title: Culture and characterization of mesenchymal stem cells from human gingival tissue.
abstract: BACKGROUND
  Tissue engineering using mesenchymal stem cells (MSCs) is a recent therapeutic modality that has several advantages. MSCs have high proliferation potential and may be manipulated to permit differentiation before being transplanted, suggesting they may be an ideal candidate for regenerative procedures. Precise identification of cells capable of regenerating the periodontium is valuable because no predictable regeneration procedure has yet been described. The purpose of this study is to determine the presence of MSCs in human gingival connective tissue and their morphologic and functional characteristics.
  
  
  METHODS
  Gingival connective tissue samples were obtained from five healthy students. The samples were deepithelialized, leaving only connective tissue. The explants were minced and cultured on tissue culture dishes for 3 to 4 weeks, after which cells were characterized by flow cytometry. Differentiation into osteogenic, chondrogenic, and adipogenic lineages was induced and evaluated by culture staining. An immunoregulation assay was also performed.
  
  
  RESULTS
  The results show that gingival tissue cells fulfill the minimal criteria proposed by the International Society for Cellular Therapy to be defined as MSCs. Cell characterization was consistently positive for CD90, CD105, CD73, CD44, and CD13 markers and negative for hematopoietic markers CD34, CD38, CD45, and CD54. We observed differentiation in positive staining of adipogenic, chondrogenic, and osteogenic lineages. Furthermore, gingival cells showed immunomodulative capacity.
  
  
  CONCLUSIONS
  Gingival connective tissue could be a reservoir of MSCs that could be used in regenerative procedures based on tissue engineering.
authors.affiliation: Faculty of Dentistry, University of the Andes, Avenue San Carlos de Apoquindo 2200, Santiago, Chile.
authors.forename: Tomas I
authors.initials: TI
authors.lastname: Mitrano
authors.forename: Melisa S
authors.initials: MS
authors.lastname: Grob
authors.forename: Flavio
authors.initials: F
authors.lastname: Carrión
authors.forename: Estefania
authors.initials: E
authors.lastname: Nova-Lamperti
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Luz
authors.forename: Francisca S
authors.initials: FS
authors.lastname: Fierro
authors.forename: Antonio
authors.initials: A
authors.lastname: Quintero
authors.forename: Alejandra
authors.initials: A
authors.lastname: Chaparro
authors.forename: Antonio
authors.initials: A
authors.lastname: Sanz
mesh_terms: D050156:Adipogenesis; D053687:Adult Stem Cells / Q000166:cytology*; D002454:Cell Differentiation; D002478:Cells, Cultured; D020219:Chondrogenesis; D003239:Connective Tissue Cells / Q000166:cytology* / Q000502:physiology; D005434:Flow Cytometry; D005881:Gingiva / Q000166:cytology*; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D007165:Immunosuppression Therapy; D007963:Leukocytes, Mononuclear / Q000276:immunology; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000502:physiology; D010012:Osteogenesis; D023822:Tissue Engineering / Q000379:methods*