Involvement of the Endocrine-Disrupting Chemical Bisphenol A (BPA) in Human Placentation

Bisphenol A alters JUN promoter methylation, impairing steroid metabolism in placental cells and linking to sub-representative phenotypes

Bisphenol A (BPA) is a widely used industrial compound commonly found in various everyday plastic products. Known for its endocrine-disrupting properties, BPA can enter the human body through multiple pathways. Prenatal exposure to BPA not only disrupts placental structure and function but also interferes with normal steroid metabolism. This study investigates the epigenetic regulatory mechanisms by which BPA influences steroid metabolism in the placenta. Using BPA-treated JEG3 cells, we analyzed hormone levels, gene promoter DNA methylation, and gene expression, further validating our findings in placental samples. Additionally, we explored the role of epigenetic modifications in regulating steroid metabolism at the cellular level and assessed related phenotypes in cohort samples. The results demonstrated that BPA significantly reduced the levels of progesterone, estradiol, and testosterone, and notably affected the promoter methylation and expression levels of 63 genes. Enrichment analysis highlighted PLA2G4F, JUN, MRAS, ERBB4, DUSP1, and GADD45G as being primarily enriched in the MAPK signaling pathway. Further studies revealed that the methylation level of the JUN promoter regulates its expression, impacting hormone levels by modulating downstream signaling pathways. In placental samples, male offspring in the hypermethylated JUN promoter group had shorter anogenital distance (AGD) compared to those in the hypomethylated group. These findings suggest that BPA reduces the expression of steroid metabolism genes via the epigenetic regulation of the JUN gene, thereby decreasing progesterone, estradiol, and testosterone levels and leading to shortened AGD in offspring.

Gestational exposure to BPA alters the expression of glucose and lipid metabolic mediators in the placenta: Role in programming offspring for obesity

Bisphenol A (BPA) exposure during pregnancy is known to predispose offspring to obesity in later life. Our previous studies demonstrated obesogenic effects in BPA-exposed offspring, including excess body fat, increased feed efficiency, adipocyte hypertrophy, and altered leptin signaling. However, the role of the placenta in mediating these effects remained unclear. This study investigates the mechanisms by which BPA exposure affects placental glucose and lipid transporters and their impact on offspring adiposity in Wistar rats. Dams were orally gavaged with BPA [0.4 (low dose-LD) and 4.0 (high dose-HD) μg/kg body weight] from gestational day (gD) 4-14. Gestational exposure to LD BPA increased the expression of 11β hydroxysteroid dehydrogenase 1 (11β HSD1) and estrogen receptor alpha (ERα) proteins (p<0.05) in the placenta compared to control and HD BPA. Similar changes were observed in the expression of mTOR signaling mediators, fatty acid transporters, and intracellular fatty acid-binding proteins. There were no changes in the dam's body weight or lipid and glucose profiles. However, there was a dose dependent increase in glucose transporter (GLUT1) expression in the placenta. While LD BPA increased hexokinase 2 expression in the placenta, HD BPA had no effect. Both doses of BPA increased IL6 expression, but only LD BPA exposure increased PPAR-gamma expression. Additionally, BPA exposure induced ADRP expression and localization, suggesting potential lipid overload in the placenta. Furthermore, BPA exposure altered the placental epigenetic profile, with increased expression of DNA methyltransferases (DNMTs). Overall, gestational BPA exposure led to dose-specific alterations in placental glucose and lipid metabolic activities, possibly playing an role in increasing the supply of these macronutrients to the fetus and predisposing the offspring to obesity.

Development of the Bisphenol A exposure scale in adults

Objective

This study was conducted to develop a scale for assessing the attitudes of adults regarding the determination of Bisphenol A exposure.

Methods

The study sample comprised of 370 individuals who volunteered to participate. According to the Explanatory Factor Analysis (EFA) results of the investigation, a scale structure consisting of a total of 3 sub-dimensions was obtained. In the Confirmatory Factor Analysis, the scale item factor loading values were acceptable.

Results

The fit indices for the scale were CMIN/df = 1,618, RMSEA = 0.058, NFI = 0.914, CFI = 0.965, and IFI = 0.790, indicating a satisfactory level of agreement. The scale was determined to have a Cronbach value of 0.79 and a high degree of reliability. The item-total score correlation coefficients of the scale ranged from 0.327 to 0.534 and exhibited a high degree of discrimination, as determined.

