SlNCED1 and SlCYP707A2: key genes involved in ABA metabolism during tomato fruit ripening

PubMed Central

Ji, Kai; Kai, Wenbin; Zhao, Bo; Sun, Yufei; Yuan, Bing; Dai, Shengjie; Li, Qian; Chen, Pei; Wang, Ya; Pei, Yuelin; Wang, Hongqing; Guo, Yangdong; Leng, Ping

2014-01-01

Abscisic acid (ABA) plays an important role in fruit development and ripening. Here, three NCED genes encoding 9-cis-epoxycarotenoid dioxygenase (NCED, a key enzyme in the ABA biosynthetic pathway) and three CYP707A genes encoding ABA 8′-hydroxylase (a key enzyme in the oxidative catabolism of ABA) were identified in tomato fruit by tobacco rattle virus-induced gene silencing (VIGS). Quantitative real-time PCR showed that VIGS-treated tomato fruits had significant reductions in target gene transcripts. In SlNCED1-RNAi-treated fruits, ripening slowed down, and the entire fruit turned to orange instead of red as in the control. In comparison, the downregulation of SlCYP707A2 expression in SlCYP707A2-silenced fruit could promote ripening; for example, colouring was quicker than in the control. Silencing SlNCED2/3 or SlCYP707A1/3 made no significant difference to fruit ripening comparing RNAi-treated fruits with control fruits. ABA accumulation and SlNCED1transcript levels in the SlNCED1-RNAi-treated fruit were downregulated to 21% and 19% of those in control fruit, respectively, but upregulated in SlCYP707A2-RNAi-treated fruit. Silencing SlNCED1 or SlCYP707A2 by VIGS significantly altered the transcripts of a set of both ABA-responsive and ripening-related genes, including ABA-signalling genes (PYL1, PP2C1, and SnRK2.2), lycopene-synthesis genes (SlBcyc, SlPSY1 and SlPDS), and cell wall-degrading genes (SlPG1, SlEXP, and SlXET) during ripening. These data indicate that SlNCED1 and SlCYP707A2 are key genes in the regulation of ABA synthesis and catabolism, and are involved in fruit ripening as positive and negative regulators, respectively. PMID:25039074

PacCYP707A2 negatively regulates cherry fruit ripening while PacCYP707A1 mediates drought tolerance

PubMed Central

Li, Qian; Chen, Pei; Dai, Shengjie; Sun, Yufei; Yuan, Bing; Kai, Wenbin; Pei, Yuelin; He, Suihuan; Liang, Bin; Zhang, Yushu; Leng, Ping

2015-01-01

Sweet cherry is a non-climacteric fruit and its ripening is regulated by abscisic acid (ABA) during fruit development. In this study, four cDNAs (PacCYP707A1–4) encoding 8′-hydroxylase, a key enzyme in the oxidative catabolism of ABA, were identified in sweet cherry fruits using tobacco rattle virus-induced gene silencing (VIGS) and particle bombardment approaches. Quantitative real-time PCR confirmed significant down-regulation of target gene transcripts in VIGS-treated cherry fruits. In PacCYP707A2-RNAi-treated fruits, ripening and fruit colouring were promoted relative to control fruits, and both ABA accumulation and PacNCED1 transcript levels were up-regulated by 140%. Silencing of PacCYP707A2 by VIGS significantly altered the transcripts of both ABA-responsive and ripening-related genes, including the ABA metabolism-associated genes NCED and CYP707A, the anthocyanin synthesis genes PacCHS, PacCHI, PacF3H, PacDFR, PacANS, and PacUFGT, the ethylene biosynthesis gene PacACO1, and the transcription factor PacMYBA. The promoter of PacMYBA responded more strongly to PacCYP707A2-RNAi-treated fruits than to PacCYP707A1-RNAi-treated fruits. By contrast, silencing of PacCYP707A1 stimulated a slight increase in fruit colouring and enhanced resistance to dehydration stress compared with control fruits. These results suggest that PacCYP707A2 is a key regulator of ABA catabolism that functions as a negative regulator of fruit ripening, while PacCYP707A1 regulates ABA content in response to dehydration during fruit development. PMID:25956880

PacCYP707A2 negatively regulates cherry fruit ripening while PacCYP707A1 mediates drought tolerance.

PubMed

Li, Qian; Chen, Pei; Dai, Shengjie; Sun, Yufei; Yuan, Bing; Kai, Wenbin; Pei, Yuelin; He, Suihuan; Liang, Bin; Zhang, Yushu; Leng, Ping

2015-07-01

Sweet cherry is a non-climacteric fruit and its ripening is regulated by abscisic acid (ABA) during fruit development. In this study, four cDNAs (PacCYP707A1-4) encoding 8'-hydroxylase, a key enzyme in the oxidative catabolism of ABA, were identified in sweet cherry fruits using tobacco rattle virus-induced gene silencing (VIGS) and particle bombardment approaches. Quantitative real-time PCR confirmed significant down-regulation of target gene transcripts in VIGS-treated cherry fruits. In PacCYP707A2-RNAi-treated fruits, ripening and fruit colouring were promoted relative to control fruits, and both ABA accumulation and PacNCED1 transcript levels were up-regulated by 140%. Silencing of PacCYP707A2 by VIGS significantly altered the transcripts of both ABA-responsive and ripening-related genes, including the ABA metabolism-associated genes NCED and CYP707A, the anthocyanin synthesis genes PacCHS, PacCHI, PacF3H, PacDFR, PacANS, and PacUFGT, the ethylene biosynthesis gene PacACO1, and the transcription factor PacMYBA. The promoter of PacMYBA responded more strongly to PacCYP707A2-RNAi-treated fruits than to PacCYP707A1-RNAi-treated fruits. By contrast, silencing of PacCYP707A1 stimulated a slight increase in fruit colouring and enhanced resistance to dehydration stress compared with control fruits. These results suggest that PacCYP707A2 is a key regulator of ABA catabolism that functions as a negative regulator of fruit ripening, while PacCYP707A1 regulates ABA content in response to dehydration during fruit development. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Genome-wide association analysis of coffee drinking suggests association with CYP1A1/CYP1A2 and NRCAM

PubMed Central

Amin, N; Byrne, E; Johnson, J; Chenevix-Trench, G; Walter, S; Nolte, I M; Vink, J M; Rawal, R; Mangino, M; Teumer, A; Keers, J C; Verwoert, G; Baumeister, S; Biffar, R; Petersmann, A; Dahmen, N; Doering, A; Isaacs, A; Broer, L; Wray, N R; Montgomery, G W; Levy, D; Psaty, B M; Gudnason, V; Chakravarti, A; Sulem, P; Gudbjartsson, D F; Kiemeney, L A; Thorsteinsdottir, U; Stefansson, K; van Rooij, F J A; Aulchenko, Y S; Hottenga, J J; Rivadeneira, F R; Hofman, A; Uitterlinden, A G; Hammond, C J; Shin, S-Y; Ikram, A; Witteman, J C M; Janssens, A C J W; Snieder, H; Tiemeier, H; Wolfenbuttel, B H R; Oostra, B A; Heath, A C; Wichmann, E; Spector, T D; Grabe, H J; Boomsma, D I; Martin, N G; van Duijn, C M

2012-01-01

Coffee consumption is a model for addictive behavior. We performed a meta-analysis of genome-wide association studies (GWASs) on coffee intake from 8 Caucasian cohorts (N=18 176) and sought replication of our top findings in a further 7929 individuals. We also performed a gene expression analysis treating different cell lines with caffeine. Genome-wide significant association was observed for two single-nucleotide polymorphisms (SNPs) in the 15q24 region. The two SNPs rs2470893 and rs2472297 (P-values=1.6 × 10−11 and 2.7 × 10−11), which were also in strong linkage disequilibrium (r2=0.7) with each other, lie in the 23-kb long commonly shared 5′ flanking region between CYP1A1 and CYP1A2 genes. CYP1A1 was found to be downregulated in lymphoblastoid cell lines treated with caffeine. CYP1A1 is known to metabolize polycyclic aromatic hydrocarbons, which are important constituents of coffee, whereas CYP1A2 is involved in the primary metabolism of caffeine. Significant evidence of association was also detected at rs382140 (P-value=3.9 × 10−09) near NRCAM—a gene implicated in vulnerability to addiction, and at another independent hit rs6495122 (P-value=7.1 × 10−09)—an SNP associated with blood pressure—in the 15q24 region near the gene ULK3, in the meta-analysis of discovery and replication cohorts. Our results from GWASs and expression analysis also strongly implicate CAB39L in coffee drinking. Pathway analysis of differentially expressed genes revealed significantly enriched ubiquitin proteasome (P-value=2.2 × 10−05) and Parkinson's disease pathways (P-value=3.6 × 10−05). PMID:21876539

A new CYP21A1P/CYP21A2 chimeric gene identified in an Italian woman suffering from classical congenital adrenal hyperplasia form

PubMed Central

Concolino, Paola; Mello, Enrica; Minucci, Angelo; Giardina, Emiliano; Zuppi, Cecilia; Toscano, Vincenzo; Capoluongo, Ettore

2009-01-01

Background More than 90% of Congenital Adrenal Hyperplasia (CAH) cases are associated with mutations in the 21-hydroxylase gene (CYP21A2) in the HLA class III area on the short arm of chromosome 6p21.3. In this region, a 30 kb deletion produces a non functional chimeric gene with its 5' and 3' ends corresponding to CYP21A1P pseudogene and CYP21A2, respectively. To date, five different CYP21A1P/CYP21A2 chimeric genes have been found and characterized in recent studies. In this paper, we describe a new CYP21A1P/CYP21A2 chimera (CH-6) found in an Italian CAH patient. Methods Southern blot analysis and CYP21A2 sequencing were performed on the patient. In addition, in order to isolate the new CH-6 chimeric gene, two different strategies were used. Results The CYP21A2 sequencing analysis showed that the patient was homozygote for the g.655C/A>G mutation and heterozygote for the p.P30L missense mutation. In addition, the promoter sequence revealed the presence, in heterozygosis, of 13 SNPs generally produced by microconversion events between gene and pseudogene. Southern blot analysis showed that the woman was heterozygote for the classic 30-kb deletion producing a new CYP21A1P/CYP21A2 chimeric gene (CH-6). The hybrid junction site was located between the end of intron 2 pseudogene, after the g.656C/A>G mutation, and the beginning of exon 3, before the 8 bp deletion. Consequently, CH-6 carries three mutations: the weak pseudogene promoter region, the p.P30L and the g.655C/A>G splice mutation. Conclusion We describe a new CYP21A1P/CYP21A2 chimera (CH-6), associated with the HLA-B15, DR13 haplotype, in a young Italian CAH patient. PMID:19624807

Frequency distribution of polymorphisms of CYP2C19, CYP2C9, VKORC1 and SLCO1B1 genes in the Yakut population.

PubMed

Vasilyev, Filipp Filippovich; Danilova, Diana Aleksandrovna; Kaimonov, Vladimir Sergeevich; Chertovskih, Yana Valerievna; Maksimova, Nadezda Romanovna

2016-01-01

Allele frequencies of single nucleotide polymorphisms (SNPs) are variable among different populations; therefore the study of SNPs in ethnic groups is important for establishing the clinical significance of the screening of these polymorphisms. The main goal of the research is to study the polymorphisms of CYP2C9, CYP2C19, VKORC1, and SLCO1B1 in Yakuts. Genomic DNA from 229 Yakut subjects were analyzed by real-time polymerase chain reaction (PCR) (SLCO1B1 +521T > C, VKORC1 -1639G>A, CYP2C19 +681G>A, +636G>A, CYP2C9 +430С>T, +1075A>C). Genotype frequencies of polymorphisms in the population of the Yakuts were more characteristic of the Asian population. The results have been included in the software application "Lekgen" that we developed for the interpretation of pharmacogenetic testing. The data of our study obtained on frequency carriers of polymorphisms of genes SLCO1B1, CYP2C19, CYP2C9, VKORC1 among the Yakuts may be useful in developing recommendations for a personalized therapy.

Frequency distribution of polymorphisms of CYP2C19, CYP2C9, VKORC1 and SLCO1B1 genes in the Yakut population

PubMed Central

Vasilyev, Filipp Filippovich; Danilova, Diana Aleksandrovna; Kaimonov, Vladimir Sergeevich; Chertovskih, Yana Valerievna; Maksimova, Nadezda Romanovna

2016-01-01

Allele frequencies of single nucleotide polymorphisms (SNPs) are variable among different populations; therefore the study of SNPs in ethnic groups is important for establishing the clinical significance of the screening of these polymorphisms. The main goal of the research is to study the polymorphisms of CYP2C9, CYP2C19, VKORC1, and SLCO1B1 in Yakuts. Genomic DNA from 229 Yakut subjects were analyzed by real-time polymerase chain reaction (PCR) (SLCO1B1 +521T > C, VKORC1 -1639G>A, CYP2C19 +681G>A, +636G>A, CYP2C9 +430С>T, +1075A>C). Genotype frequencies of polymorphisms in the population of the Yakuts were more characteristic of the Asian population. The results have been included in the software application “Lekgen” that we developed for the interpretation of pharmacogenetic testing. The data of our study obtained on frequency carriers of polymorphisms of genes SLCO1B1, CYP2C19, CYP2C9, VKORC1 among the Yakuts may be useful in developing recommendations for a personalized therapy. PMID:27499796

Metformin suppresses CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating aryl hydrocarbon receptor expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Do, Minh Truong; Kim, Hyung Gyun; Tran, Thi Thu Phuong

2014-10-01

Induction of cytochrome P450 (CYP) 1A1 and CYP1B1 by environmental xenobiotic chemicals or endogenous ligands through the activation of the aryl hydrocarbon receptor (AhR) has been implicated in a variety of cellular processes related to cancer, such as transformation and tumorigenesis. Here, we investigated the effects of the anti-diabetes drug metformin on expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and inducible conditions. Our results indicated that metformin down-regulated the expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced conditions. Down-regulation of AhR expression was required for metformin-mediated decreases in CYP1A1 andmore » CYP1B1 expression, and the metformin-mediated CYP1A1 and CYP1B1 reduction is irrelevant to estrogen receptor α (ERα) signaling. Furthermore, we found that metformin markedly down-regulated Sp1 protein levels in breast cancer cells. The use of genetic and pharmacological tools revealed that metformin-mediated down-regulation of AhR expression was mediated through the reduction of Sp1 protein. Metformin inhibited endogenous AhR ligand-induced CYP1A1 and CYP1B1 expression by suppressing tryptophan-2,3-dioxygenase (TDO) expression in MCF-7 cells. Finally, metformin inhibits TDO expression through a down-regulation of Sp1 and glucocorticoid receptor (GR) protein levels. Our findings demonstrate that metformin reduces CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating AhR signaling. Metformin would be able to act as a potential chemopreventive agent against CYP1A1 and CYP1B1-mediated carcinogenesis and development of cancer. - Graphical abstract: Schematic of the CYP1A1 and CYP1B1 gene regulation by metformin. - Highlights: • Metformin inhibits CYP1A1 and CYP1B1 expression. • Metformin down-regulates the AhR signaling. • Metformin reduces Sp1 protein expression. • Metformin suppresses TDO

Gene-Environment Interaction in Parkinson's Disease: Coffee, ADORA2A, and CYP1A2.

PubMed

Chuang, Yu-Hsuan; Lill, Christina M; Lee, Pei-Chen; Hansen, Johnni; Lassen, Christina F; Bertram, Lars; Greene, Naomi; Sinsheimer, Janet S; Ritz, Beate

2016-01-01

Drinking caffeinated coffee has been reported to provide protection against Parkinson's disease (PD). Caffeine is an adenosine A2A receptor (encoded by the gene ADORA2A) antagonist that increases dopaminergic neurotransmission and Cytochrome P450 1A2 (gene: CYP1A2) metabolizes caffeine; thus, gene polymorphisms in ADORA2A and CYP1A2 may influence the effect coffee consumption has on PD risk. In a population-based case-control study (PASIDA) in Denmark (1,556 PD patients and 1,606 birth year- and gender-matched controls), we assessed interactions between lifetime coffee consumption and 3 polymorphisms in ADORA2A and CYP1A2 for all subjects, and incident and prevalent PD cases separately using logistic regression models. We also conducted a meta-analysis combining our results with those from previous studies. We estimated statistically significant interactions for ADORA2A rs5760423 and heavy vs. light coffee consumption in incident (OR interaction = 0.66 [95% CI 0.46-0.94], p = 0.02) but not prevalent PD. We did not observe interactions for CYP1A2 rs762551 and rs2472304 in incident or prevalent PD. In meta-analyses, PD associations with daily coffee consumption were strongest among carriers of variant alleles in both ADORA2A and CYP1A2. We corroborated results from a previous report that described interactions between ADORA2A and CYP1A2 polymorphisms and coffee consumption. Our results also suggest that survivor bias may affect results of studies that enroll prevalent PD cases. © 2017 S. Karger AG, Basel.

Serotonin is an endogenous regulator of intestinal CYP1A1 via AhR.

PubMed

Manzella, Christopher; Singhal, Megha; Alrefai, Waddah A; Saksena, Seema; Dudeja, Pradeep K; Gill, Ravinder K

2018-04-17

Aryl hydrocarbon receptor (AhR) is a nuclear receptor that controls xenobiotic detoxification via induction of cytochrome P450 1A1 (CYP1A1) and regulates immune responses in the intestine. Metabolites of L-tryptophan activate AhR, which confers protection against intestinal inflammation. We tested the hypothesis that serotonin (5-HT) is an endogenous activator of AhR in intestinal epithelial cells. Treatment of Caco-2 monolayers with 5-HT induced CYP1A1 mRNA in a time- and concentration-dependent manner and also stimulated CYP1A1 activity. CYP1A1 induction by 5-HT was dependent upon uptake via serotonin transporter (SERT). Antagonism of AhR and knockdown of AhR and its binding partner aryl hydrocarbon receptor nuclear translocator (ARNT) attenuated CYP1A1 induction by 5-HT. Activation of AhR was evident by its nuclear translocation after 5-HT treatment and by induction of an AhR-responsive luciferase reporter. In vivo studies showed a dramatic decrease in CYP1A1 expression and other AhR target genes in SERT KO ileal mucosa by microarray analysis. These results suggest that intracellular accumulation of 5-HT via SERT induces CYP1A1 expression via AhR in intestinal epithelial cells, and SERT deficiency in vivo impairs activation of AhR. Our studies provide a novel link between the serotonergic and AhR pathways which has implications in xenobiotic metabolism and intestinal inflammation.

Influence of the genetic polymorphism in the 5'-noncoding region of the CYP1A2 gene on CYP1A2 phenotype and urinary mutagenicity in smokers.

PubMed

Pavanello, Sofia; Pulliero, Alessandra; Lupi, Silvia; Gregorio, Pasquale; Clonfero, Erminio

2005-11-10

The functional significance of genetic polymorphisms on tobacco smoke-induced CYP1A2 activity was examined. The influence of three polymorphisms of the cytochrome P450 1A2 gene (CYP1A2) (-3860 G-->A (allele *1C), -2467 T-->delT (allele *1D), -163C-->A (allele *1F)), located in the 5'-noncoding promoter region of the gene, on CYP1A2 activity (measured as caffeine metabolic ratio, CMR), was studied in Caucasian current smokers (n=95). Tobacco smoke intake was calculated from the number of cigarettes/day. Also, studied was the influence of these CYP1A2 genotypes on smoking-associated urinary mutagenicity, detected in Salmonella typhimurium strain YG1024 with S9 mix, considering the urinary excretion of nicotine plus its metabolites as an internal indicator of tobacco smoke exposure. Smokers with at least one of the variant alleles CYP1A2 -3860A and -2467 delT showed a significantly increased CYP1A2 CMR (-3860 G/A versus G/G, p<0.05; -2467 delT/delT versus T/delT and T/T, p<0.01). Multiple regression analysis showed that the increase in CYP1A2 CMR (ln values) was again significantly related to the presence of CYP1A2 variants -2467delT and also to variant -163A (p<0.05), but moderately to -3860A (p=0.084). No influence of the number of cigarettes smoked per day by each subject was found. Heavy smokers (n=48, with urinary nicotine plus its metabolites>or=0.69 mg/mmol creatinine) with variant allele -2467delT or -163A had significantly increased urinary mutagenicity (p<0.01 and <0.05). CYP1A2 genetic polymorphisms are shown to influence the CYP1A2 phenotype in smokers, -2467 T-->delT having the main effect. This information is of interest for future studies assessing the possible role of tobacco smoke-inducible CYP1A2 genotypes as individual susceptibility factors in exposure to carcinogens.

CYP1A1 and CYP1A2 expression: Comparing 'humanized' mouse lines and wild-type mice; comparing human and mouse hepatoma-derived cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uno, Shigeyuki; Endo, Kaori; Ishida, Yuji

2009-05-15

Human and rodent cytochrome P450 (CYP) enzymes sometimes exhibit striking species-specific differences in substrate preference and rate of metabolism. Human risk assessment of CYP substrates might therefore best be evaluated in the intact mouse by replacing mouse Cyp genes with human CYP orthologs; however, how 'human-like' can human gene expression be expected in mouse tissues? Previously a bacterial-artificial-chromosome-transgenic mouse, carrying the human CYP1A1{sub C}YP1A2 locus and lacking the mouse Cyp1a1 and Cyp1a2 orthologs, was shown to express robustly human dioxin-inducible CYP1A1 and basal versus inducible CYP1A2 (mRNAs, proteins, enzyme activities) in each of nine mouse tissues examined. Chimeric mice carryingmore » humanized liver have also been generated, by transplanting human hepatocytes into a urokinase-type plasminogen activator(+/+){sub s}evere-combined-immunodeficiency (uPA/SCID) line with most of its mouse hepatocytes ablated. Herein we compare basal and dioxin-induced CYP1A mRNA copy numbers, protein levels, and four enzymes (benzo[a]pyrene hydroxylase, ethoxyresorufin O-deethylase, acetanilide 4-hydroxylase, methoxyresorufin O-demethylase) in liver of these two humanized mouse lines versus wild-type mice; we also compare these same parameters in mouse Hepa-1c1c7 and human HepG2 hepatoma-derived established cell lines. Most strikingly, mouse liver CYP1A1-specific enzyme activities are between 38- and 170-fold higher than human CYP1A1-specific enzyme activities (per unit of mRNA), whereas mouse versus human CYP1A2 enzyme activities (per unit of mRNA) are within 2.5-fold of one another. Moreover, both the mouse and human hepatoma cell lines exhibit striking differences in CYP1A mRNA levels and enzyme activities. These findings are relevant to risk assessment involving human CYP1A1 and CYP1A2 substrates, when administered to mice as environmental toxicants or drugs.« less

Genetic variation in genes for the xenobiotic-metabolizing enzymes CYP1A1, EPHX1, GSTM1, GSTT1 and GSTP1 and susceptibility to colorectal cancer in Lynch syndrome

PubMed Central

Pande, Mala; Amos, Christopher I.; Osterwisch, Daniel R.; Chen, Jinyun; Lynch, Patrick M.; Broaddus, Russell; Frazier, Marsha L.

2011-01-01

Individuals with Lynch syndrome are predisposed to cancer due to an inherited DNA mismatch repair gene mutation. However, there is significant variability observed in disease expression, likely due to the influence of other environmental, lifestyle, or genetic factors. Polymorphisms in genes encoding xenobiotic-metabolizing enzymes may modify cancer risk by influencing the metabolism and clearance of potential carcinogens from the body. In this retrospective analysis, we examined key candidate gene polymorphisms in CYP1A1, EPHX1, GSTT1, GSTM1, and GSTP1 as modifiers of age at onset of colorectal cancer among 257 individuals with Lynch syndrome. We found that subjects heterozygous for CYP1A1 I462V (c.1384A>G) developed colorectal cancer 4 years earlier than those with the homozygous wild-type genotype (median ages 39 and 43 years, respectively; log-rank test P = 0.018). Furthermore, being heterozygous for the CYP1A1 polymorphisms, I462V and Msp1 (g.6235T>C), was associated with an increased risk for developing colorectal cancer [adjusted hazard ratio for AG relative to AA = 1.78, 95% CI = 1.16–2.74, P = 0.008; and hazard ratio for TC relative to TT = 1.53, 95% CI = 1.06–2.22, P = 0.02]. Since homozygous variants for both CYP1A1 polymorphisms were rare, risk estimates were imprecise. None of the other gene polymorphisms examined were associated with an earlier onset age for colorectal cancer. Our results suggest that the I462V and Msp1 polymorphisms in CYP1A1 may be an additional susceptibility factor for disease expression in Lynch syndrome since they modify the age of colorectal cancer onset by up to 4 years. PMID:18768509

Retinoid regulation of the zebrafish cyp26a1 promoter.

PubMed

Hu, Ping; Tian, Miao; Bao, Jie; Xing, Guangdong; Gu, Xingxing; Gao, Xiang; Linney, Elwood; Zhao, Qingshun

2008-12-01

Cyp26A1 is a major enzyme that controls retinoic acid (RA) homeostasis by metabolizing RA into bio-inactive metabolites. Previous research revealed that the mouse Cyp26A1 promoter has two canonical RA response elements (RAREs) that underlie the regulation of the gene by RA. Analyzing the 2,533-base pairs (2.5 k) genomic sequence upstream of zebrafish cyp26a1 start codon, we report that the two RAREs are conserved in zebrafish cyp26a1 promoter. Mutagenesis demonstrated that the two RAREs work synergistically in RA inducibility of cyp26a1. Fusing the 2.5 k (kilobase pairs) fragment to the enhanced yellow fluorescent protein (eYFP) reporter gene, we have generated two transgenic lines of zebrafish [Tg(cyp26a1:eYFP)]. The transgenic zebrafish display expression patterns similar to that of cyp26a1 gene in vivo. Consistent with the in vitro results, the reporter activity is RA inducible in embryos. Taken together, our results demonstrate that the 2.5 k fragment underlies the regulation of the zebrafish cyp26a1 gene by RA. (c) 2008 Wiley-Liss, Inc.

Pregnane X receptor-dependent induction of the CYP3A4 gene by o,p'-1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane.

PubMed

Medina-Díaz, Irma M; Arteaga-Illán, Georgina; de León, Mario Bermudez; Cisneros, Bulmaro; Sierra-Santoyo, Adolfo; Vega, Libia; Gonzalez, Frank J; Elizondo, Guillermo

2007-01-01

CYP3A4, the predominant cytochrome P450 (P450) expressed in human liver and intestine, contributes to the metabolism of approximately half the drugs in clinical use today. CYP3A4 catalyzes the 6beta-hydroxylation of a number of steroid hormones and is involved in the bioactivation of environmental procarcinogens. The expression of CYP3A4 is affected by several stimuli, including environmental factors such as insecticides and pesticides. The o,p'-1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane (DDT) isomer of DDT comprises approximately 20% of technical grade DDT, which is an organochloride pesticide. We have recently shown that o,p'-DDT exposure increases CYP3A4 mRNA levels in HepG2 cells. To determine the mechanism by which o,p'-DDT induces CYP3A4 expression, transactivation and electrophoretic mobility shift assays were carried out, revealing that o,p'-DDT activates the CYP3A4 gene promoter through the pregnane X receptor (PXR). CYP3A4 gene promoter activation resulted in both an increase in CYP3A4 mRNA levels and an increase in the total CYP3A4 activity in HepG2 cells. We also observed induction of CYP3A4 and mouse Cyp3a11 mRNA in the intestine of CYP3A4-transgenic mice after exposure to 1 mg/kg o,p'-DDT. At higher doses, a decrease of CYP3A4 inducibility was observed together with an increase in levels of interleukin 6 mRNA, a proinflammatory cytokine that strongly represses CYP3A4 transcription. The present study indicates that regulation of other genes under PXR control may be altered by o,p'-DDT exposure.

Genetic polymorphisms in MDR1, CYP3A4 and CYP3A5 genes in a Ghanaian population: a plausible explanation for altered metabolism of ivermectin in humans?

PubMed Central

2010-01-01

Background Ivermectin, a substrate of multidrug resistance (MDR1) gene and cytochrome P450 (CYP) 3A4, has been used successfully in the treatment of onchocerciasis in Ghana. However, there have been reports of suboptimal response in some patients after repeated treatment. Polymorphisms in host MDR1 and CYP3A genes may explain the observed suboptimal response to ivermectin. We genotyped relevant functional polymorphisms of MDR1 and CYP3A in a random sample of healthy Ghanaians and compared the data with that of ivermectin-treated patients with a view to exploring the relationship between suboptimal response to ivermectin and MDR1 and CYP3A allelic frequencies. Methods Using PCR-RFLP, relevant polymorphic alleles of MDR1 and CYP3A4 genes were analysed in 204 randomly selected individuals and in 42 ivermectin treated patients. Results We recorded significantly higher MDR1 (3435T) variant allele frequency in suboptimal responders (21%) than in patients who responded to treatment (12%) or the random population sample (11%). CYP3A4*1B, CYP3A5*3 and CYP3A5*6 alleles were detected at varied frequencies for the sampled Ghanaian population, responders and suboptimal responders to ivermectin. CYP3A5*1/CYP3A5*1 and CYP3A5*1/CYP3A5*3 genotypes were also found to be significantly different for responders and suboptimal responders. Haplotype (*1/*1/*3/*1) was determined to be significantly different between responders and suboptimal responders indicating a possible role of these haplotypes in treatment response with ivermectin. Conclusion A profile of pharmacogenetically relevant variants for MDR1, CYP3A4 and CYP3A5 genes has been generated for a random population of 204 Ghanaians to address the scarcity of data within indigenous African populations. In 42 patients treated with ivermectin, difference in MDR1 variant allele frequency was observed between suboptimal responders and responders. PMID:20630055

Genetic polymorphisms in MDR1, CYP3A4 and CYP3A5 genes in a Ghanaian population: a plausible explanation for altered metabolism of ivermectin in humans?

PubMed

Kudzi, William; Dodoo, Alexander N O; Mills, Jeremy J

2010-07-14

Ivermectin, a substrate of multidrug resistance (MDR1) gene and cytochrome P450 (CYP) 3A4, has been used successfully in the treatment of onchocerciasis in Ghana. However, there have been reports of suboptimal response in some patients after repeated treatment. Polymorphisms in host MDR1 and CYP3A genes may explain the observed suboptimal response to ivermectin. We genotyped relevant functional polymorphisms of MDR1 and CYP3A in a random sample of healthy Ghanaians and compared the data with that of ivermectin-treated patients with a view to exploring the relationship between suboptimal response to ivermectin and MDR1 and CYP3A allelic frequencies. Using PCR-RFLP, relevant polymorphic alleles of MDR1 and CYP3A4 genes were analysed in 204 randomly selected individuals and in 42 ivermectin treated patients. We recorded significantly higher MDR1 (3435T) variant allele frequency in suboptimal responders (21%) than in patients who responded to treatment (12%) or the random population sample (11%). CYP3A4*1B, CYP3A5*3 and CYP3A5*6 alleles were detected at varied frequencies for the sampled Ghanaian population, responders and suboptimal responders to ivermectin. CYP3A5*1/CYP3A5*1 and CYP3A5*1/CYP3A5*3 genotypes were also found to be significantly different for responders and suboptimal responders. Haplotype (*1/*1/*3/*1) was determined to be significantly different between responders and suboptimal responders indicating a possible role of these haplotypes in treatment response with ivermectin. A profile of pharmacogenetically relevant variants for MDR1, CYP3A4 and CYP3A5 genes has been generated for a random population of 204 Ghanaians to address the scarcity of data within indigenous African populations. In 42 patients treated with ivermectin, difference in MDR1 variant allele frequency was observed between suboptimal responders and responders.

CYP1A1 and CYP1A2 expression: Comparing ‘humanized’ mouse lines and wild-type mice; comparing human and mouse hepatoma-derived cell lines

PubMed Central

Uno, Shigeyuki; Endo, Kaori; Ishida, Yuji; Tateno, Chise; Makishima, Makoto; Yoshizato, Katsutoshi; Nebert, Daniel W.

