Interleukin-1 beta-stimulated prostaglandin synthesis by human decidual cells is independent of protein kinase C.

Basal prostaglandin E2 (PGE2) synthesis by human decidual cells was stimulated by phorbol myristate acetate (PMA) which activates protein kinase C. Staurosporine, which is an inhibitor of protein kinase C in most systems, also increased basal PGE2 synthesis. Further work is needed to explain this finding, as another inhibitor of protein kinase C, H7, inhibited PGE2 production under similar culture conditions. Interleukin-1 beta (IL-1 beta)-stimulated PGE2 synthesis was potentiated by coincubation with PMA or staurosporine, indicating that IL-1 beta and protein kinase C increase decidual PGE2 synthesis through different mechanisms. Desensitization of the decidual cells for 24 h with PMA did not affect IL-1 beta-stimulated PGE2 synthesis. The complex roles of protein kinase C in regulating decidual prostaglandin synthesis require further investigation, but it is clear that the effects of IL-1 beta are not mediated by protein kinase C.