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Updated: Jun 2, 2026

Micro-dissection of Enamel Organ from Mandibular Incisor of Rats Exposed to Environmental Toxicants
Published on: March 29, 2018
Dental enamel structure is altered by expression of dominant negative RhoA in ameloblasts
Yong Li1, Megan K Pugach, Melissa A Kuehl
1Department of Anatomy and Cell Biology, University of Pennsylvania School of Dental Medicine, Philadelphia, Pa., USA.
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.
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