Bisphenol A Treatment Research Articles

Ginger volatile oil inhibits the growth of MDA-MB-231 in the bisphenol A environment by altering gut microbial diversity

ObjectiveTo examine the impact of ginger volatile oil (GVO) on the growth of MDA-MB-231 breast cancer cells in the presence of bisphenol A (BPA) by modulating the diversity of gut microbiota. Methods: MDA-MB-231 breast cancer cells were injected subcutaneously into the right armpit of female BALB/c Nude (nu/nu) mice to create a triple negative breast cancer model. Thirty nude mice were randomly divided into 5 groups: control group (distilled water every day), BPA control group (distilled PEG-400+ DMSO + cyclodextrin every day), BPA + GVO (0.25 mL/kg) group, BPA + GVO (0.5 mL/kg) group, BPA + GVO (1 mL/kg) group, 6 mice in each group; The drug was given by gavage once a day for 4 weeks. At the end of the experiment, the changes of tumor mass and tumor volume were observed and compared in 5 groups of tumor-bearing mice. High-throughput sequencing (16S rRNA) was used to detect the changes of gut microflora in each group. Results: The volume and weight of breast cancer decreased in the low, medium and high dose groups of GVO. Among them, the difference between the high-dose group and the BPA group reached a significant level (P < 0.05). The species and abundance of gut flora decreased following BPA treatment, but increased after combined treatment of BPA with GVO. In the tumor control group, the ratio of Firmicutes(F) and Bacteroidea(B) respectively was 0.10:0.79 at the phylum level, while the ratio of BPA group further decreased (0.04:0.88). After feeding GVO, the number of Firmicutes and Bacteroidea increased, the F/B ratio increased, and the level of Lactobacillus and alistipes increased. In the BPA and GVO treatment group, the predominant gut microflora functions are cell membrane biogenesis, carbohydrate transport and metabolism. This is followed by amino acid transport and metabolism, and transcription function. After GVO administration, the Gram-positive bacteria (G+) ratio had an increasing trend and the Gram-negative bacteria (G−)ratio had a decreasing trend. Conclusion: The species and abundance of gut flora decreased following BPA treatment, but increased after combined treatment of BPA with GVO.

Bisphenol S moderately decreases the expression of syncytiotrophoblast marker genes and induces apoptosis in human trophoblast lineages

Bisphenol S (BPS) is currently used in the manufacturing of several household equipment such as water pipes and food containers. Hence, its entrance into the human body is almost inevitable. The presence of BPS in body fluids has been reported. However, its potential toxicity, especially on human placenta development and pregnancy progression, has not been explored. In this study, we assessed the impacts of BPS on the self-renewal and differentiation potentials of placental stem cells, also known as trophoblast stem cells (TSCs), by exposing them to three different BPS concentrations during their self-renewal and differentiation into syncytiotrophoblast (ST), extravillous trophoblast (EVT), and trophoblast organoids. Interestingly, BPS treatment did not affect the stemness, cell cycle and proliferation of the TSCs but it induced apoptosis in each trophoblast lineage. BPS altered the expression of several fusion-related genes. However, this alteration did not translate into significant morphological defects in the STs and organoids. Moreover, BPS did not impair the differentiation of TSCs into EVTs. These findings suggest that the presence of BPS at the feto-maternal interface may exaggerate trophoblast apoptosis and moderately inhibit the trophoblast fusion pathway to affect placenta development and pregnancy. Our study offers valuable insights into the potential toxicity of BPS on human placenta development, emphasizing the need for epidemiological assessment of the relationship between maternal serum levels of BPS and pregnancy complications.

