Latest Publications

@article{holme_lung_2023,

title = {Lung cancer associated with combustion particles and fine particulate matter (PM(2.5)) - The roles of polycyclic aromatic hydrocarbons (PAHs) and the aryl hydrocarbon receptor (AhR).},

author = {Jørn A. Holme and Jan Vondráček and Miroslav Machala and Dominique Lagadic-Gossmann and Christoph F. A. Vogel and Eric Le Ferrec and Lydie Sparfel and Johan Øvrevik},

doi = {10.1016/j.bcp.2023.115801},

issn = {1873-2968 0006-2952},

year  = {2023},

date = {2023-10-01},

journal = {Biochemical pharmacology},

volume = {216},

pages = {115801},

abstract = {Air pollution is the leading cause of lung cancer after tobacco smoking, contributing to 20% of all lung cancer deaths. Increased risk associated with living near trafficked roads, occupational exposure to diesel exhaust, indoor coal combustion and cigarette smoking, suggest that combustion components in ambient fine particulate matter (PM(2.5)), such as polycyclic aromatic hydrocarbons (PAHs), may be central drivers of lung cancer. Activation of the aryl hydrocarbon receptor (AhR) induces expression of xenobiotic-metabolizing enzymes (XMEs) and increase PAH metabolism, formation of reactive metabolites, oxidative stress, DNA damage and mutagenesis. Lung cancer tissues from smokers and workers exposed to high combustion PM levels contain mutagenic signatures derived from PAHs. However, recent findings suggest that ambient air PM(2.5) exposure primarily induces lung cancer development through tumor promotion of cells harboring naturally acquired oncogenic mutations, thus lacking typical PAH-induced mutations. On this background, we discuss the role of AhR and PAHs in lung cancer development caused by air pollution focusing on the tumor promoting properties including metabolism, immune system, cell proliferation and survival, tumor microenvironment, cell-to-cell communication, tumor growth and metastasis. We suggest that the dichotomy in lung cancer patterns observed between smoking and outdoor air PM(2.5) represent the two ends of a dose-response continuum of combustion PM exposure, where tumor promotion in the peripheral lung appears to be the driving factor at the relatively low-dose exposures from ambient air PM(2.5), whereas genotoxicity in the central airways becomes increasingly more important at the higher combustion PM levels encountered through smoking and occupational exposure.},

note = {Place: England},

keywords = {*Air Pollutants/toxicity, *Lung Neoplasms/chemically induced/genetics, *Polycyclic Aromatic Hydrocarbons/toxicity, Air pollution, Aryl Hydrocarbon/genetics, Carcinogenesis, Diesel exhaust, Environmental Monitoring, Genotoxicity, Humans, Inflammation, Occupational exposure, Particulate Matter/toxicity, Receptors, Smoking, Tumor metastasis, Tumor microenvironment, Tumor promotion},

pubstate = {published},

tppubtype = {article}

}

@article{vazquez-gomez_aryl_2023,

title = {Aryl hydrocarbon receptor (AhR) and pregnane X receptor (PXR) play both distinct and common roles in the regulation of colon homeostasis and intestinal carcinogenesis.},

author = {Gerardo Vázquez-Gómez and Jiří Petráš and Zdeněk Dvořák and Jan Vondráček},

