Nilsen Frances M, Parrott Benjamin B, Bowden John A, Kassim Brittany L, Somerville Stephen E, Bryan Teresa A, Bryan Colleen E, Lange Ted R, Delaney J Patrick, Brunell Arnold M, Long Stephen E, Guillette Louis J
National Institute of Standards and Technology, Chemical Sciences Division, Environmental Chemical Sciences Group, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States; Medical University of South Carolina, Marine Biomedicine and Environmental Sciences, 221 Fort Johnson Road, Charleston, SC 29412, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States.
Medical University of South Carolina, Marine Biomedicine and Environmental Sciences, 221 Fort Johnson Road, Charleston, SC 29412, United States; Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, SC 29403, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States.
Sci Total Environ. 2016 Mar 1;545-546:389-97. doi: 10.1016/j.scitotenv.2015.12.059. Epub 2015 Dec 31.
Mercury is a widespread environmental contaminant with exposures eliciting a well-documented catalog of adverse effects. Yet, knowledge regarding the underlying mechanisms by which mercury exposures are translated into biological effects remains incomplete. DNA methylation is an epigenetic modification that is sensitive to environmental cues, and alterations in DNA methylation at the global level are associated with a variety of diseases. Using a liquid chromatography tandem mass spectrometry-based (LC-MS/MS) approach, global DNA methylation levels were measured in red blood cells of 144 wild American alligators (Alligator mississippiensis) from 6 sites with variable levels of mercury contamination across Florida's north-south axis. Variation in mercury concentrations measured in whole blood was highly associated with location, allowing the comparison of global DNA methylation levels across different "treatments" of mercury. Global DNA methylation in alligators across all locations was weakly associated with increased mercury exposure. However, a much more robust relationship was observed in those animals sampled from locations more highly contaminated with mercury. Also, similar to other vertebrates, global DNA methylation appears to decline with age in alligators. The relationship between age-associated loss of global DNA methylation and varying mercury exposures was examined to reveal a potential interaction. These findings demonstrate that global DNA methylation levels are associated with mercury exposure, and give insights into interactions between contaminants, aging, and epigenetics.
汞是一种广泛存在的环境污染物，其暴露会引发一系列有充分文献记载的不良反应。然而，关于汞暴露转化为生物效应的潜在机制的知识仍不完整。DNA甲基化是一种对环境线索敏感的表观遗传修饰，全球范围内DNA甲基化的改变与多种疾病有关。使用基于液相色谱串联质谱（LC-MS/MS）的方法，在来自佛罗里达州南北轴上汞污染水平不同的6个地点的144只野生美国短吻鳄（密西西比鳄）的红细胞中测量了全球DNA甲基化水平。全血中汞浓度的变化与地理位置高度相关，从而能够比较不同汞“处理”下的全球DNA甲基化水平。所有地点的短吻鳄的全球DNA甲基化与汞暴露增加之间存在弱关联。然而，在从汞污染更严重的地点采样的动物中观察到了更强的关系。此外，与其他脊椎动物类似，短吻鳄的全球DNA甲基化似乎会随着年龄增长而下降。研究了与年龄相关的全球DNA甲基化丧失与不同汞暴露之间的关系，以揭示潜在的相互作用。这些发现表明全球DNA甲基化水平与汞暴露有关，并深入了解了污染物、衰老和表观遗传学之间的相互作用。
