Abstract
These studies examined the signal transduction mechanisms by which prostaglandin (PG) E2 production can occur in human amnionic WISH cells in response to the stimuli okadaic acid, interleukin (IL)-1β, tumor necrosis factor (TNF)-α, phorbol-12-myristate-13-acetate (PMA) or combinations of PMA with IL-1β or TNF-α. We also investigated whether WISH cells are capable of producing TNF-α or IL-1β in response to stimulation, because these cytokines can be produced in an autocrine fashion to perpetuate an inflammatory response. Our data indicate that the magnitude of PGE2 production induced by a given stimulus correlated temporally with the level of PGH synthase-2 (PGHS-2) protein. PMA or IL-1β induced PGE2 production 2 to 4 hr after treatment, whereas the combination of these agents produced the most rapid induction 2 hr after treatment. Only okadaic acid induced the production of both PGE2 and TNF-α, after a lag of 12 to 18 hr. PGE2 production by all stimuli was inhibited by dexamethasone, the IL-1 receptor antagonist (IL-1ra), the specific PGHS-2 inhibitor NS-398 and the protein kinase inhibitor staurosporin. In contrast, TNF-α production in response to okadaic acid was inhibited by the TNF-converting enzyme inhibitor GI 129471 and staurosporin but was unaffected by either IL-1ra, dexamethasone or NS-398. We conclude that WISH cells are capable of producing bioactive proinflammatory mediators such as TNF-α and PGE2 through separable intracellular signal transduction mechanisms. The ability of IL-1ra to reduce PGE2 production caused by all stimuli used suggests an autocrine role for IL-1 in PGHS-2 induction in these cells.
Footnotes
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Send reprint requests to: Dr. Keren I. Hulkower, Abbott Laboratories, D47K/AP9, 100 Abbott Park Road, Abbott Park, IL 60064-3500.
- Abbreviations:
- EIA
- enzyme immunoassay
- ELISA
- enzyme-linked immunosorbent assay
- IL
- interleukin
- IL-1ra
- interleukin-1 receptor antagonist
- PG
- prostaglandin
- PGHS
- prostaglandin H synthase
- PLA2
- phospholipase A2
- PMA
- phorbol-12-myristate-13-acetate
- SDS
- sodium dodecyl sulfate
- SSC
- standard saline citrate
- TBS
- Tris-buffered saline
- TNF
- tumor necrosis factor
- Received June 7, 1996.
- Accepted October 7, 1996.
- The American Society for Pharmacology and Experimental Therapeutics
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