中文摘要：

目的：利用腺病毒介导RNA干扰抑制成骨分化关键转录调控因子Runx2（Runt-related transcription factor 2）的表达,研究其对骨形态发生蛋白2（bone morphogenetic protein 2,BMP2）诱导间充质干细胞（mesenchymal stem cells,MSCs）成软骨分化的影响,并初步探讨相关机制。方法：利用腺病毒Ad-GFP、Ad-BMP2、Ad-SiRunx2感染C3H10T1/2细胞;共分4组：GFP组、BMP2组、BMP2＋SiRunx2组和SiRunx2组。Alcian blue染色检测各组软骨细胞基质糖胺聚糖分泌;RTPCR检测Runx2、早期成软骨标志物（Col2a1）、蛋白聚糖（Aggrecan）及晚期成软骨标志物（Col10a1）mRNA表达水平;Western blot检测目的蛋白BMP2、Ⅱ型胶原（Col2a1）及X型胶原（Col10a1）的蛋白表达。结果：在BMP2诱导C3H10T1/2细胞成软骨分化过程中,下调Runx2的表达可以增强Col2a1、Aggrecan及软骨细胞外基质糖胺聚糖的合成,抑制Col10a1的合成。结论：下调Runx2表达可以增强BMP2诱导间充质干细胞成软骨分化能力,并抑制软骨细胞的成熟和肥大。

英文摘要：

Objective：To investigate the potentiation effect of RNA silenced Runx2 on bone morphogenetic protein 2（BMP2）induced chondrogenic differentiation of mesenchymal stem cells（MSCs）.Method：C3H10T1/2 cells were treated with adenovirus：Ad-BMP2,Ad-SiRunx2 or Ad-GFP.The sulfated glycosaminoglycan of cellular matrix was detected by Alcian Blue Staining.The mRNA level of Runx2,Col2a1,aggrecan,and Col10a1 were detected by RT-PCR,and the protein level of BMP2,Col2a1,Col10a1 were detected by Western blot.Results：The BMP2 ＋ SiRunx2 group（C3H10T1/2 cells were treated with Ad BMP2 and Ad SiRunx2）was more blue than the BMP2 group on day 10 proven by Alcian blue staining.The BMP2 ＋SiRunx2 group showed a higher mRNA level of Col2a1 and aggrecan（P〈0.05）and a lower protein level of Col10a1（P〈0.05）than the BMP2 group on day 7 and 14.The BMP2 ＋ SiRunx2 group showed a higher protein level of Col2a1（P〈0.05）and a lower protein level of Col10a1（P〈0.05）than the BMP2 group on day 10.Conclusion：The siRNA targeting Runx2 promotes BMP2-induced stem cell chondrogenic differentiation and supresses the chondrocyte hypertrophy and maturation.