Accession Number : ADA622387


Title :   The Small Alternatively Spliced Amelogenin LRAP Modulates Early Stage Ameloblast Differentiation


Descriptive Note : Monograph


Corporate Author : NAVAL MEDICAL RESEARCH UNIT (SAN ANTONIO) FORT SAM HOUSTON TX


Personal Author(s) : Stahl, Jonathan


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a622387.pdf


Report Date : 30 Jan 2014


Pagination or Media Count : 169


Abstract : Amelogenesis is a regulated and sequential developmental cascade that results in expression of tissue specific gene products that form the enamel extracellular matrix. There remains considerable lack of knowledge regarding the precise mechanisms that control ameloblast differentiation and enamel matrix biomineralization. Amelogenins are the major protein product of ameloblasts and are comprised of multiple alternatively spliced isoforms that may function as structural molecules to regulate enamel crystal growth in addition to being signaling molecules that regulate cell differentiation. Hypothesis: The small alternatively spliced amelogenin known as leucine rich amelogenin peptide (LRAP) functions to modulate ameloblast differentiation from pre-ameloblasts to terminal differentiation. Methods: Transgenic mouse models that overexpressed LRAP in both a WT (TgLRAP) and an amelogenin null background (TgLRAP/AmelX Null) were examined to determine if this alternatively spliced protein had a direct effect in vivo on ameloblast differentiation by assaying histomorphology, gene expression, and protein expression patterns in comparison to wild-type and amelogenin null mice. Biomineralization was further assessed with microCT and von Kossa staining. In vitro primary ameloblast lineage cells were transfected with LRAP to study early developmental effects. Results: In vivo TgLRAP mice in the WT background showed a significant upregulation of enamel matrix gene products in preameloblasts with earlier and greater amelogenin protein expression in preiv secretory and secretory ameloblasts. Apoptosis was increased in secretory and transitional TgLRAP ameloblasts. Earlier mineral formation was also associated with the increased amelogenin expression. Downregulation of the master gene regulator SATB1 was also detected in pre-secretory and secretory ameloblasts.


Descriptors :   *DENTAL ENAMEL , CELLS(BIOLOGY) , GENE EXPRESSION , PEPTIDES , PROTEINS , THESES


Subject Categories : Biochemistry
      Genetic Engineering and Molecular Biology


Distribution Statement : APPROVED FOR PUBLIC RELEASE