Potential involvement of ferroptosis in BPA-induced neurotoxicity: An in vitro study

BackgroundFerroptosis is a newly recognized cell death pathway having distinct characteristics compared to traditional cell death pathways such as apoptosis, necroptosis, or autophagy. However, the potential involvement of ferroptosis in bisphenol A (BPA)-induced neurotoxicity has not been well explored so far. In present study, we analyzed the relationship between ferroptosis and BPA-induced neurotoxicity. MethodsIn this study, a human neuroblastoma cell line, SH-SY5Y, was treated with BPA, ferrostatin-1 (FS-1, ferroptosis inhibitor) and RSL-3 (ferroptosis inducer). The cell viability was measured using MTT assay. Additionally, the levels of lipid peroxidation, total iron content, reactive oxygen species (ROS) generation, and nitrite content were measured to evaluate the key markers of ferroptosis. To further confirm the involvement of ferroptosis in BPA-induced neurotoxicity, other ferroptosis markers such as glutathione peroxidase (GPx) activity, total glutathione contents and antioxidant parameters were also evaluated. ResultsThe cell viability of SH-SY5Y cells was down-regulated by BPA treatment in a concentration-dependent manner, the cell viability at 0.1 µM concentration was 97.63% whereas at highest BPA concentration i.e. 10 µM, the cell viability was 86.05% (p < 0.0001). Also the antioxidant parameters including catalase and superoxide dismutase activity of neuronal cells were down-regulated upon BPA exposure. However, the levels of lipid peroxidation, total iron, reactive oxygen species, and nitrite contents were increased in a concentration-dependent manner which could be rescued by FS-1 and exacerbated by RSL-3. The total iron in SH-SY5Y cells at 0.1 µM concentration was found to be 1.2 fold (p < 0.05) of control and at highest BPA concentration total iron was about 1.41 fold (p < 0.001) of control. ConclusionsThe present study indicated that, ferroptosis plays an important role in the progression of BPA-induced neurotoxicity, and ferroptosis may become a novel target in the treatment of various neurological disorders.

The diverse roles of halide ions in the degradation of bisphenol A via UV/peracetic acid process at different pH values: Radical chemistry, and transformation pathways

UV/Peracetic Acid (UV/PAA), as an innovative advanced oxidation process (AOP), is employed to treat bisphenol A (BPA) in water through the generation of hydroxyl radicals (•OH) and carbon-centered radicals (R−C•). The impact of halide ions (Cl−; Br−; I−) on the efficiency of UV/PAA was investigated for the first time under varying pH levels. The presence of halide ions exerted an influence on the reactivity of •OH and R−C•, exhibiting varying degrees of impact across different pH conditions. It was discovered that pH exerts a significant influence on its efficiency, with optimal removal performance observed at a pH 9. The degradation of BPA was inhibited by Cl− through the generation of reactive chlorine species (RCS), which triggers the interconversion between •OH and R−C•. Reactive bromine species (RBS) were produced in the presence of Br−, facilitating BPA degradation and generating HOBr as a supplementary source of •OH radicals. I− primarily generate reactive iodine species (RIS) through photolysis, which facilitates the degradation of BPA. The transformation of BPA involves hydroxylation, demethylation, halogenation, and cleavage reactions to form various products and pathways. The toxicity test demonstrates that the UV/PAA treatment of BPA exhibits lower toxicity, thereby indicating its environmentally friendly.

Design and synthesis of Fe2WO6/Eu-doped BiOBr nanocomposite: A novel 0D/2D Z-scheme heterojunction system for simultaneous boosted visible-light driven photocatalytic bisphenol A degradation and Cr(VI) reduction

Increasing flux of noxious organics and heavy metals emitted by industrial effluents into surface water bodies have been terrifying the ecology in recent years. Herein, we have designed new Z-scheme 0D/2D Fe2WO6/Eu-doped BiOBr (FW/Eu-BOB) nanocomposites for efficient simultaneous visible light decomposition of two endocrine disruptors, namely bisphenol A (BPA) and hexavalent chromium (Cr(VI)). The successful nanocomposite fabrication was validated via crystallography and spectroscopic analyses, whereas the morphologic traits were testified via microscopy studies. Compared to single-phase component samples, 15-FW/2Eu-BOB nanocomposite displayed enhanced photoactivity, which completely eradicated both BPA and Cr(VI) after 50 min of visible light irradiation. The ameliorated photoactivity was ascribed to the Z-scheme electron transfer between FW and Eu-BOB, and its expedition of charge separation was proven by optoelectronic analyses. Furthermore, the 15-FW/2Eu-BOB nanocomposite showed good adaptability in a broad pH range, resistance to co-existing interfering substances and great durability after multiple runs. The real-world viability of 15-FW/2Eu-BOB photocatalysis was also tested via the real printed ink effluent-containing BPA and Cr(VI) treatment. Moreover, the phytotoxicity tests presented that the photocatalytically treated effluent promoted the germination of Vigna unguiculata which shown its environmentally friendly for practical uses. The hydroxyl radical and photogenerated electron were proven to be dominant reactive species in photocatalytic reaction. This study offers a new insight for designing highly efficient visible light-active photocatalysts toward eradicating multifarious pollutants in effluent.

Bisphenol A induced neuronal apoptosis and enhanced autophagy in vitro through Nrf2/HO-1 and Akt/mTOR pathways

Bisphenol A (BPA) was traditionally used in epoxy resins and polycarbonate plastics, but it was found to be harmful to human health due to its endocrine-disrupting effects. It can affect various biological functions of human beings and interfere with brain development. However, the neurotoxic mechanisms of BPA on brain development and associated neurodegeneration remain poorly understood. Here, we reported that BPA (100, 250, 500 μM) inhibited cell viability of neural cells PC12, SH-SY5Y and caused dose-dependent cell death. In addition, BPA exposure increased intracellular reactive oxygen species (ROS) and mitochondrial ROS (mtROS) levels, decreased mitochondrial membrane potential, reduced the expression of cytochrome c oxidase IV (COX4), downregulated Bcl-2, and initiated apoptosis. Moreover, BPA treatment resulted in the accumulation of intracellular acidic vacuoles and increased the autophagy marker LC3 II to LC3 I ratio. Furthermore, BPA exposure inhibited Nrf2/ HO-1 and AKT/mTOR pathways and mediated cellular oxidative stress, apoptosis, and excessive autophagy, leading to neuronal degeneration. The interactions between oxidative stress, autophagy, and apoptosis during BPA-induced neurotoxicity remain unclear and require further in vivo confirmation.

Bisphenol S dysregulates thyroid hormone homeostasis; Testicular survival, redox and metabolic status: Ameliorative actions of melatonin

Bisphenol S (BPS) is an incipient threat for reproductive health augmenting societal burden of infertility worldwide. In the present study, we investigated the mechanism of BPS induced testicular dysfunctions and protective actions of melatonin in mice. BPS (150 mg/kg BW) treatment reduced serum T3/T4, testosterone and elevated insulin levels along with adverse effect on thyroid and testicular histoarchitecture. Further, BPS treatment compromised sperm quality, reduced mRNA expression of steroidogenic (StAR/CYP11A1) markers, elevated oxidative load and disrupts metabolic status. However, melatonin (5 mg/kg BW) administration to BPS treated mice showed improved hormonal/histological parameters, enhanced thyroid hormone (TR-α/Dio-2)/melatonin (MT-1) receptor expressions. Further, melatonin treatment modulated the expression of testicular survival/redox (SIRT1/PGC-1α/FOXO-1, Nrf2/HO-1, p-JAK2/p-STAT3), proliferative (PCNA) and metabolic (IR/pAKT/GLUT-1) markers. Furthermore, melatonin treatment enhanced testicular antioxidant status and reduced caspase-3 expression. In conclusion, our results showed that BPS induces endocrine/oxidative and metabolic anomalies while melatonin improved male reproductive health.

