Epigenetic mediators and consequences of excessive alcohol consumption

The Impact of Oxidative Stress on the Epigenetics of Fetal Alcohol Spectrum Disorders

Fetal alcohol spectrum disorders (FASD) represent a continuum of lifelong impairments resulting from prenatal exposure to alcohol, with significant global impact. The "spectrum" of disorders includes a continuum of physical, cognitive, behavioral, and developmental impairments which can have profound and lasting effects on individuals throughout their lives, impacting their health, social interactions, psychological well-being, and every aspect of their lives. This narrative paper explores the intricate relationship between oxidative stress and epigenetics in FASD pathogenesis and its therapeutic implications. Oxidative stress, induced by alcohol metabolism, disrupts cellular components, particularly in the vulnerable fetal brain, leading to aberrant development. Furthermore, oxidative stress is implicated in epigenetic changes, including alterations in DNA methylation, histone modifications, and microRNA expression, which influence gene regulation in FASD patients. Moreover, mitochondrial dysfunction and neuroinflammation contribute to epigenetic changes associated with FASD. Understanding these mechanisms holds promise for targeted therapeutic interventions. This includes antioxidant supplementation and lifestyle modifications to mitigate FASD-related impairments. While preclinical studies show promise, further clinical trials are needed to validate these interventions' efficacy in improving clinical outcomes for individuals affected by FASD. This comprehensive understanding of the role of oxidative stress in epigenetics in FASD underscores the importance of multidisciplinary approaches for diagnosis, management, and prevention strategies. Continued research in this field is crucial for advancing our knowledge and developing effective interventions to address this significant public health concern.

Learning and memory deficits produced by aspartame are heritable via the paternal lineage

Environmental exposures produce heritable traits that can linger in the population for one or two generations. Millions of individuals consume substances such as artificial sweeteners daily that are declared safe by regulatory agencies without evaluation of their potential heritable effects. We show that consumption of aspartame, an FDA-approved artificial sweetener, daily for up to 16-weeks at doses equivalent to only 7-15% of the FDA recommended maximum daily intake value (equivalent to 2-4 small, 8 oz diet soda drinks per day) produces significant spatial learning and memory deficits in mice. Moreover, the cognitive deficits are transmitted to male and female descendants along the paternal lineage suggesting that aspartame's adverse cognitive effects are heritable, and that they are more pervasive than current estimates, which consider effects in the directly exposed individuals only. Traditionally, deleterious environmental exposures of pregnant and nursing women are viewed as risk factors for the health of future generations. Environmental exposures of men are not considered to pose similar risks. Our findings suggest that environmental exposures of men can produce adverse impact on cognitive function in future generations and demonstrate the need for considering heritable effects via the paternal lineage as part of the regulatory evaluations of artificial sweeteners.

Astroglia in the Vulnerability and Maintenance of Alcohol Use Disorders

Changes induced in the morphology and the multiplicity of functional roles played by astrocytes in brain regions critical to the establishment and maintenance of alcohol abuse suggest that they make an important contribution to the vulnerability to alcohol use disorders. The understanding of the relevant mechanisms accounting for that contribution is complicated by the fact that alcohol itself acts directly on astrocytes altering their metabolism, gene expression, and plasticity, so that the ultimate result is a complex interaction of various cellular pathways, including intracellular calcium regulation, neuroimmune responses, and regulation of neurotransmitter and gliotransmitter release and uptake. The recent years have seen a steady increase in the characterization of several of the relevant mechanisms, but much remains to be done for a full understanding of the astrocytes' contribution to the vulnerability to alcohol dependence and abuse and for using that knowledge in designing effective therapies for AUDs.

Novel mechanisms in alcohol neurodevelopmental disorders via BRCA1 depletion and BRCA1-dependent NADPH oxidase regulation

The breast cancer 1 protein (BRCA1) facilitates DNA repair, preventing embryolethality and protecting the fetus from reactive oxygen species (ROS)-induced developmental disorders mediated by oxidatively damaged DNA. Alcohol (ethanol, EtOH) exposure during pregnancy causes fetal alcohol spectrum disorders (FASD), characterized by aberrant behaviour and enhanced ROS formation and proteasomal protein degradation. Herein, ROS-producing NADPH oxidase (NOX) activity was higher in Brca1 +/- vs. +/+ fetal and adult brains, and further enhanced by a single EtOH exposure. EtOH also enhanced catalase and proteasomal activities, while conversely reducing BRCA1 protein levels without affecting Brca1 gene expression. EtOH-initiated adaptive postnatal freezing behaviour was lost in Brca1 +/- progeny. Pretreatment with the free radical spin trap and ROS inhibitor phenylbutylnitrone blocked all EtOH effects, suggesting ROS-dependent mechanisms. This is the first in vivo evidence of NOX regulation by BRCA1, and of EtOH-induced, ROS-mediated depletion of BRCA1, revealing novel mechanisms of BRCA1 protection in FASD.

