Cytochrome P450 1A1 Gene Research Articles

An epigenetic memory at the CYP1A gene in cancer-resistant, pollution-adapted killifish

Human exposure to polycyclic aromatic hydrocarbons (PAH) is a significant public health problem that will worsen with a warming climate and increased large-scale wildfires. Here, we characterize an epigenetic memory at the cytochrome P450 1 A (CYP1A) gene in wild Fundulus heteroclitus that have adapted to chronic, extreme PAH pollution. In wild-type fish, CYP1A is highly induced by PAH. In PAH-tolerant fish, CYP1A induction is blunted. Since CYP1A metabolically activates PAH, this memory protects these fish from PAH-mediated cancer. However, PAH-tolerant fish reared in clean water recover CYP1A inducibility, indicating a non-genetic effect. We observed epigenetic control of this reversible memory of generational PAH stress in F1 PAH-tolerant embryos. We detected a bivalent domain in the CYP1A promoter enhancer comprising both activating and repressive histone post-translational modifications. Activating modifications, relative to repressive ones, showed greater increases in response to PAH in sensitive embryos, relative to tolerant, consistent with greater gene activation. PAH-tolerant adult fish showed persistent induction of CYP1A long after exposure cessation, which is consistent with defective CYP1A shutoff. These results indicate that PAH-tolerant fish have epigenetic protection against PAH-induced cancer in early life that degrades in response to continuous gene activation.

Retraction Note: Association between cytochrome P4501A1 (CYP1A1) gene polymorphisms and the risk of renal cell carcinoma: a meta-analysis

Retraction Note: Association between cytochrome P4501A1 (CYP1A1) gene polymorphisms and the risk of renal cell carcinoma: a meta-analysis

Exposure to Subclinical Doses of Fumonisins, Deoxynivalenol, and Zearalenone Affects Immune Response, Amino Acid Digestibility, and Intestinal Morphology in Broiler Chickens.

Fusarium mycotoxins often co-occur in broiler feed, and their presence negatively impacts health even at subclinical concentrations, so there is a need to identify the concentrations of these toxins that do not adversely affect chickens health and performance. The study was conducted to evaluate the least toxic effects of combined mycotoxins fumonisins (FUM), deoxynivalenol (DON), and zearalenone (ZEA) on the production performance, immune response, intestinal morphology, and nutrient digestibility of broiler chickens. A total of 960 one-day-old broilers were distributed into eight dietary treatments: T1 (Control); T2: 33.0 FUM + 3.0 DON + 0.8 ZEA; T3: 14.0 FUM + 3.5 DON + 0.7 ZEA; T4: 26.0 FUM + 1.0 DON + 0.2 ZEA; T5: 7.7 FUM + 0.4 DON + 0.1 ZEA; T6: 3.6 FUM + 2.5 DON + 0.9 ZEA; T7: 0.8 FUM + 1.0 DON + 0.3 ZEA; T8: 1.0 FUM + 0.5 DON + 0.1 ZEA, all in mg/kg diet. The results showed that exposure to higher mycotoxin concentrations, T2 and T3, had significantly reduced body weight gain (BWG) by 17% on d35 (p < 0.05). The T2, T3, and T4 groups had a significant decrease in villi length in the jejunum and ileum (p < 0.05) and disruption of tight junction proteins, occludin, and claudin-4 (p < 0.05). Higher mycotoxin groups T2 to T6 had a reduction in the digestibility of amino acids methionine (p < 0.05), aspartate (p < 0.05), and serine (p < 0.05); a reduction in CD4+, CD8+ T-cell populations (p < 0.05) and an increase in T regulatory cell percentages in the spleen (p < 0.05); a decrease in splenic macrophage nitric oxide production and total IgA production (p < 0.05); and upregulated cytochrome P450-1A1 and 1A4 gene expression (p < 0.05). Birds fed the lower mycotoxin concentration groups, T7 and T8, did not have a significant effect on performance, intestinal health, and immune responses, suggesting that these concentrations pose the least negative effects in broiler chickens. These findings are essential for developing acceptable thresholds for combined mycotoxin exposure and efficient feed management strategies to improve broiler performance.

