The effects of maternal exposure to bisphenol A on allergic lung inflammation into adulthood

Decreased Treg cells induced by bisphenol A is associated with up-regulation of PI3K/Akt/mTOR signaling pathway and Foxp3 DNA methylation in spleen of adolescent mice

The current study aimed to explore whether bisphenol A (BPA) exposure aggravated the decrease in Tregs induced by ovalbumin (OVA) in adolescent female mouse models of asthma, and whether the process was associated with mTOR-mediated signaling pathways and DNA methylation levels. A total of 40 female C57BL/6 mice at the age of four weeks were used and divided into five groups after 1 week of domestication. Each group consisted of eight mice: the control group, OVA group, OVA + BPA (0.1 μg mL-1) group, OVA + BPA (0.2 μg mL-1) group, and OVA + BPA (0.4 μg mL-1) group. Results revealed that Foxp3 protein levels decreased in the spleens of mice exposed to BPA compared to those in the OVA group. After an elevation in BPA dose, the mRNAs of methyltransferases (Dnmt1, Dnmt3a, and Dnmt3b) were gradually upregulated. The mechanism was related to the activity of TLR4/NF-κB and PI3K/Akt/mTOR signaling pathways and the enhancement of Foxp3 DNA methylation. Our results, collectively, provided a new view for studying the mechanisms underlying BPA exposure-induced immune dysfunction. Investigation of the regulatory mechanisms of DNA methylation in the abnormal Th immune response caused by BPA exposure could help reveal the causes and molecular mechanisms underlying the high incidence of allergic diseases in children in recent years.

Antiinflammatory effect of the ethanolic extract of Korean native herb Potentilla rugulosa Nakai in Bisphenol-a-stimulated A549 cells

Potentilla rugulosa Nakai (P. rugulosa) is a perennial herb in the Rosaceae family and found in the Korean mountains. Previously, our findings demonstrated that P. rugulosa contains numerous polyphenols and flavonoids exhibiting important antioxidant and anti-obesity bioactivities. Bisphenol A (BPA) is a xenoestrogen that was shown to produce pulmonary inflammation in humans. However, the mechanisms underlying BPA-induced inflammation remain to be determined. The aim of this study was to examine whether ethanolic extract of P. rugulosa exerted an inhibitory effect on BPA-induced inflammation utilizing an adenocarcinoma human alveolar basal epithelial cell line A549. The P. rugulosa extract inhibited BPA-mediated cytotoxicity by reducing levels of reactive oxygen species (ROS). Further, P. rugulosa extract suppressed the upregulation of various pro-inflammatory mediators induced by activation of the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. In addition, inhibition of the NF-κB and MAPK signaling pathways by P. rugulosa extract was found to occur via decrease in the transcriptional activity of NF-κB. Further, blockade of phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and stress-activated protein kinase/Jun N-terminal kinase (SAPK/JNK) was noted. Thus, our findings suggest that the ethanolic extract of P. rugulosa may act as a natural anti-inflammatory therapeutic agent.

Current knowledge on the effects of environmental contaminants in early life nutrition

Breast milk represents the optimal source of feeding for newborns, in terms of nutritional compounds and as it provides immunological, metabolic, organic, and neurological well-being. As a complex biological fluid, it consists not only of nutritional compounds but also contains environmental contaminants. Formulas through production, contact with bottles and cups, and complementary feeding can also be contaminated. The current review focuses on endocrine-disrupting chemicals, and made-man xenoestrogens present in the environment and both commonly present in food sources, agricultural practices, packaging, consumer products, industry, and medical care. These contaminants are transferred by passive diffusion to breast milk and are delivered during breastfeeding. They mainly act by activating or antagonizing hormonal receptors. We summarize the effects on the immune system, gut microbiota, and metabolism. Exposure to endocrine-disrupting chemicals and indirect food additives may induce tissue inflammation and polarize lymphocytes, increase proinflammatory cytokines, promote allergic sensitization, and microbial dysbiosis, activate nuclear receptors and increase the incidence of allergic, autoimmune, and metabolic diseases. Breast milk is the most important optimal source in early life. This mini-review summarizes current knowledge on environmental contaminants and paves the way for strategies to prevent milk contamination and limit maternal and infant exposure during pregnancy and the first months of life.

Association of urinary bisphenol A with chronic obstructive pulmonary disease-related diseases: evidence from the National Health and Nutrition Examination Survey database (2005-2016)

In vivo and in vitro studies have found that exposure to bisphenol A (BPA) can lead to pulmonary diseases, but there exists little evidence regarding the association between urinary BPA level and chronic obstructive pulmonary disease (COPD)-related diseases in the population. National Health and Nutrition Examination Survey data, from 2005 to 2016, were utilized in this study. Participants who self-reported having emphysema, chronic bronchitis, or COPD were defined as having COPD-related diseases. A multivariate logistic regression analysis was used to analyze the association of urinary BPA with COPD-related diseases in the overall population and according to sex. Three separate models including different covariates were used in our analyses. The association of urinary BPA with COPD-related diseases in different subgroups (age, smoking status, participants belonging to "ever had asthma" and "ever had cardiovascular disease") other than sex was also analyzed. Based on the different models, 9189, 7006, and 6946 participants were used in our study. BPA was found to be significantly associated with COPD-related diseases in all models. The concentration of BPA in urine was significantly associated with COPD-related diseases regardless of whether BPA concentration was treated as a continuous variable (odds ratio (OR): 1.24, 95% confidence interval (CI): 1.11-1.38, in model 3) or as tertiles (OR: 2.01, 95% CI: 1.49-2.72, between the lowest group and highest group, in model 3). This association was significant among male but not female participants. BPA also demonstrated a significant association with emphysema and chronic bronchitis in adults, particularly in males. No significant interaction was found for all the other subgroup analyses. Urinary BPA was associated with COPD-related diseases in adult participants, especially males.

Bisphenol A, TH17 cells, and allergy: a commentary

There is a continuing interest in whether Bisphenol A (BPA) is able to cause adverse health effects through interaction with elements of the immune system. That interest has been fuelled further by the recent publication of a draft opinion on BPA prepared by the European Food Safety Authority (EFSA) Panel on Food Contact Materials, Enzymes and Processing Aids (CEP). This draft opinion judged effects on the immune system to be the most sensitive health outcome, and identified BPA-induced changes in the frequency of T-helper (T_H)-17 cells in the spleens of mice as being the critical effect based on an association of these cells with inflammation. Based on these evaluations the CEP Panel recommended that a revised Tolerable Daily Intake (TDI) for BPA of 0.04 ng/kg bw/day should be adopted; representing a very substantial reduction (100,000-fold) compared with the existing TDI. The purpose of this commentary is to summarize briefly the role of T_H17 cells in immune responses, and to review relevant literature regarding the influence of BPA on these cells, and on inflammatory responses in the lung and respiratory allergy. The conclusion drawn is that based on uncertainties about the effects of BPA on T_H17 cells and lung inflammation in mice, the absence of consistent or persuasive evidence from human studies that exposure of BPA is associated with inflammation or allergy, and unresolved questions regarding the species selectivity of immune effects induced by BPA, it is inappropriate to adopt the revised TDI. Additional research is required to explore further the influence of BPA on the immune system and immune responses.

Bisphenol A attenuates the therapeutic effect of the selective G protein-coupled estrogen receptor agonist G-1 on allergic rhinitis inflammation in mice

BACKGROUND

Bisphenol A (BPA) is found in many plastics widely used in everyday life and affects the immune system. Previous studies found that the selective G protein coupled estrogen receptor (GPER) agonist G-1 can reduce the inflammation associated with asthma and allergic rhinitis (AR). BPA also interferes with the protective effect of estradiol against myocardial ischemia-reperfusion injury.

OBJECTIVE

We explored whether BPA attenuates the effect of G-1 on inflammation in a mouse AR model.

METHODS

The AR model was established by sensitizing and stimulating female BALB/c mice with ovalbumin (OVA) and G-1/BPA. Eosinophils, neutrophils, and lymphocyte subsets (including T and B cells) in nasal mucosa and Th2 and Treg cells in the spleen were detected by flow cytometry. Cytokines and transcription factors characteristic of Th2 and Treg cells in nasal mucosa were detected using cytometric bead arrays and quantitative PCR, respectively.

RESULTS

G-1 reduced OVA-induced nasal mucosal inflammation in mice. The proportions of eosinophils, neutrophils, Siglec-F⁺ neutrophils, lymphocytes, and T cell subsets were reduced by G-1, and this effect was attenuated by BPA. G-1 significantly decreased the Th2 population and levels of IL-4, IL-5, IL-13 and GATA-3; these effects were attenuated by BPA. The enhanced Treg response (as evidenced by an increased Treg population and higher IL-10 and Foxp3 levels) mediated by G-1 tended to be reduced by BPA.

DISCUSSION

We found that G-1 reduced OVA-induced nasal mucosal inflammation and significantly decreased the Th2 response, while increasing the Treg response. These effects were attenuated by BPA.

Exposure to a mixture of 23 chemicals associated with unconventional oil and gas operations alters immune response to challenge in adult mice

The prevalence of unconventional oil and gas (UOG) operations raises concerns regarding the potential for adverse health outcomes following exposure to water tainted by mixtures of UOG associated chemicals. The potential effects that exposure to complex chemical mixtures has on the immune system have yet to be fully evaluated. In this study, effects on the immune system of adult mice exposed to a mixture of 23 chemicals that have been associated with water near active UOG operations were investigated. Female and male mice were exposed to the mixture via their drinking water for at least 8 weeks. At the end of the exposure, cellularity of primary and secondary immune organs, as well as an immune system function, were assessed using three different models of disease, i.e. house dust mite (HDM)-induced allergic airway disease, influenza A virus infection, and experimental autoimmune encephalomyelitis (EAE). The results indicated exposures resulted in different impacts on T-cell populations in each disease model. Furthermore, the consequences of exposure differed between female and male mice. Notably, exposure to the chemical mixture significantly increased EAE disease severity in females, but not in male, mice. These findings indicated that direct exposure to this mixture leads to multiple alterations in T-cell subsets and that these alterations differ between sexes. This suggested to us that direct exposure to UOG-associated chemicals may alter the adult immune system, leading to dysregulation in immune cellularity and function.

The effects of bisphenol A given in ovo on bursa of Fabricius development and percentage of acid phosphatase positive lymphocyte in chicken

Bisphenol A (BPA), one of the endocrine disrupting chemicals, is the object of great concern because of its widespread use throughout the world. In this study, it was aimed to determine the effects of in ovo administrated BPA on the bursa of Fabricius and percentage of acid phosphatase positive lymphocyte in peripheral blood by means of histological and enzyme histochemical methods. For this purpose, 310 fertile eggs of Isa Brown laying parent stock were used. The eggs were divided into 5 groups as control, vehicle control, 50, 100, and 250μg/egg BPA. At days 13, 18, and 21 of incubation, eggs were opened until 10 living embryos were obtained from each group. Tissue samples were taken from the obtained embryos and processed for enzyme histochemical methods in addition to routine histological techniques. It was observed that, in BPA-treated groups, embryonic development of bursa of Fabricius was retarded. It was also indicated that the percentage of peripheral blood ACP-ase positive lymphocytes was significantly decreased. These results suggested that a limited maternal transfer of BPA into the eggs might be lead to immunosuppression in chicks.

Bisphenol A increases TLR4-mediated inflammatory response by up-regulation of autophagy-related protein in lung of adolescent mice

In previous studies we found that bisphenol A (BPA) aggravated OVA-induced lung inflammation. The aim of this research was to determine whether BPA exposure alone also induced inflammatory response in the lungs, which mechanism was associated with TLR4/NF-κB signaling pathway and the activation of mTOR-mediated autophagy. Female C57BL/6 mice aged 4 weeks were randomly divided into three groups (10/group): control group, 0.1 and 0.2 μg mL^-1 BPA groups. BPA induced the pathological changes in the lung and increased the levels of cytokines and inflammatory cells, as well as affected autophagy related proteins expression. In addition, the RAW264.7 cell culture experiment was conducted in order to confirm the role of autophagy. We found that BPA can enhance autophagy flux by enhancing autophagosome formation. It was further confirmed the details of the mechanism of action with chloroquine (CQ, a compound that inhibits the fusion of autophagosomes and lysosomes) intervention. The inhibition of autophagy led to down-regulation of expression levels associated with inflammation. This research results indicated that BPA induced inflammatory response in vitro and in vivo, and its mechanism may be related to TLR4/NF-κB signaling pathway and the activation of mTOR-mediated autophagy. After autophagy was suppressed, the inflammatory response also weakened. Our findings provide a new perspective into the mechanisms underlying inflammatory responses induced by the environmental exposure. These findings indicate that therapeutic strategies targeting autophagy may provide a new method for the treatment of inflammatory diseases.

Bisphenol A, S or F mother's dermal impregnation impairs offspring immune responses in a dose and sex-specific manner in mice

Bisphenol (BP)A is an endocrine disruptor (ED) widely used in thermal papers. Regulatory restrictions have been established to prevent risks for human health, leading to BPA substitution by structural analogues, like BPS and BPF. We previously demonstrated that oral perinatal exposure to BPA had long-term consequences on immune responses later in life. It appears now essential to enhance our understanding on immune impact of different routes of BP exposure. In this study, we aimed at comparing the impact of mother dermal exposure to BPs on offspring immune system at adulthood. Gravid mice were dermally exposed to BPA, BPS or BPF at 5 or 50 μg/kg of body weight (BW)/day (d) from gestation day 15 to weaning of pups at post-natal day (PND)21. In offspring, BPs dermal impregnation of mothers led to adverse effects on immune response at intestinal and systemic levels that was dependent on the BP, the dose and offspring sex. These findings provide, for the first time, results on long-term consequences of dermal perinatal BPs exposure on immune responses in offspring. This work warns that it is mandatory to consider immune markers, dose exposure as well as sex in risk assessment associated with new BPA’s alternatives.

Differential influences of the BPA, BPS and BPF on in vitro IL-17 secretion by mouse and human T cells

The endocrine disruptor and food contaminant bisphenol A (BPA) is frequently present in consumer plastics and can produce several adverse health effects participating in the development of inflammatory and autoimmune diseases. Regulatory restrictions have been established to prevent risks for human health, leading to the substitution of BPA by structural analogues, such as bisphenol S (BPS) and F (BPF). In this study, we aimed at comparing the in vitro impact of these bisphenols from 0.05 to 50,000 nM on Th17 differentiation, frequency and function in mouse systemic and intestinal immune T cells and in human blood T cells. This study reports the ability of these bisphenols, at low and environmentally relevant concentration, i.e, 0.05 nM, to increase significantly IL-17 production in mouse T cells but not in human T lymphocytes. The use of an aryl hydrocarbon receptor (AhR) specific inhibitor demonstrated its involvement in this bisphenol-induced IL-17 production. We also observed an increased IL-17 secretion by BPS and BPF, and not by BPA, in mouse naive T cells undergoing in vitro Th17 differentiation. In total, this study emphasizes the link between bisphenol exposures and the susceptibility to develop immune diseases, questioning thus the rational of their use to replace BPA.

Environmental pollutants and the immune response

Environmental pollution is one of the most serious challenges to health in the modern world. Pollutants alter immune responses and can provoke immunotoxicity. In this Review, we summarize the major environmental pollutants that are attracting wide-ranging concern and the molecular basis underlying their effects on the immune system. Xenobiotic receptors, including the aryl hydrocarbon receptor (AHR), sense and respond to a subset of environmental pollutants by activating the expression of detoxification enzymes to protect the body. However, chronic activation of the AHR leads to immunotoxicity. KEAP1-NRF2 is another important system that protects the body against environmental pollutants. KEAP1 is a sensor protein that detects environmental pollutants, leading to activation of the transcription factor NRF2. NRF2 protects the body from immunotoxicity by inducing the expression of genes involved in detoxification, antioxidant and anti-inflammatory activities. Intervening in these sensor-response systems could protect the body from the devastating immunotoxicity that can be induced by environmental pollutants.

Lung inflammation induced by exposure to Bisphenol-A is associated with mTOR-mediated autophagy in adolescent mice

Epidemiologic studies show that there is a link between Bisphenol A (BPA) exposure and lung inflammation. Despite this, the molecular mechanisms are not entirely known. This study sought to determine whether exposure to BPA affected the development of ovalbumin (OVA) induced lung inflammation in adolescent female mice and whether the mechanism was related to mTOR-mediated autophagy pathway. Female 4-week-old C57BL/6 mice after one week of domestication were randomly divided into five groups (8/group): control group, OVA group, 0.1 μg mL^-1 BPA + OVA group, 0.2 μg mL^-1 BPA + OVA group and 0.4 μg mL^-1 BPA + OVA group. BPA exacerbated airway hyperresponsiveness (AHR), induced the pathological changes in the lung, which also enhanced inflammatory cells and cytokine levels. In addition, BPA exposure affected expression of autophagy associated proteins and genes. This research results indicated that BPA aggravated OVA-induced lung inflammation and induced abnormal immune function in mice, and its mechanism was related to the activation of autophagy pathway by down-regulation expression of mTOR. These findings suggest that therapeutic strategies to target autophagy may offer a new approach for severe asthma therapy.

Association of urinary levels of bisphenols F and S used as bisphenol A substitutes with asthma and hay fever outcomes

BACKGROUND

Bisphenols F (BPF) and S (BPS) are bisphenol A (BPA) analogs used as substitutes in consumer products. Despite previous reports of BPA's association with asthma, no studies have examined its structural analogs in relation to asthma and allergy outcomes.

OBJECTIVE

To examine the association of urinary BPF, BPS, and BPA with asthma and hay fever in a US representative sample.

METHODS

We analyzed data from 3,538 participants aged 12 years or older in the 2013-2016 National Health and Nutrition Examination Survey (NHANES). Children aged 6-11 years (N = 738), who did not have all covariate data available, were analyzed separately. Covariate-adjusted logistic regression was used to assess the association of the exposures with the outcomes.

RESULTS

BPF, BPS, and BPA were detected in 57.1%, 88.4%, and 94.8% of the urine samples, respectively. Urinary BPF detection was positively associated with current asthma (odds ratio [OR]: 1.54, 95% confidence interval [CI]: 1.16-2.04) and hay fever (OR: 1.66, 95% CI: 1.12-2.46). Urinary BPS was associated with increased odds of current asthma in men (OR: 1.64, 95% CI: 1.13-2.40) and urinary BPA was associated with increased odds of asthma without hay fever in children aged 6-11 years (OR: 2.65, 95% CI: 1.05-6.68).

CONCLUSION

Our nationally-representative findings document that BPF and BPS exposure is common in the US and that exposure to these BPA analogs is associated with asthma and/or hay fever. Our results suggest that BPF and BPS may not be safe alternatives to BPA; however, prospective studies should be conducted to confirm these results.

Oral exposure to low dose bisphenol A aggravates allergic airway inflammation in mice

•

Oral exposure to BPA relevant to human exposure aggravated allergic asthma.

•

Low dose BPA with allergen reduced lung mRNA levels of hormone receptors.

•

Low dose BPA with allergen altered lymph node and bone marrow microenvironments.

Bisphenol A (BPA) is widely used in many consumer products and has adverse effects on human health including allergic diseases. We investigated the effects of low dose BPA, comparable to actual human oral exposure, on allergic asthma in mice. C3H/HeJ male mice were fed a chow diet containing BPA (equivalent to 0.09, 0.90, or 9.01 μg/kg/day) and were intratracheally administered ovalbumin (OVA, 1 μg/animal) every two weeks from 5–11 weeks of age. All doses of BPA plus OVA enhanced pulmonary inflammation and airway hyperresponsiveness, and increased lung mRNA levels of Th2 cytokine/chemokine, and serum OVA-specific IgE and IgG₁ compared to OVA alone, with greater effects observed in the middle- and high-dose BPA plus OVA groups. Furthermore, high-dose BPA with OVA decreased lung mRNA levels of ERβ and AR compared with OVA. Furthermore, BPA enhanced OVA-restimulated cell proliferation and protein levels of IL-4 and IL-5 in mediastinal lymph node (MLN) cells in OVA-sensitized mice. In bone marrow (BM) cells, middle-dose BPA with OVA increased Gr-1 expression. In conclusion, oral exposure to low-dose BPA at levels equivalent to human exposure can aggravate allergic asthmatic responses through enhancement of Th2-skewed responses, lung hormone receptor downregulation, and MLN and BM microenvironment change.

Memory Function, Neurological, and Immunological Biomarkers in Allergic Asthmatic Mice Intratracheally Exposed to Bisphenol A

Bisphenol A (BPA) is a major constituent of plastic products, including epoxy resin containers, mobile phones, dental sealants, as well as electronic and medical equipment. BPA is recognized as an endocrine system-disrupting chemical which has toxic effects on the brain and reproductive system. However, little is known about the effects of co-exposure of BPA with allergens on the memory function and neurological as well as immunological biomarker levels. In this study, we examined the effects of intratracheal instillation of BPA on the memory function and neuroimmune biomarker levels using a mouse model of allergic asthma. Male C3H/HeJ Jcl mice were given three doses of BPA (0.0625 pmol, 1.25 pmol, and 25 pmol BPA/animal) intratracheally once a week, and ovalbumin (OVA) intratracheally every other week from 5 to 11 weeks old. At 11 weeks of age, a novel object recognition test was conducted after the final administration of OVA, and the hippocampi and hypothalami of the animals were collected after 24 h. The expression levels of the memory function-related genes N-methyl-D-aspartate (NMDA) receptor subunits, inflammatory cytokines, microglia markers, estrogen receptor-alpha, and oxytocin receptor were examined by real-time RT-PCR (real-time reverse transcription polymerase chain reaction) and immunohistochemical methods. Impairment of the novel object recognition ability was observed in the high-dose BPA-exposed mice with allergic asthma. In addition, the allergic asthmatic mice also showed downregulation of neurological biomarkers, such as NMDA receptor subunit NR2B in the hippocampus but no significant effect on immunological biomarkers in the hypothalamus. These findings suggest that exposure to high-dose BPA triggered impairment of memory function in the allergic asthmatic mice. This is the first study to show that, in the presence of allergens, exposure to high-dose BPA may affect memory by modulating the memory function-related genes in the hippocampus.

Oral Administration of Bisphenol A Directly Exacerbates Allergic Airway Inflammation but Not Allergic Skin Inflammation in Mice

Bisphenol A (BPA) is used in various areas of daily life as a major component of plastic products. However, it is also known as a strong endocrine disruptor that affects the human immune system. Studies have indicated that BPA possibly exacerbates allergic diseases such as atopic dermatitis and asthma. The main aim of this study was to elucidate whether BPA is directly involved in the exacerbation of allergic inflammation. Initially, in vivo experiments with mouse models of allergic inflammation induced by Th2 type hapten toluene-2, 4-diisocyanate (TDI) was performed. Mice were subjected to oral administration of BPA 48, 24, and 4 h before challenge with TDI. Dermal challenge of TDI onto the ear auricle was performed for the allergic dermatitis model, and intratracheal challenge of TDI was performed for the allergic airway inflammation model. In the allergic dermatitis model, ear-swelling response was significantly downregulated by high doses of BPA. The opposite reaction was observed in the allergic airway inflammation model, including significant exacerbation of red coloration in the lung, local cytokine levels, and total IgE levels in serum by BPA administration. To confirm the in vivo results, in vitro experiments with human epidermal keratinocytes (HEKs) and bronchial epithelial (BEAS-2B) cells were carried out. Significant enhancement of cytokine release from BEAS-2B cells but not HEKs in the BPA-treated group supported the in vivo observations. Our results imply that exposure to BPA directly exacerbates allergic airway inflammation but not allergic dermatitis.

Association between bisphenol A diglycidyl ether-specific IgG in serum and food sensitization in young children

Background

Recent studies have reported that endocrine-disrupting compound (EDC) exposure is related to food sensitization. Bisphenol A diglycidyl ether (BADGE) is one of the most widespread EDCs and its biological effects are considered to be greater on children than on adults. This study investigated the relationship between serum BADGE-specific immunoglobulin G (IgG) concentrations and food sensitization in young children by measuring food-specific IgE levels.

Methods

In total, 98 young children (59 boys and 39 girls; median age: 7 months; 25th and 75th percentile ages: 6 and 8 months, respectively) were enrolled. Blood samples were collected twice from all children (median sampling interval: 6 months; 25th and 75th percentile: 5 and 7 months). Food sensitization was evaluated based on food-specific IgE titers (egg white, milk, and wheat), which were determined using the capsulated hydrophilic carrier polymer-radioallergosorbent test. Furthermore, a dot-blotting assay for BADGE-specific IgG and quantitative reverse-transcriptase PCR for IL-6, IL-8, IL-10, and COX-2 mRNA expression were conducted.

Results

BADGE-specific IgG was detected in 20% of study subjects. A significant association was observed between the presence of BADGE-specific IgG and elevated wheat-specific IgE levels (OR = 3.56; 95% CI 1.13–11.2; P = 0.031). This relationship was particularly strong in girls (OR = 9.46; 95% CI 1.01–89.0; P = 0.049). A slight but non-significant association was noted between the presence of BADGE-specific IgG and elevated milk-specific IgE levels (OR = 2.77; 95% CI 0.93–8.22; P = 0.067). The expression of IL-6 mRNA among children with BADGE-specific IgG tended to increase, along with wheat-specific IgE levels.

Conclusion

BADGE exposure might enhance food sensitization in early childhood. Therefore, this should be strictly regulated, especially in younger children.

Electronic supplementary material

The online version of this article (10.1186/s40001-018-0358-1) contains supplementary material, which is available to authorized users.

Environmental cues received during development shape dendritic cell responses later in life

Environmental signals mediated via the aryl hydrocarbon receptor (AHR) shape the developing immune system and influence immune function. Developmental exposure to AHR binding chemicals causes persistent changes in CD4+ and CD8+ T cell responses later in life, including dampened clonal expansion and differentiation during influenza A virus (IAV) infection. Naïve T cells require activation by dendritic cells (DCs), and AHR ligands modulate the function of DCs from adult organisms. Yet, the consequences of developmental AHR activation by exogenous ligands on DCs later in life has not been examined. We report here that early life activation of AHR durably reduces the ability of DC to activate naïve IAV-specific CD8+ T cells; however, activation of naïve CD4+ T cells was not impaired. Also, DCs from developmentally exposed offspring migrated more poorly than DCs from control dams in both in vivo and ex vivo assessments of DC migration. Conditional knockout mice, which lack Ahr in CD11c lineage cells, suggest that dampened DC emigration is intrinsic to DCs. Yet, levels of chemokine receptor 7 (CCR7), a key regulator of DC trafficking, were generally unaffected. Gene expression analyses reveal changes in Lrp1, Itgam, and Fcgr1 expression, and point to alterations in genes that regulate DC migration and antigen processing and presentation as being among pathways disrupted by inappropriate AHR signaling during development. These studies establish that AHR activation during development causes long-lasting changes to DCs, and provide new information regarding how early life environmental cues shape immune function later in life.

The effects of bisphenol A on some plasma cytokine levels and distribution of CD8+ and CD4+ T lymphocytes in spleen, ileal Peyer's patch and bronchus associated lymphoid tissue in rats

The effects of bisphenol A on the some plasma cytokine levels and distribution of CD8⁺ and CD4⁺ T lymphocytes in spleen, ilealPeyer's patch and bronchus-associated lymphoid tissue in rats were investigated. A total of fourty male Wistar Albino rats were divided into five groups including 8 rats in each one: control, vehicle, BPA 5, BPA 50 and BPA 500 groups. Doses of 5, 50 and 500 μg/kg BPA were dissolved in ethanol, then mixed with corn oil. The control group received no treatment. The vehicle group was given the ethanol-corn oil mixture. BPA 5, BPA 50 and BPA 500 groups were given, respectively, 5, 50, and 500 μg/kg/day orally. In blood samples, IL-4, IL-6, IL-10 and TNF-α plasma levels were determined with ELISA. Tissue samples (spleen, ileal Peyer's patches and lung) were processed by means of routine histological techniques. CD4 and CD8 were stained immunohistochemically. Data obtained from this study showed that, BPA causes the alteration on immune parameters including cytokine profile, distribution of CD8⁺ and CD4⁺ T lymhpocytes in spleen and ileal Peyer's patches. Present study indicated that BPA may affect immune systems even at lower doses.Disruption of immun system cells and cytokine levels can result in harmful outcomes triggering autoimmune diseases and immunodeficiencies.

Low-dose bisphenol A induces RIPK1-mediated necroptosis in SH-SY5Y cells: Effects on TNF-α and acetylcholinesterase

Bisphenol A (BPA) is an endocrine disruptor chemical, which is commonly used in everyday products. Adverse effects of its exposure are reported even at picomolar doses. Effects of picomolar and nanomolar concentrations of BPA on cytotoxicity, nitric oxide (NO) levels, acetylcholinesterase (AChE) gene expression and activity, and tumor necrosis factor-α (TNF-α) and caspase-8 levels were determined in SH-SY5Y cells. The current study reveals that low-dose BPA treatment induced cytotoxicity, NO, and caspase-8 levels in SH-SY5Y cells. We also evaluated the mechanism underlying BPA-induced cell death. Ours is the first report that receptor-interacting serine/threonine-protein kinase 1-mediated necroptosis is induced by nanomolar BPA treatment in SH-SY5Y cells. This effect is mediated by altered AChE and decreased TNF-α levels, which result in an apoptosis-necroptosis switch. Moreover, our study reveals that BPA is an activator of AChE.