2009-01-01

Human and rodent cytochrome P450 (CYP) enzymes sometimes exhibit striking species-specific differences in substrate preference and rate of metabolism. Human risk assessment of CYP substrates might therefore best be evaluated in the intact mouse by replacing mouse Cyp genes with human CYP orthologs; however, how “human-like” can human gene expression be expected in mouse tissues? Previously a bacterial-artificial-chromosome-transgenic mouse, carrying the human CYP1A1_CYP1A2 locus and lacking the mouse Cyp1a1 and Cyp1a2 orthologs, was shown to express robustly human dioxin-inducible CYP1A1 and basal versus inducible CYP1A2 (mRNAs, proteins, enzyme activities) in each of nine mouse tissues examined. Chimeric mice carrying humanized liver have also been generated, by transplanting human hepatocytes into a urokinase-type plasminogen activator(+/+)_severe-combined-immunodeficiency (uPA/SCID) line with most of its mouse hepatocytes ablated. Herein we compare basal and dioxin-induced CYP1A mRNA copy numbers, protein levels, and four enzymes (benzo[a]pyrene hydroxylase, ethoxyresorufin O-deethylase, acetanilide 4-hydroxylase, methoxyresorufin O-demethylase) in liver of these two humanized mouse lines versus wild-type mice; we also compare these same parameters in mouse Hepa-1c1c7 and human HepG2 hepatoma-derived established cell lines. Most strikingly, mouse liver CYP1A1-specific enzyme activities are between 38- and 170-fold higher than human CYP1A1-specific enzyme activities (per unit of mRNA), whereas mouse versus human CYP1A2 enzyme activities (per unit of mRNA) are within 2.5-fold of one another. Moreover, both the mouse and human hepatoma cell lines exhibit striking differences in CYP1A mRNA levels and enzyme activities. These findings are relevant to risk assessment involving human CYP1A1 and CYP1A2 substrates, when administered to mice as environmental toxicants or drugs. PMID:19285097

Mammalian cytochrome CYP2E1 triggered differential gene regulation in response to trichloroethylene (TCE) in a transgenic poplar.

PubMed

Kang, Jun Won; Wilkerson, Hui-Wen; Farin, Federico M; Bammler, Theo K; Beyer, Richard P; Strand, Stuart E; Doty, Sharon L

2010-08-01

Trichloroethylene (TCE) is an important environmental contaminant of soil, groundwater, and air. Studies of the metabolism of TCE by poplar trees suggest that cytochrome P450 enzymes are involved. Using poplar genome microarrays, we report a number of putative genes that are differentially expressed in response to TCE. In a previous study, transgenic hybrid poplar plants expressing mammalian cytochrome P450 2E1 (CYP2E1) had increased metabolism of TCE. In the vector control plants for this construct, 24 h following TCE exposure, 517 genes were upregulated and 650 genes were downregulated over 2-fold when compared with the non-exposed vector control plants. However, in the transgenic CYP2E1 plant, line 78, 1,601 genes were upregulated and 1,705 genes were downregulated over 2-fold when compared with the non-exposed transgenic CYP2E1 plant. It appeared that the CYP2E1 transgenic hybrid poplar plants overexpressing mammalian CYP2E1 showed a larger number of differentially expressed transcripts, suggesting a metabolic pathway for TCE to metabolites had been initiated by activity of CYP2E1 on TCE. These results suggest that either the over-expression of the CYP2E1 gene or the abundance of TCE metabolites from CYP450 2E1 activity triggered a strong genetic response to TCE. Particularly, cytochrome p450s, glutathione S-transferases, glucosyltransferases, and ABC transporters in the CYP2E1 transgenic hybrid poplar plants were highly expressed compared with in vector controls.

Molecular cloning and characterization of amh, dax1 and cyp19a1a genes and their response to 17α-methyltestosterone in Pengze crucian carp.

PubMed

Li, Meng; Wang, Lihong; Wang, Houpeng; Liang, Hongwei; Zheng, Yao; Qin, Fang; Liu, Shaozhen; Zhang, Yingying; Wang, Zaizhao

2013-05-01

The proteins encoded by amh, dax1 and cyp19a1a play important roles in gonad differentiation. Their functions have been far less studied in teleosts. In this study, the full-length cDNAs of amh, dax1 and cyp19a1a were cloned and characterized in a triploid gynogenic fish, the Pengze crucian carp. Their expression profilings in juvenile development, adult tissues and juveniles exposed to 100 ng/L 17α-methyltestosterone (MT) were investigated. Results showed that their putative proteins shared high identities to their counterparts in cyprinid fish species, respectively. The tissue distribution results indicated that amh and cyp19a1a were predominantly expressed in the ovary and dax1 was dominantly expressed in the liver. Gene profiling in the developmental stages showed that all the three target genes had a consistent highest expression at 48 days post hatching (dph). The period of 48 dph appeared to be a key time during the process of the gonad development of Pengze crucian carp. 100 ng/L MT significantly increased the mRNA expression of amh at 2- and 4-week exposures and enhanced dax1 and cyp19a1a at 6-week exposure. The present study indicated that MT could influence the gonad development in Pengze crucian carp by disturbing sex-differentiation associated gene expression. Furthermore, the present study will be of great significance to broaden the understanding of molecular mechanisms of the physiological processes of reproduction in fish. Copyright © 2013 Elsevier Inc. All rights reserved.

Cyp1b1 Regulates Ocular Fissure Closure Through a Retinoic Acid–Independent Pathway

PubMed Central

Williams, Antionette L.; Eason, Jessica; Chawla, Bahaar; Bohnsack, Brenda L.

2017-01-01

Purpose Mutations in the CYP1B1 gene are the most commonly identified genetic causes of primary infantile-onset glaucoma. Despite this disease association, the role of CYP1B1 in eye development and its in vivo substrate remain unknown. In the present study, we used zebrafish to elucidate the mechanism by which cyp1b1 regulates eye development. Methods Zebrafish eye and neural crest development were analyzed using live imaging of transgenic zebrafish embryos, in situ hybridization, immunostaining, TUNEL assay, and methylacrylate sections. Cyp1b1 and retinoic acid (RA) levels were genetically (morpholino oligonucleotide antisense and mRNA) and pharmacologically manipulated to examine gene function. Results Using zebrafish, we observed that cyp1b1 was expressed in a specific spatiotemporal pattern in the ocular fissures of the developing zebrafish retina and regulated fissure patency. Decreased Cyp1b1 resulted in the premature breakdown of laminin in the ventral fissure and altered subsequent neural crest migration into the anterior segment. In contrast, cyp1b1 overexpression inhibited cell survival in the ventral ocular fissure and prevented fissure closure via an RA-independent pathway. Cyp1b1 overexpression also inhibited the ocular expression of vsx2, pax6a, and pax6b and increased the extraocular expression of shha. Importantly, embryos injected with human wild-type but not mutant CYP1B1 mRNA also showed colobomas, demonstrating the evolutionary and functional conservation of gene function between species. Conclusions Cyp1b1 regulation of ocular fissure closure indirectly affects neural crest migration and development through an RA-independent pathway. These studies provide insight into the role of Cyp1b1 in eye development and further elucidate the pathogenesis of primary infantile-onset glaucoma. PMID:28192799

Polymorphisms in CYP1A1 and CYP3A5 Genes Contribute to the Variability in Granisetron Clearance and Exposure in Pregnant Women with Nausea and Vomiting.

PubMed

Bustos, Martha L; Zhao, Yang; Chen, Huijun; Caritis, Steve N; Venkataramanan, Raman

2016-12-01

Nausea and vomiting affect up to 90% of pregnant women. Granisetron is a potent and highly selective serotonin receptor antagonist and is an effective antiemetic. Findings from a prior study in pregnant women demonstrated a large interindividual variability in granisetron exposure. Granisetron is primarily metabolized by the cytochrome P450 (CYP) enzymes CYP1A1 and CYP3A and is likely a substrate of the ABCB1 transporter. Single-nucleotide polymorphisms (SNPs) in CYP3A, CYP1A1, and ABCB1 can alter drug metabolism. This study evaluated the influence of polymorphisms in CYP3A4, CYP3A5, CYP1A1, and ABCB1 on the pharmacokinetic properties of granisetron in pregnant women. The study enrolled 16 pregnant women (gestational age of 12-19 wks). All patients had nausea and vomiting and were treated with granisetron 1 mg. Granisetron plasma concentrations were determined using liquid chromatography tandem-mass spectrometry. The patients' genotype was determined using TaqMan SNP Genotyping Assays. The Hardy-Weinberg equilibrium was assessed by comparing observed and expected genotype frequencies, using the exact test. Intravenous granisetron clearance was used as the dependent variable for analysis of associations. Of 16 patients, 25% were homozygous for the allele variant CYP3A5*3 and had a significantly lower granisetron clearance and increased area under the plasma concentration-versus-time curve (AUC) compared with nonhomozygous patients. Approximately one-third of patients (n=5) were carriers for the allele variant CYP1A1*2A and had a significantly higher granisetron clearance and decreased AUC. We did not find significant differences in the AUC or clearance for any SNPs in CYP3A4 and ABCB1 genes. Polymorphisms in CYP3A5 and CYP1A1 account for some of the variability in systemic clearance and exposure of granisetron in pregnant women. © 2016 Pharmacotherapy Publications, Inc.

Orphan nuclear receptor oestrogen-related receptor γ (ERRγ) plays a key role in hepatic cannabinoid receptor type 1-mediated induction of CYP7A1 gene expression

PubMed Central

Zhang, Yaochen; Kim, Don-Kyu; Lee, Ji-Min; Park, Seung Bum; Jeong, Won-IL; Kim, Seong Heon; Lee, In-Kyu; Lee, Chul-Ho; Chiang, John Y.L.; Choi, Hueng-Sik

2017-01-01

Bile acids are primarily synthesized from cholesterol in the liver and have important roles in dietary lipid absorption and cholesterol homoeostasis. Detailed roles of the orphan nuclear receptors regulating cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid synthesis, have not yet been fully elucidated. In the present study, we report that oestrogen-related receptor γ (ERRγ) is a novel transcriptional regulator of CYP7A1 expression. Activation of cannabinoid receptor type 1 (CB1 receptor) signalling induced ERRγ-mediated transcription of the CYP7A1 gene. Overexpression of ERRγ increased CYP7A1 expression in vitro and in vivo, whereas knockdown of ERRγ attenuated CYP7A1 expression. Deletion analysis of the CYP7A1 gene promoter and a ChIP assay revealed an ERRγ -binding site on the CYP7A1 gene promoter. Small heterodimer partner (SHP) inhibited the transcriptional activity of ERRγ and thus regulated CYP7A1 expression. Overexpression of ERRγ led to increased bile acid levels, whereas an inverse agonist of ERRγ, GSK5182, reduced CYP7A1 expression and bile acid synthesis. Finally, GSK5182 significantly reduced hepatic CB1 receptor-mediated induction of CYP7A1 expression and bile acid synthesis in alcohol-treated mice. These results provide the molecular mechanism linking ERRγ and bile acid metabolism. PMID:26348907

Direct sequencing and comprehensive screening of genetic polymorphisms on CYP2 family genes (CYP2A6, CYP2B6, CYP2C8, and CYP2E1) in five ethnic populations.

PubMed

Kim, Jeong-Hyun; Cheong, Hyun Sub; Park, Byung Lae; Kim, Lyoung Hyo; Shin, Hee Jung; Na, Han Sung; Chung, Myeon Woo; Shin, Hyoung Doo

2015-01-01

Recently, CYP2A6, CYP2B6, CYP2C8, and CYP2E1 have been reported to play a role in the metabolic effect of pharmacological and carcinogenic compounds. Moreover, genetic variations of drug metabolism genes have been implicated in the interindividual variation in drug disposition and pharmacological response. To define the distribution of single nucleotide polymorphisms (SNPs) in these four CYP2 family genes and to discover novel SNPs across ethnic groups, 288 DNAs composed of 48 African-Americans, 48 European-Americans, 48 Japanese, 48 Han Chinese, and 96 Koreans were resequenced. A total of 143 SNPs, 26 in CYP2A6, 45 in CYP2B6, 29 in CYP2C8, and 43 in CYP2E1, were identified, including 13 novel variants. Notably, two SNPs in the regulatory regions, a promoter SNP rs2054675 and a nonsynonymous rs3745274 (p.172Q>H) in CYP2B6, showed significantly different minor allele frequencies (MAFs) among ethnic groups (minimum P = 4.30 × 10(-12)). In addition, rs2031920 in the promoter region of CYP2E1 showed a wide range of MAF between different ethnic groups, and even among other various ethnic groups based on public reports. Among 13 newly discovered SNPs in this study, 5 SNPs were estimated to have potential functions in further in silico analyses. Some differences in genetic variations and haplotypes of CYP2A6, CYP2B6, CYP2C8, and CYP2E1 were observed among populations. Our findings could be useful in further researches, such as genetic associations with drug responses.

New CYP1 genes in the frog Xenopus (Silurana) tropicalis: Induction patterns and effects of AHR agonists during development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joensson, Maria E., E-mail: maria.jonsson@ebc.uu.se; Biology Department, Redfield 3-42 MS 32, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543; Berg, Cecilia

2011-01-15

The Xenopus tropicalis genome shows a single gene in each of the four cytochrome P450 1 (CYP1) subfamilies that occur in vertebrates, designated as CYP1A, CYP1B1, CYP1C1, and CYP1D1. We cloned the cDNAs of these genes and examined their expression in untreated tadpoles and in tadpoles exposed to waterborne aryl hydrocarbon receptor agonists, 3,3',4,4',5-pentachlorobiphenyl (PCB126), {beta}-naphthoflavone ({beta}NF), or indigo. We also examined the effects of PCB126 on expression of genes involved in stress response, cell proliferation, thyroid homeostasis, and prostaglandin synthesis. PCB126 induced CYP1A, CYP1B1, and CYP1C1 but had little effect on CYP1D1 (77-, 1.7-, 4.6- and 1.4-fold induction versusmore » the control, respectively). {beta}NF induced CYP1A and CYP1C1 (26- and 2.5-fold), while, under conditions used, indigo tended to induce only CYP1A (1.9-fold). The extent of CYP1 induction by PCB126 and {beta}NF was positively correlated to the number of putative dioxin response elements 0-20 kb upstream of the start codons. No morphological effect was observed in tadpoles exposed to 1 nM-10 {mu}M PCB126 at two days post-fertilization (dpf) and screened 20 days later. However, in 14-dpf tadpoles a slight up-regulation of the genes for PCNA, transthyretin, HSC70, Cu-Zn SOD, and Cox-2 was observed two days after exposure to 1 {mu}M PCB126. This study of the full suite of CYP1 genes in an amphibian species reveals gene- and AHR agonist-specific differences in response, as well as a much lower sensitivity to CYP1 induction and short-term toxicity by PCB126 compared with in fish larvae. The single genes in each CYP1 subfamily may make X. tropicalis a useful model for mechanistic studies of CYP1 functions.« less

Diindolylmethane, a naturally occurring compound, induces CYP3A4 and MDR1 gene expression by activating human PXR

PubMed Central

Pondugula, Satyanarayana R.; Flannery, Patrick C.; Abbott, Kodye L.; Coleman, Elaine S.; Mani, Sridhar; Samuel, Temesgen; Xie, Wen

2015-01-01

Activation of human pregnane X receptor (hPXR)-regulated expression of cytochrome P450 3A4 (CYP3A4) and multidrug resistance protein 1 (MDR1) plays an important role in mediating adverse drug interactions. Given the common use of natural products as part of adjunct human health behavior, there is a growing concern about natural products for their potential to induce undesired drug interactions through the activation of hPXR-regulated CYP3A4 and MDR1. Here, we studied whether 3,3′-diindolylmethane (DIM), a natural health supplement, could induce hPXR-mediated regulation of CYP3A4 and MDR1 in human hepatocytes and intestinal cells. DIM, at its physiologically relevant concentrations, not only induced hPXR transactivation of CYP3A4 promoter activity but also induced gene expression of CYP3A4 and MDR1. DIM decreased intracellular accumulation of MDR1 substrate rhodamine 123, suggesting that DIM induces the functional expression of MDR1. Pharmacologic inhibition or genetic knockdown of hPXR resulted in attenuation of DIM induced CYP3A4 and MDR1 gene expression, suggesting that DIM induces CYP3A4 and MDR1 in an hPXR-dependent manner. Together, these results support our conclusion that DIM induces hPXR-regulated CYP3A4 and MDR1 gene expression. The inductive effects of DIM on CYP3A4 and MDR1 expression caution the use of DIM in conjunction with other medications metabolized and transported via CYP3A4 and MDR1, respectively. PMID:25542144

The CYP51F1 Gene of Leptographium qinlingensis: Sequence Characteristic, Phylogeny and Transcript Levels

PubMed Central

Dai, Lulu; Li, Zhumei; Yu, Jiamin; Ma, Mingyuan; Zhang, Ranran; Chen, Hui; Pham, Thanh

2015-01-01

Leptographium qinlingensis is a fungal associate of the Chinese white pine beetle (Dendroctonus armandi) and a pathogen of the Chinese white pine (Pinus armandi) that must overcome the terpenoid oleoresin defenses of host trees. L. qinlingensis responds to monoterpene flow with abundant mechanisms that include export and the use of these compounds as a carbon source. As one of the fungal cytochrome P450 proteins (CYPs), which play important roles in general metabolism, CYP51 (lanosterol 14-α demethylase) can catalyze the biosynthesis of ergosterol and is a target for antifungal drug. We have identified an L. qinlingensis CYP51F1 gene, and the phylogenetic analysis shows the highest homology with the 14-α-demethylase sequence from Grosmannia clavigera (a fungal associate of Dendroctonus ponderosae). The transcription level of CYP51F1 following treatment with terpenes and pine phloem extracts was upregulated, while using monoterpenes as the only carbon source led to the downregulation of CYP5F1 expression. The homology modeling structure of CYP51F1 is similar to the structure of the lanosterol 14-α demethylase protein of Saccharomyces cerevisiae YJM789, which has an N-terminal membrane helix 1 (MH1) and transmembrane helix 1 (TMH1). The minimal inhibitory concentrations (MIC) of terpenoid and azole fungicides (itraconazole (ITC)) and the docking of terpenoid molecules, lanosterol and ITC in the protein structure suggested that CYP51F1 may be inhibited by terpenoid molecules by competitive binding with azole fungicides. PMID:26016505

Effects of human blood levels of two PAH mixtures on the AHR signalling activation pathway and CYP1A1 and COMT target genes in granulosa non-tumor and granulosa tumor cell lines.

PubMed

Zajda, Karolina; Ptak, Anna; Rak, Agnieszka; Fiedor, Elżbieta; Grochowalski, Adam; Milewicz, Tomasz; Gregoraszczuk, Ewa L

2017-08-15

Epidemiological studies have shown a link between problems with offspring of couples living in a contaminated environment in comparison to those who live in an uncontaminated environment. We measured the concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) in maternal and cord blood. To explore the mechanism of the effects of PAH mixtures on nonluteinized granulosa cells (HGrC1) and granulosa tumor cells (COV434), as well as cell proliferation and apoptosis, we investigated the effect of PAH mixtures on the expression of the aryl hydrocarbon receptor (AHR), aryl hydrocarbon receptor nuclear translocator (ARNT) and aryl hydrocarbon receptor repressor (AHRR) genes, as well as the expression and activity of target genes cytochrome P450 1A1 (CYP1A1) and catechol-O-methyltransferase (COMT). The cells were exposed to mixture 1 (M1), composed of all 16 priority PAHs, and mixture 2 (M2), composed of five PAHs which are not classified as human carcinogens, and which are observed in the highest amounts both in maternal and cord blood. All 16 priority PAHs were bioavailable in maternal and cord plasma, suggesting that perinatal exposure should be considered. In HGrC1 cells, M1 increased AHR and ARNT, but decreased AHRR expression, in parallel with increased CYP1A1 and COMT expression and activity. M2 decreased AHR and AHRR, and increased ARNT, with no effect on CYP1A1 expression and activity; however, it did increase COMT expression and activity. In tumor cells, M1 lowered AHR and up-regulated AHRR and ARNT expression, consequently decreasing CYP1A1 expression and COMT activity. M2 up-regulated AHR and ARNT, down-regulated AHRR, and had no effect on CYP1A1 and COMT expression, but decreased COMT activity. We hypothesise that, dependent on composition, mixtures of PAHs activate the AHR differently through varying transcription responses: in HGrC1, a canonical AHR mechanism of M1, with activation of CYP1A1 important for detoxication, while in COV434, a

Genetic screening of non-classic CAH females with hyperandrogenemia identifies a novel CYP11B1 gene mutation.

PubMed

Shammas, Christos; Byrou, Stefania; Phelan, Marie M; Toumba, Meropi; Stylianou, Charilaos; Skordis, Nicos; Neocleous, Vassos; Phylactou, Leonidas A

2016-04-01

Congenital adrenal hyperplasia (CAH) is an endocrine autosomal recessive disorder with various symptoms of diverse severity. Mild hyperandrogenemia is the most commonclinical feature in non-classic CAH patients and 95% of the cases are identified by mutations in the CYP21A2 gene. In the present study, the second most common cause for non-classic CAH (NC-CAH), 11β-hydroxylase deficiency due to mutations in the CYP11B1 gene, is investigated. Screening of the CYP21A2 and CYP11B1 genes by direct sequencing was carried out for the detection of possible genetic defects in patients with suspected CAH. It wasobserved that CYP11B1 variants co-exist only in rare cases along with mutations in CYP21A2 in patients clinically diagnosed with CAH. A total of 23 NC-CAH female patients out of 75 were identified with only one mutation in the CYP21A2 gene. The novel CYP11B1 gene mutation, p.Val484Asp, was identified in a patient with CAH in the heterozygous state. The structural characterization of the novel p.Val484Asp was found to likely cause distortion of the surrounding beta sheet and indirect destabilization of the cavity that occurs on the opposite face of the structural elements, leading to partial impairment of the enzymatic activity. CYP21A2 gene mutations are the most frequent genetic defects in cases of NC-CAH even when these patients are in the heterozygous state. These mutations have a diverse phenotype giving rise to a variable extent of cortisol synthesis impairment; it is also clear that CYP11B1 mutants are a rare type of defects causing CAH.

Tangeretin inhibits the proliferation of human breast cancer cells via CYP1A1/CYP1B1 enzyme induction and CYP1A1/CYP1B1-mediated metabolism to the product 4' hydroxy tangeretin.

PubMed

Surichan, Somchaiya; Arroo, Randolph R; Tsatsakis, Aristidis M; Androutsopoulos, Vasilis P

2018-04-04

Tangeretin is a polymethoxylated flavone with multifaceted anticancer activity. In the present study, the metabolism of tangeretin was evaluated in the CYP1 expressing human breast cancer cell lines MCF7 and MDA-MB-468 and in the normal breast cell line MCF10A. Tangeretin was converted to 4' OH tangeretin by recombinant CYP1 enzymes and by CYP1 enzymes expressed in MCF7 and MDA-MB-468 cells. This metabolite was absent in MCF10A cells that did not express CYP1 enzymes. Tangeretin exhibited submicromolar IC50 (0.25 ± 0.15 μM) in MDA-MB-468 cells, whereas it was less active in MCF7 cells (39.3 ± 1.5 μM) and completely inactive in MCF10A cells (>100 μM). In MDA-MB-468 cells that were coincubated with the CYP1 inhibitor acacetin, an approximately 70-fold increase was noted in the IC50 (18 ± 1.6 μM) of tangeretin. In the presence of the CYP1 inhibitor acacetin, the conversion of tangeretin to 4' OH tangeretin was significantly reduced in MDA-MB-468 cells (2.55 ± 0.19 μM vs. 6.33 ± 0.12 μM). The mechanism of antiproliferative action involved cell cycle arrest at the G1 phase for MCF7 and MDA-MB-468 cells. Tangeretin was further shown to induce CYP1 enzyme activity and CYP1A1/CYP1B1 protein expression in MCF7 and MDA-MB-468 cells. These results suggest that tangeretin inhibits the proliferation of breast cancer cells via CYP1A1/CYP1B1-mediated metabolism to the product 4' hydroxy tangeretin. Copyright © 2018 Elsevier Ltd. All rights reserved.

A novel pathogenic mutation of the CYP27B1 gene in a patient with vitamin D-dependent rickets type 1: a case report.

PubMed

Babiker, Amir M I; Al Gadi, Iman; Al-Jurayyan, Nasir A M; Al Nemri, Abdulrahman M H; Al Haboob, Ali Abdu N; Al Boukai, Ahmed Amer; Al Zahrani, Ali; Habib, Hanan Ahmed

2014-11-05

Rickets can occur due to Vitamin D deficiency or defects in its metabolism. Three rare genetic types of rickets with different alterations of genes have been reported, including: Vitamin D dependent rickets type 1, Vitamin D dependent rickets type 2 or also known as Vitamin D resistant rickets and 25 hydroxylase deficiency rickets. Vitamin D dependent rickets type 1 is inherited in an autosomal recessive pattern, and is caused by mutations in the CYP27B1 gene encoding the 1α-hydroxylase enzyme. We report here a new mutation in CYP27B1, which lead to Vitamin D dependent rickets type 1. We report on a 13-month-old Arabic Saudi girl with Vitamin D dependent rickets type 1 presented with multiple fractures and classic features of rickets. A whole exome sequencing identified a novel pathogenic missense mutation (CYP27B1:Homozygous c.1510C > T(p.Q504X)) which results in a protein truncating alteration. Both parents are heterozygous carriers of the mutation. Based on data search in Human Gene Mutation Database, 63 CYP27B1 alterations were reported: only 28.6% are protein truncating (5 nonsense, 13 frameshift insertions/deletions, 0 gross deletions), while 61.9% are non-truncating (38 missense, 1 small in-frame insertions/deletion), and 9.5% are possible protein-truncating (5 splice, 1 regulatory). The deleterious effect of this alteration, which was the only mutation detected in the CYP27B1 common gene of Vitamin D dependent rickets type 1 in the proband, and its autosomal recessive inheritance fashion, both support a pathogenic nature of this mutation as the cause of Vitamin D dependent rickets type 1.

Heat shock factor-1 knockout enhances cholesterol 7α-hydroxylase (CYP7A1) and multidrug transporter (MDR1) gene expressions to attenuate atherosclerosis

PubMed Central

Krishnamurthy, Karthikeyan; Glaser, Shannon; Alpini, Gianfranco D.; Cardounel, Arturo J.; Liu, Zhenguo; Ilangovan, Govindasamy

2016-01-01

Aims Stress response, in terms of activation of stress factors, is known to cause obesity and coronary heart disease such as atherosclerosis in human. However, the underlying mechanism(s) of these pathways are not known. Here, we investigated the effect of heat shock factor-1 (HSF-1) on atherosclerosis. Methods and results HSF-1 and low-density lipoprotein receptor (LDLr) double knockout (HSF-1−/−/LDLr−/−) and LDLr knockout (LDLr−/−) mice were fed with atherogenic western diet (WD) for 12 weeks. WD-induced weight gain and atherosclerotic lesion in aortic arch and carotid regions were reduced in HSF-1−/−/LDLr−/− mice, compared with LDLr−/− mice. Also, repression of PPAR-γ2 and AMPKα expression in adipose tissue, low hepatic steatosis, and lessened plasma adiponectins and lipoproteins were observed. In HSF-1−/−/LDLr−/− liver, higher cholesterol 7α-hydroxylase (CYP7A1) and multidrug transporter [MDR1/P-glycoprotein (P-gp)] gene expressions were observed, consistent with higher bile acid transport and larger hepatic bile ducts. Luciferase reporter gene assays with wild-type CYP7A1 and MDR1 promoters showed lesser luminescence than with mutant promoters (HSF-1 binding site deleted), indicating that HSF-1 binding is repressive of CYP7A1 and MDR1 gene expressions. Conclusion HSF-1 ablation not only eliminates heat shock response, but it also transcriptionally up-regulates CYP7A1 and MDR1/P-gp axis in WD-diet fed HSF-1−/−/LDLr−/− mice to reduce atherosclerosis. PMID:27131506

Novel cytochrome P450 genes, CYP6EB1 and CYP6EC1, are over-expressed in acrinathrin-resistant Frankliniella occidentalis (Thysanoptera: Thripidae).

PubMed

Cifuentes, D; Chynoweth, R; Guillén, J; De la Rúa, P; Bielza, P

2012-06-01

Control of Frankliniella occidentalis (Pergande) is a serious problem for agriculture all over the world because of the limited range of insecticides that are available. Insecticide resistance in F. occidentalis has been reported for all major insecticide groups. Our previous studies showed that cytochrome P450-mediated detoxification is a major mechanism responsible for insecticide resistance in this pest. Degenerate polymerase chain reaction was used to identify P450 genes that might be involved in acrinathrin resistance, in a laboratory population of F. occidentalis. Associated sequences were classified as belonging to the CYP4 and CYP6 families. Real-time quantitative polymerase chain reaction analyses revealed that two genes, CYP6EB1 and CYP6EC1, were over-expressed in adults and L2 larvae of the resistant population, when compared with the susceptible population, suggesting their possible involvement in resistance to acrinathrin.

Targeted delivery of CYP2E1 recombinant adenovirus to malignant melanoma by bone marrow-derived mesenchymal stem cells as vehicles.

PubMed

Wang, Jishi; Ma, Dan; Li, Yan; Yang, Yuan; Hu, Xiaoyan; Zhang, Wei; Fang, Qin

2014-03-01

The aim of this study was to explore the effects of bone marrow-derived mesenchymal stem cells (BMSCs) as intermediate carriers on targeting of P450 gene recombinant adenovirus to malignant melanoma in vitro and in vivo. BMSCs were transduced with pAd5-CMV-CYP2E1 recombinant adenovirus. BMSC migration was detected by Transwell plates in vitro and by superparamagnetic iron oxide particles in vivo. Growth-inhibitory effect and apoptosis were determined by MTT and immunity fluorescence staining. Anticancer effects were examined by a human melanoma nude mouse model in vivo. BMSCs moved toward A375 cells in Transwell plates. Numerous superparamagnetic MSCs labeled with iron oxide were identified in the peripheral areas of the tumor, but were detected in primary organs by Prussian blue staining. BMSC-CYP2E1 cells mediated a bystander killing effect on CYP2E1-negative A375 cells during coculture (IC50 values for A375 cells cocultured with BMSC-EGFP and BMSC-CYP2E1 were 4.08 and 2.68 mmol/l, respectively). Intravenously injecting CYP2E1 recombinant adenovirus-loaded BMSCs in mice with established human melanoma managed to target the tumor site, and BMSCs with forced expression of CYP2E1 inhibited the growth of malignant cells in vivo by activating 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide. BMSCs may serve as a platform of P450 gene-directed enzyme prodrug therapy for the delivery of chemotherapeutic prodrugs to tumors.

Role of zebrafish cytochrome P450 CYP1C genes in the reduced mesencephalic vein blood flow caused by activation of AHR2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubota, Akira, E-mail: akubota@whoi.edu; Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543; Stegeman, John J.

2011-06-15

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes various signs of toxicity in early life stages of vertebrates through activation of the aryl hydrocarbon receptor (AHR). We previously reported a sensitive and useful endpoint of TCDD developmental toxicity in zebrafish, namely a decrease in blood flow in the dorsal midbrain, but downstream genes involved in the effect are not known. The present study addressed the role of zebrafish cytochrome P450 1C (CYP1C) genes in association with a decrease in mesencephalic vein (MsV) blood flow. The CYP1C subfamily was recently discovered in fish and includes the paralogues CYP1C1 and CYP1C2, both of which are induced viamore » AHR2 in zebrafish embryos. We used morpholino antisense oligonucleotides (MO or morpholino) to block initiation of translation of the target genes. TCDD-induced mRNA expression of CYP1Cs and a decrease in MsV blood flow were both blocked by gene knockdown of AHR2. Gene knockdown of CYP1C1 by two different morpholinos and CYP1C2 by two different morpholinos, but not by their 5 nucleotide-mismatch controls, was effective in blocking reduced MsV blood flow caused by TCDD. The same CYP1C-MOs prevented reduction of blood flow in the MsV caused by {beta}-naphthoflavone (BNF), representing another class of AHR agonists. Whole-mount in situ hybridization revealed that mRNA expression of CYP1C1 and CYP1C2 was induced by TCDD most strongly in branchiogenic primordia and pectoral fin buds. In situ hybridization using head transverse sections showed that TCDD increased the expression of both CYP1Cs in endothelial cells of blood vessels, including the MsV. These results indicate a potential role of CYP1C1 and CYP1C2 in the local circulation failure induced by AHR2 activation in the dorsal midbrain of the zebrafish embryo. - Research Highlights: > We examine the roles of zebrafish CYP1C1 and CYP1C2 in TCDD developmental toxicity. > TCDD induces mRNA expression of both CYP1Cs in the mesencephalic vein. > Knockdown

Influence of Genetic Ancestry on INDEL Markers of NFKβ1, CASP8, PAR1, IL4 and CYP19A1 Genes in Leprosy Patients.

