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Introduction: Cultured mouse trophoblast stem cells (mTSC) maintain proliferation/normal stemness (NS) under FGF4, which when removed, causes normal differentiation (ND). Hypoxic, or hyperosmotic stress forces trophoblast giant cells (TGC) differentiate. Hypoxic, hyperosmotic, and genotoxic benzo(a)pyrene (BaP), which is found in tobacco smoke, force down-regulation of inhibitor of differentiation (Id)2, enabling TGC differentiation. Hypoxic and hyperosmotic stress induce TGC by SAPK-dependent HAND1 increase. Here we test whether BaP forces mTSC-to-TGC while inducing SAPK and HAND1., Methods: Hand1 and SAPK activity were assayed by immunoblot, mTSC-to-TGC growth and differentiation were assayed at Tfinal after 72hr exposure of BaP, NS, ND, Retinoic acid (RA), or sorbitol. Nuclear-stained cells were micrographed automatically by a live imager, and assayed by ImageJ/FIJI, Biotek Gen 5, AIVIA proprietary artificial intelligence (AI) software or open source, CellPose artificial intelligence/AI software., Results: BaP (0.05-1μM) activated SAPK and HAND1 without diminishing growth. TSC-to-TGC differentiation was assayed with increasingly accuracy for 2-4 N cycling nuclei and >4 N differentiating TGC nuclei, using ImageJ/FIJI, Gen 5, AIVIA, or CellPose AI software. The AIVIA and Cellpose AI software matches human accuracy. The lowest BaP effects on SAPK activation/HAND1 increase are >10-fold more sensitive than similar effects for mESC. RA induces 44-47% 1st lineage TGC differentiation, but the same RA dose induces only 1% 1st lineage mESC differentiation., Discussion: First, these pilot data suggest that mTSC can be used in high throughput screens (HTS) to predict toxicant exposures that force TGC differentiation. Second, mTSC differentiated more cells than mESC for similar stress exposures, Third, open source AI can replace human micrograph quantitation and enable a miscarriage-predicting HTS., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023. Published by Elsevier Ltd.)

The Caspian Sea has faced many environmental challenges, such as oil pollution. Heat shock proteins (HSPs) play a critical role in stress conditions and physiological changes caused by disease or injury. By evaluating the effects of various HSP inducers (HSPi), including Pro-Tex® (NOP: 800 mM), amygdalin (AMG: 80 mM), and a novel synthetic compound derived from pirano piranazole (SZ: 80 µm) on isolated cells from Sterlet Sturgeon (Acipenser ruthenus) treated with 75% IC 50 PAH-benzo[a]pyrene (BaP; B75). This study examines whether there is a correlation between exposure to the BaP pollutant and HSPs in fish. In vitro, after culturing cells from the liver, kidney, and gills, they were treated with HSPi compounds in the presence and absence of BaP. Western blotting was used to assess HSP27, HSP70, and HSP90 expression patterns. A variety of enzyme activities were measured before (without treatment) and after treatment with HSPis and HSPi + B75, including cytochrome P450 (CYP450) activity, specific enzyme activity for acetylcholinesterase (AChE), antioxidant capacity, liver indicator enzymes, cortisol levels, and immunity parameters. When compared to the control group, cells treated with B75 showed the lowest AChE enzyme activity (p < 0.0001). CYP450 activity was highest in group B75, while HSPi caused the opposite effect (p < 0.0001). HSPi + B75 increased HSP levels and antioxidant parameters while decreasing cortisol and liver indicator enzymes (p < 0.0001). HSPi may be a powerful and reliable method for enhancing the resistance of A. ruthenus to BaP stresses before exposure. Treating cells with HSP-inducing compounds, such as NOP, AMG, and SZ, can assist them in managing stress and increase HSP (27, 70, and 90) protein expression. Furthermore, the study findings suggest that HSPis can also mitigate the adverse effects of stress, ultimately increasing cell survival and resistance., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Bulky DNA damages block transcription and compromise genome integrity and function. The cellular response to these damages includes global transcription shutdown. Still, active transcription is necessary for transcription-coupled repair and for induction of damage-response genes. To uncover common features of a general bulky DNA damage response, and to identify response-related transcripts that are expressed despite damage, we performed a systematic RNA-seq study comparing the transcriptional response to three independent damage-inducing agents: UV, the chemotherapy cisplatin, and benzo[a]pyrene, a component of cigarette smoke. Reduction in gene expression after damage was associated with higher damage rates, longer gene length, and low GC content. We identified genes with relatively higher expression after all three damage treatments, including NR4A2 , a potential novel damage-response transcription factor. Up-regulated genes exhibit higher exon content that is associated with preferential repair, which could enable rapid damage removal and transcription restoration. The attenuated response to BPDE highlights that not all bulky damages elicit the same response. These findings frame gene architecture as a major determinant of the transcriptional response that is hardwired into the human genome., (© 2024 Merav et al.)

Objective: This experiment is explores the genes that play a key role, their expression changes and the biological processes in the transformation of chronic obstructive pulmonary disease (COPD) into lung adenocarcinoma (LAC). Meanwhile, identify the effects of Benzo[a]pyrene (BaP) in the conversion of COPD into LAC., Methods: 1. Differential expression genes of COPD and LAC were screened and analyzed by high-throughput microarray data between the two diseases and their respective control groups. 2. The screened genes were used for routine bioinformatics analysis such as functional analysis, expression verification, protein interaction analysis and functional enrichment. 3. Cigarette smoke extract (CSE) combined with lipopolysaccharide (LPS) was used to establish an in vitro COPD model. 4. MTT assay was used to detect the influence of B(a)P in effect on A549 cell proliferation. CCK-8, Transwell invasion test and scratch test were used to detect the cell proliferation, invasion and migration ability, while qPCR and Western Blot tests were used to observe the cell proliferation, apoptosis and changes in related indicators such as EMT. 5. Experimental method of separately adding agonists (tBHQ) and inhibitors (DIC) of NQO1 was used to confirm the effect of NQO1 on A549 cell proliferation, apoptosis, migration and invasion. 6. To further clarify whether BaP exerted effect on cell proliferation, apoptosis, migration and invasion through NQO1, we knocked down NQO1 gene and then infecting cells with BaP., Results: 1. We screened genes of COPD and LAC using datasets from GSE151052, GSE118370, and GSE140797. After screening, the genes upregulated in COPD and downregulated in LAC were RTKN2, SLC6A4, and HBB, the gene downregulated in COPD and upregulated in LAC was NQO1, the genes downregulated in both COPD and LAC were FPR1, LYVE1 and PKHD1L1. 2. The main signaling pathways in which the target genes were enriched are cell cycle, EMT, PI3K/AKT, and apoptosis. In the data included GEPIA, PKHD1L1, FPR1, LYVE1, RTKN2, HBB, and SLC6A4 were significantly downregulated and NQO1 was upregulated in LAC relative to controls. In addition, there were 46 interaction proteins in the target genes, and the functions they enriched included hydrogen peroxide catabolism, etc. 3. When A549 cell was stimulated with 100 ng/mL LPS+ 10% CSE, the COX-2 expression indicated that COPD model in vitro was successfully established. 4. The optimal dose and action time were screened which were 1 μM and 24 h. Compared to the control group, COPD and BaP group increased cell proliferation and invasion capabilities. On the basis of COPD, adding BaP could further increase the proliferation and migration capabilities. Interestingly, the levels of NQO1 decreased in COPD models, while increased by BaP. 5. tBHQ can increase the proliferation and migration capacity of A549 cells, which is inhibited by the addition of DIC. 6. The enhanced proliferation, migration and invasion of A549 cells by BaP were attenuated after knockdown of NQO1., Conclusion: Our study reveals that PKHD1L1, FPR1, LYVE1, RTKN2, HBB, SLC6A4 and NQO1 may play an important role in the conversion of COPD to LAC. High NQO1 expression may increase the proliferation and migration ability of A549 cells, and BaP may promote the EMT state by increasing the expression of NQO1, thereby making the COPD model in vitro expose the tumor characteristics., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Benzo(a)pyrene (BaP) is a well-known environmental endocrine pollutant, which has ovarian toxicity in mammals. Ovarian corpus luteum (CL), as the main source of progesterone synthesis in early pregnant female, requires a large number of mitochondria for energy supply. We previously demonstrated that BaP and its metabolite benzo(a)pyren-7, 8-dihydrodiol-9, 10-epoxide (BPDE) inhibited the ovarian melatonin receptors (MTRs) expression and decreased the levels of estrogen and progesterone during early pregnancy in mice. Emerging researches show that MTRs also exist on mitochondrial membrane and participate in the regulation of mitochondrial function. However, the relationship between BaP, MTRs on mitochondrial membrane and mitochondrial function remains unknown. Consequently, this study focuses on the effect and potential mechanism of BaP on ovarian luteal mitochondrial function during early pregnancy. We found that BaP and its metabolite BPDE decreased MTRs in early pregnant CL and luteinized KGN cells, especially in mitochondria. Furthermore, BaP or BPDE up-regulated the expression of SIRT3, Mfn2 and Drp-1, damaged mitochondrial morphology and decreased the MMP and the ATP levels, thereby causing mitochondrial dysfunction. Notably, activation of the MTRs on mitochondrial membrane by MTRs agonist ramelteon partially alleviated BPDE-induced up-regulation of SIRT3, Mfn2 and Drp-1, reduced mitochondrial fragmentation and enhanced the MMP and the ATP levels, thus restoring the expression of steroid rate-limiting enzymes. Together, these findings firstly proved that BaP and BPDE down-regulate MTRs on mitochondrial membrane, and further injure mitochondrial function in early pregnant rats' CL, which provides a new insight for understanding the exact mechanism of the BaP-induced ovarian toxicity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: The purpose of this study was to investigate the effects of polycyclic aromatic hydrocarbons (PAHs) other than bisphenol A (BPA) and BPA substitutes on placental cells., Methods: HTR-8/SVneo cells were treated with anthracene, benzo[k]fluoranthene, benzo[a]pyrene, and 4,4-(9-fluorenylidene)diphenol, which is used as a substitute for BPA-free products. After confirming the dose response for each reagent using the prepared cells, the cells were incubated for 24, 48, and 72 h. Cell viability was confirmed using the XTT assay. Each experiment was performed with the minimum number of samples (n = 3) required for statistical analysis. The results were analyzed using t-tests; p < 0.05 was considered statistically significant., Results: After treatment with anthracene, benzo[k]fluoranthene, benzo[a]pyrene, and 4,4-(9-fluorenylidene)diphenol, the absorbance measured using the XTT assay decreased significantly with increasing concentration. The absorbance decreased significantly over time following treatment with each endocrine disruptor at the concentration confirmed by the dose-response analysis., Conclusions: This study showed that anthracene, benzo[k]fluoranthene, benzo[a]pyrene, and 4,4-(9-fluorenylidene)diphenol-a BPA substitute-affect cell viability and necrosis in the placental cell line. The study indicates the serious effects of PAHs that negatively affect pregnancy but were previously unknown. Further, this study would serve as a reference for the identification of harmful PAHs during pregnancy prognosis in women who are more susceptible to PAH exposure., (© 2022. The Author(s).)

