Dietary exposure to aflatoxin B1 (AFB1) is harmful to the health and performance of domestic animals. The hepatic cytochrome P450s (CYPs), CYP1A1 and CYP2A6, are the primary enzymes responsible for the bioactivation of AFB1 to the highly toxic exo-AFB1-8,9-epoxide (AFBO) in chicks. However, the transcriptional regulation mechanism of these CYP genes in the liver of chicks in AFB1 metabolism remains unknown. Dual-luciferase reporter assay, bioinformatics and site-directed mutation results indicated that specificity protein 1 (SP1) and activator protein-1 (AP-1) motifs were located in the core region -1,063/-948, -606/-541 of the CYP1A1 promoter as well as -636/-595, -503/-462, -147/-1 of the CYP2A6 promoter. Furthermore, overexpression and decoy oligodeoxynucleotide technologies demonstrated that SP1 and AP-1 were pivotal transcriptional activators regulating the promoter activity of CYP1A1 and CYP2A6. Moreover, bioactivation of AFB1 to AFBO could be increased by upregulation of CYP1A1 and CYP2A6 expression, which was trans-activated owing to the upregulalion of AP-1, rather than SP1, stimulated by AFB1-induced reactive oxygen species. Additionally, nano-selenium could reduce ROS, downregulate AP-1 expression and then decrease the expression of CYP1A1 and CYP2A6, thus alleviating the toxicity of AFB1. In conclusion, AP-1 and SP1 played important roles in the transactivation of CYP1A1 and CYP2A6 expression and further bioactivated AFB1 to AFBO in chicken liver, which could provide novel targets for the remediation of aflatoxicosis in chicks.

• MeSH
• aflatoxin B1 * metabolismus   MeSH
• aktivace transkripce MeSH
• cytochrom P-450 CYP1A1 * genetika   metabolismus   MeSH
• cytochrom P450 CYP2A6 * metabolismus   genetika   MeSH
• játra * metabolismus   MeSH
• kur domácí * metabolismus   MeSH
• promotorové oblasti (genetika) * MeSH
• transkripční faktor AP-1 * metabolismus   genetika   MeSH
• transkripční faktor Sp1 * metabolismus   genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

AIM: Plasma values of nicotine and its metabolites are highly variable, and this variability has a strong genetic influence. In our study, we analysed the impact of common polymorphisms associated with smoking on the plasma values of nicotine, nicotine metabolites and their ratios and investigated the potential effect of these polymorphisms and nicotine metabolite ratios on the successful treatment of tobacco dependence. METHODS: Five variants (rs16969968, rs6474412, rs578776, rs4105144 and rs3733829) were genotyped in a group of highly dependent adult smokers (n=103). All smokers underwent intensive treatment for tobacco dependence; 33 smokers were still abstinent at the 12-month follow-up. RESULTS: The rs4105144 (CYP2A6, P<0.005) and rs3733829 (EGLN2, P<0.05) variants were significantly associated with plasma concentrations of 3OH-cotinine and with 3OH-cotinine: cotinine ratios. Similarly, the unweighted gene score was a significant (P<0.05) predictor of both cotinine:nicotine and 3OH-cotinine:cotinine ratios. No associations between the analysed polymorphisms or nicotine metabolite ratios and nicotine abstinence rate were observed. CONCLUSION: Although CYP2A6 and EGLN2 polymorphisms were associated with nicotine metabolism ratios, neither these polymorphisms nor the ratios were associated with abstinence rates.

• MeSH
• cytochrom P450 CYP2A6 genetika   MeSH
• cytochrom P450 CYP2B6 genetika   MeSH
• dospělí MeSH
• jednonukleotidový polymorfismus * MeSH
• lidé středního věku MeSH
• lidé MeSH
• nikotin krev   metabolismus   MeSH
• nikotinové receptory genetika   MeSH
• poruchy vyvolané užíváním tabáku krev   genetika   metabolismus   terapie   MeSH
• proteiny nervové tkáně genetika   MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Objectives Cytochromes P450 play a role in human drugs metabolic pathways and their genes are among the most variable in humans. The aim of this study was to analyze genotype frequencies of five common polymorphisms of cytochromes P450 in Roma/Gypsy and Czech (non-Roma) population samples with Czech origin. Methods Roma/Gypsy (n=302) and Czech subjects (n=298) were genotyped for CYP1A2 (rs762551), CYP2A6 (rs4105144), CYP2B6 (rs3745274) and CYP2D6 (rs3892097; rs1065852) polymorphisms using PCR-RFLP or Taqman assay. Results We found significant allelic/genotype differences between ethnics in three genes. For rs3745274 polymorphism, there was increased frequency of T allele carriers in Roma in comparison with Czech population (53.1 vs. 43.7%; p=0.02). For rs4105144 (CYP2A6) there was higher frequency of T allele carriers in Roma in comparison with Czech population (68.7 vs. 49.8%; p<0.0001). For rs3892097 (CYP2D6) there was more carriers of the A allele between Roma in comparison with Czech population (39.2 vs. 38.2%; p=0.048). Genotype/allelic frequencies of CYP2D6 (rs1065852) and CYP1A2 (rs762551) variants did not significantly differ between the ethnics. Conclusions There were significant differences in allelic/genotype frequencies of some, but not all cytochromes P450 polymorphisms between the Czech Roma/Gypsies and Czech non-Roma subjects.

