2,3,7,8-tetrachlorodibenzo-p-dioxin specifically reduces mRNA for the mineralization-related dentin sialophosphoprotein in cultured mouse embryonic molar teeth.
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.
Kiukkonen
Anu
A
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
Sahlberg
Carin
C
Lukinmaa
Pirjo-Liisa
PL
Alaluusua
Satu
S
Peltonen
Eija
E
Partanen
Anna-Maija
AM
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
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