Interferon gamma antagonizes interleukin-1beta-induced cyclooxygenase-2 expression and prostaglandin E(2) production in human myometrial cells.
OBJECTIVE
To evaluate the effect of interferon gamma (IFNgamma) on interleukin-1beta (IL-1) and tumor necrosis factor-alpha (TNFalpha)-promoted prostaglandin E(2) (PGE(2)) production and to investigate the interaction of IFNgamma and IL-1 on cyclooxygenase-2 (COX-2) expression, as well as nuclear factor-kappaB (NF-kappaB) activation in human myometrial cells.


METHODS
An immortalized human myometrial cell line was cultured in Dulbecco modified Eagle medium (DMEM) fortified with 10% (v/v) fetal calf serum (FCS) in multiwell plates until near confluency. Twenty-four hours before the start of the experiments, the medium was replaced with FCS-free medium containing 0.5% bovine serum albumin. Prostaglandin E(2) was determined in the medium with a specific radioimmunoassay having a sensitivity of 10 pg. The COX-2 and NF-kappaB inhibitory protein (IkappaB) protein levels were measured in cell extracts by Western blot.


RESULTS
Cell cultures primed with IFNgamma produced significantly less (P <.05-.01) PGE(2) in response to cytokines than cells exposed to IL-1, TNF-alpha, or the combination of the two. This result corresponded to a similar inhibition of IkappaB degradation (a prerequisite of NF-kappaB activation) as well as COX-2 protein steady state levels.


CONCLUSIONS
Interferon gamma acts as a partial antagonist of IL-1 signaling in this cell model at a site upstream from the activation of the NF-kappaB pathway, causing a partial inhibition of COX-2 expression and PGE(2) production.
Department of Obstetrics, Gynecology and Women's Health, St. Louis University School of Medicine and St. Mary's Health Center, Missouri 63117, USA. hertelf@slu.edu
Frank
F
Hertelendy
Miklós
M
Molnár
Roberto
R
Romero
D015153:Blotting, Western; D002461:Cell Line, Transformed; D003470:Culture Media; D051546:Cyclooxygenase 2; D016207:Cytokines / Q000494:pharmacology; D015232:Dinoprostone / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology*; D007375:Interleukin-1 / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D007527:Isoenzymes / Q000378:metabolism*; D008565:Membrane Proteins; D009215:Myometrium / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D003470:Culture Media; D016207:Cytokines; D020672:I-kappa B Proteins; D007375:Interleukin-1; D007527:Isoenzymes; D008565:Membrane Proteins; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone