同种异体骨髓间质干细胞移植联合VEGF基因转染治疗心肌梗死的实验研究

Experimental study of allogenetic bone marrow mesenchymal stromal cells transplantation combining with vascular endothelial growth factor gene therapy on rat infracted myocardium

目的:探讨同种异体骨髓间质干细胞(BMSCs)移植联合血管内皮生长因子(VEGF)基因转染对大鼠急性心肌梗死血管再生和心功能的影响。方法:体外分离、纯化、培养大鼠BMSCs,以BrdU标记细胞;制备、抽提、纯化质粒PAdTrack/VEGF165。结扎冠状动脉建立急性心肌梗死模型2周后,随机将其分为4组(n=12),进行心肌内BMSCs移植和/或VEGF165转染,组Ⅰ:BMSCs移植+VEGF165转染;组Ⅱ:BMSCs移值;组Ⅲ:VEGF165转染;组Ⅳ:DMEM注射作为对照组。4周后行免疫组化和超声心动图检查。结果:组Ⅰ和组Ⅱ梗死及缺血心肌处可见大量BrdU标记的移植细胞,其中缺血心肌处部分移植细胞分化为血管内皮细胞并形成新生毛细血管。Ⅷ因子染色阳性的新生血管密度分布为组Ⅰ>组Ⅲ>组Ⅱ>组Ⅳ(P均<0.01)。细胞移植和基因转染治疗后室壁厚度和室壁运动幅度改善,EF值增加幅度(△EF)组Ⅰ>组Ⅱ>组Ⅲ>组Ⅳ(P均<0.01)。结论:同种异体骨髓间质干细胞移植联合VEGF基因转染能进一步增强大鼠梗死缺血区血管再生、改善室壁厚度和心功能,有利于心肌梗死后的康复。

Objiective.To investigate the effects of allogenetie bone marrow mesenchymal stromal cells（BMSCs） transplantation combining with vascular endothelial growth factor（VEGF） gene therapy on myocardial angiogenesis and cardiac performance in rats with myocardium infraction. Method：BMSCs were isolated and cultured in rats in vitro, and VEGF165 plasmid were made. Rats were randomly divided into four groups （n=12 in each group）： BMSCs implantation and VEGF transfection group,BMSCs implantation, VEGF transfection group,control group. Two weeks after left anterior descending artery ligated to create myocardial infarction, BMSCs labeled with BrdU and /or VEGF165 were injected into the infarctd and ischemia mvocardium. Four weeks later, samples were examined with immune histochemistry staining and cardiac performance were assessed using echocardiography. Result：Most donor cells labeled with BrdU could be identified in host hearts, and some cells were incorporated into the coronary capillaries outside the infracted region. After both BMSCs implantation and VEGF165 transfection, the capillary density was the highest among the four groups （P〈0.01,respeetively）,the myocardium thickness and movement were improved, and the cardiac ejection fraction was enhanced to the most extent. Conclusion：Allogenetic BMSCs implantation combining with VEGF gene therapy can enhance the efficacy of BMSCs implantation in promoting rat myocardial angiogenesis and in improving its cardiac performance.