Department of Clinical Pharmacology & Therapeutics, Nizam's Institute of Medical Sciences, Panjagutta, Hyderabad, 500082, Andhra Pradesh, India.
Mol Cell Biochem. 2013 Feb;374(1-2):203-11. doi: 10.1007/s11010-012-1520-7. Epub 2012 Nov 17.
The association between oxidative stress and coronary artery disease (CAD) is well documented. However, the role of epigenetic factors contributing to oxidative stress is relatively unexplored. In this study, we aimed to explore the impact of DNA methylation profile in BCL2/E1B adenovirus interacting protein 3 (BNIP3), extracellular superoxide dismutase (EC-SOD) and glutathione-S-transferase P1 (GSTP1) on the oxidative stress in CAD. Further, the contribution of folate pathway genetic polymorphisms in regulating epigenome was elucidated. The expression of BNIP3, EC-SOD, and GSTP1 were studied by using Maxima@SYBR-green based real-time qPCR approach in peripheral blood samples. Combined bisulfite restriction analysis and methylation-specific PCR were used to study promoter CpG island methylation. Further, the effect of homocysteine on BNIP3 gene expression was studied in human aortic endothelial cells in vitro. CAD cases exhibited upregulation of BNIP3, downregulation of EC-SOD and GSTP1. Hypomethylation of BNIP3 and hypermethylation of EC-SOD were observed in CAD cases. The expression of BNIP3 was positively correlated with homocysteine, MDA, protein carbonyls, and methylene tetrahydrofolate reductase C677T, while showing inverse association with cytosolic serine hydroxymethyl transferase C1420T. The expressions of EC-SOD and GSTP1 showed positive association with thymidylate synthase (TYMS) 2R3R, while inverse association with MDA, protein carbonyls, and methionine synthase reductase (MTRR) A66G. In vitro analysis showed homocysteine-dependent upregulation of BNIP3. The results of this study suggest that the aberrations in one-carbon metabolism appear to induce altered gene expression of EC-SOD, GSTP1, and BNIP3, and thus contribute to the increased oxidative stress and increased susceptibility to CAD.
氧化应激与冠状动脉疾病（CAD）之间的关联已有充分的文献记载。然而，促成氧化应激的表观遗传因素的作用仍在探索之中。在这项研究中，我们旨在探讨 BCL2/E1B 腺病毒相互作用蛋白 3（BNIP3）、细胞外超氧化物歧化酶（EC-SOD）和谷胱甘肽-S-转移酶 P1（GSTP1）的 DNA 甲基化谱对 CAD 中氧化应激的影响。此外，还阐明了叶酸途径遗传多态性在调节表观基因组中的作用。采用 Maxima@SYBR-green 实时 qPCR 方法检测外周血样本中 BNIP3、EC-SOD 和 GSTP1 的表达。采用联合亚硫酸氢盐限制性分析和甲基化特异性 PCR 检测启动子 CpG 岛甲基化。进一步在体外研究同型半胱氨酸对人主动脉内皮细胞 BNIP3 基因表达的影响。CAD 病例中 BNIP3 上调，EC-SOD 和 GSTP1 下调。CAD 病例中观察到 BNIP3 低甲基化和 EC-SOD 高甲基化。BNIP3 的表达与同型半胱氨酸、MDA、蛋白质羰基和亚甲基四氢叶酸还原酶 C677T 呈正相关，与胞质丝氨酸羟甲基转移酶 C1420T 呈负相关。EC-SOD 和 GSTP1 的表达与胸苷酸合成酶（TYMS）2R3R 呈正相关，与 MDA、蛋白质羰基和甲硫氨酸合成酶还原酶（MTRR）A66G 呈负相关。体外分析显示同型半胱氨酸依赖性 BNIP3 上调。本研究结果表明，一碳代谢异常似乎导致 EC-SOD、GSTP1 和 BNIP3 的基因表达异常，从而导致氧化应激增加和 CAD 易感性增加。
