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Lin B, Ye Z, Cao Z, Ye Z, Yu Y, Jiang W, Guo S, Melnikov V, Zhou P, Ji C, Shi C, Wu Z, Chen Z, Xu Y, Zhang Q, Ma Z, Qiao N, Chen L, Shou X, Cao X, Zhou X, Zhang L, He M, Wang Y, Ye H, Li Y, Zhang Z, Wang M, Gao R, Zhang Y. Integrated Microbiome and Metabolome Analysis Reveals Hypothalamic-Comorbidities Related Signatures in Craniopharyngioma. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2400684. [PMID: 39225628 DOI: 10.1002/advs.202400684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 07/15/2024] [Indexed: 09/04/2024]
Abstract
Craniopharyngioma (CP) is an intracranial tumor with high mortality and morbidity. Though biologically benign, CP will damage the hypothalamus, inducing comorbidities such as obesity, metabolic syndrome, and cognitive impairments. The roles of gut microbiome and serum metabolome in CP-associated hypothalamic comorbidities are aimed to be explored. Patients with CP are characterized by increased Shannon diversity, Eubacterium, Clostridium, and Roseburia, alongside decreased Alistipes and Bacteroides. CP-enriched taxa are positively correlated with dyslipidemia and cognitive decline, while CP-depleted taxa are negatively associated with fatty liver. Subsequent serum metabolomics identified notably up-regulated purine metabolism, and integrative analysis indicated an association between altered microbiota and elevated hypoxanthine. Phenotypic study and multi-omics analysis in the Rax-CreERT2::BrafV600E/+::PtenFlox/+ mouse model validated potential involvement of increased Clostridium and dysregulated purine metabolism in hypothalamic comorbidities. To further consolidate this, intervention experiments are performed and it is found that hypoxanthine co-variated with the severity of hypothalamic comorbidities and abundance of Clostridium, and induced dysregulated purine metabolism along with redox imbalance in target organs (liver and brain cortex). Overall, the study demonstrated the potential of increased Clostridium and up-regulated purine metabolism as signatures of CP-associated hypothalamic-comorbidities, and unveiled that elevated Clostridium, dysregulated purine metabolism, and redox imbalance may mediate the development and progression of CP-associated hypothalamic-comorbidities.
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Affiliation(s)
- Ben Lin
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Zhen Ye
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Zhan Cao
- Department of General Surgery, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, 200072, China
- Institute of Gut Microbiota Research and Engineering Development, Shanghai Tenth People's Hospital Tongji University School of Medicine, Shanghai, 200072, China
| | - Zhao Ye
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Yifei Yu
- Department of Endocrinology and Metabolism, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Weiliang Jiang
- Department of Gastroenterology, Shanghai General Hospital Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, China
- Shanghai Key Laboratory of Pancreatic Disease, Institute of Pancreatic Disease, Shanghai Jiao Tong University School of Medicine, Shanghai, 201620, China
| | - Sichen Guo
- Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Vladimir Melnikov
- Department of Endocrinology and Metabolism, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Peng Zhou
- Department of Cardiology, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Chenxing Ji
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Chengzhang Shi
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Zerui Wu
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Zhengyuan Chen
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Yihua Xu
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Qilin Zhang
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Zengyi Ma
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Nidan Qiao
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Long Chen
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Xuefei Shou
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Xiaoyun Cao
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Xiang Zhou
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Li Zhang
- Department of Endocrinology and Metabolism, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Min He
- Department of Endocrinology and Metabolism, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Yongfei Wang
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Hongying Ye
- Department of Endocrinology and Metabolism, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Yiming Li
- Department of Endocrinology and Metabolism, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Zhaoyun Zhang
- Department of Endocrinology and Metabolism, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Meng Wang
- Department of Endocrinology and Metabolism, Huashan Hospital Fudan University, Shanghai, 200040, China
| | - Renyuan Gao
- Department of General Surgery, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, 200072, China
| | - Yichao Zhang
- Department of Neurosurgery, Huashan Hospital Fudan University, Shanghai, 200040, China
- National Center for Neurological Disorders, Shanghai, 200040, China
- Shanghai Key Laboratory of Brain Function and Restoration and Neural Regeneration, Shanghai, 200040, China
- Neurosurgical Institute of Fudan University Fudan University, Shanghai, 200040, China
- Shanghai Clinical Medical Center of Neurosurgery, Shanghai, 200040, China
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Sun H, Wang X, Li Y, Shen Y, Zhang L, Xu Y, Liu J, Fan X. Targeting Liver Xor by GalNAc-siRNA Is an Effective Strategy for Hyperuricemia Therapy. Pharmaceutics 2024; 16:938. [PMID: 39065635 PMCID: PMC11279964 DOI: 10.3390/pharmaceutics16070938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 06/25/2024] [Accepted: 07/05/2024] [Indexed: 07/28/2024] Open
Abstract
Hyperuricemia, i.e., increased plasma uric acid concentration, is a common problem in clinical practice, leading to gout or nephrolithiasis, and is associated with other disorders, such as metabolic syndrome, cardiovascular disease, and chronic renal disease. Xanthine oxidoreductase (XOR) is a critical rate-limiting enzyme involved in uric acid synthesis and a promising target for hyperuricemia therapy. However, XOR inhibitors currently face clinical problems such as a short half-life and side effects. Here, we found that specifically targeting liver Xor with GalNAc-siRNAs had a good therapeutic effect on hyperuricemia. First, siRNAs were designed to target various sites in the homologous region between Homo sapiens and Mus musculus Xor mRNA and were screened in primary mouse hepatocytes. Then, the siRNAs were modified to increase their stability in vivo and conjugated with GalNAc for liver-specific delivery. The effects of GalNAc-siRNAs were evaluated in three hyperuricemia mouse models, including potassium oxonate and hypoxanthine administration in WT and humanized XDH mice and Uox knockout mice. Febuxostat, a specific XOR inhibitor used for hyperuricemia treatment, was used as a positive control. Targeting liver Xor with GalNAc-siRNAs by subcutaneous administration reduced plasma uric acid levels, uric acid accumulation in the kidney, renal inflammation, and fibrosis, thereby alleviating kidney damage in hyperuricemia mouse models without hepatoxicity. The results demonstrated that targeting liver Xor with GalNAc-siRNAs was a promising strategy for hyperuricemia therapy.
