Bisphenol A affects androgen receptor function via multiple mechanisms

Estrogenic and anti-estrogenic assessment of the flame retardant, 2-ethylhexyl diphenyl phosphate (EHDPP), and its metabolites: Evidence from in vitro, in silico, and transcriptome studies

2-Ethylhexyl diphenyl phosphate (EHDPP) is a replacement flame-retardant commonly found in several environmental matrices and human biospecimens. Although some adverse effects of EHDPP have been identified, the endocrine-disrupting effects of EHDPP and its key metabolites on the human estrogen receptor (ER) are largely unknown. Herein, we report for the first time that EHDPP, at concentrations found in the environment and humans, significantly promoted estrogenic activity and synergized with 17β-estradiol-induced ER transactivation. However, two major EHDPP metabolites 2-ethyl-3-hydroxyhexyl diphenyl phosphate (3-OH-EHDPP) and 2-ethyl-5-hydroxyhexyl diphenyl phosphate (5-OH-EHDPP), inhibited the ER through a non-competitive binding mechanism. Molecular docking showed that Pi-Pi stacking, hydrogen, and hydrophobic bonds primarily stabilize intermolecular interactions between EHDPP and the binding pockets of human ERα and ERβ. Moreover, transcriptome analysis confirmed the estrogenic effects of EHDPP, revealing notable enrichments in ER-mediated signaling and breast cancer pathways, consistent with the validated estrogenic gene expression profile. Intriguingly, EHDPP markedly promoted the clonogenic growth of two ER+ breast cancer cell lines, corroborating the expression levels of ERα protein. Our findings indicate that the common flame-retardant EHDPP activates the ER and downstream signaling, providing far-reaching implications for environmental and health risks associated with estrogen-related adversities such as the development of ER+ breast cancer.

The biological effects of bisphenol AF in reproduction and development: What do we know so far?

Due to the established endocrine-disrupting effects of Bisphenol A (BPA), alternative bisphenols entered the market. Bisphenol AF (BPAF) is now commonly used in the industrial manufacturing of polycarbonate plastics and epoxy resins. However, BPAF's effects on reproduction and development have not been thoroughly reviewed. We investigated the relationship between BPAF exposure and reproduction and early development. We performed a literature review of studies on BPAF and reproductive physiology. Using keywords, we searched PubMed, Medline, Cochrane Library Database, Embase, and ClinicalTrials.gov for English language literature available until December 2024; we additionally identified and included studies from bibliographies. We included 125 articles, spanning in vitro and in vivo model organism and human studies. BPAF is a selective estrogen receptor modulator and an androgen receptor antagonist and is more potent than BPA. It is detected in urine, blood products, saliva, amniotic fluid, and breast milk. In vitro and in vivo studies demonstrate a spectrum of BPAF-induced endocrine and reproductive changes in both sexes. There is strong evidence of alterations in the hypothalamic-pituitary-gonadal axis and of altered steroidogenesis pathways. Multiple studies using zebrafish, Xenopus, chickens, and rodents, show BPAF's effects on embryogenesis, morphology, and sexual differentiation. Decreased serum testosterone and impaired spermatogenesis and oocyte viability have been demonstrated. The current literature shows clear disruptive effects of BPAF on reproductive health and embryonic development. Though further investigation is warranted, there is ample converging evidence to support limiting the use of BPAF and other similar bisphenols.

Increased maternal urinary bisphenol F levels associated with reduced anogenital distance in male newborns

BACKGROUND

Bisphenol exposure during pregnancy has been linked to a range of adverse reproductive outcomes. However, the full extent of the effects of bisphenol analogs, particularly bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF), on fetal development, especially anogenital distance (AGD), a sensitive marker of reproductive development, remains unclear. We conducted this research to investigate association among maternal and neonatal urinary bisphenol analogs (BPA, BPS, BPF) and AGD.

METHODS

This prospective cohort study enrolled 85 mother-newborn pairs in Bangkok, Thailand, from April 2023 to January 2024. Maternal and neonatal urine samples were collected and analyzed for BPA, BPF, and BPS concentrations by liquid chromatography-tandem mass spectrometry. Neonatal AGD measurements were obtained within 72 h of birth. Correlation was analyzed by Pearson's correlation test and linear regression analysis.

RESULTS

High maternal urinary BPF concentrations were negatively associated with ano-penile distance, ano-scrotal distance, and penile length in male newborns (r -0.963, -0.844 and - 0.900, respectively, p < 0.05). No significant associations were found for BPA or BPS. Frequent maternal consumption of carton drinks was associated with higher neonatal BPS levels, while maternal obesity was positively correlated with maternal BPA concentration. No significant correlation was observed between maternal and neonatal bisphenol concentrations, nor between neonatal bisphenol levels and AGD.

CONCLUSIONS

This study is the first to report a negative association between maternal BPF exposure and AGD in male newborns. These findings highlight the potential endocrine-disrupting effects of BPF on fetal development and emphasize the need for further research.

Methanolic extract of wheatgrass (Triticum aestivum L.) prevents BPA-induced disruptions in the ovarian steroidogenic pathway and alleviates uterine inflammation in Wistar rats

The present study examined the anti-inflammatory and functional improvement of the uterus and ovary, respectively, in bisphenol-A (BPA)-fed adult Wistar rats following the ingestion of methanolic extract of wheatgrass (WG-ME). Four groups of rats were conditioned as vehicle-treated control, BPA-treated (100 mg/kg b.w.), BPA + WG-ME (100 mg BPA/kg b.w. + 200 mg WG-ME/kg b.w.), and WG-ME (200 mg/kg b.w.) groups. The LC-MS study confirmed the presence of numerous bioactive components in WG-ME. ELISA, PAGE, real-time PCR, and immunohistostaining were executed to test the efficacy of WG-ME against BPA. WG-ME was shown to induce significant weight gain of the uterus and ovaries as well as improve the estrous cycle and antioxidant status. WG-ME effectively suppressed the mRNA expression of TNF-α (tumor necrosis factor-alpha) and NF-κB (nuclear factor kappa-B). This extract also increased the expression of the antiapoptotic factor BCL2 (B-cell lymphoma 2) in the uterine tissue of rats administered BPA while impeding the abnormal expression of the tumor proteins p53, cylcin-D1, and BAX (BCL2-associated protein X). An enhanced steroidogenic event was supported by improved gonadotropins and reproductive hormone levels, feeble signaling of androgen receptors, and improved ovarian follicular growth with a distinct appearance of granulosa layer as well as better uterine histomorphology. The abundance of apigenin and catechin compounds in WG-ME may potentiate the above effects. The molecular interaction study predicted that apigenin inhibits TNF-α by interacting with its major site. Hence, WG-ME may exert its preventive efficacy in managing the functional imbalance of reproductive organs caused by BPA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-04117-0.

Prenatal Exposure to a Human Relevant Mixture of Endocrine-Disrupting Chemicals Affects Mandibular Development in Mice

Mandible is a bony structure of neuroectodermal origin with unique characteristics that support dentition and jaw movements. In the present study, we investigated the effects of gestational exposure to a mixture of endocrine-disrupting chemicals (EDCs) on mandibular growth in mice. The mixture under study (Mixture N1) has been associated with neurodevelopmental effects in both a human cohort and animal studies. Pregnant mice were exposed throughout gestation to 0.5× (times of pregnant women's exposure levels), 10×, 100× and 500× of Mixture N1, or the vehicle, and the mandibles of the male offspring were studied in adulthood. Micro-CT analysis showed non-monotonic effects of Mixture N1 in the distances between specific mandibular landmarks and in the crown width of M1 molar, as well as changes in the mandibular bone characteristics. The alveolar bone volume was reduced, and the trabecular separation was increased in the 500× exposed mice. Bone volume in the condyle head was increased in all treated groups. Τhe Safranin-O-stained area of mature hypertrophic chondrocytes and the width of their zones were reduced in 0.5×, 10× and 100× exposed groups. This is the first indication that prenatal exposure to an epidemiologically defined EDC mixture, associated with neurodevelopmental impacts, can also affect mandibular growth in mammals.

The mediating role of steroid hormones in the relationship between bisphenol A and its alternatives bisphenol S and F exposure and preeclampsia

Steroid hormone imbalance is believed to increase the odds of developing PE. Bisphenol A (BPA) and its substitutes (e.g., bisphenol S (BPS) and bisphenol F (BPF)) have estrogen-like effects, and its exposure may be related to the development of preeclampsia (PE). To explore the effects of bisphenol exposure on maternal serum steroid hormones and the potential mediating role of steroid hormones in the association between bisphenol exposure and developing PE, concentrations of bisphenols and steroid hormones in serum samples of 383 pregnant women were examined before delivery (including 160 PE cases and 223 control cases). Multivariable logistic and linear models were used to explore the associations of maternal serum bisphenols concentrations with both maternal steroid hormones and PE risk. Mediation modeling was employed to evaluate the mediating role of steroid hormones in the association between bisphenols and PE. Results showed that maternal serum BPS concentrations were positively associated with testosterone (T) concentrations. The mediation analyses suggested that approximately 10.17 % of the associations between BPS concentrations and the development of PE might be mediated by maternal T. In conclusion, maternal exposure to BPS during pregnancy is linked to higher maternal T concentrations, which might increase the odds of developing PE. T might mediate the association between BPS exposure and the development of PE.