Heritable consequences of paternal nicotine exposure: from phenomena to mechanisms†

Our understanding of the interactions between genetic and environmental factors in shaping behavioral phenotypes has expanded to include environment-induced epigenetic modifications and the intriguing possibility of their association with heritable behavioral phenotypes. The molecular basis of heritability of phenotypes arising from environment-induced epigenetic modifications is not well defined yet. However, phenomenological evidence in favor of it is accumulating rapidly. The resurgence of interest has led to focus on epigenetic modification of germ cells as a plausible mechanism of heritability. Perhaps partly because of practical reasons such as ease of access to male germ cells compared to female germ cells, attention has turned toward heritable effects of environmental influences on male founders. Public health implications of heritable effects of paternal exposures to addictive substances or to psycho-social factors may be enormous. Considering nicotine alone, over a billion people worldwide use nicotine-containing products, and the majority are men. Historically, the adverse effects of nicotine use by pregnant women received much attention by scientists and public policy experts alike. The implications of nicotine use by men for the physical and mental well-being of their children were not at the forefront of research until recently. Here, we review progress in the emerging field of heritable effects of paternal nicotine exposure and its implications for behavioral health of individuals in multiple generations.

Extracellular Vesicles in Premature Aging and Diseases in Adulthood Due to Developmental Exposures

The developmental origins of health and disease (DOHaD) is a paradigm that links prenatal and early life exposures that occur during crucial periods of development to health outcome and risk of disease later in life. Maternal exposures to stress, some psychoactive drugs and alcohol, and environmental chemicals, among others, may result in functional changes in developing fetal tissues, creating a predisposition for disease in the individual as they age. Extracellular vesicles (EVs) may be mediators of both the immediate effects of exposure during development and early childhood as well as the long-term consequences of exposure that lead to increased risk and disease severity later in life. Given the prevalence of diseases with developmental origins, such as cardiovascular disease, neurodegenerative disorders, osteoporosis, metabolic dysfunction, and cancer, it is important to identify persistent mediators of disease risk. In this review, we take this approach, viewing diseases typically associated with aging in light of early life exposures and discuss the potential role of EVs as mediators of lasting consequences.

Exposure to drugs of abuse induce effects that persist across generations

Substance use disorders are highly prevalent and continue to be one of the leading causes of disability in the world. Notably, not all people who use addictive drugs develop a substance use disorder. Although substance use disorders are highly heritable, patterns of inheritance cannot be explained purely by Mendelian genetic mechanisms. Vulnerability to developing drug addiction depends on the interplay between genetics and environment. Additionally, evidence from the past decade has pointed to the role of epigenetic inheritance in drug addiction. This emerging field focuses on how environmental perturbations, including exposure to addictive drugs, induce epigenetic modifications that are transmitted to the embryo at fertilization and modify developmental gene expression programs to ultimately impact subsequent generations. This chapter highlights intergenerational and transgenerational phenotypes in offspring following a history of parental drug exposure. Special attention is paid to parental preconception exposure studies of five drugs of abuse (alcohol, cocaine, nicotine, cannabinoids, and opiates) and associated behavioral and physiological outcomes in offspring. The highlighted studies demonstrate that parental exposure to drugs of abuse has enduring effects that persist into subsequent generations. Understanding the contribution of epigenetic inheritance in drug addiction may provide clues for better treatments and therapies for substance use disorders.

Intergenerational implications of alcohol intake: metabolic disorders in alcohol-naïve rat offspring

Alcohol drinking may be associated with an increased risk of various metabolic diseases. Rat lines selectively bred for alcohol preference and alcohol avoidance constitute an interesting model to study inherited factors related to alcohol drinking and metabolic disorders. The aim of the present study was to compare the levels of selected laboratory biomarkers of metabolic disorders in blood samples from naïve offspring of Warsaw alcohol high-preferring (WHP), Warsaw alcohol low-preferring (WLP), and wild Wistar rats. Blood samples were collected from 3-month old (300–350 g) alcohol-naïve, male offspring of WHP (n = 8) and WLP rats (n = 8), as well as alcohol-naïve, male, wild Wistar rats. Markers of metabolic, hepatic, and pancreatic disorders were analysed (levels of homocysteine, glucose, total cholesterol, triglycerides and γ-glutamyl transferase (GGT), aspartate (AST), alanine aminotransferase (ALT), and amylase serum activities). Alcohol-naïve offspring of WHP, WLP, and wild Wistar rats differed significantly in the levels of triglycerides, total cholesterol, homocysteine, as well as in the activity of GGT, ALT, AST, and amylase enzymes. Most markers in the alcohol-naïve offspring of WHP rats were altered even thought they were never exposed to alcohol pre- or postnatally. This may suggest that parental alcohol abuse can have a detrimental influence on offspring vulnerability to metabolic disorders.

Notifications to Improve Engagement With an Alcohol Reduction App: Protocol for a Micro-Randomized Trial

BACKGROUND

Drink Less is a behavior change app that aims to help users in the general adult population reduce hazardous and harmful alcohol consumption. The app includes a daily push notification, delivered at 11 am, asking users to "Please complete your mood and drinking diaries." Previous analysis of Drink Less engagement data suggests the current notification strongly influences how users engage with the app in the subsequent hour. To exploit a potential increase of vulnerability of excess drinking and opportunity to engage with the app in the evenings, we changed the delivery time from 11 am to 8 pm. We now aim to further optimise the content and sequence of notifications, testing 30 new evidence-informed notifications targeting the user's perceived usefulness of the app.

OBJECTIVE

The primary objective is to assess whether sending a notification at 8 pm increases behavioral engagement (opening the app) in the subsequent hour. Secondary objectives include comparing the effect of the new bank of messages with the standard message and effect moderation over time. We also aim to more generally understand the role notifications have on the overall duration, depth, and frequency of engagement with Drink Less over the first 30 days after download.

METHODS

This is a protocol for a micro-randomized trial with two additional parallel arms. Inclusion criteria are Drink Less users who (1) consent to participate in the trial; (2) self-report a baseline Alcohol Use Disorders Identification Test score of 8 or above; (3) reside in the United Kingdom; (4) age ≥18 years and; (5) report interest in drinking less alcohol. In the micro-randomized trial, participants will be randomized daily at 8 pm to receive no notification, a notification with text from the new message bank, or the standard message. The primary outcome is the time-varying, binary outcome of "Did the user open the app in the hour from 8 pm to 9 pm?". The primary analysis will estimate the marginal relative risk for the notifications using an estimator developed for micro-randomized trials with binary outcomes. Participants randomized to the parallel arms will receive no notifications (Secondary Arm A), or the standard notification delivered daily at 11 am (Secondary Arm B) over 30 days, allowing the comparison of overall engagement between different notification delivery strategies.

RESULTS

Approval was granted by the University College of London's Departmental Research Ethics Committee (CEHP/2016/556) on October 11, 2019, and The London School of Hygiene and Tropical Medicine Interventions Research Ethics Committee (17929) on November 27, 2019. Recruitment began on January 2, 2020, and is ongoing.

CONCLUSIONS

Understanding how push notifications may impact engagement with a behavior change app can lead to further improvements in engagement, and ultimately help users reduce their alcohol consumption. This understanding may also be generalizable to other apps that target a variety of behavior changes.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/18690.

Epigenetic mechanisms underlying pathobiology of alcohol use disorder

Purpose of review

Chronic alcohol use is a worldwide problem with multifaceted consequences including multiplying medical costs and sequelae, societal effects like drunk driving and assault, and lost economic productivity. These large-scale outcomes are driven by the consumption of ethanol, a small permeable molecule that has myriad effects in the human body, particularly in the liver and brain. In this review, we have summarized effects of acute and chronic alcohol consumption on epigenetic mechanisms that may drive pathobiology of Alcohol Use Disorder (AUD) while identifying areas of need for future research.

Recent findings

Epigenetics has emerged as an interesting field of biology at the intersection of genetics and the environment, and ethanol in particular has been identified as a potent modulator of the epigenome with various effects on DNA methylation, histone modifications, and non-coding RNAs. These changes alter chromatin dynamics and regulate gene expression that contribute to behavioral and physiological changes leading to the development of AUD psychopathology and cancer pathology.

