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

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.

Bisphenol S Promotes the Transfer of Antibiotic Resistance Genes via Transformation

The antibiotic resistance crisis has seriously jeopardized public health and human safety. As one of the ways of horizontal transfer, transformation enables bacteria to acquire exogenous genes naturally. Bisphenol compounds are now widely used in plastics, food, and beverage packaging, and have become a new environmental pollutant. However, their potential relationship with the spread of antibiotic resistance genes (ARGs) in the environment remains largely unexplored. In this study, we aimed to assess whether the ubiquitous bisphenol S (BPS) could promote the transformation of plasmid-borne ARGs. Using plasmid pUC19 carrying the ampicillin resistance gene as an extracellular ARG and model microorganism E. coli DH5α as the recipient, we established a transformation system. Transformation assays revealed that environmentally relevant concentrations of BPS (0.1-10 μg/mL) markedly enhanced the transformation frequency of plasmid-borne ARGs into E. coli DH5α up to 2.02-fold. Fluorescent probes and transcript-level analyses suggest that BPS stimulated increased reactive oxygen species (ROS) production, activated the SOS response, induced membrane damage, and increased membrane fluidity, which weakened the barrier for plasmid transfer, allowing foreign DNA to be more easily absorbed. Moreover, BPS stimulates ATP supply by activating the tricarboxylic acid (TCA) cycle, which promotes flagellar motility and expands the search for foreign DNA. Overall, these findings provide important insight into the role of bisphenol compounds in facilitating the horizontal spread of ARGs and emphasize the need to monitor the residues of these environmental contaminants.

Neurodevelopmental effects of prenatal Bisphenol A exposure on the role of microRNA regulating NMDA receptor subunits in the male rat hippocampus

Maternal bisphenol A (BPA) exposure has been reported to cause learning and memory deficits in born offspring. However, little is known that this impairment is potentially caused by epigenetic modulation on the development of NMDA receptor subunits. This study investigates the effect of prenatal BPA exposure on the hippocampal miR-19a and miR-539, which are responsible for regulating NMDA receptor subunits as well as learning and memory functions. Pregnant Sprague Dawley rats were orally administered with 5 mg/kg/day of BPA from pregnancy day 1 (PD1) until gestation day 21 (GD21), while control mothers received no BPA. The mothers were observed daily until GD21 for either a cesarean section or spontaneous delivery. The male offspring were sacrificed when reaching GD21 (fetus), postnatal days 7, 14, 21 (PND7, 14, 21) and adolescent age 35 (AD35) where their hippocampi were dissected from the brain. The expression of targeted miR-19a, miR-539, GRIN2A, and GRIN2B were determined by qRT-PCR while the level of GluN2A and GluN2B were estimated by western blot. At AD35, the rats were assessed with neurobehavioral tests to evaluate their learning and memory function. The findings showed that prenatal BPA exposure at 5 mg/kg/day significantly reduces the expression of miR-19a, miR-539, GRIN2A, and GRIN2B genes in the male rat hippocampus at all ages. The level of GluN2A and GluN2B proteins is also significantly reduced when reaching adolescent age. Consequently, the rats showed spatial and fear memory impairments when reaching AD35. In conclusion, prenatal BPA exposure disrupts the role of miR-19a and miR-539 in regulating the NMDA receptor subunit in the hippocampus which may be one of the causes of memory and learning impairment in adolescent rats.

Bisphenol A triggers apoptosis in mouse pre-antral follicle granulosa cells via oxidative stress

BACKGROUND

Bisphenol A (BPA), an endocrine disrupting chemical with weak estrogenic and anti-androgenic activity, is widely present in various environmental media and organisms. It has certain reproductive toxicity and can cause a variety of female reproductive system diseases. Although BPA-stimulated apoptosis of granulosa cells has been widely elaborated, the effect of BPA on mouse pre-antral follicle granulosa cells (mpGCs) has not been well elucidated.

RESULTS

In this study, the results of live-dead cell staining showed that high concentrations of BPA severely impaired mpGCs growth viability and affected the cell cycle transition of mpGCs. We confirmed that BPA promotes the production of reactive oxygen species (ROS) and facilitates oxidative stress in mpGCs. In addition, immunofluorescence, transmission electron microscopy, and flow cytometry experiments demonstrated that BPA treatment for mpGCs resulted in apoptotic features, such as rounding, cytoplasmic crinkling, and mitochondrial damage. This was accompanied by a large production of ROS and apoptosis-inducing factor (AIF) translocation from the mitochondria to the nucleus. RNA-seq data showed that several apoptosis-related pathways were enriched in the high concentration BPA-treated group compared with the normal group, such as the p53 pathway, MAPK pathway, etc. CONCLUSIONS: These results suggest that cells undergo oxidative stress effects and apoptosis after BPA treatment for mpGCs, which affects normal follicle development. The potential mechanism of BPA-induced female reproductive toxicity was elucidated, while providing a research basis for the prevention and treatment of female reproductive diseases.

