Effect of dexamethasone on biological characteristics of bone marrow stromal stemc ells / 中华骨科杂志

ABSTRACT

Object To investigate the effect of dexamethasone(Dex)of different concentration on the differentiation of the bone marrow stromal stem cells(MSC).Methods MSC were isolated from mice and cultured in vitro.After the third passage,the cells were treated with Dex of different concentration,the expression of typeⅠcollagen mRNA(COL1mRNA),alkaline phosphatase mRNA(ALP mRNA)and adipocyte lipid-binding protein mRNA(ap2mRNA)were detected by quantitative RT -PCR technique.The ratio of the electrophoretic results of the ap2mRNA,COL1mRNA and the ALP mRNA with the house keeping gene of glyceraldehydes-3-phosphate dehydrogenase(GADPH mRNA)respectively,were used to show the relative content of the mRNA.Results COL1mRNA,ALP mRNA and ap2mRNA were ex pressed despite of the difference of the concentration of the Dex.When Dex was1?10 -7 mol/L,the COL1mRNA was0.47?0.12,and ap2mRNA was0.21?0.16;and when Dex was1?10 -8 mol/L,the COL1mRNA was0.96?0.17,and ap2mRNA was0.06?0.03.There was significant statistic difference be-tween the two groups respectively.But the expression of the ALP mRNA were0.35?0.13and0.46?0.24re spectively,there was no significant difference among them.Conclusion Dex could regulate the differenti-ation of the MSCs into adipocyte or osteoblast by regulating special gene expression.In addition,the differ-en tia tion of MSC induced by Dex was bidirectional depending on the concentration of the Dex.When the concentra tion of the Dex was high,it could induce MSC differentiating into adipocytes.This might be the molecular mechanism of the steroid induced osteonecrosis.And the results proved when Dex was1?10 -8 mol/L,it was suitable for inducing MSCs differentiation into osteoblasts.