Modulation of cytokine expression in human macrophages by endocrine-disrupting chemical Bisphenol-A

Comparative in silico and in vitro evaluation of possible toxic effects of bisphenol derivatives in HepG2 cells

Introduction

Bisphenols are widely used in the production of polycarbonate plastics and resin coatings. Bisphenol A (BPA) is suggested to cause a wide range of unwanted effects and "low dose toxicity". With the search for alternative substances to BPA, the use of other bisphenol derivatives namely bisphenol F (BPF) and bisphenol S (BPS) has increased.

Methods

In the current study, we aimed to evaluate the in silico predicted inhibitory concentration 50s (pIC50s) of bisphenol derivatives on immune and apoptotic markers and DNA damage on HepG2 cells. Moreover, apoptotic, genotoxic and immunotoxic effects of BPA, BPF and BPS were determined comparatively. Effects of bisphenols on apoptosis were evaluated by detecting different caspase activities. The genotoxic effects of bisphenols were evaluated by measuring the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-oxoguanine glycosylase (OGG1). To determine the immunotoxic effect of bisphenol derivatives, the levels of interleukin 4 (IL-4) and interleukin 10 (IL-10), transforming growth factor beta (TGF-β) and tumor necrosis factor-alpha (TNF-α), which are known to be expressed by HepG2 cells, were measured. Results: In silico data indicate that all of the bisphenols may cause alterations in immune and apoptotic markers as well as DNA damage at low doses. İn vitro data revealed that all bisphenol derivatives could affect immune markers at inhibitory concentration 30s (IC30s). In addition, BPF and BPS may also have apoptotic immunotoxic effects.

Conclusion

Both in silico and in vivo research are needed further to examine the toxic effects of alternative bisphenol derivatives.

Examining the immunotoxicity of oil sands process affected waters using a human macrophage cell line

Oil sands process affected water (OSPW) is produced during the surface mining of the oil sands bitumen deposits in Northern Alberta. OSPW contains variable quantities of organic and inorganic components causing toxic effects on living organisms. Advanced Oxidation Processes (AOPs) are widely used to degrade toxic organic components from OSPW including naphthenic acids (NAs). However, there is no established biological procedure to assess the effectiveness of the remediation processes. Our previous study showed that human macrophage cells (THP-1) can be used as a bioindicator system to evaluate the effectiveness of OSPW treatments through examining the proinflammatory gene transcription levels. In the present study, we investigated the immunotoxicological changes in THP-1 cells following exposure to untreated and AOP-treated OSPW. Specifically, using proinflammatory cytokine protein secretion assays we showed that AOP treatment significantly abrogates the ability of OSPW to induce the secretion of IL-1β, IL-6, IL-8, TNF-α, IL-1Ra and MCP-1. By measuring transcriptional activity as well as surface protein expression levels, we also showed that two select immune cell surface markers, CD40 and CD54, were significantly elevated following OSPW exposure. However, AOP treatments abolished the immunostimulatory properties of OSPW to enhance the surface expression of these immune proteins. Finally, a transcriptome-based approach was used to examine the proinflammatory effects of OSPW as well as the abrogation of immunotoxicity following AOP treatments. Overall, this research shows how a human macrophage cell-based biomonitoring system serves as an effective in vitro tool to study the immunotoxicity of OSPW samples before and after targeted remediation strategies.

Modulatory effects of bisphenol A on the hepatic immune response

The liver is a primary line of defense for protection from external substances next to the intestinal barrier. As a result, the hepatic immune system plays a central role in liver pathophysiology. Bisphenol A (BPA) is one of the most common endocrine disrupting chemicals and is primarily metabolized in the liver. Due to its ability to bind to estrogen receptors, BPA is well known to possess estrogenic activity and disrupt reproductive functions. The phase I and Phase II metabolism reactions of BPA mainly occur in the liver with the help of enzymes including cytochrome P450 (CYP), uridine 5'-diphospho-glucuronosyltransferase-glucuronosyltransferases, sulfotransferases, and glutathione-S-transferases. Although the majority of BPA is excreted after conjugation by these enzymes, untransformed BPA induces the production of reactive oxygen species through disruption of the enzymatic complex CYP, lipid accumulation, mitochondrial dysfunction, endoplasmic reticulum stress and inflammatory injury in the liver. Moreover, it has been proposed to possess a potential immunomodulatory effect. Indeed, several in vivo and in vitro studies have reported that low doses of BPA increase the population of T cells with type 1 T helper (Th1), Th2, and Th17 cells. Although the current literature lacks clear evidence on the mechanisms by which BPA is involved in T cell mediated immune responses, recent multi-omics studies suggest that it may directly interact with the antigen processing and presentation pathways. In this review, we first discuss the metabolism of BPA in the liver, before exploring currently available data on its effects on liver injury. Finally, we review its modulatory effects on the hepatic immune response, as well as potential mechanisms. By conducting this review, we aim to improve understanding on the relationship between BPA exposure and immune-related liver injury, with a focus on the antigen processing and presentation pathway and T cell-mediated response in the liver.

Identification of a novel immune-related long noncoding RNA in carp primary macrophages associated with bisphenol A' s immunoregulatory effects

Increasing evidence suggests that long non-coding RNAs (lncRNAs) play pivotal roles in various biological processes. However, current studies on lncRNAs mostly focus on mammalian species, with little research on the functional roles of lncRNAs in teleost fish. Here, we identified a novel intergenic lncRNA (linc-93.2) in the head kidney primary macrophages of common carp (Cyprinus carpio) after exposure to a typical environmental endocrine disrupting chemical, bisphenol A (BPA). As a result, linc-93.2 was more than 3,619 bp in length and predominantly localized to the nucleus of primary macrophages other than cytoplasm, with the highest expression level in spleen followed by head kidney among different organs. Bioinformatic analysis predicted a cis-target gene, dennd1b, and 20 trans-target genes including hsp70, gna13 and rasgap, were potentially regulated by linc-93.2; NFκB and estrogen receptor (ERα) binding sites were located in the promoter region upstream of its transcription start site, which together suggested the involvement of linc-93.2 in immune and neurological functions in fish. Based on that, the expression level of linc-93.2 was determined in macrophages following acute lipopolysaccharide (LPS) and BPA treatments, both of which significantly induced linc-93.2 and IL-1β expression in cells. Moreover, a NF-κB inhibitor PDTC significantly reduced linc-93.2 expression in macrophages, but co-exposure of macrophages to PDTC with BPA or LPS could significantly rescue linc-93.2 expression, consistent with the observation on that LPS or BPA alone significantly induced both linc-93.2 and its target gene expression. Interestingly, linc-93.2 and its target gene expression was significantly suppressed by an ER antagonist ICI 182,780, however, the co-exposure of macrophages to ICI 182,780 with BPA failed to attenuate their declined expression. Overall, the current study demonstrated that linc-93.2, a novel immune-related lncRNA, may participate in the immune processes of common carp macrophages via the NF-κB and ER pathway. The results presented in this study enhance our understanding of the immunotoxin mechanisms of BPA in teleost fish.

Exposure and hazard of bisphenol A, S and F: a multi-biomarker approach in three-spined stickleback

Due to the estrogenic behavior of bisphenol (BP) A, industries have developed many substitutes, such as BPS and BPF. However, due to their structural similarities, adverse effects on reproduction are currently observed in various organisms, including fish. Even if new results have shown impacts of these bisphenols on many other physiological functions, their mode of action remains unclear. In this context, we proposed to better understand the impact of BPA, BPS, and BPF on immune responses (leucocyte sub-populations, cell death, respiratory burst, lysosomal presence, and phagocytic activity) and on biomarkers of metabolic detoxification (ethoxyresorufin-O-deethylase, EROD, and glutathione S-transferase, GST) and oxidative stress (glutathione peroxidase, GPx, and lipid peroxidation with thiobarbituric acid reactive substance method, TBARS) in an adult sentinel fish species, the three-spined stickleback. In order to enhance our understanding of how biomarkers change over time, it is essential to determine the internal concentration responsible for the observed responses. Therefore, it is necessary to explore the toxicokinetics of bisphenols. Thus, sticklebacks were exposed either to 100 μg/L of BPA, BPF or BPS for 21 days, or for seven days to 10 and 100 μg/L of BPA or BPS followed by seven days of depuration. Although BPS has very different TK, due to its lower bioaccumulation compared to BPA and BPF, BPS affect oxidative stress and phagocytic activity in the same way. For those reasons, the replacement of BPA by any substitute should be made carefully in terms of risk assessment on aquatic ecosystems.

Re-evaluation of the risks to public health related to the presence of bisphenol A (BPA) in foodstuffs

In 2015, EFSA established a temporary tolerable daily intake (t-TDI) for BPA of 4 μg/kg body weight (bw) per day. In 2016, the European Commission mandated EFSA to re-evaluate the risks to public health from the presence of BPA in foodstuffs and to establish a tolerable daily intake (TDI). For this re-evaluation, a pre-established protocol was used that had undergone public consultation. The CEP Panel concluded that it is Unlikely to Very Unlikely that BPA presents a genotoxic hazard through a direct mechanism. Taking into consideration the evidence from animal data and support from human observational studies, the immune system was identified as most sensitive to BPA exposure. An effect on Th17 cells in mice was identified as the critical effect; these cells are pivotal in cellular immune mechanisms and involved in the development of inflammatory conditions, including autoimmunity and lung inflammation. A reference point (RP) of 8.2 ng/kg bw per day, expressed as human equivalent dose, was identified for the critical effect. Uncertainty analysis assessed a probability of 57-73% that the lowest estimated Benchmark Dose (BMD) for other health effects was below the RP based on Th17 cells. In view of this, the CEP Panel judged that an additional uncertainty factor (UF) of 2 was needed for establishing the TDI. Applying an overall UF of 50 to the RP, a TDI of 0.2 ng BPA/kg bw per day was established. Comparison of this TDI with the dietary exposure estimates from the 2015 EFSA opinion showed that both the mean and the 95th percentile dietary exposures in all age groups exceeded the TDI by two to three orders of magnitude. Even considering the uncertainty in the exposure assessment, the exceedance being so large, the CEP Panel concluded that there is a health concern from dietary BPA exposure.

Immunomodulatory effect of dopamine in human keratinocytes and macrophages under chronical bisphenol-A exposure conditions

Dopamine is a key neurotransmitter that links the nervous and the immune system. Bisphenol A (BPA) is an endocrine disruptor with a wide distribution in the environment that is used in the manufacturing of plastic products. Evidence shows that BPA can interfere with the central dopaminergic transmission; however, there are no previous reports of this effect outside the central nervous system. Thus, the aim of this work was to investigate the in vitro mechanisms of action involved in the response to dopamine in both human keratinocyte and macrophage cell lines chronically exposed to BPA. Dopamine modulates cytokine secretion and NF-κB expression in BPA-treated HaCaT keratinocytes, without modifying these parameters in BPA-treated THP-1 macrophages. In addition, dopamine increases MMP activity in both BPA-treated cell lines, although it decreases keratinocytes migration. We suggest the immunomodulatory effect of dopamine might be different in keratinocytes and macrophages under chronical BPA exposure conditions. These findings revealed for the first time the in vitro immunomodulatory effect of dopamine in the presence of BPA at peripheral level.

In Vitro Effects of Bisphenol Analogs on Immune Cells Activation and Th Differentiation

AIMS

Investigate the immunomodulatory effects of bisphenols in the THP-1 cell line and peripheral blood mononuclear cells in response to lipopolysaccharide (LPS) activation or to phorbol 12-myristate 13-acetate (PMA) and ionomycin.

BACKGROUND

We have previously demonstrated the usefulness of the evaluation of RACK1 expression as a link between endocrine disrupting activity and the immunotoxic effect of xenobiotics. We demonstrated that while BPA and BPAF reduced RACK1 expression, BPS was able to increase it.

OBJECTIVE

Bisphenol A (BPA) is one of the most commonly used chemicals in the manufacturing of polycarbonate plastics and plastic consumer products. Its endocrine disrupting (ED) potential and changes in European regulations have led to replacing BPA in many uses with structurally similar chemicals, like bisphenol AF (BPAF) and bisphenol S (BPS). However, emerging data indicated that bisphenol analogues may not be safer than BPA both in toxic effects and ED potential.

METHODS

THP-1 cell line and peripheral blood mononuclear cells were activated with lipopolysaccharide (LPS) or with phorbol 12-myristate 13-acetate (PMA) and ionomycin.

RESULTS

BPA and BPAF decreased LPS-induced expression of surface markers and the release of pro-inflammatory cytokines, while BPS increased LPS-induced expression of CD86 and cytokines. BPA, BPAF, and BPS affected PMA/ionomycin-induced T helper differentiation and cytokine release with gender-related alterations in some parameters investigated.

CONCLUSION

Data confirm that bisphenols can modulate immune cell differentiation and activation, further supporting their immunotoxic effects.

New approach methods for assessing indoor air toxicity

Indoor air is typically a mixture of many chemicals at low concentrations without any adverse health effects alone, but in mixtures they may cause toxicity and risks to human health. The aim of this study was by using new approach methods to assess the potential toxicity of indoor air condensates. In specific, different in vitro test methods including cyto-and immunotoxicity, skin sensitization and endocrine disruption were applied. In addition to biological effects, the indoor air samples were subjected to targeted analysis of 25 volatile organic compounds (VOCs) and Genapol X-80 (a nonionic emulsifier) suspected to be present in the samples, and to a non-targeted "total chemical scan" to find out whether the chemical composition of the samples is associated with the biological effects. The results confirm that assessing health risks of indoor air by analysing individual chemicals is not an adequate approach: We were not able to detect the VOCs and Genapol X-80 in the indoor air samples, yet, several types of toxicity, namely, cytotoxicity, immunotoxicity, skin sensitization and endocrine disruption were detected. In the non-targeted total chemical scan of the indoor air samples, a larger number of compounds were found in the cytotoxic samples than in the non-cytotoxic samples supporting the biological findings. If only one biological method would be selected for the screening of indoor air quality, THP-1 macrophage/WST-1 assay would best fit for the purpose as it is sensitive and serves as a good representative for different sub-toxic end points, including immunotoxicity, (skin) sensitization and endocrine disruption.

Potential Pro-Tumorigenic Effect of Bisphenol A in Breast Cancer via Altering the Tumor Microenvironment

Simple Summary

Bisphenol A (BPA) is primarily used to produce polycarbonate plastics, such as water bottles. Exposure to BPA has been shown to increase the growth of breast cancer cells that depend on estrogen for growth due to its ability to mimic estrogen. More recent studies have suggested that BPA also affects the cellular and non-cellular components that compose tumor microenvironments (TMEs), namely the environment around a tumor, thereby potentially promoting breast cancer growth via altering the TME. The TME plays an essential role in cancer development and promotion. Therefore, it is crucial to understand the effect of BPA on breast TMEs to assess its role in the risk of breast cancer adequately. This review examines the potential effects of BPA on immune cells, fibroblasts, extracellular matrices, and adipocytes to highlight their roles in mediating the carcinogenic effect of BPA, and thereby proposes considerations for the risk assessment of BPA exposure.

Abstract

BPA, a chemical used in the preparation of polycarbonate plastics, is an endocrine disruptor. Exposure to BPA has been suggested to be a risk factor for breast cancer because of its potential to induce estrogen receptor signaling in breast cancer cells. More recently, it has been recognized that BPA also binds to the G protein-coupled estrogen receptor and other nuclear receptors, in addition to estrogen receptors, and acts on immune cells, adipocytes, and fibroblasts, potentially modulating the TME. The TME significantly impacts the behavior of cancer cells. Therefore, understanding how BPA affects stromal components in breast cancer is imperative to adequately assess the association between exposure to BPA and the risk of breast cancer. This review examines the effects of BPA on stromal components of tumors to highlight their potential role in the carcinogenic effect of BPA. As a result, I propose considerations for the risk assessment of BPA exposure and studies needed to improve understanding of the TME-mediated, breast cancer-promoting effect of BPA.

Bisphenol A impairs macrophages through inhibiting autophagy via AMPK/mTOR signaling pathway and inducing apoptosis

Bisphenol A (BPA) is a widespread endocrine disruptor that induces the impairment of immune cells, but the mechanism remains unknown. Macrophages are one of the most important immune cells in innate and adaptive immunity. In this study, we aimed to probe the effects of BPA on the damage of RAW264.7 cells and its mechanisms of action, especially focusing on the relationship between autophagy and apoptosis. Cells were pretreated with 10 mg/L LPS, or added autophagy activator RAPA, autophagy inhibitor 3-MA or Bcl-2 inhibitor ABT-737, then treated with BPA (0, 10, 100 and 200 μmol/L) for 12 h. Results have shown that BPA decreased the cell viability and disrupted secretory function by promoting pro-inflammatory cytokines TNF-α and IL-6 and reducing anti-inflammatory cytokines IL-10 TGF-β, as well as phagocytic ability. Moreover, autophagy was inhibited by BPA through decreasing p-AMPK/AMPK and increasing p-mTOR/mTOR, and further down-regulating autophagy proteins ATG6, LC3II/I ratio, and up-regulating autophagy flux protein p62. Additionally, BPA significantly increased Bax/Bcl-2 ratio, Caspase-3 expression and apoptosis rate. We found that RAPA ameliorated the cell viability, Bax/Bcl-2 ratio, and macrophage function damage induced by BPA. Intriguingly, ABT-737 might promote ATG6 expression. In summary, our study demonstrated that the effects of BPA on macrophages seemed to be mediated by inhibiting AMPK/mTOR-dependent autophagy and inducing apoptosis via endogenous mitochondrial pathway. Both Bcl-2 and ATG6 were involved in the regulation of apoptosis and autophagy by BPA. These findings provide a broader perspective for understanding the interaction between autophagy and apoptosis in BPA-induced immune cell injury.

The associations between endocrine disrupting chemicals and markers of inflammation and immune responses: A systematic review and meta-analysis

Exposure to endocrine disrupting chemicals (EDCs) may lead to dysregulated inflammatory responses, however, the detailed relationship between different EDCs and inflammation remains unclear. A systematic review and meta-analysis was conducted to evaluate the associations between four types of EDCs (bisphenol A (BPA), phthalates (PAEs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs)) and markers of inflammation and immune responses in humans. Three databases were searched, and 36 studies with a total of 22055 participants were included. The associations between EDCs and 26 inflammation-related acute phase proteins and cytokines were analyzed. The results demonstrated that exposure to BPA was positively associated with circulating levels of C-reactive protein (CRP) and interleukin (IL)-6. Exposure to PAEs was associated with elevated levels of CRP, IL-6 and IL-10. Subgroup analysis found that three PAE metabolites mono-benzyl phthalate (MBzP), mono-isobutyl phthalate (MiBP), and mono-n-butyl phthalate (MnBP) were directly associated with a higher level of CRP, and two other PAE metabolites mono-carboxyisononyl phthalate (MCNP) and mono-3-carboxypropyl phthalate (MCPP) were positively associated with IL-6. The positive associations between PAEs and CRP, IL-6 and IL-10 were significant in the high-molecular-weight phthalate (HMWP) exposure group, not the low-molecular-weight phthalate (LMWP) exposure group. Exposure to OCPs was positively associated with CRP, IL-1β, IL-2, and IL-10. No significant association was found between PCBs and inflammatory markers. These findings demonstrate that exposure to EDCs is closely linked to dysregulated inflammatory responses. More studies should be conducted in the future to get a comprehensive view of the associations between different EDCs and inflammation, and investigations on the underlying mechanisms are needed.

The Endocrine Disruptor Compound Bisphenol-A (BPA) Regulates the Intra-Tumoral Immune Microenvironment and Increases Lung Metastasis in an Experimental Model of Breast Cancer

Simple Summary

The widely spread microplastic component and endocrine disruptor BPA is a hazardous material recognized for a long time. Here, for the first time, we demonstrated that BPA, administered into mice in a very specific developmental step of the animal (3 days post-natal), induces an increase in metastasis to the lung in the adult life, compared to the control or vehicle mice. In addition, of novelty, it is the analysis of the cytokine tumor microenvironment, which is the reason for the increased metastasis by BPA (BPA induce the increase in pro-metastatic cytokines).

Abstract

Breast cancer (BC) metastasis represents the main physiopathology leading to poor prognosis and death. Bisphenol A (BPA) is a pollutant, classified as an endocrine-disrupting chemical compound with estrogenic properties, their exposure in the early stages of neonatal life leads to an increase in the size and weight of breast tumors and induces cellular changes in the tumoral immune microenvironment where cytokines play a key role. Thus, we used female BALB/c mice exposed neonatally to a single dose of BPA. Once mice reached sexual maturity, a mammary tumor was induced, injecting 4T1 cells in situ. After 25 days of injection, we evaluated endocrine alterations, cytokine expression, tissue alterations denoted by macro or micro-metastasis in the lung, and cell infiltration induced by metastasis. We found that BPA neonatal treatment did not show significant endocrine alterations. Noteworthy, BPA led to an augmented rate of metastasis to the lung associated with higher intratumoral expression of IL-1β, IL-6, IFN-γ, TNF-α, and VEGF. Our data suggest that cytokines are key players in the induction of BC metastasis and that BPA (an environmental pollutant) should be considered as a risk factor in the clinical history of patients as a possible inductor of BC metastasis.

Gestational and lactational xenoestrogen exposure disrupts morphology and inflammatory aspects in mammary gland of gerbil mothers during involution

In the mammary gland (MG), the developmental window for gestational/lactational differentiation and growth is highly vulnerable to hormonal disruption. Here we describe that the MG involution process in female gerbil mothers is delayed by bisphenol A (BPA) exposure during gestation and lactation. The process is directly influenced by changes in expression of extracellular matrix proteases MMP-2, MMP-9, and FAP, and the incidence of collagen and elastin is reduced after 7 and 14 days of weaning. A pro-inflammatory environment in the late involution process was confirmed by higher expression of TNF-α, COX-2 and phospho-STAT3 n the MG stroma, allied to increases in the incidence of macrophages and mast cells. These aspects impacted the proliferative pattern of epithelial cells, which decreased on the 14th post-weaning day. These data confirm that the milk production window of susceptibility is vulnerable to the impact of BPA, which promotes a suggestive pro-tumoral microenvironment during mammary involution.

Endocrine disrupting chemicals: Friend or foe to brown and beige adipose tissue?

The effects of Endocrine Disrupting Chemicals (EDCs) on the current obesity epidemic is a growing field of interest. Numerous EDCs have shown the potential to alter energy metabolism, which may increase the risk of obesity, in part, through direct actions on adipose tissue. While white adipose tissue has historically been the primary focus of this work, evidence of the EDC-induced disruption of brown and beige adipose tissues continues to build. Both brown and beige fat are thermogenic adipose depots rich in mitochondria that dispense heat when activated. Due to these properties, brown and beige fat are implicated in metabolic diseases such as obesity, diabetes, and cachexia. This review delves into the current literature of different EDCs, including bisphenols, dioxins, air pollutants, phthalates, and phytochemicals. The possible implications that these EDCs have on thermogenic adipose tissues are covered. This review also introduces the possibility of using brown and beige fat as a therapeutic target organ by taking advantage of some of the properties of EDCs. Collectively, we provide a comprehensive discussion of the evidence of EDC disruption in white, brown, and beige fat and highlight gaps worthy of further exploration.

Lycopene attenuates bisphenol A-induced lung injury in adult albino rats: a histological and biochemical study

Bisphenol A (BPA) leads to ROS production that considered the core of different inflammatory and chronic obstructive pulmonary diseases. As a natural antioxidant, lycopene plays a significant role in the prevention of many chronic diseases. This study aimed to investigate the possible protective role of lycopene against BPA-induced lung alterations using morphometric, histological, immunohistochemical and biochemical methods. Forty rats aged 3 months were divided into four groups (n=10): control group, lycopene group comprising rats that received lycopene by gavage (10 mg/kg /day) for 30 days, BPA group comprising rats that received BPA by gavage (50 mg/kg/day) for 30 days and lycopene + BPA group. On the 30th day, blood and lung tissue samples were collected for biochemical, histological and immunohistochemical studies. Morphometrical and statistical analyses were performed. The BPA group revealed significantly elevated IL-1B, IL-6, MDA and NO, and it showed significantly reduced IL-10, SOD, CAT and GSH when compared to the control and lycopene + BPA groups. Upon histopathological and immunohistochemical examination, lycopene supplementation improved the BPA-induced alveolar collapse, lymphocytic infiltration, extravasated RBCs and fibrosis. The lycopene + BPA group showed significantly reduced mean percentage of 8-OHdG immunopositive and mean area percentages of Bax and caspase 3 immunopositive cells and significantly reduced mean area percentage of Bcl2 immunopositive cells as compared with the BPA group. Lycopene is a protective agent against BPA-induced lung injury because of its anti-apoptotic, anti-inflammatory and antioxidant effects, as confirmed by biochemical and histological studies.

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.

NF-κB-An Important Player in Xenoestrogen Signaling in Immune Cells

The proper functioning of the immune system is critical for an effective defense against pathogenic factors such as bacteria and viruses. All the cellular processes taking place in an organism are strictly regulated by an intracellular network of signaling pathways. In the case of immune cells, the NF-κB pathway is considered the key signaling pathway as it regulates the expression of more than 200 genes. The transcription factor NF-κB is sensitive to exogenous factors, such as xenoestrogens (XEs), which are compounds mimicking the action of endogenous estrogens and are widely distributed in the environment. Moreover, XE-induced modulation of signaling pathways may be crucial for the proper development of the immune system. In this review, we summarize the effects of XEs on the NF-κB signaling pathway. Based on our analysis, we constructed a model of XE-induced signaling in immune cells and found that in most cases XEs activate NF-κB. Our analysis indicated that the indirect impact of XEs on NF-κB in immune cells is related to the modulation of estrogen signaling and other pathways such as MAPK and JAK/STAT. We also summarize the role of these aspects of signaling in the development and further functioning of the immune system in this paper.

Bisphenol A: A potential Toll-like receptor 4/myeloid differentiation factor 2 complex agonist

In addition to endocrine disruption, bisphenol A (BPA) is known to induce inflammation through the activation of nuclear factor-κB (NF-κB). However, detailed studies on the mechanism of NF-κB activation by BPA have not been sufficiently conducted. In the present study, we observed that low concentrations of BPA (≤1 μM) upregulated the release of proinflammatory mediators, including nitric oxide (NO) and prostaglandin E₂ (PGE₂), as well as proinflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-12, and IL-6. Molecular modeling predicted that BPA docked with the Toll-like receptor 4 (TLR4)/myeloid differentiation factor 2 (MD2) complex activates downstream molecules including myeloid differentiation primary response 88 (MyD88) and IL-1 receptor-associated kinase 4 (IRAK-4) and results in the upregulation of the NF-κB signaling pathway. Additionally, BPA increased morphological abnormalities and mortality in zebrafish larvae and enhanced the dispersal of macrophages and neutrophils in the whole body, thereby causing an endotoxemia-like disorder. However, a specific TLR4 inhibitor, TLR4-IN-C34, mitigated BPA-induced mortality and morphological abnormalities, which indicates that the TLR4/MD2 complex is a molecular target of BPA-induced immunotoxicity. Collectively, our results indicate that low concentrations of BPA, which is a potential agonist of the TLR4/MD2 complex, can intensify the immune response and eventually cause an endotoxemia-like disorder.

The effects of in ovo administered bisphenol A on tibial growth plate histology in chicken

OBJECTIVES

The aim of this study was to determine of the effects of in ovo administered BPA on embryonic development of the tibial growth plate using histological methods in chickens.

METHODS

Three hundred and ten fertile eggs of Isa Brown laying parent stock were divided into five groups as untreated control, vehicle-injected control, 50, 100, and 250 μg/egg BPA. At the 13th, 18th, and 21st days of incubation, eggs were randomly opened from each group until 10 live embryos were obtained. Embryos were weighed and crown-rump length was measured. Tibial tissue samples were taken from embryos. Tibia weight, relative tibia weight and tibia length were determined. Tissue samples were fixed in 10% buffered formalin solution. Sections were stained with Safranin O staining methods and zones in the growth plate were measured. Also, proliferating cell nuclear antigen (PCNA) was stained immunohistochemically.

RESULTS

The mortality in the BPA treated groups was higher than untreated control group. The results have revealed that mean relative embryo weights, crown-rump length, mean tibia weight, relative tibia weight, and tibia length of BPA treated groups were significantly lower when compared to the untreated control and vehicle-injected control groups. Also, proliferative zone get significantly narrowed, whereas the transitional and hypertrophic zone thickened and PCNA positive chondrocytes increased in growth plate of BPA treated groups.

CONCLUSION

These results have suggested that developmental exposure to BPA adversely affected development of the tibial growth plate.

Bisphenol A as a Factor in the Mosaic of Autoimmunity

The population worldwide is largely exposed to bisphenol A (BPA), a commonly used plasticizer, that has a similar molecular structure to endogenous estrogens. Therefore, it is able to influence physiological processes in human body, taking part in the pathophysiology of various endocrinopathies, as well as, cardiovascular, neurological and oncological diseases. BPA has been found to affect the immune system, leading to the development of autoimmunity and allergies, too. In the last few decades, the prevalence of autoimmune diseases has significantly increased, that could be explained by a rising exposure of the population to environmental factors, such as BPA. BPA has been found to play a role in the pathogenesis of systemic autoimmune diseases and also organ-specific autoimmunity (thyroid autoimmunity, diabetes mellitus type 1, myocarditis, inflammatory bowel disease, multiple sclerosis, encephalomyelitis etc), but the results of some studies remain still controversial, so further research is needed.

Estrogen Receptor Functions and Pathways at the Vascular Immune Interface

Estrogen receptor (ER) activity mediates multiple physiological processes in the cardiovascular system. ERα and ERβ are ligand-activated transcription factors of the nuclear hormone receptor superfamily, while the G protein-coupled estrogen receptor (GPER) mediates estrogenic signals by modulating non-nuclear second messengers, including activation of the MAP kinase signaling cascade. Membrane localizations of ERs are generally associated with rapid, non-genomic effects while nuclear localizations are associated with nuclear activities/transcriptional modulation of target genes. Gender dependence of endothelial biology, either through the action of sex hormones or sex chromosome-related factors, is becoming increasingly evident. Accordingly, cardiometabolic risk increases as women transition to menopause. Estrogen pathways control angiogenesis progression through complex mechanisms. The classic ERs have been acknowledged to function in mediating estrogen effects on glucose metabolism, but 17β-estradiol also rapidly promotes endothelial glycolysis by increasing glucose transporter 1 (GLUT1) and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) levels through GPER-dependent mechanisms. Estrogens alter monocyte and macrophage phenotype(s), and induce effects on other estrogen-responsive cell lineages (e.g., secretion of cytokines/chemokines/growth factors) that impact macrophage function. The pharmacological modulation of ERs for therapeutic purposes, however, is particularly challenging due to the lack of ER subtype selectivity of currently used agents. Identifying the determinants of biological responses to estrogenic agents at the vascular immune interface and developing targeted pharmacological interventions may result in novel improved therapeutic solutions.

Study on the correlation of bisphenol A exposure, pro-inflammatory gene expression, and C-reactive protein with potential cardiovascular disease symptoms in young adults

Bisphenol A (BPA) is a plasticizer used in the manufacture of polycarbonate and epoxy resins. It was found that higher urinary BPA levels are more likely to be associated with coronary artery disease (CVD). In recent years, the increasing incidence of CVD among young people is observed, which may be related with inflammation rather than the traditional triple-H risk factors. BPA is an endocrine-disrupting chemical, and can induce oxidative stress and chronic inflammation since its estrogenic effect. Inflammatory responses could come from the stimulation of IκB kinases (IKKs) by estrogen receptors (ERs). Therefore, this study investigated the association of BPA exposure with the gene expression of pro-inflammatory response (ERs and IKKs), an inflammation biomarker of CVD (C-reactive protein, CRP), and physiologic index potency of CVD development symptoms in young adults. This study divided BPA exposure levels into high and low groups based on the median plasma BPA level (4.34 ng/mL), and found that the high BPA group obviously had higher BMI, blood pressure, plasma CRP levels, and gene expression of ERβ and IKKβ. BMI and gene expression of IKKβ were also positively correlated with plasma CRP secretion. Furthermore, the study subjects with potential CVD development symptoms had the increased levels of BPA (OR 2.10, 95% CI 0.83-5.39), CRP (OR 2.61, 95% CI 1.03-10.6) and IKKβ (OR 4.29, 95% CI 1.51-15.6). These results indicated that exposure to BPA is potentially associated with expression of pro-inflammatory genes related to CRP secretion, which may promote the risk of CVD development symptoms in young adults. This study highlighted the possible connection between BPA exposure and CVD development but the mechanism between them needs to be further explored.

Physiological and metabolic approach of plastic additive effects: Immune cells responses

Human and wildlife are continually exposed to a wide range of compounds and substances, which reach the body through the air, water, food, or personal care products. Plasticizers are compounds added to plastics and can be released to the environment under certain conditions. Toxicological studies have concluded that plasticizers, phthalates, and bisphenols are endocrine disruptors, alter the endocrine system and functioning of the immune system and metabolic process. A functional immune response indicates favourable living conditions for an organism; conversely, a weak immune response could reveal a degraded environment that requires organisms to adapt. There is growing concern about the presence of plastic debris in the environment. In this review, the current knowledge of the action of plasticizers on leukocyte cells will be itemized. We also point out critically the role of some nuclear and membrane receptors as key players in the action of plasticizers on cells possess immune function. We discuss the role of erythrocytes within the immune responses and the alteration caused by plasticizers. Finally, we highlight data evidencing mitochondrial dysfunctions triggered by plasticizing toxic action, which can lead to immunosuppression.

The Putative Adverse Effects of Bisphenol A on Autoimmune Diseases

Bisphenol A (BPA) is a monomer that is widely used in the manufacture of polycarbonate plastics including storage plastics and baby bottles, and is considered one of the most widely used synthetic compounds in the manufacturing industry. Exposure to BPA mainly occurs after oral ingestion and results from leaks into food and water from plastic containers and according to epidemiological data exposure is widespread and estimated to occur in 90% of individuals. BPA exertspleiotropiceffects and demonstrates estrogen like effects, thus considered an endocrine disrupting chemical. Growing body of evidence highlight the role of BPA in modulating immune responses and signaling pathways resulting in a proinflammatory response by enhancing the differential polarization of immune cells and cytokine production profile to one that is consistent with proinflammation. Indeed, epidemiological studies have uncovered associations between several autoimmune diseases and BPA exposure. Data from animal models provided consistent evidence highlighting the role of BPA in the pathogenesis, exacerbation and perpetuation of various autoimmune phenomena including neuroinflammation in the context of multiple sclerosis, colitis in inflammatory bowel disease, nephritis in systemic lupus erythematosus, and insulitis in type 1 diabetes mellitus. Given the wide spread of BPA use and its effects in immune systemdysregulation, a call for careful assessment of patients' risks and for public health measures are needed to limit exposure and subsequent deleterious effects. The purpose of this paper is to explore the autoimmune triggering mechanisms and present the current literature supporting the role of BPA in the pathogenesis of autoimmune diseases.

Endocrine Disruptor Compounds-A Cause of Impaired Immune Tolerance Driving Inflammatory Disorders of Pregnancy?

Endocrine disrupting compounds (EDCs) are prevalent and ubiquitous in our environment and have substantial potential to compromise human and animal health. Amongst the chronic health conditions associated with EDC exposure, dysregulation of reproductive function in both females and males is prominent. Human epidemiological studies demonstrate links between EDC exposure and infertility, as well as gestational disorders including miscarriage, fetal growth restriction, preeclampsia, and preterm birth. Animal experiments show EDCs administered during gestation, or to either parent prior to conception, can interfere with gamete quality, embryo implantation, and placental and fetal development, with consequences for offspring viability and health. It has been presumed that EDCs operate principally through disrupting hormone-regulated events in reproduction and fetal development, but EDC effects on maternal immune receptivity to pregnancy are also implicated. EDCs can modulate both the innate and adaptive arms of the immune system, to alter inflammatory responses, and interfere with generation of regulatory T (Treg) cells that are critical for pregnancy tolerance. Effects of EDCs on immune cells are complex and likely exerted by both steroid hormone-dependent and hormone-independent pathways. Thus, to better understand how EDCs impact reproduction and pregnancy, it is imperative to consider how immune-mediated mechanisms are affected by EDCs. This review will describe evidence that several EDCs modify elements of the immune response relevant to pregnancy, and will discuss the potential for EDCs to disrupt immune tolerance required for robust placentation and optimal fetal development.

Bisphenol A Exacerbates Allergic Inflammation in an Ovalbumin-Induced Mouse Model of Allergic Rhinitis

Purpose

Bisphenol A (BPA) is found in many plastic products and is thus a common environmental endocrine disruptor. Plastic-related health problems, including allergic diseases, are attracting increasing attention. However, few experimental studies have explored the effect of BPA on allergic rhinitis (AR). We explore whether BPA was directly related to the allergic inflammation induced by ovalbumin (OVA) in AR mice.

Methods

We first constructed OVA-induced mouse model, and after BPA administration, we evaluated nasal symptoms and measured the serum OVA-specific IgE levels by ELISA. Th2 and Treg-related cytokines of nasal mucosa were measured by cytometric bead array. Th2 and Treg-specific transcription factor levels were assayed by PCR. The proportions of CD3⁺CD4⁺IL-4⁺Th2 and CD4⁺Helios⁺Foxp3⁺ T cells (Tregs) in spleen tissue were determined by flow cytometry.

Results

Compared to OVA-only-induced mice, BPA addition increased nasal symptoms and serum OVA-specific IgE levels. OVA and BPA coexposure significantly increased IL-4 and IL-13 protein levels compared to those after OVA exposure alone. BPA plus OVA tended to decrease the IL-10 protein levels compared to those after OVA alone. Coexposure to OVA and BPA significantly increased the GATA-3-encoding mRNA level, and decreased the levels of mRNAs encoding Foxp3 and Helios, compared to those after OVA exposure alone. BPA increased the Th2 cell proportion, and decreased that of Tregs, compared to the levels with OVA alone.

Conclusion

BPA exerted negative effects by exacerbating AR allergic symptoms, increasing serum OVA-specific IgE levels, and compromising Th2 and Treg responses.

Modulatory effect of methylsulfonylmethane against BPA/γ-radiation induced neurodegenerative alterations in rats: Influence of TREM-2/DAP-12/Syk pathway

AIMS

Methylsulfonylmethane (MSM), is an organosulfur compound, has many health benefits. Bisphenol-A (BPA) and γ-radiation (R) are two risky environmental contaminants that human beings are exposed to in everyday life. This work aims at unveiling the modulatory role of MSM in combating BPA and R co-exposure induced neurodegenerative disorder (Alzheimer's (AD)-mimic neurotoxicity).

MAIN METHODS

Female rats were randomly divided into five groups. One group was normal control and the other four groups were subjected to subacute BPA intoxication and/or exposed to fractionated weekly doses of R for 4 weeks and either untreated or treated with MSM concomitantly.