Association of coffee consumption and caffeine metabolism with arrhythmias and cardiac morphology: an observational, genetic and Mendelian Randomization study

The association of coffee intake and caffeine metabolism with arrhythmias and cardiac structure is not fully understood. We aim to explore the associations of coffee intake and caffeine metabolism with the risk of certain types of arrhythmias, a broad range of cardiovascular imaging phenotypes, and a potential gene-coffee interaction. On the basis of the UK Biobank imaging study, heart metrics were extracted via cardiovascular magnetic resonance using machine learning. Caffeine metabolism was determined by cytochrome P4501A2 gene (CYP1A2) or a polygenetic score of different genetic variants influencing caffeine metabolism. Genome-wide association data for 2-sample Mendelian randomization originated predominantly from individuals of European descent. A total of 34,992 individuals (mean age 63.5 ± 7.5 years; 52.9% female) were assessed in the principal imaging analysis. Higher daily consumption of coffee was independently associated with higher left ventricular mass, larger global ventricular volume, higher ventricular stroke volume, and larger atrial volume. The results were further supported by Mendelian randomization analysis. CYP1A2 and genetic score for caffeine metabolism were not associated with cardiovascular measurements (P>.053 for all tests). Coffee consumption was associated with a lower risk of sinus rhythm with short PR (per cup increase: odds ratio 0.90; 95% confidence interval 0.82-0.99) and atrial fibrillation (odds ratio 0.89; 95% confidence interval 0.84-0.93). Coffee consumption was associated with a lower risk of atrial fibrillation, increased left ventricular mass, elevated ventricular volume, and larger atrial volume. Caffeine metabolism did not significantly alter the association. Our results suggest that customary caffeine consumption limitations aimed at arrhythmia risk reduction might be unnecessary.

High Expression of AhR and Environmental Pollution as AhR-Linked Ligands Impact on Oncogenic Signaling Pathways in Western Patients with Gastric Cancer-A Pilot Study.

The vast majority of gastric cancer (GC) cases are adenocarcinomas including intestinal and diffuse GC. The incidence of diffuse GC, often associated with poor overall survival, has constantly increased in Western countries. Epidemiological studies have reported increased mortality from GC after occupational exposure to pro-carcinogens that are metabolically activated by cytochrome P450 enzymes through aryl hydrocarbon receptor (AhR). However, little is known about the role of AhR and environmental AhR ligands in diffuse GC as compared to intestinal GC in Western patients. In a cohort of 29, we demonstrated a significant increase in AhR protein and mRNA expression levels in GCs independently of their subtypes and clinical parameters. AhR and RHOA mRNA expression were correlated in diffuse GC. Further, our study aimed to characterize in GC how AhR and the AhR-related genes cytochrome P450 1A1 (CYP1A1) and P450 1B1 (CYP1B1) affect the mRNA expression of a panel of genes involved in cancer development and progression. In diffuse GC, CYP1A1 expression correlated with genes involved in IGF signaling, epithelial-mesenchymal transition (Vimentin), and migration (MMP2). Using the poorly differentiated KATO III epithelial cell line, two well-known AhR pollutant ligands, namely 2-3-7-8 tetrachlorodibenzo-p-dioxin (TCDD) and benzo[a]pyrene (BaP), strongly increased the expression of CYP1A1 and Interleukin1β (IL1B), and to a lesser extend UGT1, NQO1, and AhR Repressor (AhRR). Moreover, the increased expression of CYP1B1 was seen in diffuse GC, and IHC staining indicated that CYP1B1 is mainly expressed in stromal cells. TCDD treatment increased CYP1B1 expression in KATO III cells, although at lower levels as compared to CYP1A1. In intestinal GC, CYP1B1 expression is inversely correlated with several cancer-related genes such as IDO1, a gene involved in the early steps of tryptophan metabolism that contributes to the endogenous AhR ligand kynurenine expression. Altogether, our data provide evidence for a major role of AhR in GC, as an environmental xenobiotic receptor, through different mechanisms and pathways in diffuse and intestinal GC. Our results support the continued efforts to clarify the identity of exogenous AhR ligands in diffuse GC in order to define new therapeutic strategies.

