title: [Expression and significance of stromal cell-derived factor-1alpha and its receptor CXCR4 in human dental pulp cells].
abstract: OBJECTIVE
  To investigate the expression of CXCR4 in cultured human dental pulp cells (HDPC) in vitro and the corresponding ligand SDF-1alpha level of HDPC supernatants stimulated by lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF-alpha), and to explore the role of SDF-1alpha on the proliferation and the migration of HDPC.
  
  
  METHODS
  The expression of CXCR4 in HDPC was detected by immunocytochemistry technique and indirect immunofluorescence technique. The culture supernatants of HDPC were collected after HDPC had been simulated by LPS and TNF-alpha of different concentrations for 48h and then the SDF-1alpha level was assayed by quantitative sandwich ELISA. Meanwhile, the effects of recombinant human SDF-1alpha (rhSDF-1alpha) on the proliferation and the migration of HDPC at different concentrations were observed by MTT and Boyden Chamber Assay.
  
  
  RESULTS
  CXCR4 was expressed in cytomembrane of HDPC and SDF-1alpha was secreted into their normal cell supernatants with a concentration of (4513.55 +/- 962.92) ng/L. The secretion of SDF-1alpha was both significantly decreased by stimulation with LPS and TNF-alpha (P < 0.05). In addition, rhSDF-1alpha stimulated the HDPC proliferation at the concentrations of 50, 100, 200 microg/L (P < 0.01) and increased the chemotactic migration of HDPC significantly after 9h's incubation with the concentrations of 50, 100 microg/L (P < 0.05).
  
  
  CONCLUSIONS
  SDF-1alpha accelerated the proliferation and the migration of HDPC which expressed CXCR4. SDF-1-CXCR4 axis may play a role in repair of pulp injury.
authors.affiliation: Department of Cariology and Endodontology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.
authors.forename: Qi-mei
authors.initials: QM
authors.lastname: Gong
authors.forename: Jun-qi
authors.initials: JQ
authors.lastname: Ling
authors.forename: Hong-wei
authors.initials: HW
authors.lastname: Jiang
authors.forename: Yu
authors.initials: Y
authors.lastname: Du
authors.forename: Fang
authors.initials: F
authors.lastname: Yang
mesh_terms: D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D054377:Chemokine CXCL12 / Q000378:metabolism*; D003782:Dental Pulp / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D019718:Receptors, CXCR4 / Q000378:metabolism*
chemical_list: C527276:CXCR4 protein, human; D054377:Chemokine CXCL12; D019718:Receptors, CXCR4