KEY FINDINGS

BPA and R co-exposure induced typical hallmarks of neurodegenerative disorders as revealed by tremendously elevated oxidative stress, extensive neuroinflammation (tumor necrosis factor -α and interleukin-1β), elevated AD markers (amyloid-beta (Aβ₄₂), acetylcholinesterase (AchE) activity and tau-phosphorylation) in cortex and hippocampus as well as up-regulation of microglial pro-inflammatory triggering receptor expressed on myeloid cell-2(TREM-2)/DNAX-activating protein of 12 kDa (DAP-12)/spleen-tyrosine kinase (Syk) pathway and its downstream targets (PLC-γ/DAG/p38-MAPK) in hippocampus. Also, neurodegenerative lesions were revealed in histopathological examination of cortex and hippocampus coupled with marked Aβ deposition in hippocampus. Whereas, MSM treatment improved histopathological insults and ameliorated level of oxidative stress, neuroinflammation and AD markers as well as modulated TREM-2/DAP-12/Syk pathway.

SIGNIFICANCE

Our data suggest that MSM afforded neuroprotection against BPA and R; supporting its potential application in the associated neurodegenerative disorders.

Cardiovascular toxicity and mechanism of bisphenol A and emerging risk of bisphenol S

Epidemiological and animal studies indicate that increased exposure to bisphenol A (BPA) induces various human cardiovascular diseases (CVDs), including myocardial infarction, arrhythmias, dilated cardiomyopathy, atherosclerosis, and hypertension. Bisphenol S (BPS), an alternative to BPA, is increasingly present in various consumer products and human bodies worldwide. Recently, emerging evidence has shown that BPS might be related to cardiovascular disorders. In this review, we present striking evidence of the correlation between BPA exposure and various CVDs, and show that a nonmonotonic dose-response curve (NMDRC) was common in studies of the CV effects of BPA in vivo. The CV impairment induced by low doses of BPA should be highlighted, especially during developmental exposure or during coexposure with other risk factors. Furthermore, we explored the possible underlying mechanisms of these effects-particularly nuclear receptor signaling, ion channels, and epigenetic mechanisms-and the possible participation of lipid metabolism, oxidative stress and cell signaling. As the potential risks of BPA exposure in humans are still noteworthy, studies of BPA in CVDs should be strengthened, especially with respect to the mechanisms, prevention and treatment. Moreover, the potential CV risk of BPS reported by in vivo studies calls for immediate epidemiological investigations and animal studies to reveal the relationships of BPS and other BPA alternatives with human CVDs.

Recovery From a Myocardial Infarction Is Impaired in Male C57bl/6 N Mice Acutely Exposed to the Bisphenols and Phthalates That Escape From Medical Devices Used in Cardiac Surgery

Bisphenols and phthalates leach from medical devices, and this exposure is likely to increase in postcardiac surgery patients. Previous studies suggest that such chemical exposure may impact recovery and wound healing, yet the direct effects of bisphenols and phthalates are unknown in this context. To study the direct effect of clinically based chemical exposures, we measured the metabolites representative of 6 bisphenols and 10 phthalates in men before and after cardiac surgery and then replicated this exposure in a mouse model of cardiac surgery and assessed survival, cardiac function and inflammation. Bisphenol A (BPA), di-ethyl hexyl phthalate (DEHP), butylbenzyl phthalate, di-isodecyl phthalate, and di-n-butyl phthalate metabolites were increased after surgery. DEHP exposure predominated, was positively correlated with duration on the cardiopulmonary bypass machine and exceeded its tolerable daily intake limit by 37-fold. In vivo, C57bl/6 N male mice treated with BPA+phthalates during recovery from surgery-induced myocardial infarction had reduced survival, greater cardiac dilation, reduced cardiac function and increased infiltration of neutrophils, monocytes and macrophages suggesting impaired recovery. Of interest, genetic ablation or estrogen receptor beta (ERβ) antagonism did not improve recovery and replacement of DEHP with tri-octyl trimellitate or removal of BPA from the mixture did not ameliorate these effects. To examine the direct effects on inflammation, treatment of human THP-1 macrophages with BPA and phthalates induced a dysfunctional proinflammatory macrophage phenotype with increased expression of M1-type macrophage polarization markers and MMP9 secretion, yet reduced phagocytic activity. These results suggest that chemicals escape from medical devices and may impair patient recovery.

Peroxisome proliferator-activated receptor gamma (PPARγ) activation and metabolism disturbance induced by bisphenol A and its replacement analog bisphenol S using in vitro macrophages and in vivo mouse models

Bisphenol A (BPA) and its replacement analog, bisphenol S (BPS), have been proposed as environmental obesogen to disrupt the lipid metabolism through regulating peroxisome proliferator-activated receptor gamma (PPARγ) receptor. However, there is a dearth of information on whether this biological effect can occur in human macrophage, a cell type which closely interacts with adipocytes and hepatocytes to control lipid metabolism. Here, we for the first time investigate the activity of BPA and BPS on PPARγ pathway in human macrophages. The results demonstrated that BPA and BPS served as activators of PPARγ in human macrophage cell line, and significantly induced the expression of lipid metabolism-related genes, including fatty acid binding protein 4 (FABP4), cluster of differentiation 36 (CD36) and nuclear receptor subfamily 1 group H member 3 (NR₁H₃). In PPARγ knockout cells, expression of these genes was down-regulated, suggesting that these genes are dependent on PPARγ. The underlying mechanisms were further investigated using an in vivo mouse model, and the results confirmed the induction of PPARγ and its respective target genes in mice following exposure to BPA or BPS. Moreover, the observed alteration of PPARγ expression highly correlated with the disturbance of metabolism profiles in liver tissues as detected by ¹H Nuclear Magnetic Resonance (NMR)-based metabonomics. Overall, this study provided the first evidence that BPA and BPS activated PPARγ and its target genes in human macrophages, and provided comprehensive information to confirm that BPA and BPS disturb the metabolism through targeting PPARγ via both in vitro assays and in vivo animal models.

Maintenance of mitochondrial function by astaxanthin protects against bisphenol A-induced kidney toxicity in rats

Bisphenol A (BPA), a global environmental pollutant, has been reported to have the potential to induced organs toxicity. This study explored the potential benefits of astaxanthin (ATX), a natural antioxidant, against BPA toxicity in the kidney, and explored whether mitochondria are involved in this condition. Male Wistar rats were fed with a vehicle, BPA, BPA plus ATX, ATX and were evaluated after five weeks. ATX treatment significantly reversed BPA-induced changes in body weight, kidney/body weight, and renal function related markers. When treated simultaneously with ATX, the imbalance of the oxidative-antioxidant status caused by BPA was also alleviated. The high expression of BPA-induced pro-inflammatory cytokines were inhibited by ATX treatment. ATX treatment also lessened the effects of BPA-induced caspase-3, -8, -9 and -10 gene expression and enzyme activity. The benefits of ATX were associated with enhanced mitochondrial function, which led to increased mitochondrial-encoded gene expression, mitochondrial copy number, and increased mitochondrial respiratory chain complex enzyme activity. Our results demonstrate the efficacy of ATX in protecting BPA-induced kidney damage, in part by regulating oxidative imbalance and improving mitochondrial function. Collectively, these findings provide a new perspective for the rational use of ATX in the treatment of BPA-induced kidney disease.

