Characterization of the apical papilla and its residing stem cells from human immature permanent teeth: a pilot study

J Endod. 2008 Feb;34(2):166-71. doi: 10.1016/j.joen.2007.11.021.


Mesenchymal stem cells (MSCs) have been isolated from the pulp tissue of permanent teeth (dental pulp stem cells or DPSCs) and deciduous teeth (stem cells from human exfoliated deciduous teeth). We recently discovered another type of MSCs in the apical papilla of human immature permanent teeth termed stem cells from the apical papilla (SCAP). Here, we further characterized the apical papilla tissue and stem cell properties of SCAP using histologic, immunohistochemical, and immunocytofluorescent analyses. We found that the apical papilla is distinctive to the pulp in terms of containing less cellular and vascular components than those in the pulp. Cells in the apical papilla proliferated 2- to 3-fold greater than those in the pulp in organ cultures. Both SCAP and DPSCs were as potent in osteo/dentinogenic differentiation as MSCs from bone marrows, whereas they were weaker in adipogenic potential. The immunophenotype of SCAP is similar to that of DPSCs on the osteo/dentinogenic and growth factor receptor gene profiles. Double-staining experiments showed that STRO-1 coexpressed with dentinogenic markers such as bone sialophosphoprotein, osteocalcin, and growth factors FGFR1 and TGFbetaRI in cultured SCAP. Additionally, SCAP express a wide variety of neurogenic markers such as nestin and neurofilament M upon stimulation with a neurogenic medium. We conclude that SCAP are similar to DPSCs but a distinct source of potent dental stem/progenitor cells. Their implications in root development and apexogenesis are discussed.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipogenesis / physiology
  • Adolescent
  • Adult
  • Antigens, Surface / analysis
  • Cell Differentiation
  • Cell Proliferation
  • Dental Pulp / cytology
  • Dentinogenesis / physiology
  • Humans
  • Integrin-Binding Sialoprotein
  • Intermediate Filament Proteins / analysis
  • Mesenchymal Stem Cells / cytology*
  • Mesenchymal Stem Cells / physiology
  • Nerve Tissue Proteins / analysis
  • Nestin
  • Neurofilament Proteins / analysis
  • Odontogenesis / physiology
  • Osteocalcin / analysis
  • Osteogenesis / physiology
  • Periapical Tissue / cytology*
  • Pilot Projects
  • Protein-Serine-Threonine Kinases / analysis
  • Receptor, Fibroblast Growth Factor, Type 1 / analysis
  • Receptor, Transforming Growth Factor-beta Type I
  • Receptors, Growth Factor / analysis
  • Receptors, Transforming Growth Factor beta / analysis
  • Sialoglycoproteins / analysis
  • Stem Cells / cytology
  • Stem Cells / physiology


  • Antigens, Surface
  • IBSP protein, human
  • Integrin-Binding Sialoprotein
  • Intermediate Filament Proteins
  • NES protein, human
  • Nerve Tissue Proteins
  • Nestin
  • Neurofilament Proteins
  • Receptors, Growth Factor
  • Receptors, Transforming Growth Factor beta
  • STRO-1 antigen, human
  • Sialoglycoproteins
  • Osteocalcin
  • neurofilament protein M
  • FGFR1 protein, human
  • Receptor, Fibroblast Growth Factor, Type 1
  • Protein-Serine-Threonine Kinases
  • Receptor, Transforming Growth Factor-beta Type I