Exposure to bisphenol A enhanced lung eosinophilia in adult male mice

Bombesin-like receptor 3 expression induced by bisphenol A is likely associated with reduced cell proliferation by inhibiting DNA synthesis and inducing inflammation in liver cells

BACKGROUND

Bisphenol A (BPA) is an exogenous endocrine disruptor mimicking hormones closely associated with health complications, such as cancer progression. BPA is also related to an increase in the prevalence of obesity-related diseases due to its obesogenic action. Bombesin-like receptor 3 (BRS3) is an important factor that should be considered in the adipogenic gene network, as depletion of this gene alters adiposity.

METHODS

Therefore, the present study aimed to investigate the messenger ribonucleic acid (mRNA) expression of BRS3 in human liver THLE-2 cells post-BPA treatment by real-time polymerase chain reaction. The effects of BPA on the levels of pro-inflammatory proteins, interleukin 6 (IL6) and CC motif chemokine ligand 2 (CCL2), in conditioned media of BPA-treated THLE-2 cells and deoxyribonucleic acid (DNA) synthesis in replicating BPA-treated THLE-2 cells during the cell cycle were also examined by enzyme-linked immunosorbent assay (ELISA) and flow cytometry, respectively.

RESULTS

The study found that the mRNA expression of BRS3 was increased in THLE-2 cells treated with BPA. The study also showed that the expression levels of IL6 and CCL2 reached an optimum level in the conditioned media of BPA-treated THLE-2 cells after 48 h of treatment. Subsequently, the DNA synthesis analysis showed that bromodeoxyuridine/propidium iodide (BrdU/PI) stained positive cells were decreased in BPA-treated THLE-2 cells at 72 h of treatment.

CONCLUSION

The study demonstrates that BRS3 expression induced by BPA is likely associated with reduced cell proliferation by inhibiting DNA synthesis and inducing cellular inflammation in liver cells.

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

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

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.

Integrated Genomic and Bioinformatics Approaches to Identify Molecular Links between Endocrine Disruptors and Adverse Outcomes

Exposure to Endocrine Disrupting Chemicals (EDC) has been linked with several adverse outcomes. In this review, we examine EDCs that are pervasive in the environment and are of concern in the context of human, animal, and environmental health. We explore the consequences of EDC exposure on aquatic life, terrestrial animals, and humans. We focus on the exploitation of genomics technologies and in particular whole transcriptome sequencing. Genome-wide analyses using RNAseq provides snap shots of cellular, tissue and whole organism transcriptomes under normal physiological and EDC perturbed conditions. A global view of gene expression provides highly valuable information as it uncovers gene families or more specifically, pathways that are affected by EDC exposures, but also reveals those that are unaffected. Hypotheses about genes with unknown functions can also be formed by comparison of their expression levels with genes of known function. Risk assessment strategies leveraging genomic technologies and the development of toxicology databases are explored. Finally, we review how the Adverse Outcome Pathway (AOP) has exploited this high throughput data to provide a framework for toxicology studies.

Environmental exposure during pregnancy and the risk of childhood allergic diseases

BACKGROUND

Allergic diseases are one of the most common and important diseases that can exert hazardous effects on children's health. The prevalence of allergic diseases in childhood is gradually increasing all over the world in recent decades. Known causes of these diseases include anomalous immune responses and allergic inflammatory reactions, but the causes of allergic diseases in childhood are complex.

DATA SOURCES

PubMed, Cochrane Library, Embase and Web of Science were searched for articles focusing on environmental exposure during pregnancy and the risk of childhood allergic diseases, including asthma and atopic dermatitis, and the possible underlying mechanism.

RESULTS

In terms of environmental factors, allergic diseases in childhood are closely related to environmental chemical exposure during pregnancy, including bisphenols, phthalates acid esters, perfluorochemicals, polybrominated diphenyl ethers, and polychlorinated biphenyls. However, allergic diseases in childhood are also closely associated with maternal dietary nutrition, maternal intake of drugs, such as acetylsalicylic acid (aspirin), paracetamol and antibiotics, and maternal lifestyle.

CONCLUSIONS

Several harmful environmental factors during pregnancy can result in the interruption of the function of helper T cells (Th1/Th2), cytokines and immunoglobulins and may activate allergic reactions, which can lead to allergic diseases during childhood.

Sex-Specific Effects of Plastic Caging in Murine Viral Myocarditis

Background: Myocarditis is an inflammatory heart disease caused by viral infections that can lead to heart failure, and occurs more often in men than women. Since animal studies have shown that myocarditis is influenced by sex hormones, we hypothesized that endocrine disruptors, which interfere with natural hormones, may play a role in the progression of the disease. The human population is exposed to the endocrine disruptor bisphenol A (BPA) from plastics, such as water bottles and plastic food containers. Methods: Male and female adult BALB/c mice were housed in plastic versus glass caging, or exposed to BPA in drinking water versus control water. Myocarditis was induced with coxsackievirus B3 on day 0, and the endpoints were assessed on day 10 post infection. Results: We found that male BALB/c mice that were exposed to plastic caging had increased myocarditis due to complement activation and elevated numbers of macrophages and neutrophils, whereas females had elevated mast cell activation and fibrosis. Conclusions: These findings show that housing mice in traditional plastic caging increases viral myocarditis in males and females, but using sex-specific immune mechanisms.

