title: The role of SDF-1 and CXCR4 on odontoblastic differentiation in human dental pulp cells.
abstract: OBJECTIVE
  To examine the role of stromal cell-derived factor 1 (SDF-1) signalling during odontogenic differentiation in human dental pulp cells (HDPCs).
  
  
  METHODS
  Human dental pulp cells were treated with differentiation medium, recombinant human SDF-1, neutralizing antibody for SDF-1 or CXCR4, pertussis toxin (PTX) and AMD3100. The expression of SDF-1 and its receptor chemokine receptor type 4 (CXCR4) was measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. Odontoblastic differentiation was determined using alkaline phosphatase (ALP) activity assay, mineralized nodule formation and marker mRNAs by RT-PCR.
  
  
  RESULTS
  Marked upregulation of SDF-1 and CXCR4 mRNA and protein was observed in cells grown 7 days in osteogenic induction medium. The addition of recombinant human SDF-1 to HDPCs significantly (P < 0.05) increased ALP activity, mineralized nodule formation and odontoblast marker mRNAs in a dose-dependent manner. Blocking SDF-1 signalling using antibodies against SDF-1 or CXCR4, or the G-protein-coupled receptor inhibitor PTX, and CXCR4 inhibitor AMD3100, strongly suppressed induction of odontogenic differentiation in HDPCs.
  
  
  CONCLUSIONS
  Odontoblastic differentiation was stimulated by SDF-1 activation and repressed by SDF-1/CXCR4 inhibition. Thus, SDF-1/CXCR4 signalling may be a new therapeutic target and strategy to promote repair and regeneration in endodontics.
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Kyung Hee University, Seoul, Korea.
authors.forename: D S
authors.initials: DS
authors.lastname: Kim
authors.forename: Y S
authors.initials: YS
authors.lastname: Kim
authors.forename: W J
authors.initials: WJ
authors.lastname: Bae
authors.forename: H J
authors.initials: HJ
authors.lastname: Lee
authors.forename: S W
authors.initials: SW
authors.lastname: Chang
authors.forename: W S
authors.initials: WS
authors.lastname: Kim
authors.forename: E C
authors.initials: EC
authors.lastname: Kim
mesh_terms: D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D054377:Chemokine CXCL12 / Q000502:physiology*; D003470:Culture Media; D003782:Dental Pulp / Q000166:cytology*; D006801:Humans; D019718:Receptors, CXCR4 / Q000502:physiology*
chemical_list: C515255:CXCL12 protein, human; C527276:CXCR4 protein, human; D054377:Chemokine CXCL12; D003470:Culture Media; D019718:Receptors, CXCR4
keywords: CXCR4; SDF-1; human dental pulp cells; odontoblastic differentiation