Rhythm of Fetoplacental 11β-Hydroxysteroid Dehydrogenase Type 2 - Fetal Protection From Morning Maternal Glucocorticoids

Associations of serum glucocorticoid levels on hypertension and blood pressure-related indicators: a nested case-control study in rural China

BACKGROUND

The relationship between glucocorticoids and hypertension has shown inconsistent findings in previous studies. To address this, our study employed a nested case-control design in rural areas to further investigate the association between serum glucocorticoid levels and hypertension, and blood pressure-related indicators.

METHODS

This study employed a nested case-control design, involving 560 pairs of hypertensive cases and matched controls. The concentrations of serum cortisol (F), cortisone (E) and 11-deoxycortisol (S) were determined using liquid chromatography-tandem mass spectrometry. We employed various methods, including generalized linear model (GLM), conditional logistic regression model, restricted cubic spline regression, subgroup analysis, interaction, and joint effects, with adjustments for multiple covariates to analyze the relationships between glucocorticoids, hypertension, and blood pressure-related indicators.

RESULTS

After multivariable adjustments, ln-F, ln-F/E, and ln-S were positively associated with SBP, DBP, pulse pressure (PP), and mean arterial pressure (MAP), while ln-E was negatively associated with DBP and MAP ( P  < 0.05). Interestingly, ln-S showed no statistically significant association with hypertension prevalence ( P  > 0.05), whereas ln-F and ln-F/E were positively associated with it ( P  < 0.05). The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were 1.153 (1.011-1.315) for ln-F and 2.072 (1.622-2.645) for ln-F/E, respectively. In contrast, ln-E exhibited a negative association with hypertension prevalence (adjusted OR = 0.837, 95% CI 0.714-0.982). Moreover, a significant association was observed between the combined use of high-dose F/E and high-dose S with hypertension prevalence (adjusted OR = 3.273, 95% CI 2.013-5.321). Blood pressure indicators and hypertension prevalence significantly increased with elevated serum F and F/E concentrations ( P  < 0.05). Interaction analysis further revealed that among women, the positive association between F/E and hypertension prevalence was more pronounced than in men ( P  < 0.05), and S exhibited a more significant positive association with hypertension prevalence in the overweight population ( P  < 0.05).

CONCLUSION

Serum F/E and S levels demonstrated positive associations with hypertension and blood pressure-related indicators, and their combined influence exhibited a synergistic effect on hypertension. Notably, F, F/E, and S were associated with heightened hypertension risk, warranting particular attention in women and overweight populations.

Stress during pregnancy and fetal serum BDNF in cord blood at birth

INTRODUCTION

Adverse environments during pregnancy impact neurodevelopment including cognitive abilities of the developing children. The mediating biological alterations are not fully understood. Maternal stress may impact the neurotrophic regulation of the offspring as early as in utero and at birth. Brain-derived neurotrophic factor (BDNF) is essential for neurodevelopment. Short-term higher levels of BDNF in mice upon stressors associate with lower BDNF later in life, which itself associates with depression in animals and humans. Stress including glucocorticoids may impact BDNF, but there is a lack of data at birth. This study investigated if stress near term associates with fetal BDNF at birth in humans.

METHODS

Pregnant women near term who underwent primary cesarean sections (at 38.80±0.64 weeks), were included in this study (n=41). Stress at the end of pregnancy was assessed before the cesarean section by determining maternal depressive symptoms (EDPS), maternal state and trait anxiety (STAI-S and STAI-T), maternal prenatal distress (PDQ), stress over the past month (PSS), prenatal attachment to the offspring (PAI), maternal social support (F-Sozu), maternal early life stress (CTQ), socioeconomic status, and the glucocorticoids cortisol and cortisone (n=40) in amniotic fluid at birth. The association with fetal BDNF was analyzed. Cord blood serum of n=34 newborns at birth was analyzed for BDNF and newborn anthropometrics (weight, length and head circumference per gestational age at birth) were assessed. The association of fetal BDNF with anthropometrics at birth was analyzed.

RESULTS

After a BDNF-outlier (>3 SD) was removed, higher fetal BDNF associated significantly with maternal depressive symptoms (r=0.398, p=0.022), with lower socioeconomic status as assessed by the average number of people per room in the household (r=0.526, p=0.002) and with borderline significance with net income per person in the household (r=-0.313, p=0.087) in the bivariate analyses. In multivariable analysis, BDNF stayed positively associated with maternal depressive symptoms (β=0.404, 95% CI [7.057, 306.041], p=0.041) and lower net income per person in the household (β=-0.562, 95% CI [-914.511, -60.523], p=0.027) when controlling for maternal age, maternal pre-pregnancy BMI, fetal sex and gestational age. Fetal BDNF did not associate with newborn anthropometrics with the outlier removed in bivariate analyses or in multivariable analyses when controlling for maternal BMI and fetal sex.

