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Updated: Jun 23, 2026

Development of Amelogenin-chitosan Hydrogel for In Vitro Enamel Regrowth with a Dense Interface
Published on: July 10, 2014
Synergistic roles of amelogenin and ameloblastin
J Hatakeyama1, S Fukumoto, T Nakamura
1Functional Genomics Section, Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA.
Abstract:
Amelogenin and ameloblastin, the major enamel matrix proteins, are important for enamel mineralization. To identify their synergistic roles in enamel development, we generated Amel X(-/-)/Ambn(-/-) mice. These mice showed additional enamel defects in comparison with Amel X(-/-) or Ambn(-/-) mice. In 7-day-old Amel X(-/-)/Ambn(-/-) mice, not only was the ameloblast layer irregular and detached from the enamel surface, as in Ambn(-/-), but also, the enamel width was significantly reduced in the double-null mice as compared with Amel X(-/-) or Ambn(-/-) mice. Proteomic analysis of the double-null teeth revealed increased levels of RhoGDI (Arhgdia), a Rho-family-specific guanine nucleotide dissociation inhibitor, which is involved in important cellular processes, such as cell attachment. Both Amel X(-/-)/Ambn(-/-) mice and Ambn(-/-) mice displayed positive staining with RhoGDI antibody in the irregularly shaped ameloblasts detached from the matrix. Ameloblastin-regulated expression of RhoGDI suggests that Rho-mediated signaling pathway might play a role in enamel formation.
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