PubMed

Pinto, Pablo; Salgado, Claudio; Santos, Ney Pereira Carneiro; Santos, Sidney; Ribeiro-dos-Santos, Ândrea

2015-01-01

Leprosy is an insidious infectious disease caused by the obligate intracellular bacteria Mycobacterium leprae, and host genetic factors can modulate the immune response and generate distinct categories of leprosy susceptibility that are also influenced by genetic ancestry. We investigated the possible effects of CYP19A1 [rs11575899], NFKβ1 [rs28362491], IL1α [rs3783553], CASP8 [rs3834129], UGT1A1 [rs8175347], PAR1 [rs11267092], CYP2E1 [INDEL 96pb] and IL4 [rs79071878] genes in a group of 141 leprosy patients and 180 healthy individuals. The INDELs were typed by PCR Multiplex in ABI PRISM 3130 and analyzed with GeneMapper ID v3.2. The NFKβ1, CASP8, PAR1 and IL4 INDELs were associated with leprosy susceptibility, while NFKβ1, CASP8, PAR1 and CYP19A1 were associated with the MB (Multibacilary) clinical form of leprosy. NFKβ1 [rs28362491], CASP8 [rs3834129], PAR1 [rs11267092] and IL4 [rs79071878] genes are potential markers for susceptibility to leprosy development, while the INDELs in NFKβ1, CASP8, PAR1 and CYP19A1 (rs11575899) are potential markers for the severe clinical form MB. Moreover, all of these markers are influenced by genetic ancestry, and European contribution increases the risk to leprosy development, in other hand an increase in African contribution generates protection against leprosy.

Drosophila CYP6g1 and its human homolog CYP3A4 confer tolerance to methylmercury during development

PubMed Central

Rand, Matthew D.; Lowe, Jessica A.; Mahapatra, Cecon T.

2012-01-01

Methylmercury (MeHg) is a persistent environmental toxicant that is commonly encountered through dietary fish and seafood. While the fetal nervous system is a well-known primary target for MeHg toxicity, the risks of MeHg exposures that are commonly experienced today through diet and environmental exposure remain uncertain. Despite knowledge of numerous cellular processes that are affected by MeHg, the mechanisms that ultimately influence tolerance or susceptibility to MeHg in the developing fetus are not well understood. Using transcriptomic analyses of developing brains of MeHg tolerant and susceptible strains of Drosophila, we previously identified members of the cytochrome p450 (CYP) family of monooxygenases/oxidoreductases as candidate MeHg tolerance genes. While CYP genes encode Phase I enzymes best known for xenobiotic metabolism in the liver, several classes of CYPs are required for synthesis or degradation of essential endobiotics, such as hormones and fatty acids, that are critical to normal development. We now demonstrate that variation in expression CYP genes can strongly influence MeHg tolerance in the developing fly. Importantly, modulating expression of a single CYP, CYP6g1, specifically in neurons or the fat body (liver equivalent) is sufficient to rescue development in the presence of MeHg. We also demonstrate a conserved function for CYP3A4, a human homolog of CYP6g1, in conferring MeHg tolerance to flies. Finally, we show that pharmacological induction of CYPs with caffeine parallels an increase in tolerance to MeHg in developing flies. These findings establish a previously unidentified role for CYPs in MeHg toxicity and point to a potentially conserved role of CYP genes to influence susceptibility to MeHg toxicity across species. PMID:22699155

Mapping of Gene Expression Reveals CYP27A1 as a Susceptibility Gene for Sporadic ALS

PubMed Central

van Rheenen, Wouter; Franke, Lude; Jansen, Ritsert C.; van Es, Michael A.; van Vught, Paul W. J.; Blauw, Hylke M.; Groen, Ewout J. N.; Horvath, Steve; Estrada, Karol; Rivadeneira, Fernando; Hofman, Albert; Uitterlinden, Andre G.; Robberecht, Wim; Andersen, Peter M.; Melki, Judith; Meininger, Vincent; Hardiman, Orla; Landers, John E.; Brown, Robert H.; Shatunov, Aleksey; Shaw, Christopher E.; Leigh, P. Nigel; Al-Chalabi, Ammar; Ophoff, Roel A.

2012-01-01

Amyotrophic lateral sclerosis (ALS) is a progressive, neurodegenerative disease characterized by loss of upper and lower motor neurons. ALS is considered to be a complex trait and genome-wide association studies (GWAS) have implicated a few susceptibility loci. However, many more causal loci remain to be discovered. Since it has been shown that genetic variants associated with complex traits are more likely to be eQTLs than frequency-matched variants from GWAS platforms, we conducted a two-stage genome-wide screening for eQTLs associated with ALS. In addition, we applied an eQTL analysis to finemap association loci. Expression profiles using peripheral blood of 323 sporadic ALS patients and 413 controls were mapped to genome-wide genotyping data. Subsequently, data from a two-stage GWAS (3,568 patients and 10,163 controls) were used to prioritize eQTLs identified in the first stage (162 ALS, 207 controls). These prioritized eQTLs were carried forward to the second sample with both gene-expression and genotyping data (161 ALS, 206 controls). Replicated eQTL SNPs were then tested for association in the second-stage GWAS data to find SNPs associated with disease, that survived correction for multiple testing. We thus identified twelve cis eQTLs with nominally significant associations in the second-stage GWAS data. Eight SNP-transcript pairs of highest significance (lowest p = 1.27×10−51) withstood multiple-testing correction in the second stage and modulated CYP27A1 gene expression. Additionally, we show that C9orf72 appears to be the only gene in the 9p21.2 locus that is regulated in cis, showing the potential of this approach in identifying causative genes in association loci in ALS. This study has identified candidate genes for sporadic ALS, most notably CYP27A1. Mutations in CYP27A1 are causal to cerebrotendinous xanthomatosis which can present as a clinical mimic of ALS with progressive upper motor neuron loss, making it a plausible susceptibility gene for

Isolation and characterization of cyp19a1a and cyp19a1b promoters in the protogynous hermaphrodite orange-spotted grouper (Epinephelus coioides).

PubMed

Zhang, Weimin; Lu, Huijie; Jiang, Haiyan; Li, Mu; Zhang, Shen; Liu, Qiongyou; Zhang, Lihong

2012-02-01

Aromatase (CYP19A1) catalyzes the conversion of androgens to estrogens. In teleosts, duplicated copies of cyp19a1 genes, namely cyp19a1a and cyp19a1b, were identified, however, the transcriptional regulation of these two genes remains poorly understood. In the present study, the 5'-flanking regions of the orange-spotted grouper cyp19a1a (gcyp19a1a) and cyp19a1b (gcyp19a1b) genes were isolated and characterized. The proximal promoter regions of both genes were relatively conserved when compared to those of the other teleosts. Notably, a conserved FOXO transcriptional factor binding site was firstly reported in the proximal promoter of gcyp19a1a, and deletion of the region (-112 to -60) containing this site significantly decreased the promoter activities. The deletion of the region (-246 to -112) containing the two conserved FTZ-F1 sites also dramatically decreased the transcriptional activities of gcyp19a1a promoter, and both two FTZ-F1 sites were shown to be stimulatory cis-acting elements. A FTZ-F1 homologue isolated from ricefield eel (eFTZ-F1) up-regulated gcyp19a1a promoter activities possibly via the FTZ-F1 sites, however, a previously identified orange-spotted grouper FTZ-F1 homologue (gFTZ-F1) did not activate the transcription of gcyp19a1a promoter unexpectedly. As to gcyp19a1b promoter, all the deletion constructs did not show good promoter activities in either TM4 or U251-MG cells. Estradiol (100nM) up-regulated gcyp19a1b promoter activities by about 13- and 36-fold in TM4 and U251-MG cells, respectively, via the conserved ERE motif, but did not stimulate gcyp19a1a promoter activities. These results are helpful to further elucidate the regulatory mechanisms of cyp19a1a and cyp19a1b expression in the orange-spotted grouper as well as other teleosts. Copyright © 2011 Elsevier Inc. All rights reserved.

Sudan III dye strongly induces CYP1A1 mRNA expression in HepG2 cells.

PubMed

Ohno, Marumi; Ikenaka, Yoshinori; Ishizuka, Mayumi

2012-01-01

Sudan dyes possess a high affinity to the aryl hydrocarbon receptor (AHR) and potently induce its target genes, such as cytochrome P450 (CYP) 1A1, through unknown mechanisms. We investigated a detailed event occurring in cells after binding of Sudan dye to AHR in HepG2 cells. Treatment with 10 µM Sudan III caused rapid translocation of AHR into the nucleus and increased expression levels of human CYP1A1 mRNA by approximately 20-fold after 16 and 24 h. The transactivation was due to the activation of a region located at -1137 to +59 bp from CYP1A1, in particular, four xenobiotic responsive elements (XREs) existing in the region. AHR and the Ah receptor nuclear translocator interacted with XRE sequences in a gel shift assay using nuclear extract from Sudan III--treated HepG2 cells. Moreover, we suggest that constitutive androstane receptor could modify CYP1A1 transactivation by Sudan III. Copyright © 2012 Wiley Periodicals, Inc.

Concomitance of oncogenic HPV types, CHEK2 gene mutations, and CYP1B1 gene polymorphism as an increased risk factor for malignancy.

PubMed

Banaszkiewicz, Monika; Constantinou, Maria; Pietrusiński, Michał; Kępczyński, Lukasz; Jędrzejczyk, Adam; Rożniecki, Marek; Marks, Piotr; Kałużewski, Bogdan

2013-01-01

Urinary bladder carcinoma ranks the fourth position in malignancy incidence rates in men (6.1%) and the 17th position in women (1.6%). In general, neoplastic diseases should be approached from two perspectives: prevention with implementation of prophylactic measures and early diagnostics. Prophylactics is possible in the preclinical phase of neoplasm, being both justified and plausible in patients from high-risk groups. Thus, it is particularly important to select such groups, not only by referring to environmental carcinogenic factors (occupational and extra-occupational) but also from genetic predisposition, which may be conductive for neoplasm formation. The mutations / polymorphisms of CHEK2 and CYP1B1 genes predispose to neoplasm via multiorgan mechanisms, while the human papilloma virus (HPV) may participate in the neoplastic transformation as an environmental factor. 131 patients with diagnosed urinary bladder cancer were qualified to the study. Mutations/polymorphisms of CHEK2 (IVS2 + 1G > A gene, 1100delC, del5395, I157T) and CYP1B1- 355T/T were identified by the PCR in DNA isolated directly from the tumor and from peripheral blood. The ELISA test was used for the studies of 37 HPV genotypes in DNA, isolated tumour tissue. 11 mutations of CHEK2 gene were found, 355T/T polymorphism if CYP1B1 gene occurred in 18 patients (12.9%). Oncogenic HPV was found in 36 (29.3%), out of 123 examined patients. The concomitance of CHEK2 gene mutations or 355T/T polymorphism of CYP1B1 gene and the presence of oncogenic HPV types statistically significantly correlates with histological malignancy grades of urinary bladder carcinoma.

Design synthesis and evaluation of the inhibitory selectivity of novel trans-resveratrol analogues on human recombinant CYP1A1 CYP1A2 and CYP1B1

USDA-ARS?s Scientific Manuscript database

A series of trans-stilbene derivatives containing 4’-thiomethyl substituent were synthesized and evaluated for inhibitory activities on human recombinant cytochrome P450(s): CYP1A1, CYP1A2, and CYP1B1. CYP1A2-related metabolism of stilbene derivatives was estimated by using NADPH oxidation assay. A...

The cytochrome P450 2AA gene cluster in zebrafish (Danio rerio): Expression of CYP2AA1 and CYP2AA2 and response to phenobarbital-type inducers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubota, Akira; Bainy, Afonso C.D.; Departamento de Bioquímica, CCB, Universidade Federal de Santa Catarina, Florianopolis, SC 88040-900

2013-10-01

The cytochrome P450 (CYP) 2 gene family is the largest and most diverse CYP gene family in vertebrates. In zebrafish, we have identified 10 genes in a new subfamily, CYP2AA, which does not show orthology to any human or other mammalian CYP genes. Here we report evolutionary and structural relationships of the 10 CYP2AA genes and expression of the first two genes, CYP2AA1 and CYP2AA2. Parsimony reconstruction of the tandem duplication pattern for the CYP2AA cluster suggests that CYP2AA1, CYP2AA2 and CYP2AA3 likely arose in the earlier duplication events and thus are most diverged in function from the other CYP2AAs.more » On the other hand, CYP2AA8 and CYP2AA9 are genes that arose in the latest duplication event, implying functional similarity between these two CYPs. A molecular model of CYP2AA1 showing the sequence conservation across the CYP2AA cluster reveals that the regions with the highest variability within the cluster map onto CYP2AA1 near the substrate access channels, suggesting differing substrate specificities. Zebrafish CYP2AA1 transcript was expressed predominantly in the intestine, while CYP2AA2 was most highly expressed in the kidney, suggesting differing roles in physiology. In the liver CYP2AA2 expression but not that of CYP2AA1, was increased by 1,4-bis [2-(3,5-dichloropyridyloxy)] benzene (TCPOBOP) and, to a lesser extent, by phenobarbital (PB). In contrast, pregnenolone 16α-carbonitrile (PCN) increased CYP2AA1 expression, but not CYP2AA2 in the liver. The results identify a CYP2 subfamily in zebrafish that includes genes apparently induced by PB-type chemicals and PXR agonists, the first concrete in vivo evidence for a PB-type response in fish. - Highlights: • A tandemly duplicated cluster of ten CYP2AA genes was described in zebrafish. • Parsimony and duplication analyses suggest pathways to CYP2AA diversity. • Homology models reveal amino acid positions possibly related to functional diversity. • The CYP2AA locus does not share

Expression and inducibility of CYP1A1, 1A2, 1B1 by β-naphthoflavone and CYP2B22, CYP3As by rifampicin in heart regions and coronary arteries of pig.

PubMed

Messina, Andrea; Puccinelli, Emanuela; Gervasi, Pier Giovanni; Longo, Vincenzo

2013-02-01

In this study, the constitutive and inducible expression of the CYP genes (1A1, 1A2, 1B1, 2B22, 3A22, 3A29 and 3A46), related transcriptional factors (AhR, CAR, PXR, and Nrf2) and the antioxidant enzymes SOD, catalase, GSSH-reductase and GSH-peroxidase were investigated in the liver, heart regions and coronary arteries of control pigs and pigs treated with β-naphthoflavone (βNF) or with rifampicin (RIF). Real-time PCR experiments and enzymatic or immunoblot assays showed that CYP1A1 was predominantly enhanced by βNF in a similar manner in all the heart regions, whereas antioxidant enzyme activity was not affected. The rifampicin treatment resulted in an induction of CYP2B22 and CYP3As, at the transcriptional, activity and protein level in liver but not in heart nor in the coronary arteries, despite the expression of CAR and PXR in the cardiac tissues. These results obtained in vivo suggest that pig cardiac tissues may represent a useful model for humans. Copyright © 2012 Elsevier Ltd. All rights reserved.

Impact of CYP2E1, GSTA1 and GSTP1 gene variants on serum alpha glutathione S-transferase level in patients undergoing anaesthesia.

PubMed

Mikstacki, Adam; Skrzypczak-Zielinska, Marzena; Zakerska-Banaszak, Oliwia; Tamowicz, Barbara; Skibinska, Maria; Molinska-Glura, Marta; Szalata, Marlena; Slomski, Ryszard

2016-05-14

The serum glutathione S-transferase alpha (α-GST) concentration has been used as a marker of hepatic condition. After sevoflurane anaesthesia a mild impairment of hepatocellular integrity was observed. Genetic polymorphisms in CYP2E1, GSTA1 and GSTP1 genes, affecting enzymes activity, may possibly influence the hepatotoxic effect of sevoflurane. The aim of this study was to assess the influence of genetic polymorphism of CYP2E1, GSTA1 and GSTP1 genes on serum α-GST level in 86 unrelated patients representing ASA physical status I-II, undergoing laryngological surgery under general anaesthesia with sevoflurane. The serum samples from three perioperative time points were analyzed using ELISA. Genetic variants were detected by pyrosequencing and sequencing. Finally, the statistical associations between serum α-GST concentration and analyzed alleles of CYP2E1, GSTP1 and GSTA1 genes were estimated. The allele GSTA1*B (-567G, -69T, -52A) frequency was 0.43, whereas the alleles c.313G and c.341T of GSTP1 were identified with frequencies of 0.28 and 0.1 respectively. The -1053T allele of the CYP2E1 gene was observed with 0.01 frequency. We found serum α-GST concentrations in homozygous changes c.313A>G and c.341C>T of the GSTP1 gene significantly higher at the end of anaesthesia as compared with the levels at pre-anaesthetic and 24 h post-anaesthetic time points. Moreover, GSTA1 wild type genotype was associated with increased α-GST concentration at 24 h after the end of anaesthesia. GSTP1 gene polymorphism has an impact on the perioperative serum α-GST concentration in patients undergoing sevoflurane anaesthesia. A similar association, although not statistically significant exists between GSTA1 gene variants and perioperative serum α-GST level.

The roles of CYP6AY1 and CYP6ER1 in imidacloprid resistance in the brown planthopper: Expression levels and detoxification efficiency.

PubMed

Bao, Haibo; Gao, Hongli; Zhang, Yixi; Fan, Dongzhe; Fang, Jichao; Liu, Zewen

2016-05-01

Two P450 monooxygenase genes, CYP6AY1 and CYP6ER1, were reported to contribute importantly to imidacloprid resistance in the brown planthopper, Nilaparvata lugens. Although recombinant CYP6AY1 could metabolize imidacloprid efficiently, the expression levels of CYP6ER1 gene were higher in most resistant populations. In the present study, three field populations were collected from different countries, and the bioassay, RNAi and imidacloprid metabolism were performed to evaluate the importance of two P450s in imidacloprid resistance. All three populations, DOT (Dongtai) from China, CNA (Chainat) from Thailand and HCM (Ho Chi Minh) from Vietnam, showed high resistance to imidacloprid (57.0-, 102.9- and 89.0-fold). CYP6AY1 and CYP6ER1 were both over expressed in three populations, with highest ratio of 13.2-fold for CYP6ER1 in HCM population. Synergism test and RNAi analysis confirmed the roles of both P450 genes in imidacloprid resistance. However, CYP6AY1 was indicated more important in CNA population, and CYP6AY1 and CYP6ER1 were equal in HCM population, although the expression level of CYP6ER1 (13.2-fold) was much higher than that of CYP6AY1 (4.11-fold) in HCM population. Although the recombinant proteins of both P450 genes could metabolize imidacloprid efficiently, the catalytic activity of CYP6AY1 (Kcat=3.627 pmol/min/pmol P450) was significantly higher than that of CYP6ER1 (Kcat=2.785 pmol/min/pmol P450). It was supposed that both P450 proteins were important for imidacloprid resistance, in which CYP6AY1 metabolized imidacloprid more efficiently and CYP6ER1 gene could be regulated by imidacloprid to a higher level. Copyright © 2015 Elsevier B.V. All rights reserved.

Gene-environment interactions associated with CYP1A1 MspI and GST polymorphisms and the risk of upper aerodigestive tract cancers in an Indian population.

PubMed

Sam, Soya Sisy; Thomas, Vinod; Reddy, K S; Surianarayanan, Gopalakrishnan; Chandrasekaran, Adithan

2010-06-01

Genetic risk to tobacco related cancers are associated with polymorphisms in CYP1A1 and GST, which are involved in the metabolic activation and detoxification of carcinogens. The genetic variations in these drug-metabolizing enzymes may alter the susceptibility to UADT cancers triggered by environmental exposures. The hospital-based case-control study evaluated the impact of combined CYP1A1 MspI and GST (M1 & T1) polymorphisms among the individuals exposed to environmental risk factors as modulators in the risk of UADT cancers in Tamilians, a population of south India. The unrelated histopathologically confirmed 408 cases and 220 population-based controls matched by age and gender were genotyped for CYP1A1 MspI, GSTM1 and GSTT1 polymorphisms using PCR based methods. To investigate the potential gene-environment interactions, analyses were carried out stratifying by smoking and tobacco chewing status using SPSS software. The combination of genes and environment interactions by stratified analyses revealed significant interactions among the habitual tobacco smokers (CYP1A1 MspI & GSTM1 null: OR 14.06; 95% CI 3.90-50.68, CYP1A1 MspI & GSTT1 null: OR 33.28; 95% CI 4.24-261.19) and tobacco chewers (CYP1A1 MspI & GSTM1 null: OR 20.51; 95% CI 6.77-62.13, CYP1A1 MspI & GSTT1 null: OR 79.35; 95% CI 10.40-605.55) on the multiplicative scale. Our findings have indicated that the individuals polymorphic for CYP1A1 MspI either with GSTM1 null or with GSTT1 null genotypes revealed an increased risk for UADT cancers than that ascribed to a single susceptible gene among the tobacco users in the population [single gene risk among smokers and chewers, respectively, for CYP1A1 MspI (OR 6.43; 95% CI 3.69-11.21); (OR 10.24; 95% CI 5.95-17.60), GSTM1*0 (OR 3.77; 95% CI 1.94-7.37); (OR 7.97 95% CI 4.10-15.76) and GSTT1*0 (OR 6.95 95% CI 2.88-16.77); (OR 25.83 95% CI 7.78-85.76).

Role of the modulation of CYP1A1 expression and activity in chemoprevention.

PubMed

Badal, S; Delgoda, R

2014-07-01

As one of the main extra-hepatic cytochrome P450 (CYP) enzymes, CYP1A1 has been comprehensively investigated for its ability to metabolize both exogenous and endogenous compounds into their carcinogenic derivatives. These derivatives are linked to cancer initiation and progression. The compound benzo-a-pyrene (BaP), a copious and noxious compound present in coal tar, automobile exhaust fumes, cigarette smoke and charbroiled food, is metabolised by CYP1A1 and has been studied in great detail. Other compounds reliant on the same enzyme for their activation include 7,12 dimethylbenz(a)anthracene (DMBA) and heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). This review takes an in-depth look at a number of phytochemicals, plant extracts and a few synthetic compounds that have been researched and deemed potential chemopreventives via their interaction with the activity and expression of CYP1A1. It will also review a useful active site model of CYP1A1. Based on inhibitors of CYP1A1 that have demonstrated in vivo use as chemopreventors, CYP1A1 is a useful initial target for screening compounds with such potential, with the use of rapid in vitro and/or in silico assessments. Chemoprevention is a means by which healthy tissues are protected via the prevention, inhibition or reversal of carcinogenesis. This review focuses on one important pathway of carcinogenesis and identifies the important role that CYP1A1 plays in that pathway. It is hoped that highlighting the importance of such a key target, will help revive further research into and application of inhibitors of CYP1A1 towards generating improved chemopreventors. Copyright © 2014 John Wiley & Sons, Ltd.

CYP1A1, GSTM1, GSTT1 and NQO1 polymorphisms and colorectal adenomas in Japanese men

PubMed Central

Hamachi, Tadamichi; Tajima, Osamu; Uezono, Kousaku; Tabata, Shinji; Abe, Hiroshi; Ohnaka, Keizo; Kono, Suminori

2013-01-01

AIM: To investigate the role of functional genetic polymorphisms of metabolic enzymes of tobacco carcinogens in the development of colorectal adenomas. METHODS: The study subjects were 455 patients with colorectal adenomas and 1052 controls with no polyps who underwent total colonoscopy in a preretirement health examination at two Self Defense Forces hospitals. The genetic polymorphisms studied were CYP1A1*2A (rs 4646903), CYP1A1*2C (rs 1048943), GSTM1 (null or non-null genotype), GSTT1 (null or non-null genotype) and NQO1 C609T (rs 1800566). Genotypes were determined by the polymerase chain reaction (PCR)-restriction fragment length polymorphism or PCR method using genomic DNA extracted from the buffy coat. Cigarette smoking and other lifestyle factors were ascertained by a self-administered questionnaire. The associations of the polymorphisms with colorectal adenomas were examined by means of OR and 95%CI, which were derived from logistic regression analysis. Statistical adjustment was made for smoking, alcohol use, body mass index and other factors. The gene-gene interaction and effect modification of smoking were evaluated by the likelihood ratio test. RESULTS: None of the five polymorphisms showed a significant association with colorectal adenomas, nor was the combination of GSTM1 and GSTT1. A borderline significant interaction was observed for the combination of CYP1A1*2C and NQO1 (P = 0.051). The OR associated with CYP1A1*2C was significantly lower than unity among individuals with the NQO1 609CC genotype. The adjusted OR for the combination of the CYP1A1*2C allele and NQO1 609CC genotype was 0.61 (95%CI: 0.42-0.91). Although the interaction was not statistically significant (P = 0.24), the OR for individuals carrying the CYP1A1*2C allele and GSTT1 null genotype decreased significantly compared with those who had neither CYP1A1*2C allele nor GSTT1 null genotype (adjusted OR: 0.69, 95%CI: 0.49-0.97). Smoking did not modify the associations of the individual

Variation in the CYP19A1 gene and risk of colon and rectal cancer

PubMed Central

Slattery, Martha L.; Lundgreen, Abbie; Herrick, Jennifer S.; Kadlubar, Susan; Caan, Bette J.; Potter, John D.; Wolff, Roger K.

2011-01-01

CYP19A1, or aromatase, influences estrogen-metabolizing enzymes and may influence cancer risk. We examine variation in the CYP19A1 gene and risk of colorectal cancer using data from population-based case–control studies (colon n = 1,574 cases, 1,970 controls; rectal n = 791 cases, 999 controls). Four SNPs were statistically significantly associated with colon cancer and four were associated with rectal cancer. After adjustment for multiple comparisons, the AA genotype of rs12591359 was associated with an increased risk of colon cancer (OR 1.44 95% CI 1.16–1.80) and the AA genotype of rs2470144 was associated with a reduced risk of rectal cancer (OR 0.65 95% CI 0.50–0.84). Variants of CYP19A1 were associated with CIMP+ and CIMP+/KRAS2-mutated tumors. CT/TT genotypes of rs1961177 were significantly associated with an increased likelihood of a MSI+ colon tumor (OR 1.77 95% CI 1.26–2.37). We observed statistically significant interactions between genetic variation in NFκB1 and CYP19A1 for both colon and rectal cancer. Our data suggest the importance of CYP19A1 in the development of colon and rectal cancer and that estrogen may influence risk through an inflammation-related mechanism. PMID:21479914

Association of CYP1A1 and CYP1B1 polymorphisms with bone mineral density variations in postmenopausal Mexican-Mestizo women.

PubMed

Chávez, Bertha; Vilchis, Felipe; Rojano-Mejía, David; Coral Vázquez, Ramón Mauricio; Aguirre-García, María Del Carmen; Canto, Patricia

2017-08-01

Herein, we investigated potential associations between polymorphisms of genes related to estrogen metabolism and bone mineral density (BMD) in postmenopausal women. This was a cross-sectional study, in which two hundred and ninety postmenopausal Mexican-Mestizo women were studied. The BMD of the lumbar spine (LS), total hip (TH), and femoral neck (FN) was measured. The distribution of the genetic polymorphisms, including rs1799814 and rs1048943 at CYP1A1 as well as rs1056836 at CYP1B1, were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), single-stranded conformational polymorphism (SSCP), and DNA sequencing. Deviations from Hardy-Weinberg equilibrium (HWE) were tested, and linkage disequilibrium (LD) was calculated by direct correlation (r 2 ). Moreover, haplotype analysis was performed. All polymorphisms were in HWE. The genotype and allele distributions of the three single nucleotide polymorphisms (SNPs) studied showed no significant differences. However, statistical significance was reached when constructing haplotypes. The CG haplotype in CYP1A1 was associated with variations in LS and FN BMD after adjustment for covariates (p = 0.021 and 0.045, respectively), but the association with TH BMD was not significant. These results suggested that the CG haplotype in CYP1A1 may play an important role in the mechanism of osteoporosis and may be useful as a genetic marker.

Association study of ERβ, AR, and CYP19A1 genes and MtF transsexualism.

PubMed

Fernández, Rosa; Esteva, Isabel; Gómez-Gil, Esther; Rumbo, Teresa; Almaraz, Mari Cruz; Roda, Ester; Haro-Mora, Juan-Jesús; Guillamón, Antonio; Pásaro, Eduardo

2014-12-01

The etiology of male-to-female (MtF) transsexualism is unknown. Both genetic and neurological factors may play an important role. To investigate the possible influence of the genetic factor on the etiology of MtF transsexualism. We carried out a cytogenetic and molecular analysis in 442 MtFs and 473 healthy, age- and geographical origin-matched XY control males. The karyotype was investigated by G-banding and by high-density array in the transsexual group. The molecular analysis involved three tandem variable regions of genes estrogen receptor β (ERβ) (CA tandem repeats in intron 5), androgen receptor (AR) (CAG tandem repeats in exon 1), and CYP19A1 (TTTA tandem repeats in intron 4). The allele and genotype frequencies, after division into short and long alleles, were obtained. We investigated the association between genotype and transsexualism by performing a molecular analysis of three variable regions of genes ERβ, AR, and CYP19A1 in 915 individuals (442 MtFs and 473 control males). Most MtFs showed an unremarkable 46,XY karyotype (97.96%). No specific chromosome aberration was associated with MtF transsexualism, and prevalence of aneuploidy (2.04%) was slightly higher than in the general population. Molecular analyses showed no significant difference in allelic or genotypic distribution of the genes examined between MtFs and controls. Moreover, molecular findings presented no evidence of an association between the sex hormone-related genes (ERβ, AR, and CYP19A1) and MtF transsexualism. The study suggests that the analysis of karyotype provides limited information in these subjects. Variable regions analyzed from ERβ, AR, and CYP19A1 are not associated with MtF transsexualism. Nevertheless, this does not exclude other polymorphic regions not analyzed. © 2014 International Society for Sexual Medicine.

AHR/CYP1A1 interplay triggers lymphatic barrier breaching in breast cancer spheroids by inducing 12(S)-HETE synthesis.

PubMed

Nguyen, Chi Huu; Brenner, Stefan; Huttary, Nicole; Atanasov, Atanas Georgiev; Dirsch, Verena Maria; Chatuphonprasert, Waranya; Holzner, Sivio; Stadler, Serena; Riha, Juliane; Krieger, Sigurd; de Martin, Rainer; Bago-Horvath, Zsuzsanna; Krupitza, Georg; Jäger, Walter

2016-11-15

A causal link between overexpression of aryl hydrocarbon receptor (AHR) and its target cytochrome P450 1A1 (CYP1A1) and metastatic outgrowth of various cancer entities has been established. Nevertheless, the mechanism how AHR/CYP1A1 support metastasis formation is still little understood. In vitro we discovered a potential mechanism facilitating tumour dissemination based on the production of 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE). Utilising a three-dimensional lymph endothelial cell (LEC) monolayer & MDA-MB231 breast cancer cell spheroid co-culture model in combination with knock-down approach allowed elucidation of the molecular/biochemical basis of AHR/CYP1A1-induced tumour breaching through the LEC barrier. Enzyme immunoassay evidenced the potential of recombinant CYP1A1 to synthesise 12(S)-HETE in vitro and qPCR and Western blotting measured gene and protein expression in specific experimental settings. In detail, AHR induced CYP1A1 expression and 12(S)-HETE secretion in tumour spheroids, which caused LEC junction retraction thereby forming large discontinuities allowing transmigration of the tumour. This was enforced by the activating AHR ligand 6-formylindolo (3,3-b)carbazole (FICZ), or inhibited by the AHR antagonist 3,3’-diindolylmethane (DIM) as well as by siRNA against AHR and CYP1A1. AHR and NF-κB were negatively cross talking and therefore, the inhibition of AHR (but not CYP1A1) induced RELA, RELB, NFKB1, NFKB2 and the NF-κB target MMP1, which itself promotes tumour intravasation by a mechanism that is different from 12(S)-HETE. Conversely, the inhibition of NFKB2 induced AHR, CYP1A1 and 12(S)-HETE synthesis. The approved clinical drugs guanfacine and vinpocetine, which inhibit CYP1A1 and NF-κB, respectively, significantly inhibited LEC barrier breaching in vitro indicating an option to reduce metastatic dissemination.

