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Bertelmann C, Bühler B. Strategies found not to be suitable for stabilizing high steroid hydroxylation activities of CYP450 BM3-based whole-cell biocatalysts. PLoS One 2024; 19:e0309965. [PMID: 39240904 PMCID: PMC11379211 DOI: 10.1371/journal.pone.0309965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Accepted: 08/21/2024] [Indexed: 09/08/2024] Open
Abstract
The implementation of biocatalytic steroid hydroxylation processes plays a crucial role in the pharmaceutical industry due to a plethora of medicative effects of hydroxylated steroid derivatives and their crucial role in drug approval processes. Cytochrome P450 monooxygenases (CYP450s) typically constitute the key enzymes catalyzing these reactions, but commonly entail drawbacks such as poor catalytic rates and the dependency on additional redox proteins for electron transfer from NAD(P)H to the active site. Recently, these bottlenecks were overcome by equipping Escherichia coli cells with highly active variants of the self-sufficient single-component CYP450 BM3 together with hydrophobic outer membrane proteins facilitating cellular steroid uptake. The combination of the BM3 variant KSA14m and the outer membrane pore AlkL enabled exceptionally high testosterone hydroxylation rates of up to 45 U gCDW-1 for resting (i.e., living but non-growing) cells. However, a rapid loss of specific activity heavily compromised final product titers and overall space-time yields. In this study, several stabilization strategies were evaluated on enzyme-, cell-, and reaction level. However, neither changes in biocatalyst configuration nor variation of cultivation media, expression systems, or inducer concentrations led to considerable improvement. This qualified the so-far used genetic construct pETM11-ksa14m-alkL, M9 medium, and the resting-cell state as the best options enabling comparatively efficient activity along with fast growth prior to biotransformation. In summary, we report several approaches not enabling a stabilization of the high testosterone hydroxylation rates, providing vital guidance for researchers tackling similar CYP450 stability issues. A comparison with more stable natively steroid-hydroxylating CYP106A2 and CYP154C5 in equivalent setups further highlighted the high potential of the investigated CYP450 BM3-based whole-cell biocatalysts. The immense and continuously developing repertoire of enzyme engineering strategies provides promising options to stabilize the highly active biocatalysts.
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Affiliation(s)
- Carolin Bertelmann
- Department of Solar Materials Biotechnology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Saxony, Germany
- Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Saxony, Germany
| | - Bruno Bühler
- Department of Solar Materials Biotechnology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Saxony, Germany
- Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Saxony, Germany
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Bertelmann C, Mock M, Schmid A, Bühler B. Efficiency aspects of regioselective testosterone hydroxylation with highly active CYP450-based whole-cell biocatalysts. Microb Biotechnol 2024; 17:e14378. [PMID: 38018939 PMCID: PMC10832557 DOI: 10.1111/1751-7915.14378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 11/12/2023] [Indexed: 11/30/2023] Open
Abstract
Steroid hydroxylations belong to the industrially most relevant reactions catalysed by cytochrome P450 monooxygenases (CYP450s) due to the pharmacological relevance of hydroxylated derivatives. The implementation of respective bioprocesses at an industrial scale still suffers from several limitations commonly found in CYP450 catalysis, that is low turnover rates, enzyme instability, inhibition and toxicity related to the substrate(s) and/or product(s). Recently, we achieved a new level of steroid hydroxylation rates by introducing highly active testosterone-hydroxylating CYP450 BM3 variants together with the hydrophobic outer membrane protein AlkL into Escherichia coli-based whole-cell biocatalysts. However, the activity tended to decrease, which possibly impedes overall productivities and final product titres. In this study, a considerable instability was confirmed and subject to a systematic investigation regarding possible causes. In-depth evaluation of whole-cell biocatalyst kinetics and stability revealed a limitation in substrate availability due to poor testosterone solubility as well as inhibition by the main product 15β-hydroxytestosterone. Instability of CYP450 BM3 variants was disclosed as another critical factor, which is of general significance for CYP450-based biocatalysis. Presented results reveal biocatalyst, reaction and process engineering strategies auguring well for industrial implementation of the developed steroid hydroxylation platform.
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Affiliation(s)
| | - Magdalena Mock
- Department of Solar MaterialsLeipzigGermany
- Present address:
Department of Mechanical Engineering and Material SciencesGeorg Agricola University of Applied SciencesBochumGermany
| | | | - Bruno Bühler
- Department of Solar MaterialsLeipzigGermany
- Department of Microbial BiotechnologyHelmholtz Centre for Environmental Research GmbH–UFZLeipzigGermany
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Meng S, Ji Y, Zhu L, Dhoke GV, Davari MD, Schwaneberg U. The molecular basis and enzyme engineering strategies for improvement of coupling efficiency in cytochrome P450s. Biotechnol Adv 2022; 61:108051. [DOI: 10.1016/j.biotechadv.2022.108051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 09/26/2022] [Accepted: 10/13/2022] [Indexed: 11/28/2022]
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Leisegang K, Roychoudhury S, Slama P, Finelli R. The Mechanisms and Management of Age-Related Oxidative Stress in Male Hypogonadism Associated with Non-communicable Chronic Disease. Antioxidants (Basel) 2021; 10:1834. [PMID: 34829704 PMCID: PMC8615233 DOI: 10.3390/antiox10111834] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 12/24/2022] Open
Abstract
Androgens have diverse functions in muscle physiology, lean body mass, the regulation of adipose tissue, bone density, neurocognitive regulation, and spermatogenesis, the male reproductive and sexual function. Male hypogonadism, characterized by reduced testosterone, is commonly seen in ageing males, and has a complex relationship as a risk factor and a comorbidity in age-related noncommunicable chronic diseases (NCDs), such as obesity, metabolic syndrome, type 2 diabetes, and malignancy. Oxidative stress, as a significant contributor to the ageing process, is a common feature between ageing and NCDs, and the related comorbidities, including hypertension, dyslipidemia, hyperglycemia, hyperinsulinemia, and chronic inflammation. Oxidative stress may also be a mediator of hypogonadism in males. Consequently, the management of oxidative stress may represent a novel therapeutic approach in this context. Therefore, this narrative review aims to discuss the mechanisms of age-related oxidative stress in male hypogonadism associated with NCDs and discusses current and potential approaches for the clinical management of these patients, which may include conventional hormone replacement therapy, nutrition and lifestyle changes, adherence to the optimal body mass index, and dietary antioxidant supplementation and/or phytomedicines.
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Affiliation(s)
- Kristian Leisegang
- School of Natural Medicine, Faculty of Community and Health Sciences, Bellville, Cape Town 7535, South Africa
| | | | - Petr Slama
- Department of Animal Morphology, Physiology and Genetics, Faculty of AgriSciences, Mendel University in Brno, 61300 Brno, Czech Republic
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Noleto KS, de Oliveira SRS, Lima IMA, de Jesus WB, da Silva Castro J, de Santana TC, de Lima Cardoso R, Jorge MB, Santos DMS, de Souza Torres-Júnior JR, Fortes Carvalho Neta RN. Biochemical and Histological Biomarkers in Crassostrea sp. (Bivalvia, Ostreidae) for Environmental Monitoring of a Neotropical Estuarine Area (São José Bay, Northeastern Brazil). BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2021; 106:614-621. [PMID: 33609170 DOI: 10.1007/s00128-021-03149-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 02/06/2021] [Indexed: 06/12/2023]
Abstract
This study aimed to compare biochemical and histological biomarkers in oysters to identify impacted areas in a Brazilian port region. Oysters belonging to the Crassostrea genus were collected in two points in São José Bay (Brazil): (A1) Curupu Island (control area) and (A2) Braga Port (impacted area). Digestive glands from oysters were used to analyze the enzymatic activity of glutathione S-transferase and Catalase. The gills were used for standard histology analyses. Water samples were collected for metal analyses. Our results indicated that there was a change in the activity of oyster GST and CAT enzymes, especially in A2. Histological gill analysis indicated more frequent changes in A2. The analyzed metals presented higher values in A2. The results of this study suggest that enzymatic alterations, histological changes and higher metal values are indicative of initial stress caused by contaminants in São José Bay, especially in the port region.
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Affiliation(s)
- Katherine Saldanha Noleto
- Department of Oceanography and Limnology, Federal University of Maranhão (Ufma), Avenue of Portugueses 1966, Vila Bacanga, São Luís, Maranhão, Brazil.
| | - Suelen Rosana Sampaio de Oliveira
- Department of Oceanography and Limnology, Federal University of Maranhão (Ufma), Avenue of Portugueses 1966, Vila Bacanga, São Luís, Maranhão, Brazil.
| | - Ione Marly Arouche Lima
- Department of Agricultural Sciences, Postgraduate animal Science program, State University of Maranhão (Uema), University City Paulo, VI s/n, Cidade Operária, Maranhão, São Luís, Brazil
| | - Wanda Batista de Jesus
- Department of Biology, Postgraduate Program in Aquatic Resources and Fisheries, State University of Maranhão (Uema), University City Paulo, VI s/n, Cidade Operária, Maranhão, São Luís, Brazil
| | - Jonatas da Silva Castro
- Postgraduate Program in Aquaculture, Nilton Lins University (UniNiltonLins), Av. Nilton Lins, 3259, Parque das Laranjeiras, Amazonas, Manaus, Brazil
| | - Thiago Campos de Santana
- Department of Biology, Postgraduate Program in Aquatic Resources and Fisheries, State University of Maranhão (Uema), University City Paulo, VI s/n, Cidade Operária, Maranhão, São Luís, Brazil
| | - Rayssa de Lima Cardoso
- São Paulo StateUniversity (Unesp), Institute of Science and Technology, Avenue Three March, 511, Alto da Boa Vista, Sorocaba, São Paulo, Brazil
| | - Marianna Basso Jorge
- Department of Oceanography and Limnology, Federal University of Maranhão (Ufma), Avenue of Portugueses 1966, Vila Bacanga, São Luís, Maranhão, Brazil
| | - Débora Martins Silva Santos
- Department of Biology, Postgraduate Program in Aquatic Resources and Fisheries, State University of Maranhão (Uema), University City Paulo, VI s/n, Cidade Operária, Maranhão, São Luís, Brazil
| | - José Ribamar de Souza Torres-Júnior
- Department of Oceanography and Limnology, Federal University of Maranhão (Ufma), Avenue of Portugueses 1966, Vila Bacanga, São Luís, Maranhão, Brazil
| | - Raimunda Nonata Fortes Carvalho Neta
- Department of Biology, Postgraduate Program in Aquatic Resources and Fisheries, State University of Maranhão (Uema), University City Paulo, VI s/n, Cidade Operária, Maranhão, São Luís, Brazil
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Ishii N, Homma T, Guo X, Yamada KI, Yamada S, Fujii J. Ascorbic acid prevents N-nitrosodiethylamine-induced hepatic injury and hepatocarcinogenesis in Akr1a-knockout mice. Toxicol Lett 2020; 333:192-201. [PMID: 32805337 DOI: 10.1016/j.toxlet.2020.08.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 07/13/2020] [Accepted: 08/10/2020] [Indexed: 12/11/2022]
Abstract
To gain insights into the benefits of ascorbic acid (AsA) in hepatoprotection, we examined the status of Akr1a-/- (KO) mice, which biosynthesize AsA at about 10% the rate as Akr1a+/+ (WT) mice, in terms of their response to an N-nitrosodiethylamine (NDEA)-induced hepatic injury. The intraperitoneal injection of NDEA (35 mg/kg) started at 4 weeks of age and was performed at weekly intervals thereafter. While the fatality rate was substantial in the KO mice, AsA supplementation (1.5 mg/ml in the drinking water) greatly extended their life-spans. Only two out of 54 KO mice survived to 28 weeks, and both contained approximately an order of magnitude greater number of tumor nodules compared to WT mice or KO mice with AsA supplementation. Histological and biochemical examinations at 20 weeks indicated that AsA potently protected against the hepatotoxic action of NDEA. Interestingly, the AsA levels in the liver were higher in the AsA-supplemented KO mouse groups that had received the NDEA treatment compared to the corresponding control group. While the protein levels of Cyp2e1, an enzyme that plays a major role in the bioactivation of NDEA, had declined to a similar extent among the experimental groups, p-nitrophenol-oxidizing activity was sustained at high levels in the KO mouse livers but AsA supplementation suppressed this activity. These findings confirm that AsA is a potent micronutrient that copes with hepatic injury and cancer development caused by exposure to NDEA in the livers of Akr1a-knockout mice.
