PGE2 activates cementoclastogenesis by cementoblasts via EP4.
Destruction of cementum and alveolar bone is the main causative event for the exfoliation of teeth as a consequence of periodontitis. Prostaglandin E(2) (PGE(2)) and PGE receptor subtypes (EPs) play an important role in modulating osteoblast-mediated osteoclastogenesis; however, no information is available on the role of PGE(2) and EPs in regulating cementoblast-mediated cementoclastogenesis. We hypothesized that the PGE(2)-EPs pathway also regulates cementoblasts' ability to activate cementoclasts. For these studies, OCCM-30 cells (a mouse cementoblast cell line) were exposed to PGE(2) and specific EP agonists. PGE(2) (100 ng/mL) and EP4 agonist (1 microM) up-regulated RANKL and IL-6 mRNA levels, while they down-regulated OPG mRNA expression. The EP4 antagonist (1 microM) eliminated these effects of PGE(2). PGE(2) treatment of co-cultures of OCCM-30 cells with bone marrow cells induced TRAP-positive cells via the EP4 pathway. These findings suggest that PGE(2) promotes cementoblast-mediated cementoclastogenesis by regulating the expression of RANKL and OPG via the EP4 pathway.
Oka
H
H
Department of Oral and Maxillofacial Pathobiology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan.
Miyauchi
M
M
Sakamoto
K
K
Moriwaki
S
S
Niida
S
S
Noguchi
K
K
Somerman
M J
MJ
Takata
T
T
D000818:Animals; D001854:Bone Marrow Cells; D002461:Cell Line, Transformed; D018920:Coculture Techniques; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D003739:Dental Cementum / Q000378:metabolism* / Q000503:physiopathology; D015232:Dinoprostone / Q000502:physiology*; D015850:Interleukin-6 / Q000096:biosynthesis; D051379:Mice; D010010:Osteoclasts / Q000502:physiology*; D053244:Osteoprotegerin / Q000096:biosynthesis; D053245:RANK Ligand / Q000096:biosynthesis; D018078:Receptors, Prostaglandin E / Q000378:metabolism*; D058309:Receptors, Prostaglandin E, EP4 Subtype; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction
D015850:Interleukin-6; D053244:Osteoprotegerin; C545651:Ptger4 protein, mouse; D053245:RANK Ligand; D018078:Receptors, Prostaglandin E; D058309:Receptors, Prostaglandin E, EP4 Subtype; D017868:Cyclic AMP-Dependent Protein Kinases; D015232:Dinoprostone