From the Cover: Lifelong Exposure of C57bl/6n Male Mice to Bisphenol A or Bisphenol S Reduces Recovery From a Myocardial Infarction

Bisphenol A (BPA) leaches from plastics to contaminate foodstuffs. Analogs, such as bisphenol S (BPS), are now used increasingly in manufacturing. Greater BPA exposure has been correlated with exacerbation of cardiovascular disease, including myocardial infarction (MI). To test the hypothesis that bisphenol exposure impairs cardiac healing, we exposed C57bl/6n mice to water containing 25ng/ml BPA or BPS from conception and surgically induced an MI in adult male progeny. Increased early death and cardiac dilation, and reduced cardiac function were found post-MI in BPA- and BPS-exposed mice. Flow cytometry revealed increased monocyte and macrophage infiltration that correlated with increased chemokine C-C motif ligand-2 expression in the infarct. In vitro BPA and BPS addition increased matrix metalloproteinase-9 (MMP) protein and secreted activity in RAW264.7 macrophage cells suggesting that invivo increases in MMP2 and MMP9 in exposed infarcts were myeloid-derived. Bone marrow-derived monocytes isolated from exposed mice had greater expression of pro-inflammatory polarization markers when chemokine stimulated indicating an enhanced susceptibility to develop a pro-inflammatory monocyte population. Chronic BPA exposure of estrogen receptor beta (ERβ) deficient mice did not worsen early death, cardiac structure/function, or expression of myeloid markers after an MI. In contrast, BPS exposure of ERβ-deficient mice resulted in greater death and expression of myeloid markers. We conclude that lifelong exposure to BPA or BPS augmented the monocyte/macrophage inflammatory response and adverse remodeling from an MI thereby reducing the ability to survive and successfully recover, and that the adverse effect of BPA, but not BPS, is downstream of ERβ signaling.

Associations of prenatal environmental phenol and phthalate biomarkers with respiratory and allergic diseases among children aged 6 and 7 years

BACKGROUND

Prenatal environmental phenol and phthalate exposures may alter immune or inflammatory responses leading to respiratory and allergic disease.

OBJECTIVES

We estimated associations of prenatal environmental phenol and phthalate biomarkers with respiratory and allergic outcomes among children in the Mount Sinai Children's Environmental Health Study.

METHODS

We quantified urinary biomarkers of benzophenone-3, bisphenol A, paradichlorobenzene (as 2,5-dichlorophenol), triclosan, and 10 phthalate metabolites in third trimester maternal samples and assessed asthma, wheeze, and atopic skin conditions via parent questionnaires at ages 6 and 7 years (n = 164 children with 240 observations). We used logistic regression to estimate covariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) per standard deviation difference in natural log biomarker concentrations and examined effect measure modification by child's sex.

RESULTS

Associations of prenatal 2,5-dichlorophenol (all outcomes) and bisphenol A (asthma outcomes) were modified by child's sex, with increased odds of outcomes among boys but not girls. Among boys, ORs for asthma diagnosis per standard deviation difference in biomarker concentration were 3.00 (95% CI: 1.36, 6.59) for 2,5-dichlorophenol and 3.04 (95% CI: 1.38, 6.68) for bisphenol A. Wheeze in the past 12 months was inversely associated with low molecular weight phthalate metabolites among girls only (OR: 0.27, 95% CI: 0.13, 0.59) and with benzophenone-3 among all children (OR: 0.65, 95% CI: 0.44, 0.96).

CONCLUSIONS

Prenatal bisphenol A and paradichlorobenzene exposures were associated with pediatric respiratory outcomes among boys. Future studies may shed light on biological mechanisms and potential sexually-dimorphic effects of select phenols and phthalates on respiratory disease development.

Developmental Exposure to a Mixture of 23 Chemicals Associated With Unconventional Oil and Gas Operations Alters the Immune System of Mice

Chemicals used in unconventional oil and gas (UOG) operations have the potential to cause adverse biological effects, but this has not been thoroughly evaluated. A notable knowledge gap is their impact on development and function of the immune system. Herein, we report an investigation of whether developmental exposure to a mixture of chemicals associated with UOG operations affects the development and function of the immune system. We used a previously characterized mixture of 23 chemicals associated with UOG, and which was demonstrated to affect reproductive and developmental endpoints in mice. C57Bl/6 mice were maintained throughout pregnancy and during lactation on water containing two concentrations of this 23-chemical mixture, and the immune system of male and female adult offspring was assessed. We comprehensively examined the cellularity of primary and secondary immune organs, and used three different disease models to probe potential immune effects: house dust mite-induced allergic airway disease, influenza A virus infection, and experimental autoimmune encephalomyelitis (EAE). In all three disease models, developmental exposure altered frequencies of certain T cell sub-populations in female, but not male, offspring. Additionally, in the EAE model disease onset occurred earlier and was more severe in females. Our findings indicate that developmental exposure to this mixture had persistent immunological effects that differed by sex, and exacerbated responses in an experimental model of autoimmune encephalitis. These observations suggest that developmental exposure to complex mixtures of water contaminants, such as those derived from UOG operations, could contribute to immune dysregulation and disease later in life.

Biomonitoring of bisphenol A, triclosan and perfluorooctanoic acid in hair samples of children and adults

Bisphenol A (BPA), triclosan (TCS) and perfluorooctanoic acid (PFOA) are endocrine disruptors linked with negative health effects such as developmental, reproductive and cardiovascular toxicity. The aim of this study was to determine simultaneously the concentration of BPA, TCS and PFOA in hair from children and adults and examine possible associations between biomonitoring data and age, gender, dietary habits and body mass index. Methanolic extraction was applied and the compounds were determined by liquid chromatography-mass spectrometry. Low levels of exposure to PFOA were detected for children and adults at concentrations below limit of quantification. The mean concentration of BPA in children and adults was 20.6 and 16.6 pg mg^-1 , while for TCS 275.2 and 687.0 pg mg^-1 , respectively. Children were highly exposed to BPA relative to adults (P = .011) although adults had greater exposure to TCS (P = .003). Hair from girls had a greater burden of BPA (P = .06) compared to boys. Moreover, higher TCS levels were depicted for females in both examined groups (children P = .200 and adults P = .213) compared to males, but no statistical differences were observed. Significant differences were also observed between age groups (P = .0007) for TCS. No correlations were found between BPA or TCS levels and body mass index or dietary habits for both children and adults. Children have a greater exposure to BPA compared to adults, whereas exposure of adults to TCS seems to be higher than that in children and elderly people. Exposure to BPA occurs mainly via ingestion whereas exposure to TCS mainly via dermal absorption.

A systematic review of metabolomics biomarkers for Bisphenol A exposure

INTRODUCTION

Bisphenol A (BPA), 2,2-bis(4-hydroxyphenyl) propane, a common industrial chemical which has extremely huge production worldwide, is ubiquitous in the environment. Human have high risk of exposing to BPA and the health problems caused by BPA exposure have aroused public concern. However, the biomarkers for BPA exposure are lacking. As a rapidly developing subject, metabolomics has accumulated a large amount of valuable data in various fields. The secondary application of published metabolomics data could be a very promising field for generating novel biomarkers whilst further understanding of toxicity mechanisms.

OBJECTIVES

To summarize the published literature on the use of metabolomics as a tool to study BPA exposure and provide a systematic perspectives of current research on biomarkers screening of BPA exposure.

METHODS

We conducted a systematic search of MEDLINE (PubMed) up to the end of June 25, 2017 with the key term combinations of 'metabolomics', 'metabonomics', 'mass spectrometry', 'nuclear magnetic spectroscopy', 'metabolic profiling' and 'amino acid profile' combined with 'BPA exposure'. Additional articles were identified through searching the reference lists from included studies.

RESULTS

This systematic review included 15 articles. Intermediates of glycolysis, Krebs cycle, β oxidation of long chain fatty acids, pentose phosphate pathway, nucleoside metabolism, branched chain amino acid metabolism, aromatic amino acids metabolism, sulfur-containing amino acids metabolism were significantly changed after BPA exposure, suggesting BPA had a highly complex toxic effects on organism which was consistent with existing studies. The biomarkers most consistently associated with BPA exposure were lactate and choline.