Conclusion

Based on the analyses conducted, it was determined that the Adult Bisphenol A Exposure Scale is a valid and reliable instrument for determining the attitudes of adults toward contact with and use of Bisphenol A-containing products.

Short-Half-Life Chemicals: Maternal Exposure and Offspring Health Consequences-The Case of Synthetic Phenols, Parabens, and Phthalates

Phenols, parabens, and phthalates (PPPs) are suspected or known endocrine disruptors. They are used in consumer products that pregnant women and their progeny are exposed to daily through the placenta, which could affect offspring health. This review aims to compile data from cohort studies and in vitro and in vivo models to provide a summary regarding placental transfer, fetoplacental development, and the predisposition to adult diseases resulting from maternal exposure to PPPs during the gestational period. In humans, using the concentration of pollutants in maternal urine, and taking the offspring sex into account, positive or negative associations have been observed concerning placental or newborn weight, children's BMI, blood pressure, gonadal function, or age at puberty. In animal models, without taking sex into account, alterations of placental structure and gene expression linked to hormones or DNA methylation were related to phenol exposure. At the postnatal stage, pollutants affect the bodyweight, the carbohydrate metabolism, the cardiovascular system, gonadal development, the age of puberty, sex/thyroid hormones, and gamete quality, but these effects depend on the age and sex. Future challenges will be to explore the effects of pollutants in mixtures using models and to identify the early signatures of in utero exposure capable of predicting the health trajectory of the offspring.

Modeling the human placenta: in vitro applications in developmental and reproductive toxicology

During its temporary tenure, the placenta has extensive and specialized functions that are critical for pre- and post-natal development. The consequences of chemical exposure in utero can have profound effects on the structure and function of pregnancy-associated tissues and the life-long health of the birthing person and their offspring. However, the toxicological importance and critical functions of the placenta to embryonic and fetal development and maturation have been understudied. This narrative will review early placental development in humans and highlight some in vitro models currently in use that are or can be applied to better understand placental processes underlying developmental toxicity due to in utero environmental exposures.

White-to-Beige and Back: Adipocyte Conversion and Transcriptional Reprogramming

Obesity has become a pandemic, as currently more than half a billion people worldwide are obese. The etiology of obesity is multifactorial, and combines a contribution of hereditary and behavioral factors, such as nutritional inadequacy, along with the influences of environment and reduced physical activity. Two types of adipose tissue widely known are white and brown. While white adipose tissue functions predominantly as a key energy storage, brown adipose tissue has a greater mass of mitochondria and expresses the uncoupling protein 1 (UCP1) gene, which allows thermogenesis and rapid catabolism. Even though white and brown adipocytes are of different origin, activation of the brown adipocyte differentiation program in white adipose tissue cells forces them to transdifferentiate into "beige" adipocytes, characterized by thermogenesis and intensive lipolysis. Nowadays, researchers in the field of small molecule medicinal chemistry and gene therapy are making efforts to develop new drugs that effectively overcome insulin resistance and counteract obesity. Here, we discuss various aspects of white-to-beige conversion, adipose tissue catabolic re-activation, and non-shivering thermogenesis.

Endocrine-disrupting compounds and their impact on human placental function: evidence from placenta organ-on-chip studies

The effects of endocrine-disrupting compounds (EDCs) on the placenta, a critical gestational organ for xenobiotic protection, are well reported; however, models to determine the role of EDCs in placental disruption are limited. An advanced 2nd-trimester human placenta organ-on-chip model (2TPLA-OOC) was developed and validated, with six representative cells of the maternal and the fetal interface interconnected with microchannels. Various EDCs (150 ng mL-1 each of bisphenol A, bisphenol S, and polybrominated diphenyl ethers-47 and -99) were gradually propagated across the chip for 72 hours, and their various effects were determined. Cigarette smoke extract (CSE), an environmental risk factor, was used as a positive control. EDCs produced overall oxidative stress in the placental/decidual cells, induced cell-specific endocrine effects, caused limited (<10%) apoptosis/necrosis in trophoblasts and mesenchymal cells, induced localized inflammation but an overall anti-inflammatory shift, did not change immune cell migration from stroma to decidua, and did not affect placental nutrient transport. Overall, (1) the humanized 2TPLA-OOC recreated the placental organ and generated data distinct from the trophoblast and other cells studied in isolation, and (2) at doses associated with adverse pregnancies, EDCs produced limited and localized insults, and the whole organ compensated for the exposure.

Associations among bisphenol A, its analogs, and chlorinated derivatives in placenta and risk for neural tube defects: A case-control study

Bisphenol A (BPA) and its analogs such as bisphenol Z (BPZ) are widely used in the production of consumer products, but few studies have investigated the associations among BPA, its analogs, and chlorinated derivatives (collectively, BPs) and risk for NTDs. This study investigated the associations between concentrations of BPs in the placenta and risk for NTDs. This was a case-control study including 122 NTDs and 164 controls. BPs in the placenta were determined using liquid chromatography-tandem mass spectrometry. The associations between BPs and NTD risk were evaluated using conventional logistic regression and weighted quantile sum regression (WQS) models. In the logistic regression, exposure to higher levels of BPA and BPZ was associated with increased NTD risk (odds ratio [OR] = 3.17, 95 % confidence interval [CI], 1.22-8.22; OR = 3.11, 95 % CI, 1.20-8.09, respectively). Meanwhile, a significant dose-response relationship was found between BPA and BPZ concentrations and NTD risk. In the WQS model, a quartile increase in WQS index resulted in 4.34 (95 % CI: 1.69, 11.20) higher odds for NTDs, and BPA and BPZ accounted for most of the weight index in the joint effects of BPs. In conclusion, high levels of BPs in the placenta are associated with increased risk for NTDs, of which BPA and BPZ are important risk factors.

Impact of bisphenol A on cell viability and inflammatory cytokine production in human cervical epithelial cells

PROBLEM

An intact cervix is a barrier that prevents pathogenic bacteria from invading the uterine and amniotic cavity during pregnancy. Its disruption is associated with ascending infection and adverse pregnancy outcomes. This study analyzed the effects of bisphenol A (BPA), a chemical used in plastics manufacturing, on cell death and inflammation in cervical epithelial cells.

METHODS

Ectocervical epithelial (ecto) and endocervical epithelial (endo) cells were treated with 100 ng/mL and 300 ng/mL of BPA for 48 h. The cells were subjected to flow cytometry using annexin V and propidium iodide to determine apoptosis and necrosis, cell cycle analysis, and ELISA to determine the levels of inflammatory cytokines (IL-6, IL-8, and IL-10).

RESULTS

Low-dose and high-dose BPA significantly increased the live ecto cell population dose-dependently. BPA did not have any noticeable effect on cell cycle progression in either cell type. BPA treatment also decreased the apoptotic ecto and endo cell population dose-dependently. Lastly, high dose BPA significantly increased IL-6 in ecto and endo cells. However, IL-8 and IL-10 were not affected by BPA treatments.

CONCLUSION

Chemical exposure damage to the cervix can lead to adverse pregnancy outcomes. Our study showed that the BPA concentrations reported in pregnant subjects do not induce cervical cell toxicity . The decrease in apoptosis and increase in live cells may be a compensatory mechanism to preserve the integrity of the cervical epithelial layer.

Comparative Analysis of Transcriptomic Changes including mRNA and microRNA Expression Induced by the Xenoestrogens Zearalenone and Bisphenol A in Human Ovarian Cells