Involvement of ahr-dependent Cyp1a detoxification activity, oxidative stress and inflammatory regulation in response to graphene oxide exposure in rainbow trout (Oncorhynchus mykiss)

Graphene oxide (GO) is a very attractive material for use in a vast number of applications. However, before its widespread use, it is important to consider potential issues related to environmental safety to support its safe application. The aim of this study was to investigate effects on fish (rainbow trout) following GO exposure. Using both an in vitro approach with the RTL W1 rainbow trout liver cell line, and in vivo exposures, following OECD TG 203, disturbances at the cellular level as well as in the gills and liver tissue of juvenile trout were assessed. In RTL W1 cells, a time and concentration-dependent loss in cell viability, specifically plasma membrane integrity and lysosomal function, was observed after 96 h of exposure to GO at concentrations ≥18.75 mg/L. Additionally, increased reactive oxygen species (ROS) levels were evidenced at concentrations ≥18.75 mg/L, and an enhancement of metabolic activity was noted with concentrations ≥4.68 mg/L. In vivo exposures to GO did not provoke mortality in rainbow trout juveniles following 96 h exposure but led to histological alterations in gills and liver tissues, induction of enzymatic detoxification activities in the liver, as well as aryl hydrocarbon receptor (ahr)–cytochrome P450 1a (cyp1a) gene expression downregulation, and upregulation of pro-inflammatory cytokines il1b and il8 at GO concentrations ≥9.89 mg/L.

Association between CYP1A2 gene variants −163 C/A (rs762551) and −3860 G/A (rs2069514) and bladder cancer susceptibility

BackgroundBladder cancer (BLCA) poses a significant global health challenge due to its high incidence, poor prognosis, and limited treatment options.Aims and objectivesThis study aims to investigate the association between two specific polymorphisms, CYP1A2-163 C/A and CYP1A2-3860G/A, within the Cytochrome P450 1A2 (CYP1A2) gene and susceptibility to BLCA.MethodsThe study employed a case-control design, genotyping 340 individuals using Polymerase Chain Reaction-High-Resolution Melting Curve (PCR-HRM). Various genetic models were applied to evaluate allele and genotype frequencies. Genetic linkage analysis was facilitated using R packages.ResultsThe study reveals a significant association with the − 163 C/A allele, particularly in the additive model. Odds ratio (OR) analysis links CYP1A2-163 C/A (rs762551) and CYP1A2-3860G/A(rs2069514) polymorphisms to BLCA susceptibility. The rs762551 C/A genotype is prevalent in 55% of BLCA cases and exhibits an OR of 2.21. The A/A genotype has an OR of 1.54. Regarding CYP1A2-3860G/A, the G/A genotype has an OR of 1.54, and the A/A genotype has an OR of 2.08. Haplotype analysis shows a predominant C-C haplotype at 38.2%, followed by a C-A haplotype at 54.7%, and a less frequent A-A haplotype at 7.1%. This study underscores associations between CYP1A2 gene variants, particularly rs762551 (CYP1A2-163 C/A), and an increased susceptibility to BLCA. Haplotype analysis of 340 individuals reveals a predominant C-C haplotype at 38.2%, followed by a C-A haplotype at 54.7%, and a less frequent A-A haplotype at 7.1%.ConclusionIn conclusion, the − 163 C/A allele, C/A genotype of rs762551, and G/A genotype of rs2069514 emerge as potential genetic markers associated with elevated BLCA risk.