Role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to organophosphate pesticides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Satyender; Kumar, Vivek; Vashisht, Kapil

2011-11-15

Organophosphate pesticides (OPs) are primarily metabolized by several xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticide-exposed workers. The present study was designed to determine the role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to OPs. We examined 284 subjects including 150 workers occupationally exposed to OPs and 134 normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using PCR-RFLP. The results revealed that the PONase activitymore » toward paraoxonase and AChE activity was found significantly lowered in workers as compared to control subjects (p < 0.001). Workers showed significantly higher DNA damage compared to control subjects (14.37 {+-} 2.15 vs. 6.24 {+-} 1.37 tail% DNA, p < 0.001). Further, the workers with CYP2D6*3 PM and PON1 (QQ and MM) genotypes were found to have significantly higher DNA damage when compared to other genotypes (p < 0.05). In addition, significant increase in DNA damage was also observed in workers with concomitant presence of certain CYP2D6 and PON1 (Q192R and L55M) genotypes which need further extensive studies. In conclusion, the results indicate that the PON1 and CYP2D6 genotypes can modulate DNA damage elicited by some OPs possibly through gene-environment interactions. -- Highlights: Black-Right-Pointing-Pointer Role of CYP1A1, CYP3A5, CYP2C, CYP2D6 and PON1 genotypes on DNA damage. Black-Right-Pointing-Pointer Workers exposed to some OPs demonstrated increased DNA damage. Black-Right-Pointing-Pointer CYP2D6 *3 PM and PON1 (Q192R and L55M) genotypes are associated with DNA damage. Black-Right-Pointing-Pointer Concomitant presence of certain CYP2D6 and PON1 genotypes can increase DNA damage.« less

Congenital glaucoma and CYP1B1: an old story revisited.

PubMed

Alsaif, Hessa S; Khan, Arif O; Patel, Nisha; Alkuraya, Hisham; Hashem, Mais; Abdulwahab, Firdous; Ibrahim, Niema; Aldahmesh, Mohammed A; Alkuraya, Fowzan S

2018-03-19

Primary congenital glaucoma is a trabecular meshwork dysgenesis with resultant increased intraocular pressure and ocular damage. CYP1B1 mutations remain the most common identifiable genetic cause. However, important questions about the penetrance of CYP1B1-related congenital glaucoma remain unanswered. Furthermore, mutations in other genes have been described although their exact contribution and potential genetic interaction, if any, with CYP1B1 mutations are not fully explored. In this study, we employed modern genomic approaches to re-examine CYP1B1-related congenital glaucoma. A cohort of 193 patients (136 families) diagnosed with congenital glaucoma. We identified biallelic CYP1B1 mutations in 80.8% (87.5 and 66.1% in familial and sporadic cases, respectively, p < 0.0086). The large family size of the study population allowed us to systematically examine penetrance of all identified alleles. With the exception of c.1103G>A (p.R368H), previously reported pathogenic mutations were highly penetrant (91.2%). We conclude from the very low penetrance and genetic epidemiological analyses that c.1103G>A (p.R368H) is unlikely to be a disease-causing recessive mutation in congenital glaucoma as previously reported. All cases that lacked biallelic CYP1B1 mutations underwent whole exome sequencing. No mutations in LTBP2, MYOC or TEK were encountered. On the other hand, mutations were identified in genes linked to other ophthalmic phenotypes, some inclusive of glaucoma, highlighting conditions that might phenotypically overlap with primary congenital glaucoma (SLC4A4, SLC4A11, CPAMD8, and KERA). We also encountered candidate causal variants in genes not previously linked to human diseases: BCO2, TULP2, and DGKQ. Our results both expand and refine the genetic spectrum of congenital glaucoma with important clinical implications.

Harman induces CYP1A1 enzyme through an aryl hydrocarbon receptor mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

El Gendy, Mohamed A.M.; El-Kadi, Ayman O.S., E-mail: aelkadi@pharmacy.ualberta.c

Harman is a common compound in several foods, plants and beverages. Numerous studies have demonstrated its mutagenic, co-mutagenic and carcinogenic effects; however, the exact mechanism has not been fully identified. Aryl hydrocarbon receptor (AhR) is a transcription factor regulating the expression of the carcinogen-activating enzyme; cytochrome P450 1A1 (CYP1A1). In the present study, we examined the ability of harman to induce AhR-mediated signal transduction in human and rat hepatoma cells; HepG2 and H4IIE cells. Our results showed that harman significantly induced CYP1A1 mRNA in a time- and concentration-dependent manner. Similarly, harman significantly induced CYP1A1 at protein and activity levels inmore » a concentration-dependent manner. Moreover, the AhR antagonist, resveratrol, inhibited the increase in CYP1A1 activity by harman. The RNA polymerase inhibitor, actinomycin D, completely abolished the CYP1A1 mRNA induction by harman, indicating a transcriptional activation. The role of AhR in CYP1A1 induction by harman was confirmed by using siRNA specific for human AhR. The ability of harman to induce CYP1A1 was strongly correlated with its ability to stimulate AhR-dependent luciferase activity and electrophoretic mobility shift assay. At post-transcriptional and post-translational levels, harman did not affect the stability of CYP1A1 at the mRNA and the protein levels, excluding other mechanisms participating in the obtained effects. We concluded that harman can directly induce CYP1A1 gene expression in an AhR-dependent manner and may represent a novel mechanism by which harman promotes mutagenicity, co-mutagenicity and carcinogenicity.« less

Possible involvement of nuclear factor erythroid 2-related factor 2 in the gene expression of Cyp2b10 and Cyp2a5.

PubMed

Ashino, Takashi; Ohkubo-Morita, Haruyo; Yamamoto, Masayuki; Yoshida, Takemi; Numazawa, Satoshi

2014-01-01

Cytochrome P450 gene expression is altered by various chemical compounds. In this study, we used nuclear factor erythroid 2-related factor 2 (Nrf2)-deficient (Nrf2(-⧸-)) mice to investigate the involvement of Nrf2 in Cyp2b10 and Cyp2a5 gene expression. Phorone, an Nrf2 activator, strongly increased Cyp2b10 and Cyp2a5 mRNA as well as Nrf2 target genes, including NAD(P)H-quinone oxidoreductase-1 and heme oxygenase-1, in wild-type mouse livers 8 h after treatment. The phorone-induced mRNA levels in Nrf2(-⧸-) mouse livers were lower than that in wild-type mouse livers. Nrf2(-⧸-) mice showed attenuated Cyp2b10 and Cyp2a5 induction by phenobarbital, a classical Cyp2b inducer. These findings suggest that the Nrf2 pathway is involved in Cyp2b10 and Cyp2a5 gene expression.

Dioxin induces Ahr-dependent robust DNA demethylation of the Cyp1a1 promoter via Tdg in the mouse liver.

PubMed

Amenya, Hesbon Z; Tohyama, Chiharu; Ohsako, Seiichiroh

2016-10-07

The aryl hydrocarbon receptor (Ahr) is a highly conserved nuclear receptor that plays an important role in the manifestation of toxicity induced by polycyclic aromatic hydrocarbons. As a xenobiotic sensor, Ahr is involved in chemical biotransformation through activation of drug metabolizing enzymes. The activated Ahr cooperates with coactivator complexes to induce epigenetic modifications at target genes. Thus, it is conceivable that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent Ahr ligand, may elicit robust epigenetic changes in vivo at the Ahr target gene cytochrome P450 1a1 (Cyp1a1). A single dose of TCDD administered to adult mice induced Ahr-dependent CpG hypomethylation, changes in histone modifications, and thymine DNA glycosylase (Tdg) recruitment at the Cyp1a1 promoter in the liver within 24 hrs. These epigenetic changes persisted until 40 days post-TCDD treatment and there was Cyp1a1 mRNA hyperinduction upon repeat administration of TCDD at this time-point. Our demethylation assay using siRNA knockdown and an in vitro methylated plasmid showed that Ahr, Tdg, and the ten-eleven translocation methyldioxygenases Tet2 and Tet3 are required for the TCDD-induced DNA demethylation. These results provide novel evidence of Ahr-driven active DNA demethylation and epigenetic memory. The epigenetic alterations influence response to subsequent chemical exposure and imply an adaptive mechanism to xenobiotic stress.

Dioxin induces Ahr-dependent robust DNA demethylation of the Cyp1a1 promoter via Tdg in the mouse liver

NASA Astrophysics Data System (ADS)

Amenya, Hesbon Z.; Tohyama, Chiharu; Ohsako, Seiichiroh

2016-10-01

The aryl hydrocarbon receptor (Ahr) is a highly conserved nuclear receptor that plays an important role in the manifestation of toxicity induced by polycyclic aromatic hydrocarbons. As a xenobiotic sensor, Ahr is involved in chemical biotransformation through activation of drug metabolizing enzymes. The activated Ahr cooperates with coactivator complexes to induce epigenetic modifications at target genes. Thus, it is conceivable that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent Ahr ligand, may elicit robust epigenetic changes in vivo at the Ahr target gene cytochrome P450 1a1 (Cyp1a1). A single dose of TCDD administered to adult mice induced Ahr-dependent CpG hypomethylation, changes in histone modifications, and thymine DNA glycosylase (Tdg) recruitment at the Cyp1a1 promoter in the liver within 24 hrs. These epigenetic changes persisted until 40 days post-TCDD treatment and there was Cyp1a1 mRNA hyperinduction upon repeat administration of TCDD at this time-point. Our demethylation assay using siRNA knockdown and an in vitro methylated plasmid showed that Ahr, Tdg, and the ten-eleven translocation methyldioxygenases Tet2 and Tet3 are required for the TCDD-induced DNA demethylation. These results provide novel evidence of Ahr-driven active DNA demethylation and epigenetic memory. The epigenetic alterations influence response to subsequent chemical exposure and imply an adaptive mechanism to xenobiotic stress.

Thyroid hormone induction of human cholesterol 7 alpha-hydroxylase (Cyp7a1) in vitro.

PubMed

Lammel Lindemann, Jan A; Angajala, Anusha; Engler, David A; Webb, Paul; Ayers, Stephen D

2014-05-05

Thyroid hormone (TH) modulates serum cholesterol by acting on TH receptor β1 (TRβ1) in liver to regulate metabolic gene sets. In rodents, one important TH regulated step involves induction of Cyp7a1, an enzyme in the cytochrome P450 family, which enhances cholesterol to bile acid conversion and plays a crucial role in regulation of serum cholesterol levels. Current models suggest, however, that Cyp7a1 has lost the capacity to respond to THs in humans. We were prompted to re-examine TH effects on cholesterol metabolic genes in human liver cells by a recent study of a synthetic TH mimetic which showed that serum cholesterol reductions were accompanied by increases in a marker for bile acid synthesis in humans. Here, we show that TH effects upon cholesterol metabolic genes are almost identical in mouse liver, mouse and human liver primary cells and human hepatocyte cell lines. Moreover, Cyp7a1 is a direct TR target gene that responds to physiologic TR levels through a set of distinct response elements in its promoter. These findings suggest that THs regulate cholesterol to bile acid conversion in similar ways in humans and rodent experimental models and that manipulation of hormone signaling pathways could provide a strategy to enhance Cyp7a1 activity in human patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Frequency Evaluation of T6235C (m1) and A4889G (m2) Polymorphisms of CYP1A1 Gene in a Healthy Population from the west of Mazandaran Province, Iran.

PubMed

Ahangar, N; Alizadeh, B; Tousi, A

2016-06-30

CYP1A1 is an important phase I xenobiotic metabolizing enzyme involved in the metabolism of numbers of toxins, endogenous hormones and drugs. Polymorphisms in this phase I gene can alter enzyme activity and induction, also are known to be associated with cancer susceptibility related to environmental toxins and hormone exposure. The present study was aimed to determine the frequencies of commonly known functional polymorphismsof CYP1A1 gene including CYP1A1 m1 (MspI), and CYP1A1 m2 (Ile-Val) in a healthy population from the west of Mazandaran province, Iran. A total of 200 unrelated healthy subjects from Mazandaran province, residing in Tonekabon city, coming for blood donating at Tonekabon Blood Transfusion Center were enrolled. Genomic DNA was extracted from peripheral blood lymphocytes of each subject. All subjects were genotyped for CYP1A1 m1 (T>C) and m2 (A>G) by polymerase chain reaction-restriction fragment length polymorphism method. The frequencies of the TT(wt/wt), TC(wt/mt) and CC(mt/mt) genotypes were as 65.5%, 32.0% and 2.5% respectively for m1 and frequencies of the AA(wt/wt), AG(wt/mt) and GG(mt/mt) genotypes were as 84.5%, 15% and 0.5% respectively for the m2. The frequencies of T and C alleles in the population were 81.5% and 18.5% respectively and the frequencies of A and G alleles were 92% and 8% respectively. Results of the present study might be important in understanding the distribution of CYP1A1 (m1) and CYP1A1 (m2) polymorphisms in Mazandaran province of Iran. Moreover, these results may determine the susceptibilities of individuals towards environmental procarcinogens that result in several cancers.

Association between cytochrome CYP17A1, CYP3A4, and CYP3A43 polymorphisms and prostate cancer risk and aggressiveness in a Korean study population

PubMed Central

Han, Jun Hyun; Lee, Yong Seong; Kim, Hae Jong; Lee, Shin Young; Myung, Soon Chul

2015-01-01

In this study, we evaluated genetic variants of the androgen metabolism genes CYP17A1, CYP3A4, and CYP3A43 to determine whether they play a role in the development of prostate cancer (PCa) in Korean men. The study population included 240 pathologically diagnosed cases of PCa and 223 age-matched controls. Among the 789 single-nucleotide polymorphism (SNP) database variants detected, 129 were reported in two Asian groups (Han Chinese and Japanese) in the HapMap database. Only 21 polymorphisms of CYP17A1, CYP3A4, and CYP3A43 were selected based on linkage disequilibrium in Asians (r2 = 1), locations (SNPs in exons were preferred), and amino acid changes and were assessed. In addition, we performed haplotype analysis for the 21 SNPs in CYP17A1, CYP3A4, and CYP3A43 genes. To determine the association between genotype and haplotype distributions of patients and controls, logistic analyses were carried out, controlling for age. Twelve sequence variants and five major haplotypes were identified in CYP17A1. Five sequence variants and two major haplotypes were identified in CYP3A4. Four sequence variants and four major haplotypes were observed in CYP3A43. CYP17A1 haplotype-2 (Ht-2) (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.04–2.18) was associated with PCa susceptibility. CYP3A4 Ht-2 (OR: 1.87; 95% CI: 1.02–3.43) was associated with PCa metastatic potential according to tumor stage. rs17115149 (OR: 1.96; 95% CI: 1.04–3.68) and CYP17A1 Ht-4 (OR: 2.01; 95% CI: 1.07–4.11) showed a significant association with histologic aggressiveness according to Gleason score. Genetic variants of CYP17A1 and CYP3A4 may play a role in the development of PCa in Korean men. PMID:25337833

Association between cytochrome CYP17A1, CYP3A4, and CYP3A43 polymorphisms and prostate cancer risk and aggressiveness in a Korean study population.

PubMed

Han, Jun Hyun; Lee, Yong Seong; Kim, Hae Jong; Lee, Shin Young; Myung, Soon Chul

2015-01-01

In this study, we evaluated genetic variants of the androgen metabolism genes CYP17A1, CYP3A4, and CYP3A43 to determine whether they play a role in the development of prostate cancer (PCa) in Korean men. The study population included 240 pathologically diagnosed cases of PCa and 223 age-matched controls. Among the 789 single-nucleotide polymorphism (SNP) database variants detected, 129 were reported in two Asian groups (Han Chinese and Japanese) in the HapMap database. Only 21 polymorphisms of CYP17A1, CYP3A4, and CYP3A43 were selected based on linkage disequilibrium in Asians (r2 = 1), locations (SNPs in exons were preferred), and amino acid changes and were assessed. In addition, we performed haplotype analysis for the 21 SNPs in CYP17A1, CYP3A4, and CYP3A43 genes. To determine the association between genotype and haplotype distributions of patients and controls, logistic analyses were carried out, controlling for age. Twelve sequence variants and five major haplotypes were identified in CYP17A1. Five sequence variants and two major haplotypes were identified in CYP3A4. Four sequence variants and four major haplotypes were observed in CYP3A43. CYP17A1 haplotype-2 (Ht-2) (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.04-2.18) was associated with PCa susceptibility. CYP3A4 Ht-2 (OR: 1.87; 95% CI: 1.02-3.43) was associated with PCa metastatic potential according to tumor stage. rs17115149 (OR: 1.96; 95% CI: 1.04-3.68) and CYP17A1 Ht-4 (OR: 2.01; 95% CI: 1.07-4.11) showed a significant association with histologic aggressiveness according to Gleason score. Genetic variants of CYP17A1 and CYP3A4 may play a role in the development of PCa in Korean men.

Association of polymorphisms in CYP19A1 and CYP3A4 genes with lower urinary tract symptoms, prostate volume, uroflow and PSA in a population-based sample.

PubMed

Berges, Richard; Gsur, Andrea; Feik, Elisabeth; Höfner, Klaus; Senge, Theodor; Pientka, Ludger; Baierl, Andreas; Michel, Martin C; Ponholzer, Anton; Madersbacher, Stephan

2011-04-01

The known importance of testosterone for the development of benign prostatic hyperplasia (BPH) prompted us to test the hypothesis whether polymorphisms of two genes (CYP19A1 and CYP3A4) involved in testosterone metabolism are associated with clinical BPH-parameters. A random sample of the population-based Herne lower urinary tract symptoms cohort was analysed. All these men underwent a detailed urological work-up. Two polymorphisms in the CYP19A1 gene [rs700518 in exon 4 (A57G); rs10046 at the 3'UTR(C268T)] and one in the 3'UTR of CYP3A4 [rs2740574 (A392G)] were determined by TaqMan assay from genomic DNA of peripheral blood. These polymorphisms were correlated to clinical and laboratory BPH-parameters. A total of 392 men (65.4 ± 7.0 years; 52-79 years) were analysed. Mean International Prostate Symptom Score (IPSS; 7.5), Q (max) (15.4 ml/s), prostate volume (31 ml) and prostate specific antigen (PSA) (1.8 ng/ml) indicated a typical elderly population. Both polymorphisms in the CYP19A1 gene were not correlated to age, IPSS, Q (max), prostate volume and post-void residual volume. Serum PSA was higher in men carrying the heterozygous rs10046 genotype (2.0 ± 0.1 ng/ml) than in those with the CC-genotype (1.7 ± 0.2 ng/ml, P = 0.012). Men carrying one a mutated allele of the CYP3A4 gene had smaller prostates (27.0 ± 2.0 vs. 32 ± 0.8 ml, P = 0.02) and lower PSA levels (1.6 ± 0.3 vs. 1.9 ± 0.1 ng/ml). The inconsistent associations observed herein and for other gene polymorphisms warrant further studies. In general, the data regarding the association of gene polymorphism to BPH-parameters suggest that this disease is caused by multiple rather than a single genetic variant. A rigorous patient selection based on anatomo-pathological and hormonal profile may possible reduce the number of confounders for future studies thus enabling a more detailed assessment of the association between genetic factors and BPH-parameters.

Expression and Sequence Evolution of Aromatase cyp19a1 and Other Sexual Development Genes in East African Cichlid Fishes

PubMed Central

Böhne, Astrid; Heule, Corina; Boileau, Nicolas; Salzburger, Walter

2013-01-01

Sex determination mechanisms are highly variable across teleost fishes and sexual development is often plastic. Nevertheless, downstream factors establishing the two sexes are presumably conserved. Here, we study sequence evolution and gene expression of core genes of sexual development in a prime model system in evolutionary biology, the East African cichlid fishes. Using the available five cichlid genomes, we test for signs of positive selection in 28 genes including duplicates from the teleost whole-genome duplication, and examine the expression of these candidate genes in three cichlid species. We then focus on a particularly striking case, the A- and B-copies of the aromatase cyp19a1, and detect different evolutionary trajectories: cyp19a1A evolved under strong positive selection, whereas cyp19a1B remained conserved at the protein level, yet is subject to regulatory changes at its transcription start sites. Importantly, we find shifts in gene expression in both copies. Cyp19a1 is considered the most conserved ovary-factor in vertebrates, and in all teleosts investigated so far, cyp19a1A and cyp19a1B are expressed in ovaries and the brain, respectively. This is not the case in cichlids, where we find new expression patterns in two derived lineages: the A-copy gained a novel testis-function in the Ectodine lineage, whereas the B-copy is overexpressed in the testis of the speciest-richest cichlid group, the Haplochromini. This suggests that even key factors of sexual development, including the sex steroid pathway, are not conserved in fish, supporting the idea that flexibility in sexual determination and differentiation may be a driving force of speciation. PMID:23883521

Protective role of cytochrome P450 1A1 (CYP1A1) against benzo[a]pyrene-induced toxicity in mouse aorta.

PubMed

Uno, Shigeyuki; Sakurai, Kenichi; Nebert, Daniel W; Makishima, Makoto

2014-02-28

Benzo[a]pyrene (BaP) is an environmental pollutant produced by combustive processes, such as cigarette smoke and coke ovens, and is implicated in the pathogenesis of atherosclerosis. Cytochrome P450 1A1 (CYP1A1) plays a role in both metabolic activation and detoxication of BaP in a context-dependent manner. The role of CYP1A1 in BaP-induced toxicity in aorta remains unknown. First, we fed Apoe⁻/⁻ mice an atherogenic diet plus BaP and found that oral BaP-enhanced atherosclerosis is associated with increased reactive oxygen species (ROS) and inflammatory markers, such as plasma tumor necrosis factor levels and aortic mRNA expression of vascular endothelial growth factor A (Vegfa). We next examined the effect of an atherogenic diet plus BaP on ROS and inflammatory markers in Cyp1a1⁻/⁻ mice. Although this treatment was not sufficient to induce atherosclerotic lesions in Cyp1a1⁻/⁻ mice, plasma antioxidant levels were decreased in Cyp1a1⁻/⁻ mice even in the absence of BaP treatment. The atherogenic diet plus BaP effectively elevated plasma ROS levels and expression of atherosclerosis-related genes, specifically Vegfa, in Cyp1a1⁻/⁻ mice compared with wild-type mice. BaP treatment increased Vegfa mRNA levels in mouse embryonic fibroblasts from Cyp1a1⁻/⁻ mice but not from wild-type mice. BaP-induced DNA adduct formation was increased in the aorta of Cyp1a1⁻/⁻ mice, but not wild-type or Apoe⁻/⁻ mice, and the atherogenic diet decreased BaP-induced DNA adducts in Cyp1a1⁻/⁻ mice compared with mice on a control diet. These data suggest that ROS production contributes to BaP-exacerbated atherosclerosis and that CYP1A1 plays a protective role against oral BaP toxicity in aorta. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

[Gene polymorphism of CYP450 2C9 and VKORC1 in Chinese population and their relationships to the maintaining dosage of warfarin].

PubMed

Zhang, Ya-nan; Cui, Wei; Han, Mei; Zheng, Bin; Liu, Fan; Xie, Rui-qin; Yang, Xiao-hong; Gu, Guo-qiang; Zheng, Hong-mei; Wen, Jin-kun

2010-02-01

To investigate the distribution of gene polymorphism of CYP450 2C9 and VKORC1-1639A/G in the Chinese population as well as the difference of genetic polymorphism between Chinese Han population and other ethnic populations. Contribution of CYP2C9 and VKORC1 genotype to the maintenance doses on warfarin was also studied. The genotype and allele frequencies were calculated and compared with those in other populations. One hundred and one patients with stable anticoagulation with warfarin under a target international normalized ratio (INR) of 2.0 to 3.0 were enrolled for studying the relationship between the CYP2C9 and VKORC1 gene polymorphism and the warfarin maintaining dosage. CYP450 2C9*3 + 1075C/A allele frequencies were:AA in 449 cases (92.2%), AC in 36 cases (7.4%) and CC in 2 cases (0.4%), respectively. VKORC1 -1639A/G allele frequencies were AA in 415 cases (85.2%), GA in 72 cases (14.8%), but GG in no case (0.0%), respectively. When linear stepwise regression analysis was used to identify factors contributing to warfarin stable dose, the final equation was: ln (D) = 0.346 + 0.017 (weight) - 0.376 (CYP450 2C9*3 + 1075C/A) + 0.148 (VKORC1-1639A/G) - 0.002 (age) (r = 0.827, P = 0.02). There existed significant gene polymorphism CYP450 2C9*3 + 1075C/A and VKORC1-1639A/G in the Chinese Han population. Both Gene polymorphisms of CYP450 2C9*3 + 1075C/A and VKORC1-1639A/G were significantly affecting the maintaining dose of warfarin in the Chinese population.

Analysis of CYP1A1 and COMT polymorphisms in women with cervical cancer.

PubMed

Kleine, J P; Camargo-Kosugi, C M; Carvalho, C V; Silva, F C; Silva, I D C G

2015-12-29

The aim of this case-control study was to obtain a comprehensive panel of genetic polymorphisms present only in genes (cytochrome P-450 1A1--CYP1A1 and catechol-O-methyl transferase--COMT) within the metabolic pathway of sex steroids and determine their possible associations with the presence or absence of cervical cancer. Genotypes of 222 women were analyzed: a) 81 with cancer of the cervix treated at the Cancer Hospital Alfredo Abram, between June 2012 and May 2013, with diagnosis confirmed surgically and/or through histomorphological examination; and b) 141 healthy women who assisted at the Endocrine Gynecology and Climacteric Ambulatory, Department of Gynecology, UNIFESP-EPM. These polymorphisms were detected by polymerase chain reaction amplification-restriction fragment length polymorphism analysis and visualized on 3% agarose gels stained with ethidium bromide. We found a significant association between the frequency of the CYP1A1 polymorphism and the development of cervical cancer. A statistical difference was observed between patient and control groups for CYP1A1 polymorphism genotype distributions (P < 0.05). However, no significant differences were found in the COMT gene polymorphism genotype distributions between the patient and control groups (P > 0.05) or between other risk variables analyzed. The CYP1A1 gene involved in the metabolic pathway of sex steroids might influence the emergence of pathological conditions such as cervical cancer in women who carry a mutated allele, and result in 1.80 and 13.46 times increased risk for women with heterozygous or homozygous mutated genotypes, respectively.

The impact of Cytochrome P450 CYP1A2, CYP2C9, CYP2C19 and CYP2D6 genes on suicide attempt and suicide risk-a European multicentre study on treatment-resistant major depressive disorder.

PubMed

Höfer, Peter; Schosser, Alexandra; Calati, Raffaella; Serretti, Alessandro; Massat, Isabelle; Kocabas, Neslihan Aygun; Konstantinidis, Anastasios; Linotte, Sylvie; Mendlewicz, Julien; Souery, Daniel; Zohar, Joseph; Juven-Wetzler, Alzbeta; Montgomery, Stuart; Kasper, Siegfried

2013-08-01

Recently published data have reported associations between cytochrome P450 metabolizer status and suicidality. The aim of our study was to investigate the role of genetic polymorphisms of the cytochrome P450 genes on suicide risk and/or a personal history of suicide attempts. Two hundred forty-three major depressive disorder patients were collected in the context of a European multicentre resistant depression study and treated with antidepressants at adequate doses for at least 4 weeks. Suicidality was assessed using the Mini International Neuropsychiatric Interview and the Hamilton Rating Scale for Depression (HAM-D). Treatment response was defined as HAM-D ≤ 17 and remission as HAM-D ≤ 7 after 4 weeks of treatment with antidepressants at adequate dose. Genotyping was performed for all relevant variations of the CYP1A2 gene (*1A, *1F, *1C, *1 J, *1 K), the CYP2C9 gene (*2, *3), the CYP2C19 gene (*2, *17) and the CYP2D6 gene (*3, *4, *5, *6, *9, *19, *XN). No association between both suicide risk and personal history of suicide attempts, and the above mentioned metabolic profiles were found after multiple testing corrections. In conclusion, the investigated cytochrome gene polymorphisms do not seem to be associated with suicide risk and/or a personal history of suicide attempts, though methodological and sample size limitations do not allow definitive conclusions.

Effect of TBT and PAHs on CYP1A, AhR and Vitellogenin Gene Expression in the Japanese Eel, Anguilla japonica.

PubMed

Choi, Min Seop; Kwon, Se Ryun; Choi, Seong Hee; Kwon, Hyuk Chu

2012-12-01

Gene expressions of cytochrome P4501A (CYP1A), aryl hydrocarbon receptor (AhR) and vitellogenin (Vg) by endocrine disruptors, benzo[α]pyrene (B[a]P) and tributyltin (TBT) were examined in cultured eel hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) or estradiol-17β (20 mg/kg) in vivo, and the relationship between CYP1A, AhR and Vg genes were studied. When the cultured eel hepatocytes were treated with B[a]P (10(-6)-10(-5) M) the gene expressions of CYP1A and AhR were enhanced in a concentration-dependent manner. However, when treated with TBT (10(-9)-10(-5) M) the gene expressions of CYP1A and AhR were suppressed at high concentrations (10(-6)-10(-5) M), while having no effects at low concentrations (10(-9)-10(-7) M). Gene expression of Vg was also suppressed by TBT in a concentration-dependent manner in cultured eel hepatocytes which was previously treated in vivo with estradiol-17β.

Effect of TBT and PAHs on CYP1A, AhR and Vitellogenin Gene Expression in the Japanese Eel, Anguilla japonica

PubMed Central

Choi, Min Seop; Kwon, Se Ryun; Choi, Seong Hee; Kwon, Hyuk Chu

2012-01-01

Gene expressions of cytochrome P4501A (CYP1A), aryl hydrocarbon receptor (AhR) and vitellogenin (Vg) by endocrine disruptors, benzo[α]pyrene (B[a]P) and tributyltin (TBT) were examined in cultured eel hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) or estradiol-17β (20 mg/kg) in vivo, and the relationship between CYP1A, AhR and Vg genes were studied. When the cultured eel hepatocytes were treated with B[a]P (10-6-10-5 M) the gene expressions of CYP1A and AhR were enhanced in a concentration-dependent manner. However, when treated with TBT (10-9-10-5 M) the gene expressions of CYP1A and AhR were suppressed at high concentrations (10-6-10-5 M), while having no effects at low concentrations (10-9-10-7 M). Gene expression of Vg was also suppressed by TBT in a concentration-dependent manner in cultured eel hepatocytes which was previously treated in vivo with estradiol-17β. PMID:25949102

Role of CYP1B1 in PAH-DNA Adduct Formation and Breast Cancer Risk

DTIC Science & Technology

2006-03-01

32 cases and 11 controls) undergoing surgery and analyzed these specimens for CYP1B1 gene expression, CYP1B1 genotype and PAH-DNA adducts. CYP1B1...quantitated and its purity determined by its 260/280 nm absorption. Samples were aliqoted for later measurements of CYP1B1 genotype and DNA adducts...19.78) 0.06 – 73.7 d. Perform CYP1B1 genotype analysis The CYP1B1 genotype at two polymorphic sites located in the catalytic side of the enzyme

Role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to organophosphate pesticides.

PubMed

Singh, Satyender; Kumar, Vivek; Vashisht, Kapil; Singh, Priyanka; Banerjee, Basu Dev; Rautela, Rajender Singh; Grover, Shyam Sunder; Rawat, Devendra Singh; Pasha, Syed Tazeen; Jain, Sudhir Kumar; Rai, Arvind

2011-11-15

Organophosphate pesticides (OPs) are primarily metabolized by several xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticide-exposed workers. The present study was designed to determine the role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to OPs. We examined 284 subjects including 150 workers occupationally exposed to OPs and 134 normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using PCR-RFLP. The results revealed that the PONase activity toward paraoxonase and AChE activity was found significantly lowered in workers as compared to control subjects (p<0.001). Workers showed significantly higher DNA damage compared to control subjects (14.37±2.15 vs. 6.24±1.37 tail% DNA, p<0.001). Further, the workers with CYP2D6*3PM and PON1 (QQ and MM) genotypes were found to have significantly higher DNA damage when compared to other genotypes (p<0.05). In addition, significant increase in DNA damage was also observed in workers with concomitant presence of certain CYP2D6 and PON1 (Q192R and L55M) genotypes which need further extensive studies. In conclusion, the results indicate that the PON1 and CYP2D6 genotypes can modulate DNA damage elicited by some OPs possibly through gene-environment interactions. Copyright © 2011 Elsevier Inc. All rights reserved.

Cloning, expression pattern and promoter functional analysis of cyp19a1a gene in miiuy croaker.

PubMed

Huang, Wei; Yang, Pan; Lv, Zhenming; Wu, Changwen; Gui, Jianfang; Lou, Bao

2017-09-05

Gonadal-specific aromatase encoded by cyp19a1a is the important enzyme controlling estrogen biosynthesis in teleosts. In the present study, the cDNA sequence of cyp19a1a was cloned and characterized from miiuy croaker Miichthys miiuy. The cDNA encoded a protein of 519 amino acids with five structural regions. Higher identities of amino acid sequences and conserved structural regions were found between Mmcyp19a1a and other cyp19a1a genes. In addition, Mmcyp19a1a was clustered together with other seawater fishes. Immunohistochemical analysis revealed that Mmcyp19a1a was localized exclusively in the cytoplasmic of thecal and granulosa cells surrounding the oocytes. Both the protein and mRNA levels of Mmcyp19a1a were increased significantly at the stage III follicles (mid-vitellogenic) and then decreased along with vitellogenesis. Interestingly, strong immunoreactive signals were also detected in the supporting cells of connective tissues during ovarian development. A 1777bp promoter fragment of Mmcyp19a1a was also isolated, and functional analysis using an EGFP reporter fusion in zebrafish larvae presented positive signals in the above of yolk sac, where is the region of pronephros and germ plasm occur. The Mmcyp19a1a:EGFP expression pattern was generally consistent with the endogenous cyp19a1a genesis. These results indicate that the Mmcyp19a1a gene plays an important role during vitellogenesis and oocyte maturation. The constructor of Mmcyp19a1a:EGFP may provide a useful tool for genetic analysis of gonad development in teleost. Copyright © 2017 Elsevier B.V. All rights reserved.

