title: Role of atypical protein kinase C isozymes and NF-kappaB in IL-1beta-induced expression of cyclooxygenase-2 in human myometrial smooth muscle cells.
abstract: Increased myometrial expression of cyclooxygenase-2 (Cox-2) at term results from elevated local levels of inflammatory cytokines, and its inhibition provides a potential route for intervention in human pre-term labor. We have identified a role for atypical protein kinase C (PKC) isozymes in IL-1beta-induced Cox-2 expression in human myometrial smooth muscle cells (HMSMC). The PKC inhibitor GF109203X (10 microM) inhibited IL-1beta-induced Cox-2 protein and RNA expression, which were also reduced by MAPK and nuclear factor kappaB (NF-kappaB) inhibitors. GF109203X did not affect MAPK activities, and neither did it replicate the effect of p38 MAPK inhibition on Cox-2 mRNA stability, suggesting that PKC operates through an independent mechanism. The effect of GF109203X remained intact after depletion of conventional and novel PKC isozymes by phorbol ester pre-treatment. In contrast LY379196 (10 microM), which at micromolar concentrations inhibits all but atypical PKCs, did not affect Cox-2 expression. A peptide corresponding to the pseudosubstrate sequence of atypical PKCs blocked Cox-2 protein expression, whereas the sequence from conventional PKCs was ineffective. GF109203X did not affect NF-kappaB binding to nuclear proteins, but strongly reduced NF-kappaB-dependent transcription in luciferase reporter assays. Our findings indicate that IL-1beta-induced Cox-2 expression in HMSMC in culture requires p38-MAPK-mediated mRNA stabilization and an independent activation of Cox-2 transcription which is dependent on the action of atypical PKCs, probably through direct stimulation of the transactivating activity of NF-kappaB.
authors.affiliation: Cardiovascular Division, School of Biomedical and Health Sciences, King's College London, Guy's Campus, London, United Kingdom.
authors.forename: Sara V
authors.initials: SV
authors.lastname: Duggan
authors.forename: Tamsin
authors.initials: T
authors.lastname: Lindstrom
authors.forename: Teresa
authors.initials: T
authors.lastname: Iglesias
authors.forename: Phillip R
authors.initials: PR
authors.lastname: Bennett
authors.forename: Giovanni E
authors.initials: GE
authors.lastname: Mann
authors.forename: Simon R
authors.initials: SR
authors.lastname: Bartlett
mesh_terms: D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D007375:Interleukin-1 / Q000502:physiology*; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology; D008301:Maleimides / Q000494:pharmacology; D008698:Mesylates / Q000494:pharmacology; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000201:enzymology*; D009215:Myometrium / Q000166:cytology / Q000201:enzymology*; D016328:NF-kappa B / Q000235:genetics / Q000502:physiology*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D011758:Pyrroles / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: C434605:5,21 - 12,17-dimetheneo-18H-dibenzo(i,o)pyrrolo(3,4-1)(1,8)diazacyclohexandecine-18,10(19H)dione,8((dimethylamino)methyl)-6,7,8,9,10,11-hexahydro,monomethanesulfonate; D004791:Enzyme Inhibitors; D007211:Indoles; D007375:Interleukin-1; D007527:Isoenzymes; D008301:Maleimides; D008698:Mesylates; D016328:NF-kappa B; D011758:Pyrroles; D012333:RNA, Messenger; D051546:Cyclooxygenase 2; D011493:Protein Kinase C; D048051:p38 Mitogen-Activated Protein Kinases; C070515:bisindolylmaleimide I