title: 2,3,7,8-tetrachlorodibenzo-p-dioxin specifically reduces mRNA for the mineralization-related dentin sialophosphoprotein in cultured mouse embryonic molar teeth.
abstract: Previous studies show that the most toxic dioxin congener, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), interferes with mineralization of the dental matrices in developing mouse and rat teeth. Culture of mouse embryonic molar teeth with TCDD leads to the failure of enamel to be deposited and dentin to undergo mineralization. Lactationally exposed rats show defectively matured enamel and retardation of dentin mineralization. To see if the impaired mineralization is associated with changes in the expression of dentin sialophosphoprotein (Dspp), Bono1 and/or matrix metalloproteinase-20 (MMP-20), thought to be involved in mineralization of the dental hard tissues, we cultured mouse (NMRI) E18 mandibular molars for 3, 5 or 7 days and exposed them to 1 microM TCDD after 2 days of culture. As detected by in situ hybridization of tissue sections, localization and intensity of Bono1 and MMP-20 expression showed no definite difference between the control and exposed tooth explants, suggesting that TCDD does not affect their expression. On the contrary, TCDD reduced or prevented the expression of Dspp in secretory odontoblasts and decreased it in presecretory ameloblasts. The results suggest that the retardation of dentin mineralization by TCDD in mouse molar teeth involves specific interference with Dspp expression.
authors.affiliation: Department of Pediatric and Preventive Dentistry, Institute of Dentistry, University of Helsinki, and Department of Pathology, Helsinki University Central Hospital, Finland. Anu.Kiukkonen@helsinki.fi
authors.forename: Anu
authors.initials: A
authors.lastname: Kiukkonen
authors.forename: Carin
authors.initials: C
authors.lastname: Sahlberg
authors.forename: Pirjo-Liisa
authors.initials: PL
authors.lastname: Lukinmaa
authors.forename: Satu
authors.initials: S
authors.lastname: Alaluusua
authors.forename: Eija
authors.initials: E
authors.lastname: Peltonen
authors.forename: Anna-Maija
authors.initials: AM
authors.lastname: Partanen
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003804:Dentin / Q000378:metabolism*; D004121:Dimethyl Sulfoxide / Q000633:toxicity; D004785:Environmental Pollutants / Q000633:toxicity*; D016326:Extracellular Matrix Proteins; D017403:In Situ Hybridization; D018969:Insulin-Like Growth Factor Binding Proteins / Q000378:metabolism; D053519:Matrix Metalloproteinase 20 / Q000378:metabolism; D051379:Mice; D008963:Molar / Q000378:metabolism*; D009804:Odontoblasts / Q000187:drug effects / Q000378:metabolism; D009924:Organ Culture Techniques; D010750:Phosphoproteins; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D011498:Protein Precursors / Q000378:metabolism*; D012333:RNA, Messenger / Q000037:antagonists & inhibitors*; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein
chemical_list: D004121:Dimethyl Sulfoxide; D004785:Environmental Pollutants; D016326:Extracellular Matrix Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D053519:Matrix Metalloproteinase 20; D010750:Phosphoproteins; D000072317:Polychlorinated Dibenzodioxins; D011498:Protein Precursors; D012333:RNA, Messenger; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein; C495062:Kazald1 protein, mouse