Environmental Alterations of Epigenetics Prior to the Birth

Abstract

The etiology of many brain diseases remains allusive to date after intensive investigation of genomic background and symptomatology from the day of birth. Emerging evidences indicate that a third factor, epigenetics prior to the birth, can exert profound influence on the development and functioning of the brain and over many neurodevelopmental syndromes. This chapter reviews how aversive environmental exposure to parents might predispose or increase vulnerability of offspring to neurodevelopmental deficit through alteration of epigenetics. These epigenetic altering environmental factors will be discussed in the category of addictive agents, nutrition or diet, prescriptive medicine, environmental pollutant, and stress. Epigenetic alterations induced by these aversive environmental factors cover all aspects of epigenetics including DNA methylation, histone modification, non-coding RNA, and chromatin modification. Next, the mechanisms how these environmental inputs influence epigenetics will be discussed. Finally, how environmentally altered epigenetic marks affect neurodevelopment is exemplified by the alcohol-induced fetal alcohol syndrome. It is hoped that a thorough understanding of the nature of prenatal epigenetic inputs will enable researchers with a clear vision to better unravel neurodevelopmental deficit, late onset neuropsychiatric diseases, or idiosyncratic mental disorders.

Neurological and neuropsychological effects of low and moderate prenatal alcohol exposure

“…Epigenetic changes in DNA methylation, DNA histone modification and micro RNA biogenesis in animal and in vitro models of FASD have been recently reviewed in a systematic manner by ref. In addition, substantial information has been presented regarding alcohol‐induced alteration of the epigenome prior to birth and the profound effects on the global transcriptome (Zhou 2016) in two recent reviews.…”

Cord Blood DNA Methylation Biomarkers for Predicting Neurodevelopmental Outcomes

“…Whether these cell types are equally epigenetically affected by environmental exposures is currently unknown, and hence the magnitude of their individual contribution to whole cord blood methylation status may vary. However, in terms of intrauterine exposures and developmental outcomes, whole cord blood DNA methylation levels have been assessed and correlated with various maternal exposures [27,28,29,30,31]. …”

Effects of Prenatal Exposure to Endocrine Disruptors and Toxic Metals on The Fetal Epigenome

“…Given the link between prenatal exposures to toxic metals, endocrine disruptors and diseases occurring later in life, epigenetic modifications are believed, at least in part, to underlie these effects [18]. This review summarizes the current literature related to four toxic metals where prenatal exposure is common and early life exposure yields both early developmental and later life effects, namely arsenic (As), cadmium (Cd), lead (Pb) and mercury (Hg).…”