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Affiliation(s)
- Naoki Ishii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata, 990-9585, Japan
| | - Takujiro Homma
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata, 990-9585, Japan
| | - Xin Guo
- Department of Pathology and Laboratory Medicine, Kanazawa Medical University, 1-1 Uchinada, Ishikawa, 920-0293, Japan
| | - Ken-Ichi Yamada
- Physical Chemistry for Life Science Laboratory, Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka 812-8582, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Sohsuke Yamada
- Department of Pathology and Laboratory Medicine, Kanazawa Medical University, 1-1 Uchinada, Ishikawa, 920-0293, Japan
| | - Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata, 990-9585, Japan.
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Diesinger T, Buko V, Lautwein A, Dvorsky R, Belonovskaya E, Lukivskaya O, Naruta E, Kirko S, Andreev V, Buckert D, Bergler S, Renz C, Schneider E, Kuchenbauer F, Kumar M, Günes C, Büchele B, Simmet T, Müller-Enoch D, Wirth T, Haehner T. Drug targeting CYP2E1 for the treatment of early-stage alcoholic steatohepatitis. PLoS One 2020; 15:e0235990. [PMID: 32701948 PMCID: PMC7377376 DOI: 10.1371/journal.pone.0235990] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 06/25/2020] [Indexed: 02/07/2023] Open
Abstract
Background and aims Alcoholic steatohepatitis (ASH)—the inflammation of fatty liver—is caused by chronic alcohol consumption and represents one of the leading chronic liver diseases in Western Countries. ASH can lead to organ dysfunction or progress to hepatocellular carcinoma (HCC). Long-term alcohol abstinence reduces this probability and is the prerequisite for liver transplantation—the only effective therapy option at present. Elevated enzymatic activity of cytochrome P450 2E1 (CYP2E1) is known to be critically responsible for the development of ASH due to excessively high levels of reactive oxygen species (ROS) during metabolization of ethanol. Up to now, no rational drug discovery process was successfully initiated to target CYP2E1 for the treatment of ASH. Methods In this study, we applied a rational drug design concept to develop drug candidates (NCE) including preclinical studies. Results A new class of drug candidates was generated successfully. Two of the most promising small compounds named 12-Imidazolyl-1-dodecanol (abbr.: I-ol) and 1-Imidazolyldodecane (abbr.: I-an) were selected at the end of this process of drug discovery and developability. These new ω-imidazolyl-alkyl derivatives act as strong chimeric CYP2E1 inhibitors at a nanomolar range. They restore redox balance, reduce inflammation process as well as the fat content in the liver and rescue the physiological liver architecture of rats consuming continuously a high amount of alcohol. Conclusions Due to its oral application and therapeutic superiority over an off-label use of the hepatoprotector ursodeoxycholic acid (UDCA), this new class of inhibitors marks the first rational, pharmaceutical concept in long-term treatment of ASH.
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Affiliation(s)
- Torsten Diesinger
- Donauklinik Neu-Ulm, Abteilung für Innere Medizin, Neu-Ulm, Germany
- Institute of Physiological Chemistry, Ulm University, Ulm, Germany
- Department of Internal Medicine, Neu-Ulm Hospital, Neu-Ulm, Germany
- * E-mail:
| | - Vyacheslav Buko
- Division of Biochemical Pharmacology, Institute of Biochemistry of Biologically Active Substances, Grodno, Belarus
- Department of Biotechnology, University of Medical Sciences, Bialystok, Poland
| | - Alfred Lautwein
- Institute of Physiological Chemistry, Ulm University, Ulm, Germany
| | - Radovan Dvorsky
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
- Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Elena Belonovskaya
- Division of Biochemical Pharmacology, Institute of Biochemistry of Biologically Active Substances, Grodno, Belarus
| | - Oksana Lukivskaya
- Division of Biochemical Pharmacology, Institute of Biochemistry of Biologically Active Substances, Grodno, Belarus
| | - Elena Naruta
- Division of Biochemical Pharmacology, Institute of Biochemistry of Biologically Active Substances, Grodno, Belarus
| | - Siarhei Kirko
- Division of Biochemical Pharmacology, Institute of Biochemistry of Biologically Active Substances, Grodno, Belarus
| | - Viktor Andreev
- Department of Medical Biology and Genetics, Grodno State Medical University, Grodno, Belarus
| | - Dominik Buckert
- Institute of Physiological Chemistry, Ulm University, Ulm, Germany
- Department of Internal Medicine II, University Hospital Ulm, Ulm, Germany
| | | | - Christian Renz
- Institute of Physiological Chemistry, Ulm University, Ulm, Germany
| | - Edith Schneider
- Department of Internal Medicine III, University Hospital Ulm, Ulm, Germany
| | - Florian Kuchenbauer
- Department of Internal Medicine III, University Hospital Ulm, Ulm, Germany
- University of British Columbia, Terry Fox Laboratory, Vancouver, Canada
| | - Mukesh Kumar
- Department of Urology, University Hospital Ulm, Ulm, Germany
| | - Cagatay Günes
- Department of Urology, University Hospital Ulm, Ulm, Germany
| | - Berthold Büchele
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, University Ulm, Ulm, Germany
| | - Thomas Simmet
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, University Ulm, Ulm, Germany
| | | | - Thomas Wirth
- Institute of Physiological Chemistry, Ulm University, Ulm, Germany
| | - Thomas Haehner
- Institute of Physiological Chemistry, Ulm University, Ulm, Germany
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Dare NA, Egan TJ. Heterogeneous catalysis with encapsulated haem and other synthetic porphyrins: Harnessing the power of porphyrins for oxidation reactions. OPEN CHEM 2018. [DOI: 10.1515/chem-2018-0083] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
AbstractEncapsulated metalloporphyrins have been widely studied for their use as efficient heterogeneous catalysts, inspired by the known catalytic activity of porphyrins in haemoproteins. The oxidation of organic substrates by haemoproteins is one of the well-known roles of these proteins, in which the haem (ferriprotoporphyrin IX = FePPIX) cofactor is the centre of reactivity. While these porphyrins are highly efficient catalysts in the protein environment, once removed, they quickly lose their reactivity. It is for this reason that they have garnered much interest in the field of heterogeneous catalysis of oxidation reactions. This review details current research in the field, focusing on the application of encapsulated haem, and other synthetic metalloporphyrins, applied to oxidation reactions.
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Affiliation(s)
- Nicola A. Dare
- Department of Chemistry, University of Cape Town, Cape Town, Private Bag, Rondebosch 7701, South Africa
| | - Timothy J. Egan
- Department of Chemistry, University of Cape Town, Cape Town, Private Bag, Rondebosch 7701, South Africa
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Shi Q, Fijten RR, Spina D, Riffo Vasquez Y, Arlt VM, Godschalk RW, Van Schooten FJ. Altered gene expression profiles in the lungs of benzo[a]pyrene-exposed mice in the presence of lipopolysaccharide-induced pulmonary inflammation. Toxicol Appl Pharmacol 2017; 336:8-19. [PMID: 28987381 PMCID: PMC5703654 DOI: 10.1016/j.taap.2017.09.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/22/2017] [Accepted: 09/29/2017] [Indexed: 12/13/2022]
Abstract
Patients with inflammatory lung diseases are often additionally exposed to polycyclic aromatic hydrocarbons like B[a]P and B[a]P-induced alterations in gene expression in these patients may contribute to the development of lung cancer. Mice were intra-nasally treated with lipopolysaccharide (LPS, 20μg/mouse) to induce pulmonary inflammation and subsequently exposed to B[a]P (0.5mg/mouse) by intratracheal instillation. Gene expression changes were analyzed in mouse lungs by RNA microarrays. Analysis of genes that are known to be involved in the cellular response to B[a]P indicated that LPS significantly inhibited gene expression of various enzymes linked to B[a]P metabolism, which was confirmed by phenotypic analyses of enzyme activity. Ultimately, these changes resulted in higher levels of B[a]P-DNA adducts in the lungs of mice exposed to B[a]P with prior LPS treatment compared to the lungs of mice exposed to B[a]P alone. Using principle component analysis (PCA), we found that of all the genes that were significantly altered in their expression, those that were able to separate the different exposure conditions were predominantly related to immune-response. Moreover, an overall analysis of differentially expressed genes indicated that cell-cell adhesion and cell-cell communication was inhibited in lungs of mice that received both B[a]P and LPS. Our results indicate that pulmonary inflammation increased the genotoxicity of B[a]P via inhibition of both phase I and II metabolism. Therefore, inflammation could be a critical contributor to B[a]P-induced carcinogenesis in humans.
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Affiliation(s)
- Q Shi
- Department of Toxicology & Pharmacology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands
| | - R R Fijten
- Department of Toxicology & Pharmacology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands
| | - D Spina
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, 150 Stamford Street, London SE1 9NH, United Kingdom
| | - Y Riffo Vasquez
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, 150 Stamford Street, London SE1 9NH, United Kingdom
| | - V M Arlt
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environmental & Health, King's College London, 150 Stamford Street, London SE1 9NH, United Kingdom
| | - R W Godschalk
- Department of Toxicology & Pharmacology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands.
| | - F J Van Schooten
- Department of Toxicology & Pharmacology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands
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Di Meo S, Reed TT, Venditti P, Victor VM. Role of ROS and RNS Sources in Physiological and Pathological Conditions. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:1245049. [PMID: 27478531 PMCID: PMC4960346 DOI: 10.1155/2016/1245049] [Citation(s) in RCA: 756] [Impact Index Per Article: 94.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 05/04/2016] [Accepted: 05/23/2016] [Indexed: 12/19/2022]
Abstract
There is significant evidence that, in living systems, free radicals and other reactive oxygen and nitrogen species play a double role, because they can cause oxidative damage and tissue dysfunction and serve as molecular signals activating stress responses that are beneficial to the organism. Mitochondria have been thought to both play a major role in tissue oxidative damage and dysfunction and provide protection against excessive tissue dysfunction through several mechanisms, including stimulation of opening of permeability transition pores. Until recently, the functional significance of ROS sources different from mitochondria has received lesser attention. However, the most recent data, besides confirming the mitochondrial role in tissue oxidative stress and protection, show interplay between mitochondria and other ROS cellular sources, so that activation of one can lead to activation of other sources. Thus, it is currently accepted that in various conditions all cellular sources of ROS provide significant contribution to processes that oxidatively damage tissues and assure their survival, through mechanisms such as autophagy and apoptosis.
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Affiliation(s)
- Sergio Di Meo
- Dipartimento di Biologia, Università di Napoli “Federico II”, 80126 Napoli, Italy
| | - Tanea T. Reed
- Department of Chemistry, Eastern Kentucky University, Richmond, KY 40475, USA
| | - Paola Venditti
- Dipartimento di Biologia, Università di Napoli “Federico II”, 80126 Napoli, Italy
| | - Victor Manuel Victor
- Service of Endocrinology, University Hospital Dr. Peset, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region (FISABIO), 46010 Valencia, Spain
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11
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Brummund J, Müller M, Schmitges T, Kaluzna I, Mink D, Hilterhaus L, Liese A. Process development for oxidations of hydrophobic compounds applying cytochrome P450 monooxygenases in-vitro. J Biotechnol 2016; 233:143-50. [PMID: 27396939 DOI: 10.1016/j.jbiotec.2016.07.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 06/06/2016] [Accepted: 07/06/2016] [Indexed: 11/18/2022]
Abstract
Cytochrome P450 monooxygenases are a unique family of enzymes that are able to catalyze regio- and stereospecific oxidations for a broad substrate range. However, due to limited enzyme activities and stabilities, hydrophobicity of substrates, as well as the necessity of a continuous electron and oxygen supply the implementation of P450s for industrial processes remains challenging. Aim of this study was to point out key aspects for the development of an efficient synthesis concept for cytochrome P450 catalyzed oxidations. In order to regenerate the natural cofactor NADPH, a glucose dehydrogenase was applied. The low water soluble terpene α-ionone was used as substrate for the model reaction system. The studies reveal that an addition of surfactants in combination with low volumetric amounts of co-solvent can significantly increase substrate availability and reaction rates. Furthermore, these additives facilitated a reliable sampling procedure during the process. Another key factor for the process design was the oxygen supply. Based on various investigations, a bubble-aerated stirred tank reactor in batch mode represents a promising reactor concept for P450 oxidations. Main restriction of the investigated reaction system was the low process stability of the P450 monooxygenase, characterized by maximum total turnover numbers of ∼4100molα-ionone/molP450.
