The role of Dentin Sialophosphoprotein (DSPP) in craniofacial development

  • Author / Creator
    Dos Santos Figueredo Junior, Carlos Alberto
  • Mineralized tissues of the body are composed of organic and inorganic matter. The organic matter forms the framework necessary for the inorganic matter to mineralize. Dentin sialophosphoprotein (DSPP) is known to be extremely important in the formation of dentin. In DSPP absence, a severely hypomineralized dentin is formed, in two conditions known as dentinogenesis imperfecta (DGI) and dentin dysplasia (DD). DSPP has recently been found in several non-dental tissues, including the mandibular condylar cartilage (MCC) and craniofacial skeleton. However, there is limited literature on the role of DSPP in these tissues.
    To explore the role of DSPP in the craniofacial complex, two mice strains, DSPP knockout (DSPP-/-) and wild type (C57BL/6J), were compared at 1, 3, and 6 months of age. Long bones, skulls, and hemi-mandibles were used for investigation. Morphological analysis was composed of radiographic images, micro-computed tomography reconstructions, and dual-energy x-rays analyses. Histological analysis was composed of hematoxylin and eosin staining and immunohistochemistry. Cell culture was also conducted to investigate the potential effects of DSPP absence in osteoblasts from the calvaria.
    Results from this investigation showed mineralization defects in the structures of alveolar bones, skulls, and MCC, with the most significant impact at 1 month of age. In addition, hematoxylin and eosin staining showed what differences in tissue histology were potentially related to large scale anatomical changes.
    This study concluded that DSPP is an essential protein for the normal mineralization of craniofacial tissues. Furthermore, it was shown that DSPP absence caused defects in the mineralization of skulls, MCC, and alveolar bones at the early stages of development.

  • Subjects / Keywords
  • Graduation date
    Fall 2021
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.