ABSTRACT
Objective To observe the effect of dexamethasone(Dex)on the proliferation and os- teogenic differentiation of human marrow stromal cells(MSCs)in vitro.Methods The primary human MSCs were isolated and cultured by Ficoll seperation culture in vitro.In subcultures,human MSCs were respectively treated with dexamethasone 10~(-9),10~(-8) and 10~(-7) mol/L.The proliferation of human MSCs was measured using MTF method;cytoplasmic alkaline phosphatase(ALP)activity was measured;the osteogenic marker osteopontin (OPN)mRNA were examined by reverse transcriptase polymerase chain reaction(RT-PCR).Results The op- tical density values in cultures treated with dexamethasone 10~(-8) and 10~(-7) mol/L for 8 days were significantly lower than those in the controls(P＜0.05).Treatment of cells with Dex for 12 days led to a significant increase in cytoplasmic ALP activity(P＜0.05)in a dose-dependent manner.Dex induced OPN mRNA.Conclusion Dex inhibits the proliferation of human MSCs and dexamethasone 10~(-7) mol/L leads to a strong decrease in cell number.Dex induces human MSCs differentiate to osteoblastic cells.