Environmental pollutants and hydroxysteroid dehydrogenases

A Novel Organophosphate Ester, Tris(2,4-ditert-butylphenyl) Phosphate, Induced Reproductive Toxicity in Male Zebrafish at Environmentally Relevant Concentrations

As a novel organophosphate ester (NOPE), tris(2,4-ditert-butylphenyl) phosphate (TDtBPP) has attracted significant attention due to its unexpectedly high detection in natural environments. However, the ecological toxic effects of environmentally relevant concentrations of TDtBPP in organisms remain entirely unknown. In this study, 1 month old zebrafish were exposed to 0, 50, 500, or 5000 ng/L TDtBPP for 150 days, and the reproductive toxicity in male fish was evaluated. Results demonstrated that TDtBPP exposure significantly inhibited the maturation of spermatozoa and thus decreased spermatogenesis. Furthermore, abnormal sperm morphology and decreased sperm motility were also observed. The decrease in sperm quantity and quality eventually resulted in the declining fecundity. Moreover, TDtBPP exposure downregulated the expression of hsd3b1 in vivo and in vitro and subsequently inhibited the synthesis of androgens in zebrafish testes and Leydig cells. This inhibition of androgen synthesis appeared to be responsible for the observed reproductive toxicity in male fish. Molecular docking and dual-luciferase reporter gene experiments elucidated that TDtBPP inhibited the promotion of vitamin D on hsd3b1 transcription by the vitamin D receptor and thus downregulated the expression of hsd3b1. Our findings provide first time evidence that TDtBPP poses a risk to male fish reproduction at environmentally relevant levels.

Diagnostic and therapeutic use of oral micronized progesterone in endocrinology

Progesterone is a natural steroid hormone, while progestins are synthetic molecules. In the female reproductive system, progesterone contributes to the control of luteinizing hormone and follicle-stimulating hormone secretion and their pulsatility, via its receptors on the kisspeptin, neurokinin B, and dynorphin neurons in the hypothalamus. Progesterone together with estradiol controls the cyclic changes of proliferation and decidualization of the endometrium; exerts anti-mitogenic actions on endometrial epithelial cells; regulates normal menstrual bleeding; contributes to fertilization and pregnancy maintenance; participates in the onset of labor. In addition, it exerts numerous effects on other endocrine systems. Micronized progesterone (MP) is natural progesterone with increased bioavailability, due to its pharmacotechnical micronized structure, which makes it an attractive diagnostic and therapeutic tool. This critical literature review aims to summarize and put forward the potential diagnostic and therapeutic uses of MP in the field of endocrinology. During reproductive life, MP is used for diagnostic purposes in the evaluation of primary or secondary amenorrhea as a challenge test. Moreover, it can be prescribed to women presenting with amenorrhea or oligomenorrhea for induction of withdrawal bleeding, in order to time blood-sampling for diagnostic purposes in early follicular phase. Therapeutically, MP, alone or combined with estrogens, is a useful tool in various endocrine disorders including primary amenorrhea, abnormal uterine bleeding due to disordered ovulation, luteal phase deficiency, premenstrual syndrome, polycystic ovary syndrome, secondary amenorrhea [functional hypothalamic amenorrhea, premature ovarian insufficiency], perimenopause and menopause. When administrated per os, acting as a neurosteroid directly or through its metabolites, it exerts beneficial effects on brain function such as alleviation of symptoms of anxiety and depression, asw well as of sleep problems, while it improves working memory in peri- and menopausal women. Micronized progesterone preserves full potential of progesterone activity, without presenting many of the side-effects of progestins. Although it has been associated with more frequent drowsiness and dizziness, it can be well tolerated with nocturnal administration. Because of its better safety profile, especially with regard to metabolic ailments, breast cancer risk and veno-thromboembolism risk, MP is the preferred option for individuals with an increased risk of cardiovascular and metabolic diseases and of all-cause mortality.

Structure-activity relationship and mechanistic study of organotins as inhibitors of human, pig, and rat gonadal 3β-hydroxysteroid dehydrogenases

Organotins have been widely used in various industrial applications. This study investigated the structure-activity relationship as inhibitors of human, pig, and rat gonadal 3β-hydroxysteroid dehydrogenases (3β-HSD). Human KGN cell, pig, and rat testis microsomes were utilized to assess the inhibitory effects of 18 organotins on the conversion of pregnenolone to progesterone. Among them, diphenyltin, triethyltin, and triphenyltin exhibited significant inhibitory activity against human 3β-HSD2 with IC50 values of 114.79, 106.98, and 5.40 μM, respectively. For pig 3β-HSD, dipropyltin, diphenyltin, triethyltin, tributyltin, and triphenyltin demonstrated inhibitory effects with IC50 values of 172.00, 100.19, 87.00, 5.75, and 1.65 μM, respectively. Similarly, for rat 3β-HSD1, dipropyltin, diphenyltin, triethyltin, tributyltin, and triphenyltin displayed inhibitory activity with IC50 values of 81.35, 43.56, 55.55, 4.09, and 0.035 μM, respectively. They were mixed inhibitors of pig and rat 3β-HSD, while triphenyltin was identified as a competitive inhibitor of human 3β-HSD2. The mechanism underlying the inhibition of organotins on 3β-HSD was explored, revealing that they may disrupt the enzyme activity by binding to cysteine residues in the catalytic sites. This proposition was supported by the observation that the addition of dithiothreitol reversed the inhibition caused by all organotins except for triethyltin, which was partially reversed. In conclusion, this study provides valuable insights into the structure-activity relationship of organotins as inhibitors of human, pig, and rat gonadal 3β-HSD. The mechanistic investigation suggests that these compounds likely exert their inhibitory effects through binding to cysteine residues in the catalytic sites.

Evaluating Mixtures of Urinary Phthalate Metabolites and Serum Per-/Polyfluoroalkyl Substances in Relation to Adolescent Hair Cortisol: The HOME Study

Results of toxicological studies indicate that phthalates and per-/polyfluoroalkyl substances (PFAS), 2 classes of endocrine-disrupting chemicals, may alter the functioning of the hypothalamic-pituitary-adrenocortical (HPA) axis. We evaluated the associations of urinary phthalate metabolites and serum PFAS during gestation and childhood with adolescent hair cortisol concentrations (pg/mg hair) at age 12 years, an integrative marker of HPA axis activity (n = 205 mother-child pairs; Cincinnati, Ohio; enrolled 2003-2006). We used quantile-based g-computation to estimate associations between mixtures of urinary phthalate metabolites or serum PFAS and hair cortisol. We also examined whether associations of individual phthalate metabolites or PFAS with cortisol varied by the timing of exposure. We found that a 1-quartile increase in all childhood phthalate metabolites was associated with 35% higher adolescent hair cortisol (phthalate mixture ψ = 0.13; 95% confidence interval: 0.03, 0.22); these associations were driven by monoethyl phthalate, monoisobutyl phthalate, and monobenzyl phthalate. We did not find evidence that phthalate metabolites during gestation or serum PFAS mixtures were related to adolescent hair cortisol concentrations. We found suggestive evidence that higher childhood concentrations of individual PFAS were related to higher and lower adolescent hair cortisol concentrations. Our results suggest that phthalate exposure during childhood may contribute to higher levels of chronic HPA axis activity.

Engineering the cofactor binding site of 7α-hydroxysteroid dehydrogenase for improvement of catalytic activity, thermostability, and alteration of substrate preference

Hydroxysteroid dehydrogenases (HSDHs) are crucial for bile acid metabolism and influence the size of the bile acid pool and gut microbiota composition. HSDHs with high activity, thermostability, and substrate selectivity are the basis for constructing engineered bacteria for disease treatment. In this study, we designed mutations at the cofactor binding site involving Thr15 and Arg16 residues of HSDH St-2-2. The T15A, R16A, and R16Q mutants exhibited 7.85-, 2.50-, and 4.35-fold higher catalytic activity than the wild type, respectively, while also displaying an altered substrate preference (from taurocholic acid (TCA) to taurochenodeoxycholic acid (TCDCA)). These mutants showed lower Km and higher kcat values, indicating stronger binding to the substrate and resulting in 3190-, 3123-, and 3093-fold higher kcat/Km values for TCDCA oxidation. Furthermore, the Tm values of the T15A, R16A, and R16Q mutants were found to increase by 4.3 °C, 6.0 °C, and 7.0 °C, respectively. Molecular structure analysis indicated that reshaped internal hydrogens and surface mutations could improve catalytic activity and thermostability, and altered interactions among the catalytic triad, cofactor binding sites, and substrates could change substrate preference. This work provides valuable insights into modifying substrate preference as well as enhancing the catalytic activity and thermostability of HSDHs by targeting the cofactor binding site.

