title: Induction of cyclooxygenase-2 mRNA and protein expression by epoxy resin and zinc oxide-eugenol based root canal sealers in human osteoblastic cells.
abstract: An ideal root canal sealer should be nonirritating to the surrounding tissues. Unfortunately, all histological investigation demonstrated that all types of root canal sealer can induce mild to severe inflammatory alternations. However, there is little information on the precise mechanisms about root canal sealers-induced inflammatory reaction. Cyclooxygenase-2 (COX-2) is an inducible enzyme believed to be responsible for prostaglandin synthesis at site of inflammation. The aim of the present study was to investigate the effects of epoxy resin (AH26) and zinc oxide-eugenol based (Endomethansone and N2) root canal sealers on the expression of COX-2 mRNA gene and protein in cultured human osteoblastic cells. Investigations of the time dependence of COX-2 mRNA expression in root canal sealer-treated human osteoblastic cells revealed a rapid accumulation of the transcript, a significant signal first detectable within 2h and diminished to control level after 24h. In addition, all root canal sealers also induced COX-2 protein expression in human osteoblastic cells. Furthermore, to elucidate whether induction of COX-2 is associated with cytotoxicity, NS-398 (a selective COX-2 inhibitor), was added to test its protective effects. NS-398 at non-cytotoxic dose is not able to prevent root canal sealers-induced cytotoxicity. Taken together, the activation of COX-2 expression may be one of the pathogenesis of root canal sealers-induced periapical inflammation. In addition, root canal sealers-induced cytotoxicity is not directly via the induction of COX-2 expression.
authors.affiliation: Department of Prosthodontics, Oral Medicine Center, Chung Shan Medical University Hospital, Taichung, Taiwan.
authors.forename: Fu-Mei
authors.initials: FM
authors.lastname: Huang
authors.forename: Ming-Yung
authors.initials: MY
authors.lastname: Chou
authors.forename: Yu-Chao
authors.initials: YC
authors.lastname: Chang
mesh_terms: D002478:Cells, Cultured; D051546:Cyclooxygenase 2; D004853:Epoxy Resins / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis* / Q000187:drug effects / Q000235:genetics; D008422:Materials Testing / Q000379:methods; D008565:Membrane Proteins; D009578:Nitrobenzenes / Q000494:pharmacology; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism; D012516:Osteosarcoma / Q000235:genetics* / Q000378:metabolism*; D010482:Periapical Abscess / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis*; D012387:Root Canal Filling Materials / Q000494:pharmacology* / Q000633:toxicity; D013449:Sulfonamides / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D015035:Zinc Oxide-Eugenol Cement / Q000494:pharmacology
chemical_list: D004853:Epoxy Resins; D007527:Isoenzymes; D008565:Membrane Proteins; D009578:Nitrobenzenes; D012333:RNA, Messenger; D012387:Root Canal Filling Materials; D013449:Sulfonamides; D015035:Zinc Oxide-Eugenol Cement; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases