Latest Publications

@article{pencikova_vitro_2018,

title = {In vitro profiling of toxic effects of prominent environmental lower-chlorinated PCB congeners linked with endocrine disruption and tumor promotion.},

author = {Kateřina Pěnčíková and Lucie Svržková and Simona Strapáčová and Jiří Neča and Iveta Bartoňková and Zdeněk Dvořák and Martina Hýžďalová and Jakub Pivnička and Lenka Pálková and Hans-Joachim Lehmler and Xueshu Li and Jan Vondráček and Miroslav Machala},

doi = {10.1016/j.envpol.2018.02.067},

issn = {1873-6424 0269-7491},

year  = {2018},

date = {2018-06-01},

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

volume = {237},

pages = {473–486},

abstract = {The mechanisms contributing to toxic effects of airborne lower-chlorinated PCB congeners (LC-PCBs) remain poorly characterized. We evaluated in vitro toxicities of environmental LC-PCBs found in both indoor and outdoor air (PCB 4, 8, 11, 18, 28 and 31), and selected hydroxylated metabolites of PCB 8, 11 and 18, using reporter gene assays, as well as other functional cellular bioassays. We focused on processes linked with endocrine disruption, tumor promotion and/or regulation of transcription factors controlling metabolism of both endogenous compounds and xenobiotics. The tested LC-PCBs were found to be mostly efficient anti-androgenic (within nanomolar - micromolar range) and estrogenic (at micromolar concentrations) compounds, as well as inhibitors of gap junctional intercellular communication (GJIC) at micromolar concentrations. PCB 8, 28 and 31 were found to partially inhibit the aryl hydrocarbon receptor (AhR)-mediated activity. The tested LC-PCBs were also partial constitutive androstane receptor (CAR) and pregnane X receptor (PXR) agonists, with PCB 4, 8 and 18 being the most active compounds. They were inactive towards other nuclear receptors, such as vitamin D receptor, thyroid receptor α, glucocorticoid receptor or peroxisome proliferator-activated receptor γ. We found that only PCB 8 contributed to generation of oxidative stress, while all tested LC-PCBs induced arachidonic acid release (albeit without further modulations of arachidonic acid metabolism) in human lung epithelial cells. Importantly, estrogenic effects of hydroxylated (OH-PCB) metabolites of LC-PCBs (4-OH-PCB 8, 4-OH-PCB 11 and 4'-OH-PCB 18) were higher than those of the parent PCBs, while their other toxic effects were only slightly altered or suppressed. This suggested that metabolism may alter toxicity profiles of LC-PCBs in a receptor-specific manner. In summary, anti-androgenic and estrogenic activities, acute inhibition of GJIC and suppression of the AhR-mediated activity were found to be the most relevant modes of action of airborne LC-PCBs, although they partially affected also additional cellular targets.},

note = {Place: England},

keywords = {Air Pollutants/*toxicity, Airborne polychlorinated biphenyls, Cell Line, Constitutive Androstane Receptor, Cytoplasmic and Nuclear/metabolism, Endocrine disruption, Endocrine Disruptors/metabolism/*toxicity, Epithelial Cells/drug effects, Humans, HydroxyLated PCBs, Hydroxylation, Metabolism of xenobiotics, Neoplasms/metabolism, Polychlorinated Biphenyls/metabolism/*toxicity, Pregnane X receptor, Receptors, Signal Transduction/drug effects, Steroid/metabolism, Tumor promotion},

pubstate = {published},

tppubtype = {article}

}

@article{palkova_aryl_2015,

title = {The aryl hydrocarbon receptor-mediated and genotoxic effects of fractionated extract of standard reference diesel exhaust particle material in pulmonary, liver and prostate cells.},

author = {Lenka Pálková and Jan Vondráček and Lenka Trilecová and Miroslav Ciganek and Kateřina Pěnčíková and Jiří Neča and Alena Milcová and Jan Topinka and Miroslav Machala},

doi = {10.1016/j.tiv.2014.12.002},

issn = {1879-3177 0887-2333},

year  = {2015},

date = {2015-04-01},

journal = {Toxicology in vitro : an international journal published in association with BIBRA},

volume = {29},

number = {3},

pages = {438–448},

abstract = {Diesel exhaust particles (DEP) and the associated complex mixtures of organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), or their derivatives, have been suggested to exert deleterious effects on human health. We used a set of defined cellular models representing liver, lung and prostate tissues, in order to compare non-genotoxic and genotoxic effects of crude and fractionated extract of a standard reference DEP material - SRM 1650b. We focused on the aryl hydrocarbon receptor (AhR)-mediated activity, modulation of cell proliferation, formation of DNA adducts, oxidative DNA damage, and induction of DNA damage responses, including evaluation of apoptosis, and phosphorylation of p53 tumor suppressor and checkpoint kinases (Chk). Both PAHs and the polar aromatic compounds contributed to the AhR-mediated activity of DEP-associated organic pollutants. The principal identified AhR agonists included benzo[k]fluoranthene, indeno[1,2,3-c,d]pyrene, chrysene and several non-priority PAHs, including benzochrysenes and methylated PAHs. In contrast to PAHs, polar compounds contributed more significantly to overall formation of DNA adducts associated with phosphorylation of p53, Chk1 or Chk2, and partly with apoptosis. Therefore, more attention should be paid to identification of DEP-associated polar organic compounds, contributing to the AhR activation and cytotoxic/genotoxic effects of complex airborne mixtures of organic contaminants produced by diesel engines.},

note = {Place: England},

keywords = {Air Pollutants/*toxicity, Air pollution, Animals, Apoptosis, Apoptosis/drug effects, Aryl Hydrocarbon/*drug effects, Cell Cycle/drug effects, Cell Death/drug effects, Cell Proliferation, DNA adducts, DNA Damage, DNA damage response, Liver/*pathology, Lung/*pathology, Male, Mutagens/*toxicity, PAHs, Particulate Matter/*toxicity, Prostate/*pathology, Rats, Receptors, SRM 1650b, Vehicle Emissions/*toxicity},

pubstate = {published},

tppubtype = {article}

}