Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street W6509, Baltimore, MD, 21205, USA.
Center on the Early Life Origins of Disease, Department of Population, Family and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Clin Epigenetics. 2023 Aug 18;15(1):132. doi: 10.1186/s13148-023-01551-4.
Acetaminophen is a commonly used medication by pregnant women and is known to cross the placenta. However, little is known about the biological mechanisms that regulate acetaminophen in the developing offspring. Cytochrome 2E1 (CYP2E1) is the primary enzyme responsible for the conversion of acetaminophen to its toxic metabolite. Ex vivo studies have shown that the CYP2E1 gene expression in human fetal liver and placenta is largely controlled by DNA methylation (DNAm) at CpG sites located in the gene body of CYP2E1 at the 5' end. To date, no population studies have examined the association between acetaminophen metabolite and fetal DNAm of CYP2E1 at birth.
We utilized data from the Boston Birth Cohort (BBC) which represents an urban, low-income, racially and ethnically diverse population in Boston, Massachusetts. Acetaminophen metabolites were measured in the cord plasma of newborns enrolled in BBC between 2003 and 2013 using liquid chromatography-tandem mass spectrometry. DNAm at 28 CpG sites of CYP2E1 was measured by Illumina Infinium MethylationEPIC BeadChip. We used linear regression to identify differentially methylated CpG sites and the "DiffVar" method to identify differences in methylation variation associated with the detection of acetaminophen, adjusting for cell heterogeneity and batch effects. The false discovery rate (FDR) was calculated to account for multiple comparisons.
Among the 570 newborns included in this study, 96 (17%) had detectable acetaminophen in cord plasma. We identified 7 differentially methylated CpGs (FDR < 0.05) associated with the detection of acetaminophen and additional 4 CpGs showing a difference in the variation of methylation (FDR < 0.05). These CpGs were all located in the gene body of CYP2E1 at the 5' end and had a 3-6% lower average methylation level among participants with detectable acetaminophen compared to participants without. The CpG sites we identified overlap with previously identified DNase hypersensitivity and open chromatin regions in the ENCODE project, suggesting potential regulatory functions.
In a US birth cohort, we found detection of cord biomarkers of acetaminophen was associated with DNAm level of CYP2E1 in cord blood. Our findings suggest that DNA methylation of CYP2E1 may be an important regulator of acetaminophen levels in newborns.
对乙酰氨基酚是一种常见的孕妇用药，已知可穿过胎盘。然而，人们对调节发育中后代对乙酰氨基酚的生物学机制知之甚少。细胞色素 2E1（CYP2E1）是将对乙酰氨基酚转化为其有毒代谢物的主要酶。体外研究表明，人胎儿肝和胎盘的 CYP2E1 基因表达主要受位于 CYP2E1 基因体 5'端 CpG 位点的 DNA 甲基化（DNAm）控制。迄今为止，尚无人群研究探讨出生时脐带血中对乙酰氨基酚代谢物与 CYP2E1 的胎儿 DNAm 之间的关联。
我们利用了代表马萨诸塞州波士顿市的城市、低收入、种族和族裔多样化人群的波士顿出生队列（BBC）的数据。2003 年至 2013 年间，在 BBC 中招募的新生儿的脐带血浆中使用液相色谱-串联质谱法测量了对乙酰氨基酚代谢物。通过 Illumina Infinium MethylationEPIC BeadChip 测量 CYP2E1 的 28 个 CpG 位点的 DNAm。我们使用线性回归来鉴定差异甲基化 CpG 位点，并使用“DiffVar”方法来鉴定与对乙酰氨基酚检测相关的甲基化变化差异，同时调整细胞异质性和批次效应。使用错误发现率（FDR）来考虑多次比较。
在本研究纳入的 570 名新生儿中，有 96 名（17%）脐带血浆中可检测到对乙酰氨基酚。我们鉴定出 7 个与对乙酰氨基酚检测相关的差异甲基化 CpG（FDR<0.05），以及另外 4 个在甲基化变异方面存在差异的 CpG（FDR<0.05）。这些 CpG 均位于 CYP2E1 基因体的 5'端，与未检测到对乙酰氨基酚的参与者相比，有检测到对乙酰氨基酚的参与者的平均甲基化水平低 3-6%。我们鉴定的 CpG 位点与 ENCODE 项目中先前鉴定的 DNA 酶超敏和开放染色质区域重叠，表明潜在的调节功能。
在美国出生队列中，我们发现脐带生物标志物对乙酰氨基酚的检测与脐带血中 CYP2E1 的 DNAm 水平相关。我们的研究结果表明，CYP2E1 的 DNA 甲基化可能是新生儿对乙酰氨基酚水平的重要调节因子。