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.

[Effects of bisphenol A on apoptosis of ovarian preantral follicular granulosa cells and ovarian development in mice]

OBJECTIVE

To investigate the effect of environmental estrogen bisphenol A (BPA) exposure on apoptosis of mouse ovarian preantral follicular granulosa cells and ovarian development and explore the underlying mechanism.

METHODS

Mouse ovarian preantral follicular granulosa cells were isolated from female ICR mice at postnatal day (PND) 10 and cultured in vitro. The cultured cells were treated with 0, 1, 10, 50, 100, 150, 200 and 500 μmol/L BPA, and the changes in cell proliferation, cell cycle, apoptosis and mitochondrial membrane potential were analyzed with CCK-8 method and flow cytometry. The protein expressions of Bcl-2, Bax, p53 and cyclin D1 in the treated cells were determined with Western blotting. Pregnant ICR mice were treated for a week with BPA at the concentration that produced significant effects on the preantral follicular granulosa cells, and the weight changes of the pregnant mice were recorded. The ovarian tissues of the offspring female mice were weighed at PND 10, 17, 21 and 42 followed by histological observation with HE staining and examination of Bcl-2 mRNA expression level with RT-qPCR.

RESULTS

Compared with the control cells group, the isolated cells exposed to a low concentration of BPA (50 μmol/L) showed a significantly lowered apoptosis rate, increased mitochondrial membrane potential, and enhanced cellular proliferation (P < 0.05). Exposure to a higher BPA concentration at 200 μmol/L obviously enhanced cell apoptosis by reducing the mitochondrial membrane potential and repressed the cell proliferation (P < 0.05). BPA exposure at 50 μmol/L and 200 μmol/L produced opposite effects on the protein expressions of Bcl-2 (P < 0.01), Bax (P < 0.05) and p53 (P < 0.05) in mouse ovarian preantral follicular granulosa cells. BPA exposure at the doses of 10 and 35 mg/kg caused rapid weight increment of the pregnant mice and changes in ovarian index of the offspring female mice. In the offspring female mice, the changes in Bcl-2 mRNA expression in the ovarian tissue showed a similar pattern to that of ovarian index. Exposure of the pregnant mice to a high BPA concentration at 35 mg/kg resulted in accelerated follicular development into antral follicular stage in PND 21 offspring female mice.

CONCLUSIONS

BPA can concentration-dependently regulate the function of ovarian preantral follicular granulosa cells in mice and potentially affects both the pregnant mice and the offspring female mice in light of early ovarian development.

Dietary exposure to bisphenol A affects memory function and neuroimmune biomarkers in allergic asthmatic mice

Bisphenol A (BPA) is a raw material of polycarbonate and epoxy resin. It is used for various household electrical appliances, electronic equipment, office automation equipment, medical equipment, mobile phones, paints for automobiles, internal surface coating of cans, and adhesives for civil engineering and construction. BPA is a well-known endocrine-disrupting chemical, and it was reported that BPA has an adverse effect on the nervous and immune systems. However, BPA-induced memory impairment and changes in neuroimmune biomarkers in the allergic asthmatic subject are not known yet. We aim to investigate the dietary exposure effect of BPA on brain function and biomarkers using allergic an asthmatic mouse model. Five-week-old male C3H/HeJSlc mice were fed two doses of BPA [0.901, 9.01 μg/kg/day] contained chow diet from 5 to 11 weeks old and ovalbumin (OVA) was given by intratracheal instillation every 2 weeks. Memory function was determined by a novel object recognition test. Genes related to memory and immune markers in the hippocampus were investigated with the real-time polymerase chain reaction (RT-PCR) method. In this study, impaired novel object recognition occurred in BPA-exposed mice in the presence of an allergen. Moreover, upregulation of expression level of neuroimmune biomarkers such as N-methyl-D-aspartate receptor, tumor necrosis factor-α, ionized calcium-binding adapter molecule-1, cyclooxygenase-2, and heme oxygenase-1 in the hippocampus was observed in BPA-exposed allergic asthmatic mice. These findings show that BPA exposure can induce neuroinflammation and which triggers impairment of memory function in mice with allergic asthma. Our study indicated that dietary exposure to BPA may affect higher brain functions by modulating neuroimmune biomarkers in allergic asthmatic subjects.

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.

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.

