The Effect of Dexamethasone on the Proliferation and Osteoblastic Differentiation of Human Mesenchymal Stem Cells Treated with Fluvastatin

Abstract

Statins, known as HMG-CoA reductase inhibitors, were reported to have osteogenic effects. However, the mechanism of the effect of dexamethasone on statin-induced osteogenesis remains elusive. This study investigated the effects of dexamethasone (Dex) on cell proliferation and osteoblastic differentiation of human mesenchymal stem cells (hMSCs) treated with fluvastatin (Flu). The addition of 10 nM Dex increased, by day 7, the growth of hMSCs treated with 0.5 µM Flu. Moreover, Dex of all tested concentrations increased the growth of hMSCs in the presence of 1.0 µM Flu by day 7. An alkaline phosphatase (ALP) activity assay showed the addition of Dex resulted in increased ALP activity of the hMSCs treated with 0.5 µM Flu in a concentration-independent manner, while Dex did not increase ALP levels in the presence of high Flu concentrations including 1.0 µM and 2.0 µM. These results suggest that the addition of 10 nM Dex may be necessary for cell proliferation and osteoblastic differentiation of hMSCs in the presence of 0.5 µM Flu.