Dental enamel structure is altered by expression of dominant negative RhoA in ameloblasts

Cells Tissues Organs. 2011;194(2-4):227-31. doi: 10.1159/000324559. Epub 2011 May 13.

Abstract

Using in vitrotooth germ cultures and analysis by confocal microscopy, ameloblasts treated with sodium fluoride were found to have elevated amounts of filamentous actin. Because this response is reduced by inhibitors of the Rho/ROCK signaling pathway, we generated mice that express dominant negative RhoA (RhoA(DN)) in ameloblasts for in vivo analysis. Expression of the EGFP-RhoA(DN) fusion protein was evaluated by RT-PCR and immunohistochemistry, and teeth were analyzed by scanning electron microscopy. The 3 strains expressed at either low (TgEGFP-RhoA(DN)-8), intermediate (TgEGFP-RhoA(DN)-2), or high (TgEGFP-RhoA(DN)-13) levels, and the molar teeth from the 3 strains had enamel hypoplasia and surface defects. We conclude that RhoA(DN) expressed in ameloblasts interferes with normal enamel development through the pathway that is induced by sodium fluoride.

Publication types

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

MeSH terms

  • Ameloblasts / drug effects
  • Ameloblasts / metabolism*
  • Ameloblasts / pathology
  • Animals
  • Dental Enamel / drug effects
  • Dental Enamel / metabolism*
  • Dental Enamel / pathology*
  • Dental Enamel / ultrastructure
  • Genes, Dominant / genetics*
  • Mice
  • Mice, Transgenic
  • Molar / drug effects
  • Molar / metabolism
  • Molar / pathology
  • Molar / ultrastructure
  • Protein Kinase Inhibitors / pharmacology
  • Tooth Germ / drug effects
  • Tooth Germ / pathology
  • Transgenes / genetics
  • rhoA GTP-Binding Protein / metabolism*

Substances

  • Protein Kinase Inhibitors
  • rhoA GTP-Binding Protein