Summary

Evidence and discussion presented here from preclinical results and available translational studies have increased our knowledge of the epigenetic effects of alcohol consumption. These studies have identified targets that can be used to develop better therapies to reduce chronic alcohol abuse and mitigate its societal burden and pathophysiology.

Long-term epigenetic changes in offspring mice exposed to alcohol during gestation and lactation

BACKGROUND

Alcohol exposure impairs brain development and leads to a range of behavioural and cognitive dysfunctions, termed as foetal alcohol spectrum disorders. Although different mechanisms have been proposed to participate in foetal alcohol spectrum disorders, the molecular insights of such effects are still uncertain. Using a mouse model of foetal alcohol spectrum disorder, we have previously shown that maternal binge-like alcohol drinking causes persistent effects on motor, cognitive and emotional-related behaviours associated with neuroimmune dysfunctions.

AIMS

In this study, we sought to evaluate whether the long-term behavioural alterations found in offspring with early exposure to alcohol are associated with epigenetic changes in the hippocampus and prefrontal cortex.

METHODS

Pregnant C57BL/6 female mice underwent a model procedure for binge alcohol drinking throughout both the gestation and lactation periods. Subsequently, adult offspring were assessed for their cognitive function in a reversal learning task and brain areas were extracted for epigenetic analyses.

RESULTS

The results demonstrated that early binge alcohol exposure induces long-term behavioural effects along with alterations in histone acetylation (histone H4 lysine 5 and histone H4 lysine 12) in the hippocampus and prefrontal cortex. The epigenetic effects were linked with an imbalance in histone acetyltransferase activity that was found to be increased in the prefrontal cortex of mice exposed to alcohol.

CONCLUSIONS

In conclusion, our results reveal that maternal binge-like alcohol consumption induces persistent epigenetic modifications, effects that might be associated with the long-term cognitive and behavioural impairments observed in foetal alcohol spectrum disorder models.

Chromatin remodeling complexes are involvesd in the regulation of ethanol production during static fermentation in budding yeast

The budding yeast Saccharomyces cerevisiae remains a central position among biofuel-producing organisms. However, the gene expression regulatory networks behind the ethanol fermentation is still not fully understood. Using a static fermentation model, we have examined the ethanol yields on biomass of deletion mutants for all yeast nonessential genes encoding transcription factors and their related proteins in the yeast genome. A total of 20 (about 10%) transcription factors are identified to be regulators of ethanol production during fermentation. These transcription factors are mainly involved in cell cycling, chromatin remodeling, transcription, stress response, protein synthesis and lipid synthesis. Our data provides a basis for further understanding mechanisms regulating ethanol production in budding yeast.

Epigenomic mechanisms of alcohol-induced impaired differentiation of skeletal muscle stem cells; role of Class IIA histone deacetylases

Loss of functional metabolic muscle mass remains a strong and consistent predictor of mortality among people living with human immunodeficiency virus (PLWH). PLWH have a higher incidence of alcohol use disorder (AUD), and myopathy is a significant clinical comorbidity due to AUD. One mechanism of skeletal muscle (SKM) mass maintenance and repair is by differentiation and fusion of satellite cells (SCs) to existing myofibers. Previous studies demonstrated that chronic binge alcohol (CBA) administration decreases SC differentiation potential, myogenic gene expression, and miR-206 expression in simian immunodeficiency virus (SIV)-infected male rhesus macaques and that miR-206 targets the Class IIA histone deacetylase, HDAC4. The aim of this study was to determine whether alcohol-induced increases in Class IIA HDACs mediate the observed decrease in differentiation potential of SCs. Data show that CBA dysregulated HDAC gene expression in SKM and myoblasts of SIV-infected macaques. CBA and antiretroviral therapy increased HDAC activity in SKM and this was positively correlated with HDAC4 gene expression. In vitro ethanol (ETOH) treatment increased HDAC expression during differentiation and decreased differentiation potential of myoblasts. HDAC expression was negatively correlated with fusion index and myotube formation, indicators of differentiation potential. Treatment with a Class II HDAC inhibitor, TMP195, restored differentiation in ETOH-treated myoblasts. MEF2C expression at day 3 of differentiation was positively correlated with fusion index and myotube formation. These findings suggest that an alcohol-mediated increase in Class IIA HDAC expression contributes to decreased myoblast differentiation by downregulating MEF2C, a transcription factor critical for myogenesis.

