Enzymes involved in the formation and transformation of steroid hormones in the fetal and placental compartments

Profile of steroid metabolites in human breast milk in different stages of lactation

Breast milk (BM), as an optimal food, provides the newborn with a variety of minor compounds relevant for health and wellbeing. Endogenous steroids, also minor constituents, are mainly secreted in BM as conjugated metabolites. Recent research has revealed the relevance of steroid conjugates in many physiological processes. Thus, their presence in BM appears to be very intriguing, especially in relation to breastfeeding. The objective of our study was to profile conjugated steroid metabolites present in BM in relation to the lactation stage, and to promote further evaluation of their importance in breastfeeding. For this purpose, we developed and used a direct UHPLC-MS/MS metabolomics approach capable to detect more than 60 conjugated metabolites (mono-sulfated, mono-glucuronylated, bis-sulfated and sulfate-glucuronylated) from all steroid families. We compared the occurrence of these metabolites in samples collected from breastfeeding mothers and stratified by lactation stages: colostrum, transitional and mature milk. Our results showed that many biologically relevant conjugated steroids are secreted in BM. Their concentrations were highest in colostrum, decreased remarkably in transitional and were much lower in mature milk, with some exceptions. The profile of metabolites also differed considerably between lactation stages. The approximate daily secretion in BM indicated that infants are exposed to significant oral doses of steroid conjugates during the first week of lactation. The supply of these metabolites in BM declined and became constant after the second week postpartum. Overall, our data provide a foundation for further investigation on the physiological relevance of BM secreted steroid metabolites in relation to both mother and child.

Prenatal Exposure to Synthetic Phenols Assessed in Multiple Urine Samples and Dysregulation of Steroid Hormone Homeostasis in Two European Cohorts

BACKGROUND

Some synthetic phenols alter hormonal pathways involved in successful pregnancy and fetal development. Despite high within-subject temporal variability of phenols, previous studies mostly utilized spot urine samples to assess pregnancy exposure. Herein, we investigated associations between pregnancy exposure to eight phenols assessed in multiple pooled urine samples and steroid hormones assessed in maternal hair reflecting cumulative hormone levels over the previous weeks to months.

METHODS

We assessed phenol-hormone associations in 928 pregnant women from two pooled cohorts recruited in Spain [Barcelona Life Study Cohort (BiSC), 2018-2021] and France [Assessment of Air Pollution exposure during Pregnancy and Effect on Health (SEPAGES), 2014-2017] using pools of up to 21 samples each, collected in early pregnancy (median gestational age: 18.0 wk), as well as hair collected in late pregnancy (BiSC) or at birth (SEPAGES). We measured two bisphenols, four parabens, benzophenone-3, and triclosan along with metabolites of three adrenal (∑ cortisol , ∑ cortisone , and 11-dehydrocorticosterone) and two reproductive (progesterone and testosterone) hormones. We ran adjusted linear regressions for each exposure biomarker-outcome pair and Bayesian kernel machine regression for phenols mixture.

RESULTS

Bisphenol S was associated with higher cortisol and 11-dehydrocorticosterone concentrations. Propylparaben was associated with lower levels of cortisol, cortisone, and 11-dehydrocorticosterone, while methylparaben was linked to a reduction in cortisol levels. Interestingly, associations identified for parabens were stronger for women carrying female fetuses. No associations for phenol mixture were detected.

CONCLUSIONS

Our study suggests that pregnancy exposure to bisphenol S and some parabens (propyl- and methylparaben) may affect production of maternal corticosteroid hormones that are important for a successful pregnancy and fetal development. https://doi.org/10.1289/EHP15117.

Placental RTN3L-dependent ER-Phagy Contributes to Fetal Testicular Dysplasia Upon Environmental Stress

Prenatal environmental stress damages fetal testicular development, leading to male infertility. However, the precise mechanisms underlying the impact of gestational environmental stress on fetal testicular development require further investigation. This study demonstrates that gestational environmental stressor cadmium exposure caused placental estradiol synthesis inhibition and fetal testicular dysplasia. Gestational estradiol supplementation restores fetal testicular dysplasia caused by environmental stress-induced placental estradiol synthesis inhibition. Analysis of human placentae and cadmium-stimulated human primary placental trophoblasts confirmed that ER-phagy is associated with the inhibition of estradiol synthesis in placentae. Subsequently, the data reveals that environmental stress significantly activates RTN3L-mediated ER-phagy. RTN3L-deficient cells and placental Rtn3l-specific knockout mice confirm that environmental stress-activated RTN3L-mediated ER-phagy inhibited placental estradiol synthesis. Total N6-methyladenosine level increasing in gestational environmental stress-exposed placentae. METTL3-mediated N6-methyladenosine modification suppression obviously restrains environmental stress-activated RTN3L-dependent ER-phagy. In conclusion, gestational environmental stress activates ER-phagy by increasing placental Rtn3l mRNA N6-methyladenosine modification, inhibiting placental estradiol synthesis, and contributing to fetal testicular dysplasia. The study demonstrates the early prevention and treatment of adult male infertility from the perspective of fetal-derived diseases.

Maternal metabolomics linking prenatal exposure to fine particulate matter and birth weight: a cross-sectional analysis of the MADRES cohort

BACKGROUND

Prenatal exposure to air pollution has been associated with an increased risk of low birth weight. Disrupted metabolism may serve as an underlying mechanism, but the specific metabolic pathways involved remain unclear.

METHODS

In the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) study, 382 third-trimester maternal serum samples were analyzed for untargeted metabolomics using liquid chromatography with Fourier transform high-resolution mass spectrometry. Ambient concentrations of fine particulate matter (PM2.5), particulate matter ≤ 10 μm in diameter (PM10), nitrogen dioxide (NO2), and ozone (O3) were estimated using inverse-distance-squared weighted spatial interpolation based on daily residential histories. Birth weight was retrieved from medical records. Linear regression identified metabolomic features associated with air pollution exposure or birth weight, followed by Mummichog pathway enrichment and mediation analyses for the selected features.

RESULTS

Second-trimester PM2.5 exposure was associated with lower birth weight. Fourteen metabolic pathways were significantly associated with second-trimester PM2.5 exposure, with C21-steroid hormone biosynthesis and metabolism showing the most significant association. Sixteen metabolic pathways were significantly associated with birth weight, with vitamin A (retinol) metabolism being the most significantly enriched pathway. Seven pathways were associated with both PM2.5 exposure and birth weight, including C21-steroid hormone biosynthesis and metabolism, bile acid biosynthesis, tyrosine metabolism, ascorbate (vitamin C) and aldarate metabolism, vitamin D3 (cholecalciferol) metabolism, vitamin A (retinol) metabolism, and pyrimidine metabolism. Overweight or obese women exhibited more metabolomic features and metabolic pathways associated with PM2.5 exposure compared to underweight or normal-weight women. No associations were observed between PM10, NO2, or O3 and birth weight.

CONCLUSIONS

Maternal metabolic pathways involving steroid metabolism, oxidative stress and inflammation, vitamin metabolism, and DNA damage may link prenatal PM2.5 exposure to lower birth weight, with overweight or obese women potentially more susceptible to these metabolic disruptions.

Risk Factors in Fetal Ovarian Cysts for Postnatal Adverse Outcomes

AIM

To investigate the natural history of fetal ovarian cysts and elucidate the risk factors for postnatal adverse outcomes in fetal ovarian cysts.

METHODS

The study subjects were 18 cases with ovarian cysts prenatally diagnosed using ultrasonography at our hospital between 2007 and 2020. The subjects were classified by cyst characteristics according to echogenic patterns [simple cyst (S) and complex cyst (C)], changes in echogenic patterns (S-to-S, S-to-C, and C-to-C), and diameters (<40 and ≥ 40 mm). Clinical parameters and outcomes were compared between S and C patterns, S-to-S and S-to-C patterns, and <40 and ≥ 40 mm diameters.

RESULTS

Cases with S and C patterns (15 and 3, respectively) had median gestational ages of 35 and 36 weeks, respectively, and maximum cyst diameters of 36 and 57mm, respectively. The number of cases with S-to-S, S-to-C and C-to-C patterns were 11, 4 and 3, respectively. The maximum cyst diameter in cases with S-to-C patterns (58 mm) was larger than that in cases with S-to-S patterns (34 mm) (P<0.05). Placental weight in cases with cysts >40 mm and/or cyst expansion was greater than that in cases with neither or both conditions (P<0.05). Spontaneous resolution (before and after birth) occurred in 8 of 9 and 3 of 9 cases with maximum cyst diameters <40 and ≥ 40 mm, respectively. Ovarian function was lost in 2 cases with S-to-C patterns and in 2 cases with C-to-C patterns.

CONCLUSION

Cases with cyst diameters ≥ 40 mm and/or cyst expansion during the late third trimester had greater placental weight and more postnatal adverse outcomes.

