title: Effect of prostaglandin E2 on mineralization of bone nodules formed by fetal rat calvarial cells.
abstract: The effects of PGE2 on mineralized bone nodule formation were studied in fetal rat calvarial (RC) cells in vitro. Continuous exposure of RC cells to 3 x 10(-8) M PGE2 induced a twofold increase in mineralized bone nodule formation and a 1.5-fold increase in alkaline phosphatase (ALPase) activity without affecting RC cell growth. These stimulatory effects were evoked by concentrations of 3 x 10(-9)-3 x 10(-6) M PGE2 and the maximal effect was observed with 3 x 10(-8) M PGE2. The in vitro effects of PGE2 were evident when RC cells were exposed to it on days 8-14 and 8-21, which correspond to the post-confluent culture stage, but no effects were observed when the cells were exposed on days 1-7, the growth stage. The ALPase activity was also higher (1.2-1.4-fold) when 3 x 10(-8) M PGE2 was added during the post-confluent stage. In order to determine the effect of PGE2 during the mineralization phase of bone nodules in the presence of a large population of osteoprogenitor cells, RC cells were exposed to dexamethasone for 7 days before PGE2 was added during the post-confluent stage. A significantly higher percentage of nodules mineralized were observed with 3 x 10(-8)-3 x 10(-9) M PGE2 (1.6- and 1.4-fold, respectively), than in control cultures. Analysis of the mineral-related proteins by EDTA extraction of bone nodules followed by electrophoresis and Stains-All staining revealed an increased total amount of osteopontin extracted from the mineralized matrix after PGE2 treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Periodontology and Endodontology, Tokushima University School of Dentistry, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nagata
authors.forename: K
authors.initials: K
authors.lastname: Kaho
authors.forename: S
authors.initials: S
authors.lastname: Nishikawa
authors.forename: H
authors.initials: H
authors.lastname: Shinohara
authors.forename: Y
authors.initials: Y
authors.lastname: Wakano
authors.forename: H
authors.initials: H
authors.lastname: Ishida
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001846:Bone Development / Q000187:drug effects*; D001842:Bone and Bones / Q000166:cytology / Q000187:drug effects* / Q000196:embryology; D002113:Calcification, Physiologic / Q000187:drug effects*; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology; D015232:Dinoprostone / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D010006:Osteoblasts / Q000187:drug effects*; D053495:Osteopontin; D010750:Phosphoproteins / Q000378:metabolism; D051381:Rats; D012795:Sialoglycoproteins / Q000378:metabolism; D013234:Stem Cells / Q000187:drug effects
chemical_list: D010750:Phosphoproteins; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; D053495:Osteopontin; D003907:Dexamethasone; D000469:Alkaline Phosphatase; D015232:Dinoprostone