Novel approaches in IBD therapy: targeting the gut microbiota-bile acid axis

Inflammatory bowel disease (IBD) is a chronic and recurrent condition affecting the gastrointestinal tract. Disturbed gut microbiota and abnormal bile acid (BA) metabolism are notable in IBD, suggesting a bidirectional relationship. Specifically, the diversity of the gut microbiota influences BA composition, whereas altered BA profiles can disrupt the microbiota. IBD patients often exhibit increased primary bile acid and reduced secondary bile acid concentrations due to a diminished bacteria population essential for BA metabolism. This imbalance activates BA receptors, undermining intestinal integrity and immune function. Consequently, targeting the microbiota-BA axis may rectify these disturbances, offering symptomatic relief in IBD. Here, the interplay between gut microbiota and bile acids (BAs) is reviewed, with a particular focus on the role of gut microbiota in mediating bile acid biotransformation, and contributions of the gut microbiota-BA axis to IBD pathology to unveil potential novel therapeutic avenues for IBD.

Serum perfluoroalkyl substances and growth and development in US adolescents: a nationally representative cross-sectional study

Per- and polyfluoroalkyl substances (PFAS), synthetic organic chemicals, have been discovered in the blood of both humans and animals throughout the world. This has raised widespread concerns about its toxicity, especially for growing children and adolescents. Most research on growth and development to date has concentrated on children at birth and during the first two years, while few studies have analyzed weight, height, and Body Mass Index (BMI) changes in children later in life. The present study aims to assess the association between serum PFAS levels and growth and development in adolescents. Through multiple linear regression, we explored the relationship between serum PFAS levels and weight, height, and BMI in adolescents (aged 12 to 19 years) participating in the 2015-2018 National Health and Nutrition Examination Survey (NHANES). After covariate adjustment, serum perfluorooctane sulfonic acid (PFOS) was associated with decreased weight-for-age z-score in females (tertile 2 of PFOS: β =  - 0.22, 95% CI: -0.68, 0.23; tertile 3 of PFOS: β =  - 0.78, 95% CI: -1.20, - 0.36; P for trend = 0.009), while serum perfluorononanoic acid (PFNA) was associated with decreased weight-for-age z-score in males (tertile 2 of PFNA: β = 0.09, 95% CI: -0.40, 0.58; tertile 3 of PFNA: β =  - 0.44, 95% CI: -0.86, - 0.03; P for trend = 0.018).In addition, serum PFOS was associated with decreased BMI z-score in all participants (tertile 2 of PFOS: β =  - 0.15, 95% CI: -0.46, 0.16; tertile 3 of PFOS: β =  - 0.63, 95% CI: -1.06, - 0.20; P for trend = 0.013).

CONCLUSION

Our findings indicate a negative association between serum PFAS levels and weight, and BMI among adolescents, and we observed that the negative association was sex-specific in weight.

WHAT IS KNOWN

• Wide exposure to PFAS has led to concerns about its adverse effects, especially for children during their growth and development. • So far, much research has evaluated the effects of prenatal PFAS exposures on children, and the current results are mixed, with some research showing that there are sex differences.

WHAT IS NEW

• This study investigated the relationship between serum PFAS levels and height and weight in adolescents and is a good addition to current research. • Our study found that exposure to PFAS negatively affects adolescent growth and development and that this effect is sex-specific.

Ketonization of Ginsenoside C-K by Novel Recombinant 3-β-Hydroxysteroid Dehydrogenases and Effect on Human Fibroblast Cells

BACKGROUND AND OBJECTIVE

The ginsenoside compound K (C-K) (which is a de-glycosylated derivative of major ginsenosides) is effective in the treatment of cancer, diabetes, inflammation, allergy, angiogenesis, aging, and has neuroprotective, and hepatoprotective than other minor ginsenosides. Thus, a lot of studies have been focused on the conversion of major ginsenosides to minor ginsenosides using glycoside hydrolases but there is no study yet published for the bioconversion of minor ginsenosides into another high pharmacological active compound. Therefore, the objective of this study to identify a new gene (besides the glycoside hydrolases) for the conversion of minor ginsenosides C-K into another highly pharmacological active compound.

METHODS AND RESULTS

Lactobacillus brevis which was isolated from Kimchi has showed the ginsenoside C-K altering capabilities. From this strain, a novel potent decarboxylation gene, named HSDLb1, was isolated and expressed in Escherichia coli BL21 (DE3) using the pMAL-c5X vector system. Recombinant HSDLb1 was also characterized. The HSDLb1 consists of 774 bp (258 amino acids residues) with a predicted molecular mass of 28.64 kDa. The optimum enzyme activity was recorded at pH 6.0-8.0 and temperature 30 °C. Recombinant HSDLb1 effectively transformed the ginsenoside C-K to 12-β-hydroxydammar-3-one-20(S)-O-β-D-glucopyranoside (3-oxo-C-K). The experimental data proved that recombinant HSDLb1 strongly ketonized the hydroxyl (-O-H) group at C-3 of C-K via the following pathway: C-K → 3-oxo-C-K. In vitro study, 3-oxo-C-K showed higher solubility than C-K, and no cytotoxicity to fibroblast cells. In addition, 3-oxo-C-K induced the inhibitory activity of ultraviolet A (UVA) against matrix metalloproteinase-1 (MMP-1) and promoted procollagen type I synthesis. Based on these expectations, we hypothesized that 3-oxo-C-K can be used in cosmetic products to block UV radiations and anti-ageing agent. Furthermore, we expect that 3-oxo-C-K will show higher efficacy than C-K for the treatment of cancer, ageing and other related diseases, for which more studies are needed.

The analysis of pesticides and fungicides in the inhibition of human and rat placental 3β-hydroxysteroid dehydrogenase activity: mode of inhibition and mechanism

3β-Hydroxysteroid dehydrogenase/steroid Δ^5,4-isomerase 1 (3β-HSD1) plays a critical role in the biosynthesis of progesterone from pregnenolone in the human placenta to maintain normal pregnancy. Whether they inhibit placental 3β-HSD1 and mode of inhibition remains unclear. In this study, we screened 21 pesticides and fungicides in five classes to inhibit human 3β-HSD1 and compared them to rat homolog 3β-HSD4. 3β-HSD activity was measured by catalyzing pregnenolone to progesterone in the presence of NAD⁺. Of the 21 chemicals, azoles (difenoconazole), thiocarbamates (thiram and ferbam) and organochlorine (hexachlorophene) significantly inhibited human 3β-HSD1 with half maximal inhibitory concentration (IC₅₀) values of 2.77, 0.24, 0.68, and 17.96 μM, respectively. We also found that difenoconazole, ferbam and hexachlorophene are mixed/competitive inhibitors of 3β-HSD1 while thiram is a mixed/noncompetitive inhibitor. Docking analysis showed that difenoconazole and hexachlorophene bound steroid-binding site. Difenoconazole and hexachlorophene except thiram and ferbam also significantly inhibited rat 3β-HSD4 activity with IC₅₀ of 1.12 and 2.28µM, respectively. Thiram and ferbam significantly inhibited human 3β-HSD1 possibly by interfering with cysteine residues, while they had no effects on rat 3β-HSD4. In conclusion, some pesticides potently inhibit placental 3β-HSD, leading to the reduction of progesterone formation.