Modulation of fetoplacental growth, development and reproductive function by endocrine disrupters

Maternal endocrine homeostasis is vital to a successful pregnancy, regulated by several hormones such as human chorionic gonadotropin, estrogen, leptin, glucocorticoid, insulin, prostaglandin, and others. Endocrine stress during pregnancy can modulate nutrient availability from mother to fetus, alter fetoplacental growth and reproductive functions. Endocrine disrupters such as bisphenols (BPs) and phthalates are exposed in our daily life's highest volume. Therefore, they are extensively scrutinized for their effects on metabolism, steroidogenesis, insulin signaling, and inflammation involving obesity, diabetes, and the reproductive system. BPs have their structural similarity to 17-β estradiol and their ability to bind as an agonist or antagonist to estrogen receptors to elicit an adverse response to the function of the endocrine and reproductive system. While adults can negate the adverse effects of these endocrine-disrupting chemicals (EDCs), fetuses do not equip themselves with enzymatic machinery to catabolize their conjugates. Therefore, EDC exposure makes the fetoplacental developmental window vulnerable to programming in utero. On the one hand prenatal BPs and phthalates exposure can impair the structure and function of the ovary and uterus, resulting in placental vascular defects, inappropriate placental expression of angiogenic growth factors due to altered hypothalamic response, expression of nutrient transporters, and epigenetic changes associated with maternal endocrine stress. On the other, their exposure during pregnancy can affect the offspring's metabolic, endocrine and reproductive functions by altering fetoplacental programming. This review highlights the latest development in maternal metabolic and endocrine modulations from exposure to estrogenic mimic chemicals on subcellular and transgenerational changes in placental development and its effects on fetal growth, size, and metabolic & reproductive functions.

Pathophysiological Implications of Interstitial Cajal-like Cells (ICC-like) in Uterus: A Comparative Study with Gastrointestinal ICCs

The main function of interstitial cells of Cajal (ICCs) is to regulate gastrointestinal peristalsis by acting as a "pacemaker" cell by generating spontaneous slow electrical waves. In 2005, electron microscopy revealed a cell type similar to ICCs (ICC-like) outside the gastrointestinal tract, with contractile activity and c-Kit+ immunohistochemistry shared with ICCs. Among the locations where ICC-like cells have been observed, it is in the uterus where they have a significant functional and pathophysiological role. These cells are involved in obstetric phenomena of contractile action, such as ascending sperm transport, embryo implantation, pregnancy, delivery, and the expulsion of menstrual debris. Within the pathophysiology related to these cells, we find obstetric alterations such as recurrent miscarriages, premature deliveries, abolition of uterine contractions, and failures of embryo implantation, in addition to other common conditions in the fertile age, such as endometriosis and leiomyoma.

Comparative steroid profiling of newborn hair and umbilical cord serum highlights the role of fetal adrenals, placenta, and pregnancy outcomes in fetal steroid metabolism

Previous steroid hormone studies concerning pregnancy and newborns have mainly focused on glucocorticoids; wider steroid profiles have been less commonly investigated. Here, we performed a comparative analysis of 17 steroids from newborn hair and umbilical cord serum at the time of delivery. The study participants (n = 42, 50% girls) were a part of the Kuopio Birth Cohort and represent usual Finnish pregnancies. The hair and cord serum samples were analyzed with liquid chromatography high resolution mass spectrometry and triple quadrupole tandem mass spectrometry, respectively. We detected high individual variations in steroid hormone concentrations in both sample matrices. The concentrations of cortisol (F), corticosterone (B), estrone (E1), estradiol (E2), dehydroepiandrosterone (DHEA), 11β-hydroxyandostenedione (11bOHA4), 5α-androstanedione (DHA4), and 17α-hydroxypregnenolone (17OHP5) correlated positively between cord serum and newborn hair samples. In addition, F and 11bOHA4 concentrations correlated positively with each other in both newborn hair and cord serum samples. The cortisone-to-cortisol ratio (E/F) was significantly higher in cord serum than in newborn hair samples reflecting high placental 11βHSD2 enzyme activity. Only minor sex differences in steroid concentrations were observed; higher testosterone (T) and 11-deoxycortisol (S) with lower 11bOHA4 in male cord serum, and higher DHEA, androstenedione (A4) and 11bOHA4 in female newborn hair samples. Parity and delivery mode were the most significant pregnancy- and birth-related parameters associating with F and some other adrenocortical steroid concentrations. This study provides novel information about intrauterine steroid metabolism in late pregnancy and typical concentration ranges for several newborn hair steroids, including also 11-oxygenated androgens.

Biosynthesis of estetrol in human pregnancy: Potential pathways

Estetrol (E4) has emerged as a novel and highly promising estrogen for therapeutic use. E4 is a weak natural estrogen produced only in pregnancy. Because of its novelty, there is considerable interest by clinicians in how it is produced in pregnancy. Although the fetal liver plays a key role in its production, the placenta is also involved. A current view is that estradiol (E2) formed in the placenta enters the fetal compartment and is then rapidly sulfated. E2 sulfate then undergoes 15α-/16α-hydroxylation in the fetal liver thereby forming E4 sulfate (phenolic pathway). However, another pathway involving 15α,16α-dihydroxy-DHEAS formed in the fetal liver and converted to E4 in the placenta also plays a significant role (neutral pathway). It is not known which pathway predominates, but both pathways appear to be important in E4 biosynthesis. In this commentary, we summarize the well-established pathways in the formation of estrogens in the nonpregnant and pregnant female. We then review what is known about the biosynthesis of E4 and describe the 2 proposed pathways involving the fetus and placenta.

Human cytochrome P450 3A7 binding four copies of its native substrate dehydroepiandrosterone 3-sulfate

Human fetal cytochrome P450 3A7 (CYP3A7) is involved in both xenobiotic metabolism and the estriol biosynthetic pathway. Although much is understood about cytochrome P450 3A4 and its role in adult drug metabolism, CYP3A7 is poorly characterized in terms of its interactions with both categories of substrates. Herein, a crystallizable mutated form of CYP3A7 was saturated with its primary endogenous substrate dehydroepiandrosterone 3-sulfate (DHEA-S) to yield a 2.6 Å X-ray structure revealing the unexpected capacity to simultaneously bind four copies of DHEA-S. Two DHEA-S molecules are located in the active site proper, one in a ligand access channel, and one on the hydrophobic F'-G' surface normally embedded in the membrane. While neither DHEA-S binding nor metabolism exhibit cooperative kinetics, the current structure is consistent with cooperativity common to CYP3A enzymes. Overall, this information suggests that mechanism(s) of CYP3A7 interactions with steroidal substrates are complex.

Role of the Sodium-Dependent Organic Anion Transporter (SOAT/SLC10A6) in Physiology and Pathophysiology

The sodium-dependent organic anion transporter (SOAT, gene symbol SLC10A6) specifically transports 3'- and 17'-monosulfated steroid hormones, such as estrone sulfate and dehydroepiandrosterone sulfate, into specific target cells. These biologically inactive sulfo-conjugated steroids occur in high concentrations in the blood circulation and serve as precursors for the intracrine formation of active estrogens and androgens that contribute to the overall regulation of steroids in many peripheral tissues. Although SOAT expression has been detected in several hormone-responsive peripheral tissues, its quantitative contribution to steroid sulfate uptake in different organs is still not completely clear. Given this fact, the present review provides a comprehensive overview of the current knowledge about the SOAT by summarizing all experimental findings obtained since its first cloning in 2004 and by processing SOAT/SLC10A6-related data from genome-wide protein and mRNA expression databases. In conclusion, despite a significantly increased understanding of the function and physiological significance of the SOAT over the past 20 years, further studies are needed to finally establish it as a potential drug target for endocrine-based therapy of steroid-responsive diseases such as hormone-dependent breast cancer.

Gestational cadmium exposure disrupts fetal liver development via repressing estrogen biosynthesis in placental trophoblasts

Cadmium (Cd), commonly found in diet and drinking water, is known to be harmful to the human liver. Nevertheless, the effects and mechanisms of gestational Cd exposure on fetal liver development remain unclear. Here, we reported that gestational Cd (150 mg/L) exposure obviously downregulated the expression of critical proteins including PCNA, Ki67 and VEGF-A in proliferation and angiogenesis in fetal livers, and lowered the estradiol concentration in fetal livers and placentae. Maternal estradiol supplement alleviated aforesaid impairments in fetal livers. Our data showed that the levels of pivotal estrogen synthases, such as CYP17A1 and 17β-HSD, was markedly decreased in Cd-stimulated placentae but not fetal livers. Ground on ovariectomy (OVX), we found that maternal ovarian-derived estradiol had no major effects on Cd-impaired development in fetal liver. In addition, Cd exposure activated placental PERK signaling, and inhibited PERK activity could up-regulated the expressions of CYP17A1 and 17β-HSD in placental trophoblasts. Collectively, gestational Cd exposure inhibited placenta-derived estrogen synthesis via activating PERK signaling, and therefore impaired fetal liver development. This study suggests a protective role for placenta-derived estradiol in fetal liver dysplasia shaped by toxicants, and provides a theoretical basis for toxicants to impede fetal liver development by disrupting the placenta-fetal-liver axis.

