The Role of Placental 11-Beta Hydroxysteroid Dehydrogenase Type 1 and Type 2 Methylation on Gene Expression and Infant Birth Weight

Placental epigenetic signatures of maternal distress in glucocorticoid-related genes and newborn outcomes: A study of Spanish primiparous women

Maternal stress during pregnancy can impact offspring health, increasing the risk of neuropsychiatric disorders. The human placenta plays a crucial role in understanding this effect, influencing fetal programming as it connects maternal and fetal circulation. Our hypothesis centers on maternal stress influencing children's outcomes through placental DNA methylation, targeting three cortisol-regulating genes: NR3C1, FKBP5, and HSD11B2. In this pilot study, chorionic villi and maternal decidua placental layers from 45 mother-infant dyads (divided into two groups based on high/low maternal stress exposure) were analyzed for DNA methylation at the genes of interest via targeted bisulfite sequencing. Pregnant women provided four saliva samples throughout a day for cortisol determinations and were assessed for the presence of depressive symptoms at each of the three trimesters of pregnancy. Newborns underwent neurodevelopmental assessments and salivary cortisol evaluations at 7 weeks. Increased maternal diurnal cortisol levels in the first trimester of pregnancy was significantly associated with elevated DNA methylation at exon 1D of the NR3C1 gene and lower DNA methylation at intron 7 of the FKBP5 gene, both in chorionic villi samples. Elevated DNA methylation at introns 1 and 7 of FKBP5 in the maternal decidua were strongly linked to an anticipated delivery. DNA methylation at the HSD11B2 promoter region was uniformly low across all placental samples. No associations with newborn neurodevelopment were found. These results emphasize the importance of exploring layer-specific methylation differences at distinct pregnancy stages, highlighting the complex interplay between maternal stress, placental epigenetic modifications, and fetal development throughout the prenatal period.

Is There a Relationship Between Prenatal Dexamethasone and Postnatal Fructose Overexposure and Testicular Development, Function, and Oxidative Stress Parameters in Rats?

Prenatal glucocorticoid overexposure alters the developmental program of fetal reproductive organs and results in numerous changes that can lead to various disorders later in life. Moderate fructose consumption during childhood and adolescence may impair the development and function of reproductive organs. The aim of this study was to investigate the effects of prenatal dexamethasone (Dx) exposure in combination with postnatal fructose overconsumption on testicular development and function in fetal and adult male rat offspring. Pregnant female rats were treated with a subcutaneous injection of Dx at a dose of 0.5 mg/kg/day on gestation days 16, 17, and 18, and the effects on fetal growth and testicular development were analyzed. Spontaneously born male offspring were fed 10% fructose in drinking water until the age of 3 months. Prenatal exposure to Dx led to a reduction in fetal weight and testicular volume. However, testicular development normalized by adulthood, with testosterone levels decreasing. After moderate fructose consumption, impaired redox homeostasis and structural changes in the testicles and decreased testosterone levels were observed, indicating reduced testicular function. The results suggest that the synergistic effect of prenatal Dx exposure and moderate postnatal fructose consumption leads to more deleterious changes in testicular tissue.

Does brain-derived neurotrophic factor play a role in the association between maternal prenatal mental health and neurodevelopment in 2-year-old children?

OBJECTIVE

To evaluate the role of brain-derived neurotrophic factor (BDNF)-a crucial modulator of neural development and plasticity-in the association between prenatal maternal anxiety, depression, and perceived stress and child neurodevelopment in a prospective cohort study.

METHODS

We included 526 eligible mother-child pairs from the Shanghai Birth Cohort in the study. Maternal mental health was assessed at mid-pregnancy using Zung's Self-Rating Anxiety Scale, Center for Epidemiologic Studies Depression Scale, and Perceived Stress Scale. The concentration of BDNF in cord blood was measured by ELISA. The offspring neurodevelopment at 24 months of age was assessed using the Bayley Scales. Linear and non-linear regression models were used.

RESULTS

The average cord blood BDNF levels were higher in female newborns and those born via vaginal delivery, full term, and normal birth weight. Prenatal maternal anxiety (β = -0.32; 95 % CI: -0.55, -0.09), depression (β = -0.30; 95 % CI: -0.52, -0.08), and perceived stress (β = -0.41; 95 % CI: -0.71, -0.12) scores were negatively associated with social-emotional performance at 24 months of age. However, no significant associations were found between prenatal maternal anxiety, depression, or perceived stress at mid-pregnancy and cord blood BDNF levels, as well as between cord blood BDNF levels and child neurodevelopment.

LIMITATIONS

Maternal mental health at different timepoints during pregnancy and generalizability of the results warrant further assessment.

CONCLUSIONS

Prenatal mental health was not associated with cord blood BDNF level and that BDNF may not be a mediator in the association between prenatal mental health and child neurodevelopment.

Rapid retinoic acid-induced trophoblast cell model from human induced pluripotent stem cells

A limited number of accessible and representative models of human trophoblast cells currently exist for the study of placentation. Current stem cell models involve either a transition through a naïve stem cell state or precise dynamic control of multiple growth factors and small-molecule cues. Here, we demonstrated that a simple five-day treatment of human induced pluripotent stem cells with two small molecules, retinoic acid (RA) and Wnt agonist CHIR 99021 (CHIR), resulted in rapid, synergistic upregulation of CDX2. Transcriptomic analysis of RA + CHIR-treated cells showed high similarity to primary trophectoderm cells. Multipotency was verified via further differentiation towards cells with syncytiotrophoblast or extravillous trophoblast features. RA + CHIR-treated cells were also assessed for the established criteria defining a trophoblast cell model, and they possess all the features necessary to be considered valid. Collectively, our data demonstrate a facile, scalable method for generating functional trophoblast-like cells in vitro to better understand the placenta.

DNA methylation landscape in pregnancy-induced hypertension: progress and challenges

Gestational hypertension (PIH), especially pre-eclampsia (PE), is a common complication of pregnancy. This condition poses significant risks to the health of both the mother and the fetus. Emerging evidence suggests that epigenetic modifications, particularly DNA methylation, may play a role in initiating the earliest pathophysiology of PIH. This article describes the relationship between DNA methylation and placental trophoblast function, genes associated with the placental microenvironment, the placental vascular system, and maternal blood and vascular function, abnormalities of umbilical cord blood and vascular function in the onset and progression of PIH, as well as changes in DNA methylation in the progeny of PIH, in terms of maternal, fetal, and offspring. We also explore the latest research on DNA methylation-based early detection, diagnosis and potential therapeutic strategies for PIH. This will enable the field of DNA methylation research to continue to enhance our understanding of the epigenetic regulation of PIH genes and identify potential therapeutic targets.