Expression Profile of Hydroxysteroid Dehydrogenase-like 2 in Polychaete Perinereis aibuhitensis in Response to BPA

Hydroxysteroid dehydrogenases (HSDs) play an important role in the metabolism of steroids and xenobiotics. However, the function of HSDs in invertebrates is unclear. In this study, we cloned the hydroxysteroid dehydrogenase-like 2 (HSDL2) gene in Perinereis aibuhitensis, which is 1652 bp in length, encoding 400 amino acids. This sequence contains conserved short-chain dehydrogenase and sterol carrier protein-2 domain, and the alignment analysis showed its close relationship with other invertebrate HSDL2. Further, the tissue distribution analysis of the HSDL2 gene showed it is expressed strongly in the intestine. The expression level of HSDL2 after inducement with bisphenol A (BPA) was also detected both at transcriptional and translational levels. The results inferred that BPA exposure can induce HSDL2 expression, and the inductive effect was obvious in the high-concentration BPA group (100 μg/L). In summary, our results showed the detoxification function of HSDL2 in polychaetes.

Using follicular fluid metabolomics to investigate the association between air pollution and oocyte quality

BACKGROUND AND AIM

Our objective was to use metabolomics in a toxicological-relevant target tissue to gain insight into the biological processes that may underlie the negative association between air pollution exposure and oocyte quality.

METHODS

Our study included 125 women undergoing in vitro fertilization at an academic fertility center in Massachusetts, US (2005-2015). A follicular fluid sample was collected during oocyte retrieval and untargeted metabolic profiling was conducted using liquid chromatography with ultra-high-resolution mass spectrometry and two chromatography columns (C18 and HILIC). Daily exposure to nitrogen dioxide (NO2), ozone, fine particulate matter, and black carbon was estimated at the women's residence using spatiotemporal models and averaged over the period of ovarian stimulation (2-weeks). Multivariable linear regression models were used to evaluate the associations between the air pollutants, number of mature oocytes, and metabolic feature intensities. A meet-in-the-middle approach was used to identify overlapping features and metabolic pathways.

RESULTS

Of the air pollutants, NO2 exposure had the largest number of overlapping metabolites (C18: 105; HILIC: 91) and biological pathways (C18: 3; HILIC: 6) with number of mature oocytes. Key pathways of overlap included vitamin D3 metabolism (both columns), bile acid biosynthesis (both columns), C21-steroid hormone metabolism (HILIC), androgen and estrogen metabolism (HILIC), vitamin A metabolism (HILIC), carnitine shuttle (HILIC), and prostaglandin formation (C18). Three overlapping metabolites were confirmed with level-1 or level-2 evidence. For example, hypoxanthine, a metabolite that protects against oxidant-induced cell injury, was positively associated with NO2 exposure and negatively associated with number of mature oocytes. Minimal overlap was observed between the other pollutants and the number of mature oocytes.

CONCLUSIONS

Higher exposure to NO2 during ovarian stimulation was associated with many metabolites and biologic pathways involved in endogenous vitamin metabolism, hormone synthesis, and oxidative stress that may mediate the observed associations with lower oocyte quality.

Mechanism of 17β-estradiol degradation by Rhodococcus equi via the 4,5-seco pathway and its key genes

Steroid estrogens have been detected in oceans, rivers, lakes, groundwaters, soils, and even urban water supply systems, thereby inevitably imposing serious impacts on human health and ecological safety. Indeed, many estrogen-degrading bacterial strains and degradation pathways have been reported, with the 4,5-seco pathway being particularly important. However, few studies have evaluated the use of the 4,5-seco pathway by actinomycetes to degrade 17β-estradiol (E2). In this study, 5 genes involved in E2 degradation were identified in the Rhodococcus equi DSSKP-R-001 (R-001) genome and then heterologously expressed to confirm their functions. The transformation of E2 with hsd17b14 reached 63.7% within 30 h, resulting in transformation into estrone (E1). Furthermore, we found that At1g12200-encoded flavin-binding monooxygenase (FMO_At1g12200) can transform E1 at a rate of 51.6% within 30 h and can transform E1 into 4-hydroxyestrone (4-OH E1). In addition, catA and hsaC genes were identified to further transform 4-OH E1 at a rate of 97-99%, and this reaction was accomplished by C-C cleavage at the C4 position of the A ring of 4-OH E1. This study represents the first report on the roles of these genes in estrogen degradation and provides new insights into the mechanisms of microbial estrogen metabolism and a better understanding of E2 degradation via the 4,5-seco pathway by actinomycetes.

Technologies for Solubility, Dissolution and Permeation Enhancement of Natural Compounds

The current review is based on the advancements in the field of natural therapeutic agents which could be utilized for a variety of biomedical applications and against various diseases and ailments. In addition, several obstacles have to be circumvented to achieve the desired therapeutic effectiveness, among which limited dissolution and/or solubility and permeability are included. To counteract these issues, several advancements in the field of natural therapeutic substances needed to be addressed. Therefore, in this review, the possible techniques for the dissolution/solubility and permeability improvements have been addressed which could enhance the dissolution and permeability up to several times. In addition, the conventional and modern isolation and purification techniques have been emphasized to achieve the isolation and purification of single or multiple therapeutic constituents with convenience and smarter approaches. Moreover, a brief overview of advanced natural compounds with multiple therapeutic effectiveness have also been anticipated. In brief, enough advancements have been carried out to achieve safe, effective and economic use of natural medicinal agents with improved stability, handling and storage.

PFAS Concentrations and Cardiometabolic Traits in Highly Exposed Children and Adolescents

Background: Residents of a large area of north-eastern Italy were exposed for decades to high concentrations of perfluoroalkyl and polyfluoroalkyl substances (PFAS) via drinking water. Despite the large amount of evidence in adults of a positive association between serum PFAS and metabolic outcomes, studies focusing on children and adolescents are limited. We evaluated the associations between serum PFAS concentrations that were quantifiable in at least 40% of samples and lipid profile, blood pressure (BP) and body mass index (BMI) in highly exposed adolescents and children. Methods: A cross-sectional analysis was conducted in 6669 adolescents (14–19 years) and 2693 children (8–11 years) enrolled in the health surveillance program of the Veneto Region. Non-fasting blood samples were obtained and analyzed for perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexanesulfonic acid (PFHxS), perfluorononanoic acid (PFNA), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and triglycerides. Low-density lipoprotein cholesterol (LDL-C) was calculated. Systolic and diastolic BP were measured, and BMI z-score accounting for age and sex was estimated. The associations between ln-transformed PFAS (and categorized into quartiles) and continuous outcomes were assessed using generalized additive models. The weighted quantile sum regression approach was used to assess PFAS-mixture effects for each outcome. Analyses were stratified by gender and adjusted for potential confounders. Results: Among adolescents, significant associations were detected between all investigated PFAS and TC, LDL-C, and to a lesser extent HDL-C. Among children, PFOS and PFNA had significant associations with TC, LDL-C and HDL-C, while PFOA and PFHxS had significant associations with HDL-C only. Higher serum concentrations of PFAS, particularly PFOS, were associated with lower BMI z-score. No statistically significant associations were observed between PFAS concentrations and BP. These results were confirmed by the multi-pollutant analysis. Conclusions: Our study supports a consistent association between PFAS concentration and serum lipids, stronger for PFOS and PFNA and with a greater magnitude among children compared to adolescents, and a negative association of PFAS with BMI.

The association between maternal urinary phthalate metabolites concentrations and pregnancy induced hypertension: Results from the EDEN Mother-Child Cohort

BACKGROUND

Studies have suggested that exposure to endocrine disruptors such as phthalates that are widely used in our daily life (food wrapping, cosmetics, toys, medical devices, polyvinyl chloride flooring, and building materials) might be related to raised blood pressure and increased risk of cardiovascular diseases. Phthalates might induce a pro-inflammatory response and increased oxidative stress and may be a cause of pregnancy induced hypertension.