Many environmental pollutants, natural compounds, as well as endogenous chemicals exert their biological/toxicological effects by reacting with the aryl hydrocarbon receptor (AhR). Previous evidence shed new light on the role of AhR in skin physiology by regulating melanin production. In this study, we investigated the effect of oxidative imbalance induced by AhR ligands on the melanogenesis process in B16 murine melanoma cells. Exposure to 6-formylindolo[3,2-b] carbazole (FICZ) or benzo-α-pyrene (BαP) led to enhanced expression of CTNNB1, MITF, and TYR genes following increased tyrosinase enzyme activity and melanin content in an AhR-dependent manner. Analysis of the presence of reactive oxygen species (ROS) as well as reduced glutathione (GSH) / oxidized glutathione (GSSG) ratio revealed that treatment with AhR ligands is associated with oxidative stress which can be ameliorated with NAC (N-acetyl cysteine) or diphenyleneiodonium chloride (DPI). On the other hand, NAC and DPI enhanced melanogenesis induced by AhR ligands by reducing the level of ROS. We have shown for the first time that a cellular redox status is a critical event during AhR ligand-induced melanogenesis., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This study focused on immunomodulatory effects of aryl hydrocarbon receptor (AhR) activation through benzo[ a ]pyrene (BaP) during systemic bacterial infection. Using a well-established mouse model of systemic Salmonella enterica (S.E.) infection, we studied the influence of BaP on the cellular and humoral immune response and the outcome of disease. BaP exposure significantly reduced mortality, which is mainly caused by septic shock. Surprisingly, the bacterial burden in BaP-exposed surviving mice was significantly higher compared to non-exposed mice. During the early phase of infection (days 1-3 post-infection (p.i.)), the transcription of proinflammatory factors (i.e., IL-12, IFN-γ, TNF-α, IL-1β, IL-6, IL-18) was induced faster under BaP exposure. Moreover, BaP supported the activity of antigen-presenting cells (i.e., CD64 (FcγRI), MHC II, NO radicals, phagocytosis) at the site of infection. However, early in infection, the anti-inflammatory cytokines IL-10 and IL-22 were also locally and systemically upregulated in BaP-exposed S.E.-infected mice. BaP-exposure resulted in long-term persistence of salmonellae up to day 90 p.i., which was accompanied by significantly elevated S.E.-specific antibody responses (i.e., IgG1, IgG2c). In summary, these data suggest that BaP-induced AhR activation is capable of preventing a fatal outcome of systemic S.E. infection, but may result in long-term bacterial persistence, which, in turn, may support the development of chronic inflammation.

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) primarily formed by burning of fossil fuels, wood and other organic materials. BaP as group I carcinogen shows mutagenic and carcinogenic effects. One of the important mechanisms of action of (BaP) is its free radical activity, the effect of which is the induction of oxidative stress in cells. BaP induces oxidative stress through the production of reactive oxygen species (ROS), disturbances of the activity of antioxidant enzymes, and the reduction of the level of non-enzymatic antioxidants as well as of cytokine production. Chemical compounds, such as vitamin E, curcumin, quercetin, catechin, cyanidin, kuromanin, berberine, resveratrol, baicalein, myricetin, catechin hydrate, hesperetin, rhaponticin, as well as taurine, atorvastatin, diallyl sulfide, and those contained in green and white tea, lower the oxidative stress induced by BaP. They regulate the expression of genes involved in oxidative stress and inflammation, and therefore can reduce the level of ROS. These substances remove ROS and reduce the level of lipid and protein peroxidation, reduce formation of adducts with DNA, increase the level of enzymatic and non-enzymatic antioxidants and reduce the level of pro-inflammatory cytokines. BaP can undergo chemical modification in the living cells, which results in more reactive metabolites formation. Some of protective substances have the ability to reduce BaP metabolism, and in particular reduce the induction of cytochrome (CYP P450), which reduces the formation of oxidative metabolites, and therefore decreases ROS production. The aim of this review is to discuss the oxidative properties of BaP, and describe protective activities of selected chemicals against BaP activity based on of the latest publications.

Background: Benzo [a] pyrene (BaP), a potent carcinogen, has been proved that it has toxicological effects via activation the aryl hydrocarbon receptor (AhR) pathway. AhR can participate in regulating lipogenesis and lipolysis. This topic will verify whether BaP regulates lipid metabolism via AhR., Methods: (1) C57BL/6 mice were gavaged with BaP for 12 weeks to detect serum lipids, glucose tolerance, and insulin resistance. Morphological changes in white adipose tissue (WAT) were detected by Hematoxylin and Eosin staining. The mRNA expression levels of adipogenesis-related factors included recombinant human CCAAT/enhancer binding protein alpha (C/EBPα), peroxisome proliferator-activated receptor gamma (PPARγ), and fatty acid binding protein 4 (FABP 4 ) and inflammatory factors included nuclear factor kappa-B (NF-κB), monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor alpha (TNF-α) were detected using PCR. (2) Neutral lipid content changes in differentiated 3 T3-L1 adipocytes treated with BaP with and w/o AhR inhibitor were detected by Oil red staining. The protein expression levels of adipogenesis- and decomposition-related factors included PPARγ coactivator-1 alpha (PGC-1α), and peroxisome proliferation-activated receptor alpha (PPARα) were detected using western blotting. The mRNA expression levels of inflammatory factors were detected using PCR., Results: (1) BaP inhibited body weight gain, decreased lipid content, increased lipid levels, and decreased glucose tolerance and insulin tolerance in mice; (2) BaP reduced the expressions of C/EBPα, PPARγ, FABP 4 , PGC-1α, and PPARα and increased the expressions of NF-κB, MCP-1, and TNF-α by activating AhR., Conclusion: BaP inhibit fat synthesis and oxidation while inducing inflammation by activating AhR, leading to WAT dysfunction and causing metabolic complications., (© 2022. The Author(s).)

Epigenetic changes constitute one of the processes that is involved in the mechanisms of carcinogenicity. They include dysregulation of DNA methylation processes, disruption of post-translational patterns of histone modifications, and changes in the composition and/or organization of chromatin. Benzo(a)pyrene (BaP) influences DNA methylation and, depending on its concentrations, as well as the type of cell, tissue and organism it causes hypomethylation or hypermethylation. Moreover, the exposure to polyaromatic hydrocarbons (PAHs), including BaP in tobacco smoke results in an altered methylation status of the offsprings. Researches have indicated a potential relationship between toxicity of BaP and deregulation of the biotin homeostasis pathway that plays an important role in the process of carcinogenesis. Animal studies have shown that parental-induced BaP toxicity can be passed on to the F1 generation as studied on marine medaka ( Oryzias melastigma ), and the underlying mechanism is likely related to a disturbance in the circadian rhythm. In addition, ancestral exposure of fish to BaP may cause intergenerational osteotoxicity in non-exposed F3 offsprings. Epidemiological studies of lung cancer have indicated that exposure to BaP is associated with changes in methylation levels at 15 CpG; therefore, changes in DNA methylation may be considered as potential mediators of BaP-induced lung cancer. The mechanism of epigenetic changes induced by BaP are mainly due to the formation of CpG-BPDE adducts, between metabolite of BaP-BPDE and CpG, which leads to changes in the level of 5-methylcytosine. BaP also acts through inhibition of DNA methyltransferases activity, as well as by increasing histone deacetylases HDACs, i.e., HDAC2 and HDAC3 activity. The aim of this review is to discuss the mechanism of the epigenetic action of BaP on the basis of the latest publications.

