联合转染血管内皮生长因子165和组织纤溶酶原激活物基因抑制兔血管损伤后内膜增生的研究

To study the effects of local co-transfection vascular endothelial growth factor165 and tissue-type plasminogen activator genes on inhibiting intimal hyperplasia after operation injury artery in rabbits

目的观察血管局部联合转染血管内皮生长因子165(VEGF165)和组织纤溶酶原激活物(tPA)基因对损伤动脉内膜增生的影响并探讨可能机制。方法采用显微外科手术方法建立兔动脉损伤模型;用微注射装置将基因转染液注入损伤血管壁,按实验终点(术后2d、1周、2周、4周和8周)分为5个亚组(每个亚组8只兔);术后各实验终点取损伤段血管用于病理学检测、电镜观察、RTPCR和免疫组织化学检查。结果术后各时间点基因转染组血管壁的VEGF165基因的mRNA表达量和tPA阳性细胞数明显高于对照组(P<0.01)。与对照组比较,术后各时间点基因转染组血管内膜面积和狭窄率均显著减小(P<0.01),术后8周时基因转染组管腔狭窄率比对照组降低了59.0%。结论局部联合转染VEGF165和tPA基因可抑制血管新生内膜增生及血管再狭窄。

Objective To observe the effects of local co-transfection vascular endothelial growth factor165 (VEGF165) and tissue-type plasminogen activator genes on inhibiting intimal hyperplasia and restenosis in rabbits artery after operation injury and possible mechanisms. Methods Micrology operation injury was used to establish the model of intimal injury of right external iliac artery in rabbits. To select 120 male New Zealand rabbits and were randomly divided into 3 groups(n=40,in each group): Group A(physiological brine control group), Group B(pBudCE4.1 group), Group C(pBudCE4.1/VEGF165-tPA group). The vas-wall of micrology operation injury were infused respectively physiological brine, pBudCE4.1 and pBudCE4.1/VEGF165-tPA transfection solution by micro-injector. Each group were divided into 5 subgroups(n=8,in each subgroup) randomly according to the sacrifice times(2 d, 1 week, 2 week, 4 week and 8 week after operation). The injured vascular specimen were harvested for pathology test, electric microscopy study, reverse transcripition-PCR examining and immunochemisty detecting. Results The intimal area and narrow ratio of vases in Group C at every time point after operation were significantly lessened than that in Group A and Group B(P<0.01). The narrow ratio of vases in Group C at 8 week after operation were decreased respectively by 57.9% and 59.0% than that in Group A and B. The expression of VEGF165 mRNA in Group C were increased significantly than that in GroupA and B at every time point after operation(P<0.01), the expression reached the peak at 1 week and continued to 4 week after operation. Immunohistochemical identified that tPA positive cell in Group C were significantly increased than that in Group A and B(P<0.01) at every time point after operation. Conclusion Local co-transfection VEGF165 and tPA genes could restrain intimal hyperplasia and restenosis of vas, which lay a foundation for future multi-gene therapy of vascular intimal hyperplasia.