Cardiogenesis impairment promoted by bisphenol A exposure is successfully counteracted by epigallocatechin gallate

Toxicity of low dose bisphenols in human iPSC-derived cardiomyocytes and human cardiac organoids - Impact on contractile function and hypertrophy

Bisphenol A (BPA) and its analogs are common environmental chemicals with various adverse health impacts, including cardiac toxicity. In this study, we examined the long term effect of low dose BPA and three common BPA analogs, bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF), in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) based models. HiPSC-CMs and human cardiac organoids were exposed to these chemicals for 4-5 or 20 days. 1 nM BPA, BPS, and BPAF, but not BPF, resulted in suppressed myocyte contractility, retarded contraction kinetics, and aberrant Ca2+ transients in hiPSC-CMs. In cardiac organoids, BPAF and BPA, but not the other bisphenols, resulted in suppressed contraction and Ca2+ transients, and aberrant contraction kinetics. The order of toxicities was BPAF > BPA>∼BPS > BPF and the toxicities of BPAF and BPA were more pronounced under longer exposure. The impact of BPAF on myocyte contraction and Ca2+ handling was mediated by reduction of sarcoplasmic reticulum Ca2+ load and inhibition of L-type Ca2+ channel involving alternation of Ca2+ handling proteins. Impaired myocyte Ca2+ handling plays a key role in cardiac pathophysiology and is a characteristic of cardiac hypertrophy; therefore we examined the potential pro-hypertrophic cardiotoxicity of these bisphenols. Four to five day exposure to BPAF did not cause hypertrophy in normal hiPSC-CMs, but significantly exacerbated the hypertrophic phenotype in myocytes with existing hypertrophy induced by endothelin-1, characterized by increased cell size and elevated expression of the hypertrophic marker proBNP. This pro-hypertrophic cardiotoxicity was also occurred in cardiac organoids, with BPAF having the strongest toxicity, followed by BPA. Our findings demonstrate that long term exposures to BPA and some of its analogs cause contractile dysfunction and abnormal Ca2+ handling, and have potential pro-hypertrophic cardiotoxicity in human heart cells/tissues, and suggest that some bisphenol chemicals may be a risk factor for cardiac hypertrophy in human hearts.

Parental Exposure to Environmentally Relevant Concentrations of Bisphenol-A Bis(diphenyl phosphate) Impairs Vascular Development in Offspring through DNA/RNA Methylation-Dependent Transmission

Bisphenol-A bis(diphenyl phosphate) (BDP) has been increasingly detected in indoor environmental and human samples. Little is known about its developmental toxicity, particularly the intergenerational effects of parental exposure. In this study, adult zebrafish were exposed to BDP at 30-30,000 ng/L for 28 days, with results showing that exposure did not cause a transfer of BDP or its metabolites to offspring. Vascular morphometric profiling revealed that parental exposure to BDP at 30 and 300 ng/L exerted significant effects on the vascular development of offspring, encompassing diverse alterations in multiple types of blood vessels. N6-Methyladenosine (m6A) methylated RNA immunoprecipitation sequencing of larvae in the 300 ng/L group revealed 378 hypomethylated and 350 hypermethylated m6A peaks that were identified in mRNA transcripts of genes crucial for vascular development, including the Notch/Vegf signaling pathway. Concomitant changes in 5 methylcytosine (m5C) DNA methylation and gene expression of m6A modulators (alkbh5, kiaa1429, and ythdf1) were observed in both parental gonads and offspring exposed to BDP. These results reveal that parental exposure to low concentrations of BDP caused offspring vascular disorders by interfering with DNA and RNA methylation, uncovering a unique DNA-RNA modification pattern in the intergenerational transmission of BDP's developmental toxicity.

Low-dose Bisphenol A exposure alters the functionality and cellular environment in a human cardiomyocyte model

Early embryonic development represents a sensitive time-window during which the foetus might be vulnerable to the exposure of environmental contaminants, potentially leading to heart diseases also later in life. Bisphenol A (BPA), a synthetic chemical widely used in plastics manufacturing, has been associated with heart developmental defects, even in low concentrations. This study aims to investigate the effects of environmentally relevant doses of BPA on developing cardiomyocytes using a human induced pluripotent stem cell (hiPSC)-derived model. Firstly, a 2D in vitro differentiation system to obtain cardiomyocytes from hiPSCs (hiPSC-CMs) have been established and characterised to provide a suitable model for the early stages of cardiac development. Then, the effects of a repeated BPA exposure, starting from the undifferentiated stage throughout the differentiation process, were evaluated. The chemical significantly decreased the beat rate of hiPSC-CMs, extending the contraction and relaxation time in a dose-dependent manner. Quantitative proteomics analysis revealed a high abundance of basement membrane (BM) components (e.g., COL4A1, COL4A2, LAMC1, NID2) and a significant increase in TNNC1 and SERBP1 proteins in hiPSC-CMs treated with BPA. Network analysis of proteomics data supported altered extracellular matrix remodelling and provided a disease-gene association with well-known pathological conditions of the heart. Furthermore, upon hypoxia-reoxygenation challenge, hiPSC-CMs treated with BPA showed higher rate of apoptotic events. Taken together, our results revealed that a long-term treatment, even with low doses of BPA, interferes with hiPSC-CMs functionality and alters the surrounding cellular environment, providing new insights about diseases that might arise upon the toxin exposure. Our study contributes to the current understanding of BPA effects on developing human foetal cardiomyocytes, in correlation with human clinical observations and animal studies, and it provides a suitable model for New Approach Methodologies (NAMs) for environmental chemical hazard and risk assessment.

