中文摘要：

目的：探索不同年龄骨髓间充质干细胞中miR203的表达变化，及其对骨髓间充质干细胞自我更新的作用机制。方法分别分离培养4周龄和18～24月龄的Balb/c小鼠BMSCs，对比不同年龄小鼠BMSCs增殖潜能的差异，并检测不同年龄小鼠BMSCs中miR-203的表达变化差异，从而探讨miR-203在骨髓间充质干细胞增殖调节中的作用机制。结果根据干细胞贴壁特性获得了稳定的骨髓间充质干细胞，其在分化诱导条件下可获得经茜素红染色呈红色结节及油红O 染色显示有脂质沉淀，且成骨诱导后Ⅰ型胶原蛋白显著表达。在增殖条件下，与年轻BMSCs相比，老年BMSCs增殖（传代）能力明显下降。年轻小鼠（4周龄）BMSCs中miR-203远低于老年小鼠（18～24月龄）BMSCs中miR-203表达（P＜0．05）。结论年轻骨髓间充质干细胞增殖能力优于老年骨髓间充质干细胞，可能与miR-203表达较低有关。

英文摘要：

Objective To investigate the differential expression of miR203 in bone marrow mesenchymal stem cells （ BMSCs） with different age, and to explore the mechanism of miR203 during the self-renew of BMSCs.Methods BMSCs from 4-week and 18-24-month Balb/c mice were isolated and cultured.The proliferation potential of BMSCs in mice with different age was compared.And the different expression level of miR-203 in BMSCs with different age was also detected, in order to identify the mechanism of miR-203 in regulating the proliferation of BMSCs.Results BMSCs were acquired and stably cultured in vitro using adherent separation method.After the induction of BMSCs, the result of Alizarin red staining showed salmon tubercles in BMSCs, while the result of oil red O staining showed lipid sediment in BMSCs.After the osteogenic induction, the significant expression of type I collagen was observed.The capability of proliferation of aged BMSCs was distinctively decreased compared with that of young BMSCs during proliferation.The expression of miR-203 in BMSCs from young mice （4 weeks） was significantly lower than that in BMSCs from the aged mice （ 18 -24 months, P〈0.05 ） .Conclusion The capability of proliferation in BMSCs from young mice is superior to that in BMSCs from the aged mice, which may be related to the low expression level of miR-203.