Developmental Programming: Impact of Prenatal Exposure to Bisphenol A on Senescence and Circadian Mediators in the Liver of Sheep

Prenatal exposure to endocrine disruptors such as bisphenol A (BPA) plays a critical role in the developmental programming of liver dysfunction that is characteristic of nonalcoholic fatty liver disease (NAFLD). Circadian and aging processes have been implicated in the pathogenesis of NAFLD. We hypothesized that the prenatal BPA-induced fatty-liver phenotype of female sheep is associated with premature hepatic senescence and disruption in circadian clock genes. The expression of circadian rhythm and aging-associated genes, along with other markers of senescence such as telomere length, mitochondrial DNA copy number, and lipofuscin accumulation, were evaluated in the liver tissue of control and prenatal BPA groups. Prenatal BPA exposure significantly elevated the expression of aging-associated genes GLB1 and CISD2 and induced large magnitude differences in the expression of other aging genes-APOE, HGF, KLOTHO, and the clock genes PER2 and CLOCK-in the liver; the other senescence markers remained unaffected. Prenatal BPA-programmed aging-related transcriptional changes in the liver may contribute to pathological changes in liver function, elucidating the involvement of aging genes in the pathogenesis of liver steatosis.

New insights into brain injury in chickens induced by bisphenol A and selenium deficiency-Mitochondrial reactive oxygen species and mitophagy-apoptosis crosstalk homeostasis

Bisphenol A (BPA), a component of plastic products, can penetrate the blood-brain barrier and pose a threat to the nervous system. Selenium (Se) deficiency can also cause nervous system damage. Resulting from the rapid industrial development, BPA pollution and Se deficiency often coexist. However, it is unclear whether brain damage in chickens caused by BPA exposure and Se deficiency is related to the crosstalk disorder between mitophagy and apoptosis. In this study, 60 chickens (1 day old) were fed with a diet that contained 20 mg/kg BPA but was insufficient in Se (only 0.039 mg/kg) for 42 days to establish a chicken brain injury model. In vitro, the primary chicken embryo brain neurons were treated for 24 h with Se-deficient medium containing 75 μM BPA. The results showed that BPA exposure and Se deficiency inhibited the expression of the mitochondrial respiratory chain complex in brain neurons, and a large number of mitochondrial reactive oxygen species were released. Furthermore, the expression levels of mitochondrial fusion proteins (OPA1, Mfn1, and Mfn2) decreased, while the expression levels of mitochondrial fission proteins (Drp1, Mff, and Fis1) increased, thus exacerbating mitochondrial division. In addition, the results of immunofluorescence and flow cytometry analysis, as well as the elevated expressions of mitophagy related genes (PINK1, Parkin, ATG5, and LC3II/I) and pro-apoptotic markers (Bax, Cytc, Caspase3, and Caspase9) indicated that BPA exposure and Se deficiency disrupted the crosstalk homeostasis between mitophagy and apoptosis. However, this crosstalk homeostasis was restored after Mito-Tempo and Rapamycin treatment. In contrast, 3-methyladenine treatment exacerbated this crosstalk disorder. In conclusion, BPA exposure and Se deficiency can induce mitochondrial reactive oxygen species bursts and disorders of mitochondrial dynamics by destroying the mitochondrial respiratory chain complex. The result is indicative of an imbalance in mitochondrial autophagy and apoptosis crosstalk homeostasis, which damages the chicken brain.

The evaluation of serum bisphenol A in patients with preeclampsia

AIMS

High bisphenol A (BPA) concentration may compromise normal placental development. The aim of this study was to determine maternal serum BPA concentrations in pregnant women with complicated preeclampsia (PE) and normal pregnant women, to compare BPA concentrations, and to examine pregnancy outcomes.

METHODS

This prospective case-control study was conducted between March 2021 and October 2021. Serum BPA levels of preeclamptic pregnancy and normal pregnancy were statistically evaluated. In addition, the PE group was divided into three subgroups according to the course of pregnancy. Group 1: patients with non-severe PE who delivered at 37 weeks or later, Group 2: patients with severe PE who delivered at less than 34 weeks, Group 3: patients with severe PE who delivered between 34 and 37 weeks. The association between BPA levels and pregnancy outcome was investigated.

RESULTS

Forty-six cases in the PE group were compared with 46 cases of normal pregnancies. The median BPA level was 19.46 ng/mL in the PE group and 16.36 ng/mL in the control group. The median BPA levels in the PE group were significantly higher than those in the control group (p = 0.007). Serum BPA levels were significantly lower in women who delivered at 37 weeks or later than in women who delivered at less than 34 weeks due to severe PE (p ≤ 0.018).

CONCLUSION

Our study highlights the association between elevated maternal serum levels of BPA and PE. Moreover, knowledge of BPA levels in women with PE may provide information about the prognosis of pregnancy.

Tetramethyl bisphenol A stimulates proliferation but inhibits fetal Leydig cell function in male rats by targeting estrogen receptor α after in utero exposure

Tetramethyl bisphenol A (TMBPA) is a widely used flame retardant. TMBPA has been a toxic to Leydig cells in puberty, but it remains unclear whether TMBPA has a similar inhibitor effect on fetal Leydig cells (FLCs). This study reported morphological and functional alterations of FLCs in the testes of male offspring at birth after in utero exposure to TMBPA. Pregnant Sprague Dawley rats were dosed via continuous gavage of TMBPA (0, 10, 50, and 200 mg/kg/day) from gestational day 14 to 21. TMBPA markedly raised serum total testosterone level, testicular volume, and FLC number of male offspring at 200 mg/kg dose. The up-regulation of Insl3, Star, and Cyp11a1 mRNAs was observed after 200 mg/kg TMBPA exposure. After normalization to the number of FLCs, TMBPA significantly reduced Lhcgr and Hsd3b1 expressions at 10 mg/kg, and Cyp17a1 at 200 mg/kg paralleling with their protein levels. TMBPA compromised the expression of Esr1, while increased the expression of Cdk2 and Cdk4 as well as their protein levels. TMBPA particularly increased the phosphorylation of AKT1 and AKT2 at 200 mg/kg. In conclusion, the present study suggests that TMBPA may promote FLC proliferation via ESR1-CDK2/4-AKT pathway, while inhibits the function of FLCs by reducing steroidogenic enzyme activity.

Fetal Myocardial Expression of GLUT1: Roles of BPA Exposure and Cord Blood Exosomes in a Rat Model

Dietary exposure to Bisphenol A (BPA), an industrial chemical present in food containers, affects nutrient metabolism in the myocardium of offspring during intrauterine life. Using a murine model, we observed that fetal hearts from mothers exposed to BPA (2.5 μg/kg/day) for 20 days before mating and for all of the gestation had decreased expression of glucose transporter-1 (GLUT1), the principal sugar transporter in the fetal heart, and increased expression of fatty acid cluster of differentiation 36 transporter (CD36), compared to control fetuses from vehicle-treated mothers. We confirmed the suppression of GLUT1 by exposing fetal heart organotypic cultures to BPA (1 nM) for 48 h but did not detect changes in CD36 compared to controls. During pregnancy, the placenta continuously releases extracellular vesicles such as exosomes into fetal circulation. These vesicles influence the growth and development of fetal organs. When fetal heart cultures were treated with cord blood-derived exosomes isolated from BPA-fed animals, GLUT1 expression was increased by approximately 40%. Based on our results, we speculate that exosomes from cord blood, in particular placenta-derived nanovesicles, could contribute to the stabilization of the fetal heart metabolism by ameliorating the harmful effects of BPA on GLUT1 expression.

Three-dimensional ordered macroporous imprinted polymer for bisphenol A recognition

A novel kind of three-dimensional ordered macroporous molecular imprinted polymer (3DOM MIP) was prepared and studied. Monodisperse silica microspheres were used to form silica crystal template via simple centrifuge. In the presence of template molecule, acrylamide and trimethylolpropane trimethacrylate were co-polymerized in the interstices of crystal template bisphenol A (BPA). Hydrofluoric acid were employed to etch silica crystal and the mixed solvent of methanol with acetic acid were employed to extract template molecule. The results of SEM and FTIR confirmed the successful synthesis of 3DOM MIP. The obtained 3DOM MIP exhibited a rapid adsorption kinetics and a specific adsorption capacities toward template molecule because of the small size of MIP wall, which possessed much more effective imprinted cavies. Meanwhile, 3DOM MIP could selective recognized BPA from its structural analogues.

The Impact of Bisphenol A on Thyroid Function in Neonates and Children: A Systematic Review of the Literature

Background: Bisphenol A (BPA) is an endocrine-disrupting chemical widely used in plastic products that may have an adverse effect on several physiologic functions in children. The aim of this systematic review is to summarize the current knowledge of the impact of BPA concentrations on thyroid function in neonates, children, and adolescents. Methods: A systematic search of Medline, Scopus, Clinical Trials.gov, Cochrane Central Register of Controlled Trials CENTRAL, and Google Scholar databases according to PRISMA guidelines was performed. Only case–control, cross-sectional, and cohort studies that assessed the relationship between Bisphenol A and thyroid function in neonates and children aged <18 years were included. Initially, 102 articles were assessed, which were restricted to 73 articles after exclusion of duplicates. A total of 73 articles were assessed by two independent researchers based on the title/abstract and the predetermined inclusion and exclusion criteria. According to the eligibility criteria, 18 full-text articles were selected for further assessment. Finally, 12 full-text articles were included in the present systematic review. Results: The presented studies offer data that suggest a negative correlation of BPA concentrations with TSH in children, a gender-specific manner of action, and a potential effect on proper neurodevelopment. However, the results are inconclusive with respect to specific thyroid hormone concentrations and the effect on thyroid autoimmunity. Conclusion: The potential negative effect of BPA in the developing thyroid gland of children that may affect proper neurodevelopment, suggesting the need to focus future research on designing studies that elucidate the underlying mechanisms and the effects of BPA in thyroid function in early life.