人血管内皮生长因子裸质粒DNA心肌注射促进缺血心肌侧支循环形成的研究

Gene therapy with naked DNA encoding vascular endothelial growth factor enhances collateral circulation in ischemic myocardium

目的 :观察人血管内皮生长因子 (h VEGF)裸质粒 DNA直接心肌注射对大鼠急性心肌缺血后侧支循环形成的影响。方法 :建立大鼠左冠状动脉结扎的急性心肌缺血模型 ,取缺血边缘区以先期构建的真核表达质粒 pc DNA3/ h VEGF1 6 5和真核载体 pc DNA3的 DNA分别多点心肌注射。给药后 4周先行大鼠冠状动脉造影 ,再取材分别行苏木精 -伊红染色、平滑肌肌动蛋白 (SMA)染色和 Northern Blot分析。结果 :给药后 4周冠状动脉造影示治疗组左室造影剂聚集较对照组明显增加 ;SMA染色示治疗组新生血管数目明显多于对照组 ;Northern Blot分析显示治疗组 VEGF m RNA表达较对照组明显增强。结论 :pc DNA3/ h V EGF1 6 5裸质粒 DNA心肌注射能转染心肌细胞并持续表达至少 4周 。

Objective:To determine whether direct intr am yocardial injection of naked DNA encoding for vascular endothelial growth factor could enhance collateral circulation in a mouse model of acute myocardial ische mia.Method:A mouse model of acute myocardial ischemia was made by ligation of left main coronary artery. The pcDNA 3/hVEGF 165 and pcDNA 3 were separately intramyocardial injected into the border zone of the ischemic myocardium. The coronary vessel was imaged by arotic root angiography at the end of 4-weeks. The left ventricular myocardium was taken for histologic studies a nd Northern Blot analysis.Result:Coronary angiography showed a pronounced accumulati on of contrast medium in left ventricular myocardium of the experimental group a s compared with that in the control group. SMA immunostaining confirmed that the densities of vessels in ischemic areas were obviously increased in experimental group than that in control group. Northern Blot analysis showed that the expres sion of hVEGF 165 mRNA in experimental group were up-regulated more than t hat in control group.Conclusion: pcDNA 3/hVEGF 165 can be intramyocardial transfected and continued to secrete bioactivity protein at least for 4-weeks and can promote angiogenesis and augment collateral vessel development in ischem ic myocardium.