CONCLUSION

Existing metabolomics studies of BPA exposure present heterogeneous findings regarding metabolite profile characteristics. We need more evidence from target metabolomics and epidemiological studies to further examine the reliability of these biomarkers which link to low, environmentally relevant, exposure of BPA in human body.

Urinary bisphenol A concentrations in relation to asthma in a sample of Egyptian children

BACKGROUND

Bronchial asthma is one of the top disabling diseases in pediatrics. Limited research has been studied the association of the widely used plastic monomer bisphenol A (BPA) with childhood asthma.

OBJECTIVE

To compare the levels of urinary BPA in asthmatic and control children and to investigate the implication of BPA among other risk factors for the development of asthma.

SUBJECTS AND METHODS

This case-control study included 97 children (45 asthmatic and 52 healthy controls) aged 3-8 years. Asthmatic children were diagnosed according to Global initiative for asthma (GINA) guidelines. Sociodemographic factors were assessed and urinary levels of BPA were determined in spot urine samples using high-performance liquid chromatography. The contribution of BPA among predictors for developing asthma was studied in asthmatic children.

RESULTS

Median total urinary BPA levels were significantly higher in asthmatic children than in control group (1.56 ng/mL in asthmatic children compared to 0.790 ng/mL in control group, p = 0.001). Children who had total urinary BPA levels >1.3 ng/mL were more likely to be asthmatic (odds ratio: 2.84, 95% confidence interval 1.22-6.59, p = 0.015). Multiple logistic regression analysis for predictors of asthma showed the importance of higher levels of BPA (>1.3 ng/mL) as a more significant predictor than passive smoking ( p = 0.006 for BPA categories vs. p = 0.049 for passive smoking).

CONCLUSION

Association of higher levels of urinary BPA with the diagnosis of asthma in children may indicate the potential risk of BPA exposure in the precipitation of bronchial asthma. Further clinical and biochemical research are needed to clarify the proper mechanism explaining this association.

Functional and Proteomic Alterations of F1 Capacitated Spermatozoa of Adult Mice Following Gestational Exposure to Bisphenol A

Studies regarding bisphenol A (BPA) exposure and male (in)fertility have conventionally focused on modifications in ejaculated spermatozoa function from exposed individuals. However, mammalian spermatozoa are incapable of fertilization prior to achieving capacitation, the penultimate step in maturation. Therefore, it is necessary to investigate BPA-induced changes in capacitated spermatozoa and assess the consequences on subsequent fertilization. Here, we demonstrate the effect of gestational BPA exposure (50 μg/kg bw/day, 5 mg/kg bw/day, and 50 mg/kg bw/day) on the functions, biochemical properties, and proteomic profiles of F1 capacitated spermatozoa from adult mice. The data showed that high concentrations of BPA inhibited motility, motion kinematics, and capacitation of spermatozoa, perhaps because of increased lipid peroxidation and protein tyrosine nitration, and decreased intracellular ATP levels and protein kinase-A activity in spermatozoa. We also found that BPA compromised the rates of fertilization and early embryonic development. Differentially expressed proteins identified between BPA-exposed and control groups play a critical role in energy metabolism, stress responses, and fertility. Protein function abnormalities were responsible for the development of several diseases according to bioinformatics analysis. On the basis of these results, gestational exposure to BPA may alter capacitated spermatozoa function and the proteomic profile, ultimately affecting their fertility potential.

Bisphenol A induces COX-2 through the mitogen-activated protein kinase pathway and is associated with levels of inflammation-related markers in elderly populations

Bisphenol A (BPA) is a well-known endocrine-disrupting chemical, and it is one of the highest volume chemicals produced worldwide. Even though several in vivo and in vitro studies showed positive associations of BPA exposure with pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin (IL)-6, the mechanism by which BPA induces inflammation is unclear. We investigated the mechanism by which BPA induces inflammation (expression of inflammation-related genes, changes in oxidative stress, and cell proliferation and migration) and evaluated the effect of BPA exposure on inflammation-related markers in epidemiologic studies using repeat urine and serum samples from elderly subjects. BPA induced COX-2 expression via nuclear translocation of NF-κB and activation of mitogen-activated protein kinase (MAPK) by phosphorylation of ERK1/2 and enhanced the migration of lung cancer A549 and breast cancer MDAMB-231 cells. In two epidemiologic studies, we detected associations of BPA with six inflammation-related markers (WBC, CRP, IL-10, ALT, AST, and γ-GTP levels). Our findings probably suggest that BPA exposure induces inflammation and exacerbates tumorigenesis.

Anti-allergic and anti-inflammatory activity of Phellinus linteus grown on Panax ginseng

Panax ginseng (PG) or Phellinus linteus (PL) have been widely used as traditional medicine owing to their many biological activities, including anti-inflammatory and anti-allergic activities. Previously, our group produced PL that was grown on PG media (PGP) to enhance anti-cancer activities of PGP. Here we studied the anti-allergic activity of PGP and its mechanism of action. The ethyl acetate fraction of PGP exhibited the anti-allergic activity by suppressing β-hexosaminidase release, a marker of degranulation, from antigen/immunoglobulin E (IgE)-stimulated RBL-2H3 cells. Exposure to PGP inhibited the level of antigen/IgE-induced TNF-alpha in RBL-2H3 cells. It markedly suppressed the phosphorylation of spleen associated tyrosine kinase, GRB2-associated-binding protein 2 (Gab2) and extracellular signal-regulated kinases proteins, which are required for the degranulation and production of pro-inflammatory cytokines. Its anti-inflammatory activity was observed in lipopolysaccharide-stimulated RAW 264.7 cells. In addition, PGP contained higher contents of Rg1 than PG. Our findings suggest that PGP might be developed as a therapeutic agent for IgE-mediated allergic diseases.

Impacts of Bisphenol A and Ethinyl Estradiol on Male and Female CD-1 Mouse Spleen

The endocrine disruptor bisphenol A (BPA) and the pharmaceutical 17α-ethinyl estradiol (EE) are synthetic chemicals with estrogen-like activities. Despite ubiquitous human exposure to BPA, and the wide-spread clinical use of EE as oral contraceptive adjuvant, the impact of these estrogenic endocrine disrupting chemicals (EDCs) on the immune system is unclear. Here we report results of in vivo dose response studies that analyzed the histology and microstructural changes in the spleen of adult male and female CD-1 mice exposed to 4 to 40,000 μg/kg/day BPA or 0.02 to 2 μg/kg/day EE from conception until 12–14 weeks of age. Results of that analysis indicate that both BPA and EE have dose- and sex-specific impacts on the cellular and microanatomical structures of the spleens that reveal minor alterations in immunomodulatory and hematopoietic functions. These findings support previous studies demonstrating the murine immune system as a sensitive target for estrogens, and that oral exposures to BPA and EE can have estrogen-like immunomodulatory affects in both sexes.

Gestational Exposure to Bisphenol A Affects the Function and Proteome Profile of F1 Spermatozoa in Adult Mice

BACKGROUND

Maternal exposure to the endocrine disruptor bisphenol A (BPA) has been linked to offspring reproductive abnormalities. However, exactly how BPA affects offspring fertility remains poorly understood.

OBJECTIVES

The aim of the present study was to evaluate the effects of gestational BPA exposure on sperm function, fertility, and proteome profile of F1 spermatozoa in adult mice.

METHODS

Pregnant CD-1 mice (F0) were gavaged with BPA at three different doses (50 μg/kg bw/day, 5 mg/kg bw/day, and 50 mg/kg bw/day) on embryonic days 7 to 14. We investigated the function, fertility, and related processes of F1 spermatozoa at postnatal day 120. We also evaluated protein profiles of F1 spermatozoa to monitor their functional affiliation to disease.

