Conditioned Medium from Periapical Follicle Cells Induces the Odontogenic Differentiation of Stem Cells from the Apical Papilla In Vitro

IntroductionWe investigated the biological effects of conditioned medium (CM) from periapical follicle cells (PAFCs) of root-developing tooth on the proliferation and differentiation of stem cells from the apical papilla (SCAP) in vitro.MethodsHuman SCAP and PAFCs were isolated and expanded. CM from PAFCs was prepared with the primary cells. Cell cycle analysis, methyl-thiazol-diphenyltetrazolium assay, alkaline phosphatase activity, mineralization behavior, and gene expression of odontoblast phenotype SCAP cultured with or without CM from PAFCs were evaluated.ResultsIn the CM-treated group, the cell growth, alkaline phosphatase activity, and mineralization of SCAP were up-regulated. The expression of dentin sialophosphoprotein, alkaline phosphatase, and osteocalcin mRNA progressively increased in SCAP treated with CM from PAFCs.ConclusionsOur findings suggest that CM from PAFCs is able to provide a favorable odontogenic microenvironment to induce differentiation of SCAP along the odontoblast lineage.