Comparative analysis of in vitro periodontal characteristics of stem cells from apical papilla (SCAP) and periodontal ligament stem cells (PDLSCs)

Objective: The aim of this study was to compare the in vitro periodontal properties of stem cells from apical papilla (SCAP) and periodontal ligament stem cells (PDLSCs). Design: SCAP and PDLSCs cultures were established from normal human impacted third molars with immature roots. The cells were cultured in differentiation medium containing dexamethasone, beta-glycerophosphate and ascorbate phosphate for 3 weeks and in normal medium for as long as 60 days, and then were analysed for mineralisation potential. Cell proliferation, colony-forming capacity and periodontal ligament (PDL)-specific markers were also measured. The mineralisation markers, including alkaline phosphatase (ALP), bone sialoprotein (BSP) and osteocalcin (OC), were investigated by immunofluorescence staining and real-time polymerase chain reaction. The expression of PDL markers, including periostin and S100A4, was confirmed by reverse transcription polymerase chain reaction. Results: SCAP showed a significantly higher proliferation rate and colony-forming capacity than PDLSCs. Both types of cells displayed mineralisation potential after induction and long-term culture. The SCAP, however, exhibited higher levels of ALP, BSP and OC expression than the PDLSCs. Like the PDLSCs, the SCAP exhibited periostin and S100A4 expression. Conclusions: Our study provides the first evidence showing that SCAP express periodontal properties in vitro. SCAP not only showed PDL-related markers, but also displayed a higher proliferation rate and a greater mineralisation capacity than those of PDLSCs. It might help understand the development of tooth root and periodontium. Furthermore, SCAP could be a promising candidate for periodontal tissue engineering. (c) 2013 Elsevier Ltd. All rights reserved.