Polycyclic aromatic hydrocarbons (PAHs) may cause lipid peroxidation via reactive oxygen species generation. 15-F2t-isoprostane (IsoP), an oxidative stress marker, is formed from arachidonic acid (AA) by a free-radical induced oxidation. AA may also be converted to prostaglandins (PG) by prostaglandin-endoperoxide synthase (PTGS) induced by NF-κB. We treated human embryonic lung fibroblasts (HEL12469) with benzo[a]pyrene (B[a]P), 3-nitrobenzanthrone (3-NBA) and extractable organic matter (EOM) from ambient air particulate matter <2.5 µm for 4 and 24 h. B[a]P and 3-NBA induced expression of PAH metabolising, but not antioxidant enzymes. The concentrations of IsoP decreased, whereas the levels of AA tended to increase. Although the activity of NF-κB was not detected, the tested compounds affected the expression of prostaglandin-endoperoxide synthase 2 (PTGS2). The levels of prostaglandin E2 (PGE2) decreased following exposure to B[a]P, whereas 3-NBA exposure tended to increase PGE2 concentration. A distinct response was observed after EOM exposure: expression of PAH-metabolising enzymes was induced, IsoP levels increased after 24-h treatment but AA concentration was not affected. The activity of NF-κB increased after both exposure periods, and a significant induction of PTGS2 expression was found following 4-h treatment. Similarly to PAHs, the EOM exposure was associated with a decrease of PGE2 levels. In summary, exposure to PAHs with low pro-oxidant potential results in a decrease of IsoP levels implying 'antioxidant' properties. For such compounds, IsoP may not be a suitable marker of lipid peroxidation.
- MeSH
- aromatické hydroxylasy metabolismus MeSH
- benz(a)anthraceny toxicita MeSH
- benzopyren toxicita MeSH
- cyklooxygenasa 2 metabolismus MeSH
- dinoprost analogy a deriváty biosyntéza metabolismus MeSH
- dinoproston biosyntéza metabolismus MeSH
- fibroblasty účinky léků enzymologie MeSH
- kultivované buňky MeSH
- kyselina arachidonová metabolismus MeSH
- látky znečišťující vzduch toxicita MeSH
- lidé MeSH
- NF-kappa B metabolismus MeSH
- oxidační stres účinky léků MeSH
- peroxidace lipidů účinky léků MeSH
- pevné částice toxicita MeSH
- plíce cytologie účinky léků embryologie enzymologie MeSH
- polycyklické aromatické uhlovodíky toxicita MeSH
- reaktivní formy kyslíku metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Butyrate, a short-chain fatty acid produced by fermentation of dietary fiber, is an important regulator of colonic epithelium homeostasis. In this study, we investigated the impact of this histone deacetylase (HDAC) inhibitor on expression/activity of cytochrome P450 family 1 (CYP1) and on metabolism of carcinogenic polycyclic aromatic hydrocarbon, benzo[a]pyrene (BaP), in colon epithelial cells. Sodium butyrate (NaBt) strongly potentiated the BaP-induced expression of CYP1A1 in human colon carcinoma HCT116 cells. It also co-stimulated the 7-ethoxyresorufin-O-deethylase (EROD) activity induced by the 2,3,7,8-tetrachlorodibenzo-p-dioxin, a prototypical ligand of the aryl hydrocarbon receptor. Up-regulation of CYP1A1 expression/activity corresponded with an enhanced metabolism of BaP and formation of covalent DNA adducts. NaBt significantly potentiated CYP1A1 induction and/or metabolic activation of BaP also in other human colon cell models, colon adenoma AA/C1 cells, colon carcinoma HT-29 cells, or in NCM460D cell line derived from normal colon mucosa. Our results suggest that the effects of NaBt were due to its impact on histone acetylation, because additional HDAC inhibitors (trichostatin A and suberanilohydroxamic acid) likewise increased both the induction of EROD activity and formation of covalent DNA adducts. NaBt-induced acetylation of histone H3 (at Lys14) and histone H4 (at Lys16), two histone modifications modulated during activation of CYP1A1 transcription, and it reduced binding of HDAC1 to the enhancer region of CYP1A1 gene. This in vitro study suggests that butyrate, through modulation of histone acetylation, may potentiate induction of CYP1A1 expression, which might in turn alter the metabolism of BaP within colon epithelial cells.
