title: Characterization of progenitor cells and stem cells from the periodontal ligament tissue derived from a single person.
abstract: BACKGROUND
  Periodontal ligament progenitor cells (PDLPs) and PDL stem cells (PDLSCs) are progenitor and stem cells that were isolated from PDL tissues using the outgrowth and single cell isolation methods respectively. The differences between PDLPs and PDLSCs characteristics could be observed from previous studies. However, these cells were obtained from different patients. This study was the first report to compare the characterization of PDLPs and PDLSCs from the same person.
  
  
  METHODS
  The characterization of PDLPs and PDLSCs includes flow cytometry analysis, cell proliferation assay and the assessment of the colony-forming unit fibroblast. The osteogenic differentiation was evaluated by alkaline phosphatase activity, biomineralization (alizarin red staining) and gene expression of osteogenic markers. The adipogenic differentiation was examined by Oil Red O staining and adipocyte-related gene expression.
  
  
  RESULTS
  Mesenchymal stem cell marker expression and colony-forming unit fibroblast analysis of PDLPs and PDLSCs were similar. However, PDLSCs grew faster than PDLPs on days 3 and 5 of the cell proliferation assay. Both PDLPs and PDLSCs could differentiate into osteoblast and adipocyte-like cells. However, the mineralization of PDLSCs was stronger than that of PDLPs.
  
  
  CONCLUSIONS
  The characteristics of undifferentiated PDL cells in our study were not significantly impacted by the isolation method. We assumed that both PDLPs and PDLSCs are valuable cell sources for periodontal regeneration. However, PDLSCs have a possible advantage for the regeneration of alveolar bone.
authors.affiliation: Department of Cranio- and Maxillofacial Surgery, University Hospital Regensburg, Regensburg, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Prateeptongkum
authors.affiliation: Department of Cranio- and Maxillofacial Surgery, University Hospital Regensburg, Regensburg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Klingelhöffer
authors.affiliation: Department of Cranio- and Maxillofacial Surgery, University Hospital Regensburg, Regensburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Müller
authors.affiliation: Department of Cranio- and Maxillofacial Surgery, University Hospital Regensburg, Regensburg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Ettl
authors.affiliation: Department of Cranio- and Maxillofacial Surgery, University Hospital Regensburg, Regensburg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Morsczeck
mesh_terms: D002454:Cell Differentiation; D002478:Cells, Cultured; D006801:Humans; D010012:Osteogenesis; D010513:Periodontal Ligament; D012847:Single Person; D013234:Stem Cells
keywords: isolation method; periodontal ligament; progenitor cells; regeneration; stem cells