Biochemical Screening for Fetal Trisomy 21: Pathophysiology of Maternal Serum Markers and Involvement of the Placenta

It is now well established that maternal serum markers are often abnormal in fetal trisomy 21. Their determination is recommended for prenatal screening and pregnancy follow-up. However, mechanisms leading to abnormal maternal serum levels of such markers are still debated. Our objective was to help clinicians and scientists unravel the pathophysiology of these markers via a review of the main studies published in this field, both in vivo and in vitro, focusing on the six most widely used markers (hCG, its free subunit hCGβ, PAPP-A, AFP, uE3, and inhibin A) as well as cell-free feto-placental DNA. Analysis of the literature shows that mechanisms underlying each marker's regulation are multiple and not necessarily directly linked with the supernumerary chromosome 21. The crucial involvement of the placenta is also highlighted, which could be defective in one or several of its functions (turnover and apoptosis, endocrine production, and feto-maternal exchanges and transfer). These defects were neither constant nor specific for trisomy 21, and might be more or less pronounced, reflecting a high variability in placental immaturity and alteration. This explains why maternal serum markers can lack both specificity and sensitivity, and are thus restricted to screening.

Lavender Essential Oil Modulates Hepatic Cholesterol Metabolism in HepG2 Cells

Cholesterol is an essential lipid that guarantees several biological processes in eukaryotic cells. Its metabolism is regulated by a complex protein network that could be significantly influenced by numerous exogenous sources, such as essential oils (EOs). For instance, it has been speculated that monoterpenoid and sesquiterpenoid compounds contained in lavender essential oil (LEO) may exert important hypocholesterolemic activities. However, the molecular mechanisms by which LEO influences cholesterol homeostasis are not characterized. In this work, we evaluated the ability of LEO to regulate the protein network that controls cholesterol metabolism in the HepG2 cell line. The main findings indicate that LEO administration increases intracellular cholesterol content. Concurrently, LEO affects the expression of proteins involved in cholesterol uptake, biosynthesis, and trafficking. These effects are partially mediated by terpinene-4-ol, one of the most abundant compounds in LEO. These results demonstrate that LEO modulates cholesterol metabolism in hepatic cells.

Environmental cadmium exposure during gestation impairs fetal brain and cognitive function of adult offspring via reducing placenta-derived E2 level

Early-life exposure to environmental cadmium (Cd) is known to cause developmental disorders, yet the effect and mechanism of gestational exposure to Cd on the offspring's cognitive function remains unclear. Placenta as a well-established target organ for Cd-impaired fetal development, its role in estrogen regulation and offspring cognitive function is unknown. Our in vivo experiments found that gestational Cd exposure impaired cognitive function in adult male offspring, accompanied with lowered 17β-estradiol (E2) level in the male fetal brain upon Cd exposure. Correspondingly, the expression of synapse-associated proteins including brain-derived neurotrophic factor (BDNF), post-synaptic density protein 95 (PSD95) and synapsin-1 were downregulated, which were reversed when supplemented with E2 hormone during gestation. Further observation showed placental estrogen synthesis inhibition and general control non-derepressible 2 (GCN2) signaling activation upon Cd exposure, whereas placental estrogen synthesis could be restored through inhibiting GCN2 activity. Based on ovariectomy (OVX) of pregnant mice, we confirmed that Cd exposure reduced E2 level in fetal brain via inhibiting placenta-derived estrogen synthesis. The aforementioned Cd-induced fetal brain injury and cognitive impairment in adult offspring were significantly alleviated when pregnant dams were supplemented with anti-stress agent N-Acetyl-l-cysteine. In summary, Cd disrupted placenta-derived estrogen synthesis via activating GCN2 signaling, and thereby caused cognitive impairment in adult offspring mice. Our findings suggest that placenta-derived estrogen may be an effect marker of environmental toxicants-evoked cognitive dysfunction in adult offspring and suggest that environmental toxicants may affect the fetal brain development via placenta-fetal-brain axis.

Revisiting the physiological role of androgens in women

INTRODUCTION

Extensive research underlines the critical functions of androgens in females. Nevertheless, the precise mechanisms of their action are poorly understood. Here, we review the existing literature regarding the physiological role of androgens in women throughout life.

AREAS COVERED

Several studies show that androgen receptors (ARs) are broadly expressed in numerous female tissues. They are essential for many physiological processes, including reproductive, sexual, cardiovascular, bone, muscle, and brain health. They are also involved in adipose tissue and liver function. Androgen levels change with the menstrual cycle and decrease in the first decades of life, independently of menopause.

EXPERT OPINION

To date, studies are limited by including small numbers of women, the difficulty of dosing androgens, and their cyclical variations. In particular, whether androgens play any significant role in regulating the establishment of pregnancy is poorly understood. The neural functions of ARs have also been investigated less thoroughly, although it is expressed at high levels in brain structures. Moreover, the mechanism underlying the decline of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) with age is unclear. Other factors, including estrogen's effect on adrenal androgen production, reciprocal regulation of ARs, and non-classical effects of androgens, remain to be determined.

Basics of androgen synthesis and action

Androgens are essential sex steroid hormones for both sexes. Testosterone (T) is the predominant androgen in males, while in adult females, T concentrations are about 15-fold lower and androgen precursors are converted to estrogens. T is produced primarily in testicular Leydig cells in men, while in women precursors are biosynthesised in the adrenal cortex and ovaries and converted into T in the periphery. The biosynthesis of T occurs via a series of enzymatic reactions in steroidogenic organs. Notably, the more potent androgen, dihydrotestosterone, may be synthesized from T in the classic pathway, however, alternate metabolic pathways also exist. The classic action of androgens on target organs is mediated through the androgen receptor, which regulates nuclear receptor gene transcription. However, the androgen-androgen receptor complex may also interact directly with membrane proteins or signaling molecules to exert more rapid effects. This review summarizes the current knowledge of androgen biosynthesis, mechanisms of action and endocrine effects in human biology, and relates these effects to respective human congenital and acquired disorders.

Bilirubin Reduces the Uptake of Estrogen Precursors and the Followed Synthesis of Estradiol in Human Placental Syncytiotrophoblasts via Inhibition and Downregulation of Organic Anion Transporter 4

Estrogen biosynthesis in human placental trophoblasts requires the human organic anion transporter 4 (hOAT4)-mediated uptake of fetal derived precursors such as dehydroepiandrosterone-3-sulfate (DHEAS) and 16α-hydroxy-DHEA-S (16α-OH-DHEAS). Scant information is available concerning the contribution of fetal metabolites on the impact of placental estrogen precursor transport and the followed estrogen synthesis. This study substantiated the roles of bilirubin as well as bile acids (taurochenodeoxycholic acid, taurocholic acid, glycochenodeoxycholic acid, chenodeoxycholic acid) on the inhibition of hOAT4-mediated uptake of probe substrate 6-carboxylfluorescein and DHEAS in stably transfected hOAT4-Chinese hamster ovary cells, with the IC50 of 1.53 and 0.98 μM on 6-carboxylfluorescein and DHEAS, respectively, for bilirubin, and 90.2, 129, 16.4, and 12.3 μM on 6-CF for taurochenodeoxycholic acid, glycochenodeoxycholic acid, taurocholic acid, and chenodeoxycholic acid. Bilirubin (2.5-10 μM) concentration-dependently inhibited the accumulation of estradiol precursor DHEAS in human choriocarcinoma JEG-3 cells (reduced by 60% at 10 μM) and primary human trophoblast cells (reduced by 80% at 10 μM). Further study confirmed that bilirubin (0.625-2.5 μM) concentration-dependently reduced the synthesis and secretion of estradiol in primary human trophoblast cells, among which 2.5 μM of bilirubin reduced the synthesis of estradiol by 30% and secretion by 35%. In addition, immunostaining and Western blot results revealed a distinct downregulation of hOAT4 protein expression in primary human trophoblast cells pretreated with 2.5 μM of bilirubin. In conclusion, this study demonstrated that bilirubin reduced the uptake of estrogen precursors and the followed synthesis of estradiol in human placenta via inhibition and downregulation of organic anion transporter 4. SIGNIFICANCE STATEMENT: Fetal metabolites, especially bilirubin, were first identified with significant inhibitory effects on the hOAT4-mediated uptake of estrogen precursor DHEAS in hOAT4-CHO, JEG-3 and PHTCs. Bilirubin concentration-dependently suppressed the estradiol synthesis and secretion in PHTCs treated with DHEAS, which was synchronized with the decline of hOAT4 protein expression. Additionally, those identified bile acids exhibited a weaker inhibitory effect on the secretion of estradiol.

Fetoplacental vasculature as a model to study human cardiovascular endocrine disruption

Increasing evidence has associated the exposure of endocrine-disrupting chemicals (EDCs) with the cardiovascular (CV) system. This exposure is particularly problematic in a sensitive window of development, pregnancy. Pregnancy exposome can affect the overall health of the pregnancy by dramatic changes in vascular physiology and endocrine activity, increasing maternal susceptibility. Moreover, fetoplacental vascular function is generally altered, increasing the risk of developing pregnancy complications (including cardiovascular diseases, CVD) and predisposing the foetus to adverse health risks later in life. Thus, our review summarizes the existing literature on exposures to EDCs during pregnancy and adverse maternal health outcomes, focusing on the human placenta, vein, and umbilical artery associated with pregnancy complications. The purpose of this review is to highlight the role of fetoplacental vasculature as a model for the study of human cardiovascular endocrine disruption. Therefore, we emphasize that the placenta, together with the umbilical arteries and veins, allows a better characterization of the pregnant woman's exposome. Consequently, it contributes to the protection of the mother and foetus against CV disorders in life.

