中文摘要：

目的 观察骨形态发生蛋白-2（BMP-2）联合氯化锶对人脐带间充质干细胞（hUCMSV）的增殖和分化的影响.方法 体外培养hUCMSC,实验分为3组,空白组：10%胎牛血清＋DMEM培养基,对照组：10%胎牛血清＋DMEM培养基＋成骨培养基,实验组：10%胎牛血清＋DMEM培养基＋BMP-2＋氯化锶,噻唑蓝（MTT）比色法观察hUCMSC的增殖效果,并检测3组不同培养基培养后hUCMSC的碱性磷酸酶（ALP）活性变化,逆转录-聚合酶链反应（RT-PCR）测量不同组hUCMSC的骨桥蛋白（OPN）、ALP、Ⅰ型胶原蛋白（COL1）的mRNA表达,蛋白印迹法检测Smad和p38蛋白表达的变化.Yon kossa染色实验观察人脐带间充质干细胞钙结节的形成.结果 实验组的hUCMSC增殖率在第5天和第7天明显高于空白组和对照组（P＜0.05）.实验组细胞在第5天,碱性磷酸酶活性由（33.443±9.061）U/g.prot增加到（80.209±17.011）U/g.prot,在第14天,实验组的碱性磷酸酶活性可以高达（145.705±45.871）U/g.prot,与空白组和对照组比较都有明显增加（P＜0.05）.在实验组人脐带间充质干细胞的碱性磷酸酶（ALP）mRNA出现高表达（P＜0.05）.空白组的OPN表达很弱,而对照组和实验组的OPN出现明显的表达（P＜0.05）.对比空白组和对照组,实验组COL1的表达可见明显增强（P＜0.05）.实验组中hUCMSC的Smad1/5/8蛋白出现高表达（P＜0.05）.空白组的p38蛋白表达很弱,而对照组和实验组的p38蛋白出现明显的表达（P＜0.05）,含有BMP-2和氯化锶的培养基中培养28 d后,可以看到hUCMSC形成大量的钙结节.结论 联合骨形态发生蛋白-2和氯化锶对hUCMSC细胞增殖和成骨诱导分化都有促进作用.

英文摘要：

Objective To study the effects of combination of bone morphogenetic protein-2 （ BMP-2） and strontium chloride on proliferation and osteogenic differentiation of human umbilical cord mesenchymal stem cells （hUCMSCs） in vitro culture. Methods hUCMSCs were cultured in vitro, and added with BMP-2 and strontium chloride. Accoding to the culture media used, three experimental groups were set up：blank group（10% FCS/DMEM）, control group （10% FCS/DMEM ＋ osteogenic medium）, experimental group （10% FCS/DMEM ＋ BMP-2 ＋ strontium chloride）. Cell proliferation was measured by methylthiazol tetrazolium （MTT） method. Cell differentiation was examined by alkaline phosphatase （ALP） measurement kit. The expression levels of Osteopontin （OPN）, alkaline phosphatase （ALP） and type 1 collagen （COL1） mRNA was detected by using reverse transcription-polymerase chain reaction （RT-PCR）. The expression of smad1/5/8 and p38 was assayed by Western boltting. Von Kossa staining method was used to study the calcification effects. Results As compared with blank group and control group, the proliferation in experiment group was significnatly promoted after culture for 5 days and 7 days （P〈0.05）. The ALP activity in experimental group was increased from （33.443±9.061） U/g. prot at 3rd day to （80.209±17. 011） U/g. prot at 5th day, even to （145.705 ±45. 871 ） U/g. prot at 14th day as compared with other groups （P〈0.05 ）. In experimental group, ALP, COL 1 and OPN mRNA were highly expressed. On the contrary, OPN mRNA was weakly expressed in blank group （P〈0.05）.Smad1/5/8 and p38 was highly expressed in experimental group, but weakly in blank group（P〈0.05）. Many mineralized nodes were observed after culture for 28 days in the BMP-2 ＋ strontium chloride medium. Conclusion BMP-2 in combination with strontium chloride can promote the proliferation and osteogenic differentiation of hUCMSCs.