A Potential Role and Contribution of Androgens in Placental Development and Pregnancy

Prenatal exposure to PM2.5 led to impaired respiratory function in adult mice

BACKGROUND

PM2.5 is a complex mixture, with water-soluble inorganic ions (WSII), mainly NH4+, SO42-, and NO3-, constituting major components. Early-life PM2.5 exposure has been shown to induce adverse health consequence but it is difficult to determine whether such an effect occurs prenatally (preconception, gestational) or postnatally in human studies.

METHODS

Four groups of C57BL/6 J mice were assigned to four exposure conditions: PM2.5 NO3-, PM2.5 SO42-, PM2.5 NH4+ and clean air, and exposure started at 4 weeks old. At 8 weeks old, mice bred within group. The exposure continued during gestation. After delivery, both the maternal and F1 mice (offspring) were kept in clean air without exposure to PM2.5. Respiratory function and pulmonary pathology were assessed in offspring mice at 8 weeks of age. In parallel, placenta tissue was collected for transcriptome profiling and mechanistic investigation.

RESULTS

F1 mice in PM2.5 NH4+, SO42- and NO3- groups had 32.2 % (p=6.0e-10), 30.3 % (p=3.8e-10) and 16.9 % (p=5.7e-8) lower peak expiratory flow (PEF) than the clean air group. Importantly, the exposure-induced lung function decline was greater in male than female offspring. Moreover, exposure to PM2.5 WSII before conception and during gestation was linked to increased airway wall thickness and elevated pulmonary neutrophil and macrophage counts in the offspring mice. At the molecular level, the exposure significantly disrupted gene expression in the placenta, affecting crucial functional pathways related to sex hormone response and inflammation.

CONCLUSIONS

PM2.5 WSII exposure during preconception and gestational period alone without post-natal exposure substantially impacted offspring's respiratory function as measured at adolescent age. Our results support the paradigm of fetal origin of environmentally associated chronic lung disease and highlight sex differences in susceptibility to air pollution exposure.

Pre-Conception Androgen Levels and Obstetric Outcomes in Polycystic Ovary Syndrome: A Single-Center Retrospective Study

Hyperandrogenism is a determining diagnostic factor for PCOS. If pregnancy is conceived, it is considered high-risk due to several potential complications, but the correlation between pre-pregnancy androgen levels and obstetric outcomes is poorly characterized.

OBJECTIVE

To determine if pre-pregnancy serum androgen concentrations and androgen indexes differed when certain obstetric and neonatal outcomes appeared in PCOS.

METHODS

A single-center, retrospective study was carried out. All patients were treated between 2012 and 2019. A total of 73 patients had all the endocrine and obstetric data available. Pre-pregnancy hormone levels (total testosterone-T, androstenedione-AD, DHEAS (dehydroepiandrosterone sulfate), SHBG (sex-hormone-binding globulin), and TSH (thyroid-stimulating hormone) were collected, and T/SHBG, AD/SHBG, DHEAS/SHBG, T/AD indexes were calculated and compared.

RESULTS

When miscarriage was present in the history, significantly elevated pre-pregnancy AD levels were observed. Higher pre-pregnancy AD level was noted in PCOS patients delivering female newborns as compared to males. Additionally, a higher T/AD ratio was associated with subsequent preterm delivery, but significance was lost after age adjustment. Maternal age at delivery had a significant negative correlation with pre-pregnancy DHEAS levels and DHEAS/SHBG ratio. Pre-pregnancy SHBG displayed a significant negative correlation, while pre-pregnancy androgen/SHBG ratios exhibited positive correlations with both birth weight and birth weight percentile.

CONCLUSIONS

Based on our data, AD and the T/AD ratio emerge as distinctive factors in certain outcomes, implying a potential specific role of altered 17-β-HSD (17β-hydroxysteroid dehydrogenase) enzyme activity, possibly influencing offspring outcomes. The pre-pregnancy T/SHBG ratio exhibits a potentially stronger correlation with fetal growth potential compared to SHBG alone. DHEAS and maternal age at delivery are strongly correlated in PCOS patients.