Xenoestrogens are natural or synthetic compounds that mimic the effect of endogenous estrogens and might cause cancer. We aimed to compare the global transcriptomic response to zearalenone (ZEA; mycotoxin) and bisphenol A (BPA; plastic additive) with the effect of physiological estradiol (E2) in the PEO1 human ovarian cell line by mRNA and microRNA sequencing. Estrogen exposure induced remarkable transcriptomic changes: 308, 288 and 63 genes were upregulated (log₂FC > 1); 292, 260 and 45 genes were downregulated (log₂FC < -1) in response to E2 (10 nM), ZEA (10 nM) and BPA (100 nM), respectively. Furthermore, the expression of 13, 11 and 10 miRNAs changed significantly (log₂FC > 1, or log₂FC < -1) after exposure to E2, ZEA and BPA, respectively. Functional enrichment analysis of the significantly differentially expressed genes and miRNAs revealed several pathways related to the regulation of cell proliferation and migration. The effect of E2 and ZEA was highly comparable: 407 genes were coregulated by these molecules. We could identify 83 genes that were regulated by all three treatments that might have a significant role in the estrogen response of ovarian cells. Furthermore, the downregulation of several miRNAs (miR-501-5p, let-7a-2-3p, miR-26a-2-3p, miR-197-5p and miR-582-3p) was confirmed by qPCR, which might support the proliferative effect of estrogens in ovarian cells.

The effect of endocrine-disrupting chemicals on placental development

Endocrine-disrupting chemicals (EDCs) or endocrine disruptors are substances that are either naturally occurring or artificial and are released into the natural environment. Humans are exposed to EDCs through ingestion, inhalation, and skin contact. Many everyday household items, such as plastic bottles and containers, the liners of metal food cans, detergents, flame retardants, food, gadgets, cosmetics, and pesticides, contain endocrine disruptors. Each hormone has a unique chemical makeup and structural attributes. The way that endocrine hormones connect to receptors is described as a "lock and key" mechanism, with each hormone serving as the key (lock). This mechanism is enabled by the complementary shape of receptors to their hormone, which allows the hormone to activate the receptors. EDCs are described as exogenous chemicals or compounds that have a negative impact on organisms' health by interacting with the functioning of the endocrine system. EDCs are associated with cancer, cardiovascular risk, behavioural disorders, autoimmune abnormalities, and reproductive disorders. EDCs exposure in humans is highly harmful during critical life stages. Nonetheless, the effect of EDCs on the placenta is often underestimated. The placenta is especially sensitive to EDCs due to its abundance of hormone receptors. In this review, we evaluated the most recent data on the effects of EDCs on placental development and function, including heavy metals, plasticizers, pesticides, flame retardants, UV filters and preservatives. The EDCs under evaluation have evidence from human biomonitoring and are found in nature. Additionally, this study indicates important knowledge gaps that will direct future research on the topic.

The effect of training about environmental toxicant Bisphenol-A exposure in pregnancy on maternal urine Bisphenol-A level

Purpose

Bisphenol A (BPA) is an environmental toxin, clearly capable of initiating epigenetic modifications, leading to the development of numerous human illnesses such as metabolic, reproductive, and behavioural abnormalities. It also causes oxidative stress, which has been shown to be alleviated by selenium supplementation. The purpose of this study was to determine the effect of training of BPA exposure during pregnancy on urine BPA levels.

Methods

This research enrolled 30 pregnant women who were in their first trimester and were free of chronic illness. Women were asked questions on their sociodemographic features, anthropometric measures, obstetric characteristics, BPA awareness level, BPA exposure and the Health Practices in Pregnancy Scale as a Pre-test and Post-Test. The initial urine samples were taken from women in their first trimester and stored in BPA-free bags. Then, training was delivered to encourage BPA exposure reduction and maternal health awareness. First-trimester face-to-face instruction and brochure distribution were followed by refresher, reminder, and follow-up trainings during the second and third trimesters. Urine samples from women in their second and third trimesters were obtained again. The levels of BPA in urine were measured using the liquid chromatography-mass spectrometry on 90 samples. Each person's urine concentration differs, thus the creatinine level in all samples was also calculated and compared to the BPA content, and the results were evaluated.

Results

Our study shown that BPA exposure may be lowered by training. It has been demonstrated that reducing BPA exposure and increasing knowledge can result in an improvement in health status. Additionally, it has been demonstrated that trainings greatly minimize exposure-causing behaviours.

Conclusion

It was discovered that while the duration of a single training does not make a meaningful effect, the continuing of reminder trainings did make a substantial difference in the urine BPA level.

