Functional study on elastase regulation of inflammatory neutrophils recruitment
Objective:To explore the effect of neutrophil elastase(NE)on neutrophil inflammatory recruitment.Methods:Mice bone marrow-derived neutrophils were pretreated with an exogenous elastase inhibitor-sivelestat sodium.The effects of elastase inhibition on the in vivo inflammatory recruitment,chemotaxis,adhesion,cell polarization and spreading of NE were examined by peritonitis adoptive transfer assay,dunn chamber,flow chamber,immunofluorescence staining and spreading assay,respectively.The effects of elastase inhibition on NE phagocytosis and reactive oxygen species(ROS)release capacity were detected by flow cytom-etry and the luminol chemiluminescence system.Results:Sivelestat sodium pretreatment significantly attenuated neutrophil in vivo in-flammatory recruitment(P<0.001);impaired neutrophil perception of chemotaxis in vitro(P<0.05),slowed chemotactic velocity(P<0.05),and decreased the chemotactic distance(P<0.05);reduced the adhesion of neutrophils to inflamed endothelial cells(P<0.000 1)and inhibited the phagocytosis of bacteria by neutrophils(P<0.01);however,there was no significant effect on neutrophil spreading,polarization and ROS.Conclusion:NE inhibition significantly impaired the inflammatory recruitment cascade response and phagocyto-sis of neutrophils in vitro and in vivo but had no significant effect on the spreading,polarization and ROS release of neutrophils.