title: The dental pulp stem cell niche based on aldehyde dehydrogenase 1 expression.
abstract: OBJECTIVE
  To detect cells expressing the stem cell marker ALDH1 (aldehyde dehydrogenase1) in the pulp of human permanent teeth and to investigate the expression of ALDH1 in isolated dental pulp cells.
  
  
  METHODS
  Pulp tissue was collected and processed for immunohistochemistry to detect ALDH1-, STRO-1- and CD90-positive cells. In addition, cells were isolated and analysed by flow cytometry for ALDH1 activity and for the cell surface markers CD44, CD73, CD90, STRO-1 and CD45. Cells were also examined for multidifferentiation capacity. Within these cells, an ALDH1(+) cell subpopulation was selected and evaluated for multidifferentiation capacity.
  
  
  RESULTS
  The immunohistochemistry analyses showed that ALDH1-, CD90- and STRO-1-positive cells were located mainly in the perivascular areas and nerve fibres of dental pulps. Cells on the fifth passage had high expression for CD44, CD73 and CD90, whereas moderate labelling was observed for STRO-1 and ALDH1 in flow cytometry analysis. On the same passages, cells were able to differentiate into osteogenic, adipogenic and chondrogenic lineages. The ALDH1(+) cell subpopulation also demonstrated multilineage differentiation ability.
  
  
  CONCLUSIONS
  Dental pulp stem cells reside in the vicinity of blood vessels and nerve fibres, indicating the possible existence of more than one stem cell niche in dental pulps. Furthermore, ALDH1 was expressed by isolated dental pulp cells, which had mesenchymal stem cell characteristics. Thus, it can be suggested that ALDH1 may be used as a DPSC marker.
authors.affiliation: Department of Bio-Interaction, Institute of Health Sciences, Federal University of Bahia, Salvador, Brazil.
authors.forename: C V
authors.initials: CV
authors.lastname: Machado
authors.affiliation: Department of Bio-Interaction, Institute of Health Sciences, Federal University of Bahia, Salvador, Brazil.
authors.forename: S T
authors.initials: ST
authors.lastname: Passos
authors.affiliation: Department of Bio-Interaction, Institute of Health Sciences, Federal University of Bahia, Salvador, Brazil.
authors.forename: T M C
authors.initials: TM
authors.lastname: Campos
authors.affiliation: Department of Bio-Interaction, Institute of Health Sciences, Federal University of Bahia, Salvador, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Bernardi
authors.affiliation: Department of Bio-Interaction, Institute of Health Sciences, Federal University of Bahia, Salvador, Brazil.
authors.forename: D S
authors.initials: DS
authors.lastname: Vilas-Bôas
authors.affiliation: Department of Bio-Interaction, Institute of Health Sciences, Federal University of Bahia, Salvador, Brazil.
authors.forename: J E
authors.initials: JE
authors.lastname: Nör
authors.affiliation: Department of Bio-Interaction, Institute of Health Sciences, Federal University of Bahia, Salvador, Brazil.
authors.forename: P D S
authors.initials: PD
authors.lastname: Telles
authors.affiliation: Department of Bio-Interaction, Institute of Health Sciences, Federal University of Bahia, Salvador, Brazil.
authors.forename: I L
authors.initials: IL
authors.lastname: Nascimento
mesh_terms: D000293:Adolescent; D000328:Adult; D000080924:Aldehyde Dehydrogenase 1 Family; D000954:Antigens, Surface / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D001808:Blood Vessels / Q000378:metabolism; D003782:Dental Pulp / Q000098:blood supply / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D008964:Molar, Third; D050697:Retinal Dehydrogenase / Q000378:metabolism*; D013234:Stem Cells; D018800:Thy-1 Antigens / Q000378:metabolism; D055815:Young Adult
chemical_list: D000954:Antigens, Surface; D015415:Biomarkers; D007527:Isoenzymes; C525591:STRO-1 antigen, human; D018800:Thy-1 Antigens; D000080924:Aldehyde Dehydrogenase 1 Family; C510223:ALDH1A1 protein, human; D050697:Retinal Dehydrogenase
keywords: aldehyde dehydrogenase 1; dental pulp; stem cell niche; stem cells