Amnion cell biosynthesis of interleukin-8: regulation by inflammatory cytokines.
The cellular constituents of the placenta are important participants in the recruitment and trafficking of inflammatory cells within the placenta. In infection-induced labor, gestational tissues synthesize and release a variety of inflammatory cytokines whose effects include increased prostaglandin biosynthesis and the initiation of uterine contractions. Interleukin-8 (IL-8), a potent neutrophil chemoattractant, has been recently described as being elevated in the amniotic fluid of mothers with chorioamnionitis. We investigated the biosynthesis of IL-8 by human amnion cells and its regulation by other inflammatory cytokines. Cultured amnion cells obtained from normal term placentae were found to produce IL-8 in response to pathophysiologic concentrations of interleukin 1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF-alpha). Treatment of amnion cells stimulated by IL-1 beta with cycloheximide resulted in increased IL-8 production, while incubation of IL-1 beta treated amnion cells with actinomycin D resulted in a concentration-dependent decrease in detectable amounts of IL-8. Northern blot analysis of cultured amnion cells stimulated with IL-1 beta demonstrated a rapid increase in IL-8 mRNA which peaked at 2-4 hr. These in vitro results suggest inflammation of gestational tissues in vivo may result in locally produced IL-8 and, in association with other inflammatory mediators, may be important in the pathophysiology of infection-induced labor.
Trautman
M S
MS
Department of Pediatrics, University of Utah, Salt Lake City 84132.
Dudley
D J
DJ
Edwin
S S
SS
Collmer
D
D
Mitchell
M D
MD
D000650:Amnion / Q000378:metabolism*; D015152:Blotting, Northern; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D015232:Dinoprostone / Q000032:analysis / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D007375:Interleukin-1; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D003609:Dactinomycin; D003513:Cycloheximide; D015232:Dinoprostone