Resveratrol analogues and metabolites selectively inhibit human and rat 11β-hydroxysteroid dehydrogenase 1 as the therapeutic drugs: structure-activity relationship and molecular dynamics analysis

Resveratrol is converted to various metabolites by gut microbiota. Human and rat liver 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) are critical for glucocorticoid activation, while 11β-HSD2 in the kidney does the opposite reaction. It is still uncertain whether resveratrol and its analogues selectively inhibit 11β-HSD1. In this study, the inhibitory strength, mode of action, structure-activity relationship (SAR), and docking analysis of resveratrol analogues on human, rat, and mouse 11β-HSD1 and 11β-HSD2 were performed. The inhibitory strength of these chemicals on human 11β-HSD1 was dihydropinosylvin (6.91 μM) > lunularin (45.44 μM) > pinostilbene (46.82 μM) > resveratrol (171.1 μM) > pinosylvin (193.8 μM) > others. The inhibitory strength of inhibiting rat 11β-HSD1 was pinostilbene (9.67 μM) > lunularin (17.39 μM) > dihydropinosylvin (19.83 μM) > dihydroresveratrol (23.07 μM) > dihydroxystilbene (27.84 μM) > others and dihydropinosylvin (85.09 μM) and pinostilbene (>100 μM) inhibited mouse 11β-HSD1. All chemicals did not inhibit human, rat, and mouse 11β-HSD2. It was found that dihydropinosylvin, lunularin, and pinostilbene were competitive inhibitors of human 11β-HSD1 and that pinostilbene, lunularin, dihydropinosylvin, dihydropinosylvin and dihydroxystilbene were mixed inhibitors of rat 11β-HSD1. Docking analysis showed that they bind to the steroid-binding site of human and rat 11β-HSD1. In conclusion, resveratrol and its analogues can selectively inhibit human and rat 11β-HSD1, and mouse 11β-HSD1 is insensitive to the inhibition of resveratrol analogues.

Abnormal DNA methylation within HPA-axis genes years after paediatric critical illness

BACKGROUND

Critically ill children suffer from impaired physical/neurocognitive development 2 years later. Glucocorticoid treatment alters DNA methylation within the hypothalamus-pituitary-adrenal (HPA) axis which may impair normal brain development, cognition and behaviour. We tested the hypothesis that paediatric-intensive-care-unit (PICU) patients, sex- and age-dependently, show long-term abnormal DNA methylation within the HPA-axis layers, possibly aggravated by glucocorticoid treatment in the PICU, which may contribute to the long-term developmental impairments.

RESULTS

In a pre-planned secondary analysis of the multicentre PEPaNIC-RCT and its 2-year follow-up, we identified differentially methylated positions and differentially methylated regions within HPA-axis genes in buccal mucosa DNA from 818 former PICU patients 2 years after PICU admission (n = 608 no glucocorticoid treatment; n = 210 glucocorticoid treatment) versus 392 healthy children and assessed interaction with sex and age, role of glucocorticoid treatment in the PICU and associations with long-term developmental impairments. Adjusting for technical variation and baseline risk factors and correcting for multiple testing (false discovery rate < 0.05), former PICU patients showed abnormal DNA methylation of 26 CpG sites (within CRHR1, POMC, MC2R, NR3C1, FKBP5, HSD11B1, SRD5A1, AKR1D1, DUSP1, TSC22D3 and TNF) and three DNA regions (within AVP, TSC22D3 and TNF) that were mostly hypomethylated. These abnormalities were sex-independent and only partially age-dependent. Abnormal methylation of three CpG sites within FKBP5 and one CpG site within SRD5A1 and AKR1D1 was partly attributable to glucocorticoid treatment during PICU stay. Finally, abnormal methylation within FKBP5 and AKR1D1 was most robustly associated with long-term impaired development.

CONCLUSIONS

Two years after critical illness in children, abnormal methylation within HPA-axis genes was present, predominantly within FKBP5 and AKR1D1, partly attributable to glucocorticoid treatment in the PICU, and explaining part of the long-term developmental impairments. These data call for caution regarding liberal glucocorticoid use in the PICU.

Obesity in pregnancy-Long-term effects on offspring hypothalamic-pituitary-adrenal axis and associations with placental cortisol metabolism: A systematic review

Obesity, affecting one in three pregnant women worldwide, is not only a major obstetric risk factor. The resulting low-grade inflammation may have a long-term impact on the offspring's HPA axis through dysregulation of maternal, placental and fetal corticosteroid metabolism, and children born of obese mothers have increased risk of diabetes and cardiovascular disease. The long-term effects of maternal obesity on offspring neurodevelopment are, however, undetermined and could depend on the specific effects on placental and fetal cortisol metabolism. This systematic review evaluates how maternal obesity affects placental cortisol metabolism and the offspring's HPA axis. Pubmed, Embase and Scopus were searched for original studies on maternal BMI, obesity, and cortisol metabolism and transfer. Fifteen studies were included after the screening of 4556 identified records. Studies were small with heterogeneous exposures and outcomes. Two studies found that maternal obesity reduced placental HSD11β2 activity. In one study, umbilical cord blood cortisol levels were affected by maternal BMI. In three studies, an altered cortisol response was consistently seen among offspring in childhood (n = 2) or adulthood (n = 1). Maternal BMI was not associated with placental HSD11β1 or HSD11β2 mRNA expression, or placental HSD11β2 methylation. In conclusion, high maternal BMI is associated with reduced placental HSD11β2 activity and a dampened cortisol level among offspring, but the data is sparse. Further investigations are needed to clarify whether the HPA axis is affected by prenatal factors including maternal obesity and investigate if adverse effects can be ameliorated by optimising the intrauterine environment.

