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

Maternal affective symptoms and sleep quality have sex-specific associations with placental topography

BACKGROUND

The impacts of prenatal maternal affective symptoms on the placental structure are not well-established. Employing Geographic Information System (GIS) spatial autocorrelation, Moran's I, can help characterize placental thickness uniformity/variability and evaluate the impacts of maternal distress on placental topography.

METHODS

This study (N = 126) utilized cohort data on prenatal maternal affective symptoms and placental 2D and 3D morphology. Prenatal maternal depression, stress, anxiety and sleep quality were scored for each trimester using the Edinburgh Postnatal Depression Scale (EPDS), Stressful Life Event Scale (SLE), Penn State Worry Questionnaire (PSWQ), and Pittsburgh Sleep Quality Index (PSQI), respectively. Placental shape was divided into Voronoi cells and thickness variability among these cells was computed using Moran's I for 4-nearest neighbors and neighbors within a 10 cm radius. Sex-stratified Spearman correlations and linear regression were used to study associations between mean placental thickness, placental GIS variables, placental weight and the average score of each maternal variable.

RESULTS

For mothers carrying boys, poor sleep was associated with higher mean thickness (r = 0.308,p = 0.035) and lower placental thickness uniformity (r = -0.36,p = 0.012). Lower placental weight (r = 0.395,p = 0.003), higher maternal depression (r = -0.318,p = 0.019) and worry/anxiety (r = -0.362,p = 0.007) were associated with lower placental thickness uniformity for mothers carrying girls.

LIMITATIONS

The study is exploratory and not all GIS models were developed. Excluding high-risk pregnancies prevented investigating pregnancy complications related hypotheses. A larger sample size is needed for greater confidence for clinical application.

CONCLUSIONS

Placental topography can be studied using GIS theory and has shown that prenatal maternal affective symptoms and sleep have sex-specific associations with placental thickness.

RNA epitranscriptomics dysregulation: A major determinant for significantly increased risk of ASD pathogenesis

Autism spectrum disorders (ASDs) are perhaps the most severe, intractable and challenging child psychiatric disorders. They are complex, pervasive and highly heterogeneous and depend on multifactorial neurodevelopmental conditions. Although the pathogenesis of autism remains unclear, it revolves around altered neurodevelopmental patterns and their implications for brain function, although these cannot be specifically linked to symptoms. While these affect neuronal migration and connectivity, little is known about the processes that lead to the disruption of specific laminar excitatory and inhibitory cortical circuits, a key feature of ASD. It is evident that ASD has multiple underlying causes and this multigenic condition has been considered to also dependent on epigenetic effects, although the exact nature of the factors that could be involved remains unclear. However, besides the possibility for differential epigenetic markings directly affecting the relative expression levels of individual genes or groups of genes, there are at least three mRNA epitranscriptomic mechanisms, which function cooperatively and could, in association with both genotypes and environmental conditions, alter spatiotemporal proteins expression patterns during brain development, at both quantitative and qualitative levels, in a tissue-specific, and context-dependent manner. As we have already postulated, sudden changes in environmental conditions, such as those conferred by maternal inflammation/immune activation, influence RNA epitranscriptomic mechanisms, with the combination of these processes altering fetal brain development. Herein, we explore the postulate whereby, in ASD pathogenesis, RNA epitranscriptomics might take precedence over epigenetic modifications. RNA epitranscriptomics affects real-time differential expression of receptor and channel proteins isoforms, playing a prominent role in central nervous system (CNS) development and functions, but also RNAi which, in turn, impact the spatiotemporal expression of receptors, channels and regulatory proteins irrespective of isoforms. Slight dysregulations in few early components of brain development, could, depending upon their extent, snowball into a huge variety of pathological cerebral alterations a few years after birth. This may very well explain the enormous genetic, neuropathological and symptomatic heterogeneities that are systematically associated with ASD and psychiatric disorders at large.

The obstetric aspects of maternal asthma

Asthma is the commonest chronic medical condition encountered in pregnancy. Poor asthma control and exacerbations are frequently encountered due to treatment non-adherence, pregnancy-related aggravating factors such as increased susceptibility to viral infections, and comorbidities that are commonly associated. Asthma-related inflammatory reactions and placental effects, the effect of medications, and respiratory symptoms and hypoxia are probably to interact to result in an increased adverse obstetric outcomes including miscarriage, foetal congenital anomalies, pregnancy hypertensive disorders, gestational diabetes, preterm labour and birth, antepartum haemorrhage, low birthweight and foetal growth restriction (FGR), caesarean delivery, postpartum haemorrhage (PPH), maternal intensive care admission, and even mortality, while the offspring also has increased long-term morbidity. Interdisciplinary management with frequent assessment by symptoms, spirometry, and biomarkers, together with removal of risk factors such as smoking and appropriate instigation of treatment including short courses of systemic corticosteroid, could ensure optimal and tailored treatment to control symptoms, prevent exacerbations, and ultimately enhancing maternal and perinatal outcomes.

Autism spectrum disorders pathogenesis: Toward a comprehensive model based on neuroanatomic and neurodevelopment considerations

Autism spectrum disorder (ASD) involves alterations in neural connectivity affecting cortical network organization and excitation to inhibition ratio. It is characterized by an early increase in brain volume mediated by abnormal cortical overgrowth patterns and by increases in size, spine density, and neuron population in the amygdala and surrounding nuclei. Neuronal expansion is followed by a rapid decline from adolescence to middle age. Since no known neurobiological mechanism in human postnatal life is capable of generating large excesses of frontocortical neurons, this likely occurs due to a dysregulation of layer formation and layer-specific neuronal migration during key early stages of prenatal cerebral cortex development. This leads to the dysregulation of post-natal synaptic pruning and results in a huge variety of forms and degrees of signal-over-noise discrimination losses, accounting for ASD clinical heterogeneities, including autonomic nervous system abnormalities and comorbidities. We postulate that sudden changes in environmental conditions linked to serotonin/kynurenine supply to the developing fetus, throughout the critical GW7 - GW20 (Gestational Week) developmental window, are likely to promote ASD pathogenesis during fetal brain development. This appears to be driven by discrete alterations in differentiation and patterning mechanisms arising from in utero RNA editing, favoring vulnerability outcomes over plasticity outcomes. This paper attempts to provide a comprehensive model of the pathogenesis and progression of ASD neurodevelopmental disorders.

Sex-dependence and comorbidities of the early-life adversity induced mental and metabolic disease risks: Where are we at?

Early-life adversity (ELA) is a major risk factor for developing later-life mental and metabolic disorders. However, if and to what extent ELA contributes to the comorbidity and sex-dependent prevalence/presentation of these disorders remains unclear. We here comprehensively review and integrate human and rodent ELA (pre- and postnatal) studies examining mental or metabolic health in both sexes and discuss the role of the placenta and maternal milk, key in transferring maternal effects to the offspring. We conclude that ELA impacts mental and metabolic health with sex-specific presentations that depend on timing of exposure, and that human and rodent studies largely converge in their findings. ELA is more often reported to impact cognitive and externalizing domains in males, internalizing behaviors in both sexes and concerning the metabolic dimension, adiposity in females and insulin sensitivity in males. Thus, ELA seems to be involved in the origin of the comorbidity and sex-specific prevalence/presentation of some of the most common disorders in our society. Therefore, ELA-induced disease states deserve specific preventive and intervention strategies.

Sex Differences Are Here to Stay: Relevance to Prenatal Care

Sex differences exist in the incidence and presentation of many pregnancy complications, including but not limited to pregnancy loss, spontaneous preterm birth, and fetal growth restriction. Sex differences arise very early in development due to differential gene expression from the X and Y chromosomes, and later may also be influenced by the action of gonadal steroid hormones. Though offspring sex is not considered in most prenatal diagnostic or therapeutic strategies currently in use, it may be beneficial to consider sex differences and the associated mechanisms underlying pregnancy complications. This review will cover (i) the prevalence and presentation of sex differences that occur in perinatal complications, particularly with a focus on the placenta; (ii) possible mechanisms underlying the development of sex differences in placental function and pregnancy phenotypes; and (iii) knowledge gaps that should be addressed in the development of diagnostic or risk prediction tools for such complications, with an emphasis on those for which it would be important to consider sex.

