Effect of FGF-2 on human periodontal ligament STRO-1+/CD146+ cells

Objectives: Fibroblast growth factor-2 (FGF-2) plays a key role in the tissue regeneration process such as angiogenesis and proliferation of mesenchymal stem cells. We have previously reported that swine periodontal ligament stem cells showed tube-like structure formation with the addition of FGF-2 in the culture. Although several studies suggested that STRO-1+/CD146+ cells in human periodontal ligament cells (HPDL cells) have characteristics of stem cells, the effects of FGF-2 on STRO-1+/CD146+ cells in HPDL cells has not been fully understood. The objective of this study was to examine effects of FGF-2 on the STRO-1+/CD146+cells in HPDL cells. Methods: HPDL cells (n=15) were obtained from extracted teeth using out growth method. The HPDL cells were cultured in DMEM supplemented with 10% FBS with or without FGF-2. The percentage of STRO-1+/CD146+ cells in HPDL cells were analyzed and the cells were sorted using FACSAria. To examine multi differentiative potency of the HPDL cells and the sorted STRO-1+/CD146+ cells, the cells were cultured in adipogenic or osteogenic induction medium and stained with Oil red O and alizarin red, respectively. Expression of mRNA of the cells was examined using RT-PCR. Results: The percentage of STRO-1+/CD146+ cells in HPDL cells cultured with FGF-2 significantly increased compared to that cultured without FGF-2 (p<0.05 ANOVA with Tukey's test). The number of STRO-1+/CD146+ cells in HPDL cells cultured with FGF-2 was 15-fold higher than those without FGF-2. The sorted STRO-1+/CD146+ cells from HPDL cells expressed PLAP-1, periostin, S100 A4 and scleraxis mRNA, and had potential to differentiate into both adipocytes and osteoblasts. Conclusion: Present study suggested that FGF-2 augmented the number of STRO-1+/CD146+ cells with maintaining the differentiative potency of the cells. Expansion of stem cells using FGF-2 can be useful strategy for the periodontal regeneration.