Effect of ceramide analogs on interleukin-1alpha-induced production of prostaglandin E2 by amnion-derived (WISH) cells.

Background: Prostaglandin E2 (PGE2) is reportedly synthesized in the amnion, and its levels are increased during labor. Our objective was to measure the level of PGE2 induced by interleukin (IL)-1alpha following treatment with ceramide analogs in amnion-derived cells.

Methods: Amnion-derived (WISH) cells were cultured and stimulated by IL-1alpha, IL-1 receptor antagonist (ra), C2-ceramide and C6-ceramide. The levels of PGE2 in the media were measured by ELISA. The induction of prostaglandin H synthase (PGHS)-2 mRNA was detected by reverse transcription and polymerase chain reaction (RT-PCR).

Results: Following stimulation with IL-1alpha, the production of PGE2 could not be detected until incubation had continued for 2 h, but this production appeared to continue after 4 h of incubation. The production of PGE2 was significantly increased by IL-1alpha, and was suppressed by IL-1 ra, in a dose-dependent manner. PGE2 production was significantly increased by IL-1alpha and C2-ceramide as compared with IL-1alpha alone. However, PGE2 production was not significantly increased by IL-1alpha and C6-ceramide as compared with IL-1alpha alone. PGHS-2 mRNA were induced by treatment with IL-1alpha, and were strongly induced by treatment with IL-1alpha and C2-ceramide by RT-PCR.

Conclusions: Results suggest that IL-1alpha induce the PGHS-2 mRNA and stimulate the production of PGE2 by a mechanism that involves the sphingomyelin-ceramide system. Ceramide may be important in increasing the production of PGE2 during parturition.