SAT426 Long-term Nanomolar Bisphenol A (BPA) Exposure of MCF7 Cells Induces DNA Methylation Changes

Abstract Disclosure: S.L. Dela Cruz: None. M.C. Velarde: None. P.D. Bagamasbad: None. Breast cancer (BCa) has the highest worldwide prevalence and mortality rate among cancers. For ER-positive luminal BCa, hormone deprivation therapy using drugs that inhibit the estrogen signaling axis is commonly employed. However, activation of ER may persist due to the presence of endocrine disrupting chemicals (EDCs) that are structurally similar to endogenous estrogens. Bisphenol A (BPA) is a known EDC found in consumer products and has been associated with increased BCa risk in various animal models. Mechanistically, BPA weakly binds and activates ER resulting in transcriptional changes. In addition, studies show that BPA potentially reprograms the epigenome through changes in DNA methylation. While methylome studies on BPA-exposed cancer models have been conducted, to the best of our knowledge, this has not been done on luminal BCa cells chronically exposed to environmentally relevant doses of BPA. The use of a chronic, nanomolar-dose treatment paradigm is significant as it more accurately reflects non-occupational environmental exposure. In this study, we investigated the epigenetic effects of chronic (8 weeks) nanomolar doses (10 nM) of BPA on the ER-positive BCa cell line MCF7. We probed single gene-level DNA methylation through Bisulfite Sequencing PCR (BSP) and genome-wide methylation through Reduced Representation Bisulfite PCR (RRBS). In silico analysis of publicly available data identified potential differentially methylated regions (DMRs) upon chronic BPA treatment. BSP showed minimal changes in methylation levels of CpGs within the target DMRs, while gene expression analysis via RT-qPCR did not find significant changes in mRNA levels of genes encompassing the target regions. Methylome-wide profiling of chronically treated cells identified DMRs that fall under gene promoters (DMPs) and gene coding regions (DMGs). Pathway analysis of DMPs indicated an association with death receptor signaling, with an overall predicted effect in inhibiting apoptosis. Network analysis revealed genes encompassing DMPs that interact with the BCa markers ESR1/2, BRCA1, and PGR. Based on the pathway and network analyses, we selected 8 genes for gene expression analysis and found that the expression of all 8 genes are unchanged following chronic BPA treatment. Taken together, our results show that chronic BPA exposure of MCF7 can induce subtle changes in DNA methylation. Although initial validation did not reveal changes in gene expression associated with differential methylation, we speculate that the incremental DNA methylation changes could accumulate over time resulting in further ER signaling dysregulation, exacerbating the BCa phenotype. Presentation: Saturday, June 17, 2023

Impact of bisphenol A on cell viability and inflammatory cytokine production in human cervical epithelial cells.

An intact cervix is a barrier that prevents pathogenic bacteria from invading the uterine and amniotic cavity during pregnancy. Its disruption is associated with ascending infection and adverse pregnancy outcomes. This study analyzed the effects of bisphenol A (BPA), a chemical used in plastics manufacturing, on cell death and inflammation in cervical epithelial cells. Ectocervical epithelial (ecto) and endocervical epithelial (endo) cells were treated with 100ng/mL and 300ng/mL of BPA for 48h. The cells were subjected to flow cytometry using annexin V and propidium iodide to determine apoptosis and necrosis, cell cycle analysis, and ELISA to determine the levels of inflammatory cytokines (IL-6, IL-8, and IL-10). Low-dose and high-dose BPA significantly increased the live ecto cell population dose-dependently. BPA did not have any noticeable effect on cell cycle progression in either cell type. BPA treatment also decreased the apoptotic ecto and endo cell population dose-dependently. Lastly, high dose BPA significantly increased IL-6 in ecto and endo cells. However, IL-8 and IL-10 were not affected by BPA treatments. Chemical exposure damage to the cervix can lead to adverse pregnancy outcomes. Our study showed that the BPA concentrations reported in pregnant subjects do not induce cervical cell toxicity . The decrease in apoptosis and increase in live cells may be a compensatory mechanism to preserve the integrity of the cervical epithelial layer.

Mechanism of piRNA in bisphenol A-promoted invasion and migration of prostate cancer cells

Objective: To investigate the regulatory mechanisms of piwi-interacting RNA (piRNA) in bisphenol A (BPA)-induced prostate cancer cell invasion and migration. Methods: The Cancer Genome Atlas (TCGA) data was used to analyze and screen for piRNAs with significantly increased expression in prostate cancer tissues. PC-3 cells were treated with different concentrations of BPA for 12, 24, and 48 h, respectively, and the 20% inhibitory concentration (IC20) was measured using a CCK-8 assay. The expression levels of piRNAs before and after BPA treatment were determined by reverse transcription-quantitative PCR. Target genes regulated by BPA and associated with prostate cancer were screened in the Comparative Toxicogenomics Database (CTD). Dual-luciferase reporter gene assay was performed to verify the relationship between piRNA and target genes, and the expression change of the piRNA target gene was detected by Western blotting. Cell migration and invasion assays were used to determine the effects of piRNA on the malignant phenotype of prostate cancer cells. Results: After treatment of PC-3 cells with 160 μmol/L BPA, the expression of piR-sno48 was most significantly increased (P<0.05). Transfection of piR-sno48 antagomir resulted in decreased expression of endogenous piR-sno48 and a significant increase in the expression of its target gene GSTP1 (P<0.05). However, the expression of GSTP1 did not change significantly in BPA-treated PC-3 cells after transfection with piR-sno48 antagomir (P>0.05). The dual-luciferase reporter gene confirmed that piR-sno48 inhibited the expression of GSTP1 by forming an inversely complementary sequence with the 3'-UTR of GSTP1. The Transwell assay results showed that treatment with BPA significantly increased the invasion and migration ability of prostate cancer cells (P<0.01), whereas piR-sno48 antagonists significantly inhibited the effects above (P<0.01). Conclusion: BPA promotes the invasion and migration of prostate cancer cells by upregulating the expression of piR-sno48 and suppressing the expression of GSTP1. Interfering with the expression of endogenous piR-sno48 may inhibit the malignant phenotype of prostate cancer cells caused by BPA.

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.

G protein-coupled estrogen receptor activation by bisphenol-A disrupts lipid metabolism and induces ferroptosis in the liver

As a metabolic disruptor, bisphenol A (BPA) has been widely reported to disrupt lipid balance. Moreover, BPA has gained significant attention due to its estrogenic activity. While both ferroptosis and the G-protein-coupled estrogen receptor (GPER) have been implicated in lipid metabolism, their link to BPA-induced lipid accumulation remains unclear. In this study, chickens were randomly assigned to three groups and housed them for 4 weeks: a control group (0 μg/L BPA), a low dose group (50 μg/L BPA) and a high dose group (5000 μg/L BPA) to investigate the underlying mechanism of BPA-induced hepatotoxicity. Our results showed that BPA exposure significantly increased the contents of TG, TC, and LDL-C while decreasing HDL-C levels. We also found that BPA treatment altered the levels of genes involved in fatty acid β-oxidation (ampkα, cpt-1, and ppaα), synthesis (acc, fas, scd-1, and srebp-1) and absorption (lpl and cd36). Moreover, the results showed that the BPA group had higher levels of IL-1β, IL-18 and TNF-α. These results indicated that BPA exposure disrupted lipid metabolism and induced inflammation in the liver. We also demonstrated that BPA caused hepatic ferroptosis by raising iron content and the expression of genes related to lipid peroxidation (lpcat3, acsl4 and alox15), while reducing the expression of antioxidant system-associated genes (gpx4, slc7a11 and slc3a2). Importantly, BPA remarkably activated GPER expression in the liver. Interestingly, inhibition of GPER remarkably ameliorated BPA-induced lipid metabolism disorder, inflammatory response, and ferroptosis, indicating the crucial role of GPER in BPA-induced liver abnormalities. These findings highlight the link between GPER and ferroptosis in BPA-induced hepatotoxicity, providing new insights into the potential hazard of BPA.