Background: Urban pollution is correlated with an increased prevalence of skin pigmentation disorders, however the physiological processes underlying this association are unclear., Objectives: To delineate the relationship between polycyclic aromatic hydrocarbons (PAHs), a key constituent of atmospheric pollution, and immunity/skin pigmentation pathways., Methods: We exposed peripheral blood mononuclear cells (PBMC) to PAHs and performed cytokines/chemokine profiling. We then examined the effect of immune activation on pigmentation by co-culturing PBMC and Benzo(a)pyrene (BaP) with reconstructed human pigmented epidermis (RHPE). To study the mechanism, we treated keratinocytes with conditioned medium from BaP-exposed PBMC and studied DNA damage responses, aryl hydrocarbon receptor (AhR) activation and pro-pigmentation factor, proopiomelanocortin (POMC) secretion., Results: PAHs induced up-regulation of inflammatory cytokines/chemokine in PBMC. Co-culturing of RHPE with PBMC+BaP resulted in increased melanin content and localization. BaP-conditioned medium significantly increased DNA damage, p53 stabilization, AhR activation and POMC secretion in keratinocytes. We found that IFNγ induced DNA damage, while TNFα and IL-8 potentiated POMC secretion in keratinocytes. Importantly, BaP-conditioned medium-induced DNA damage and POMC secretion is prevented by antioxidants vitamin E, vitamin C and sulforaphane, as well as the prototypical corticosteroid dexamethasone. Finally, vitamin C and sulforaphane enhanced the genome protective and depigmentation effects of dexamethasone, providing proof-of-concept for a combinatorial approach for the prevention and/or correction of PAH-induced pigment spots formation., Conclusion: Our study reveals the importance of systemic immunity in regulating PAH-induced skin pigmentation, and provide a new keratinocyte DNA damage response mechanistic target for the prevention or reversal of pollution-associated skin pigmentation., Competing Interests: Conflict of interest The authors are employees of a company with a commercial interest in protecting skin from the adverse effect of pollution., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Polycyclic aromatic hydrocarbons (PAH) such as benzo[ a ]pyrene (B[ a ]P) are among the most abundant environmental pollutants, resulting in continuous exposure of human skin and its microbiota. However, effects of the latter on B[ a ]P toxicity, absorption, metabolism, and distribution in humans remain unclear. Here, we demonstrate that the skin microbiota does metabolize B[ a ]P on and in human skin in situ , using a recently developed commensal skin model. In this model, microbial metabolism leads to high concentrations of known microbial B[ a ]P metabolites on the surface as well as in the epidermal layers. In contrast to what was observed for uncolonized skin, B[ a ]P and its metabolites were subject to altered rates of skin penetration and diffusion, resulting in up to 58% reduction of metabolites recovered from basal culture medium. The results indicate the reason for this altered behavior to be a microbially induced strengthening of the epidermal barrier. Concomitantly, colonized models showed decreased formation and penetration of the ultimate carcinogen B[ a ]P-7,8-dihydrodiol-9,10-epoxide (BPDE), leading, in consequence, to fewer BPDE-DNA adducts being formed. Befittingly, transcript and expression levels of key proteins for repairing environmentally induced DNA damage such as xeroderma pigmentosum complementation group C (XPC) were also found to be reduced in the commensal models, as was expression of B[ a ]P-associated cytochrome P450-dependent monooxygenases (CYPs). The results show that the microbiome can have significant effects on the toxicology of external chemical impacts. The respective effects rely on a complex interplay between microbial and host metabolism and microbe-host interactions, all of which cannot be adequately assessed using single-system studies. IMPORTANCE Exposure to xenobiotics has repeatedly been associated with adverse health effects. While the majority of reported cases relate to direct substance effects, there is increasing evidence that microbiome-dependent metabolism of xenobiotic substances likewise has direct adverse effects on the host. This can be due to microbial biotransformation of compounds, interaction between the microbiota and the host's endogenous detoxification enzymes, or altered xenobiotic bioavailability. However, there are hardly any studies addressing the complex interplay of such interactions in situ and less so in human test systems. Using a recently developed microbially competent three-dimensional (3D) skin model, we show here for the first time how commensal influence on skin physiology and gene transcription paradoxically modulates PAH toxicity.

Polycyclic aromatic hydrocarbons (PAHs) are commonly ingested via meat and are produced from high-temperature cooking of meat. Some of these PAHs have potential roles in carcinogenesis of colorectal cancer (CRC). We aimed to investigate PAH concentrations in eight types of commonly consumed ready-to-eat meat samples and their potential effects on gene expressions related to CRC. Extraction and clean-up of meat samples were performed using QuEChERS method, and PAHs were detected using GC-MS. Nine different PAHs were found in meat samples. Interestingly, roast turkey contained the highest total PAH content, followed by salami meat. Hams of varying levels of smokedness showed a proportional increase of phenanthrene (PHEN), anthracene (ANTH), and fluorene (FLU). Triple-smoked ham samples showed significantly higher levels of these PAHs compared to single-smoked ham. These three PAHs plus benzo[a]pyrene (B[a]P), being detected in three meat samples, were chosen as treatments to investigate in vitro gene expression changes in human colon cells. After PAH treatment, total RNA was extracted and rtPCR was performed, investigating gene expression related to CRC. B[a]P decreased mRNA expression of TP53 . In addition, at high concentrations, B[a]P significantly increased KRAS expression. Treatments with 1 µM PHEN, 25 µM, and 10 µM FLU significantly increased KRAS mRNA expression in vitro, implying the potential basis for PAH-induced colorectal carcinogenesis. Opposingly, the ANTH treatment led to increased TP53 and APC expression and decreased KRAS expression, suggesting an anti-carcinogenic effect. To conclude, PAHs are common in ready-to-eat meat samples and are capable of significantly modifying the expression of key genes related to CRC.

ERCC1 is a gene for repairing DNA damage whose function is related to carcinogenic-induced tumorigenesis and the effectiveness of platinum therapies. Circular RNAs (circRNAs) are products of posttranscriptional regulation with pleiotropic effects on the pathogenesis of lung cancer. We aim to identify that specific circRNAs derived from ERCC1 can regulate key biological processes involved in the development of lung cancer. We performed bioinformatics analysis, in vitro experiments, and analyzed clinical samples, to determine the biological features of a certain ERCC1-derived circRNA termed as hsa&#95;circ&#95;0051488 in benzo[a]pyrene diol epoxide-induced malignant transformed cell and lung cancer cell. The well-established model of transformed cells provided an ideal platform for analyzing the molecular characteristics of this circRNA in the malignant transformation of lung epithelial cell, which supports that hsa&#95;circ&#95;0051488 functions in the onset and growth of lung squamous cell carcinoma (LUSC). Further analysis indicates that the absence of hsa&#95;circ&#95;0051488 promoted the proliferation of cells with the malignant phenotype. Extensive experiments confirm that hsa&#95;circ&#95;0051488 is present in the cytoplasm and functioned as a competing endogenous RNA. In particular, hsa&#95;circ&#95;0051488 binds to mir-6717-5p, thereby modulating the expression of SATB2 gene, a lung cancer suppressor. Furthermore, our in silico experiments indicate that SATB2 can inhibit multiple tumor pathways and its expression positively correlated with the tumor suppressor gene CRMP1. These findings suggest a possible regulatory mechanism of hsa&#95;circ&#95;0051488 in LUSC, and that the newly discovered hsa&#95;circ&#95;0051488/miR-6717-5p/SATB2 axis may be a potential route for therapeutic intervention of LUSC., (© 2021 Wiley Periodicals LLC.)

Polar cod (Boreogadus saida) is a key species in the arctic marine ecosystem vulnerable to effects of pollution, particularly from petroleum related activities. To facilitate studying the effects of those pollutants, we adapted a precision-cut liver slice culture protocol for this species. Using this system on board a research vessel, we studied gene expression in liver slice after exposure to the polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (BaP), ethynylestradiol (EE2), and their mixtures, to map their molecular targets and examine possible anti-estrogenic effects of BaP. The exposure experiments were performed with BaP alone (0.1, 1, and 10 μM) or in combination with low concentrations of EE2 (5 nM) to mimic physiological estradiol levels in early vitellogenic female fish. Transcriptome analysis (RNA-seq) was performed after 72 h exposure in culture to map the genes and cellular pathways affected. The results provide a view of global transcriptome responses to BaP and EE2, which resulted in enrichment of many pathways such as the aryl hydrocarbon (Ahr) and estrogen receptor pathways. In the mixture exposure, BaP resulted in anti-estrogenic effects, shown by attenuation of EE2 activated transcription of many estrogen target genes. The results from this ex vivo experiment suggest that pollutants that activate the Ahr pathway such as the PAH compound BaP can result in anti-estrogenic effects that may lead to endocrine disruption in polar cod., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Exposure to polycyclic aromatic hydrocarbons (PAHs) contributes to development and exacerbation of atherosclerosis and cardiovascular disease. However, the underlying molecular mechanisms remain elusive. In the current study, the effect of benzo(α)pyrene (BaP) in human umbilical vein endothelial cells (HUVECs) was investigated, including its impact on apoptosis, cell viability, oxidative stress and inflammatory cytokine release. The role of aryl hydrocarbon receptor (AhR) and NF-κB signaling pathways involved in BaP-induced oxidative stress and inflammation was further investigated. Exposure to BaP induced cell apoptosis and terminal oxidative stress and inflammation responses in HUVECs. BaP also increased the expression of ICAM-1 and VCAM-1. Furthermore, BaP treatment of HUVECs activated AhR and NF-κB signaling pathways, and promoted reactive oxygen species generation and inflammatory cytokine release. The current findings suggest that BaP induced inflammatory cytokine release from HUVECs through oxidative stress accompanied with AhR and NF-κB pathway activation., (Copyright © 2021. Published by Elsevier Inc.)

An increased risk of developing lung cancer has been associated with exposure to cigarette smoke carcinogens and alteration in the gut microbiota. However, there is limited understanding about the impact of exposure to NNK and BaP, the two important components of cigarette smoke carcinogens, on gut microbiota in lung cancer. The present study characterized the influence of exposure to a mixture of NNK plus BaP on lung cancer, feces metabolite composition, and gut microbiota in the A/J mice. The A/J mice were administered NNK plus BaP, and the changes in gut microbiota and feces metabolic profiles were characterized using 16S rRNA gene sequencing and metabolomics, respectively. Results presented here illustrated that a mixture of NNK plus BaP exposure triggered lung carcinogenesis as shown by light microscopy and histopathological evaluation. 16S rRNA sequencing of gut microbiota indicated that exposure to NNK plus BaP could modified fecal bacterial composition. Elevated levels of Actinobacteria, Bifidobacterium, and Intestinimonas and reduced levels of Alistipes, Odoribacter, and Acetatifactor are associated with NNK plus BaP triggered lung cancer. In addition, metabolomics profile revealed the regulation of metabolism including purine metabolism, phenylalanine metabolism, primary bile acid biosynthesis, steroid hormone biosynthesis, biosynthesis of unsaturated fatty acids, linoleic acid metabolism, and others. In conclusion, the results provide some guidance for using gut microbes as biomarkers to assess the progression of lung cancer, and lead to interventional targets to control the development of the disease in the future., (Copyright © 2021. Published by Elsevier B.V.)

Cervical cancer, as the most frequent cancer in women globally and accounts almost 14% in India. It can be prevented or treated with vaccines, radiation, chemotherapy, and brachytherapy. The chemotherapeutic agents cause adverse post effects by the destruction of the neighboring normal cells or altering the properties of the cells. In order to reduce the severity of the side effects caused by the chemically synthesized therapeutic agents, the current research developed an anti-cancer agent dimer of epicatechin (DoE), a natural bioactive secondary metabolite (BSM) mediated from an endophytic fungus Curvularia australiensis FC2AP. The investigation has initiated with the evaluation of inhibiting the angiogenesis which is a main activity in metastasis, and it was assessed through Hen's Egg Test on Chorio Allantoic Membrane (HET-CAM) test; the BSM inhibited the growth of blood vessels in the developing chick embryo. Further the DoE was evaluated for its acute toxicity levels in albino mice, whereas the survival dose was found to be 1250 mg/kg and the lethal dose was 1500 mg/kg body weight of albino mice; hematological, biochemical, and histopathological analyses were assessed. The anti-inflammatory responses of the DoE were evaluated in carrageenan induced Wistar rats and the reduction of inflammation occurred in a dose-dependent manner. By fixing the effective dose for anti-inflammation analysis, the DoE was taken for the anti-cervical cancer analysis in benzo (a) pyrene induced female Sprague-Dawley rats for 60 days trial. After the stipulated days, the rats were taken for hematological antioxidants, lipid peroxidation (LPO), member bound enzymes, cervical histopathological and carcinogenic markers analyses. The results specified that the DoE has the capability of reducing the tumor in an efficient way. This is the first report of flavonoid-DoE production from an endophytic fungus C. australiensis has the anticancer potentiality and it can be stated as anti-cancer drug.

Aim: Benzo[a]pyrene [BP] is one of the major carcinogenic precursors of cigarette smoke that primary affects the lung at its first proximity. The goal of the current research was to elucidate new mechanisms underlying the tumorigenic impact of oral BP in the lung of mice, with focus on immunosuppressive effects and cancer stemming properties., Methods: Female albino mice (n = 44) were divided into 2 groups: normal control and BP group. BP was administered orally to mice (50 mg/kg body weight), twice a week for four weeks in succession. At the end of experiment (22 weeks), gene expression were measured for transforming growth factor-β (TGF-β), cytotoxic T lymphocyte antigen-4 (CTLA-4), programmed death ligand 1(PD-L1), forkhead box protein P3 (FOXP3) and interleukin 12 (IL-12) and CD83 + , CD8 + and CD166 + cell percentage were measured in lung tissue., Results: The results indicated the tumorigenic role of BP in the lung which was evidenced by histopathological examination. BP group also showed immunosuppressive role which evidenced by increased expression of lung TGF-β, CTLA-4, PD-L1, FOXP3 genes and decreased expression of lung IL-12 gene compared with normal control group. BP group also showed decreased CD83 + cells, CD8 + cells and increased number of CD166 + cells., Conclusion: Our findings indicated that BP has immunosuppressive role in lung cancer besides increasing the percentage of cancer stem like cells., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Polycyclic aromatic hydrocarbons (PAHs) are widely spread persistent environmental toxicants. Its typical representative benzo[a]pyrene (BaP) is a human carcinogen. BaP can pass through the placental barrier and is finally metabolized into benzo[a]pyren-7, 8-dihydrodiol-9, 10-epoxide (BPDE). BPDE can form DNA adducts, which directly affect the female reproductive health. Based on the special physiological functions of trophoblast cells and its important effect on normal pregnancy, this chapter describes the toxicity and molecular mechanism of BPDE-induced dysfunctions of trophoblast cells. By affecting the invasion, migration, apoptosis, proliferation, inflammation, and hormone secretion of trophoblast cells, BPDE causes diseases such as choriocarcinoma, intrauterine growth restriction, eclampsia, and abortion. In the end, it is expected to provide a scientific basis and prevention approach for women's reproductive health and decision-making basis for the formulation of environmental health standards.

&lt;b&gt;Background and Objective:&lt;/b&gt; &lt;i&gt;Moringa peregrina&lt;/i&gt; (family Moringaceae) is a common flowering plant found in the Arabian Peninsula, Horn of Africa and Southern Sinai, Egypt. The purpose of this study was to investigate the protective activity of MP-SeNPs against BaP-induced mammal tissue injury in rats. &lt;b&gt;Materials and Methods:&lt;/b&gt; MP-SeNPs were prepared and characterized in terms of particle size and zeta potential. Furthermore, the IC&lt;sub&gt;50&lt;/sub&gt; of MP-SeNPs against the Mcf7 breast carcinoma cell line and LD&lt;sub&gt;50&lt;/sub&gt; was evaluated. Adult albino rats weighing approximately 187±10 g was used to assess the lung protective activity of MP-SeNPs (28.7 and 71.75 mg kg&lt;sup&gt;1&lt;/sup&gt; b.wt.) against BaP-induced mammal tissue injury in rats. &lt;b&gt;Results:&lt;/b&gt; The mean particle size of MP-SeNPs was 134.69±8.24 nm with negative zeta potential of +26.04 with the observed shapes of nano particle was spherical. Also, IC&lt;sub&gt;50&lt;/sub&gt; of MP-SeNPs against Mcf7 breast carcinoma cell line = 89.57 μg mL&lt;sup&gt;1&lt;/sup&gt; and LD&lt;sub&gt;50&lt;/sub&gt; equals and 1435 mg kg&lt;sup&gt;1&lt;/sup&gt; b.wt., respectively. The daily oral administration of MP-SeNPs at concentrations of 28.7 and 71.75 mg kg&lt;sup&gt;1&lt;/sup&gt; b.wt. for 30 days to rats treated with BaP (20 mg kg&lt;sup&gt;1&lt;/sup&gt; b.wt.) resulted in a significant improvement of IL-2, IL-6 and IL-10. Oral administration of MP-SeNPs, on the other hand, increased the levels of SOD, GPx, TNF-α, iNOs and GSH as well as decreased the level of MDA in mammal tissue of BaP-treated rats. Furthermore, MP-SeNPs almost normalized these effects in mammal tissue histoarchitecture and MRI examination. &lt;b&gt;Conclusion:&lt;/b&gt; The biochemical, histological and MRI findings incurrent study demonstrated that MP-SeNPs have protective activity against BaP-induced mammal tissue injury in rats.

Benzo[a]pyrene (B[a]P), a potent carcinogen, has been proved that it can induce apoptosis via activation of the aryl hydrocarbon receptor (AhR) pathway. The metabolite of tryptophan 6-formylindolo[3,2-b]carbazole (FICZ), an endogenous activator of AhR, plays bifunctional roles in cell growth and apoptosis. However, whether and how FICZ can reduce the toxicity of B[a]P and the mechanism underlying this remain unclear. In this study, FICZ interfered with the toxicity of B[a]P in mouse hepatocarcinoma cell line Hepa1-6. The results of the MTT assay indicated that FICZ and B[a]P made opposite effects on cell proliferation. The scratch-wound healing assay showed that B[a]P (1 µM for 24 hr) exposure triggered cell migration and that was inhibited by FICZ (10 nM). In addition, FICZ ameliorated B[a]P-induced apoptosis by inhibiting reactive oxygen species generation and caspase-3 activation, as well as increasing reduced glutathione level in mitochondria. Furthermore, gene expression analyses indicated that FICZ competed with B[a]P, which reduced the transcriptional activation of the cyp1a1 and cyp1b1 genes, as well as Bcl2 and P53. Accordingly, the interaction between FICZ and B[a]P in the AhR pathway inhibited apoptosis in a mitochondrial-dependent manner, suggesting that endogenous compound may reduce the toxicity of exogenous pollutant in vivo and providing an available way to improve health condition related to the hepatic metabolic disorder., (© 2020 International Federation for Cell Biology.)

The biotransformation ability of the organism is the result of organ-specific responses. This paper presents a molecular and biochemical approach to elucidate the biotransformation mechanisms in different organs of Prochilodus lineatus induced at 6, 24, and 96 h after a benzo[a]pyrene (B[a]P) injection. The induction in cyp1a transcription showed an organ-specific intensity at every tested time time. The EROD (ethoxyresorufin-O-deethylase) activity increased rapidly (6 h) in the liver and the kidney; the gills and the brain showed an increase at 24 h; and the gills demonstrated the highest activity among all the organs tested. There was no increase in glutathione S-transferase (GST) activity or lipoperoxidation. The decreased hepatic glutathione content (GSH) may be due to its role as an antioxidant. B[a]P was detected in the bile, confirming the xenobiotic efflux from the metabolizing organs. The gills, liver, brain, and kidney of P. lineatus presented an integrated mechanism to deal with the xenobiotic biotransformation., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Cytochrome P4501A (CYP1A) has been used as a specific biomarker for monitoring water contamination such as PAHs, PCBs and dioxins. In the present study, the cyp1a gene of Gambusia affinis was cloned and sequenced and their expressions under PAHs exposure were characterized. The newly identified cyp1a encodes a protein with 521 amino acids that shared 96-80% identity with other Cyprinodontiformes fishes. RT-PCR analysis revealed that the basal mRNA level of cyp1a was highly expressed in liver and intestine. The expression level of cyp1a was significantly induced by exposure to 100 μg/L 3, 4-Benzopyrene (BaP) for 5 days in the muscle, testis, brain, liver and intestine of adult male fish. Except in the testis, the induced mRNA level of cyp1a ultimately decreased after prolonging the exposure time to 25 days. As for testis, the induced mRNA level of cyp1a was maintained at a high level during the entire exposure time under 100 μg/L BaP exposure. Furthermore, the expression of cyp1a increased with exposure time under a relatively low exposure concentrations 1 μg/L. Regarding the effects of other PAHs, D(a,h)A, BbF, and BaA showed a statistically significant effect of induction on mRNA level of cyp1a in the muscle, testis, brain, liver and intestine.