Rsad2 mediates Bisphenol A-induced actin cytoskeletal disruption in mouse spermatocytes

Bisphenol A (BPA) is widely exposed in populations worldwide and has negative effects on spermatogenesis both in animals and humans. The homeostasis of the actin cytoskeleton in the spermatogenic epithelium is crucial for spermatogenesis. Actin cytoskeleton destruction in the seminiferous epithelium is one of the important reasons for BPA-induced spermatogenesis disorder. However, the underlying molecular mechanisms remain largely unexplored. Herein, we explored the role and mechanism of Rsad2, an interferon-stimulated gene in BPA-induced actin cytoskeleton disorder in mouse GC-2 spermatocyte cell lines. After BPA exposure, the actin cytoskeleton was dramatically disrupted and the cell morphology was markedly altered accompanied by a significant increase in Rsad2 expression both in mRNA and protein levels in GC-2 cells. Furthermore, the phalloidin intensities and cell morphology were restored obviously when interfering with the expression of Rsad2 in BPA-treated GC-2 cells. In addition, we observed a significant decrease in intracellular ATP levels after BPA treatment, while the ATP level was obviously upregulated when knocking down the expression of Rsad2 in BPA-treated cells compared to cells treated with BPA alone. Moreover, Rsad2 relocated to mitochondria after BPA exposure in GC-2 cells. BPA promoted Rsad2 expression by activating type I IFN-signaling in GC-2 cells. In summary, Rsad2 mediated BPA-induced actin cytoskeletal disruption in GC-2 cells, which provided data to reveal the mechanism of BPA-induced male reproductive toxicity.

High seminal BPA in IVF patients correlates with lower sperm count and up-regulated miR-21 and miR-130a

Bisphenol A (BPA) is a widespread industrial chemical, used as the key monomer of polycarbonate plastics and epoxy resins. BPA has been detected in human seminal fluid and has been correlated with changes in sperm parameters, crucial in determining male fertility. In this study, semen samples were collected from 100 patients aged 29-47 years undergoing fertility assessment between 2021 and 2023 and analyzed according to WHO guidelines. BPA levels in the seminal plasma were then measured through an enzyme-linked immunosorbent assay (ELISA) and compared to sperm quality metrics. The relative mRNA/miRNA expression of key genes associated to male reproduction, including androgen receptor, miR-34c, miR-21, miR-130a, was then quantified and compared between groups with high or low BPA content. Our results revealed that BPA levels were increased with age and were negatively correlated with sperm counts (p<0.05). The negative correlation remained significant when patients were age-matched. No other relationships between seminal BPA and motility, morphology or DNA fragmentation levels were observed. qPCR analysis showed that androgen receptor mRNA expression was significantly greater in sperm with high seminal BPA (p<0.05). Moreover, we found that the expression of miR-21 and miR-130a was also upregulated in the higher BPA group (p<0.05). These results display a relationship between BPA content in the semen and male fertility parameters, and provide insights into the molecular mechanisms through which BPA may be affecting male reproductive capability. Ultimately, this research can potentially drive changes to guidelines and exposure limits for BPA exposure.

The Dual Faces of Oestrogen: The Impact of Exogenous Oestrogen on the Physiological and Pathophysiological Functions of Tissues and Organs

Oestrogen plays a crucial physiological role in both women and men. It regulates reproductive functions and maintains various non-reproductive tissues through its receptors, such as oestrogen receptor 1/oestrogen receptor α (ESR1/Erα), oestrogen receptor 2/oestrogen receptor β (ESR2/Erβ), and G protein-coupled oestrogen receptor 1 (GPER). This hormone is essential for the proper functioning of women's ovaries and uterus. Oestrogen supports testicular function and spermatogenesis in men and contributes to bone density, cardiovascular health, and metabolic processes in both sexes. Nuclear receptors Er-α and Er-β belong to the group of transcription activators that stimulate cell proliferation. In the environment, compounds similar in structure to the oestrogens compete with endogenous hormones for binding sites to receptors and to disrupt homeostasis. The lack of balance in oestrogen levels can lead to infertility, cancer, immunological disorders, and other conditions. Exogenous endocrine-active compounds, such as bisphenol A (BPA), phthalates, and organic phosphoric acid esters, can disrupt signalling pathways responsible for cell division and apoptosis processes. The metabolism of oestrogen and its structurally similar compounds can produce carcinogenic substances. It can also stimulate the growth of cancer cells by regulating genes crucial for cell proliferation and cell cycle progression, with long-term elevated levels linked to hormone-dependent cancers such as breast cancer. Oestrogens can also affect markers of immunological activation and contribute to the development of autoimmune diseases. Hormone replacement therapy, oral contraception, in vitro fertilisation stimulation, and hormonal stimulation of transgender people can increase the risk of breast cancer. Cortisol, similar in structure to oestrogen, can serve as a biomarker associated with the risk of developing breast cancer. The aim of this review is to analyse the sources of oestrogens and their effects on the endogenous and exogenous process of homeostasis.

Developmental programming: An exploratory analysis of pancreatic islet compromise in female sheep resulting from gestational BPA exposure

Developmental exposure to endocrine disruptors like bisphenol A (BPA) are implicated in later-life metabolic dysfunction. Leveraging a unique sheep model of developmental programming, we conducted an exploratory analysis of the programming effects of BPA on the endocrine pancreas. Pregnant ewes were administered environmentally relevant doses of BPA during gestational days (GD) 30-90, and pancreata from female fetuses and adult offspring were analyzed. Prenatal BPA exposure induced a trend toward decreased islet insulin staining and β-cell count, increased glucagon staining and α-cell count, and increased α-cell/β-cell ratio. Findings were most consistent in fetal pancreata assessed at GD90 and in adult offspring exposed to the lowest BPA dose. While not assessed in fetuses, adult islet fibrosis was increased. Collectively, these data provide further evidence that early-life BPA exposure is a likely threat to human metabolic health. Future studies should corroborate these findings and decipher the molecular mechanisms of BPA's developmental endocrine toxicity.

Deciphering the mechanisms and interactions of the endocrine disruptor bisphenol A and its analogs with the androgen receptor

Bisphenol A (BPA) and its various forms used as BPA alternatives in industries are recognized toxic compounds and antiandrogenic endocrine disruptors. These chemicals are widespread in the environment and frequently detected in biological samples. Concerns exist about their impact on hormones, disrupting natural biological processes in humans, together with their negative impacts on the environment and biotic life. This study aims to characterize the interaction between BPA analogs and the androgen receptor (AR) and the effect on the receptor's normal activity. To achieve this goal, molecular docking was conducted with BPA and its analogs and dihydrotestosterone (DHT) as a reference ligand. Four BPA analogs exhibited higher affinity (-10.2 to -8.7 kcal/mol) for AR compared to BPA (-8.6 kcal/mol), displaying distinct interaction patterns. Interestingly, DHT (-11.0 kcal/mol) shared a binding pattern with BPA. ADMET analysis of the top 10 compounds, followed by molecular dynamics simulations, revealed toxicity and dynamic behavior. Experimental studies demonstrated that only BPA disrupts DHT-induced AR dimerization, thereby affecting AR's function due to its binding nature. This similarity to DHT was observed during computational analysis. These findings emphasize the importance of targeted strategies to mitigate BPA toxicity, offering crucial insights for interventions in human health and environmental well-being.

Effects and mechanisms of endocrine disruptor bisphenol AF on male reproductive health: A mini review

Bisphenol AF (BPAF), an analogue of bisphenol A (BPA), is commonly found in manufacturing industries and known for its endocrine-disrupting properties. Despite potential similarities in adverse effects with BPA, limited toxicological data exist specifically for BPAF and its impact on male reproductive physiology. This mini-review aims to elucidate the influence of BPAF on the male reproductive system, focusing on estrogenic effects, effects on the hypothalamus-pituitary-gonad (HPG) axis, steroidogenesis, spermatogenesis, and transgenerational reproductive toxicity. Additionally, we outline the current insights into the potential mechanisms underlying BPAF-induced male reproductive disorders. BPAF exposure, either directly or maternally, has been associated with detrimental effects on male reproductive functions, including damage to the blood-testis barrier (BTB) structure, disruptions in steroidogenesis, testis dysfunction, decreased anogenital distance (AGD), and defects in sperm and semen quality. Mechanistically, altered gene expression in the HPG axis, deficits in the steroidogenesis pathway, activation of the aromatase pathway, cascade effects induced by reactive oxygen species (ROS), activation of ERK signaling, and immunological responses collectively contribute to the adverse effects of BPAF on the male reproductive system. Given the high prevalence of male reproductive issues and infertility, along with the widespread environmental distribution of bisphenols, this study provides valuable insights into the negative effects of BPAF. The findings underscore the importance of considering the safe use of this compound, urging further exploration and regulatory attention to decrease potential risks associated with BPAF exposure.

