Sexually dimorphic effects of maternal alcohol intake and adrenalectomy on left ventricular hypertrophy in rat offspring

Effect of docosahexaenoic acid and olive oil supplementation on pup weight in alcohol-exposed pregnant rats

Background

Low birth weight has been observed in offspring of alcoholic mothers due likely to unresolved inflammation and oxidative injury. Dietary lipids play a role in inflammation and its resolution. The primary objective was to investigate the effect of DHA and olive oil on the birth weight of pups born to alcohol-exposed dams.

Methods

Pregnant rats were randomized to the control or three treatment (alcohol) groups. From gestational days (GD) 8-19, the control group received daily olive oil and malto/dextrose, whereas groups 2 and 3 received olive oil and low-dose alcohol or high-dose alcohol, respectively. Group 4 received daily DHA and high-dose alcohol. The dam's blood was collected on GD 15 and 20 for cytokine analysis. Dams were sacrificed on GD 20. The mean birth weight of pups was compared by one-way ANOVA with post hoc Duncan's test.

Results

There was a significant increase in the pups' mean birth weight in the high-dose alcohol/DHA and high-dose alcohol/olive oil. Higher pro-inflammatory cytokines (IL-1β and IL-12p70) were noted in the alcohol-exposed dams.

Conclusions

DHA and olive oil supplementation in alcohol-exposed pregnant rats significantly increased their pups' birth weight despite having high pro-inflammatory cytokines. The mechanism of this effect remains to be determined.

Prenatal ethanol exposure and changes in fetal neuroendocrine metabolic programming

Prenatal ethanol exposure (PEE) (mainly through maternal alcohol consumption) has become widespread. However, studies suggest that it can cause intrauterine growth retardation (IUGR) and multi-organ developmental toxicity in offspring, and susceptibility to various chronic diseases (such as neuropsychiatric diseases, metabolic syndrome, and related diseases) in adults. Through ethanol's direct effects and its indirect effects mediated by maternal-derived glucocorticoids, PEE alters epigenetic modifications and organ developmental programming during fetal development, which damages the offspring health and increases susceptibility to various chronic diseases after birth. Ethanol directly leads to the developmental toxicity of multiple tissues and organs in many ways. Regarding maternal-derived glucocorticoid-mediated IUGR, developmental programming, and susceptibility to multiple conditions after birth, ethanol induces programmed changes in the neuroendocrine axes of offspring, such as the hypothalamus-pituitary-adrenal (HPA) and glucocorticoid-insulin-like growth factor 1 (GC-IGF1) axes. In addition, the differences in ethanol metabolic enzymes, placental glucocorticoid barrier function, and the sensitivity to glucocorticoids in various tissues and organs mediate the severity and sex differences in the developmental toxicity of ethanol exposure during pregnancy. Offspring exposed to ethanol during pregnancy have a "thrifty phenotype" in the fetal period, and show "catch-up growth" in the case of abundant nutrition after birth; when encountering adverse environments, these offspring are more likely to develop diseases. Here, we review the developmental toxicity, functional alterations in multiple organs, and neuroendocrine metabolic programming mechanisms induced by PEE based on our research and that of other investigators. This should provide new perspectives for the effective prevention and treatment of ethanol developmental toxicity and the early prevention of related fetal-originated diseases.

The interaction of genetic sex and prenatal alcohol exposure on health across the lifespan

Prenatal alcohol exposure (PAE) can reprogram the development of cells and tissues, resulting in a spectrum of physical and neurobehavioral teratology. PAE immediately impacts fetal growth, but its effects carry forward post-parturition, into adolescence and adulthood, and can result in a cluster of disabilities, collectively termed Fetal Alcohol Spectrum Disorders. Emerging preclinical and clinical research investigating neurological and behavioral outcomes in exposed offspring point to genetic sex as an important modifier of the effects of PAE. In this review, we discuss the literature on sex differences following PAE, with studies spanning the fetal period through adulthood, and highlight gaps in research where sex differences are likely, but currently under-investigated. Understanding how sex and PAE interact to affect offspring health outcomes across the lifespan is critical for identifying the full complement of PAE-associated secondary conditions, and for refining targeted interventions to improve the quality of life for individuals with PAE.