RNA-sequencing analysis of bisphenol A biodegradation by white-rot fungus Phanerochaete sordida YK-624

Bisphenol A (BPA) is a representative example of an endocrine-disrupting chemical. It is one of the most produced chemical substances in the world, but it causes harmful effects in organisms, such that the effective degradation of BPA is critical. The white-rot fungus Phanerochaete sordida YK-624 has been shown to effectively degrade BPA under ligninolytic and non-ligninolytic conditions. However, it is still unclear what kinds of enzymes are involved in BPA degradation. To explore the mechanism of BPA degradation, the present study analysed the functional genes of P. sordida YK-624 using RNA-sequencing (RNA-Seq). Oxidation-reduction process and metabolic pathway were enriched under ligninolytic and non-ligninolytic conditions by Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. It is suggested that BPA might be used as a carbon source by P. sordida YK-624. Lignin peroxidase and cytochrome P450 were detected in upregulated differentially expressed genes (DEGs). The lignin-degrading enzyme lignin peroxidase and the intracellular cytochrome P450 system were involved in BPA degradation by P. sordida YK-624, respectively. Furthermore, quantitative real-time PCR (qPCR) was used to validate the reliability of the RNA-Seq results.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03298-w.

Impact of Environmentally Relevant Concentrations of Bisphenol A (BPA) on the Gene Expression Profile in an In Vitro Model of the Normal Human Ovary

Endocrine-disrupting chemicals (EDCs), including the xenoestrogen Bisphenol A (BPA), can interfere with hormonal signalling. Despite increasing reports of adverse health effects associated with exposure to EDCs, there are limited data on the effect of BPA in normal human ovaries. In this paper, we present a detailed analysis of the transcriptomic landscape in normal Human Epithelial Ovarian Cells (HOSEpiC) treated with BPA (10 and 100 nM). Gene expression profiles were determined using high-throughput RNA sequencing, followed by functional analyses using bioinformatics tools. In total, 272 and 454 differentially expressed genes (DEGs) were identified in 10 and 100 nM BPA-treated HOSEpiCs, respectively, compared to untreated controls. Biological pathways included mRNA surveillance pathways, oocyte meiosis, cellular senescence, and transcriptional misregulation in cancer. BPA exposure has a considerable impact on 10 genes: ANAPC2, AURKA, CDK1, CCNA2, CCNB1, PLK1, BUB1, KIF22, PDE3B, and CCNB3, which are also associated with progesterone-mediated oocyte maturation pathways. Future studies should further explore the effects of BPA and its metabolites in the ovaries in health and disease, making use of validated in vitro and in vivo models to generate data that will address existing knowledge gaps in basic biology, hazard characterisation, and risk assessment associated with the use of xenoestrogens such as BPA.

Actions of Bisphenol A on Different Feto-Maternal Compartments Contributing to Preterm Birth

Preterm birth remains to be one of the most prevalent obstetric complications worldwide. Since there are multiple etiological factors associated with this disease process, an integrative literature search in PubMed and Scopus databases on possible mechanism of action and effect of bisphenols on exposure on human or animal placental samples in preterm birth was conducted. From 2332 articles on initial literature search, 63 studies were included for full data extraction. Altogether, several pathways were shown to be possibly affected by bisphenols, leading to dysregulations in structural and endocrine foundation in the placenta, potential induction of senescence and failure of decidualization in the decidua, and possible propagation of inflammation in the fetal membranes. Combined, these actions may eventually counteract bisphenol-induced relaxation of the myometrium and promote contractility alongside fetal membrane weakening. In totality, these individual impairments in gestation-critical processes may lead to failure of maintenance of pregnancy, and thus effecting preterm birth.

Impact of bisphenol A (BPA) on cells and tissues at the human materno-fetal interface

Bisphenol A (BPA) is an endocrine disruptor extensively used in the production of polycarbonate plastics and epoxy resins and a component of liquid and food containers. It is a hazard in the prenatal period because of its presence in the placenta, fetal membranes, amniotic fluid, maternal and fetal blood and its ability to cross the placenta and reach the fetus. Estimation of the risk of BPA exposure during in utero life is extremely important in order to prevent complications of pregnancy and fetal growth. This review describes in vitro models of the human materno-fetal interface. It also outlines the effects of BPA at doses indicated as "physiological", namely at the concentrations found in the general population, and at "supraphysiological" and "subphysiological" doses, i.e. above and below the physiological range. This work will help clarify the discrepancies observed in studies on the effects of BPA on human reproduction and pregnancy, and it will be useful for the choice of appropriate in vitro models for future studies aimed at identifying the potential impact of BPA on specific functional processes.

The Role of the 3Rs for Understanding and Modeling the Human Placenta

Modeling the physiology of the human placenta is still a challenge, despite the great number of scientific advancements made in the field. Animal models cannot fully replicate the structure and function of the human placenta and pose ethical and financial hurdles. In addition, increasingly stricter animal welfare legislation worldwide is incentivizing the use of 3R (reduction, refinement, replacement) practices. What efforts have been made to develop alternative models for the placenta so far? How effective are they? How can we improve them to make them more predictive of human pathophysiology? To address these questions, this review aims at presenting and discussing the current models used to study phenomena at the placenta level: in vivo, ex vivo, in vitro and in silico. We describe the main achievements and opportunities for improvement of each type of model and critically assess their individual and collective impact on the pursuit of predictive studies of the placenta in line with the 3Rs and European legislation.

Epigenetic Modifications Associated with Exposure to Endocrine Disrupting Chemicals in Patients with Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) remains a significant clinical and public health issue due to its increasing prevalence and the possibility for numerous short- and long-term complications. The growing incidence of GDM seems to coincide with the widespread use of endocrine disrupting chemicals (EDCs). The extensive production and common use of these substances in everyday life has resulted in constant exposure to harmful substances from the environment. That may result in epigenetic changes, which may manifest themselves also after many years and be passed on to future generations. It is important to consider the possible link between environmental exposure to endocrine disrupting chemicals (EDCs) during pregnancy, epigenetic mechanisms and an increased risk for developing gestational diabetes mellitus (GDM). This manuscript attempts to summarize data on epigenetic changes in pregnant women suffering from gestational diabetes in association with EDCs. There is a chance that epigenetic marks may serve as a tool for diagnostic, prognostic, and therapeutic measures.

Antioxidative Molecules in Human Milk and Environmental Contaminants

Breastfeeding provides overall beneficial health to the mother-child dyad and is universally recognized as the preferred feeding mode for infants up to 6-months and beyond. Human milk provides immuno-protection and supplies nutrients and bioactive compounds whose concentrations vary with lactation stage. Environmental and dietary factors potentially lead to excessive chemical exposure in critical windows of development such as neonatal life, including lactation. This review discusses current knowledge on these environmental and dietary contaminants and summarizes the known effects of these chemicals in human milk, taking into account the protective presence of antioxidative molecules. Particular attention is given to short- and long-term effects of these contaminants, considering their role as endocrine disruptors and potential epigenetic modulators. Finally, we identify knowledge gaps and indicate potential future research directions.

Bisphenol A Exposure Changes the Transcriptomic and Proteomic Dynamics of Human Retinoblastoma Y79 Cells

Bisphenol A (BPA) is a xenoestrogen chemical commonly used to manufacture polycarbonate plastics and epoxy resin and might affect various human organs. However, the cellular effects of BPA on the eyes have not been widely investigated. This study aimed to investigate the cellular cytotoxicity by BPA exposure on human retinoblastoma cells. BPA did not show cytotoxic effects, such as apoptosis, alterations to cell viability and cell cycle regulation. Comparative analysis of the transcriptome and proteome profiles were investigated after long-term exposure of Y79 cells to low doses of BPA. Transcriptome analysis using RNA-seq revealed that mRNA expression of the post-transcriptional regulation-associated gene sets was significantly upregulated in the BPA-treated group. Cell cycle regulation-associated gene sets were significantly downregulated by exposure to BPA. Interestingly, RNA-seq analysis at the transcript level indicated that alternative splicing events, particularly retained introns, were noticeably altered by low-dose BPA treatment. Additionally, proteome profiling using MALDI-TOF-MS identified a total of nine differentially expressed proteins. These results suggest that alternative splicing events and altered gene/protein expression patterns are critical phenomena affected by long-term low-dose BPA exposure. This represents a novel marker for the detection of various diseases associated with environmental pollutants such as BPA.