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Affiliation(s)
- Huiyan Sun
- Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xinxia Wang
- Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yongqiang Li
- Shanghai Synvida Biotechnology Co., Ltd., Shanghai 201203, China
| | - Yingzhi Shen
- Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Lin Zhang
- Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yingjie Xu
- Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Junling Liu
- Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
- Shanghai Synvida Biotechnology Co., Ltd., Shanghai 201203, China
| | - Xuemei Fan
- Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
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Maghsoud Y, Dong C, Cisneros GA. Investigation of the Inhibition Mechanism of Xanthine Oxidoreductase by Oxipurinol: A Computational Study. J Chem Inf Model 2023; 63:4190-4206. [PMID: 37319436 PMCID: PMC10405278 DOI: 10.1021/acs.jcim.3c00624] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Xanthine oxidoreductase (XOR) is an enzyme found in various organisms. It converts hypoxanthine to xanthine and urate, which are crucial steps in purine elimination in humans. Elevated uric acid levels can lead to conditions like gout and hyperuricemia. Therefore, there is significant interest in developing drugs that target XOR for treating these conditions and other diseases. Oxipurinol, an analogue of xanthine, is a well-known inhibitor of XOR. Crystallographic studies have revealed that oxipurinol directly binds to the molybdenum cofactor (MoCo) in XOR. However, the precise details of the inhibition mechanism are still unclear, which would be valuable for designing more effective drugs with similar inhibitory functions. In this study, molecular dynamics and quantum mechanics/molecular mechanics calculations are employed to investigate the inhibition mechanism of XOR by oxipurinol. The study examines the structural and dynamic effects of oxipurinol on the pre-catalytic structure of the metabolite-bound system. Our results provide insights on the reaction mechanism catalyzed by the MoCo center in the active site, which aligns well with experimental findings. Furthermore, the results provide insights into the residues surrounding the active site and propose an alternative mechanism for developing alternative covalent inhibitors.
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Affiliation(s)
- Yazdan Maghsoud
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Chao Dong
- Department of Chemistry and Physics, The University of Texas Permian Basin, Odessa, Texas 79762, United States
| | - G Andrés Cisneros
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
- Department of Physics, The University of Texas at Dallas, Richardson, Texas 75080, United States
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Nishino T. XDH and XO Research and Drug Discovery-Personal History. Molecules 2023; 28:molecules28114440. [PMID: 37298917 DOI: 10.3390/molecules28114440] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 06/12/2023] Open
Abstract
The author will outline the research history of the main issues addressed in this paper. The author has worked on this research himself. XDH, which is responsible for purine degradation, is present in various organisms. However, conversion to XO only occurs in mammals. The molecular mechanism of this conversion was elucidated in this study. The physiological and pathological significance of this conversion is presented. Finally, enzyme inhibitors were successfully developed, two of which are used as therapeutic agents for gout. Their wide application potential is also discussed.
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Affiliation(s)
- Takeshi Nishino
- NESA LLC, Yamatomura Greenhouse 501, Honkomagome 6-13-6, Bunkyo-ku, Tokyo 113-0021, Japan
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5
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Rodríguez-Rovira I, Arce C, De Rycke K, Pérez B, Carretero A, Arbonés M, Teixidò-Turà G, Gómez-Cabrera MC, Campuzano V, Jiménez-Altayó F, Egea G. Allopurinol blocks aortic aneurysm in a mouse model of Marfan syndrome via reducing aortic oxidative stress. Free Radic Biol Med 2022; 193:538-550. [PMID: 36347404 DOI: 10.1016/j.freeradbiomed.2022.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/28/2022] [Accepted: 11/02/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND Increasing evidence indicates that redox stress participates in MFS aortopathy, though its mechanistic contribution is little known. We reported elevated reactive oxygen species (ROS) formation and NADPH oxidase NOX4 upregulation in MFS patients and mouse aortae. Here we address the contribution of xanthine oxidoreductase (XOR), which catabolizes purines into uric acid and ROS in MFS aortopathy. METHODS AND RESULTS In aortic samples from MFS patients, XOR protein expression, revealed by immunohistochemistry, increased in both the tunicae intima and media of the dilated zone. In MFS mice (Fbn1C1041G/+), aortic XOR mRNA transcripts and enzymatic activity of the oxidase form (XO) were augmented in the aorta of 3-month-old mice but not in older animals. The administration of the XOR inhibitor allopurinol (ALO) halted the progression of aortic root aneurysm in MFS mice. ALO administrated before the onset of the aneurysm prevented its subsequent development. ALO also inhibited MFS-associated endothelial dysfunction as well as elastic fiber fragmentation, nuclear translocation of pNRF2 and increased 3'-nitrotyrosine levels, and collagen maturation remodeling, all occurring in the tunica media. ALO reduced the MFS-associated large aortic production of H2O2, and NOX4 and MMP2 transcriptional overexpression. CONCLUSIONS Allopurinol interferes in aortic aneurysm progression acting as a potent antioxidant. This study strengthens the concept that redox stress is an important determinant of aortic aneurysm formation and progression in MFS and warrants the evaluation of ALO therapy in MFS patients.
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Affiliation(s)
- Isaac Rodríguez-Rovira
- Department of Biomedical Sciences, University of Barcelona School of Medicine and Health Sciences, 08036, Barcelona, Spain
| | - Cristina Arce
- Department of Biomedical Sciences, University of Barcelona School of Medicine and Health Sciences, 08036, Barcelona, Spain
| | - Karo De Rycke
- Department of Biomedical Sciences, University of Barcelona School of Medicine and Health Sciences, 08036, Barcelona, Spain
| | - Belén Pérez
- Department of Pharmacology, Toxicology and Therapeutics, Neuroscience Institute, School of Medicine, Autonomous University of Barcelona, 08193, Cerdanyola del Vallès, Spain
| | - Aitor Carretero
- Department of Physiology, Faculty of Medicine, University of Valencia, CIBERFES, Fundación Investigación Hospital Clínico Universitario/INCLIVA, Valencia, Spain
| | - Marc Arbonés
- Department of Biomedical Sciences, University of Barcelona School of Medicine and Health Sciences, 08036, Barcelona, Spain
| | - Gisela Teixidò-Turà
- Department of Cardiology, Hospital Universitari Vall d'Hebron, Barcelona, Spain; CIBER-CV, Vall d'Hebrón Institut de Recerca (VHIR), Barcelona, Spain
| | - Mari Carmen Gómez-Cabrera
- Department of Physiology, Faculty of Medicine, University of Valencia, CIBERFES, Fundación Investigación Hospital Clínico Universitario/INCLIVA, Valencia, Spain
| | - Victoria Campuzano
- Department of Biomedical Sciences, University of Barcelona School of Medicine and Health Sciences, 08036, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Spain
| | - Francesc Jiménez-Altayó
- Department of Pharmacology, Toxicology and Therapeutics, Neuroscience Institute, School of Medicine, Autonomous University of Barcelona, 08193, Cerdanyola del Vallès, Spain
| | - Gustavo Egea
- Department of Biomedical Sciences, University of Barcelona School of Medicine and Health Sciences, 08036, Barcelona, Spain.
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Otani N, Ouchi M, Misawa K, Hisatome I, Anzai N. Hypouricemia and Urate Transporters. Biomedicines 2022; 10:biomedicines10030652. [PMID: 35327453 PMCID: PMC8945357 DOI: 10.3390/biomedicines10030652] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 02/07/2023] Open
Abstract
Hypouricemia is recognized as a rare disorder, defined as a serum uric acid level of 2.0 mg/dL or less. Hypouricemia is divided into an overexcretion type and an underproduction type. The former typical disease is xanthinuria, and the latter is renal hypouricemia (RHUC). The frequency of nephrogenic hypouricemia due to a deficiency of URAT1 is high in Japan, accounting for most asymptomatic and persistent cases of hypouricemia. RHUC results in a high risk of exercise-induced acute kidney injury and urolithiasis. It is vital to promote research on RHUC, as this will lead not only to the elucidation of its pathophysiology but also to the development of new treatments for gout and hyperuricemia.
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Affiliation(s)
- Naoyuki Otani
- Department of Clinical Pharmacology and Therapeutics, Faculty of Medicine, Oita University, Yufu 879-5593, Oita, Japan;
| | - Motoshi Ouchi
- Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Mibu 321-0293, Tochigi, Japan;
| | - Kazuharu Misawa
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Kanagawa, Japan;
| | - Ichiro Hisatome
- Yonago Medical Center, National Hospital Organization, Yonago 683-0006, Tottori, Japan;
- Department of Genetic Medicine and Regenerative Therapeutics, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Sciences, Tottori University, Yonago 680-8550, Tottori, Japan
| | - Naohiko Anzai
- Department of Pharmacology, Chiba University Graduate School of Medicine, Chiba 260-8670, Chiba, Japan
- Correspondence:
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Miyazaki S, Hamada T, Sugihara S, Mizuta E, Endo Y, Ohtahara A, Komatsu K, Kuwabara M, Fukuuchi T, Kaneko K, Ichida K, Ogino K, Ninomiya H, Yamamoto K, Nakamura T, Hisatome I. Xanthinuria Type 1 with a Novel Mutation in Xanthine Dehydrogenase and a Normal Endothelial Function. Intern Med 2022; 61:1383-1386. [PMID: 35491177 PMCID: PMC9152847 DOI: 10.2169/internalmedicine.7897-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Whether or not extremely low levels of serum uric acid (SUA) in xanthinuria are associated with impairment of the endothelial function and exercise-induced acute kidney injury (EIAKI) is unclear. A 59-year-old woman without EIAKI or urolithiasis had undetectable levels of UA in serum and urine and elevated levels of hypoxanthine and xanthine in urine. A genetic analysis revealed homozygous mutations in the XDH gene [c.1585 C>T (p. Gln529*)]. Flow-mediated dilation was within the normal range. This is the first report of a case with extremely low levels of SUA, xanthinuria with novel mutations of xanthine dehydrogenase (XDH) and a normal endothelial function.
