Nitric oxide regulates neutrophil migration through microparticle formation.
The role of nitric oxide (NO) in regulating neutrophil migration has been investigated. Human neutrophil migration to interleukin (IL)-8 (1 nmol/L) was measured after a 1-hour incubation using a 96-well chemotaxis plate assay. The NO synthase inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME) significantly (P < 0.001) enhanced IL-8-induced migration by up to 45%. Anti-CD18 significantly (P < 0.001) inhibited both IL-8-induced and L-NAME enhanced migration. Antibodies to L-selectin or PSGL-1 had no effect on IL-8-induced migration but prevented the increased migration to IL-8 induced by L-NAME. L-NAME induced generation of neutrophil-derived microparticles that was significantly (P < 0.01) greater than untreated neutrophils or D-NAME. This microparticle formation was dependent on calpain activity and superoxide production. Only microparticles from L-NAME and not untreated or D-NAME-treated neutrophils induced a significant (P < 0.01) increase in IL-8-induced migration and transendothelial migration. Pretreatment of microparticles with antibodies to L-selectin (DREG-200) or PSGL-1 (PL-1) significantly (P < 0.001) inhibited this effect. The ability of L-NAME-induced microparticles to enhance migration was found to be dependent on the number of microparticles produced and not an increase in microparticle surface L-selectin or PSGL-1 expression. These data show that NO can modulate neutrophil migration by regulating microparticle formation.
Nolan
Sarah
S
Cardiovascular Research Unit, University of Sheffield, School of Medicine and Biomedical Sciences, LU112 L Floor Royal Hallamshire Hospital, Glossop Rd., Sheffield S10 2JF UK.
Dixon
Rachel
R
Norman
Keith
K
Hellewell
Paul
P
Ridger
Victoria
V
D018821:CD18 Antigens / Q000096:biosynthesis; D002460:Cell Line; D002465:Cell Movement; D042783:Endothelial Cells / Q000166:cytology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry / Q000379:methods; D005786:Gene Expression Regulation; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D008854:Microscopy, Electron; D008954:Models, Biological; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology* / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism
D018821:CD18 Antigens; D004791:Enzyme Inhibitors; D016209:Interleukin-8; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester