Effect of 1 year B and D vitamin supplementation on LINE-1 repetitive element methylation in older subjects
Effect of 1 year B and D vitamin supplementation on LINE-1 repetitive element methylation in older subjects
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DOI：
10.1515/cclm-2012-0624
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发表时间：
2013-03-01
影响因子：
6.8
通讯作者：
Obeid, Rima
中科院分区：
文献类型：
--
作者：
Huebner, Ulrich;Geisel, Juergen;Obeid, Rima
背景：DNA 甲基化紊乱与癌症和动脉粥样硬化等慢性疾病存在因果关系。 B 族维生素是甲基合成所需的辅助因子，因此可能影响 DNA 甲基化。维生素 D 具有表观遗传效应。我们测试了补充 B 族和 D 族维生素是否对基因组长散布核元件 1 (LINE-1) 甲基化以及代谢物 S-腺苷甲硫氨酸 (SAM) 和 S-腺苷同型半胱氨酸 (SAH) 产生影响。方法：50 名受试者（中位年龄 68.0 岁）每天补充口服剂量的 B 族维生素（500 微克叶酸、500 微克维生素 B12 和50 毫克维生素 B6)、1200 IU 维生素 D 和 456 毫克钙。在补充补充剂一年之前和之后收集空腹血样。血细胞基因组 DNA 中的 LINE-1 甲基化被确定为全基因组甲基化的替代。此外，还测量了血浆样本中的 SAM、SAH 和总同型半胱氨酸 (tHcy)。 结果：补充后血浆同型半胱氨酸显着下降（12.8 vs. 9.1 μmol/L；p < 0.05），而 SAM、SAH、SAM/SAH 比值和 LINE-1 甲基化没有显着变化。 LINE-1甲基化与SAH、同型半胱氨酸或B族维生素没有显着相关性。结论：长期补充维生素B对血细胞中的LINE-1甲基化以及SAM和SAH的血浆水平没有影响。补充维生素 B 和 D 似乎对 DNA 甲基化没有影响，尤其是在不存在严重缺乏的情况下。
Background: Disturbed DNA methylation is causally related to chronic diseases like cancer and atherosclerosis. B vitamins are cofactors required for methyl group synthesis and may therefore affect DNA methylation. Vitamin D has epigenetic effects. We tested if B and D vitamin supplementation has an effect on genomic long interspersed nuclear element-1 (LINE-1) methylation and the metabolites S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH).Methods: Fifty subjects (median age 68.0 years) were supplemented with a daily oral dose of B vitamins (500 mu g folic acid, 500 mu g vitamin B12 and 50 mg vitamin B6), 1200 IU vitamin D and 456 mg calcium. Fasting blood samples were collected before and after 1 year of supplementation. LINE-1 methylation was determined in genomic DNA from blood cells as a surrogate for whole genome methylation. In addition, SAM, SAH and total homocysteine (tHcy) were measured in plasma samples.Results: Plasma homocysteine decreased significantly after supplementation (12.8 vs. 9.1 mu mol/L; p < 0.05), whereas SAM, SAH, the SAM/SAH ratio and LINE-1 methylation did not change significantly. LINE-1 methylation was not significantly correlated with SAH, homocysteine or B vitamins.Conclusions: Long-term vitamin B supplementation had no effect on LINE-1 methylation in blood cells nor on plasma levels of SAM and SAH. Vitamin B and D supplementation seems to have no effect on DNA methylation, especially in cases where no severe deficiency exists.