In Utero Alcohol Exposure and the Alteration of Histone Marks in the Developing Fetus: An Epigenetic Phenomenon of Maternal Drinking

Enforced activation of the CREB/KDM2B axis prevents alcohol-induced embryonic developmental delay

Unintentional, early pregnancy alcohol consumption affects embryonic development. During the peri-implantation stage, coinciding with the transition from naive to primed pluripotency, the long isoform of KDM2B (KDM2BLF) underlies the de novo establishment of polycomb repressive complex (PRC) functions at promoters after fertilization. However, it remains unclear whether and how ethanol exposure affects this spatiotemporal chromatin setting. Here, we show that exposing peri-implantation mouse embryos to ethanol leads to impaired post-implantation development, mirrored by the delayed exit of naive pluripotency in acetaldehyde-treated embryonic stem cells. Remarkably, these abnormalities are linked to inadequate KDM2BLF expression and compromised deposition of PRC marks, which arise from cAMP response element-binding protein (CREB) inactivation. Accordingly, pharmacological activation of CREB effectively restores pluripotency transition partly dependent on KDM2BLF in vitro and ameliorates post-implantation embryonic defects in vivo. Therefore, our study highlights the pivotal role of the CREB/KDM2B axis in chromatin configuration and developmental programming, proposing potential preventive strategies against ethanol exposure-induced detrimental effects.

Contributing roles of mitochondrial dysfunction and hepatocyte apoptosis in liver diseases through oxidative stress, post-translational modifications, inflammation, and intestinal barrier dysfunction

This review provides an update on recent findings from basic, translational, and clinical studies on the molecular mechanisms of mitochondrial dysfunction and apoptosis of hepatocytes in multiple liver diseases, including but not limited to alcohol-associated liver disease (ALD), metabolic dysfunction-associated steatotic liver disease (MASLD), and drug-induced liver injury (DILI). While the ethanol-inducible cytochrome P450-2E1 (CYP2E1) is mainly responsible for oxidizing binge alcohol via the microsomal ethanol oxidizing system, it is also responsible for metabolizing many xenobiotics, including pollutants, chemicals, drugs, and specific diets abundant in n-6 fatty acids, into toxic metabolites in many organs, including the liver, causing pathological insults through organelles such as mitochondria and endoplasmic reticula. Oxidative imbalances (oxidative stress) in mitochondria promote the covalent modifications of lipids, proteins, and nucleic acids through enzymatic and non-enzymatic mechanisms. Excessive changes stimulate various post-translational modifications (PTMs) of mitochondrial proteins, transcription factors, and histones. Increased PTMs of mitochondrial proteins inactivate many enzymes involved in the reduction of oxidative species, fatty acid metabolism, and mitophagy pathways, leading to mitochondrial dysfunction, energy depletion, and apoptosis. Unique from other organelles, mitochondria control many signaling cascades involved in bioenergetics (fat metabolism), inflammation, and apoptosis/necrosis of hepatocytes. When mitochondrial homeostasis is shifted, these pathways become altered or shut down, likely contributing to the death of hepatocytes with activation of inflammation and hepatic stellate cells, causing liver fibrosis and cirrhosis. This review will encapsulate how mitochondrial dysfunction contributes to hepatocyte apoptosis in several types of liver diseases in order to provide recommendations for targeted therapeutics.

Altered Epigenetic Marks and Gene Expression in Fetal Brain, and Postnatal Behavioural Disorders, Following Prenatal Exposure of Ogg1 Knockout Mice to Saline or Ethanol