Sexual dimorphism in neurological function after SCI is associated with disrupted neuroinflammation in both injured spinal cord and brain

Whereas human spinal cord injury (SCI) is more common in men, the prevalence is growing in women. However, little is known about the effect of biological sex on brain dysfunction and injury mechanisms. To model the highest per capita rate of injury (ages between 16 and 30 years old) in humans, in the present study, young adult or a young/middle-aged male and female C57BL/6 mice were subjected to moderate contusion SCI. When mice were injured at 10-12-week-old, transcriptomic analysis of inflammation-related genes and flow cytometry revealed a more aggressive neuroinflammatory profile in male than females following 3 d SCI, ostensibly driven by sex-specific changes myeloid cell function rather than cell number. Female mice were generally more active at baseline, as evidenced by greater distance traveled in the open field. After SCI, female mice had more favorable locomotor function than male animals. At 13 weeks post-injury, male mice showed poor performance in cognitive and depressive-like behavioral tests, while injured female mice showed fewer deficits in these tasks. However, when injured at 6 months old followed by 8 months post-injury, male mice had considerably less inflammatory activation compared with female animals despite having similar or worse outcomes in affective, cognitive, and motor tasks. Collectively, these findings indicate that sex differences in functional outcome after SCI are associated with the age at onset of injury, as well as disrupted neuroinflammation not only at the site of injury but also in remote brain regions. Thus, biological sex should be considered when designing new therapeutic agents.

Maternal choline supplementation in a rat model of periconceptional alcohol exposure: Impacts on the fetus and placenta

BACKGROUND

Maternal choline supplementation in rats can ameliorate specific neurological and behavioral abnormalities caused by alcohol exposure during pregnancy. We tested whether choline supplementation ameliorates fetal growth restriction and molecular changes in the placenta associated with periconceptional ethanol exposure (PCE) in the rat.

METHODS

Sprague Dawley dams were given either 12.5% ethanol (PCE) or 0% ethanol (Con) in a liquid diet from 4 days prior to 4 days after conception. At day 5 of pregnancy, dams were either placed on a standard chow (1.6 g choline/kg chow) or an intermediate chow (2.6 g choline/kg chow). On day 10 of pregnancy, a subset of the intermediate dams were placed on a chow further supplemented with choline (7.2 g choline/kg chow), resulting in 6 groups. Fetuses and placentas were collected on day 20 of pregnancy for analysis.

RESULTS

Choline supplementation resulted in increased fetal weight at late gestation, ameliorating the deficits due to PCE. This was most pronounced in litters on a standard chow during pregnancy. Choline also increased fetal liver weight and decreased fetal brain:liver ratio, independent of alcohol exposure. Placental weight was reduced as choline levels in the chow increased, particularly in female placentas. This resulted in a greater ratio of fetal:placental weight, suggesting increased placental efficiency. Global DNA methylation in the placenta was altered in a sex-specific manner by both PCE and choline. However, the increased glycogen deposition in female placentas, previously reported in this PCE model, was not prevented by choline supplementation.

CONCLUSIONS

Our results suggest that choline has the potential to ameliorate fetal growth restriction associated with PCE and improve placental efficiency following prenatal alcohol exposure. Our study highlights the importance of maternal nutrition in moderating the severity of adverse fetal and placental outcomes that may arise from prenatal alcohol exposure around the time of conception.

Sexual dimorphisms in brain gene expression in the growth-restricted guinea pig can be modulated with intra-placental therapy

BACKGROUND

Fetal responses to adverse pregnancy environments are sex-specific. In fetal guinea pigs (GPs), we assessed morphology and messenger RNA (mRNA) expression in fetal growth-restricted (FGR) tissues at midpregnancy.

METHODS

Female GPs were assigned either an ad libitum diet (C) or 30% restricted diet (R) prior to pregnancy to midpregnancy. At midpregnancy, a subset of R females underwent ultrasound-guided nanoparticle (NP) injection to enhance placental function. Five days later, fetuses were sampled. Fetal brain, heart, and liver were assessed for morphology (hematoxylin and eosin), proliferation (Ki67), and vascularization (CD31), as well as expression of inflammatory markers.

RESULTS

R fetuses were 19% lighter with reduced organ weights and evidence of brain sparing compared to controls. No increased necrosis, proliferation, or vascularization was found between C and R nor male or female fetal organs. Sexual dimorphism in mRNA expression of Tgfβ and Ctgf was observed in R but not C fetal brains: increased expression in females. NP treatment increased fetal brain mRNA expression of Tgfβ and Ctgf in R males, abolishing the significant difference observed in untreated R fetuses.

CONCLUSIONS

Sex-specific differences in mRNA expression in the fetal brain with FGR could impart a potential survival bias and may be useful for the development of treatments for obstetric diseases.

IMPACT

Male and female fetuses respond differently to adverse pregnancy environments. Under fetal growth restriction conditions, inflammatory marker mRNA expression in the fetal brain was higher in females compared to males. Differences in gene expression between males and females may confer a selective advantage/disadvantage under adverse conditions. Better characterization of sexual dimorphism in fetal development will aid better development of treatments for obstetric diseases.

Expression of Stress-Mediating Genes is Increased in Term Placentas of Women with Chronic Self-Perceived Anxiety and Depression

Anxiety, chronical stress, and depression during pregnancy are considered to affect the offspring, presumably through placental dysregulation. We have studied the term placentae of pregnancies clinically monitored with the Beck’s Anxiety Inventory (BAI) and Edinburgh Postnatal Depression Scale (EPDS). A cutoff threshold for BAI/EPDS of 10 classed patients into an Index group (>10, n = 23) and a Control group (<10, n = 23). Cortisol concentrations in hair (HCC) were periodically monitored throughout pregnancy and delivery. Expression differences of main glucocorticoid pathway genes, i.e., corticotropin-releasing hormone (CRH), 11β-hydroxysteroid dehydrogenase (HSD11B2), glucocorticoid receptor (NR3C1), as well as other key stress biomarkers (Arginine Vasopressin, AVP and O-GlcNAc transferase, OGT) were explored in medial placentae using real-time qPCR and Western blotting. Moreover, gene expression changes were considered for their association with HCC, offspring, gender, and birthweight. A significant dysregulation of gene expression for CRH, AVP, and HSD11B2 genes was seen in the Index group, compared to controls, while OGT and NR3C1 expression remained similar between groups. Placental gene expression of the stress-modulating enzyme 11β-hydroxysteroid dehydrogenase (HSD11B2) was related to both hair cortisol levels (Rho = 0.54; p < 0.01) and the sex of the newborn in pregnancies perceived as stressful (Index, p < 0.05). Gene expression of CRH correlated with both AVP (Rho = 0.79; p < 0.001) and HSD11B2 (Rho = 0.45; p < 0.03), and also between AVP with both HSD11B2 (Rho = 0.6; p < 0.005) and NR3C1 (Rho = 0.56; p < 0.03) in the Control group but not in the Index group; suggesting a possible loss of interaction in the mechanisms of action of these genes under stress circumstances during pregnancy.

Prenatal caffeine exposure increases the susceptibility to non-alcoholic fatty liver disease in female offspring rats via activation of GR-C/EBPα-SIRT1 pathway

This study aimed to evaluate female adult offspring induced by prenatal caffeine exposure (PCE) are susceptible to non-alcoholic fatty liver disease (NAFLD) and to explore the underlying programming mechanisms. Pregnant rats were intragastrically administered caffeine (30, 60, and 120 mg/kg.d) on gestational day (GD) 9-20. The female adult offspring were randomly divided into three groups: offspring without or with chronic stress during postnatal week (PW) 10-12 and PW28 offspring. Results showed that PW28 PCE female offspring had a higher hepatic triglyceride content and Kleiner scores, accompanied by elevated serum corticosterone levels. Moreover, the expression levels of hepatic glucocorticoid receptor (GR), CCAAT enhancer binding protein α (C/EBPα), fatty acid synthetase (FASN) and the transcription factor-sterol regulatory element binding protein 1c (SREBP1c) were increased, but SIRT1 expression was decreased. The fetal rats and PW12 offspring with chronic stress exhibited similar changes as PW28 offspring, accompanied by increased levels of H3K14ac and H3K27ac in the SREBP1c and FASN gene promoters. These effects were also observed by treating L02 cells with cortisol and were partially reversed by GR or C/EBPα siRNA or treatment with the SIRT1 agonist resveratrol. Taken together, PCE-induced high glucocorticoids levels enhanced histone modifications and expression of SREBP1c and FASN via activation of the GR-C/EBPα-SIRT1 pathway in utero. This enhanced female fetal hepatic triglyceride synthesis and continued throughout postnatal and adult life, increasing the susceptibility to adult NAFLD.

Exposure to maternal obesity alters gene expression in the preimplantation ovine conceptus

Background

Embryonic and fetal exposure to maternal obesity causes several maladaptive morphological and epigenetic changes in exposed offspring. The timing of these events is unclear, but changes can be observed even after a short exposure to maternal obesity around the time of conception. The hypothesis of this work is that maternal obesity influences the ovine preimplantation conceptus early in pregnancy, and this exposure will affect gene expression in embryonic and extraembryonic tissues.

Results

Obese and lean ewe groups were established by overfeeding or normal feeding, respectively. Ewes were then bred to genetically similar rams. Conceptuses were collected at day 14 of gestation. Morphological assessments were made, conceptuses were sexed by genomic PCR analysis, and samples underwent RNA-sequencing analysis. While no obvious morphological differences existed between conceptuses, differentially expressed genes (≥ 2-fold; ≥ 0.2 RPKM; ≤ 0.05 FDR) were detected based on maternal obesity exposure (n = 21). Also, differential effects of maternal obesity were noted on each conceptus sex (n = 347). A large portion of differentially expressed genes were associated with embryogenesis and placental development.

Conclusions

Findings reveal that the preimplantation ovine conceptus genome responds to maternal obesity in a sex-dependent manner. The sexual dimorphism in response to the maternal environment coupled with changes in placental gene expression may explain aberrations in phenotype observed in offspring derived from obese females.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5120-0) contains supplementary material, which is available to authorized users.

Alcohol and fetoplacental vasoconstrictor reactivity

Alcohol abuse during pregnancy is a well-known factor in fetal morbidity, including smaller fetal size. We have shown that chronic hypoxia, considered the main pathogenetic factor in intrauterine growth restriction, elevates fetoplacental vascular resistance (and vasoconstrictor reactivity) and thus, presumably, reduces placental blood flow. We thus hypothesized that alcohol may affect the fetus - in addition to other mechanisms - by altering fetoplacental vascular resistance and/or reactivity. Using isolated, double-perfused rat placenta model, we found that maternal alcohol intake in the last third of gestation doubled the vasoconstrictor responses to angiotensin II but did not affect resting vascular resistance. Reactivity to acute hypoxic challenges was unchanged. Chronic maternal alcohol intake in a rat model alters fetoplacental vasculature reactivity; nevertheless, these changes do not appear as serious as other detrimental effects of alcohol on the fetus.

Early sex-dependent differences in response to environmental stress

Developmental plasticity enables the appearance of long-term effects in offspring caused by exposure to environmental stressors during embryonic and foetal life. These long-term effects can be traced to pre- and post-implantation development, and in both cases, the effects are usually sex specific. During preimplantation development, male and female embryos exhibit an extensive transcriptional dimorphism mainly driven by incomplete X chromosome inactivation. These early developmental stages are crucial for the establishment of epigenetic marks that will be conserved throughout development, making it a particularly susceptible period for the appearance of long-term epigenetic-based phenotypes. Later in development, gonadal formation generates hormonal differences between the sexes, and male and female placentae exhibit different responses to environmental stressors. The maternal environment, including hormones and environmental insults during pregnancy, contributes to sex-specific placental development that controls genetic and epigenetic programming during foetal development, regulating sex-specific differences, including sex-specific epigenetic responses to environmental hazards, leading to long-term effects. This review summarizes several human and animal studies examining sex-specific responses to environmental stressors during both the periconception period (caused by differences in sex chromosome dosage) and placental development (caused by both sex chromosomes and hormones). The identification of relevant sex-dependent trajectories caused by sex chromosomes and/or sex hormones is essential to define diagnostic markers and prevention/intervention protocols.

Maternal obese-type gut microbiota differentially impact cognition, anxiety and compulsive behavior in male and female offspring in mice

Maternal obesity is known to predispose offspring to metabolic and neurodevelopmental abnormalities. While the mechanisms underlying these phenomena are unclear, high fat diets dramatically alter intestinal microbiota, and gut microbiota can impact physiological function. To determine if maternal diet-induced gut dysbiosis can disrupt offspring neurobehavioral function, we transplanted high fat diet- (HFD) or control low fat diet-associated (CD) gut microbiota to conventionally-housed female mice. Recipient mice were then bred and the behavioral phenotype of male and female offspring was tracked. While maternal behavior was unaffected, neonatal offspring from HFD dams vocalized less upon maternal separation than pups from CD dams. Furthermore, weaned male offspring from HFD dams had significant and selective disruptions in exploratory, cognitive, and stereotypical/compulsive behavior compared to male offspring from CD dams; while female offspring from HFD dams had increases in body weight and adiposity. 16S metagenomic analyses confirmed establishment of divergent microbiota in CD and HFD dams, with alterations in diversity and taxonomic distribution throughout pregnancy and lactation. Likewise, significant alterations in gut microbial diversity and distribution were noted in offspring from HFD dams compared to CD dams, and in males compared to females. Regression analyses of behavioral performance against differentially represented taxa suggest that decreased representation of specific members of the Firmicutes phylum predict behavioral decline in male offspring. Collectively, these data establish that high fat diet-induced maternal dysbiosis is sufficient to disrupt behavioral function in murine offspring in a sex-specific manner. Thus these data reinforce the essential link between maternal diet and neurologic programming in offspring and suggest that intestinal dysbiosis could link unhealthy modern diets to the increased prevalence of neurodevelopmental and childhood disorders.

Maternal height and its relationship to offspring birth weight and adiposity in 6- to 10-year-old Maya children from poor neighborhoods in Merida, Yucatan

OBJECTIVE

To analyze the relationship between maternal height, offspring birth weight, and adiposity at 6-10 years of age in a sample of 197 mother-child dyads from Merida, Mexico.

MATERIALS AND METHODS

During 2008-2009 and 2011-2013, measurements were taken of maternal height and weight; and height, waist circumference (WC), and skinfolds (triceps, subscapular, and suprailiac) of their children. Participant body composition was estimated using a bioelectrical impedance analyzer. A questionnaire was applied to document household socioeconomic conditions. Multiple linear regression models were used to study the association between maternal height, offspring birth weight and fat mass index (FMI), WC, and sum of skinfolds (SumSkfZ) in boys and girls, separately.

RESULTS

After adjusting for child age and household socioeconomic conditions, maternal height was identified to be significantly associated (p < .05) with FMI, WC, and SumSkf only in boys. In all models, child adiposity was inversely related to maternal height. Offspring birth weight was not associated with any adiposity parameter.

DISCUSSION

The results suggest that maternal nutritional history as reflected in short maternal stature is associated with higher body fat in children, and that male offspring are more vulnerable to intergenerational influences.

Prenatal alcohol exposure and prenatal stress differentially alter glucocorticoid signaling in the placenta and fetal brain

Adverse intrauterine environments increase vulnerability to chronic diseases across the lifespan. The hypothalamic-pituitary-adrenal (HPA) axis, which integrates multiple neuronal signals and ultimately controls the response to stressors, may provide a final common pathway linking early adversity and adult diseases. Both prenatal alcohol exposure (PAE) and prenatal stress (PS) induce a hyperresponsive HPA phenotype in adulthood. As glucocorticoids are pivotal for the normal development of many fetal tissues including the brain, we used animal models of PAE and PS to investigate possible mechanisms underlying fetal programing of glucocorticoid signaling in the placenta and fetal brain at gestation day (GD) 21. We found that both PAE and PS dams had higher corticosterone (CORT) levels than control dams. However, 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) enzyme levels were increased in PAE and unchanged in PS placentae, although there were no differences in 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) levels. Moreover, only PAE fetuses showed decreased body weight and increased placental weight, and hence a lower fetal/placental weight ratio, a marker of placenta efficiency, compared to all other prenatal groups. Importantly, PAE and PS differentially altered corticosteroid receptor levels in placentae and brains. In the PS condition, maternal CORT was negatively correlated with both 11β-HSD1 and mineralocorticoid receptor (MR) protein levels in male and female placentae, whereas in the PAE condition, there were trends for a positive correlation between maternal CORT and 11β-HSD1, regardless of sex, and a negative correlation between maternal alcohol intake and MR in male placentae. In fetal brains, sexually dimorphic changes in MR and glucocorticoid receptor (GR) levels, and the MR/GR ratio seen in C fetuses were absent in PAE and PS fetuses. In addition, PS but not PAE female fetuses had higher MR and lower GR expression levels in certain limbic areas compared to C female fetuses. Thus the similar adult HPA hyperresponsive phenotype in PAE and PS animals likely occurs through differential effects on glucocorticoid signaling in the placenta and fetal brain.

Hypothesis: genetic and epigenetic risk factors interact to modulate vulnerability and resilience to FASD

Fetal alcohol spectrum disorder (FASD) presents a collection of symptoms representing physiological and behavioral phenotypes caused by maternal alcohol consumption. Symptom severity is modified by genetic differences in fetal susceptibility and resistance as well as maternal genetic factors such as maternal alcohol sensitivity. Animal models demonstrate that both maternal and paternal genetics contribute to the variation in the fetus' vulnerability to alcohol exposure. Maternal and paternal genetics define the variations in these phenotypes even without the effect of alcohol in utero, as most of these traits are polygenic, non-Mendelian, in their inheritance. In addition, the epigenetic alterations that instigate the alcohol induced neurodevelopmental deficits can interact with the polygenic inheritance of respective traits. Here, based on specific examples, we present the hypothesis that the principles of non-Mendelian inheritance, or "exceptions" to Mendelian genetics, can be the driving force behind the severity of the prenatal alcohol-exposed individual's symptomology. One such exception is when maternal alleles lead to an altered intrauterine hormonal environment and, therefore, produce variations in the long-term consequences on the development of the alcohol-exposed fetus. Another exception is when epigenetic regulation of allele-specific gene expression generates disequilibrium between the maternal vs. paternal genetic contributions, and thereby, modifies the effect of prenatal alcohol exposure on the fetus. We propose that these situations in which one parent has an exaggerated influence over the offspring's vulnerability to prenatal alcohol are major contributing mechanisms responsible for the variations in the symptomology of FASD in the exposed generation and beyond.

Sex differences in developmental programming models

The theory of developmental programming suggests that diseases such as the metabolic syndrome may be ‘programmed’ by exposure to adverse stimuli during early development. The developmental programming literature encompasses the study of a wide range of suboptimal intrauterine environments in a variety of species and correlates these with diverse phenotypic outcomes in the offspring. At a molecular level, a large number of variables have been measured and suggested as the basis of the programmed phenotype. The range of both dependent and independent variables studied often makes the developmental programming literature complex to interpret and the drawing of definitive conclusions difficult. A common, though under-explored, theme of many developmental programming models is a sex difference in offspring outcomes. This holds true across a range of interventions, including dietary, hypoxic, and surgical models. The molecular and phenotypic outcomes of adversein uteroconditions are often more prominent in male than female offspring, although there is little consideration given to the basis for this observation in most studies. We review the evidence that maternal energy investment in male and female conceptuses may not be equal and may be environment dependent. It is suggested that male and female development could be viewed as separate processes from the time of conception, with differences in both timing and outcomes.

Role of the hypothalamic-pituitary-adrenal axis in developmental programming of health and disease

Adverse environments during the fetal and neonatal development period may permanently program physiology and metabolism, and lead to increased risk of diseases in later life. Programming of the hypothalamic-pituitary-adrenal (HPA) axis is one of the key mechanisms that contribute to altered metabolism and response to stress. Programming of the HPA axis often involves epigenetic modification of the glucocorticoid receptor (GR) gene promoter, which influences tissue-specific GR expression patterns and response to stimuli. This review summarizes the current state of research on the HPA axis and programming of health and disease in the adult, focusing on the epigenetic regulation of GR gene expression patterns in response to fetal and neonatal stress. Aberrant GR gene expression patterns in the developing brain may have a significant negative impact on protection of the immature brain against hypoxic-ischemic encephalopathy in the critical period of development during and immediately after birth.

Strain-specific vulnerability to alcohol exposure in utero via hippocampal parent-of-origin expression of deiodinase-III

Prenatal exposure to alcohol is thought to be the most prevalent nongenetic cause of a wide range of neurodevelopmental deficits. Insufficient thyroid hormone levels are one mechanism that hampers development of the alcohol-exposed brain, and we hypothesized that altered dosage of the imprinted thyroid hormone-inactivating gene deiodinase-III (Dio3) is responsible. To follow parent-of-origin allelic expression of Dio3 in the fetal and adult offspring of alcohol-consuming and control dams, we reciprocally crossed 2 polymorphic rat strains. In the frontal cortex, prenatal alcohol exposure altered imprinting patterns and total expression of Dio3 in the fetus and produced a permanent hypothyroid milieu in the adult. In the hippocampus, alcohol affected the paternal and total expression of Dio3 in the fetus and in the adult male, where thyroid hormone levels were concomitantly increased. Hippocampus-dependent behavioral deficits were identified exclusively in males, suggesting they are dependent on aberrant allelic Dio3 expression. None of these effects were observed in offspring of the reciprocal cross. Thus, genetic background and sex modify vulnerability to prenatal alcohol via brain region-specific expression of Dio3. This finding implies that phenotypic heterogeneity in human fetal alcohol spectrum disorder can be linked to genetic vulnerability in affected brain regions.

Child health, developmental plasticity, and epigenetic programming

Plasticity in developmental programming has evolved in order to provide the best chances of survival and reproductive success to the organism under changing environments. Environmental conditions that are experienced in early life can profoundly influence human biology and long-term health. Developmental origins of health and disease and life-history transitions are purported to use placental, nutritional, and endocrine cues for setting long-term biological, mental, and behavioral strategies in response to local ecological and/or social conditions. The window of developmental plasticity extends from preconception to early childhood and involves epigenetic responses to environmental changes, which exert their effects during life-history phase transitions. These epigenetic responses influence development, cell- and tissue-specific gene expression, and sexual dimorphism, and, in exceptional cases, could be transmitted transgenerationally. Translational epigenetic research in child health is a reiterative process that ranges from research in the basic sciences, preclinical research, and pediatric clinical research. Identifying the epigenetic consequences of fetal programming creates potential applications in clinical practice: the development of epigenetic biomarkers for early diagnosis of disease, the ability to identify susceptible individuals at risk for adult diseases, and the development of novel preventive and curative measures that are based on diet and/or novel epigenetic drugs.

Nutrition and human health from a sex-gender perspective

Nutrition exerts a life-long impact on human health, and the interaction between nutrition and health has been known for centuries. The recent literature has suggested that nutrition could differently influence the health of male and female individuals. Until the last decade of the 20th century, research on women has been neglected, and the results obtained in men have been directly translated to women in both the medicine and nutrition fields. Consequently, most modern guidelines are based on studies predominantly conducted on men. However, there are many sex-gender differences that are the result of multifactorial inputs, including gene repertoires, sex steroid hormones, and environmental factors (e.g., food components). The effects of these different inputs in male and female physiology will be different in different periods of ontogenetic development as well as during pregnancy and the ovarian cycle in females, which are also age dependent. As a result, different strategies have evolved to maintain male and female body homeostasis, which, in turn, implies that there are important differences in the bioavailability, metabolism, distribution, and elimination of foods and beverages in males and females. This article will review some of these differences underlying the impact of food components on the risk of developing diseases from a sex-gender perspective.

Candidate placental biomarkers for intrauterine alcohol exposure

BACKGROUND

Fetal alcohol spectrum disorder (FASD) is a leading cause of nongenetic mental retardation and other neurodevelopmental deficits. Earlier diagnosis of FASD would greatly improve prognosis for individuals and families affected by this disorder. Here, we identify candidate placental biomarkers in an animal model of FASD that recapitulates many aspects of human FASD.

METHODS

Pregnant Sprague-Dawley (SD) females were assigned to 1 of 3 diet groups on gestation day 8 (G8): Ethanol (E), Pair-fed (PF) or Control (C). E dams received ethanol-containing liquid diet and PF dams received isocaloric liquid diet in an amount that matched the paired E dam's diet consumption the previous day. Control dams received laboratory chow and water ad libitum. Whole placentae from individual fetuses were collected on gestational day 21 (G21) for analyses. Western blotting and quantitative real-time RT-PCR were used to measure protein and mRNA levels of placental iodothyronine deiodinase III (Dio3), thyroid hormone receptor α1 (TRα1), and glucocorticoid receptor (GR). Placental mRNA levels of insulin-like growth factor 2 (Igf-2), pleckstrin homology-like domain family A member 2 (Phlda2), and cyclin-dependent kinase inhibitor 1C (Cdkn1c) were also measured.

RESULTS

Placental protein and mRNA levels from ethanol (E)-consuming dams showed the following changes: increased Dio3, decreased TRα1, and decreased GR compared to both C and PF dams. Placental mRNA levels of intrauterine growth restriction (IUGR) markers Igf-2, Phlda2, and Cdkn1c were altered similarly in PF and E dams.

CONCLUSIONS

We propose the specific pattern of increased Dio3 and decreased TRα1 and GR protein levels in the placenta as selective biomarker for intrauterine alcohol exposure.

Prenatal ethanol exposure enhances NMDAR-dependent long-term potentiation in the adolescent female dentate gyrus

The dentate gyrus (DG) is a region of the hippocampus intimately involved with learning and memory. Prenatal exposure to either stress or ethanol can reduce long-term potentiation (LTP) in the male hippocampus but there is little information on how these prenatal events affect LTP in the adolescent female hippocampus. Previous studies suggest that deleterious effects of PNEE can, in part, be mediated by corticosterone, suggesting that prenatal stress might further enhance any alterations to LTP induced PNEE. When animals were exposed to a combination of prenatal stress and PNEE distinct sex differences emerged. Exposure to ethanol throughout gestation significantly reduced DG LTP in adolescent males but enhanced LTP in adolescent females. Combined exposure to stress and ethanol in utero reduced the ethanol-induced enhancement of LTP in females. On the other hand, exposure to stress and ethanol in utero did not alter the ethanol-induced reduction of LTP in males. These results indicate that prenatal ethanol and prenatal stress produce sex-specific alterations in synaptic plasticity in the adolescent hippocampus.

Paternal genetic contribution influences fetal vulnerability to maternal alcohol consumption in a rat model of fetal alcohol spectrum disorder

BACKGROUND

Fetal alcohol exposure causes in the offspring a collection of permanent physiological and neuropsychological deficits collectively termed Fetal Alcohol Spectrum Disorder (FASD). The timing and amount of exposure cannot fully explain the substantial variability among affected individuals, pointing to genetic influences that mediate fetal vulnerability. However, the aspects of vulnerability that depend on the mother, the father, or both, are not known.

METHODOLOGY/PRINCIPAL FINDINGS

Using the outbred Sprague-Dawley (SD) and inbred Brown Norway (BN) rat strains as well as their reciprocal crosses, we administered ethanol (E), pair-fed (PF), or control (C) diets to the pregnant dams. The dams' plasma levels of free thyroxine (fT4), triiodothyronine (T3), free T3 (fT3), and thyroid stimulating hormone (TSH) were measured to elucidate potential differences in maternal thyroid hormonal environment, which affects specific aspects of FASD. We then compared alcohol-exposed, pair fed, and control offspring of each fetal strain on gestational day 21 (G21) to identify maternal and paternal genetic effects on bodyweight and placental weight of male and female fetuses.

CONCLUSIONS

SD and BN dams exhibited different baseline hypothalamic-pituitary-thyroid function. Moreover, the thyroid function of SD dams was more severely affected by alcohol consumption while that of BN dams was relatively resistant. This novel finding suggests that genetic differences in maternal thyroid function are one source of maternal genetic effects on fetal vulnerability to FASD. The fetal vulnerability to decreased bodyweight after alcohol exposure depended on the genetic contribution of both parents, not only maternal contribution as previously thought. In contrast, the effect of maternal alcohol consumption on placental weight was consistent and not strain-dependent. Interestingly, placental weight in fetuses with different paternal genetic contributions exhibited opposite responses to caloric restriction (pair feeding). In summary, these novel findings demonstrate both maternal and paternal genetic contributions to in utero vulnerability to alcohol, refining our understanding of the genetically-based heterogeneity seen in human FASD.

