Suppression of lipopolysaccharide-induced macrophage nitric oxide and cytokine production in vitro by a novel lipopolysaccharide antagonist.
BACKGROUND
Many of the physiologic derangements resulting in septic shock are caused by inflammatory mediators such as nitric oxide (NO) and cytokines produced in response to bacterial endotoxin or, more specifically, lipopolysaccharide. The recent development of a novel class of lipopolysaccharide antagonists offers the opportunity to block this response selectively. In this article we investigated the ability of one of these antagonists, B464 (Eisai), to block lipopolysaccharide-induced release of macrophage NO and cytokines.


METHODS
The mouse macrophage cell line RAW264.7 was grown in vitro and exposed to (1) media control, (2) B464 alone, (3) lipopolysaccharide alone, or (4) lipopolysaccharide plus graded concentrations of B464. Supernatants were assayed for nitrite plus nitrate, the stable end products of NO, as well as tumor necrosis factor-alpha and interleukin-6. Total cellular RNA was examined for inducible NO synthase and interleukin-6 mRNA.


RESULTS
Lipopolysaccharide-stimulated increases in NO, tumor necrosis factor, and interleukin-6 production were blocked by B464. Reduction of NO was also seen at the level of inducible NO synthase mRNA. Induction of interleukin-6 mRNA was also suppressed.


CONCLUSIONS
B464 is a novel potent specific antagonist of lipopolysaccharide-induced macrophage NO and cytokine production.
Wang
S C
SC
Department of Surgery, University of Pittsburgh School of Medicine, PA 15261.
Rossignol
D P
DP
Christ
W J
WJ
Geller
D A
DA
Freeswick
P D
PD
Thai
N L
NL
Su
G L
GL
Simmons
R L
RL
D000594:Amino Acid Oxidoreductases / Q000235:genetics; D000818:Animals; D002240:Carbohydrate Sequence; D002460:Cell Line; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics; D008050:Lipid A / Q000031:analogs & derivatives* / Q000032:analysis; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors*; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase; D012333:RNA, Messenger / Q000032:analysis; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
C088580:B 464; D015850:Interleukin-6; D008050:Lipid A; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases