兔动脉粥样硬化斑块稳定性与趋化因子的相关性研究

Correlation of RANTES and stability of rabbit atherosclerotic plaque

目的:研究调节激活正常T细胞表达和分泌趋化因子(RANTES)水平与家兔动脉粥样硬化斑块稳定性的关系。方法:40只雄性家兔随机分为4组:空白组、对照组、稳定斑块(AS)组和易损斑块(VAP)组,每组10只;空白组和对照组给予普通饲料喂养,AS组和VAP组给予高脂饮食喂养;16周后各组随机处死1只家兔,病理检查证实AS组和VAP组主动脉有粥样斑块形成,且VAP组和对照组于处死前24h和48h分别给予两次药物触发形成VAP。测定各组0周及16周处死前兔空腹血脂和血浆RANTES水平,Masson染色法计算校正斑块面积与易损指数评价斑块稳定性,免疫组织化学证实RANTES在组织斑块中表达,Western blot及RT-PCR测定斑块中RANTES的表达及转录水平,分别统计分析血浆RANTES水平、斑块中RANTES的表达和转录水平与两个斑块稳定性评价指标的相关性。结果:0周时,各组RANTES水平差异无统计学意义,16周后RAN-TES水平VAP组[(97.48±12.22)ng/ml]明显高于AS组[(45.01±8.54)ng/ml]、对照组[(24.88±5.22)ng/ml]和空白组[(25.01±4.45)ng/ml](均P<0.01);斑块的免疫组织化学染色、Western blot和RT-PCR结果均显示,VAP组斑块内RANTES的表达及转录水平明显高于其他3组(均P<0.01),AS组显著高于空白组及对照组(均P<0.01);斑块稳定性比较发现,VAP组校正斑块面积和易损指数均明显大于AS组[(63.47±13.49)︰(42.58±7.12),(2.65±0.63)︰(0.94±0.23);均P<0.01];相关性分析显示,对于VAP组和AS组,血浆RANTES和斑块局部RANTES转录及表达水平均与校正的斑块面积、易损指数呈明显正相关(P<0.05)。结论:无论是血浆还是斑块局部的RANTES水平,均与斑块稳定性有一定关系,RANTES可成为斑块破裂血管事件监测的可靠炎性指标。

Objective：To study the correlation between the level of regulated on activated normal T cell expressed and secreted（RANTES） and rabbit atherosclerotic plaque stability. Method：Forty male rabbits were randomly divided into 4 groups： blank group,control group,stable atherosclerotic plaque（AS） group and vulnerable atherosclerotic plaque（VAP） group,with 10 rabbits in each group.The blank and control group were given normal diet while the AS and VAP group were given high fat diet for 16 weeks.After 16 weeks,4 rabbits randomly selected from each group were executed for the pathologic examination of aorta to confirm atherosclerotic plaque formation in AS and VAP group.According to literature method pharmacological triggers inducing the vulnerable atherosclerotic plaque formation in the VAP group.Fasting blood was extracted at 0 week and the 16th week before executed,and serum lipids files and RANTES level were examined.The corrected plaque area and vulnerability index were calculated by Masson staining to evaluate the plaque stability.RANTES expression localizing in plaques was confirmed by immunohistochemical staining.Western blot and RT-PCR were used to determine the level of RANTES expression and transcription in plaques.The correlation between RANTES（the level in peripheral blood serum and the level of its expression and transcription in local tissue plaque） and plaque stability（the corrected plaque area and vulnerability index） were analysed by statistical method respectively. Result：The level of RANTES in VAP group [（97.48±12.22）ng/ml] was significantly increased comparing with AS group [（45.01±8.54）ng/ml],control group [（24.88±5.22）ng/ml） and blank group [（25.01±4.45）ng/ml]（both P〈0.01） after 16 weeks fed and pharmacological triggers.The results from immunohistochemical staining,Western blot and RT-PCR showed that the levels of the expression and transcription of RANTES in VAP group within the plaque were significantly increased comparing with other 3 groups（both P〈0.01）,and AS group was significantly increased omparing with blank and control group（both P〈0.01）.VAP group showed significant higher plaque area and vulnerability index than AS group [（63.47±13.49）︰（42.58±7.12）,（2.65±0.63）︰（0.94± 0.23）;both P〈0.01] by Masson staining.The levels of RANTES both in peripheral blood serum and its expre-ssion and transcription in local tissue plaque exhibited significantly positive correlation with the corrected plaque area and vulnerability index respectively by statistical analysis（P〈0.05）. Conclusion：The levels of RANTES both in peripheral blood serum and its expression and transcription in local tissue plaque have a certain positive correlation with plaque stability.RANTES could be a reliable inflammatory indicator for vascular events monitoring triggered by plaque rupture.