Additive cardiotoxicity of a bisphenol mixture in zebrafish embryos: The involvement of calcium channel and pump

Bisphenol A (BPA) and its analogs, such as bisphenol F (BPF), bisphenol AF (BPAF), and bisphenol B (BPB), are often simultaneously detected in environmental and human specimens. Thus, assessing the toxicity of bisphenol (BP) mixtures is more relevant than assessing that of each BP type. Here, we found that BPs, individually or in a mixture, concentration-dependently and additively increased the mortality of zebrafish embryos (ZFEs) at 96 h post fertilization (hpf) and induced bradycardia (i.e., reduced heart rate) at 48 hpf, indicating their cardiotoxic potency. BPAF was the most potent, followed by BPB, BPA, and BPF. We then explored the mechanism underlying BP-induced bradycardia in ZFEs. Although BPs increased the mRNA expression of the estrogen-responsive gene, treatment with the estrogen receptor inhibitor ICI 182780 did not prevent BP-induced bradycardia. Because they did not change cardiomyocyte counts or heart development-related gene expression, BPs might not affect cardiomyocyte development. By contrast, BPs might impair calcium homeostasis during cardiac contraction and relaxation through the downregulation of the expression of the mRNAs for the pore-forming subunit of L-type Ca2+ channel (LTCC; cacna1c) and sarco/endoplasmic reticulum Ca2+-ATPase (SERCA; atp2a2a). BPs reduced SERCA activity significantly. BPs also potentiated the cardiotoxicity induced by the LTCC blocker nisoldipine, conceivably by inhibiting SERCA activity. In conclusion, BPs additively induced bradycardia in ZFEs, possibly by impeding calcium homeostasis during cardiac contraction and relaxation. BPs also potentiated the cardiotoxicity of calcium channel blockers.

Zebrafish as model organisms for toxicological evaluations in the field of food science

Food safety has long been an area of concern. The selection of stable and efficient model organisms is particularly important for food toxicology studies. Zebrafish (Danio rerio) are small model vertebrates, and 70% of human genes have at least one zebrafish ortholog. Zebrafish have advantages as model organisms due to their short life cycle, strong reproductive ability, easy rearing, and low cost. Zebrafish embryos have the advantage of being sensitive to the breeding environment and thus have been used as biosensors. Zebrafish and their embryos have been widely used for food toxicology assessments. This review provides a systematic and comprehensive summary of food toxicology studies using zebrafish as model organisms. First, we briefly introduce the multidimensional mechanisms and structure-activity relationship studies of food toxicological assessment. Second, we categorize these studies according to eight types of hazards in foods, including mycotoxins, pesticides, antibiotics, heavy metals, endocrine disruptors, food additives, nanoparticles, and other food-related ingredients. Finally, we list the applications of zebrafish in food toxicology studies in line with future research prospects, aiming to provide a valuable reference for researchers in the field of food science.

Evaluation of the bisphenol A-induced vascular toxicity on human umbilical artery

Bisphenol A (BPA) is one of the most widely used synthetic compound in the manufacture of polycarbonate plastics and epoxy resins. Worryingly, BPA is an endocrine disrupting chemical (EDC) with an estrogenic, androgenic, or anti-androgenic activities. However, the vascular implications of BPA exposome in pregnancy is unclear. In this sense, the present work proposed to understand how BPA exposure impair the vasculature of the pregnant women. To elucidate this, ex vivo studies were performed using human umbilical arteries to explore the acute and chronic effects of BPA. The mode of action of BPA was also explored by analysing the activity (by ex vivo studies) and expression (in vitro studies) analysis of Ca²⁺ and K⁺-channels and soluble guanyl cyclase. Moreover, in silico docking simulations were performed to unveil the modes of interactions of BPA with the proteins involved in these signalling pathways. Our study showed that the exposure to BPA may modify the vasorelaxant response of HUA, interfering with NO/sGC/cGMP/PKG pathway by modulation of sGC and activation of BKCa channels. Moreover, our findings suggest that BPA can modulate the HUA reactivity, increasing the L-type Ca²⁺ Channels (LTCC) activity, a common vascular response observed in hypertensive disorders of pregnancy.

Risk assessment of bisphenol analogues towards mortality, heart rate and stress-mediated gene expression in cladocerans Moina micrura

Bisphenol A (BPA) is a well-known endocrine-disrupting compound that causes several toxic effects on human and aquatic organisms. The restriction of BPA in several applications has increased the substituted toxic chemicals such as bisphenol F (BPF) and bisphenol S (BPS). A native tropical freshwater cladoceran, Moina micrura, was used as a bioindicator to assess the adverse effects of bisphenol analogues at molecular, organ, individual and population levels. Bisphenol analogues significantly upregulated the expressions of stress-related genes, which are the haemoglobin and glutathione S-transferase genes, but the sex determination genes such as doublesex and juvenile hormone analogue genes were not significantly different. The results show that bisphenol analogues affect the heart rate and mortality rate of M. micrura. The 48-h lethal concentration (LC₅₀) values based on acute toxicity for BPA, BPF and BPS were 611.6 µg L^-1, 632.0 µg L^-1 and 819.1 µg L^-1, respectively. The order of toxicity based on the LC₅₀ and predictive non-effect concentration values were as follows: BPA > BPF > BPS. Furthermore, the incorporated method combining the responses throughout the organisation levels can comprehensively interpret the toxic effects of bisphenol analogues, thus providing further understanding of the toxicity mechanisms. Moreover, the output of this study produces a comprehensive ecotoxicity assessment, which provides insights for the legislators regarding exposure management and mitigation of bisphenol analogues in riverine ecosystems.