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Affiliation(s)
- Jan Brummund
- Hamburg University of Technology, Institute of Technical Biocatalysis, Denickestr. 15, 21073 Hamburg, Germany
| | - Monika Müller
- DSM Chemical Technology R&D B.V., Urmonderbaan 22, P.O. Box 18, 6160 MD Geleen, The Netherlands
| | - Thomas Schmitges
- DSM Chemical Technology R&D B.V., Urmonderbaan 22, P.O. Box 18, 6160 MD Geleen, The Netherlands
| | - Iwona Kaluzna
- DSM Chemical Technology R&D B.V., Urmonderbaan 22, P.O. Box 18, 6160 MD Geleen, The Netherlands
| | - Daniel Mink
- DSM Chemical Technology R&D B.V., Urmonderbaan 22, P.O. Box 18, 6160 MD Geleen, The Netherlands
| | - Lutz Hilterhaus
- Hamburg University of Technology, Institute of Technical Biocatalysis, Denickestr. 15, 21073 Hamburg, Germany
| | - Andreas Liese
- Hamburg University of Technology, Institute of Technical Biocatalysis, Denickestr. 15, 21073 Hamburg, Germany.
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Shirato T, Homma T, Lee J, Kurahashi T, Fujii J. Oxidative stress caused by a SOD1 deficiency ameliorates thioacetamide-triggered cell death via CYP2E1 inhibition but stimulates liver steatosis. Arch Toxicol 2016; 91:1319-1333. [PMID: 27349771 DOI: 10.1007/s00204-016-1785-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/22/2016] [Indexed: 12/30/2022]
Abstract
We investigated the responses of mice that are defective in the superoxide-scavenging enzyme SOD1 to thioacetamide (TAA)-induced hepatotoxicity. When a lethal dose of TAA (500 mg/kg) was intraperitoneally injected, the wild-type (WT) mice all died within 36 h, but all of the SOD1-knockout (KO) mice survived. Treatment with an SOD1 inhibitor rendered the WT mice resistant to TAA toxicity. To elucidate the mechanism responsible for this, we examined the acute effects of a sublethal dose of TAA (200 mg/kg) on the livers of WT and KO mice. The extent of TAA-induced liver damage was less in the KO mice, but, instead, lipogenesis was further advanced in the SOD1-KO livers. The levels of proteins modified with acetyllysine, a marker for TAA-mediated injury, were lower in the KO mice than the WT mice upon the TAA treatment. The KO mice, which were under oxidative stress per se, exhibited a lower CYP2E1 activity, and this appeared to result in a decrease in the production of reactive oxygen species (ROS) during TAA metabolism. Both cleaved ATF6, a transcriptional regulator that is activated by endoplasmic reticulum (ER) stress, and CHOP, a death signal mediator, were highly elevated in the WT mice as the result of the TAA treatment and consistent with the liver damage. We conclude that elevated TAA metabolites and reactive oxygen species that are produced by CYP-mediated drug metabolism trigger lipogenesis as well as liver damage via ER stress and determine the fate of the mice.
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Affiliation(s)
- Takaya Shirato
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata, 990-9585, Japan
| | - Takujiro Homma
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata, 990-9585, Japan
| | - Jaeyong Lee
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata, 990-9585, Japan
| | - Toshihiro Kurahashi
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata, 990-9585, Japan.,Department of Pathology and Cell Regulation, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata, 990-9585, Japan.
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13
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Otsuki N, Homma T, Fujiwara H, Kaneko K, Hozumi Y, Shichiri M, Takashima M, Ito J, Konno T, Kurahashi T, Yoshida Y, Goto K, Fujii S, Fujii J. Trichloroethylene exposure aggravates behavioral abnormalities in mice that are deficient in superoxide dismutase. Regul Toxicol Pharmacol 2016; 79:83-90. [PMID: 27166294 DOI: 10.1016/j.yrtph.2016.05.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 12/11/2022]
Abstract
Trichloroethylene (TCE) has been implicated as a causative agent for Parkinson's disease (PD). The administration of TCE to rodents induces neurotoxicity associated with dopaminergic neuron death, and evidence suggests that oxidative stress as a major player in the progression of PD. Here we report on TCE-induced behavioral abnormality in mice that are deficient in superoxide dismutase 1 (SOD1). Wild-type (WT) and SOD1-deficient (Sod1(-/-)) mice were intraperitoneally administered TCE (500 mg/kg) over a period of 4 weeks. Although the TCE-administrated Sod1(-/-) mice showed marked abnormal motor behavior, no significant differences were observed among the experimental groups by biochemical and histopathological analyses. However, treating mouse neuroblastoma-derived NB2a cells with TCE resulted in the down regulation of the SOD1 protein and elevated oxidative stress under conditions where SOD1 production was suppressed. Taken together, these data indicate that SOD1 plays a pivotal role in protecting motor neuron function against TCE toxicity.
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Affiliation(s)
- Noriyuki Otsuki
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata 990-9585, Japan
| | - Takujiro Homma
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata 990-9585, Japan
| | - Hiroki Fujiwara
- Department of Physiology, Yamagata University School of Medicine, 2-2-2 Iidanishi, Yamagata 990-9585, Japan
| | - Kenya Kaneko
- Department of Physiology, Yamagata University School of Medicine, 2-2-2 Iidanishi, Yamagata 990-9585, Japan
| | - Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iidanishi 2-2-2, Yamagata 990-9585, Japan
| | - Mototada Shichiri
- Health Research Institute (HRI), National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
| | - Mizuki Takashima
- Health Research Institute (HRI), National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
| | - Junitsu Ito
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata 990-9585, Japan
| | - Tasuku Konno
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata 990-9585, Japan
| | - Toshihiro Kurahashi
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata 990-9585, Japan
| | - Yasukazu Yoshida
- Health Research Institute (HRI), National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
| | - Kaoru Goto
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Iidanishi 2-2-2, Yamagata 990-9585, Japan
| | - Satoshi Fujii
- Department of Physiology, Yamagata University School of Medicine, 2-2-2 Iidanishi, Yamagata 990-9585, Japan
| | - Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata 990-9585, Japan.
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Sahebekhtiari N, Thomsen MM, Sloth JJ, Stenbroen V, Zeviani M, Gregersen N, Viscomi C, Palmfeldt J. Quantitative proteomics suggests metabolic reprogramming during ETHE1 deficiency. Proteomics 2016; 16:1166-76. [PMID: 26867521 DOI: 10.1002/pmic.201500336] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 01/22/2016] [Accepted: 02/08/2016] [Indexed: 11/11/2022]
Abstract
Deficiency of mitochondrial sulfur dioxygenase (ETHE1) causes the severe metabolic disorder ethylmalonic encephalopathy, which is characterized by early-onset encephalopathy and defective cytochrome C oxidase because of hydrogen sulfide accumulation. Although the severe systemic consequences of the disorder are becoming clear, the molecular effects are not well defined. Therefore, for further elucidating the effects of ETHE1-deficiency, we performed a large scale quantitative proteomics study on liver tissue from ETHE1-deficient mice. Our results demonstrated a clear link between ETHE1-deficiency and redox active proteins, as reflected by downregulation of several proteins related to oxidation-reduction, such as different dehydrogenases and cytochrome P450 (CYP450) members. Furthermore, the protein data indicated impact of the ETHE1-deficiency on metabolic reprogramming through upregulation of glycolytic enzymes and by altering several heterogeneous ribonucleoproteins, indicating novel link between ETHE1 and gene expression regulation. We also found increase in total protein acetylation level, pointing out the link between ETHE1 and acetylation, which is likely controlled by both redox state and cellular metabolites. These findings are relevant for understanding the complexity of the disease and may shed light on important functions influenced by ETHE1 deficiency and by the concomitant increase in the gaseous mediator hydrogen sulfide. All MS data have been deposited in the ProteomeXchange with the dataset identifiers PXD002741 (http://proteomecentral.proteomexchange.org/dataset/PXD002741) and PXD002742 (http://proteomecentral.proteomexchange.org/dataset/PXD002741).
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Affiliation(s)
- Navid Sahebekhtiari
- Research Unit for Molecular Medicine, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, Aarhus, Denmark
| | - Michelle M Thomsen
- Research Unit for Molecular Medicine, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, Aarhus, Denmark
| | - Jens J Sloth
- Research Group for NanoBio Science, National Food Institute, Technical University of Denmark, Søborg, Denmark
| | - Vibeke Stenbroen
- Research Unit for Molecular Medicine, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, Aarhus, Denmark
| | - Massimo Zeviani
- Mitochondrial Biology Unit, Medical Research Council, Wellcome Trust/MRC Building, Cambridge, UK
| | - Niels Gregersen
- Research Unit for Molecular Medicine, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, Aarhus, Denmark
| | - Carlo Viscomi
- Mitochondrial Biology Unit, Medical Research Council, Wellcome Trust/MRC Building, Cambridge, UK.,IRCCS Foundation Neurological Institute "C. Besta,", Milano, Italy
| | - Johan Palmfeldt
- Research Unit for Molecular Medicine, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, Aarhus, Denmark
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15
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Arlt VM, Krais AM, Godschalk RW, Riffo-Vasquez Y, Mrizova I, Roufosse CA, Corbin C, Shi Q, Frei E, Stiborova M, van Schooten FJ, Phillips DH, Spina D. Pulmonary Inflammation Impacts on CYP1A1-Mediated Respiratory Tract DNA Damage Induced by the Carcinogenic Air Pollutant Benzo[a]pyrene. Toxicol Sci 2015; 146:213-25. [PMID: 25911668 PMCID: PMC4517052 DOI: 10.1093/toxsci/kfv086] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Pulmonary inflammation can contribute to the development of lung cancer in humans. We investigated whether pulmonary inflammation alters the genotoxicity of polycyclic aromatic hydrocarbons (PAHs) in the lungs of mice and what mechanisms are involved. To model nonallergic acute inflammation, mice were exposed intranasally to lipopolysaccharide (LPS; 20 µg/mouse) and then instilled intratracheally with benzo[a]pyrene (BaP; 0.5 mg/mouse). BaP-DNA adduct levels, measured by (32)P-postlabeling analysis, were approximately 3-fold higher in the lungs of LPS/BaP-treated mice than in mice treated with BaP alone. Pulmonary Cyp1a1 enzyme activity was decreased in LPS/BaP-treated mice relative to BaP-treated mice suggesting that pulmonary inflammation impacted on BaP-induced Cyp1a1 activity in the lung. Our results showed that Cyp1a1 appears to be important for BaP detoxification in vivo and that the decrease of pulmonary Cyp1a1 activity in LPS/BaP-treated mice results in a decrease of pulmonary BaP detoxification, thereby enhancing BaP genotoxicity (ie, DNA adduct formation) in the lung. Because less BaP was detoxified by Cyp1a1 in the lungs of LPS/BaP-treated mice, more BaP circulated via the blood to extrapulmonary tissues relative to mice treated with BaP only. Indeed, we observed higher BaP-DNA adduct levels in livers of LPS/BaP-treated mice compared with BaP-treated mice. Our results indicate that pulmonary inflammation could be a critical determinant in the induction of genotoxicity in the lung by PAHs like BaP. Cyp1a1 appears to be involved in both BaP bioactivation and detoxification although the contribution of other enzymes to BaP-DNA adduct formation in lung and liver under inflammatory conditions remains to be explored.
