title: Regulatory effects of interleukin-1beta and prostaglandin E2 on expression of receptor activator of nuclear factor-kappaB ligand in human periodontal ligament cells.
abstract: BACKGROUND
  Receptor activator of nuclear factor-kappaB ligand (RANKL), which is expressed on the cell membrane of osteoblasts/stromal cells, stimulates osteoclastogenesis. We investigated the regulatory effects of interleukin-1beta (IL-1beta) and prostaglandin E2 (PGE2) on expression of RANKL in human periodontal ligament (HPDL) cells and the mechanisms involved in the PGE2 effect.
  
  
  METHODS
  The HPDL cells were treated with IL-1beta, alone or in combination with indomethacin (INDO) or NS398, a cyclooxygenase-2 (COX-2) inhibitor. The HPDL cells were also pretreated with H89, a protein kinase A (PKA) inhibitor or GF109203X, a protein kinase C (PKC) inhibitor and subsequently treated with PGE2, PGE receptor (EP)2 agonist, EP4 agonist, forskolin, dibutyryl cAMP (db-cAMP), or 3-(isobutyl)-1-methylxantine (IBMX). After each treatment, expression of EP2, EP4, or RANKL mRNA was analyzed by reverse transcription-polymerase chain reaction and Southern hybridization. Expression of RANKL protein was detected by Western blotting, and cAMP accumulation was determined using a cAMP enzyme immunoassay kit.
  
  
  RESULTS
  IL-1beta stimulated the expression of RANKL at messenger RNA (mRNA) and protein levels in HPDL cells. Endogenous PGE2 partially mediated the IL-1beta-induced RANKL mRNA expression. Exogenously added PGE2 also stimulated RANKL expression at mRNA and protein levels in the cells. The PGE2-stimulated RANKL expression was mediated by EP2/4 and cAMP-dependent PKA, while PKC was possibly involved in the PGE2 action.
  
  
  CONCLUSIONS
  Human periodontal ligament cells activated with inflammatory factors such as IL-1beta and PGE2 may directly stimulate osteoclastogenesis through RANKL, which is stimulated to express by these factors.
authors.affiliation: Department of Periodontology, Showa University Dental School, Tokyo, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Nukaga
authors.forename: Makoto
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Shinki
authors.forename: Hong
authors.initials: H
authors.lastname: Song
authors.forename: Takatora
authors.initials: T
authors.lastname: Takada
authors.forename: Takashi
authors.initials: T
authors.lastname: Takiguchi
authors.forename: Ryutarou
authors.initials: R
authors.lastname: Kamijo
authors.forename: Kohji
authors.initials: K
authors.lastname: Hasegawa
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000293:Adolescent; D000328:Adult; D003994:Bucladesine / Q000494:pharmacology; D002352:Carrier Proteins / Q000187:drug effects* / Q000235:genetics; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D015232:Dinoprostone / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D008024:Ligands; D008297:Male; D008562:Membrane Glycoproteins / Q000187:drug effects* / Q000235:genetics; D016328:NF-kappa B / Q000187:drug effects* / Q000235:genetics; D010010:Osteoclasts / Q000187:drug effects / Q000378:metabolism; D010513:Periodontal Ligament / Q000187:drug effects* / Q000378:metabolism; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D053245:RANK Ligand; D012333:RNA, Messenger / Q000187:drug effects; D053246:Receptor Activator of Nuclear Factor-kappa B; D018078:Receptors, Prostaglandin E / Q000819:agonists; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058309:Receptors, Prostaglandin E, EP4 Subtype
chemical_list: D002352:Carrier Proteins; D016861:Cyclooxygenase Inhibitors; D007375:Interleukin-1; D008024:Ligands; D008562:Membrane Glycoproteins; D016328:NF-kappa B; C545644:PTGER2 protein, human; C545650:PTGER4 protein, human; D010726:Phosphodiesterase Inhibitors; D053245:RANK Ligand; D012333:RNA, Messenger; D053246:Receptor Activator of Nuclear Factor-kappa B; D018078:Receptors, Prostaglandin E; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058309:Receptors, Prostaglandin E, EP4 Subtype; C505686:TNFRSF11A protein, human; C505688:TNFSF11 protein, human; D005576:Colforsin; D003994:Bucladesine; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D015232:Dinoprostone; D015056:1-Methyl-3-isobutylxanthine