title: Loss of dentin sialophosphoprotein leads to periodontal diseases in mice.
abstract: OBJECTIVE
  Dentin sialophosphoprotein (DSPP) and its cleaved products, dentin phosphoprotein (DPP) and dentin sialoprotein (DSP), play important roles in biomineralization. Recently, we observed that DSPP is highly expressed in the alveolar bone and cementum, indicating that this molecule may play an important role in the formation and maintenance of a healthy periodontium, and its deletion may cause increased susceptibility to periodontal diseases. The objective of this investigation was to study the effects of Dspp ablation on periodontal tissues by analyzing Dspp null mice.
  
  
  METHODS
  Newborn to 6-mo-old Dspp null mice were examined, and the 3- and 6-mo-old Dspp null mice were characterized in detail using X-ray radiography, histology and scanning electron microscopy (backscattered as well as resin-infiltrating). Wild-type mice of the same age groups served as the normal controls.
  
  
  RESULTS
  The Dspp null mice showed significant loss of alveolar bone and cementum, particularly in the furcation and interproximal regions of the molars. The alveolar bone appeared porous while the quantity of cementum was reduced in the apical region. The canalicular systems and osteocytes in the alveolar bone were abnormal, with reduced numbers of canaliculi and altered osteocyte morphology. The loss of alveolar bone and cementum along with the detachment of the periodontal ligaments (PDL) led to the apical migration of the epithelial attachment and formation of periodontal pockets.
  
  
  CONCLUSIONS
  Inactivation of DSPP leads to the loss of alveolar bone and cementum and increased susceptibility to bacterial infections in PDL of Dspp null mice. The fact that the loss of DSPP results in periodontal diseases indicates that this molecule plays a vital role in maintaining the health of the periodontium.
authors.affiliation: Department of Biomedical Sciences, Baylor College of Dentistry, Texas A&M Health Science Center, Dallas, TX, USA.
authors.forename: M P
authors.initials: MP
authors.lastname: Gibson
authors.forename: Q
authors.initials: Q
authors.lastname: Zhu
authors.forename: Q
authors.initials: Q
authors.lastname: Liu
authors.forename: R N
authors.initials: RN
authors.lastname: D'Souza
authors.forename: J Q
authors.initials: JQ
authors.lastname: Feng
authors.forename: C
authors.initials: C
authors.lastname: Qin
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D000539:Alveolar Process / Q000000981:diagnostic imaging / Q000473:pathology; D000818:Animals; D048430:Cell Shape; D003739:Dental Cementum / Q000473:pathology; D004846:Epithelial Attachment / Q000473:pathology; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000502:physiology*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000473:pathology; D008768:Methylmethacrylates / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008963:Molar / Q000000981:diagnostic imaging / Q000473:pathology; D010011:Osteocytes / Q000473:pathology; D017622:Periodontal Attachment Loss / Q000209:etiology / Q000473:pathology; D010510:Periodontal Diseases / Q000209:etiology* / Q000473:pathology; D010514:Periodontal Pocket / Q000209:etiology / Q000473:pathology; D010519:Periodontium / Q000502:physiology*; D010750:Phosphoproteins / Q000235:genetics / Q000502:physiology*; D016613:Plastic Embedding / Q000379:methods; D012542:Scattering, Radiation; D012795:Sialoglycoproteins / Q000235:genetics / Q000502:physiology*; D019227:Tooth Apex / Q000473:pathology; D019237:Tooth Cervix / Q000473:pathology; D014092:Tooth Root / Q000000981:diagnostic imaging / Q000473:pathology; D055114:X-Ray Microtomography / Q000379:methods; D000099311:Dentin Sialophosphoprotein
chemical_list: D016326:Extracellular Matrix Proteins; D008768:Methylmethacrylates; D010750:Phosphoproteins; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein