1
|
Heterologous Expression of Recombinant Human Cytochrome P450 (CYP) in Escherichia coli: N-Terminal Modification, Expression, Isolation, Purification, and Reconstitution. BIOTECH 2023; 12:biotech12010017. [PMID: 36810444 PMCID: PMC9944785 DOI: 10.3390/biotech12010017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 02/10/2023] Open
Abstract
Cytochrome P450 (CYP) enzymes play important roles in metabolising endogenous and xenobiotic substances. Characterisations of human CYP proteins have been advanced with the rapid development of molecular technology that allows heterologous expression of human CYPs. Among several hosts, bacteria systems such as Escherichia coli (E. coli) have been widely used thanks to their ease of use, high level of protein yields, and affordable maintenance costs. However, the levels of expression in E. coli reported in the literature sometimes differ significantly. This paper aims to review several contributing factors, including N-terminal modifications, co-expression with a chaperon, selections of vectors and E. coli strains, bacteria culture and protein expression conditions, bacteria membrane preparations, CYP protein solubilizations, CYP protein purifications, and reconstitution of CYP catalytic systems. The common factors that would most likely lead to high expression of CYPs were identified and summarised. Nevertheless, each factor may still require careful evaluation for individual CYP isoforms to achieve a maximal expression level and catalytic activity. Recombinant E. coli systems have been evidenced as a useful tool in obtaining the ideal level of human CYP proteins, which ultimately allows for subsequent characterisations of structures and functions.
Collapse
|
2
|
Penning TM, Su AL, El-Bayoumy K. Nitroreduction: A Critical Metabolic Pathway for Drugs, Environmental Pollutants, and Explosives. Chem Res Toxicol 2022; 35:1747-1765. [PMID: 36044734 PMCID: PMC9703362 DOI: 10.1021/acs.chemrestox.2c00175] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Nitro group containing xenobiotics include drugs, cancer chemotherapeutic agents, carcinogens (e.g., nitroarenes and aristolochic acid) and explosives. The nitro group undergoes a six-electron reduction to form sequentially the nitroso-, N-hydroxylamino- and amino-functional groups. These reactions are catalyzed by nitroreductases which, rather than being enzymes with this sole function, are enzymes hijacked for their propensity to donate electrons to the nitro group either one at a time via a radical mechanism or two at time via the equivalent of a hydride transfer. These enzymes include: NADPH-dependent flavoenzymes (NADPH: P450 oxidoreductase, NAD(P)H-quinone oxidoreductase), P450 enzymes, oxidases (aldehyde oxidase, xanthine oxidase) and aldo-keto reductases. The hydroxylamino group once formed can undergo conjugation reactions with acetate or sulfate catalyzed by N-acetyltransferases or sulfotransferases, respectively, leading to the formation of intermediates containing a good leaving group which in turn can generate a nitrenium or carbenium ion for covalent DNA adduct formation. The intermediates in the reduction sequence are also prone to oxidation and produce reactive oxygen species. As a consequence, many nitro-containing xenobiotics can be genotoxic either by forming stable covalent adducts or by oxidatively damaging DNA. This review will focus on the general chemistry of nitroreduction, the enzymes responsible, the reduction of xenobiotic substrates, the regulation of nitroreductases, the ability of nitrocompounds to form DNA adducts and act as mutagens as well as some future directions.
Collapse
Affiliation(s)
| | | | - Karam El-Bayoumy
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Pennsylvania State University, Hershey, Pennsylvania 17033-2360, United States
| |
Collapse
|
3
|
Rao J, Peng T, Li N, Wang Y, Yan C, Wang K, Qiu F. Nephrotoxicity induced by natural compounds from herbal medicines - a challenge for clinical application. Crit Rev Toxicol 2022; 52:757-778. [PMID: 36815678 DOI: 10.1080/10408444.2023.2168178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Herbal medicines (HMs) have long been considered safe and effective without serious toxic and side effects. With the continuous use of HMs, more and more attention has been paid to adverse reactions and toxic events, especially the nephrotoxicity caused by natural compounds in HMs. The composition of HMs is complex and various, especially the mechanism of toxic components has been a difficult and hot topic. This review comprehensively summarizes the kidney toxicity characterization and mechanism of nephrotoxic natural compounds (organic acids, alkaloids, glycosides, terpenoids, phenylpropanoids, flavonoids, anthraquinones, cytotoxic proteins, and minerals) from different sources. Recommendations for the prevention and treatment of HMs-induced kidney injury were provided. In vitro and in vivo models for evaluating nephrotoxicity and the latest biomarkers are also included in this investigation. More broadly, this review may provide theoretical basis for safety evaluation and further comprehensive development and utilization of HMs in the future.
Collapse
Affiliation(s)
- Jinqiu Rao
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China.,State Key Laboratory of Component-Based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China
| | - Ting Peng
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China.,State Key Laboratory of Component-Based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China
| | - Na Li
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China.,State Key Laboratory of Component-Based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China
| | - Yuan Wang
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China.,State Key Laboratory of Component-Based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China
| | - Caiqin Yan
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China
| | - Kai Wang
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China
| | - Feng Qiu
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China.,State Key Laboratory of Component-Based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China
| |
Collapse
|
4
|
Inhibition of Escherichia coli nitroreductase by the constituents in Syzygium aromaticum. Chin J Nat Med 2022; 20:506-517. [DOI: 10.1016/s1875-5364(22)60163-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Indexed: 11/23/2022]
|
5
|
Bárta F, Dedíková A, Bebová M, Dušková Š, Mráz J, Schmeiser HH, Arlt VM, Hodek P, Stiborová M. Co-Exposure to Aristolochic Acids I and II Increases DNA Adduct Formation Responsible for Aristolochic Acid I-Mediated Carcinogenicity in Rats. Int J Mol Sci 2021; 22:ijms221910479. [PMID: 34638820 PMCID: PMC8509051 DOI: 10.3390/ijms221910479] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 09/20/2021] [Accepted: 09/23/2021] [Indexed: 11/16/2022] Open
Abstract
The plant extract aristolochic acid (AA), containing aristolochic acids I (AAI) and II (AAII) as major components, causes aristolochic acid nephropathy (AAN) and Balkan endemic nephropathy (BEN), unique renal diseases associated with upper urothelial cancer. Recently (Chemical Research in Toxicology 33(11), 2804–2818, 2020), we showed that the in vivo metabolism of AAI and AAII in Wistar rats is influenced by their co-exposure (i.e., AAI/AAII mixture). Using the same rat model, we investigated how exposure to the AAI/AAII mixture can influence AAI and AAII DNA adduct formation (i.e., AA-mediated genotoxicity). Using 32P-postlabelling, we found that AA-DNA adduct formation was increased in the livers and kidneys of rats treated with AAI/AAII mixture compared to rats treated with AAI or AAII alone. Measuring the activity of enzymes involved in AA metabolism, we showed that enhanced AA-DNA adduct formation might be caused partially by both decreased AAI detoxification as a result of hepatic CYP2C11 inhibition during treatment with AAI/AAII mixture and by hepatic or renal NQO1 induction, the key enzyme predominantly activating AA to DNA adducts. Moreover, our results indicate that AAII might act as an inhibitor of AAI detoxification in vivo. Consequently, higher amounts of AAI might remain in liver and kidney tissues, which can be reductively activated, resulting in enhanced AAI DNA adduct formation. Collectively, these results indicate that AAII present in the plant extract AA enhances the genotoxic properties of AAI (i.e., AAI DNA adduct formation). As patients suffering from AAN and BEN are always exposed to the plant extract (i.e., AAI/AAII mixture), our findings are crucial to better understanding host factors critical for AAN- and BEN-associated urothelial malignancy.
Collapse
Affiliation(s)
- František Bárta
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic; (F.B.); (A.D.); (M.B.); (P.H.); (M.S.)
| | - Alena Dedíková
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic; (F.B.); (A.D.); (M.B.); (P.H.); (M.S.)
| | - Michaela Bebová
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic; (F.B.); (A.D.); (M.B.); (P.H.); (M.S.)
| | - Šárka Dušková
- Centre of Occupational Health, National Institute of Public Health, Šrobárova 48, 100 42 Prague 10, Czech Republic; (Š.D.); (J.M.)
| | - Jaroslav Mráz
- Centre of Occupational Health, National Institute of Public Health, Šrobárova 48, 100 42 Prague 10, Czech Republic; (Š.D.); (J.M.)
| | - Heinz H. Schmeiser
- Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany;
| | - Volker M. Arlt
- Department of Analytical, Environmental and Forensic Sciences Division, King’s College London, 150 Stamford Street, London SE1 9NH, UK
- Toxicology Department, GAB Consulting GmbH, Heinrich-Fuchs-Str. 96, 69126 Heidelberg, Germany
- Correspondence: ; Tel.: +49-6221-432018-0
| | - Petr Hodek
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic; (F.B.); (A.D.); (M.B.); (P.H.); (M.S.)
| | - Marie Stiborová
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic; (F.B.); (A.D.); (M.B.); (P.H.); (M.S.)
| |
Collapse
|
6
|
Human Family 1-4 cytochrome P450 enzymes involved in the metabolic activation of xenobiotic and physiological chemicals: an update. Arch Toxicol 2021; 95:395-472. [PMID: 33459808 DOI: 10.1007/s00204-020-02971-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 12/29/2020] [Indexed: 12/17/2022]
Abstract
This is an overview of the metabolic activation of drugs, natural products, physiological compounds, and general chemicals by the catalytic activity of cytochrome P450 enzymes belonging to Families 1-4. The data were collected from > 5152 references. The total number of data entries of reactions catalyzed by P450s Families 1-4 was 7696 of which 1121 (~ 15%) were defined as bioactivation reactions of different degrees. The data were divided into groups of General Chemicals, Drugs, Natural Products, and Physiological Compounds, presented in tabular form. The metabolism and bioactivation of selected examples of each group are discussed. In most of the cases, the metabolites are directly toxic chemicals reacting with cell macromolecules, but in some cases the metabolites formed are not direct toxicants but participate as substrates in succeeding metabolic reactions (e.g., conjugation reactions), the products of which are final toxicants. We identified a high level of activation for three groups of compounds (General Chemicals, Drugs, and Natural Products) yielding activated metabolites and the generally low participation of Physiological Compounds in bioactivation reactions. In the group of General Chemicals, P450 enzymes 1A1, 1A2, and 1B1 dominate in the formation of activated metabolites. Drugs are mostly activated by the enzyme P450 3A4, and Natural Products by P450s 1A2, 2E1, and 3A4. Physiological Compounds showed no clearly dominant enzyme, but the highest numbers of activations are attributed to P450 1A, 1B1, and 3A enzymes. The results thus show, perhaps not surprisingly, that Physiological Compounds are infrequent substrates in bioactivation reactions catalyzed by P450 enzyme Families 1-4, with the exception of estrogens and arachidonic acid. The results thus provide information on the enzymes that activate specific groups of chemicals to toxic metabolites.
Collapse
|
7
|
Enhanced catalytic activity of natural hematite-supported ppm levels of Pd in nitroarenes reduction. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2020. [DOI: 10.1007/s13738-020-01908-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
8
|
Han J, Xian Z, Zhang Y, Liu J, Liang A. Systematic Overview of Aristolochic Acids: Nephrotoxicity, Carcinogenicity, and Underlying Mechanisms. Front Pharmacol 2019; 10:648. [PMID: 31244661 PMCID: PMC6580798 DOI: 10.3389/fphar.2019.00648] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/20/2019] [Indexed: 12/13/2022] Open
Abstract
Aristolochic acids (AAs) are a group of toxins commonly present in the plants of genus Aristolochia and Asarum, which are spread all over the world. Since the 1990s, AA-induced nephropathy (AAN) and upper tract urothelial carcinoma (UTUC) have been reported in many countries. The underlying mechanisms of AAN and AA-induced UTUC have been extensively investigated. AA-derived DNA adducts are recognized as specific biomarkers of AA exposure, and a mutational signature predominantly characterized by A→T transversions has been detected in AA-induced UTUC tumor tissues. In addition, various enzymes and organic anion transporters are involved in AA-induced adverse reactions. The progressive lesions and mutational events initiated by AAs are irreversible, and no effective therapeutic regimen for AAN and AA-induced UTUC has been established until now. Because of several warnings on the toxic effects of AAs by the US Food and Drug Administration and the regulatory authorities of some other countries, the sale and use of AA-containing products have been banned or restricted in most countries. However, AA-related adverse events still occur, especially in the Asian and Balkan regions. Therefore, the use of AA-containing herbal remedies and the consumption of food contaminated by AAs still carry high risk. More strict precautions should be taken to protect the public from AA exposure.
Collapse
Affiliation(s)
- Jiayin Han
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Zhong Xian
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yushi Zhang
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jing Liu
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Aihua Liang
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| |
Collapse
|
9
|
DNA Adducts Formed by Aristolochic Acid Are Unique Biomarkers of Exposure and Explain the Initiation Phase of Upper Urothelial Cancer. Int J Mol Sci 2017; 18:ijms18102144. [PMID: 29036902 PMCID: PMC5666826 DOI: 10.3390/ijms18102144] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 09/29/2017] [Accepted: 10/11/2017] [Indexed: 02/06/2023] Open
Abstract
Aristolochic acid (AA) is a plant alkaloid that causes aristolochic acid nephropathy (AAN) and Balkan endemic nephropathy (BEN), unique renal diseases frequently associated with upper urothelial cancer (UUC). This review summarizes the significance of AA-derived DNA adducts in the aetiology of UUC leading to specific A:T to T:A transversion mutations (mutational signature) in AAN/BEN-associated tumours, which are otherwise rare in individuals with UCC not exposed to AA. Therefore, such DNA damage produced by AA-DNA adducts is one rare example of the direct association of exposure and cancer development (UUC) in humans, confirming that the covalent binding of carcinogens to DNA is causally related to tumourigenesis. Although aristolochic acid I (AAI), the major component of the natural plant extract AA, might directly cause interstitial nephropathy, enzymatic activation of AAI to reactive intermediates capable of binding to DNA is a necessary step leading to the formation of AA-DNA adducts and subsequently AA-induced malignant transformation. Therefore, AA-DNA adducts can not only be utilized as biomarkers for the assessment of AA exposure and markers of AA-induced UUC, but also be used for the mechanistic evaluation of its enzymatic activation and detoxification. Differences in AA metabolism might be one of the reasons for an individual’s susceptibility in the multi-step process of AA carcinogenesis and studying associations between activities and/or polymorphisms of the enzymes metabolising AA is an important determinant to identify individuals having a high risk of developing AA-mediated UUC.
Collapse
|
10
|
Jadot I, Declèves AE, Nortier J, Caron N. An Integrated View of Aristolochic Acid Nephropathy: Update of the Literature. Int J Mol Sci 2017; 18:ijms18020297. [PMID: 28146082 PMCID: PMC5343833 DOI: 10.3390/ijms18020297] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 01/20/2017] [Accepted: 01/23/2017] [Indexed: 01/09/2023] Open
Abstract
The term “aristolochic acid nephropathy” (AAN) is used to include any form of toxic interstitial nephropathy that is caused either by ingestion of plants containing aristolochic acids (AA) as part of traditional phytotherapies (formerly known as “Chinese herbs nephropathy”), or by the environmental contaminants in food (Balkan endemic nephropathy). It is frequently associated with urothelial malignancies. Although products containing AA have been banned in most of countries, AAN cases remain regularly reported all over the world. Moreover, AAN incidence is probably highly underestimated given the presence of AA in traditional herbal remedies worldwide and the weak awareness of the disease. During these two past decades, animal models for AAN have been developed to investigate underlying molecular and cellular mechanisms involved in AAN pathogenesis. Indeed, a more-in-depth understanding of these processes is essential to develop therapeutic strategies aimed to reduce the global and underestimated burden of this disease. In this regard, our purpose was to build a broad overview of what is currently known about AAN. To achieve this goal, we aimed to summarize the latest data available about underlying pathophysiological mechanisms leading to AAN development with a particular emphasis on the imbalance between vasoactive factors as well as a focus on the vascular events often not considered in AAN.