CONCLUSION

Maternal depressive symptoms and lower socioeconomic status associated with higher fetal BDNF when controlling for confounders. Fetal BDNF did not associate with newborn anthropometrics with the outlier removed. Further studies should investigate how early altered BDNF associate with the development and possibly psychopathology of the offspring.

Stress in pregnancy - Implications for fetal BDNF in amniotic fluid at birth

Introduction

At the maternal-fetal interface in pregnancy, stress during pregnancy can lead to an increased vulnerability to later psychopathology of the fetus. Potential mediators of this association have scarcely been studied and may include early alterations of fetal brain-derived neurotrophic factor (BDNF). Amniotic fluid is of particular interest for effects on fetal endocrine alterations, as the assessment in amniotic fluid allows for measurements over a time integral. This study hypothesized that maternal psychometrics, socioeconomic status and glucocorticoids are related to BDNF levels in amniotic fluid at birth. The association of fetal BDNF with newborn anthropometrics was tested.

Methods

Women near term who underwent elective cesarean section and their newborns were investigated (n = 37). Maternal psychometrics, socioeconomic status and glucocorticoids (the sum of cortisol and cortisone) in amniotic fluid at birth were analyzed for an association with fetal BDNF in amniotic fluid at birth. Newborn anthropometrics were assessed by length, weight, head circumference and gestational age at birth.

Results

In bivariate analysis, maternal psychometrics and socioeconomic status were not related to fetal BDNF in amniotic fluid at birth. The sum of cortisol and cortisone related to increased fetal BDNF in amniotic fluid at birth (r = 0.745, p < 0.001). BDNF in amniotic fluid was associated negatively with fetal birth weight per gestational age (r = -0.519, p < 0.001), length per gestational age (r = -0.374, p = 0.023), head circumference per gestational age (r = -0.508, p = 0.001), but not with gestational age at birth. In multiple regression analysis, the sum of cortisol and cortisone (p < 0.001) and birth weight per gestational age (p = 0.012) related to higher fetal BDNF levels in amniotic fluid at birth (R2 = 0.740, p < 0.001) when controlling for fetal sex and maternal age. Head circumference per gestational age predicted fetal BDNF with borderline significance (p = 0.058) when controlling for confounders.

Conclusion

Glucocorticoids in amniotic fluid were positively associated with high fetal BDNF at birth, which may be an adaptive fetal response. Maternal psychological variables and socioeconomic status did not link to fetal BDNF. Birth weight and head circumference per gestational age were inversely associated with fetal BDNF at birth, which may represent a compensatory upregulation of BDNF in fetuses with low anthropometrics. Longitudinal studies are needed to assess the role of stress during pregnancy on later offspring development. The analysis of additional fetal growth factors and inflammation upon maternal stress in further biomaterials such as the placenta is warranted, to understand mechanistic alterations of how maternal stress links to fetal development and an increased vulnerability for psychopathology.

Light pollution during pregnancy influences the growth of offspring in rats

OBJECTIVE

To investigate the effects of excessive light exposure during gestation on intrauterine development and early growth of neonates in rats.

METHODS

Pregnant rats were randomly allocated to three groups: the constant light exposure group, non-light exposure group and control group. Blood samples were collected from the tail vein to analyze melatonin and cortisol levels. Weight, daily food and water consumption were recorded. Uterine weight, placental weight and placental diameter were measured on gestational day 19. Natural birth and neonate growth were also monitored. The expression of NR1D1(nuclear receptor subfamily 1 group D member 1) in offspring's SCN (suprachiasmatic nuclei), liver and adipose tissue was measured. Expression of NR1D1, MT1(melatonin 1 A receptor) and 11β-HSD2 (placental 11β-hydroxysteroid dehydrogenase type 2) in placenta was also measured. Finally, the expression of MT1 and 11β-HSD2 in NR1D1 siRNA transfected JEG-3 cells was evaluated.

RESULTS

There were no significant differences in maternal weight gain, pregnancy duration, uterine weight, placental body weight, placental diameter, fetal number among three groups. There were no significant differences in weights or lengths of offspring at birth. Compared to other two groups, constant light exposure group showed significantly more rapid growth of offspring in 21st day post-birth. The expression of NR1D1 in SCN, liver and adipose tissues of offspring was not significantly different among three groups. The maternal serum melatonin and cortisol levels of the constant light exposure group were lower and higher than other two groups, respectively. The expressions of NR1D1, MT1 and 11β-HSD2 were all decreased in placenta of the constant light exposure group. The expression of MT1 and 11β-HSD2 in JEG-3 cells were decreased after NR1D1 siRNA transfection.

CONCLUSION

Excessive light exposure during pregnancy results in elevated cortisol and reduced melatonin exposure to fetuses in uterus, potentially contributing to an accelerated early growth of offspring in rats.

How is prenatal stress transmitted from the mother to the fetus?

Prenatal stress programmes long-lasting neuroendocrine and behavioural changes in the offspring. Often this programming is maladaptive and sex specific. For example, using a rat model of maternal social stress in late pregnancy, we have demonstrated that adult prenatally stressed male, but not prenatally stressed female offspring display heightened anxiety-like behaviour, whereas both sexes show hyperactive hypothalamo-pituitary-adrenal (HPA) axis responses to stress. Here, we review the current knowledge of the mechanisms underpinning dysregulated HPA axis responses, including evidence supporting a role for reduced neurosteroid-mediated GABAergic inhibitory signalling in the brains of prenatally stressed offspring. How maternal psychosocial stress is signalled from the mother to the fetuses is unclear. Direct transfer of maternal glucocorticoids to the fetuses is often considered to mediate the programming effects of maternal stress on the offspring. However, protective mechanisms including attenuated maternal stress responses and placental 11β-hydroxysteroid dehydrogenase-2 (which inactivates glucocorticoids) should limit materno-fetal glucocorticoid transfer during pregnancy. Moreover, a lack of correlation between maternal stress, circulating maternal glucocorticoid levels and circulating fetal glucocorticoid levels is reported in several studies and across different species. Therefore, here we interrogate the evidence for a role for maternal glucocorticoids in mediating the effects of maternal stress on the offspring and consider the evidence for alternative mechanisms, including an indirect role for glucocorticoids and the contribution of changes in the placenta in signalling the stress status of the mother to the fetus.

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.

Cholic acid exposure during late pregnancy causes placental dysfunction and fetal growth restriction by reactive oxygen species-mediated activation of placental GCN2/eIF2α pathway

Epidemiological studies suggest that fetal growth restriction (FGR) caused by gestational cholestasis is associated with elevated serum cholic acid (CA). Here, we explore the mechanism by which CA induces FGR. Pregnant mice except controls were orally administered with CA daily from gestational day 13 (GD13) to GD17. Results found that CA exposure decreased fetal weight and crown-rump length, and increased the incidence of FGR in a dose-dependent manner. Furthermore, CA caused placental glucocorticoid (GC) barrier dysfunction via down-regulating the protein but not the mRNA level of placental 11β-Hydroxysteroid dehydrogenase-2 (11β-HSD2). Additionally, CA activated placental GCN2/eIF2α pathway. GCN2iB, an inhibitor of GCN2, significantly inhibited CA-induced down-regulation of 11β-HSD2 protein. We further found that CA caused excessive reactive oxygen species (ROS) production and oxidative stress in mouse placentas and human trophoblasts. NAC significantly rescued CA-induced placental barrier dysfunction by inhibiting activation of GCN2/eIF2α pathway and subsequent down-regulation of 11β-HSD2 protein in placental trophoblasts. Importantly, NAC rescued CA-induced FGR in mice. Overall, our results suggest that CA exposure during late pregnancy induces placental GC barrier dysfunction and subsequent FGR may be via ROS-mediated placental GCN2/eIF2α activation. This study provides valuable insight for understanding the mechanism of cholestasis-induced placental dysfunction and subsequent FGR.

Prenatal Hypoxia Affects Foetal Cardiovascular Regulatory Mechanisms in a Sex- and Circadian-Dependent Manner: A Review

Prenatal hypoxia during the prenatal period can interfere with the developmental trajectory and lead to developing hypertension in adulthood. Prenatal hypoxia is often associated with intrauterine growth restriction that interferes with metabolism and can lead to multilevel changes. Therefore, we analysed the effects of prenatal hypoxia predominantly not associated with intrauterine growth restriction using publications up to September 2021. We focused on: (1) The response of cardiovascular regulatory mechanisms, such as the chemoreflex, adenosine, nitric oxide, and angiotensin II on prenatal hypoxia. (2) The role of the placenta in causing and attenuating the effects of hypoxia. (3) Environmental conditions and the mother's health contribution to the development of prenatal hypoxia. (4) The sex-dependent effects of prenatal hypoxia on cardiovascular regulatory mechanisms and the connection between hypoxia-inducible factors and circadian variability. We identified that the possible relationship between the effects of prenatal hypoxia on the cardiovascular regulatory mechanism may vary depending on circadian variability and phase of the days. In summary, even short-term prenatal hypoxia significantly affects cardiovascular regulatory mechanisms and programs hypertension in adulthood, while prenatal programming effects are not only dependent on the critical period, and sensitivity can change within circadian oscillations.

Life Course Impact of Glucocorticoids During Pregnancy on Muscle Development and Function

Maternal stress, such as maternal obesity, can induce severe gestational disease and hormonal disorder which may disrupt fetal organ maturation and further cause endangered early or future health in offspring. During fetal development, glucocorticoids are essential for the maturation of organ systems. For instance, in clinical applications, glucocorticoids are commonly utilized to pregnant women with the risk of preterm delivery to reduce mortality of the newborns. However, exposure of excessive glucocorticoids at embryonic and fetal developmental stages can cause diseases such as cardiovascular disease and muscle atrophy in adulthood. Effects of excessive glucocorticoids on human health are well-recognized and extensively studied. Nonetheless, effects of these hormones on farm animal growth and development, particularly on prenatal muscle development, and postnatal growth, did not attract much attention until the last decade. Here, we provided a short review of the recent progress relating to the effect of glucocorticoids on prenatal skeletal muscle development and postnatal muscle growth as well as heart muscle development and cardiovascular disease during life course.

Childhood trauma and insulin-like growth factors in amniotic fluid: An exploratory analysis of 79 women

BACKGROUND

Perinatal stress has adverse effects on fetal outcome, yet the effect of early maternal trauma on fetal outcome has scarcely been studied. We investigated effects of maternal childhood trauma and current environment on important regulators of prenatal growth, fetal insulin-like growth factor (IGF)-1 and IGF-2 in amniotic fluid and assessed the impact of IGFs on newborn anthropometrics.

METHODS

79 pregnant women in their second trimester who underwent amniocentesis (15.9 ± 0.9 weeks of gestational age) and their newborns at birth were analyzed. Maternal childhood trauma was assessed using the childhood trauma questionnaire (CTQ) and current environment was operationalized by assessing maternal psychosocial, physical health and endocrine measurements in amniotic fluid.

RESULTS

In this exploratory analysis of 79 pregnant women, maternal childhood trauma, defined as reporting at least low scores on any of the CTQ subscales, negatively correlated with fetal IGF-1 (M_ln = 3.48 vs. 2.98; p = 0.012) and IGF-2 (Mdn_ln = 4.99 vs. 4.70; p = 0.002). Trauma severity, defined as the overall trauma score, negatively correlated with fetal IGF-2 (r = -0.24; p = 0.037). From trauma subscales, maternal sexual abuse correlated with fetal IGF-1 (r = -0.32; p = 0.006) and IGF-2 (r = -0.39; p = 0.001). Maternal BMI negatively correlated with fetal IGF-1 (r = -0.26; p = 0.023) and IGF-2 (r = -0.29; p = 0.011). Newborn anthropometrics were operationalized by length, weight, sex, gestational age, length/gestational age and weight/gestational age at birth. Fetal weight at birth associated with a trend with fetal IGF-1 when controlling for BMI. Maternal hypothalamus-pituitary-adrenal axis activity and maternal exercise did not contribute significantly to predicting fetal IGFs. Maternal childhood trauma (β = -0.27; p = 0.011) and BMI (β = -0.24; p = 0.026) remained significantly associated with fetal IGF-1. Maternal childhood trauma (β = -0.32; p = 0.003), maternal BMI (β = -0.30; p = 0.005) and maternal sexual abuse (β = -0.22; p = 0.049) remained significantly associated with fetal IGF-2 and with a trend with fetal IGF-1 (β = -0.21; p = 0.076) when excluding women with gestational diabetes.

CONCLUSION

Maternal childhood trauma and BMI associate negatively with fetal IGF-1 and IGF-2 in amniotic fluid. Controlling for maternal BMI, fetal weight at birth remains associated with a trend with fetal IGF-1. The presented data suggests that childhood trauma can affect endocrine measurements of the developing next generation, providing a mechanism by which adverse maternal life events are transmitted to the next generation.