Genetic variation present in the CYP3A4 gene in Ni-Vanuatu and Kenyan populations in malaria endemicity

Cytochrome P450 3A4 (CYP3A4) enzyme is involved in the metabolism of about 30 % of clinically used drugs, including the antimalarials artemether and lumefantrine. CYP3A4 polymorphisms yield enzymatic variants that contribute to inter-individual variation in drug metabolism. Here, we examined CYP3A4 polymorphisms in populations from malaria-endemic islands in Lake Victoria, Kenya, and Vanuatu, to expand on the limited data sets. We used archived dried blood spots collected from 142 Kenyan and 263 ni-Vanuatu adults during cross-sectional malaria surveys in 2013 and 2005–13, respectively, to detect CYP3A4 variation by polymerase chain reaction (PCR) and sequencing. In Kenya, we identified 14 CYP3A4 single nucleotide polymorphisms (SNPs), including the 4713G (CYP3A4∗1B; allele frequency 83.9 %) and 19382A (CYP3A4∗15; 0.7 %) variants that were previously linked to altered metabolism of antimalarials. In Vanuatu, we detected 15 SNPs, including the 4713A (CYP3A4∗1A; 88.6 %) and 25183C (CYP3A4∗18; 0.6 %) variants. Additionally, we detected a rare and novel SNP C4614T (0.8 %) in the 5′ untranslated region. A higher proportion of CYP3A4 genetic variance was found among ni-Vanuatu populations (16 %) than among Lake Victoria Kenyan populations (8 %). Our work augments the scarce data sets and contributes to improved precision medicine approaches, particularly to anti-malarial chemotherapy, in East African and Pacific Islander populations.

THE APPLICATION OF BIOANALYTICAL METHOD OF TAMOXIFEN AND ITS ACTIVE METABOLITES FOR THERAPEUTIC DRUG MONITORING IN BREAST CANCER PATIENTS: A REVIEW

Breast cancer is the most common cancer around the world and in Indonesia. The most widely used agent for breast cancer treatment is tamoxifen, with a fixed dose of 20 mg per day. Tamoxifen is metabolized by cytochrome P450 3A4 (CYP3A4) and 2D6 (CYP2D6) to endoxifen and 4-hydroxytamoxifen, which have 30-to 100-fold more potent antiestrogenic activity than tamoxifen. High variations of CYP3A4 and CYP2D6 genes can lead to interpatient variability in its metabolites concentration. The dose can be increased to 40 or 60 mg per day based on individual needs. Therapeutic drug monitoring (TDM) is required to measure the concentration of tamoxifen and its metabolites to decide the individualized dose. The measurement of drug levels should use a sensitive, selective, accurate, precise, and reliable bioanalytical method. Various bioanalytical methods have been developed in several matrices: urine, scalp hair, serum, plasma, dried blood spot (DBS), and volumetric absorptive microsampling (VAMS) samples, with different sample preparations, and frequently using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The bioanalytical method of tamoxifen and its metabolites in the DBS sample was more suitable in the TDM application due to the low invasive sampling technique, more stable sample, and rapid sample preparation. Therefore, it is more time-and cost-efficient than the other methods.

Generation and characterization of cytochrome P450 3A74 CRISPR/Cas9 knockout bovine foetal hepatocyte cell line (BFH12)

In human, the cytochrome P450 3A (CYP3A) subfamily of drug-metabolizing enzymes (DMEs) is responsible for a significant number of phase I reactions, with the CYP3A4 isoform superintending the hepatic and intestinal metabolism of diverse endobiotic and xenobiotic compounds. The CYP3A4-dependent bioactivation of chemicals may result in hepatotoxicity and trigger carcinogenesis. In cattle, four CYP3A genes (CYP3A74, CYP3A76, CYP3A28 and CYP3A24) have been identified. Despite cattle being daily exposed to xenobiotics (e.g., mycotoxins, food additives, drugs and pesticides), the existing knowledge about the contribution of CYP3A in bovine hepatic metabolism is still incomplete. Nowadays, CRISPR/Cas9 mediated knockout (KO) is a valuable method to generate in vivo and in vitro models for studying the metabolism of xenobiotics. In the present study, we successfully performed CRISPR/Cas9-mediated KO of bovine CYP3A74, human CYP3A4-like, in a bovine foetal hepatocyte cell line (BFH12). After clonal expansion and selection, CYP3A74 ablation was confirmed at the DNA, mRNA, and protein level. The subsequent characterization of the CYP3A74 KO clone highlighted significant transcriptomic changes (RNA-sequencing) associated with the regulation of cell cycle and proliferation, immune and inflammatory response, as well as metabolic processes. Overall, this study successfully developed a new CYP3A74 KO in vitro model by using CRISPR/Cas9 technology, which represents a novel resource for xenobiotic metabolism studies in cattle. Furthermore, the transcriptomic analysis suggests a key role of CYP3A74 in bovine hepatocyte cell cycle regulation and metabolic homeostasis.

Identification and Functional Assessment of Eight CYP3A4 Allelic Variants *39-*46 Detected in the Chinese Han Population.

Cytochrome P450 3A4 (CYP3A4), a key enzyme, is pivotal in metabolizing approximately half of the drugs used clinically. The genetic polymorphism of the CYP3A4 gene significantly influences individual variations in drug metabolism, potentially leading to severe adverse drug reactions (ADRs). In this study, we conducted a genetic analysis on CYP3A4 gene in 1163 Chinese Han individuals to identify the genetic variations that might affect their drug metabolism capabilities. For this purpose, a multiplex polymerase chain reaction (PCR) amplicon sequencing technique was developed, enabling us to perform the genotyping of CYP3A4 gene efficiently and economically on a large scale. As a result, a total of 14 CYP3A4 allelic variants were identified, comprising six previously reported alleles and eight new nonsynonymous variants that were nominated as new allelic variants *39-*46 by the PharmVar Association. Further, functional assessments of these novel CYP3A4 variants were undertaken by coexpressing them with cytochromes P450 oxidoreductase (CYPOR) in Saccharomyces cerevisiae microsomes. Immunoblot analysis indicated that with the exception of CYP3A4.40 and CYP3A4.45, the protein expression levels of most new variants were similar to that of the wild-type CYP3A4.1 in yeast cells. To evaluate their catalytic activities, midazolam was used as a probe drug. The results showed that variant CYP3A4.45 had almost no catalytic activity, whereas the other variants exhibited significantly reduced drug metabolism abilities. This suggests that the majority of the CYP3A4 variants identified in the Chinese population possess markedly altered capacities for drug metabolism. SIGNIFICANCE STATEMENT: In this study, we established a multiplex polymerase chain reaction (PCR) amplicon sequencing method and detected the maximum number of new CYP3A4 variants in a single ethnic population. Additionally, we performed the functional characterizations of these eight novel CYP3A4 allele variants in vitro. This study not only contributes to the understanding of CYP3A4 genetic polymorphism in the Chinese Han population but also holds substantial reference value for their potential clinical applications in personalized medicine.

Pathogenic Missense Mutations in Nicotine-metabolizing Cytochrome P450 2A6 Gene – An In silico Study

ABSTRACT Introduction: Nicotine is an environmental agent that can have a significant impact on the emergence of nicotine dependence when it interacts with particular candidate nicotine genes. Pharmacogenetics may have a role in the interindividual difference in adolescent smoking cessation. Identification of missense mutations (which are deleterious) in advance will help to formulate medication targeting it, to prevent the consequences in the future. The current study aimed to identify more potential and functional mutations of the cytochrome P450 2A6 (CYP2A6) gene by employing computational tools. Materials and Methods: The Ensembl database was used to collect the data on missense mutations of the human CYP2A6 gene. Computational tools such as Sorting Intolerant From Tolerant, Polymorphism Phenotyping, and PROtein Variation Effect ANalyzer are used to identify and screen missense mutation. One hundred and thirty missense mutations were identified and screened. The stability of protein variants and their pathogenicity were identified using I-Mutant and MutPred, respectively. Results: One hundred and eighteen single-nucleotide polymorphisms were determined to be harmful among the 130 missense variants that were examined, as predicted by all three of the computational tools mentioned in the methodology section. I-Mutant Suite identified about 104 variants with decreased stability and the other 14 variants showed increased stability. MutPred tool identified that out of the 118 missense variants, 69 were found to be highly pathogenic, 33 were found to be pathogenic, and two of them were not pathogenic. Conclusions: Nearly a hundred alleles in the CYP2A6 gene were identified as potentially pathogenic variants using data mining.

Cigarette Smoking and Intracranial Aneurysms: A Pilot Analysis of SNPs in the CYP2A6 Gene in the Italian Population

Cigarette smoking is a modifiable risk factor associated with formation and rupture of intracranial aneurysms (IAs). Cytochrome P450 2A6 (CYP2A6) is the main enzyme implied in catabolism of nicotine and xenobiotics, giving rise to oxidative stress products. Our study investigated the associations between specific single-nucleotide polymorphisms (SNPs) in the CYP2A6 gene and the presence of sporadic IAs in a cluster of Italian patients, as well as their rupture regarding cigarette smoking habit. Three hundred and thirty-one Italian patients with sporadic IAs were recruited in a single institution. We recorded data on clinical onset with subarachnoid hemorrhage (SAH) and smoking habit. Genetic analysis was performed with a standard procedure on peripheral blood samples: CYP2A6 ∗1B2, CYP2A6 ∗2, and CYP2A6 ∗14 SNPs were analyzed in the study group along with 150 healthy control subjects. Statistical analysis was conducted according to genetic association study guidelines. In the patient cohort, the frequency of aSAH was significantly higher in current smokers (P < 0.001; OR=17.45), regardless of the pattern of CYP2A6 SNPs. There was a correlation between IA rupture and cigarette smoking in patients with the heterozygous CYP2A6 ∗1B2 allele (P < 0.001; OR=15.47). All patients carrying the heterozygous CYP2A6 ∗14 allele had an aSAH event (100%), regardless of smoking habit, although this correlation was not statistically significant (P= 1). According to our findings, a cigarette smoker carrying a fully active CYP2A6 enzyme (heterozygous ∗1B2 allele) may have an increased risk of IA rupture compared to those with functionally less active variants: further investigation on a larger sample is needed to verify this result. The role of the heterozygous CYP2A6 ∗14 allele in aSAH is yet to be clarified.

Fetal and neonatal dioxin exposure causes sex-specific metabolic alterations in mice.

Epidemiological studies report associations between early-life exposure to persistent organic pollutants (POPs) and impaired metabolic homeostasis in adulthood. We investigated the impact of early-life exposure to low-dose 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or 'dioxin') on the establishment of β-cell area during the perinatal period, as well as β-cell health and glucose homeostasis later in life. Adult female mice were injected with either corn oil (CO; vehicle control) or TCDD (20 ng/kg/day) 2×/week throughout mating, pregnancy, and lactation; offspring were thus indirectly exposed to maternal TCDD in utero and during lactation, with pollutant exposure ending at weaning. All offspring were maintained on chow diet from weaning until 12-17 weeks of age, after which a subset of CO- and TCDD-exposed offspring were transferred to a 45% high fat diet (HFD) as a metabolic stressor for an additional 10 weeks. TCDD significantly upregulated cytochrome P450 1a1 (Cyp1a1) gene expression in offspring pancreas at birth and weaning, indicating that maternal TCDD directly reaches the developing pancreas. TCDD-exposed pups were transiently hypoglycemic at birth and females were born with reduced % β-cell area, which persisted into adulthood. Early-life TCDD exposure had no persistent long-term effects on glucose homeostasis in chow-fed offspring, but when transferred to HFD, TCDD-exposed female offspring had a delayed onset of HFD-induced hyperglycemia, more pronounced HFD-induced hyperinsulinemia, and increase % PCNA+ β-cells compared with CO-exposed female offspring. This study demonstrates that early-life exposure of mice to TCDD has modest effects on metabolic health in chow-fed offspring but alters metabolic adaptability to HFD feeding in females.