Maternal active asthma in pregnancy influences associations between polyunsaturated fatty acid intake and child asthma

BACKGROUND

Studies evaluating effects of prenatal polyunsaturated fatty acid (PUFA) intake on childhood asthma reveal mixed results. Inconsistencies may result from not accounting for important modifying factors such as maternal asthma or child sex.

OBJECTIVE

To evaluate whether associations between prenatal PUFA intake and childhood asthma are modified by prenatal active maternal asthma or child sex in 412 mother-child dyads.

METHODS

Energy-adjusted prenatal dietary and supplement intakes of omega-3 (n-3) and omega-6 (n-6) PUFAs were estimated using the Block98 Food Frequency Questionnaire, administered during pregnancy. Mothers reported asthma in children followed prospectively to 4.0 plus or minus 1.7 years. Generalized additive models with smooth terms for PUFA (n-3, n-6, n-6/n-3 ratio) effects were used to investigate associations between PUFAs and child asthma, without prespecifying the form of these relationships, including effect modification by active maternal asthma or child sex.

RESULTS

Among mothers (40% Black, 31% Hispanic), 22% had active asthma in pregnancy; 17.5% of children developed asthma. Lower maternal n-3 PUFA intake was significantly associated with risk of childhood asthma (P = .03), in particular among children of mothers with active asthma and low n-3 PUFA intake (P = .01). This inverse association was more apparent in girls (P = .01) compared with boys (P = .30), regardless of maternal asthma status. For n-6 PUFA and the n-6/n-3 ratio, there was a lower risk of childhood asthma in the midrange of intake and increased risk at higher intake (n-6 PUFA P = .10, n-6/n-3 ratio P = .13).

CONCLUSION

Consideration of factors that modify effects of prenatal PUFA intake on childhood asthma has implications for designing intervention strategies tailored to impact those at greatest risk.

First trimester mechanisms of gestational sac placental and foetal teratogenicity: a framework for birth cohort studies

BACKGROUND

The function of the gestational sac (GS) and the placenta in the closely related processes of embryogenesis and teratogenicity in the first trimester has been minimally described. The prevailing assumption is that direct teratogenic effects are mediated by the critical extraembryonic organ, the placenta, which either blocks or transfers exposures to the foetus. Placental transfer is a dominant mechanism, but there are other paradigms by which the placenta can mediate teratogenic effects. Knowledge of these paradigms and first trimester human developmental biology can be useful to the epidemiologist in the conduct of biomarker-based studies of both maternal and child health.

OBJECTIVE AND RATIONALE

Our aim is to provide a causal framework for modelling the teratogenic effects of first trimester exposures on child health outcomes mediated by the GS and placenta using biomarker data collected in the first trimester. We initially present first trimester human developmental biology for the sake of informing and strengthening epidemiologic approaches. We then propose analytic approaches of modelling placental mechanisms by way of causal diagrams using classical non-embryolethal teratogens (diethylstilboestrol [DES], folic acid deficiency and cytomegalovirus [CMV]) as illustrative examples. We extend this framework to two chronic exposures of particular current interest, phthalates and maternal adiposity.

SEARCH METHODS

Information on teratogens was identified by a non-systematic, narrative review. For each teratogen, we included papers that answered the five following questions: (i) why were these exposures declared teratogens? (ii) is there a consensus on biologic mechanism? (iii) is there reported evidence of a placental mechanism? (iv) can we construct a theoretical model of a placental mechanism? and (v) can this knowledge inform future work on measurement and modelling of placental-foetal teratogenesis? We prioritized literature specific to human development, the organogenesis window in the first trimester and non-embryolethal mechanisms.

OUTCOMES

As a result of our review of the literature on five exposures considered harmful in the first trimester, we developed four analytic strategies to address first trimester placental mechanisms in birth cohort studies: placental transfer and direct effects on the foetus (DES and maternal adiposity), indirect effects through targeted placental molecular pathways (DES and phthalates), pre-placental effects through disruptions in embryonic and extraembryonic tissue layer differentiation (folic acid deficiency), and multi-step mechanisms that involve maternal, placental and foetal immune function and inflammation (DES and CMV).

WIDER IMPLICATIONS

The significance of this review is to offer a causal approach to classify the large number of potentially harmful exposures in pregnancy when the exposure occurs in the first trimester. Our review will facilitate future research by advancing knowledge of the first trimester mechanisms necessary for researchers to effectively associate environmental exposures with child health outcomes.

Placental Antioxidant Defenses and Autophagy-Related Genes in Maternal Obesity and Gestational Diabetes Mellitus

Maternal obesity and gestational diabetes mellitus (GDM) are increasing worldwide, representing risk factors for both mother and child short/long-term outcomes. Oxidative stress, lipotoxicity and altered autophagy have already been reported in obesity, but few studies have focused on obese pregnant women with GDM. Antioxidant and macro/chaperone-mediated autophagy (CMA)-related gene expressions were evaluated herein in obese and GDM placentas. A total of 47 women with singleton pregnancies delivered by elective cesarean section were enrolled: 16 normal weight (NW), 18 obese with no comorbidities (OB GDM(–)), 13 obese with GDM (OB GDM(+)). Placental gene expression was assessed by real-time PCR. Antioxidant gene expression (CAT, GPX1, GSS) decreased, the pro-autophagic ULK1 gene increased and the chaperone-mediated autophagy regulator PHLPP1 decreased in OB GDM(–) vs. NW. On the other hand, PHLPP1 expression increased in OB GDM(+) vs. OB GDM(–). When analyzing results in relation to fetal sex, we found sexual dimorphism for both antioxidant and CMA-related gene expressions. These preliminary results can pave the way for further analyses aimed at elucidating the placental autophagy role in metabolic pregnancy disorders and its potential targetability for the treatment of diabetes outcomes.

Genome-wide microRNA expression analysis in human placenta reveals sex-specific patterns: an ENVIRONAGE birth cohort study

There is an increasing interest in microRNAs (miRNAs) as they are of utmost importance in gene regulation at the posttranscriptional level. Sex-related susceptibility for non-communicable diseases later in life could originate in early life. Until now, no data on sex-specific miRNA expression are available for the placenta. Therefore, we investigated the difference by sex of newborn's miRNA expression in human placental tissue. Within the ENVIRONAGE birth cohort, miRNA and mRNA expression profiling was performed in 60 placentae (50% boys) using Agilent (8 × 60 K) microarrays. The distribution of chromosome locations was studied and pathway analysis of the identified sex-specific miRNAs in the placenta was carried out. Of the total 2558 miRNAs on the array, 597 miRNAs were expressed in over 70% of the samples and were included for further analyses. A total of 142 miRNAs were significantly (FDR<0.05) associated with the newborn's sex. In newborn girls, 76 miRNAs had higher expression (hsa-miR-361-5p as most significant) and 66 miRNAs had lower expression (hsa-miR-4646-5p as most significant) than in newborn boys. In the same study population, placental differentially expressed genes by sex were also identified using a whole genome approach. The placental gene expression revealed 27 differentially expressed genes by comparing girls to boys. Ultimately, we studied the miRNA-RNA interactome and identified 14 miRNA-mRNA interactions as sex-specific. Sex differences in placental m(i)RNA expression may reveal sex-specific patterns already present during pregnancy, which may influence physiological conditions in early or later life. These molecular processes might play a role in sex-specific disease susceptibility in later life.

Sex-biased transgenerational transmission of betaine-induced epigenetic modifications in glucocorticoid receptor gene and its down-stream BDNF/ERK pathway in rat hippocampus

Objectives: Glucocorticoid receptor (GR) expressed in hippocampus is critical for the homeostasis of stress responses and susceptible to epigenetic modulation caused by maternal factors. Here we show that maternal methyl nutrition causes sex-biased changes in hippocampal expression of GR exon 1 mRNA variants, associated with promoter DNA methylation, across two offspring generations in rats.Methods: Three-month-old female Sprague-Dawley rats (F0) were fed a diet supplemented with 1% betaine throughout the gestation and lactation. F0 dams and their F1 and F2 offspring of both sexes at weaning were used in the study.Results: A sex-specific transgenerational effect was observed. F2 females, but not males, followed the same pattern of their grand dams showing increased mRNA expression of total GR and its exons 1.4, 1.7, 1.10 and 1.11 variants coincided with promoter DNA hypomethylation in the hippocampus. However, F1 females, but not males, exhibited an opposite pattern, showing decreased expression of GR and its mRNA variants accompanied with promoter hypermethylation. The protein content of phospho-GR and BDNF/ERK in the hippocampus displayed the same sex and generation specificity.Discussion: These results indicate that maternal betaine exerts transgenerational effects on hippocampal GR expression and BDNF/ERK pathway in female rat offspring, with generation-dependent patterns of DNA methylation on alternative GR promoters.

Association between exposure to the Chinese famine during early life and the risk of chronic kidney disease in adulthood

BACKGROUND AND OBJECTIVES

Famine exposure in human early life is proven to be associated with urinary protein concentration and renal function but has not been studied with chronic kidney disease. We aimed to explore the association between exposure to the Chinese famine (from 1959 to 1962) in early life and the risk of chronic kidney disease in adulthood.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

We selected 6267 participants from the baseline survey of China Health and Retirement Longitudinal Study (CHARLS) 2011-2012. Based on the birth year, they were divided into fetal exposed, preschool exposed, school-aged exposed, and non-exposed groups. The estimated glomerular filtration rate (eGFR) was calculated according to Japanese coefficient-modified Chronic Kidney Disease Epidemiology Collaboration equation. Chronic kidney disease (CKD) was defined as eGFR less than 60 mL/min per 1.73 m².

RESULTS

The prevalence of CKD in fetal exposed, preschool exposed, school-aged exposed and non-exposed groups was 4.27%, 5.41%, 9.65% and 2.42%, respectively. The risk of CKD in fetal exposed, preschool exposed and school-aged exposed groups was significantly higher than the non-exposed group. In addition, after stratification by gender and famine severity, we found that only fetal exposure to the severe famine was associated with the elevated risk of CKD among male adults (OR 4.44, 95%CI 1.10-17.92, P < 0.05), even after adjusting for age, marital status, household per capita income, history of kidney disease, hypertension, diabetes or abnormal glucose tolerance, smoking, drinking, rural/urban residence and highest educational attainment of parents.

CONCLUSIONS

Severe famine exposure as a fetus might increase the risk of chronic kidney disease in male adults.

Fetal growth and well-being in a study of maternal hypertension in rabbits

Obtaining growth and physiologic data in the postnatal laboratory animal is common. However, monitoring growth in utero is far more difficult, with little data available except upon termination of pregnancy. High-resolution ultrasound was used to monitor growth, morphology, and fetal well-being in normotensive and hypertensive rabbits (21 fetuses) at day 16, 20, and 26 of the 32 day gestational period. Set protocols, comparable to those routinely assessed in humans, were devised and followed for each examination. Birth weight was greater in offspring of hypertensive as compared to normotensive mothers (p < 0.001); however, litter size was reduced. The greater birth weight was reflected in growth parameters measured throughout gestation indicating the predictive value of ultrasound. High-resolution ultrasound was a reliable and sensitive method for biometric and morphologic assessment of the fetal rabbit, demonstrating that growth trajectory of offspring of hypertensive mothers may be altered early in gestation.

Sex modifies placental gene expression in response to metabolic and inflammatory stress

INTRODUCTION

Metabolic stress (e.g., gestational diabetes mellitus (GDM) and obesity) and infections are common during pregnancy, impacting fetal development and the health of offspring. Such antenatal stresses can differentially impact male and female offspring. We sought to determine how metabolic stress and maternal immune activation (MIA), either alone or in combination, alters inflammatory gene expression within the placenta and whether the effects exhibited sexual dimorphism.

METHODS

Female C57BL/6 J mice were fed a normal diet or a high fat diet for 6 weeks prior to mating, with the latter diet inducing a GDM phenotype during pregnancy. Dams within each diet group at gestational day (GD) 12.5 received either an intraperitoneal injection of the viral mimic, polyinosinic:polycytidylic acid (poly(I:C)) or saline. Three hours post injection; placentae were collected and analyzed for changes in the expression of 248 unique immune genes.

RESULTS

Placental immune gene expression was significantly altered by GDM, MIA and the combination of the two (GDM+MIA). mRNA expression was generally lower in placentae of mice exposed to GDM alone compared with the other experimental groups, while mice exposed to MIA exhibited the highest transcript levels. Notably, fetal/placental sex influenced the responses of many immune genes to both metabolic and inflammatory stress.

DISCUSSION

GDM and MIA provoke inflammatory responses within the placenta and such effects exhibit sexual dimorphism. The combination of these stressors impacts the placenta differently than either condition alone. These findings may help explain sexual dimorphism observed in adverse pregnancy outcomes in human offspring exposed to similar stressors.

Microvascular circulatory dysregulation driven in part by cystathionine gamma-lyase: A new paradigm for cardiovascular compromise in the preterm newborn

OBJECTIVE

H₂ S may explain the dysregulation of microvascular tone associated with poor outcome following preterm birth. In adult vasculature, H₂ S is predominantly produced by CSE. We hypothesized that vascular CSE activity contributes to microvascular tone regulation during circulatory transition.

METHODS

Preterm (GA62) and full-term (GA69) guinea pig fetuses and neonates were studied. Microvascular blood flow was assessed by laser Doppler flowmetry. Thiosulfate, primary urinary metabolite of H₂ S, was determined by high-performance liquid chromatography. Real-time H₂ S production was assessed using a microrespiration system in fetal and postnatal (10, 24 hours) skin and heart samples. CSE contribution was investigated by inhibition via propargylglycine.

RESULTS

In preterm animals, postnatal H₂ S production capacity in peripheral vasculature increased significantly and was significantly reduced by the inhibition of CSE. Urinary thiosulfate correlated with both microvascular blood flow and capacity of the vasculature to produce H₂ S. H₂ S produced via CSE did not correlate directly with microvascular blood flow.

CONCLUSIONS

In preterm neonates, H₂ S production increases during fetal-to-neonatal transition and CSE contribution to total H₂ S increases postnatally. CSE-dependent mechanisms may therefore underpin the increase in H₂ S production over the first 72 hours of life in preterm human neonates, associated with both central and peripheral cardiovascular instability.

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.

Perinatal inflammation and childhood adiposity - a gender effect?

Background: To determine the association of maternal and fetal inflammatory factors with gender-specific infant adiposity, independent of leptin.Methods: Analysis of anthropometry from 265 mother-infant pairs at birth and 280 pairs at 6 months from the randomised control trial of low glycaemic index diet in pregnancy (ROLO) study (Randomised control trial of low glycaemic index diet) and their association with Maternal TNF-alpha, interleukin 6 and leptin as measured in early and late pregnancy and fetal levels in cord blood.Results: No associations were noted in the male cohort. On multiple regression amongst the female neonatal cohort late pregnancy IL-6 was inversely associated with sum of skinfolds (p ≤ .001); at 6 months infant sum of skinfolds were positively associated with early pregnancy IL-6 (p = .046) and central adiposity positively associated with early pregnancy TNF alpha (p = .018) independent of leptin.Conclusion: Although maternal inflammatory cytokines were not associated with neonatal adiposity independent of leptin (as this association is known), both IL-6 and TNF-α were associated with female infant anthropometry at 6 months of age independent of leptin. These results suggest inflammatory cytokines may exert an in-utero influence on later infant adiposity with a tendency to influence female adiposity more than male. Further research is required to ascertain whether these cytokines may be used as reliable early predictors of infant adiposity.

Risk of childhood cerebral palsy following prenatal exposure to ß2-adrenergic receptor agonist: A nationwide cohort study

Background

Cerebral palsy (CP) is the most common physical developmental disability in childhood with a prevalence of 2 to 3 per 1000 live births. β2-adrenoreceptor agonist (β2AA) are widely used for the treatment of asthma. Maternal use of β2AAs may increase the risk of adverse neuro-psychiatric health outcomes in the offspring. No study, however, has evaluated the effect of prenatal exposure to β2AAs on the risk of CP.

Objective

To examine the association between prenatal exposure to β2AAs and the risk of childhood cerebral palsy.

Methods

This population-based cohort study included all live singleton births in Denmark from January 1, 1997 to December 31, 2003. The information on outpatient prescriptions of β2AAs was extracted from Danish National Prescription Registry. Children born to mothers who used β2AAs from 30 days before pregnancy until delivery were categorized as the exposed. To differentiate the effect of β2AAs from the underlying indications, the exposure window was further extended to 2 years before pregnancy and the exposed groups were re-defined to represent different periods of exposure to maternal use of β2AAs (use only before pregnancy, use only during pregnancy, and use both before and during pregnancy). Cases of CP were identified from the Danish Cerebral Palsy Register. Logistic regression was used to estimate incidence odds ratio (OR) of CP.