Maternal glucocorticoid deficit affects hypothalamic-pituitary-adrenal function and behavior of rat offspring

Detrimental consequences of prenatal stress include increased hypothalamic-pituitary-adrenal (HPA) function, anxiety and depression-like behavior in adult offspring. To identify the role of maternal corticosterone milieu in the fetal programming of adult function, we measured these same behavioral and hormonal endpoints after maternal adrenalectomy (ADX) and replacement with normal or moderately high levels of corticosterone (CORT). Adult male and female offspring exhibited differing HPA responses to maternal ADX. In female offspring of ADX mothers, exaggerated plasma ACTH stress responses were reversed by the higher, but not the lower, dose of maternal CORT. In contrast, male offspring of both ADX and ADX dams with higher CORT replacement showed exaggerated ACTH stress responses. Hypothalamic glucocorticoid receptor (GR) expression was decreased in these latter groups, while hippocampal GR increased only in the ADX offspring. Activity of young offspring of ADX dams replaced with the higher dose of CORT decreased in the open field test of exploration/anxiety, while immobility behavior of adult offspring in the forced swim test of depression increased following maternal ADX or higher levels of CORT replacement. Interestingly, for some measures, none or moderately high CORT replacement resulted in similar deficits in this study. These findings are in accord with consequences of prenatal stress or prenatal dexamethasone exposure, suggesting that a common mechanism may underlie the effects of too low or too high maternal glucocorticoids on adult HPA function and behavior.

Sexually dimorphic effects of maternal asthma during pregnancy on placental glucocorticoid metabolism and fetal growth

Human pregnancy is associated with sexually dimorphic differences in mortality and morbidity of the fetus with the male fetus experiencing the poorest outcome following complications such as pre-eclampsia, pre-term delivery and infection. The physiological mechanisms that confer these differences have not been well characterised in the human. Work conducted on the effect of maternal asthma during pregnancy, combining data collected from the mother, placenta and fetus has found some significant sex-related mechanistic differences associated with fetal growth in both normal pregnancies and pregnancies complicated by asthma. Specifically, sexually dimorphic differences have been found in placental glucocorticoid metabolism in male and female fetuses of normal pregnancies. In response to the presence of maternal asthma, only the female fetus alters placental glucocorticoid metabolism resulting in decreased growth. The male fetus does not alter placental function or growth in response to maternal asthma. As a result of the alterations in glucocorticoid metabolism in the female, downstream changes occur in pathways regulated by glucocorticoids. These data suggest that the female fetus adjusts placental function and reduces growth to compensate for maternal disease. However, the male fetus continues to grow in response to maternal asthma with no changes in placental function. This response by the male fetus may partially contribute to the increased risk of morbidity and mortality in this sex.

Maternal-fetal glucocorticoid milieu programs hypothalamic-pituitary-thyroid function of adult offspring

To assess the role of maternal glucocorticoid milieu on the hypothalamic-pituitary-thyroid function of the offspring, we adrenalectomized (ADX) pregnant dams on gestation d 8 and implanted a placebo pellet or a continuous release 50- or 75-mg corticosterone (CORT) pellet. Maternal ADX led to realignment of the balance between maternal and fetal plasma CORT levels, resulting in an increase in CORT of fetal origin in the maternal compartment. Maternal ADX and low levels of CORT replacement had no discernable effect on maternal pituitary-thyroid measures. In contrast, the increase in fetal CORT, as a consequence of the absence of maternal glucocorticoids, decreased birth weight in neonates, decreased adult hypothalamic TRH mRNA levels, and increased plasma TSH levels in both male and female adult offspring, all of which were reversed by administration of basal levels of CORT to the pregnant ADX dam. Decreased plasma T3 concentrations in female offspring were reversed by administration of the higher levels of CORT to the ADX dams. Our data indicate that maternal glucocorticoids modulate the developing hypothalamic-pituitary-thyroid axis.

Prenatal programming of adult thyroid function by alcohol and thyroid hormones

Increasing evidence associates environmental challenges early in life with permanent alterations of physiological functions in adulthood. These changes in fetal environment can trigger physiological adaptations by the fetus, called fetal programming, which may be beneficial before birth but permanently influence the physiology of the organism. In this study, we investigated the potential connection between alcohol-induced decreased maternal thyroid function and the hypothalamic-pituitary-thyroid (HPT) function of adult rat offspring. Plasma 3,5,3'-triiodothyronine (T(3)), thyroxine (T(4)), and thyroid-stimulating hormone (TSH) levels were decreased in alcohol-consuming (E) dams on gestational day 21 compared with ad libitum- (C) and pair-fed (PF) controls. No significant differences were found in HPT function in young offspring (3 wk of age) between diet groups. However, adult fetal alcohol-exposed (FAE) offspring had significantly decreased levels of T(3) along with elevated TSH compared with control offspring. T(4) administration to the mother did not normalize the hypothyroid state of the adult FAE offspring. Interestingly, administration of T(4) to control pregnant dams decreased plasma T(3) of the adult female offspring only, whereas T(4) together with maternal alcohol consumption or pair-feeding led to decreased TSH and T(4) in the adult female offspring. Our results suggest that ethanol consumption and T(4) administration alter maternal HPT function, leading to prenatally programmed permanent alterations in the thyroid function of the adult offspring.