Halogen atoms determine the inhibitory potency of halogenated bisphenol A derivatives on human and rat placental 11β-hydroxysteroid dehydrogenase 2

Some halogenated bisphenol A (BPA) derivatives (tetrabromobisphenol A, TBBPA, and tetrachlorobisphenol A, TCBPA) are produced in a high volume and exist in PM_2.5 after waste burning. 11β-Hydroxysteroid dehydrogenase 2 (11β-HSD2) is a critical enzyme for placental function. However, whether halogenated bisphenols inhibit 11β-HSD2 and the mode of action remains unclear. The objective of this study was to investigate BPA derivatives on human and rat placental 11β-HSD2. The inhibitory strength on human 11β-HSD2 was TBBPA (IC₅₀, 0.665 μM)>TCBPA (2.22 μM)>trichloro BPA (TrCBPA, 19.87 μM)>tetrabromobisphenol S (TBBPS, 36.76 μM)>monochloro BPA (MCBPA, 104.0 μM)>BPA (144.9 μM)>bisphenol S. All chemicals are mixed and competitive inhibitors. Rat 11β-HSD2 was less sensitive to BPA derivatives, with TBBPA (IC₅₀, 96.63 μM)>TCBPA (99.69 μM)>TrCBPA (104.1 μM)>BPA (117.1 μM)>others. Docking analysis showed that BPA derivatives bind steroid active sites. Structure-activity relationship revealed that halogen atoms and LogP were inversely correlated with inhibitory strength on human 11β-HSD2, while LogS and polar desolvation energy were positively correlated with the inhibitory strength. In conclusion, halogenated BPA derivatives are mostly potent inhibitors on human 11β-HSD2 and there is structure-dependent inhibition.

Maternal history of childhood maltreatment is associated with diurnal cortisol and DNA methylation of placental 11-beta-hydroxysteroid dehydrogenase type 2

Background

Accumulating evidence indicates that maternal hypothalamic-pituitary-adrenal (HPA) axis activity over pregnancy differs according to maternal history of childhood maltreatment. DNA methylation of the placental 11-beta-hydroxysteroid dehydrogenase (BHSD) type 2 enzyme regulates fetal exposure to maternal cortisol, yet the association between maternal history of childhood maltreatment and methylation of placental 11BHSD type 2 has not been previously studied.

Methods

We examined if maternal cortisol production at 11 and 32 weeks' gestation (n = 89) and placental methylation of the 11BHSD type 2 gene (n = 19) differed among pregnant women with and without histories of childhood maltreatment. Twenty-nine percent of participants reported a history of childhood maltreatment (physical/sexual abuse).

Results

Women with histories of childhood maltreatment displayed lower cortisol in early gestation, hypo-methylation of placental 11BHSD type 2, and lower levels of cord blood cortisol.

Conclusion

Preliminary results suggest alterations in cortisol regulation over pregnancy according to maternal history of childhood maltreatment.

Stress and spirituality in relation to HPA axis gene methylation among US Black women: results from the Black Women's Health Study and the Study on Stress, Spirituality and Health

Background: Few epigenetics studies have been conducted within the Black community to examine the impact of diverse psychosocial stressors and resources for resiliency on the stress pathway (hypothalamus-pituitary-adrenal axis). Methods: Among 1000 participants from the Black Women's Health Study, associations between ten psychosocial stressors and DNA methylation (DNAm) of four stress-related genes (NR3C1, HSDB1, HSD11B2 and FKBP5) were tested. Whether religiosity or spirituality (R/S) significantly modified these stress-DNAm associations was also assessed. Results: Associations were found for several stressors with DNAm of individual CpG loci and average DNAm levels across each gene, but no associations remained significant after false discovery rate (FDR) correction. Several R/S variables appeared to modify the relationship between two stressors and DNAm, but no identified interaction remained significant after FDR correction. Conclusion: There is limited evidence for a strong signal between stress and DNAm of hypothalamus-pituitary-adrenal axis genes in this general population cohort of US Black women.

Gender-specific associations of pregnancy-related anxiety with placental epigenetic patterning of glucocorticoid response genes and preschooler's emotional symptoms and hyperactivity

BACKGROUD

We have recently reported that maternal prenatal pregnancy-related anxiety predicts preschoolers' emotional and behavioral development in a gender-dependent manner. This study aims to test for this gender-specific effect in a different cohort and investigate whether the gender difference was specific to placental methylation of genes regulating glucocorticoids.

METHODS

A total of 2405 mother-child pairs from the Ma'anshan Birth Cohort Study were included in present study. The maternal pregnancy-related anxiety symptoms were evaluated with the Pregnancy-Related Anxiety Questionnaire in the third trimester of pregnancy. Child neurobehavior was assessed with the Strengths and Difficulties Questionnaire at 4 years old. Placental methylation of FKBP5, NR3C1 and HSD11B2 genes was quantified using the MethylTarget approach in 439 pregnant women. After exploratory factor analysis, the associations between methylation factor scores and pregnancy-related anxiety and child neurobehavior were examined using logistic regression analysis.

RESULTS

After controlling for confounding factors, pregnancy-related anxiety in the third trimester of pregnancy increased the risk of hyperactivity only in boys and emotional symptoms only in girls. Decreased scores of the factor characterized by FKBP5 methylation were associated with maternal pregnancy-related anxiety only in boys. Furthermore, increased scores of the factors characterized by NR3C1 and HSD11B2 methylation were associated with hyperactivity (NR3C1: adjusted OR = 1.80, 95%CI = 1.15-2.83) and emotional symptoms (HSD11B2: adjusted OR = 0.53, 95%CI = 0.29-0.97; NR3C1: adjusted OR = 1.64, 95%CI = 1.03-2.59) only in boys. However, the scores of the factor characterized by FKBP5, NR3C1 and HSD11B2 did not mediate the relationship between maternal pregnancy-related anxiety and preschoolers' emotional symptoms and hyperactivity.

CONCLUSIONS

Our results suggested that pregnancy-related anxiety in the third trimester of pregnancy predicted preschoolers' emotional symptoms and hyperactivity in a gender-dependent manner. Although we did not find the mediation role of the placental methylation of genes regulating glucocorticoids, we found it was associated with both maternal pregnancy-related anxiety and preschoolers' emotional symptoms and hyperactivity in a gender-dependent manner.

The Prenatal Hormone Milieu in Autism Spectrum Disorder

Though the etiology of autism spectrum disorder (ASD) remains largely unknown, recent findings suggest that hormone dysregulation within the prenatal environment, in conjunction with genetic factors, may alter fetal neurodevelopment. Early emphasis has been placed on the potential role of in utero exposure to androgens, particularly testosterone, to theorize ASD as the manifestation of an "extreme male brain." The relationship between autism risk and obstetric conditions associated with inflammation and steroid dysregulation merits a much broader understanding of the in utero steroid environment and its potential influence on fetal neuroendocrine development. The exploration of hormone dysregulation in the prenatal environment and ASD development builds upon prior research publishing associations with obstetric conditions and ASD risk. The insight gained may be applied to the development of chronic adult metabolic diseases that share prenatal risk factors with ASD. Future research directions will also be discussed.

Maternal Prenatal Depression in Pregnancies With Female and Male Fetuses and Developmental Associations With C-reactive Protein and Cortisol

BACKGROUND

Prenatal depression has lasting effects on development in offspring, including later mental illness risk. Maternal responses to depression include inflammation and hypothalamic-pituitary-adrenal axis stimulation. Effects on development of cerebral inhibitory neurocircuits may differ for female and male fetuses.

METHODS

Mothers (N = 181) were assessed periodically, beginning at 16 weeks' gestation, using the Center for Epidemiologic Studies-Depression Scale. Maternal prenatal C-reactive protein and hair cortisol and cortisone levels were determined. Cortisone was determined in neonatal hair. Development of cerebral inhibitory neurocircuits was assessed in 162 1-month-old newborns by inhibition of P50 electrophysiological responses to repeated sounds.

RESULTS

Maternal depression was associated with decreased newborn P50 inhibition in both sexes. Maternal C-reactive protein levels were significantly associated with depression only in pregnancies with male fetuses and with decreased newborn P50 inhibition only in male newborns. Maternal cortisol levels were significantly associated with depression only in pregnancies with female fetuses and with decreased newborn P50 inhibition only in female newborns. In pregnancies with male fetuses compared with pregnancies with female fetuses, cortisol was more robustly metabolized to cortisone, which does not activate cortisol receptors.

CONCLUSIONS

This study finds sex-specific associations of C-reactive protein and cortisol levels with prenatal depression in women and with decreased development of newborn P50 inhibition. Sex-based differences in maternal response to depression with inflammation or cortisol and their developmental effects may reflect evolutionary influences to promote survival in adversity. Decreased newborn P50 inhibition is associated with later childhood behavioral problems, and decreased P50 inhibition is a pathophysiological feature of several mental illnesses.

Placental Gene Expression and Offspring Temperament Trajectories: Predicting Negative Affect in Early Childhood

Exposure to prenatal stress increases offspring risk for long-term neurobehavioral impairments and psychopathology, such as Attention Deficit Hyperactivity Disorder (ADHD). Epigenetic regulation of glucocorticoid pathway genes may be a potential underlying mechanism by which maternal conditions 'program' the fetal brain for downstream vulnerabilities. The present study aims to investigate whether mRNA expression of glucocorticoid pathway genes in the placenta predict offspring negative affect during early childhood (between 6 and 24 months). Participants include 318 mother-child dyads participating in a longitudinal birth cohort study. Placental mRNA expression of glucocorticoid pathway genes (HSD11B1, HSD11B2, NR3C1, NCOR2) were profiled and negative affect traits of the offspring were measured at 6, 12, 18, and 24 months. HSD11B1 mRNA expression significantly predicted negative affect (β = -.09, SE = .04; p = .036), and Distress to Limitations trajectories (β = -.13, SE = .06; p = .016). NCOR2 mRNA expression significantly predicted Distress to Limitations (β = .43, SE = .21; p = .047), and marginally predicted Sadness trajectories (β = .39, SE = .21; p = .068). HSD11B2 and NR3C1 did not predict trajectories of Negative Affect or subscale scores. Infant negative affect traits were assessed via maternal self-report, and deviated from linearity across follow-up. mRNA expression of glucocorticoid pathway genes in the placenta may be a potentially novel tool for early identification of infants at greater risk for elevated negative affect. Further study is needed to validate the utility of mRNA expression of glucocorticoid pathway genes in the placenta.

Assessment of adrenal function at birth using adrenal glucocorticoid precursor to product ratios to predict short-term neonatal outcomes

BACKGROUND

Most neonatal outcomes in neonates are related to normal adrenal gland function. Assessment of adrenal function in a sick preterm neonate remains a challenge, thus we hypothesized that adrenal steroid precursors to their product ratios have a direct relationship with neonatal outcomes.

METHODS

We studied demographics of pregnancy and neonatal outcomes in 99 mother-infant pairs (24-41 weeks) and assayed 7 glucocorticoid precursors in the cortisol biosynthesis/degradation pathway. We correlated antenatal factors and short-term neonatal outcomes with these precursors and their ratios to assess maturity of individual enzymes.

RESULTS

We found no correlation between cortisol levels with antenatal factors and outcomes. Antenatal steroid use impacted several cortisol precursors. 17-OH pregnenolone-to-cortisol ratio at birth was the best predictor of short-term neonatal outcomes, such as hypotension, RDS, IVH and PDA. A cord blood 17-OH pregnenolone:cortisol ratio of <0.21 predicts which neonate will have a normal outcome with a high sensitivity and specificity.

CONCLUSIONS

Maternal factors and antenatal steroids impact neonatal adrenal function and leads to maturation of adrenal function. 17-OH pregnenolone:cortisol ratio and not cortisol is the best predictor of adrenal function. Adrenal function can be assessed by evaluating the profile of adrenal steroids.

The significance of the placental genome and methylome in fetal and maternal health

The placenta is a crucial organ for supporting a healthy pregnancy, and defective development or function of the placenta is implicated in a number of complications of pregnancy that affect both maternal and fetal health, including maternal preeclampsia, fetal growth restriction, and spontaneous preterm birth. In this review, we highlight the role of the placental genome in mediating fetal and maternal health by discussing the impact of a variety of genetic alterations, from large whole-chromosome aneuploidies to single-nucleotide variants, on placental development and function. We also discuss the placental methylome in relation to its potential applications for refining diagnosis, predicting pathology, and identifying genetic variants with potential functional significance. We conclude that understanding the influence of the placental genome on common placental-mediated pathologies is critical to improving perinatal health outcomes.