METHODS

We evaluated the association between maternal exposure to phthalates during pregnancy and pregnancy induced hypertension. 604 pregnant women were included and eleven phthalate metabolites were quantified in spot maternal urine samples collected between the 23rd and 28th week of gestation in a French EDEN mother-child cohort. The associations were assessed by applying multiple logistic regression analysis.

RESULTS

Twenty nine (4,8%) mothers developed pregnancy induced hypertension. Two low molecular weight phthalate metabolites: Monoethyl phthalate (MEP) and Mono-n‑butyl phthalate (MBP) were positively associated with pregnancy induced hypertension in crude (Odds Ratio: 1.43, 95% Confidence Interval: 1.04-1.96, p-value = 0.02 and 1.48, 1.10-2.01, p-value =0.01) and in adjusted (1.47, 1.01-2.14, p-value = 0.04 and 1.66, 1.11-2.47, p-value = 0.01) models respectively.

CONCLUSION

Our data suggest that prenatal exposure to some phthalates, including MEP and MBP, might play a role in pregnancy induced hypertension.

Temperature-Dependent Dynamical Evolution in Coum/SBE-β-CD Inclusion Complexes Revealed by Two-Dimensional FTIR Correlation Spectroscopy (2D-COS)

A combination of Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR) and 2D correlation analysis (2D-COS) was applied here for the first time in order to investigate the temperature-dependent dynamical evolution occurring in a particular type of inclusion complex, based on sulfobutylether-β-cyclodextrin (SBE-β-CD) as hosting agent and Coumestrol (7,12-dihydorxcoumestane, Coum), a poorly-soluble active compound known for its anti-viral and anti-oxidant activity. For this purpose, synchronous and asynchronous 2D spectra were calculated in three different wavenumber regions (960-1320 cm^-1, 1580-1760 cm^-1 and 2780-3750 cm^-1) and over a temperature range between 250 K and 340 K. The resolution enhancement provided by the 2D-COS offers the possibility to extract the sequential order of events tracked by specific functional groups of the system, and allows, at the same time, the overcoming of some of the limits associated with conventional 1D FTIR-ATR analysis. Acquired information could be used, in principle, for the definition of an optimized procedure capable to provide high-performance T-sensitive drug carrier systems for different applications.

Gestational perfluoroalkyl substance exposure and body mass index trajectories over the first 12 years of life

BACKGROUND/OBJECTIVES

Gestational exposure to perfluoroalkyl substances (PFAS), a ubiquitous class of persistent endocrine disrupting chemicals, is associated with increased risk of obesity and cardiometabolic disease. However, it is unclear if gestational PFAS exposure is associated with adiposity trajectories related to adult obesity and cardiometabolic health.

SUBJECTS/METHODS

We measured perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononaoic acid, and perfluorohexanesulfonic acid (PFHxS) concentrations in maternal serum collected between 16 weeks gestation and delivery in a cohort of 345 mother-child pairs in Cincinnati, OH (enrolled 2003-06). From age 4 weeks to 12 years, we measured weight and length or height up to eight times and calculated child body mass index (BMI) (1865 repeated measures). Using covariate-adjusted linear mixed models and splines to account for repeated BMI measures and nonlinear BMI patterns, respectively, we estimated the age/magnitude of infancy BMI zenith (~1 year) and childhood BMI nadir (~5 years), BMI accrual from 8 to 12 years, and BMI at age 12 years by PFAS terciles.

RESULTS

BMI trajectories varied by PFOA concentrations (age × PFOA interaction p value = 0.03). Children born to women with higher PFOA concentrations had lower infancy and early childhood BMI, earlier BMI nadir, accelerating BMI gains in mid-childhood and adolescence, and higher BMI at age 12 years. Some of these associations were non-monotonic. PFOS and PFHxS were not associated with alterations in BMI trajectories, but were monotonically associated with lower BMI across infancy, childhood, and adolescence. Compared to children in the first PFOS tercile, those in the second (β: -0.83; 95% confidence interval (CI): -2.11, 0.51 kg/m2), and third (β: -1.41; 95% CI: -2.65, -0.14 kg/m2) had lower BMI at age 12 years.

CONCLUSIONS

These results suggest that gestational PFOA exposure may be associated with BMI trajectories related to adult obesity and cardiometabolic disease, while PFOS and PFHxS exposure is associated with lower BMI in the first 12 years of life.

Leydig Cell and Spermatogenesis

Leydig cells of the testis have the capacity to synthesize androgen (mainly testosterone) from cholesterol. Adult Leydig cells are the cell type for the synthesis of testosterone, which is critical for spermatogenesis. At least four steroidogenic enzymes take part in testosterone synthesis: cytochrome P450 cholesterol side chain cleavage enzyme, 3β-hydroxysteroid dehydrogenase, cytochrome P450 17α-hydroxylase/17,20-lyase and 17β-hydroxysteroid dehydrogenase isoform 3. Testosterone metabolic enzyme steroid 5α-reductase 1 and 3α-hydroxysteroid dehydrogenase are expressed in some precursor Leydig cells. Androgen is transported by androgen-binding protein to Sertoli cells, where it binds to androgen receptor to regulate spermatogenesis.

Early-Life Exposure to Per- and Poly-Fluorinated Alkyl Substances and Growth, Adiposity, and Puberty in Children: A Systematic Review

Per- or polyfluoroalkyl substances (PFAS), a family of synthetic polyfluorinated compounds, are widely used in consumer products. Ubiquitous exposures to PFAS, in consideration of their persistence, bioaccumulation potential, and toxicities have led to concerns regarding possible harmful effects during critical periods of development in early-life and long-term consequences on health. The potential effects of PFAS depend on various factors including the type of PFAS and the timing and level of exposure. We performed a systematic review of the epidemiologic literature to assess the effects of early-life PFAS exposure on prenatal and postnatal growth, adiposity, and puberty in children and adolescents. For birth size, most studies indicated that prenatal PFAS exposure, in particular long-chain PFAS, may impair fetal growth, albeit some reports of null associations with maternal PFAS. For growth within 2 years of age, prenatal PFAS exposure showed no associations with height and either null or negative associations with weight. However, postnatal PFAS exposures were inversely related to height and weight at 2 years in a cross-sectional study. For postnatal adiposity, prenatal PFAS may mostly have negative associations with body mass index in the first 2 years of life, but positive relationships with adiposity in childhood and adolescence, although some studies showed null associations. For puberty, the evidence for associations between early-life PFAS exposure and pubertal development or sex hormone levels were limited and inconclusive. From experimental studies, plausible mechanisms through which PFAS may affect early-life growth and puberty include PFAS-induced activation of peroxisome proliferator-activated receptor, alterations of thyroid or steroid hormone synthesis and metabolism, and their weak estrogenic or anti-androgenic properties. Although the published literature suggests possible effects of PFAS exposures on early-life growth, adiposity, and puberty, current human evidence is limited in establishing PFAS-induced effects on early-life physical development. Further investigation is warranted to clarify PFAS-induced effects on growth and physical development in consideration of the critical time-window of exposure, concomitant exposure to chemical mixtures including various PFAS types, and possible non-monotonic dose-response relationship for growth and adiposity trajectories.

Measuring fecal metabolites of endogenous steroids using ESI-MS/MS spectra in Taiwanese pangolin, (order Pholidota, family Manidae, Genus: Manis): A non-invasive method for endangered species

Pangolins are 'keystone species' driven towards extinction due to a lack of profound awareness and illegal trade. The drivers urge for immediate development in the understanding of demographics and reproductive dynamics of this species. In this study, we developed and validated a quantitative method to measure pangolin fecal extracts using the electrospray (ESI-MS/MS) interface in positive ionization mode. The method aids in the measurement of hormones from the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axis, making it a possibly appropriate technique to understand the cross-talk between the axes. The study aims to measure the relative abundance of adrenal and gonadal hormones such as corticosterone, cortisol, estrone, estradiol-17β, progesterone, testosterone, and a number of its metabolites. From the dried fecal extract, the principal metabolite identified from the estrogen family was estradiol-17β, whereas the gestagen family revealed that the pregnane series is predominated in 5α-configuration. On the other hand, epiandrosterone was seen as the dominant form in the male fecal extracts. Additionally, the glucocorticoids are excreted majorly as corticosterone, but traces of cortisol are also present in both the male and female fecal samples. The physiological validation confirmed that the ESI-MS/MS technique is suitable to determine physiologically caused differences in the fecal steroid concentrations. Physiologically, the age structure in pangolin is not responsible for causing differences within gender. However, the results revealed that glucocorticoids might vary between the sexes, i.e., males have a higher relative abundance of glucocorticoids over females. Therefore, our studies show that some of the main adrenal and gonadal metabolites can be predicted by exploiting MS/MS, which can steer research to potentially assess the reproductive status of captive and free-ranging pangolin species.

Autism spectrum disorder at the crossroad between genes and environment: contributions, convergences, and interactions in ASD developmental pathophysiology

The complex pathophysiology of autism spectrum disorder encompasses interactions between genetic and environmental factors. On the one hand, hundreds of genes, converging at the functional level on selective biological domains such as epigenetic regulation and synaptic function, have been identified to be either causative or risk factors of autism. On the other hand, exposure to chemicals that are widespread in the environment, such as endocrine disruptors, has been associated with adverse effects on human health, including neurodevelopmental disorders. Interestingly, experimental results suggest an overlap in the regulatory pathways perturbed by genetic mutations and environmental factors, depicting convergences and complex interplays between genetic susceptibility and toxic insults. The pervasive nature of chemical exposure poses pivotal challenges for neurotoxicological studies, regulatory agencies, and policy makers. This highlights an emerging need of developing new integrative models, including biomonitoring, epidemiology, experimental, and computational tools, able to capture real-life scenarios encompassing the interaction between chronic exposure to mixture of substances and individuals' genetic backgrounds. In this review, we address the intertwined roles of genetic lesions and environmental insults. Specifically, we outline the transformative potential of stem cell models, coupled with omics analytical approaches at increasingly single cell resolution, as converging tools to experimentally dissect the pathogenic mechanisms underlying neurodevelopmental disorders, as well as to improve developmental neurotoxicology risk assessment.

Acephate interferes with androgen synthesis in rat immature Leydig cells

Acephate is an organophosphate pesticide. It is widely used. However, whether it inhibits androgen synthesis and metabolism remains unclear. In the current study, we investigated the effect of acephate on the inhibition of androgen synthetic and metabolic pathways in rat immature Leydig cells after 3-h culture. Acephate inhibited basal androgen output in a dose-dependent manner with the inhibition starting at 0.5 μM. It significantly inhibited luteinizing hormone and 8-Br-cAMP stimulated androgen output at 50 μM. It significantly inhibited progesterone-mediated androgen output at 50 μM. Further study demonstrated that acephate down-regulated the expression of Hsd3b1 and its protein at ≥ 0.5 μM, Lhcgr at 5 μM and Star at 50 μM. Acephate directly blocked rat testicular HSD3B1 activity at 50 μM. Acephate did not affect other androgen synthetic and metabolic enzyme activities as well as ROS production, proliferation, and apoptosis of immature Leydig cells. In conclusion, acephate targets LHCGR, STAR, and HSD3B1, thus blocking androgen synthesis in rat immature Leydig cells and HSD3B1 is being the most sensitive target of acephate.

Beta-Hydroxysteroid Dehydrogenase Genes in Orange-Spotted Grouper (Epinephelus coioides): Genome-Wide Identification and Expression Analysis During Sex Reversal

Beta-hydroxysteroid dehydrogenases (β-HSDs) are a group of steroidogenic enzymes that are involved in steroid biosynthesis and metabolism, and play a crucial role in mammalian physiology and development, including sex determination and differentiation. In the present study, a genome-wide analysis identified the numbers of β-hsd genes in orange-spotted grouper (Epinephelus coioides) (19), human (Homo sapiens) (22), mouse (Mus musculus) (24), chicken (Gallus gallus) (16), xenopus (Xenopus tropicalis) (24), coelacanth (Latimeria chalumnae) (17), spotted gar (Lepisosteus oculatus) (14), zebrafish (Danio rerio) (19), fugu (Takifugu rubripes) (19), tilapia (Oreochromis niloticus) (19), medaka (Oryzias latipes) (19), stickleback (Gasterosteus aculeatus) (17) and common carp (Cyprinus carpio) (27) samples. A comparative analysis revealed that the number of β-hsd genes in teleost fish was no greater than in tetrapods due to gene loss followed by a teleost-specific whole-genome duplication event. Based on transcriptome data from grouper brain and gonad samples during sex reversal, six β-hsd genes had relatively high expression levels in the brain, indicating that these genes may be required for neurogenesis or the maintenance of specific biological processes in the brain. In the gonad, two and eight β-hsd genes were up- and downregulated, respectively, indicating their important roles in sex reversal. Our results demonstrated that β-hsd genes may be involved in the sex reversal of grouper by regulating the synthesis and metabolism of sex steroid hormones.

Dimethoate blocks pubertal differentiation of Leydig cells in rats

Dimethoate is an organophosphate pesticide. It is widely used in agriculture. However, whether it blocks pubertal development of Leydig cells remains unknown. In the current study, we exposed male Sprague Dawley rats with 7.5 and 15 mg kg^-1 dimethoate from postnatal day 35-56. We also exposed Leydig cells isolated from 35-day-old rats for 3 h. Dimethoate reduced serum testosterone levels at 7.5 and 15 mg kg-1 but increased serum luteinizing hormone and follicle stimulating hormone levels at 15 mg kg-1. Dimethoate did not influence Leydig cell number but reduced Leydig cell size and down-regulated Star, Cyp11a1, and Hsd3b1 in Leydig cells as well as their protein expression. Dimethoate inhibited basal androgen output in a dose-dependent manner with the inhibition starting at 0.05 μM. It significantly inhibited luteinizing hormone and 8Br-cAMP stimulated androgen outputs at 50 μM. It significantly inhibited 22R-hydroxycholesterol and progesterone-mediated androgen outputs at 50 μM. Further study demonstrated that dimethoate also down-regulated the expression of Star, Cyp11a1, and Hsd3b1 at 5 or 50 μM in vitro. Dimethoate did not directly inhibit rat testicular steroidogenic enzyme activities at 50 μM. In conclusion, dimethoate targets Star, Cyp11a1, and Hsd3b1 transcription, thus blocking Leydig cell differentiation during puberty.

A New LC-MS/MS Method for Simultaneous and Quantitative Detection of Bisphenol-A and Steroids in Target Tissues: A Power Tool to Characterize the Interference of Bisphenol-A Exposure on Steroid Levels

Bisphenol A (BPA), an endocrine disruptor, may affect in situ steroidogenesis and alter steroids levels. The present work proposes a liquid chromatography tandem mass spectrometry method to simultaneously quantify BPA, 17β-Estradiol and testosterone in two target tissues: testis and visceral fat mass. Analytes were isolated and lipophilic impurities removed by two serial steps: liquid-liquid and solid phase extraction. All compounds were separated in a single gradient run by Kinetex F5 column and detected via multiple reaction monitoring using a triple quadrupole with a TurboIon electrospray source in both negative and positive modes. The method is selective and very sensitive. In the investigated concentration range, the linearity of the detector response is verified in both tissues. The use of specific SPE cartridges for affinity chromatography purification allows obtaining high percentages of process efficiency (68.0-83.3% for testicular tissue; 63.7-70.7% for visceral fat mass). Good repeatability and reproducibility was observed. The validated method can be efficiently applied for direct biological monitoring in testis and visceral fat mass from mice exposed to BPA. The quantification of compounds in a single assay could be achieved without a loss of sensitivity.