Environmental carcinogen benzo(a)pyrene (BaP) is a representative compound of polycyclic aromatic hydrocarbons (PAHs). BaP is strongly associated with prostate carcinogenesis. However, the molecular mechanism of BaP in development of prostate carcinoma remains largely unknown. The aim of this study was to investigate the effect and mechanism of BaP on the development in prostate cancer. PC-3 cells were exposed to different concentrations of BaP for 24, 48, 72 h, respectively. We analyzed the effect of BaP on PC-3 cell viability, cell cycle, DNA strand breaks, mutagenic activity, and migration. The expression of associated regulatory genes and the effect of JAK2/STAT3 signaling were also measured to explore the relationships among BaP metabolism, the JAK2/STAT3 pathway and proliferative activity in PC-3 cells. We observed significant effects on proliferation, DNA strand breaks and mutagenic activity after BaP exposure in PC-3 cells, and inhibitors of CYP1 and the AhR transcription factor α -naphthoflavone (ANF) and CH223191 treatment clearly reduced both cell survival and mutagenesis associated with BaP exposure. Reduction in G0-G1 phase population and elevation in S phase were observed after BaP exposure. Migratory cells for PC-3 were significantly increased. The results were further confirmed by the expression of mRNA levels in the significant increments of Snail, Slug, MMP-9, CYP1A1, CYP1B1, CycilnD1, CDK4 and significant reduction of E-cadherin. Significant enhancements were found in the expression of JAK2, STAT3 after BaP treatment. Additionally, activator IL-6 significantly enhanced the effect of BaP on cell survival, mutagenic activity, Cyclin D1, CDK4, Snail, and JAK2/STAT3 expression in PC-3 cells. Significant reductions in cell survival, mutagenic activity, Cyclin D1, CDK4, Snail, and JAK2/STAT3 expression were found after inhibitor AG490, ANF and CHJ223191 treatment. These findings reveal that BaP enhances the proliferative and mutagenic activity via JAK2-STAT3 pathway in PC-3 cells, and provide the additional evidence to understand the crucial role of BaP in prostate cancer carcinogenesis., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Nonalcoholic fatty liver disease (NAFLD) is a chronic hepatic disease associated with the excessive accumulation of lipids in the liver. Premenopausal women are protected from the liver metabolic complications of obesity compared with body mass index (BMI)-matched men. This protection may be related to estrogen's ability to limit liver fat accumulation. Aryl hydrocarbon receptor (AhR), a novel regulator of NAFLD, may be an important target for regulating estrogen homeostasis. In present study, we used benzo[a]pyrene (BaP), a classic and potent ligand of AhR, to activate AhR pathway causes overexpression of the estrogen-metabolizing enzyme cytochrome P450 1A1 (CYP1A1) and affects the expression of important genes involved in hepatic lipid regulation. BaP induces CYP1A1 expression through AhR signaling and inhibits the protective effect of 17β-estradiol (E2) on hepatic steatosis, characterized by triglyceride accumulation, and markers of liver damage are significantly elevated. The expression of adipogenic genes involved in the hepatic lipid metabolism of sterol regulatory element-binding protein-1c (SREBP-1c) was increased compared with that in the control group. Furthermore, the mRNA and protein levels of peroxisome proliferator-activated receptor alpha (PPARα), which is involved in fatty acid oxidation, were significantly reduced. Taken together, our results revealed that the steatotic effect of AhR is likely due to overexpression of the E2 metabolic enzyme CYP1A1, which affects the estrogen signaling pathway, leading to the suppression of fatty acid oxidation, inhibition of the hepatic export of triglycerides, and an increase in peripheral fat mobilization. The results from this study may help establish AhR as a novel therapeutic and preventive target for fatty liver disease., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: To study whether minimal doses of arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and lipoxin A4 (LXA4) and brain-derived neurotrophic factor (BDNF), when used in combination can protect RIN5F cells from chemical-induced cytotoxicity. As a corollary, to know whether plasma BDNF and LXA4 are altered in STZ-induced type 2 DM animals., Materials and Methods: RIN5F cells, alloxan (AL), streptozotocin (STZ), doxorubicin (DB), and benzo(a)pyrene (BP) were used in this study. Chemical-induced apoptosis and changes in antioxidants, lipid peroxides and nitric oxide (NO) and LXA4 and BDNF levels in RIN5F cells were studied. Alterations in plasma concentrations of BDNF and LXA4 in STZ-induced type 2 diabetes animals was estimated., Results: BDNF, LXA4 and AA, EPA and DHA protected (P < 0.001 and P < 0.01 respectively) against AL/STZ/DB/BP-induced toxicity to RIN5F cells in vitro. AL/ STZ/DB/BP inhibited BDNF and LXA4 production by RIN5F cells and were restored to normal by AA, EPA and DHA. Sub-optimal doses of BDNF, LXA4, AA and EPA when used in combination protected against cytotoxic action of AL/STZ/DB/BP on RIN5F cells in vitro by restoring LXA4/BDNF levels and altered antioxidant/lipid peroxides/NO levels (P < 0.01) to normal. STZ (65 mg/kg)-induced type 2 diabetes mellitus animals showed reduced plasma BDNF and LXA4 levels (P < 0.001)., Discussion: AL/STZ/DB/BP-induced cytotoxicity to RIN5F cells in vitro can be prevented by BDNF, LXA4 and AA. AL/STZ/DB/BP are cytotoxic, possibly, by suppressing the production of LXA4 and BDNF in RIN5F cells. STZ-induced type 2 DM animals have decreased plasma levels of LXA4 and BDNF., Conclusion: The results of the present study suggest that BDNF, LXA4, EPA, DHA, AA, GLA and BDNF protect pancreatic β cells from the cytotoxic action of various chemicals and prevent development of diabetes mellitus. LXA4 seems to be the mediator of these cytoprotective actions of BDNF and PUFAs suggesting a close interaction exists among these molecules (BDNF, PUFAs and LXA4). Hence, methods developed to deliver a combination of PUFAs (especially AA), LXA4 and BDNF may prevent development of diabetes mellitus (both type 1 and type 2).

The main purpose of the current study is to reveal the anticancer action of limonin against benzo(a)pyrene [B(a)P]-treated lung carcinogenesis in Swiss albino mice and A549 lung cancer cells. B(a)P was orally supplemented (50 mg/kg body weight) twice a week for four weeks induction of lung cancer in mice. The lung weight, body weight, incidence of tumor, lipid peroxidation, carcinoembryonic antigen (CEA), enzymatic and nonenzymatic antioxidants (superoxide dismutase, GPx, glutathione, glutathione reductase, catalase, and glutathione S-transferase), serum marker enzymes (aryl hydroxylase, lactate dehydrogenase, 5'-nucleotidases, and γ-glutamyl transpeptidase), and inflammatory mediators (interleukin-1β, interleukin-6, and tumor necrosis factor-α) were estimated. Moreover, a histopathological study of lung tissues was supported by the biochemical analysis. Furthermore, the anticancer activity of limonin on A549 cells was measured by cell viability, production of reactive oxygen species (ROS), apoptotic morphological changes by AO/EtBr staining. Additionally, the status of apoptosis protein (caspase-9 and -3) expressions was analyzed by the colorimetric analysis. B(a)P-induced mice showed increased lipid peroxidation, CEA, serum marker enzymes and inflammatory cytokines levels with simultaneously decreased in the nonenzymatic and enzymatic antioxidants levels. Limonin supplements significantly reverted back to all these changes in this manner, showing the efficiency of anticancer effect. Furthermore, our in vitro study also supported the anticancer effect of the treatment of limonin-enhanced apoptosis by loss of cell viability, improved ROS production, apoptotic morphological changes, and apoptosis protein expression were analyzed. Overall, these results suggest the anticancer potential of limonin against B(a)P-induced lung cancer in Swiss albino mice and A549 lung cancer cells., (© 2019 Wiley Periodicals, Inc.)

