Tumor necrosis factor-alpha upregulates the prostaglandin E-2 EP1 receptorsubtype and the cyclooxygenase-2 isoform in cultured amnion WISH cells

Recent studies have demonstrated a strong correlation between infection and preterm labor. Preterm delivery is also associated with high levels of cyt okines and prostaglandins in amniotic fluid. The purpose of this study was to investigate the effect of tumor necrosis factor-alpha (TNF-alpha) on the levels of cyclooxygenase, prostaglandin E-2 production (PGE(2)), and expre ssion of the PGE(2) receptor subtype EP1 in amnion WISH cell culture. Amnio n WISH cell cultures were incubated in increasing concentrations of TNF-alp ha (0-50 ng/ml). Changes in cyclooxygenase and EP1 receptor proteins were e valuated by Western blot analysis. Changes in EPI mRNA were evaluated by No rthern blot, and culture fluid concentrations of PGE2 were estimated by enz yme immunoassay (EIA). EP1 protein (p < 0.01), EP1 mRNA (p < 0.05), cycloox ygenase-2 (COX-2) protein (p < 0.001), and PGE(2) concentrations (p < 0.01) all increased with increasing concentrations of TNF-alpha. Changes in COX- 1 protein were not observed following TNF-alpha-incubation. The results sug gest that TNF-alpha may play a role in infection-induced preterm labor by i ts pleiotropic ability to simultaneously stimulate COX-2 activity, PGE(2) c oncentrations, and PGE(2) EP1 receptor levels in human amnion.