Application of the Key Characteristics of Carcinogens to Bisphenol A

The ten key characteristics (KCs) of carcinogens are based on characteristics of known human carcinogens and encompass many types of endpoints. We propose that an objective review of the large amount of cancer mechanistic evidence for the chemical bisphenol A (BPA) can be achieved through use of these KCs. A search on metabolic and mechanistic data relevant to the carcinogenicity of BPA was conducted and web-based software tools were used to screen and organize the results. We applied the KCs to systematically identify, organize, and summarize mechanistic information for BPA, and to bring relevant carcinogenic mechanisms into focus. For some KCs with very large data sets, we utilized reviews focused on specific endpoints. Over 3000 studies for BPA from various data streams (exposed humans, animals, in vitro and cell-free systems) were identified. Mechanistic data relevant to each of the ten KCs were identified, with receptor-mediated effects, epigenetic alterations, oxidative stress, and cell proliferation being especially data rich. Reactive and bioactive metabolites are also associated with a number of KCs. This review demonstrates how the KCs can be applied to evaluate mechanistic data, especially for data-rich chemicals. While individual entities may have different approaches for the incorporation of mechanistic data in cancer hazard identification, the KCs provide a practical framework for conducting an objective examination of the available mechanistic data without a priori assumptions on mode of action. This analysis of the mechanistic data available for BPA suggests multiple and inter-connected mechanisms through which this chemical can act.

Vitamin D Deficiency Exacerbates Poor Sleep Outcomes with Endocrine-Disrupting Chemicals Exposure: A Large American Population Study

Phthalates and bisphenol A are recognized as the predominant endocrine-disrupting substances (EDCs) in the environment, but their impact on sleep health remains unclear. Vitamin D has often been reported to play a role in sleep health and may be affected by endocrine-disrupting compounds. The study utilized data from 5476 individuals in the NHANES project to investigate the correlation between combined exposure to environmental EDCs and sleep duration through modeling various exposures. Furthermore, it emphasizes the importance of vitamin D in the present scenario. Preliminary analyses suggested that vitamin D-deficient individuals generally slept shorter than individuals with normal vitamin D (p < 0.05). Exposure to Mono-ethyl phthalate (MEP), triclosan (TRS), and Mono-benzyl phthalate (MZP), either alone or in combination, was associated with reduced sleep duration and a greater risk of vitamin D deficiency. Individuals with low vitamin D levels exposed to TRS experienced shorter sleep duration than those with normal vitamin D levels (p < 0.05). TRS and MZP were identified as crucial factors in patient outcomes when evaluating mixed exposures (p < 0.05). The results provide new data supporting a link between exposure to EDCs and insufficient sleep length. Additionally, they imply that a vitamin D shortage may worsen the sleep problems induced by EDCs.

Deciphering the molecular mechanism of NLRP3 in BPA-mediated toxicity: Implications for targeted therapies

Bisphenol-A (BPA), a pervasive industrial chemical used in polymer synthesis, is found in numerous consumer products including food packaging, medical devices, and resins. Detectable in a majority of the global population, BPA exposure occurs via ingestion, inhalation, and dermal routes. Extensive research has demonstrated the adverse health effects of BPA, particularly its disruption of immune and endocrine systems, along with genotoxic potential. This review focuses on the complex relationship between BPA exposure and the NOD-like receptor protein 3 (NLRP3) inflammasome, a multiprotein complex central to inflammatory disease processes. We examine how BPA induces oxidative stress through the generation of intracellular free radicals, subsequently activating NLRP3 signaling. The mechanistic details of this process are explored, including the involvement of signaling cascades such as PI3K/AKT, JAK/STAT, AMPK/mTOR, and ERK/MAPK, which are implicated in NLRP3 inflammasome activation. A key focus of this review is the wide-ranging organ toxicities associated with BPA exposure, including hepatic, renal, gastrointestinal, and cardiovascular dysfunction. We investigate the immunopathogenesis and molecular pathways driving these injuries, highlighting the interplay among BPA, oxidative stress, and the NLRP3 inflammasome. Finally, this review explores the emerging concept of targeting NLRP3 as a potential therapeutic strategy to mitigate the organ toxicities stemming from BPA exposure. This work integrates current knowledge, emphasizes complex molecular mechanisms, and promotes further research into NLRP3-targeted interventions.

Gene Target Prediction of Environmental Chemicals Using Coupled Matrix-Matrix Completion

Human exposure to toxic chemicals presents a huge health burden. Key to understanding chemical toxicity is knowledge of the molecular target(s) of the chemicals. Because a comprehensive safety assessment for all chemicals is infeasible due to limited resources, a robust computational method for discovering targets of environmental exposures is a promising direction for public health research. In this study, we implemented a novel matrix completion algorithm named coupled matrix-matrix completion (CMMC) for predicting direct and indirect exposome-target interactions, which exploits the vast amount of accumulated data regarding chemical exposures and their molecular targets. Our approach achieved an AUC of 0.89 on a benchmark data set generated using data from the Comparative Toxicogenomics Database. Our case studies with bisphenol A and its analogues, PFAS, dioxins, PCBs, and VOCs show that CMMC can be used to accurately predict molecular targets of novel chemicals without any prior bioactivity knowledge. Our results demonstrate the feasibility and promise of computationally predicting environmental chemical-target interactions to efficiently prioritize chemicals in hazard identification and risk assessment.

Screening of the Antagonistic Activity of Potential Bisphenol A Alternatives toward the Androgen Receptor Using Machine Learning and Molecular Dynamics Simulation

Over the past few decades, extensive research has indicated that exposure to bisphenol A (BPA) increases the health risks in humans. Toxicological studies have demonstrated that BPA can bind to the androgen receptor (AR), resulting in endocrine-disrupting effects. In recent investigations, many alternatives to BPA have been detected in various environmental media as major pollutants. However, related experimental evaluations of BPA alternatives have not been systematically implemented for the assessment of chemical safety and the effects of structural characteristics on the antagonistic activity of the AR. To promote the green development of BPA alternatives, high-throughput toxicological screening is fundamental for prioritizing chemical tests. Therefore, we proposed a hybrid deep learning architecture that combines molecular descriptors and molecular graphs to predict AR antagonistic activity. Compared to previous models, this hybrid architecture can extract substantial chemical information from various molecular representations to improve the model's generalization ability for BPA alternatives. Our predictions suggest that lignin-derivable bisguaiacols, as alternatives to BPA, are likely to be nonantagonist for AR compared to bisphenol analogues. Additionally, molecular dynamics (MD) simulations identified the dihydrotestosterone-bound pocket, rather than the surface, as the major binding site of bisphenol analogues. The conformational changes of key helix H12 from an agonistic to an antagonistic conformation can be evaluated qualitatively by accelerated MD simulations to explain the underlying mechanism. Overall, our computational study is helpful for toxicological screening of BPA alternatives and the design of environmentally friendly BPA alternatives.

Machine learning identifies phenotypic profile alterations of human dopaminergic neurons exposed to bisphenols and perfluoroalkyls

Parkinson's disease (PD) is the second most common neurodegenerative disease and is characterized by the loss of midbrain dopaminergic neurons. Endocrine disrupting chemicals (EDCs) are active substances that interfere with hormonal signaling. Among EDCs, bisphenols (BPs) and perfluoroalkyls (PFs) are chemicals leached from plastics and other household products, and humans are unavoidably exposed to these xenobiotics. Data from animal studies suggest that EDCs exposure may play a role in PD, but data about the effect of BPs and PFs on human models of the nervous system are lacking. Previous studies demonstrated that machine learning (ML) applied to microscopy data can classify different cell phenotypes based on image features. In this study, the effect of BPs and PFs at different concentrations within the real-life exposure range (0.01, 0.1, 1, and 2 µM) on the phenotypic profile of human stem cell-derived midbrain dopaminergic neurons (mDANs) was analyzed. Cells exposed for 72 h to the xenobiotics were stained with neuronal markers and evaluated using high content microscopy yielding 126 different phenotypic features. Three different ML models (LDA, XGBoost and LightGBM) were trained to classify EDC-treated versus control mDANs. EDC treated mDANs were identified with high accuracies (0.88-0.96). Assessment of the phenotypic feature contribution to the classification showed that EDCs induced a significant increase of alpha-synuclein (αSyn) and tyrosine hydroxylase (TH) staining intensity within the neurons. Moreover, microtubule-associated protein 2 (MAP2) neurite length and branching were significantly diminished in treated neurons. Our study shows that human mDANs are adversely impacted by exposure to EDCs, causing their phenotype to shift and exhibit more characteristics of PD. Importantly, ML-supported high-content imaging can identify concrete but subtle subcellular phenotypic changes that can be easily overlooked by visual inspection alone and that define EDCs effects in mDANs, thus enabling further pathological characterization in the future.

Distinct inhibitory strength of bisphenol A analogues on human and rat 11β-hydroxysteroid dehydrogenase 1: 3D quantitative structure-activity relationship and in silico molecular docking analysis

Bisphenol A (BPA) analogues are developed to replace BPA usage. However, their effects on 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) are largely unknown. The inhibitory effects of BPA and 10 BPA analogues with the substituents on the bridge moiety on human and rat 11β-HSD1 were explored in human and rat liver microsomes. The strength of inhibiting human 11β-HSD1 was bisphenol FL (IC50, 3.87 μM) > bisphenol Z (6.86 μM) > bisphenol AF (9.42 μM) > bisphenol C (16.14 μM) > bisphenol AP (32.14 μM) = bisphenol B (32.34 μM) > 4,4'-thiodiphenol (67.35 μM) > BPA (297.35 μM) > other BPA analogues (ineffective at 100 μM). The strength of inhibiting rat 11β-HSD1 was bisphenol Z (IC50, 14.44 μM) > 4,4'-thiodiphenol (19.01 μM) > bisphenol B (20.13 μM) > bisphenol F (22.10 μM) > bisphenol E (33.04 μM) > bisphenol AF (49.67 μM) > bisphenol C > (56.97 μM) > bisphenol AP (62.71 μM) >bisphenol FL (96.31 μM) > other BPA analogues (ineffective at 100 μM). Bisphenol A, AF, AP, B, C, F, FL, Z, and 4,4'-thiodiphenol bind to the active sites of human and rat 11β-HSD1. Regression of LogP and molecular weight with IC50 values revealed distinct inhibitory pattern (negative correlation for human 11β-HSD1 vs. positive correlation for rat enzyme). Regression of the lowest binding energy with IC50 values revealed a significant positive regression. 3D QSAR pharmacophore analysis showed one hydrogen bond acceptor and two hydrogen bond donors for human 11β-HSD1. In conclusion, most BPA analogues are more potent inhibitors of human and rat 11β-HSD1 enzymes and there is structure-dependent and species-dependent inhibition.

Alterations induced by Bisphenol A on cellular organelles and potential relevance on human health

Bisphenol A (BPA) is a chemical partially soluble in water and exists in a solid state. Its structural similarity with estrogen makes it an endocrine-disrupting chemical. BPA can disrupt signaling pathways at very low doses and may cause organellar stress. According to in vitro and in vivo studies, BPA interacts with various cell surface receptors to cause organellar stress, producing free radicals, cellular toxicity, structural changes, DNA damage, mitochondrial dysfunction, cytoskeleton remodeling, centriole duplication, and aberrant changes in several cell signaling pathways. The current review summarizes the impact of BPA exposure on the structural and functional aspects of subcellular components of cells such as the nucleus, mitochondria, endoplasmic reticulum, lysosome, ribosome, Golgi apparatus, and microtubules and its consequent impact on human health.

Control of social status by sex steroids: insights from teleost fishes

Many animals live in highly social environments, in which individuals must behave in a way that enables them to survive and live harmoniously among conspecifics. Dominance hierarchies are typical among social species and are essential for determining and preserving stability within social groups. Although there is considerable evidence that sex steroid hormones regulate behaviors associated with dominance, such as aggression and mating, fewer studies have examined the role of these hormones in controlling social status, especially in species that exhibit social hierarchies. Furthermore, despite this research, we know remarkably little about the precise neural and molecular mechanisms through which sex steroids modulate traits associated with social rank. Here, we review the neuroendocrine regulation of social status by sex steroids in teleost fishes, the largest and most diverse vertebrate group that shows extensive variation in reproductive systems and social structures between species. First, we describe the function of sex steroids and novel steroid-related genes that teleost fishes possess due to a lineage-specific whole-genome duplication event. Then, we discuss correlational, pharmacological, and molecular genetic studies on the control of social status by sex steroids in teleost fishes, including recent studies that have implemented gene editing technologies, such as CRISPR/Cas9. Finally, we argue that gene editing approaches in teleost studies, within both integrative and comparative frameworks, will be vital for elucidating the role of sex steroids in controlling social rank and characterizing their neural and molecular mechanisms of action. Collectively, ongoing and future research in these species will provide novel insight into the evolution of the regulation of social status by sex steroids and other neuroendocrine substrates across vertebrates.

New environmental factors related to diabetes risk in humans: Emerging bisphenols used in synthesis of plastics

BACKGROUND

Diabetes mellitus (DM) is one of the largest global health emergencies of the 21st century. In recent years, its connection with environmental pollutants, such as bisphenol A (BPA), has been demonstrated; consequently, new structurally similar molecules are used to replace BPA in the plastics industry (BPS, BPF and BPAF).

AIM

To carry out a systematic review to allow coherent evaluation of the state of the art. Subsequently, a meta-analysis was performed to unify the existing quantitative data.

METHODS

Firstly, a systematic review was carried out, using the terms "(bisphenol) AND (Diabetes OR Hyperglycemia)", to maximize the number of results. Subsequently, three authors analyzed the set of articles. Finally, a meta-analysis was performed for each BP, using RevMan software. In addition, funnel plots were developed to study publication bias.

RESULTS

The systematic analysis of the literature revealed 13 recent articles (2017-2023) related to the study paradigm. The qualitative analysis showed interesting data linking diabetes to the three most widely used substitute BPs in the industry: BPS, BPF and BPAF. Finally, the meta-analysis determined a positive relationship with BPS, BPF and BPAF, which was only statistically significant with BPS.

CONCLUSION

There is a need to apply the precautionary principle, regulating the use of new BPs. Therefore, replacing BPA with BPS, BPF or BPAF is unlikely to protect the population from potential health risks, such as DM.

Neonatal exposure to bisphenol analogues disrupts genital development in male mice

The public concern and governmental regulations on bisphenol A (BPA) have stimulated the development and production of alternative analogues to replace BPA in a myriad of applications. Given the endocrine disrupting activities of BPA and potentially other analogues, the present study investigated and compared the effects of neonatal exposure to BPA, BPB, BPE, BPF, and BPS on the genital development in male mice. Pups were injected subcutaneously on the right shoulder in the mornings of postnatal days P0.5, P2, P4, and P6, resulting in a low dose of 0.05 μg/g body weight (bw)/day and a high dose of 10 μg/g bw/day. Mice were sacrificed at predetermined time and evaluated for gene expression levels (3 days after birth or P3), steroid hormone levels (P5), and morphological changes (P21). The results demonstrated that BPA, BPB, BPE, or BPF significantly shortened glans penis length and anogenital distance, while BPS didn't. Testis weight and anogenital distance were also significantly affected by BPA, BPE or BPF. The results also revealed that bisphenol analogues exposure significantly reduced testosterone levels, and altered the expression levels of developmental genes networks in developing penis of mice. Our data demonstrate that selected bisphenol analogues may possess similar endocrine disrupting effects compared to BPA, and exposure to these analogues could affect reproductive development of male mice. This raises the concern on the environmental and health safety of bisphenol analogues applied as industrial BPA replacements.

Endocrine disrupting compounds in the baby's world - A harmful environment to the health of babies

Globally, there has been a significant increase in awareness of the adverse effects of chemicals with known or suspected endocrine-acting properties on human health. Human exposure to endocrine disrupting compounds (EDCs) mainly occurs by ingestion and to some extent by inhalation and dermal uptake. Although it is difficult to assess the full impact of human exposure to EDCs, it is well known that timing of exposure is of importance and therefore infants are more vulnerable to EDCs and are at greater risk compared to adults. In this regard, infant safety and assessment of associations between prenatal exposure to EDCs and growth during infancy and childhood has been received considerable attention in the last years. Hence, the purpose of this review is to provide a current update on the evidence from biomonitoring studies on the exposure of infants to EDCs and a comprehensive view of the uptake, the mechanisms of action and biotransformation in baby/human body. Analytical methods used and concentration levels of EDCs in different biological matrices (e.g., placenta, cord plasma, amniotic fluid, breast milk, urine, and blood of pregnant women) are also discussed. Finally, key issues and recommendations were provided to avoid hazardous exposure to these chemicals, taking into account family and lifestyle factors related to this exposure.

Origin, dietary exposure, and toxicity of endocrine-disrupting food chemical contaminants: A comprehensive review

Endocrine-disrupting chemicals (EDCs) are a growing public health concern worldwide. Consumption of foodstuffs is currently thought to be one of the principal exposure routes to EDCs. However, alternative ways of human exposure are through inhalation of chemicals and dermal contact. These compounds in food products such as canned food, bottled water, dairy products, fish, meat, egg, and vegetables are a ubiquitous concern to the general population. Therefore, understanding EDCs' properties, such as origin, exposure, toxicological impact, and legal aspects are vital to control their release to the environment and food. The present paper provides an overview of the EDCs and their possible disrupting impact on the endocrine system and other organs.

Estrogenic and non-estrogenic effects of bisphenol A and its action mechanism in the zebrafish model: An overview of the past two decades of work

Bisphenol A (BPA) is the most simple and predominant component of the Bisphenol family. BPA is widely present in the environment and the human body as a result of its extensive usage in the plastic and epoxy resins of consumer goods like water bottles, food containers, and tableware. Since the 1930s, when BPA's estrogenic activity was first observed, and it was labeled as a "mimic hormone of E2", studies on the endocrine-disrupting effects of BPA then have been widely conducted. As a top vertebrate model for genetic and developmental studies, the zebrafish has caught tremendous attention in the past two decades. By using the zebrafish, the negative effects of BPA either through estrogenic signaling pathways or non-estrogenic signaling pathways were largely found. In this review, we tried to draw a full picture of the current state of knowledge on the estrogenic and non-estrogenic effects of BPA with their mechanisms of action through the zebrafish model of the past two decades, which may help to fully understand the endocrine-disrupting effects of BPA and its action mechanism, and give a direction for the future studies.

Bisphenol A modulates proliferation, apoptosis, and wound healing process of normal prostate cells: Involvement of G2/M-phase cell cycle arrest, MAPK signaling, and transcription factor-mediated MMP regulation

Bisphenol A (BPA) is commonly used to produce epoxy resins and polycarbonate plastics. BPA is an endocrine-disrupting chemical that is leaked from the polymer and absorbed into the body to disrupt the endocrine system. Although BPA may cause cytotoxicity in the prostate, a hormone-dependent reproductive organ, its underlying mechanism has not yet been elucidated. Here, we investigated the effects of BPA on cell proliferation, apoptosis, and the wound healing process using prostate epithelial cells (RWPE-1) and stromal cells (WPMY-1). Observations revealed that BPA induced G2/M cell cycle arrest in both cell types through the ATM-CHK1/CHK2-CDC25c-CDC2 signaling pathway, and the IC₅₀ values were estimated to be 150 μM. Furthermore, BPA was found to induce caspase-dependent apoptosis through initiator (caspase-8 and -9) and executioner (caspase-3 and -7) caspase cascades. In addition, BPA interfered with the wound healing process through inhibition of MMP-2 and - 9 expression, accompanied by reductions in the binding activities of AP-1 as well as NF-κB motifs. Phosphorylation of MAPKs was associated with the BPA-mediated toxicity of prostate cells. These results suggest that BPA exhibits prostate toxicity by inhibiting cell proliferation, inducing apoptosis, and interfering with the wound healing process. Our study provided new insights into the precise molecular mechanisms of BPA-induced toxicity in human prostate cells.

Impact of a bisphenol A, F, and S mixture and maternal care on the brain transcriptome of rat dams and pups

Products containing BPA structural analog replacements have increased in response to growing public concern over adverse effects of BPA. Although humans are regularly exposed to a mixture of bisphenols, few studies have examined effects of prenatal exposure to BPA alternatives or bisphenol mixtures. In the present study, we investigate the effect of exposure to an environmentally-relevant, low-dose (150 ug/kg body weight per day) mixture of BPA, BPS, and BPF during gestation on the brain transcriptome in Long-Evans pups and dams using Tag RNA-sequencing. We also examined the association between dam licking and grooming, which also has enduring effects on pup neural development, and the transcriptomes. Associations between licking and grooming and the transcriptome were region-specific, with the hypothalamus having the greatest number of differentially expressed genes associated with licking and grooming in both dams and pups. Prenatal bisphenol exposure also had region-specific effects on gene expression and pup gene expression was affected more robustly than dam gene expression. In dams, the prelimbic cortex had the greatest number of differentially expressed genes associated with prenatal bisphenol exposure. Prenatal bisphenol exposure changed the expression of over 2000 genes in pups, with the majority being from the pup amygdala. We used Gene Set Enrichment Analysis (GSEA) to asses enrichment of gene ontology biological processes for each region. Top GSEA terms were diverse and varied by brain region and included processes known to have strong associations with steroid hormone regulation, cilium-related terms, metabolic/biosynthetic process terms, and immune terms. Finally, hypothesis-driven analysis of genes related to estrogen response, parental behavior, and epigenetic regulation of gene expression revealed region-specific expression associated with licking and grooming and bisphenol exposure that were distinct in dams and pups. These data highlight the effects of bisphenols on multiple physiological process that are highly dependent on timing of exposure (prenatal vs. adulthood) and brain region, and reiterate the contributions of multiple environmental and experiential factors in shaping the brain.

Relationship between emergent BPA-substitutes and renal and cardiovascular diseases in adult population

Plastic waste pollution is one of the leading environmental problems of modern society. Its use, disposal, and recycling lead to the release of xenobiotic compounds such as bisphenol A (BPA), a known endocrine disruptor related to numerous pathologies. Due to the new restrictions on its use, it is gradually being replaced by derived molecules, such as bisphenol F or S (BPF or BPS), whose health risks have not yet been adequately studied. In the present work, significant relationships between the new BPA substitute molecules and renal and cardiovascular diseases have been detected by performing binomial and multinomial logistic regressions in one of the world's largest cohorts of urinary phenols. The results have shown a significant relationship between urinary BPF and renal function or heart disease (specifically congestive heart failure). Urinary BPS has shown a positive relationship with the risk of hypertension and a negative relationship with kidney disease. Consequently, applying new substitute molecules could imply potential health risks equivalent to BPA.

Sex-specific Effects of Endocrine-disrupting Chemicals on Brain Monoamines and Cognitive Behavior

The period of brain sexual differentiation is characterized by the development of hormone-sensitive neural circuits that govern the subsequent presentation of sexually dimorphic behavior in adulthood. Perturbations of hormones by endocrine-disrupting chemicals (EDCs) during this developmental period interfere with an organism's endocrine function and can disrupt the normative organization of male- or female-typical neural circuitry. This is well characterized for reproductive and social behaviors and their underlying circuitry in the hypothalamus and other limbic regions of the brain; however, cognitive behaviors are also sexually dimorphic, with their underlying neural circuitry potentially vulnerable to EDC exposure during critical periods of brain development. This review provides recent evidence for sex-specific changes to the brain's monoaminergic systems (dopamine, serotonin, norepinephrine) after developmental EDC exposure and relates these outcomes to sex differences in cognition such as affective, attentional, and learning/memory behaviors.

Using in vitro bioassays to guide the development of safer bio-based polymers for use in food packaging

Petroleum-based polymers traditionally used for plastic packaging production have been shown to leach dangerous chemicals such as bisphenol-A (BPA). Bio-based polymers are potentially safer alternatives, and many can be sustainably sourced from waste streams in the food industry. This study assesses bio-based polymers undergoing food packaging development for migration of endocrine disrupting leachates at the level of estrogen, androgen and progestagen nuclear receptor transcriptional activity. Reporter gene assays were coupled with migration testing, performed using standardised test conditions for storage and temperature. Test samples include nine bio-based polymers and four inorganic waste additives mixed with a traditional petroleum-based polymer, polypropylene. Thermoplastic starch material, polybutylene succinate, polycaprolactone, polybutylene adipate terephthalate (PBAT), two polylactic acid (PLA)/PBAT blends, polyhydroxybutyrate (PHB) and eggshell/polypropylene (10:90) presented no significant reduction in metabolic activity or hormonal activity under any test condition. Polypropylene (PP) presented no hormonal activity. Metabolic activity was reduced in the estrogen responsive cell line after 10 days migration testing of eggshell/polypropylene (0.1:99.9) in MeOH at 40°C, and PP in MeOH and dH20. Estrogenic agonist activity was observed after 10 days in poultry litter ash/polypropylene (10:90) in MeOH at 20°C and 40°C, poultry feather based polymer in MeOH and dH2O at 40°C, and eggshell/polypropylene (40:60) and PLA in dH2O at 40°C. Activity was within a range of 0.26-0.50 ng 17β-estradiol equivalents per ml, equating to an estrogenic potency of 3-∼2800 times less than the estrogenic leachate BPA. Poultry litter ash/polypropylene (10:90) in MeOH for 10 days presented estrogenic activity at 20°C and 40°C within the above range and anti-androgenic activity at 40°C. Progestagenic activity was not observed for any of the compounds under any test condition. Interestingly, lower concentrations of eggshell or PP may eliminate eggshell estrogenicity and PP toxicity. Alternatively eggshell may bind and eliminate the toxic elements of PP. Similarly, PLA estrogenic activity was removed in both PLA/PBAT blends. This study demonstrates the benefits of bioassay guidance in the development of safer and sustainable packaging alternatives to petroleum-based plastics. Manipulating the types of additives and their formulations alongside toxicological testing may further improve safety aspects.

