中文摘要：

目的体外研究趋化因子12（CXCL12）对大鼠少突胶质前体细胞（oligodendrocyte precursor cells,OPCs）增殖的影响及其机制。方法振荡分离和差速贴壁等方法获得OPCs,采用免疫细胞化学技术进行鉴定;CCK-8检测OPCs在不同浓度CXCL12（0、5、10、20 ng/m L）作用不同时间点（0、24、48、72 h）的增殖,Western blot检测OPCs在各浓度下72 h后下游CXCR4、CXCR7、MMP9蛋白表达;CXCR4 siRNA、CXCR7 siRNA分别干扰CXCR4、CXCR7蛋白表达后,检测在20 ng/m L CXCL12下OPCs在各时间点的增殖,Western blot检测该条件下CXCR4、CXCR7、MMP9蛋白表达;MMP9 siRNA干扰MMP9蛋白表达后,检测在20 ng/m L CXCL12下OPCs在各时间点的增殖。结果在一定浓度范围内,CXCL12能够明显促进OPCs增殖,并且促进OPCs内CXCR4、CXCR7、MMP9蛋白表达。与0 ng/m L相比,20 ng/m L CXCL12作用72 h后,OPCs增殖及CXCR4、CXCR7、MMP9蛋白表达增加最明显（P〈0.05,P〈0.01）;CXCR4、CXCR7分别干扰后,OPCs增殖受到抑制,MMP9蛋白表达量也明显降低（P〈0.05,P〈0.01）;MMP9干扰后,OPCs增殖受到抑制（P〈0.05）。结论 CXCL12对OPCs增殖有明显促进作用,与CXCR4、CXCR7、MMP9蛋白表达上调相关。

英文摘要：

Objective To determine the effect of CXCL12 on the proliferation of rat oligodendrocyte precursor cells（ OPCs） and explore the related mechanism. Methods OPCs were dissociated by shaking process and differential adhesion, and identified by immunocytochemical assay. The effect of different concentrations（ 0,5,10 and 20 ng/m L） of CXCL12 on the proliferation of OPCs at 0,24,48,and 72 h was assessed by CCK-8 assay,and the expression levels of downstream CXCR4,CXCR7 and MMP9 at 72 h were detected by Western blotting. CXCR4 siRNA and CXCR7 siRNA were used to inhibit CXCR4 and CXCR7 expression,respectively. Then,the effect of 20 ng/m L CXCL12 on the proliferation of OPCs was assessed by CCK-8 assay,and the expression levels of downstream CXCR4,CXCR7 and MMP9 at 72 h were detected by Western blotting. MMP9 siRNA was used to inhibit MMP9 expression,and the effect of 20 ng/m L CXCL12 on proliferation of OPCs was assessed by CCK-8 assay. Results Certain concentration range of CXCL12 significantly promoted the proliferation of OPCs,and enhanced the expression levels of CXCR4,CXCR7 and MMP9. Compared with 0 ng/m L CXCL12,20 ng/m L CXCL12 treatment for 72 h significantly promoted the proliferation of OPCs and the expression levels of CXCR4,CXCR7 and MMP9（ P〈0. 05）. After inhibiting CXCR4 and CXCR7 expression,the proliferation of OPCs was inhibited,and the MMP9 expression was also significantly reduced（ P〈0. 05）. After inhibiting MMP9 expression,the proliferation of OPCs was inhibited（ P〈0. 05）. Conclusion CXCL12 can significantly promote the proliferation of OPCs through promoting CXCR4,CXCR7 and MMP9 expression,which provides an experimental foundation for OPCs transplantation therapy of spinal cord injury（ SCI）.