Human placental 3β-hydroxysteroid dehydrogenase/steroid Δ5,4-isomerase 1: Identity, regulation and environmental inhibitors

Human placental 3β-hydroxysteroid dehydrogenase/steroid Δ5, 4-isomerase 1 (HSD3B1), a high-affinity type I enzyme, uses pregnenolone to make progesterone, which is critical for maintenance of pregnancy. HSD3B1 is located in the mitochondrion and the smooth endoplasmic reticulum of placental cells and is encoded by HSD3B1 gene. HSD3B1 contains GATA and TEF-5 regulatory elements. Many endocrine disruptors, including phthalates, methoxychlor and its metabolite, organotins, and gossypol directly inhibit placental HSD3B1 thus blocking progesterone production. In this review, we discuss the placental HSD3B1, its gene regulation, biochemistry, subcellular location, and inhibitors from the environment.

Association between gestational urinary bisphenol a concentrations and adiposity in young children: The MIREC study

BACKGROUND

Bisphenol A (BPA) is a high production volume chemical and because of its use in many consumer products, exposure is ubiquitous. Gestational BPA exposure has been associated with excess adiposity in rodent studies, but not consistently in human studies. We investigated the relation between gestational BPA exposure and early childhood adiposity in a prospective cohort study of 719 mother-child pairs.

METHODS

We used data from the MIREC Study, a prospective Pan-Canadian pregnancy and birth cohort study. We measured BPA in urine samples collected at an average of 12.1 weeks (range: 6.3-15 weeks) gestation and measured children's weight, height, waist/hip circumference, and subscapular/triceps skinfold thickness at an average age of 3.5 years (range: 1.9-6.2). We estimated covariate-adjusted associations of log2-transformed BPA concentrations with child adiposity measures and examined whether these associations differed in boys and girls.

RESULTS

Median BPA concentrations were 0.8 ng/mL (IQR: 0.5-1.4). Among both boys and girls, each 2-fold increase in BPA concentrations was associated with higher waist-to-hip ratio (β: 0.003; 95% CI: 0.001, 0.005). The association of BPA with waist circumference and subscapular skinfold thickness was modified by sex (sex x BPA interaction p-values<0.2). In girls, each 2-fold increase in BPA concentrations was associated with a 0.2 cm (95% CI: 0.0, 0.5) and 0.15 mm (95% CI: 0.01, 0.30) increase in waist circumference and subscapular skinfolds, respectively. Associations were generally null or slightly inverse in boys.

CONCLUSIONS

In this cohort, gestational urinary BPA concentrations were associated with subtle increases in girl's central adiposity during early childhood.

Endocrine disruptors of inhibiting testicular 3β-hydroxysteroid dehydrogenase

Testicular 3β-hydroxysteroid dehydrogenase (HSD3B) is a steroidogenic enzyme, catalyzing the conversion of 3β-hydroxysteroids into 3-keto-steroids. Two distinct isoforms in the human are cloned, HSD3B1 and HSD3B2, and HSD3B2 is located in the testis. HSD3B2 is a two-substrate enzyme, which binds to cofactor NAD⁺ and a 3β-steroid. Many endocrine disruptors, including industrial compounds (phthalates, bisphenols, and perfluoroalkyl substances), insecticides and biocides (organochlorine insecticides and organotins), food additives (butylated hydroxyanisole, resveratrol, gossypol, flavones, and isoflavones), and drugs (etomidate, troglitazone, medroxyprogesterone acetate, and ketoconazole) inhibit testicular HSD3B, possibly interfering with androgen synthesis. In this review, we discuss the distinct testicular isoform of HSD3B, its gene, chemistry, subcellular location, and the endocrine disruptors that directly inhibit testicular HSD3B and their inhibitory modes.

Low-Level Prenatal Toxin Exposures and Breastfeeding Duration: A Prospective Cohort Study

Introduction Maternal exposure to tobacco smoke is associated with shortened breastfeeding duration, but few studies have examined the effects on breastfeeding outcomes of low level exposures to other toxic chemicals. Moreover, it is unclear if passive smoking is associated with duration of breastfeeding. Our objective was therefore to examine the effect of low-level prenatal exposures to common environmental toxins (tobacco smoke, lead, and phthalates) on breastfeeding exclusivity and duration. Methods We conducted an analysis of data from the Health Outcomes and Measures of the Environment (HOME) Study. Serum and urine samples were collected at approximately 16 and 26 weeks gestation and at delivery from 373 women; 302 breastfed their infants. Maternal infant feeding interviews were conducted a maximum of eight times through 30 months postpartum. The main predictor variables for this study were gestational exposures to tobacco smoke (measured by serum cotinine), lead, and phthalates. Passive smoke exposure was defined as cotinine levels of 0.015-3.0 μg/mL. Primary outcomes were duration of any and exclusive breastfeeding. Results Serum cotinine concentrations were negatively associated with the duration of any breastfeeding (29.9 weeks unexposed vs. 24.9 weeks with passive exposure, p = 0.04; and 22.4 weeks with active exposure, p = 0.12; p = 0.03 for linear trend), but not duration of exclusive breastfeeding. Prenatal levels of blood lead and urinary phthalate metabolites were not significantly associated with duration of any or exclusive breastfeeding. Conclusions Passive exposure to tobacco smoke during pregnancy was associated with shortened duration of any breastfeeding.

A high-fat, high-protein diet attenuates the negative impact of casein-induced chronic inflammation on testicular steroidogenesis and sperm parameters in adult mice

The interaction between obesity and chronic inflammation has been studied. Diet-induced obesity or chronic inflammation could reduce the testicular functions of males. However, the mechanism underlying the reproductive effects of fattening foods in males with or without chronic inflammation still needs further discussion. This study was aimed to investigate the effects of high-fat, high-protein diet on testicular steroidogenesis and sperm parameters in adult mice under physiological and chronic inflammatory conditions. Because casein can trigger a non-infectious systemic inflammatory response, we used casein injection to induce chronic inflammation in male adult Kunming mice. Twenty-four mice were randomly and equally divided into four groups: (i) normal diet+saline (Control); (ii) normal diet+casein (ND+CS); (iii) high-fat, high-protein diet+saline (HFPD+SI); (iv) high-fat, high-protein diet+casein (HFPD+CS). After 8weeks, there was a significant increase in body weight for groups HFPD+SI and HFPD+CS and a decrease in group ND+CS compared with the control. The serum levels of tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10) and lipid profiles were increased markedly in groups ND+CS, HFPD+SI and HFPD+CS compared with the control. A remarkable reduction of serum adiponectin level occurred in group HFPD+CS compared with group ND+CS. Sperm parameters (sperm count, viability and abnormality) were also adversely affected in groups ND+CS and HFPD+SI. Groups ND+CS and HFPD+SI showed severe pathological changes in testicular tissues. Semiquantitative RT-PCR, Western blot and immunohistochemical staining also showed significant reductions in both testicular mRNA and protein levels of steroidogenic acute regulatory (StAR) and cytochrome P450scc (CYP11A1) in groups HFPD+SI and HFPD+CS compared with the control, whereas testicular mRNA and protein levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) in groups HFPD+SI and HFPD+CS significantly increased. The mRNA and protein levels of the StAR and 3β-HSD in group HFPD+CS were both higher than those of in group ND+CS. These results indicated that Kunming male mice with high-fat, high-protein diet and casein injection for 8weeks can be used to establish a diet-induced obesity and chronic systemic inflammation. The sperm parameters in groups ND+CS and HFPD+SI decreased accompanied by pathological changes of testicular tissue. This resultant effect of reduced serum testosterone levels was associated with the overproduction of TNF-α and IL-10 and down-regulation of StAR and CYP11A1. Under the same casein-induced chronic inflammation condition, the mice with high-fat, high-protein diet had better testicular steroidogenesis activity and sperm parameters compared with the mice in normal diet, indicating that the mice with casein-induced inflammatory injury consuming a high-fat, high-protein diet gained weight normally, reduced serum adiponectin level and increased testosterone production by an upregulation of 3β-HSD expression. High-fat, high-protein diet attenuated the negative impact of casein-induced chronic inflammation on testicular steroidogenesis and sperm parameters.

Obesity Pathogenesis: An Endocrine Society Scientific Statement

Obesity is among the most common and costly chronic disorders worldwide. Estimates suggest that in the United States obesity affects one-third of adults, accounts for up to one-third of total mortality, is concentrated among lower income groups, and increasingly affects children as well as adults. A lack of effective options for long-term weight reduction magnifies the enormity of this problem; individuals who successfully complete behavioral and dietary weight-loss programs eventually regain most of the lost weight. We included evidence from basic science, clinical, and epidemiological literature to assess current knowledge regarding mechanisms underlying excess body-fat accumulation, the biological defense of excess fat mass, and the tendency for lost weight to be regained. A major area of emphasis is the science of energy homeostasis, the biological process that maintains weight stability by actively matching energy intake to energy expenditure over time. Growing evidence suggests that obesity is a disorder of the energy homeostasis system, rather than simply arising from the passive accumulation of excess weight. We need to elucidate the mechanisms underlying this "upward setting" or "resetting" of the defended level of body-fat mass, whether inherited or acquired. The ongoing study of how genetic, developmental, and environmental forces affect the energy homeostasis system will help us better understand these mechanisms and are therefore a major focus of this statement. The scientific goal is to elucidate obesity pathogenesis so as to better inform treatment, public policy, advocacy, and awareness of obesity in ways that ultimately diminish its public health and economic consequences.

The Effects of Fungicides on Human 3β-Hydroxysteroid Dehydrogenase 1 and Aromatase in Human Placental Cell Line JEG-3

Placenta secretes a large amount of progesterone and estradiol, which are critical for maintaining pregnancy. In human placenta, 3β-hydroxysteroid dehydrogenase 1 (HSD3B1) catalyzes pregnenolone to form progesterone, and aromatase (CYP19A1) catalyzes testosterone into estradiol. Fungicides display antifungal activities and are widely used to prevent fungal infections in agricultural plants. These chemicals include azoles, such as tebuconazole (TEB), triadimefon (TRI), and vinclozolin (VCZ) or organotins, such as tributyltin (TBT) and tetrabutyltin (TTBT). Fungicides may disrupt the activities of these 2 enzymes. In the present study, we investigated the effects of these fungicides on steroid production in a human placental cell line JEG-3 and on HSD3B1 and CYP19A1 activities. Of all fungicides tested at 100 µmol/L, only TBT inhibited pregnenolone-mediated progesterone production in JEG-3 cells by over 50%. Except TTBT, all other 4 fungicides inhibited testosterone-mediated estradiol production by over 50%. TBT was a moderate HSD3B1 inhibitor with a half maximal inhibitory concentration (IC50) of 45.60 ± 0.12 µmol/L. When pregnenolone was used to determine the mode of inhibition, TBT was a competitive inhibitor of HSD3B1. The IC50 values of TEB, TRI, VCZ, and TBT for CYP19A1 were 56.84 ± 0.13, 58.73 ± 0.14, 57.42 ± 0.171, and 4.58 ± 0.048 µmol/L, respectively. TEB, TRI, and VCZ were noncompetitive inhibitors of CYP19A1, while TBT was a competitive inhibitor of this enzyme. Therefore, they are endocrine disruptors.

Early-life exposure to EDCs: role in childhood obesity and neurodevelopment

Endocrine-disrupting chemicals (EDCs) might increase the risk of childhood diseases by disrupting hormone-mediated processes that are critical for growth and development during gestation, infancy and childhood. The fetus, infant and child might have enhanced sensitivity to environmental stressors such as EDCs due to their rapid development and increased exposure to some EDCs as a consequence of development-specific behaviour, anatomy and physiology. In this Review, I discuss epidemiological studies examining the relationship between early-life exposure to bisphenol A (BPA), phthalates, triclosan and perfluoroalkyl substances (PFAS) with childhood neurobehavioural disorders and obesity. The available epidemiological evidence suggest that prenatal exposure to several of these ubiquitous EDCs is associated with adverse neurobehaviour (BPA and phthalates) and excess adiposity or increased risk of obesity and/or overweight (PFAS). Quantifying the effects of EDC mixtures, improving EDC exposure assessment, reducing bias from confounding, identifying periods of heightened vulnerability and elucidating the presence and nature of sexually dimorphic EDC effects would enable stronger inferences to be made from epidemiological studies than currently possible. Ultimately, improved estimates of the causal effects of EDC exposures on child health could help identify susceptible subpopulations and lead to public health interventions to reduce these exposures.

Prenatal Exposure to Perfluoroalkyl Substances and Adiposity in Early and Mid-Childhood

BACKGROUND

Few studies have examined whether prenatal exposure to perfluoroalkyl substances (PFASs) is associated with childhood adiposity.

OBJECTIVE

We examined associations of prenatal exposure to PFASs with adiposity in early and mid-childhood.

METHODS

We measured plasma PFAS concentrations in 1,645 pregnant women (median, 9.6 weeks gestation) enrolled in Project Viva, a prospective pre-birth cohort study in Massachusetts (USA), between 1999 and 2002. We assessed overall and central adiposity in 1,006 children in early childhood (median, 3.2 years) and 876 in mid-childhood (median, 7.7 years) using anthropometric and dual X-ray absorptiometry (DXA) measurements. We fitted multivariable linear regression models to estimate exposure-outcome associations and evaluated effect modification by child sex.

RESULTS

Median (25-75th percentiles) prenatal plasma perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), and perfluorononanoate (PFNA) concentrations in children assessed in early childhood were 5.6 (4.1-7.7), 24.8 (18.4-33.9), 2.4 (1.6-3.8), and 0.6 (0.5-0.9) ng/mL, respectively. Among girls, each interquartile range increment of prenatal PFOA concentrations was associated with 0.21 kg/m2 (95% CI: -0.05, 0.48) higher body mass index, 0.76 mm (95% CI: -0.17, 1.70) higher sum of subscapular and triceps skinfold thickness, and 0.17 kg/m2 (95% CI: -0.02, 0.36) higher DXA total fat mass index in mid-childhood. Similar associations were observed for PFOS, PFHxS, and PFNA. We observed null associations for boys and early-childhood adiposity measures.

CONCLUSIONS

In this cohort, prenatal exposure to PFASs was associated with small increases in adiposity measurements in mid-childhood, but only among girls. Citation: Mora AM, Oken E, Rifas-Shiman SL, Webster TF, Gillman MW, Calafat AM, Ye X, Sagiv SK. 2017. Prenatal exposure to perfluoroalkyl substances and adiposity in early and mid-childhood. Environ Health Perspect 125:467-473; http://dx.doi.org/10.1289/EHP246.

Environmental chemicals and preterm birth: Biological mechanisms and the state of the science

PURPOSE OF REVIEW

Preterm birth is a significant worldwide health problem of uncertain origins. The extant body of literature examining environmental contaminant exposures in relation to preterm birth is extensive but results remain ambiguous for most organic pollutants, metals and metalloids, and air pollutants. In the present review we examine recent epidemiologic studies investigating these associations, and identify recent advances and the state of the science. Additionally, we highlight biological mechanisms of action in the pathway between chemical exposures and preterm birth, including inflammation, oxidative stress, and endocrine disruption, that deserve more attention in this context.

RECENT FINDINGS

Important advances have been made in the study of the environment and preterm birth, particularly in regard to exposure assessment methods, exploration of effect modification by co-morbidities and exposures, and in identification of windows of vulnerability during gestation. There is strong evidence for an association between maternal exposure to some persistent pesticides, lead, and fine particulate matter, but data on other contaminants is sparse and only suggestive trends can be noted with the current data.

SUMMARY

Beyond replicating current findings, further work must be done to improve understanding of mechanisms underlying the associations observed between environmental chemical exposures and preterm birth. By examining windows of vulnerability, disaggregating preterm birth by phenotypes, and measuring biomarkers of mechanistic pathways in these epidemiologic studies we can improve our ability to detect associations with exposure, provide additional evidence for causality in an observational setting, and identify opportunities for intervention.

The Association of Prenatal Exposure to Perfluorinated Chemicals with Glucocorticoid and Androgenic Hormones in Cord Blood Samples: The Hokkaido Study

BACKGROUND

Perfluorinated chemicals (PFCs) disrupt cholesterol homeostasis. All steroid hormones are derived from cholesterol, and steroid hormones such as glucocorticoids and androgenic hormones mediate several vital physiologic functions. However, the in utero effects of PFCs exposure on the homeostasis of these steroid hormones are not well understood in humans.