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Affiliation(s)
| | - Toshihiro Hamada
- Department of Community-Based Family Medicine, Tottori University, Faculty of Medicine, Japan
| | | | | | - Yusuke Endo
- Advanced Medicine, Innovation and Clinical Research Center, Tottori University Hospital, Japan
| | | | - Koji Komatsu
- Department of Psychiatry Disease, Tottori University, Japan
| | | | - Tomoko Fukuuchi
- Laboratory of Biomedical and Analytical Sciences, Faculty of Pharma-Science, Teikyo University, Japan
| | - Kiyoko Kaneko
- Faculty of Pharmaceutical Sciences, Teikyo Heisei University, Japan
| | - Kimiyoshi Ichida
- Department of Pathophysiology, Tokyo University of Pharmacy and Life Sciences, Japan
| | - Kazuhide Ogino
- Department of Cardiology, Japanese Red Cross Tottori Hospital, Japan
| | - Haruaki Ninomiya
- Department of Biological Regulation, Tottori University Faculty of Medicine, Japan
| | - Kazuhiro Yamamoto
- Division of Cardiovascular Medicine, Department of Molecular Medicine and Therapeutics, Faculty of Medicine, Tottori University, Japan
| | | | - Ichiro Hisatome
- Department of Cardiovascular Medicine, Yonago Medical Center, Japan
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Abstract
Xanthine oxidase inhibitors are primarily used in the clinical prevention and treatment of gout associated with hyperuricemia. The archetypal xanthine oxidase inhibitor, Allopurinol has been shown to have other beneficial effects such as a reduction in vascular reactive oxygen species and mechano-energetic uncoupling. This chapter discusses these properties and their relevance to human pathophysiology with a focus on Allopurinol as well as newer xanthine oxidase inhibitors such as Febuxostat and Topiroxostat. Xanthine oxidase (XO) and xanthine dehydrogenase (XDH) are collectively referred to as xanthine oxidoreductase (XOR). XDH is initially synthesised as a 150-kDa protein from which XO is derived, e.g. under conditions of ischemia/hypoxia either reversibly by conformational changes (calcium or SH oxidation) or irreversibly by proteolysis, the latter leading to formation of a 130-kDa form of XO. Both, XO and XDH, catalyse the conversion of hypoxanthine via xanthine to uric acid, the former by using oxygen forming superoxide and hydrogen peroxide and the latter NAD+. However, XDH is in principle also able to generate ROS.
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Terao M, Garattini E, Romão MJ, Leimkühler S. Evolution, expression, and substrate specificities of aldehyde oxidase enzymes in eukaryotes. J Biol Chem 2020; 295:5377-5389. [PMID: 32144208 PMCID: PMC7170512 DOI: 10.1074/jbc.rev119.007741] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aldehyde oxidases (AOXs) are a small group of enzymes belonging to the larger family of molybdo-flavoenzymes, along with the well-characterized xanthine oxidoreductase. The two major types of reactions that are catalyzed by AOXs are the hydroxylation of heterocycles and the oxidation of aldehydes to their corresponding carboxylic acids. Different animal species have different complements of AOX genes. The two extremes are represented in humans and rodents; whereas the human genome contains a single active gene (AOX1), those of rodents, such as mice, are endowed with four genes (Aox1-4), clustering on the same chromosome, each encoding a functionally distinct AOX enzyme. It still remains enigmatic why some species have numerous AOX enzymes, whereas others harbor only one functional enzyme. At present, little is known about the physiological relevance of AOX enzymes in humans and their additional forms in other mammals. These enzymes are expressed in the liver and play an important role in the metabolisms of drugs and other xenobiotics. In this review, we discuss the expression, tissue-specific roles, and substrate specificities of the different mammalian AOX enzymes and highlight insights into their physiological roles.
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Affiliation(s)
- Mineko Terao
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, via La Masa 19, 20156 Milano, Italy
| | - Enrico Garattini
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, via La Masa 19, 20156 Milano, Italy
| | - Maria João Romão
- UCIBIO-Applied Biomolecular Sciences Unit, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Silke Leimkühler
- Department of Molecular Enzymology, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany.
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Chen Y, Li Y, Chao H, Wu J, Zhu W, Fang T, Gao X, Yan D. Molecular cloning and characterisation of a novel xanthine oxidase from Cellulosimicrobium cellulans ATCC21606. Process Biochem 2020. [DOI: 10.1016/j.procbio.2019.11.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Stiburkova B, Pavelcova K, Petru L, Krijt J. Thiopurine-induced toxicity is associated with dysfunction variant of the human molybdenum cofactor sulfurase gene (xanthinuria type II). Toxicol Appl Pharmacol 2018; 353:102-108. [PMID: 29935280 DOI: 10.1016/j.taap.2018.06.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/30/2018] [Accepted: 06/17/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND The aim of our study was to identify the genetic background of thiopurine-induced toxicity in a patient with a wild-type thiopurine methyltransferase genotype and activity. A 38-year-old Caucasian woman presented with cutaneous necrotizing vasculitis pancytopenia one month after starting azathioprine therapy. METHODS During a routine biochemical follow-up of the patient, undetectable serum uric acid (<10 μl) was observed. A high performance liquid chromatography analysis of urinary purines revealed increased levels of xanthine (137 mmol/mol creatinine). The suspected diagnosis of hereditary xanthinuria, a rare autosomal recessive disorder of the last two steps of purine metabolism, was confirmed by sequence analysis. RESULTS An analysis of XDH/XO and AOX1 revealed common polymorphisms, while analysis of the MOCOS gene identified a rare homozygous variant c.362C > T. Dysfunction of this variant was confirmed by significantly decreased xanthine dehydrogenase/oxidase activity in the patient's plasma (<2% of control mean activity). CONCLUSIONS We present a biochemical, enzymatic, and molecular genetic case study suggesting an important association between a hitherto undescribed dysfunction variant in the MOCOS gene and thiopurine-induced toxicity. The identified variant c.362C > T results in slower thiopurine metabolism caused by inhibition of 6-mercaptopurine oxidation (catabolism) to 6-thioxanthine and 6-thiouric acid, which increases the formation of the nucleotide 6-thioguanine, which is toxic. This is the first clinical case to identify the crucial role of the MOCOS gene in thiopurine intolerance and confirm the impact of genetic variability of purine enzymes on different therapeutic outcomes in patients undergoing thiopurine treatment.
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Affiliation(s)
- Blanka Stiburkova
- Institute of Rheumatology, Prague, Czech Republic; Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, General University Hospital in Prague, Prague, Czech Republic.
| | - Katerina Pavelcova
- Institute of Rheumatology, Prague, Czech Republic; Department of Rheumatology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Lenka Petru
- Institute of Rheumatology, Prague, Czech Republic; Department of Rheumatology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jakub Krijt
- Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, General University Hospital in Prague, Prague, Czech Republic
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13
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Liu H, Zhu H, Shi W, Lin Y, Ma G, Tao G, Gong W, Zhao Q, Du M, Wang M, Chu H, Zhang Z. Genetic variants in XDH are associated with prognosis for gastric cancer in a Chinese population. Gene 2018; 663:196-202. [PMID: 29551504 DOI: 10.1016/j.gene.2018.03.043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 03/05/2018] [Accepted: 03/14/2018] [Indexed: 01/26/2023]
Abstract
OBJECTIVE We explored the association between single nucleotide polymorphisms (SNPs) rs207454 and rs494852 located in xanthine dehydrogenase (XDH) and gastric cancer (GC) survival. METHODS A total of 940 patients with gastric cancer were enrolled and genotyped using TaqMan allelic discrimination method. The Kaplan-Meier test and log-rank examine were used to assess the effect of genetic variation. RESULTS Patients carrying rs207454 CC genotype had a longer survival time than those with the AA genotype (P = 0.042). The similar association was detected in the recessive model (P = 0.017). We conducted expression quantitative trait loci (eQTL) analysis and found that gastric cancer patients carrying rs207454 CC genotype had significant lower XDH levels than those with AA/AC genotype, suggesting that rs207454 polymorphism effected the expression of XDH. Additionally, the Kaplan-Meier curves showed that gastric cancer patients with high expression of XDH had remarkably poor survival outcome than those with low expression (hazard ratio [HR] = 1.53, 95% confidence interval [CI] = 1.29-1.82). CONCLUSIONS Genetic variants in XDH were associated with the survival of gastric cancer and may act as prognostic markers for individual suffered from gastric cancer.
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Affiliation(s)
- Hanting Liu
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China; Department of Genetic Toxicology, The Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Haixia Zhu
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China; Core Laboratory, Nantong Tumor Hospital, Nantong, China
| | - Weihong Shi
- Department of Clinical Medicine, Jiangsu Vocational College of Medicine, Yancheng, China
| | - Yadi Lin
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China; Department of Genetic Toxicology, The Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Gaoxiang Ma
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China; Department of Genetic Toxicology, The Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Guoquan Tao
- Department of General Surgery, Huai-An First People's Hospital Affiliated to Nanjing Medical University, Huai-An, China
| | - Weida Gong
- Department of General Surgery, Yixing Cancer Hospital, Yixing, China
| | - Qinghong Zhao
- Department of General Surgery, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Mulong Du
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China; Department of Genetic Toxicology, The Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Meilin Wang
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China; Department of Genetic Toxicology, The Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Haiyan Chu
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China; Department of Genetic Toxicology, The Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China.
| | - Zhengdong Zhang
- Department of Environmental Genomics, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China; Department of Genetic Toxicology, The Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China.
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Palmer M, Steenkamp ET, Coetzee MPA, Blom J, Venter SN. Genome-Based Characterization of Biological Processes That Differentiate Closely Related Bacteria. Front Microbiol 2018; 9:113. [PMID: 29467735 PMCID: PMC5808187 DOI: 10.3389/fmicb.2018.00113] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/17/2018] [Indexed: 12/21/2022] Open
Abstract
Bacteriologists have strived toward attaining a natural classification system based on evolutionary relationships for nearly 100 years. In the early twentieth century it was accepted that a phylogeny-based system would be the most appropriate, but in the absence of molecular data, this approach proved exceedingly difficult. Subsequent technical advances and the increasing availability of genome sequencing have allowed for the generation of robust phylogenies at all taxonomic levels. In this study, we explored the possibility of linking biological characters to higher-level taxonomic groups in bacteria by making use of whole genome sequence information. For this purpose, we specifically targeted the genus Pantoea and its four main lineages. The shared gene sets were determined for Pantoea, the four lineages within the genus, as well as its sister-genus Tatumella. This was followed by functional characterization of the gene sets using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. In comparison to Tatumella, various traits involved in nutrient cycling were identified within Pantoea, providing evidence for increased efficacy in recycling of metabolites within the genus. Additionally, a number of traits associated with pathogenicity were identified within species often associated with opportunistic infections, with some support for adaptation toward overcoming host defenses. Some traits were also only conserved within specific lineages, potentially acquired in an ancestor to the lineage and subsequently maintained. It was also observed that the species isolated from the most diverse sources were generally the most versatile in their carbon metabolism. By investigating evolution, based on the more variable genomic regions, it may be possible to detect biologically relevant differences associated with the course of evolution and speciation.
