CITED2基因CpG岛甲基化与先天性心脏病的关系

Relationship of CpG islands methylation of CITED2 and congenital heart disease

目的研究先天性心脏病患儿CITED2基因启动子区CpG岛的甲基化情况,并探讨其在该病发病中所起的作用。方法收集43例先天性心脏病患儿及2例意外死亡儿童右心耳组织,对CITED2基因进行突变筛查,同时利用生物信息学筛选,分别用亚硫酸氢盐修饰结合测序(BSP)及甲基化特异性PCR(MSP)检测CITED2基因启动子区CpG岛的甲基化情况,并运用实时荧光定量PCR检测CITED2基因mRNA的表达。结果先天性心脏病组启动子区存在4例杂合子突变(均为-341 T>G),此突变对CITED2基因mRNA的表达无影响。其中BSP法成功检测到先天性心脏病组甲基化阳性率为83.3%(10/12),MSP法分析发现甲基化阳性率为84.2%(16/19),同时CITED2基因异常甲基化使其mRNA的表达明显减低(P<0.05)。结论先天性心脏病中存在CITED2基因CpG岛的异常甲基化,此甲基化下调了CITED2基因mRNA的表达。

Objective To determine the role of methylation of CITED2 promoter in congenital heart disease. Methods Myocardial tissues from 43 children with congenital heart disease were collected during surgery in the Department of Cardiothoracic Surgery from March 2011 to March 2012. and the tissue samples of 2 health children were harvested after accidental death. Bisulfite-sequencing PCR （BSP） and methylation- specific PCR （MSP） were used to screening mutation and detect methylation in CITED2 promoter. Results Heterozygous mutation （ - 341T 〉 G） was found in 4 children with congenital heart disease. But this mutation had no effect on mRNA expression of CITED2. Positive rate of CITED2 methylation was 83.3% （10/12） by BSP and 84.2% （16/19） by MSP. Compared with the control group, CITED2 mRNA expression was signifi- cantly reduced （P 〈 0.05 ）. Conclusion Abnormal methylation of CITED2 promoter （ CpG island） is found in congenital heart disease. The abnormal methylation leads to a decrease in mRNA expression of CITED2, which might be involved in the incidence and development of congenital heart disease.