doi = {10.1016/j.bcp.2023.115797},

issn = {1873-2968 0006-2952},

year  = {2023},

date = {2023-10-01},

journal = {Biochemical pharmacology},

volume = {216},

pages = {115797},

abstract = {Both aryl hydrocarbon receptor (AhR) and pregnane X receptor (PXR) belong among key regulators of xenobiotic metabolism in the intestinal tissue. AhR in particular is activated by a wide range of environmental and dietary carcinogens. The data accumulated over the last two decades suggest that both of these transcriptional regulators play a much wider role in the maintenance of gut homeostasis, and that both transcription factors may affect processes linked with intestinal tumorigenesis. Intestinal epithelium is continuously exposed to a wide range of AhR, PXR and dual AhR/PXR ligands formed by intestinal microbiota or originating from diet. Current evidence suggests that specific ligands of both AhR and PXR can protect intestinal epithelium against inflammation and assist in the maintenance of epithelial barrier integrity. AhR, and to a lesser extent also PXR, have been shown to play a protective role against inflammation-induced colon cancer, or, in mouse models employing overactivation of Wnt/β-catenin signaling. In contrast, other evidence suggests that both receptors may contribute to modulation of transformed colon cell behavior, with a potential to promote cancer progression and/or chemoresistance. The review focuses on both overlapping and separate roles of the two receptors in these processes, and on possible implications of their activity within the context of intestinal tissue.},

note = {Place: England},

keywords = {*Receptors, Animals, Aryl hydrocarbon receptor, Aryl Hydrocarbon/genetics/metabolism, Carcinogenesis/genetics/metabolism, Colon cancer, Colon/metabolism, Dietary contaminants, Epithelial barrier, Inflammation, Inflammation/metabolism, Intestine, Mice, Microbial agonists, Pregnane X receptor, Pregnane X Receptor/metabolism, Steroid/metabolism},

pubstate = {published},

tppubtype = {article}

}

@article{bernal_combinatorial_2022,

title = {Combinatorial pathway disruption is a powerful approach to delineate metabolic impacts of endocrine disruptors.},

author = {Kévin Bernal and Charbel Touma and Chedi Erradhouani and Talía Boronat-Belda and Lucas Gaillard and Sara Al Kassir and Hélène Le Mentec and Corinne Martin-Chouly and Normand Podechard and Dominique Lagadic-Gossmann and Sophie Langouet and François Brion and Anja Knoll-Gellida and Patrick J. Babin and Iva Sovadinova and Pavel Babica and Karine Andreau and Robert Barouki and Jan Vondracek and Paloma Alonso-Magdalena and Etienne Blanc and Min Ji Kim and Xavier Coumoul},

doi = {10.1002/1873-3468.14465},

issn = {1873-3468 0014-5793},

year  = {2022},

date = {2022-12-01},

journal = {FEBS letters},

volume = {596},

number = {24},

pages = {3107–3123},

abstract = {The prevalence of metabolic diseases, such as obesity, diabetes, metabolic syndrome and chronic liver diseases among others, has been rising for several years. Epidemiology and mechanistic (in vivo, in vitro and in silico) toxicology have recently provided compelling evidence implicating the chemical environment in the pathogenesis of these diseases. In this review, we will describe the biological processes that contribute to the development of metabolic diseases targeted by metabolic disruptors, and will propose an integrated pathophysiological vision of their effects on several organs. With regard to these pathomechanisms, we will discuss the needs, and the stakes of evolving the testing and assessment of endocrine disruptors to improve the prevention and management of metabolic diseases that have become a global epidemic since the end of last century.},

note = {Place: England},

keywords = {*Endocrine Disruptors/toxicity, *Metabolic Syndrome, appetite, bisphenol, dioxin, Humans, Inflammation, insulin resistance, microbiota, Obesity/chemically induced, perfluorinated compounds, Phenols, phthalate, TBT},

pubstate = {published},

tppubtype = {article}

}

@article{smutna_macrophage-mediated_2022,

title = {Macrophage-mediated tissue response evoked by subchronic inhalation of lead oxide nanoparticles is associated with the alteration of phospholipases C and cholesterol transporters.},

author = {Tereza Smutná and Jana Dumková and Daniela Kristeková and Markéta Laštovičková and Adriena Jedličková and Lucie Vrlíková and Bohumil Dočekal and Lukáš Alexa and Hana Kotasová and Vendula Pelková and Zbyněk Večeřa and Kamil Křůmal and Jiří Petráš and Pavel Coufalík and Dalibor Všianský and Samuel Záchej and Dominik Pinkas and Jan Vondráček and Aleš Hampl and Pavel Mikuška and Marcela Buchtová},

