Cyclooxygenase 2 plays a role in Emdogain-induced proliferation.
OBJECTIVE
Enamel matrix proteins are involved in the development and regeneration of root cementum and in its attachment to dentin; however, the mechanisms through which this occurs have yet to be elucidated. The present study was therefore carried out to evaluate the mitogenic and proliferative responses of human periodontal fibroblast (HPLF) cells to Emdogain (EMD), and the potential role of cyclooxygenase 2 (COX-2) in this process.


METHODS
We investigated the effects of EMD on 5-bromo-2'-deoxyuridine (BrdU) incorporation, colchicine freezing of mitosis, XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction and Trypan Blue dye exclusion, with or without celecoxibe, a selective cyclooxygenase-2 (COX-2) inhibitor; we also evaluated the expression of COX-2 mRNA and COX-2 protein in response to EMD.


RESULTS
EMD significantly enhanced mitosis in, and proliferation of, human periodontal ligament fibroblasts in a dose-dependent manner; however, there was a small increase of DNA synthesis only in response to a high dose of EMD (200 μg/mL). EMD (100 and 200 μg/mL) elicited an increase in COX-2 expression (p ≤ 0.05). Celecoxibe (20 μm) diminished the EMD-induced mitosis and proliferation of HPLF cells (p ≤ 0.05).


CONCLUSIONS
Celecoxibe hampered EMD-induced mitosis and proliferation, which, in association with EMD-increased COX-2 expression, indicates that COX-2 may be involved in the proliferative response of HPLF cells to EMD.
Khedmat
S
S
Department of Endodontics and Dental Research Center, Faculty of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
Seyedabadi
M
M
Ghahremani
M H
MH
Ostad
S N
SN
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000068579:Celecoxib; D002448:Cell Adhesion / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004396:Coloring Agents / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D003746:Dental Enamel Proteins / Q000494:pharmacology*; D005347:Fibroblasts / Q000201:enzymology; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D008938:Mitosis / Q000187:drug effects*; D010513:Periodontal Ligament / Q000166:cytology / Q000201:enzymology*; D011720:Pyrazoles / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology; D013778:Tetrazolium Salts / Q000378:metabolism; D014343:Trypan Blue / Q000378:metabolism; D055815:Young Adult
D004396:Coloring Agents; D052246:Cyclooxygenase 2 Inhibitors; D003746:Dental Enamel Proteins; D011720:Pyrazoles; D013449:Sulfonamides; D013778:Tetrazolium Salts; C109069:enamel matrix proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D014343:Trypan Blue; D000068579:Celecoxib