Turning the spotlight on the C11-oxy androgens in human fetal development

Research into the biosynthesis of C11-oxy C₁₉ steroids during human fetal development, specifically fetal adrenal development and during the critical period of sex differentiation, is currently lacking. Cortisol, which possesses a C11-hydroxyl moiety has, however, been firmly established in this context. Compelling questions are whether the C11-oxy C₁₉ steroids (11β-hydroxyandrostenedione, 11β-hydroxytestosterone, 11-ketoandrostenedione and 11-ketotestosterone [11KT]) and the C11-oxy C₂₁ steroids (11β-hydroxyprogesterone and 11-ketoprogesterone) are biosynthesised during gestation, and whether these hormones circulate between the placenta and the developing fetus, and between the placenta and the mother. This review will consider the role of cortisol, 11KT and 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2) in determining the sex of teleost fish, while these hormones and 11βHSD2 will also be discussed with regards to murine mammals. The focus of the review will shift to highlight the potential role of C11-oxy steroids in human fetal development based on the timely expression of steroidogenic enzymes in the adrenal, testes and ovary, as well as in the placenta; summarising reported evidence of C11-oxy steroids in neonatal life.

Accurate prediction of birth implementing a statistical model through the determination of steroid hormones in saliva

Steroidal hormone interaction in pregnancy is crucial for adequate fetal evolution and preparation for childbirth and extrauterine life. Estrone sulphate, estriol, progesterone and cortisol play important roles in the initiation of labour mechanism at the start of contractions and cervical effacement. However, their interaction remains uncertain. Although several studies regarding the hormonal mechanism of labour have been reported, the prediction of date of birth remains a challenge. In this study, we present for the first time machine learning algorithms for the prediction of whether spontaneous labour will occur from week 37 onwards. Estrone sulphate, estriol, progesterone and cortisol were analysed in saliva samples collected from 106 pregnant women since week 34 by enzyme-immunoassay (EIA) techniques. We compared a random forest model with a traditional logistic regression over a dataset constructed with the values observed of these measures. We observed that the results, evaluated in terms of accuracy and area under the curve (AUC) metrics, are sensibly better in the random forest model. For this reason, we consider that machine learning methods contribute in an important way to the obstetric practice.

Association of Maternal-Neonatal Steroids With Early Pregnancy Endocrine Disrupting Chemicals and Pregnancy Outcomes

CONTEXT

Steroids play an important role in fetal development and parturition. Gestational exposures to endocrine-disrupting chemicals (EDCs) affect steroidal milieu and pregnancy outcomes, raising the possibility of steroids serving as biomarkers. Most studies have not addressed the impact of EDC mixtures, which are reflective of real life scenarios.

OBJECTIVE

Assess the association of maternal and neonatal steroids with pregnancy outcomes and early pregnancy EDC levels.

DESIGN

Prospective analysis of mother-infant dyads.

SETTING

University hospital.

PARTICIPANTS

121 mother-infant dyads.

MAIN OUTCOME MEASURES

The associations of maternal and neonatal steroidal hormones from 121 dyads with pregnancy outcomes, the associations of first trimester EDCs individually and as mixtures with maternal and neonatal steroids in a subset of 56 dyads and the influence of body mass index (BMI), age, and offspring sex in modulating the EDC associations with steroids were determined.

RESULTS

Steroid-specific positive or negative associations with pregnancy measures were evident; many maternal first trimester EDCs were negatively associated with estrogens and positively with androgen/estrogen ratios; EDC-steroid associations were influenced by maternal age, pre-pregnancy BMI, and fetal sex; and EDCs individually and as mixtures showed direct and inverse fetal sex-dependent associations with maternal and neonatal steroids.

CONCLUSIONS

This proof-of-concept study indicates association of steroids with pregnancy outcomes depending on maternal age, prepregnancy BMI, and fetal sex, with the effects of EDCs differing when considered individually or as mixtures. These findings suggest that steroidal hormonal measures have potential to serve as biomarkers of impact of EDC exposures and pregnancy outcome.

Revisiting Steroidogenic Pathways in the Human Placenta and Primary Human Trophoblast Cells

Steroid hormones play a crucial role in supporting a successful pregnancy and ensuring proper fetal development. The placenta is one of the principal tissues in steroid production and metabolism, expressing a vast range of steroidogenic enzymes. Nevertheless, a comprehensive characterization of steroidogenic pathways in the human placenta and potential developmental changes occurring during gestation are poorly understood. Furthermore, the specific contribution of trophoblast cells in steroid release is largely unknown. Thus, this study aimed to (i) identify gestational age-dependent changes in the gene expression of key steroidogenic enzymes and (ii) explore the role of trophoblast cells in steroid biosynthesis and metabolism. Quantitative and Droplet Digital PCR analysis of 12 selected enzymes was carried out in the first trimester (n = 13) and term (n = 20) human placentas. Primary trophoblast cells (n = 5) isolated from human term placentas and choriocarcinoma-derived cell lines (BeWo, BeWo b30 clone, and JEG-3) were further screened for gene expression of enzymes involved in placental synthesis/metabolism of steroids. Finally, de novo steroid synthesis by primary human trophoblasts was evaluated, highlighting the functional activity of steroidogenic enzymes in these cells. Collectively, we provide insights into the expression patterns of steroidogenic enzymes as a function of gestational age and delineate the cellular origin of steroidogenesis in the human placenta.

Protease Inhibitor Anti-HIV, Lopinavir, Impairs Placental Endocrine Function

Protease Inhibitors (PI e.g., ritonavir (RTV) and lopinavir (LPV)) used to treat pregnant mothers infected by HIV induce prematurity and endocrine dysfunctions. The maintenance of pregnancy relies on placental hormone production (human Chorionic Gonadotrophin (hCG) and progesterone (P4)). Those functions are ensured by the villous trophoblast and are mainly regulated by the Unfolded Protein Response (UPR) pathway and mitochondria. We investigated, in vitro, if PI impair hCG and P4 production and the potential intracellular mechanisms involved. Term villous cytotrophoblast (VCT) were cultured with or without RTV or LPV from 6 to 48 h. VCT differentiation into syncytiotrophoblast (ST) was followed measuring hCG and P4 secretion. We evaluated the expression of P4 synthesis partners (Metastatic Lymph Node 64 (MLN64), cholesterol side-chain cleavage (P450SCC), Hydroxy-delta-5-Steroid Dehydrogenase and 3 Beta-and steroid delta-isomerase 1 (HSD3B1)), of mitochondrial pro-fusion factors (Mitofusin 2 (Mfn2), Optic Atrophy 1 (OPA1)) and of UPR factors (Glucose-Regulated Protein 78 (GRP78), Activating Transcription Factor 4 (ATF4), Activating Transcription Factor 6 (ATF6), spliced X-box Binding Protein 1 (sXBP1)). RTV had no significant effect on hCG and P4 secretion, whereas lopinavir significantly decreased both secretions. LPV also decreased P450SCC and HSD3B1 expression, whereas it increased Mfn2, GRP78 and sXBP1 expression in ST. RTV has no effect on the endocrine placenta. LPV impairs both villous trophoblast differentiation and P4 production. It is likely to act via mitochondrial fusion and UPR pathway activation. These trophoblastic alterations may end in decreased P4 levels in maternal circulation, inducing prematurity.

Metabolomic Changes after Coffee Consumption: New Paths on the Block

SCOPE

Several studies suggest that regular coffee consumption may help preventing chronic diseases, but the impact of daily intake and the contribution of coffee metabolites in disease prevention are still unclear. The present study aims at evaluating whether and how different patterns of coffee intake (one cup of espresso coffee/day, three cups of espresso coffee/day, and one cup of espresso coffee/day and two cocoa-based products containing coffee two times per day) may impact endogenous molecular pathways.

METHODS AND RESULTS

A three-arm, randomized, crossover trial is performed in 21 healthy volunteers who consumed each treatment for one month. Urine samples are collected to perform untargeted metabolomics based on UHPLC-IMS-HRMS. A total of 153 discriminant metabolites are identified. Several molecular features are associated with coffee consumption, while others are linked with different metabolic pathways, such as phenylalanine, tyrosine, energy metabolism, steroid hormone biosynthesis, and arginine biosynthesis and metabolism.

CONCLUSION

This information has provided new insights into the metabolic routes by which coffee and coffee-related metabolites may exert effects on human health.

Maternal exercise alters rat fetoplacental stress response: Minimal effects of maternal growth restriction and high-fat feeding

INTRODUCTION

Fetal growth restriction complicates 10% of pregnancies and increases offspring (F1) risk of metabolic disorders, including obesity and gestational diabetes mellitus (GDM). This disease predisposition can be passed onto the next generation (F2). Importantly, the risk of pregnancy complications in obese women can be exacerbated by a stressful pregnancy. Exercise can reduce adiposity and improve health outcomes in obese women and those with GDM. This study investigated the impacts of maternal growth restriction, obesity, exercise, and stress on fetal and placental endocrine function.