Pregnancy Disorders: A Potential Role for Mitochondrial Altered Homeostasis

Pregnancy is a complex and challenging process associated with physiological changes whose objective is to adapt the maternal organism to the increasing energetic requirements due to embryo and fetal development. A failed adaptation to these demands may lead to pregnancy complications that threaten the health of both mothers and their offspring. Since mitochondria are the main organelle responsible for energy generation in the form of ATP, the adequate state of these organelles seems crucial for proper pregnancy development and healthy pregnancy outcomes. The homeostasis of these organelles depends on several aspects, including their content, biogenesis, energy production, oxidative stress, dynamics, and signaling functions, such as apoptosis, which can be modified in relation to diseases during pregnancy. The etiology of pregnancy disorders like preeclampsia, fetal growth restriction, and gestational diabetes mellitus is not yet well understood. Nevertheless, insufficient placental perfusion and oxygen transfer are characteristic of many of them, being associated with alterations in the previously cited different aspects of mitochondrial homeostasis. Therefore, and due to the capacity of these multifactorial organelles to respond to physiological and pathophysiological stimuli, it is of great importance to gather the currently available scientific information regarding the relationship between main pregnancy complications and mitochondrial alterations. According to this, the present review is intended to show clear insight into the possible implications of mitochondria in these disorders, thus providing relevant information for further investigation in relation to the investigation and management of pregnancy diseases.

Effects of social environments on male primate HPG and HPA axis developmental programming

Developmental plasticity is particularly important for humans and other primates because of our extended period of growth and maturation, during which our phenotypes adaptively respond to environmental cues. The hypothalamus-pituitary-gonadal (HPG) and hypothalamus-pituitary-adrenal (HPA) axes are likely to be principal targets of developmental "programming" given their roles in coordinating fitness-relevant aspects of the phenotype, including sexual development, adult reproductive and social strategies, and internal responses to the external environment. In social animals, including humans, the social environment is believed to be an important source of cues to which these axes may adaptively respond. The effects of early social environments on the HPA axis have been widely studied in humans, and to some extent, in other primates, but there are still major gaps in knowledge specifically relating to males. There has also been relatively little research examining the role that social environments play in developmental programming of the HPG axis or the HPA/HPG interface, and what does exist disproportionately focuses on females. These topics are likely understudied in males in part due to the difficulty of identifying developmental milestones in males relative to females and the general quiescence of the HPG axis prior to maturation. However, there are clear indicators that early life social environments matter for both sexes. In this review, we examine what is known about the impact of social environments on HPG and HPA axis programming during male development in humans and nonhuman primates, including the role that epigenetic mechanisms may play in this programming. We conclude by highlighting important next steps in this research area.

Relationship between Androgens and Vascular and Placental Function during Pre-eclampsia

Hypertensive disorders of pregnancy (HDP) represent a substantial risk to maternal and fetal health. Emerging evidence suggests an association between testosterone and pre-eclampsia (PE), potentially mediated through androgen receptors (AR). Nevertheless, the mechanism driving this association is yet to be elucidated. On the other hand, reports of transgender men's pregnancies offer a limited and insightful opportunity to understand the role of high androgen levels in the development of HDP. In this sense, a literature review was performed from a little over 2 decades (1998-2022) to address the association of testosterone levels with the development of HDP. Furthermore, this review addresses the case of transgender men for the first time. The main in vitro outcomes reveal placenta samples with greater AR mRNA expression. Moreover, ex vivo studies show that testosterone-induced vasorelaxation impairment promotes hypertension. Epidemiological data point to greater testosterone levels in blood samples during PE. Studies with transgender men allow us to infer that exogenous testosterone administration can be considered a risk factor for PE and that the administration of testosterone does not affect fetal development. Overall, all studies analyzed suggested that high testosterone levels are associated with PE.

