超声爆破微泡介导内皮抑素基因抑制兔颈动脉粥样硬化的实验研究

Experimental research on inhibition of carotid artery atherosclerosis induced by endostatin gene mediated by ultrasound targeted microbubble destruction in rabbits

目的 探讨利用超声爆破微泡介导内皮抑素（endostatin,ES）基因转染对兔颈动脉粥样硬化斑块内新生血管及斑块生长的抑制作用.方法 20只颈动脉粥样硬化模型兔随机分为三组：A组,微泡＋超声;B组,对照质粒＋微泡＋超声;C组,ES质粒＋微泡＋超声.建模2周行超声爆破微泡介导基因转染,间隔3周时重复转染1次.建模14周时行超声及数字减影血管造影（DSA）检查,病理检测病变血管新生内膜、斑块内新生血管及ES表达情况.结果 超声显示A组和B组内膜明显增厚,斑块较大,管腔明显狭窄,收缩期峰值流速（PSV）增加,C组上述指标明显较A组和B组低（P＜0.05）.病理检测C组内中膜厚度（IMT）、内膜厚度（IT）、内中膜厚度比（IT/MT）、内膜面积（IA）、内中膜面积比（IA/MA）及新生内膜狭窄率与A组和B组比较差异均有统计学意义（P＜0.05）.C组颈动脉新生血管及血管内皮生长因子（VEGF）表达均较A组和B组低,内膜及胫前肌可见较多ES表达,而A组和B组无明显ES表达.结论 一定超声辐照条件下,超声爆破微泡介导ES基因转染可抑制兔颈动脉粥样硬化病变的发展,有可能为动脉粥样硬化性疾病的基因治疗提供一种安全有效的方法 .

Objective To explore the inhibition effect on angiogenesis and plaque growth of carotid atherosclerosis by transfection of endostatin gene using microbubbles combined with ultrasound exposure.Methods Twenty rabbit models of carotid atherosclerosis were randomly divided into 3 groups：group A,microbubble＋ ultrasound; group B, control plasmid ＋ microbubble ＋ ultrsound; group C, ES plasmid ＋microbubble＋ ultrasound. Two weeks after surgery, ultrasound/microbubble mediated gene transfer was performed,and it was performed once again three weeks after the first transfection. Ultrasonography and digital subtraction angiography（DSA） were performed at the time of 14 weeks. The carotid arteries were taken to detect the neointima and angiogenesis, and the expression of endostatin was detected using pathological means. Results The imagings of ultrasound showed that the intima in group A and B were thick significantly with larger plaques, and the lumen became stenosis with the peak systolic velocity increasing,however,in group C,the parameters mentioned above were significantly less than those of group A and B （ P〈0.05）. Pathological results displayed that intima-media thickness （IMT）, intima thickness （IT）, intima thickness/media thickness （IT/MT）, intima area （IA）, intima area/media area （IA/MA） and neointimal stenosis rates were greater in group A and B, however, they were less in group C （ P〈0.05）.The number of neovascularization and vascular endothelial growth factor（VEGF） expression in group A and B were more than those of group C. There was more endostatin positive expression in carotid arteries and anterior tibial muscles of group C, while there was nearly no expression in group A and B. Conclusions Under the conditioned ultrasonic irradiation, ultrasound/microbubble mediated endostatin gene transfection can inhibit the development of carotid atherosclerosis in rabbits, which might provide a safe and effective strategy for gene therapy of atherosclerotic disease in future.