METHODS

Uteroplacental insufficiency (Restricted) or sham (Control) surgery was induced on embryonic day (E) 18 in F0 Wistar-Kyoto rats. F1 offspring were fed a Chow or High-fat (HFD) diet from weaning and, at 16 weeks, were randomly allocated an exercise protocol; Sedentary, Exercised prior to and during pregnancy (Exercise), or Exercised only during pregnancy (PregEx). Females were mated and further randomly allocated to either undergo (Stress), or not undergo (Unstressed), physiological measurements during pregnancy. On E20, F2 fetal plasma (steroid hormones), tissues (brain, liver), and placentae (morphology, stress genes) were collected.

RESULTS

Maternal growth restriction and high-fat feeding had minimal impact on fetoplacental endocrine function. PregEx and Exercise increased cross-sectional labyrinth and junctional zone areas. PregEx, but not Exercise, increased fetal deoxycorticosterone concentrations and reduced placental Hsd11b2 and Nr3c2 gene abundance. Maternal stress increased fetal corticosterone concentrations in Sedentary HFD dams and increased placental cross-sectional areas in PregEx mothers.

DISCUSSION

PregEx and Stress independently dysregulates the endocrine status of the developing fetus, which may program future disease.

Elucidating Potential Profibrotic Mechanisms of Emerging Biomarkers for Early Prognosis of Hepatic Fibrosis

Hepatic fibrosis has been associated with a series of pathophysiological processes causing excessive accumulation of extracellular matrix proteins. Several cellular processes and molecular mechanisms have been implicated in the diseased liver that augments fibrogenesis, fibrogenic cytokines and associated liver complications. Liver biopsy remains an essential diagnostic tool for histological evaluation of hepatic fibrosis to establish a prognosis. In addition to being invasive, this methodology presents with several limitations including poor cost-effectiveness, prolonged hospitalizations, and risks of peritoneal bleeding, while the clinical use of this method does not reveal underlying pathogenic mechanisms. Several alternate noninvasive diagnostic strategies have been developed, to determine the extent of hepatic fibrosis, including the use of direct and indirect biomarkers. Immediate diagnosis of hepatic fibrosis by noninvasive means would be more palatable than a biopsy and could assist clinicians in taking early interventions timely, avoiding fatal complications, and improving prognosis. Therefore, we sought to review some common biomarkers of liver fibrosis along with some emerging candidates, including the oxidative stress-mediated biomarkers, epigenetic and genetic markers, exosomes, and miRNAs that needs further evaluation and would have better sensitivity and specificity. We also aim to elucidate the potential role of cardiotonic steroids (CTS) and evaluate the pro-inflammatory and profibrotic effects of CTS in exacerbating hepatic fibrosis. By understanding the underlying pathogenic processes, the efficacy of these biomarkers could allow for early diagnosis and treatment of hepatic fibrosis in chronic liver diseases, once validated.

Heterocyclic steroids: Efficient routes for annulation of pentacyclic steroidal pyrimidines

Steroids are components of cell membranes, signaling molecules and are a type of secondary metabolites as a result of their high impact of biological significance. The present review described the literature reports of pentacyclic steroidal pyrimidines as a type of heterocyclic steroids. The main sections included the synthesis of the investigated steroids fused at rings-A or B or D of steroid skeleton, synthesis of binary or linked-type pyrimidines, pyrimidine oxides, macromolecules and mono- or di- or tri-peptides linked-steroidal pyrimidines. Besides, the present research highlighted the biological significance of steroidal pyrimidines, in which the compounds revealed potent anticancer, antioxidant, antibacterial, and anti-Alzheimer agents. In addition, some hetero-steroids were screened for binding DNA assay and gene expression analysis. It was settled that the incorporation of pyrimidine scaffold into steroid basic skeleton is crucial for better biological results.

Vascular mechanisms of testosterone: The non-genomic point of view

Testosterone (T) is the predominant endogenous androgen in the bloodstream. At the vascular level, T presents genomic and non-genomic effects, and both effects may overlap. The genomic actions assume that androgens can freely cross the plasma membrane of target cells and bind to nuclear androgen receptors, inducing gene transcription and protein synthesis. The non-genomic effects have a more rapid onset and may be related to the interaction with protein/receptor/ion channels of the plasma membrane. The key T effect at the vascular level is vasorelaxation, which is primarily due to its rapid effect. Thus, the main purpose of this review is to discuss the T non-genomic effects at the vascular level and the molecular pathways involved in its vasodilator effect observed in in vivo and in vitro studies. In this sense, the nuclear receptor activation, the influence of vascular endothelium and the activation or inhibition of ion channels (potassium and calcium channels, respectively) will be reviewed regarding all the data that corroborated or not. Moreover, this review also provides a brief update on the association of T with the risk factors for cardiovascular diseases, namely metabolic syndrome, type 2 diabetes mellitus, obesity, atherosclerosis, dyslipidaemia, and hypertension. In summary, in this paper we consider the non-genomic vascular mode of action of androgen in physiological conditions and the main risk factors for cardiovascular diseases.

Placental production of progestins is fully effective in villous cytotrophoblasts and increases with the syncytiotrophoblast formation

Placental syncytiotrophoblast (ST) is considered as the main placental endocrine tissue secreting progesterone, a steroid essential for maintenance of pregnancy. However, each step of progestins production has been poorly investigated in villous cytotrophoblast (VCT) regarding ST formation. We aimed to characterize progestins production during human differentiation of VCT into ST. VCTs were isolated from term placenta and cultivated, with or without forskolin (FSK), to stimulate trophoblast differentiation. Secreted progestins concentrations were determined by immuno-assay and Gas Chromatography-tandem mass spectrometry. Intracellular expression of cholesterol transporter and enzymes involved in steroidogenesis were studied by immunofluorescence, western-blot, and RT-qPCR. Progesterone and pregnenolone are produced by VCT and their secretion increases with VCT differentiation while 17-hydroxyprogesterone concentration remains undetectable. HSD3B1 enzyme expression increases whereas MLN64, the cholesterol placental mitochondrial transporter and P450SCC expressions do not. FSK induces progestins production. Progestins placental synthesis is effective since VCT and increases with ST formation thanks to mitochondria.

Reproductive immunomodulatory functions of B cells in pregnancy

Pregnancy, a challenging physiological state, requires shuffling of conventional immune work-sets. Strategies to tolerate the semi-allogenic fetus in normal human pregnancy are multivariate with perfect modulation of the immune cells. Pregnancy is marked by B cell lymphocytopenia accompanied by reduced responsiveness to infectious agents. Besides this old age concept, plenty of research confirms that B cells have other crucial roles in pregnancy and undergo a wide range of modifications in terms of its proliferation, switching between its subtypes, variation in antibody productions, shifting the tides of cytokines as well as regulating other immune cells. B cells establish tolerant environment in pregnancy by producing protective antibodies to encounter the foreign paternal antigens. Regulatory B cells (Bregs) have adopted anti-inflammatory characteristics to sustain normal pregnancy. Moreover, the colossal physiological alterations during human pregnancy also include synchronized changes in the cross-talks between the pregnancy hormones and B cells. These aspects of pregnancy from the view point of B cell functions have so far appeared individually in discrete reports. This review finds its novelty in concisely presenting every facet of association of B cell with human pregnancy.

Plasma steroid hormone concentrations and their relationships in Suffolk ewes during gestation and parturition

In this study, we measured plasma concentrations of progesterone, pregnenolone, estradiol, estrone, estrone sulfate, and cortisol and analyzed the correlations between these hormones during gestation in 13 Suffolk ewes, the main breed in Japan. Progesterone increased during gestation and decreased a few days before parturition; however, this pattern was different in samples with high progesterone concentrations (P4 spike samples). This P4 spike was associated with a high pregnenolone concentration. Apart from the P4 spike, the progesterone change was similar to that in other sheep breeds. Pregnenolone increased during gestation and decreased after parturition. A significant correlation between progesterone and pregnenolone was observed a few days before parturition. Estrone sulfate and estradiol concentrations increased during gestation, but estrone did not. They increased shortly before parturition, and then decreased immediately after parturition. At parturition, the correlation between estrone and estrone sulfate was significantly stronger. Moreover, a strong correlation between estrone sulfate and estradiol was observed after parturition. Cortisol did not change during gestation and increased shortly before parturition. The results showed steroid hormone dynamics in normal pregnant Suffolk ewes, which were mostly in line with those of other sheep breeds. It should be noted that high progesterone concentrations altered the typical patterns.