Oxidative stress and DNA damage in the mechanism of fetal alcohol spectrum disorders

This review covers molecular mechanisms involving oxidative stress and DNA damage that may contribute to morphological and functional developmental disorders in animal models resulting from exposure to alcohol (ethanol, EtOH) in utero or in embryo culture. Components covered include: (a) a brief overview of EtOH metabolism and embryopathic mechanisms other than oxidative stress; (b) mechanisms within the embryo and fetal brain by which EtOH increases the formation of reactive oxygen species (ROS); (c) critical embryonic/fetal antioxidative enzymes and substrates that detoxify ROS; (d) mechanisms by which ROS can alter development, including ROS-mediated signal transduction and oxidative DNA damage, the latter of which leads to pathogenic genetic (mutations) and epigenetic changes; (e) pathways of DNA repair that mitigate the pathogenic effects of DNA damage; (f) related indirect mechanisms by which EtOH enhances risk, for example by enhancing the degradation of some DNA repair proteins; and, (g) embryonic/fetal pathways like NRF2 that regulate the levels of many of the above components. Particular attention is paid to studies in which chemical and/or genetic manipulation of the above mechanisms has been shown to alter the ability of EtOH to adversely affect development. Alterations in the above components are also discussed in terms of: (a) individual embryonic and fetal determinants of risk and (b) potential risk biomarkers and mitigating strategies. FASD risk is likely increased in progeny which/who are biochemically predisposed via genetic and/or environmental mechanisms, including enhanced pathways for ROS formation and/or deficient pathways for ROS detoxification or DNA repair.

Social Environment and Epigenetics

Our social environment, from the microscopic to the macro-social, affects us for the entirety of our lives. One integral line of research to examine how interpersonal and societal environments can get "under the skin" is through the lens of epigenetics. Epigenetic mechanisms are adaptations made to our genome in response to our environment which include tags placed on and removed from the DNA itself to how our DNA is packaged, affecting how our genes are read, transcribed, and interact. These tags are affected by social environments and can persist over time; this may aid us in responding to experiences and exposures, both the enriched and the disadvantageous. From memory formation to immune function, the experience-dependent plasticity of epigenetic modifications to micro- and macro-social environments may contribute to the process of learning from comfort, pain, and stress to better survive in whatever circumstances life has in store.

Stem cells under the influence of alcohol: effects of ethanol consumption on stem/progenitor cells

Stem cells drive embryonic and fetal development. In several adult tissues, they retain the ability to self-renew and differentiate into a variety of specialized cells, thus contributing to tissue homeostasis and repair throughout life span. Alcohol consumption is associated with an increased risk for several diseases and conditions. Growing and developing tissues are particularly vulnerable to alcohol's influence, suggesting that stem- and progenitor-cell function could be affected. Accordingly, recent studies have revealed the possible relevance of alcohol exposure in impairing stem-cell properties, consequently affecting organ development and injury response in different tissues. Here, we review the main studies describing the effects of alcohol on different types of progenitor/stem cells including neuronal, hepatic, intestinal and adventitial progenitor cells, bone-marrow-derived stromal cell, dental pulp, embryonic and hematopoietic stem cells, and tumor-initiating cells. A better understanding of the nature of the cellular damage induced by chronic and episodic heavy (binge) drinking is critical for the improvement of current therapeutic strategies designed to treat patients suffering from alcohol-related disorders.

A Whole Methylome Study of Ethanol Exposure in Brain and Blood: An Exploration of the Utility of Peripheral Blood as Proxy Tissue for Brain in Alcohol Methylation Studies

BACKGROUND

Recent reviews have highlighted the potential use of blood-based methylation biomarkers as diagnostic and prognostic tools of current and future alcohol use and addiction. Due to the substantial overlap that often exists between methylation patterns across different tissues, including blood and brain, blood-based methylation may track methylation changes in brain; however, little work has explored the overlap in alcohol-related methylation in these tissues.

METHODS

To study the effects of alcohol on the brain methylome and identify possible biomarkers of these changes in blood, we performed a methylome-wide association study in brain and blood from 40 male DBA/2J mice that received either an acute ethanol (EtOH) or saline intraperitoneal injection. To investigate all 22 million CpGs in the mouse genome, we enriched for the methylated genomic fraction using methyl-CpG binding domain (MBD) protein capture followed by next-generation sequencing (MBD-seq). We performed association tests in blood and brain separately followed by enrichment testing to determine whether there was overlapping alcohol-related methylation in the 2 tissues.

