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Interleukin‐1 (IL‐1) is an important mediator of immunoinflammatory responses in the brain. In the present study, we examined whether prostaglandin E₂ (PGE₂) production after IL‐1β stimulation is dependent upon activation of protein kinases in astroglial cells.

Astrocyte cultures stimulated with IL‐1β or the phorbol ester, PMA significantly increased PGE₂ secretion. The stimulatory action of IL‐1β on PGE₂ production was totally abolished by NS‐398, a specific inhibitor of cyclo‐oxygenase‐2 activity, as well as by the protein synthesis inhibitor cycloheximide, and the glucocorticoid dexamethasone. Furthermore, IL‐1β induced the expression of COX‐2 mRNA. This occurred early at 2 h, with a maximum at 4 h and declined at 12 h. IL‐1 β treatment also induced the expression of COX‐2 protein as determined by immunoblot analysis. In that case the expression of the protein remained high at least up to 12 h …