Maternal and Paternal Preconception Serum Concentrations of Per and Polyfluoroalkyl Substances in Relation to Birth Outcomes

Prenatal per and polyfluoroalkyl substances (PFAS) exposure is associated with adverse birth outcomes. There is an absence of evidence on the relationship between maternal and paternal preconception PFAS exposure and birth outcomes. This study included 312 mothers and 145 fathers with a singleton live birth from a preconception cohort of subfertile couples seeking fertility treatment at a U.S. clinic. PFAS were quantified in serum samples collected before conception. Gestational age (GA) and birthweight (BW) were abstracted from delivery records. We also assessed low birthweight (BW < 2500 g) and preterm birth (GA < 37 completed weeks). We utilized multivariable linear regression, logistic regression, and quantile-based g computation to examine maternal or paternal serum concentrations of individual PFAS and mixture with birth outcomes. Maternal serum concentrations of perfluorooctanesulfonate (PFOS), perfluorohexanesulfonate (PFHxS), and the total PFAS mixture were inversely associated with birthweight. Maternal PFOS concentration was associated with a higher risk of low birthweight. Conversely, paternal PFOS and PFHxS concentrations were imprecisely associated with higher birthweight. No associations were found for gestational age or preterm birth. The findings have important implications for preconception care. Future research with larger sample sizes would assist in validating these findings.

Associations between neighborhood stress and maternal sex steroid hormones in pregnancy

BACKGROUND

Neighborhood stressors (e.g., crime and deprivation) have been associated with adverse pregnancy outcomes including preterm birth and low birth weight. A potential mechanism is disruption of maternal endocrine pathways. While stress hormones (e.g., cortisol) have received much attention, other relevant hormones, including sex steroids, have been overlooked.

METHODS

Pregnant women in the Understanding Pregnancy Signals and Infant Development (UPSIDE) study contributed biospecimens, questionnaires, and medical record data (n = 262). In each trimester, maternal serum total testosterone [TT], estrone, estradiol, and estriol were measured using LC/MS-MS and serum free testosterone was measured by equilibrium dialysis. In the third trimester, participants reported on neighborhood stress over the last year through the validated City Stress Inventory. We examined two subscales: 11-item neighborhood disorder (e.g., vacant buildings, crime) and 7-item exposure to violence (personal experiences of violence). Composite scores were calculated and examined categorically (quartile (Q) for neighborhood disorder and any/none for exposure to violence). We fitted linear mixed models examining associations between neighborhood stressors and sex steroid hormones across pregnancy as well as trimester-specific linear regression models, all adjusting for confounders. Secondarily, we stratified by fetal sex. Results are presented as percentage change (∆%) and 95% confidence interval (CI) in hormones.

RESULTS

Most participants (73%) reported one or more exposures to neighborhood disorder; 22% reported any exposure to violence. In adjusted models, neighborhood disorder was associated with higher TT across pregnancy (Q2: %∆= 37.3, 95%CI: 13.2, 66.5; Q3: %∆= 22.2, 95%CI: 1.2, 47.5; and Q4: %∆= 25.7, 95%CI: 1.6, 55.3), with the strongest associations observed in the third trimester (Q2: %∆= 38.0, 95%CI: 10.6, 72.1; Q3: %∆= 29.2, 95%CI: 4.4, 59.9; and Q4: %∆=33.4, 95%CI: 4.9, 69.6). In stratified models, neighborhood disorder was associated with higher TT among women carrying male fetuses (%∆ range: 48.2-84.8). Exposure to violence was not associated with any hormones.

CONCLUSION

Neighborhood disorder is associated with higher maternal testosterone levels, which may have implications for maternal and child health. Additional research is needed to understand the mechanisms by which neighborhood stress impacts endocrine physiology.

Spatial and temporal expression profile of sex steroid receptors and antioxidant enzymes in the maternal-fetal interface of domestic cats