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Affiliation(s)
- Marike Palmer
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Emma T Steenkamp
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Martin P A Coetzee
- Department of Genetic, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Stephanus N Venter
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
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Peng M, Li S, He Q, Zhao J, Li L, Ma H. Proteomics reveals changes in hepatic proteins during chicken embryonic development: an alternative model to study human obesity. BMC Genomics 2018; 19:29. [PMID: 29310583 PMCID: PMC5759888 DOI: 10.1186/s12864-017-4427-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 12/29/2017] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Chicken embryos are widely used as a model for studies of obesity; however, no detailed information is available about the dynamic changes of proteins during the regulation of adipose biology and metabolism. Thus, the present study used an isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic approach to identify the changes in protein abundance at different stages of chicken embryonic development. RESULTS In this study, the abundances of 293 hepatic proteins in 19-day old of chicken embryos compared with 14-day old and 160 hepatic proteins at hatching compared with 19-day old embryos were significantly changed. Pathway analysis showed that fatty acid degradation (upregulated ACAA2, CPT1A, and ACOX1), protein folding (upregulated PDIs, CALR3, LMAN1, and UBQLN1) and gluconeogenesis (upregulated ACSS1, AKR1A1, ALDH3A2, ALDH7A1, and FBP2) were enhanced from embryonic day 14 (E14) to E19 of chicken embryo development. Analysis of the differentially abundant proteins indicated that glycolysis was not the main way to produce energy from E19 to hatching day during chicken embryo development. In addition, purine metabolism was enhanced, as deduced from increased IMPDH2, NT5C, PGM2, and XDH abundances, and the decrease of growth rate could be overcome by increasing the abundance of ribosomal proteins from E19 to the hatching day. CONCLUSION The levels of certain proteins were coordinated with each other to regulate the changes in metabolic pathways to satisfy the requirement for growth and development at different stages of chicken embryo development. Importantly, ACAA2, CPT1A, and ACOX1 might be key factors to control fat deposition during chicken embryonic development. These results provided information showing that chicken is a useful model to further investigate the mechanism of obesity and insulin resistance in humans.
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Affiliation(s)
- Mengling Peng
- Key Laboratory of Animal Physiology and Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shengnan Li
- Key Laboratory of Animal Physiology and Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qianian He
- Key Laboratory of Animal Physiology and Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jinlong Zhao
- Key Laboratory of Animal Physiology and Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Longlong Li
- Key Laboratory of Animal Physiology and Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Haitian Ma
- Key Laboratory of Animal Physiology and Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
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16
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Wright RM, Vaitaitis GM, Weigel LK, Repine TB, McManaman JL, Repine JE. Identification of the candidate ALS2 gene at chromosome 2q33 as a human aldehyde oxidase gene. Redox Rep 2016; 1:313-21. [DOI: 10.1080/13510002.1995.11747005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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17
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A case of xanthinuria type I with a novel mutation in xanthine dehydrogenase. CEN Case Rep 2016; 5:158-162. [PMID: 28508967 DOI: 10.1007/s13730-016-0216-3] [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: 01/25/2016] [Accepted: 02/19/2016] [Indexed: 12/13/2022] Open
Abstract
Hereditary hypouricemia is generally caused by renal hypouricemia, an autosomal recessive disorder that is characterized by impaired renal tubular uric acid transport, or by xanthinuria, a rare autosomal recessive disorder caused by a deficiency of xanthine dehydrogenase (XDH; xanthinuria type I) or by a deficiency of both XDH and aldehyde oxidase (xanthinuria type II). In contrast to renal hypouricemia, which sometimes leads to exercise-induced acute kidney injury (EIAKI), xanthinuria has not been associated with this disorder. We report here a case of xanthinuria type I due to a compound heterozygous mutation. A 46-year-old woman was found to have undetectable plasma and urinary levels of uric acid. She had no symptoms and no history of EIAKI. Xanthinuria type I was diagnosed following the allopurinol loading test. Mutation analysis revealed a compound heterozygous mutation [c.305A>G (p.Gln102Arg) and c.2567delC (p.Thr856Lysfs*73)] in the XDH gene. Of these two mutations, the former is novel. The patient did not exhibit EIAKI. However, because xanthinuria is a rare disease, the identification of additional cases is necessary to determine whether this disease is complicated with EIAKI.
