Neutrophil elastase and oxygen radicals enhance monocyte chemoattractant protein- expression after ischemia/reperfusion in rat liver.
BACKGROUND
The monocyte chemoattractant protein-1 (MCP-1) is produced during reperfusion injury and induces tissue factor that is the initiator of the clotting cascade. Neutrophil elastase is a crucial mediator of inflammatory tissue damage. Activation of the coagulation system stimulates cytokine production by activated leukocytes. We investigated the effects of neutrophil elastase and oxygen radicals generated by hypoxia associated with microthrombus formation on MCP-1 expression after ischemia/reperfusion in rat liver.


METHODS
In vitro MCP-1 production by macrophages after stimulation with human neutrophil elastase (HNE) or oxygen radicals generated by hypoxanthine and xanthine oxidase was examined. Liver ischemia was induced in rats by occluding the portal vein for 30 min. An inhibitor of human neutrophil elastase (ONO-5046*Na, 10 mg/kg) and antithrombin III (AT-III, 250 U/kg) were injected i.v. 5 min before vascular clamping. Serum concentrations of MCP-1 were measured by enzyme-linked immunosorbent assay.


RESULTS
Human neutrophil elastase or oxygen radicals significantly enhanced in vitro MCP-1 production by macrophage. Serum MCP-1 concentrations reached a peak at 6 hr after reperfusion and then gradually decreased. However, pretreatment of animals with AT-III or ONO-5046*Na alone resulted in significantly smaller increases in serum concentrations of MCP-1 after reperfusion. Pretreatment with both ONO-5046*Na and AT-III produced additive effects. The combined treatment with ONO-5046*Na and AT-III significantly reduced MCP-1 mRNA in liver after ischemia/reperfusion.


CONCLUSIONS
MCP-1 production by macrophages is stimulated by neutrophil elastase and oxygen radicals generated by hypoxia, probably due to microthrombus formation after ischemia/reperfusion of the rat liver.
Yamaguchi
Y
Y
Department of Surgery II, Kumamoto University Medical School, Japan.
Matsumura
F
F
Liang
J
J
Okabe
K
K
Ohshiro
H
H
Ishihara
K
K
Matsuda
T
T
Mori
K
K
Ogawa
M
M
D000818:Animals; D000990:Antithrombin III / Q000494:pharmacology; D015687:Cell Hypoxia; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000097:blood / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007511:Ischemia / Q000378:metabolism*; D007728:Kupffer Cells / Q000187:drug effects / Q000378:metabolism; D019272:Leukocyte Elastase / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D008099:Liver / Q000098:blood supply* / Q000378:metabolism*; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015424:Reperfusion; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology; D013481:Superoxides / Q000494:pharmacology*; D014158:Transcription, Genetic
D018932:Chemokine CCL2; D015842:Serine Proteinase Inhibitors; D013449:Sulfonamides; D013481:Superoxides; D000990:Antithrombin III; D006861:Hydrogen Peroxide; C069195:sivelestat; D019272:Leukocyte Elastase; D005998:Glycine