Collapse
Affiliation(s)
- Inès Jadot
- Molecular Physiology Research Unit-URPhyM, Namur Research Institute for Life Sciences (NARILIS), University of Namur (UNamur), Namur 5000, Belgium.
| | - Anne-Emilie Declèves
- Laboratory of Molecular Biology, Faculty of Medicine and Pharmacy, Research Institute for Health Sciences and Technology, University of Mons (UMons), Mons 7000, Belgium.
| | - Joëlle Nortier
- Nephrology Department, Erasme Academic Hospital and Laboratory of Experimental Nephrology, Faculty of Medicine, Université Libre de Bruxelles (ULB), Brussels 1070, Belgium.
| | - Nathalie Caron
- Molecular Physiology Research Unit-URPhyM, Namur Research Institute for Life Sciences (NARILIS), University of Namur (UNamur), Namur 5000, Belgium.
| |
Collapse
|
11
|
Stiborová M, Arlt VM, Schmeiser HH. Balkan endemic nephropathy: an update on its aetiology. Arch Toxicol 2016; 90:2595-2615. [PMID: 27538407 PMCID: PMC5065591 DOI: 10.1007/s00204-016-1819-3] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/04/2016] [Indexed: 02/02/2023]
Abstract
Balkan endemic nephropathy (BEN) is a unique, chronic renal disease frequently associated with upper urothelial cancer (UUC). It only affects residents of specific farming villages located along tributaries of the Danube River in Bosnia-Herzegovina, Croatia, Macedonia, Serbia, Bulgaria, and Romania where it is estimated that ~100,000 individuals are at risk of BEN, while ~25,000 have the disease. This review summarises current findings on the aetiology of BEN. Over the last 50 years, several hypotheses on the cause of BEN have been formulated, including mycotoxins, heavy metals, viruses, and trace-element insufficiencies. However, recent molecular epidemiological studies provide a strong case that chronic dietary exposure to aristolochic acid (AA) a principal component of Aristolochia clematitis which grows as a weed in the wheat fields of the endemic regions is the cause of BEN and associated UUC. One of the still enigmatic features of BEN that need to be resolved is why the prevalence of BEN is only 3-7 %. This suggests that individual genetic susceptibilities to AA exist in humans. In fact dietary ingestion of AA along with individual genetic susceptibility provides a scenario that plausibly can explain all the peculiarities of BEN such as geographical distribution and high risk of urothelial cancer. For the countries harbouring BEN implementing public health measures to avoid AA exposure is of the utmost importance because this seems to be the best way to eradicate this once mysterious disease to which the residents of BEN villages have been completely and utterly at mercy for so long.
Collapse
Affiliation(s)
- Marie Stiborová
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40, Prague 2, Czech Republic.