Oxoguanine glycosylase 1 (OGG1) is widely known to repair the reactive oxygen species (ROS)-initiated DNA lesion 8-oxoguanine (8-oxoG), and more recently was shown to act as an epigenetic modifier. We have previously shown that saline-exposed Ogg1 -/- knockout progeny exhibited learning and memory deficits, which were enhanced by in utero exposure to a single low dose of ethanol (EtOH) in both Ogg1 +/+ and -/- progeny, but more so in Ogg1 -/- progeny. Herein, OGG1-deficient progeny exposed in utero to a single low dose of EtOH or its saline vehicle exhibited OGG1- and/or EtOH-dependent alterations in global histone methylation and acetylation, DNA methylation and gene expression (Tet1 (Tet Methylcytosine Dioxygenase 1), Nlgn3 (Neuroligin 3), Hdac2 (Histone Deacetylase 2), Reln (Reelin) and Esr1 (Estrogen Receptor 1)) in fetal brains, and behavioural changes in open field activity, social interaction and ultrasonic vocalization, but not prepulse inhibition. OGG1- and EtOH-dependent changes in Esr1 and Esr2 mRNA and protein levels were sex-dependent, as was the association of Esr1 gene expression with gene activation mark histone H3 lysine 4 trimethylation (H3K4me3) and gene repression mark histone H3 lysine 27 trimethylation (H3K27me3) measured via ChIP-qPCR. The OGG1-dependent changes in global epigenetic marks and gene/protein expression in fetal brains, and postnatal behavioural changes, observed in both saline- and EtOH-exposed progeny, suggest the involvement of epigenetic mechanisms in developmental disorders mediated by 8-oxoG and/or OGG1. Epigenetic effects of OGG1 may be involved in ESR1-mediated gene regulation, which may be altered by physiological and EtOH-enhanced levels of ROS formation, possibly contributing to sex-dependent developmental disorders observed in Ogg1 knockout mice. The OGG1- and EtOH-dependent associations provide a basis for more comprehensive mechanistic studies to determine the causal involvement of oxidative DNA damage and epigenetic changes in ROS-mediated neurodevelopmental disorders.

Impact of alcohol exposure on neural development and network formation in human cortical organoids

Prenatal alcohol exposure is the foremost preventable etiology of intellectual disability and leads to a collection of diagnoses known as Fetal Alcohol Spectrum Disorders (FASD). Alcohol (EtOH) impacts diverse neural cell types and activity, but the precise functional pathophysiological effects on the human fetal cerebral cortex are unclear. Here, we used human cortical organoids to study the effects of EtOH on neurogenesis and validated our findings in primary human fetal neurons. EtOH exposure produced temporally dependent cellular effects on proliferation, cell cycle, and apoptosis. In addition, we identified EtOH-induced alterations in post-translational histone modifications and chromatin accessibility, leading to impairment of cAMP and calcium signaling, glutamatergic synaptic development, and astrocytic function. Proteomic spatial profiling of cortical organoids showed region-specific, EtOH-induced alterations linked to changes in cytoskeleton, gliogenesis, and impaired synaptogenesis. Finally, multi-electrode array electrophysiology recordings confirmed the deleterious impact of EtOH on neural network formation and activity in cortical organoids, which was validated in primary human fetal tissues. Our findings demonstrate progress in defining the human molecular and cellular phenotypic signatures of prenatal alcohol exposure on functional neurodevelopment, increasing our knowledge for potential therapeutic interventions targeting FASD symptoms.

The impact of early-life environment on absence epilepsy and neuropsychiatric comorbidities

This review discusses the long-term effects of early-life environment on epileptogenesis, epilepsy, and neuropsychiatric comorbidities with an emphasis on the absence epilepsy. The WAG/Rij rat strain is a well-validated genetic model of absence epilepsy with mild depression-like (dysthymia) comorbidity. Although pathologic phenotype in WAG/Rij rats is genetically determined, convincing evidence presented in this review suggests that the absence epilepsy and depression-like comorbidity in WAG/Rij rats may be governed by early-life events, such as prenatal drug exposure, early-life stress, neonatal maternal separation, neonatal handling, maternal care, environmental enrichment, neonatal sensory impairments, neonatal tactile stimulation, and maternal diet. The data, as presented here, indicate that some early environmental events can promote and accelerate the development of absence seizures and their neuropsychiatric comorbidities, while others may exert anti-epileptogenic and disease-modifying effects. The early environment can lead to phenotypic alterations in offspring due to epigenetic modifications of gene expression, which may have maladaptive consequences or represent a therapeutic value. Targeting DNA methylation with a maternal methyl-enriched diet during the perinatal period appears to be a new preventive epigenetic anti-absence therapy. A number of caveats related to the maternal methyl-enriched diet and prospects for future research are discussed.

