Role of PDGF-BB in proliferation, differentiation and maintaining stem cell properties of PDL cells in vitro

Abstract

Objective: Platelet-derived growth factor-BB (PDGF-BB) is one of the most abundant growth factors in platelet derived products and has been shown to stimulate regeneration after tissue injury. There is a population of mesenchymal stem cells (MSC) in human periodontal ligament (PDL) which can contribute to tissue regeneration under appropriate conditions.

Design: PDL cells were isolated and characterized using stem cell and differentiation markers via immunofluorescence and flow cytometry and then cultured in vitro and treated with different concentrations of PDGF-BB. The effect of PDGF-BB on cell proliferation, stem cell and differentiation markers expression, soluble collagen production, lysyl oxidase (LOX) activity, alkaline phosphatase (ALP) activity and calcium nodules formation was assessed.

Results: PDGF-BB stimulated the proliferation of cells with the maximum effect at 50ng/mL. The growth factor increased the expression of stem cell markers and SPARC; Col1a2 expression was decreased, whereas the expression of Col3a1 remain unchanged. Soluble collagen production, ALP activity and calcium nodules formation were also significantly decreased by PDGF-BB; LOX activity was significantly increased.

Conclusions: PDGF-BB is a powerful promoter of cell proliferation and increases the expression of stem cell markers; inhibites collagen production and mineraliration but accelerates the maturation of collagen chains through increased LOX activity and SPARC expression.

Keywords: Mesenchymal stem cells; Periodontal ligament; Platelet-derived growth factor.