| | - Volker M Arlt
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environmental and Health, King's College London, 150 Stamford Street, London, SE1 9NH, UK
- NIHR Health Protection Research Unit in Health Impact of Environmental Hazards at King's College London in partnership with Public Health England, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NH, UK
| | - Heinz H Schmeiser
- Division of Radiopharmaceutical Chemistry (E030), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| |
Collapse
|
12
|
Stiborová M, Indra R, Moserová M, Frei E, Schmeiser HH, Kopka K, Philips DH, Arlt V. NADH:Cytochrome b5 Reductase and Cytochrome b5 Can Act as Sole Electron Donors to Human Cytochrome P450 1A1-Mediated Oxidation and DNA Adduct Formation by Benzo[a]pyrene. Chem Res Toxicol 2016; 29:1325-34. [PMID: 27404282 PMCID: PMC4987862 DOI: 10.1021/acs.chemrestox.6b00143] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Indexed: 11/29/2022]
Abstract
Benzo[a]pyrene (BaP) is a human carcinogen that covalently binds to DNA after activation by cytochrome P450 (P450). Here, we investigated whether NADH:cytochrome b5 reductase (CBR) in the presence of cytochrome b5 can act as sole electron donor to human P450 1A1 during BaP oxidation and replace the canonical NADPH:cytochrome P450 reductase (POR) system. We also studied the efficiencies of the coenzymes of these reductases, NADPH as a coenzyme of POR, and NADH as a coenzyme of CBR, to mediate BaP oxidation. Two systems containing human P450 1A1 were utilized: human recombinant P450 1A1 expressed with POR, CBR, epoxide hydrolase, and cytochrome b5 in Supersomes and human recombinant P450 1A1 reconstituted with POR and/or with CBR and cytochrome b5 in liposomes. BaP-9,10-dihydrodiol, BaP-7,8-dihydrodiol, BaP-1,6-dione, BaP-3,6-dione, BaP-9-ol, BaP-3-ol, a metabolite of unknown structure, and two BaP-DNA adducts were generated by the P450 1A1-Supersomes system, both in the presence of NADPH and in the presence of NADH. The major BaP-DNA adduct detected by (32)P-postlabeling was characterized as 10-(deoxyguanosin-N(2)-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydro-BaP (assigned adduct 1), while the minor adduct is probably a guanine adduct derived from 9-hydroxy-BaP-4,5-epoxide (assigned adduct 2). BaP-3-ol as the major metabolite, BaP-9-ol, BaP-1,6-dione, BaP-3,6-dione, an unknown metabolite, and adduct 2 were observed in the system using P450 1A1 reconstituted with POR plus NADPH. When P450 1A1 was reconstituted with CBR and cytochrome b5 plus NADH, BaP-3-ol was the predominant metabolite too, and an adduct 2 was also generated. Our results demonstrate that the NADH/cytochrome b5/CBR system can act as the sole electron donor both for the first and second reduction of P450 1A1 during the oxidation of BaP in vitro. They suggest that NADH-dependent CBR can replace NADPH-dependent POR in the P450 1A1-catalyzed metabolism of BaP.
Collapse
Affiliation(s)
- Marie Stiborová
- Department
of Biochemistry, Faculty of Science, Charles
University, Albertov
2030, 128 40, Prague 2, Czech
Republic
| | - Radek Indra
- Department
of Biochemistry, Faculty of Science, Charles
University, Albertov
2030, 128 40, Prague 2, Czech
Republic
| | - Michaela Moserová
- Department
of Biochemistry, Faculty of Science, Charles
University, Albertov
2030, 128 40, Prague 2, Czech
Republic
| | - Eva Frei
- Department
of Biochemistry, Faculty of Science, Charles
University, Albertov
2030, 128 40, Prague 2, Czech
Republic
| | - Heinz H. Schmeiser
- Division
of Radiopharmaceutical Chemistry, German
Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Klaus Kopka
- Department
of Biochemistry, Faculty of Science, Charles
University, Albertov
2030, 128 40, Prague 2, Czech
Republic
| | - David H. Philips
- Analytical
and Environmental Sciences Division, MRC-PHE Centre for Environment
and Health, King’s College London, Franklin-Wilkins Building, 150 Stamford
Street, London SE1 9NH, United Kingdom
- NIHR
Health Protection Research Unit in Health Impact of Environmental
Hazards at King’s College London in Partnership with Public
Health England, Franklin-Wilkins
Building, 150 Stamford Street, London SE1 9NH, United Kingdom
| | - Volker
M. Arlt
- Analytical
and Environmental Sciences Division, MRC-PHE Centre for Environment
and Health, King’s College London, Franklin-Wilkins Building, 150 Stamford
Street, London SE1 9NH, United Kingdom
- NIHR
Health Protection Research Unit in Health Impact of Environmental
Hazards at King’s College London in Partnership with Public
Health England, Franklin-Wilkins
Building, 150 Stamford Street, London SE1 9NH, United Kingdom
| |
Collapse
|