Results

Among all the 442,278 singletons, 19,616 (4.44%) were exposed to β2AAs in utero (from 30 days before pregnancy until delivery). The risk of childhood CP was 0.21% in exposed and 0.19% in unexposed group, yielding an adjusted OR (aOR) 1.12 (95% confidence interval (CI): 0.82, 1.53). When extending the exposure time window to 2 years prior to pregnancy, no overall significant association was observed regardless of the exposure period. However, an increased risk of CP (aOR = 1.41, 95%CI: 0.92, 2.18) for maternal β2AAs use during pregnancy was observed in female offspring, especially in those born at term (aOR = 1.65, 95%CI: 1.02, 2.67). This increase was mainly attributed to an increased risk in those born to mothers who used β2AAs both before and during pregnancy (aOR = 1.81, 95%CI: 0.99, 3.33).

Conclusions

We observed an association between maternal β2AAs use during pregnancy and an increased risk of CP in female offspring, but we could not rule out confounding by the underlying indications for β2AAs.

Maternal exercise in rats upregulates the placental insulin-like growth factor system with diet- and sex-specific responses: minimal effects in mothers born growth restricted

KEY POINTS

The placental insulin-like growth factor (IGF) system is critical for normal fetoplacental growth, which is dysregulated following several pregnancy perturbations including uteroplacental insufficiency and maternal obesity. We report that the IGF system was altered in placentae of mothers born growth restricted compared to normal birth weight mothers, with maternal diet- and fetal sex-specific responses. Additionally, we report increased body weight and plasma IGF1 concentrations in fetuses from chow-fed normal birth weight mothers that exercised prior to and continued during pregnancy compared to sedentary mothers. Exercise initiated during pregnancy, on the other hand, resulted in placental morphological alterations and increased IGF1 and IGF1R protein expression, which may in part be modulated by reduced Let 7f-1 miRNA abundance. Growth restriction of mothers before birth and exercise differentially regulate the placental IGF system with diet- and sex-specific responses, probably as a means to improve fetoplacental growth and development, and hence neonatal survival. This increased neonatal survival may prevent adult disease onset.

ABSTRACT

The insulin-like growth factor (IGF) system regulates fetoplacental growth and plays a role in disease programming. Dysregulation of the IGF system is implicated in several pregnancy perturbations associated with altered fetal growth, including intrauterine growth restriction and maternal obesity. Limited human studies have demonstrated that maternal exercise enhances fetoplacental growth and decreases cord IGF ligands, which may restore the placental IGF system in complicated pregnancies. This study investigated the impact maternal exercise has on the placental IGF system in placentae from mothers born growth restricted and if these outcomes are dependent on maternal diet or fetal sex. Uteroplacental insufficiency (Restricted) or sham (Control) surgery was induced on embryonic day (E) 18 in Wistar-Kyoto rats. F1 offspring were fed a chow or high-fat diet from weaning, and at 16 weeks were randomly allocated an exercise protocol: Sedentary, Exercised prior to and during pregnancy (Exercise), or Exercised during pregnancy only (PregEx). Females were mated (20 weeks) with placentae associated with F2 fetuses collected at E20. The placental IGF system mRNA abundance and placental morphology was altered in mothers born growth restricted. Exercise increased fetal weight and Control plasma IGF1 concentrations, and decreased female placental weight. PregEx did not influence fetoplacental growth but increased placental IGF1 and IGF1R (potentially modulated by reduced Let 7f-1 miRNA) and decreased placental IGF2 protein. Importantly, these placental IGF system changes occurred with sex-specific responses. These data highlight that exercise differently influences fetoplacental growth and the placental IGF system depending on maternal exercise initiation, which may prevent the transgenerational transmission of deficits and dysfunction.

Sexual dimorphism in activation of placental autophagy in obese women with evidence for fetal programming from a placenta-specific mouse model

The incidence of maternal obesity and its co-morbidities (diabetes, cardiovascular disease) continues to increase at an alarming rate, with major public health implications. In utero exposure to maternal obesity has been associated with development of cardiovascular and metabolic diseases in the offspring as a result of developmental programming. The placenta regulates maternal-fetal metabolism and shows significant changes in its function with maternal obesity. Autophagy is a cell-survival process, which is responsible for the degradation of damaged organelles and misfolded proteins. Here we show an activation of autophagosomal formation and autophagosome-lysosome fusion in placentas of males but not females from overweight (OW) and obese (OB) women vs. normal weight (NW) women. However, total autophagic activity in these placentas appeared to be decreased as it showed an increase in SQSTM1/p62 and a decrease in lysosomal biogenesis. A mouse model with a targeted deletion of the essential autophagy gene Atg7 in placental tissue showed significant placental abnormalities comparable to those seen in human placenta with maternal obesity. These included a decrease in expression of mitochondrial genes and antioxidants, and decreased lysosomal biogenesis. Strikingly, the knockout mice were developmentally programmed as they showed an increased sensitivity to high-fat diet-induced obesity, hyperglycemia, hyperinsulinemia, increased adiposity, and cardiac remodeling. In summary, our results indicate a sexual dimorphism in placental autophagy in response to maternal obesity. We also show that autophagy plays an important role in placental function and that inhibition of placental autophagy programs the offspring to obesity, and to metabolic and cardiovascular diseases.

Human relaxins (RLNH1, RLNH2), their receptor (RXFP1) and fetoplacental growth

Relaxin, a systemic and placental hormone, has potential roles in fetoplacental growth. Human placenta expresses two RLN genes, RLNH1 and RLNH2 Maternal obesity is common and is associated with abnormal fetal growth. Our aims were to relate systemic and cord blood RLNH2, placental RLNs and their receptor (RXFP1) with fetoplacental growth in context of maternal body mass index, and associations with insulin-like growth factor 2 (IGF2) and vascular endothelial growth factor A (VEGFA) in the same placentas. Systemic, cord blood and placental samples were collected prior to term labor, divided by prepregnancy body mass index: underweight/normal (N = 25) and overweight/obese (N = 44). Blood RLNH2 was measured by ELISA; placental RLNH2, RLNH1, RXFP1, IGF2 and VEGFA were measured by quantitative immunohistochemistry and mRNAs were measured by quantitative reverse transcription PCR. Birthweight increased with systemic RLNH2 only in underweight/normal women (P = 0.036). Syncytiotrophoblast RLNH2 was increased in overweight/obese patients (P = 0.017) and was associated with placental weight in all subjects (P = 0.038). RLNH1 had no associations with birthweight or placental weight, but was associated with increased trophoblast and endothelial IGF2 and VEGFA, due to female fetal sex. Thus, while systemic RLNH2 may be involved in birthweight regulation in underweight/normal women, placental RLNH2 in all subjects may be involved in placental weight. A strong association of trophoblast IGF2 with birthweight and placental weight in overweight/obese women suggests its importance. However, an association of only RLNH1 with placental IGF2 and VEGFA was dependent upon female fetal sex. These results suggest that both systemic and placental RLNs may be associated with fetoplacental growth.

Impact of Maternal Lifetime Interpersonal Trauma on Children's Asthma: Mediation Through Maternal Active Asthma During Pregnancy

OBJECTIVE

Traumatic stressors, including child abuse and/or interpersonal violence over a woman's lifecourse, can affect the health of her children. This study examines the associations between maternal lifetime interpersonal trauma (IPT) and children's asthma by age 6 years (n = 857).

METHODS

Pregnant women completed the Revised Conflict Tactics Scale; IPT exposure was categorized as unexposed (55%), early (childhood and/or teen years only, 25%), late (adulthood and/or index pregnancy, 7%), and chronic (early and late, 13%). Clinician-diagnosed asthma in children was reported by mothers at each follow-up visit until the child reached age 6 years. We examined the effects of maternal IPT categories and child's asthma using logistic regression. Using structural equation models, we also examined indirect relationships between maternal chronic IPT and child asthma operating through active asthma in pregnancy, prepregnancy BMI, prenatal smoking, and/or increased exposure to other adverse life events or environmental toxins prenatally. Effect modification by the child's sex was examined.

RESULTS

Mothers were primarily Hispanic (55%) or black (30%) with less than high school education (62%). In logistic regression models, chronic maternal IPT (compared with unexposed) was associated with asthma in boys (odds ratio = 2.87, 95% confidence interval = 1.48-5.57) but not girls (odds ratio = 0.69, 95% confidence interval = 0.23-2.12; pinteraction = .042). In structural equation models, chronic IPT was associated with maternal active asthma in pregnancy (β = 0.59, p < .001), maternal active asthma was associated with children's asthma (β = 0.20, p = .009), and the total indirect effect for this path was significant (β = 0.12, p = .031). Associations were most evident among boys.

CONCLUSIONS

Mothers' history of chronic IPT was associated with asthma in boys. This association was mediated through active maternal asthma in pregnancy.

The gestational foundation of sex differences in development and vulnerability

Despite long-standing interest in the role of sex on human development, the functional consequences of fetal sex on early development are not well-understood. Here we explore the gestational origins of sex as a moderator of development. In accordance with the focus of this special issue, we examine evidence for a sex differential in vulnerability to prenatal and perinatal risks. Exposures evaluated include those present in the external environment (e.g., lead, pesticides), those introduced by maternal behaviors (e.g., alcohol, opioid use), and those resulting from an adverse intrauterine environment (e.g., preterm birth). We also provide current knowledge on the degree to which sex differences in fetal neurobehavioral development (i.e., cardiac and motor patterns) are present prior to birth. Also considered are contemporaneous and persistent sex of fetus effects on the pregnant woman. Converging evidence confirms that infant and early childhood developmental outcomes of male fetuses exposed to prenatal and perinatal adversities are more highly impaired than those of female fetuses. In certain circumstances, male fetuses are both more frequently exposed to early adversities and more affected by them when exposed than are female fetuses. The mechanisms through which biological sex imparts vulnerability or protection on the developing nervous system are largely unknown. We consider models that implicate variation in maturation, placental functioning, and the neuroendocrine milieu as potential contributors. Many studies use sex as a control variable, some analyze and report main effects for sex, but those that report interaction terms for sex are scarce. As a result, the true scope of sex differences in vulnerability is unknown.

The impact of maternal synthetic glucocorticoid administration in late pregnancy on fetal and early neonatal hypothalamic-pituitary-adrenal axes regulatory genes is dependent upon dose and gestational age at exposure

In this study, we determined the gene and/or protein expression of hypothalamic-pituitary-adrenal (HPA) axis regulatory molecules following synthetic glucocorticoid exposures. Pregnant sheep received intramuscular saline or betamethasone (BET) injections at 104 (BET-1), 104 and 111(BET-2) or 104, 111 and 118 (BET-3) days of gestation (dG). Samples were collected at numerous time-points between 75 dG and 12 weeks postnatal age. In the BET-3 treatment group, fetal plasma cortisol levels were lower at 145 dG than controls and gestational length was lengthened significantly. The cortisol:adrenocorticotropic hormone (ACTH) ratio in fetal plasma of control and BET-3 fetuses rose significantly between132 and 145 dG, and remained elevated in lambs at 6 and 12 weeks of age; this rise was truncated at day 145 in fetuses of BET-3 treated mothers. After BET treatment, fetal and postnatal pituitary proopiomelanocortin mRNA levels were reduced from 109 dG to 12 weeks postnatal age; pituitary prohormone convertase 1 and 2 mRNA levels were reduced at 145 dG and postnatally; hypothalamic arginine vasopressin mRNA levels were lowered at all time-points, but corticotrophin-releasing hormone mRNA levels were reduced only in postnatal lambs. Maternal BET increased late fetal and/or postnatal adrenal mRNA levels of ACTH receptor and 3β hydroxysteroid dehydrogenase but decreased steroidogenic acute regulatory protein and P450 17-α hydroxylase. The altered mRNA levels of key HPA axis regulatory proteins after maternal BET injections suggests processes that may subserve long-term changes in HPA activity in later life after prenatal exposure to synthetic glucocorticoids.

Hyper-responsiveness to acute stress, emotional problems and poorer memory in former preterm children

The prevalence of preterm birth (PTB) is high worldwide, especially in developing countries like Brazil. PTB is marked by a stressful environment in intra- as well as extrauterine life, which can affect neurodevelopment and hormonal and physiological systems and lead to long-term negative outcomes. Nevertheless, little is known about PTB and related outcomes later on in childhood. Thus, the goals of the current study were threefold: (1) comparing cortisol and alpha-amylase (sAA) profiles, including cortisol awakening response (CAR), between preterm and full-term children; (2) evaluating whether preterm children are more responsive to acute stress and (3) assessing their memory skills and emotional and behavioral profiles. Basal cortisol and sAA profiles, including CAR of 30 preterm children, aged 6 to 10 years, were evaluated. Further, we assessed memory functions using the Wide Range Assessment of Memory and Learning, and we screened behavior/emotion using the Strengths and Difficulties Questionnaire. The results of preterm children were compared to an age- and sex-matched control group. One week later, participants were exposed to a standardized laboratory stressor [Trier Social Stress Test for Children (TSST-C)], in which cortisol and sAA were measured at baseline, 1, 10 and 25 min after stressor exposure. Preterm children had higher cortisol concentrations at awakening, a flattened CAR and an exaggerated response to TSST-C compared to full-term children. These alterations were more pronounced in girls. In addition, preterm children were characterized by more emotional problems and poorer memory performance. Our findings illustrate the long-lasting and in part sex-dependent effects of PTB on the hypothalamic-pituitary-adrenal (HPA) axis, internalizing behavior and memory. The findings are in line with the idea that early adversity alters the set-point of the HPA axis, thereby creating a more vulnerable phenotype.

Impaired mitochondrial function in human placenta with increased maternal adiposity

The placenta plays a key role in regulation of fetal growth and development and in mediating in utero developmental programming. Obesity, which is associated with chronic inflammation and mitochondrial dysfunction in many tissues, exerts a programming effect in pregnancy. We determined the effect of increasing maternal adiposity and of fetal sex on placental ATP generation, mitochondrial biogenesis, expression of electron transport chain subunits, and mitochondrial function in isolated trophoblasts. Placental tissue was collected from women with prepregnancy BMI ranging from 18.5 to 45 following C-section at term with no labor. Increasing maternal adiposity was associated with excessive production of reactive oxygen species and a significant reduction in placental ATP levels in placentae with male and female fetuses. To explore the potential mechanism of placental mitochondrial dysfunction, levels of transcription factors regulating the expression of genes involved in electron transport and mitochondrial biogenesis were measured. Our in vitro studies showed significant reduction in mitochondrial respiration in cultured primary trophoblasts with increasing maternal obesity along with an abnormal metabolic flexibility of these cells. This reduction in placental mitochondrial respiration in pregnancies complicated by maternal obesity could compromise placental function and potentially underlie the increased susceptibility of these pregnancies to fetal demise in late gestation and to developmental programming.

Inverse relationship between gestational weight gain and glucose uptake in human placenta from female foetuses

BACKGROUND

Maternal obesity and gestational weight gain (GWG) have a significant impact on the in utero environment, and thus on foetal development and the health of the offspring later in life.

OBJECTIVE

The aim of this study was to determine the effect of maternal pre-existing obesity and maternal GWG on glucose uptake from placentas from male and female offspring.

METHODS

Total glucose uptake was measured in placental explants using radio-labelled glucose.

RESULTS

In the female placentas (n = 36), GWG and glucose uptake were significantly negatively correlated (r = -0.7, P < 0.0001; n = 36), and customized birthweight centile correlated with placental glucose uptake (r = 0.36, P = 0.03) but not GWG. In the male placentas (n = 45), GWG and glucose uptake were not related, and customized birthweight centile correlated with GWG (r = 0.34, P = 0.02; n = 45), but not placental glucose uptake.

CONCLUSIONS

The female placenta can adapt glucose uptake in the face of excessive GWG. The male placenta showed no evidence of changing glucose uptake in response to maternal GWG.

