Platelet-rich plasma stimulates cytokine expression and alkaline phosphatase activity in osteoblast-derived osteosarcoma cells.

Objective: The aim of this study was to investigate the effects of PRP on SAOS-2 cells in terms of cytokine expression, cell activity and oxidative stress.

Design: Cell line SAOS-2 (1×10(5)cells/mL) were grown in culture medium α-MEM with 10% FBS for 24h and stimulated (or not) with PRP at concentrations of 3, 10 and 20%, LPS (E. coli, 10g/mL) and IL-1β (1mg/mL) for 24h. The supernatant was collected and analyzed for the expression of cytokines in a panel array, ALP using a commercial kit and NO(2)(-) with Griess reaction method. Also, the cells were analyzed using Western blot for RANKL and slot blotting for nitrotyrosine expression.

Result: There were no significant differences amongst the groups in terms of NO(2)(-), protein nitrotyrosine content and RANKL expression. However, all stimuli increased ALP activity and in case of PRP, it was in a dose-dependent manner (p<0.001). Also, all stimuli induced an increase in cytokines and chemokines expression, but only PRP promoted an increase of component C5, sICAM-1 and RANTES expression. Whilst IL-1 receptor antagonist (IL-1ra) expression was down-regulated by PRP, both LPS and IL-1β caused up-regulation of this cytokine.

Conclusions: PRP can stimulate osteoblast activity and cytokine/chemokine release, as well as indicate some of the mediators that can (and cannot) be involved in this activation.