【摘要】 目的探讨野生型p53基因对血管平滑肌细胞(VSMC)的促凋亡作用在构建动脉粥样硬化(As)不稳定斑块动物模型中的价值。方法54只雄性新西兰纯种兔用球囊损伤腹主动脉+高脂喂养10周,于8周末随机分成A组(p53基因组,27只)和B组(LacZ基因组,27只),在腹主动脉斑块形成处分别转染携带野生型p53基因或LacZ基因的重组腺病毒载体;2周后,A组和B组各处死10只,观察斑块的自发破裂情况。然后两组剩余实验兔给予中国斑点蝰蛇毒(CRVV)和组胺药物触发,比较两组发生斑块破裂的发生率。应用免疫组织化学染色、流式细胞仪、原位末端脱氧核苷酸转移酶介导的缺口末端标记法(TUNEL)及电镜检测基因转染部位的平滑肌细胞的凋亡情况。结果A组TUNEL测定的凋亡阳性细胞率显著高于B组(分别为2.5%±0.8%,1.0%±0.3%,P<0.05),流式细胞仪测定的细胞凋亡率亦明显高于B组(分别为20.04%±6.20%,6.89%±1.20%,P<0.01);电镜结果显示胞核中异染色体边聚明显,凋亡小体多见;斑块中的VSMC显著减少,纤维帽变薄以及纤维帽/内中膜厚度明显少于B组(纤维帽厚度分别为132.9±56.7,181.8±59.7,P<0.05;纤维帽/内中膜厚度0.20±0.18,0.21±0.11,P<0.05),药物触发后斑块破裂的发生率显著高于B组(分别为85.7%,23.1%,P<0.01)。结论外源性人野生型p53基因转染As家?更多还原

【Abstract】 AIM: To study the apoptotic role of wild-type p53 in induction of plaque instability in atherosclerotic rabbits. METHODS: Fifty-four New Zealand White rabbits underwent balloon-induced abdominal aortic wall injury and then were fed on a diet of 1% cholesterol. At the end of the eighth week, the rabbits were randomly divided into two groups: group A and group B. Recombinant adenovirus carrying p53 and β-galactosidase (LacZ) genes were injected in group A and B, respectively. Two weeks later, 10 rabbits each in group A and B was killed and the remaining rabbits all underwent pharmacological triggering with injection of Chinese Russell’s viper venom and histamine. RESULTS: Compared with group B, p53 gene over-expression in group A resulted in a marked increase in number of positive apoptotic cells (2.5%±0.8% vs 1.0%±0.3%, P<0.05) and a significant decrease in vascular smooth muscle cells (47.5%±6.8% vs 80.4%±10.6%, P<0.01), the thickness of the fibrous cap [(132.9±56.7)μm vs (181.8±59.7) μm, P<0.05] and the cap/intima-media ratio (0.20±0.18 vs 0.21±0.11, P<0.05). CONCLUSION: Transfer of human wild-type p53 genes effectively promotes apoptosis of VSMCs in atherosclerotic plaques, which makes the plaques vulnerable to rupture.更多还原