Analysis of gene polymorphisms of Amel, Ambn, Enam, Tuft, Amtn, Mmp20, Klk4, Fam83h, Fam20a, Wdr72, Cftr, Serpinh1, Serpinf1 and Col1a1 genes in mice with different genetic susceptibilities of dental fluorosis

Abstract

The mechanisms by which excessive intake of fluoride (F) during amelogenesis can lead to fluorosis are not precisely known yet. It has been demonstrated that certain strains of mice are more susceptible than others to dental fluorosis, which make these strains the ideal model to study the molecular phenomena involved in this defect of development. It is known that fluorosis is characterized by retention of proteins in the maturation stage of enamel and that the secretion of these proteins is not altered by F, which changes only the degradation in the maturation stage. Furthermore, it is known that several genes expressed in amelogenesis control these phenomena. However, the role of polymorphisms of genes encoding structural proteins and proteases resident in enamel fluorosis is still unknown. Thus, this study aims to evaluate the association between polymorphisms in Amel, Ambn, Enam, Tuft, Amtn, Mmp20, Klk4, Fam83h, Fam20a, Wdr72, Cftr, Serpinh1, Serpinf1 and Col1a1 genes, with susceptibility to dental fluorosis, using mice susceptible or resistant to this disease. Thus, we will analyze the association between polymorphic variations in Amel, Ambn, Enam, Tuft, Amtn, Mmp20, Klk4, Fam83h, Fam20a, Wdr72, Cftr, Serpinh1, Serpinf1 and Col1a1 genes and fluorosis phenotype in mice with different susceptibilities to dental fluorosis. Mice of both genders, representing strains 129P3/J (n=40; resistant to dental fluorosis) and A/J (n=40; susceptible to dental fluorosis) will be divided into two groups for each strain that will receive diet with low concentration of F and drinking water containing 0 or 50 mg/L F for 6 weeks. At the end of the experimental period, the animals will be anesthetized and blood will be collected for genomic DNA extraction. For polymorphisms analyses allelic discrimination will be employed, using real-time PCR. As future perspective, the identification of genetic polymorphisms associated with dental fluorosis in this experimental model might support the selection of candidate genes for this disease in human populations living in endemic areas of fluorosis