Abstract
Arachidonic acid, but not eicosapentaenoic acid, increased prostaglandin G/H endoperoxide synthase-2 transcription in cultured intestinal epithelial cells. This stimulatory effect on PGHS-2 synthesis was prevented by an AA utilization inhibitor, eicosatetraynoic acid. Specific inhibitors of the cyclooxygenase or the lipoxygenase pathways of AA metabolism did not prevent AA-mediated induction of PGHS-2 synthesis; however, the involvement of cytochrome P450 monoxygenases (CYP450) was indicated as several CYP450 blockers, ketoconazole, miconazole, and metyrapone, inhibited the induction of PGHS-2 mRNA synthesis by AA. This blockade by CYP450 inhibitors could be overcome by the addition of the AA epoxygenase metabolite 14,15-epoxyeicosatrienoic acid (14,15-EET); other EET regio-isomers were unable to elevate PGHS-2 mRNA level. Blockade of protein kinase C with a specific inhibitor, bisindolyl maleimide-1, or translational inhibition of protein kinase C alpha by antisense oligonucleotides reduced PGHS-2 transcription, suggesting the involvement of protein kinase C alpha in the signal transduction pathway.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
16,16-Dimethylprostaglandin E2 / pharmacology
-
8,11,14-Eicosatrienoic Acid / analogs & derivatives*
-
8,11,14-Eicosatrienoic Acid / pharmacology
-
Animals
-
Cell Line
-
Colforsin / pharmacology
-
Cyclooxygenase 2
-
Diclofenac / pharmacology
-
Epithelial Cells
-
Intestinal Mucosa
-
Isoenzymes / genetics*
-
Isoenzymes / physiology*
-
Ketoconazole / pharmacology
-
Metyrapone / pharmacology
-
Miconazole / pharmacology
-
Peroxidases / genetics
-
Prostaglandin-Endoperoxide Synthases / genetics*
-
Prostaglandins F, Synthetic / pharmacology
-
Protein Kinase C / physiology*
-
Protein Kinase C-alpha
-
RNA, Messenger / metabolism
-
Rats
-
Signal Transduction / drug effects
-
Signal Transduction / genetics
-
Tetradecanoylphorbol Acetate / pharmacology
-
Transcription, Genetic* / drug effects
Substances
-
Isoenzymes
-
Prostaglandins F, Synthetic
-
RNA, Messenger
-
Diclofenac
-
Colforsin
-
Miconazole
-
14,15-epoxy-5,8,11-eicosatrienoic acid
-
Peroxidases
-
Cyclooxygenase 2
-
Prostaglandin-Endoperoxide Synthases
-
Protein Kinase C
-
Protein Kinase C-alpha
-
8,11,14-Eicosatrienoic Acid
-
16,16-Dimethylprostaglandin E2
-
Tetradecanoylphorbol Acetate
-
Ketoconazole
-
fenprostalene
-
Metyrapone