2013
Smerdová, Lenka; Neča, Jiří; Svobodová, Jana; Topinka, Jan; Schmuczerová, Jana; Kozubík, Alois; Machala, Miroslav; Vondráček, Jan
In: Toxicology, vol. 314, no. 1, pp. 30–38, 2013, ISSN: 1879-3185 0300-483X, (Place: Ireland).
Abstract | Links | BibTeX | Tags: 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
@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}
}
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.