Regulation of calbindin-D(28k) expression by Msx2 in the dental epithelium

J Histochem Cytochem. 2012 Aug;60(8):603-10. doi: 10.1369/0022155412450641. Epub 2012 May 21.

Abstract

Amelogenesis involves the coordinated expression of a set of molecules that includes enamel matrix proteins and calcium-binding proteins. Msx2 is a member of the divergent homeobox gene family and is instrumental in dental morphogenesis and biomineralization. This study focused on an EF-hand calcium-binding protein, calbindin-D(28k), which is highly expressed in dental epithelium. In vivo data showed that calbindin-D(28k) levels were higher in ameloblasts from Msx2(+/-) mice than Msx2(+/+) mice. Consistent with this finding, calbindin-D(28k) distribution was affected in transgenic mice with ectopic expression in root epithelium in rests of Malassez in Msx2(+/-) and more clearly in Msx2(-/-) mice. In accordance with these in vivo data, calbindin-D(28k) protein and mRNA levels were decreased in LS8 ameloblast-like cells by exogenous Msx2 overexpression. Furthermore, calbindin-D(28k) promoter activity (nt-1075/+34) was specifically diminished in the presence of Msx2 overexpression, showing that Msx2 behave as a transcriptional repressor for calbindin-D(28k) gene expression. In conclusion, Msx2 may control the spatiotemporally restricted frame of calbindin-D(28k) production in the dental epithelium in relation to enamel mineralization, as previously shown for amelogenin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ameloblasts / cytology
  • Ameloblasts / metabolism
  • Animals
  • Calbindins
  • Cell Line
  • Epithelial Cells / metabolism*
  • Gene Knock-In Techniques
  • Homeodomain Proteins / genetics
  • Immunohistochemistry
  • Incisor / metabolism
  • Mice
  • Mice, Transgenic
  • Organ Specificity
  • Promoter Regions, Genetic
  • RNA, Messenger / metabolism
  • S100 Calcium Binding Protein G / genetics
  • S100 Calcium Binding Protein G / metabolism*
  • Tooth Root / metabolism

Substances

  • Calbindins
  • Homeodomain Proteins
  • MSX2 protein
  • RNA, Messenger
  • S100 Calcium Binding Protein G