Adverse Prenatal Exposures and Fetal Brain Development: Insights From Advanced Fetal Magnetic Resonance Imaging

Converging evidence from clinical and preclinical studies suggests that fetal vulnerability to adverse prenatal exposures increases the risk for neuropsychiatric diseases such as autism spectrum disorder, schizophrenia, and depression. Recent advances in fetal magnetic resonance imaging have allowed us to characterize typical fetal brain growth trajectories in vivo and to interrogate structural and functional alterations associated with intrauterine exposures, such as maternal stress, environmental toxins, drugs, and obesity. Here, we review proposed mechanisms for how prenatal influences disrupt neurodevelopment, including the role played by maternal and fetal inflammatory responses. We summarize insights from magnetic resonance imaging research in fetuses, highlight recent discoveries in normative fetal development using quantitative magnetic resonance imaging techniques (i.e., three-dimensional volumetry, proton magnetic resonance spectroscopy, placental diffusion imaging, and functional imaging), and discuss how baseline trajectories are shaped by prenatal exposures.

Epigenetic changes in inflammatory genes and the protective effect of cooked rhubarb on pancreatic tissue of rats with chronic alcohol exposure

Chronic alcohol consumption, which is observed worldwide, can damage pancreatic tissue and promote pancreatitis. Rhubarb is a widely used traditional Chinese herbal medicine for treating pancreatitis in China. However, few pharmacological studies have investigated its epigenetic regulation. In this study, we investigated whether chronic exposure to alcohol can alter inflammatory gene expression and the epigenetic regulation effect of cooked rhubarb in the pancreatic tissue of rats. First, changes in inflammatory cytokine DNA methylation (IL-10, IL-1α, TNF-α, NF-κB and TGF-β) were detected in pancreatic tissue of Sprague-Dawley rats with varying alcohol exposure times (4, 6, 8, or 12 weeks), and then with varying doses of cooked rhubarb treatment (3, 6, or 12 g/day). DNA methylation levels, related RNA concentrations and protein expression of specific inflammatory cytokines, and histopathological score were analysed in pancreatic tissue of Sprague-Dawley rats. The results showed that chronic alcohol exposure (8 weeks) reduced the level of IL-1α DNA methylation and increased its protein expression in acinar cells (P < 0.05). In the acinar cells, the level of IL-10 DNA methylation increased, resulting in a reduction of protein expression (P < 0.05). Simultaneously, chronic alcohol exposure increased the pathological damage to the pancreas (P < 0.05). Finally, cooked rhubarb treatment (3 g/kg/day) effectively alleviated these changes in pancreatic tissue from chronic alcohol exposure (P < 0.05). These results indicate that chronic exposure to alcohol leads to changes in DNA methylation and protein expression of inflammatory genes, and cooked rhubarb may have a protective effect on the pancreatic tissue of rats.

Sex- and OGG1-dependent reversal of in utero ethanol-initiated changes in postnatal behaviour by neonatal treatment with the histone deacetylase inhibitor trichostatin A (TSA) in oxoguanine glycosylase 1 (Ogg1) knockout mice

