直接心肌内注射血管内皮生长因子基因对慢性缺血心肌侧枝循环生成的影响

Direct myocardial injection of recombinant adeno-associated viral vector 2-mediated VEGF_(165) gene induces neovascular formation in chronic ischemic swine myocardium

目的观察血管内皮生长因子基因(rAAV2-hVEGF165)直接心肌内注射促进慢性缺血心肌侧枝循环生成的作用。方法小型猪左冠状动脉回旋支放置血管缩窄环,建立慢性心肌缺血模型。5周后应用心电图、冠脉造影和心脏核磁共振成像确认左回旋支闭塞或相应心肌的缺血。动物随机分为实验组和对照组,分别在缺血心肌内直接注射rAAV2-VEGF165(1×1012virus genomeml)或同等量的磷酸盐缓冲液或rAAV2-LACZ(1×1012virus genomeml)。治疗后6个月,冠状动脉造影了解有无侧枝循环生成。结果放置血管缩窄环后5周,所有动物均出现左回旋支完全、次全闭塞和旋支供血区域的心肌缺血。治疗后3个月,缺血心肌内可检测到LACZ和VEGF蛋白的阳性表达;治疗后6个月,VEGF组缺血心肌内毛细血管和小动脉密度均高于对照组(P<0.05);结论直接在小型猪慢性缺血心肌内注射rAAV2-VEGF165,VEGF165基因可转染入心肌组织内,并可在缺血部位显著促进侧枝循环形成。

Objective To study the efficiency of rAAV2 mediated vascular endothelial growth factor165 gene in inducing angiogenesis and arteriogenesis by direct myocardial injection, improving the growth of side branch vessels in a swine chronic myocardial ischemic model. Methods Chinese experimental minipigs underwent placement of a left circumflex artery ameroid constrictor. Five weeks later, electrocardiogram, coronary angiogaphy and magnetic resonance imaging were performed to confirm occlusion of LCX and ischemia of myocardium in LCX territory. Then the animals were randomized to receive with rAAV2-VEGF165（ 1 × 10^12virus genome） or PBS or rAAV2-LACZ（ 1 × 10^12virus genome） ,both by direct myocardial injection. Coronary angiography were performed six months after therapy, Capillary density and arteriole density of the ischemic myocardium were evaluated also. Results Five weeks after artery ameroid constrictor implantation,all the animals demeustrated complete or near-complete occlusion of LCX and peffusion deficiency in LCX territory. Three months after experiment,LACZ was positive in the ischemic myocardium. There was significant increase in capillary density and arteriole density in VEGF group compared with control.There were more side branch vessels formed in animals treated with rAAV2-VEGF165, compared with control. Condusion Direct myocardial injection of recombinant Adeno-Associate Viral Vector2-Mediated VEGF165 gene could deliver rAAV2-VFGF165 to myocardium and stimulated angiogenesis and arteriogenesis in porcine model of chronic myocardial ischemia.