基因学干预研究:血红素氧合酶1微卫星多态性表达水平上调的作用

Abstract

背景:人类血红素氧合酶1(Heme Oxygenase-1,HO-1)基因启动子区域有一双核苷酸(GT)n重复序列,有高度多态性,又称为微卫星多态性,体外实验表明通过测定GT重复次数可间接了解人体内HO-1的表达水平.目的:探讨HO-1基因启动子双核苷酸GT n重复序列的微卫星多态性与冠状动脉支架术后再狭窄的关系.设计:以接受冠状动脉支架置入术的冠心病患者为研究对象的病例对照研究.单位:一所大学医院的心内科病房.对象:研究对象为1996-04/2002-05北京大学第一医院心内科病房成功接受冠状动脉支架置入术的冠心病患者,共118例.纳入标准:支架术后3个月以上行冠状动脉造影随访的冠心病患者;排除标准:冠状动脉造影显示原靶病变管腔直径狭窄＜50%和冠状动脉造影随访时间＜3个月的冠心病患者.入选患者年龄(62±10)岁,男92例,女26例,所有患者均签署知情同意书.根据美国心肺血液协会的标准定义,将患者分为支架内再狭窄组与无再狭窄组,分别为68例和50例.方法:提取患者外周血DNA,经PCR扩增HO-1微卫星序列后采用Spreadex凝胶电泳来进行基因分型.主要观察指标:HO-1基因启动子微卫星基因型频率及其与再狭窄的关系. 结果:携带GT重复＜25次等位基因患者的再狭窄率为47.5%,携带两条GT重复均≥25次等位基因患者的再狭窄率为68.4%(P＜0.05).经多元回归分析校正冠心病危险因素及介入治疗的相关影响因素后,两组患者的再狭窄率差异仍有显著性意义(OR=0.418,95%可信区间0.197～0.887,P＜0.05).结论:HO-1基因启动子微卫星多态性与再狭窄相关,对冠心病患者冠状动脉支架置入术后的二级预防有十分重要的意义.

BACKGROUND: Heme oxygenase-1 (HO-1) promotor region has a pair of dinucleotide(guanosine thymidine, GT) repeats with a lengthy polymorphism, also named microsatellite polymorphism. Experiments in vitro have shown that we can indirectly learn about the level of gene transcription by measuring the number of GT repeats.OBJECTIVE: To investigate if an association exists between restenosis after percutaneous coronary intervention(PCI) and microsatellite polymorphism in HO-1 gene promoter.DESIGN: A case-control study based on the observation of the patients with coronary heart disease after undergoing coronary stenting.SETTING: Wards of the department of cardiology of a university hospital.PARTICIPANTS: A total of 118 patients were admitted from April 1996 to May 2002 at the Department of Cardiology of the First Hospital of Peking University who underwent successful coronary stenting. Inclusion criteria: The patients with coronary heart disease who underwent coronary stent implantation for more than 3 months now came to perform coronary angiography in follow-up. Exclusion criteria: Angiography showed that the stenosis of lumen in diameter in the patients with coronary heart disease was less than 50%and the follow-up in angiography was less than three months. There were 92males and 26 females aged(62±10) years old and the informed consents were obtained. The patients were divided into two groups according to the criteria stipulated by American Heart,Lung and Blood Association: in-stent restenosis(68 cases) and non-restenosis (50 cases).METHODS: DNA of the peripheral blood was isolated from the whole blood. The length of GT repeat was confirmed by PCR amplification and Spreadex Gel electrophoresis. Selected samples were sequenced with Sanger's method.MAIN OUTCOME MEASURES: Microsatellite gene frequency of HO-1promoter and its relationship with restenosis RESULTS: Patients with GT repeats <25 GT in the HO-1 gene promoter on either allele had significantly less often restenosis than patients without (47.5% vs. 68.4% ,P<0.05). After controlling some possible confound ing factorsfor coronary heart diseases, multivariate analysis indicated that still there was a significant difference between the two groups in restenosis rate(odd ratio 0. 418,95% CI: 0. 197 to 0. 887,P<0.05).CONCLUSION: The present study indicated that short(GT) n repeats of HO-1 gene promoter is associated with reduced post-PCI restenosis, which suggests the genetic contribution to in-stent restenosis after stent implantation. It may have important meanings to prevent the occurrence of restenosis.