DNA hypermethylation: A novel mechanism of CREG gene suppression and atherosclerogenic endothelial dysfunction
DNA hypermethylation: A novel mechanism of CREG gene suppression and atherosclerogenic endothelial dysfunction
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DNA 高甲基化：CREG 基因抑制和动脉粥样硬化内皮功能障碍的新机制。
DOI：
10.1016/j.redox.2020.101444
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发表时间：
2020-05-01
期刊：
影响因子：
11.4
通讯作者：
Han, Yaling
中科院分区：
文献类型：
--
作者：
Liu, Yanxia;Tian, Xiaoxiang;Han, Yaling
目的：E1 A刺激基因的细胞阻遏物（CREG）是一种血管保护分子，在动脉粥样硬化血管中通过不清楚的机制显著下调。虽然表观遗传调控参与动脉粥样硬化的发展，但尚不清楚CREG基因是否受表观遗传调控。本研究的目的是评估CREG甲基化的潜在作用，在促成atherosclerosis.Approach和结果：DNA甲基转移酶（DNMT）3B的过表达显着抑制CREG表达在人脐静脉内皮细胞（HUVECs）和人冠状动脉内皮细胞（HCAECs）。相反，用5-氮杂-2 '-脱氧胞苷（5-aza-dC）抑制DNA甲基化剂量依赖性地增加CREG表达。CREG启动子分析确定+168至+255 bp为关键调控区，+201/+202 bp处的CG位点为关键甲基化位点。转录因子GR-α可以结合到+201/+202 bp CG位点，促进CREG转录，DNMT 3B过表达显著抑制该过程。用氧化低密度脂蛋白（ox-LDL）（一种关键的致动脉粥样硬化因子）处理细胞显著增加了DNMT 3B表达，增加了CREG启动子甲基化，阻断了GR-α结合，并抑制了CREG表达。一致的是，在人动脉粥样硬化动脉中，CREG启动子片段中的CG位点被过度甲基化，并且CREG表达显著降低。在人动脉粥样硬化动脉中观察到DNMT 3B和CREG表达水平之间的负相关性。最后，Ox-LDL诱导的内皮功能障碍显着衰减5-氮杂-dC和抗氧化分子N-乙酰半胱氨酸（NAC）管理通过救援CREG的表达和激活的p-eNOS/NO pathway.Conclusions：我们的研究提供了第一个直接证据，DNMT 3B介导的CREG基因高甲基化是一种新的机制，有助于内皮功能障碍和动脉粥样硬化的发展。阻断CREG甲基化可能是治疗ox-LDL诱导的动脉粥样硬化的新方法。
Objective: Cellular repressor of E1A-stimulated genes (CREG), a vasculoprotective molecule, is significantly downregulated in atherosclerotic vessels through unclear mechanisms. While epigenetic regulation is involved in atherosclerosis development, it is not known if the CREG gene is epigenetically regulated. The aim of this study was to assess the potential role of CREG methylation in contributing to atherosclerosis.Approach and results: Overexpression of DNA methyltransferase (DNMT)3B significantly inhibited CREG expression in human umbilical vein endothelial cells (HUVECs) and human coronary aortic endothelial cells (HCAECs). Conversely, inhibition of DNA methylation with 5-aza-2'-deoxycytidine (5-aza-dC) dose-dependently increased CREG expression. A CREG promoter analysis identified +168 to +255 bp as a key regulatory region and the CG site at +201/+202 bp as a key methylation site. The transcription factor GR-alpha could bind to the +201/+202 bp CG site promoting CREG transcription, a process significantly inhibited by DNMT3B overexpression. Treatment of cells with oxidized low-density lipoprotein (ox-LDL), a critical atherosclerogenic factor, significantly increased DNMT3B expression, increasing CREG promotor methylation, blocking GR-a binding, and inhibiting CREG expression. Consistently, CG sites in the CREG promoter fragment were hyper-methylated in human atherosclerotic arteries, and CREG expression was significantly reduced. A negative correlation between DNMT3B and CREG expression levels was observed in human atherosclerotic arteries. Finally, Ox-LDL-induced endothelium dysfunction was significantly attenuated by both 5-aza-dC and an anti-oxidative molecular N-acetylcysteine (NAC) administration through rescue the expression of CREG and activation of the p-eNOS/NO pathway.Conclusions: Our study provides the first direct evidence that DNMT3B-mediated CREG gene hypermethylation is a novel mechanism that contributes to endothelial dysfunction and atherosclerosis development. Blocking CREG methylation may represent a novel therapeutic approach to treat ox-LDL-induced atherosclerosis.