Over-activation of microglia disrupts the physiological homeostasis of the brain, and induces inflammatory response and other processes which are implicated in neurodegenerative diseases. Therefore, theoretically, suppression of neuroinflammation would slow the progression of neurodegenerative disease. In this study, we investigated the possible protective effects of Ferulic acid (FA) against benzo(a)pyrene (BaP)-induced microglial activation using BV2 cells as the model system. Exposure of BV2 cells to BaP (10 μM) significantly increased DNA damage and the production of pro-inflammatory mediators, including nitric oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), reactive oxygen species (ROS), malondialdehyde (MDA), and cytokines (interleukins-1β and -6). On the other hand, when BaP-treated BV2 cells were further incubated with FA (10, 20, 40, or 80 mg/mL) for another 24 h, a significant reduction in BaP-induced DNA damage and the release of multiple pro-inflammatory and cytotoxic factors (including interleukin-1β, interleukin-6, NO, and ROS) was observed in a dose-dependent manner. Further study revealed that the microglial NOD-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) signaling pathway was involved in the protective effect of FA. Taken together, these results suggested that FA suppressed BaP-induced toxicity in microglia, and thus may exert neuroprotective effects by inhibiting microglia-mediated pro-inflammatory response., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Gonadotropin-releasing hormones (GnRH) regulate gonadal growth of teleosts. Benzo(a)pyrene (BaP) functions as a reproductive endocrine disruptor. Furthermore, endocrine regulation on brood pouch growth of Syngnathidaes is elusive. To better understand the role of GnRH in brood pouch growth and effects of BaP on reproductive endocrine in lined seahorse (Hippocampus erectus), gnrh2 and gnrh3 genes were identified. Results showed that lined seahorse GnRH2 and GnRH3 precursors included the conservative tripartite structure and their transcripts highly expressed in brain as other teleosts. Expression profiles of gnrh2 and gnrh3 transcripts were detected during brood pouch growth. Results indicated that brain gnrh2 transcripts remarkably increased at the middle-stage and late-stage of brood pouch growth, while brain gnrh3 transcripts significantly raised at the early-stage and middle-stage. These suggested that GnRH2 and GnRH3 regulated brood pouch growth at different stages. Short-term BaP exposure in lined seahorse was performed. Transcripts of gnrh2 and gnrh3 remarkably increased in females and males exposed to BaP. Besides, plasma 17-beta estradiol (E2) levels presented a reduced trend during female fish exposed to BaP. This revealed that BaP functioned as anti-estrogenic effects and it may result in high expression of gnrh mRNA. However, plasma 11-ketone testosterone (11-KT) levels showed an increased trend during male fish exposed to BaP. Taken together, these indicated interesting results of BaP on reproduction in each sex of seahorse. These observations contribute to provide novel information of regulation on brood pouch growth and effects of BaP on reproductive endocrine in Syngnathidaes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Here, we suggested that the epigenetic mechanism of benzo(a)pyrene (BP) action might be based on the aryl hydrocarbon receptor (AhR)-mediated transcription of the target genes, including miRNAs, that have the dioxin response element (DRE) in their promoters. The effect of BP on the expression of the oncogenic miR-483-3p, its host gene IGF2, and target gene IGF1 in primary hepatocytes and in the liver of Wistar female rats was investigated. The activation of AhR was confirmed using selective AhR inhibitor CH-223191 and by evaluating expression of the target CYP1A1 gene. The lack of coordination between the expression of miR-483-3p and its host gene IGF2 was revealed, which may be due to the presence of the binding site for the estrogen receptor alpha (ERα), which is a negative expression regulator. Our results confirm the existence of the AhR-mediated pathway in the regulation of expression of miR-483-3p, IGF1, and IGF2 under BP exposure, which is of considerable interest for understanding the epigenetic mechanisms of the carcinogenic effect of BP.

Aryl hydrocarbon receptor (AhR) is a highly conserved ligand-activated transcription factor with high affinity to aromatic planar compounds, such as β-naphthoflavone (BNF), benzo[a]pyrene (BaP) or dioxin (TCDD). After binding the ligand, AhR triggers induction of the expression of phase I and phase II drug-metabolizing genes, together with numerous other genes that are not directly involved in the metabolism of xenobiotics. Several studies have shown that AhR plays a role in tumor initiation, promotion and progression, but the molecular mechanisms involved in these processes are not fully understood. A previous study from our laboratory indicated that the SERPINB2 gene is presumably regulated by AhR. To prove that such induction is really AhR-dependent, in the present study we knocked down the expression of AhR by stable transfection of a laryngeal squamous cell carcinoma cell line (UT-SCC-34) with shRNA, resulting in 92% reduction of BNF-induced expression of SERPINB2. However, in silico analysis did not reveal AhR-dependent responsive elements in the promoter of the SERPINB2 gene. Therefore, to address this problem, we have used cycloheximide, an inhibitor of translation, and our results clearly indicate that an additional, newly synthesized protein is involved in AhR-dependent induction of SERPINB2 expression by BNF. So, to exclude that AhR binds to the putative xenobiotic-responsive elements (XREs) localized upstream of the SERPINB2 gene, we performed chromatin immunoprecipitation assays. As expected, we found no direct binding of AhR to its responsive elements in the vicinity of the SERPINB2 gene, further demonstrating the indirect SERPINB2 induction by AhR. However, the further analysis demonstrated that the expression of the enhancer RNA encoded by the region of DNA 20 kbp upstream from the SERPINB2 gene was AhR-dependent. Although AhR-mediated SERPINB2 induction clearly requires the synthesis of an additional protein, the kinetics of SERPINB2 induction is as fast as the kinetics of CYP1A1 and CYP1B1 induction (both genes directly regulated by AhR). Therefore, given previous studies regarding the induction of SERPINB2 expression by bacterial lipopolysaccharides (LPS), we think that, similarly, the interaction with pause-release proteins may be responsible for AhR-dependent regulation of SERPINB2 expression., (Copyright © 2019. Published by Elsevier B.V.)

Background: Benzo[a]pyrene (BaP) is an environmental pollutant known to cause teratogenesis. However, the mechanism underlying this teratogenic effect is not fully understood. Recently, the alteration of DNA methylation of imprinting genes has emerged as a specific epigenetic mechanism linking the impact of environmental pollutants on embryonic development to paternal exposures. The aim of this study was to investigate the transgenerational effects of paternal BaP exposure on the imprinting genes in mouse sperm DNA., Methods: Male C57BL/6J mice received BaP (1.0 or 2.5 mg/kg) or olive oil twice a week for 12 weeks. The methylation status of 6 imprinting genes (H19, Meg3, Peg1, Peg3, Igf2 and Snrpn) was examined by bisulfite pyrosequencing of the sperm DNA of BaP-exposed F0 generation and their offspring., Results: BaP exposure reduced the methylation levels in the imprinting genes H19 and Meg3 and increased the methylation levels of Peg1 and Peg3; however, no significant differences was observed for the methylation levels of Igf2 or Snrpn in the sperm DNA. Furthermore, BaP-exposed male mice were mated with unexposed female mice to generate F1-2 generations. The methylation levels of the 6 genes in the sperm DNA from F1-2 offspring showed a similar pattern as that of the F0 male. The effects were attenuated in F1-2 generations., Conclusions: Paternal BaP exposure altered the methylation levels of imprinting genes, implicating that imprinting genes are susceptible to environmental toxicants. Furthermore, a similar alteration was observed in the F1-2 generations although the attenuated in methylation in F2 generation, revealing a potential transgenerational effect., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Benzo(a)pyrene (BaP) is an endocrine-disrupting pollutant present in various aspects of daily life, and studies have demonstrated that BaP exerts reproductive toxicity. We previously showed that BaP damages endometrial morphology and decreases the number of implantation sites in early pregnant mice, but the mechanisms underlying these effects remain unclear. The endometrial function is crucial for implantation, which is associated with endometrial cell apoptosis. In this study, we focused on the effect of BaP on endometrial cell apoptosis and the role of WNT signaling during this process. Pregnant mice were gavaged with corn oil (control group) or 0.2 mg·kg -1 ·day -1 BaP (treatment group) from Days 1 to 6 of pregnancy. BaP impaired endometrial function by decreasing the expression of HOXA10 and BMP2, two markers of receptivity and decidualization. WNT5A and β-catenin were activated in the BaP group. BaP affected the expression of apoptosis-related proteins and inhibited the apoptosis of endometrial stromal cells. In vitro, human endometrial stromal cells (HESCs) were treated with different concentrations of BaP (dimethyl sulfoxide (DMSO); 5, 10 µM). WNT5A and β-catenin were also upregulated in the BaP treatment group. HESC apoptosis was restrained by BaP. Inhibiting WNT5A by SFRP5 partially restored the effect of BaP on apoptosis. In summary, these results suggested that BaP exposure during early pregnancy activates WNT5A/β-catenin signaling pathway, which inhibits the endometrial cell apoptosis and potentially destroys endometrial function., (© 2018 Wiley Periodicals, Inc.)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants generated from combustion of carbon-based matter. Upon ingestion, these molecules can be bioactivated by cytochrome P450 monooxygenases to oxidized toxic metabolites. Some of these metabolites are potent carcinogens that can form irreversible adducts with DNA and other biological macromolecules. Conjugative enzymes, such as glutathione S-transferases or UDP-glucuronosyltransferases, are responsible for the detoxification and/or facilitate the elimination of these carcinogens. While responses to PAH exposures have been extensively studied for the bioactivating cytochrome P450 enzymes, much less is known regarding the response of glutathione S-transferases in mammalian systems. In this study, we investigated the expression and activity responses of murine hepatic glutathione S-transferases to benzo[ a]pyrene exposure using global proteomics and activity-based protein profiling for chemoproteomics, respectively. Using this approach, we identified several enzymes exhibiting increased activity including GSTA2, M1, M2, M4, M6, and P1. The activity of one GST enzyme, GSTA4, was found to be downregulated with increasing B[ a]P dose. Activity responses of several of these enzymes were identified as being expression-independent when comparing global and activity-based data sets, possibly alluding to as of yet unknown regulatory post-translational mechanisms.

Benzo [a] pyrene (BaP), the most ubiquitous polycyclic aromatic hydrocarbons (PAHs) found in sludge, can impact the composting processes of sewage sludge as well as the quality of compost produced. In the present study, we investigated the effects of BaP at various concentrations on physicochemical characteristics, heavy metal passivation, and microbial community during the composting processes. The removal efficiency of BaP at 5 and 20 mg kg -1 after composting was 51.1% and 74.2%, respectively. In comparison with the control, the content of residual Cu, Pb, Cr and Ni in 5 mg kg -1 BaP contained system declined dramatically on the second day of composting, while such content in 20 mg kg -1 BaP system significantly decreased on the 8th day. Regardless of the presence of BaP in the sludge, composting process had a positive passivation effect on Cu, Pb, Cr and Ni. A stronger inhibitory effect of BaP at higher concentration was observed on microorganism, which reduced microbial abundance and species in the composting, and influenced microbial diversity. Besides, microbial communities in BaP-containing composting would improve the transformation of silicates and minerals, increase the concentration of humus and extend the passivation time of heavy metals. As these results verified, composting process could remove BaP from the sludge effectively, and BaP had a significant impact on heavy metal passivation and abundance and composition of microbial community during the composting process., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background/aim: Benzo[a]pyrene (BaP), an environmental pollutant produced by combustion processes, induces expression of cytochrome P450 (CYP) 1A1 via the activation of aryl hydrocarbon receptor (AHR). Induced CYP1A1 is involved in BaP metabolism, resulting in either detoxification or metabolic activation in a context-dependent manner. The effect of diallyl trisulfide (DATS), a garlic-derived organosulfur compound, on BaP metabolism has not been investigated., Materials and Methods: The combined effect of DATS and BaP on BaP metabolism in hepatocyte-derived HepG2 cells was examined., Results: DATS enhanced BaP-induced CYP1A1 and CYP1B1 mRNA expression, BaP hydroxylation and BaP-DNA adduct formation. Combined treatment of BaP and DATS also increased reactive oxygen species levels. DATS enhanced BaP-induced AHR recruitment and histone H3 acetylation on the CYP1A1 promoter., Conclusion: DATS combined treatment enhances BaP metabolic activation through an AHR-modulating mechanism., (Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Anti-genotoxic or anti-mutagenic activity has been described for a number of Gram-positive probiotic bacterial species. Here we present evidence that Gram-negative Escherichia coli Nissle 1917 (EcN) also displays anti-genotoxic/anti-mutagenic activity, as assessed in vitro by the Comet Assay and the Ames Test, respectively. This activity was demonstrated by use of the mutagens 4-nitroquinoline-1-oxide (NQO), hydrogen peroxide (H 2 O 2 ) and benzo(a) pyrene (B[a]P). For both assays and all three test agents the anti-genotoxic/anti-mutagenic activity of EcN was shown to be concentration dependent. By the use of extracts of bacteria that were inactivated by various procedures (heat treatment, ultrasound sonication or ultraviolet light irradiation), mechanistic explanations could be put forward. The proposed mechanisms were enforced by treating the bacterial material with proteinase K prior to testing. The mutagen H 2 O 2 is most likely inactivated by enzymic activity, with catalase a likely candidate, while several explanations can be put forward for inactivation of B[a]P. NQO is most likely inactivated by metabolising enzymes, since the formation of the metabolite 4-aminoquinoline could be demonstrated. In conclusion, the in vitro results presented here make a strong case for antimutagenic properties of EcN.

Previous studies have shown the adversely neurodevelopmental effects of exposure to benzo(a)pyrene (BaP) at early life stage. However, it is unclear the effects of lactational exposure to environmentally relevant BaP on anxiety-like behavior and the molecular mechanisms related. In this study, lactational exposure to 1 and 10 μg/kg bw BaP from postnatal day 3-21 caused anxiety-like behavior and alterations of the expressions of the neurodevelopment and anxiety-related genes in adolescence male mice using O cycle maze. Moreover, BaP exposure increased the expression level of glial fibrillary acidic protein, a typical marker of astrocytes, in hippocampus of male offspring. The release of pro-inflammatory cytokines interleukin 6 and tumor necrosis factor α was also elevated in BaP-treated offspring. Further, lactational exposure to BaP decreased the level of glutathione and the expressions of antioxidant genes (Thioredoxin 1 and Glutaredoxin 2) in male offspring. Our study demonstrated that environmentally relevant BaP lactational exposure caused anxiety-like behavior in male offspring involved in astrocytic activation, neuroinflammation, and antioxidant capability dysfunction., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Glycine N-methyltransferase (GNMT) protein is highly expressed in certain tissues, such as liver, pancreas, and prostate. GNMT serves multiple roles which include a methyl group transfer enzyme and a liver tumor suppressor. Benzo(a)pyrene (BaP), a family member of polycyclic aromatic hydrocarbon (PAH), is a known environmental carcinogen found in coal tar, tobacco smoke, barbecued food and incomplete combustion of auto fuel. BaP recruits cytochrome P450 to transform itself into benzo(a)pyrene-7,8-diol-9,10-epoxide (B(a)PDE), which covalently interacts with DNA causing tumorigenesis. BaP can be detoxified through GNMT and induces GNMT translocation into the cellular nucleus. GNMT translocation is accompanied by phosphorylation, but the role of phosphorylation in GNMT remains to be explored. Using liquid chromatography coupled with tandem mass spectrometry, this study identified serine 9 of GNMT as the phosphorylation site upon BaP treatment. When serine 9 was mutated and lost the capability to be phosphorylated, the occurrence of BaP-induced GNMT nuclear translocation was dramatically decreased. Also, this mutant from of GNMT lost the ability of phosphorylation and increased cytochrome P450 1A1 (Cyp1a) expression upon BaP treatment. In addition, protein kinase C (PKC) and c-Jun NH2-terminal kinase (JNK) may be required for such phosphorylation. Further characterization of phosphorylated GNMT for its link to BaP may bring new insights into chemical detoxification., (Copyright © 2019. Published by Elsevier Taiwan LLC.)

Cadmium (Cd) and benzo [a]pyrene (BaP) often co-occur in the environment, and the critical body residue of organisms is used as an indicator of the toxic effects of contaminants. However, little is known about their distributions and toxicities when pollution of Cd and BaP are combined. Semi-static solution culture experiment was used to study the impacts of BaP on the subcellular distribution of the toxic metal Cd in the earthworm Eisenia fetida. We explored the mechanisms by which this organism responds to combined exposure to these pollutants by measuring the protein content of each of three subcellular fractions, as well as acetylcholinesterase (AChE) and glutathione S-transferase (GST) activities. The subcellular partitioning of Cd was heterogeneous and Cd mainly accumulated in the cytosolic fraction (Fraction C), which was previously reported to be involved in metal immobilization. In Fraction C, Cd accumulation was correlated with the external concentration to which the earthworm had been exposed; however, in the presence of BaP, Cd accumulation was inhibited and plateaued at high external Cd concentrations. A principal component analysis revealed that this decreased Cd accumulation might be caused by increases in GST activity, which likely increased the excretion of Cd. BaP was also found to stimulate protein biosynthesis and upregulate AChE and GST activities in the debris fraction (Fraction E), indicating other potential detoxification mechanisms in this fraction. Granule fraction (Fraction D) had a lower protein content, AChE and GST activities than the other subcellular fractions, supporting previous findings that Fraction D is largely inert., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Amphioxus, a cephalochordate found in sand habitats in shallow in-shore seawaters, has been widely used as a model in comparative immunology of chordates. However, the role of microRNAs (miRNAs) in amphioxus under abiotic stress, particularly xenobiotics with strong toxicity, remains largely unknown. Here, a widespread marine contaminant, benzo(a)pyrene (BaP) is used to evaluate its toxic effects on miRNA expression of amphioxus. Six small RNA libraries were sequenced from Branchiostoma belcheri. A total of 144 known and 157 novel miRNAs were identified using deep sequencing and bioinformatics approaches. A total of 58 differentially expressed miRNAs (DEMs) were screened, including 25 up- and 33 down-regulated DEMs under BaP stress. Target genes possibly regulated by DEMs were predicted, and their functional enrichment analyses were performed. Targets of DEMs are primarily involved in xenobiotic and cellular homeostasis, catabolic and transport process. They could be largely linked to nine immune- and toxin detoxification-related pathways, including metabolism of xenobiotics by cytochrome P450, drug metabolism-other enzymes, and drug metabolism-cytochrome P450, etc. Furthermore, quantitative real-time PCR (qRT-PCR) analysis for 12 key BaP-responsive DEMs validates the accuracy of deep sequencing. Experiments were then conducted to investigate their expression responses to BaP stress at different time intervals in detail to further determine their expression dynamic in responses of B. belcheri towards BaP exposure. This study, to the best of our knowledge, investigates the regulatory roles of miRNAs in the toxicological response of amphioxus for the first time, providing valuable information for the protection of lone existing cephalochordate amphioxus., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

This study aimed to evaluate the effect of lignin-derived polyphenolic composition BP-C3 on the efficacy and hematological toxicity of cyclophosphamide (CPA). Male and female Swiss-H derived mice bearing benzo[a]pyrene-induced soft tissue sarcomas were treated with CPA 300 mg/kg, BP-C3 75 mg/kg, or a combination. Tumor growth inhibition in male mice treated with CPA, BP-C3, or a combination of CPA and BP-C3 was significant and corresponded to 78%, 45%, and 82%, respectively, on day 21 after CPA administration on day 0. In female mice, tumor growth inhibition was 58%, -11%, and 35% when treated with CPA, BP-C3, or a combination of CPA and BP-C3, respectively. CPA administration resulted in significant hematological toxicity evidenced by a decreased white blood cell count on day 4 (2.43 ± 1.77 × 10 9 /L in male mice and 1.19 ± 0.71 × 10 9 /L in female mice) and anemia development on day 7 (6.55 ± 1.74 × 10 12 /L in male mice and 5.89 ± 2.24 × 10 12 /L in female mice). The red blood cell count measured on day 7 in animals treated with the combination of BP-C3 and CPA constituted 7.12 ± 1.17 × 10 12 /L and 7.36 ± 2.07 × 10 12 /L for male and female mice, respectively. The results of our study demonstrate the antitumor activity of BP-C3 in male mice bearing soft tissue sarcomas. Neither the antitumor activity nor the hematological toxicity of CPA were significantly influenced by BP-C3. A less pronounced effect of CPA on RBC count is demonstrated when this agent is given jointly with BP-C3.

