Objective: Periodontal ligament stem cells (PDLSCs), undifferentiated mesenchymal cells with multipotent differentiation and self-renewal capacities, constitute the optimal MSC population for periodontal regeneration. This study sought to elucidate the effects of concentrated growth factor (CGF) on the osteogenic differentiation of PDLSCs and analyze the underlying mechanisms.
Methods: PDLSCs were isolated from the molars of patients with malocclusion and characterized by flow cytometry, osteogenic induction, lipogenic induction, ARS staining and ORO staining. PDLSCs were treated with osteogenic induction medium containing different concentrations of CGF. The osteogenic ability of CGF in PDLSCs was analyzed via ALP staining, ARS staining, and ALP activity assays. WNK1, RUNX2 and OPN were detected by RT-qPCR. WNK1, RUNX2, OPN, β-catenin, GSK3β and p-GSK3β were detected by WB. The role of CGF in PDLSC osteogenic differentiation through the Wnt pathway was verified.
Results: PDLSCs were successfully isolated and cultured in vitro. After CGF treatment, ALP activity, mineralization nodule formation, and the expression of RUNX2 and OPN in PDLSCs were increased, with 0.1 mg/mL CGF showing the best osteogenic differentiation ability. WNK1, β-catenin, and p-GSK3β/GSK3β were elevated. CGF activated the Wnt pathway through WNK1. The promoting effects of CGF on osteogenic differentiation of PDLSCs were partially reversed after inhibition of WNK1 and the Wnt pathway.
Conclusion: CGF promotes PDLSC osteogenic differentiation by activating the Wnt pathway through WNK1.
Keywords: ALP; CGF; OPN; PDLSCs; RUNX2; WNK1; Wnt path; osteogenic differentiation.