骨相关生长因子对兔骨髓基质干细胞生长及分化的量效作用

目的研究地塞米松、重组人成纤维细胞生长因子（recombinant human fibroblast growth factor，rhFGF）及重组人骨形成蛋白2（recombinant human bone morphogenetic protein 2，rhBMP-2）对兔骨髓基质干细胞（marrow slromal stem cells，MSCs）生长及分化的量效作用，为其在骨组织上程中的应用提供实验基础。方法体外分离培养免MSCs，分为1个空白对照组及9个实验组。实验组分别与终浓度为10^-8、10^-7、10^-6mol／L地塞米松；终浓度为50、200、500ngng/ml FGF；终浓度为50、500、1000ng／ml rhBMP-2培养。于4、7d终止培养并测定细胞总蛋白及碱性磷酸酶（alkaline phosphatase。ALP）活性。结果与空白对照组比较，10mol／L地塞米松显著抑制细胞蛋白合成（P〈0．05），而10^-8、10^-7mol／L地塞米松对细胞蛋白合成无明显影响；10^-6,10^-7mol／L地塞米松刺激MSCs高度表达ALP（P〈0．05）。rhFGF各浓度组显著促进细胞蛋白合成量差异有统计学意义（P〈0．05），表现ALP活性抑制。rhBMP-2符浓度组对细胞蛋白合成九明显影响；50ng／ml rhBMP2不影响MSCs的ALP活性；当浓度增至500ng／ml与1000ng／ml时，ALP活性显苦增加（P〈0．05）。结论10^-7mol／L地塞米松及500、1000ng／ml rhBMP-2在不影响MSCs增殖的前提下，适当浓度能显著促进MSCs向成骨细胞转化，在骨组织工程的研究中有重要的应用价值。

THE EFFECT OF BONE-RELATED GROWTH FACTORS ON THE PROLIFERATION AND DIFFERENTIATION OF MARROW MESENCHYMAL STEM CELLS IN VITRO

Objective To investigate the effect of dexamethasone, recombinant human fibroblast growth factor (rhFGF) and recombinant human bone morphogenetic protein 2 (rhBMP-2) on the proliferation and differentiation of marrow stromal stem cells (MSCs) for their further application in tissue engineering.Methods MSCs were isolated and cultured in vitro, and then exposed to different dose of dexamethasone (10 -8 molL,10 -7 molL,10 -6 molL), rhFGF (50 ngml,200 ngml,500 ngml) and rhBMP-2 (50 ngml,500 ngml, 1 000 ngml) respectively. The total protein and alkaline phosphatase (ALP) activity of each group was measured on 4th and 7th day. Results Exposure of MSCs with 10-6 molL dexamethasone inhibited protein synthesis without obvious effects on ALP expression. The application of rhFGF significantly promoted cell proliferation but inhibited ALP activity. In comparison, ALP expression was significantly enhanced by treatment of rhBMP-2 at concentration of 500 ngml, 1 000 ngml. Conclusion The exposure of dexamethasone as well as rhBMP-2 to MSCs with an appropriate concentration promotes osteogenic expression without reverse effects on cell proliferation, which indicates the great potential value in cell-based strategy of bone tissue engineering.