【摘要】 目的观察不同浓度地塞米松对体外培养人骨髓间充质干细胞(hMSCs)成骨分化、增殖能力及凋亡率的影响。方法以梯度密度分离法获取人骨髓间充质干细胞进行体外培养,以1×10-9、1×10-8、1×10-7、1×10-6mol/L 4种不同浓度地塞米松分别处理细胞。检测各组细胞的碱性磷酸酶(ALP)活性;RT-PCR法检测骨桥蛋白(OPN)基因的表达;四甲基偶氮唑蓝(MTT)比色法测定各组细胞的增殖率;流式细胞仪分析细胞凋亡率。结果低浓度(1×10-9mol/L)地塞米松对ALP的表达无显著作用(P>0.05),而1×10-8mol/L及以上浓度的地塞米松可明显增加ALP的活性(P<0.01);所有实验组的hMSCs均有OPNmRNA表达,其表达强度随着地塞米松浓度增加而增强;1×10-9mol/L地塞米松对细胞增殖无明显影响(P>0.05),1×10-8mol/L及以上浓度的地塞米松可明显抑制细胞的增殖(P<0.01);体外培养的hMSCs凋亡率随地塞米松浓度的增加而升高(P<0.01)。结论1×10-8mol/L及以上浓度的地塞米松可显著增强hMSCs成骨分化能力,同时抑制细胞增殖并促进其凋亡。更多还原

【Abstract】 Objective To observe the effect of dexamethasone on the biological characteristics of human mesenchymal stem cells(hMSCs) derived from bone marrow in vitro.Methods The primary hMSCs were isolated and cultured in vitro.In subcultures,hMSCs were respectively treated with four different concentrations of dexamethasone(1×10-9,1×10-8,1×10-7 and 1×10-6 mo1/L).The alkaline phosphatase(ALP) activity was measured;mRNA of osteopontin was observed by reverse transcriptase polymerase chain reaction(RT-PCR);the proliferation of hMSCs was evaluated by MTT assay;apoptosis was examined with flow cytometer.Results Treatment of cells with high concentration of dexamethasone(1×10-8,1×10-7 and 1×10-6 mo1/L) for 8 days led to a significant increase in ALP activity(P <0.01).The osteopontin mRNA was induced by different concentration of dexamethasone respectively.The optical density value of hMSCs treated with high concentration of dexamethasone for 6 days was significantly lower than that of the controls(P <0.01).Dexamethasone increased the apoptosis rate of all hMSCs cultured in vitro.Conclusion The high concentration of dexamethasone(1×10-8,1×10-7 and 1×10-6 mol/L) induces the differentiation of hMSCs to osteoblastic cells,inhibits the proliferation of cells and leads to an increase of its apoptosis rate.更多还原