• MeSH
• cytochrom P-450 CYP1A2 genetika   metabolismus   MeSH
• cytochrom P-450 CYP2D6 genetika   metabolismus   MeSH
• cytochrom P450 CYP2A6 genetika   metabolismus   MeSH
• cytochrom P450 CYP2B6 genetika   metabolismus   MeSH
• dospělí MeSH
• genotyp MeSH
• lidé MeSH
• polymorfismus genetický genetika   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

Cytochrome P450 (CYP) is a major group of enzymes, which conduct Phase I metabolism. Among commonly used animal models, the pig has been suggested as the most suitable model for investigating drug metabolism in human beings. Moreover, porcine CYP2A19 and CYP2E1 are responsible for the biotransformation of both endogenous and exogenous compounds such as 3-methylindole (skatole), sex hormones and food compounds. However, little is known about the regulation of porcine CYP2A19 and CYP2E1. In this MiniReview, we summarise the current knowledge about the regulation of porcine CYP2A19 and CYP2E1 by environmental, biological and dietary factors. Finally, we reflect on the need for further research, to clarify the interaction between active feed components and the porcine CYP system.

• MeSH
• biotransformace MeSH
• cytochrom P-450 CYP2E1 genetika   metabolismus   MeSH
• cytochrom P450 CYP2A6 genetika   metabolismus   MeSH
• krmivo pro zvířata * MeSH
• lidé MeSH
• pohlavní steroidní hormony metabolismus   MeSH
• prasata metabolismus   MeSH
• sekvenční homologie MeSH
• skatol metabolismus   MeSH
• xenobiotika metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

PURPOSE: Tobacco/nicotine dependence has a significant heritable component. Genome-wide association studies have associated the single nucleotide polymorphisms (SNPs) rs578776, rs16969968, rs6474412, rs3733829 and rs4105144 with nicotine dependence in Western European populations. We examined whether these SNPs influence nicotine dependence and successful treatment of tobacco dependence in the Czech middle-European population. MATERIALS AND METHODS: Variants were analysed by PCR-RFLP or by TaqMan assay in 807 adult heavy tobacco-dependent smokers - patients of the Centre for Treatment of Tobacco Dependence (Prague) as well as 1,362 self-reported non-smokers. RESULTS AND DISCUSSION: Except for rs3733829, association with tobacco dependence was confirmed for all other genetic variants. In agreement with previous studies, the strongest determinant of tobacco dependence was rs16969968 with OR (95%CI) 1.32 (1.08-1.62) for A allele carriers vs. GG comparison (P=0.003). In contrast, none of the analysed variants reached significance with respect to a 1-year course of successful tobacco dependence treatment (all P over 0.18) in a subset of 525 patients. CONCLUSION: We confirmed the association between variants within genes that code nicotinic-acetylcholine receptors (-A3, -A5 and -B3), CYP2A6/B6 and tobacco dependence development in the Czech population. The success of the tobacco dependence treatment was not influenced by the analysed SNPs.

• MeSH
• celogenomová asociační studie MeSH
• cytochrom P450 CYP2A6 MeSH
• cytochrom P450 CYP2B6 genetika   MeSH
• dospělí MeSH
• genetická predispozice k nemoci * MeSH
• jednonukleotidový polymorfismus * MeSH
• lidé MeSH
• nikotinové receptory genetika   MeSH
• poruchy vyvolané užíváním tabáku genetika   terapie   MeSH
• proteiny nervové tkáně MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Československo MeSH