Endocrine Disruptor Bisphenol A (BPA) Triggers Systemic Para-Inflammation and is Sufficient to Induce Airway Allergic Sensitization in Mice

Allergic airway diseases are accompanied by increased permeability and an inflammatory state of epithelial barriers, which are thought to be susceptible to allergen sensitization. Although exogenous drivers (proteases, allergens) of epithelial barrier disruption and sensitization are well studied, endogenous contributors (diet, xenobiotics, hormones, and metabolism) to allergic sensitization are much less understood. Xenoestrogens are synthetic or natural chemical compounds that have the ability to mimic estrogen and are ubiquitous in the food and water supply of developed countries. By interfering with the estrogen produced by the endocrine system, these compounds have the systemic potential to disrupt the homeostasis of multiple tissues. Our study examined the potential of prototypical xenoestrogen bisphenol A (BPA) to disrupt epithelial homeostasis in vitro and promote allergic responses in vivo. We found that BPA exposure in epithelial cultures in vitro significantly inhibited epithelial cell proliferation and wound healing, as well as promoted the expression of the innate alarmin cytokine TSLP in a time-and dose-dependent manner. In vivo, the exposure to BPA through water supply or inhalation induced a systemic para-inflammatory response by promoting the expression of innate inflammatory mediators in the skin, gut, and airway. In a murine tolerogenic antigen challenge model, chronic systemic exposure to BPA was sufficient to induce airway sensitization to innocuous chicken egg ovalbumin in the complete absence of adjuvants. Mechanistic studies are needed to test conclusively whether endocrine disruptors may play an upstream role in allergic sensitization via their ability to promote a para-inflammatory state.

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

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

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

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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.

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.

Exposure to low-dose bisphenol A during the juvenile period of development disrupts the immune system and aggravates allergic airway inflammation in mice

Bisphenol A (BPA) is used in the production of polycarbonate plastics and epoxy resins and found in many consumer products. Previous studies have reported that perinatal exposure to BPA through the oral route promotes the development of allergic airway inflammation. We investigated the effects of exposure to low-dose BPA during the juvenile period of development on allergic airway inflammation. Six-week-old male C3H/HeJ mice were intratracheally administered ovalbumin (OVA, 1 μg) every 2 weeks and/or BPA (0, 0.0625, 1.25, and 25 pmol/animal/week) once per week for 6 weeks. Following the final intratracheal instillation, we examined the cellular profile of the bronchoalveolar lavage fluid, histological changes and expression of inflammatory/anti-inflammatory mediators in the lungs, OVA-specific immunoglobulin (Ig) production, serum corticosterone levels, and changes in the lymphoid tissues (mediastinal lymph node (MLN) and spleen). Exposure to OVA + BPA enhanced inflammatory cell infiltration and protein expression of Th2 cytokines/chemokines (e.g. interleukin (IL)-13 and IL-33) in the lungs, OVA-specific immunoglobulin E (IgE) production, the numbers of total cells and activated antigen-presenting cells (MHC class II⁺ CD86⁺, CD11c⁺), as well as the production of Th2 cytokines (i.e. IL-4 and IL-5) and stromal cell-derived factor-1α in MLN cells compared to OVA exposure alone. These effects were more prominent with 0.0625 or 1.25 pmol/animal/week of BPA. Furthermore, exposure to OVA + BPA altered serum levels of anti-inflammatory corticosterone, estrogen receptor 2 messenger RNA (mRNA) expression in the lungs and spleen functionality. These findings suggest that low-dose BPA exposure may aggravate allergic airway inflammation by enhancing Th2 responses via disruption of the immune system.

Maternal engineered nanomaterial inhalation during gestation alters the fetal transcriptome

Background

The integration of engineered nanomaterials (ENM) is well-established and widespread in clinical, commercial, and domestic applications. Cardiovascular dysfunctions have been reported in adult populations after exposure to a variety of ENM. As the diversity of these exposures continues to increase, the fetal ramifications of maternal exposures have yet to be determined. We, and others, have explored the consequences of ENM inhalation during gestation and identified many cardiovascular and metabolic outcomes in the F1 generation. The purpose of these studies was to identify genetic alterations in the F1 generation of Sprague-Dawley rats that result from maternal ENM inhalation during gestation. Pregnant dams were exposed to nano-titanium dioxide (nano-TiO₂) aerosols (10 ± 0.5 mg/m³) for 7-8 days (calculated, cumulative lung deposition = 217 ± 1 μg) and on GD (gestational day) 20 fetal hearts were isolated. DNA was extracted and immunoprecipitated with modified chromatin marks histone 3 lysine 4 tri-methylation (H3K4me3) and histone 3 lysine 27 tri-methylation (H3K27me3). Following chromatin immunoprecipitation (ChIP), DNA fragments were sequenced. RNA from fetal hearts was purified and prepared for RNA sequencing and transcriptomic analysis. Ingenuity Pathway Analysis (IPA) was then used to identify pathways most modified by gestational ENM exposure.

Results

The results of the sequencing experiments provide initial evidence that significant epigenetic and transcriptomic changes occur in the cardiac tissue of maternal nano-TiO₂ exposed progeny. The most notable alterations in major biologic systems included immune adaptation and organismal growth. Changes in normal physiology were linked with other tissues, including liver and kidneys.

Conclusions

These results are the first evidence that maternal ENM inhalation impacts the fetal epigenome.

Electronic supplementary material

The online version of this article (10.1186/s12989-017-0239-8) contains supplementary material, which is available to authorized users.