Molecular biological analysis of coronary spasm

冠状动脉痉挛是日本人缺血性心脏病的常见原因。我们最近报道了氧化应激参与冠状动脉痉挛的发病机制，并且这种疾病具有遗传危险因素。通过对冠状动脉痉挛患者内皮型一氧化氮合酶（eNOS）基因的遗传学分析，发现eNOS基因第7外显子存在Glu 298 Asp错义突变，<-786>5 '端侧翼区存在T^ →C突变，提示eNOS基因的突变与冠状动脉痉挛密切相关，通过功能分析，发现eNOS基因的突变不仅是冠状动脉痉挛的标志物，而且存在功能异常。在T^<-786>→C突变中，转录因子，复制蛋白A-1（RPA-1）与变异序列结合，减少eNOS基因的转录。此外，关于Glu 298 Asp，已经阐明了细胞内加工因野生型蛋白质和突变型蛋白质而不同;突变型蛋白质倾向于在细胞内裂解。这一结果表明 关于我们 鉴于另一个多态性内含子4 b/a与白种人缺血性心脏病有关，我们对所有这些突变进行了连锁分析。我们发现内含子4 b/a与T^<-786>→C突变相关，提示T^<-786>→C突变是内含子4a等位基因功能特征的基础，并对T^<-786>→C和Glu 298 Asp突变与其他心血管疾病的相关性研究进行了综述。每种突变都与心肌梗死相关;此外，T^<-786>→C突变与冠状动脉无器质性狭窄的心肌梗死密切相关。我们注意到Glu 298 Asp突变与原发性高血压显著相关，尽管T^<-786>→C突变与原发性高血压无关。我们还报道了Glu 298 Asp与重度先兆子痫相关，表明eNOS基因突变与一些具有潜在氧化应激的疾病相关。少

Coronary spasm is a common cause of ischemic heart disease in Japanese. We have recently reported that oxidative stress is involved in the pathogenesis of coronary spasm, and that this disorder has genetic risk factors. By genetic analysis of endothelial nitric oxide synthase (eNOS) in coronary spasm patients, we found a missense Glu298Asp mutation in exon 7 and a T^<-786>→C mutation in the 5'-flanking region, and concluded that the mutations are significantly associated with coronary spasm.By functional analysis, we revealed that each mutation was not merely a maker of coronary spasm, but showed functional abnormality. In the T^<-786>→C mutation, a transcription factor, a replication protein A-1 (RPA-1) binds to the variant sequence, reducing transcription of the eNOS gene. Also, regarding Glu298Asp, it has been clarified that intracelluar processing differs by the wild type protein and the mutant type one ; the mutant protein is tended to be cleaved within a cell. This result suggest … More s that the Glu298Asp variant itself results in functional abnormality.As it has been reported that another polymorphism, intron 4b/a, is linked to ischemic heart disease in Caucasians, we did a linkage analysis of all these mutations. We found that intron 4b/a is linked to the T^<-786>→C mutation, suggesting that the T^<-786>→C mutation underlies the functional characteristic of the intron 4a allele.We have also reviewed association studies, of the T^<-786>→C and Glu298Asp mutations, with other cardiovascular diseases. Each mutation was associated with myocardial infarction ; further, the T^<-786>→C mutation was strongly associated with myocardial infarction without organic stenosis in coronary arteries. We noted that the Glu298Asp mutation was significantly associated with essential hypertension, although the T^<-786>→C mutation was not. We have also reported that Glu298Asp is associated with severe preeclampsia, suggesting that eNOS gene mutations are associated with some diseases having underlying oxidative stress. Less