鼠间充质干细胞向成骨细胞定向诱导分化的研究

Studies on the directed differentiation of mesenchymal stem cells into osteoblasts

目的:探讨干细胞向成骨细胞诱导分化的特征。方法:利用成骨细胞诱导体系诱导小鼠骨髓间充质干细胞系(D1细胞)向成骨细胞定向分化,D1细胞诱导不同时间后,运用免疫组化方法检测碱性磷酸酶(alkaline phosphatase,ALP),Ⅰ型胶原(typeⅠcollagen,COL1)的表达;RT-PCR检测Osterx和OCN mRNA的表达。结果:细胞诱导培养3、7、14和21 d后结果显示:3 d时ALP、COL1呈阴性表达,7 d ALP呈阳性表达,14 d ALP表达最高,21 d ALP表达明显减少;7 d COL1呈阳性表达,14 d和21 d表达显著增强;14 d有矿化结节形成,21 d形成典型的矿化结节。7 d时OSX和OCN基因表达上调,14 d时OSX基因表达下调,21 d其表达上调;14 d时OCN表达上调,21 d后表达下调。结论:间充质干细胞能定向诱导为成骨细胞,OSX基因的表达是其分化的关键。

Objective：To investigate the characteristics of directed differentiation of mesenchymal stem cells （MSCs） into osteoblasts. Methods： MSCs were cultured in osteogenic media for different times to induce the osteogenic differentiation. The methods, such as immunohistochemistry and RT - PCR were used to study the expression of alkaline phosphatase （ALP）, type Ⅰ collagen （COL1）, osterx and OCN genes. Results： ALP was not detected on day 3, but began to express on day 7. The ALP activity on day 14 was obviously higher than that onday 7 and 21. The expression of COL1 was significantly increased on day 14 and 21. The expression of Osx were upregulated on day 7 and 21, but were down regulated on day 14. The expression of OCN were increased on day 7 and 14, but decreased on day 21. Conclusion： D1 cells were induced into osteoblasts, OSX gene play an important role in the course.