Polychlorinated Dibenzo-p-Dioxins, Polychlorinated Dibenzofurans, and Dioxin-Like Polychlorinated Biphenyls in Umbilical Cord Serum from Pregnant Women Living Near a Chemical Plant in Tianjin, China

Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs), and dioxin-like polychlorinated biphenyls (dl-PCBs) are bioaccumulative compounds that may affect fetal growth and infant development. The aim of this study was to determine whether the pregnant women living near a chemical plant in Tianjin had a risk of exposure to dioxins. Concentrations of PCDD/Fs and dl-PCBs in 24 umbilical cord serum samples collected from pregnant women were measured using a high-resolution gas chromatograph with a high-resolution mass spectrometer (HRGC-HRMS) and an isotopic dilution method. The levels of ∑(PCDD/Fs + dl-PCBs) were in the range 476-8307 pg·g^-1 lipid, with a mean of 3037 pg·g^-1. The mean World Health Organization toxicity equivalent (WHO-TEQ) for PCDD/Fs and dl-PCBs was 14.0 and 2.14 pg·g^-1 lipid, respectively. The PCDD/Fs and dl-PCBs contributed 86.7% and 13.3%, respectively, to the total TEQ. The octa-CDFs and penta-CBs were predominant for the PCDD/Fs and dl-PCBs, accounting for 57.6% and 74.3%, respectively. Several PCDD/F and dl-PCB congeners were highly correlated, such as PCB 105 and PCB 118 (r = 0.982, p < 0.001). Although the results hint at decreasing trends for PCDD/F and dl-PCBs by comparison with a similar study in Tianjin, a total TEQ of 41.7% of study participants had a body burden that exceeded the biomonitoring equivalents for dioxins. It was shown that pregnant women and infants had a health risk of exposure to dioxins.

Steroid hormones and pregnancy

Pregnancy is associated with physiological adjustments in order to allow adequate growth and fetal development. In particular, steroids are necessary to maintain in balance numerous functions during gestation. Steroidogenesis in the maternal, placental and fetal compartments and the biological effects of progestins and estrogens that play a pivotal role before and during pregnancy are described. Although it is well-known that androgens are considered as substrate for estrogens biosynthesis, their biosynthesis and functionality in placental and other tissues have been questioned. As compared with healthy pregnancy, steroid hormones levels have been found altered in complicated pregnancies and hormonal treatments have been used is some pathologies. Therefore, the aim of this work was to review the biosynthesis, function and regulation of progestins, androgens and estrogens during gestation. Furthermore, steroid hormones concentrations during healthy and complicated pregnancy as well hormonal therapies for the prevention of miscarriages and preterm deliveries are discussed in the present review.

Altered umbilical sex steroids in preterm infants born small for gestational age

Background: Boys born small for gestational age (SGA) are at increased risk of testicular dysgenesis syndrome, and girls born SGA face the risk of polycystic ovary syndrome later in life. Our aim was to study whether neonates born SGA have an altered profile of steroid hormones at birth.Materials and methods: A total of 168 singletons (99 boys, 69 girls) born at 32.0-36.9 gestational weeks were recruited to a population-based, university hospital, single-center study. Of these, 31 infants (17 boys, 14 girls) were born SGA. The concentrations of dehydroepiandrosterone sulfate (DHEAS), androstenedione, testosterone, dihydrotestosterone, estrone, estradiol, cortisone, and cortisol were analyzed in umbilical cord serum with mass spectrometry.Results: Girls born SGA had higher levels of androstenedione than girls born appropriate for gestational age (AGA) (4.0 versus 2.6 nmol/L, p = .002). Boys born SGA had lower levels of estrone than boys born AGA (33 822 versus 62 471 pmol/L, p = .038). Infants born SGA had lower levels of cortisone than infants born AGA, both in girls (340 versus 579 nmol/L, p = .010) and in boys (308 versus 521 nmol/L, p = .045). Furthermore, boys born SGA had a higher cortisol/cortisone ratio than boys born AGA (0.41 versus 0.25, p = .028). Gestational age correlated with DHEAS (boys r = 0.48, p = .000, girls r = 0.35, p = .013), and cortisol (boys r = 0.48, p = .000, girls r = 0.29, p = .039).Conclusions: In moderate-to-late preterm infants born SGA, we observed a different steroid hormone profile in cord serum. Girls born SGA show increased levels of androstenedione and boys born SGA show decreased levels of estrone in cord serum, which could be related to placental aromatase deficiency in intrauterine growth restriction.

Alternative (backdoor) androgen production and masculinization in the human fetus

Masculinization of the external genitalia in humans is dependent on formation of 5α-dihydrotestosterone (DHT) through both the canonical androgenic pathway and an alternative (backdoor) pathway. The fetal testes are essential for canonical androgen production, but little is known about the synthesis of backdoor androgens, despite their known critical role in masculinization. In this study, we have measured plasma and tissue levels of endogenous steroids in second trimester human fetuses using multidimensional and high-resolution mass spectrometry. Results show that androsterone is the principal backdoor androgen in the male fetal circulation and that DHT is undetectable (<1 ng/mL), while in female fetuses, there are significantly lower levels of androsterone and testosterone. In the male, intermediates in the backdoor pathway are found primarily in the placenta and fetal liver, with significant androsterone levels also in the fetal adrenal. Backdoor intermediates, including androsterone, are only present at very low levels in the fetal testes. This is consistent with transcript levels of enzymes involved in the alternate pathway (steroid 5α-reductase type 1 [SRD5A1], aldo-keto reductase type 1C2 [AKR1C2], aldo-keto reductase type 1C4 [AKR1C4], cytochrome P450 17A1 [CYP17A1]), as measured by quantitative PCR (qPCR). These data identify androsterone as the predominant backdoor androgen in the human fetus and show that circulating levels are sex dependent, but also that there is little de novo synthesis in the testis. Instead, the data indicate that placental progesterone acts as substrate for synthesis of backdoor androgens, which occurs across several tissues. Masculinization of the human fetus depends, therefore, on testosterone and androsterone synthesis by both the fetal testes and nongonadal tissues, leading to DHT formation at the genital tubercle. Our findings also provide a solid basis to explain why placental insufficiency is associated with disorders of sex development in humans.

Fetal human masculinisation depends on testosterone production by the testes and an alternative “backdoor” androgen. This study shows that this androgen is likely to be androsterone, which is sexually dimorphic in the fetus but does not come from the testes; instead, synthesis probably depends on placental substrates.

The human penis starts to develop before birth from a structure called the genital tubercle. This process is dependent on the secretion of testosterone from the fetal testes and subsequent conversion of testosterone into dihydrotestosterone (DHT) by enzymes in the genital tubercle. Recently, an alternative "backdoor" route to the formation of DHT, which does not require testosterone, has also been shown to be essential for normal development of the human penis. In this study we provide evidence indicating that androsterone is the major backdoor androgen involved in human masculinization and that it is produced in nongonadal tissues. Steroid hormone levels were measured in the plasma of second trimester human fetuses, and testosterone and androsterone were the only androgens with higher levels in males than in females. Analysis of tissue steroid levels showed that plasma androsterone did not primarily originate from the testes but, instead, was probably formed in other tissues via metabolism of placental progesterone. These data indicate, therefore, that masculinization of the human fetus depends on steroid hormone secretion from both the testes and the placenta, and would explain why placental dysfunction is associated with disorders of sex development.

Identification of amniotic fluid metabolomic and placental transcriptomic changes associated with abnormal development of cloned pig fetuses

Piglets cloned by somatic cell nuclear transfer (SCNT) show a high incidence of malformations and a high death rate during the perinatal period. To investigate the underlying mechanisms for abnormal development of cloned pig fetuses, we compared body weight, amniotic fluid (AF) metabolome, and placental transcriptome between SCNT- and artificial insemination (AI)-derived pig fetuses. Results showed that the body weight of SCNT pig fetuses was significantly lower than that of AI pig fetuses. The identified differential metabolites between the two groups of AF were mainly involved in bile acids and steroid hormones. The levels of all detected bile acids in SCNT AF were significantly higher than those in AI AF. The increase in the AF bile acid levels in SCNT fetuses was linked with the downregulation of placental bile acid transporter expression and the abnormal development of placental folds (PFs), both of which negatively affected the transfer of bile acids from AF across the placenta into the mother's circulation. Alteration in the AF steroid hormone levels in cloned fetuses was associated with decreased expression of enzymes responsible for steroid hormone biosynthesis in the placenta. In conclusion, cloned pig fetuses undergo abnormal intrauterine development associated with alteration of bile acid and steroid hormone levels in AF, which may be due to the poor development of PFs and the erroneous expression of bile acid transporters and enzymes responsible for steroid hormone biosynthesis in the placentas.

