr,and ros production by luminol-amplified chemiluminescence,reduction of ferricytochrome c,and facs. intracellular ph changes were detected by spectrofluorescence. erk1/2,p38 mapk,and akt phosphorylation were analysed by immunoblotting and nf-b was analysed by immunocytochemistry. hydroxy-3-methoxyaceto-phenone (hmap),diphenyleneiodonium (dpi),and sirna nox2 reduced the ros and il-8 release in neutrophils treated with fmlp. hmap,dpi,and amiloride (a na+/h+ exchanger inhibitor) inhibited the akt phosphorylation and did not affect the p38 mapk and erk1/2 activity. dpi and hmap reduced nf-b translocation induced by fmlp. we showed that il-8 release induced by fmlp is dependent on nadph oxidase,and ros could play a redundant role in cell signalling,ultimately activating the pi3k/akt and nf-b pathways in neutrophils. © 2015 maría a. hidalgo et al.