Ailesel Koroner Arter Hastalığına Yatkınlıkta Güçlü Adaylar PON1, ITGB3 ve CYP3A4 Genlerinin Hastalıkla İlişkisi ve Haplotip Analizi

Objective: Genetic predisposition is very common among the patients with coronary artery disease (CAD), a complex and multifactorial disease. Our objective was to determine the possible association between the most remarkable functional variants in the paraoxonase 1(PON1), cytochrome P450 3A4 (CYP3A4), integrin subunit beta 3 (ITGB3) genes and familial CAD. Materials and Methods: We included 117 patients diagnosed with familial CAD and 99 healthy subjects with no family history of CAD. PON1 Q192R, PON1 L55M, CYP3A4*1G and ITGB3 L33P single nucleotide polymorphisms were genotyped using the Sequenom MassARRAY system. Results: Comparison of genotype and allele frequencies in inheritance models of polymorphisms between the patient and control groups did not reveal any significant findings related to CAD. Stratified analysis by gender did also not display any association both in females and males. There was no significant difference in the frequencies of the haplotypes of the PON1 Q192R and L55M polymorphisms between the groups. Conclusions: Our findings confirmed previous studies that did not consider PON1, CYP3A4 and ITGB3 genes as risk loci. The fact that our study was conducted only in patients with familial CAD shows the originality and importance of our results.

Newly identified cytochrome P450 3A genes of tree shrews and pigs are expressed and encode functional enzymes

Novel cytochrome P450 3A5 (CYP3A5) cDNA in tree shrews (which are non-rodent primate-like species) and pig CYP3A227 cDNA were identified, along with known pig CYP3A22, CYP3A29, and CYP3A46 cDNAs. All five cDNAs contained open reading frames encoding a polypeptide of 503 amino acids that shared high sequence identity (72–78 %) with human CYP3A4 and were more closely related to human CYP3As than rat CYP3As by phylogenetic analysis. CYP3A5 was the only CYP3A in the tree shrew genome, but pig CYP3A genes formed a CYP3A gene cluster in the genomic region corresponding to that of human CYP3A genes. Tree shrew CYP3A5 mRNA was predominantly expressed in liver and small intestine, among the tissues analyzed, whereas pig CYP3A227 mRNA was most abundantly expressed in jejunum, followed by liver. Metabolic assays established that tree shrew CYP3A5 and pig CYP3A proteins heterologously expressed in Escherichia coli metabolized typical human CYP3A4 substrates nifedipine and midazolam. These results suggest that novel tree shrew CYP3A5 and pig CYP3A227 were functional enzymes able to metabolize human CYP3A4 substrates in liver and small intestine, similar to human CYP3A4, although pig CYP3A227 mRNA was minimally expressed in all tissues analyzed.

Beverage preference (coffee vs. tea) according to CYP1A2 gene rs2470893 SNP genotypes in the Tunisian population

BackgroundCaffeine intake has been positively or negatively associated with the risk of chronic disease. Genome-wide association studies identified single-nucleotide polymorphisms (rs2472297 and rs2470893) in Cytochrome P450 1A2 (CYP1A2) gene that are involved in habitual caffeine intake. In this study, we investigated the association of common CYP1A2 SNPs (rs762551, rs2472297 and rs2470893) with most consumed caffeinated beverages intake (coffee and tea) in the Tunisian population. Five hundred and twenty healthy blood donors were enrolled. Coffee and tea intake data were extracted from dietary questionnaires of the participants. Genotyping was performed using PCR–RFLP. p < 0.05 was considered as statistically significant.ResultsThere were no significant genetic effects of rs762551 and rs2472297 SNPs on coffee (p = 0.083 and p = 0.70) or tea (p = 0.49 and p = 0.49) consumption, respectively. However, rs2470893 SNP A carriers displayed higher coffee consumption [p = 0.001, OR (95% CI) 1.46 (1.16–1.86)] and lower tea consumption [p = 0.001, OR (95% CI) 0.80 (0.70–0.97)]. After stratification by confounding factors, the genetic effect was observed in women (1.2% of variation in coffee intake and 9.6% of variation in tea intake), subjects ≤ 35 years (1.5% of variation in coffee intake) and nonsmokers (1.4% of variation in tea intake).ConclusionsOur data are consistent with a beverage preference (coffee vs. tea) according to rs2470893 SNP genotypes (A carriers vs. GG). Furthermore, genetic variation is significant at the condition of lower CYP1A2 enzyme activity (among women, nonsmokers and younger age groups).

