The specific role of FAM20C in amelogenesis

J Dent Res. 2013 Nov;92(11):995-9. doi: 10.1177/0022034513504588. Epub 2013 Sep 11.

Abstract

Previously, we showed that Sox2-Cre;Fam20C(fl/fl) mice in which Fam20C was ubiquitously inactivated had severe defects in dentin, enamel, and bone, along with hypophosphatemia. It remains to be determined if the enamel defects in the mice with universal inactivation of Family with sequence similarity 20-C (FAM20C) were associated with the dentin defects and whether hypophosphatemia in the knockout mice contributed to the enamel defects. In this study, we crossed Fam20C(fl/fl) mice with keratin 14-Cre (K14-Cre) transgenic mice to specifically inactivate Fam20C in the epithelial cells, including the dental epithelial cells that are responsible for forming tooth enamel. X-ray, backscattered scanning electron microscopic, and histological analyses showed that the K14-Cre;Fam20C(fl/fl) mice had severe enamel and ameloblast defects, while their dentin and alveolar bone were not significantly affected. Accordingly, serum biochemistry of the K14-Cre;Fam20C(fl/fl) mice showed normal phosphate and FGF23 levels in the circulation. Analysis of these data indicates that, while FAM20C is a molecule essential to amelogenesis, its inactivation in the dental epithelium does not significantly affect dentinogenesis. Hypophosphatemia makes no significant contribution to the enamel defects in the mice with the ubiquitous deletion of Fam20C.

Keywords: FAM20C; FGF23; amelogenesis; biomineralization; hypophosphatemia; kinase.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Alveolar Process / diagnostic imaging
  • Alveolar Process / pathology
  • Ameloblasts / pathology
  • Amelogenesis / genetics
  • Amelogenesis / physiology*
  • Animals
  • Calcium / blood
  • Calcium-Binding Proteins / genetics
  • Calcium-Binding Proteins / physiology*
  • Dental Enamel / abnormalities
  • Dental Enamel / pathology
  • Dental Enamel Hypoplasia / genetics
  • Dental Enamel Hypoplasia / pathology
  • Dentin / diagnostic imaging
  • Dentin / pathology
  • Dentinogenesis / genetics
  • Dentinogenesis / physiology
  • Epithelial Cells / pathology
  • Extracellular Matrix Proteins / genetics
  • Extracellular Matrix Proteins / physiology*
  • Fibroblast Growth Factor-23
  • Fibroblast Growth Factors / blood
  • Heterozygote
  • Hypophosphatemia / blood
  • Hypophosphatemia / physiopathology
  • In Situ Hybridization
  • Keratin-14 / genetics
  • Mandible / diagnostic imaging
  • Mandible / pathology
  • Mice
  • Mice, Knockout
  • Mice, Transgenic
  • Microscopy, Electron, Scanning
  • Odontoblasts / pathology
  • Phosphates / blood
  • Radiography
  • Real-Time Polymerase Chain Reaction
  • SOXB1 Transcription Factors / genetics
  • Transgenes / genetics

Substances

  • Calcium-Binding Proteins
  • Extracellular Matrix Proteins
  • FAM20C protein, mouse
  • Fgf23 protein, mouse
  • Keratin-14
  • Krt14 protein, mouse
  • Phosphates
  • SOXB1 Transcription Factors
  • Sox2 protein, mouse
  • Fibroblast Growth Factors
  • Fibroblast Growth Factor-23
  • Calcium