title: Phosphatidylinositol 3-Kinase and Protein Kinase C Signaling Pathways Are Involved in Stromal Cell-derived Factor-1α-mediated Transmigration of Stem Cells from Apical Papilla.
abstract: BACKGROUND
  Previously, we have shown that stem cells from apical papilla (SCAPs) can be chemoattracted by stromal cell-derived factor-1α (SDF-1α). The purpose of this study was to investigate the intracellular signaling pathways involved in SDF-1α-mediated migration of SCAPs.
  
  
  METHODS
  Chemotaxis assays were performed to assess the effect of phosphatidylinositol 3-kinase (PI3K) and protein kinase C (PKC) signaling pathways in the SDF-1α-mediated migration of SCAPs using inhibitors of PI3K (LY294002) or PKC (GF109203X). The Cell Counting Kit-8 assay (Dojindo Laboratories, Kumamoto, Japan) was used to evaluate the effect of the inhibitors on the proliferation of SCAPs. The expression of focal adhesion-related proteins was examined by immunofluorescence staining and Western blot analysis. Phosphorylation of PI3K subunit p85 and PKC after SDF-1α induction was evaluated by Western blot.
  
  
  RESULTS
  The inhibition of PI3K or PKC signaling pathways significantly reduced SDF-1α-mediated migration of SCAPs. The inhibitors had no effect on the proliferation of SCAPs. Immunofluorescence analysis revealed that SDF-1α stimulated focal adhesion formation and stress fiber assembly in SCAPs, in addition to up-regulation of the expression of focal adhesion molecules, including p-focal adhesion kinase, p-paxillin, and vinculin. Pretreatment with PI3K or PKC inhibitors before SDF-1α induction significantly inhibited focal adhesion molecule expression. Moreover, increased phosphorylation of p85 and PKC were observed after SDF-1α stimulation, whereas these phosphorylations were down-regulated by the inhibition of PI3K or PKC signaling pathways.
  
  
  CONCLUSIONS
  PI3K and PKC signaling pathways appear to be required for SDF-1α-mediated transmigration of SCAPs. These findings provide insights into the signaling mechanisms that underlie SDF-1α-mediated migration of SCAPs.
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing, PR China.
authors.forename: Xue
authors.initials: X
authors.lastname: Chen
authors.affiliation: Center of Dental Medicine, China-Japan Friendship Hospital, Beijing, PR China.
authors.forename: Jing-Yi
authors.initials: JY
authors.lastname: Liu
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Yue
authors.affiliation: Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, Memphis, Tennessee.
authors.forename: George T-J
authors.initials: GT
authors.lastname: Huang
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing, PR China. Electronic address: zouxiaoying1125@163.com.
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Zou
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000032:analysis; D015153:Blotting, Western; D002448:Cell Adhesion / Q000187:drug effects*; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D054377:Chemokine CXCL12 / Q000502:physiology*; D002633:Chemotaxis; D003771:Dental Papilla / Q000166:cytology*; D005434:Flow Cytometry; D006801:Humans; D058539:Phosphatidylinositol 3-Kinase / Q000502:physiology*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000502:physiology*; D015398:Signal Transduction; D055815:Young Adult
chemical_list: D015415:Biomarkers; D054377:Chemokine CXCL12; D058539:Phosphatidylinositol 3-Kinase; D011493:Protein Kinase C
keywords: Migration; phosphatidylinositol 3-kinase; protein kinase C; stem cells from apical papilla; stromal cell–derived factor-1α