Effects of low-dose bisphenol AF on mammal testis development via complex mechanisms: alterations are detectable in both infancy and adulthood

Despite growing concern about adverse effects of bisphenol AF (BPAF) due to its endocrine disrupting properties, there is a lack of toxicity data from low-dose studies and direct evidence linking its adverse effects to endocrine disrupting properties. Here, we investigated the effects of gestational and postnatal exposure to BPAF through drinking water (0.15-15 μg/mL, equivalent to the daily intake of ~ 50 and 5 mg/kg/day) on testis development in mice. We found that like mestranol, 5 mg/kg/day BPAF resulted in remarkable decreases in multiple male reproductive parameters in adulthood, such as the sperm number and serum testosterone level. Notably, 50 μg/kg/day BPAF also caused significant decreases in anogenital distance (AGD), the luteinizing hormone level and spermatocyte number, along with declining trends in sperm number and the serum levels of testosterone and follicle-stimulating hormone. In line with the adverse outcomes observed in adulthood, on postnatal day (PND) 9, we also observed BPAF-caused dose-dependent alterations, including reduced AGD, seminiferous tubule area and numbers of total germ cells, spermatocytes and Leydig cells, coupled with down-regulated expression of male-biased genes in testes. Even when exposure to 5 mg/kg/day BPAF as well as MES was initiated from PND 0, similar alterations in male reproductive parameters were also found on PND 9, along with a decrease in the GnRH content in the hypothalamus; moreover, testicular alterations and the reduction in AGD were partly antagonized by the estrogen receptor (ER) antagonist ICI 182,780, but the reduction of GnRH production was not done, showing that the effects of BPAF on testis development may be partially mediated by ER signaling. In conclusion, all the findings demonstrate that low-dose BPAF can partly disrupt mammal testis development and cause adverse testicular outcomes in adulthood, indicating a potential reproductive risk to mammals including humans. Importantly, our finding that developmental alterations elicited by BPAF have been detectable on PND 9 provides important motivation for the development of effective methods for early detection of adverse effects of estrogenic chemicals on testis development.

Natural Products in Mitigation of Bisphenol A Toxicity: Future Therapeutic Use

Bisphenol A (BPA) is a ubiquitous environmental toxin with deleterious endocrine-disrupting effects. It is widely used in producing epoxy resins, polycarbonate plastics, and polyvinyl chloride plastics. Human beings are regularly exposed to BPA through inhalation, ingestion, and topical absorption routes. The prevalence of BPA exposure has considerably increased over the past decades. Previous research studies have found a plethora of evidence of BPA’s harmful effects. Interestingly, even at a lower concentration, this industrial product was found to be harmful at cellular and tissue levels, affecting various body functions. A noble and possible treatment could be made plausible by using natural products (NPs). In this review, we highlight existing experimental evidence of NPs against BPA exposure-induced adverse effects, which involve the body’s reproductive, neurological, hepatic, renal, cardiovascular, and endocrine systems. The review also focuses on the targeted signaling pathways of NPs involved in BPA-induced toxicity. Although potential molecular mechanisms underlying BPA-induced toxicity have been investigated, there is currently no specific targeted treatment for BPA-induced toxicity. Hence, natural products could be considered for future therapeutic use against adverse and harmful effects of BPA exposure.

Role of Nrf2 in bisphenol effects: a review study

Bisphenols (BPs), the main endocrine-disrupting chemicals used in polycarbonate plastics, epoxy-phenol resins, and some other manufacturers, have been interestingly focused to find their toxic effects in recent years. Due to the strong relation between bisphenols and some crucial receptors such as ERs, AR, glucocorticoid receptor, THRs, ERRs, hPXR, AhR, and etcetera, the disrupting and oncogenic role of these chemicals on reproductive, respiratory, and circulatory systems and a broad group of body tissues have been investigated. BPs induce oxidant enzymes, exert antioxidant enzymes from body cells, and result in the expression of proinflammatory genes, leading to cell apoptosis and inflammation. To maintain the homeostasis of human body cells, Nrf2, the key regulator of oxidative stress (Ashrafizadeh et al., 2020a; Ashrafizadeh et al., 2020c; Boroumand et al., 2018), confronts BP-induced ROS and RNS through the activation of antioxidant enzymes such as SOD1/2, CAT, GSH, GPX, HO-1, and etcetera. Chemicals and drugs such as LUT, NAC, GEN, L-NMMA, Ph2Se2, and GE can regulate the interactions between BPs and Nrf2. Despite the vital role of controlled levels of Nrf2 as an anti-inflammatory and antiapoptotic element, the uncontrolled activity of this transcription factor could lead to cell proliferation and tumorigenesis through NQO1, SLC7a11, Gclm, HMOX1, NQO1 gene activation, and some other genes. To avoid the excessive activity of Nrf2, some protein complexes like CUL3-RBX1-Keap1 (as the primary regulator), β-TrCP, and WDR23 regulate Nrf2's function. It is necessary to note that BPA, as the most famous member, is further reviewed due to its resemblance to the bisphenol family to each other.

A systematic review on the effects of acrylamide and bisphenol A on the development of Drosophila melanogaster

The current global scenario has instigated a steady upsurge of synthetic chemicals usage thereby creating a toxic environment unsuitable for animals and humans. Acrylamide and bisphenol A are some of the most common toxins found in the atmosphere due to their extensive involvement in numerous industrial processes. Acrylamide, an occupational hazard toxin has been known to cause severe nerve damage and peripheral neuronal damage in both animals and humans. General sources of acrylamide exposure are effluents from textile and paper industries, cosmetics, and thermally processed foods rich in starch. Bisphenol A (BPA) is generally found in food packaging materials, dental sealants, and plastic bottles. It is highly temperature-sensitive that can easily leach into the food products or humans on contact. The genotoxic and neurotoxic effects of acrylamide and bisphenol A have been widely researched; however, more attention should be dedicated to understanding the developmental toxicity of these chemicals. The developmental impacts of toxin exposure can be easily understood using Drosophila melanogaster as a model given considering its short life span and genetic homology to humans. In this review, we have discussed the toxic effects of acrylamide and BPA on the developmental process of Drosophila melanogaster.

In Vitro characterization of the endocrine disrupting effects of per- and poly-fluoroalkyl substances (PFASs) on the human androgen receptor

Per- and poly-fluoroalkyl substances (PFASs) are used extensively in a broad range of industrial applications and consumer products. While a few legacy PFASs have been voluntarily phased out, over 5000 PFASs have been produced as replacements for their predecessors. The potential endocrine disrupting hazards of most emerging PFASs have not been comprehensively investigated. In silico molecular docking to the human androgen receptor (hAR) combined with machine learning techniques were previously applied to 5206 PFASs and predicted 23 PFASs bind the hAR. Herein, the in silico results were validated in vitro for the five candidate AR ligands that were commercially available. Three manufactured PFASs namely (9-(nonafluorobutyl)- 2,3,6,7-tetrahydro-1 H,5 H,11 H-pyrano[2,3-f]pyrido[3,2,1-ij]quinolin-11-one (NON), 2-(heptafluoropropyl)- 3-phenylquinoxaline (HEP), and 2,2,3,3,4,4,5,5,5-nonafluoro-N-(4-nitrophenyl)pentanamide (NNN) elicited significant antiandrogenic effects at relatively low concentrations. We further investigated the mechanism of AR inhibition and found that all three PFASs inhibited AR transactivation induced by testosterone through a competitive binding mechanism. We then examined the antiandrogenic effects of these PFASs on AR expression and its responsive genes. Consistently, these PFASs significantly decreased the expression of PSA and FKBP5 and increased the expression of AR, similar to the effects elicited by a known competitive AR inhibitor, hydroxyflutamide. This suggests they are competitive antagonists of AR activity and western blot analysis revealed these PFASs decreased intracellular AR protein in androgen sensitive human prostate cancer cells. Hence, the findings presented here corroborate our published in silico approach and indicate these emerging PFASs may adversely affect the human endocrine system.

Advanced human developmental toxicity and teratogenicity assessment using human organoid models

Tremendous progress has been made in the field of toxicology leading to the advance of developmental toxicity assessment. Conventional animal models and in vitro two-dimensional models cannot accurately describe toxic effects and predict actual in vivo responses due to obvious inter-species differences between humans and animals, as well as the lack of a physiologically relevant tissue microenvironment. Human embryonic stem cell (hESC)- and induced pluripotent stem cell (iPSC)-derived three-dimensional organoids are ideal complex and multicellular organotypic models, which are indispensable in recapitulating morphogenesis, cellular interactions, and molecular processes of early human organ development. Recently, human organoids have been used for drug discovery, chemical toxicity and safety in vitro assessment. This review discusses the recent advances in the use of human organoid models, (i.e., brain, retinal, cardiac, liver, kidney, lung, and intestinal organoid models) for developmental toxicity and teratogenicity assessment of distinct tissues/organs following exposure to pharmaceutical compounds, heavy metals, persistent organic pollutants, nanomaterials, and ambient air pollutants. Combining next-generation organoid models with innovative engineering technologies generates novel and powerful tools for developmental toxicity and teratogenicity assessment, and the rapid progress in this field is expected to continue.

