title: Signal pathways involved in the regulation of prostaglandin E synthase-1 in human gingival fibroblasts.
abstract: Microsomal prostaglandin E synthase-1 (mPGES-1) is the terminal enzyme regulating the synthesis of prostaglandin E2 (PGE2) in inflammatory conditions. In this study we investigated the regulation of mPGES-1 in gingival fibroblasts stimulated with the inflammatory mediators interleukin-1 beta (IL-1beta) and tumour necrosis factor alpha (TNFalpha). The results showed that IL-1beta and TNFalpha induce the expression of mPGES-1 without inducing the expression of early growth response factor-1 (Egr-1). Treatment of the cells with the PLA2 inhibitor 4-bromophenacyl bromide (BPB) decreased the cytokine-induced mPGES-1 expression accompanied by decreased PGE2 production whereas the addition of arachidonic acid (AA) upregulated mPGES-1 expression and PGE2 production. The protein kinase C (PKC) activator PMA did not upregulate the expression of mPGES-1 in contrast to COX-2 expression and PGE2 production. In addition, inhibitors of PKC, tyrosine and p38 MAP kinase markedly decreased the cytokine-induced PGE2 production but not mPGES-1 expression. Moreover, the prostaglandin metabolites PGE2 and PGF2alpha induced mPGES-1 expression as well as upregulated the cytokine-induced mPGES-1 expression indicating positive feedback regulation of mPGES-1 by prostaglandin metabolites. The peroxisome proliferator-activated receptor-gamma (PPARgamma) ligand, 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2), decreased mPGES-1 expression but not COX-2 expression or PGE2 production. The results indicate that the inflammatory-induced mPGES-1 expression is regulated by PLA2 and 15d-PGJ2 but not by PKC, tyrosine kinase or p38 MAP kinase providing new insights into the regulation of mPGES-1.
authors.affiliation: Department of Pediatric Dentistry, Institute of Odontology, Karolinska Institutet, Box 4064, SE-141 04 Huddinge, Sweden. Tulay.Lindberg@ofa.ki.se
authors.forename: Tülay
authors.initials: T
authors.lastname: Yucel-Lindberg
authors.forename: Tove
authors.initials: T
authors.lastname: Olsson
authors.forename: Tomomi
authors.initials: T
authors.lastname: Kawakami
mesh_terms: D016718:Arachidonic Acid / Q000494:pharmacology; D015153:Blotting, Western; D002478:Cells, Cultured; D002648:Child; D015237:Dinoprost / Q000494:pharmacology; D015232:Dinoprostone / Q000096:biosynthesis / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D005881:Gingiva / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D053583:Interleukin-1beta / Q000494:pharmacology; D019746:Intramolecular Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D008301:Maleimides / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism; D015230:Prostaglandin D2 / Q000031:analogs & derivatives / Q000494:pharmacology; D000071876:Prostaglandin-E Synthases; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D011799:Quinazolines / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: C477819:15-deoxyprostaglandin J2; D007093:Imidazoles; D007211:Indoles; D053583:Interleukin-1beta; D008301:Maleimides; D016328:NF-kappa B; D011725:Pyridines; D011799:Quinazolines; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D016718:Arachidonic Acid; D015237:Dinoprost; D011505:Protein-Tyrosine Kinases; D011493:Protein Kinase C; D048051:p38 Mitogen-Activated Protein Kinases; D019746:Intramolecular Oxidoreductases; C000605862:PTGES protein, human; D000071876:Prostaglandin-E Synthases; D015232:Dinoprostone; C088060:bisindolylmaleimide; C093642:SB 203580; D015230:Prostaglandin D2; C088860:4-((3-bromophenyl)amino)-6,7-dimethoxyquinazoline