南方医科大学学报

南方医科大学学报 ›› 2013, Vol. 33 ›› Issue (03): 376-.

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雷奈酸锶通过骨形态发生蛋白-2/Smad通路促进骨髓间充质干细胞成骨分化

吕辉珍，黄晓丹，靳思思，郭润民，吴文   

  • 出版日期:2013-03-20 发布日期:2013-03-20

Strontium ranelate promotes osteogenic differentiation of rat bone mesenchymal stem cells through bone morphogenetic protein-2/Smad signaling pathway

  • Online:2013-03-20 Published:2013-03-20

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摘要： 目的探讨骨形态发生蛋白-2（BMP-2）/Smad通路在雷奈酸锶（Sr）促进大鼠骨髓间充质干细胞（BMSCs）分化为成骨细胞
过程中的作用。方法体外分离培养大鼠BMSCs，根据实验目的加入不同浓度Sr、BMP-2 的拮抗剂noggin 及Smad1 小干扰
RNA（SiRNA）。酶标法检测碱性磷酸酶（ALP）活性，茜素红染色检测钙结节，Western blotting法检测磷酸化Smad1/5/8及Runt
相关转录因子-2（Runx2）蛋白的表达。结果应用0.1~10 mmol/L Sr处理BMSCs细胞1 h后，细胞内磷酸化Smad1/5/8表达增
高，其中浓度为1 mmol/L时，表达达到高峰；在Sr处理BMSCs前，应用BMP-2拮抗剂noggin预处理细胞2 h能抑制Sr对磷酸化
Smad1/5/8表达的上调作用；应用0.1~5 mmol/L Sr处理细胞6 h后，细胞内Runx2表达增高，其中浓度为1 mmol/L时，表达达到
高峰；在Sr处理BMSCs前，应用Smad1 SiRNA转染细胞后能下调Smad1/5/8、磷酸化Smad1/5/8的表达，并抑制Sr对Runx2表
达的上调作用，还拮抗Sr对ALP活性及钙化结节形成的促进作用。结论BMP-2/Smad通路参与了Sr促进BMSCs成骨分化。

Abstract: Objective To explore whether strontium ranelate (Sr) promotes osteoblast lineage differentiation of rat bone
mesenchymal stem cells (BMSCs) through the bone morphogenetic protein-2 (BMP-2)/Smad signaling pathway. Methods
Cultured rat BMSCs were exposed to different concentrations of Sr, noggin (an inhibitor of BMP-2) or Smad1 siRNA. The
activity of alkaline phosphatase (ALP) in the exposed cells was detected by colorimetry, and the formation of mineralized
nodules was observed with alizarin red staining. The expressions of phosphorylated (p) Smad1/5/8 and Runt-related
transcription factor 2 (Runx2) in the cells were detected by Western blotting. Results Exposure to Sr at 0.1 to 10 mmol/L for 1 h
markedly increased the expression of p-Smad1/5/8 in the BMSCs, and the increment was the most obvious following 1 mmol/L
Sr exposure. Preconditioning with 100 ng/ml noggin for 2 h inhibited Sr-induced up-regulation of p-Smad1/5/8 expressions.
Exposure of the cells to 0.1 to 5 mmol/L Sr for 6 h significantly enhanced Runx2 expression, and the peak enhancement
occurred following 1 mmol/L Sr exposure. Transfection of the BMSCs with Smad1 siRNA decreased the basal level of Smad1/5/
8 protein expression, and also inhibited Sr-induced up-regulation of p-Smad1/5/8 and Runx2 expressions as well as Sr-induced
enhancement of ALP activity and formation of mineralized nodules. Conclusion The BMP-2/Smad pathway is involved in
Sr-induced osteoblast differentiation of rat BMSCs.