The hazardous threat of Bisphenol A: Toxicity, detection and remediation

Bisphenol A (or BPA) is a toxic endocrine disrupting chemical that is released into the environment through modern manufacturing practices. BPA can disrupt the production, function and activity of endogenous hormones causing irregularity in the hypothalamus-pituitary-gonadal glands and also the pituitary-adrenal function. BPA has immuno-suppression activity and can downregulate T cells and antioxidant genes. The genotoxicity and cytotoxicity of BPA is paramount and therefore, there is an immediate need to properly detect and remediate its influence. In this review, we discuss the toxic effects of BPA on different metabolic systems in the human body, followed by its mechanism of action. Various novel detection techniques (LC-MS, GC-MS, capillary electrophoresis, immunoassay and sensors) involving a pretreatment step (liquid-liquid microextraction and molecularly imprinted solid-phase extraction) have also been detailed. Mechanisms of various remediation strategies, including biodegradation using native enzymes, membrane separation processes, photocatalytic oxidation, use of nanosorbents and thermal degradation has been detailed. An overview of the global regulations pertaining to BPA has been presented. More investigations are required on the efficiency of integrated remediation technologies rather than standalone methods for BPA removal. The effect of processing operations on BPA in food matrices is also warranted to restrict its transport into food products.

Comparison of the renal effects of bisphenol A in mice with and without experimental diabetes. Role of sexual dimorphism

Bisphenol-A (BPA), a chemical -xenoestrogen- used in the production of the plastic lining of food and beverage containers, is present in the urine of almost the entire population. Recent studies have shown that BPA exposure is associated with podocytopathy, increased urinary albumin excretion (UAE), and hypertension. Since these changes are characteristic of early diabetic nephropathy (DN), we explored the renal effects of BPA and diabetes including the potential role of sexual dimorphism. Male and female mice were included in the following animals' groups: control mice (C), mice treated with 21.2 mg/kg of BPA in the drinking water (BPA), diabetic mice induced by streptozotocin (D), and D mice treated with BPA (D + BPA). Male mice form the D + BPA group died by the tenth week of the study due probably to hydro-electrolytic disturbances. Although BPA treated mice did not show an increase in serum creatinine, as observed in D and D + BPA groups, they displayed similar alteration to those of the D group, including increased in kidney damage biomarkers NGAL and KIM-1, UAE, hypertension, podocytopenia, apoptosis, collapsed glomeruli, as well as TGF-β, CHOP and PCNA upregulation. UAE, collapsed glomeruli, PCNA staining, TGF-β, NGAL and animal survival, significantly impaired in D + BPA animals. Moreover, UAE, collapsed glomeruli and animal survival also displayed a sexual dimorphism pattern. In conclusion, oral administration of BPA is capable of promoting in the kidney alterations that resemble early DN. Further translational studies are needed to clarify the potential role of BPA in renal diseases, particularly in diabetic patients.

Summary of 17 chemicals evaluated by OECD TG229 using Japanese Medaka, Oryzias latipes in EXTEND 2016

In June 2016, the Ministry of the Environment of Japan announced a program "EXTEND2016" on the implementation of testing and assessment for endocrine active chemicals, consisting of a two-tiered strategy. The aim of the Tier 1 screening and the Tier 2 testing is to identify the impacts on the endocrine system and to characterize the adverse effects to aquatic animals by endocrine disrupting chemicals detected in the aquatic environment in Japan. For the consistent assessment of the effects on reproduction associated with estrogenic, anti-estrogenic, androgenic, and/or anti-androgenic activities of chemicals throughout Tier 1 screening to Tier 2 testing, a unified test species, Japanese medaka (Oryzias latipes), has been used. For Tier 1 screening, the in vivo Fish Short-Term Reproduction Assay (OECD test guideline No. 229) was conducted for 17 chemicals that were nominated based on the results of environmental monitoring, existing knowledge obtained from a literature survey, and positive results in reporter gene assays using the estrogen receptor of Japanese medaka. In the 17 assays using Japanese medaka, adverse effects on reproduction (i.e., reduction in fecundity and/or fertility) were suggested for 10 chemicals, and a significant increase of hepatic vitellogenin in males, indicating estrogenic (estrogen receptor agonistic) potency, was found for eight chemicals at the concentrations in which no overt toxicity was observed. Based on these results, and the frequency and the concentrations detected in the Japanese environment, estrone, 4-nonylphenol (branched isomers), 4-tert-octylphenol, triphenyl phosphate, and bisphenol A were considered as high priority candidate substances for the Tier 2 testing.

Bisphenol A and its effects on the systemic organs of children

For the past two decades, growing research has been pointing to multiple repercussions of bisphenol A (BPA) exposure to human health. BPA is a synthetic oestrogen which primarily targets the endocrine system; however, the compound also disturbs other systemic organ functions, in which the magnitude of impacts in those other systems is as comparable to those in the endocrine system. To date, the discoveries on the association between BPA and health outcomes mainly came from animal and in vitro studies, with limited human studies which emphasised on children's health. In this comprehensive review, we summarised studies on human, in vivo and in vitro models to understand the consequences of pre-, post- and perinatal BPA exposure on the perinatal, children and adult health, encompassing cardiovascular, neurodevelopmental, endocrine and reproductive effects.Conclusion: Evidence from in vitro and animal studies may provide further support and better understanding on the correlation between environmental BPA exposure and its detrimental effects in humans and child development, despite the difficulties to draw direct causal relations of BPA effects on the pathophysiology of the diseases/syndromes in children, due to differences in body system complexity between children and adults, as well as between animal and in vitro models and humans. What is known: • Very limited reviews are available on how BPA adversely affects children's health. • Previous papers mainly covered two systems in children. What is new: • Comprehensive review on the detrimental effects of BPA on children health outcomes, including expectations on adult health outcomes following perinatal BPA exposure, as well as covering a small part of BPA alternatives. • Essentially, BPA exposure during pregnancy has huge impacts on the foetus in which it may cause changes in foetal epigenetic programming, resulting in disease onsets during childhood as well as adulthood.

Bisphenol A substitutes and sex hormones in children and adolescents

Bisphenol F (BPF) and bisphenol S (BPS) are increasingly used as bisphenol A (BPA) substitutes in consumer products. Little is known about the effects of BPA substitutes on reproductive endocrine function in children and adolescents. Thus, we conducted a cross-sectional study to examine the associations of BPA, BPF, and BPS with sex steroid hormones among 6-19-year old participants. Included were 1317 participants with information on BPA, BPF, BPS, and serum sex hormones [total testosterone (TT), estradiol (E₂), and sex hormone binding globulin (SHBG)]. Multiple linear regression accounting for complex survey design was used to assess the association between bisphenols and sex hormones by sex-age groups. Exposure-response (ER) relationships were examined via restricted cubic splines. Significant association with BPF or BPS was sporadic, but BPA presented inverse association with the free androgen index (FAI, calculated as the ratio of TT to SHBG) and E₂ and positive association with SHBG and TT/E₂ in female adolescents. Further exploration of ER relationships showed that BPA (P for non-linearity = 0.03), BPF (P for non-linearity = 0.005), and BPS (P for non-linearity = 0.08) had a U-shaped relationship with FAI among female adolescents. Additionally, an inverse U-shaped curve was observed for BPA (P for non-linearity = 0.03), BPS (P for non-linearity = 0.01), and BPF (P for non-linearity = 0.01) with SHBG. The associations were virtually nonsignificant among males. Our study demonstrated that BPS and BPF may possess similar endocrine interrupting abilities as BPA.

Bisphenol A-induced DNA damages promote to lymphoma progression in human lymphoblastoid cells through aberrant CTNNB1 signaling pathway

Lymphoma is a group of blood cancers that develop from the immune system, and one of the main risk factors is associated with exposure to environmental chemicals. Bisphenol A (BPA) is a common chemical used in the manufacture of materials in polycarbonate and epoxy plastic products and can interfere with the immune system. BPA is considered to possibly induce lymphoma development by affecting the immune system, but its potential mechanisms have not been well established. This study performed a gene-network analysis of microarray data sets in human lymphoma tissues as well as in human cells with BPA exposure to explore module genes and construct the potential pathway for lymphomagenesis in response to BPA. This study provided evidence that BPA exposure resulted in disrupted cell cycle and DNA damage by activating CTNNB1, the initiator of the aberrant constructed CTNNB1-NFKB1-AR-IGF1-TWIST1 pathway, which may potentially lead to lymphomagenesis.

