MS Research Center, Neurosciences Institute of Tehran University of Medical Sciences, Tehran, Iran.
Department of Medicine, Section of Endocrinology, Nutrition, and Diabetes, Vitamin D, Skin and Bone Research Laboratory, Boston University Medical Center, Boston, Massachusetts, United States of America.
PLoS One. 2018 Jul 6;13(7):e0199772. doi: 10.1371/journal.pone.0199772. eCollection 2018.
Health in early life is crucial for health later in life. Exposure to air pollution during embryonic and early-life development can result in placental epigenetic modification and foetus reprogramming, which can influence disease susceptibility in later life. Objectives: The aim of this paper was to investigate the placental adaptation in the level of global DNA methylation and differential gene expression in the methylation cycle in new-borns exposed to high fine particulate matter in the foetal stage.
This is a nested case-control study. We enrolled pregnant healthy women attending prenatal care clinics in Tehran, Iran, who were residents of selected polluted and unpolluted regions, before the 14th week of pregnancy. We calculated the regional background levels of particle mass- particles with aerodynamics diameter smaller than 2.5 μm (PM2.5) and 10 μm (PM10)-of two regions of interest. At the time of delivery, placental tissue was taken for gene expression and DNA methylation analyses. We also recorded birth outcomes (the new-born's sex, birth date, birth weight and length, head and chest circumference, gestational age, Apgar score, and level of neonatal care required).
As regards PM2.5 and PM10 concentrations in different time windows of pregnancy, there were significantly independent positive correlations between PM10 and PM2.5 in the first trimester of all subjects and placental global DNA methylation levels (p-value = 0.01, p-value = 0.03, respectively). The gene expression analysis showed there was significant correlation between S-adenosylmethionine expression and PM2.5 (p = 0.003) and PM10 levels in the first trimester (p = 0.03).
Our data showed prenatal exposures to air pollutants in the first trimester could influence placental adaptation by DNA methylation.
生命早期的健康对晚年健康至关重要。胚胎期和生命早期暴露于空气污染可导致胎盘表观遗传修饰和胎儿重编程，从而影响晚年的疾病易感性。目的：本研究旨在探讨胎儿期暴露于高浓度细颗粒物对新生儿胎盘整体 DNA 甲基化水平和甲基化循环中差异基因表达的适应性变化。
这是一项巢式病例对照研究。我们招募了在伊朗德黑兰接受产前保健的健康孕妇，这些孕妇在妊娠第 14 周前居住在选定的污染和非污染地区。我们计算了两个感兴趣区域的区域背景水平，即空气动力学直径小于 2.5μm（PM2.5）和 10μm（PM10）的颗粒质量。在分娩时，采集胎盘组织进行基因表达和 DNA 甲基化分析。我们还记录了新生儿出生结局（新生儿性别、出生日期、出生体重和身长、头围和胸围、胎龄、阿普加评分和所需的新生儿护理水平）。
就妊娠不同时间窗的 PM2.5 和 PM10 浓度而言，所有受试者的第一孕期 PM10 和 PM2.5 浓度与胎盘整体 DNA 甲基化水平呈显著独立正相关（p 值分别为 0.01 和 0.03）。基因表达分析显示，S-腺苷甲硫氨酸表达与 PM2.5（p = 0.003）和第一孕期 PM10 水平呈显著正相关（p = 0.03）。
我们的数据表明，妊娠早期暴露于空气污染物可能通过 DNA 甲基化影响胎盘的适应性。