Foetal and placental 11β-HSD2: a hub for developmental programming

Foetal growth restriction (FGR), reflective of an adverse intrauterine environment, confers a significantly increased risk of perinatal mortality and morbidity. In addition, low birthweight associates with adult diseases including hypertension, metabolic dysfunction and behavioural disorders. A key mechanism underlying FGR is exposure of the foetus to glucocorticoids which, while critical for foetal development, in excess can reduce foetal growth and permanently alter organ structure and function, predisposing to disease in later life. Foetal glucocorticoid exposure is regulated, at least in part, by the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which catalyses the intracellular inactivation of glucocorticoids. This enzyme is highly expressed within the placenta at the maternal-foetal interface, limiting the passage of glucocorticoids to the foetus. Expression of 11β-HSD2 is also high in foetal tissues, particularly within the developing central nervous system. Down-regulation or genetic deficiency of placental 11β-HSD2 is associated with significant reductions in foetal growth and birth weight, and programmed outcomes in adulthood. To unravel the direct significance of 11β-HSD2 for developmental programming, placental function, neurodevelopment and adult behaviour have been extensively investigated in a mouse knockout of 11β-HSD2. This review highlights the evidence obtained from this mouse model for a critical role of feto-placental 11β-HSD2 in determining the adverse programming outcomes.

Neonatal health of infants born to mothers with asthma

BACKGROUND

Maternal asthma is associated with serious pregnancy complications, but newborn morbidity is understudied.

OBJECTIVE

We wanted to determine whether infants of asthmatic mothers have more neonatal complications.

METHODS

The Consortium on Safe Labor (2002-2008), a retrospective cohort, included 223,512 singleton deliveries at ≥ 23 weeks' gestation. Newborns of mothers with asthma (n = 17,044) were compared with newborns of women without asthma by using logistic regression models with generalized estimating equations to calculate adjusted odds ratios (ORs) and 95% CIs. Electronic medical record data included gestational week at delivery, birth weight, resuscitation, neonatal intensive care unit (NICU) admission, NICU length of stay, hyperbilirubinemia, respiratory distress syndrome, apnea, sepsis, anemia, transient tachypnea of the newborn, infective pneumonia, asphyxia, intracerebral hemorrhage, seizure, cardiomyopathy, periventricular or intraventricular hemorrhage, necrotizing enterocolitis, aspiration, retinopathy of prematurity, and perinatal mortality.

RESULTS

Preterm delivery was associated with maternal asthma for each week after 33 completed weeks of gestation and not earlier. Maternal asthma also increased the adjusted odds of small for gestational age (OR = 1.10; 95% CI, 1.05-1.16), NICU admission (OR = 1.12; 95% CI, 1.07-1.17), hyperbilirubinemia (OR = 1.09; 95% CI, 1.04-1.14), respiratory distress syndrome (OR = 1.09; 95% CI, 1.01-1.19), transient tachypnea of the newborn (OR = 1.10; 95% CI, 1.02-1.19), and asphyxia (OR = 1.34; 95% CI, 1.03-1.75). Findings persisted for term infants (≥ 37 weeks) who had additional increased odds of intracerebral hemorrhage (OR = 1.84; 95% CI, 1.11-3.03) and anemia (OR = 1.30; 95% CI, 1.04-1.62).

CONCLUSIONS

Maternal asthma was associated with prematurity and small for gestational age. Adverse neonatal outcomes, including respiratory complications, hyperbilirubinemia, and NICU admission, were increased in association with maternal asthma even among term deliveries.

Effect of preeclampsia on placental function: influence of sexual dimorphism, microRNA's and mitochondria

In pregnancy fetal growth and development occur in a sexually dimorphic manner. Male and female fetuses respond differently to the intrauterine environment with males disproportionately suffering from perinatal morbidity and mortality. We have demonstrated placental dysfunction and sexually dimorphic responses in pregnancies complicated by severe preeclampsia. Production of cytokines and apoptosis in the male placenta is heightened relative to that of the female placenta. We also find increased expression and stabilization and a sexual dimorphism in expression of the transcription factor HIF-1α, but a defect in binding to the hypoxia response element with corresponding reduced expression of HIF-1α target genes including VEGF and Glut-1. HIF-1α is involved in crosstalk with the redox sensitive transcription factor NFκB in regulation by cytokines, reactive oxygen species and expression of inflammatory genes. We find increased placental expression and DNA binding of NFκB and a sexually dimorphic response suggesting a role for NFκB in placental dysfunction with preeclampsia. Placental mitochondrial complex III activity and complex I and IV expression are reduced and alterations in mitochondrial morphology are found in preeclampsia and are linked to the hypoxamir miR-210. We propose that with severe PE placental HIF-1α is stabilized by excessive ROS, inflammation and relative hypoxia. This increases the expression of miR-210 in the placenta causing repression of mitochondria-associated target genes, potentially leading to mitochondrial and placental dysfunction. This placental dysfunction may lead to a fetal programming effect that results in disease in later life.

Early-life glucocorticoid exposure: the hypothalamic-pituitary-adrenal axis, placental function, and long-term disease risk

An adverse early-life environment is associated with long-term disease consequences. Adversity early in life is hypothesized to elicit developmental adaptations that serve to improve fetal and postnatal survival and prepare the organism for a particular range of postnatal environments. These processes, although adaptive in their nature, may later prove to be maladaptive or disadvantageous if the prenatal and postnatal environments are widely discrepant. The exposure of the fetus to elevated levels of either endogenous or synthetic glucocorticoids is one model of early-life adversity that contributes substantially to the propensity of developing disease. Moreover, early-life glucocorticoid exposure has direct clinical relevance because synthetic glucocorticoids are routinely used in the management of women at risk of early preterm birth. In this regard, reports of adverse events in human newborns have raised concerns about the safety of glucocorticoid treatment; synthetic glucocorticoids have detrimental effects on fetal growth and development, childhood cognition, and long-term behavioral outcomes. Experimental evidence supports a link between prenatal exposure to synthetic glucocorticoids and alterations in fetal development and changes in placental function, and many of these alterations appear to be permanent. Because the placenta is the conduit between the maternal and fetal environments, it is likely that placental function plays a key role in mediating effects of fetal glucocorticoid exposure on hypothalamic-pituitary-adrenal axis development and long-term disease risk. Here we review recent insights into how the placenta responds to changes in the intrauterine glucocorticoid environment and discuss possible mechanisms by which the placenta mediates fetal hypothalamic-pituitary-adrenal development, metabolism, cardiovascular function, and reproduction.

Evidence of sexual dimorphism in the placental function with severe preeclampsia

Preeclampsia (PE) affects 5-8% of pregnancies and is responsible for 18% of maternal deaths in the US, and for long-term complications in mother and child. PE is an inflammatory state and may influence placental function in a sex-specific manner. We determined if there is a sexual dimorphism in the placental inflammatory and apoptotic responses in preeclamptic pregnancies. Placentas were collected from normotensive and preeclamptic pregnancies with either male or female fetuses (MPE and FPE respectively) after c-section at term with no labor. Expression patterns of markers of inflammation measured by ELISA, as well as hypoxia, apoptosis and angiogenesis markers measured by Western blotting were determined in the placenta. Consistent with previous studies, an increase in inflammation, hypoxia, and apoptotic cell death was observed in PE compared to normotensive pregnancies. Levels of TNFα, IL-6 and IL-8, and HIF-1α were significantly greater, whereas the angiogenic marker VEGF was significantly reduced in MPE vs. FPE. Sexual dimorphism was also observed in the activation of cell death: the number of TUNEL-positive cells, and the expression pro-apoptotic markers PUMA and Bax being higher in MPE vs. FPE. We also found an increase in the levels of protein and DNA-binding activity of NFκB p65 in MPE vs. FPE. In summary, we show here that in preeclamptic pregnancies the placentas of males were associated with significantly higher expression of inflammatory, hypoxia and apoptotic molecules but reduced expression of a pro-angiogenic marker compared to placentas of female fetuses. We propose that the transcription factor NFκB p65 might, at least partially, be involved in sexual dimorphism during PE.

Placental contribution to the origins of sexual dimorphism in health and diseases: sex chromosomes and epigenetics

Sex differences occur in most non-communicable diseases, including metabolic diseases, hypertension, cardiovascular disease, psychiatric and neurological disorders and cancer. In many cases, the susceptibility to these diseases begins early in development. The observed differences between the sexes may result from genetic and hormonal differences and from differences in responses to and interactions with environmental factors, including infection, diet, drugs and stress. The placenta plays a key role in fetal growth and development and, as such, affects the fetal programming underlying subsequent adult health and accounts, in part for the developmental origin of health and disease (DOHaD). There is accumulating evidence to demonstrate the sex-specific relationships between diverse environmental influences on placental functions and the risk of disease later in life. As one of the few tissues easily collectable in humans, this organ may therefore be seen as an ideal system for studying how male and female placenta sense nutritional and other stresses, such as endocrine disruptors. Sex-specific regulatory pathways controlling sexually dimorphic characteristics in the various organs and the consequences of lifelong differences in sex hormone expression largely account for such responses. However, sex-specific changes in epigenetic marks are generated early after fertilization, thus before adrenal and gonad differentiation in the absence of sex hormones and in response to environmental conditions. Given the abundance of X-linked genes involved in placentogenesis, and the early unequal gene expression by the sex chromosomes between males and females, the role of X- and Y-chromosome-linked genes, and especially those involved in the peculiar placenta-specific epigenetics processes, giving rise to the unusual placenta epigenetic landscapes deserve particular attention. However, even with recent developments in this field, we still know little about the mechanisms underlying the early sex-specific epigenetic marks resulting in sex-biased gene expression of pathways and networks. As a critical messenger between the maternal environment and the fetus, the placenta may play a key role not only in buffering environmental effects transmitted by the mother but also in expressing and modulating effects due to preconceptional exposure of both the mother and the father to stressful conditions.

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.

Fetal sex and preterm birth

Rates of preterm birth vary between different populations and ethnic groups. Epidemiologic studies have suggested that the incidence of preterm birth is also higher in pregnancies carrying a male fetus; the male:female difference is greater in earlier preterm pregnancy. Placental or chorion trophoblast cells from pregnancies with a male fetus produced more pro-inflammatory TNFα in response to LPS stimulation and less anti-inflammatory IL-10 and granulocyte colony stimulating factor (G-CSF) than cells from pregnancies with a female fetus, more prostaglandin synthase (PTGS-2) and less prostaglandin dehydrogenase (PGDH). These results suggest that in the presence of a male fetus the trophoblast has the potential to generate a more pro-inflammatory environment. Maturation of the fetal hypothalamic-pituitary-adrenal axis and expression of placental genes, particularly 11β hydroxysteroid dehydrogenase-2 are also expressed in a sex dependent manner, consistent with the sex-biasing influences on gene networks. Sex differences in these activities may affect clinical outcomes of pre- and post-dates pregnancies and fetal/newborn wellbeing. These factors need consideration in studies of placental function and in the development of personalized strategies for the diagnosis of preterm labor and postnatal health.

Antenatal glucocorticoids reduce growth in appropriately grown and growth-restricted ovine fetuses in a sex-specific manner

Antenatal glucocorticoids are administered to mature the fetal lungs before preterm birth. Glucocorticoids also have non-pulmonary effects, including reducing fetal body and brain growth. The present study examined whether glucocorticoid administration has a sex-specific effect on growth in appropriately grown (control) and intrauterine growth-restricted (IUGR) fetal sheep. IUGR was induced at 0.7 gestation in fetal sheep by single umbilical artery ligation. On Days 5 and 6 after surgery, IUGR or control fetuses were exposed to the synthetic glucocorticoid betamethasone (BM; 11.4mg) or saline via intramuscular maternal administration. On Day 7, a postmortem was conducted to determine fetal sex and weight. Compared with control fetuses, the birthweight of male and female IUGR fetuses was significantly reduced (by 18.5±4.4% (P=0.002) and 21.7±6.0% (P=0.001), respectively). Maternal administration of BM significantly reduced bodyweight in both control and IUGR fetuses (by 11.3±2.8% and 20.5±3.6% in control male and female fetuses, respectively; and by 22.9±3.1% and 38.3±3.4% in IUGR male and female fetuses, respectively; P<0.001 for all, versus control+saline) fetuses. In control and IUGR animals the degree of growth restriction was greater in females than males (P<0.05) following administration of BM. These data suggest that antenatal glucocorticoids reduce fetal growth in a sex-specific manner, with females more growth restricted than males.

Sex differences in the programming effects of prenatal stress on psychopathology and stress responses: an evolutionary perspective

There is strong evidence from animal studies that prenatal stress has different effects on male and female offspring. In general, although not always, prenatal stress increases anxiety, depression and stress responses, both hypothalamic-pituitary-adrenal and cardiovascular, in female offspring rather than in male. Males are more likely to show learning and memory deficits. There have been few studies so far in humans which differentiate effects of prenatal stress on male and female psychopathology. Some studies support the animal models, but the evidence is inconsistent. The mediating mechanisms for any sex specific effects are little understood, but there is evidence that placental function can differ depending on the sex of the fetus. We suggest that there may be an evolutionary reason for any sex differences in the long term effects of prenatal stress. In a stressful environment it may be adaptive for females, who are more likely to stay in one place and look after children, to be more vigilant, alert to danger and thus show more stress responsiveness. This can give rise to a more anxious or depressed phenotype. With males it may be more adaptive to go out and explore new environments, compete with other males, and be more aggressive. For this it may help to be less responsive to external stressors. More research is needed into sex differences in the effects of prenatal stress in humans, to test these ideas.

Placental size is associated with mental health in children and adolescents

BACKGROUND

The role of the placenta in fetal programming has been recognized as a highly significant, yet often neglected area of study. We investigated placental size in relation to psychopathology, in particular attention deficit hyperactivity disorder (ADHD) symptoms, in children at 8 years of age, and later as adolescents at 16 years.

METHODOLOGY/PRINCIPAL FINDINGS

Prospective data were obtained from The Northern Finland Birth Cohort (NFBC) 1986. Placental weight, surface area and birth weight were measured according to standard procedures, within 30 minutes after birth. ADHD symptoms, probable psychiatric disturbance, antisocial disorder and neurotic disorder were assessed at 8 years (n = 8101), and ADHD symptoms were assessed again at 16 years (n = 6607), by teachers and parents respectively. We used logistic regression analyses to investigate the association between placental size and mental health outcomes, and controlled for gestational age, birth weight, socio-demographic factors and medical factors, during gestation. There were significant positive associations between placental size (weight, surface area and placental-to-birth-weight ratio) and mental health problems in boys at 8 and 16 years of age. Increased placental weight was linked with overall probable psychiatric disturbance (at 8 y, OR= 1.14 [95% CI= 1.04-1.25]), antisocial behavior (at 8 y, OR = 1.14 [95% CI= 1.03-1.27]) and ADHD symptoms (inattention-hyperactivity at 16 y, OR= 1.19 [95% CI = 1.02-1.38]). No significant associations were detected among girls.

CONCLUSIONS/SIGNIFICANCE

Compensatory placental growth may occur in response to prenatal insults. Such overgrowth may affect fetal development, including brain development, and ultimately contribute to psychopathology.

The placenta in preeclampsia

The root cause of preeclampsia is the placenta. Preeclampsia begins to abate with the delivery of the placenta and can occur in the absence of a fetus but with the presence of trophoblast tissue with hydatidiform moles. In view of this, study of the placenta should provide insight into the pathophysiology of preeclampsia. In this presentation we examine placental pathological and pathophysiological changes with preeclampsia and fetal growth restriction (FGR). It would seem that this comparison should be illuminating as both conditions are associated with similarly abnormal placentation yet only in preeclampsia is there a maternal pathophysiological syndrome. Similar insights about early and late onset preeclampsia should also be provided by such information.We report that the placental abnormalities in preeclampsia are what would be predicted in a setting of reduced perfusion and oxidative stress. However, the differences from FGR are inconsistent. The most striking differences between the two conditions are found in areas that have been the least studied. There are differences between the placental findings in early and late onset preeclampsia but whether these are qualitative, indicating different diseases, or simply quantitative differences within the same disease is difficult to determine.We attempt to decipher the true differences, seek an explanation for the disparate results and provide recommendations that we hope may help resolve these issues in future studies.

Mortality and adverse neurologic outcomes are greater in preterm male infants

OBJECTIVES

To determine whether male gender has an effect on survival, early neonatal morbidity, and long-term outcome in neonates born extremely prematurely.

METHODS

Retrospective review of the New South Wales and Australian Capital Territory Neonatal Intensive Care Unit Data Collection of all infants admitted to New South Wales and Australian Capital Territory neonatal intensive care units between January 1998 and December 2004. The primary outcome was hospital mortality and functional impairment at 2 to 3 years follow-up.