Multi- and transcriptomic changes of chronic exposure to bisphenol A reveals reproductive toxicity in male zebrafish.

Bisphenol A (BPA) is considered to be a threat to marine organisms owning to its widespread usage and potential aquatic toxicity. However, the reproductive toxicity of BPA to transgenerational inheritance in aquatic organisms is still unclarified. In this study, the morphological, histological, and transgenerational changes by BPA in zebrafish testis were investigated. Results showed that BPA caused abnormities in sperm number, activity, and fertility rate. Testicular transcriptional alterations detected by RNA-seq identified 1940 differentially expressed genes (DEGs) after BPA exposure, of which 392 were upregulated and 1548 were downregulated. Gene Ontology analysis showed that acrosin binding, binding of sperm to zona pellucida, and positive regulation of acrosome reaction were significantly enriched in BPA-induced DEGs. Pathway analysis indicated that cell adhesion molecules, steroid hormone biosynthesis and fatty acid biosynthesis, elongation, and metabolism were remarkably changed after BPA treatment. Thus, we deduce here that multi- and transcriptomic changes of chronic exposure to BPA reveals reproductive toxicity in male zebrafish.

Bisphenols as promoters of the dysregulation of cellular junction proteins of the blood-testis barrier in experimental animals: A systematic review of the literature.

Daily, people are exposed to chemicals and environmental compounds such as bisphenols (BPs). These substances are present in more than 80% of human fluids. Human exposure to BPs is associated with male reproductive health disorders. Some of the main targets of BPs are intercellular junction proteins of the blood-testis barrier (BTB) in Sertoli cells because BPs alter the expression or induce aberrant localization of these proteins. In this systematic review, we explore the effects of BP exposure on the expression of BTB junction proteins and the characteristics of in vivo studies to identify potential gaps and priorities for future research. To this end, we conducted a systematic review of articles. Thirteen studies met our inclusion criteria. In most studies, animals treated with bisphenol-A (BPA) showed decreased occludin expression at all tested doses. However, bisphenol-AF treatment did not alter occludin expression. Cx43, ZO-1, β-catenin, nectin-3, cortactin, paladin, and claudin-11 expression also decreased in some tested doses of BP, while N-cadherin and FAK expression increased. BP treatment did not alter the expression of α and γ catenin, E-cadherin, JAM-A, and Arp 3. However, the expression of all these proteins was altered when BPA was administered to neonatal rodents in microgram doses. The results show significant heterogeneity between studies. Thus, it is necessary to perform more research to characterize the changes in BTB protein expression induced by BPs in animals to highlight future research directions that can inform the evaluation of risk of toxicity in humans.

Microanatomy and behaviour of the date mussel's adductor and foot muscles after chronic exposure to bisphenol A, with inhibition of ATPase enzyme activities and DNA damage

Environmental contaminants with estrogenic activity have recently received attention due to the potential harm they could cause to humans and wildlife. To assess the toxic effects of bisphenol A (BPA) on marine mussels, Lithophaga lithophaga were exposed for 4 weeks to 0, 0.25, 1, 2, and 5 μg/L BPA. Aside from DNA damage, a behavioural study including valve closure duration (VCD), valve opening duration (VOD), levels of malondialdehyde (MDA), and total glutathione, as well as superoxide dismutase (SOD) and ATPase activities in adductor muscle extracts, and histopathological examination of the adductor muscle and foot were performed. The behavioural response was marked by an increase in the percentage of VCD and a decrease in the percentage of VOD during 8 h. Furthermore, BPA treatments resulted in a significant concentration-dependent increase in muscle MDA and total glutathione levels. However, when compared to controls, SOD and ATPase activity was significantly reduced in the adductor muscles of BPA treatments. Histological examination of the adductor and foot muscles revealed qualitatively distinct abnormalities. DNA damage was strongly induced in a concentration-dependent manner. Our findings suggested that BPA exposure altered detoxification, antioxidation, ATPase activity, histopathological characteristics, and DNA damage, which resulted in behavioural changes. The multi-biomarker approach used suggests that clear relationships exist between genotoxic and higher-level effects in some cases, which could be used as an integrated tool to evaluate various long-term toxic effects of BPA.