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18
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Structure and function of mammalian aldehyde oxidases. Arch Toxicol 2016; 90:753-80. [DOI: 10.1007/s00204-016-1683-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 02/16/2016] [Indexed: 12/12/2022]
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19
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Chattopadhyay R, Tinnikov A, Dyukova E, Singh NK, Kotla S, Mobley JA, Rao GN. 12/15-Lipoxygenase-dependent ROS production is required for diet-induced endothelial barrier dysfunction. J Lipid Res 2015; 56:562-577. [PMID: 25556764 DOI: 10.1194/jlr.m055566] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
To understand the mechanisms of 15(S)-HETE-induced endothelial cell (EC) barrier dysfunction, we examined the role of xanthine oxidase (XO). 15(S)-HETE induced junction adhesion molecule A (JamA) phosphorylation on Y164, Y218, and Y280 involving XO-mediated reactive oxygen species production and Src and Pyk2 activation, resulting in its dissociation from occludin, thereby causing tight junction (TJ) disruption, increased vascular permeability, and enhanced leukocyte and monocyte transmigration in vitro using EC monolayer and ex vivo using arteries as models. The phosphorylation of JamA on Y164, Y218, and Y280 appears to be critical for its role in 15(S)-HETE-induced EC barrier dysfunction, as mutation of any one of these amino acid residues prevented its dissociation from occludin and restored TJ integrity and barrier function. In response to high-fat diet (HFD) feeding, WT, but not 12/15-lipoxygenase (LO)(-/-), mice showed enhanced XO expression and its activity in the artery, which was correlated with increased aortic TJ disruption and barrier permeability with enhanced leukocyte adhesion and these responses were inhibited by allopurinol. These observations provide novel insights on the role of XO in 12/15-LO-induced JamA tyrosine phosphorylation and TJ disruption leading to increased vascular permeability in response to HFD.
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Affiliation(s)
- Rima Chattopadhyay
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38138
| | - Alexander Tinnikov
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38138
| | - Elena Dyukova
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38138
| | - Nikhlesh K Singh
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38138
| | - Sivareddy Kotla
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38138
| | - James A Mobley
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35291
| | - Gadiparthi N Rao
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38138.
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Pathophysiology of circulating xanthine oxidoreductase: New emerging roles for a multi-tasking enzyme. Biochim Biophys Acta Mol Basis Dis 2014; 1842:1502-17. [DOI: 10.1016/j.bbadis.2014.05.022] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 05/21/2014] [Accepted: 05/22/2014] [Indexed: 02/07/2023]
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21
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Chen C, Cheng G, Hao H, Dai M, Wang X, Huang L, Liu Z, Yuan Z. Mechanism of porcine liver xanthine oxidoreductase mediated N-oxide reduction of cyadox as revealed by docking and mutagenesis studies. PLoS One 2013; 8:e73912. [PMID: 24040113 PMCID: PMC3767608 DOI: 10.1371/journal.pone.0073912] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 07/24/2013] [Indexed: 11/19/2022] Open
Abstract
Xanthine oxidoreductase (XOR) is a cytoplasmic molybdenum-containing oxidoreductase, catalyzing both endogenous purines and exogenous compounds. It is suggested that XOR in porcine hepatocytes catalyzes the N-oxide reduction of quinoxaline 1,4-di-N-oxides (QdNOs). To elucidate the molecular mechanism underlying this metabolism, the cDNA of porcine XOR was cloned and heterologously expressed in Spodoptera frugiperda insect cells. The bovine XOR, showing sequence identity of 91% to porcine XOR, was employed as template for homology modeling. By docking cyadox, a representative compound of QdNOs, into porcine XOR model, eight amino acid residues, Gly47, Asn352, Ser360, Arg427, Asp430, Asp431, Ser1227 and Lys1230, were located at distances of less than 4Å to cyadox. Site-directed mutagenesis was performed to analyze their catalytic functions. Compared with wild type porcine XOR, G47A, S360P, D431A, S1227A, and K1230A displayed altered kinetic parameters in cyadox reduction, similarly to that in xanthine oxidation, indicating these mutations influenced electron-donating process of xanthine before subsequent electron transfer to cyadox to fulfill the N-oxide reduction. Differently, R427E and D430H, both located in the 424-434 loop, exhibited a much lower K(m) and a decreased V(max) respectively in cyadox reduction. Arg427 may be related to the substrate binding of porcine XOR to cyadox, and Asp430 is suggested to be involved in the transfer of electron to cyadox. This study initially reveals the possible catalytic mechanism of porcine XOR in cyadox metabolism, providing with novel insights into the structure-function relationship of XOR in the reduction of exogenous di-N-oxides.