RESULTS

The top result for brain was a CpG located in an intron of Ttc39b (p = 5.65 × 10^-08 ), and for blood, the top result was located in Espnl (p = 5.11 × 10^-08 ). Analyses implicated pathways involved in inflammation and neuronal differentiation, such as CXCR4, IL-7, and Wnt signaling. Enrichment tests indicated significant overlap among the top results in brain and blood. Pathway analyses of the overlapping genes converge on MAPKinase signaling (p = 5.6 × 10^-05 ) which plays a central role in acute and chronic responses to alcohol and glutamate receptor pathways, which can regulate neuroplastic changes underlying addictive behavior.

CONCLUSIONS

Overall, we have shown some methylation changes in brain and blood after acute EtOH administration and that the changes in blood partly mirror the changes in brain suggesting the potential for DNA methylation in blood to be biomarkers of alcohol use.

Epigenetic Discrimination: Emerging Applications of Epigenetics Pointing to the Limitations of Policies Against Genetic Discrimination

Over more than two decades, various policies have been adopted worldwide to restrict the use of individual genetic information for non-medical reasons by third parties and prevent ‘genetic discrimination’. In this paper, we bring attention to the growing interest for individual epigenetic information by insurers and forensic scientists. We question whether such interest could lead to ‘epigenetic discrimination’ – the differential adverse treatment or abusive profiling of individuals or groups based on their actual or presumed epigenetic characteristics – and argue that we might already be facing the limitations of recently adopted normative approaches against genetic discrimination. First, we highlight some similarities and differences between genetic and epigenetic modifications, and stress potential challenges to regulating epigenetic discrimination. Second, we argue that most existing normative approaches against genetic discrimination fall short in providing oversight into the field of epigenetics. We conclude with a call for discussion on the issue, and the development of comprehensive and forward-looking preventive strategies against epigenetic discrimination.

Molecular Neuropathology of Astrocytes and Oligodendrocytes in Alcohol Use Disorders

Postmortem studies reveal structural and molecular alterations of astrocytes and oligodendrocytes in both the gray and white matter (GM and WM) of the prefrontal cortex (PFC) in human subjects with chronic alcohol abuse or dependence. These glial cellular changes appear to parallel and may largely explain structural and functional alterations detected using neuroimaging techniques in subjects with alcohol use disorders (AUDs). Moreover, due to the crucial roles of astrocytes and oligodendrocytes in neurotransmission and signal conduction, these cells are very likely major players in the molecular mechanisms underpinning alcoholism-related connectivity disturbances between the PFC and relevant interconnecting brain regions. The glia-mediated etiology of alcohol-related brain damage is likely multifactorial since metabolic, hormonal, hepatic and hemodynamic factors as well as direct actions of ethanol or its metabolites have the potential to disrupt distinct aspects of glial neurobiology. Studies in animal models of alcoholism and postmortem human brains have identified astrocyte markers altered in response to significant exposures to ethanol or during alcohol withdrawal, such as gap-junction proteins, glutamate transporters or enzymes related to glutamate and gamma-aminobutyric acid (GABA) metabolism. Changes in these proteins and their regulatory pathways would not only cause GM neuronal dysfunction, but also disturbances in the ability of WM axons to convey impulses. In addition, alcoholism alters the expression of astrocyte and myelin proteins and of oligodendrocyte transcription factors important for the maintenance and plasticity of myelin sheaths in WM and GM. These changes are concomitant with epigenetic DNA and histone modifications as well as alterations in regulatory microRNAs (miRNAs) that likely cause profound disturbances of gene expression and protein translation. Knowledge is also available about interactions between astrocytes and oligodendrocytes not only at the Nodes of Ranvier (NR), but also in gap junction-based astrocyte-oligodendrocyte contacts and other forms of cell-to-cell communication now understood to be critical for the maintenance and formation of myelin. Close interactions between astrocytes and oligodendrocytes also suggest that therapies for alcoholism based on a specific glial cell type pathology will require a better understanding of molecular interactions between different cell types, as well as considering the possibility of using combined molecular approaches for more effective therapies.