Expression patterns of Cytochrome P4501A gene induced by environmental conditions and glucocorticoid response elements (GRE) in wild fish lagoon Fundulus species

Several species of the genus Fundulus survive in environments highly impacted by human activities. When fish are exposed to environmental stress conditions, the expression of enzyme cytochrome P4501A is induced. The capacity of fish to adapt to environmental conditions could influence their survival and distribution. We evaluate the gene expression of CYP4501A in two endemic Fundulus species from Chelem Lagoon (22 individuals of Fundulus grandissimus and 31 of Fundulus persimilis) and Carbonera Lagoon (12 individuals of F. persimilis), both located in the north coast of the Yucatan Peninsula. Individuals of F. grandissmus exhibit higher expression values compared to F. persimilis. A statistically significant difference was detected in CYP4501A gene expression between populations of F. persimilis in Chelem Lagoon and between lagoons, possibly induced by environmental conditions. We also found Glucocorticoid Response Elements (GRE) in the sequences of the regulatory region of the CYP4501A gene. GRE act as glucocorticoid recognition sites, which regulate the expression of CYP enzymes. F. grandissimus individuals with higher expression levels exhibit a mutation in a GRE site, affecting the regulation of CYP enzymes inducing overexpression. Our results suggest that gene expression of CYP enzymes is induced by environmental conditions and also affects the function of their regulatory GRE sites.

Role of AHR, NF-kB and CYP1A1 crosstalk with the X protein of Hepatitis B virus in hepatocellular carcinoma cells

In this study, it was aimed to elucidate the interaction between aryl hydrocarbon receptor (AHR), nuclear factor-kappa B (NF-kB), and cytochrome P4501A1 (CYP1A1) with hepatitis B virus X protein (HBX) in a human liver cancer cell line (HepG2) transfected with HBX. First, AHR, NF-kB, and CYP1A1 genes were cloned into the appropriate region of the CheckMate mammalian two-hybrid recipient plasmids using a flexi vector system. Renilla and firefly luciferases were quantified using the dual-luciferase reporter assay system to measure the interactions. Secondly, transient transfections of CYP1A1 and NF-kB (RelA) were performed into HBX–positive and HBX–negative HepG2 cells. The mRNA expression of CYP1A1 and NF-kB genes were confirmed with RT-PCR, and cell viability was measured by WST-1. Further verification was assessed by measuring the activity and protein level of CYP1A1. Additionally, CYP1A1/HBX protein–protein interactions were performed with co-immunoprecipitation, which demonstrated no interaction. These results have clearly shown that the NF-kB and AHR genes interact with HBX without involving CYP1A1 and HBX protein–protein interactions. The present study confirms that AHR and NF-kB interaction plays a role in the HBV mechanism mediated via HBX and coordinating the carcinogenic or inflammatory responses; still, the CYP1A1 gene has no effect on this interaction.

The Effect of Benzo[a]pyrene on Xenobiotic Metabolizing Cytochrome P4501A (CYP1A) Expression in Spotted Scat, Scatophagus argus (Linnaeus, 1766)

Low molecular weight Polycyclic Aromatic Hydrocarbons (PAHs) are widely concerned due to their significant health risks such as carcinogenicity, reproductive- and endocrine-disrupting effects, immunotoxicity and neurotoxicity on human and marine animals. The induction pattern of xenobiotic metabolizing cytochrome P4501A (CYP1A1) gene was studied on 150 spotted scat Scatophagus argus (weight 32±3 g) captured from Northern Persian Gulf and exposed to 0, 5, 10, 15, 20 mg kg-1 of benzo[a]pyrene in 100L aquarium. The induction of CYP1A1 was quantified using reverse-transcription real-time PCR from treated fish liver samples. The results revealed that the expression of CYP1A1 gene in S. argus liver is time-dependent and directly correlated to the concentration of B[a] P, therefore the study provides the basis for further use of CYP1A1 of this commercially ad ecologically important species as a biomarker.