摘要
目的应用重组腺相关病毒2型载体(recombinant adenovirus-associated virus2,rAAV2)介导血管内皮生长因子165(vascular endothelial growth factor,VEGF165)基因转染,观察其促进小型猪慢性缺血心肌血管生成并改善心肌血流灌注和心功能的有效性。方法小型猪左冠状动脉回旋支(LCX)放置血管缩窄环,建立慢性心肌缺血模型。5周后行心电图、冠状动脉造影和心脏核磁共振成像检查确认LCX闭塞或相应心肌的缺血。动物随机分为实验组和对照组,每组8只,分别在心肌内直接注射rAAV2-VEGF165(1×1012virus genome)或磷酸盐缓冲液。治疗后3个月和6个月,观察心肌VEGF mRNA和蛋白的表达;6个月后,观察心肌毛细血管和小动脉密度,行冠状动脉造影进行LCX血流分级,应用心脏核磁共振成像观察心肌灌注及左心室功能。结果放置血管缩窄环后5周,所有动物均出现LCX完全/次全闭塞或LCX支配区域的心肌缺血。基因治疗后3个月,实验组心肌VEGF mRNA和蛋白表达显著高于对照组;6个月时,实验组VEGF表达水平较3个月时下降。基因治疗后6个月,VEGF组心肌毛细血管密度和小动脉密度[分别为(1404.06±250.48)/mm2和(167.81±36.29)/mm2]均高于对照组[分别为(976.88±344.79)/mm2和(116.56±34.48)/mm2](P<0.05);潘生丁负荷后心肌灌注成像显示VEGF组心肌灌注明显优于对照组(P<0.05),且较治疗前有改善(P<0.05);两组左心室功能在治疗前后均无明显变化。结论在小型猪慢性心肌缺血模型中,心肌内注射rAAV2-VEGF165后外源VEGF基因的表达至少可持续3个月;rAAV2-VEGF165能够促进缺血心肌毛细血管和小动脉生成并改善心肌灌注。
and six months after therapy, the animals were evaluated with regard to expression of VEGF165. Capillary density and arteriole density of the ischemic myocardium, coronary angiography, myocardial perfusion and left ventricular function were also assessed six months after therapy. Results Five weeks after aneroid occluder implantation, all the animals demonstrated complete or nearly complete occlusion of LCX and perfusion deficiency in LCX territory. Three months after therapy, expression of VEGF165 mRNA and protein were higher in the VEGF than control group. The difference between the two groups diminished after six months. There was significant increase in capillary density（ 1404. 06 ± 250.48/mm^2 vs 976. 88 ± 344. 79/ mm^2 ,P 〈 0.05 ） and arteriole density （ 167.81± 36. 29/mm^2 vs 116. 56 ± 34.48/mm^2 , P 〈 0. 05 ） in VEGF group compared with control. Comparison of myocardial perfusion demonstrated marked differences between the two groups with significant improvement in animals treated with rAAV2-VEGF165,No significant improvement in left ventricular function was seen in either the VEGF or control group. Condusions Transmyocardial delivery of rAAV2-VEGF165 resulted in VEGF gene expression for at least three months and stimulated angiogenesis and arteriogenesis in porcine model of chronic myocardial ischemia. Myocardial perfusion was also improved after VEGF gene delivery.
出处
《中华心血管病杂志》
CAS
CSCD
北大核心
2005年第8期732-737,共6页
Chinese Journal of Cardiology
基金
国家高技术研究发展计划(863计划)资助项目(2002AA2Z3324)