Pre-conceptional and Peri-Gestational Maternal Binge Alcohol Drinking Produces Inheritance of Mood Disturbances and Alcohol Vulnerability in the Adolescent Offspring

Although binge drinking is on the rise in women of reproductive age and during pregnancy, the consequences in the offspring, in particular the inheritance of alcohol-related mood disturbances and alcohol abuse vulnerability, are still poorly investigated. In this study, we modeled both Habitual- and Binge Alcohol Drinking (HAD and BAD) in female rats by employing a two-bottle choice paradigm, with 20% alcohol and water. The exposure started 12 weeks before pregnancy and continued during gestation and lactation. The consequences induced by the two alcohol drinking patterns in female rats were assessed before conception in terms of behavioral reactivity, anxiety- and depressive-like behavior. Afterwards, from adolescence to young-adulthood, male offspring was assessed for behavioral phenotype and alcohol abuse vulnerability. At pre-conceptional time BAD female rats showed higher mean alcohol intake and preference than HAD group; differences in drinking trajectories were attenuated during pregnancy and lactation. Pre-conceptional BAD induced a prevalent depressive/anhedonic-like behavior in female rats, rather than an increase in anxiety-like behavior, as observed in HAD rats. In the adolescent offspring, peri-gestational BAD did not affect behavioral reactivity in the open field and anxiety-like behavior in the elevated plus maze. Rather, BAD dams offspring displayed higher despair-behavior and lower social interaction with respect to control- and HAD dams progeny. Notably, only binge drinking exposure increased offspring vulnerability to alcohol abuse and relapse following forced abstinence. This is the first report showing that binge-like alcohol consumption from pre-conceptional until weaning induces relevant consequences in the affective phenotype of both the mothers and the offspring, and that such effects include heightened alcohol abuse vulnerability in the offspring. These findings highlight the need for more incisive public education campaigns about detrimental consequences of peri-gestational alcohol exposure.

DNA methylation-independent growth restriction and altered developmental programming in a mouse model of preconception male alcohol exposure

The preconception environment is a significant modifier of dysgenesis and the development of environmentally-induced disease. To date, fetal alcohol spectrum disorders (FASDs) have been exclusively associated with maternal exposures, yet emerging evidence suggests male-inherited alterations in the developmental program of sperm may be relevant to the growth-restriction phenotypes of this condition. Using a mouse model of voluntary consumption, we find chronic preconception male ethanol exposure associates with fetal growth restriction, decreased placental efficiency, abnormalities in cholesterol trafficking, sex-specific alterations in the genetic pathways regulating hepatic fibrosis, and disruptions in the regulation of imprinted genes. Alterations in the DNA methylation profiles of imprinted loci have been identified in clinical studies of alcoholic sperm, suggesting the legacy of paternal drinking may transmit via heritable disruptions in the regulation of imprinted genes. However, the capacity of sperm-inherited changes in DNA methylation to broadly transmit environmentally-induced phenotypes remains unconfirmed. Using bisulphite mutagenesis and second-generation deep sequencing, we find no evidence to suggest that these phenotypes or any of the associated transcriptional changes are linked to alterations in the sperm-inherited DNA methylation profile. These observations are consistent with recent studies examining the male transmission of diet-induced phenotypes and emphasize the importance of epigenetic mechanisms of paternal inheritance beyond DNA methylation. This study challenges the singular importance of maternal alcohol exposures and suggests paternal alcohol abuse is a significant, yet overlooked epidemiological factor complicit in the genesis of alcohol-induced growth defects, and may provide mechanistic insight into the failure of FASD children to thrive postnatally.

Association of Smoking, Alcohol Use, and Betel Quid Chewing with Epigenetic Aberrations in Cancers

Numerous environmental factors such as diet, alcohol use, stress, and environmental chemicals are known to elicit epigenetic changes, leading to increased rates of cancers and other diseases. The incidence of head and neck cancer, one of the most common cancers in Taiwanese males, is increasing: oral cancer and nasopharyngeal carcinoma are ranked fourth and tenth respectively, among the top ten cancers in this group, and a major cause of cancer-related deaths in Taiwanese males. Previous studies have identified smoking, alcohol use, and betel quid chewing as the three major causes of head and neck cancers; these three social habits are commonly observed in Taiwanese males, resulting in an increasing morbidity rate of head and neck cancers in this population. In this literature review, we discuss the association between specific components of betel quid, alcohol, and tobacco, and the occurrence of head and neck cancers, lung cancer, gastrointestinal cancers, and urethral cancer. We focus on regulatory mechanisms at the epigenetic level and their oncogenic effects. The review further discusses the application of FDA-approved epigenetic drugs as therapeutic strategies against cancer.