Oxoguanine glycosylase 1 (OGG1) is both a DNA repair enzyme and an epigenetic modifier. We assessed behavioural abnormalities in OGG1-deficient progeny exposed once in utero to a low dose of ethanol (EtOH) and treated postnatally with a global histone deacetylase inhibitor, trichostatin A (TSA). The goal of this study was to determine if neurodevelopmental disorders initiated in the fetal brain by in utero exposure to EtOH could be mitigated by postnatal treatment with TSA. EtOH and TSA alone improved preference for novel location (short-term, 90 min) and novel object (long-term, 24 h) sex- and OGG1-dependently. Combined EtOH/TSA treatment reversed these effects in the short-term novel location test sex- and OGG1-dependently. In females but not males, the incidence of high shredders of nesting material was not altered by either TSA or EtOH alone, but was reduced by combined EtOH/TSA treatment in +/+ progeny. Similar but non-significant effects were observed in Ogg1 -/- females. Accelerated rotarod performance was enhanced by both EtOH and TSA alone in only male Ogg1 +/+ but not -/- progeny, and was not altered by combined EtOH/TSA exposure. The OGG1-dependent effects of EtOH and TSA particularly on novel location and the incidence of high shredders, and the reversal of EtOH effects on these parameters by combined EtOH/TSA treatment, suggests both xenobiotics may alter behaviour via a mechanism involving OGG1 acting as an epigenetic modifier, in addition to repairing DNA damage. These preliminary results suggest that the postnatal use of more selective epigenetic modifying agents may constitute a novel strategy for mitigating some components of ROS-initiated neurodevelopmental disorders.

Exogenous ethanol treatment alleviates oxidative damage of Arabidopsis thaliana under conditions of high-light stress

Abiotic stresses, such as high light and salinity, are major factors that limit crop productivity and sustainability worldwide. Chemical priming is a promising strategy for improving the abiotic stress tolerance of plants. Recently, we discovered that ethanol enhances high-salinity stress tolerance in Arabidopsis thaliana and rice by detoxifying reactive oxygen species (ROS). However, the effect of ethanol on other abiotic stress responses is unclear. Therefore, we investigated the effect of ethanol on the high-light stress response. Measurement of chlorophyll fluorescence showed that ethanol mitigates photoinhibition under high-light stress. Staining with 3,3'-diaminobenzidine (DAB) showed that the accumulation of hydrogen peroxide (H₂O₂) was inhibited by ethanol under high-light stress conditions in A. thaliana. We found that ethanol increased the gene expressions and enzymatic activities of antioxidative enzymes, including ASCORBATE PEROXIDASE1 (AtAPX1), Catalase (AtCAT1 and AtCAT2). Moreover, the expression of flavonoid biosynthetic genes and anthocyanin contents were upregulated by ethanol treatment during exposure to high-light stress. These results imply that ethanol alleviates oxidative damage from high-light stress in A. thaliana by suppressing ROS accumulation. Our findings support the hypothesis that ethanol improves tolerance to multiple stresses in field-grown crops.

Young-Onset Carcinogenesis - The Potential Impact of Perinatal and Early Life Metabolic Influences on the Epigenome

The last decade has witnessed a significant rise in cancers in young adults. This spectrum of solid organ cancers occurring in individuals under the age of 40 years (some reports extending the age-group to <50 years) in whom aetiology of cancer cannot be traced back to pre-existing familial cancer syndromes, is referred to as termed young-, or early- onset cancers. The underlying causes for young-onset carcinogenesis have remained speculative. We recently proposed a hypothesis to explain the causation of this entity. We propose that the risk for young-onset cancer begins in the perinatal period as a result of the exposure of the foetus to stressors, including maternal malnutrition, smoking or alcohol, with the consequent epigenomic events triggered to help the foetus cope/adapt. Exposure to the same stressors, early in the life of that individual, facilitates a re-activation of these 'responses designed to be protective' but ultimately resulting in a loss of regulation at a metabolic and/or genetic level culminating in the evolution of the neoplastic process. In this manuscript, we will provide a rationale for this hypothesis and present evidence to further support it by clarifying the pathways involved, including elucidating a role for Acetyl-CoA and its effect on the epigenome. We present strategies and experimental models that can be used to test the hypothesis. We believe that a concerted effort by experts in different, but complementary fields, such as epidemiology, genetics, and epigenetics united towards the common goal of deciphering the underlying cause for young-onset cancers is the urgent need. Such efforts might serve to prove, or disprove, the presented hypothesis. However, the more important aim is to develop strategies to reverse the disturbing trend of the rise in young-onset cancers.

