Dioxin alters gene expression in mouse embryonic tooth explants.
Dioxins are ubiquitous environmental poisons that cause disturbances in developing organs, including the teeth. Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) at the cap stage leads to reduced tooth size and deformation of cuspal morphology. Our hypothesis was that TCDD affects the expression of genes specific for tooth development, which leads to these aberrations. Mouse embryonic E14 tooth germs were cultured for 24 hrs with/without 1 microM TCDD. Analysis of total RNA on Affymetrix arrays showed that TCDD altered the expression of 31 known genes by a fold factor of at least 2. Genes implied in tooth development expressed only slight changes. Genes active at the cap stage were selected for quantitative PCR analysis. Of these, the most highly up-regulated were Follistatin and Runx2, while TGFbeta1 and p21 were the most down-regulated genes. Incomplete tooth morphogenesis caused by TCDD may thus result from modified expression of developmentally regulated genes.
Sahlberg
C
C
Department of Pediatric and Preventive Dentistry, Institute of Dentistry, Biomedicum Helsinki, FIN-00014 UNiversity of Helsinki, Helsinki, Finland. carin.sahlberg@helsinki.fi
Peltonen
E
E
Lukinmaa
P-L
PL
Alaluusua
S
S
D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000096:biosynthesis; D050659:Core Binding Factor Alpha 1 Subunit / Q000096:biosynthesis; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000096:biosynthesis; D019363:Cytochrome P-450 CYP1A1 / Q000096:biosynthesis; D065633:Cytochrome P-450 CYP1B1; D004785:Environmental Pollutants / Q000633:toxicity*; D038681:Follistatin / Q000096:biosynthesis; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D051379:Mice; D008815:Mice, Inbred Strains; D009693:Nucleic Acid Hybridization; D009805:Odontogenesis / Q000187:drug effects* / Q000235:genetics; D009924:Organ Culture Techniques; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D016133:Polymerase Chain Reaction / Q000379:methods; D014083:Tooth Germ / Q000187:drug effects*; D053773:Transforming Growth Factor beta1 / Q000096:biosynthesis
D050659:Core Binding Factor Alpha 1 Subunit; D050759:Cyclin-Dependent Kinase Inhibitor p21; D004785:Environmental Pollutants; D038681:Follistatin; D000072317:Polychlorinated Dibenzodioxins; C493716:Runx2 protein, mouse; D053773:Transforming Growth Factor beta1; D001189:Aryl Hydrocarbon Hydroxylases; C585498:Cyp1b1 protein, mouse; D019363:Cytochrome P-450 CYP1A1; D065633:Cytochrome P-450 CYP1B1