Possible involvement of nuclear factor erythroid 2-related factor 2 in the gene expression of Cyp2b10 and Cyp2a5☆

PubMed Central

Ashino, Takashi; Ohkubo-Morita, Haruyo; Yamamoto, Masayuki; Yoshida, Takemi; Numazawa, Satoshi

2014-01-01

Cytochrome P450 gene expression is altered by various chemical compounds. In this study, we used nuclear factor erythroid 2-related factor 2 (Nrf2)–deficient (Nrf2−⧸−) mice to investigate the involvement of Nrf2 in Cyp2b10 and Cyp2a5 gene expression. Phorone, an Nrf2 activator, strongly increased Cyp2b10 and Cyp2a5 mRNA as well as Nrf2 target genes, including NAD(P)H-quinone oxidoreductase-1 and heme oxygenase-1, in wild-type mouse livers 8 h after treatment. The phorone-induced mRNA levels in Nrf2−⧸− mouse livers were lower than that in wild-type mouse livers. Nrf2−⧸− mice showed attenuated Cyp2b10 and Cyp2a5 induction by phenobarbital, a classical Cyp2b inducer. These findings suggest that the Nrf2 pathway is involved in Cyp2b10 and Cyp2a5 gene expression. PMID:24494203

BDE47 induces rat CYP3A1 by targeting the transcriptional regulation of miR-23b

NASA Astrophysics Data System (ADS)

Sun, Zhenzhen; Zhang, Zhan; Ji, Minghui; Yang, Hongbao; Cromie, Meghan; Gu, Jun; Wang, Chao; Yang, Lu; Yu, Yongquan; Gao, Weimin; Wang, Shou-Lin

2016-08-01

Cytochrome P450 3A (CYP3A) is the most abundant CYP450 enzyme in the liver and is involved in the metabolism of over 50% of xenobiotics. Our previous studies revealed that 2,2‧,4,4‧-tetrabromodiphenyl ether (BDE47) could induce rat CYP3A1 expression, but the molecular basis remains unclear. Using in silico analysis, we identified a potential miR-23b recognition element (MRE23b) in the 3‧-UTR region of CYP3A1 mRNA, which was verified by the luciferase assay. The miR-23b mimic and inhibitor significantly down- and up-regulated the expression of CYP3A1, respectively. Additionally, BDE47 significantly down-regulated the expression of miR-23b in rats and in hepatic H4IIE cells. Induction or blockage of CYP3A1 by a miR-23b inhibitor or mimic could correspondingly alter BDE47-induced expression of CYP3A1 and cytotoxicity in H4IIE cells. Furthermore, LV-anti-miR-23b significantly decreased endogenous levels of miR-23b and increased the expression and activity of CYP3A1 in rat liver. LV-anti-miR-23b also significantly increased the hydroxylated metabolites of BDE47 (3-OH-BDE47, 4-OH-BDE42, and 4‧-OH-BDE49) in rat serum. In conclusion, we first found that BDE47 induced rat CYP3A1 expression by targeting the transcriptional regulation of miR-23b. This study helps provide a better understanding of CYP3A regulation and offers novel clues for the role of miRNAs in the metabolism and distribution of environmental pollutants.

Role of CYP24A1, VDR and GC gene polymorphisms on deferasirox pharmacokinetics and clinical outcomes.

PubMed

Allegra, S; Cusato, J; De Francia, S; Arduino, A; Longo, F; Pirro, E; Massano, D; De Nicolò, A; Piga, A; D'Avolio, A

2018-05-22

β-Thalassemia patients develop deficiency in vitamin D absorption and liver hydroxylation, resulting in extremely low calcitriol levels. We explored the role of single-nucleotide polymorphisms (SNPs) involved in vitamin D metabolism, transport and activity on deferasirox pharmacokinetics and outcomes (effectiveness trough levels (C trough ) and the area under the curve (AUC) cutoffs of 20 μg ml -1 and 360 μg ml -1  h -1 , respectively; nonresponse AUC limit of 250 μg ml -1  h -1 ). Ninety-nine β-thalassemic patients were enrolled. Drug plasma C trough and AUC were measured by the high-performance liquid chromatography system coupled with an ultraviolet determination method. Allelic discrimination for VDR, CYP24A1, CYP27B1 and GC gene SNPs was performed by real-time PCR. CYP24A1 22776 TT significantly influenced C min and negatively predicted it in regression analysis. CYP24A1 3999 CC was associated with C trough and C min and was a negative predictor of T max , whereas CYP24A1 8620 GG seemed to have a role in C trough , AUC, t 1/2 and C min , and was an AUC negative predictor factor. Considering treatment outcome, Cdx2 and GC 1296 were retained in regression analysis as AUC efficacy cutoff negative predictors.

A kidney-specific genetic control module in mice governs endocrine regulation of the cytochrome P450 gene Cyp27b1 essential for vitamin D3 activation.

PubMed

Meyer, Mark B; Benkusky, Nancy A; Kaufmann, Martin; Lee, Seong Min; Onal, Melda; Jones, Glenville; Pike, J Wesley

2017-10-20

The vitamin D endocrine system regulates mineral homeostasis through its activities in the intestine, kidney, and bone. Terminal activation of vitamin D 3 to its hormonal form, 1α,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ), occurs in the kidney via the cytochrome P450 enzyme CYP27B1. Despite its importance in vitamin D metabolism, the molecular mechanisms underlying the regulation of the gene for this enzyme, Cyp27b1 , are unknown. Here, we identified a kidney-specific control module governed by a renal cell-specific chromatin structure located distal to Cyp27b1 that mediates unique basal and parathyroid hormone (PTH)-, fibroblast growth factor 23 (FGF23)-, and 1,25(OH) 2 D 3 -mediated regulation of Cyp27b1 expression. Selective genomic deletion of key components within this module in mice resulted in loss of either PTH induction or FGF23 and 1,25(OH) 2 D 3 suppression of Cyp27b1 gene expression; the former loss caused a debilitating skeletal phenotype, whereas the latter conferred a quasi-normal bone mineral phenotype through compensatory homeostatic mechanisms involving Cyp24a1 We found that Cyp27b1 is also expressed at low levels in non-renal cells, in which transcription was modulated exclusively by inflammatory factors via a process that was unaffected by deletion of the kidney-specific module. These results reveal that differential regulation of Cyp27b1 expression represents a mechanism whereby 1,25(OH) 2 D 3 can fulfill separate functional roles, first in the kidney to control mineral homeostasis and second in extra-renal cells to regulate target genes linked to specific biological responses. Furthermore, we conclude that these mouse models open new avenues for the study of vitamin D metabolism and its involvement in therapeutic strategies for human health and disease. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

A kidney-specific genetic control module in mice governs endocrine regulation of the cytochrome P450 gene Cyp27b1 essential for vitamin D3 activation

PubMed Central

Meyer, Mark B.; Benkusky, Nancy A.; Kaufmann, Martin; Lee, Seong Min; Onal, Melda; Jones, Glenville; Pike, J. Wesley

2017-01-01

The vitamin D endocrine system regulates mineral homeostasis through its activities in the intestine, kidney, and bone. Terminal activation of vitamin D3 to its hormonal form, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3), occurs in the kidney via the cytochrome P450 enzyme CYP27B1. Despite its importance in vitamin D metabolism, the molecular mechanisms underlying the regulation of the gene for this enzyme, Cyp27b1, are unknown. Here, we identified a kidney-specific control module governed by a renal cell-specific chromatin structure located distal to Cyp27b1 that mediates unique basal and parathyroid hormone (PTH)-, fibroblast growth factor 23 (FGF23)-, and 1,25(OH)2D3-mediated regulation of Cyp27b1 expression. Selective genomic deletion of key components within this module in mice resulted in loss of either PTH induction or FGF23 and 1,25(OH)2D3 suppression of Cyp27b1 gene expression; the former loss caused a debilitating skeletal phenotype, whereas the latter conferred a quasi-normal bone mineral phenotype through compensatory homeostatic mechanisms involving Cyp24a1. We found that Cyp27b1 is also expressed at low levels in non-renal cells, in which transcription was modulated exclusively by inflammatory factors via a process that was unaffected by deletion of the kidney-specific module. These results reveal that differential regulation of Cyp27b1 expression represents a mechanism whereby 1,25(OH)2D3 can fulfill separate functional roles, first in the kidney to control mineral homeostasis and second in extra-renal cells to regulate target genes linked to specific biological responses. Furthermore, we conclude that these mouse models open new avenues for the study of vitamin D metabolism and its involvement in therapeutic strategies for human health and disease. PMID:28808057

Cytochrome P450, CYP93A1, as a defense marker in soybean

USDA-ARS?s Scientific Manuscript database

CYP93A1 is a cytochrome P450 that is involved in the synthesis of the phytoalexin glyceollin in soybean (Glycine max L. Merr). The gene encoding CYP93A1 has been used as a defense marker in soybean cell cultures, however, little is known regarding how this gene is expressed in the intact plant. To f...

Cytochrome P450 CYP4DE1 and CYP6CW3v2 contribute to ethiprole resistance in Laodelphax striatellus (Fallén).

PubMed

Elzaki, M E A; Zhang, W; Han, Z

2015-06-01

Laodelphax striatellus Fallén (Hemiptera: Delphacidae), a destructive pest of rice, has developed high resistance to multiple insecticides, threatening the success of pest management programmes. The present study investigated ethiprole resistance mechanisms in a field population that is highly resistant to ethiprole. That population was used to establish a laboratory population that was subjected to further selection to produce a resistant strain. Target genes were cloned and compared between the resistant and the susceptible strains, the role of detoxification enzymes was examined, and the relative expression levels of 71 detoxification enzyme genes were tested using quantitative real time (RT)-PCR. The laboratory selection enhanced the resistance from 107-fold to 180-fold. The Rdl-type target site mutation seldom occurred in the resistant strain and is unlikely to represent the major mechanism underlying the observed resistance. Of the three important detoxification enzymes, only P450 monooxygenase was found to be associated with ethiprole resistance. Moreover, two genes, CYP4DE1 and CYP6CW3v2, were found to be overexpressed in the resistant strain. Furthermore, gene-silencing via a double-stranded RNA feeding test was carried out, and the results showed that the mRNA levels of CYP4DE1 and CYP6CW3v2 were reduced in the resistant strain, whereas ethiprole susceptibility was increased. These results suggest that CYP4DE1 and CYP6CW3v2 play an important role in ethiprole resistance in L. striatellus. © 2015 The Royal Entomological Society.

CYP17A1 gene polymorphisms and environmental exposure to organochlorine pesticides contribute to the risk of small for gestational age.

PubMed

Chand, S; Mustafa, M D; Banerjee, B D; Guleria, K

2014-09-01

The cytochrome P-450c17α enzyme encoded by the cytochrome P-450c17α (CYP17A1) gene plays a role in oestrogen synthesis. Genetic variation in the maternal CYP17A1 gene leads to differences in oestrogen level that affect fetal growth and cause small for gestational age (SGA). Organochlorine pesticides (OCPs) are endocrine disruptors that alter the normal oestrogen-progesterone balance, and are associated with adverse reproductive outcomes. This study was designed to investigate the effect of the gene-environment interaction between maternal CYP17A1 gene polymorphisms and maternal and cord OCP levels on the risk of SGA. Maternal and cord blood samples of 50 term SGA cases (birth weight <10th percentile for gestational age as per Lubchenco's growth chart) and 50 normal pregnancies (controls) were collected. Women with occupational exposure to OCPs, anaemia, hypertension, antiphospholipid antibody syndrome, medical disease, parity of more than four, or a history of smoking, alcohol consumption or chronic drug intake were excluded from both groups. Maternal and cord blood samples were collected at the time of delivery or after delivery, respectively. The OCP levels of the samples were analyzed using a gas chromatography system equipped with an electron capture detector, and polymerase chain reaction-restriction fragment length polymorphism was used for polymorphic analysis of the CYP17A1 gene. Significantly (p<0.05) higher levels of α-hexachlorocyclohexane (HCH), β-HCH and γ-HCH were found in maternal and cord blood samples of the SGA cases compared with the controls. The frequency of the A1A2/A2A2 genotype was significantly lower [p=0.041, odds ratio (OR) 0.421, 95% confidence interval (CI) 0.184-0.966] in the SGA cases compared with the controls. When gene-environment interactions between CYP17A1 gene polymorphisms and OCP levels were considered, a significant (p=0.004) association was found between a high level of endosulfan in cord blood and the A1A1 (wild

Hypoxia perturbs aryl hydrocarbon receptor signaling and CYP1A1 expression induced by PCB 126 in human skin and liver-derived cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vorrink, Sabine U.; Department of Radiation Oncology, The University of Iowa, Iowa City, IA; Severson, Paul L.

2014-02-01

The aryl hydrocarbon receptor (AhR) is an important mediator of toxic responses after exposure to xenobiotics including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and dioxin-like polychlorinated biphenyls (PCBs). Activation of AhR responsive genes requires AhR dimerization with the aryl hydrocarbon receptor nuclear translocator (ARNT), a heterodimeric partner also shared by the hypoxia-inducible factor-1α (HIF-1α) protein. TCDD-stimulated AhR transcriptional activity can be influenced by hypoxia; however, it less well known whether hypoxia interferes with AhR transcriptional transactivation in the context of PCB-mediated AhR activation in human cells. Elucidation of this interaction is important in liver hepatocytes which extensively metabolize ingested PCBs and experience varying degreesmore » of oxygen tension during normal physiologic function. This study was designed to assess the effect of hypoxia on AhR transcriptional responses after exposure to 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126). Exposure to 1% O{sub 2} prior to PCB 126 treatment significantly inhibited CYP1A1 mRNA and protein expression in human HepG2 and HaCaT cells. CYP1A1 transcriptional activation was significantly decreased upon PCB 126 stimulation under conditions of hypoxia. Additionally, hypoxia pre-treatment reduced PCB 126 induced AhR binding to CYP1 target gene promoters. Importantly, ARNT overexpression rescued cells from the inhibitory effect of hypoxia on XRE-luciferase reporter activity. Therefore, the mechanism of interference of the signaling crosstalk between the AhR and hypoxia pathways appears to be at least in part dependent on ARNT availability. Our results show that AhR activation and CYP1A1 expression induced by PCB 126 were significantly inhibited by hypoxia and hypoxia might therefore play an important role in PCB metabolism and toxicity. - Highlights: • Significant crosstalk exists between AhR and HIF-1α signaling. • Hypoxia perturbs PCB 126 induced Ah

Genetic Polymorphisms of Cytochrome P4501A1 (CYP1A1) and Glutathione S-Transferase P1 (GSTP1) and Risk of Hepatocellular Carcinoma Among Chronic Hepatitis C Patients in Egypt.

PubMed

Abo-Hashem, Ekbal M; El-Emshaty, Wafaa M; Farag, Raghda El Sayed; Zakaria, Sahar; Abd El-Aziz, Mohammed; Ghonaim, Azza

2016-10-01

Cytochrome P450 1A1 (CYP1A1) and Glutathione S-transferase P1 (GSTP1) genes are involved in the metabolism of many carcinogens. Polymorphisms in these genes with altered enzyme activity have been reported. The present study evaluated the synergistic effect between CYP1A1 and GSTP1 gene polymorphisms and smoking on development of HCV-related liver disease and hepatocellular carcinoma (HCC). The patients group comprised 40 patients with HCC and 40 patients with liver cirrhosis. The control group comprised 40 healthy subjects having no history of malignancy. The genetic polymorphisms were studied using polymerase chain reaction restriction fragment length polymorphism (PCR RFLP) technique on blood samples. The number of current or former smoker among HCC and cirrhotic patients as well as the median Pack/year of cigarette smoked were significantly higher in HCC and liver cirrhotic patients than in control group. Subjects with CYP1A1 gene variants (m1 and m3) had no significant risk to develop cirrhosis or HCC compared to control group. Individuals carrying the Ile/Val genotype of GSTP1 had a significant increased risk of HCC (OR of 2.2, 95 % CI 1.143-4.261) and had larger tumor size. No significant risk was observed on combining both genes variants or on combining smoking with variants of both genes. In conclusion, the GSTP1 Ile/Val genotype and Val allele are associated with an increased risk of HCC. CYP1A1 and GSTP1 genes variants interaction did not increase the risk of HCC.

Korean Red Ginseng Up-regulates C21-Steroid Hormone Metabolism via Cyp11a1 Gene in Senescent Rat Testes

PubMed Central

Kim, In-Hye; Kim, Si-Kwan; Kim, Eun-Hye; Kim, Sung-Won; Sohn, Sang-Hyun; Lee, Soo Cheol; Choi, Sangdun; Pyo, Suhkneung; Rhee, Dong-Kwon

2011-01-01

Ginseng (Panax ginseng Meyer) has been shown to have anti-aging effects in animal and clinical studies. However, the molecular mechanisms by which ginseng exerts these effects remain unknown. Here, the anti-aging effect of Korean red ginseng (KRG) in rat testes was examined by system biology analysis. KRG water extract prepared in feed pellets was administered orally into 12 month old rats for 4 months, and gene expression in testes was determined by microarray analysis. Microarray analysis identified 33 genes that significantly changed. Compared to the 2 month old young rats, 13 genes (Rps9, Cyp11a1, RT1-A2, LOC365778, Sv2b, RGD1565959, RGD1304748, etc.) were up-regulated and 20 genes (RT1-Db1, Cldn5, Svs5, Degs1, Vdac3, Hbb, LOC684355, Svs5, Tmem97, Orai1, Insl3, LOC497959, etc.) were down-regulated by KRG in the older rats. Ingenuity Pathway Analysis of untreated aged rats versus aged rats treated with KRG showed that the affected most was Cyp11a1, responsible for C21-steroid hormone metabolism, and the top molecular and cellular functions are organ morphology and reproductive system development and function. When genes in young rat were compared with those in the aged rat, sperm capacitation related genes were down-regulated in the old rat. However, when genes in the old rat were compared with those in the old rat treated with KRG, KRG treatment up-regulated C21-steroid hormone metabolism. Taken together, Cyp11a1 expression is decreased in the aged rat, however, it is up-regulated by KRG suggesting that KRG seems enhance testes function via Cyp11a1. PMID:23717070

Association between NAT2, CYP1A1, and CYP1A2 genotypes, heterocyclic aromatic amines, and prostate cancer risk: a case control study in Japan.

PubMed

Koda, Masahide; Iwasaki, Motoki; Yamano, Yuko; Lu, Xi; Katoh, Takahiko

2017-10-24

Heterocyclic aromatic amines (HAAs) may confer prostate cancer risk; however, the evidence is inconclusive and the activity of HAA-metabolizing enzymes is modulated by gene variants. The purpose of our study was to determine whether there was evidence of an association between HAA intake, polymorphisms in NAT2, CYP1A1, and CYP1A2 and prostate cancer risk in Japanese men. Secondary data analysis of an observational case control study was performed. Among 750 patients with prostate cancer and 870 healthy controls, 351 cases and 351 age-matched controls were enrolled for analysis. HAA intake was estimated using a food frequency questionnaire and genotypes were scored by TaqMan real-time PCR assay. Logistic regression analysis was conducted according to affected/control status. We found that high HAA intake was significantly associated with an increased risk of prostate cancer (odds ratio (OR), 1.90; 95% confidence interval (95% CI), 1.40-2.59). The increased risk of prostate cancer was observed among individuals with the NAT2 slow acetylator phenotype (OR, 1.65; 95% CI, 1.04-2.61), CYP1A1 GA + GG genotype (OR, 1.27; 95% CI, 1.02-1.59), and CYP1A2 CA + AA genotype (OR, 1.43; 95% CI, 1.03-2.00). In addition, CYP1A1 GA + GG genotypes were associated with increased cancer risk in low (OR, 2.05; 95% CI, 1.19-3.63), moderate (OR, 1.72; 95% CI, 1.07-2.76), and high (OR, 2.86; 95% CI, 1.83-4.47) HAA intake groups. Our results suggest that high HAA intake is a risk factor of prostate cancer, and genotypes related to HAA metabolic enzymes can modulate the degree of the risk.

Influence of CYP3A5 and ABCB1 gene polymorphisms on calcineurin inhibitor-related neurotoxicity after hematopoietic stem cell transplantation.

PubMed

Yanagimachi, Masakatsu; Naruto, Takuya; Tanoshima, Reo; Kato, Hiromi; Yokosuka, Tomoko; Kajiwara, Ryosuke; Fujii, Hisaki; Tanaka, Fumiko; Goto, Hiroaki; Yagihashi, Tatsuhiko; Kosaki, Kenjiro; Yokota, Shumpei

2010-01-01

One severe side effect of calcineurin inhibitors (CNIs: such as cyclosporine [CsA] and tacrolimus [FK506]) is neurotoxicity. CNIs are substrates for CYP3A5 and P-glycoprotein (P-gp), encoded by ABCB1 gene. In the present study, we hypothesized that genetic variability in CYP3A5 and ABCB1 genes may be associated with CNI-related neurotoxicity. The effects of the polymorphisms, such as CYP3A5 A6986G, ABCB1 C1236T, G2677T/A, and C3435T, associated with CNI-related neurotoxicity were evaluated in 63 patients with hematopoietic stem cell transplantation.   Of the 63 cases, 15 cases developed CNI-related neurotoxicity. In the CsA patient group (n = 30), age (p = 0.008), hypertension (p = 0.017), renal dysfunction (p < 0.001), ABCB1 C1236T (p < 0.001), and G2677T/A (p = 0.014) were associated with neurotoxicities. The CC genotype at ABCB1 C1236T was associated with it, but not significantly so (p = 0.07), adjusted for age, hypertension, and renal dysfunction. In the FK506 patient group (n = 33), CYP3A5 A6986G (p < 0.001), and ABCB1 C1236T (p = 0.002) were associated with neurotoxicity. At least one A allele at CYP3A5 A6986G (expressor genotype) was strongly associated with it according to logistic regression analysis (p = 0.01; OR, 8.5; 95% CI, 1.4-51.4).   The polymorphisms in CYP3A5 and ABCB1 genes were associated with CNI-related neurotoxicity. This outcome is probably because of CYP3A5 or P-gp functions or metabolites of CNIs. © 2009 John Wiley & Sons A/S.

Epigenetic Regulation of Vitamin D 24-Hydroxylase/CYP24A1 in Human Prostate Cancer

PubMed Central

Luo, Wei; Karpf, Adam R.; Deeb, Kristin K.; Muindi, Josephia R.; Morrison, Carl D.; Johnson, Candace S.; Trump, Donald L.

2010-01-01

Calcitriol, a regulator of calcium homeostasis with antitumor properties, is degraded by the product of the CYP24A1 gene which is downregulated in human prostate cancer by unknown mechanisms. We found that CYP24A1 expression is inversely correlated with promoter DNA methylation in prostate cancer cell lines. Treatment with the DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine (DAC) activates CYP24A1 expression in prostate cancer cells. In vitro methylation of the CYP24A1 promoter represses its promoter activity. Furthermore, inhibition of histone deacetylases by trichostatin A (TSA) enhances the expression of CYP24A1 in prostate cancer cells. ChIP-qPCR reveals that specific histone modifications are associated with the CYP24A1 promoter region. Treatment with TSA increases H3K9ac and H3K4me2 and simultaneously decreases H3K9me2 at the CYP24A1 promoter. ChIP-qPCR assay reveals that treatment with DAC and TSA increases the recruitment of VDR to the CYP24A1 promoter. RT-PCR analysis of paired human prostate samples reveals that CYP24A1 expression is down-regulated in prostate malignant lesions compared to adjacent histologically benign lesions. Bisulfite pyrosequencing shows that CYP24A1 gene is hypermethylated in malignant lesions compared to matched benign lesions. Our findings indicate that repression of CYP24A1 gene expression in human prostate cancer cells is mediated in part by promoter DNA methylation and repressive histone modifications. PMID:20587525

Inhibition of protein kinase CK2 reduces CYP24A1 expression and enhances 1,25-dihydroxyvitamin D3 anti-tumor activity in human prostate cancer cells

PubMed Central

Luo, Wei; Yu, Wei-Dong; Ma, Yingyu; Chernov, Mikhail; Trump, Donald L.; Johnson, Candace S.

2013-01-01

Vitamin D has broad range of physiological functions and anti-tumor effects. 24-hydroxylase, encoded by the CYP24A1 gene, is the key enzyme for degrading many forms of vitamin D including the most active form, 1,25D3. Inhibition of CYP24A1 enhances 1,25D3 anti-tumor activity. In order to isolate regulators of CYP24A1 expression in prostate cancer cells, we established a stable prostate cancer cell line PC3 with CYP24A1 promoter driving luciferase expression to screen a small molecular library for compounds that inhibit CYP24A1 promoter activity. From this screening, we identified, 4,5,6,7-tetrabromobenzimidazole (TBBz), a protein kinase CK2 selective inhibitor as a disruptor of CYP24A1 promoter activity. We show that TBBz inhibits CYP24A1 promoter activity induced by 1,25D3 in prostate cancer cells. In addition, TBBz downregulates endogenous CYP24A1 mRNA level in TBBz treated PC3 cells. Furthermore, siRNA-mediated CK2 knockdown reduces 1,25D3 induced CYP24A1 mRNA expression in PC3 cells. These results suggest that CK2 contributes to 1,25D3 mediated target gene expression. Lastly, inhibition of CK2 by TBBz or CK2 siRNA significantly enhanced 1,25D3 mediated anti-proliferative effect in vitro and in vivo in a xenograft model. In summary, our findings reveal that protein kinase CK2 is involved in the regulation of CYP24A1 expression by 1,25D3 and CK2 inhibitor enhances 1,25D3 mediated anti-tumor effect. PMID:23358686

Retinal and Nonocular Abnormalities in Cyp27a1−/−Cyp46a1−/− Mice with Dysfunctional Metabolism of Cholesterol

PubMed Central

Saadane, Aicha; Mast, Natalia; Charvet, Casey D.; Omarova, Saida; Zheng, Wenchao; Huang, Suber S.; Kern, Timothy S.; Peachey, Neal S.; Pikuleva, Irina A.

2015-01-01

Cholesterol elimination from nonhepatic cells involves metabolism to side-chain oxysterols, which serve as transport forms of cholesterol and bioactive molecules modulating a variety of cellular processes. Cholesterol metabolism is tissue specific, and its significance has not yet been established for the retina, where cytochromes P450 (CYP27A1 and CYP46A1) are the major cholesterol-metabolizing enzymes. We generated Cyp27a1−/−Cyp46a1−/− mice, which were lean and had normal serum cholesterol and glucose levels. These animals, however, had changes in the retinal vasculature, retina, and several nonocular organs (lungs, liver, and spleen). Changes in the retinal vasculature included structural abnormalities (retinal-choroidal anastomoses, arteriovenous shunts, increased permeability, dilation, nonperfusion, and capillary degeneration) and cholesterol deposition and oxidation in the vascular wall, which also exhibited increased adhesion of leukocytes and activation of the complement pathway. Changes in the retina included increased content of cholesterol and its metabolite, cholestanol, which were focally deposited at the apical and basal sides of the retinal pigment epithelium. Retinal macrophages of Cyp27a1−/−Cyp46a1−/− mice were activated, and oxidative stress was noted in their photoreceptor inner segments. Our findings demonstrate the importance of retinal cholesterol metabolism for maintenance of the normal retina, and suggest new targets for diseases affecting the retinal vasculature. PMID:25065682

Cytochrome P450 1b1 in polycyclic aromatic hydrocarbon (PAH)-induced skin carcinogenesis: Tumorigenicity of individual PAHs and coal-tar extract, DNA adduction and expression of select genes in the Cyp1b1 knockout mouse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siddens, Lisbeth K.; Superfund Research Center, Oregon State University, Corvallis, OR 97331; Bunde, Kristi L.

FVB/N mice wild-type, heterozygous or null for Cyp 1b1 were used in a two-stage skin tumor study comparing PAH, benzo[a]pyrene (BaP), dibenzo[def,p]chrysene (DBC), and coal tar extract (CTE, SRM 1597a). Following 20 weeks of promotion with TPA the Cyp 1b1 null mice, initiated with DBC, exhibited reductions in incidence, multiplicity, and progression. None of these effects were observed with BaP or CTE. The mechanism of Cyp 1b1-dependent alteration of DBC skin carcinogenesis was further investigated by determining expression of select genes in skin from DBC-treated mice 2, 4 and 8 h post-initiation. A significant reduction in levels of Cyp 1a1,more » Nqo1 at 8 h and Akr 1c14 mRNA was observed in Cyp 1b1 null (but not wt or het) mice, whereas no impact was observed in Gst a1, Nqo 1 at 2 and 4 h or Akr 1c19 at any time point. Cyp 1b1 mRNA was not elevated by DBC. The major covalent DNA adducts, dibenzo[def,p]chrysene-(±)-11,12-dihydrodiol-cis and trans-13,14-epoxide-deoxyadenosine (DBCDE-dA) were quantified by UHPLC-MS/MS 8 h post-initiation. Loss of Cyp1 b1 expression reduced DBCDE-dA adducts in the skin but not to a statistically significant degree. The ratio of cis- to trans-DBCDE-dA adducts was higher in the skin than other target tissues such as the spleen, lung and liver (oral dosing). These results document that Cyp 1b1 plays a significant role in bioactivation and carcinogenesis of DBC in a two-stage mouse skin tumor model and that loss of Cyp 1b1 has little impact on tumor response with BaP or CTE as initiators. - Highlights: • Cyp1b1 null mice exhibit lower skin cancer sensitivity to DBC but not BaP or CTE. • Cyp1b1 expression impacts expression of other PAH metabolizing enzymes. • cis/trans-DBCDE-dA ratio significantly higher in the skin than the spleen, lung or liver • Potency of DBC and CTE in mouse skin is higher than predicted by RPFs.« less

CYP1B1 and MYOC Mutations in Vietnamese Primary Congenital Glaucoma Patients.

PubMed

Do, Tan; Shei, William; Chau, Pham Thi Minh; Trang, Doan Le; Yong, Victor H K; Ng, Xiao Yu; Chen, Yue Ming; Aung, Tin; Vithana, Eranga N

2016-05-01

Primary congenital glaucoma (PCG, OMIM 231300), the most common glaucoma in infancy, is caused by developmental defects in the anterior chamber angle. The 3 implicated genes are cytochrome P450 family I subfamily B polypeptide 1 (CYP1B1), latent transforming growth factor β-binding protein 2 (LTBP2), and myocilin (MYOC). In this study, we sought to determine CYP1B1 and MYOC sequence variations in a Vietnamese cohort of index cases with PCG and their families. Thirty Vietnamese subjects with PCG and 120 normal Vietnamese subjects were recruited. PCG was defined by the presence of at least 2 of the following clinical manifestations: increased corneal diameter (>10 mm at birth), corneal edema, Haab's striae, optic disc changes, and absence of other ocular or systemic diseases associated with childhood glaucoma. The coding exons, intron and exon boundaries, and untranslated regions of CYP1B1 and MYOC genes were PCR amplified and subjected to bidirectional sequencing in all subjects. We identified 2 homozygous and 3 heterozygous CYP1B1 sequence alterations in our study subjects. Among the 5 mutations identified, 2 (p.H279L and p.L283F) were novel mutations, whereas 3 (p.A121_S122insDRPAFA, p.L107V, and p.V320L) had been previously reported in PCG cases. None of these mutations was observed in any of the 120 controls. Haplotypes generated with 6 non-disease-causing intragenic single nucleotide polymorphisms detected in CYP1B1 indicated that the most common haplotype in Vietnamese population is similar to that found in Chinese and Japanese. The genotype-phenotype correlation showed no significant difference between mutation and no-mutation groups for quantitative clinical features (presenting intraocular pressure, corneal diameter, number of surgeries performed, the cup-to-disc ratio) as well as for qualitative factors (bilateral cases, phenotype severity, and the prognosis) (P>0.05). Five out of 30 families with PCG (16.7%) had disease attributable to CYP1B1 alterations

Genetic polymorphisms in warfarin and tacrolimus-related genes VKORC1, CYP2C9 and CYP3A5 in the Greek-Cypriot population

PubMed Central

2014-01-01

Background Two variants in the gene encoding the cytochrome P450 2C9 enzyme (CYP2C9) are considered the most significant genetic risk factors associated with bleeding after warfarin prescription. A variant in the vitamin K epoxide reductase (VKORC1) has been also associated by several studies with warfarin response. Another variant in the P450 3A5 enzyme (CYP3A5) gene is known to affect the metabolism of many drugs, including tacrolimus. Findings We conducted a population genetic study in 148 unrelated healthy Greek-Cypriot volunteers (through PCR-RFLP assays), in order to determine the frequencies of the above pharmacogenetics variants and to compare allele frequencies with those in other major ethnic groups. The allele frequencies of CYP2C9*2, CYP2C9*3 and CYP3A5*3 were found to be 0.162, 0.112 and 0.943 respectively, whereas VKORC1 - 1639A was 0.534. The latter frequency differs significantly when compared with Caucasians, Asians and Africans (p < 0.001) and is still significant when compared with the geographically and culturally closely related to Greek-Cypriots, Hellenes of Greece (p = 0.01). Interestingly ~18% of our population are carriers of four or three risk alleles regarding warfarin sensitivity, therefore they have a high predisposition for bleeding after taking high or even normal warfarin doses. Conclusions Our data show no significant difference in the frequency of CYP2C9 and CYP3A5 allelic variants when compared to the Caucasian population, but differ significantly when compared with Africans and Asians (p < 0.001). Also, the frequency of variant VKORC1 - 1639A differs between Greek-Cypriots and every other population we compared. Finally, about 1/5 Greek-Cypriots carry three or four risk alleles and ~50% of them carry at least two independent risk alleles regarding warfarin sensitivity, a potentially high risk for over-anticoagulation. PMID:24593903

The P450 CYP6Z1 confers carbamate/pyrethroid cross-resistance in a major African malaria vector beside a novel carbamate-insensitive N485I acetylcholinesterase-1 mutation.

PubMed

Ibrahim, Sulaiman S; Ndula, Miranda; Riveron, Jacob M; Irving, Helen; Wondji, Charles S

2016-07-01

Carbamates are increasingly used for vector control notably in areas with pyrethroid resistance. However, a cross-resistance between these insecticides in major malaria vectors such as Anopheles funestus could severely limit available resistance management options. Unfortunately, the molecular basis of such cross-resistance remains uncharacterized in An. funestus, preventing effective resistance management. Here, using a genomewide transcription profiling, we revealed that metabolic resistance through upregulation of cytochrome P450 genes is driving carbamate resistance. The P450s CYP6P9a, CYP6P9b and CYP6Z1 were the most upregulated detoxification genes in the multiple resistant mosquitoes. However, in silico docking simulations predicted CYP6Z1 to metabolize both pyrethroids and carbamates, whereas CYP6P9a and CYP6P9b were predicted to metabolize only the pyrethroids. Using recombinant enzyme metabolism and inhibition assays, we demonstrated that CYP6Z1 metabolizes bendiocarb and pyrethroids, whereas CYP6P9a and CYP6P9b metabolize only the pyrethroids. Other upregulated gene families in resistant mosquitoes included several cuticular protein genes suggesting a possible reduced penetration resistance mechanism. Investigation of the target-site resistance in acetylcholinesterase 1 (ace-1) gene detected and established the association between the new N485I mutation and bendiocarb resistance (odds ratio 7.3; P < 0.0001). The detection of multiple haplotypes in single mosquitoes after cloning suggested the duplication of ace-1. A TaqMan genotyping of the N485I in nine countries revealed that the mutation is located only in southern Africa with frequency of 10-15% suggesting its recent occurrence. These findings will help in monitoring the spread and evolution of carbamate resistance and improve the design of effective resistance management strategies to control this malaria vector. © 2016 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Interaction between Maternal Passive Smoking during Pregnancy and CYP1A1 and GSTs Polymorphisms on Spontaneous Preterm Delivery

PubMed Central

Luo, Yi-Juan; Wen, Xiao-Zhong; Ding, Peng; He, Yan-Hui; Xie, Chuan-Bo; Liu, Tao; Lin, Jian-miao; Yuan, Shi-Xin; Guo, Xiao-Ling; Jia, De-Qin; Chen, Li-Hua; Huang, Bao-Zhen; Chen, Wei-Qing

2012-01-01

Objective The present study aimed to examine the association between maternal passive smoking during pregnancy and the risk of spontaneous PTD and to explore the potential interaction of the single or joint gene polymorphism of CYP1A1 and GSTs with maternal passive smoking on the risk of spontaneous PTD. Method We investigated whether the association between maternal passive smoking and PTD can be modified by 2 metabolic genes, i.e. cytochrome P4501A1 (CYP1A1) and glutathione S-transferases (GSTs), in a case-control study with 198 spontaneous preterm and 524 term deliveries in Shenzhen and Foshan, China. We used logistic regression to test gene-passive smoking interaction, adjusting for maternal socio-demographics and prepregnancy body mass index. Results Overall, maternal passive smoking during pregnancy was associated with higher risk of PTD (adjusted odds ratio = 2.20 [95% confidence interval: 1.56–3.12]). This association was modified by CYP1A1 and GSTs together, but not by any single genotype. For cross-categories of CYP1A1 Msp I and GSTs, maternal passive smoking was associated with higher risk of PTD among those women with CYP1A1 “TC/CC”+ GSTs “null”, but not among women with other genotypes; and this interaction was significant (OR = 2.66 [95% CI: 1.19–5.97]; P-value: 0.017). For cross-categories of CYP1A1 BsrD I and GSTs, maternal passive smoking was associated with higher risk of PTD only among those women with CYP1A1“AG/GG”+ GSTs “null”, but not among women with other genotypes; and this interaction was significant (OR = 3.00 [95% CI: 1.17–7.74]; P-value: 0.023). Conclusions Our findings suggest that the combined genotypes of CYP1A1 and GSTs can help to identify vulnerable pregnant women who are subject to high risk of spontaneous PTD due to passive smoking. PMID:23152866

Sequence variants at CYP1A1–CYP1A2 and AHR associate with coffee consumption

PubMed Central

Sulem, Patrick; Gudbjartsson, Daniel F.; Geller, Frank; Prokopenko, Inga; Feenstra, Bjarke; Aben, Katja K.H.; Franke, Barbara; den Heijer, Martin; Kovacs, Peter; Stumvoll, Michael; Mägi, Reedik; Yanek, Lisa R.; Becker, Lewis C.; Boyd, Heather A.; Stacey, Simon N.; Walters, G. Bragi; Jonasdottir, Adalbjorg; Thorleifsson, Gudmar; Holm, Hilma; Gudjonsson, Sigurjon A.; Rafnar, Thorunn; Björnsdottir, Gyda; Becker, Diane M.; Melbye, Mads; Kong, Augustine; Tönjes, Anke; Thorgeirsson, Thorgeir; Thorsteinsdottir, Unnur; Kiemeney, Lambertus A.; Stefansson, Kari

2011-01-01

Coffee is the most commonly used stimulant and caffeine is its main psychoactive ingredient. The heritability of coffee consumption has been estimated at around 50%. We performed a meta-analysis of four genome-wide association studies of coffee consumption among coffee drinkers from Iceland (n = 2680), the Netherlands (n = 2791), the Sorbs Slavonic population isolate in Germany (n = 771) and the USA (n = 369) using both directly genotyped and imputed single nucleotide polymorphisms (SNPs) (2.5 million SNPs). SNPs at the two most significant loci were also genotyped in a sample set from Iceland (n = 2430) and a Danish sample set consisting of pregnant women (n = 1620). Combining all data, two sequence variants significantly associated with increased coffee consumption: rs2472297-T located between CYP1A1 and CYP1A2 at 15q24 (P = 5.4 · 10−14) and rs6968865-T near aryl hydrocarbon receptor (AHR) at 7p21 (P = 2.3 · 10−11). An effect of ∼0.2 cups a day per allele was observed for both SNPs. CYP1A2 is the main caffeine metabolizing enzyme and is also involved in drug metabolism. AHR detects xenobiotics, such as polycyclic aryl hydrocarbons found in roasted coffee, and induces transcription of CYP1A1 and CYP1A2. The association of these SNPs with coffee consumption was present in both smokers and non-smokers. PMID:21357676

Disinfection by-products exposure and intra-uterine growth restriction: do genetic polymorphisms of CYP2E1or deletion of GSTM1 or GSTT1 modify the association?

PubMed Central

Levallois, Patrick; Giguère, Yves; Nguile-Makao, Molière; Rodriguez, Manuel; Campagna, Céline; Tardif, Robert; Bureau, Alexandre

2016-01-01

Background Exposure to disinfection by-products (DBPs) during pregnancy was associated with reduced fetal growth. Genetic susceptibility might play a role, especially for genes encoding for the Cytochrome P450 (CYP2E1) and Glutathione S-Transferase (GST) enzymes, involved in metabolism and activation of DBPs. Few epidemiological studies evaluated these gene-environment interactions and their results were never replicated. Objective This study aims to examine interactions between trihalomethanes (THM) or haloacetic acids (HAA) exposure and genetic polymorphisms on small for gestational age (SGA) neonates by investigating single nucleotide polymorphisms (SNPs) in CYP2E1 gene and GSTM1 and GSTT1 deletions in mothers-children pairs. Methods A population-based case-control study of 1549 mothers and 1455 children was conducted on SGA and THM/HAA exposure. DNA was extracted from blood or saliva cells. Targeted SNPs and deletions were genotyped. Statistical interaction between SNPs/deletions and THMs or HAAs in utero exposure with regard to SGA occurrence was evaluated by unconditional logistic regression with control of potential confounders. Results Previously reported positive modification of the effect of THM uterine exposure by mothers or newborns CYP2E1 rs3813867 C allele or GSTM1 deletion was not replicated. However interactions with CYP2E1 rs117618383 and rs2515641 were observed but were not statistically significant after correction for multiple testing. Conclusions Previous positive interactions between THMs exposure and CYP2E1 and GSTM1 were not replicated but interactions with other CYP2E1 polymorphisms are reported. PMID:27107227

Disinfection by-products exposure and intra-uterine growth restriction: Do genetic polymorphisms of CYP2E1or deletion of GSTM1 or GSTT1 modify the association?

PubMed

Levallois, Patrick; Giguère, Yves; Nguile-Makao, Molière; Rodriguez, Manuel; Campagna, Céline; Tardif, Robert; Bureau, Alexandre

2016-01-01

Exposure to disinfection by-products (DBPs) during pregnancy was associated with reduced foetal growth. Genetic susceptibility might play a role, especially for genes encoding for the Cytochrome P450 (CYP2E1) and Glutathione S-Transferase (GST) enzymes, involved in metabolism and activation of DBPs. Few epidemiological studies evaluated these gene-environment interactions and their results were never replicated. This study aims to examine interactions between trihalomethanes (THM) or haloacetic acids (HAA) exposure and genetic polymorphisms on small for gestational age (SGA) neonates by investigating single nucleotide polymorphisms (SNPs) in CYP2E1 gene and GSTM1 and GSTT1 deletions in mothers-children pairs. A population-based case-control study of 1549 mothers and 1455 children was conducted on SGA and THM/HAA exposure. DNA was extracted from blood or saliva cells. Targeted SNPs and deletions were genotyped. Statistical interaction between SNPs/deletions and THMs or HAAs in utero exposure with regard to SGA occurrence was evaluated by unconditional logistic regression with control of potential confounders. Previously reported positive modification of the effect of THM uterine exposure by mothers or newborns CYP2E1 rs3813867 C allele or GSTM1 deletion was not replicated. However interactions with CYP2E1 rs117618383 and rs2515641 were observed but were not statistically significant after correction for multiple testing. Previous positive interactions between THMs exposure and CYP2E1 and GSTM1 were not replicated but interactions with other CYP2E1 polymorphisms are reported. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of ACTH, dexamethasone, and adrenalectomy on 11β-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) gene expression in the rat central nervous system

PubMed Central

Ye, Ping; Kenyon, Christopher J; MacKenzie, Scott M; Nichol, Katherine; Seckl, Jonathan R; Fraser, Robert; Connell, John M C; Davies, Eleanor

2008-01-01

Using a highly sensitive quantitative RT-PCR method for the measurement of CYP11B1 (11β-hydroxylase) and CYP11B2 (aldosterone synthase) mRNAs, we previously demonstrated that CYP11B2 expression in the central nervous system (CNS) is subject to regulation by dietary sodium. We have now quantified the expression of these genes in the CNS of male Wistar Kyoto (WKY) rats in response to systemic ACTH infusion, dexamethasone infusion, and to adrenalectomy. CYP11B1 and CYP11B2 mRNA levels were measured in total RNA isolated from the adrenal gland and discrete brain regions using real-time quantitative RT-PCR. ACTH infusion (40 ng/day for 7 days, N=8) significantly increased CYP11B1 mRNA in the adrenal gland, hypothalamus, and cerebral cortex compared with animals infused with vehicle only. ACTH infusion decreased adrenal CYP11B2 expression but increased expression in all of the CNS regions except the cortex. Dexamethasone (10 μg/day for 7 days, N=8) reduced adrenal CYP11B1 mRNA compared with control animals but had no significant effect on either gene's expression in the CNS. Adrenalectomy (N=6 per group) significantly increased CYP11B1 expression in the hippocampus and hypothalamus and raised CYP11B2 expression in the cerebellum relative to sham-operated animals. This study confirms the transcription of CYP11B1 and CYP11B2 throughout the CNS and demonstrates that gene transcription is subject to differential regulation by ACTH and circulating corticosteroid levels. PMID:18252953

FGF-23 Regulates CYP27B1 Transcription in the Kidney and in Extra-Renal Tissues

PubMed Central

Chanakul, Ankanee; Zhang, Martin Y. H.; Louw, Andrew; Armbrecht, Harvey J.; Miller, Walter L.; Portale, Anthony A.; Perwad, Farzana

2013-01-01

The mitochondrial enzyme 25-hydroxyvitamin D 1α-hydroxylase, which is encoded by the CYP27B1 gene, converts 25OHD to the biological active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)2D). Renal 1α-hydroxylase activity is the principal determinant of the circulating 1,25(OH)2D concentration and enzyme activity is tightly regulated by several factors. Fibroblast growth factor-23 (FGF-23) decreases serum 1,25(OH)2D concentrations by suppressing CYP27B1 mRNA abundance in mice. In extra-renal tissues, 1α-hydroxylase is responsible for local 1,25(OH)2D synthesis, which has important paracrine actions, but whether FGF-23 regulates CYP27B1 gene expression in extra-renal tissues is unknown. We sought to determine whether FGF-23 regulates CYP27B1 transcription in the kidney and whether extra-renal tissues are target sites for FGF-23-induced suppression of CYP27B1. In HEK293 cells transfected with the human CYP27B1 promoter, FGF-23 suppressed promoter activity by 70%, and the suppressive effect was blocked by CI-1040, a specific inhibitor of extracellular signal regulated kinase 1/2. To examine CYP27B1 transcriptional activity in vivo, we crossed fgf-23 null mice with mice bearing the CYP27B1 promoter-driven luciferase transgene (1α-Luc). In the kidney of FGF-23 null/1α-Luc mice, CYP27B1 promoter activity was increased by 3-fold compared to that in wild-type/1α-Luc mice. Intraperitoneal injection of FGF-23 suppressed renal CYP27B1 promoter activity and protein expression by 26% and 60% respectively, and the suppressive effect was blocked by PD0325901, an ERK1/2 inhibitor. These findings provide evidence that FGF-23 suppresses CYP27B1 transcription in the kidney. Furthermore, we demonstrate that in FGF-23 null/1α-Luc mice, CYP27B1 promoter activity and mRNA abundance are increased in several extra-renal sites. In the heart of FGF-23 null/1α-Luc mice, CYP27B1 promoter activity and mRNA were 2- and 5-fold higher, respectively, than in control mice. We also

Overexpression of the CYP51A1 Gene and Repeated Elements are Associated with Differential Sensitivity to DMI Fungicides in Venturia inaequalis.

PubMed

Villani, Sara M; Hulvey, Jon; Hily, Jean-Michel; Cox, Kerik D

2016-06-01

The involvement of overexpression of the CYP51A1 gene in Venturia inaequalis was investigated for isolates exhibiting differential sensitivity to the triazole demethylation inhibitor (DMI) fungicides myclobutanil and difenoconazole. Relative expression (RE) of the CYP51A1 gene was significantly greater (P < 0.0001) for isolates with resistance to both fungicides (MRDR phenotype) or with resistance to difenoconazole only (MSDR phenotype) compared with isolates that were resistant only to myclobutanil (MRDS phenotype) or sensitive to both fungicides (MSDS phenotype). An average of 9- and 13-fold increases in CYP51A1 RE were observed in isolates resistant to difenoconazole compared with isolates with MRDS and MSDS phenotypes, respectively. Linear regression analysis between isolate relative growth on myclobutanil-amended medium and log10 RE revealed that little to no variability in sensitivity to myclobutanil could be explained by CYP51A1 overexpression (R(2) = 0.078). To investigate CYP51A1 upstream anomalies associated with CYP51A1 overexpression or resistance to difenoconazole, Illumina sequencing was conducted for three isolates with resistance to difenoconazole and one baseline isolate. A repeated element, "EL 3,1,2", with the properties of a transcriptional enhancer was identified two to four times upstream of CYP51A1 in difenoconazole-resistant isolates but was not found in isolates with the MRDS phenotype. These results suggest that different mechanisms may govern resistance to different DMI fungicides in the triazole group.

Detection and molecular cloning of CYP74Q1 gene: identification of Ranunculus acris leaf divinyl ether synthase.

PubMed

Gorina, Svetlana S; Toporkova, Yana Y; Mukhtarova, Lucia S; Chechetkin, Ivan R; Khairutdinov, Bulat I; Gogolev, Yuri V; Grechkin, Alexander N

2014-09-01

Enzymes of the CYP74 family, including the divinyl ether synthase (DES), play important roles in plant cell signalling and defence. The potent DES activities have been detected before in the leaves of the meadow buttercup (Ranunculus acris L.) and few other Ranunculaceae species. The nature of these DESs and their genes remained unrevealed. The PCR with degenerate primers enabled to detect the transcript of unknown P450 gene assigned as CYP74Q1. Besides, two more CYP74Q1 isoforms with minimal sequence variations have been found. The full length recombinant CYP74Q1 protein was expressed in Escherichia coli. The preferred substrates of this enzyme are the 13-hydroperoxides of α-linolenic and linoleic acids, which are converted to the divinyl ether oxylipins (ω5Z)-etherolenic acid, (9Z,11E)-12-[(1'Z,3'Z)-hexadienyloxy]-9,11-dodecadienoic acid, and (ω5Z)-etheroleic acid, (9Z,11E)-12-[(1'Z)-hexenyloxy]-9,11-dodecadienoic acid, respectively, as revealed by the data of mass spectrometry, NMR and UV spectroscopy. Thus, CYP74Q1 protein was identified as the R. acris DES (RaDES), a novel DES type and the opening member of new CYP74Q subfamily. Copyright © 2014 Elsevier B.V. All rights reserved.

Pharmacogenetics of CYP1A2 activity and inducibility in smokers and exsmokers.

PubMed

Dobrinas, Maria; Cornuz, Jacques; Eap, Chin B

2013-05-01

There is a high interindividual variability in cytochrome P4501A2 (CYP1A2) activity and in its inducibility by smoking, only poorly explained by known CYP1A2 polymorphisms. We aimed to study the contribution of other regulatory pathways, including transcription factors and nuclear receptors, toward this variability. CYP1A2 activity was determined by the paraxanthine/caffeine ratio in 184 smokers and in 113 of them who were abstinent for 4 weeks. Participants were genotyped for 22 polymorphisms in 12 genes. A significant influence on CYP1A2 inducibility was observed for the NR1I3 rs2502815 (P=0.0026), rs4073054 (P=0.029), NR2B1 rs3818740 (P=0.0045), rs3132297 (P=0.036), AhR rs2282885 (P=0.040), rs2066853 (P=0.019), NR1I1 rs2228570 (P=0.037), and NR1I2 rs1523130 (P=0.044) polymorphisms. Among these, the NR1I3 rs2502815 (P=0.0045), rs4073054 (P=0.048), and NR2B1 rs3818740 (P=0.031) also influenced CYP1A2 basal activity. This is the first in-vivo demonstration of the influence of genes involved in CYP1A2 regulatory pathways on its basal activity and inducibility by smoking. These results need to be confirmed by other studies.

Differential vitamin D 24-hydroxylase/CYP24A1 gene promoter methylation in endothelium from benign and malignant human prostate

PubMed Central

Karpf, Adam R; Omilian, Angela R; Bshara, Wiam; Tian, Lili; Tangrea, Michael A; Morrison, Carl D; Johnson, Candace S

2011-01-01

Epigenetic alterations occur in tumor-associated vessels in the tumor microenvironment. Methylation of the CYP24A1 gene promoter differs in endothelial cells isolated from tumors and non-tumor microenvironments in mice. The epigenetic makeup of endothelial cells of human tumor-associated vasculature is unknown due to difficulty of isolating endothelial cells populations from a heterogeneous tissue microenvironment. To ascertain CYP24A1 promoter methylation in tumor-associated endothelium, we utilized laser microdissection guided by CD31 immunohistochemistry to procure endothelial cells from human prostate tumor specimens. Prostate tissues were obtained following robotic radical prostatectomy from men with clinically localized prostate cancer. Adjacent histologically benign prostate tissues were used to compare endothelium from benign versus tumor microenvironments. Sodium bisulfite sequencing of CYP24A1 promoter region showed that the average CYP24A1 promoter methylation in the endothelium was 20% from the tumor microenvironment compared with 8.2% in the benign microenvironment (p < 0.05). A 2-fold to 17-fold increase in CYP24A1 promoter methylation was observed in the prostate tumor endothelium compared with the matched benign prostate endothelium in four patient samples, while CYP24A1 promoter methylation remained unchanged in two patient samples. In addition, there is no correlation of the level of CYP24A1 promoter methylation in prostate tumor-associated endothelium with that of epithelium/stroma. This study demonstrates that the CYP24A1 promoter is methylated in tumor-associated endothelium, indicating that epigenetic alterations in CYP24A1 may play a role in determining the phenotype of tumor-associated vasculature in the prostate tumor microenvironment. PMID:21725204

Cyp15F1: a novel cytochrome P450 gene linked to juvenile hormone-dependent caste differention in the termite Reticulitermes flavipes.

PubMed

Tarver, Matthew R; Coy, Monique R; Scharf, Michael E

2012-07-01

Termites are eusocial insects that jointly utilize juvenile hormone (JH), pheromones, and other semiochemicals to regulate caste differentiation and achieve caste homeostasis. Prior EST sequencing from the symbiont-free gut transcriptome of Reticulitermes flavipes unexpectedly revealed a number of unique cytochrome P450 (Cyp) transcripts, including fragments of a Cyp15 family gene (Cyp15F1) with homology to other insect Cyp15s that participate in JH biosynthesis. The present study investigated the role of Cyp15F1 in termite caste polyphenism and specifically tested the hypothesis that it plays a role in JH-dependent caste differentiation. After assembling the full-length Cyp15F1 cDNA sequence, we (i) determined its mRNA tissue expression profile, (ii) investigated mRNA expression changes in response to JH and the caste-regulatory primer pheromones γ-cadinene (CAD) and γ-cadinenal (ALD), and (iii) used RNA interference (RNAi) in combination with caste differentiation bioassays to investigate gene function at the phenotype level. Cyp15F1 has ubiquitous whole-body expression (including gut tissue); is rapidly and sustainably induced from 3 h to 48 h by JH, CAD, and ALD; and functions at least in part by facilitating JH-dependent soldier caste differentiation. These findings provide the second example of a termite caste regulatory gene identified through the use of RNAi, and significantly build upon our understanding of termite caste homeostatic mechanisms. These results also reinforce the concept of environmental caste determination in termites by revealing how primer pheromones, as socioenvironmental factors, can directly influence Cyp15 expression and caste differentiation. © 2012 Wiley Periodicals, Inc.

AHR and CYP1A expression link historical contamination events to modern day developmental effects in the American alligator.

PubMed

Hale, Matthew D; Galligan, Thomas M; Rainwater, Thomas R; Moore, Brandon C; Wilkinson, Philip M; Guillette, Louis J; Parrott, Benjamin B

2017-11-01

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that initiates a transcriptional pathway responsible for the expression of CYP1A subfamily members, key to the metabolism of xenobiotic compounds. Toxic planar halogenated aromatic hydrocarbons, including dioxin and PCBs, are capable of activating the AHR, and while dioxin and PCB inputs into the environment have been dramatically curbed following strict regulatory efforts in the United States, they persist in the environment and exposures remain relevant today. Little is known regarding the effects that long-term chronic exposures to dioxin or dioxin-like compounds might have on the development and subsequent health of offspring from exposed individuals, nor is much known regarding AHR expression in reptilians. Here, we characterize AHR and CYP1A gene expression in embryonic and juvenile specimen of a long-lived, apex predator, the American alligator (Alligator mississippiensis), and investigate variation in gene expression profiles in offspring collected from sites conveying differential exposures to environmental contaminants. Both age- and tissue-dependent patterning of AHR isoform expression are detected. We characterize two downstream transcriptional targets of the AHR, CYP1A1 and CYP1A2, and describe conserved elements of their genomic architecture. When comparisons across different sites are made, hepatic expression of CYP1A2, a direct target of the AHR, appears elevated in embryos from a site associated with a dioxin point source and previously characterized PCB contamination. Elevated CYP1A2 expression is not persistent, as site-specific variation was absent in juveniles originating from field-collected eggs but reared under lab conditions. Our results illustrate the patterning of AHR gene expression in a long-lived environmental model species, and indicate a potential contemporary influence of historical contamination. This research presents a novel opportunity to link

Competitive inhibition of carcinogen-activating CYP1A1 and CYP1B1 enzymes by a standardized complex mixture of PAH extracted from coal tar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahadevan, B.; Marston, C.P.; Luch, A.

2007-03-15

A complex mixture of polycyclic aromatic hydrocarbons (PAH) extracted from coal tar, the Standard Reference Material (SRM) 1597, was recently shown to decrease the levels of DNA binding of the 2 strong carcinogens benzo(a)pyrene (BP) and dibenzo(a,l)pyrene (DBP) in the human mammary carcinoma-derived cell line MCF-7. The present study was designed to further elucidate the biochemical mechanisms involved in this inhibition process. We examined the effects of SRM 1597 on the metabolic activation of BP and DBP toward DNA-binding derivatives in Chinese hamster cells expressing either human cytochrome P450 (CYP) 1A1 or CYP1B1. The data obtained from biochemical experiments revealedmore » that SRM 1597 competitively inhibited the activity of both human enzymes as analyzed by 7-ethoxyresorufin O-deethylation assays. While the Michaelis-Menten constant (K-M) was {lt} 0.4 {mu}M in the absence of SRM 1597, this value increased up to 1.12 (CYP1A1) or 4.45 {mu}M (CYP1B1) in the presence of 0.1 {mu} g/ml SRM 1597. Hence the inhibitory effects of the complex mixture on human CYP1B1 were much stronger when compared to human CYP1A1 Taken together, the decreases in PAH-DNA adduct formation on co-treatment with SRM 1597 revealed inhibitory effects on the CYP enzymes that convert carcinogenic PAH into DNA-binding metabolites. The implications for the tumorigenicity of complex environmental PAR mixtures are discussed.« less

Effects of bisphenol A (BPA) on brain-specific expression of cyp19a1b gene in swim-up fry of Labeo rohita.

PubMed

Gupta, Shreyasi; Guha, Payel; Majumder, Suravi; Pal, Puja; Sen, Koushik; Chowdhury, Piyali; Chakraborty, Arindam; Panigrahi, Ashis Kumar; Mukherjee, Dilip

2018-07-01

Estrogen regulates numerous developmental and physiological processes and effects are mediated mainly by estrogenic receptors (ERs), which function as ligand-regulated transcription factor. ERs can be activated by many different types endocrine disrupting chemicals (EDCs) and interfere with behaviour and reproductive potential of living organism. Estrogenic regulation of membrane associated G protein-coupled estrogen receptor, GPER activity has also been reported. Bisphenol A (BPA), a ubiquitous endocrine disruptor is present in many household products, has been linked to many adverse effect on sexual development and reproductive potential of wild life species. The present work is aimed to elucidate how an environmentally pervasive chemical BPA affects in vivo expression of a known estrogen target gene, cyp19a1b in the brain, and a known estrogenic biomarker, vitellogenin (Vg) in the whole body homogenate of 30 days post fertilization (dpf) swim-up fry of Labeo rohita. We confirm that, like estrogen, the xenoestrogen BPA exposure for 5-15 days induces strong overexpression of cyp19a1b, but not cyp19a1a mRNA in the brain and increase concentration of vitellogenin in swim-up fry. BPA also induces strong overexpression of aromatase B protein and aromatase activity in brain. Experiments using selective modulators of classical ERs and GPER argue that this induction is largely through nuclear ERs, not through GPER. Thus, BPA has the potential to elevate the levels of aromatase and thereby, levels of endogenous estrogen in developing brain. These results indicate that L. rohita swim-up fry can be used to detect environmental endocrine disruptors either using cyp19a1b gene expression or vitellogenin induction. Copyright © 2018 Elsevier Inc. All rights reserved.

Utility of Nicotiana tabacum cell suspension cultures expressing human CYP1A1, CYP1A2 and CYP3A4 to study the oxidative metabolism of the herbicide 14C-fluometuron.

PubMed

Breuer, Maren Anne; Schmidt, Burkhard; Schuphan, Ingolf

2009-01-01

The metabolism and biotransformation of the (14)C-labeled phenylurea herbicide fluometuron was examined using tobacco cell suspension cultures transformed separately with human cyp1a1, cyp1a2 and cyp3a4, and corresponding non-transformed cultures in order to screen and predict metabolic patterns. Experimental parameters modified were concentration of (14)C-fluometuron, incubation period, and additional application of inhibitor carbaryl. Media and cell extracts were analyzed by radio-TLC and radio-HPLC, isolated metabolites by LC-MS, and non-extractable residues by combustion. During 48 hours, the CYP1A1 expressing cultures metabolized 90.0 % of applied fluometuron, while the non-transgenic controls transformed 67.0 %. The CYP1A2 expressing cultures exhibited highest rates (95.1 %), CYP3A4 expressing cultures lowest rates (43.0 %). The primary metabolites identified were mono-demethyl (main metabolite in controls) and di-demethyl fluometuron (mainly in CYP1A2 cultures), besides a non-identified primary product (mainly in CYP1A1 cultures); metabolic profiles differed distinctly among cultures. After addition of carbaryl, rates of fluometuron decreased noticeably in controls and not in CYP3A4 expressing cultures. This may indicate inhibition of endogenous tobacco P450s involved in fluometuron metabolism but not of CYP3A4. Additionally, the P450-transgenic cultures proved to be valuable tools to produce large amounts of metabolites for thorough identification.

Upregulation of microRNA-320 decreases the risk of developing steroid-induced avascular necrosis of femoral head by inhibiting CYP1A2 both in vivo and in vitro.

PubMed

Wei, Ji-Hua; Luo, Qun-Qiang; Tang, Yu-Jin; Chen, Ji-Xia; Huang, Chun-Lan; Lu, Ding-Gui; Tang, Qian-Li

2018-06-20

Steroid-induced avascular necrosis of femoral head (SANFH) occurs frequently in patients receiving high-dose steroid treatment for these underlying diseases. The target of this study is to investigate the effect of microRNA-320 (miR-320) on SANFH by targeting CYP1A2. CYP1A2 expression was detected using immunohistochemistry. Specimens were collected from patients with SANFH and femoral neck fracture. Seventy rats were assigned into seven groups. The targeting relationship between miR-320 and CYP1A2 was verified by bioinformatics website and dual luciferase reporter gene assay. RT-qPCR and Western blot analysis were used to detect miR-320 and CYP1A2 expressions. The enzymatic activity of CYP1A2 was detected by fluorescence spectrophotometry. Hemorheology and microcirculation were measured in rats. MiR-320 expression decreased and CYP1A2 expression and enzymatic activity increased in SANFH patients compared to those with femoral neck fracture. CYP1A2 was the target gene of miR-320. Hemorheology and microcirculation results showed that up-regulated expression of CYP1A2 promoted the development of SANFH while increased expression of miR-320 inhibited the development of SANFH. Compared with the SANFH group, the SANFH + miR-320 mimic group showed increased miRNA-320 expression, and decreased CYP1A2 expression and enzymatic activity. Opposite results were found in the SANFH + miR-320 inhibitor group. The SANFH + miR-320 inhibitor + pCR-CYP1A2_KO group showed decreased miRNA-320 expression and the SANFH + pCR-CYP1A2_KO group showed decreased CYP1A2 expression and enzymatic activity. Our findings provide evidences that miR-320 might inhibit the development of SANFH by targeting CYP1A2. Copyright © 2018 Elsevier B.V. All rights reserved.

Combination analysis in genetic polymorphisms of drug-metabolizing enzymes CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A5 in the Japanese population.

PubMed

Ota, Tomoko; Kamada, Yuka; Hayashida, Mariko; Iwao-Koizumi, Kyoko; Murata, Shigenori; Kinoshita, Kenji

2015-01-01

The Cytochrome P450 is the major enzyme involved in drug metabolism. CYP enzymes are responsible for the metabolism of most clinically used drugs. Individual variability in CYP activity is one important factor that contributes to drug therapy failure. We have developed a new straightforward TaqMan PCR genotyping assay to investigate the prevalence of the most common allelic variants of polymorphic CYP enzymes CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A5 in the Japanese population. Moreover, we focused on the combination of each genotype for clinical treatment. The genotype analysis identified a total of 139 out of 483 genotype combinations of five genes in the 1,003 Japanese subjects. According to our results, most of subjects seemed to require dose modification during clinical treatment. In the near future, modifications should be considered based on the individual patient genotype of each treatment.

Impact of genetic factors (VKORC1, CYP2C9, CYP4F2 and EPHX1) on the anticoagulation response to fluindione

PubMed Central

Lacut, Karine; Ayme-Dietrich, Estelle; Gourhant, Lenaick; Poulhazan, Elise; Andro, Marion; Becquemont, Laurent; Mottier, Dominique; Le Gal, Gregoire; Verstuyft, Celine

2012-01-01

AIM Genetic variants of the enzyme that metabolizes warfarin, cytochrome P-450 2C9 (CYP2C9) and of a key pharmacologic target of vitamin K antagonists, vitamin K epoxide reductase (VKORC1), contribute to differences in patients' responses to coumarin derivatives. The role of these variants in fluindione response is unknown. Our aim was to assess whether genetic factors contribute to the variability in the response to fluindione. METHODS Four hundred sixty-five patients with a venous thromboembolic event treated by fluindione for at least 3 months with a target international normalized ratio (INR) of 2.0 to 3.0 were studied. VKORC1, CYP2C9, CYP4F2 and EPHX1 genotypes were assessed. INR checks, fluindione doses and bleeding events were collected. RESULTS VKORC1 genotype had a significant impact on early anticoagulation (INR value ≥2 after the first two intakes) (P < 0.0001), on the time required to reach a first INR within the therapeutic range (P < 0.0001) and on the time to obtain a first INR value > 4 (P = 0.0002). The average daily dose of fluindione during the first period of stability was significantly associated with the VKORC1 genotype: 19.8 mg (±5.5) for VKORC1 CC, 14.7 mg (±6.2) for VKORC1 CT and 8.2 mg (±2.5) for VKORC1 TT (P < 0.0001). CYP2C9, CYP4F2 and EPHX1 genotypes did not significantly influence the response to fluindione. CONCLUSIONS VKORC1 genotype strongly affected anticoagulation induced by fluindione whereas CYP2C9, CYP4F2 and EPHX1 genotypes seemed less determining. PMID:21883387

Comparison of CYP2C9, CYP2C19, CYP2D6, ABCB1, and SLCO1B1 gene-polymorphism frequency in Russian and Nanai populations

PubMed Central

Sychev, Dmitrij Alekseevitch; Shuev, Grigorij Nikolaevich; Suleymanov, Salavat Shejhovich; Ryzhikova, Kristina Anatol’evna; Mirzaev, Karin Badavievich; Grishina, Elena Anatol’evna; Snalina, Natalia Evgenievna; Sozaeva, Zhannet Alimovna; Grabuzdov, Anton Mikhailovich; Matsneva, Irina Andreevna

2017-01-01

Background The efficiency and safety of drug therapy depends on the peculiarities of functioning of the P450 cytochrome group and transporting proteins. There are significant differences for single-nucleotide polymorphism (SNP) frequency. Materials and methods We studied the peculiarities of P450 cytochrome polymorphisms, SLCO1B1 transporting protein, and P-glycoprotein carriage in healthy volunteers in the Nanai ethnic group living in Russia, and compared them to the carriage of SNPs in the Russian population according to literature data. Results After performing the real-time polymerase chain reactions on the samples from 70 healthy volunteers from the Nanai group, for the CYP2C9*2C430T polymorphism we determined 70 CC-genotype carriers. As for the CYP2C9*3A1075C polymorphism, we found 62 AA-genotype carriers and eight AC-genotype carriers. For the CYP2C19*2G681A polymorphism, we determined 39 GG-genotype carriers and 28 GA-genotype carriers, for the CYP2C19*3G636A polymorphism 58 GG-genotype carriers and 12 GA-genotype carriers, and for the CYP2C19*17C806T polymorphism 67 CC-genotype carriers and three CT-genotype carriers. For the CYP2D6*4G1846A polymorphism, the GG genotype had 68 carriers, and the GA genotype two carriers. For the ABCB1*6C3435T polymorphism, there were 19 CC-genotype carriers and 39 CT-genotype carriers. For the SLCO1B1*5T521C polymorphism, the TT genotype had 41 carriers and the CT genotype 25 carriers. The distribution of genotypes fitted the Hardy–Weinberg equilibrium for all the polymorphisms, except those of CYP2C9*2. There were also significant differences in allele frequencies for some polymorphisms between the Nanais and the Russians. Conclusion In the Nanai population, there are polymorphisms connected with the decrease in safety and efficiency of drug therapy. Studying the ethnic differences might influence the determination of priority in the introduction of pharmacogenetic tests in clinical practice in different regions of

Transgenic plants of Petunia hybrida harboring the CYP2E1 gene efficiently remove benzene and toluene pollutants and improve resistance to formaldehyde

PubMed Central

Zhang, Daoxiang; Xiang, Taihe; Li, Peihan; Bao, Lumin

2011-01-01

The CYP2E1 protein belongs to the P450 enzymes family and plays an important role in the metabolism of small molecular and organic pollutants. In this study we generated CYP2E1 transgenic plants of Petunia using Agrobacterium rhizogenes K599. PCR analysis confirmed that the regenerated plants contained the CYP2E1 transgene and the rolB gene of the Ri plasmid. Southern blotting revealed the presence of multiple copies of CYP2E1 in the genome of transgenic plants. Fluorescent quantitative PCR revealed exogenous CYP2E1 gene expression in CYP2E1 transgenic plants at various levels, whereas no like expression was detected in either GUS transgenic plants or wild-types. The absorption of benzene and toluene by transgenic plants was analyzed through quantitative gas chromatography. Transgenic plants with high CYP2E1 expression showed a significant increase in absorption capacity of environmental benzene and toluene, compared to control GUS transgenic and wild type plants. Furthermore, these plants also presented obvious improved resistance to formaldehyde. This study, besides being the first to reveal that the CYP2E1 gene enhances plant resistance to formaldehyde, also furnishes a new method for reducing pollutants, such as benzene, toluene and formaldehyde, by using transgenic flowering horticultural plants. PMID:22215968

Idiopathic hirsutism: local and peripheral expression of aromatase (CYP19A) and 5α-reductase genes (SRD5A1 and SRD5A2).

PubMed

Caglayan, A Okay; Dundar, Munis; Tanriverdi, Fatih; Baysal, Nuran A; Unluhizarci, Kursad; Ozkul, Yusuf; Borlu, Murat; Batukan, Cem; Kelestimur, Fahrettin

2011-08-01

To evaluate idiopathic hirsutism etiology via molecular studies testing peripheral and local aromatase and 5α-reductase expression. Assessment of the expression of messenger RNA (mRNA) for type 1 and 2,5α-reductase isoenzyme gene (SDR5A1, SDR5A2) and aromatase (CYP19A) in dermal papillae cells and peripheral blood mononuclear cells. University hospital. 28 untreated idiopathic hirsute patients and 20 healthy women (controls). Human skin biopsies and peripheral venous blood. SDR5A1, SDR5A2, CYP19A gene expression in skin biopsies and peripheral blood. A statistically significant reduction of SRD5A1, SRD5A2, and CYP19A gene expression was found in the dermal papillae cells and peripheral blood mononuclear cell between the study and control group. Further study, including protein expression and enzyme activity assays, are warranted to characterize the paradoxically low gene expression levels of local 5α-reductase and aromatase in women with idiopathic hirsutism. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Triclosan activates aryl hydrocarbon receptor (AhR)-dependent apoptosis and affects Cyp1a1 and Cyp1b1 expression in mouse neocortical neurons.

PubMed

Szychowski, Konrad A; Wnuk, Agnieszka; Kajta, Małgorzata; Wójtowicz, Anna K

2016-11-01

Triclosan (TCS) is an antimicrobial agent that is used extensively in personal care and in sanitizing products, such as soaps, toothpastes, and hair products. A number of studies have revealed the presence of TCS in human tissues, such as fat, liver and brain, in addition to blood and breast milk. The aim of the present study was to investigate the impact of TCS on AhR and Cyp1a1/Cyp1b1 signaling in mouse neocortical neurons in primary cultures. In addition to the use of selective ligands and siRNAs, expression levels of mRNA and proteins as well as caspase-3 activity, reactive oxygen species (ROS) formation, and lactate dehydrogenase (LDH) release have been measured. We also studied the involvement of the AhR in TCS-induced LDH release and caspase-3 activation as well as the effect of TCS on ROS generation. Cultures of neocortical neurons were prepared from Swiss mouse embryos on day 15/16 of gestation. The cells were cultured in phenol red-free Neurobasal medium with B27 and glutamine, and the neurons were exposed to 1 and 10µM TCS. Our experiments showed that the expression of AhR and Cyp1a1 mRNA decreased in cells exposed to 10µM TCS for 3 or 6h. In the case of Cyp1b1, mRNA expression remained unchanged compared with the control group following 3h of exposure to TCS, but after 6h, the mRNA expression of Cyp1b1 was decreased. Our results confirmed that the AhR is involved in the TCS mechanism of action, and our data demonstrated that after the cells were transfected with AhR siRNA, the cytotoxic and pro-apoptotic properties of TCS were decreased. The decrease in Cyp1a1 mRNA and protein expression levels accompanied by a decrease in its activity. The stimulation of Cyp1a1 activity produced by the application of an AhR agonist (βNF) was attenuated by TCS, whereas the addition of AhR antagonist (αNF) reversed the inhibitory effects of TCS. In our experiments, TCS diminished Cyp1b1 mRNA and enhanced its protein expression. In case of Cyp1a1 we observed

Genetic polymorphisms of genes coding to alcohol-metabolizing enzymes in western Mexicans: association of CYP2E1*c2/CYP2E1*5B allele with cirrhosis and liver function.

PubMed

García-Bañuelos, Jesús; Panduro, Arturo; Gordillo-Bastidas, Daniela; Gordillo-Bastidas, Elizabeth; Muñoz-Valle, José Francisco; Gurrola-Díaz, Carmen M; Sánchez-Enríquez, Sergio; Ruiz-Madrigal, Bertha; Bastidas-Ramírez, Blanca Estela

2012-03-01

Alcoholic cirrhosis constitutes a major public health problem in the world where ADH1B, ALDH2, and CYP2E1 polymorphisms could be playing an important role. We determined ADH1B*2, ALDH2*2, and CYP2E1*c2 allele frequencies in healthy control individuals (C) and patients with alcoholic cirrhosis (AC) from western Mexico. Ninety C and 41 patients with AC were studied. Genotype and allele frequency were determined through polymerase chain reaction-restriction fragment length polymorphisms. Polymorphic allele distribution in AC was 1.6%ADH1B*2, 0.0%ALDH2*2, and 19.5%CYP2E1*c2; in C: 6.1%ADH1B*2, 0%ALDH2*2, and 10.6%CYP2E1*c2. CYP2E1*c2 polymorphic allele and c1/c2 genotype frequency were significantly higher (p < 0.05 and p < 0.01, respectively) in patients with AC when compared to C. Patients with AC, carrying the CYP2E1*c2 allele, exhibited more decompensated liver functioning evaluated by total bilirubin and prothrombin time, than c1 allele carrying patients (p < 0.05). Cirrhosis severity, assessed by Child's Pugh score and mortality, was higher in patients carrying the c2 allele, although not statistically significant. In this study, CYP2E1*c2 allele was associated with susceptibility to AC; meanwhile, ADH1B*2 and ALDH2*2 alleles were not. CYP2E1*c2 allele was associated with AC severity, which could probably be attributed to the oxidative stress promoted by this polymorphic form. Further studies to clearly establish CYP2E1*c2 clinical relevance in the development of alcohol-induced liver damage and its usefulness as a probable prognostic marker, should be performed. Also, increasing the number of patients and including a control group conformed by alcoholic patients free of liver damage may render more conclusive results. These findings contribute to the understanding of the influence of gene variations in AC development among populations, alcohol metabolism, and pharmacogenetics. Copyright © 2011 by the Research Society on Alcoholism.

Genetic polymorphism analysis of cytochrome P4502E1 (CYP2E1) in a Chinese Tibetan population

PubMed Central

Wang, Li; Ren, Guoxia; Li, Jingjie; Zhu, Linhao; Niu, Fanglin; Yan, Mengdan; Li, Jing; Yuan, Dongya; Jin, Tianbo

2017-01-01

Abstract Cytochrome P4502E1 (CYP2E1) gene genetic polymorphisms vary markedly in frequency among different ethnic and racial groups. We studied the genotype distributions and allele frequencies of 3 CYP2E1 polymorphisms: CYP2E1∗1A, CYP2E1∗7A, and CYP2E1∗7C by polymerase chain reaction technique in a sample of 100 healthy subjects representing Tibetan population. The frequencies of CYP2E1∗1A, ∗7A, and ∗7C alleles were 0.705, 0.125, and 0.170, respectively. Compared with other populations, we found that the allele frequencies of the variants −352A>G (rs2070672) and −333A>T (rs2070673) in this Tibetan population have significant differences compared with European-American, African-American, Japanese, Korean, and other different geographic areas in Chinese Han population. Furthermore, the results of protein prediction revealed that the variant 6397G>A (rs61710826) could influence the protein structure and function. These findings in this study would be valuable for pharmacogenetics for drug therapy and drug discovery. However, further studies in larger samples are warranted to confirm our results. PMID:29381998

Gene-gene interactions of CYP2A6 and MAOA polymorphisms on smoking behavior in Chinese male population.

PubMed

Tang, Xun; Guo, Song; Sun, Hongqiang; Song, Xuemei; Jiang, Zuonin; Sheng, Lixiang; Zhou, Dongfeng; Hu, Yonghua; Chen, Dafang

2009-05-01

Nicotine is the major psychoactive ingredient in tobacco, and is responsible for dependence through the nicotine-stimulated reward pathway mediated by the central dopaminergic system. Consequently, genetic polymorphisms in both nicotine metabolism and dopamine catabolism genes may influence smoking behavior, and interact with each other resulting in risk modulation. In this study, we investigated the association and multilocus gene-gene interactions of cytochrome P450 2A6 (CYP2A6), dopamine beta-hydroxylase (DBH), catechol O-methyl transferase (COMT), and monoamine oxidase A (MAOA) polymorphisms with smoking behavior in a community-based Chinese male population. The polymorphisms were genotyped in 203 current smokers, 66 former smokers, and 102 never smokers. Multivariate logistic regression models and the multifactor dimensionality reduction method were used to analyze the association and multilocus gene-gene interactions. Statistically significant trends were shown for increased risk of smoking initiation in participants with CYP2A6*1B/CYP2A6*1B genotypes compared with those with CYP2A6*1A/CYP2A6*1A genotypes [odds ratio (OR)=3.5, 95% confidence interval (CI)= 1.5-8.1], and participants with CYP2A6*1/CYP2A6*1 genotypes were at higher risk of smoking initiation (OR=2.4, 95% CI=1.2-4.5) and smoking persistence (OR=4.0, 95% CI=1.5-10.3) than those who have CYP2A6*4C genotypes. Moreover, the best model involved a gene-gene interaction between MAOA and CYP2A6 was characterized by the multifactor dimensionality reduction method (64.11% accuracy, P<0.001), and indicated that carriers of the combined 1460 T/O genotype for MAOA EcoRV and CYP2A6*1/CYP2A6*1 genotypes were at higher risk of smoking (OR=15.4, 95% CI=4.5-52.5). These findings suggested a substantial influence of CYP2A6 polymorphism as well as the interaction with MAOA resulting in risk modulation on smoking behavior in Chinese male population.

Structure and expression of the rat CYP3A1 gene: isolation of the gene (P450/6betaB) and characterization of the recombinant protein.

PubMed

Nagata, K; Ogino, M; Shimada, M; Miyata, M; Gonzalez, F J; Yamazoe, Y

1999-02-15

A P450 gene (P450/6betaB) of the CYP3A subfamily was isolated from a rat genomic library. Nucleotide sequencing of the exons revealed a high similarity with P450PCN1 cDNA (Gonzalez et al. (1985), J. Biol. Chem. 260, 7345-7441), but differed in 41 nucleotides, resulting in 11 changes and 2 deletions of amino acid residues. The P450/6betaB spanned about 30 kbp and consisted of 13 exons, and was in exon number and size identical with CYP3A2 gene except in the 6th exon, which was shorter than that of CYP3A2. 6beta-B mRNA, which may be transcribed from P450/6betaB, was detected on Northern blotting and by reverse transcription-polymerase chain reaction (RT-PCR). Profiles of the developmental change and induction by a treatment with several chemicals were very similar to those of P450PCN1 mRNA reported previously. P450PCN1 mRNA and gene, however, were not detected by PCR in rats. To determine whether P450/6betaB encodes an active protein, a cDNA was isolated and expressed. Expression of 6beta-B cDNA in COS-1 cells was carried out and revealed that the recombinant protein comigrated with purified P4506beta-4 previously identified as CYP3A1. The recombinant 6beta-B protein showed similar turnover rate and regioselectivity for testosterone with purified P4506beta-4 by the simultaneous addition of NADPH-cytochrome P450 reductase and cytochrome b5. These data suggest that P450/6betaB encodes an active P450 form corresponding to CYP3A1 and P450PCN1 reported previously does not exist in rats. Copyright 1999 Academic Press.

Impaired dacarbazine activation and 7-ethoxyresorufin deethylation in vitro by polymorphic variants of CYP1A1 and CYP1A2: implications for cancer therapy.

PubMed

Lewis, Benjamin C; Korprasertthaworn, Porntipa; Miners, John O

2016-10-01

To extend our understanding of how interindividual variability mediates the efficacy of cancer treatment. The kinetics of dacarbazine (DTIC) N-demethylation by the most frequent polymorphic variants of CYP1A1 (T461N, I462V) and CYP1A2 (F186L, D348N, I386F, R431W, R456H) were characterized, along with kinetic parameters for the O-deethylation of the prototypic CYP1A substrate 7-ethoxyresorufin, using recombinant protein expression and high-performance liquid chromatographic techniques. A reduction of ∼30% in the catalytic efficiencies (measured as in-vitro intrinsic clearance, CLint) was observed for DTIC N-demethylation by the two CYP1A1 variants relative to wild type. Although a modest increase in the CLint value for DTIC N-demethylation was observed for the CYP1A2 D348N variant relative to the wild type, the CLint for the F186L variant was reduced and the I386F, R431W, and R456H variants all showed loss of catalytic function. Comparison of the kinetic data for DTIC N-demethylation and 7-ethoxyresorufin O-deethylation indicated that alterations in the kinetic parameters (Km, Vmax, CLint) observed with each of the CYP1A1 and CYP1A2 polymorphic variants were substrate dependent. These data indicate that cancer patients treated with DTIC who possess any of the CYP1A1-T461N and I462V variants or the CYP1A2-F186L, D348N, I386F, R431W, and R456H variants are likely to have decreased prodrug activation, and hence may respond less favorably to DTIC treatment compared with individuals with wild-type CYP1A alleles.

Characterization of 107 Genomic DNA Reference Materials for CYP2D6, CYP2C19, CYP2C9, VKORC1, and UGT1A1

PubMed Central

Pratt, Victoria M.; Zehnbauer, Barbara; Wilson, Jean Amos; Baak, Ruth; Babic, Nikolina; Bettinotti, Maria; Buller, Arlene; Butz, Ken; Campbell, Matthew; Civalier, Chris; El-Badry, Abdalla; Farkas, Daniel H.; Lyon, Elaine; Mandal, Saptarshi; McKinney, Jason; Muralidharan, Kasinathan; Noll, LeAnne; Sander, Tara; Shabbeer, Junaid; Smith, Chingying; Telatar, Milhan; Toji, Lorraine; Vairavan, Anand; Vance, Carlos; Weck, Karen E.; Wu, Alan H.B.; Yeo, Kiang-Teck J.; Zeller, Markus; Kalman, Lisa

2010-01-01

Pharmacogenetic testing is becoming more common; however, very few quality control and other reference materials that cover alleles commonly included in such assays are currently available. To address these needs, the Centers for Disease Control and Prevention's Genetic Testing Reference Material Coordination Program, in collaboration with members of the pharmacogenetic testing community and the Coriell Cell Repositories, have characterized a panel of 107 genomic DNA reference materials for five loci (CYP2D6, CYP2C19, CYP2C9, VKORC1, and UGT1A1) that are commonly included in pharmacogenetic testing panels and proficiency testing surveys. Genomic DNA from publicly available cell lines was sent to volunteer laboratories for genotyping. Each sample was tested in three to six laboratories using a variety of commercially available or laboratory-developed platforms. The results were consistent among laboratories, with differences in allele assignments largely related to the manufacturer's assay design and variable nomenclature, especially for CYP2D6. The alleles included in the assay platforms varied, but most were identified in the set of 107 DNA samples. Nine additional pharmacogenetic loci (CYP4F2, EPHX1, ABCB1, HLAB, KIF6, CYP3A4, CYP3A5, TPMT, and DPD) were also tested. These samples are publicly available from Coriell and will be useful for quality assurance, proficiency testing, test development, and research. PMID:20889555

Comparison of the biotransformation of the 14C-labelled insecticide carbaryl by non-transformed and human CYP1A1-, CYP1A2-, and CYP3A4-transgenic cell cultures of Nicotiana tabacum.

PubMed

Schmidt, Burkhard; Faymonville, Tanja; Gembé, Eva; Joussen, Nicole; Schuphan, Ingolf

2006-08-01

Transgenic tobacco-cell-suspension cultures expressing separately the human cytochrome P450 monooxygenases CYP1A1, CYP1A2, and CYP3A4 were utilized to study the biotransformation of the 14C-labelled insecticide carbaryl (=naphthalen-1-yl methylcarbamate). The resulting data were compared to similar data from the corresponding non-transformed (NT) tobacco-cell culture and commercially available membrane preparations (Bactosomes) of genetically modified bacteria separately containing the same human P450s. A rapid conversion rate of carbaryl was observed with the CYP1A1 and CYP1A2 cells, where only 49.7 and 0.2% of applied carbaryl (1 mg/l), respectively, remained after 24 h, as compared to 77.7% in the non-transformed culture. Unexpectedly, the corresponding results obtained from the CYP3A4 cultures were not definite. With 25 mg/l of carbaryl and 96 h of incubation, it was proven that the insecticide is also substrate of CYP3A4. This finding was supported by GC/EI-MS analysis of the primary metabolite pattern produced by the isozyme. This consisted of naphthalene-1-ol, N-(hydroxymethyl)carbaryl, 4-hydroxycarbaryl, and 5-hydroxycarbaryl, whereas the main product in non-transformed cells was N-(hydroxymethyl)carbaryl. Data obtained from the CYP1A1, CYP1A2, or CYP3A4 Bactosomes agreed with those of the P450-transgenic tobacco cells. Problems with GC/EI-MS analysis of carbaryl and its metabolites are discussed.

CYP79F1 and CYP79F2 have distinct functions in the biosynthesis of aliphatic glucosinolates in Arabidopsis.

PubMed

Chen, Sixue; Glawischnig, Erich; Jørgensen, Kirsten; Naur, Peter; Jørgensen, Bodil; Olsen, Carl-Erik; Hansen, Carsten H; Rasmussen, Hasse; Pickett, John A; Halkier, Barbara A

2003-03-01

Cytochromes P450 of the CYP79 family catalyze the conversion of amino acids to oximes in the biosynthesis of glucosinolates, a group of natural plant products known to be involved in plant defense and as a source of flavor compounds, cancer-preventing agents and bioherbicides. We report a detailed biochemical analysis of the substrate specificity and kinetics of CYP79F1 and CYP79F2, two cytochromes P450 involved in the biosynthesis of aliphatic glucosinolates in Arabidopsis thaliana. Using recombinant CYP79F1 and CYP79F2 expressed in Escherichia coli and Saccharomyces cerevisiae, respectively, we show that CYP79F1 metabolizes mono- to hexahomomethionine, resulting in both short- and long-chain aliphatic glucosinolates. In contrast, CYP79F2 exclusively metabolizes long-chain elongated penta- and hexahomomethionines. CYP79F1 and CYP79F2 are spatially and developmentally regulated, with different gene expression patterns. CYP79F2 is highly expressed in hypocotyl and roots, whereas CYP79F1 is strongly expressed in cotyledons, rosette leaves, stems, and siliques. A transposon-tagged CYP79F1 knockout mutant completely lacks short-chain aliphatic glucosinolates, but has an increased level of long-chain aliphatic glucosinolates, especially in leaves and seeds. The level of long-chain aliphatic glucosinolates in a transposon-tagged CYP79F2 knockout mutant is substantially reduced, whereas the level of short-chain aliphatic glucosinolates is not affected. Biochemical characterization of CYP79F1 and CYP79F2, and gene expression analysis, combined with glucosinolate profiling of knockout mutants demonstrate the functional role of these enzymes. This provides valuable insights into the metabolic network leading to the biosynthesis of aliphatic glucosinolates, and into metabolic engineering of altered aliphatic glucosinolate profiles to improve nutritional value and pest resistance.

Quantitative assessment of CYP11B1 and CYP11B2 expression in aldosterone-producing adenomas.

PubMed

Fallo, F; Pezzi, V; Barzon, L; Mulatero, P; Veglio, F; Sonino, N; Mathis, J M

2002-12-01

The presence and pathophysiological role of CYP11B1 (11beta-hydroxylase) gene in the zona glomerulosa of human adrenal cortex is still controversial. In order to specifically quantify CYP11B1, CYP11B2 (aldosterone synthase) and CYP17(17alpha-hydroxylase) mRNA levels, we developed a real-time RT-PCR assay and examined the expression in a series of adrenal tIssues, including six normal adrenals from patients adrenalectomized for renal cancer and twelve aldosterone-producing adenomas (APA) from patients with primary aldosteronism. CYP11B1 mRNA levels were clearly detected in normal adrenals, which comprised both zona glomerulosa and fasciculata/reticularis cells, but were also measured at a lower range (P<0.05) in APA. The levels of CYP11B2 mRNA were lower (P<0.005) in normal adrenals than in APA. CYP17 mRNAlevels were similar in normal adrenals and in APA. In patients with APA, CYP11B2 and CYP11B1 mRNA levels were not correlated either with basal aldosterone or with the change from basal aldosterone in response to posture or to dexamethasone. No correlation between CYP11B1 mRNA or CYP11B2 mRNA and the percentage of zona fasciculata-like cells was observed in APA. Real-time RT-PCR can be reliably used to quantify CYP11B1 and CYP11B2 mRNA levels in adrenal tIssues. Expression of CYP11B1 in hyperfunctioning zona glomerulosa suggests an additional formation of corticosterone via 11beta-hydroxylase, providing further substrate for aldosterone biosynthesis. CYP11B1 and CYP11B2 mRNA levels in APA are not related to the in vivo secretory activity of glomerulosa cells, where post-transcriptional factors might ultimately regulate aldosterone production.

Suppression of CYP1 members of the AHR response by pathogen-associated molecular patterns.

PubMed

Peres, Adam G; Zamboni, Robert; King, Irah L; Madrenas, Joaquín

2017-12-01

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that triggers a broad response, which includes the regulation of proinflammatory cytokine production by monocytes and macrophages. AHR is negatively regulated by a set of genes that it transcriptionally activates, including the AHR repressor ( Ahrr ) and the cytochrome P450 1 ( Cyp1 ) family, which are critical for preventing exacerbated AHR activity. An imbalance in these regulatory mechanisms has been shown to cause severe defects in lymphoid cells. Therefore, we wanted to assess how AHR activation is regulated in monocytes and macrophages in the context of innate immune responses induced by pathogen-associated molecular patterns (PAMPs). We found that concomitant stimulation of primary human monocytes with PAMPs and the AHR agonist 6-formylindolo(3,2-b)carbazole (FICZ) led to a selective dose-dependent inhibition of Cyp1 family members induction. Two other AHR-dependent genes [ Ahrr and NADPH quinone dehydrogenase 1 ( Nqo1 )] were not affected under these conditions, suggesting a split in the AHR regulation by PAMPs. This down-regulation of Cyp1 family members did not require de novo protein production nor signaling through p38, ERK, or PI3K-Akt-mammalian target of rapamycin (mTOR) pathways. Furthermore, such a split regulation of the AHR response was more apparent in GM-CSF-derived macrophages, a finding corroborated at the functional level by decreased CYP1 activity and decreased proinflammatory cytokine production in response to FICZ and LPS. Collectively, our findings identify a role for pattern recognition receptor (PRR) signaling in regulating the AHR response through selective down-regulation of Cyp1 expression in human monocytes and macrophages. © Society for Leukocyte Biology.

Lack of Association between ESR1 and CYP1A1 Gene Polymorphisms and Susceptibility to Uterine Leiomyoma in Female Patients of Iranian Descent.

PubMed

Taghizade Mortezaee, Fatemeh; Tabatabaiefar, Mohammad Amin; Hashemzadeh Chaleshtori, Morteza; Miraj, Sepideh

2014-01-01

Uterine leiomyoma (UL) is the most common benign smooth muscle cell tumor with as yet unknown etiology and pathogenesis. This study was carried out to investigate the association of ESR1-351 A>G, ESR1 -397 T>C and CYP1A1 (Ile462Val) polymorphisms with UL in female patients of Iranian origin. In this case-control study, 276 patients with UL and 156 healthy women were recruited. The genetic polymorphisms ESR1-351 A>G, ESR1-397 T>C and CYP1A1 (Ile462Val) were genotyped by polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP). No significant difference were found in frequencies of both genotypes and alleles of ESR1-351 A>G, ESR1-397 T>C and CYP1A1 (Ile462Val) polymorphisms between the two groups (p>0.05). Our findings indicated that these ESR1 and CYP1A1 polymorphisms were not associated with the development of UL in the cases reported here.

A Case of Vitamin-D-Dependent Rickets Type 1A with Normal 1,25-Dihydroxyvitamin D Caused by Two Novel Mutations of the CYP27B1 Gene.

PubMed

Giannakopoulos, Aris; Efthymiadou, Alexandra; Chrysis, Dionisios

2017-01-01

Vitamin-D-dependent rickets 1A (VDDR-1A) is caused by mutations of the renal CYP27B1 gene and is a rare form of rickets. Herein, we report a 20-month-old toddler who presented with inability to walk and failure to thrive. The clinical, biochemical and radiological findings were consistent with a diagnosis of rickets, specifically of the genetic type due to increased 25-OH vitamin D stores. Our patient was a compound heterozygote with 2 novel mutations: c.242G>A(p.Gly81Glu) and c.1144C>G (p.Pro382Ala) in the CYP27B1 gene. Analysis of both mutations with in silico models predicted a deleterious effect on 25-OH vitamin D 1α-hydroxylase function. Interestingly, the levels of 1,25-(OH)2 vitamin D were within normal limits. Our patient was initiated on 1α-hydroxyvitamin D (alfacalcidol) and supplemental calcium. Monitoring of bone metabolism showed a normalization of all bone metabolism serum indices after 3 months of therapy and, thereafter, only alfacalcidol was given at a maintenance dose. The clinical follow-up showed a dramatic improvement in musculoskeletal activity, and the patient regained acceleration in height and weight appropriate for his age. This rare case report of VDDR-1A with normal levels of 1,25-(OH)2 vitamin D enhances our awareness for this type of rickets in clinical practice. © 2016 S. Karger AG, Basel.

CYP3C1, the first member of a new cytochrome P450 subfamily found in zebrafish (Danio rerio).