The State of Research and Weight of Evidence on the Epigenetic Effects of Bisphenol A

Bisphenol A (BPA) is a high-production-volume chemical with numerous industrial and consumer applications. BPA is extensively used in the manufacture of polycarbonate plastics and epoxy resins. The widespread utilities of BPA include its use as internal coating for food and beverage cans, bottles, and food-packaging materials, and as a building block for countless goods of common use. BPA can be released into the environment and enter the human body at any stage during its production, or in the process of manufacture, use, or disposal of materials made from this chemical. While the general population is predominantly exposed to BPA through contaminated food and drinking water, non-dietary exposures through the respiratory system, integumentary system, and vertical transmission, as well as other routes of exposure, also exist. BPA is often classified as an endocrine-disrupting chemical as it can act as a xenoestrogen. Exposure to BPA has been associated with developmental, reproductive, cardiovascular, neurological, metabolic, or immune effects, as well as oncogenic effects. BPA can disrupt the synthesis or clearance of hormones by binding and interfering with biological receptors. BPA can also interact with key transcription factors to modulate regulation of gene expression. Over the past 17 years, an epigenetic mechanism of action for BPA has emerged. This article summarizes the current state of research on the epigenetic effects of BPA by analyzing the findings from various studies in model systems and human populations. It evaluates the weight of evidence on the ability of BPA to alter the epigenome, while also discussing the direction of future research.

Comparative pharyngeal cartilage developmental toxicity of bisphenol A, bisphenol S and bisphenol AF to zebrafish (Danio rerio) larvae: A combination of morphometry and global transcriptome analyses

Exposure to BPA is recently shown to affect cartilage development in teleost fishes; whether BPS and BPAF, its two most frequently used phenolic analogues have similar effect, however, remains unclear. Here, we utilize zebrafish (Danio rerio) as an in-vivo larval model for systematic comparison of the pharyngeal arch-derived cartilage developmental toxicity of BPA, BPS and BPAF. Zebrafish are continuously exposed to three bisphenol analogues (3-BPs) at a range of concentrations since the embryonic stage (0.5 hpf), and identified cartilage malformations of the mandibular and hyoid pharyngeal arches at larval stage (120 hpf). BPA and BPAF prolong length and broaden cartilage angles; however, BPS shortens length and narrows the angles of skull cartilages. The results of the comparative transcriptome show that FoxO and MAPK signaling pathways are closely associated with the toxicity of BPA and BPAF, while BPS exposure affects energy metabolism-related pathways. Moreover, exposure to 3-BPs have an impact on the oxidative stress status. Our data collectively indicate that BPS and BPAF may not be safer than BPA regarding the impact on pharyngeal cartilage development in fish model, the mechanisms still need explorations, and that these two analogues should be applied with caution.

Transcriptomic analysis of lipid metabolism in zebrafish offspring of parental long-term exposure to bisphenol A

Bisphenol A (BPA) is one of the most common environmental endocrine disruptor chemicals (EDCs) and exhibits reproductive, cardiovascular, immune, and neurodevelopmental toxic effects. The development of the offspring was examined in the present investigation to determine the cross-generational effects of long-term exposure of parental zebrafish to environmental concentrations of BPA (15 and 225 µg/L). Parents were exposed to BPA for 120 days, and their offspring were evaluated at 7 days after fertilization in BPA-free water. The offspring exhibited higher mortality, deformity, and heart rates, and showed significant fat accumulation in abdominal region. RNA-Seq data showed that more lipid metabolism-related KEGG pathways, such as the PPAR signaling pathway, adipocytokine signaling pathway, and ether lipid metabolism pathway were enriched in the 225 µg/L BPA-treated offspring compared to 15 µg/L BPA-treated offspring, indicating greater effects of high dose BPA on offspring lipid metabolism. Lipid metabolism-related genes implied that BPA is responsible for disrupting lipid metabolic processes in the offspring through increased lipid production, abnormal transport, and disruption of lipid catabolism. The present study will be helpful for further evaluation of the reproductive toxicity of environmental BPA to organisms and the subsequent parent-mediated intergenerational toxicity.

Associations of bisphenol F and S, as substitutes for bisphenol A, with cardiovascular disease in American adults

Bisphenol A (BPA) exposure may be positively associated with cardiovascular disease (CVD). For more than a past decade, exposure to bisphenol F (BPF) and bisphenol S (BPS), as substitutes for BPA, has gradually increased in the population. Whether BPF and BPS exposure are associated with CVD remains unclear. We used data from the United States National Health and Nutrition Examination Survey (NHANES) from 2013 to 2016. A total of 3,502 participants, including 368 with CVD, were enrolled in the final analysis. Associations of BPA, BPF and BPS with CVD were determined using multivariate logistic regression analysis. The highest level of urinary BPA (≥2.5 ng/ml) was significantly associated with a higher CVD prevalence (odds ratio [OR], 1.58; 95% confidence interval [CI], 1.08-2.3) among all participants in the quartile analysis. In stratified analyses, the highest level of urinary BPA was positively associated with CVD prevalence in males (1.86, 1.1-3.13) and the elderly population (≥60 years old) (1.89, 1.2-2.97). Higher levels of urinary BPF were positively associated with CVD prevalence in females (Q2: 1.81, 1.03-3.18; Q4: 1.73, 1.07-2.79) and in the elderly population (Q3: 1.7, 1.16-2.48). No associations were found between urinary BPS levels and CVD, regardless of whether the participants were stratified by age or sex. In conclusion, exposure to BPA or BPF was positively correlated with CVD prevalence, but an association was not found for exposure to BPS. BPF may not be as safe as assumed for human health.

Endocrine-Disrupting Effects of Bisphenol A on the Cardiovascular System: A Review

Currently, the plastic monomer and plasticizer bisphenol A (BPA) is one of the most widely used chemicals. BPA is present in polycarbonate plastics and epoxy resins, commonly used in food storage and industrial or medical products. However, the use of this synthetic compound is a growing concern, as BPA is an endocrine-disrupting compound and can bind mainly to estrogen receptors, interfering with different functions at the cardiovascular level. Several studies have investigated the disruptive effects of BPA; however, its cardiotoxicity remains unclear. Therefore, this review’s purpose is to address the most recent studies on the implications of BPA on the cardiovascular system. Our findings suggest that BPA impairs cardiac excitability through intracellular mechanisms, involving the inhibition of the main ion channels, changes in Ca²⁺ handling, the induction of oxidative stress, and epigenetic modifications. Our data support that BPA exposure increases the risk of developing cardiovascular diseases (CVDs) including atherosclerosis and its risk factors such as hypertension and diabetes. Furthermore, BPA exposure is also particularly harmful in pregnancy, promoting the development of hypertensive disorders during pregnancy. In summary, BPA exposure compromises human health, promoting the development and progression of CVDs and risk factors. Further studies are needed to clarify the human health effects of BPA-induced cardiotoxicity.

Developmental Exposure to Endocrine Disrupting Chemicals and Its Impact on Cardio-Metabolic-Renal Health

Developmental origin of health and disease postulates that the footprints of early life exposure are followed as an endowment of risk for adult diseases. Epidemiological and experimental evidence suggest that an adverse fetal environment can affect the health of offspring throughout their lifetime. Exposure to endocrine disrupting chemicals (EDCs) during fetal development can affect the hormone system homeostasis, resulting in a broad spectrum of adverse health outcomes. In the present review, we have described the effect of prenatal EDCs exposure on cardio-metabolic-renal health, using the available epidemiological and experimental evidence. We also discuss the potential mechanisms of their action, which include epigenetic changes, hormonal imprinting, loss of energy homeostasis, and metabolic perturbations. The effect of prenatal EDCs exposure on cardio-metabolic-renal health, which is a complex condition of an altered biological landscape, can be further examined in the case of other environmental stressors with a similar mode of action.

Bisphenol A (BPA) Leading to Obesity and Cardiovascular Complications: A Compilation of Current In Vivo Study

BPA is one of the most common endocrine disruptors that is widely being manufactured daily nationwide. Although scientific evidence supports claims of negative effects of BPA on humans, there is also evidence suggesting that a low level of BPA is safe. However, numerous in vivo trials contraindicate with this claim and there is a high possibility of BPA exposure could lead to obesity. It has been speculated that this does not stop with the exposed subjects only, but may also cause transgenerational effects. Direct disruption of endocrine regulation, neuroimmune and signaling pathways, as well as gut microbiata, has been identified to be interrupted by BPA exposure, leading to overweight or obesity. In these instances, cardiovascular complications are one of the primary notable clinical signs. In regard to this claim, this review paper discusses the role of BPA on obesity in the perspective of endocrine disruptions and possible cardiovascular complications that may arise due to BPA. Thus, the aim of this review is to outline the changes in gut microbiota and neuroimmune or signaling mechanisms involved in obesity in relation to BPA. To identify potentially relevant articles, a depth search was done on the databases Nature, PubMed, Wiley Online Library, and Medline & Ovid from the past 5 years. According to Boolean operator guideline, selected keywords such as (1) BPA OR environmental chemical AND fat OR LDL OR obese AND transgenerational effects or phenocopy (2) Endocrine disruptors OR chemical AND lipodystrophy AND phenocopy (3) Lipid profile OR weight changes AND cardiovascular effect (4) BPA AND neuroimmune OR gene signaling, were used as search terms. Upon screening, 11 articles were finalized to be further reviewed and data extraction tables containing information on (1) the type of animal model (2) duration and dosage of BPA exposure (3) changes in the lipid profile or weight (4) genes, signaling mechanism, or any neuroimmune signal involved, and (5) transgenerational effects were created. In toto, the study indicates there are high chances of BPA exposure affecting lipid profile and gene associated with lipolysis, leading to obesity. Therefore, this scoping review recapitulates the possible effects of BPA that may lead to obesity with the evidence of current in vivo trials. The biomarkers, safety concerns, recommended dosage, and the impact of COVID-19 on BPA are also briefly described.

Zebrafish (Danio rerio): A potential model to assess developmental toxicity of ketamine

Ketamine is a non-competitive antagonist of NMDA glutamate receptor. It is used as an anesthetic, analgesic, sedative, and anti-depressive agent in clinical practice and also an illegal recreational drug. The increasing use has contributed to the measurable levels of ketamine in both wastewaters and hospital effluents, thereby classified as an emergent contaminant. Lately, the potential toxicity of ketamine has raised serious concerns about its iatrogenic or illicit use during pregnancy, neonatal and childhood stages. However, to assess its long-term toxicity potentially by the use of early life stages in human and rodents is limited. In this regard, the zebrafish has been considered as excellent model organism for biosafety assessments of ketamine due to it boasts an in vivo model with the advantages of an in vitro assay. In this review, we summarize the current understanding of the reported toxicity studies with ketamine in early life stage of zebrafish. The adverse effects of ketamine are known to cause overall developmental and multi-organ toxicity, including cardio-, neuro-, and skeletal toxicity. Furthermore, multiple mechanisms are found to be responsible for perpetrating toxicity of ketamine. The current findings confluence to emphasize the zebrafish embryo as an appealing model system for developmental toxicity testing in higher vertebrates.

Bisphenol A Induces Histopathological, Hematobiochemical Alterations, Oxidative Stress, and Genotoxicity in Common Carp (Cyprinus carpio L.)

Bisphenol A (BPA) is one of the environmental endocrine disrupting toxicants and is widely used in the industry involving plastics, polycarbonate, and epoxy resins. This study was designed to investigate the toxicological effects of BPA on hematology, serum biochemistry, and histopathology of different organs of common carp (Cyprinus carpio). A total of 60 fish were procured and haphazardly divided into four groups. Each experimental group contained 15 fish. The fish retained in group A was kept as the untreated control group. Three levels of BPA 3.0, 4.5, and 6 mg/L were given to groups B, C, and D for 30 days. Result indicated significant reduction in hemoglobin (Hb), lymphocytes, packed cell volume (PCV), red blood cells (RBC), and monocytes in a dose-dependent manner as compared to the control group. However, significantly higher values of leucocytes and neutrophils were observed in the treated groups (P < 0.05). Results on serum biochemistry revealed that the quantity of glucose, cholesterol, triglycerides, urea, and creatinine levels was significantly high (P < 0.05). Our study results showed significantly (P < 0.05) increase level of oxidative stress parameters like reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) and lower values of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) in treated groups (4.5 mg/L and 6 mg/L)) in the brain, liver, gills, and kidneys. Our study depicted significant changes in erythrocytes (pear shaped erythrocytes, leptocytes, microcytes, spherocytes, erythrocytes with broken, lobed, micronucleus, blabbed, vacuolated nucleus, and nuclear remnants) among treated groups (4.5 mg/L and 6 mg/L). Comet assay showed increased genotoxicity in different tissues including the brain, liver, gills, and kidneys in the treated fish group. Based on the results of our experiment, it can be concluded that the BPA exposure to aquatic environment is responsible for deterioration of fish health, performance leading to dysfunction of multiple vital organs.

Effects of bisphenol A exposure during cardiac cell differentiation

Heart development requires a precise temporal regulation of gene expression in cardiomyoblasts. Therefore, the transcriptional changes in differentiating cells can lead to congenital heart diseases. Although the genetic mutations underlie most of these alterations, exposure to environmental contaminants, such as bisphenol A (BPA), has been recently considered as a risk factor as well. In this study we investigated the genotoxic and epigenotoxic effects of BPA throughout cardiomyocyte differentiation. H9c2 cells (rat myoblasts) were exposed to 10 and 30 μM BPA before and during the last two days of cardiac-driven differentiation. Then, we have analysed the phenotypic and molecular modifications (at transcriptional, genetic and epigenetic level). The results showed that treated myoblasts developed a skeletal muscle cell-like phenotype. The transcriptional changes induced by BPA in genes codifying proteins involved in heart differentiation and function depend on the window of exposure to BPA. The exposure before differentiation repressed the expression of heart transcription factors (Hand2 and Gata4), whereas exposure during differentiation reduced the expression of cardiac-specific genes (Tnnt2, Myom2, Sln, and Atp2a1). Additionally, significant effects were observed regarding DNA damage and histone acetylation levels after the two periods of BPA exposure: in cells exposed to the toxicant the percentage of DNA repair foci (formed by the co-localization of γH2AX and 53BP1) increased in a dose-dependent manner, whereas the treatment with the toxicant triggered a decrease in the epigenetic marks H3K9ac and H3K27ac. Our in vitro results reveal that BPA seriously interferes with the process of cardiomyocyte differentiation, which could be related to the reported in vivo effects of this toxicant on cardiogenesis.

Environmental Alterations during Embryonic Development: Studying the Impact of Stressors on Pluripotent Stem Cell-Derived Cardiomyocytes

Non-communicable diseases (NCDs) sauch as diabetes, obesity and cardiovascular diseases are rising rapidly in all countries world-wide. Environmental maternal factors (e.g., diet, oxidative stress, drugs and many others), maternal illnesses and other stressors can predispose the newborn to develop diseases during different stages of life. The connection between environmental factors and NCDs was formulated by David Barker and colleagues as the Developmental Origins of Health and Disease (DOHaD) hypothesis. In this review, we describe the DOHaD concept and the effects of several environmental stressors on the health of the progeny, providing both animal and human evidence. We focus on cardiovascular diseases which represent the leading cause of death worldwide. The purpose of this review is to discuss how in vitro studies with pluripotent stem cells (PSCs), such as embryonic and induced pluripotent stem cells (ESC, iPSC), can underpin the research on non-genetic heart conditions. The PSCs could provide a tool to recapitulate aspects of embryonic development “in a dish”, studying the effects of environmental exposure during cardiomyocyte (CM) differentiation and maturation, establishing a link to molecular mechanism and epigenetics.

Effect of bisphenol A on craniofacial cartilage development in zebrafish (Danio rerio) embryos: A morphological study

Bisphenol A (BPA), an endocrine-disrupting chemical, is present in everyday-used consumables and common household products. Although the side effects of BPA have been sufficiently explored, little is known the effects of environmentally relevant low levels of BPA on chondrogenesis in skeletal development. Here we used a morphological approach to investigate whether exposure to BPA (0, 0.0038, 0.05, 0.1, 1.0 μM) could affect craniofacial cartilage development of zebrafish embryo. Furthermore, we sought to determine receptor-mediated BPA induced chondrogenesis toxicity by co-exposing developing embryos to BPA and various inhibitors. Low-dose BPA affected heart rate and induced body and head elongation of larvae. Quantitative morphometric and histopathological analysis revealed that BPA exposure changed the angle and length of craniofacial cartilage elements and disrupted chondrocytes. BPA induced pharyngeal cartilage defects via multiple cellular pathways, including estrogen receptor, androgen receptor, and estrogen-related receptors. Our findings demonstrate that BPA alters the normal development of cartilage and craniofacial structures in zebrafish embryos. Furthermore, in this study we find multiple cellular pathways mediating the effects of BPA-induced craniofacial chondrogenesis toxicity. Further experiments will allow for establishing a connection between BPA and increased risk of congenital malformation of the facial cranium in BPA-exposed populations.

The effects of endocrine disruptors on the male germline: an intergenerational health risk

Environmental pollution is becoming one of the major concerns of society. Among the emerging contaminants, endocrine-disrupting chemicals (EDCs), a large group of toxicants, have been the subject of many scientific studies. Besides the capacity of these compounds to interfere with the endocrine system, they have also been reported to exert both genotoxic and epigenotoxic effects. Given that spermatogenesis is a coordinated process that requires the involvement of several steroid hormones and that entails deep changes in the chromatin, such as DNA compaction and epigenetic remodelling, it could be affected by male exposure to EDCs. A great deal of evidence highlights that these compounds have detrimental effects on male reproductive health, including alterations to sperm motility, sexual function, and gonad development. This review focuses on the consequences of paternal exposure to such chemicals for future generations, which still remain poorly known. Historically, spermatozoa have long been considered as mere vectors delivering the paternal haploid genome to the oocyte. Only recently have they been understood to harbour genetic and epigenetic information that plays a remarkable role during offspring early development and long-term health. This review examines the different modes of action by which the spermatozoa represent a key target for EDCs, and analyses the consequences of environmentally induced changes in sperm genetic and epigenetic information for subsequent generations.

Paternal Inheritance of Bisphenol A Cardiotoxic Effects: The Implications of Sperm Epigenome

Parental exposure to bisphenol A (BPA) has been linked to a greater incidence of congenital diseases. We have demonstrated that BPA induces in zebrafish males an increase in the acetylation of sperm histones that is transmitted to the blastomeres of the unexposed progeny. This work is aimed to determine whether histone hyperacetylation promoted by paternal exposure to BPA is the molecular mechanism underlying the cardiogenesis impairment in the descendants. Zebrafish males were exposed to 100 and 2000 µg/L BPA during early spermatogenesis and mated with non-exposed females. We analyzed in the progeny the expression of genes involved in cardiogenesis and the epigenetic profile. Once the histone hyperacetylation was confirmed, treatment with epigallocatechin gallate (EGCG), an inhibitor of histone acetyltransferases, was assayed on F1 embryos. Embryos from males exposed to 2000 µg/L BPA overexpressed the transcription factor hand2 and the receptor esr2b, showing their own promoters—as well as that of kat6a—an enrichment in H3K9ac. In embryos treated with EGCG, both gene expression and histone acetylation (global and specific) returned to basal levels, and the phenotype was recovered. As shown by the results, the histone hyperacetylated landscape promoted by BPA in the sperm alters the chromatin structure of the progeny, leading to the overexpression of the histone acetyltransferase and genes involved in cardiogenesis.

Identification of receptors for eight endocrine disrupting chemicals and their underlying mechanisms using zebrafish as a model organism

Herein, eight common endocrine disrupting chemicals (EDCs) were exposed to zebrafish (Danio rerio) to investigate the relationship between different EDCs and their activated estrogen receptors. Under acute exposure, we identified five major malformation types whose incidence and deformity modes differed among EDCs. Luciferase analysis divided the EDC receptors into four categories: (i) triclosan (TCS), 17ß-estradiol (E2) and estriol (E3) mainly activated GPER expression; (ii) bisphenol A (BPA), p-(tert-octyl) phenol (POP), 17α-ethynylestradiol (EE2), E2 and E3 activated ERβ expression; (iii) E2 and E3 acted on both GPER and ERβ; and (iv) estrone (E1) and 9,9-bis(4-hydroxyphenyl)fluorene (BHPF) had little effect on the two receptors. In vivo immunofluorescence experiments on 96-hpf larvae provided evidence that TCS and POP acted on GPER and ERβ, respectively, while E2 acted on the two receptors simultaneously. Luciferase activities in the promoter regions of gper (-986 to -488) and erβ (-1998 to -1496) were higher than those in other regions, identifying these key regions as targets for transcription activity. TCS promoted GPER expression by acting on the JUND transcription factor, while POP promoted ERβ expression by activating the Foxl1 transcription factor. In contrast, E2 mainly regulated transcription of GPER and ERβ by Arid3a. These findings provide compelling evidence that different EDCs possess varying estrogen receptors, leading to differential regulatory pathways and abnormality symptoms. These results offer an experimental strategy and fundamental information to assess the molecular mechanisms of EDC-induced estrogen effects.

Potential Mechanisms of Bisphenol A (BPA) Contributing to Human Disease

Bisphenol A (BPA) is an organic synthetic compound serving as a monomer to produce polycarbonate plastic, widely used in the packaging for food and drinks, medical devices, thermal paper, and dental materials. BPA can contaminate food, beverage, air, and soil. It accumulates in several human tissues and organs and is potentially harmful to human health through different molecular mechanisms. Due to its hormone-like properties, BPA may bind to estrogen receptors, thereby affecting both body weight and tumorigenesis. BPA may also affect metabolism and cancer progression, by interacting with GPR30, and may impair male reproductive function, by binding to androgen receptors. Several transcription factors, including PPARγ, C/EBP, Nrf2, HOX, and HAND2, are involved in BPA action on fat and liver homeostasis, the cardiovascular system, and cancer. Finally, epigenetic changes, such as DNA methylation, histones modification, and changes in microRNAs expression contribute to BPA pathological effects. This review aims to provide an extensive and comprehensive analysis of the most recent evidence about the potential mechanisms by which BPA affects human health.

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.

Parental exposure to bisphenol A affects pharyngeal cartilage development and causes global transcriptomic changes in zebrafish (Danio rerio) offspring

BACKGROUND

As one of the most common endocrine-disrupting chemicals (EDCs), bisphenol A (BPA) is a threat to aquatic ecosystems. Despite a rich literature addressing the adverse effects of BPA on various systems in fish models, the potential impact of parental BPA exposure on offspring pharyngeal cartilage development is poorly understood.

METHODS

Adult zebrafish (F0) were exposed to BPA (1.0 μM) or control for 7 days. Eggs (F1) were collected and exposed to BPA (control, 0.05, 0.1, 1, 10 μM) until 120 h post-fertilization. Histomorphometrical essay was used to quantitatively and qualitatively assess the effects of BPA on pharyngeal cartilage development. RNA sequencing (RNA-seq) was used to discover differentially expressed genes (DEGs), and KEGG pathway and GO enrichment analysis were performed to interpret functional ontology.

RESULTS

Parental BPA exposure affected hatchability and heart rates of F1 progeny. By pathology analysis, parental BPA exposure caused craniofacial deformity, characterized by wider angles of cartilage elements, disrupted pharyngeal chondrocytes and promoted apoptosis and elongation of head length. RNA-seq suggested that many DEGs were involved in multiple biological processes and signaling pathways; defense responses, reactive oxygen species metabolic process, apoptosis, p53 signaling pathway and MAPK signaling pathway were closely associated with the toxicity of parental BPA exposure.

CONCLUSIONS

Parental BPA exposure affected chondrogenesis in the viscerocranium of zebrafish offspring and led to global transcriptomic changes involved in apoptosis, hyperplasia and oxidative stress. These newly identified gene expression patterns, pathways and gene networks of zebrafish eleutheroembryos after early-life waterborne BPA exposure, may lead to severe and permanent morphological and functional consequences.

Effects of Bisphenol A Exposure during Pregnancy and lactation on Hippocampal Function in Newborn Rats

Bisphenol A (BPA) is widely used in industrial production. It is closely related to the growth and development of the nervous system, and can enter the fetal circulation through the placental barrier, and can be secreted through breast milk. The development of nervous system is very important in fetus and neonatal period. The purpose of this study is to investigate the effects of different doses of BPA on learning and memory function of nervous system in rats. Pregnant rats were randomly divided into three treatment groups (control group, 5 mg/kg/d, 50 mg/kg/d). All animals received BPA from the discovery of pregnancy to 21 days after birth. Results had shown that after high concentration BPA exposure, the increase of PS amplitude and f-EPSP slope in hippocampal CA1 area of male offspring was lower than that of control group. High concentration of BPA could inhibit Nestin, Cyclin D1, bcl-2 and Rac1 in male offspring rats and the expression of bax and RhoA was promoted by BPA. In summary, our study indicated that BPA exposure during pregnancy and lactation could impair the hippocampal function of male offspring by affecting the growth and apoptosis of hippocampal neurons, which might be due to the abnormal regulation of RhoA and Rac1.

The Promises and Challenges of Toxico-Epigenomics: Environmental Chemicals and Their Impacts on the Epigenome

BACKGROUND

It has been estimated that a substantial portion of chronic and noncommunicable diseases can be caused or exacerbated by exposure to environmental chemicals. Multiple lines of evidence indicate that early life exposure to environmental chemicals at relatively low concentrations could have lasting effects on individual and population health. Although the potential adverse effects of environmental chemicals are known to the scientific community, regulatory agencies, and the public, little is known about the mechanistic basis by which these chemicals can induce long-term or transgenerational effects. To address this question, epigenetic mechanisms have emerged as the potential link between genetic and environmental factors of health and disease.

OBJECTIVES

We present an overview of epigenetic regulation and a summary of reported evidence of environmental toxicants as epigenetic disruptors. We also discuss the advantages and challenges of using epigenetic biomarkers as an indicator of toxicant exposure, using measures that can be taken to improve risk assessment, and our perspectives on the future role of epigenetics in toxicology.

DISCUSSION

Until recently, efforts to apply epigenomic data in toxicology and risk assessment were restricted by an incomplete understanding of epigenomic variability across tissue types and populations. This is poised to change with the development of new tools and concerted efforts by researchers across disciplines that have led to a better understanding of epigenetic mechanisms and comprehensive maps of epigenomic variation. With the foundations now in place, we foresee that unprecedented advancements will take place in the field in the coming years. https://doi.org/10.1289/EHP6104.

Genetic and epigenetic alterations induced by bisphenol A exposure during different periods of spermatogenesis: from spermatozoa to the progeny

Exposure to bisphenol A (BPA) has been related to male reproductive disorders. Since this endocrine disruptor also displays genotoxic and epigenotoxic effects, it likely alters the spermatogenesis, a process in which both hormones and chromatin remodeling play crucial roles. The hypothesis of this work is that BPA impairs early embryo development by modifying the spermatic genetic and epigenetic information. Zebrafish males were exposed to 100 and 2000 μg/L BPA during early spermatogenesis and during the whole process. Genotoxic and epigenotoxic effects on spermatozoa (comet assay and immunocytochemistry) as well as progeny development (mortality, DNA repairing activity, apoptosis and epigenetic profile) were evaluated. Exposure to 100 µg/L BPA during mitosis slightly increased sperm chromatin fragmentation, enhancing DNA repairing activity in embryos. The rest of treatments promoted high levels of sperm DNA damage, triggering apoptosis in early embryo and severely impairing survival. Regarding epigenetics, histone acetylation (H3K9Ac and H3K27Ac) was similarly enhanced in spermatozoa and embryos from males exposed to all the treatments. Therefore, BPA male exposure jeopardizes embryonic survival and development due to the transmission of a paternal damaged genome and of a hyper-acetylated histone profile, both alterations depending on the dose of the toxicant and the temporal window of exposure.

Embryonic Exposure to Bisphenol A Impairs Primordial Germ Cell Migration without Jeopardizing Male Breeding Capacity

A large amount of chemicals are released to the environment each year. Among them, bisphenol A (BPA) is of utmost concern since it interferes with the reproductive system of wild organisms due to its capacity to bind to hormone receptors. Additionally, BPA epigenotoxic activity is known to affect basic processes during embryonic life. However, its effects on primordial germ cells (PGCs) proliferation and migration, both mechanisms being crucial for gametogenesis, remain unknown. To investigate the effects of BPA on PGCs migration and eventual testicle development, zebrafish embryos were exposed to 100, 2000 and 4000 µg/L BPA during the first 24 h of development. Vasa immunostaining of PGCs revealed that exposure to 2000 and 4000 µg/L BPA impaired their migration to the genital ridge. Two pivotal genes of PGCs migration (cxcr4b and sdf1a) were highly dysregulated in embryos exposed to these doses, whereas DNA methylation and epigenetic marks in PGCs and their surrounding somatic cells were not altered. Once embryos reached adulthood, the morphometric study of their gonads revealed that, despite the reduced number of PGCs which colonized the genital ridges, normal testicles were developed. Although H3K9ac decreased in the sperm from treated fishes, it did not affect the progeny development.

Effects and Mechanisms of Tea and Its Bioactive Compounds for the Prevention and Treatment of Cardiovascular Diseases: An Updated Review

Cardiovascular diseases (CVDs) are critical global public health issues with high morbidity and mortality. Epidemiological studies have revealed that regular tea drinking is inversely associated with the risk of CVDs. Additionally, substantial in vitro and in vivo experimental studies have shown that tea and its bioactive compounds are effective in protecting against CVDs. The relevant mechanisms include reducing blood lipid, alleviating ischemia/reperfusion injury, inhibiting oxidative stress, enhancing endothelial function, attenuating inflammation, and protecting cardiomyocyte function. Moreover, some clinical trials also proved the protective role of tea against CVDs. In order to provide a better understanding of the relationship between tea and CVDs, this review summarizes the effects of tea and its bioactive compounds against CVDs and discusses potential mechanisms of action based on evidence from epidemiological, experimental, and clinical studies.