Folic acid prevents functional and structural heart defects induced by prenatal ethanol exposure

State-of-the-art biophotonic tools captured blood flow and endocardial cushion volumes in tiny beating quail embryo hearts, an accessible model for studying four-chambered heart development. Both hemodynamic flow and endocardial cushion volumes were altered with ethanol exposure but normalized when folic acid was introduced with ethanol. Folic acid supplementation preserved hemodynamic function that is intimately involved in sculpting the heart from the earliest stages of heart development.

Alcohol messages disseminated to pregnant women by midwives

BACKGROUND

Pregnant women frequently report inconsistent messages regarding alcohol consumption from their healthcare providers. Midwives play a major role in prenatal care. However, little research has examined alcohol-related information provided by midwives.

OBJECTIVE

To examine alcohol-related messages disseminated to pregnant women by midwives.

METHODS

In 2018, 61 certified professional midwives (CPMs) and certified nurse-midwives (CNMs) were recruited from professional organizations in a southwestern state. Midwives responded to an online cross-sectional survey containing the prompt: "A pregnant patient confides in you that she drinks alcohol. She then asks you to tell her a "safe" level of alcohol consumption that won't cause harm to her unborn fetus. How would you respond?" Open-ended responses were analyzed through content analysis and categorized using an inductive approach.

RESULTS

Responses were grouped into five non-exclusive themes: "harmful effects and unknown safe limits" (77.0%); "abstaining is best" (50.8%); "light drinking is acceptable" (16.4%); "describe your drinking" (21.3%); "I will refer you" (16.4%). The most frequently shared messages were "safe levels of prenatal alcohol use are unknown" (68.9%) and "discontinue alcohol during pregnancy" (45.9%). However, some messages contradicted US dietary guidelines, including "a little bit of alcohol unlikely to cause harm" (11.5%); "cut-down if having more than 1-2 drinks per occasion" (4.9%); and "if you must drink, wine is best" (1.6%). CPMs were less likely to share abstinence messages (p = .003) and more likely to suggest referrals (p = .024), compared to CNMs.

CONCLUSION

Concerted efforts are needed to ensure information disseminated aligns with health guidelines and encourages abstinence during pregnancy.

Dissemination of Prenatal Drinking Guidelines: A Preliminary Study Examining Personal Alcohol Use Among Midwives in a Southwestern US State

INTRODUCTION

The constellation of birth defects seen in fetuses exposed to alcohol in utero have been described as fetal alcohol spectrum disorders. Evidence suggests that health care providers' communication practices regarding prenatal alcohol use could have beneficial outcomes. There is a paucity of investigations, however, that have examined the health professionals' personal alcohol use and prenatal alcohol recommendations they provide.

METHODS

This study sought to examine and compare midwives' personal alcohol use and communication practices regarding prenatal alcohol consumption. Certified nurse-midwives (CNMs) and certified professional midwives (CPMs) in a southwestern US state participated. Inclusion criteria included training in prenatal care, labor, birth, and membership in a midwife professional organization. Personal drinking behaviors were assessed with Alcohol Use Disorder Identification Test-Consumption (AUDIT-C).

RESULTS

All midwives (N = 61; 100%) reported they typically screened a patient for alcohol use during an initial prenatal visit. However, 5 (8.2%) respondents opted for recommendations that advised patients to drink once in a while. Similarly, 4 (6.6%) midwives counseled no more than one drink per day. In the cohort of participants (n = 40) with AUDIT-C scores, 25 (62.5%) engaged in nonrisky drinking (AUDIT-C scores <3). Most respondents (n = 39 of 40; 97.5%) typically consumed 1 to 2 standard drinks on the day they drank. There was no statistically significant difference in mean overall AUDIT-C scores between CNMs and CPMs (P = .42). When examining midwives' (1) responses on the AUDIT-C questionnaire, (2) nonrisky or risky drinking behaviors, and 3) communication practices regarding prenatal alcohol use, Fisher's exact test showed no statistically significant differences between CNMs and CPMs.