RESULTS

BPA inhibited sperm count, motility parameters, and intracellular ATP levels in a dose-dependent manner. These effects appeared to be caused by reduced numbers of stage VIII seminiferous epithelial cells in testis and decreased protein kinase A (PKA) activity and tyrosine phosphorylation in spermatozoa. We also found that BPA compromised average litter size. Proteins differentially expressed in spermatozoa from BPA treatment groups are known to play a critical role in ATP generation, oxidative stress response, fertility, and in the pathogenesis of several diseases.

CONCLUSIONS

Our study provides mechanistic support for the hypothesis that gestational exposure to BPA alters sperm function and fertility via down-regulation of tyrosine phosphorylation through a PKA-dependent mechanism. In addition, we anticipate that the BPA-induced changes in the sperm proteome might be partly responsible for the observed effects in spermatozoa. Citation: Rahman MS, Kwon WS, Karmakar PC, Yoon SJ, Ryu BY, Pang MG. 2017. Gestational exposure to bisphenol-A affects the function and proteome profile of F1 spermatozoa in adult mice. Environ Health Perspect 125:238-245; http://dx.doi.org/10.1289/EHP378.

Molecular targets of developmental exposure to bisphenol A in diabesity: a focus on endoderm-derived organs

Several studies associate foetal human exposure to bisphenol A (BPA) to metabolic/endocrine diseases, mainly diabesity. They describe the role of BPA in the disruption of pancreatic beta cell, adipocyte and hepatocyte functions. Indeed, the complexity of the diabesity phenotype is due to the involvement of different endoderm-derived organs, all targets of BPA. Here, we analyse this point delineating a picture of different mechanisms of BPA toxicity in endoderm-derived organs leading to diabesity. Moving from epidemiological data, we summarize the in vivo experimental data of the BPA effects on endoderm-derived organs (thyroid, pancreas, liver, gut, prostate and lung) after prenatal exposure. Mainly, we gather molecular data evidencing harmful effects at low-dose exposure, pointing to the risk to human health. Although the fragmentation of molecular data does not allow a clear conclusion to be drawn, the present work indicates that the developmental exposure to BPA represents a risk for endoderm-derived organs development as it deregulates the gene expression from the earliest developmental stages. A more systematic analysis of BPA impact on the transcriptomes of endoderm-derived organs is still missing. Here, we suggest in vitro toxicogenomics approaches as a tool for the identification of common mechanisms of BPA toxicity leading to the diabesity in organs having the same developmental origin.

A statement on the developmental immunotoxicity of bisphenol A (BPA): answer to the question from the Dutch Ministry of Health, Welfare and Sport

This statement addresses a request to EFSA from the Dutch Ministry of Public Health, Welfare and Sport to assess the impact of recent evidence underlying the conclusions of the 2016 RIVM report on the current temporary tolerable intake (t-TDI) for BPA of 4 μg/kg bw/day set by EFSA in 2015. The CEF Panel has then evaluated the results of two studies published by Ménard et al. in 2014, suggesting food intolerance and impaired immune response to parasitic infection in rats exposed perinatally to BPA doses in the microgram/kg bw/day range. The same appraisal criteria and weight-of-evidence analysis used for the 2015 EFSA opinion on BPA were applied to these studies. This new evidence adds to the indications of immunotoxicity of BPA in animals reported in previous reviews. For the only endpoint for which three BPA doses were tested (IgG levels), a benchmark dose analysis of the dose-response data was carried out. Due to the high inter-animal variability within the treatment groups resulting in high confidence intervals and limited dose-response, the CEF Panel concluded that these data on anti-OVA IgG antibodies are not suitable to derive a reference point for BPA on immunotoxicity. Furthermore, the limitations of both Menard et al. studies observed by the Panel confound the interpretation of the study results and prevent the assessment of the relevance to human health. The CEF Panel overall considers that the results from the two Menard et al. studies are not sufficient to call for a revision of the EFSA t-TDI for BPA. EFSA will start a review of all the scientific evidence published after 2012 and relevant for BPA hazard assessment (including immunotoxicity) in 2017. The results of immunological studies such as the two evaluated here would form a useful contribution to this evaluation provided that the limitations identified herein were addressed.

Bisphenol A exposure alters release of immune and developmental modulators and expression of estrogen receptors in human fetal lung fibroblasts

Bisphenol A (BPA) has been shown to exert biological effects through estrogen receptor (ER)-dependent and ER-independent mechanisms. Recent studies suggest that prenatal exposure to BPA may increase the risk of childhood asthma. To investigate the underlying mechanisms in the actions of BPA, human fetal lung fibroblasts (hFLFs) were exposed to varying doses of BPA in culture for 24hr. Effects of BPA on localization and uptake of BPA, cell viability, release of immune and developmental modulators, cellular localization and expression of ERα, ERβ and G-protein coupled estrogen receptor 30 (GPR30), and effects of ERs antagonists on BPA-induced changes in endothelin-1 (ET-1) release were examined. BPA at 0.01-100μmol/L caused no changes in cell viability after 24hr of exposure. hFLFs expresses all three ERs. BPA had no effects on either cellular distribution or protein expression of ERα, however, at 100μmol/L (or 23μmol/L intracellular BPA) increased ERβ protein levels in the cytoplasmic fractions and GPR30 protein levels in the nuclear fractions. These paralleled with increased release of growth differentiation factor-15, decreased phosphorylation of nuclear factor kappa B p65 at serine 536, and decreased release of ET-1, interleukin-6, and interferon gamma-induced protein 10. ERs antagonists had no effects on BPA-induced decrease in ET-1 release. These data suggest that BPA at 100μmol/L altered the release of immune and developmental modulators in hFLFs, which may negatively influence fetal lung development, maturation, and susceptibility to environmental stressors, although the role of BPA in childhood asthma remains to be confirmed in in vivo studies.

Gestational and lactational exposure to low-dose bisphenol A increases Th17 cells in mice offspring

Increasing evidence demonstrates that perinatal exposure to Bisphenol A (BPA) can cause immune disorders throughout the life span. However, the biological basis for these immune disorders is poorly understood and the effects of exposure to BPA on Th17 development are unknown. The present study sought to characterize alterations of Th17 cells in childhood and adulthood following gestational and lactational exposure to environmentally relevant low-dose of BPA and the underlying mechanisms. Pregnant dams were exposed to BPA (10, 100 or 1000nM) via drinking water from gestational day (GD) 0 to postnatal day (PND) 21. At PNDs 21 and 42, offspring mice were anesthetized, blood was obtained for cytokine assay and spleens were collected for Th17 cell frequency and RORγt mRNA expression analysis. Perinatal exposure to low-dose BPA resulted in a dose-dependent and gender-specific persistent rise in Th17 cells accompanied by an increase of RORγt mRNA expression in the offsprings. The contents of major Th17 cell-derived cytokines (IL-17 and IL-21) and those essential for Th17 cell differentiation (IL-6 and IL-23) were also increased compared to those in controls. These changes were more pronounced in female than in male offsprings. However, perinatal exposure to low-dose BPA had little effect on serum TGF-β, another key regulator for Th17 cell development. Our results suggest that gestational and lactational exposure to a low-dose of BPA can affect Th17 cell development via an action on its transcription factor and the regulatory cytokines. These findings provide novel insight into sustained immune disorders by BPA exposure during development.

Developmental Bisphenol A Exposure Modulates Immune-Related Diseases

Bisphenol A (BPA), used in polycarbonate plastics and epoxy resins, has a widespread exposure to humans. BPA is of concern for developmental exposure resulting in immunomodulation and disease development due to its ability to cross the placental barrier and presence in breast milk. BPA can use various mechanisms to modulate the immune system and affect diseases, including agonistic and antagonistic effects on many receptors (e.g., estrogen receptors), epigenetic modifications, acting on cell signaling pathways and, likely, the gut microbiome. Immune cell populations and function from the innate and adaptive immune system are altered by developmental BPA exposure, including decreased T regulatory (Treg) cells and upregulated pro- and anti-inflammatory cytokines and chemokines. Developmental BPA exposure can also contribute to the development of type 2 diabetes mellitus, allergy, asthma and mammary cancer disease by altering immune function. Multiple sclerosis and type 1 diabetes mellitus may also be exacerbated by BPA, although more research is needed. Additionally, BPA analogs, such as bisphenol S (BPS), have been increasing in use, and currently, little is known about their immune effects. Therefore, more studies should be conducted to determine if developmental exposure BPA and its analogs modulate immune responses and lead to immune-related diseases.

Exposure to bisphenol A and the development of asthma: A systematic review of cohort studies

BACKGROUND

There is conflicting evidence about the association between bisphenol A (BPA) exposure and childhood asthma risk. We aimed to review the epidemiological literature on the relationship between prenatal or postnatal exposure to BPA and the risk of childhood asthma/wheeze.

METHODS

The PubMed database was systematically searched, and additional studies were found by searching reference lists of relevant articles.

RESULTS

Six studies fulfilled the eligibility criteria. Three studies found that prenatal BPA exposure is associated with an increased risk of childhood wheeze, while another study reported a reduced risk of wheeze. Regarding the postnatal BPA exposure, three studies demonstrated an increased risk of childhood asthma/wheeze.

CONCLUSIONS

The mean prenatal BPA was associated with the risk of childhood wheeze/asthma. Besides, the influence of BPA exposure during the second trimester of pregnancy on the prevalence of childhood wheeze was marked. Further studies are urgently needed to explore the underlying mechanism about adverse effect of BPA exposure on childhood wheeze/asthma.

A novel approach to assessing bisphenol-A hazards using an in vitro model system

Background

Although the toxicological impacts of the xenoestrogen bisphenol-A (BPA) have been studied extensively, but the mechanism of action is poorly understood. Eventually, no standard method exists for evaluating the possible health hazards of BPA exposure. Considering mice spermatozoa as a potential in vitro model, we investigated the effects of BPA exposure (0.0001, 0.01, 1, and 100 μM for 6 h) on spermatozoa and the related mechanisms of action. The same doses were also employed to evaluate protein profiles of spermatozoa as a means to monitor their functional affiliation to diseases.

Results

Our results demonstrated that high concentrations of BPA negatively affect sperm motility, viability, mitochondrial functions, and intracellular ATP levels by activating the mitogen-activated protein kinase, phosphatidylinositol 3-kinase, and protein kinase-A pathways. Moreover, short-term exposure of spermatozoa to high concentrations of BPA induced differential expressions of 24 proteins. These effects appeared to be caused by protein degradation and phosphorylation in spermatozoa. Proteins differentially expressed in spermatozoa from BPA treatment groups are putatively involved in the pathogenesis of several diseases, mainly cancer, carcinoma, neoplasm, and infertility.

Conclusions

Based on these results, we propose that BPA adversely affects sperm function by the activation of several kinase pathways in spermatozoa. In addition, BPA-induced changes in the sperm proteome might be partly responsible for the observed effects in spermatozoa, subsequently involve in the pathogenesis of many diseases. Therefore, we anticipated that current strategy might broadly consider for the health hazards assessment of other toxicological agents.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-2979-5) contains supplementary material, which is available to authorized users.

Assessment of recent developmental immunotoxicity studies with bisphenol A in the context of the 2015 EFSA t-TDI

Humans are exposed to bisphenol A (BPA) mainly through the diet, air, dust, skin contact and water. There are concerns about adverse health effects in humans due to exposure to bisphenol A (BPA). The European Food Safety Authority (EFSA) has extensively reviewed the available literature to establish a temporary Tolerable Daily Intake (t-TDI). This exposure level was based on all available literature published before the end of 2012. Since then, new experimental animal studies have emerged, including those that identified effects of BPA on the immune system after developmental exposure. These studies indicate that developmental immunotoxicity might occur at lower dose levels than previously observed and on which the current EFSA t-TDI is based. The Dutch National Institute for Public Health and the Environment (RIVM) organized an expert workshop in September 2015 to consider recently published studies on the developmental immunotoxicity of bisphenol A (BPA). Key studies were discussed in the context of other experimental studies. The workshop concluded that these new experimental studies provide credible evidence for adverse immune effects after developmental exposure to BPA at 5μg/kg BW/day from gestation day 15 to postnatal day 21. Supportive evidence for adverse immune effects in similar dose ranges was obtained from other publications that were discussed during the workshop. The dose level associated with adverse immune effects is considerably lower than the dose used by EFSA for deriving the t-TDI. The workshop unanimously concluded that the current EFSA t-TDI warrants reconsideration in the context of all currently available data.

The Impact of Bisphenol A and Phthalates on Allergy, Asthma, and Immune Function: a Review of Latest Findings

In recent years, the impact of environmental exposure to chemicals and their immunological effects, including the development of allergy, has been a topic of great interest. Epidemiologic studies indicate that exposure to endocrine-disrupting chemicals produced in high volumes, including bisphenol A (BPA) and phthalates, is ubiquitous. The links between their exposure and the development of allergy, asthma, and immune dysfunction have been studied in vitro, in vivo, and through human cohort studies. The purpose of this review is to examine the current body of research and to highlight deficits and strengths of current findings. Emerging science indicates that deleterious immunologic changes, including increased propensity to develop wheeze, allergy, and asthma after dietary and inhalation exposure to these chemicals, may be occurring.

Exposure to bisphenol A enhanced lung eosinophilia in adult male mice

Background

Bisphenol A (BPA) is useful in many manufacturing processes and is also found in commonly used consumer products. Previous experimental studies have reported that perinatal exposure to BPA promotes the development of allergic lung inflammation in childhood and even into adulthood. In this study, the effects of BPA on allergic lung inflammation in adults were investigated in murine lungs.

Methods

CD-1 mice were orally administrated with 1 mg of BPA/mouse four times at one-week intervals with or without ovalbumin (OVA). The pathologic changes in the airways, cytological alterations in bronchoalveolar lavage fluid (BALF), levels of inflammatory cytokines/chemokines in BALF, and OVA-specific IgE and IgG1 antibodies in serum were measured in the treated CD-1 mice. In vitro study using RAW264.7 cells, which are macrophage-like cells derived from BALB/c male mice, was conducted. The gene expression of cytokines and chemokines were measured.

Results

BPA enhanced eosinophil recruitment induced by OVA in the alveoli and in the submucosa of the airway, which has a goblet cell proliferation in the bronchial epithelium. BPA increased Th2 cytokines-interleukin-13 (IL-13), eosinophil-relevant cytokines and chemokines, such as IL-5, and CCL2 induced by OVA, in BALF. BPA induced adjuvant effects on OVA-specific IgG1 production. In the in vitro study using RAW264.7 cells, BPA increased the mRNA expression of IL-1β, IL-6, CCL2 and CCL3 compared with the control and OVA groups.

Conclusions

These results suggest that (1) the exposure of BPA could synergize with an OVA challenge to aggravate the severity of lung eosinophilia in adult mice, possibly by promoting a Th2-biased immune response and (2) the activation of macrophages and inflammatory cytokines released from these cells by BPA could be participating in this phenomenon.