Sex steroids and antioxidant enzymes modulate uterine and placental physiology. Failures in the expression, signaling, and/or secretion of these mediators are associated with female infertility and gestational problems. However, there is no data on the expression profile of receptors for sex steroids and antioxidant enzymes in the maternal-fetal interface of domestic cats. Uterus and placenta samples from non-pregnant diestrus cats and cats in mid- and late pregnancy were used to analyze the protein and gene expression of the receptors for estrogen alpha (ERα), progesterone (PR), and androgen (AR) and the antioxidant enzymes superoxide dismutase 1 (SOD1), catalase, and glutathione peroxidase 1 (GPX1) by immunohistochemistry and qPCR. Higher uterine expression of ERα, Pr, and Sod1 was observed in the pregnant cats, especially in mid-pregnancy, compared to non-pregnant diestrus cats, as well as reduced endometrial catalase immunostaining. In the placenta, the mRNA expression of Erα, Pr, Ar, and Gpx1 was higher in late pregnancy in relation to mid-pregnancy. Moreover, weak or no placental expression was observed for catalase in mid- and late pregnancy, while strong immunostaining was observed for AR in trophoblasts and decidual cells in mid-pregnancy. The findings of this study demonstrated that pregnancy in female cats increases the uterine expression of sex steroid receptors and antioxidant enzymes, and that the placental expression of these mediators varies according to gestational age.

Mechanism of leptin-NPY on the onset of puberty in male offspring rats after androgen intervention during pregnancy

OBJECTIVES

The time of onset of puberty has been increasingly earlier, but its mechanism is still unclear. This study aimed to reveal the mechanism of leptin and NPY in the onset of puberty in male offspring rats after androgen intervention during pregnancy.

METHODS

Eight-week-old specific pathogen-free (SPF) healthy male Sprague-Dawley (SD) rats and 16 female SD rats were selected and caged at 1:2. The pregnant rats were randomly divided into the olive oil control group (OOG) and testosterone intervention group (TG), with 8 rats in each group. Olive oil and testosterone were injected from the 15th day of pregnancy, for a total of 4 injections (15th, 17th, 19th, 21st day). After the onset of puberty, the male offspring rats were anesthetized with 2% pentobarbital sodium to collect blood by ventral aorta puncture and decapitated to peel off the hypothalamus and abdominal fat. Serum testosterone (T), free testosterone (FT), dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA), sex hormone binding globulin (SHBG), and leptin were detected by ELISA, and then the free androgen index (FAI) was calculated. The mRNA levels of androgen receptor (AR), estrogen receptor α (ERα), NPY, leptinR, and NPY2R in the hypothalamus and abdominal fat were detected by RT-PCR. Protein expression levels of AR, ERα, NPY, leptinR, and NPY2R in the arcuate nucleus (ARC) of the hypothalamus were detected by immunohistochemistry.

RESULTS

The time of onset of puberty was significantly earlier in the TG than in the OOG (P< 0.05) and was positively correlated with body weight, body length, abdominal fat, and leptinR mRNA levels in adipose tissue in the OOG (P< 0.05), while it was positively correlated with serum DHT and DHEA concentrations and FAI and AR mRNA levels in the hypothalamus in the TG (P< 0.05). The NPY2R mRNA level and protein expression levels of ERα, NPY2R, and leptinR in the TG were significantly higher than those in the OOG, while the protein expression levels of AR and NPY in the TG were significantly lower than those in the OOG (P< 0.05).

CONCLUSIONS

Testosterone intervention during pregnancy led to an earlier onset of puberty in male offspring rats, which may render the male offspring rats more sensitive to androgens, leptin, and NPY at the onset of puberty.

The Relationship of Maternal Gestational Mass Spectrometry-Derived Metabolites with Offspring Congenital Heart Disease: Results from Multivariable and Mendelian Randomization Analyses

Background: It is plausible that maternal pregnancy metabolism influences the risk of offspring congenital heart disease (CHD). We sought to explore this through a systematic approach using different methods and data. Methods: We undertook multivariable logistic regression of the odds of CHD for 923 mass spectrometry (MS)-derived metabolites in a sub-sample of a UK birth cohort (Born in Bradford (BiB); N = 2605, 46 CHD cases). We considered metabolites reaching a p-value threshold <0.05 to be suggestively associated with CHD. We sought validation of our findings, by repeating the multivariable regression analysis within the BiB cohort for any suggestively associated metabolite that was measured by nuclear magnetic resonance (NMR) or clinical chemistry (N = 7296, 87 CHD cases), and by using genetic risk scores (GRS: weighted genetic risk scores of single nucleotide polymorphisms (SNPs) that were associated with any suggestive metabolite) in Mendelian randomization (MR) analyses. The MR analyses were performed in BiB and two additional European birth cohorts (N = 38,662, 319 CHD cases). Results: In the main multivariable analyses, we identified 44 metabolites suggestively associated with CHD, including those from the following super pathways: amino acids, lipids, co-factors and vitamins, xenobiotics, nucleotides, energy, and several unknown molecules. Of these 44, isoleucine and leucine were available in the larger BiB cohort (NMR), and for these the results were validated. The MR analyses were possible for 27/44 metabolites and for 11 there was consistency with the multivariable regression results. Conclusions: In summary, we have used complimentary data sources and statistical techniques to construct layers of evidence. We found that pregnancy amino acid metabolism, androgenic steroid lipids, and levels of succinylcarnitine could be important contributing factors for CHD.

