INTERLEUKIN-1-BETA-STIMULATED PGE2 PRODUCTION FROM EARLY FIRST TRIMESTER HUMAN DECIDUAL CELLS IS INHIBITED BY DEXAMETHASONE AND PROGESTERONE

Cytokines are known to increase the production of prostaglandins by hu man decidual cells, but negative regulators have not been identified. We have examined the effects of dexamethasone and progesterone on pros taglandin (PG) E2 synthesis by cultured human first trimester decidual cells. The numbers of cyclooxygenase (COX) enzyme positive cells were visualised by immunocytochemistry, using antibodies specific for COX- 1 and COX-2. Interleukin-1 beta stimulated the production of prostagla ndins E2 and F2 alpha dose-dependently, and this was associated with i ncreased numbers of COX-2 positive cells. Progesterone(10(-7)-10(-6) M ) and dexamethasone (10(-7)-10(-6) M) inhibited basal and interleukin- 1 beta-stimulated prostaglandin production, and decreased the numbers of COX-2 positive cells. Neither interleukin-1 beta nor the steroids a ffected numbers of COX-1 positive cells. COX-2 seems to be the main en zyme controlling the synthesis of PGE2 by human decidual cells, and ma y be negatively regulated by progesterone.