在小型猪模型由蛋白涂层金属支架局部转染尿激酶前体基因对冠状动脉再狭窄的影响

Intracoronary prourokinase gene transfer with protein coated stent prevents coronary restenosis in mini swine

目的 为了评估蛋白涂层金属支架局部转染尿激酶前体 (Pro UK)基因对冠状动脉内血小板沉积、早期血栓形成和平滑肌细胞增生的影响。方法 金属支架涂层为交联明胶制成。载体为复制缺陷的、携载Pro UK基因的重组腺病毒。采用标准球囊导管技术 ,将携带有Pro UK基因的蛋白涂层支架置入小型猪冠状动脉前降支中段 ,以相同方法置入单纯蛋白涂层支架或裸露支架做为对照。结果 支架置入后 3天 ,Pro UK基因转染血管段 (n =6) 111In标记血小板及扫描电镜显示 :血小板沉积和纤维蛋白形成明显少于对照血管 (P <0 0 5 )。在基因转染后 7天RT PCR(n =2 )和免疫组化染色(n =1)证实 ,有Pro UKmRNA的表达及Pro UK蛋白质生成。 3个月后冠状动脉造影显示 :Pro UK基因转染组 (n =4 )无再狭窄发生 ,而对照组 (n =8)均发生再狭窄 ,组织病理学形态分析结果显示 :在Pro UK基因转染组 (n =4 ) ,平均新生内膜厚度 ,新生内膜面积和百分狭窄面积均明显小于对照组 (n =8,P <0 0 5 )。结论 在再狭窄动物模型上 ,通过蛋白涂层支架 ,Pro UK基因在腺病毒载体介导下能被直接导入血管成形部位 ,并预防再狭窄的发生。

Objective To assess the effect of adenovirus mediated local prourokinase (Pro UK) gene transfer using protein coated metallic stents on platelet deposition, early thrombosis and smooth muscle cell proliferation after intracoronary stent implantation Methods The metallic stent was coated by cross linked gelatin A replication defective recombinant adenovirus carrying Pro UK gene was used The coated stents were mounted on 3 0 mm PTCA balloon and submersed into high titer Ad prourokinase viral stock (2×10 10 pfu/ml) for 3 minutes Protein coated stainless steel stents and bare stainless steel stents were used as controls All stents were implanted into the middle segment of LAD through 8F large lumen guiding catheter (The ratio of balloon to vessel diameter was 1 1 1 3:1) Results At the 3rd day after stenting, in comparison to control vessels ( n =6),there was less 111 In platelet deposition in Pro UK gene transferred vessels ( n =6, P <0 05) Scanning electron microscopy showed that platelet deposition and fibrin formation were significantly less than those in the control group ( n =6) At the 7 th day after stenting, RT PCR ( n =2) and immunohistochemical staining ( n =1) confirmed the expression of Pro UK mRNA and the presence of Pro UK protein at the site of gene transfer After 3 months of stenting coronary angiogram showed that in all animals with the coated stents loading and Pro UK gene ( n =4) no restenosis and thrombosis occurred, while in the control groups ( n =8) restenosis developed in all animals Meanwhile recanalized, organized thrombosis and old myocardial infarction in the anterior wall with aneurysm formation was revealed in 2 animals Morphometric analysis showed that in the Pro UK gene group ( n =4), mean neointimal thickness, neointimal area and mean percent area stenosis were significantly less than those in the control groups ( n =8, P <0 05) Conclusion (1)Restenosis animal model can be successfully produced by oversized stent (2) Protein coated stent can deliver locally adenovirus mediated Pro UK gene to stenting site and may prevent coronary restenosis