Effects of two Bisphenol A replacement compounds, 1,7-bis (4-hydroxyphenylthio)-3,5-dioxaheptane and Bisphenol AF, on development and mRNA expression in chicken embryos

Concerns about the estrogenic properties of Bisphenol A (BPA) have led to increased efforts to find BPA replacements. 1,7-bis(4-Hydroxyphenylthio)-3,5-dioxaheptane (DD-70) and 4,4'-(hexafluoroisopropylidene) diphenol (bisphenol AF, BPAF) are two potential chemical substitutes for BPA; however, toxicity data for these chemicals in avian species are limited. To determine effects on avian embryonic viability, development, and hepatic mRNA expression at two distinct developmental periods (mid-incubation [day 11] and term [day 20]), two egg injection studies were performed. Test chemicals were injected into the air cell of unincubated, fertilized chicken eggs at concentrations ranging from 0-88.2 µg/g for DD-70 and 0-114 µg/g egg for BPAF. Embryonic concentrations of DD-70 and BPAF decreased at mid-incubation and term compared to injected concentrations suggesting embryonic metabolism. Exposure to DD-70 (40.9 and 88.2 µg/g) and BPAF (114 µg/g) significantly decreased embryonic viability at mid-incubation. Exposure to DD-70 (88.2 µg/g) decreased embryo mass and increased gallbladder mass, while 114 µg/g BPAF resulted in increased gallbladder mass in term embryos. Expression of hepatic genes related to xenobiotic metabolism, lipid homeostasis, and response to estrogen were altered at both developmental stages. Given the importance of identifying suitable BPA replacements, the present study provides novel, whole animal avian toxicological data for two replacement compounds, DD-70 and BPAF. DATA AVAILABILITY: Data, associated metadata, and calculation tools are available from the corresponding author (doug.crump@canada.ca).

Endocrine disrupting chemicals (EDCs) and sex steroid receptors

Sex-steroid receptors (SSRs) are essential mediators of estrogen, progestin, and androgen signaling that are critical in vast aspects of human development and multi-organ homeostasis. Dysregulation of SSR function has been implicated in numerous pathologies including cancers, obesity, Type II diabetes mellitus, neuroendocrine disorders, cardiovascular disease, hyperlipidemia, male and female infertility, and other reproductive disorders. Endocrine disrupting chemicals (EDCs) modulate SSR function in a wide variety of cell and tissues. There exists strong experimental, clinical, and epidemiological evidence that engagement of EDCs with SSRs may disrupt endogenous hormone signaling leading to physiological abnormalities that may manifest in disease. In this chapter, we discuss the molecular mechanisms by which EDCs interact with estrogen, progestin, and androgen receptors and alter SSR functions in target cells. In addition, the pathological consequences of disruption of SSR action in reproductive and other organs by EDCs is described with an emphasis on underlying mechanisms of receptors dysfunction.

Gestational low-dose BPA exposure impacts suprachiasmatic nucleus neurogenesis and circadian activity with transgenerational effects

Critical physiological processes such as sleep and stress that underscore health are regulated by an intimate interplay between the endocrine and nervous systems. Here, we asked how fetal exposure to the endocrine disruptor found in common plastics, bisphenol A (BPA), causes lasting effects on adult animal behaviors. Adult mice exposed to low-dose BPA during gestation displayed notable disruption in circadian activity, social interactions, and associated neural hyperactivity, with some phenotypes maintained transgenerationally. Gestational BPA exposure increased vasopressin+ neurons in the suprachiasmatic nucleus (SCN), the region that regulates circadian rhythms, of F1 and F3 generations. Mechanistically, BPA increased proliferation of hypothalamic neural progenitors ex vivo and caused precocious neurogenesis in vivo. Co-antagonism of both estrogen and androgen receptors was necessary to block BPA's effects on hypothalamic neural progenitors, illustrating a dual role for these endocrine targets. Together, gestational BPA exposure affects development of circadian centers, with lasting consequences across generations.

Serum bisphenol A analogues in women diagnosed with the polycystic ovary syndrome - is there an association?

Due to the endocrine disrupting effects of bisphenol A (BPA) several governmental authorities have banned its use and the manufacturers had to find alternative substances with similar chemical properties. This led to the increase in the use of so-called BPA analogues, which however also turn out to possess mild estrogenic and ani-androgenic properties and thus, may cause fertility problems and sex-hormone dependent endocrinopathies. The aim of this study was to evaluate the potential association between the exposure to BPA and its two analogues: BPS and BPF, with the diagnosis of the polycystic ovary syndrome (PCOS), which remains the most common female endocrinopathy. Serum concentrations of BPA, BPS and BPF were measured using high performance liquid chromatography method with tandem mass spectrometry (HPLC-MS/MS) among 199 women with PCOS and 158 control subjects. In women with PCOS serum BPS concentrations were significantly higher compared to the control subjects (geometric mean [95% CI]: 0.14 ng/mL [0.10; 1.17] vs. 0.08 ng/mL [0.06; 0.09], P = 0.023). Serum BPA and BPF concentrations did not differ between the studied groups. There was however a negative correlation between serum BPA and HOMA-IR (r = - 0.233, P = 0.001) and TST (r = - 0.203, P = 0.006) in women with PCOS. No correlations were found between the serum BPs and other metabolic parameters such as serum lipids, insulin, DHEA-S, androstenedione and FAI. When studying the association between serum BPA analogues and PCOS it turned out that women whose serum BPS concentrations were in the first tertile were more likely to be diagnosed with this endocrinopathy (OR [95% CI]: 1.21 [1.04; 3.46], P = 0.017). This association was also statistically significant when adjusted for age, education, BMI, smoking, income, and alcohol consumption (adjusted OR [95% CI]: 1.12 [1.03; 3.71], P = 0.029). These results point to the potential association between the exposure to BPS and the diagnosis of PCOS. The role of BPA is not clear and warrants further studies.

Sex-specific oxidative damage effects induced by BPA and its analogs on primary hippocampal neurons attenuated by EGCG

BPA analogs, including bisphenol S (BPS) and bisphenol B (BPB), have been used to replace BPA since it was banned to be added. To investigate whether BPA and its analogs cause oxidative damage effects on primary hippocampal neurons of rats, reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), mitochondrial membrane potential (MMP), apoptosis and cell viability assays were conducted after hippocampal neurons exposure to different concentrations of BPA, BPS, and BPB (1, 10, 100 nM and 1, 10, 100 μM). Moreover, the effects of EGCG (5 and 6 μM for male and female, respectively) added on neurons exposed to BPA were assessed. Results showed that 24 h exposure to these bisphenols (BPs) could increase the levels of ROS and contents of MDA, but reduce the activity of SOD significantly. A decline of cell viabilities accompanied with the increasing of apoptosis rates was observed after 7 d exposure to BPs and the reduction of MMP was also observed after 7 d exposure to BPA. Interestingly, BPS has the lower toxicity to hippocampal neurons compared with BPA and BPB. Non-monotonic dose-effect relationships between the concentrations of BPs and the cytotoxic effects were observed, and the effects of BPs on male hippocampal neurons are greater than those of female ones in general. While EGCG can protect neurons free of oxidative damages. In conclusion, the results suggest that BPs may induce sex-specific neurotoxic effects involving oxidative stress, which can be attenuated by EGCG, and males are more sensitive to BPs than females.

Bisphenol A(BPA), BPS and BPB-induced oxidative stress and apoptosis mediated by mitochondria in human neuroblastoma cell lines

The analogues of biphenol A (BPA), including bisphenol S (BPS) and bisphenol B (BPB), are commonly used to replace the application of BPA in containers and wrappers of daily life. However, their safeties are questioned due to their similar chemical structure and possible physiological effects as BPA. To investigate the neurotoxic effects of BPA, BPS, and BPB as well as their underlying mechanism, IMR-32 cell line from male and SK-N-SH cell line from female were exposed respectively to BPA, BPS and BPB with concentrations of 1 nM, 10 nM, 100 nM, 1 μM, 10 μM, and 100 μM for 24 h. Additionally, 24 h exposure of BPA combining epigallocatechin gallate (EGCG) (4 μM and 8 μM for IMR-32 and SK-N-SH respectively) were conducted. Results demonstrated that BPs exposure could promote reactive oxygen species production and increase level of malondialdehyde (MDA) while decrease levels of superoxide dismutase (SOD). Intensive study revealed that after exposure to BPA mitochondrial membrane potential (MMP) dropped down and the protein expression levels of Bak-1, Bax, cytochrome c and Caspase-3 were up-regulated but Bcl-2 were down-regulated significantly. Moreover, apoptosis rate was raised and cell activity declined remarkably in the neuroblastoma cells. All the effects induced by BPA could be alleviated by the adding of EGCG, which similar alleviations could be inferred in IMR-32 and SK-N-SH cells induced by BPS and BPB. Furthermore, BPS showed lower neurotoxic effects compared to BPA and BPB. Interestingly, the neurotoxic effects of BPA on IMR-32 cells were significantly higher than those on SK-N-SH cells. In conclusion, the results suggested that BPA, BPS and BPB could induce oxidative stress and apoptosis via mitochondrial pathway in the neuroblastoma cells and male is more susceptible to BPs than female.