Comparative profiling of adrenal steroids in maternal and umbilical cord blood

Fetal steroidome in late pregnancy receives multiple contributions from both maternal and fetal adrenals as well as from placenta. Depressed glucocorticoid levels have been reported in fetal blood at birth, yet studies on mineralocorticoid pathways are sparse. To investigate biosynthesis pathways at birth, adrenal steroids profiles were established in paired mothers and neonates. Forty-six paired healthy term newborns and their mothers from the Aldo cohort were assessed. Steroidomic profiles of mineralocorticoids, glucocorticoids and adrenal androgens were established from umbilical cord and maternal blood at birth using a highly sensitive and specific LC-MS/MS methodology. As compared to maternal blood, umbilical cord blood exhibited high levels of steroids precursors (progesterone and 11-deoxycorticosterone) contrasting with a collapse in corticosterone levels. Consecutively, 18-hydroxycorticosterone and aldosterone levels were also depressed in neonates. Similarly, umbilical cord blood levels of both 17-hydroxyprogesterone and 11-deoxycortisol were higher while cortisol levels sharply decreased. The product-to-substrate ratios evaluating the 11-hydroxylation step (corticosterone/11-deoxycorticosterone and cortisol/11-deoxycortisol) fell for both pathways. As expected, cortisone and 11-dehydrocorticosterone levels exceed those of cortisol and corticosterone in umbilical cord blood reflecting the strong placental 11-β-hydroxysteroid-dehydrogenase type 2 (11βHSD2) activity. Dehydroepiandrosterone-sulphate levels are higher in neonates, while both androstenedione and testosterone levels sharply fell. No significant difference in steroid levels could be observed according the gender except higher testosterone concentrations in umbilical cord of boys. Moreover, a strong and negative relationship between testosterone and progesterone levels was recorded in umbilical cord of boys. These adrenal steroidomic profiling demonstrate a deficit in mineralocorticoids (aldosterone, 18-hydroxycorticosterone and corticosterone) and glucocorticoids (cortisol) in term neonates, reflecting either a relative defect in 11-hydroxylase activity or more likely the strong placental 11-β-HSD2 activity. Collectively, these findings should be taken into account for a better understanding of regulatory interactions between placenta and fetal adrenal.

Prenatal exposure to glycol ethers and sex steroid hormones at birth

BACKGROUND

Glycol ethers (GEs) are oxygenated solvents widely found in occupational and consumer water-based products. Some of them are well-known reproductive and developmental toxicants.

OBJECTIVES

To study the variations in circulating sex steroid hormones, measured in cord blood, according to biomarkers of prenatal GE exposure.

METHODS

The study population comes from the PELAGIE mother-child cohort, which enrolled pregnant women from Brittany (France, 2002-2006). Maternal urine samples were collected from a random subcohort (n = 338) before 19 weeks' gestation, from which we measured 8 alkoxycarboxylic metabolites of GEs. We subsequently measured 13 sex steroid hormones and sex hormone-binding globulin (SHBG) in cord blood samples. Linear regressions adjusted for potential confounders were used, and nonlinear dose-response associations were investigated.

RESULTS

The detection rates of GE metabolites ranged from 4% to 98%; only the 5 most detected (>20%) metabolites were investigated further. Phenoxyacetic acid (detection rate > 95%) was associated with lower levels of SHBG and various steroids (17-alpha-hydroxy-Pregnenolone, delta-5-androstenediol, and dehydroepiandrosterone) among boys and higher SHBG and 16-alpha-hydroxy-dehydroepiandrosterone levels among girls. The two other highly detected metabolites, methoxyetoxyacetic acid and butoxyacetic acid, were associated with variations in estradiol. Butoxyacetic acid was associated with higher delta-5-androstenediol levels while detectable levels of methoxyacetic acid were associated with lower levels of this hormone.

CONCLUSION

Our study suggests that prenatal exposure to GE may affect endocrine response patterns, estimated by determining blood levels of sex steroid hormones in newborns. These results raise questions about the potential role of these changes in the pathways between prenatal GE exposure and previously reported adverse developmental outcomes, including impaired neurocognitive performance.

Alterations of adrenal steroidomic profiles in preterm infants at birth

OBJECTIVE

Preterm infants have relative adrenal and kidney immaturity. Recently, we linked their urine sodium loss to a hypoaldosteronism at variance with an appropriate stimulation of the renin-angiotensin system. To investigate this defective aldosterone secretion, we analyse the biosynthesis pathways of adrenal steroids in neonates according to gestational age (GA).

DESIGN

Multicentre study (Premaldo) including 152 neonates classified into three groups: group 1 (very preterm (VPT)): <33  gestational weeks (GW); group 2 (preterm (PT)): 33-36 GW and group 3 (term (T)): ≥GW.

METHOD

Steroidomic profiles of mineralocorticoids, glucocorticoids and adrenal androgens were established from umbilical cord at birth (n=152) and peripheral blood at day 3 (n=70) using a recently developed liquid chromatography mass spectrometry method (LC-MS/MS). The enzymatic activity of each biosynthesis step was estimated by the product-to-substrate ratio.

RESULTS

At birth, VPT infants exhibit a global defect in adrenal steroid synthesis pathways leading to lower levels of aldosterone, cortisol and androstenedione than in term infants. This defect was strongly related to GA. On day 3, steroid precursors (progesterone, 11-deoxycorticosterone (DOC), 17-hydroxyprogesterone(17-OH-P) and 11-deoxycortisol (S)) were higher in VPT and negatively correlated with GA. Despite of precursors' accumulation, aldosterone and cortisol were similar in the three groups. At birth and day 3, a low cortisol/11-deoxycortisol ratio was found in preterm infants, suggesting an 11-beta-hydroxylase activity (CYP11B1) deficiency.

CONCLUSIONS

At birth, VPT infants exhibit a global deficit in mineralocorticoids, glucocorticoids and adrenal androgens that attenuates on day 3 of life. Steroid profiling using LC-MS/MS provides evidence for a partial defect in 11-hydroxylase along with prematurity.

The effects of di-2-ethylhexyl phthalate on testicular ultrastructure and hormone-regulated gene expression in male rats

The objective of this study is to determine testicular pathological damage and explore its molecular mechanisms after di-2-ethylhexyl phthalate (DEHP) treatment. A total of 40 healthy 5-week-old male Sprague-Dawley rats were randomly divided into four groups, which received intragastric administration of 0 mg kg^-1, 100 mg kg^-1, 500 mg kg^-1 and 1500 mg kg^-1 DEHP for six continuous weeks. After DEHP treatment, the testes wet weight and testes coefficient were calculated, the histopathological changes of the testes were examined by HE staining and the testicular ultrastructure was examined by transmission electron microscopy. The gene expression levels were analyzed by quantitative RT-PCR and the protein expression levels were analyzed by western blotting. Both 500 mg kg^-1 and 1500 mg kg^-1 DEPH treatments decreased the wet weight of the testes and testes coefficient, due to vacuoles in Sertoli cells, broken mitochondrial ridges, and degranulation. Quantitative RT-PCR showed that the relative gene expression levels of steroidogenic acute regulatory protein (StAR) and 3β-hydroxysteroid dehydrogenase (3β-HSD) increased in the 100 mg kg^-1, 500 mg kg^-1, and 1500 mg kg^-1 DEHP groups, respectively. Additionally, 17β-hydroxysteroid dehydrogenase (17β-HSD) expression levels were increased in the 1500 mg kg^-1 DEHP treatment group. Gonadotropin-releasing hormone (GnRH) expression levels were decreased with 500 mg kg^-1 and 1500 mg kg^-1 DEHP treatments. DEHP induced serious pathological damage and ultrastructure changes in rat testes, caused endocrine disorders, interfered with the synthesis of male hormones, and ultimately led to male reproductive system dysfunction.

The role of sulfated steroid hormones in reproductive processes

Sulfated steroid hormones, such as dehydroepiandrosterone sulfate or estrone-3-sulfate, have long been regarded as inactive metabolites as they cannot activate classical steroid receptors. Some of them are present in the blood circulation at quite high concentrations, but generally sulfated steroids exhibit low membrane permeation due to their hydrophilic properties. However, sulfated steroid hormones can actively be imported into specific target cells via uptake carriers, such as the sodium-dependent organic anion transporter SOAT, and, after hydrolysis by the steroid sulfatase (so-called sulfatase pathway), contribute to the overall regulation of steroid responsive organs. To investigate the biological significance of sulfated steroid hormones for reproductive processes in humans and animals, the research group "Sulfated Steroids in Reproduction" was established by the German Research Foundation DFG (FOR1369). Projects of this group deal with transport of sulfated steroids, sulfation of free steroids, desulfation by the steroid sulfatase, effects of sulfated steroids on steroid biosynthesis and membrane receptors as well as MS-based profiling of sulfated steroids in biological samples. This review and concept paper presents key findings from all these projects and provides a broad overview over the current research on sulfated steroid hormones in the field of reproduction.

Obesity during pregnancy affects sex steroid concentrations depending on fetal gender

BACKGROUND/OBJECTIVE

It is not clear whether maternal obesity along with fetal gender affect sex steroid metabolism during pregnancy. Therefore, we compared sex steroid concentrations and placental expression of steroidogenic enzymes between non-obese and obese pregnant women with non-pathological pregnancies, and investigated the influence of fetal gender on these parameters.

METHODS

In 35 normal weight (body mass index (BMI) 20-24.9 kg m^-2) (controls) and 36 obese women (BMI 30-36 kg m^-2) (obese), a fasting blood sample was obtained at first and at third trimester of gestation to measure progesterone, dehydroepiandrosterone (DHEA), DHEA sulfate, androstenedione, testosterone and estradiol by liquid chromatography-tandem mass spectrometry and estrone by radioimmunoassay. In a subset of women, placental mRNA and protein expression of steroidogenic enzymes was measured by quantitative PCR and western blot, respectively. The comparisons were primarily made between controls and obese, and then separately according to fetal gender.

