Resveratrol Promotes in vitro Differentiation of Osteoblastic MC3T3-E1 Cells via Potentiation of the Calcineurin/NFATc1 Signaling Pathway

Resveratrol has been shown to stimulate differentiation of osteoblastic MC3T3-E1 cells in vitro ; however, the mechanisms underlying the anabolic effect of resveratrol on osteoblasts remain largely unknown. Our study was aimed to investigate the molecular mechanism of resveratrol-induced differentiation of MC3T3-E1 cells. MC3T3-E1 cells were treated for 8 days with different concentrations of resveratrol (10 −8 -10 −6 M) and 10 −6 M cyclosporine A (CsA), a specific inhibitor of the calcineurin/NFAT pathway. According to the results of pilot studies of cell proliferation and alkaline phos-phatase activity, 10 −7 M concentration of resveratrol was used in subsequent experiments. The levels of mRNA expression of the osteosis-related genes CaN , NFATc1 , and Runx2 were analyzed by real-time RT-PCR; the levels of the corresponding proteins were estimated by Western blot analysis. Resveratrol upregulated expression of the CaN , NFATc1 , and Runx2 genes at both mRNA and protein levels compared to the control group ( p < 0.05), while CsA reduced the effects of resveratrol ( p < 0.05). Using immunohistochemical staining, we showed that resveratrol induced NFATc1 accumulation in the cell nuclei, and treatment with CsA inhibited resveratrol-mediated induction of NFATc1, suggesting that the calcineurin/NFATc1 signaling pathway plays an important role in the regulatory effect of resveratrol on osteoblasts.