- MeSH
- adukty DNA účinky léků metabolismus MeSH
- benzopyren metabolismus farmakokinetika MeSH
- beta-katenin metabolismus MeSH
- buňky HT-29 MeSH
- cytochrom P-450 CYP1A1 genetika metabolismus MeSH
- HCT116 buňky MeSH
- histondeacetylasa 1 antagonisté a inhibitory metabolismus MeSH
- histony metabolismus MeSH
- inhibitory histondeacetylas farmakologie MeSH
- kolon účinky léků metabolismus MeSH
- kyselina máselná farmakologie MeSH
- lidé MeSH
- metabolická inaktivace MeSH
- zesilovače transkripce účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The human population is continually exposed to numerous harmful environmental stressors, causing negative health effects and/or deregulation of biomarker levels. However, studies reporting no or even positive impacts of some stressors on humans are also sometimes published. The main aim of this review is to provide a comprehensive overview of the last decade of Czech biomonitoring research, concerning the effect of various levels of air pollution (benzo[a]pyrene) and radiation (uranium, X-ray examination and natural radon background), on the differently exposed population groups. Because some results obtained from cytogenetic studies were opposite than hypothesized, we have searched for a meaningful interpretation in genomic/epigenetic studies. A detailed analysis of our data supported by the studies of others and current epigenetic knowledge, leads to a hypothesis of the versatile mechanism of adaptation to environmental stressors via DNA methylation settings which may even originate in prenatal development, and help to reduce the resulting DNA damage levels. This hypothesis is fully in agreement with unexpected data from our studies (e.g. lower levels of DNA damage in subjects from highly polluted regions than in controls or in subjects exposed repeatedly to a pollutant than in those without previous exposure), and is also supported by differences in DNA methylation patterns in groups from regions with various levels of pollution. In light of the adaptation hypothesis, the following points may be suggested for future research: (i) the chronic and acute exposure of study subjects should be distinguished; (ii) the exposure history should be mapped including place of residence during the life and prenatal development; (iii) changes of epigenetic markers should be monitored over time. In summary, investigation of human adaptation to the environment, one of the most important processes of survival, is a new challenge for future research in the field of human biomonitoring that may change our view on the results of biomarker analyses and potential negative health impacts of the environment.
- MeSH
- benzopyren toxicita MeSH
- chromozomální aberace účinky léků účinky záření MeSH
- cytogenetika * MeSH
- fyziologická adaptace účinky léků účinky záření MeSH
- lidé MeSH
- metylace DNA účinky léků účinky záření MeSH
- monitorování životního prostředí * MeSH
- poškození DNA účinky léků účinky záření MeSH
- rentgenové záření škodlivé účinky MeSH
- uran toxicita MeSH
- znečištění ovzduší škodlivé účinky MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Geografické názvy
- Česká republika MeSH
Three series of salicylanilides, esters of N-phenylsalicylamides and 2-hydroxy-N-[1-(2-hydroxyphenylamino)-1-oxoalkan-2-yl]benzamides, in total thirty target compounds were synthesized and characterized. The compounds were evaluated against seven bacterial and three mycobacterial strains. The antimicrobial activities of some compounds were comparable or higher than the standards ampicillin, ciprofloxacin or isoniazid. Derivatives 3f demonstrated high biological activity against Staphylococcus aureus (⩽0.03μmol/L), Mycobacterium marinum (⩽0.40μmol/L) and Mycobacterium kansasii (1.58μmol/L), 3g shows activity against Clostridium perfringens (⩽0.03μmol/L) and Bacillus cereus (0.09μmol/L), 3h against Pasteurella multocida (⩽0.03μmol/L) and M. kansasii (⩽0.43μmol/L), 3i against methicillin-resistant S. aureus and B. cereus (⩽0.03μmol/L). The structure-activity relationships are discussed for all the compounds.
- MeSH
- ampicilin farmakologie MeSH
- antiinfekční látky chemická syntéza chemie farmakologie MeSH
- ciprofloxacin farmakologie MeSH
- gramnegativní bakterie účinky léků MeSH
- grampozitivní bakterie účinky léků MeSH
- mikrobiální testy citlivosti MeSH
- salicylamidy chemická syntéza chemie farmakologie MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
During their development and aging on solid substrates, yeast giant colonies produce ammonia, which acts as a quorum sensing molecule. Ammonia production is connected with alkalization of the surrounding medium and with extensive reprogramming of cell metabolism. In addition, ammonia signaling is important for both horizontal (colony centre versus colony margin) and vertical (upper versus lower cell layers) colony differentiations. The centre of an aging differentiated giant colony is thus composed of two major cell subpopulations, the subpopulation of long-living, metabolically active and stress-resistant cells that form the upper layers of the colony and the subpopulation of stress-sensitive starving cells in the colony interior. Here, we show that microcolonies originating from one cell pass through similar developmental phases as giant colonies. Microcolony differentiation is linked to ammonia signaling, and cells similar to the upper and lower cells of aged giant colonies are formed even in relatively young microcolonies. A comparison of the properties of these cells revealed a number of features that are similar in microcolonies and giant colonies as well as a few that are only typical of chronologically aged giant colonies. These findings show that colony age per se is not crucial for colony differentiation.