Genome-wide expression changes induced by bisphenol A, F and S in human stem cell derived hepatocyte-like cells

The debate about possible adverse effects of bisphenol A (BPA) has been ongoing for decades. Bisphenol F (BPF) and S (BPS) have been suggested as “safer” alternatives. In the present study we used hepatocyte-like cells (HLCs) derived from the human embryonic stem cell lines Man12 and H9 to compare the three bisphenol derivatives. Stem cell-derived progenitors were produced using an established system and were exposed to BPA, BPF and BPS for 8 days during their transition to HLCs. Subsequently, we examined cell viability, inhibition of cytochrome P450 (CYP) activity, and genome-wide RNA profiles. Sub-cytotoxic, inhibitory concentrations (IC₅₀) of CYP3A were 20, 9.5 and 25 µM for BPA, BPF and BPS in Man12 derived HLCs, respectively. The corresponding concentrations for H9-derived HLCs were 19, 29 and 31 µM. These IC₅₀ concentrations were used to study global expression changes in this in vitro study and are higher than unconjugated BPA in serum of the general population. A large overlap of up- as well as downregulated genes induced by the three bisphenol derivatives was seen. This is at least 28-fold higher compared to randomly expected gene expression changes. Moreover, highly significant correlations of expression changes induced by the three bisphenol derivatives were obtained in pairwise comparisons. Dysregulated genes were associated with reduced metabolic function, cellular differentiation, embryonic development, cell survival and apoptosis. In conclusion, no major differences in cytochrome inhibitory activities of BPA, BPF and BPS were observed and gene expression changes showed a high degree of similarity.

Is There a Link between Bisphenol A (BPA), a Key Endocrine Disruptor, and the Risk for SARS-CoV-2 Infection and Severe COVID-19?

Infection by the severe acute respiratory syndrome (SARS) coronavirus-2 (SARS-CoV-2) is the causative agent of a new disease (COVID-19). The risk of severe COVID-19 is increased by certain underlying comorbidities, including asthma, cancer, cardiovascular disease, hypertension, diabetes, and obesity. Notably, exposure to hormonally active chemicals called endocrine-disrupting chemicals (EDCs) can promote such cardio-metabolic diseases, endocrine-related cancers, and immune system dysregulation and thus, may also be linked to higher risk of severe COVID-19. Bisphenol A (BPA) is among the most common EDCs and exerts its effects via receptors which are widely distributed in human tissues, including nuclear oestrogen receptors (ERα and ERβ), membrane-bound oestrogen receptor (G protein-coupled receptor 30; GPR30), and human nuclear receptor oestrogen-related receptor gamma. As such, this paper focuses on the potential role of BPA in promoting comorbidities associated with severe COVID-19, as well as on potential BPA-induced effects on key SARS-CoV-2 infection mediators, such as angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). Interestingly, GPR30 appears to exhibit greater co-localisation with TMPRSS2 in key tissues like lung and prostate, suggesting that BPA exposure may impact on the local expression of these SARS-CoV-2 infection mediators. Overall, the potential role of BPA on the risk and severity of COVID-19 merits further investigation.

Advanced glycation end products increased placental vascular permeability of human BeWo cells via RAGE/NF-kB signaling pathway

OBJECTIVE

This study aimed to investigate the mechanisms of advanced glycation end products (AGEs) on cell tight conjunction and placental vascular permeability in BeWo cells.

STUDY DESIGN

Monolayer permeability assay and transmission electron microscopy were employed to reveal the transformation of the placental vascular permeability and cell tight conjunction. Immunofluorescence, western blot and RT-qPCR were adopted to determine the protein and mRNA levels. Anti-RAGE and NF-kB inhibitor (PDTC) were used to inactivate the RAGE/NF-kB signaling pathway.

RESULTS

AGEs significantly decreased trans-epithelial electrical resistance (TEER), while increased paracellular permeability (P <  0.05). TEM showed that AGEs made cell junction loose. AGEs inhibited ZO-1 and Occludin expressions, while anti-RAGE or PDTC partially restored their levels. AGEs also significantly increased mRNA RAGE and NF-kB expressions in BeWo cells (P <  0.05), and their expressions were inhibited by anti-RAGEy or PDTC.

CONCLUSION

AGEs could reduce the expressions of ZO-1 and Occludin by activating RAGE/NF-kB signaling pathway, thus increasing placental vascular permeability.