Effects of prostaglandin E2, cholera toxin and 8-bromo-cyclic AMP on lipopolysaccharide-induced gene expression of cytokines in human macrophages.
Prostaglandin E2 (PGE2) appears to regulate macrophage cytokine production through the stimulatory GTP-binding protein (Gs protein)-mediated cyclic AMP (cAMP)-dependent transmembrane signal transduction pathway. In this study, we used PGE2, cholera toxin (CT; a direct G alpha s protein stimulator) and 8-bromo-cAMP (a membrane permeable cAMP analogue) to stimulate this pathway, and investigated their influence on cytokine gene expression in lipopolysaccharide (LPS)-activated human macrophages. The mRNA expression for interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumour necrosis factor-alpha (TNF-alpha), IL-6 and IL-8 were determined employing reverse transcription polymerase chain reaction (RT-PCR) using specific primers. We demonstrated that PGE2, CT and 8-bromo-cAMP inhibited the LPS-induced gene activation of TNF-alpha and IL-1 alpha, and had no effect on the gene activation of IL-1 beta and IL-8. Further, our data indicate that PGE2 suppressed the gene activation of IL-6 following LPS stimulation, but neither CT nor 8-bromo-cAMP had an effect. These data suggest that PGE2 alters LPS-stimulated gene activation of only some of the early macrophage cytokines, and does so either by a Gs transmembrane cAMP-dependent or an independent system.
Zhong
W W
WW
Surgical Metabolism Laboratory, New England Deaconess Hospital, Harvard Medical School, Boston, MA 02215, USA.
Burke
P A
PA
Drotar
M E
ME
Chavali
S R
SR
Forse
R A
RA
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000328:Adult; D002478:Cells, Cultured; D002772:Cholera Toxin / Q000494:pharmacology; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics; D015232:Dinoprostone / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects / Q000276:immunology; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology; D008262:Macrophage Activation / Q000235:genetics / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects*
D016207:Cytokines; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D015124:8-Bromo Cyclic Adenosine Monophosphate; D002772:Cholera Toxin; D015232:Dinoprostone