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Affiliation(s)
- Volker M Arlt
- *Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment & Health, King's College London, London SE1 9NH, United Kingdom,
| | - Annette M Krais
- *Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment & Health, King's College London, London SE1 9NH, United Kingdom
| | - Roger W Godschalk
- Department of Toxicology, School for Nutrition, Toxicology and Metabolism (NUTRIM), Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
| | - Yanira Riffo-Vasquez
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London SE1 9NH, United Kingdom
| | - Iveta Mrizova
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague 2, Czech Republic
| | - Candice A Roufosse
- Department of Histopathology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London W12 0HS, United Kingdom, and
| | - Charmaine Corbin
- *Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment & Health, King's College London, London SE1 9NH, United Kingdom
| | - Quan Shi
- Department of Toxicology, School for Nutrition, Toxicology and Metabolism (NUTRIM), Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
| | - Eva Frei
- Division of Preventive Oncology, National Center for Tumor Diseases, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Marie Stiborova
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague 2, Czech Republic
| | - Frederik-Jan van Schooten
- Department of Toxicology, School for Nutrition, Toxicology and Metabolism (NUTRIM), Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
| | - David H Phillips
- *Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment & Health, King's College London, London SE1 9NH, United Kingdom
| | - Domenico Spina
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London SE1 9NH, United Kingdom
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16
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Inhibition of cytochrome P450 2E1 and activation of transcription factor Nrf2 are renoprotective in myoglobinuric acute kidney injury. Kidney Int 2014; 86:338-49. [PMID: 24717297 DOI: 10.1038/ki.2014.65] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 01/15/2014] [Accepted: 01/23/2014] [Indexed: 12/30/2022]
Abstract
Rhabdomyolysis accounts for ∼10% of acute kidney injuries. In glycerol-induced myoglobinuric acute kidney injury, we found an increase in the nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear protein, a key redox-sensitive transcription factor, and Nrf2-regulated genes and proteins including upregulation of heme oxygenase-1. In in vitro studies, pretreatment of LLC-PK1 cells with an activator of Nrf2 before myoglobin exposure significantly decreased oxidant generation and cytotoxicity, whereas Nrf2 inhibition and gene silencing exacerbated the injury. Chlormethiazole, a specific CYP2E1 transcription inhibitor, prevented an increase in catalytic iron in the kidneys, decreased oxidative stress, blocked nuclear translocation of the Nrf2 protein, decreased heme oxygenase-1 upregulation, and provided functional and histological protection against acute kidney injury. CYP2E1 inhibitors and gene silencing in renal tubular epithelial cells significantly decreased reactive oxygen species generation and provided marked protection against myoglobin-induced cytotoxicity. Thus, during CYP2E1-induced oxidative stress, the transcription factor Nrf2 has a pivotal role in the early adaptive response. Inhibition of CYP2E1 coupled with the prior induction of Nrf2 may be a valuable tool to reduce CYP2E1-mediated rhabdomyolysis-induced acute kidney injury.
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17
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Lim SJ, Fox P. Estimating the persistence of organic contaminants in indirect potable reuse systems using quantitative structure activity relationship (QSAR). THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 433:1-7. [PMID: 22766422 DOI: 10.1016/j.scitotenv.2012.06.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 05/19/2012] [Accepted: 06/11/2012] [Indexed: 06/01/2023]
Abstract
Predictions from the quantitative structure activity relationship (QSAR) model EPI Suite were modified to estimate the persistence of organic contaminants in indirect potable reuse systems. The modified prediction included the effects of sorption, biodegradation, and oxidation that may occur during sub-surface transport. A retardation factor was used to simulate the mobility of adsorbed compounds during sub-surface transport to a recovery well. A set of compounds with measured persistent properties during sub-surface transport was used to validate the results of the modifications to the predictions of EPI Suite. A comparison of the predicted values and measured values was done and the residual sum of the squares showed the importance of including oxidation and sorption. Sorption was the most important factor to include in predicting the fates of organic chemicals in the sub-surface environment.
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Affiliation(s)
- Seung Joo Lim
- Research Division for Industry & Environment, Korea Atomic Energy Research Institute, 1266 Sinjeong, Jeongeup, 580-185, Republic of Korea.
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18
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Coleman NV, Yau S, Wilson NL, Nolan LM, Migocki MD, Ly MA, Crossett B, Holmes AJ. Untangling the multiple monooxygenases of Mycobacterium chubuense strain NBB4, a versatile hydrocarbon degrader. ENVIRONMENTAL MICROBIOLOGY REPORTS 2011; 3:297-307. [PMID: 23761275 DOI: 10.1111/j.1758-2229.2010.00225.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Mycobacterium strain NBB4 was isolated on ethene as part of a bioprospecting study searching for novel monooxygenase (MO) enzymes of interest to biocatalysis and bioremediation. Previous work indicated that strain NBB4 contained an unprecedented diversity of MO genes, and we hypothesized that each MO type would support growth on a distinct hydrocarbon substrate. Here, we attempted to untangle the relationships between MO types and hydrocarbon substrates. Strain NBB4 was shown to grow on C2 -C4 alkenes and C2 -C16 alkanes. Complete gene clusters encoding six different monooxygenases were recovered from a fosmid library, including homologues of ethene MO (etnABCD), propene MO (pmoABCD), propane MO (smoABCD), butane MO (smoXYB1C1Z), cytochrome P450 (CYP153; fdx-cyp-fdr) and alkB (alkB-rubA1-rubA2). Catabolic enzymes involved in ethene assimilation (EtnA, EtnC, EtnD, EtnE) and alkane assimilation (alcohol and aldehyde dehydrogenases) were identified by proteomics, and we showed for the first time that stress response proteins (catalase/peroxidase, chaperonins) were induced by growth on C2 -C5 alkanes and ethene. Surprisingly, none of the identified MO genes could be specifically associated with oxidation of small alkanes, and thus the nature of the gaseous alkane MO in NBB4 remains mysterious.
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Affiliation(s)
- Nicholas V Coleman
- School of Molecular Bioscience, Building G08, University of Sydney, Sydney, NSW 2006, Australia
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19
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Genotoxic effect of chronic exposure to DDT on lymphocytes, oral mucosa and breast cells of female rats. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2011; 8:540-53. [PMID: 21556202 PMCID: PMC3084477 DOI: 10.3390/ijerph8020540] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Revised: 01/27/2011] [Accepted: 01/28/2011] [Indexed: 11/17/2022]
Abstract
The genotoxicity of some environmental contaminants may affect human health directly by damaging genetic material and thus plays an important role in cancer development. Xenoestrogens are one kind of environmental pollutants that may alter hormonal routes or directly affect DNA. The number of available biomarkers used to assess genetic risk and cancer is very extensive. The present study evaluated genotoxicity produced by the pesticide DDT on systemic and mammary gland cells obtained from adult female Wistar rats. Oral mucosa cells micronuclei were assessed; the comet assay in peripheral blood-isolated lymphocytes and mammary epithelial cells was also carried out. Additionally, oxidative stress was studied in mammary tissue through a lipid peroxidation assay. Our data showed an increase in lipid peroxidation, product of an increase in free oxygen radical levels, which leads to an oxidative stress status. Our results suggest that DDT is genotoxic, not only for lymphocytes but also to mammary epithelial cells.
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20
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Liu H, Tian N, Arany I, Bigler SA, Waxman DJ, Shah SV, Baliga R. Cytochrome P450 2B1 mediates complement-dependent sublytic injury in a model of membranous nephropathy. J Biol Chem 2010; 285:40901-10. [PMID: 20947506 PMCID: PMC3003390 DOI: 10.1074/jbc.m110.165498] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 09/27/2010] [Indexed: 11/06/2022] Open
Abstract
Membranous nephropathy is a disease that affects the filtering units of the kidney, the glomeruli, and results in proteinuria accompanied by loss of kidney function. Passive Heymann nephritis is an experimental model that mimics membranous nephropathy in humans, wherein the glomerular epithelial cell (GEC) injury induced by complement C5b-9 leads to proteinuria. We examined the role of cytochrome P450 2B1 (CYP2B1) in this complement-mediated sublytic injury. Overexpression of CYP2B1 in GECs significantly increased the formation of reactive oxygen species, cytotoxicity, and collapse of the actin cytoskeleton following treatment with anti-tubular brush-border antiserum (anti-Fx1A). In contrast, silencing of CYP2B1 markedly attenuated anti-Fx1A-induced reactive oxygen species generation and cytotoxicity with preservation of the actin cytoskeleton. Gelsolin, which maintains an organized actin cytoskeleton, was significantly decreased by complement C5b-9-mediated injury but was preserved in CYP2B1-silenced cells. In rats injected with anti-Fx1A, the cytochrome P450 inhibitor cimetidine blocked an increase in catalytic iron and ROS generation, reduced the formation of malondialdehyde adducts, maintained a normal distribution of nephrin in the glomeruli, and provided significant protection at the onset of proteinuria. Thus, GEC CYP2B1 contributes to complement C5b-9-mediated injury and plays an important role in the pathogenesis of passive Heymann nephritis.
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Affiliation(s)
- Hua Liu
- From the Departments of Pediatrics and
| | - Niu Tian
- From the Departments of Pediatrics and
| | | | - Steven A. Bigler
- Pathology, University of Mississippi Medical Center, Jackson, Mississippi 39216
| | - David J. Waxman
- the Division of Cell and Molecular Biology, Department of Biology, Boston University, Boston, Massachusetts 02215, and
| | - Sudhir V. Shah
- the Division of Nephrology, Department of Internal Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
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21
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Characterization of cytochrome P450 monooxygenase CYP154H1 from the thermophilic soil bacterium Thermobifida fusca. Appl Microbiol Biotechnol 2010; 89:1475-85. [PMID: 21057946 PMCID: PMC3036808 DOI: 10.1007/s00253-010-2965-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 10/13/2010] [Accepted: 10/14/2010] [Indexed: 10/25/2022]
Abstract
Cytochrome P450 monooxygenases are valuable biocatalysts due to their ability to hydroxylate unactivated carbon atoms using molecular oxygen. We have cloned the gene for a new cytochrome P450 monooxygenase, named CYP154H1, from the moderately thermophilic soil bacterium Thermobifida fusca. The enzyme was overexpressed in Escherichia coli at up to 14% of total soluble protein and purified to homogeneity in three steps. CYP154H1 activity was reconstituted using putidaredoxin reductase and putidaredoxin from Pseudomonas putida DSM 50198 as surrogate electron transfer partners. In biocatalytic reactions with different aliphatic and aromatic substrates of varying size, the enzyme converted small aromatic and arylaliphatic compounds like ethylbenzene, styrene, and indole. Furthermore, CYP154H1 also accepted different arylaliphatic sulfides as substrates chemoselectively forming the corresponding sulfoxides and sulfones. The enzyme is moderately thermostable with an apparent melting temperature of 67°C and exhibited still 90% of initial activity after incubation at 50°C.
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22
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Shahabi HN, Westberg L, Melke J, Håkansson A, Belin AC, Sydow O, Olson L, Holmberg B, Nissbrandt H. Cytochrome P450 2E1 gene polymorphisms/haplotypes and Parkinson's disease in a Swedish population. J Neural Transm (Vienna) 2009; 116:567-73. [PMID: 19381774 DOI: 10.1007/s00702-009-0221-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Accepted: 03/21/2009] [Indexed: 11/26/2022]
Abstract
Cytochrome P450 2E1 (CYP2E1), which inter alia is located in dopamine containing neurons in the substantia nigra, has been hypothesized to be of importance for the pathophysiology of Parkinson's disease (PD), either by its production of reactive oxygen species (ROS) or by its capability to detoxify putative neurotoxins. Numerous polymorphisms in the coding and non-coding regions of the gene for this enzyme have been reported. Different variants may account for inter-individual differences in the activity of the enzyme or production of ROS. In this study, the CYP2E1 gene was examined in a control population (n = 272) and a population with PD (n = 347), using a tag-single nucleotide polymorphism (tSNP) approach founded on HapMap Data. Six tSNPs were used in the analysis and haplotype block data were obtained. In case of significance, the SNP was further examined regarding early/late age of disease onset and presence of relatives with PD. We found an association between allele and genotype frequencies of the C/G polymorphism at intron 7 (rs2070676) of this gene and PD (P value of 0.026 and 0.027, respectively). Furthermore, analysis of the rs2070676 polymorphism in subgroups of patients with age of disease onset higher than 50 years and those not having a relative with PD also demonstrated a significant difference with controls. This was seen in both genotype (corresponding to P value = 0.039 and 0.032) and allele (P = 0.027 and 0.017 respectively) frequency. As a representative of many polymorphisms or in possible linkage disequilibrium with other functional variants, it is possible that rs2070676 could influence the regulation of the enzyme. In conclusion, our results display an association between the rs2070676 polymorphism and PD. Additional investigations are needed to elucidate the importance of this polymorphism for the activity of CYP2E1 and PD susceptibility.