DISCUSSION

Results of this study highlight the importance of advocating healthy lifestyles among health care professionals while also promoting communication practices that align with national alcohol guidelines. Future investigations that examine associations between health care professionals' personal alcohol use and type or effectiveness of services offered to patients may be beneficial.

Murine Models for the Study of Fetal Alcohol Spectrum Disorders: An Overview

Prenatal alcohol exposure is associated to different physical, behavioral, cognitive, and neurological impairments collectively known as fetal alcohol spectrum disorder. The underlying mechanisms of ethanol toxicity are not completely understood. Experimental studies during human pregnancy to identify new diagnostic biomarkers are difficult to carry out beyond genetic or epigenetic analyses in biological matrices. Therefore, animal models are a useful tool to study the teratogenic effects of alcohol on the central nervous system and analyze the benefits of promising therapies. Animal models of alcohol spectrum disorder allow the analysis of key variables such as amount, timing and frequency of ethanol consumption to describe the harmful effects of prenatal alcohol exposure. In this review, we aim to synthetize neurodevelopmental disabilities in rodent fetal alcohol spectrum disorder phenotypes, considering facial dysmorphology and fetal growth restriction. We examine the different neurodevelopmental stages based on the most consistently implicated epigenetic mechanisms, cell types and molecular pathways, and assess the advantages and disadvantages of murine models in the study of fetal alcohol spectrum disorder, the different routes of alcohol administration, and alcohol consumption patterns applied to rodents. Finally, we analyze a wide range of phenotypic features to identify fetal alcohol spectrum disorder phenotypes in murine models, exploring facial dysmorphology, neurodevelopmental deficits, and growth restriction, as well as the methodologies used to evaluate behavioral and anatomical alterations produced by prenatal alcohol exposure in rodents.

Curcumin treatment attenuates alcohol-induced alterations in a mouse model of foetal alcohol spectrum disorders

Alcohol exposure during development produces physical and mental abnormalities in the foetus that result in long-term molecular adjustments in the brain, which could underlie the neurobehavioural deficits observed in individuals suffering from foetal alcohol spectrum disorders. In this study, we assessed the effects of curcumin on cognitive impairments caused by prenatal and lactational alcohol exposure (PLAE). Furthermore, we examined whether curcumin could counteract the molecular alterations that may underlie these behavioural impairments. We focused on inflammatory and epigenetic mechanisms by analysing the expression of pro-inflammatory mediators, such as IL-6, TNF-α, and NF-κB, in the hippocampus and prefrontal cortex, as well as microglia and astrocyte activation in the dentate gyrus. We also assessed the activity of histone acetyltransferase in these brain areas. To model binge alcohol drinking, we exposed pregnant C57BL/6 mice to a 20% v/v alcohol solution during gestation and lactation, with limited access periods. We treated male offspring with curcumin during postnatal days (PD28-35) and then evaluated their behaviour in adulthood (PD60). Our results showed that curcumin treatment during the peri-adolescence period improved the anxiety and memory deficits observed in PLAE mice. At the molecular level, we found enhanced histone acetyltransferase activity in mice subjected to PLAE that curcumin treatment could not reverse to baseline levels. These mice also showed increased expression of pro-inflammatory mediators, which could be rescued by curcumin treatment. They also displayed astrogliosis and microglia activation. Our study provides further evidence to support the use of curcumin as a therapeutic agent for counteracting behavioural and molecular alterations induced by PLAE.

Histone deacetylases inhibitor trichostatin A reverses anxiety-like symptoms and memory impairments induced by maternal binge alcohol drinking in mice

BACKGROUND

Alcohol exposure during development has detrimental effects, including a wide range of physical, cognitive and neurobehavioural anomalies known as foetal alcohol spectrum disorders. However, alcohol consumption among pregnant woman is an ongoing latent health problem.

AIM

In the present study, the effects of trichostatin A (TSA) on emotional and cognitive impairments caused by prenatal and lactational alcohol exposure were assessed. TSA is an inhibitor of class I and II histone deacetylases enzymes (HDAC), and for that, HDAC4 activity was determined. We also evaluated mechanisms underlying the behavioural effects observed, including the expression of brain-derived neurotrophic factor (BDNF) in discrete brain regions and newly differentiated neurons in the dentate gyrus (DG).

METHODS

C57BL/6 female pregnant mice were used, with limited access to a 20% v/v alcohol solution as a procedure to model binge alcohol drinking during gestation and lactation. Male offspring were treated with TSA during the postnatal days (PD28-35) and behaviourally evaluated (PD36-55).

RESULTS

Early alcohol exposure mice presented increased anxiogenic-like responses and memory deterioration - effects that were partially reversed with TSA. Early alcohol exposure produces a decrease in BDNF levels in the hippocampus (HPC) and prefrontal cortex, a reduction of neurogenesis in the DG and increased activity levels of the HDAC4 in the HPC.

CONCLUSIONS

Such findings support the participation of HDAC enzymes in cognitive and emotional alterations induced by binge alcohol consumption during gestation and lactation and would indicate potential benefits of HDAC inhibitors for some aspects of foetal alcohol spectrum disorders.

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.

Low birth weight in a subnormal urban cluster under Family Health Strategy’s care

Abstract Objectives: to identify the prevalence and to analyze the factors associated with low birth weight in a subnormal urban cluster in Pernambuco under Family Health Strategy’s care. Methods: a cross-sectional study with a census sample carried out between July and October in 2015. The variables studied were age and years of maternal schooling, social status, housing, water supply, waste disposal, prenatal care, alcohol consumption and cigarette smoking during pregnancy, along with gender, birth weight and prematurity. Stata 12.1 was utilized in order to understand the factors associated with low birth weight through uni-and-multivariate Poisson analysis, adjusted and gross prevalence ratios, composing a final statistical model considering p value <0.05 for statistical significance. Results: regarding the 294 children the LBW prevalence was 12.2% (CI95% = 8.7-16.5). Children whose mothers reported drinking during pregnancy were 2.78 times more at risk of being born with low birth weight (p<0.001) when compared with children whose mothers did not report this practice in gestation. Conclusions: the study evidenced the relevance maternal habits bears in the newborns’ health.

Alcohol metabolism contributes to brain histone acetylation

Emerging evidence suggests that epigenetic regulation is dependent on metabolic state, and implicates specific metabolic factors in neural functions that drive behaviour¹. In neurons, acetylation of histones relies on the metabolite acetyl-CoA, which is produced from acetate by chromatin-bound acetyl-CoA synthetase 2 (ACSS2)². Notably, the breakdown of alcohol in the liver leads to a rapid increase in levels of blood acetate³, and alcohol is therefore a major source of acetate in the body. Histone acetylation in neurons may thus be under the influence of acetate that is derived from alcohol⁴, with potential effects on alcohol-induced gene expression in the brain, and on behaviour⁵. Here, using in vivo stable-isotope labelling in mice, we show that the metabolism of alcohol contributes to rapid acetylation of histones in the brain, and that this occurs in part through the direct deposition of acetyl groups that are derived from alcohol onto histones in an ACSS2-dependent manner. A similar direct deposition was observed when mice were injected with heavy-labelled acetate in vivo. In a pregnant mouse, exposure to labelled alcohol resulted in the incorporation of labelled acetyl groups into gestating fetal brains. In isolated primary hippocampal neurons ex vivo, extracellular acetate induced transcriptional programs related to learning and memory, which were sensitive to ACSS2 inhibition. We show that alcohol-related associative learning requires ACSS2 in vivo. These findings suggest that there is a direct link between alcohol metabolism and gene regulation, through the ACSS2-dependent acetylation of histones in the brain.