Epigenomics in Environmental Health

Abstract

This review considers the emerging relationships between environmental factors and epigenetic alterations and the application of genome-wide assessments to better define these relationships. First we will briefly cover epigenetic programming in development, one-carbon metabolism, and exposures that may disrupt normal developmental programming of epigenetic states. In addition, because a large portion of epigenetic research has focused on cancer, we discuss exposures associated with carcinogenesis including asbestos, alcohol, radiation, arsenic, and air pollution. Research on other exposures that may affect epigenetic states such as endocrine disruptors is also described, and we also review the evidence for epigenetic alterations associated with aging that may reflect cumulative effects of exposures. From this evidence, we posit potential mechanisms by which exposures modify epigenetic states, noting that understanding the true effect of environmental exposures on the human epigenome will require additional research with appropriate epidemiologic studies and application of novel technologies. With a more comprehensive understanding of the affects of exposures on the epigenome, including consideration of genetic background, the prediction of the toxic potential of new compounds may be more readily achieved, and may lead to the development of more personalized disease prevention and treatment strategies.

Dietary factors, epigenetic modifications and obesity outcomes: Progresses and perspectives

“…Lower blood DNA methylation has been also found after exposure to traffic particles (Baccarelli et al, 2009) and after prolonged exposure to black carbon and SO 4 particles (Madrigano et al, 2011). Other toxics associated with carcinogenesis, including asbestos, alcohol, radiation and arsenic, are known to act also by epigenetic mechanisms (Christensen and Marsit, 2011). However, as their importance in obesity pandemics is not well known, more studies in humans are necessary.…”

“…Epigenetics, that has been defined as heritable changes in gene expression that cannot be explained by changes in DNA sequence (Christensen and Marsit, 2011), has been subject of special interest in the last years mainly because there is evidence on the impact of different nutrients, environmental compounds and metabolic situations on the epigenome, which may lead to the development of more personalized disease prevention and treatment strategies (Campion et al, 2010;Choi and Friso, 2010). As epigenetic changes are modulated by environmental exposures, epigenetics is considered the interface between genetics and the environment.…”

Globalisation and the Epigenetic Landscape

“…Over the past two decades, much research has gone into the role of epigenetic changes in the development of diseases like cancer (Feinberg and Tycko, 2004;Salnikow and Zhitkovich, 2008). The most broadly researched and studied epigenetic mechanism is DNA methylation (Christensen and Marsit, 2011). First observed in the early 1980s in studies of carcinogenesis (Feinberg and Tycko, 2004), DNA methylation occurs mainly at CpG dinucleotides, which are found grouped together in promoter regions of around 50 per cent of all human genes (so-called CpG islands).…”

“…First observed in the early 1980s in studies of carcinogenesis (Feinberg and Tycko, 2004), DNA methylation occurs mainly at CpG dinucleotides, which are found grouped together in promoter regions of around 50 per cent of all human genes (so-called CpG islands). DNA methylation involves the addition of a methyl group to a CpG dinucleotide (Christensen and Marsit, 2011). Methylation of CpG islands can cause gene silencing.…”

“…Exposure to environmental carcinogens and the associated epigenetic changes such as the ones described above can also occur in utero; epigenetic programming may play a major role in embryonic development and the health of an individual in the long term (Christensen and Marsit, 2011). A study conducted on rats by Martínez et al in 2011 showed that arsenic exposure during gestation resulted in altered patterns of DNA methylation of brain cells affecting memory, thus suggesting that arsenic exposure in utero could have long-standing effects on growth and development (Martínez et al, 2011).…”