Effect of bisphenol-A (BPA) on placental biomarkers for inflammation, neurodevelopment and oxidative stress

Background Bisphenol-A (BPA) is a widespread pollutant whose effects on pregnant women are poorly understood. Therefore, we investigated the effects of BPA on basal and bacteria-stimulated production of proinflammatory cytokines [interleukin (IL)-1β, tumor necrosis factor-α (TNF-α) and IL-6], anti-inflammatory mediators [soluble glycoprotein 130 (sgp) 130, heme oxidase-1 (HO-1) and IL-10] and biomarkers for neurodevelopment [brain-derived neurotrophic factor (BDNF)], and oxidative stress [8-isoprostane (8-IsoP)] by the placenta. Methods Placental explant cultures were treated with BPA (0-10,000 nM) in the presence or absence of 107 colony-forming unit (CFU)/mL heat-killed Escherichia coli for 24 h. Biomarker concentrations in conditioned medium were quantified by the enzyme-linked immunosorbent assay (ELISA). Results Under basal conditions, IL-1β and IL-6 production was enhanced by BPA in a dose-dependent manner. Sgp130, a soluble receptor that reduces IL-6 bioactivity, was suppressed by BPA at 1000-10,000 nM. BPA also enhanced BDNF production at 1000 and 10,000 nM, and 8-IsoP expression at 10 and 100 nM. For bacteria-treated cultures, BPA increased IL-6 production at 100 nM and reduced sgp130 at 1000 nM but had no effect on IL-1β, TNF-α, BDNF, HO-1, 8-IsoP or IL-10 production. Conclusion BPA may increase placental inflammation by promoting IL-1β and IL-6 but inhibiting sgp130. It may also disrupt oxidative balance and neurodevelopment by increasing 8-IsoP and BDNF production.

Bisphenol A Promotes the Invasive and Metastatic Potential of Ductal Carcinoma In Situ and Protumorigenic Polarization of Macrophages

Increased cancer risk and immune disorders linked with exposure to environmental endocrine disruptors like bisphenol A (BPA) have been steadily reported. Nevertheless, the impacts of BPA on the breast ductal carcinoma in situ (DCIS) progression and macrophage polarization remain to be elucidated. Here, we analyzed the differentially expressed genes in BPA-exposed DCIS cells and explored BPA effects on DCIS progression and macrophage polarization in vitro and in vivo. Two hundred and ninety-one genes were differentially expressed in 10−8 M BPA-exposed DCIS cells, in which the gene ontology terms of biological processes associated with negative regulation of cell death, cell adhesion, and immune response was enriched. 10−8 M BPA promoted the proliferation and migration of DCIS cells and the migration of macrophages, and upregulated the expression of M1 (NOS2) or M2 markers (Arg-1 and CD206) in macrophages. In coculture system, the migratory capacity of both cells and the expression levels of NOS2, Arg-1, and CD206 in macrophages were significantly enhanced upon 10−8 M BPA. In a DCIS xenograft model, oral exposure to an environmentally human-relevant low dose of 2.5 µg/l BPA for 70 days via drinking water led to an approximately 2-fold promotion in the primary tumor growth rate and a significant enhancement of lymph node metastasis along with increased protumorigenic CD206+ M2 polarization of macrophages. These results demonstrate that BPA acts as an accelerator to promote DCIS progression to invasive breast cancer by affecting DCIS cell proliferation and migration as well macrophage polarization toward a protumorigenic phenotype.

Bisphenol A promotes macrophage proinflammatory subtype polarization via upregulation of IRF5 expression in vitro

Exposure to environmental endocrine-disrupting chemical Bisphenol-A (BPA) is closely associated with an imbalance of immune homeostasis, but the underlying mechanisms are not fully understood. In the present study, the effects of BPA on the polarization of mouse peritoneal macrophages were investigated in vitro. Environmentally relevant low concentrations of BPA treatment under M1 type polarization conditions increased the number of M1 subtype macrophages, the gene expression of M1 phenotypic marker CD11c and the activity and gene expression of M1 functional marker iNOS, as well as the production of pro-inflammatory cytokines. However, The same dose BPA treatment under M2 type polarization conditions reduced the number of M2 subtype macrophages, the gene expression of M2 phenotypic marker CD206 and the activity and gene expression of M2 functional marker Arg-1, along with the production of anti-inflammatory cytokines. We also identified that the expression of transcription factor IRF5 was upregulated by BPA exposure in M1 macrophages under M1 type polarization conditions. Our results demonstrate that BPA promotes macrophage polarization toward proinflammatory M1 subtype and M1 activity, associated with upregulated expression of IRF5, while BPA inhibits macrophage toward anti-inflammatory M2 subtype polarization. These findings provide new insight into the link between exposure to BPA and impairment of immune functions.

Phthalates affect the in vitro expansion of human hematopoietic stem cell

Phthalates are esters of phthalic acid used industrially as plastic additives, however, these are not covalently bound to the polymer matrix and therefore can be released to the environment. The aim of this study was to evaluate the effect of four phthalates: dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), diethyl phthalate (DEP) and diethylhexyl phthalate (DEHP) on the in vitro expansion of human hematopoietic cells from umbilical cord blood. For this, 0.5 × 106 cells/mL were exposure to concentrations ranging from 0.1 to 100 μg/mL and the total cell expansion was determined after 14 days of culture in IMDM-cytokines medium. The control cultures attained 1.31 ± 0.21 × 106 cell/mL, whereas the cultures exposed to DBP, BBP and DEHP showed a reduction from 23 to 81%, 17 to 69% and 15 to 93.5%, respectively. DEP did not affect the total cell expansion. The most significant decrease on total cell expansion was observed at 0.1 μg/mL DBP, 100 μg/mL BBP and 10 μg/mL DEHP (p < 0.05). Additionally, the effect of these compounds on the expansion of hematopoietic progenitors was analyzed by clonogenic assays as colony forming units (CFU). The CFU decreased considerably compared with respect to the control cultures. The reduction was 74.6 and 99.1% at 10 and 100 μg/mL DBP respectively, whereas 100 μg/mL BBP and 100 μg/mL DEHP reduced the CFU expansion in 97.1% and 81%, respectively. Cultures exposed to DEP did not show significant differences. The results demonstrate the toxicity of DBP, BBP and DEHP on the human hematopoietic stem cells.

Expression of pro-inflammatory cytokines and mediators induced by Bisphenol A via ERK-NFκB and JAK1/2-STAT3 pathways in macrophages

Macrophages not only play an important role in the innate immune response but also participate in many inflammatory and infectious diseases including asthma, diabetes, obesity, cardiovascular diseases, and cancers. Bisphenol A (BPA) is the most commonly used component for plastic products. However, BPA is an endocrine disruptor for mammals and participates in several inflammatory and infectious diseases. Up until now, there are no researches demonstrated the potential role of BPA in macrophage activation and its relative mechanism. BPA promoted the generation of proinflammatory cytokines IL-1β, IL-6, and TNFα in a concentration-dependent manner (P < 0.05). BPA was identified to increase the expression of proinflammatory mediators NO and PGE2, and its upstream factors iNOS, COX2, and cPLA2 in a concentration-dependent manner (P < 0.05). Phosphorylation and nuclear translocation of NF-κB p65 were significantly induced by BPA via IκB degradation (P < 0.05). In addition, phosphorylation of ERK significantly induced by BPA at a concentration which was less than that for phosphorylation of p38 MAPK and JNK (P < 0.05). Furthermore, phosphorylation of STAT3 significantly induced by BPA at a concentration lower than that for phosphorylation of STAT1 (P < 0.05). Phosphorylation of JAK1 and JAK2 was also significantly induced by BPA in a concentration-dependent manner (P < 0.05).

BPA Alters Estrogen Receptor Expression in the Heart After Viral Infection Activating Cardiac Mast Cells and T Cells Leading to Perimyocarditis and Fibrosis

Myocarditis is an inflammatory heart disease that leads to dilated cardiomyopathy (DCM) and heart failure. Sex hormones play an important role in the development of myocarditis with testosterone driving disease in males and estrogen being cardioprotective in females. The human population is widely exposed to the endocrine disruptor bisphenol A (BPA) from plastics such as water bottles, plastic food containers, copy paper, and receipts. Several clinical and numerous animal studies have found an association between elevated BPA levels and cardiovascular disease. A recent report found elevated levels of BPA in the serum of patients with DCM compared to healthy controls. In this study we examined whether exposure to BPA for 2 weeks prior to viral infection and leading up to myocarditis at day 10 altered inflammation in female BALB/c mice housed in standard plastic cages/water bottles with soy-free food and bedding. We found that a human relevant dose of BPA (25 μg/L) in drinking water, with an estimated exposure of 5 μg BPA/kg BW, significantly increased myocarditis and pericarditis compared to control water without altering viral genome levels in the heart. BPA exposure activated ERα and ERβ in the spleen 24 h after infection and phosphorylated ERα and ERβ during myocarditis, but decreased ERα and increased ERβ mRNA in the heart as measured by qRT-PCR. Exposure to BPA significantly increased CD4⁺ T cells, IFNγ, IL-17A, TLR4, caspase-1, and IL-1β in the heart. BPA exposure also increased cardiac fibrosis compared to controls. Mast cells, which are associated with cardiac remodeling, were found to increase in number and degranulation, particularly along the pericardium. Interestingly, plastic caging/water bottle exposure alone led to increased mast cell numbers, pericardial degranulation and fibrosis in female BALB/c mice compared to animals housed in glass cages/water bottles with soy-free food and bedding. These data suggest that BPA exposure may increase the risk of developing myocarditis after a viral infection in women.

