基因芯片检测apoE基因敲除小鼠动脉粥样硬化相关基因的表达节律

Expression rhythms of atherosclerosis related genes in apoE knockout mice by microarray

目的利用基因芯片筛选apoE-/-动脉粥样硬化小鼠心脏与主动脉内膜中可能受到生物钟调控的动脉粥样硬化基因,并研究其表达情况。方法采用apoE-/-小鼠建立动脉粥样硬化模型,以同品系C57BL/6J小鼠作为对照;使用动脉粥样硬化基因芯片检测在ZT0与ZT12处死的两种小鼠心脏与主动脉内膜中113个动脉粥样硬化相关基因的表达情况;应用Real-time PCR检测在心脏与主动脉内膜中表达均发生改变的ACE与MMP3的昼夜表达节律。结果饲以高脂膳食(含0.15%的胆固醇和21%的脂肪)4周的apoE-/-小鼠主动脉粥样斑块形成;apoE-/-动脉粥样硬化小鼠血清胆固醇与低密度脂蛋白明显高于对照组C57BL/6J小鼠,高密度脂蛋白则明显低于对照组;基因芯片结果显示apoE-/-动脉粥样硬化小鼠与C57BL/6J小鼠心脏与主动脉内膜动脉粥样硬化相关基因表达有较大差异,apoE-/-小鼠心脏与主动脉内膜分别有6个及10个基因在两个时间点表达均下调,此外,心脏与主动脉内膜中分别有15及12个原本在C57BL/6J小鼠表达随时间改变的基因在apoE-/-小鼠中不再随时间改变;Real-time PCR结果显示ACE与MMP3在对照组C57BL/6J小鼠心脏中具有昼夜节律,但在apoE-/-动脉粥样硬化小鼠中,这种表达节律消失,且表达水平降低。结论动脉粥样硬化相关基因表达节律发生改变,这可能在动脉粥样硬化的病理过程中发挥了重要作用,对其机制的研究对我们更好地认识这种心血管疾病将具有重要意义。

Purpose Using microarray to screen the atherosclerosis related genes which might be regulated by circadian clock, and to study their expression changes in apoE-/- atherosclerostic mice. Methods apoE-/- mice were used to establish the atherosclerosis model and C57BL/6J mice were used as control group. Oligo Atherosclerosis Microarray was used to detect the expression level of atherosclerosis related genes in the hearts and aorta intima of the two kinds of mice which were sacrificed at different time points： ZT0 and ZT12. Real-time PCR was used to detect the expression rhythms of ACE and MMP3 which lost expression changes at ZT0 and ZT12 in both the heart and aorta intima. Results After feeding a western type diet （containing 0.15% cholesterol and 21% fat） for 4 weeks, atherosclerotic lesions formed in the aortas of apoE -/- mice. The serum total cholesterol and LDL levels were significantly higher in apoE-/- mice than in C57BL/6J mice. Meanwhile, the HDL level of apoE -/- mice was significantly lower. The results of microarray showed that the expression profiles of atherosclerosis related genes in the heart and aorta intima were different in apoE-/- mouse compared with C57BL/6J mouse. Six genes in the heart and 10 genes in aorta intima showed decreased expres-sion levels in apoE-/- mice compared to apoE-/- mice. And 15 and 12 genes in the heart and aorta intima respectively which showed different expression levels at ZT0 and ZT12 in C57BL/6J mice did not have such differences in apoE-/- mice. We further used Real-time RCR to detect the expression rhythm of ACE and MMP3 and we found that the two genes showed circadian rhythms in C57BL/6J mice, but no such rhythms were found in apoE-/- mice. Conclusions The expression rhythms of atherosclerosis related genes change in apoE-/- mice, and these changes may play important roles in atherosclerosis. And further explore of the mechanisms underlying the phenomenon can help us to understand the cardiovascular disease.