Wan Dongjun, Hou Lei, Zhang Xiaofei, Han Xun, Chen Min, Tang Wenjing, Liu Ruozhuo, Dong Zhao, Yu Shengyuan
Department of Neurology, Chinese PLA General Hospital, 28 Fuxing Road, Haidan District, Beijing, 100853, China.
J Headache Pain. 2015;16:90. doi: 10.1186/s10194-015-0576-7. Epub 2015 Oct 26.
Receptor activity modifying protein 1(RAMP1) is a key receptor subunit of calcitonin gene related peptide (CGRP) playing a critical role in migraine. But variations in RAMP1 gene have not been found to link with migraine. Still it is elusive that DNA methylation at RAMP1 promoter is associated with migraine.
A total of 51 blood DNA samples from 26 patients with migraine and 25 matched healthy controls were collected, extracted and treated with bisulfate. Subsequently DNA methylation levels at RAMP1 promoter region were measured using Sequenom Mass ARRAY systems.
Among 13 detected CpG sites or units at RAMP1 promoter region, there were no significant differences between the migraine and control groups, but indicating a low methylation trend overall in migraine group (total average methylation level: 8.41 % ±1.92 % vs. 9.90 % ± 3.88 %, p = 0.197). Stratification analysis showed that methylation level at (+25, +27, +31, related to the transcription start site) CpG unit was higher in migraineurs with migraine family history compared to those without (13.92 % ± 5.97 % vs. 8.77 % ± 6.61 %, p = 0.034), and methylation level at (+89, +94, +96) CpG unit was lower in migraine female than that in healthy female (2.18 % ± 1.91 % vs. 5.85 % ± 5.41 %, p = 0.02). For female with methylation level at (+89, +94, +96) CpG unit below 3.50 %, the probability of being a migraine patient was significantly higher than those with methylation level above the threshold (OR: 7.313; 95%CI: 1.439-37.164).
This study provides the first evidence that DNA methylation at RAMP1 promoter might play a role in migraine. A low methylation trend overall was presented in migraine subjects, and two CpG units were observed to link with positive migraine family history and female migraine, respectively. Lower methlytion level at (+89, +94, +96) CpG unit may be a risk of migraine in females.
受体活性修饰蛋白1（RAMP1）是降钙素基因相关肽（CGRP）的关键受体亚基，在偏头痛中起关键作用。但尚未发现RAMP1基因变异与偏头痛有关。RAMP1启动子处的DNA甲基化是否与偏头痛相关仍不清楚。
收集26例偏头痛患者和25例匹配的健康对照者的51份血液DNA样本，提取并进行亚硫酸氢盐处理。随后使用Sequenom Mass ARRAY系统测量RAMP1启动子区域的DNA甲基化水平。
在RAMP1启动子区域检测到的13个CpG位点或单元中，偏头痛组与对照组之间无显著差异，但偏头痛组总体呈现低甲基化趋势（总平均甲基化水平：8.41%±1.92% vs. 9.90%±3.88%，p = 0.197）。分层分析显示，有偏头痛家族史的偏头痛患者在（与转录起始位点相关的+25、+27、+31）CpG单元处的甲基化水平高于无家族史者（13.92%±5.97% vs. 8.77%±6.61%，p = 0.034），偏头痛女性在（+89、+94、+96）CpG单元处的甲基化水平低于健康女性（2.18%±1.91% vs. 5.85%±5.41%，p = 0.02）。对于（+89、+94、+96）CpG单元甲基化水平低于3.50%的女性，其患偏头痛的概率显著高于甲基化水平高于阈值的女性（比值比：7.313；95%置信区间：1.439 - 37.164）。
本研究首次提供证据表明RAMP1启动子处的DNA甲基化可能在偏头痛中起作用。偏头痛患者总体呈现低甲基化趋势，观察到两个CpG单元分别与偏头痛家族史阳性和女性偏头痛有关。（+89、+94、+96）CpG单元较低的甲基化水平可能是女性偏头痛的一个风险因素。