doi = {10.1186/s12989-022-00494-7},

issn = {1743-8977},

year  = {2022},

date = {2022-08-01},

journal = {Particle and fibre toxicology},

volume = {19},

number = {1},

pages = {52},

abstract = {BACKGROUND: Inhalation of lead oxide nanoparticles (PbO NPs), which are emitted to the environment by high-temperature technological processes, heavily impairs target organs. These nanoparticles pass through the lung barrier and are distributed via the blood into secondary target organs, where they cause numerous pathological alterations. Here, we studied in detail, macrophages as specialized cells involved in the innate and adaptive immune response in selected target organs to unravel their potential involvement in reaction to subchronic PbO NP inhalation. In this context, we also tackled possible alterations in lipid uptake in the lungs and liver, which is usually associated with foam macrophage formation. RESULTS: The histopathological analysis of PbO NP exposed lung revealed serious chronic inflammation of lung tissues. The number of total and foam macrophages was significantly increased in lung, and they contained numerous cholesterol crystals. PbO NP inhalation induced changes in expression of phospholipases C (PLC) as enzymes linked to macrophage-mediated inflammation in lungs. In the liver, the subchronic inhalation of PbO NPs caused predominantly hyperemia, microsteatosis or remodeling of the liver parenchyma, and the number of liver macrophages also significantly was increased. The gene and protein expression of a cholesterol transporter CD36, which is associated with lipid metabolism, was altered in the liver. The amount of selected cholesteryl esters (CE 16:0, CE 18:1, CE 20:4, CE 22:6) in liver tissue was decreased after subchronic PbO NP inhalation, while total and free cholesterol in liver tissue was slightly increased. Gene and protein expression of phospholipase PLCβ1 and receptor CD36 in human hepatocytes were affected also in in vitro experiments after acute PbO NP exposure. No microscopic or serious functional kidney alterations were detected after subchronic PbO NP exposure and CD68 positive cells were present in the physiological mode in its interstitial tissues. CONCLUSION: Our study revealed the association of increased cholesterol and lipid storage in targeted tissues with the alteration of scavenger receptors and phospholipases C after subchronic inhalation of PbO NPs and yet uncovered processes, which can contribute to steatosis in liver after metal nanoparticles exposure.},

note = {Place: England},

keywords = {*Metal Nanoparticles/chemistry, *Type C Phospholipases, Cholesterol, Cholesterol metabolism, Humans, Inflammation, Inhalation, Lead, Lead oxide nanoparticles, Liver macrophages, Lung macrophages, Macrophages, Oxides},

pubstate = {published},

tppubtype = {article}

}

@article{vazquez-gomez_aryl_2022,

title = {Aryl Hydrocarbon Receptor (AhR) Limits the Inflammatory Responses in Human Lung Adenocarcinoma A549 Cells via Interference with NF-κB Signaling.},

author = {Gerardo Vázquez-Gómez and Martina Karasová and Zuzana Tylichová and Markéta Kabátková and Aleš Hampl and Jason Matthews and Jiří Neča and Miroslav Ciganek and Miroslav Machala and Jan Vondráček},

doi = {10.3390/cells11040707},

issn = {2073-4409},

year  = {2022},

date = {2022-02-01},

journal = {Cells},

volume = {11},

number = {4},

abstract = {Apart from its role in the metabolism of carcinogens, the aryl hydrocarbon receptor (AhR) has been suggested to be involved in the control of inflammatory responses within the respiratory tract. However, the mechanisms responsible for this are only partially known. In this study, we used A549 cell line, as a human model of lung alveolar type II (ATII)-like cells, to study the functional role of the AhR in control of inflammatory responses. Using IL-1β as an inflammation inducer, we found that the induction of cyclooxygenase-2 and secretion of prostaglandins, as well as expression and release of pro-inflammatory cytokines, were significantly higher in the AhR-deficient A549 cells. This was linked with an increased nuclear factor-κB (NF-κB) activity, and significantly enhanced phosphorylation of its regulators, IKKα/β, and their target IκBα, in the AhR-deficient A549 cells. In line with this, when we mimicked the exposure to a complex mixture of airborne pollutants, using an organic extract of reference diesel exhaust particle mixture, an exacerbated inflammatory response was observed in the AhR-deficient cells, as compared with wild-type A549 cells. Together, the present results indicate that the AhR may act as a negative regulator of the inflammatory response in the A549 model, via a direct modulation of NF-κB signaling. Its role(s) in the control of inflammation within the lung alveoli exposed to airborne pollutants, especially those which simultaneously activate the AhR, thus deserve further attention.},

note = {Place: Switzerland},

keywords = {*Environmental Pollutants/toxicity, *Inflammation/pathology, *NF-kappa B/metabolism, *Receptors, A549 Cells, AhR, alveolar epithelial type II cells, Aryl Hydrocarbon/metabolism, cytokines, Humans, Inflammation, NF-κB, prostaglandins},

pubstate = {published},

tppubtype = {article}

}

@article{kabatkova_interactive_2015,

title = {Interactive effects of inflammatory cytokine and abundant low-molecular-weight PAHs on inhibition of gap junctional intercellular communication, disruption of cell proliferation control, and the AhR-dependent transcription.},

author = {Markéta Kabátková and Jana Svobodová and Kateřina Pěnčíková and Dilshad Shaik Mohatad and Lenka Šmerdová and Alois Kozubík and Miroslav Machala and Jan Vondráček},

doi = {10.1016/j.toxlet.2014.09.023},

issn = {1879-3169 0378-4274},

year  = {2015},

date = {2015-01-01},

journal = {Toxicology letters},

volume = {232},

number = {1},

pages = {113–121},

abstract = {Polycyclic aromatic hydrocarbons (PAHs) with lower molecular weight exhibit lesser genotoxicity and carcinogenicity than highly carcinogenic PAHs with a higher number of benzene rings. Nevertheless, they elicit specific effects linked with tumor promotion, such as acute inhibition of gap junctional intercellular communication (GJIC). Although inflammatory reaction may alter bioactivation and toxicity of carcinogenic PAHs, little is known about the impact of pro-inflammatory cytokines on toxic effects of the low-molecular-weight PAHs. Here, we investigated the impact of a pro-inflammatory cytokine, tumor necrosis factor-α (TNF-α), on the effects associated with tumor promotion and with induction of the aryl hydrocarbon receptor (AhR)-dependent gene expression in rat liver epithelial cells. We found that a prolonged incubation with TNF-α induced a down-regulation of GJIC, associated with reduced expression of connexin 43 (Cx43), a major connexin isoform found in liver epithelial cells. The Cx43 down-regulation was partly mediated by the activity of the mitogen-activated protein (MAP) p38 kinase. Independently of GJIC modulation, or p38 activation, TNF-α potentiated the AhR-dependent proliferative effect of a model low-molecular-weight PAH, fluoranthene, on contact-inhibited cells. In contrast, this pro-inflammatory cytokine repressed the fluoranthene-induced expression of a majority of model AhR gene targets, such as Cyp1a1, Ahrr or Tiparp. The results of the present study indicate that inflammatory reaction may differentially modulate various toxic effects of low-molecular-weight PAHs; the exposure to pro-inflammatory cytokines may both strengthen (inhibition of GJIC, disruption of contact inhibition) and repress (expression of a majority of AhR-dependent genes) their impact on toxic endpoints associated with carcinogenesis.},

note = {Place: Netherlands},

keywords = {Animals, Aryl hydrocarbon receptor, Aryl Hydrocarbon/*agonists/genetics/metabolism, Basic Helix-Loop-Helix Transcription Factors/*agonists/genetics/metabolism, Cell Communication/*drug effects, Cell Line, Cell Proliferation, Cell Proliferation/*drug effects, Cell Transformation, Connexin 43/genetics/metabolism, Dose-Response Relationship, Drug, Enzyme Activation, Epithelial Cells/*drug effects/metabolism/pathology, Fluorenes/*toxicity, Gap junctions, Gap Junctions/*drug effects/metabolism/pathology, Gene Expression Regulation/drug effects, Genetic/*drug effects, Inflammation, Inflammation/chemically induced/genetics/metabolism/pathology, Liver Neoplasms/chemically induced/metabolism/pathology, Liver/*drug effects/metabolism/pathology, Molecular Weight, Neoplastic/chemically induced/metabolism/pathology, p38 Mitogen-Activated Protein Kinases/metabolism, PAHs, Rats, Receptors, Signal Transduction/drug effects, Time Factors, Transcription, Tumor Necrosis Factor-alpha/*toxicity},

pubstate = {published},

tppubtype = {article}

}

@article{smerdova_inflammatory_2013,

title = {Inflammatory mediators accelerate metabolism of benzo[a]pyrene in rat alveolar type II cells: the role of enhanced cytochrome P450 1B1 expression.},

author = {Lenka Smerdová and Jiří Neča and Jana Svobodová and Jan Topinka and Jana Schmuczerová and Alois Kozubík and Miroslav Machala and Jan Vondráček},

doi = {10.1016/j.tox.2013.09.001},

issn = {1879-3185 0300-483X},

year  = {2013},

date = {2013-12-01},

journal = {Toxicology},

volume = {314},

number = {1},

pages = {30–38},

abstract = {Long-term deregulated inflammation represents one of the key factors contributing to lung cancer etiology. Previously, we have observed that tumor necrosis factor-α (TNF-α), a major pro-inflammatory cytokine, enhances genotoxicity of benzo[a]pyrene (B[a]P), a highly carcinogenic polycyclic aromatic hydrocarbon, in rat lung epithelial RLE-6TN cells, a model of alveolar type II cells. Therefore, we analyzed B[a]P metabolism in RLE-6TN cells under inflammatory conditions, simulated using either recombinant TNF-α, or a mixture of inflammatory mediators derived from activated alveolar macrophage cell line. Inflammatory conditions significantly accelerated BaP metabolism, as evidenced by decreased levels of both parent B[a]P and its metabolites. TNF-α altered production of the metabolites associated with dihydrodiol-epoxide and radical cation pathways of B[a]P metabolism, especially B[a]P-dihydrodiols, and B[a]P-diones. We then evaluated the role of cytochrome P450 1B1 (CYP1B1), which is strongly up-regulated in cells treated with B[a]P under inflammatory conditions, in the observed effects. The siRNA-mediated CYP1B1 knock-down increased levels of B[a]P and reduced formation of stable DNA adducts, thus confirming the essential role of CYP1B1 in B[a]P metabolism under inflammatory conditions. TNF-α also reduced expression of aldo-keto reductase 1C14, which may compete with CYP1B1 for B[a]P-7,8-dihydrodiol and divert it from the formation of ultimate B[a]P dihydrodiol epoxide. Together, the present data suggests that the CYP1B1-catalyzed metabolism of polycyclic aromatic hydrocarbons might contribute to their enhanced bioactivation and genotoxic effects under inflammatory conditions.},

note = {Place: Ireland},

keywords = {Animals, Aryl Hydrocarbon Hydroxylases/*biosynthesis/genetics, ATP Binding Cassette Transporter, Benzo(a)pyrene/*metabolism, Blotting, Cell Line, Conditioned, Culture Media, CYP1B1, Cytochrome P-450 CYP1B1, Cytokines/metabolism, DNA adducts, Inflammation, Inflammation Mediators/*pharmacology, metabolism, Oxidoreductases Acting on Aldehyde or Oxo Group Donors/biosynthesis/genetics, Polycyclic aromatic hydrocarbons, Pulmonary Alveoli/cytology/drug effects/*metabolism, Rats, Real-Time Polymerase Chain Reaction, RNA, Small Interfering, Subfamily B/biosynthesis/genetics, Tandem Mass Spectrometry, Transfection, Western},

pubstate = {published},

tppubtype = {article}

}