RESULTS

Included in the study were 2549 neonates; 54.7% were male. Risks of grade III/IV intraventricular hemorrhage, sepsis, and major surgery were found to be increased in male neonates. Hospital mortality (odds ratio 1.285, 95% confidence interval 1.035-1.595) and moderate to severe functional disability at 2 to 3 years of age (odds ratio 1.877, 95% confidence interval 1.398-2.521) were more likely in male infants. Gender differences for mortality and long-term neurologic outcome loses significance at 27 weeks gestation.

CONCLUSIONS

In the modern era of neonatal management, male infants still have higher mortality and poorer long-term neurologic outcome. Gender differences for mortality and long-term neurologic outcome appear to lose significance at 27 weeks gestation.

Neonatal respiratory infection and adult re-infection: effect on glucocorticoid and mineralocorticoid receptors in the hippocampus in BALB/c mice

Stressful events during the perinatal period in both humans and animals have long-term consequences for the development and function of physiological systems and susceptibility to disease in adulthood. One form of stress commonly experienced in the neonatal period is exposure to bacterial and viral infections. The current study investigated the effects of live Chlamydia muridarum bacterial infection at birth followed by re-infection in adulthood on hippocampal glucocorticoid receptors (GR) and mineralocorticoid receptors (MR) and stress response outcomes. Within 24 h of birth, neonatal mice were infected intranasally with C. muridarum (400 inclusion-forming units [ifu]) or vehicle. At 42 days, mice were re-infected (100 ifu) and euthanized 10 days later. In males, infection in adulthood alone had the most impact on the parameters measured with significant increases in GR protein compared to adult infection alone; and significant increases MR protein and circulating corticosterone compared to other treatment groups. Neonatal infection alone induced the largest alterations in the females with results showing reciprocal patterns for GR protein and TH protein. Perinatal infection resulted in a blunted response following adult infection for both males and females across all parameters. The present study demonstrates for the first time that males and females respond differently to infection based on the timing of the initial insult and that there is considerable sex differences in the hippocampal phenotypes that emerge in adulthood after neonatal infection.

The placental response to excess maternal glucocorticoid exposure differs between the male and female conceptus in spiny mice

The placenta is the intermediary between the mother and fetus, and its primary role is to provide for the appropriate growth of the fetus. A suboptimal in utero environment has been shown to differentially affect the health of offspring, depending on their sex. Here we show that excess maternal glucocorticoids administered in midgestation (Day 20, 0.5 gestation in the spiny mouse) for 60 h, have persisting effects on the placenta that differ by fetal sex, placental region, and time after glucocorticoid exposure. Dexamethasone (DEX) exposure altered placental structure and mRNA expression from male and female fetuses both immediately (Day 23) and 2 wk posttreatment (Day 37). The immediate consequences (Day 23) of DEX were similar between males and females, with reductions in the expression of IGF1, IGF1R, and SLC2A1 in the placenta. However, by Day 37, the transcriptional and structural response of the placenta was dependent on the sex of the fetus, with placentas of male fetuses having an increase in GCM1 expression, a decrease in SLC2A1 expression, and an increase in the amount of maternal blood sinusoids in the DEX-exposed placenta. Female placentas, on the other hand, showed increased SLC2A1 and MAP2K1 expression and a decrease in the amount of maternal blood sinusoids in response to DEX exposure. We have shown that the effect of a brief glucocorticoid exposure at midgestation has persisting effects on the placenta, and this is likely to have ongoing and dynamic effects on fetal development that differ for a male and female fetus.

Activation of the maternal immune system induces endocrine changes in the placenta via IL-6

Activation of the maternal immune system in rodent models sets in motion a cascade of molecular pathways that ultimately result in autism- and schizophrenia-related behaviors in offspring. The finding that interleukin-6 (IL-6) is a crucial mediator of these effects led us to examine the mechanism by which this cytokine influences fetal development in vivo. Here we focus on the placenta as the site of direct interaction between mother and fetus and as a principal modulator of fetal development. We find that maternal immune activation (MIA) with a viral mimic, synthetic double-stranded RNA (poly(I:C)), increases IL-6 mRNA as well as maternally-derived IL-6 protein in the placenta. Placentas from MIA mothers exhibit increases in CD69+ decidual macrophages, granulocytes and uterine NK cells, indicating elevated early immune activation. Maternally-derived IL-6 mediates activation of the JAK/STAT3 pathway specifically in the spongiotrophoblast layer of the placenta, which results in expression of acute phase genes. Importantly, this parallels an IL-6-dependent disruption of the growth hormone-insulin-like growth factor (GH-IGF) axis that is characterized by decreased GH, IGFI and IGFBP3 levels. In addition, we observe an IL-6-dependent induction in pro-lactin-like protein-K (PLP-K) expression as well as MIA-related alterations in other placental endocrine factors. Together, these IL-6-mediated effects of MIA on the placenta represent an indirect mechanism by which MIA can alter fetal development.

Renal programming: cause for concern?

Development of the kidney can be altered in utero in response to a suboptimal environment. The intrarenal factors that have been most well characterized as being sensitive to programming events are kidney mass/nephron endowment, the renin-angiotensin system, tubular sodium handling, and the renal sympathetic nerves. Newborns that have been subjected to an adverse intrauterine environment may thus begin life at a distinct disadvantage, in terms of renal function, at a time when the kidney must take over the primary role for extracellular fluid homeostasis from the placenta. A poor beginning, causing renal programming, has been linked to increased risk of hypertension and renal disease in adulthood. However, although a cause for concern, increasingly, evidence demonstrates that renal programming is not a fait accompli in terms of future cardiovascular and renal disease. A greater understanding of postnatal renal maturation and the impact of secondary factors (genes, sex, diet, stress, and disease) on this process is required to predict which babies are at risk of increased cardiovascular and renal disease as adults and to be able to devise preventative measures.

Proteomics in asthma

Proteomic approaches have already been successfully implemented in areas such as cancer research. Surprisingly, only a few proteomics analyses have been published reporting on the protein profiles associated with asthma. Although proteomics has its limitations and experimental challenges, it can successfully contribute to the understanding of a complex disease such as asthma. We have reviewed the current literature that has reported the use of proteomic techniques to identify proteins that may contribute to altered lung function in asthma. Only a few of these studies have used proteomic techniques on human tissues associated with asthma, while most research has been performed with animal models of asthma. Proteomic applications have been used as a complimentary technique to verify the suspected candidate proteins involved in asthma. In addition, novel proteins have been identified as potential therapeutic targets. Future collaboration between the different scientific disciplines using proteomic studies of animal models of asthma and confirmation of these findings in human tissues will significantly contribute to the understanding of the etiology of asthma and lead to the development of new therapeutic strategies for this highly prevalent disease.

Effect of maternal asthma, inhaled glucocorticoids and cigarette use during pregnancy on the newborn insulin-like growth factor axis

BACKGROUND

Fetal growth varies in a sex-specific manner in response to maternal asthma during pregnancy, but the mechanisms are unclear.

OBJECTIVE

We examined the influence of maternal asthma severity and associated exposures, inhaled glucocorticoid treatment, maternal cigarette use, and fetal sex on fetal growth and placental function during pregnancy and on the newborn insulin-like growth factor (IGF) axis. STUDY SUBJECTS AND DESIGN: Fetal growth was assessed in a prospective cohort of asthmatic and non-asthmatic women (n=145). At delivery, umbilical vein plasma was collected from male (n=61, controls n=16 and asthmatic n=45) or female (n=84, controls n=22 and asthmatic n=62) fetuses. Cord plasma insulin-like growth factor (IGF) binding protein (BP)-1, IGFBP-3, IGF-1 and IGF-2 were measured by radioimmunoassay and ELISA.

RESULTS

Cord plasma IGF-1 was the main component of the neonatal IGF axis altered by asthma and cigarette use. IGF-1 was increased in the presence of mild asthma and a male fetus and decreased in the presence of a female fetus and maternal asthma with cigarette use. IGFBP-3 was also decreased in the female fetuses of pregnancies complicated by asthma and cigarette use. Inhaled glucocorticoid use for the treatment of asthma did not affect the IGF axis. The strongest overall predictor of female birth weight after accounting for asthma severity, inhaled glucocorticoid treatment and cigarette use was IGF-1. For males, the strongest predictor of birth weight was IGFBP-3.

CONCLUSION

The data suggest male and female fetuses institute different strategies in response to adverse pregnancy conditions such as asthma and cigarette use.