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Affiliation(s)
- H Niazi Shahabi
- Department of Pharmacology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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23
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Viaggi C, Vaglini F, Pardini C, Caramelli A, Corsini GU. MPTP-induced model of Parkinson's disease in cytochrome P450 2E1 knockout mice. Neuropharmacology 2009; 56:1075-81. [PMID: 19298832 DOI: 10.1016/j.neuropharm.2009.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 03/05/2009] [Accepted: 03/10/2009] [Indexed: 11/27/2022]
Abstract
Evidence for involvement of cytochrome P450 2E1 in the MPTP-induced mouse model of PD has been reported [Vaglini, F., Pardini, C., Viaggi, C., Bartoli, C., Dinucci, D., Corsini, G.U., 2004. Involvement of cytochrome P450 2E1 in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced mouse model of Parkinson's disease. J. Neurochem. 91, 285-298]. We studied the sensitivity of Cyp2e1(-/-) mice to the acute administration of MPTP in comparison with their wild-type counterparts. In Cyp2e1(-/-) mice, the reduction of striatal DA content was less pronounced 7 days after MPTP treatment compared to treated wild-type mice. Similarly, TH immunoreactivity analysis of the substantia nigra of Cyp2e1(-/-) mice did not show any neuronal lesions after MPTP treatment. In contrast to this, wild-type animals showed a minimal but significant lesioning by the toxin as evaluated also by means of non-stereologic computerized assisted analysis of this brain area. Striatal levels of DA metabolites after 7 days were variably affected by the toxin, but consistent differences between the two animal strains were not observed. We evaluated short-term changes in the levels of striatal DA and its metabolites, and we monitored striatal MPP(+) levels. Striatal MPP(+) was cleared more rapidly in Cyp2e1(-/-) mice than in wild-type animals and, consistently, striatal DA content decreased faster in Cyp2e1(-/-) mice than in wild-type animals, and 3-methoxytyramine and HVA levels showed an early and sharp rise. Our findings suggest that Cyp2e1(-/-) mice are weakly sensitive to MPTP-induced brain lesions, markedly in contrast with a protective role of the enzyme as suggested previously. The differences observed between the knockout mice and their wild-type counterparts are modest and may be due to an efficient compensatory mechanism or genetic drift in the colonies.
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Affiliation(s)
- C Viaggi
- Department of Neuroscience, Section of Pharmacology, University of Pisa and Center of Excellence AMBISEN for the Study of Environmental Toxins and CNS Diseases, Pisa, Italy.
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Maier KG. Nicotinamide adenine dinucleotide phosphate oxidase and diabetes: vascular implications. Vasc Endovascular Surg 2008; 42:305-13. [PMID: 18621880 DOI: 10.1177/1538574408320172] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Vascular disease associated with diabetes mellitus is a major cause of morbidity and mortality and is increasing in the United States. It is now recognized that oxidative stress plays a substantial role in the underlying vascular pathology of several diseases, including hypertension and diabetes. In diabetes, there is an increase in the steady state levels of reactive oxygen species. One of the primary generators of reactive oxygen species is nicotinamide adenine dinucleotide phosphate oxidase. Studies have indicated that inhibition of this system is associated with vascular benefits in diabetes. Therefore, there may be a role for therapies directed at nicotinamide adenine dinucleotide phosphate oxidase in this disease. This review will examine the structure, activation, potential role in vascular disease, and benefits of inhibition of nicotinamide adenine dinucleotide phosphate oxidase.
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Affiliation(s)
- Kristopher G Maier
- Upstate Medical University College of Medicine, Syracuse, New York 13210, USA.
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Shahabi HN, Andersson D, Nissbrandt H. Cytochrome P450 2E1 in the substantia nigra: Relevance for dopaminergic neurotransmission and free radical production. Synapse 2008; 62:379-88. [DOI: 10.1002/syn.20505] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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26
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Guo J, Liu D, Nikolic D, Zhu D, Pezzuto JM, van Breemen RB. In vitro metabolism of isoliquiritigenin by human liver microsomes. Drug Metab Dispos 2007; 36:461-8. [PMID: 18006650 DOI: 10.1124/dmd.107.018721] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Isoliquiritigenin (2',4',4-trihydroxychalcone), a chalcone found in licorice root and other plants, has shown potent antitumor, antioxidant, and phytoestrogenic activity in vitro. In preparation for in vivo studies, the metabolism of isoliquiritigenin by human liver microsomes was investigated, and seven phase 1 metabolites were identified. In addition to aromatic hydroxylation that occurred on the A or B ring to form 2',4,4',5'-tetrahydroxychalcone or butein, respectively, reduction of the carbon-carbon double bond of an alpha,beta-unsaturated ketone and cyclization occurred to form 2',4,4'-trihydroxydihydrochalcone and (Z/E)-6,4'-dihydroxyaurone. All metabolites were characterized and identified by using liquid chromatography-tandem mass spectrometry with comparison to authenticated compounds. Finally, monoclonal antibody inhibitors of specific human cytochrome P450 (P450) enzymes and recombinant human P450 enzymes were used to identify the enzymes responsible for the formation of the major mono-oxygenated metabolites, and P450 2C19 was found to be a significant enzyme in the formation of butein from isoliquiritigenin, which also has anticancer activity. Cytochromes P450, reactive oxygen species, and peroxidases can all contribute to the formation of (Z/E)-6,4'-dihydroxyaurone in human liver microsomes.
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Affiliation(s)
- Jian Guo
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois College of Pharmacy, 833 S. Wood St., Chicago, IL 60612-7231, USA
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27
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Lentz O, Feenstra A, Habicher T, Hauer B, Schmid RD, Urlacher VB. Altering the regioselectivity of cytochrome P450 CYP102A3 of Bacillus subtilis by using a new versatile assay system. Chembiochem 2006; 7:345-50. [PMID: 16381045 DOI: 10.1002/cbic.200500266] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A novel monooxygenase (CYP102A3) has been discovered within the Bacillus subtilis genome that reveals a similarity of 76 % to the well-known cytochrome P450 BM-3 of B. megaterium (CYP102A1). Both enzymes are natural fusion proteins consisting of a heme domain and a FAD/FMN-reductase domain. Because of their high turnover rates, these biocatalysts are of special interest for industrial applications, but show only limited regioselectivity. In this work, the regioselectivity of CYP102A3 was changed by directed evolution and protein design to hydroxylate substrates not only in different subterminal, but also to a high extent, in terminal carbon chain positions. To enable a high-throughput screening procedure, a very versatile assay was developed that is capable of discriminating between terminal and subterminal hydroxylation of carbon chains. A double mutant of CYP102A3 was obtained that produces 48 % octan-1-ol as the main product of the reaction.
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Affiliation(s)
- Oliver Lentz
- Institute for Technical Biochemistry, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
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Denisov IG, Makris TM, Sligar SG, Schlichting I. Structure and Chemistry of Cytochrome P450. Chem Rev 2005; 105:2253-77. [PMID: 15941214 DOI: 10.1021/cr0307143] [Citation(s) in RCA: 1512] [Impact Index Per Article: 79.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ilia G Denisov
- Department of Biochemistry, Center for Biophysics and Computational Biology, University of Illinois, Urbana-Champaign, 61801, USA
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29
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Letelier ME, Izquierdo P, Godoy L, Lepe AM, Faúndez M. Liver microsomal biotransformation of nitro-aryl drugs: mechanism for potential oxidative stress induction. J Appl Toxicol 2004; 24:519-25. [PMID: 15558828 DOI: 10.1002/jat.999] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Toxic effects of several nitro-aryl drugs are attributed to the nitro-reduction that may be suffered in vivo, a reaction that may be catalysed by different reductases. One of these enzymes is NADPH-cytochrome P450 reductase, which belongs to the cytochrome P450 oxidative system mainly localized in the endoplasmic reticulum of the hepatic cell. This system is responsible for the biotransformation of oxidative lipophilic compounds, so that oxidative and reductive metabolic pathways of lipophilic nitro-aryl drugs can take place simultaneously. Because of the affinity of nitro-aryl drugs (xenobiotics) for the endoplasmic reticulum, we propose this subcellular organelle as a good biological system for investigating the toxicity induced by the biotransformation of these or another compounds. In this work we used rat liver microsomes to assess the oxidative stress induced by nitro-aryl drug biotransformation. Incubation of microsomes of rat liver with nifurtimox and nitrofurantoin in the presence of NADPH induced lipoperoxidation, UDP-glucuronyltransferase activation and an increase in the basal microsomal oxygen consumption. Nitro-aryl-1,4-dihydropyridines did not elicit these prooxidant effects; furthermore, they inhibited lipoperoxidation and oxygen consumption induced by Fe3+/ascorbate. Nifurtimox and nitrofurantoin modified the maximum absorption of cytochrome P450 oxidase and inhibited p-nitroanisole O-demethylation, an oxidative reaction catalysed by the cytochrome P450 system, signifying that oxidation may proceed in a similar way to that described for nitro-aryl-1,4-dihydropyridines. Thus the balance between lipophilic nitro-aryl drug oxidation and reduction may be involved in the potential oxidative stress induced by biotransformation.
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Affiliation(s)
- M E Letelier
- Laboratorio de Farmacología, Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Olivos 1007, Independencia, Santiago, Chile.
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30
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Liu H, Baliga M, Bigler SA, Baliga R. Role of cytochrome P450 2B1 in puromycin aminonucleoside-induced cytotoxicity to glomerular epithelial cells. NEPHRON. EXPERIMENTAL NEPHROLOGY 2003; 94:e17-24. [PMID: 12806184 DOI: 10.1159/000070815] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2002] [Accepted: 12/03/2002] [Indexed: 11/19/2022]
Abstract
Puromycin aminonucleoside (PAN)-induced glomerular injury in rats mimics minimal-change nephrotic syndrome (NS) in humans. We have demonstrated an important role of cytochrome P450 (CYP) as a significant source of catalytic iron in this model of NS. The current study was designed to identify CYP isozyme(s) present in the rat glomerular epithelial cells (GEC) and to explore the role of the specific CYP isozyme in PAN-induced cytotoxicity. CYP2B1 was identified in GEC by immunocytochemistry and Western blot. Treatment of GEC with PAN resulted in a marked generation of hydrogen peroxide (H(2)O(2)) and reduction of CYP2B1 content associated with significant increase in catalytic iron and hydroxyl radical formation. Preincubating GEC with CYP2B1 inhibitors (piperine and cimetidine) and H(2)O(2) scavenger (pyruvate) significantly reduced H(2)O(2 )generation, preserved CYP2B1 content, prevented the increase in catalytic iron and hydroxyl radical formation including PAN-induced cytotoxicity. We also observed the induction of heme oxygenase (HO-1) in PAN-treated GEC, and this up-regulation was reduced by pretreatment of the CYP inhibitors and pyruvate. Our data thus indicate an important role of CYP2B1 in PAN-induced cytotoxicity by serving as a site of reactive oxygen metabolite generation and a significant source of catalytic iron.
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Affiliation(s)
- Hua Liu
- Department of Pediatrics, University of Mississippi Medical Center, Jackson 39216-4505, USA
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31
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Fradette C, Bleau AM, Pichette V, Chauret N, du Souich P. Hypoxia-induced down-regulation of CYP1A1/1A2 and up-regulation of CYP3A6 involves serum mediators. Br J Pharmacol 2002; 137:881-91. [PMID: 12411420 PMCID: PMC1573556 DOI: 10.1038/sj.bjp.0704933] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. Acute moderate hypoxia modifies the catalytic activity and expression of certain isoenzymes of hepatic cytochrome P450 (P450). The aim of this study was to document whether hypoxia affects hepatic P450 directly or through the release of serum mediators. 2. Rabbits were subjected to a FiO(2) of 8% for 48 h, sacrificed, and serum and hepatocytes were isolated; hepatocytes from control and rabbits with hypoxia were incubated with serum from control and hypoxic rabbits for 4 and 24 h, and total P450 content, CYP1A1, 1A2 and 3A6 activities and expressions were assessed. Sera were fractionated by size exclusion chromatography and fractions tested for their ability to modify activity and amount of P450, and serum mediators were identified through neutralization experiments. 3. Total serum and fractions with proteins of 15-23 and 65-94 kDa of M(r) reduced P450 content and expression of CYP1A1, 1A2 and 3A6, as well as CYP1A1, 1A2 and 3A6 mRNA. Total serum and the fraction with 32-44 kDa proteins increased CYP3A6 activity and protein and mRNA. The serum mediators implicated in the decrease in activity and expression of CYP1A1, 1A2 and 3A6 were interferon-gamma (IFN-gamma), interleukin-1beta (IL-1beta) and IL-2. Erythropoietin (Epo) was partly responsible for the increase in P450 content and CYP3A6 expression. 4. In conclusion, acute moderate hypoxia diminishes the activity and expression of CYP1A1, 1A2 and CYP1A1, 1A2 mRNA, and increases CYP3A6 protein, activity and CYP3A6 mRNA. Several mechanisms contribute to these changes in P450, among them the release of cytokines acting as serum mediators.
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Affiliation(s)
- Caroline Fradette
- Department of Pharmacology, Faculty of Medicine, University of Montréal, Montréal, Québec, Canada, H3C 3J7
| | - Anne-Marie Bleau
- Department of Pharmacology, Faculty of Medicine, University of Montréal, Montréal, Québec, Canada, H3C 3J7
| | - Vincent Pichette
- Department of Pharmacology, Faculty of Medicine, University of Montréal, Montréal, Québec, Canada, H3C 3J7
| | - Nathalie Chauret
- Merck Frosst Centre for Therapeutic Research, P.O. Box 1005, Pointe Claire-Dorval, Québec, Canada H9R 4P8
| | - Patrick du Souich
- Department of Pharmacology, Faculty of Medicine, University of Montréal, Montréal, Québec, Canada, H3C 3J7
- Author for correspondence:
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Liu H, Bigler SA, Henegar JR, Baliga R. Cytochrome P450 2B1 mediates oxidant injury in puromycin-induced nephrotic syndrome. Kidney Int 2002; 62:868-76. [PMID: 12164868 DOI: 10.1046/j.1523-1755.2002.00515.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Reactive oxygen metabolites (ROM) are important mediators of puromycin aminonucleoside (PAN) induced minimal change nephrotic syndrome (NS) in rats. We have recently shown that cytochrome P450 (CYP) is a significant source of catalytic iron in this model of glomerular injury. The current study was designed to identify the CYP isozyme(s) in the rat glomeruli and explore the role of the specific isozyme(s) in PAN-induced minimal change NS. METHODS NS was induced in rats by a single intravenous injection of PAN. Animals were sacrificed at different time points for variety of biochemical assays including Western blot, immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Ultrastructural histochemistry was utilized to study hydrogen peroxide (H2O2) generation in the kidney. RESULTS Several CYP isozymes were tested and CYP2B1 was localized exclusively in the rat glomeruli but not in the tubules. Treatment with PAN resulted in the generation of H2O2 in the glomerular basement membrane with significant loss of CYP2B1 content accompanied by a marked increase in the catalytic iron. CYP2B1 inhibitors cimetidine and piperine significantly reduced H2O2 generation, and prevented the loss of CYP2B1 content and the increase in the catalytic iron. CYP2B1 inhibitors also provided significant protection against PAN induced proteinuria. The induction of heme oxygenase and ferritin also was observed in the glomeruli in PAN-treated rats. Both cimetidine and piperine reduced the up-regulation of these proteins. CONCLUSION Our data indicate that CYP2B1 plays an important role in PAN induced NS by serving as a site for ROM generation and a significant source of catalytic iron.
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Affiliation(s)
- Hua Liu
- Department of Pediatrics, Division of Nephrology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216-4505, USA
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33
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Moshkovskii SA, Kolesanova EF, Archakov AI. Continuous B-epitope maps of cytochrome P450cam (CYP101) obtained by peptide scanning: correlation to spatial structure. Arch Biochem Biophys 2002; 398:269-74. [PMID: 11831859 DOI: 10.1006/abbi.2001.2714] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Protein continuous B-epitopes can be revealed using short synthetic peptides that overlap a known protein sequence. Since the whole protein surface is considered to possess antigenic properties, a question that arises is whether a set of linear B-epitopes determined by peptide scanning correlates with a protein spatial structure. We have chosen cytochrome P450cam (CYP101) of Pseudomonas putida, with known 3D structure, as a template. Sera of two rabbits and antibody egg yolk preparations from three chickens were produced against the P450cam molecule. These polyclonals were analyzed separately in ELISA with 409 overlapping P450cam hexapeptides. The whole set of continuous antigenic sites of P450cam covered about 45% of the P450cam sequence. However, immunodominant sites (those revealed with more than 50% antibody preparations), the so-called "antigenic core," represent only 9% of the protein sequence. While the amount of water-accessible residues in the total antigenic map (42%) was close to that in the whole native P450cam molecule (39%), the amount of water-accessible residues in the antigenic core was significantly higher (64%). These results led to the conclusion that antigenic core epitopes can be associated to the molecular surface, whereas epitopes with low detection frequency may partly correspond to unfolded regions of the protein molecule.
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Chen C, Thakker DR. The fallacy of using adrenochrome reaction for measurement of reactive oxygen species formed during cytochrome p450-mediated metabolism of xenobiotics. J Pharmacol Exp Ther 2002; 300:417-20. [PMID: 11805199 DOI: 10.1124/jpet.300.2.417] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The adrenochrome reaction (oxidation of epinephrine to adrenochrome) has been widely employed as a standard assay for reactive oxygen species, produced under a variety of conditions, including those produced during cytochrome P450 (CYP)-mediated oxidation of substrates such as cyclosporine. However, it has been reported that epinephrine and adrenochrome can be metabolized by hepatic microsomes and that adrenochrome can also be metabolized by NADPH-CYP reductase. Thus, in the present report, we provide evidence that measurement of adrenochrome cannot be used as an index of reactive oxygen species generated during CYP-mediated metabolism of xenobiotics because adrenochrome and its precursor, epinephrine, interact with the CYP enzyme system as substrates and inhibitors. Our results indicated that adrenochrome was moderately stable in phosphate buffer but degraded rapidly (over 50% consumed in less than 2 min) by (cloned and expressed) CYP3A4 and CYP reductase in the presence of NADPH. Furthermore, both epinephrine and adrenochrome were found to be inhibitors of CYP3A4-mediated oxidation of testosterone. Together, these results lead to the conclusion that the use of adrenochrome reaction for measurement of reactive oxygen species formed during CYP3A4-mediated metabolism of xenobiotics is inappropriate.
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Affiliation(s)
- Cuiping Chen
- Division of Drug Delivery and Disposition, School of Pharmacy, The University of North Carolina at Chapel Hill, 27599-7360, USA
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Archakov AI, Karuzina II, Petushkova NA, Lisitsa AV, Zgoda VG. Production of carbon monoxide by cytochrome P450 during iron-dependent lipid peroxidation. Toxicol In Vitro 2002; 16:1-10. [PMID: 11812634 DOI: 10.1016/s0887-2333(01)00094-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Carbon monoxide (CO) formation was studied in the process of lipid peroxidation in phenobarbital-induced rabbit liver microsomes. The reaction was NADPH-dependent and required Fe(2+), which occurs in microsomes as being protein bound and is not a consequence of heme destruction. Zn-protoporphyrin IX, an inhibitor of the heme oxygenase activity, proved to have no effect on CO production, suggesting that heme oxygenase is not involved into the CO generation reaction. At the same time, the addition of cytochrome P450 typical inhibitors SKF 525A and metyrapone to the reaction mixture had an inhibitory effect on the CO formation rate. Antioxidants such as alpha-tocopherol and desferal inhibited lipid peroxidation in phenobarbital-induced rabbit liver microsomes, and in this case the CO production was not registered. Thus, on the basis of the results presented here it is possible to assert that the process of NADPH, Fe(2+)-dependent carbon monoxide formation in microsomes is a result of lipid peroxidation with cytochrome P450 2B4 participation.
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Affiliation(s)
- A I Archakov
- Institute of Biomedical Chemistry RAMS, 119832, Pogodinskaya Street, 10, Moscow, Russia
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Serron SC, Dwivedi N, Backes WL. Ethylbenzene induces microsomal oxygen free radical generation: antibody-directed characterization of the responsible cytochrome P450 enzymes. Toxicol Appl Pharmacol 2000; 164:305-11. [PMID: 10799341 DOI: 10.1006/taap.2000.8910] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Small aromatic hydrocarbons cause changes in oxidative metabolism by modulating the levels of cytochrome P450 enzymes, with the changes in these enzymes being responsible for qualitative changes in aromatic hydrocarbon metabolism. The goal of this study was to determine if exposure to the small alkylbenzene ethylbenzene (EB) leads to an increase in hepatic free radical production. Male F344 rats were treated with ip injections of EB (10 mmol/kg) and compared to corn oil controls. Hepatic free radical production was examined by measuring the conversion of 2',7'-dichlorofluorescin diacetate (DCFH-DA) to its fluorescent product 2',7'-dichlorofluorescein (DCF). A significant elevation of fluorescent DCF production was observed after treatment with EB, despite the lack of effect on overall cytochrome P450 levels. This process was shown to be inhibitable by metyrapone, an inhibitor of P450. DCF production was also inhibited by catalase, suggesting that hydrogen peroxide (H(2)O(2)) is one of the reactive oxygen intermediates involved in EB-mediated reactive oxygen species (ROS) formation. Interestingly, superoxide dismutase (SOD) did not inhibit DCF production in corn oil-treated rats but was an effective inhibitor in the EB-treated groups. In an effort to determine if the increase in ROS production was related to changes in specific P450 enzymes, DCF production was measured in the presence of anti-CYP2B, anti-CYP2C11, anti-CYP2E1, and anti-CYP3A2 inhibitory antibodies. Anti-CYP2B antibodies inhibited DCF production in EB-treated, but not corn oil groups, which is consistent with the low constitutive levels of this enzyme and its induction by EB. The data also demonstrate that CYP2B contributes to ROS production. Anti-CYP2C11 did not influence DCF production in either group. ROS formation in corn oil-treated rats as well as in ethylbenzene-treated rats was also inhibited with antibodies to anti-CYP2E1 and anti-CYP3A2. These results suggest that CYP2C11 does not appear to influence free radical production and that the increase in free radical production in EB treated rats is consistent with the EB-mediated elevation of CYP2B, CYP 2E1, and CYP3A2. Such alterations in free radical generation in response to hydrocarbon treatment may contribute to the toxicity of these compounds.
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Affiliation(s)
- S C Serron
- Department of Pharmacology and Experimental Therapeutics, The Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, Louisiana, 70112, USA
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Galal A, du Souich P. 21-aminosteroids prevent the down-regulation of hepatic cytochrome P450 induced by hypoxia and inflammation in conscious rabbits. Br J Pharmacol 1999; 128:374-9. [PMID: 10510447 PMCID: PMC1571640 DOI: 10.1038/sj.bjp.0702796] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1 This study was conducted to assess whether a 21-aminosteroid, U74389G, could prevent the down-regulation of hepatic cytochrome P450 (P450) induced by acute moderate hypoxia or an inflammatory reaction. 2 The rabbits of two groups (n = 6 per group) were subjected to acute moderate hypoxia (PaO2 approximately 35 mmHg), one pre-treated with U74389G (3 mg kg-1 i.v. every 6 h, for 48 h). The rabbits of two other groups received 5 ml of turpentine s.c., one of them being pre-treated with U74389G (3 mg kg-1 i.v. every 6 h, for 72 h). The kinetics of theophylline (2.5 mg kg-1) were assessed to evaluate the activity of the P450. Once the rabbits were sacrificed, the P450 content and the amount of thiobarbituric acid reactive substances (TBARS), a marker of lipid peroxidation, were estimated in the liver. 3 Compared with control rabbits, hypoxia and inflammation increased theophylline plasma concentrations, as a result of a decrease in theophylline systemic clearance (P<0.05). Both experimental conditions reduced hepatic content of P450 by 40-50% (P<0.05) and increased the amount of hepatic TBARS by around 50% (P<0.05). Pre-treatment with U74389G prevented the hypoxia- and inflammation-induced decrease in theophylline systemic clearance, the down-regulation of hepatic P450, and the increase in liver TBARS. 4 It is concluded that in the rabbit, U74389G prevents hepatic P450 depression produced by acute moderate hypoxia and a turpentine-induced inflammatory reaction, possibly by eliciting a radical quenching antioxidant activity.
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Affiliation(s)
- Ahmed Galal
- Department of Pharmacology, Faculty of Medicine, University of Montréal, Montréal, Québec, Canada
| | - Patrick du Souich
- Department of Pharmacology, Faculty of Medicine, University of Montréal, Montréal, Québec, Canada
- Author for correspondence:
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Kurdi J, Maurice H, El-Kadi AOS, Ong H, Dalkara S, Bélanger PM, du Souich P. Effect of hypoxia alone or combined with inflammation and 3-methylcholanthrene on hepatic cytochrome P450 in conscious rabbits. Br J Pharmacol 1999; 128:365-73. [PMID: 10510446 PMCID: PMC1571639 DOI: 10.1038/sj.bjp.0702795] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/1999] [Revised: 06/16/1999] [Accepted: 06/22/1999] [Indexed: 11/08/2022] Open
Abstract
1 To investigate the effect of moderate hypoxia alone or combined with an inflammatory reaction or after 3-methylcholanthrene (3MC) pre-treatment on cytochrome P450 (P450), conscious rabbits were exposed for 24 h to a fractional concentration of inspired O2 of 10% (mean PaO2 of 34 mmHg). Hypoxia decreased theophylline metabolic clearance (ClM) from 1.73+/-0.43 to 1.48+/-0.13 ml min-1 kg-1 (P<0. 05), and reduced (P<0.05) the formation clearance of theophylline metabolites, 3-methylxanthine (3MX), 1-methyluric acid (1MU) and 1,3-dimethyluric acid (1,3DMU). Hypoxia reduced the amount of CYP1A1 and 1A2 but increased CYP3A6 proteins. 2 Turpentine-induced inflammatory reaction reduced (P<0.05) the formation clearance of 3MX, 1MU, and 1,3DMU, and diminished the amount of CYP1A1, 1A2 and 3A6 proteins. However, when combined with hypoxia, inflammation partially prevented the decrease in ClM, especially by impeding the reduction of 1,3DMU. The amount of CYP1A1 and 1A2 remained reduced but the amount of CYP3A6 protein returned to normal values. 3 Pre-treatment with 3MC augmented the ClM by 114% (P<0.05) due to the increase in the formation clearance of 3MX, 1MU and 1,3DMU. 3MC treatment increased the amount of CYP1A1 and 1A2 proteins. Pre-treatment with 3MC prevented the hypoxia-induced decrease in amount and activity of the P450. 4 It is concluded that acute moderate hypoxia and an inflammatory reaction individually reduce the amount and activity of selected apoproteins of the P450. However, the combination of hypoxia and the inflammatory reaction restores P450 activity to near normal values. On the other hand, pre-treatment with 3MC prevents the hypoxia-induced depression of the P450.
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Affiliation(s)
- J Kurdi
- Department of Pharmacology, Faculty of Medicine, C.P. 6128, Succ. ‘Centre-ville', Montréal, Québec, Canada H3C 3J7
| | - H Maurice
- Department of Pharmacology, Faculty of Medicine, C.P. 6128, Succ. ‘Centre-ville', Montréal, Québec, Canada H3C 3J7
| | - A O S El-Kadi
- Department of Pharmacology, Faculty of Medicine, C.P. 6128, Succ. ‘Centre-ville', Montréal, Québec, Canada H3C 3J7
| | - H Ong
- Faculty of Pharmacy, University of Montréal, C.P. 6128, Succ. ‘Centre-ville', Montréal, Québec, Canada H3C 3J7
| | - S Dalkara
- Faculty of Pharmacy, University of Laval, Québec, Canada
| | - P M Bélanger
- Faculty of Pharmacy, University of Laval, Québec, Canada
| | - P du Souich
- Department of Pharmacology, Faculty of Medicine, C.P. 6128, Succ. ‘Centre-ville', Montréal, Québec, Canada H3C 3J7
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Venditti P, Masullo P, Meo SD. Effect of exercise duration on characteristics of mitochondrial population from rat liver. Arch Biochem Biophys 1999; 368:112-20. [PMID: 10415118 DOI: 10.1006/abbi.1999.1269] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Young male rats were sacrificed either at rest or immediately after a single bout of swimming lasting either 5 or 8 h. Mitochondrial population, obtained by centrifugation (10,000g for 10 min) from liver homogenates freed from debris and nuclei, was resolved by differential centrifugation into three fractions. Homogenates and mitochondrial preparations were examined for their protein content, oxidative capacity (by cytochrome oxidase activity), peroxidative processes (by thiobarbituric acid reactive substance and hydroperoxide levels), antioxidant status (by reduced glutathione and vitamin E levels and whole antioxidant capacity), and susceptibility to in vitro oxidative stress. In all groups, the antioxidant level was smaller and oxidative capacity, lipid peroxidation, and susceptibility to oxidants were greater in the heavy mitochondrial fraction. Exercise of shorter duration did not significantly affect most of the parameters; only the resulting homogenate glutathione level and susceptibility to oxidative stress decreased and increased, respectively, compared with control values. In contrast, more prolonged exercise was associated with increased lipid peroxidation and susceptibility to oxidative stress and decreased antioxidant levels in all preparations. The contribution of each fraction to the whole mitochondrial population was also modified in that the heavy fraction decreased and light fractions increased. These results suggest that liver antioxidant defence systems are able to withstand oxidative challenge due to low-intensity exercise of moderate duration. In contrast, the free radical production associated with long-lasting exercise causes oxidative injury in cellular components and in particular induces protein degradation in the heavy mitochondrial fraction characterized by higher susceptibility to oxidative stress.
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Affiliation(s)
- P Venditti
- Dipartimento di Fisiologia Generale ed Ambientale, Università di Napoli, V. Mezzocannone 8, Napoli, I 80134, Italy
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Premalatha B, Sachdanandam P. Semecarpus anacardium L. nut extract administration induces the in vivo antioxidant defence system in aflatoxin B1 mediated hepatocellular carcinoma. JOURNAL OF ETHNOPHARMACOLOGY 1999; 66:131-139. [PMID: 10433469 DOI: 10.1016/s0378-8741(99)00029-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The antioxidant defence system which plays a critical role in carcinogenesis is severely altered in aflatoxin B1 induced hepatocellular carcinoma conditions. In order to assess the antitumour activity of Semecarpus anacardium nut extract, a flavonoid containing drug, non-enzymic antioxidant levels were analysed in control and experimental animals. Plasma was analysed for uric acid, vitamin E and vitamin C. Glutathione, total thiols, non-protein thiols, vitamin E, vitamin C and cytochrome P450 were estimated in liver and kidney homogenates. Depletion of all these antioxidants were recorded in cancer conditions. These deleterious effects are controlled by the administration of Semecarpus anacardium nut extract. Following drug administration, there was a marked increase in antioxidant levels and a dramatic elevation in cytochrome P450 content. It can be concluded that the observed anticancer property of Semecarpus anacardium nut extract may also be explained by its strong antioxidant capacity and capability to induce the in vivo antioxidant system.
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Affiliation(s)
- B Premalatha
- Department of Medical Biochemistry, Dr. A.L.M.P-G I.B.M.S., University of Madras, Chennai, India.
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42
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Buko VU, Artsukevich AA, Ignatenko KV. Aldehydic products of lipid peroxidation inactivate cytochrome P-450. EXPERIMENTAL AND TOXICOLOGIC PATHOLOGY : OFFICIAL JOURNAL OF THE GESELLSCHAFT FUR TOXIKOLOGISCHE PATHOLOGIE 1999; 51:294-8. [PMID: 10445385 DOI: 10.1016/s0940-2993(99)80009-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The effects of aldehydic products of lipid peroxidation, malondialdehyde (MDA) and 4-hydroxynonenal (HNE), on the structure of rat liver microsomal membrane and cytochrome P-450 was studied. MDA (15-30 microM) similarly to p-chlormercuribenzoate decreased the cytochrome P-450 content by 50 % and lowered microviscosity of lipid surrounding of the spin label OTMB bound to SH-groups of membrane proteins. OTMB was effectively reduced by K3Fe(CN)6 in microsomes preincubated with MDA (20 (M), but not in native microsomes. HNE (10 microM) decreased the cytochrome P-450 content by 90 %. Reduced glutathione and cysteine (5 mM) prevented the decrease of cytochrome P-450 under influence of both MDA or HNE, whereas cytochrome P-420 formation remains unchanged. MDA and HNE decreased activities of NADPH oxidase and NADPH cytochrome c reductase. HNE increased microviscosity of the OTMB lipid environment. The further increase of HNE concentration did not affect this parameter. Both MDA and HNE increased the absorbance at 420 nm, which indicated inactivation of cytochrome P-450 by changes in hydrophobicity of lipid surrounding. We suggest that HNE and aliphatic aldehydes at low concentrations can enter into hydrophobic environment of cytochrome P-450 binding to its SH-groups, which led to inactivation of cytochrome P-450. At the same time, the modification of membrane surface layer and subsequent decrease of hydrophobicity of cytochrome P-450 environment preceded the binding of MDA to SH-groups of cytochrome P-450 to develop its inactivating effect.
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Affiliation(s)
- V U Buko
- Institute of Biochemistry, National Academy of Sciences, Grodno, Belarus.
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Lee K. Benzene-induced uncoupling of naphthalene dioxygenase activity and enzyme inactivation by production of hydrogen peroxide. J Bacteriol 1999; 181:2719-25. [PMID: 10217759 PMCID: PMC93710 DOI: 10.1128/jb.181.9.2719-2725.1999] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Naphthalene dioxygenase (NDO) is a multicomponent enzyme system that oxidizes naphthalene to (+)-cis-(1R,2S)-1,2-dihydroxy-1, 2-dihydronaphthalene with consumption of O2 and two electrons from NAD(P)H. In the presence of benzene, NADH oxidation and O2 utilization were partially uncoupled from substrate oxidation. Approximately 40 to 50% of the consumed O2 was detected as hydrogen peroxide. The rate of benzene-dependent O2 consumption decreased with time, but it was partially increased by the addition of catalase in the course of the O2 consumption by NDO. Detailed experiments showed that the total amount of O2 consumed and the rate of benzene-induced O2 consumption increased in the presence of hydrogen peroxide-scavenging agents, and further addition of the terminal oxygenase component (ISPNAP) of NDO. Kinetic studies showed that ISPNAP was irreversibly inactivated in the reaction that contained benzene, but the inactivation was relieved to a high degree in the presence of catalase and partially relieved in the presence of 0.1 mM ferrous ion. Benzene- and naphthalene-reacted ISPNAP gave almost identical visible absorption spectra. In addition, hydrogen peroxide added at a range of 0.1 to 0.6 mM to the reaction mixtures inactivated the reduced ISPNAP containing mononuclear iron. These results show that hydrogen peroxide released during the uncoupling reaction acts both as an inhibitor of benzene-dependent O2 consumption and as an inactivator of ISPNAP. It is proposed that the irreversible inactivation of ISPNAP occurs by a Fenton-type reaction which forms a strong oxidizing agent, hydroxyl radicals (. OH), from the reaction of hydrogen peroxide with ferrous mononuclear iron at the active site. Furthermore, when [14C]benzene was used as the substrate, cis-benzene 1,2-dihydrodiol formed by NDO was detected. This result shows that NDO also couples a trace amount of benzene to both O2 consumption and NADH oxidation.
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Affiliation(s)
- K Lee
- Department of Microbiology and Center for Biocatalysis and Bioprocessing, University of Iowa, Iowa City, Iowa 52242, USA.
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Karuzina II, Zgoda VG, Kuznetsova GP, Samenkova NF, Archakov AI. Heme and apoprotein modification of cytochrome P450 2B4 during its oxidative inactivation in monooxygenase reconstituted system. Free Radic Biol Med 1999; 26:620-32. [PMID: 10218650 DOI: 10.1016/s0891-5849(98)00252-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The mechanism of the cytochrome P450 2B4 modification by hydrogen peroxide (H2O2) formed as a result of partial coupling of NADPH-dependent monooxygenase reactions has been studied in the monooxygenase system reconstituted from the highly purified microsomal proteins: cytochrome P450 2B4 (P450) and NADPH-cytochrome P450 reductase in the presence of detergent Emulgen 913. It was found, that H2O2-mediated P450 self-inactivation during benzphetamine oxidation is accompanied by heme degradation and apoenzyme modification. The P450 heme modification involves the heme release from the enzyme under the action of H2O2 formed within P450s active center via the peroxycomplex decay. Additionally, the heme lost is destroyed by H2O2 localized outside of enzyme's active center. The modification of P450 apoenzyme includes protein aggregation that may be due to the change in the physico-chemical properties of the inactivated enzyme. The modified P450 changes the surface charge that is confirmed by the increasing retention time on the DEAE column. Oxidation of amino acid residues (at least cysteine) may lead to the alteration into the protein hydrophobicity. The appearance of the additional ionic and hydrophobic attractions may lead to the increase of the protein aggregation. Hydrogen peroxide can initiate formation of crosslinked P450 dimers, trimers, and even polymers, but the main role in this process plays nonspecific radical reactions. Evidence for the involvement of hydroxyl radical into the P450 crosslinking is carbonyl groups formation.
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Affiliation(s)
- I I Karuzina
- Institute of Biomedical Chemistry, Russian Academy of Medical Sciences, Moscow
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45
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Pietersma A, de Jong N, de Wit LE, Kraak-Slee RG, Koster JF, Sluiter W. Evidence against the involvement of multiple radical generating sites in the expression of the vascular cell adhesion molecule-1. Free Radic Res 1998; 28:137-50. [PMID: 9645391 DOI: 10.3109/10715769809065800] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The present study was undertaken to investigate the hypothesis that multiple oxygen radical generating systems contribute to the tumor necrosis factor (TNF) alpha-stimulated transcriptional activation of the vascular cell adhesion molecule (VCAM)-1 in endothelial cells. Experimental evidence has implicated the cytochrome P450 monooxygenase and a phagocyte type NADPH-oxidase as a source of oxygen radicals in these cells. We show here that endothelial cells exhibit cytochrome P450 activity by measuring the O-dealkylation of the exogenous substrate 7-ethoxyresorufin, but components of the phagocyte-type NADPH oxidase could not be demonstrated in endothelial cells. In that latter respect it was surprising that the NADPH oxidase inhibitor apocynin completely prevented the accumulation of VCAM-1 mRNA. However, we found that apocynin also acts as an inhibitor of cytochrome P450 activity in endothelial cells. Therefore the inhibitory effect of apocynin on the induction of VCAM-1 may no longer be used to demonstrate a role for the NADPH oxidase in this process. Furthermore, different cytochrome P450 inhibitors Co2+, metyrapone, SKF525a decreased the endothelial VCAM-1 expression stimulated by TNFalpha. Also under hypoxic conditions the expression of VCAM-1 was reduced. On this basis we assume that the oxygen dependent step in the intracellular signalling cascade underlying the TNFalpha stimulated transcriptional activation of VCAM-1 resides in the activity of a cytochrome P450 dependent monooxygenase. The finding that the phospholipase A2 inhibitor bromophenacylbromide inhibited the expression of VCAM-1 may indicate that arachidonic acid serves as a substrate for the cytochrome P450 monooxygenase reaction, but further research is needed to elucidate the particular cytochrome P450 family member mediating the expression of VCAM-1.
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Affiliation(s)
- A Pietersma
- Department of Biochemistry, Cardiovascular Research Institute (COEUR), Erasmus University Rotterdam, The Netherlands
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46
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Morel I, Hamon-Bouer C, Abalea V, Cillard P, Cillard J. Comparison of oxidative damage of DNA and lipids in normal and tumor rat hepatocyte cultures treated with ferric nitrilotriacetate. Cancer Lett 1997; 119:31-6. [DOI: 10.1016/s0304-3835(97)00247-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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47
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Peuchen S, Bolaños JP, Heales SJ, Almeida A, Duchen MR, Clark JB. Interrelationships between astrocyte function, oxidative stress and antioxidant status within the central nervous system. Prog Neurobiol 1997; 52:261-81. [PMID: 9247965 DOI: 10.1016/s0301-0082(97)00010-5] [Citation(s) in RCA: 133] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Astrocytes have, until recently, been thought of as the passive supporting elements of the central nervous system. However, recent developments suggest that these cells actually play a crucial and vital role in the overall physiology of the brain. Astrocytes selectively express a host of cell membrane and nuclear receptors that are responsive to various neuroactive compounds. In addition, the cell membrane has a number of important transporters for these compounds. Direct evidence for the selective co-expression of neurotransmitters, transporters on both neurons and astrocytes, provides additional evidence for metabolic compartmentation within the central nervous system. Oxidative stress as defined by the excessive production of free radicals can alter dramatically the function of the cell. The free radical nitric oxide has attracted a considerable amount of attention recently, due to its role as a physiological second messenger but also because of its neurotoxic potential when produced in excess. We provide, therefore, an in-depth discussion on how this free radical and its metabolites affect the intra and intercellular physiology of the astrocyte(s) and surrounding neurons. Finally, we look at the ways in which astrocytes can counteract the production of free radicals in general by using their antioxidant pathways. The glutathione antioxidant system will be the focus of attention, since astrocytes have an enormous capacity for, and efficiency built into this particular system.
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Affiliation(s)
- S Peuchen
- Department of Neurochemistry, Institute of Neurology, London, U.K.
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48
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White RD, Shea D, Solow AR, Stegeman JJ. Induction and post-transcriptional suppression of hepatic cytochrome P450 1A1 by 3,3',4,4'-tetrachlorobiphenyl. Biochem Pharmacol 1997; 53:1029-40. [PMID: 9174117 DOI: 10.1016/s0006-2952(96)00902-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
3,3',4,4'-Tetrachlorobiphenyl (TCB) can induce and inhibit cytochrome P450 1A1 (CYP1A1) in vertebrates. TCB may also suppress CYP1A1 protein levels, but the mechanism is unknown. This study examined transcriptional and translational aspects of hepatic CYP1A1 regulation in the fish scup (Stenotomus chrysops) given single intraperitoneal injections of low (0.1 mg/kg) or high (5 mg/kg) doses of TCB, and sampled over 16 days. The low dose strongly induced hepatic CYP1A1 mRNA (25-fold), protein (12-fold), and activity [ethoxyresorufin O-deethylase (EROD)] (15-fold). The high dose also strongly induced CYP1A1 mRNA (29-fold), in a pattern like that at the low dose, but microsomal CYP1A1 protein content was induced only 4-fold and EROD rates were near control levels. Both TCB doses caused similar increases in microsomal cytochrome b5 content, and in rates of NADPH-cytochrome c (P450) reductase and UDP-glucuronosyltransferase (with p-nitrophenol). The contents of CYP forms other than CYP1A1 (putative CYP2B or CYP3A) were only weakly affected by TCB at either dose. The strong and largely specific post-transcriptional suppression of CYP1A1 content was associated with high concentrations of TCB measured in the liver. Incubation of scup hepatic microsomes with TCB plus NADPH led to a time-dependent inactivation of CYP1A1 that was distinct from catalytic inhibition, and appeared not to involve reactive metabolites of TCB. This in vitro result suggests that TCB may inactivate CYP1A1 in vivo, which could account for the apparent antagonistic effect of TCB on CYP1A1 induction.
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Affiliation(s)
- R D White
- Biology Department, Woods Hole Oceanographic Institution, MA 02543, U.S.A
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49
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Guiney PD, Smolowitz RM, Peterson RE, Stegeman JJ. Correlation of 2,3,7,8-tetrachlorodibenzo-p-dioxin induction of cytochrome P4501A in vascular endothelium with toxicity in early life stages of lake trout. Toxicol Appl Pharmacol 1997; 143:256-73. [PMID: 9144443 DOI: 10.1006/taap.1996.8051] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Edema and cardiovascular dysfunction occur in vertebrates exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during early development. This study examined cytochrome P4501A (CYP1A) induction in endothelium and its possible association with mortality due to the edema and vascular effects of TCDD in lake trout early life stages. Lake trout (Salvelinus namaycush) eggs were injected at 24-50 hr postfertilization with 0.2 microl of 50 mM phosphatidylcholine liposomes or liposomes containing TCDD to give seven doses ranging from 11 to 176 pg TCDD/g egg. Doses of TCDD greater than 44 pg/g egg elicited hemorrhages; yolk sac, pericardial, and meningial edema; craniofacial malformations; regional ischemia; growth retardation; and mortality at the sac fry stage of development. Expression of CYP1A was assessed at four developmental stages, by immunohistochemical analysis of serial sections of individual fish with monoclonal antibody 1-12-3 to teleost CYP1A. CYP1A staining occurred in endothelial cells of many organs of TCDD-exposed but not vehicle-exposed embryos at 1 week prehatch and sac fry at 2 weeks posthatch. Earlier developmental stages examined were negative for CYP1A expression at any dose of TCDD. The strongest response occurred in sac fry at TCDD doses greater than 88 pg TCDD/g egg but was detected at doses as low as 22 pg TCDD/g egg. CYP1A staining in endothelium appeared at lower doses and was stronger than that in other cell types, in both prehatch embryos and posthatch sac fry. Thus, the vascular system is a major initial site affected by TCDD in lake trout early life stages, and the vascular endothelium is a cell type uniquely sensitive to induction of CYP1A in these developing animals. Based on an index of immunohistochemical staining of CYP1A, endothelial CYP1A induction in sac fry by TCDD occurred with an ED50 of 64-69 pg TCDD/g egg, similar to the dose-response for mortality occurring during the sac fry stage of development (LD50 = 47 pg TCDD/g egg). The correlations seen here suggest that CYP1A or aryl hydrocarbon receptor (AhR) in the endothelium may be linked to early lesions that result in TCDD-induced vascular derangements leading to yolk sac, pericardial, and meningial edema that is associated with lake trout sac fry mortality, but the precise mechanism remains to be determined.
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Affiliation(s)
- P D Guiney
- Department of Biological Sciences and NIEHS Marine and Freshwater Biomedical Core Center, University of Wisconsin, Milwaukee 53204, USA
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50
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Sugiyama K, Highet RJ, Woods A, Cotter RJ, Osawa Y. Hydrogen peroxide-mediated alteration of the heme prosthetic group of metmyoglobin to an iron chlorin product: evidence for a novel oxidative pathway. Proc Natl Acad Sci U S A 1997; 94:796-801. [PMID: 9023336 PMCID: PMC19593 DOI: 10.1073/pnas.94.3.796] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Treatment of metmyoglobin with H2O2 is known to lead to the crosslinking of an active site tyrosine residue to the heme [Catalano, C. E., Y. S. Choe, and P. R. Ortiz de Montellano (1989) J. Biol. Chem. 264, 10534-10541]. We have found in this study that this reaction also leads to an altered heme product not covalently bound to the protein. This product was characterized by visible absorption, infrared absorption, and mass and NMR spectrometry as an iron chlorin product formed from the saturation of the double bond between carbon atoms at positions 17 and 18 of pyrrole ring D with concomitant addition of a hydroxyl group on the carbon atom at position 18 and lactonization of the propionic acid to the carbon atom at position 17. Studies with the use of (18)O-labeled H2O2, O2, and H2O clearly indicate that the source of the added oxygen on the heme is water. Evidently, water adds regiospecifically to a cationic site formed on a carbon atom at position 18 after oxidation of the ferric heme prosthetic group with peroxide. Prolonged incubation of the reaction mixture containing the iron hydroxychlorin product led to the formation of an iron dihydroxychlorin product, presumably from a slow addition of water to the initial iron hydroxychlorin. The iron chlorin products characterized in this study are distinct from the meso-oxyheme species, which is thought to be formed during peroxide-mediated degradation of metmyoglobin, cytochrome P450, ferric heme, and model ferric hemes, and give further insight into the mechanism of H2O2-induced heme alterations.
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Affiliation(s)
- K Sugiyama
- Chemical Pharmacology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
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