Differential placental DNA methylation of VEGFA and LEP in small-for-gestational age fetuses with an abnormal cerebroplacental ratio

Background

In Fetal Growth Restriction ‘fetal programming’ may take place via DNA methylation, which has implications for short-term and long-term health outcomes. Small-for-gestational age fetuses are considered fetal growth restricted, characterized by brain-sparing when fetal Doppler hemodynamics are abnormal, expressed as a cerebroplacental ratio (CPR) <1. We aimed to determine whether brain-sparing is associated with altered DNA methylation of selected genes.

Methods

We compared DNA methylation of six genes in 41 small-for-gestational age placentas with a normal or abnormal CPR. We selected EPO, HIF1A, VEGFA, LEP, PHLDA2, and DHCR24 for their role in angiogenesis, immunomodulation, and placental and fetal growth. DNA methylation was analyzed by pyrosequencing.

Results

Growth restricted fetuses with an abnormal CPR showed hypermethylation of the VEGFA gene at one CpG (VEGFA-309, p = .001) and an overall hypomethylation of the LEP gene, being significant at two CpGs (LEP-123, p = .049; LEP-51, p = .020). No differences in methylation were observed for the other genes.

Conclusions

VEGFA and LEP genes are differentially methylated in placentas of small-for-gestational age fetuses with brain-sparing. Hypermethylation of VEGFA-309 in abnormal CPR-placentas could indicate successful compensatory mechanisms. Methylation of LEP-51 is known to suppress LEP expression. Hypomethylation in small-for-gestational age placentas with abnormal CPR may result in hyperleptinemia and predispose to leptin-resistance later in life.

[Effect of prednisolone and adrenocorticotropic hormone in the treatment of infantile spasms: a Meta analysis]

OBJECTIVE

To compare the effect and safety of prednisolone and adrenocorticotropic hormone (ACTH) in the treatment of infantile spasms (IS).

METHODS

Cochrane Library, Embase, PubMed, China Biology Medicine Disc, CNKI, and Wanfang Data were searched for clinical studies on the comparison between prednisolone and ACTH in the treatment of IS. Literature screening, data extraction, and quality assessment were performed. Review Manager 5.3 was used for Meta analysis.

RESULTS

Five clinical studies were included according to the inclusion criteria and exclusion criteria. Meta analysis showed that there was no significant difference in the spasm remission rate, spasm remission time, complicating infection rate, and irritability rate between the prednisolone and ACTH treatment groups (P>0.05), but the disappearance rate of hypsarrhythmia in the electroencephalogram was higher in the ACTH treatment group than in the prednisolone treatment group (P<0.05).

CONCLUSIONS

The available evidence shows no difference in the clinical efficacy of prednisolone versus ACTH in the treatment of IS. However, ACTH is superior to prednisolone in stabilizing EEG. The two therapies have no difference in the incidence of adverse reactions such as infection and irritability.

Phthalate Exposures, DNA Methylation and Adiposity in Mexican Children Through Adolescence

Phthalates are a class of endocrine disrupting chemicals with near ubiquitous exposure to populations around the world. Phthalates have been associated with children's adiposity in previous studies, though discrepancies exist across studies that may be due to timing of exposure or outcome assessment and population differences (i.e., genetics, other confounders). DNA methylation, an epigenetic modification involved in gene regulation, may mediate the effects of early life phthalate exposures on health outcomes. This study aims to evaluate the mediating effect of DNA methylation at growth-related genes on the association between phthalate exposure and repeat measures of adiposity (BMI-for-age z-score, waist circumference, and skinfolds thickness) in Mexican children. Urinary phthalate metabolite concentrations were quantified in mothers at each of the three trimesters of pregnancy and in children at the first peri-adolescent study visit. Blood leukocyte DNA methylation at H19 and HSD11B2 was quantified during the first peri-adolescent visit, and adiposity was measured at the first visit and again ~3 years later among participants (n = 109 boys, 114 girls) from the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) project. Associations between phthalates or DNA methylation and repeat outcome measures were assessed separately in boys and girls using generalized estimating equation models including covariates (urinary specific gravity, maternal education, and child's age). Sobel tests were used to assess DNA methylation as a mediator in models adjusting for the same covariates. Associations between phthalates and adiposity varied by phthalate and timing of exposure. Early gestation MBP, MIBP, and MBzP were associated with adiposity among girls. For example, among girls first trimester maternal urine concentrations of MIBP were associated with increases in skinfold thickness, BMI-for-age, and waist circumference (p < 0.01). Second trimester and adolescent MBzP were associated with adiposity among boys in opposite directions. In girls, H19 methylation was positively associated with skinfold thickness. No significant mediation of phthalate exposure on adiposity by DNA methylation of H19 or HSD11B2 was observed (Sobel p > 0.05). However, the mediation analysis was underpowered to detect small to medium effect sizes, and the role of DNA methylation as a mediator between phthalates and outcomes merits further study.

Fetal glucocorticoid receptor (Nr3c1) deficiency alters the landscape of DNA methylation of murine placenta in a sex-dependent manner and is associated to anxiety-like behavior in adulthood

Prenatal stress defines long-term phenotypes through epigenetic programming of the offspring. These effects are potentially mediated by glucocorticoid release and by sex. We hypothesized that the glucocorticoid receptor (Gr, Nr3c1) fashions the DNA methylation profile of offspring. Consistent with this hypothesis, fetal Nr3c1 heterozygosity leads to altered DNA methylation landscape in fetal placenta in a sex-specific manner. There was a significant overlap of differentially methylated genes in fetal placenta and adult frontal cortex in Nr3c1 heterozygotes. Phenotypically, Nr3c1 heterozygotes show significantly more anxiety-like behavior than wildtype. DNA methylation status of fetal placental tissue is significantly correlated with anxiety-like behavior of the same animals in adulthood. Thus, placental DNA methylation might predict behavioral phenotypes in adulthood. Our data supports the hypothesis that Nr3c1 influences DNA methylation at birth and that DNA methylation in placenta correlates with adult frontal cortex DNA methylation and anxiety-like phenotypes.