Atorvastatin, fluvastatin and rosuvastatin are drugs used for treatment of hypercholesterolemia. They cause numerous drug-drug interactions by inhibiting and inducing drug-metabolizing cytochromes P450. These three statins exist in four optical forms, but they are currently used as enantiopure drugs, i.e., only one single enantiomer. There are numerous evidences that efficacy, adverse effects and toxicity of drugs may be enantiospecific. Therefore, we investigated the effects of optical isomers of atorvastatin, fluvastatin and rosuvastatin on the expression of drug-metabolizing P450s in primary human hepatocytes, using western blots and RT-PCR for measurement of proteins and mRNAs, respectively. The activity of P450 transcriptional regulators, including pregnane X receptor (PXR), aryl hydrocarbon receptor (AhR) and glucocorticoid receptor (GR), was assessed by gene reporter assays and EMSA. Transcriptional activity of AhR was not influenced by any statin tested. Basal transcriptional activity of GR was not affected by tested statins, but dexamethasone-inducible activity of GR was dose-dependently and enantioselectively inhibited by fluvastatin. Basal and ligand-inducible transcriptional activity of PXR was dose-dependently influenced by all tested statins, and the potency and efficacy between individual optical isomers varied depending on statin and optical isomer. The expression of CYP1A1 and CYP1A2 in human hepatocytes was not influenced by tested statins. All statins induced CYP2A6, CYP2B6 and CYP3A4, and the effects on CYP2C9 were rather modulatory. The effects varied between statins and enantiomers and induction potency decreased in order: atorvastatin (RR>RS = SR>SS) > fluvastatin (SR>RS = SS>RR) > rosuvastatin (only RS active). The data presented here might be of toxicological and clinical importance.

• MeSH
• atorvastatin farmakologie   MeSH
• cytochrom P-450 CYP3A biosyntéza   MeSH
• cytochrom P450 CYP2A6 biosyntéza   MeSH
• cytochrom P450 CYP2B6 biosyntéza   MeSH
• dospělí MeSH
• enzymová indukce účinky léků   MeSH
• hepatocyty cytologie   enzymologie   MeSH
• indoly farmakologie   MeSH
• induktory cytochromu P450 CYP2B6 farmakologie   MeSH
• induktory cytochromu P450 CYP3A farmakologie   MeSH
• kyseliny mastné mononenasycené farmakologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• rosuvastatin kalcium farmakologie   MeSH
• senioři MeSH
• stereoizomerie MeSH
• steroidní receptory biosyntéza   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVES: Cytochromes P450 (CYPs) are heme enzymes oxygenating a broad range of substrates. Their activity is dependent on the presence of a suitable electron donor (eukaryotic NADPH:CYP oxidoreductase or cytochrome b5). The Escherichia naturally contain no CYPs and no NADPH:CYP oxidoreductase, however it was reported that some CYPs heterologously expressed in E. coli may exist in the ferrous form. A small bacterial flavoprotein, flavodoxin is considered to be responsible for reduction some of these CYPs. METHODS: The reduction state of several human CYPs expressed in the intact living E. coli cells was examined. In addition, molecular dynamics and steered molecular dynamics simulations were performed to predict and compare affinity of flavodoxin toward selected CYPs. RESULTS: We determined the reduction state of five human CYPs heterologously expressed in E. coli. The computationally predicted stabilities of CYP-flavodoxin complexes correlate with the percentage of reduced CYPs in bacterial cells. The mean electron transfer distance within optimized complexes was also related to the percentage of reduced CYPs. CONCLUSION: Depending on the resting state, the CYPs heterologously expressed in E. coli could be divided into two groups; CYP2C8, 2C9, 3A4 are in E. coli present mainly in the oxidized form; while CYP1A1, 1A2, 2A6, 2A13, 2B6, 2D6 are found predominantly in the reduced form. We found a significant correlation between the stability of CYP-flavodoxin complexes and the percentage of reduced CYPs in bacteria. Hence, the naturally expressed flavodoxin is probably responsible for reduction of a larger group of human CYPs in bacterial cells.

• MeSH
• aromatické hydroxylasy metabolismus   MeSH
• cytochrom P-450 CYP1A1 metabolismus   MeSH
• cytochrom P-450 CYP1A2 metabolismus   MeSH
• cytochrom P-450 CYP2D6 metabolismus   MeSH
• cytochrom P-450 CYP3A metabolismus   MeSH
• cytochrom P450 CYP2A6 metabolismus   MeSH
• cytochrom P450 CYP2B6 metabolismus   MeSH
• cytochrom P450 CYP2C8 metabolismus   MeSH
• cytochrom P450 CYP2C9 metabolismus   MeSH
• Escherichia coli MeSH
• flavodoxin metabolismus   MeSH
• geneticky modifikované organismy MeSH
• lidé MeSH
• NADPH-cytochrom c-reduktasa metabolismus   MeSH
• oxidace-redukce MeSH
• systém (enzymů) cytochromů P-450 metabolismus   MeSH
• železité sloučeniny metabolismus   MeSH
• železnaté sloučeniny metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• cytochrom P450 CYP2A6 účinky léků   MeSH
• hyperlipoproteinemie typ IV farmakoterapie   chemicky indukované   MeSH
• messenger RNA genetika   účinky léků   MeSH
• modely u zvířat MeSH
• potkani transgenní MeSH
• silymarin farmakokinetika   farmakologie   MeSH
• systém (enzymů) cytochromů P-450 účinky léků   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH