Oral Biosci Med 2 (2005), No. 4 27. Jan. 2006
Oral Biosci Med 2 (2005), No. 4 (27.01.2006)
Dentin and Enamel Phenotype in Fabry Mice
Goldberg, M./Septier, D./Limaye, A./Sreenath, T./Kulkarni, A. B.
Our aim was to investigate the dental phenotype of α-galactosidase A deficient (AGA-/-) mice - the mutant mice that mimic human Fabry disease. Fabry mice were generated by the gene targeting technique. Segments of mandibles of 21- day-old mice were processed after demineralization for transmission electron microscopy. Comparison was carried out with teeth of mice heterozygous for α-galactosidase A deletion, AGA ±, (HT). In addition, undemineralized sections of mandibles from one-, six- and 18-month-old mice were observed with a scanning electron microscope. Electron-dense lysosomes containing myelin-like structures loaded the odontoblasts, whereas lipid-like structures were mostly present in intercellular spaces in the enamel organ. The diameter of collagen fibrils in the proximal and distal predentin was identical in the two groups. Metadentin was porous but not enlarged in the Fabry mice. Pericellular collagen fibrils filled the lumen of dentin tubules. Bubble-like structures were seen in the lingual part of mandibular incisors of six-month-old mice, with an increase in number and size at 18 months, suggesting that asymmetric differences exist in the Fabry mice in response to mechanical loading. Although the forming enamel of the Fabry mice displayed porosities containing cell membrane remnants, no defect was detectable in mature enamel. The phenotype differences detected between Fabry and HT mice were discrete and mostly related to odontoblast and dentin. Although the Fabry mice display a lysosomal storage disease, disorders of glycosphingolipid degradation seems to play only a minor role in odontogenesis.
Keywords: A-deficient mouse, α-galactosidase, dental abnormalities, Fabry disease, odontogenesis