Coronary-Heart-Disease-Associated Genetic Variant at the COL4A1/COL4A2 Locus Affects COL4A1/COL4A2 Expression, Vascular Cell Survival, Atherosclerotic Plaque Stability and Risk of Myocardial Infarction.
Coronary-Heart-Disease-Associated Genetic Variant at the COL4A1/COL4A2 Locus Affects COL4A1/COL4A2 Expression, Vascular Cell Survival, Atherosclerotic Plaque Stability and Risk of Myocardial Infarction.
复制标题
COL4A1/COL4A2 位点的冠心病相关遗传变异影响 COL4A1/COL4A2 表达、血管细胞存活、动脉粥样硬化斑块稳定性和心肌梗死风险
DOI：
10.1371/journal.pgen.1006127
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发表时间：
2016-07
期刊：
影响因子：
4.5
通讯作者：
Ye S
中科院分区：
文献类型：
--
作者：
Yang W;Ng FL;Chan K;Pu X;Poston RN;Ren M;An W;Zhang R;Wu J;Yan S;Situ H;He X;Chen Y;Tan X;Xiao Q;Tucker AT;Caulfield MJ;Ye S
全基因组关联研究揭示了冠心病（CHD）与染色体13 q34上的遗传变异之间的关联，其中位于该基因组区域的COL 4A 2基因中的前导单核苷酸多态性rs 4773144。我们研究了这种遗传变异的功能效应。对不同个体的血管平滑肌细胞（SMC）和内皮细胞（EC）原代培养物的分析显示，COL 4A 2和COL 4A 1表达水平在rs 4773144基因型之间存在差异，G/G基因型最低，A/G基因型居中，A/A基因型最高。染色质免疫沉淀，其次是等位基因不平衡测定的原代培养的SMC和EC的A/G基因型显示，G等位基因具有较低的转录活性比A等位基因。电泳迁移率变动分析和荧光素酶报告基因分析表明，包含rs 4773144位点的短DNA序列与核蛋白相互作用，G等位基因的效率较低，并且G等位基因序列在驱动报告基因表达方面具有较低的活性。对不同个体培养的平滑肌细胞的分析表明，G/G基因型的细胞具有较高的凋亡率。不同个体的离体动脉粥样硬化冠状动脉的免疫组织化学和组织学检查显示，G/G基因型的动脉粥样硬化斑块具有较低的IV型胶原丰度和较薄的纤维帽，这是不稳定的、易破裂斑块的标志。一项对血管造影证实的冠心病患者队列的研究显示，G/G基因型患者的心肌梗死发生率较高，心肌梗死是一种常由斑块破裂引起的表型。这些结果表明，CHD相关的基因变异在COL 4A 2基因座影响COL 4A 2/COL 4A 1的表达，SMC的生存，动脉粥样硬化斑块的稳定性，提供了一个机制解释之间的关联遗传变异和CHD风险。
Genome-wide association studies have revealed an association between coronary heart disease (CHD) and genetic variation on chromosome 13q34, with the lead single nucleotide polymorphism rs4773144 residing in the COL4A2 gene in this genomic region. We investigated the functional effects of this genetic variant. Analyses of primary cultures of vascular smooth muscle cells (SMCs) and endothelial cells (ECs) from different individuals showed a difference between rs4773144 genotypes in COL4A2 and COL4A1 expression levels, being lowest in the G/G genotype, intermediate in A/G and highest in A/A. Chromatin immunoprecipitation followed by allelic imbalance assays of primary cultures of SMCs and ECs that were of the A/G genotype revealed that the G allele had lower transcriptional activity than the A allele. Electrophoretic mobility shift assays and luciferase reporter gene assays showed that a short DNA sequence encompassing the rs4773144 site interacted with a nuclear protein, with lower efficiency for the G allele, and that the G allele sequence had lower activity in driving reporter gene expression. Analyses of cultured SMCs from different individuals demonstrated that cells of the G/G genotype had higher apoptosis rates. Immunohistochemical and histological examinations of ex vivo atherosclerotic coronary arteries from different individuals disclosed that atherosclerotic plaques with the G/G genotype had lower collagen IV abundance and thinner fibrous cap, a hallmark of unstable, rupture-prone plaques. A study of a cohort of patients with angiographically documented coronary artery disease showed that patients of the G/G genotype had higher rates of myocardial infarction, a phenotype often caused by plaque rupture. These results indicate that the CHD-related genetic variant at the COL4A2 locus affects COL4A2/COL4A1 expression, SMC survival, and atherosclerotic plaque stability, providing a mechanistic explanation for the association between the genetic variant and CHD risk.