RESULTS

At first and third trimesters of gestation serum progesterone was lower whereas testosterone was higher in obese women (P<0.05, respectively). Upon analyzing according to fetal gender, lower progesterone levels were present in obese pregnant women with male fetuses at first trimester and with female fetuses at third trimester (P<0.05, respectively). Testosterone was higher in obese women with male fetuses compared to control women with male fetuses (P<0.05). The placental protein expression of P450scc was higher in obese women compared to controls (P<0.05). P450 aromatase was higher in obese women with female fetuses (P=0.009), whereas in obese women with male fetuses P450 aromatase was lower compared to control women (P=0.026).

CONCLUSIONS

Obesity in non-pathological pregnancies alters the maternal serum progesterone and testosterone concentrations depending on fetal gender. These changes can be attributed to gender-related placental adaptations, as the expression of P450 aromatase is different in placentas from females compared to males.

Administration of Progesterone Throughout Pregnancy Increases Maternal Steroids Without Adverse Effect on Mature Oligodendrocyte Immunostaining in the Guinea Pig

Progesterone is administered to pregnant women at risk of premature labor, despite systematic reviews showing conflicting outcomes regarding its use, highlighting doubt over the effectiveness of the therapy. Progesterone can be rapidly metabolized into a number of steroids, but to date, there has been a lack of investigation into the fetal steroid profiles following administration and whether this impacts fetal neurodevelopment. The objective of this study was to determine the effect of progesterone treatment on allopregnanolone and cortisol levels in the fetus and on a marker of myelination in the fetal brain. We used a guinea pig model where pregnant dams were administered vehicle (β-cyclodextrin) or progesterone orally throughout pregnancy (GA29-61). Maternal and fetal fluids and tissues were collected at both preterm (GA61) and term (GA68) ages. Maternal and fetal progesterone and cortisol were analyzed by enzyme immunoassay and allopregnanolone by radioimmunoassay. Measurement of myelination of fetal brains (hippocampus, cingulum, and subcortical white matter) at preterm and term ages was performed by immunohistochemistry staining for myelin basic protein. We found that dams receiving progesterone had significantly elevated progesterone and cortisol concentrations, but there was no effect on allopregnanolone. Interestingly, the increased cortisol concentrations were not reflected in the fetuses, and there was no effect of progesterone treatment on myelination. Therefore, we conclude that in our guinea pig model, maternal administration of progesterone has no effect on cortisol levels or markers of mature oligodendrocytes in the fetus and suggest this is potentially due to the protective cortisol barrier in the placenta.

Hydroxylation and sulfation of sex steroid hormones in inflammatory liver

Sex steroids, also known as gonadal steroids, are oxidized with hydroxylation by cytochrome P450, glucuronidation by UDP-glucuronosyltransferase, sulfation by sulfotransferase, andO-methylation by catechol O-methyltransferase. Thus, it is important to determine the process by which inflammation influences metabolism of gonadal hormones. Therefore, we investigated the mechanism of metabolic enzymes against high physiologic inflammatory responsein vivo to study their biochemical properties in liver diseases. In this study, C57BL/6N mice were induced with hepatic inflammation by diethylnitrosamine (DEN) exposure. We observed upregulation of Cyp19a1, Hsd17b1, Cyp1a1, Sult1e1 in the DEN-treated livers compared to the control-treated livers using real time PCR. Moreover, the increased Cyp19a1 and Hsd17b1 levels support the possibility that estrogen biosynthesis from androgens are accumulated during inflammatory liver diseases. Furthermore, the increased levels of Cyp1a1 and Cyp1b1 in the hydroxylation of estrogen facilitated the conversion of estrogen to 2- or 4-hydroxyestrogen, respectively. In addition, the substantial increase in the Sult1e1 enzyme levels could lead to sulfate conjugation of hydroxyestrogen. The present information supports the concept that inflammatory response can sequester sulfate conjugates from the endogenous steroid hormones and may suppress binding of sex steroid hormones to their receptors in the whole body.

Maternal and Fetal Pharmacokinetics of Oral Radiolabeled and Authentic Bisphenol A in the Rhesus Monkey

The present study was conducted in pregnant rhesus monkeys to determine the rapidity and extent to which BPA reaches the fetal compartment following oral ingestion, and the 24-hr fate of BPA. To assess metabolism changes during the course of pregnancy, we compared BPA biotransformation during the second and third trimesters in the same animals, measuring the levels of sulfated, gluronidated, and free BPA in maternal serum, amniotic fluid, and fetal serum. All animals showed measurable unconjugated and conjugated BPA in the fetal compartment and slow clearance compared to maternal serum. There were higher levels of BPA-G in amniotic fluid at 150 days gestation compared to 100 days gestation, as well as higher levels of BPA-G than BPA-S. We also monitored ³H-BPA (and metabolites) in key tissues and excreta from a mother and fetus and from a non-pregnant female. The elimination of radioactivity was rapid, but residues were still detectable 24 hr after dosing in all tissues analyzed. These data suggest that, in primates, rapid maternal processing of BPA does not alleviate the risk of exposure to the developing fetus. This study elevates concerns about levels of current BPA human exposure from potentially a large number of unknown sources and the risks posed to developing fetuses.

Maternal first trimester serum levels of free-beta human chorionic gonadotrophin and male genital anomalies

STUDY QUESTION

Are maternal first trimester levels of serum free-beta hCG associated with the development of hypospadias or undescended testis (UDT) in boys?

SUMMARY ANSWER

Overall, first trimester maternal levels of serum free-beta hCG are not associated with hypospadias or UDT. However, elevated levels were found in severe phenotypes (proximal hypospadias and bilateral UDT) suggesting an altered pathway of hormonal release in early pregnancy.

WHAT IS KNOWN ALREADY

Human chorionic gonadotrophin peaks in first trimester of pregnancy stimulating fetal testosterone production, which is key to normal male genital development. Endocrine-disrupting insults early in pregnancy have been associated with increased risk of common genital anomalies in males such as hypospadias and UDT. One plausible etiological pathway is altered release of hCG.

STUDY DESIGN, SIZE, DURATION

We conducted a record-linkage study of two separate populations of women attending first trimester aneuploidy screening in two Australian states, New South Wales (NSW) and Western Australia (WA), in 2006-2009 and 2001-2003, respectively.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Included were women who gave birth to a singleton live born male infant. There were 12 099 boys from NSW and 10 518 from WA included, of whom 90 and 77 had hypospadias; and 107 and 109 UDT, respectively. Serum levels of free-beta hCG were ascertained from laboratory databases and combined with relevant birth outcomes and congenital anomalies via record linkage of laboratory, birth, congenital anomalies and hospital data. Median and quartile levels of gestational age specific free-beta hCG multiple of the median (MoM) were compared between affected and unaffected boys. Logistic regression was used to evaluate the association between levels of free-beta hCG MoM and hypospadias or UDT, stratified by suspected placental dysfunction and co-existing anomalies. Where relevant, pooled analysis was conducted.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no difference in median hCG levels amongst women with an infant with hypospadias (NSW = 0.88 MoM, P = 0.83; WA = 0.84 MoM, P = 0.76) or UDT (NSW = 0.89 MoM, P = 0.54; WA = 0.95 MoM, P = 0.95), compared with women with an unaffected boy (NSW = 0.92 MoM; WA = 0.88 MoM). Low (<25th centile) or high (>75th centile) hCG levels were not associated with hypospadias or UDT, nor when stratifying by suspected placental dysfunction and co-existing anomalies. However, there was a tendency towards high levels for severe types, although confidence intervals were wide. When combining NSW and WA results, high hCG MoM levels (>75th centile) were associated with increased risk of proximal hypospadias (odds ratio (OR) 4.34; 95% CI: 1.08-17.4) and bilateral UDT (OR 2.86; 95% CI: 1.02-8.03).

LIMITATIONS, REASONS FOR CAUTION

There were only small numbers of proximal hypospadias and bilateral UDT in both cohorts and although we conducted pooled analyses, results reported on these should be interpreted with caution. Gestational age by ultrasound may have been inaccurately estimated in small and large for gestational age fetuses affecting hCG MoM calculation in those pregnancies. Despite the reliability of our datasets in identifying adverse pregnancy outcomes, we did not have pathology information to confirm tissue lesions in the placenta and therefore our composite outcome should be considered as a proxy for placental dysfunction.

WIDER IMPLICATIONS OF THE FINDINGS

This is one of the largest population-based studies examining the association between maternal first trimester serum levels of free-beta hCG and genital anomalies-hypospadias and UDT; and the first to compare specific phenotypes by severity. Overall, our findings does not support the hypothesis that alteration in maternal hCG levels is associated with the development of male genital anomalies; however, high hCG free-beta levels found in severe types suggest different underlying etiology involving higher production and secretion of hCG. These findings require further exploration and replication.

STUDY FUNDING/COMPETING INTERESTS

This work was funded by the National Health and Medical Research Council (NHMRC) grant APP1047263. N.N. is supported by a NHMRC Career Development Fellowship APP1067066. C.B. was supported by a NHMRC Principal Research Fellowship #634341. The funding agencies had no role in the design, analysis, interpretation or reporting of the findings. There are no competing interests.

TRIAL REGISTRATION NUMBER

Not applicable.