OBJECTIVES

We examined the relationship between prenatal exposure to perfluorooctane sulfonate (PFOS)/perfluorooctanoate (PFOA) and cord blood levels of glucocorticoid and androgenic hormones.

METHODS

We conducted a hospital-based birth cohort study between July 2002 and October 2005 in Sapporo, Japan (n = 514). In total, 185 mother-infant pairs were included in the present study. Prenatal PFOS and PFOA levels in maternal serum samples were measured using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Cord blood levels of glucocorticoid (cortisol and cortisone) and androgenic hormones [dehydroepiandrosterone (DHEA) and androstenedione] were also measured in the same way.

RESULTS

We found a dose-response relationship of prenatal PFOS, but not PFOA, exposure with glucocorticoid levels after adjusting for potential confounders. Cortisol and cortisone concentrations were -23.98-ng/mL (95% CI: -0.47.12, -11.99; p for trend = 0.006) and -63.21-ng/mL (95% CI: -132.56, -26.72; p for trend < 0.001) lower, respectively, in infants with prenatal PFOS exposure in the fourth quartile compared with those in the first quartile. The highest quartile of prenatal PFOS exposure was positively associated with a 1.33-ng/mL higher DHEA level compared with the lowest quartile (95% CI: 0.17, 1.82; p for trend = 0.017), whereas PFOA showed a negative association with DHEA levels (quartile 4 vs. quartile 1: -1.23 ng/mL, 95% CI: -1.72, -0.25; p for trend = 0.004). We observed no significant association between PFCs and androstenedione levels.

CONCLUSIONS

Our results indicate that prenatal exposure to PFCs is significantly associated with glucocorticoid and DHEA levels in cord blood. Citation: Goudarzi H, Araki A, Itoh S, Sasaki S, Miyashita C, Mitsui T, Nakazawa H, Nonomura K, Kishi R. 2017. The association of prenatal exposure to perfluorinated chemicals with glucocorticoid and androgenic hormones in cord blood samples: the Hokkaido Study. Environ Health Perspect 125:111-118; http://dx.doi.org/10.1289/EHP142.

Leukemia inhibitory factor stimulates steroidogenesis of rat immature Leydig cells via increasing the expression of steroidogenic acute regulatory protein

Leukemia inhibitory factor (LIF) has many physiological roles. However, its effects on Leydig cell development are still unclear. Rat immature and adult Leydig cells were cultured with different concentrations of LIF alone or in combination with luteinizing hormone (LH) for 24 h. LIF (1 and 10 ng/ml) significantly increased androgen production in immature Leydig cells, but had no effects on testosterone production in adult Leydig cells. Further studies revealed that LIF dose-dependently increased Star and Hsd17b3 expression levels in immature Leydig cells. Gene microarray revealed that the upregulation of anti-oxidative genes and Star might contribute to LIF-induced androgen production. In conclusion, LIF has stimulatory effects on androgen production in rat immature Leydig cells.

High-Throughput Screening of Chemical Effects on Steroidogenesis Using H295R Human Adrenocortical Carcinoma Cells

Disruption of steroidogenesis by environmental chemicals can result in altered hormone levels causing adverse reproductive and developmental effects. A high-throughput assay using H295R human adrenocortical carcinoma cells was used to evaluate the effect of 2060 chemical samples on steroidogenesis via high-performance liquid chromatography followed by tandem mass spectrometry quantification of 10 steroid hormones, including progestagens, glucocorticoids, androgens, and estrogens. The study employed a 3 stage screening strategy. The first stage established the maximum tolerated concentration (MTC; ≥ 70% viability) per sample. The second stage quantified changes in hormone levels at the MTC whereas the third stage performed concentration-response (CR) on a subset of samples. At all stages, cells were prestimulated with 10 µM forskolin for 48 h to induce steroidogenesis followed by chemical treatment for 48 h. Of the 2060 chemical samples evaluated, 524 samples were selected for 6-point CR screening, based in part on significantly altering at least 4 hormones at the MTC. CR screening identified 232 chemical samples with concentration-dependent effects on 17β-estradiol and/or testosterone, with 411 chemical samples showing an effect on at least one hormone across the steroidogenesis pathway. Clustering of the concentration-dependent chemical-mediated steroid hormone effects grouped chemical samples into 5 distinct profiles generally representing putative mechanisms of action, including CYP17A1 and HSD3B inhibition. A distinct pattern was observed between imidazole and triazole fungicides suggesting potentially distinct mechanisms of action. From a chemical testing and prioritization perspective, this assay platform provides a robust model for high-throughput screening of chemicals for effects on steroidogenesis.

Differences in Bisphenol A and Estrogen Levels in the Plasma and Seminal Plasma of Men With Different Degrees of Infertility

The general population is potentially exposed to many chemicals that can affect the endocrine system. These substances are called endocrine disruptors (EDs), and among them bisphenol A (BPA) is one of the most widely used and well studied. Nonetheless, there are still no data on simultaneous measurements of various EDs along with steroids directly in the seminal fluid, where deleterious effects of EDs on spermatogenesis and steroidogenesis are assumed. We determined levels of BPA and 3 estrogens using LC-MS/MS in the plasma and seminal plasma of 174 men with different degrees of infertility. These men were divided according their spermiogram values into 4 groups: (1) healthy men, and (2) slightly, (3) moderate, and (4) severely infertile men. Estradiol levels differed across the groups and body fluids. Slightly infertile men have significantly higher BPA plasma and seminal plasma levels in comparison with healthy men (p<0.05 and p<0.01, respectively). Furthermore, seminal BPA, but not plasma BPA, was negatively associated with sperm concentration and total sperm count (–0.27; p<0.001 and –0.24; p<0.01, respectively). These findings point to the importance of seminal plasma in BPA research. Overall, a disruption of estrogen metabolism was observed together with a weak but significant impact of BPA on sperm count and concentration.

The association between maternal urinary phthalate concentrations and blood pressure in pregnancy: The HOME Study

BACKGROUND

Exposure to phthalates, a class of endocrine disrupting chemicals, is ubiquitous. We examined the association of urinary phthalate metabolite concentrations during pregnancy with maternal blood pressure and risk of pregnancy-induced hypertensive diseases.

METHODS

We used data from the Health Outcomes and Measures of the Environment Study, a prospective birth cohort of low-risk pregnant women recruited between March 2003 and January 2006. We analyzed maternal urine samples collected at 16 and 26 weeks gestation for 9 phthalate monoester metabolites reflecting exposure to 6 phthalate diesters. Outcomes included maternal blood pressure at <20 and ≥ 20 weeks gestation and pregnancy induced hypertensive diseases (gestational hypertension, preeclampsia, eclampsia, and HELLP syndrome).

RESULTS

Data were available for 369 women who gave birth to singleton, live-born infants without congenital anomalies. Of the phthalate metabolites evaluated, only mono-benzyl phthalate (MBzP) concentrations were significantly associated with maternal diastolic blood pressure at <20 weeks gestation. Women in the third MBzP tercile at 16 weeks gestation had diastolic blood pressure 2.2 (95% CI: 0.5-3.9) mm Hg higher at <20 weeks gestation and 2.8 (95% CI: 0.9-4.7) mm Hg higher at ≥ 20 weeks gestation compared to women in the first tercile. Compared to women in the first tercile, women in the top MBzP tercile at 16 weeks had an increased risk of developing pregnancy-induced hypertensive diseases (RR = 2.92, 95 % CI 1.15-7.41, p-value for trend = 0.01). MBzP concentrations at 26 weeks gestation were not as strongly associated with blood pressure at ≥ 20 weeks gestation or risk of pregnancy-induced hypertensive diseases.

CONCLUSION

This study suggests that maternal urinary MBzP concentrations may be associated with increased diastolic blood pressure and risk of pregnancy-induced hypertensive diseases.