Mechanisms for establishment of the placental glucocorticoid barrier, a guard for life

The fetus is shielded from the adverse effects of excessive maternal glucocorticoids by 11β-HSD2, an enzyme which is expressed in the syncytial layer of the placental villi and is capable of converting biologically active cortisol into inactive cortisone. Impairment of this placental glucocorticoid barrier is associated with fetal intrauterine growth restriction (IUGR) and development of chronic diseases in later life. Ontogeny studies show that the expression of 11β-HSD2 is initiated at a very early stage after conception and increases with gestational age but declines around term. The promoter for HSD11B2, the gene encoding 11β-HSD2, has a highly GC-rich core. However, the pattern of methylation on HSD11B2 may have already been set up in the blastocyst when the trophoblast identity is committed. Instead, hCG-initiated signals appear to be responsible for the upsurge of 11β-HSD2 expression during trophoblast syncytialization. By activating the cAMP/PKA pathway, hCG not only alters the modification of histones but also increases the expression of Sp1 which activates the transcription of HSD11B2. Adverse conditions such as stress, hypoxia and nutritional restriction can cause IUGR of the fetus. It appears that different causes of IUGR may attenuate HSD11B2 expression differentially in the placenta. While stress and nutritional restriction may reduce HSD11B2 expression by increasing its methylation, hypoxia may decrease HSD11B2 expression via alternative mechanisms rather than by methylation. Herein, we summarize the advances in the study of mechanisms underlying the establishment of the placental glucocorticoid barrier and the attenuation of this barrier by adverse conditions during pregnancy.

Intrauterine multi-metal exposure is associated with reduced fetal growth through modulation of the placental gene network

BACKGROUND

Intrauterine metal exposures and aberrations in placental processes are known contributors to being born small for gestational age (SGA). However, studies to date have largely focused on independent effects, failing to account for potential interdependence among these markers.

OBJECTIVES

We evaluated the inter-relationship between multi-metal indices and placental gene network modules related to SGA status to highlight potential molecular pathways through which in utero multi-metal exposure impacts fetal growth.

METHODS

Weighted quantile sum (WQS) regression was performed using a panel of 16 trace metals measured in post-partum maternal toe nails collected from the Rhode Island Child Health Study (RICHS, n = 195), and confirmation of the derived SGA-related multi-metal index was conducted using Bayesian kernel machine regression (BKMR). We leveraged existing placental weighted gene coexpression network data to examine associations between the SGA multi-metal index and placental gene expression. Expression of select genes were assessed using RT-PCR in an independent birth cohort, the New Hampshire Birth Cohort Study (NHBCS, n = 237).

RESULTS

We identified a multi-metal index, predominated by arsenic (As) and cadmium (Cd), that was positively associated with SGA status (Odds ratio = 2.73 [1.04, 7.18]). This index was also associated with the expression of placental gene modules involved in "gene expression" (β = -0.02 [-0.04, -0.01]) and "metabolic hormone secretion" (β = 0.02 [0.00, 0.05]). We validated the association between cadmium exposure and the expression of GRHL1 and INHBA, genes in the "metabolic hormone secretion" module, in NHBCS.

CONCLUSION

We present a novel approach that integrates the application of advanced bioinformatics and biostatistics methods to delineate potential placental pathways through which trace metal exposures impact fetal growth.

Prenatal stress and models explaining risk for psychopathology revisited: Generic vulnerability and divergent pathways

The present review revisits three hypothesized models that potentially could explain how prenatal maternal stress influences fetal development, birth outcomes, and subsequent developmental psychopathology. These models were mostly based on animal models, and new evidence for these models from human studies is evaluated. Furthermore, divergent trajectories from prenatal exposure to adversities to offspring affected outcomes are reviewed, including the comparison of studies on prenatal maternal stress with research on maternal substance use and maternal malnutrition during pregnancy. Finally, new directions in research on the mechanism underlying prenatal stress effects on human offspring is summarized. While it is concluded that there is abundant evidence for the negative associations between prenatal maternal stress and offspring behavioral, brain, and psychopathological outcomes in humans, there is no consistent evidence for specific mechanisms or specific outcomes in relation to stress exposure in utero. Rather, principles of multifinality and equifinality best describe the consequences for the offspring, suggesting a generic vulnerability and different pathways from prenatal adversities to developmental psychopathology, which complicates the search for underlying mechanisms. New and promising directions for research are provided to get a better understanding of how prenatal stress gets under the skin to affect fetal development.

Prenatal stress and enhanced developmental plasticity

Two separate lines of inquiry indicate (a) that prenatal stress is associated with heightened behavioral and physiological reactivity, and (b) that these postnatal phenotypes are associated with increased susceptibility to both positive and negative developmental experiences and environmental exposures. This research considered together raises the intriguing hypothesis first advanced by Pluess and Belsky (Dev Psychopathol 23:29-38, 2011) that prenatal-stress fosters, promotes or "programs" postnatal developmental plasticity. In this paper, we review further evidence consistent with this proposition, including a novel animal study which experimentally manipulated both prenatal stress and postnatal rearing. Directions for future work focused on mechanisms mediating the plasticity-inducing effects of prenatal stress and the moderators of such effects are outlined.

Sex-specific and lasting effects of a single course of antenatal betamethasone treatment on human placental 11β-HSD2

INTRODUCTION

We have previously shown that even a single course of antenatal betamethasone (BET) as an inductor for lung maturity reduces birth weight and head circumference. Moreover, animal studies link BET administration to alterations of the hypothalamic-pituitary-adrenal-gland-axis (HPA). The unhindered development of the fetal HPA axis is dependent on the function and activity of 11β-hydroxysteroiddehydrogenase type 2 (11β-HSD2), a transplacental cortisol barrier. Therefore, we investigated the effects of BET on this transplacental barrier and fetal growth.

METHODS

Pregnant women treated with a single course of BET between 23 + 5 to 34 + 0 weeks of gestation were compared to gestational-age-matched controls. Placental size and neonatal anthropometrics were taken. Cortisol and ACTH levels were measured in maternal and umbilical cord blood samples. Placental 11β-hydroxysteroiddehydrogenase type 1 (11β-HSD1) protein levels and 11β-HSD2 protein and activity levels were determined. Parameters were analyzed independent of sex, and in subgroups divided by gender and gestational age.

RESULTS

In term born females, BET administration was associated with reduced head circumference and decreased 11β-HSD2 protein levels and enzyme activity. Males treated with BET, especially those born prematurely, showed increased 11β-HSD2 protein levels.

CONCLUSION

A single course of BET alters placental glucocorticoid metabolism in a sex-specific manner. Decreased 11β-HSD2 levels in term born females may lead to an increased placental transfer of maternal cortisol and therefore result in a reduced head circumference and a higher risk for altered stress response in adulthood. Further research is needed to conclude the significance of increased 11β-HSD2 levels in males.

Epigenetic effects of the pregnancy Mediterranean diet adherence on the offspring metabolic syndrome markers

Metabolic syndrome (MS) has a multifactorial and not yet fully clarified origin. Insulin resistance is a key element that connects all the accepted components of MS (obesity, dyslipemia, high blood pressure, and hyperglycemia). There is strong evidence that epigenetic changes during fetal development are key factors in the development of MS. These changes are induced by maternal nutrition, among different factors, affecting the intrauterine environment. The Mediterranean diet has been shown to be a healthy eating pattern that protects against the development of MS in adults. Similarly, the Mediterranean diet could have a similar action during pregnancy, protecting the fetus against the development of MS throughout life. This review assembles studies carried out, both in animals and humans, on the epigenetic modifications associated with the consumption, during pregnancy, of Mediterranean diet main components. The relationship between these modifications and the occurrence of factors involved in development of MS is also explained. In addition, the results of our group relating adherence to the Mediterranean diet with MS markers are discussed. The paper ends suggesting future actuation lines in order to increase knowledge on Mediterranean diet adherence as a prevention tool of MS development.

Maternal distress in late pregnancy alters obstetric outcomes and the expression of genes important for placental glucocorticoid signalling

The experience of maternal distress in pregnancy is often linked with poorer obstetric outcomes for women as well as adverse outcomes for offspring. Alterations in placental glucocorticoid signalling and subsequent increased fetal exposure to cortisol have been suggested to underlie this relationship. In the current study, 121 pregnant women completed the Perceived Stress Scale, State Trait Anxiety Inventory and Edinburgh Postnatal Depression Scale in the third trimester of pregnancy. Placental samples were collected after delivery. Maternal history of psychiatric illness and miscarriage were significant predictors of poorer mental health in pregnancy. Higher anxiety was associated with an increase in women delivering via elective Caesarean Section, and an increase in bottle-feeding. Birth temperature was mildly reduced among infants of women with high levels of depressive symptomology. Babies of mothers who scored high in all stress (cumulative distress) measures had reduced 5-min Apgar scores. High cumulative distress reduced the expression of placental HSD11B2 mRNA and increased the expression of placental NR3C1 mRNA. These data support a role for prenatal distress as a risk factor for altered obstetric outcomes. The alterations in placental gene expression support a role for altered placental glucocorticoid signalling in the relationship between maternal prenatal distress and adverse outcomes.

Preterm behavioral epigenetics: A systematic review

Behavioral epigenetics is revealing new pathways that lead individuals from early adversity exposures to later-in-life detrimental outcomes. Preterm birth constitutes one of the major adverse events in human development. Preterm infants are hospitalized in the Neonatal Intensive Care Unit (NICU) where they are exposed to life-saving yet pain-inducing procedures and to protective care. The application of behavioral epigenetics to the field of preterm studies (i.e., Preterm Behavioral Epigenetics, PBE) is rapidly growing and holds promises to provide valid insights for research and clinical activity. Here, the evidence of the epigenetic correlates of prenatal adversities, NICU-related environment and development of preterm infants is systematically reviewed. The findings suggest that a number of prenatal adverse (e.g., maternal depression and stress) and post-natal (e.g., NICU-related pain-related stress) events affect the developmental trajectories of preterm infants and children via epigenetic alterations of imprinted and stress-related genes. Nonetheless, the potential epigenetic vestiges of early care and protective interventions in NICU have not been investigated yet and this represents a fascinating challenge for future PBE research.

11 beta-hydroxysteroid dehydrogenase 2 promoter methylation is associated with placental protein expression in small for gestational age newborns

Small for gestational age infants have greater risk of developing metabolic diseases in adult life. It has been suggested that low birth weight may result from glucocorticoid excess in utero, a key mechanism in fetal programming. The placental enzyme 11-beta hydroxysteroid dehydrogenase type 2 (11β-HSD2, HSD11B2 gene) acts as a barrier protecting the fetus from maternal corticosteroid deleterious effects. Low placental 11β-HSD2 transcription and activity have been associated with low birth weight, yet the mechanism regulating its protein expression is not fully understood. In the present study we aimed to analyze 11β-HSD2 protein expression in placentas of adequate and small for gestational age (AGA and SGA, respectively) newborns from healthy mothers, and to explore whether 11β-HSD2 protein expression could be modulated by DNA methylation. 11β-HSD2 protein levels were measured by western blot in placental biopsies from term AGA and SGA infants (n=10 per group). DNA methylation was profiled both globally and in the HSD11B2 promoter by liquid chromatography with UV detection and methylation-specific melting curve analysis, respectively. We found lower placental 11β-HSD2 protein expression and higher HSD11B2 promoter methylation in SGA compared to AGA. Promoter methylation was inversely correlated with both protein expression and, importantly, birth weight. No changes in global placental methylation were found. In conclusion, lower 11β-HSD2 protein expression is associated with higher HSD11B2 promoter methylation, correlating with birth weight in healthy pregnancy. Our data support the role of 11β-HSD2 in determining birth weight, providing evidence of its regulation by epigenetic mechanisms, which may affect postnatal metabolic disease risk.

Variants of HSD11B2 gene in hypertensive disorders of pregnancy

INTRODUCTION

One of the hypotheses concerning the etiology of gestational hypertension (GH) and pre-eclampsia (PE) assumes that they develop as a result of placenta malfunctioning at the early stage of pregnancy. Placental dysfunction is also associated with the decreased activity of 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2), which in normal pregnancy protects the fetus from the excess of maternal cortisol.

OBJECTIVE

The aim of the study was to analyze the sequence of HSD11B2, a gene that encodes 11β-HSD2, searching for mutations and haplotypes associated with the increased risk of GH or PE. Those may serve as potential genetic markers of GH and PE.

METHODS

The study was performed in case-control structure and included pregnant women (in third trimester) diagnosed with: GH, PE or being normotensive (control group). The research comprised DNA sequencing of HSD11B2, followed by restriction analysis (PCR-RFLP). The linkage disequilibrium analysis and haplotype-based case-control analysis were performed.

RESULTS

Six sequence variations were observed. Four mutations were indicated in the coding region of HSD11B2 and the other two in 3'-UTR. Two SNPs: c.468C > A and c.534G > A were found to be in total disequilibrium.

CONCLUSIONS

High variability in HSD11B2 sequence was indicated in the study population, but the relevance of observed SNPs to GH or PE development was not confirmed.

Adverse maternal exposures, methylation of glucocorticoid-related genes and perinatal outcomes: a systematic review

Aim: Maternal environmental exposures affect perinatal outcomes through epigenetic placental changes. We examine the literature addressing associations between adverse maternal exposures, perinatal outcomes and methylation of key genes regulating placental cortisol metabolism. Methods: We searched three databases for studies that examined NR3C1 and HSD11β1/HSD11 β 2 methylation with maternal exposures or perinatal outcomes. Nineteen studies remained after screening. We followed Cochrane's PRISMA reporting guidelines (2009). Results: NR3C1 and HSD11 β methylation were associated with adverse infant neurobehavior, stress response, blood pressure and physical development. In utero exposure to maternal stress, nutrition, preeclampsia, smoking and diabetes were associated with altered NR3C1 and HSD11 β methylation. Conclusion: NR3C1 and HSD11 β methylation are useful biomarkers of specific environmental stressors associated with important perinatal outcomes that determine pediatric and adult disease risk.

Neuroendocrinological and Epigenetic Mechanisms Subserving Autonomic Imbalance and HPA Dysfunction in the Metabolic Syndrome

Impact of environmental stress upon pathophysiology of the metabolic syndrome (MetS) has been substantiated by epidemiological, psychophysiological, and endocrinological studies. This review discusses recent advances in the understanding of causative roles of nutritional factors, sympathomedullo-adrenal (SMA) and hypothalamic-pituitary adrenocortical (HPA) axes, and adipose tissue chronic low-grade inflammation processes in MetS. Disturbances in the neuroendocrine systems for leptin, melanocortin, and neuropeptide Y (NPY)/agouti-related protein systems have been found resulting directly in MetS-like conditions. The review identifies candidate risk genes from factors shown critical for the functioning of each of these neuroendocrine signaling cascades. In its meta-analytic part, recent studies in epigenetic modification (histone methylation, acetylation, phosphorylation, ubiquitination) and posttranscriptional gene regulation by microRNAs are evaluated. Several studies suggest modification mechanisms of early life stress (ELS) and diet-induced obesity (DIO) programming in the hypothalamic regions with populations of POMC-expressing neurons. Epigenetic modifications were found in cortisol (here HSD11B1 expression), melanocortin, leptin, NPY, and adiponectin genes. With respect to adiposity genes, epigenetic modifications were documented for fat mass gene cluster APOA1/C3/A4/A5, and the lipolysis gene LIPE. With regard to inflammatory, immune and subcellular metabolism, PPARG, NKBF1, TNFA, TCF7C2, and those genes expressing cytochrome P450 family enzymes involved in steroidogenesis and in hepatic lipoproteins were documented for epigenetic modifications.

11β-Hydroxysteroid Dehydrogenase 2 in Preeclampsia

Preeclampsia is a serious medical problem affecting the mother and her child and influences their health not only during the pregnancy, but also many years after. Although preeclampsia is a subject of many research projects, the etiology of the condition remains unclear. One of the hypotheses related to the etiology of preeclampsia is the deficiency in placental 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2), the enzyme which in normal pregnancy protects the fetus from the excess of maternal cortisol. The reduced activity of the enzyme was observed in placentas from pregnancies complicated with preeclampsia. That suggests the overexposure of the developing child to maternal cortisol, which in high levels exerts proapoptotic effects and reduces fetal growth. The fetal growth restriction due to the diminished placental 11β-HSD2 function may be supported by the fact that preeclampsia is often accompanied with fetal hypotrophy. The causes of the reduced function of 11β-HSD2 in placental tissue are still discussed. This paper summarizes the phenomena that may affect the activity of the enzyme at various steps on the way from the gene to the protein.

Effects of prenatal maternal stress on serotonin and fetal development

Fetuses are exposed to many environmental perturbations that can influence their development. These factors can be easily identifiable such as drugs, chronic diseases or prenatal maternal stress. Recently, it has been demonstrated that the serotonin synthetized by the placenta was crucial for fetal brain development. Moreover, many studies show the involvement of serotonin system alteration in psychiatric disease during childhood and adulthood. This review summarizes existing studies showing that prenatal maternal stress, which induces alteration of serotonin systems (placenta and fetal brain) during a critical window of early development, could lead to alteration of fetal development and increase risks of psychiatric diseases later in life. This phenomenon, termed fetal programming, could be moderated by the sex of the fetus. This review highlights the need to better understand the modification of the maternal, placental and fetal serotonin systems induced by prenatal maternal stress in order to find early biomarkers of psychiatric disorders.

Epigenetic regulation of human placental function and pregnancy outcome: considerations for causal inference

Epigenetic mechanisms, often defined as regulating gene activity independently of underlying DNA sequence, are crucial for healthy development. The sum total of epigenetic marks within a cell or tissue (the epigenome) is sensitive to environmental influence, and disruption of the epigenome in utero has been associated with adverse pregnancy outcomes. Not surprisingly, given its multifaceted functions and important role in regulating pregnancy outcome, the placenta shows unique epigenetic features. Interestingly however, many of these are only otherwise seen in human malignancy (the pseudomalignant placental epigenome). Epigenetic variation in the placenta is now emerging as a candidate mediator of environmental influence on placental functioning and a key regulator of pregnancy outcome. However, replication of findings is generally lacking, most likely due to small sample sizes and a lack of standardization of analytical approaches. Defining DNA methylation "signatures" in the placenta associated with maternal and fetal outcomes offers tremendous potential to improve pregnancy outcomes, but care must be taken in interpretation of findings. Future placental epigenetic research would do well to address the issues present in epigenetic epidemiology more generally, including careful consideration of sample size, potentially confounding factors, issues of tissue heterogeneity, reverse causation, and the role of genetics in modulating epigenetic profile. The importance of animal or in vitro models in establishing a functional role of epigenetic variation identified in human beings, which is key to establishing causation, should not be underestimated.