title: Inorganic phosphate stimulates apoptosis in murine MO6-G3 odontoblast-like cells.
abstract: OBJECTIVE
  Dental pathologies such as caries are the most prevalent disease worldwide with infectious and social complications. During the process of caries formation, the tooth is degraded and demineralization of enamel and dentine leads to the release of large amounts of inorganic phosphate (Pi) within dental tubuli. As Pi has been shown to induce apoptosis in skeletal cells, including osteoblasts and chondrocytes, we questioned whether high concentrations of Pi could affect odontoblast viability, proliferation and apoptosis.
  
  
  METHODS
  Using the odontoblast-like MO6-G3 cell line as a model, we used cell counting and MTS-based colorimetric assays to measure cell viability and proliferation. Apoptosis was assessed using Hoechst nuclei staining and detection of the early apoptotic markers annexin V and Apo2.7.
  
  
  RESULTS
  We show for the first time that a high Pi concentration (7 mM) induced a decrease in odontoblast viability and proliferation together with a large increase in apoptosis. These effects were blunted in calcium-free medium, possibly due to the formation of calcium-phosphate crystals in the presence of high Pi concentrations.
  
  
  CONCLUSIONS
  This study contributes to clarifying the effect of Pi on odontoblast viability and apoptosis, which may improve our understanding of the role of Pi during caries formation.
authors: INSERM, U791, Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), Group STEP Skeletal Tissue Engineering and Physiopathology, Nantes F-44042, France.
authors: A
authors: A
authors: Bourgine
authors: L
authors: L
authors: Beck
authors: S
authors: S
authors: Khoshniat
authors: F
authors: F
authors: Wauquier
authors: L
authors: L
authors: Oliver
authors: E
authors: E
authors: Hue
authors: B
authors: B
authors: Alliot-Licht
authors: P
authors: P
authors: Weiss
authors: J
authors: J
authors: Guicheux
authors: Y
authors: Y
authors: Wittrant
mesh_terms: D000818:Animals; D017304:Annexin A5 / Q000032:analysis; D000911:Antibodies, Monoclonal; D017209:Apoptosis / Q000187:drug effects*; D001562:Benzimidazoles; D015415:Biomarkers / Q000032:analysis; D002118:Calcium / Q000494:pharmacology; D002452:Cell Count; D002460:Cell Line; D002467:Cell Nucleus / Q000648:ultrastructure; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003124:Colorimetry; D004396:Coloring Agents; D003470:Culture Media; D004791:Enzyme Inhibitors / Q000032:analysis; D005434:Flow Cytometry; D005562:Formazans; D007202:Indicators and Reagents; D051379:Mice; D009804:Odontoblasts / Q000187:drug effects*; D010710:Phosphates / Q000494:pharmacology*; D014343:Trypan Blue
chemical_list: D017304:Annexin A5; D000911:Antibodies, Monoclonal; D001562:Benzimidazoles; D015415:Biomarkers; D004396:Coloring Agents; D003470:Culture Media; D004791:Enzyme Inhibitors; D005562:Formazans; D007202:Indicators and Reagents; D010710:Phosphates; C447680:hoechst 32258; D014343:Trypan Blue; D002118:Calcium