Wu Zhi-jie, Feng Hu-yi, Li De-wei, Shi De, Zheng Shu-sen
Department of General Surgery, First Affiliated Hospital, Zhejiang University, Hangzhou 310012, China.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2005 Mar;21(2):213-7.
To observe the effects of local transfection of tissue-type plasminogen activator(tPA) gene on intimal hyperplasia of right external iliac artery in rabbits after operation injury, and its possible mechanism.
Microsurgery injury was used to establish the intimal injury model of right external iliac artery in rabbits. 105 male New zealand rabbits were randomly divided into 3 groups (35 rabbits each group). Group A was normal saline control group, group B was pBudCE4.1-transfected group, and group C was pBudCE4.1/tPA-tansfected group. The normal saline, pBudCE4.1 and pBudCE4.1/tPA transfection solutions were injected into injured vessel walls. Each group was again divided into five subgroups (7 rabbits each subgroup) which were sacrificed at different time (2 d, 3 d, 7 d, 14 d and 28 d after operation). The injured vascular specimens were then harvested for pathologic examination, electron microscope observation, RT-PCR and immunohistochemical staining detection.
The intimal thickness and area of vessel walls in group C at every time points after operation were significantly less than those in group A and group B (P<0.01). The stenosis rate of vessels in group C at 28 days after operation decreased by 51.5% and 54.2%, respectively, as compared with groups A and B. The expression of tPA mRNA in group C was significantly higher than that in groups A and B at every time points after operation (P<0.01), reaching the peak at 7 days. The scanning electron microscope examination showed that there were a few thrombocytes adhering to vessel walls in group C but no thrombus, whereas a lot of thrombocytes and thrombi on vessel walls in groups A and B. Immunohistochemical staining exhibited that platelet-derived growth factor (PDGF)-positive cells in the vessels of group C were significantly more than those in group A and B (P<0.01).
Local transfection of tPA gene can inhibit hyperplasia of neo-intima and prevent restenosis, which is proof of concept for gene therapy of intimal hyperplasia.
观察组织型纤溶酶原激活剂（tPA）基因局部转染对兔髂外动脉术后损伤内膜增生的影响及其可能机制。
采用显微手术损伤建立兔髂外动脉内膜损伤模型。105只雄性新西兰兔随机分为3组（每组35只）。A组为生理盐水对照组，B组为pBudCE4.1转染组，C组为pBudCE4.1/tPA转染组。将生理盐水、pBudCE4.1和pBudCE4.1/tPA转染液注入损伤血管壁。每组再分为5个亚组（每组7只），于术后不同时间（术后2 d、3 d、7 d、14 d和28 d）处死。然后采集损伤血管标本进行病理检查、电镜观察、RT-PCR和免疫组化染色检测。
术后各时间点C组血管内膜厚度及血管壁面积均显著小于A组和B组（P<0.01）。术后28 d，C组血管狭窄率分别较A组和B组降低51.5%和54.2%。术后各时间点C组tPA mRNA表达均显著高于A组和B组（P<0.01），7 d时达峰值。扫描电镜检查显示，C组血管壁有少量血小板黏附但无血栓形成，而A组和B组血管壁有大量血小板及血栓形成。免疫组化染色显示，C组血管中血小板衍生生长因子（PDGF）阳性细胞显著多于A组和B组（P<0.01）。
tPA基因局部转染可抑制新生内膜增生，预防再狭窄，为内膜增生的基因治疗提供了概念验证。
