Induction of cyclooxygenase-2 expression in human myometrial smooth muscle cells by interleukin-1beta: involvement of p38 mitogen-activated protein kinase

J Physiol. 1999 Oct 15;520 Pt 2(Pt 2):399-406. doi: 10.1111/j.1469-7793.1999.00399.x.


1. Human myometrial smooth muscle cells (HMSMCs) in culture were exposed to recombinant human interleukin-1beta (IL-1beta, 10 ng ml-1) for 1 to 24 h. Cyclooxygenase-2 (COX-2) mRNA and protein were rapidly induced, with expression sustained at 24 h. 2. Cycloheximide (10 microg ml-1, 6 h) blocked IL-1beta-induced COX-2 protein expression and super-induced COX-2 mRNA expression. Induction of COX-2 mRNA and protein was blocked by dexamethasone (1 microm, 6 h). 3. IL-1beta-induced COX-2 expression was accompanied by a 3-fold increase of prostaglandin E2 release into the culture medium. 4. IL-1beta induced a transient (5-30 min) activation of p42/44 and p38 mitogen-activated protein kinase (MAPK) enzymes in HMSMCs. Activity of p38 MAPK was monitored by in-gel activity of its substrate MAP kinase-activated protein kinase-2 (MAPKAP kinase-2). Induction of MAPKAP kinase-2 activity was prevented by the p38 MAPK inhibitor SB 203580 (10 microm, 5-30 min). 5. COX-2 protein expression detected after 6 h IL-1beta stimulation was blocked by SB 203580 (10 microM). Exposure of HMSMCs to 10 ng ml-1 IL-1beta for only 30 min induced a level of COX-2 protein expression at 6 h culture similar to that detected in cells exposed to the cytokine for 6 h. 6. Exposure of cells to SB 203580 (10 microM during only the first 30 min of IL-1beta stimulation was effective in blocking COX-2 protein expression assayed after 6 h in culture. 7. This study has established that a transient activation of the p38 MAPK cascade is involved in IL-1beta-stimulated COX-2 expression in human myometrial smooth muscle cells. Induction of COX-2 by IL-1beta in HMSMCs provides support for the hypothesis that autocrine prostaglandin signalling in the myometrium, initiated by elevated intrauterine cytokine concentrations, plays a role in regulating myometrial contractility during labour.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cells, Cultured
  • Cycloheximide / pharmacology
  • Cyclooxygenase 2
  • Dexamethasone / pharmacology
  • Enzyme Inhibitors / pharmacology
  • Female
  • Gene Expression Regulation / drug effects
  • Humans
  • Imidazoles / pharmacology
  • Interleukin-1 / pharmacology*
  • Isoenzymes / biosynthesis*
  • Isoenzymes / genetics
  • Membrane Proteins
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinases / metabolism
  • Muscle Contraction
  • Muscle, Smooth / enzymology*
  • Myometrium / enzymology
  • Prostaglandin-Endoperoxide Synthases / biosynthesis*
  • Prostaglandin-Endoperoxide Synthases / genetics
  • Pyridines / pharmacology
  • RNA, Messenger / biosynthesis
  • p38 Mitogen-Activated Protein Kinases


  • Enzyme Inhibitors
  • Imidazoles
  • Interleukin-1
  • Isoenzymes
  • Membrane Proteins
  • Pyridines
  • RNA, Messenger
  • Dexamethasone
  • Cycloheximide
  • Cyclooxygenase 2
  • PTGS2 protein, human
  • Prostaglandin-Endoperoxide Synthases
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases
  • SB 203580