Reproductive Medicine Center of People's Hospital of Zhengzhou University, Zhengzhou 450003, Henan Province, P.R. China.
Reproductive Medicine Center of Henan Provincial People's Hospital, Zhengzhou 450003, Henan Province, P.R. China.
Hum Reprod. 2018 Mar 1;33(3):474-481. doi: 10.1093/humrep/dey006.
What are the effects of high-glucose concentrations on DNA methylation of human oocytes?
High-glucose concentrations altered DNA methylation levels of Peg3 and Adiponectin in human in vitro maturation oocytes.
Maternal diabetes has a detrimental influence on oocyte quality including epigenetic modifications, as shown in non-human mammalian species.
STUDY DESIGN, SIZE, DURATION: Immature metaphase I (MI) stage oocytes of good quality were retrieved from patients who had normal ovarian potential and who underwent ICSI in the Reproductive Medicine Center of People's Hospital of Zhengzhou University. MI oocytes were cultured in medium with different glucose concentrations (control, 10 mM and 15 mM) in vitro and 48 h later, oocytes with first polar body extrusion were collected to check the DNA methylation levels.
PARTICIPANTS/MATERIALS, SETTING, METHODS: MI oocytes underwent in vitro maturation (IVM) at 37°C with 5% mixed gas for 48 h. Then the mature oocytes were treated with bisulfite buffer. Target sequences were amplified using nested or half-nested PCR and the DNA methylation status was tested using combined bisulfite restriction analysis (COBRA) and bisulfite sequencing (BS).
High-glucose concentrations significantly decreased the first polar body extrusion rate. Compared to controls, the DNA methylation levels of Peg3 in human IVM oocytes were significantly higher in 10 mM (P < 0.001) and 15 mM (P < 0.001) concentrations of glucose. But the DNA methylation level of H19 was not affected by high-glucose concentrations in human IVM oocytes. We also found that there was a decrease in DNA methylation levels in the promoter of adiponectin in human IVM oocytes between controls and oocytes exposed to 10 mM glucose (P = 0.028).
N/A.
It is not clear whether the alterations are beneficial or not for the embryo development and offspring health. The effects of high-glucose concentrations on the whole process of oocyte maturation are still not elucidated. Another issue is that the number of oocytes used in this study was limited.
This is the first time that the effects of high-glucose concentration on DNA methylation of human oocytes have been elucidated. Our result indicates that in humans, the high risk of chronic diseases in offspring from diabetic mothers may originate from abnormal DNA modifications in oocytes.
STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the fund of National Natural Science Foundation of China (81401198) and Doctor Foundation of Qingdao Agricultural University (1116008).The authors declare that there are no potential conflicts of interest relevant to this article.
高葡萄糖浓度对人卵母细胞 DNA 甲基化的影响是什么？
高葡萄糖浓度改变了人体外成熟卵母细胞中 Peg3 和脂联素的 DNA 甲基化水平。
母体糖尿病对卵母细胞质量有不利影响，包括表观遗传修饰，在非人类哺乳动物物种中已有显示。
研究设计、规模、持续时间：从具有正常卵巢潜能并在郑州大学人民医院生殖医学中心接受 ICSI 的患者中获取优质的不成熟中期 I（MI）期卵母细胞。MI 卵母细胞在不同葡萄糖浓度（对照、10mM 和 15mM）的体外培养基中进行培养，48 小时后，收集具有第一极体排出的卵母细胞以检查 DNA 甲基化水平。
参与者/材料、设置、方法：MI 卵母细胞在 37°C 下用 5%混合气进行 48 小时体外成熟（IVM）。然后用亚硫酸氢盐缓冲液处理成熟卵母细胞。使用巢式或半巢式 PCR 扩增靶序列，并使用联合亚硫酸氢盐限制分析（COBRA）和亚硫酸氢盐测序（BS）测试 DNA 甲基化状态。
高葡萄糖浓度显著降低了第一极体排出率。与对照组相比，10mM（P < 0.001）和 15mM（P < 0.001）葡萄糖浓度下，人 IVM 卵母细胞中 Peg3 的 DNA 甲基化水平显著升高。但高葡萄糖浓度对人 IVM 卵母细胞中 H19 的 DNA 甲基化水平没有影响。我们还发现，在人 IVM 卵母细胞中，与对照相比，脂联素启动子中的 DNA 甲基化水平在暴露于 10mM 葡萄糖时降低（P = 0.028）。
无。
尚不清楚这些改变对胚胎发育和后代健康是有益还是有害。高葡萄糖浓度对卵母细胞成熟全过程的影响仍不清楚。另一个问题是，本研究中使用的卵母细胞数量有限。
这是首次阐明高葡萄糖浓度对人卵母细胞 DNA 甲基化的影响。我们的结果表明，在人类中，糖尿病母亲后代患慢性疾病的高风险可能源于卵母细胞中异常的 DNA 修饰。
研究基金/利益冲突：本工作得到国家自然科学基金（81401198）和青岛农业大学博士基金（1116008）的支持。作者声明与本文无关的潜在利益冲突。
