中文摘要：

目的观察转化生长因子β1（TGF-β1）短时间干预间充质干细胞（MSCs）后趋化因子受体4（CXCR4）的表达及对MSCs迁移能力的影响。方法 MSCs被不同浓度（0、0.01、0.1、1、10ng/mL）和时间梯度（6、12、24、48h）的TGF-β1干预后,采用流式细胞术鉴定MSCs细胞,通过Western blot和real-time quantitative PCR检测CXCR4的表达,并使用transwell小室实验来鉴定MSCs细胞的迁移能力。CXCR4基因的甲基化状态通过甲基化特异性PCR（methylation-spe-cific PCR,MSP）检测。结果将MSCs细胞短时间暴露在TGF-β1中会导致CXCR4的蛋白水平以浓度依赖性的方式升高,且随着干预时间的延长表达升高,于24h时达到高峰;而此时,检测MSCs细胞暴露于TGF-β124h这个时间点的CXCR4的mRNA水平,发现其以浓度依赖性的方式升高,而且MSCs的迁移能力增强,但MSP的结果显示CXCR4基因甲基化状态并未发生改变。结论 MSCs细胞经TGF-β1干预后,其CXCR4的表达增加,迁移能力增强。

英文摘要：

Objective To investigate the effects of short-term exposure of mesenchymal stem cells（MSCs）to transforming growth factor β1（TGF-β1）on the expression of chemokine receptor 4（CXCR4）and the migratory capacity of the cells in vitro.Methods MSCs were intervened with different concentrations of TGF-β1.MSCs were identified by flow cytometry.The expression of CXCR4 was detected by using Western blot and real-time quantitative PCR.The migratory ability of MSCs was measured by cell migration assay.The methylation status of CXCR4 gene in MSCs was examined by methylation-specific PCR（MSP）.Results Short-term exposure of MSCs to TGF-β1 resulted in increased CXCR4 protein expression in a concentration-and time-dependent manner.The CXCR4 protein expression peaked at the time of 24 h.Meanwhile,CXCR4 mRNA level was increased in a concentration-dependent way at 24 h after exposure of MSCs to TGF-β1 and migration ability of MSCs was enhanced,though methylation status of CXCR4 gene in MSCs was not modified after TGF-β1 treatment.Conclusion After the MSCs were treated by TGF-β1,the expression of CXCR4 was increased and the migration ability of MSCs was enhanced.