Bisphenol A-induced autophagy ameliorates human B cell death through Nrf2-mediated regulation of Atg7 and Beclin1 expression by Syk activation

The widely used plasticizer bisphenol A (BPA) is known as an endocrine-disrupting chemical (EDC). Many studies have shown that BPA contributes to diseases involving immune system alterations, but the underlying mechanisms have yet to be elucidated. We previously reported that BPA at concentration of 100 μM caused human B cell death in accordance with an increase in nuclear factor (erythroid-derived 2)-like 2(Nrf2) expression. Autophagy is a cellular process that degraded and recycles cytoplasmic constituents. Here, we investigated whether BPA induces autophagy through Nrf2, which is associated with regulation of B cell death using human WiL2-NS lymphoblast B cells. Then, cell viability was assessed by various assays using trypan blue, MTT or Celltiter glo luminescent substrate and DAPI. When WiL2-NS cells were treated with BPA, cell viability was decreased and LC3 autophagy cargo protein/puncta was increased. BPA-induced autophagy was confirmed by the modification of LC3 puncta formation or autophagy flux turnover with the treatment of hydroxychloroquine(HCQ), NH4Cl and PI3K inhibitors including 3-methyladenine(3-MA), LY294002 and wortmannin. BPA treatment increased the expression of autophagy-related gene(Atg)7 and Beclin1 as well as Nrf2 induced by the production of reactive oxygen species (ROS). The inhibition of autophagy with siAtg7 or siBeclin1 and Nrf2 depletion aggravated BPA-induced cell death. BPA enhanced the bound of Nrf2 to the specific region on Beclin1 and Atg7 promoter. Spleen tyrosine kinase(Syk) activity was enhanced in response to BPA treatment. Bay61–3606, Syk inhibitor, decreased LC3 and the expression of Atg7 and Beclin1, leading to the increase of BPA-induced B cell death. The results suggest that BPA-induced autophagy ameliorates human B cell death through Nrf2-mediated regulation of Atg7 and Beclin1 expression.

Efficient adsorption of bisphenol A from water by a hierarchically porous hyper-crosslinked polymer containing β-cyclodextrin polyurethane

Bisphenol A (BPA) is a common industrial products ingredient, whose widespread utilization leads to a non-negligible problem of water pollution. For efficient adsorption of BPA, hyper-crosslinked β-cyclodextrin polyurethane (CDPU-HCP) was synthesized via crosslinking β-cyclodextrin (β-CD) with 4,4′-diphenylmethane diisocyanate followed by further external crosslinking reaction. CDPU-HCP showed high surface area (1133.12 m2∙g−1) and has hierarchically pores, such as β-CD nanocavities, micropore and mesopores. Adsorption data fitted better with Freundlich adsorption isotherm model and the pseudo second order kinetic model. The fitted maximum adsorption capacity toward BPA was shown to be 371.8 mg∙g−1. The stable adsorption performance during successive six recycling experiments indicated the excellent recyclability of CDPU-HCP. Furthermore, the density functional theory (DFT) calculations showed hydrophobic interaction of β-CD cavity and π-π interactions between aromatic moieties and BPA synergistically promoted the adsorption process. Therefore, CDPU-HCP was suggested to be a promising adsorbent in the treatment of BPA.