PubMed

Corley-Smith, Graham E; Su, Hsiao-Ting; Wang-Buhler, Jun-Lan; Tseng, Hua-Pin; Hu, Chin-Hwa; Hoang, Thuy; Chung, Woon-Gye; Buhler, Donald R

2006-02-24

We report a new cytochrome P450 (CYP) subfamily CYP3C and the cloning through PCR from zebrafish (Danio rerio) of the first member, CYP3C1. The CYP3C1 gene is on Chromosome 3 with 13 ORF exons encoding a 505 amino acid protein which has 44-54% identities with mammalian and teleost CYP3A and CYP3B forms. As evidenced by spectral analysis, the CYP3C1 protein heterologously expressed in yeast is functional. In silico analysis identified, on the same region of the chromosome, three more genes encoding CYP3C1-like proteins that formed a clade with CYP3C1 in a phylogenetic tree. Using RT-PCR, the CYP3C1 mRNA was detected in 1-6dpf embryo/larvae and in adult fish liver and seven extrahepatic tissues. Whole-mount in situ hybridization using a riboprobe demonstrated expression in the brain during 12-120 hpf. At the 120 hpf larval stage, CYP3C1 mRNA was also detected in the pharynx and gastrointestinal tract. TCDD, dexamethasone, and rifampicin, which up-regulated CYP3A65 mRNA in zebrafish larvae, did not alter the CYP3C1 transcript levels suggesting regulatory differences between CYP3A and CYP3C enzymes in this species.

Identification and Characterization of the Gene CYP340W1 from Plutella xylostella and Its Possible Involvement in Resistance to Abamectin

PubMed Central

Gao, Xue; Yang, Jiaqiang; Xu, Baoyun; Xie, Wen; Wang, Shaoli; Zhang, Youjun; Yang, Fengshan; Wu, Qingjun

2016-01-01

Abamectin has been used to control the diamondback moth, Plutella xylostella (P. xylostella), which is a major agricultural pest that can rapidly develop resistance against insecticides including abamectin. Although cytochrome P450 has been confirmed to play an important role in resistance in P. xylostella, the specific P450 genes associated with the resistance are unclear. The full-length cDNA of the cytochrome P450 gene CYP340W1 was cloned and characterized in the present study. The cDNA assembly yielded a sequence of 1929 bp, containing the open reading frame (ORF) 1491 bp and encodes a 496-amino acid peptide. CYP340W1 was expressed in all P. xylostella developmental stages but its expression level was highest in larvae and especially in the heads of larvae. The expression of CYP340W1 was significantly higher in an abamectin-resistant strain (ABM-R) than in its susceptible counterpart (ABM-S). In addition, expression of CYP340W1 was increased when the ABM-R strain was exposed to abamectin. When injected into third-stage ABM-R larvae, CYP340W1 dsRNA significantly reduced CYP340W1 expression at 6 h and reduced expression by 83% at 12 h. As a consequence of RNAi, the mortality of the injected abamectin-resistant larvae increased after a 48-h exposure to abamectin. The results indicate that the overexpression of CYP340W1 plays an important role in abamectin resistance in P. xylostella. PMID:26999122

Identification and Characterization of the Gene CYP340W1 from Plutella xylostella and Its Possible Involvement in Resistance to Abamectin.

PubMed

Gao, Xue; Yang, Jiaqiang; Xu, Baoyun; Xie, Wen; Wang, Shaoli; Zhang, Youjun; Yang, Fengshan; Wu, Qingjun

2016-03-18

Abamectin has been used to control the diamondback moth, Plutella xylostella (P. xylostella), which is a major agricultural pest that can rapidly develop resistance against insecticides including abamectin. Although cytochrome P450 has been confirmed to play an important role in resistance in P. xylostella, the specific P450 genes associated with the resistance are unclear. The full-length cDNA of the cytochrome P450 gene CYP340W1 was cloned and characterized in the present study. The cDNA assembly yielded a sequence of 1929 bp, containing the open reading frame (ORF) 1491 bp and encodes a 496-amino acid peptide. CYP340W1 was expressed in all P. xylostella developmental stages but its expression level was highest in larvae and especially in the heads of larvae. The expression of CYP340W1 was significantly higher in an abamectin-resistant strain (ABM-R) than in its susceptible counterpart (ABM-S). In addition, expression of CYP340W1 was increased when the ABM-R strain was exposed to abamectin. When injected into third-stage ABM-R larvae, CYP340W1 dsRNA significantly reduced CYP340W1 expression at 6 h and reduced expression by 83% at 12 h. As a consequence of RNAi, the mortality of the injected abamectin-resistant larvae increased after a 48-h exposure to abamectin. The results indicate that the overexpression of CYP340W1 plays an important role in abamectin resistance in P. xylostella.

Pregnane X receptor regulates the AhR/Cyp1A1 pathway and protects liver cells from benzo-[α]-pyrene-induced DNA damage.

PubMed

Cui, Hongmei; Gu, Xinsheng; Chen, Jingshu; Xie, Ying; Ke, Sui; Wu, Jing; Golovko, Andrei; Morpurgo, Benjamin; Yan, Chunhong; Phillips, Timothy D; Xie, Wen; Luo, Jianyuan; Zhou, Zhijun; Tian, Yanan

2017-06-05

Pregnane X receptor (PXR) plays an important role in protecting cells from mutagenic DNA damages induced by endogenous and exogenous toxicants. This protective function is often attributed to the PXR-regulated metabolic detoxification. Here we report a novel potential mechanism that PXR reduces benzo-[α]-pyrene(BaP)-induced DNA damage through inhibiting the transcriptional activity of aryl hydrocarbon receptor (AhR) which plays a pivotal role in the bioactivation of BaP. We have utilized three well-characterized cell lines, i.e. Hepa1c1c7, AhR +/+; Bpr lacks AhR obligatory partner ARNT; Tao, lacks AhR, to analyze pivotal role of AhR/ARNT complex in mediating the BaP-induced DNA damages using comet assay (single-cell gel electrophoresis). We found that PXR activation could significantly inhibit BaP-induced DNA damage in the HepG2 cells as well as mouse hepatocytes. Using PXR-null and wild type mouse hepatocytes we showed that PXR activation by pregnenolone 16α-carbonitrile (PCN) significantly inhibited BaP-induced DNA damage and this protective effect was abolished in PXR-null hepatocytes. Mechanistically, PXR activation inhibited expression of AhR-target genes for CYP1A1, CYP1B1 and CYP1A2 that are required for BaP biotransformation in cultured liver cells, or in the livers of C57BL/6J mice. Using an AhR-responsive reporter assay as well as chromatin immunoprecipitation assay we found that PXR activation transcriptionally represses AhR-regulated gene expression. Furthermore, we found that PXR directly bound AhR at its DNA-binding domain, and this association may play a role in preventing of the AhR from binding to its target genes as shown in the ChIP assay. Taken together, our study has revealed a novel mechanism by which PXR protects liver cells from BaP-induced DNA damage through inhibiting the BaP biotransformation. Copyright © 2017 Elsevier B.V. All rights reserved.

Functional analysis of CYP6ER1, a P450 gene associated with imidacloprid resistance in Nilaparvata lugens.

PubMed

Pang, Rui; Chen, Meng; Liang, Zhikun; Yue, Xiangzhao; Ge, Hu; Zhang, Wenqing

2016-10-10

The cytochrome P450 CYP6ER1 has been reported to play an important role in imidacloprid resistance of the brown planthopper (BPH), Nilaparvata lugens, and is overexpressed in most resistant populations. In the present study, we confirmed that CYP6ER1 expression can be induced by certain levels of imidacloprid. Developmental expression analysis revealed that CYP6ER1 was expressed highly in the adult stage, and tissue distribution analysis showed that CYP6ER1 was expressed mainly in the fat body and midgut. RNA interference (RNAi) of CYP6ER1 and transgenic expression of CYP6ER1 in Drosophila melanogaster both suggested that the expression of CYP6ER1 is sufficient to confer imidacloprid resistance. Furthermore, we analyzed the interaction of imidacloprid and CYP6ER1 monooxygenase by using dynamic simulations and molecular docking. We found that Nitrogen atoms in the heterocycle of the imidacloprid molecule may bind to iron atoms in the center of the homology model of CYP6ER1 via 4,5-dihedro-1H-imidazole. This finding contributes to a better understanding of how CYP6ER1 takes part in the insecticide metabolism.

Ethanol Induction of CYP2A5: Role of CYP2E1-ROS-Nrf2 Pathway

PubMed Central

Lu, Yongke; Zhang, Xu Hannah

2012-01-01

Chronic ethanol consumption was previously shown to induce CYP2A5 in mice, and this induction of CYP2A5 by ethanol was CYP2E1 dependent. In this study, the mechanisms of CYP2E1-dependent ethanol induction of CYP2A5 were investigated. CYP2E1 was induced by chronic ethanol consumption to the same degree in wild-type (WT) mice and CYP2A5 knockout (Cyp2a5 –/–) mice, suggesting that unlike the CYP2E1-dependent ethanol induction of CYP2A5, ethanol induction of CYP2E1 is not CYP2A5 dependent. Microsomal ethanol oxidation was about 25% lower in Cyp2a5 –/– mice compared with that in WT mice, suggesting that CYP2A5 can oxidize ethanol although to a lesser extent than CYP2E1 does. CYP2A5 was induced by short-term ethanol consumption in human CYP2E1 transgenic knockin (Cyp2e1 –/– KI) mice but not in CYP2E1 knockout (Cyp2e1 –/–) mice. The redox-sensitive transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2) was also induced by acute ethanol in Cyp2e1 –/– KI mice but not in Cyp2e1 –/– mice. Ethanol induction of CYP2A5 in Nrf2 knockout (Nrf2 –/–) mice was lower compared with that in WT mice, whereas CYP2E1 induction by ethanol was comparable in WT and Nrf2 –/– mice. Antioxidants (N-acetyl-cysteine and vitamin C), which blocked oxidative stress induced by chronic ethanol in WT mice and acute ethanol in Cyp2e1 –/– KI mice, also blunted the induction of CYP2A5 and Nrf2 by ethanol but not the induction of CYP2E1 by ethanol. These results suggest that oxidative stress induced by ethanol via induction of CYP2E1 upregulates Nrf2 activity, which in turn regulates ethanol induction of CYP2A5. Results obtained from primary hepatocytes, mice gavaged with binge ethanol or fed chronic ethanol, show that Nrf2-regulated ethanol induction of CYP2A5 protects against ethanol-induced steatosis. PMID:22552773

Systemic effects of arctic pollutants in beluga whales indicated by CYP1A1 expression.

PubMed

Wilson, Joanna Y; Cooke, Suzy R; Moore, Michael J; Martineau, Daniel; Mikaelian, Igor; Metner, Donald A; Lockhart, W Lyle; Stegeman, John J

2005-11-01

Cytochrome P450 1A1 (CYP1A1) is induced by exposure to polycyclic aromatic hydrocarbons (PAHs) and planar halogenated aromatic hydrocarbons (PHAHs) such as non-ortho polychlorinated biphenyls (PCBs). In this study, we examined CYP1A1 protein expression immunohistochemically in multiple organs of beluga whales from two locations in the Arctic and from the St. Lawrence estuary. These beluga populations have some of the lowest (Arctic sites) and highest (St. Lawrence estuary) concentrations of PCBs in blubber of all cetaceans. Samples from these populations might be expected to have different contaminant-induced responses, reflecting their different exposure histories. The pattern and extent of CYP1A1 staining in whales from all three locations were similar to those seen in animal models in which CYP1A has been highly induced, indicating a high-level expression in these whales. CYP1A1 induction has been related to toxic effects of PHAHs or PAHs in some species. In St. Lawrence beluga, the high level of CYP1A1 expression coupled with high levels of contaminants (including CYP1A1 substrates, e.g., PAH procarcinogens potentially activated by CYP1A1) indicates that CYP1A1 could be involved in the development of neoplastic lesions seen in the St. Lawrence beluga population. The systemic high-level expression of CYP1A1 in Arctic beluga suggests that effects of PAHs or PHAHs may be expected in Arctic populations, as well. The high-level expression of CYP1A1 in the Arctic beluga suggests that this species is highly sensitive to CYP1A1 induction by aryl hydrocarbon receptor agonists.

Phenobarbital Mediates an Epigenetic Switch at the Constitutive Androstane Receptor (CAR) Target Gene Cyp2b10 in the Liver of B6C3F1 Mice

PubMed Central

Brasa, Sarah; Teo, Soon-Siong; Roloff, Tim-Christoph; Morawiec, Laurent; Zamurovic, Natasa; Vicart, Axel; Funhoff, Enrico; Couttet, Philippe; Schübeler, Dirk; Grenet, Olivier; Marlowe, Jennifer; Moggs, Jonathan; Terranova, Rémi

2011-01-01

Evidence suggests that epigenetic perturbations are involved in the adverse effects associated with some drugs and toxicants, including certain classes of non-genotoxic carcinogens. Such epigenetic changes (altered DNA methylation and covalent histone modifications) may take place at the earliest stages of carcinogenesis and their identification holds great promise for biomedical research. Here, we evaluate the sensitivity and specificity of genome-wide epigenomic and transcriptomic profiling in phenobarbital (PB)-treated B6C3F1 mice, a well-characterized rodent model of non-genotoxic liver carcinogenesis. Methylated DNA Immunoprecipitation (MeDIP)-coupled microarray profiling of 17,967 promoter regions and 4,566 intergenic CpG islands was combined with genome-wide mRNA expression profiling to identify liver tissue-specific PB-mediated DNA methylation and transcriptional alterations. Only a limited number of significant anti-correlations were observed between PB-induced transcriptional and promoter-based DNA methylation perturbations. However, the constitutive androstane receptor (CAR) target gene Cyp2b10 was found to be concomitantly hypomethylated and transcriptionally activated in a liver tissue-specific manner following PB treatment. Furthermore, analysis of active and repressive histone modifications using chromatin immunoprecipitation revealed a strong PB-mediated epigenetic switch at the Cyp2b10 promoter. Our data reveal that PB-induced transcriptional perturbations are not generally associated with broad changes in the DNA methylation status at proximal promoters and suggest that the drug-inducible CAR pathway regulates an epigenetic switch from repressive to active chromatin at the target gene Cyp2b10. This study demonstrates the utility of integrated epigenomic and transcriptomic profiling for elucidating early mechanisms and biomarkers of non-genotoxic carcinogenesis. PMID:21455306

Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.

PubMed

Lempiäinen, Harri; Müller, Arne; Brasa, Sarah; Teo, Soon-Siong; Roloff, Tim-Christoph; Morawiec, Laurent; Zamurovic, Natasa; Vicart, Axel; Funhoff, Enrico; Couttet, Philippe; Schübeler, Dirk; Grenet, Olivier; Marlowe, Jennifer; Moggs, Jonathan; Terranova, Rémi

2011-03-24

Evidence suggests that epigenetic perturbations are involved in the adverse effects associated with some drugs and toxicants, including certain classes of non-genotoxic carcinogens. Such epigenetic changes (altered DNA methylation and covalent histone modifications) may take place at the earliest stages of carcinogenesis and their identification holds great promise for biomedical research. Here, we evaluate the sensitivity and specificity of genome-wide epigenomic and transcriptomic profiling in phenobarbital (PB)-treated B6C3F1 mice, a well-characterized rodent model of non-genotoxic liver carcinogenesis. Methylated DNA Immunoprecipitation (MeDIP)-coupled microarray profiling of 17,967 promoter regions and 4,566 intergenic CpG islands was combined with genome-wide mRNA expression profiling to identify liver tissue-specific PB-mediated DNA methylation and transcriptional alterations. Only a limited number of significant anti-correlations were observed between PB-induced transcriptional and promoter-based DNA methylation perturbations. However, the constitutive androstane receptor (CAR) target gene Cyp2b10 was found to be concomitantly hypomethylated and transcriptionally activated in a liver tissue-specific manner following PB treatment. Furthermore, analysis of active and repressive histone modifications using chromatin immunoprecipitation revealed a strong PB-mediated epigenetic switch at the Cyp2b10 promoter. Our data reveal that PB-induced transcriptional perturbations are not generally associated with broad changes in the DNA methylation status at proximal promoters and suggest that the drug-inducible CAR pathway regulates an epigenetic switch from repressive to active chromatin at the target gene Cyp2b10. This study demonstrates the utility of integrated epigenomic and transcriptomic profiling for elucidating early mechanisms and biomarkers of non-genotoxic carcinogenesis.

Identification of a single ancestral CYP1B1 mutation in Slovak Gypsies (Roms) affected with primary congenital glaucoma.

PubMed

Plásilová, M; Stoilov, I; Sarfarazi, M; Kádasi, L; Feráková, E; Ferák, V

1999-04-01

Primary congenital glaucoma (PCG) is an autosomal recessive eye disease that occurs at an unusually high frequency in the ethnic isolate of Roms (Gypsies) in Slovakia. Recently, we linked the disease in this population to the GLC3A locus on 2p21. At this locus, mutations in the cytochrome P4501B1 (CYP1B1) gene have been identified as a molecular basis for this condition. Here, we report the results of CYP1B1 mutation screening of 43 PCG patients from 26 Slovak Rom families. A homozygous G-->A transition at nucleotide 1505 in the highly conserved region of exon 3 was detected in all families. This mutation results in the E387K substitution, which affects the conserved K helix region of the cytochrome P450 molecule. Determination of the CYP1B1 polymorphic background showed a common DNA haplotype in all patients, thus indicating that the E387K mutation in Roms has originated from a single ancestral mutational event. The Slovak Roms represent the first population in which PCG is found to result from a single mutation in the CYP1B1 gene, so that a founder effect is the most plausible explanation of its increased incidence. An ARMS-PCR assay has been developed for fast detection of this mutation, thus allowing direct DNA based prenatal diagnosis as well as gene carrier detection in this particular population. Screening of 158 healthy Roms identified 17 (10.8%) mutation carriers, indicating that the frequency of PCG in this population may be even higher than originally estimated.

Analysis of the binding sites of vitamin D 1α-hydroxylase (CYP27B1) and vitamin D 24-hydroxylase (CYP24A1) for the design of selective CYP24A1 inhibitors: Homology modelling, molecular dynamics simulations and identification of key binding requirements.

PubMed

Taban, Ismail M; Zhu, Jinge; DeLuca, Hector F; Simons, Claire

2017-10-15

A homology model of human CYP27B1 was built using MOE and was further optimised by molecular dynamics simulations of the hCYP27B1 homology model and a hCYP27B1-SDZ-88357 complex. Docking results from the hCYP27B1-SDZ-88357 complex showed amino acids Arg107, Asn387 and Asp320 have an important role in binding interaction, with Asp320 part of the important acid-alcohol pair situated in the I-helix with the conserved sequence (A/G) GX (E/D) (T/S), which assumes an essential role in the binding of an oxygen molecule for catalysis. Additional docking experiments with selective hCYP27B1 or hCYP24A1 inhibitors using both the hCYP27B1 model and a triple mutant hCYP24A1 model provided further support for the importance of H-bonding interactions with the three identified active site amino acids. To confirm the role of Arg107, Asn387 and Asp320 in the active site of hCYP27B1 compounds were designed that would form H-bonding interactions, as determined from docking experiments with the hCYP27B1 model. Subsequent synthesis and CYP24A1 and CYP27B1 enzyme assays of the designed compounds 1a and 1b showed a∼5-fold selectivity for CYP27B1 confirming the importance of Asp320 in particular and also Asn387 and Arg107 as important amino acids for CYP27B1 inhibitory activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

CYP2R1 mutations causing vitamin D-deficiency rickets.

PubMed

Thacher, Tom D; Levine, Michael A

2017-10-01

CYP2R1 is the principal hepatic 25-hydroxylase responsible for the hydroxylation of parent vitamin D to 25-hydroxyvitamin D [25(OH)D]. Serum concentrations of 25(OH)D reflect vitamin D status, because 25(OH)D is the major circulating metabolite of vitamin D. The 1α-hydroxylation of 25(OH)D in the kidney by CYP27B1 generates the fully active vitamin D metabolite, 1,25-dihydroxyvitamin D (1,25(OH) 2 D). The human CYP2R1 gene, located at 11p15.2, has five exons, coding for an enzyme with 501 amino acids. In Cyp2r1-/- knockout mice, serum 25(OH)D levels were reduced by more than 50% compared wild-type mice. Genetic polymorphisms of CYP2R1 account for some of the individual variability of circulating 25(OH)D values in the population. We review the evidence that inactivating mutations in CYP2R1 can lead to a novel form of vitamin D-deficiency rickets resulting from impaired 25-hydroxylation of vitamin D. We sequenced the promoter, exons and intron-exon flanking regions of the CYP2R1 gene in members of 12 Nigerian families with rickets in more than one family member. We found missense mutations (L99P and K242N) in affected members of 2 of 12 families. The L99P mutation had previously been reported as a homozygous defect in an unrelated child of Nigerian origin with rickets. In silico analyses predicted impaired CYP2R1 folding or reduced interaction with substrate vitamin D by L99P and K242N mutations, respectively. In vitro studies of the mutant CYP2R1 proteins in HEK293 cells confirmed normal expression levels but completely absent or markedly reduced 25-hydroxylase activity by the L99P and K242N mutations, respectively. Heterozygous subjects had more moderate biochemical and clinical features of vitamin D deficiency than homozygous subjects. After an oral bolus dose of 50,000 IU of vitamin D 2 or vitamin D 3 , heterozygous subjects had lower increases in serum 25(OH)D than control subjects, and homozygous subjects had minimal increases, supporting a semidominant

Functional analysis of CYP6ER1, a P450 gene associated with imidacloprid resistance in Nilaparvata lugens

PubMed Central

Pang, Rui; Chen, Meng; Liang, Zhikun; Yue, Xiangzhao; Ge, Hu; Zhang, Wenqing

2016-01-01

The cytochrome P450 CYP6ER1 has been reported to play an important role in imidacloprid resistance of the brown planthopper (BPH), Nilaparvata lugens, and is overexpressed in most resistant populations. In the present study, we confirmed that CYP6ER1 expression can be induced by certain levels of imidacloprid. Developmental expression analysis revealed that CYP6ER1 was expressed highly in the adult stage, and tissue distribution analysis showed that CYP6ER1 was expressed mainly in the fat body and midgut. RNA interference (RNAi) of CYP6ER1 and transgenic expression of CYP6ER1 in Drosophila melanogaster both suggested that the expression of CYP6ER1 is sufficient to confer imidacloprid resistance. Furthermore, we analyzed the interaction of imidacloprid and CYP6ER1 monooxygenase by using dynamic simulations and molecular docking. We found that Nitrogen atoms in the heterocycle of the imidacloprid molecule may bind to iron atoms in the center of the homology model of CYP6ER1 via 4,5-dihedro-1H-imidazole. This finding contributes to a better understanding of how CYP6ER1 takes part in the insecticide metabolism. PMID:27721443

Systemic Effects of Arctic Pollutants in Beluga Whales Indicated by CYP1A1 Expression

PubMed Central

Wilson, Joanna Y.; Cooke, Suzy R.; Moore, Michael J.; Martineau, Daniel; Mikaelian, Igor; Metner, Donald A.; Lockhart, W. Lyle; Stegeman, John J.

2005-01-01

Cytochrome P450 1A1 (CYP1A1) is induced by exposure to polycyclic aromatic hydrocarbons (PAHs) and planar halogenated aromatic hydrocarbons (PHAHs) such as non-ortho polychlorinated biphenyls (PCBs). In this study, we examined CYP1A1 protein expression immunohistochemically in multiple organs of beluga whales from two locations in the Arctic and from the St. Lawrence estuary. These beluga populations have some of the lowest (Arctic sites) and highest (St. Lawrence estuary) concentrations of PCBs in blubber of all cetaceans. Samples from these populations might be expected to have different contaminant-induced responses, reflecting their different exposure histories. The pattern and extent of CYP1A1 staining in whales from all three locations were similar to those seen in animal models in which CYP1A has been highly induced, indicating a high-level expression in these whales. CYP1A1 induction has been related to toxic effects of PHAHs or PAHs in some species. In St. Lawrence beluga, the high level of CYP1A1 expression coupled with high levels of contaminants (including CYP1A1 substrates, e.g., PAH procarcinogens potentially activated by CYP1A1) indicates that CYP1A1 could be involved in the development of neoplastic lesions seen in the St. Lawrence beluga population. The systemic high-level expression of CYP1A1 in Arctic beluga suggests that effects of PAHs or PHAHs may be expected in Arctic populations, as well. The high-level expression of CYP1A1 in the Arctic beluga suggests that this species is highly sensitive to CYP1A1 induction by aryl hydrocarbon receptor agonists. PMID:16263517

Vitamin D insufficiency in Arabs and South Asians positively associates with polymorphisms in GC and CYP2R1 genes.

PubMed

Elkum, Naser; Alkayal, Fadi; Noronha, Fiona; Ali, Maisa M; Melhem, Motasem; Al-Arouj, Monira; Bennakhi, Abdullah; Behbehani, Kazem; Alsmadi, Osama; Abubaker, Jehad

2014-01-01

A number of genetic studies have reported an association between vitamin D related genes such as group-specific component gene (GC), Cytochrome P450, family 2, subfamily R, polypeptide 1 (CYP2R1) and 7-dehydrocholesterol reductase/nicotinamide-adenine dinucleotide synthetase 1 (DHCR7/NADSYN1) and serum levels of the active form of Vitamin D, 25 (OH) D among African Americans, Caucasians, and Chinese. Little is known about how genetic variations associate with, or contribute to, 25(OH)D levels in Arabs populations. Allele frequencies of 18 SNPs derived from CYP2R1, GC, and DHCR7/NADSYN1 genes in 1549 individuals (Arabs, South Asians, and Southeast Asians living in Kuwait) were determined using real time genotyping assays. Serum levels of 25(OH)D were measured using chemiluminescence immunoassay. GC gene polymorphisms (rs17467825, rs3755967, rs2282679, rs7041 and rs2298850) were found to be associated with 25(OH)D serum levels in Arabs and South Asians. Two of the CYP2R1 SNPs (rs10500804 and rs12794714) and one of GC SNPs (rs1155563) were found to be significantly associated with 25(OH)D serum levels only in people of Arab origin. Across all three ethnicities none of the SNPs of DHCR7/NADSYN1 were associated with serum 25(OH)D levels and none of the 18 SNPs were significantly associated with serum 25(OH)D levels in people from South East Asia. Our data show for the first time significant association between the GC (rs2282679 and rs7041), CYP2R1 (rs10741657) SNPs and 25(OH)D levels. This supports their roles in vitamin D Insufficiency in Arab and South Asian populations respectively. Interestingly, two of the CYP2R1 SNPs (rs10500804 and rs12794714) and one GC SNP (rs1155563) were found to correlate with vitamin D in Arab population exclusively signifying their importance in this population.

Vitamin D Insufficiency in Arabs and South Asians Positively Associates with Polymorphisms in GC and CYP2R1 Genes

PubMed Central

Elkum, Naser; Alkayal, Fadi; Noronha, Fiona; Ali, Maisa M.; Melhem, Motasem; Al-Arouj, Monira; Bennakhi, Abdullah; Behbehani, Kazem; Alsmadi, Osama; Abubaker, Jehad

2014-01-01

Background A number of genetic studies have reported an association between vitamin D related genes such as group-specific component gene (GC), Cytochrome P450, family 2, subfamily R, polypeptide 1 (CYP2R1) and 7-dehydrocholesterol reductase/nicotinamide-adenine dinucleotide synthetase 1 (DHCR7/NADSYN1) and serum levels of the active form of Vitamin D, 25 (OH) D among African Americans, Caucasians, and Chinese. Little is known about how genetic variations associate with, or contribute to, 25(OH)D levels in Arabs populations. Methods Allele frequencies of 18 SNPs derived from CYP2R1, GC, and DHCR7/NADSYN1 genes in 1549 individuals (Arabs, South Asians, and Southeast Asians living in Kuwait) were determined using real time genotyping assays. Serum levels of 25(OH)D were measured using chemiluminescence immunoassay. Results GC gene polymorphisms (rs17467825, rs3755967, rs2282679, rs7041 and rs2298850) were found to be associated with 25(OH)D serum levels in Arabs and South Asians. Two of the CYP2R1 SNPs (rs10500804 and rs12794714) and one of GC SNPs (rs1155563) were found to be significantly associated with 25(OH)D serum levels only in people of Arab origin. Across all three ethnicities none of the SNPs of DHCR7/NADSYN1 were associated with serum 25(OH)D levels and none of the 18 SNPs were significantly associated with serum 25(OH)D levels in people from South East Asia. Conclusion Our data show for the first time significant association between the GC (rs2282679 and rs7041), CYP2R1 (rs10741657) SNPs and 25(OH)D levels. This supports their roles in vitamin D Insufficiency in Arab and South Asian populations respectively. Interestingly, two of the CYP2R1 SNPs (rs10500804 and rs12794714) and one GC SNP (rs1155563) were found to correlate with vitamin D in Arab population exclusively signifying their importance in this population. PMID:25405862

Dioxin activation of CYP1A5 promoter/enhancer regions from two avian species, common cormorant (Phalacrocorax carbo) and chicken (Gallus gallus): Association with aryl hydrocarbon receptor 1 and 2 isoforms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jin-Seon; Kim, Eun-Young; Iwata, Hisato

The present study focuses on the molecular mechanism and interspecies differences in susceptibility of avian aryl hydrocarbon receptor (AHR)-cytochrome P4501A (CYP1A) signaling pathway. By the cloning of 5'-flanking regions of CYP1A5 gene from common cormorant (Phalacrocorax carbo) and chicken (Gallus gallus), seven putative xenobiotic response elements (XREs) were identified within 2.7 kb upstream region of common cormorant CYP1A5 (ccCYP1A5), and six XREs were found within 0.9 kb of chicken CYP1A5 (ckCYP1A5). Analysis of sequential deletion and mutagenesis of the binding sites in avian CYP1A5 genes by in vitro reporter gene assays revealed that two XREs at -613 bp and -1585more » bp in ccCYP1A5, and one XRE at -262 bp in ckCYP1A5 conferred TCDD-responsiveness. The binding of AHR1 with AHR nuclear translocator 1 (ARNT1) to the functional XRE in a TCDD-dependent manner was verified with gel shift assays, suggesting that avian CYP1A5 is induced by TCDD through AHR1/ARNT1 signaling pathway as well as mammalian CYP1A1 but through a distinct pathway from mammalian CYP1A2, an ortholog of the CYP1A5. TCDD-EC{sub 50} for the transcriptional activity in both cormorant AHR1- and AHR2-ccCYP1A5 reporter construct was 10-fold higher than that in chicken AHR1-ckCYP1A5 reporter construct. In contrast, chicken AHR2 showed no TCDD-dependent response. The TCDD-EC{sub 50} for CYP1A5 transactivation was altered by switching AHR1 between the two avian species, irrespective of the species from which the regulatory region of CYP1A5 gene originates. Therefore, the structural difference in AHR, not the CYP1A5 regulatory region may be a major factor to account for the dioxin susceptibility in avian species.« less

Role of CYP1B1 in PAH-DNA adduct formation and breast cancer risk

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goth-Goldstein, Regine; Russell, Marion L.; Muller, A.P.

2010-04-01

This study investigated the hypothesis that increased exposure to polycyclic aromatic hydrocarbons (PAHs) increases breast cancer risk. PAHs are products of incomplete burning of organic matter and are present in cigarette smoke, ambient air, drinking water, and diet. PAHs require metabolic transformation to bind to DNA, causing DNA adducts, which can lead to mutations and are thought to be an important pre-cancer marker. In breast tissue, PAHs appear to be metabolized to their cancer-causing form primarily by the cytochrome P450 enzyme CYP1B1. Because the genotoxic impact of PAH depends on their metabolism, we hypothesized that high CYP1B1 enzyme levels resultmore » in increased formation of PAH-DNA adducts in breast tissue, leading to increased development of breast cancer. We have investigated molecular mechanisms of the relationship between PAH exposure, CYP1B1 expression and breast cancer risk in a clinic-based case-control study. We collected histologically normal breast tissue from 56 women (43 cases and 13 controls) undergoing breast surgery and analyzed these specimens for CYP1B1 genotype, PAH-DNA adducts and CYP1B1 gene expression. We did not detect any difference in aromatic DNA adduct levels of cases and controls, only between smokers and non-smokers. CYP1B1 transcript levels were slightly lower in controls than cases, but the difference was not statistically significant. We found no correlation between the levels of CYP1B1 expression and DNA adducts. If CYP1B1 has any role in breast cancer etiology it might be through its metabolism of estrogen rather than its metabolism of PAHs. However, due to the lack of statistical power these results should be interpreted with caution.« less