Latest Publications

@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{sladekova_switching_2023,

title = {Switching on/off aryl hydrocarbon receptor and pregnane X receptor activities by chemically modified tryptamines.},

author = {Lucia Sládeková and Eliška Zgarbová and Radim Vrzal and David Vanda and Miroslav Soural and Klára Jakubcová and Gerardo Vázquez-Gómez and Jan Vondráček and Zdeněk Dvořák},

doi = {10.1016/j.toxlet.2023.09.012},

issn = {1879-3169 0378-4274},

year  = {2023},

date = {2023-09-01},

journal = {Toxicology letters},

volume = {387},

pages = {63–75},

abstract = {Microbial indoles have been demonstrated as selective or dual agonists and ligands of the pregnane X receptor (PXR) and aryl hydrocarbon receptor (AhR). However, structural determinants of microbial indoles selectivity towards both receptors remain elusive. Here, we studied the effects of existing and newly synthesized derivatives of indole microbial metabolite tryptamine on the activity of AhR and PXR receptors. We show that the elongation of indolyl-3-alkaneamine chain, indole N-methylation and conversion of indolyl-3-alkaneamines to oleamides resulted in a major increase of PXR activity and in parallel loss of AhR activity. Using reporter gene assays, RT-PCR and TR-FRET techniques, we have characterized in detail the activation of PXR by novel indolyl-3-alkanyl-oleamides, 1-methyltryptamine and 1-methyltryptamine-acetamide. As a proof of concept, we demonstrated anti-inflammatory and epithelial barrier-protective activity of lead derivatives in intestinal Caco-2 cells, employing the measurement of expression of pro-inflammatory chemokines, tight junction genes, trans-epithelial electric resistance TEER, and dextran-FITC permeability assay. In conclusion, we show that a subtle chemical modifications of simple microbial indole metabolite tryptamine, leads to substantial changes in AhR and PXR agonist activities.},

note = {Place: Netherlands},

keywords = {*Receptors, Aryl hydrocarbon receptor, Aryl Hydrocarbon/metabolism, Caco-2 Cells, Humans, Indoles/pharmacology, Microbial indoles, Pregnane X receptor, Pregnane X Receptor/genetics, Steroid/metabolism, Tryptamine, Tryptamines/pharmacology},

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{vondracek_environmental_2020,

title = {Environmental six-ring polycyclic aromatic hydrocarbons are potent inducers of the AhR-dependent signaling in human cells.},

author = {Jan Vondráček and Kateřina Pěnčíková and Miroslav Ciganek and Jakub Pivnička and Martina Karasová and Martina Hýžďalová and Simona Strapáčová and Lenka Pálková and Jiří Neča and Jason Matthews and Michal Vojtíšek Lom and Jan Topinka and Alena Milcová and Miroslav Machala},

doi = {10.1016/j.envpol.2020.115125},

issn = {1873-6424 0269-7491},

year  = {2020},

date = {2020-11-01},

journal = {Environmental pollution (Barking, Essex : 1987)},

volume = {266},

number = {Pt 2},

pages = {115125},

abstract = {The toxicities of many environmental polycyclic aromatic hydrocarbons (PAHs), in particular those of high-molecular-weight PAHs (with MW higher than 300), remain poorly characterized. The objective of this study was to evaluate the ability of selected environmentally relevant PAHs with MW 302 (MW302 PAHs) to activate the aryl hydrocarbon receptor (AhR), since this represents a major toxic mode of action of PAHs. A large number of the evaluated compounds exhibited strong AhR-mediated activities, in particular in human models. The studied MW302 PAHs also significantly contributed to the overall calculated AhR activities of complex environmental mixtures, including both defined standard reference materials and collected diesel exhaust particles. The high AhR-mediated activities of representative MW302 PAHs, e.g. naphtho[1,2-k]fluoranthene, corresponded with the modulation of expression of relevant AhR target genes in a human lung cell model, or with the AhR-dependent suppression of cell cycle progression/proliferation in estrogen-sensitive cells. This was in a marked contrast with the limited genotoxicity of the same compound(s). Given the substantial levels of the AhR-activating MW302 PAHs in combustion particles, it seems important to continue to investigate the toxic modes of action of this large group of PAHs associated with airborne particulate matter.},

note = {Place: England},

keywords = {*Polycyclic Aromatic Hydrocarbons, *Receptors, AhR, Anti-estrogenicity, Aryl Hydrocarbon, Carcinogenic PAHs, Genotoxicity, Humans, Lung cell toxicity, Particulate Matter, Signal Transduction, Vehicle Emissions},

pubstate = {published},

tppubtype = {article}

}