Exposure to bisphenol A induces neurotoxicity associated with synaptic and cytoskeletal dysfunction in neuro-2a cells.

Bisphenol A (BPA) has been reported to injure the developing and adult brain. However, the underlying mechanism still remains elusive. This study used neuro-2a cells as a cellular model to investigate the neurotoxic effects of BPA. Microtubule-associated protein 2 (MAP2) and tau protein maintain microtubule normal function and promote the normal development of the nervous system. Synaptophysin (SYP) and drebrin (Dbn) proteins are involved in regulating synaptic plasticity. Cells were exposed to the minimum essential medium (MEM), 0.01% (v/v) DMSO, and 150μM BPA for 12, 24, or 36h. Morphological analysis revealed that the cells in the BPA-treated groups shrank and collapsed compared with those in the control groups. CCK-8 and lactate dehydrogenase assay (LDH) assays showed that the mortality of neuro-2a cells increased as the BPA treatment time was prolonged. Ultrastructural analysis further revealed that cells demonstrated nucleolar swelling, dissolution of nuclear and mitochondrial membranes, and partial mitochondrial condensation following exposure to BPA. BPA also decreased the relative protein expression levels of MAP2, tau, and Dbn. Interestingly, the relative protein expression levels of SYP increased. These results indicated that BPA inhibited the proliferation and disrupted cytoskeleton and synaptic integrity of neuro-2a cells.

NTS, NTSR1 and ERs in the Pituitary-Gonadal Axis of Cycling and Postnatal Female Rats after BPA Treatment.

The neuropeptide neurotensin (NTS) is involved in regulating the reproductive axis and is expressed at each level of this axis (hypothalamus-pituitary-gonads). This dependence on estrogen levels has been widely demonstrated in the hypothalamus and pituitary. We focused on confirming the relationship of NTS with estrogens and the gonadal axis, using a particularly important environmental estrogenic molecule, bisphenol-A (BPA). Based on the experimental models or in vitro cell studies, it has been shown that BPA can negatively affect reproductive function. We studied for the first time the action of an exogenous estrogenic substance on the expression of NTS and estrogen receptors in the pituitary-gonadal axis during prolonged in vivo exposure. The exposure to BPA at 0.5 and 2 mg/kg body weight per day during gestation and lactation was monitored through indirect immunohistochemical procedures applied to the pituitary and ovary sections. Our results demonstrate that BPA induces alterations in the reproductive axis of the offspring, mainly after the first postnatal week. The rat pups exposed to BPA exhibited accelerated sexual maturation to puberty. There was no effect on the number of rats born per litter, although the fewer primordial follicles suggest a shorter fertile life.

Unraveling the instability of Nitrogen-Doped carbon during BPA treatment by peroxymonosulfate Activation: Effect of free radical grafting

Nitrogen-doped carbon has been established as an effective catalyst for peroxymonosulfate (PMS) activation to remove pollutants from water. However, the easy deactivation during the reaction process limits its potential for widespread application. In this study, nitrogen-rich carbocatalysts was synthesized by two-step pyrolysis and used to activate PMS for degradation of bisphenol A (BPA). The nitrogen-rich catalysts calcined at 900 ℃ with the amount of 2 mg degraded more than 80 % of 20 mg/L BPA in 20 min and the degradation of TOC has reached 65 %, showing excellent catalytic performance. Based on free radical quenching experiments and electron spin resonance (ESR), the non-radical process played a key role in BPA degradation. The characterization results of fresh and used catalysts suggested that the instability of the nitrogen-rich carbon materials resulted from the grafting reaction between free radicals on the graphite carbon site of the N-doped carbon materials and the intermediate degradation products of BPA, which covered the active sites of the catalysts. This new discovery elucidates the reason of N-doped carbon materials deactivation in PMS oxidation and provides a complementary for the reaction mechanism of carbon catalysis.