title: The isolation of stem cells from human deciduous teeth pulp is related to the physiological process of resorption.
abstract: BACKGROUND
  The aim of this study was to isolate and grow cells from sound human deciduous teeth pulp with different levels of resorption and evaluate stem cell parameters.
  
  
  METHODS
  Pulp tissue was removed from 30 different patients, aged from 6 to 12 years. From all the teeth, 21 were in advanced levels of resorption (group 1), and the remaining nine teeth did not show any visible resorption (group 2). Pulp tissue was removed and dissociated, and the suspension was seeded onto 12-well plates. The phenotype of the cells (n = 5) was analyzed on fifth and tenth passages by flow cytometry for clusters of differentiation (CD)29/PE, CD34/PE, CD44/FITC, CD45/FITC, CD90/FITC, CD117/PE, CD133/PE, CD146/FITC, CD184/PE, Stromal Cell Surface Marker 1 (STRO-1)/FITC and human leukocyte antigen major histocompatibility complex class II surface receptor (HLA-DR)/FITC, and by reverse transcription-polymerase chain reaction (RT-PCR) for octamer-binding transcription factor 4 (OCT-4). On the same passages, cells were differentiated into adipocytes, osteoblasts, and chondrocytes.
  
  
  RESULTS
  Cell isolation was successful in 25 samples, but only 17 of these reached 90% confluence. It was not possible to establish cell culture from group 2. Cells on both fifth and tenth passages were positive for CD29, CD44, and CD90 and also for the expression of OCT-4. Moderate labeling was observed for CD117 and CD133, whereas a low expression was detected for CD34, CD45, HLA-DR, CD184, CD146, and STRO-1. All cultures differentiated into three cell types.
  
  
  CONCLUSIONS
  The isolated pulp cells can be considered stem cells. The facility for obtaining cells seems to be related to the root resorption process, so, therefore, the cells from group 1 were able to proliferate in vitro, whereas group 2 cells were not.
authors.affiliation: Faculty of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Lisiane
authors.initials: L
authors.lastname: Bernardi
authors.forename: Simone Bonato
authors.initials: SB
authors.lastname: Luisi
authors.forename: Raquel
authors.initials: R
authors.lastname: Fernandes
authors.forename: Tiago Pires
authors.initials: TP
authors.lastname: Dalberto
authors.forename: Lauren
authors.initials: L
authors.lastname: Valentim
authors.forename: José Artur
authors.initials: JA
authors.lastname: Bogo Chies
authors.forename: Anna Christina
authors.initials: AC
authors.lastname: Medeiros Fossati
authors.forename: Patricia
authors.initials: P
authors.lastname: Pranke
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation; D002469:Cell Separation; D002478:Cells, Cultured; D002648:Child; D003782:Dental Pulp / Q000166:cytology* / Q000502:physiology; D005434:Flow Cytometry; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000145:classification / Q000166:cytology* / Q000378:metabolism; D012391:Root Resorption / Q000145:classification*; D014092:Tooth Root / Q000502:physiology; D014094:Tooth, Deciduous / Q000166:cytology*
chemical_list: D015415:Biomarkers