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.

Maternal exposure to nonylphenol during pregnancy and lactation induces microglial cell activation and pro-inflammatory cytokine production in offspring hippocampus

Recently, environmental nonylphenol (NP) exposure in the fetus and child has received increasing attention because of its potentially deleterious effects on the central nervous system (CNS). Microglia (MG), resident immune cells in the CNS, are vital to CNS homeostasis and defense against exogenous chemicals, which makes them a potentially sensitive target of NP. The present study aims to explore the effects of maternal NP exposure during pregnancy and lactation on MG in offspring hippocampus, the production of pro-inflammatory cytokines by MG, and associated underlying mechanisms. We found that maternal NP exposure increased the production of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in offspring hippocampus. Increases in both activation and number of MG were observed in offspring hippocampus. Increased phosphorylation of Akt was found to co-localize with hippocampal MG, while increased phosphorylation of c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) were observed in offspring hippocampus. Activator protein 1 (AP-1), an inflammatory transcription factor, was also activated in the hippocampus of pups subjected to maternal NP exposure. These results suggest that maternal NP exposure might activate MG in offspring hippocampus. This activation seems to subsequently increase the production of IL-1β, IL-6, and TNF-α. Furthermore, Akt/MAPK/AP-1 signaling may be involved in this activation of MG and increased production of pro-inflammatory cytokines.

Organic UV filters exposure induces the production of inflammatory cytokines in human macrophages

Organic ultraviolet (UV) filters, found in many personal care products, are considered emerging contaminants due to growing concerns about potential long-term deleterious effects. We investigated the immunomodulatory effects of four commonly used organic UV filters (2-hydroxy-4-methoxybenzophenone, BP-3; 4-methylbenzylidene camphor, 4-MBC; 2-ethylhexyl 4-methoxycinnamate, EHMC; and butyl-methoxydibenzoylmethane, BDM) on human macrophages. Our results indicated that exposure to these four UV filters significantly increased the production of various inflammatory cytokines in macrophages, particular tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). After exposure to the UV filters, a significant 1.1-1.5 fold increase were found in TNF-α and IL-6 mRNA expression. In addition, both the p38 MAPK and the NF-κB signaling pathways were enhanced 2 to 10 times in terms of phosphorylation after exposure to the UV filters, suggesting that these pathways are involved in the release of TNF-α and IL-6. Molecular docking analysis predicted that all four UV filter molecules would efficiently bind transforming growth factor beta-activated kinase 1 (TAK1), which is responsible for the activation of the p38 MAPK and NF-κB pathways. Our results therefore demonstrate that exposure to the four organic UV filters investigated may alter human immune system function. It provides new clue for the development of asthma or allergic diseases in terms of the environmental pollutants.

The in vivo action of chronic bisphenol F showing potential immune disturbance in juvenile common carp (Cyprinus carpio)

Bisphenol F (BPF) has been increasingly introduced into industrial applications as a replacement for bisphenol A (BPA), and has emerged as a ubiquitous environmental contaminant worldwide. Few studies have assessed the in vivo toxicities of BPF, particularly long-term exposure toxicities. In the present study, we examined whether long-term BPF exposure in vivo would evoke oxidative stress in the immune system of juvenile common carp. The results suggested that BPF exposure increased ROS content, oxidative stress indices, complement component 3, and immunoglobulin M contents, as well as the expression of inflammatory cytokine genes. Moreover, higher levels of nf-κb p65 gene expression were correlated with the induced ROS content and NF-κB pathway-associated genes, a strong indication that the mode of action of BPF is related to the NF-κB signaling pathway. We also provide evidence that the effects of BPF are comparable to those of BPA with regards to regulation of the immune response in teleosts, and therefore suggest that such chemical analogs should be thoroughly evaluated for their potential toxicity before they can be considered as "safer" replacements.

Bisphenol A affects trophoblast invasion by inhibiting CXCL8 expression in decidual stromal cells

Bisphenol A (BPA), an environmental endocrine-disrupting organic chemical, has been positively associated with the rate of implantation failure of in vitro fertilization. However, the underlying mechanisms remain unclear. To reveal the impact and the underlying mechanism of BPA on the crosstalk between trophoblast and decidual stromal cells (DSCs), we determined whether BPA was able to affect trophoblast invasion in vitro. We found that BPA significantly inhibited CXCL8 expression in DSCs, which hindered trophoblast invasion, and activated the phosphorylation of ERK in DSCs. U0126, an inhibitor of ERK activation, remarkably rescued trophoblast invasion and the inhibition of CXCL8 expression caused by BPA treatment. Moreover, the nuclear estrogen receptor antagonist ICI 182,780 and transmembrane G protein-coupled receptor GPR30 (membrane estrogen receptor) antagonist G15 significantly blocked the phosphorylation of ERK and reversed the reduction of trophoblast invasion. In brief, BPA activated ERK through nuclear and membrane estrogen receptors and inhibited CXCL8 expression in DSCs, thereby affecting their regulation of trophoblast invasion.

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.

Bisphenol-A alters microbiota metabolites derived from aromatic amino acids and worsens disease activity during colitis

Inflammatory bowel disease is a complex collection of disorders. Microbial dysbiosis as well as exposure to toxins including xenoestrogens are thought to be risk factors for inflammatory bowel disease development and relapse. Bisphenol-A has been shown to exert estrogenic activity in the colon and alter intestinal function, but the role that xenoestrogens, such as bisphenol-A , play in colonic inflammation has been previously described but with conflicting results. We investigated the ability of bisphenol-A to exacerbate colonic inflammation and alter microbiota metabolites derived from aromatic amino acids in an acute dextran sulfate sodium-induced colitis model. Female C57BL/6 mice were ovariectomized and exposed to bisphenol-A daily for 15 days. Disease activity measures include body weight, fecal consistency, and rectal bleeding. Colons were scored for inflammation, injury, and nodularity. Alterations in the levels of microbiota metabolites derived from aromatic amino acids known to reflect phenotypic changes in the gut microbiome were analyzed. Bisphenol-A exposure increased mortality and worsened disease activity as well as inflammation and nodularity scores in the middle colon region following dextran sulfate sodium exposure. Unique patterns of metabolites were associated with bisphenol-A consumption. Regardless of dextran sulfate sodium treatment, bisphenol-A reduced levels of tryptophan and several metabolites associated with decreased inflammation in the colon. This is the first study to show that bisphenol-A treatment alone can reduce microbiota metabolites derived from aromatic amino acids in the colon which may be associated with increased colonic inflammation and inflammatory bowel disease. Impact statement As rates of inflammatory bowel disease rise, discovery of the mechanisms related to the development of these conditions is important. Environmental exposure is hypothesized to play a role in etiology of the disease, as are alterations in the gut microbiome and the metabolites they produce. This study is the first to show that bisphenol-A alone alters tryptophan and microbiota metabolites derived from aromatic amino acids in a manner consistent with autoimmune diseases, specifically inflammatory bowel diseases, regardless of dextran sulfate sodium treatment. These findings indicate a potential mechanism by which bisphenol-A negatively affects gut physiology to exacerbate inflammation.