Department of Molecular Genetics and Biology of Complex Diseases, Institute of Medical Research, A. Lanari-IDIM, University of Buenos Aires, National Council of Scientific and Technological Research (CONICET), Ciudad Autónoma de Buenos Aires C1427ARO, Argentina.
Mol Genet Metab. 2010 May;100(1):83-7. doi: 10.1016/j.ymgme.2010.02.004. Epub 2010 Feb 12.
To explore whether DNA methylation of the mitochondrial transcription factor A (TFAM) promoter is associated with insulin resistance in a sample of adolescents with features of metabolic syndrome.
The data and blood samples were collected from 122 adolescents out of a cross-sectional study of 934 high-school students. The population was divided into two groups: noninsulin resistance (NIR) and insulin resistance (IR). After bisulfite treatment of genomic DNA from peripheral leukocytes, we used methylation-specific polymerase chain reaction (PCR) to assess DNA methylation of three putative methylation target sites (CpG) in the TFAM promoter.
The ratio of the promoter methylated DNA/unmethylated DNA was 0.012+/-0.0009 (1.2% of alleles), and inversely correlated with the biochemical features of insulin resistance (plasma fasting insulin R: -0.26, p<0.004 and homeostasis model assessment (HOMA) index R: -0.27, p<0.002), and obesity (R: -0.27, p<0.002). Multiple regression analysis showed that the log-transformed HOMA index correlated with the status of promoter methylation of TFAM, independently of body mass index (BMI) Z score (beta: -0.33+/-0.094, p=0.00094). Finally, the TFAM promoter methylated DNA/unmethylated DNA ratio was found to be significantly associated with insulin resistance as dichotomous variable (NIR n=45, 0.014+/-0.002 and IR n=77, 0.011+/-0.001, respectively, p<0.016).
Our findings suggest a potential role of promoter TFAM methylation in the pathogenesis of insulin resistance in adolescents.
在患有代谢综合征特征的青少年样本中,探索线粒体转录因子 A(TFAM)启动子的 DNA 甲基化是否与胰岛素抵抗有关。
从一项横断面研究的 934 名高中生中抽取了 122 名青少年的数据和血液样本。人群分为两组:非胰岛素抵抗(NIR)和胰岛素抵抗(IR)。外周白细胞基因组 DNA 经亚硫酸氢盐处理后,我们使用甲基化特异性聚合酶链反应(PCR)来评估 TFAM 启动子中三个假定甲基化靶位(CpG)的 DNA 甲基化。
启动子甲基化 DNA/未甲基化 DNA 的比值为 0.012+/-0.0009(等位基因的 1.2%),与胰岛素抵抗的生化特征呈负相关(血浆空腹胰岛素 R:-0.26,p<0.004 和稳态模型评估(HOMA)指数 R:-0.27,p<0.002),与肥胖呈负相关(R:-0.27,p<0.002)。多元回归分析表明,log 转换的 HOMA 指数与 TFAM 启动子甲基化状态相关,独立于体重指数(BMI)Z 评分(β:-0.33+/-0.094,p=0.00094)。最后,发现 TFAM 启动子甲基化 DNA/未甲基化 DNA 的比值与胰岛素抵抗作为二分类变量显著相关(NIR n=45,0.014+/-0.002 和 IR n=77,0.011+/-0.001,分别,p<0.016)。
我们的研究结果表明,TFAM 启动子甲基化在青少年胰岛素抵抗的发病机制中可能具有潜在作用。