Our understanding of dose-related effects of polymeric black tea polyphenols (PBPs), the most abundant polyphenols in black tea, is limited. In the present study, the effect of various doses of black tea (0.75, 1.5, and 3%)-derived PBP-rich extract on biochemical parameters and lung carcinogenicity in A/J mice was investigated. Pretreatment with PBPs showed the dose-related decrease in B(a)P-induced expression and activity of CYP1A1 in the liver while CYP1A2 expression and activity in the lung. Dose-dependent significant increase in PBP-mediated over-expression and activity of GSTs (alpha in the liver while pi in the lung) were observed in polyphenol-treated groups. Significant dose-related decrease in number and intensity of BPDE-DNA adducts were observed in liver and lung. Black tea (1.5%, 3%)-derived PBPs showed dose-mediated decrease in lung tumor incidence and multiplicity which was further correlated with different molecular markers like cell proliferation and apoptosis in B(a)P and NNK model. In conclusion, dose-dependent chemopreventive effects of PBPs, both anti-initiating (induction of phase II and inhibition of carcinogen-induced phase-I enzymes leading to decrease in BPDE-DNA adducts) and anti-promoting (decreased cell proliferation and increased apoptosis lowering incidence and/or multiplicity of lung lesions), were observed in A/J mice without significant toxicity.

Reduction of the number of animals used in in vivo genotoxicity tests is encouraged. For this purpose, we conducted integrated toxicity tests combining gene mutation assays with multiple-organ micronucleus (MN) tests (peripheral blood, bone marrow, liver, and colon) in F344 gpt delta transgenic (Tg) rats. Seven-week-old male F344 gpt delta rats were orally administered 62.5 or 125 mg/kg/day benzo[a]pyrene (B[a]P) for 28 days. One day after the final day of treatment (day 29) and three days after the final treatment (day 31), bone marrow, liver, and colon samples were collected, and mutation assays and MN tests were performed. The gpt mutant frequency (MF) significantly increased in bone marrow, liver and colon but MN induction was only significant in bone marrow but not in liver and colon. Similarly MN induction was only observed in bone marrow in non-Tg F344 rats. In peripheral blood obtained on day 4, 15, 29, 31, a time-dependent increase was observed in reticulocyte MN frequency during the treatment. Thus, our integrated method successfully detected both gene mutations and MN induction caused by B[a]P. In addition, no significant differences were observed between sampling times (day 29 versus 31), suggesting that sampling on day 29 is also valid to evaluate gene mutations. On the other hand, MN results in bone marrow and peripheral blood were different depending on the sampling day. An appropriate sampling day should be designated according to which assays are integrated. We confirmed that integration of the MN test with a gene mutation assay using F344 gpt delta Tg rats is useful to evaluate different endpoints related to genotoxicity using the same animals and to reduce animal use., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Polycyclic aromatic hydrocarbons such as benzo(a)pyrene (BaP) are environmental contaminants known to be immunosuppressive. Most effects of BaP towards immune cells are thought to be mediated through activation of the aryl hydrocarbon receptor (AhR). The AhR is a ligand-activated transcription factor, which plays a critical modulatory role in various cells during immune response. Macrophages are key players in innate immunity against intracellular bacteria and are discussed to be a target of AhR-mediated immune regulation. However, so far there is only incomplete knowledge about the effects of BaP on activated macrophages and whether these effects are AhR-dependent in each case. Using murine bone marrow-derived macrophages (BMMs) stimulated with heat-killed salmonellae as a source of different pathogen-associated molecular patterns (PAMPs) for stimulation of different pattern recognition receptors (PRRs) as an in-vitro model, we studied the immunomodulatory effects of low-dose BaP exposure. PRR-activated BMMs produced nitric oxide (NO) and a spectrum of proinflammatory cytokines, i.e. tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-12 but also the anti-inflammatory cytokine IL-10. While BaP exposure suppressed the production of proinflammatory cytokines, the secretion of IL-10 was augmented. Moreover, BaP exposure increased the expression of major histocompatibility complex class II (MHC-II), CD14, Fcγ receptor I (FcγRI/CD64), or CD86, enhanced NO production and phagocytosis what may be beneficial for phagocytosis and killing of microbial pathogens. Of note, without PRR activation low-dose BaP exposure has little influence on the macrophage phenotype. BMMs from AhR-deficient (Ahr -/- ) mice were widely refractory to BaP-induced modulation of cytokine production, surface marker expression, and functional properties in response to PAMPs stimulation, indicating that these effects are dependent on AhR. In summary, these data suggest that induction of AhR-mediated signalling pathways by BaP may attenuate the proinflammatory phenotype of PRR-activated BMMs, while activating IL-10-mediated anti-inflammatory properties but also enhancing uptake and killing of pathogens as well as antigen presentation. Together these features imply a favourable role of BaP exposure for macrophage functions in an ongoing immune response. However, the strong induction of IL-10 may lead to defective pathogen clearance and subsequently to chronic persistent infection. This concept suggests an inhibitory rather than a supporting influence of environmental BaP on immunity to infection or cancer and also emphasises the important regulatory role of AhR in immunity and inflammation., (Copyright © 2018. Published by Elsevier B.V.)

Intensive research during the past decade has highlighted the impact of the regulatory function of the aryl hydrocarbon receptor (AhR) in immunity. In this study, we focused on the influence of AhR activation on the differentiation of murine bone marrow-derived myeloid precursor cells into mature macrophages. Our results show that the activation of AhR by subtoxic doses of the AhR ligand benzo(a)pyrene (BaP) impaired the proliferation of bone marrow cells (BMCs) whereas the proportion of resulting adherent cells was not affected. Flow cytometric analysis revealed that the number of mature bone marrow-derived macrophages (BMMs) was significantly decreased by AhR activation. However, expression of the murine macrophage marker F4/80, the major histocompatibility complex class II (MHC-II) and the Fcγ receptor I (FcγRI/CD64) were upregulated on BaP-exposed BMMs in an AhR-dependent manner. Analysis of cytokine secretion after BMM activation with heat-killed (hk) salmonellae showed that BaP exposure resulted in suppressed secretion of interleukin (IL)-1β, IL-6 and the chemokine CXC motif ligand 1 (CXCL1). In contrast, the release of tumor necrosis factor (TNF)-α and IL-10 was increased following BaP exposure. In addition, the production of antimicrobial nitric oxide (NO) was increased AhR-dependently. Bacterial stimulation of BaP exposed BMMs also induced the expression of MHC-II and CD64, while the expression of F4/80 was dramatically decreased. In summary, this study demonstrates for the first time that sustained exposure over 6 days of bone marrow-derived myeloid precursors to subtoxic doses of BaP critically interferes with differentiation and activation of BMMs. We could convincingly show that AhR-induced gene regulation is crucial for homeostasis of pro- and anti-inflammatory cytokines during macrophage activation., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Cytochromes p450 (CYPs) metabolize thousands of endogenous and exogenous chemicals, including toxic compounds and drugs. The primary cells have relative short life span and are not able to sustain levels of metabolic enzymes CYPs expression and activity long enough in vitro. The immortalized cell lines are also not ideal for toxicity testing because of their low levels of CYPs expression. In this study, we established human normal bronchial epithelial cells using conditional reprogramming (CR) technique from three human donors (named as CR-HNBE1-3). These CR cells can proliferate continuously in defined culture system over 50 PDs within 2 months. The CR-HNBE cells exhibited the normal diploid karyotype, normal response to DNA damage and normal differentiation potential under the matrigel 3D culture condition. The CR-HNBE cells express the basal epithelial marker cytokeratin 14 (CK14) and epithelial secretory marker Mucin 5AC. Most importantly, CR-HNBE cells express comparable levels of CYP1B1 and CYP2E1 as those in lung tissue. These CR cells also express comparable mRNA of CYP1A1/CYP1A2, CYP2B6/CYP2C9/CYP2D6 and CYP3A4/CYP3A5 compared to the lung tissue. The basal activity of CYP1A1/CYP1B1 in these CR cells was 3-6 folds higher than that of 16HBE cells (an immortalized cell line widely used in toxicology field). Our data also demonstrated that Benzo(a)pyrene (BaP) induced up to 100 folds of mRNA expression of CYP1A1 or CYP1A2 in CR-HNBE cells. The activity of CYP1A1/CYP1B1 was induced by BaP up to 7-8 folds in CR-HNBE cells, while the activity of CYP1A1/CYP1B1 was induced maximum 2.5 folds in 16HBE cells. Taken together, CR-HNBE cells express comparable levels of CYPs and are sensitive to BaP induction, and will serve a sensitive, physiological and valuable in vitro toxicity testing model. This is the first report that normal human airway cells can be propagated for a long time and maintain comparable levels of CYPs., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Respiratory disease is an important cause of morbidity and mortality in cetaceans, which are also threatened by environmental degradation caused by crude oil spills. Following oil spills, cetaceans at the water surface may inhale droplets of oil containing toxic polycyclic aromatic hydrocarbons (PAHs), which could potentially alter respiratory immunity via activation of the aryl hydrocarbon receptor (AHR) and its subsequent interaction with nuclear factor kappa B (NF-κB). β-defensins are antimicrobial peptides secreted by airway epithelial cells and their expression is known to be dependent on NF-κB. We hypothesized that PAHs may suppress the expression of β-defensins, and thereby contribute to the pathogenesis of pneumonia. This hypothesis was modeled by measuring the in vitro effects of benzo(a)pyrene (BAP), phenanthrene, and naphthalene on tracheal antimicrobial peptide (TAP) gene expression in bovine tracheal epithelial cells. Stimulation with lipopolysaccharide (LPS) induced 20 ± 17-fold (mean ± SD) increased TAP gene expression. Exposure of tracheal epithelial cells to 5 μM BAP for 4 or 8 h, followed by incubation with a combination of LPS and 5 μM BAP for another 16 h, significantly (P = 0.002) suppressed LPS-induced TAP gene expression by 40.6 ± 21.8% (mean ± SD) in tracheal epithelial cells from 9 calves tested. BAP-induced suppression of TAP gene expression coincided with induction of cytochrome P450 1A1 gene expression. In contrast, phenanthrene and naphthalene had no consistent effect, and exposure to PAHs did not significantly affect constitutive TAP gene expression (i.e. without LPS). These findings characterize the suppressive effects of BAP-a toxic pollutant found in crude oil-on this respiratory innate immune response., (Copyright © 2018 Elsevier B.V. All rights reserved.)