VEGF基因修饰MSCs移植对脑梗死大鼠血管源性机制的实验研究

Experimental Study on the angiogenesis of Transplantation of VEGF Gene-modified Mesenchymal stem cells after Cerebral Infarction in Rats

目的观察经尾静脉注射携带VEGF基因的MSCs移植对脑梗死模型大鼠血管生成方面的影响。方法采用直接贴壁全骨髓法分离纯化MSCs,通过脂质体转染技术将pIRES2-EGFP-VEGF导入MSCs,另采用改良Zea Longa线栓法将40只SD大鼠制成左侧大脑中动脉栓塞/再灌注模型,并随机分4组:VEGF-MSCs组、MSCs组、PBS组、Model组;造模24 h后Model组不做处理,前3组大鼠分别经尾静脉注射1 ml VEGF-MSCs、MSCs、PBS悬液;细胞移植7d后用免疫组织化学法测定脑梗死周围Ang-2、CD34的表达水平。结果 VEGF-MSCs组和MSCs组Ang-2、CD34阳性表达水平较PBS组、Model组高(P<0.05),且VEGF-MSCs组较MSCs组更高(P<0.05);Model组与PBS组差异不明显(P>0.05)。结论经尾静脉注射携带VEGF基因的MSCs移植入MCAO模型大鼠可以促进缺血脑组织新生血管的形成,其机制可能为VEGF上调缺血周边区域Ang-2、CD34的表达水平。

To survey the angiogenesis of intravenous transplantation of VEGF genemodified Mesenchymal stem cells （MSCs） in rats after Cerebral Infarction. Methods To abstract and purify MSCs from bone marrow, pIRES2-EGFPVEGFA transfected MSCs with lipofectamine 2000. The rat model of focal cerebral ischemia was established with the left middle cerebral artery suture occlusion （MCAO） method and reperfused with suture extracted after MCAO 90 rains. Rats were randomly divided into VEGFMSCs group, MSCs group, PBS group and Model group; lml VEGF genemodified MSCs, MSCs and PBS were injected respectively through tail vein on the next day after ischemia. Then 7d after transplantation, the expressions of Ang 2 and CD34 in cortex around cerebral infarction zone were detected through immunohistochemistry. Results The expressions of Ang-2 and CD34 in cortex around cerebral infarction were detected through immunohistochemistry after transfecting. Compared with PBS group and Model group, the expressions of VEGFMSCs group and MSCs group were higher （P〈0. 05）, and the group of VEGF-MSCs was much higher than the MSCs group （P〈0. 05） PBS group and Model group have no statistical significance（P〈0. 05）. Conclusions Intravenous transplantation of VEGF genemodified MSCs in rats after cerebral infarction can elevate the expression of Ang-2 and facilitate angiogenesis.