Napoli Claudio, de Nigris Filomena, Welch John S, Calara Federico B, Stuart Robert O, Glass Christopher K, Palinski Wulf
Department of Medicine, University of California San Diego, La Jolla, Calif 92093, USA.
Circulation. 2002 Mar 19;105(11):1360-7. doi: 10.1161/hc1102.106792.
Maternal hypercholesterolemia during pregnancy is associated with markedly enhanced fatty streak formation in human fetal aortas and accelerated progression of atherosclerosis in normocholesterolemic children.
To establish the causal role of maternal hypercholesterolemia in a genetically homogeneous murine model and to test the hypothesis that pathogenic events during fetal development result in persistent changes in arterial gene expression, female LDL receptor-deficient (LDLR(-/-)) mice were fed regular chow or high-fat diets supplemented with 0.075% or 1.25% cholesterol during pregnancy. Lesion sizes were determined in the aortic origin of their chow-fed offspring at 3 months. Maternal hypercholesterolemia more than doubled lesion sizes in male offspring (P<0.0001 for the 0.0075% cholesterol group). Microarray analysis of the expression of 11 000 murine genes in the nonatherosclerotic descending aorta by Affymetrix gene chips suggested that 139 genes were significantly regulated in offspring of hypercholesterolemic mothers. A subset of 12 of the upregulated transcripts was subjected to secondary analysis by semiquantitative PCR of pooled RNA and 4 genes were found to be upregulated >1.7-fold. Quantitative PCR for one of these genes using RNA from individual mice yielded similar results. Comparative immunostaining for several of the above genes also indicated increased protein content in offspring of hypercholesterolemic mothers.
These findings establish an atherogenic effect of maternal hypercholesterolemia in genetically uniform mice and indicate that changes in aortic gene expression persist long after fetal exposure to hypercholesterolemia. In addition to elucidating pathogenic mechanisms initiated during fetal development, this approach may identify genes in morphologically normal arteries that influence the susceptibility to classical risk factors of atherosclerosis.
孕期母体高胆固醇血症与人类胎儿主动脉中脂肪条纹形成显著增加以及正常胆固醇水平儿童动脉粥样硬化进展加速有关。
为了在基因同质的小鼠模型中确定母体高胆固醇血症的因果作用，并检验胎儿发育期间的致病事件导致动脉基因表达持续变化这一假设，在孕期给雌性低密度脂蛋白受体缺陷（LDLR(-/-)）小鼠喂食常规饲料或添加0.075%或1.25%胆固醇的高脂饮食。在3个月时测定其喂食普通饲料的后代主动脉起始处的病变大小。母体高胆固醇血症使雄性后代的病变大小增加了一倍多（0.0075%胆固醇组P<0.0001）。通过Affymetrix基因芯片对非动脉粥样硬化降主动脉中11000个小鼠基因的表达进行微阵列分析表明，高胆固醇血症母亲的后代中有139个基因受到显著调控。对上调转录本中的12个进行了二次分析，通过对混合RNA进行半定量PCR，发现4个基因上调超过1.7倍。使用来自个体小鼠的RNA对其中一个基因进行定量PCR得到了类似结果。对上述几个基因进行比较免疫染色也表明，高胆固醇血症母亲的后代中蛋白质含量增加。
这些发现证实了母体高胆固醇血症在基因一致的小鼠中的致动脉粥样硬化作用，并表明胎儿暴露于高胆固醇血症后很长时间，主动脉基因表达的变化仍然持续。除了阐明胎儿发育期间启动的致病机制外，这种方法还可能识别形态正常动脉中影响对动脉粥样硬化经典危险因素易感性的基因。