Hyperandrogenism and Polycystic ovary syndrome: Effects in pregnancy and offspring development

Polycystic ovary syndrome (PCOS) is one of the major endocrine disorders affecting women of reproductive age. Its etiology remains unclear. It is suggested that environmental factors, and particularly the intrauterine environment, play key roles in PCOS development. Besides the role of androgens in PCOS pathogenesis, exposure to endocrine disruptors, as is Bisphenol A, could also contribute to its development. Although PCOS is considered one of the leading causes of ovarian infertility, many PCOS patients can get pregnant. Some of them by natural conception and others by assisted reproductive technique treatments. As hyperandrogenism (one of PCOS main features) affects ovarian and uterine functions, PCOS women, despite reaching pregnancy, could present high-risk pregnancies, including implantation failure, an increased risk of gestational diabetes, preeclampsia, and preterm birth. Moreover, hyperandrogenism may also be maintained in these women during pregnancy. Therefore, as an altered uterine milieu, including hormonal imbalance, could affect the developing organisms, monitoring these patients throughout pregnancy and their offspring development is highly relevant. The present review focuses on the impact of androgenism and PCOS on fertility issues and pregnancy-related outcomes and offspring development. The evidence suggests that the increased risk of pregnancy complications and adverse offspring outcomes of PCOS women would be due to the factors involved in the syndrome pathogenesis and the related co-morbidities. A better understanding of the involved mechanisms is still needed and could contribute to a better management of these women and their offspring. This article is categorized under: Reproductive System Diseases > Molecular and Cellular Physiology Reproductive System Diseases > Environmental Factors.

Steroidomics of Pregnant Women at Advanced Age

OBJECTIVES

To discover the profiles of different steroid hormones at the maternal-fetal interface and reveal the change characteristics in pregnant women at advanced maternal age (AMA).

METHODS

Forty pregnant women were recruited in the study, including 20 AMA women (age ≥ 35) and 20 normal controls (age < 35 and without pregnancy complications). Among AMA women, 6 (AMA2) had pregnancy complications, and 14 (AMA1) had no complications. Their maternal blood (MB), placental tissue (P), and fetal cord blood (CB) were collected, and 18 different steroid hormone metabolites were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS).

RESULTS

The estradiol (E2) levels in MB were higher than those in P and CB. In contrast, the estrone (E1) and estriol (E3) levels were higher in P and CB. Compared with the progesterone levels (P4) in MB, those in P and CB were higher; however, cortisol (F) levels were deficient. In contrast, F in MB was maintained at an elevated level. Further, cortisone (E) levels in CB were higher than those in MB and P. Except for the decline of testosterone (T), androstenedione (A2) and Dihydrotestosterone (DHT), there were no significant differences in the other 15 steroid hormones in MB between the AMA1 and the control group (p>0.05). Compared with the AMA1 group, androgen levels were significantly higher in AMA2, especially in T (1.55 vs. 0.68 ng/ml, p=0.023), A2 (2.27 vs. 0.92 ng/ml, p=0.011) and Dehydroepiandrosterone (DHEA) (2.39 vs. 1.50 ng/ml, p=0.028). However, there were no significant changes in P and CB between two groups.

CONCLUSION

There are distribution rules and cascade changes of steroid profiles in maternal-fetal compartments. Significantly high androgen levels in AMA women have a positive relationship with adverse pregnancy complications.