Expression and function of enamel-related gene products in calvarial development

J Dent Res. 2013 Jul;92(7):622-8. doi: 10.1177/0022034513487906. Epub 2013 Apr 26.

Abstract

Enamel-related gene products (ERPs) are detected in non-enamel tissues such as bone. We hypothesized that, if functional, ERP expression corresponds with distinct events during osteoblast differentiation and affects bone development and mineralization. In mouse calvariae and MC3T3 cells, expression profiles of enamel-related gene products (ERPs) correlated with key events in post-natal calvarial development and MC3T3 cell mineralization. Developing skulls from both Amel- and Ambn-deficient animals were approximately 15% shorter when compared with those of wild-type controls, and their sutures remained patent for a longer period of time. Analysis of Amel- and Ambn-deficient calvariae and calvarial osteoblast cultures revealed a dramatic reduction in mineralized nodules, a significant reduction in Runx2, Sp7, Ibsp, and Msx2 expression, and a reduction in Alx4 in Amel-deficient calvariae vs. an increase in Alx4 in Ambn-deficient calvariae. Analysis of these data indicates that ERP expression follows defined developmental profiles and affects osteoblast differentiation, mineralization, and calvarial bone development. We propose that, in parallel to their role in the developing enamel matrix, ERPs have retained an evolutionary conserved function related to the biomineralization of bones.

Keywords: ameloblastin; amelogenin; calvaria; evolution; osteoblast; suture.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Amelogenin / analysis
  • Animals
  • Bone Development / genetics
  • Calcification, Physiologic / genetics
  • Cell Culture Techniques
  • Cell Differentiation / physiology
  • Collagen Type I / analysis
  • Collagen Type I, alpha 1 Chain
  • Conserved Sequence / genetics
  • Core Binding Factor Alpha 1 Subunit / analysis
  • Cranial Sutures / growth & development
  • Dental Enamel Proteins / analysis*
  • Dental Enamel Proteins / physiology
  • Homeodomain Proteins / analysis
  • Integrin-Binding Sialoprotein / analysis
  • Intracellular Signaling Peptides and Proteins
  • Kallikreins / analysis
  • Matrix Metalloproteinase 20 / analysis
  • Mice
  • Osteoblasts / physiology
  • Proteins / analysis
  • Skull / growth & development*
  • Sp7 Transcription Factor
  • Transcription Factors / analysis
  • Zinc Fingers / genetics

Substances

  • Alx4 protein, mouse
  • Ambn protein, mouse
  • Amelogenin
  • Amelx protein, mouse
  • Amtn protein, mouse
  • Collagen Type I
  • Collagen Type I, alpha 1 Chain
  • Core Binding Factor Alpha 1 Subunit
  • Dental Enamel Proteins
  • Homeodomain Proteins
  • Ibsp protein, mouse
  • Integrin-Binding Sialoprotein
  • Intracellular Signaling Peptides and Proteins
  • MSX2 protein
  • ODAM protein, mouse
  • Proteins
  • Runx2 protein, mouse
  • Sp7 Transcription Factor
  • Sp7 protein, mouse
  • Transcription Factors
  • Kallikreins
  • kallikrein 4
  • Matrix Metalloproteinase 20
  • Mmp20 protein, mouse