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Affiliation(s)
- Chigang Chen
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MOA Key Laboratory for the Detection of Veterinary Drug Residues in Foods, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Guyue Cheng
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MOA Key Laboratory for the Detection of Veterinary Drug Residues in Foods, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Haihong Hao
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MOA Key Laboratory for the Detection of Veterinary Drug Residues in Foods, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Menghong Dai
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MOA Key Laboratory for the Detection of Veterinary Drug Residues in Foods, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Xu Wang
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MOA Key Laboratory for the Detection of Veterinary Drug Residues in Foods, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Lingli Huang
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MOA Key Laboratory for the Detection of Veterinary Drug Residues in Foods, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Zhenli Liu
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MOA Key Laboratory for the Detection of Veterinary Drug Residues in Foods, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Zonghui Yuan
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MOA Key Laboratory for the Detection of Veterinary Drug Residues in Foods, Huazhong Agricultural University, Wuhan, Hubei, China
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22
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Jankowska D, Trautwein-Schult A, Cordes A, Hoferichter P, Klein C, Bode R, Baronian K, Kunze G. Arxula adeninivorans
xanthine oxidoreductase and its application in the production of food with low purine content. J Appl Microbiol 2013; 115:796-807. [DOI: 10.1111/jam.12284] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 06/04/2013] [Accepted: 06/11/2013] [Indexed: 11/29/2022]
Affiliation(s)
- D.A. Jankowska
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK); Gatersleben Germany
| | - A. Trautwein-Schult
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK); Gatersleben Germany
| | - A. Cordes
- ASA Spezialenzyme GmbH; Am Exer 19c; Wolfenbüttel Germany
| | - P. Hoferichter
- ASA Spezialenzyme GmbH; Am Exer 19c; Wolfenbüttel Germany
| | - C. Klein
- ASA Spezialenzyme GmbH; Am Exer 19c; Wolfenbüttel Germany
| | - R. Bode
- Institute of Biochemistry; University of Greifswald; Greifswald Germany
| | - K. Baronian
- School of Biological Sciences; University of Canterbury; Christchurch New Zealand
| | - G. Kunze
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK); Gatersleben Germany
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23
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Mutations associated with functional disorder of xanthine oxidoreductase and hereditary xanthinuria in humans. Int J Mol Sci 2012. [PMID: 23203137 PMCID: PMC3509653 DOI: 10.3390/ijms131115475] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Xanthine oxidoreductase (XOR) catalyzes the conversion of hypoxanthine to xanthine and xanthine to uric acid with concomitant reduction of either NAD+ or O2. The enzyme is a target of drugs to treat hyperuricemia, gout and reactive oxygen-related diseases. Human diseases associated with genetically determined dysfunction of XOR are termed xanthinuria, because of the excretion of xanthine in urine. Xanthinuria is classified into two subtypes, type I and type II. Type I xanthinuria involves XOR deficiency due to genetic defect of XOR, whereas type II xanthinuria involves dual deficiency of XOR and aldehyde oxidase (AO, a molybdoflavo enzyme similar to XOR) due to genetic defect in the molybdenum cofactor sulfurase. Molybdenum cofactor deficiency is associated with triple deficiency of XOR, AO and sulfite oxidase, due to defective synthesis of molybdopterin, which is a precursor of molybdenum cofactor for all three enzymes. The present review focuses on mutation or chemical modification studies of mammalian XOR, as well as on XOR mutations identified in humans, aimed at understanding the reaction mechanism of XOR and the relevance of mutated XORs as models to estimate the possible side effects of clinical application of XOR inhibitors.
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24
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Niu Y, Lu W, Gao L, Lin H, Liu X, Li L. Reducing effect of mangiferin on serum uric acid levels in mice. PHARMACEUTICAL BIOLOGY 2012; 50:1177-1182. [PMID: 22881143 DOI: 10.3109/13880209.2012.663763] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
CONTEXT Mangiferin, a natural bioactive xanthone C-glycoside, is widely present in medicinal plants like the leaf of Mangifera indica L. (Anacardiaceae). It has been reported that mangiferin possesses a variety of biological activities, including antidiabetic, hepatoprotective, anti-inflammatory, antioxidant, and anticarcinogenic. OBJECTIVE The hypouricemic effect and xanthine oxidoreductase (XOR) inhibitory activity of mangiferin were investigated here for the first time. MATERIALS AND METHODS The hypouricemic effect of mangiferin was investigated in normal and hyperuricemic mice induced by potassium oxonate. Mangiferin at a dose of 0.75-100.0 mg/kg was given intragastrically to mice. The serum urate levels were determined using the phosphotungstic acid method. The hepatic activities of xanthine dehydrogenase (XDH) and xanthine oxidase (XOD) in hyperuricemic mice were assayed using commercially available kits. RESULTS The results showed that mangiferin at a dose of 1.5, 3.0, and 6.0 mg/kg significantly reduced the serum urate levels (148.7 ± 37.8, 142.2 ± 44.5, 121.7 ± 21.7 µmmol/L) in hyperuricemic mice, compared with untreated hyperuricemic mice (201.8 ± 71.2 µmmol/L). However, mangiferin did not decrease the serum urate levels in normal mice until mangiferin was up to 100 mg/kg. In addition, the hepatic activities of XDH in hyperuricemic mice were significantly decreased by mangiferin, while no changes of XOD were observed. Acute toxicity study in mice showed that mangiferin was very safe at a dose of up to 25 g/kg. DISCUSSION AND CONCLUSION These findings demonstrate that mangiferin has the potential to be developed as a new therapeutic agent for the treatment of hyperuricemia and gout.
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Affiliation(s)
- Yanfen Niu
- Biomedical Engineering Research Center, Kunming Medical University, Kunming, PR China
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25
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Nakamura M, Yuichiro Y, Sass JO, Tomohiro M, Schwab KO, Takeshi N, Tatsuo H, Ichida K. Identification of a xanthinuria type I case with mutations of xanthine dehydrogenase in an Afghan child. Clin Chim Acta 2012; 414:158-60. [PMID: 22981351 DOI: 10.1016/j.cca.2012.08.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Accepted: 08/12/2012] [Indexed: 11/28/2022]
Abstract
Xanthinuria due to xanthine dehydrogenase (XDH) deficiency is a rare genetic disorder characterized by hypouricemia and the accumulation of xanthine in the urine. We have identified an Afghan girl whose xanthinuria could be classified as type I xanthinuria based on an allopurinol loading test. Three mutations were identified in the XDH gene, 141insG, C2729T (T910M) and C3886T (R1296W). Site-directed mutagenesis followed by expression analysis in Escherichia coli revealed that not only the frame shift mutation 141insG impairs XDH activity, but also the missense mutation C2729T, while C3886T resulted in major residual activity of about 50% of the wild type. In this report, a case of xanthinuria type I with mutations of XDH was identified and characterized by expression studies.
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Affiliation(s)
- Makiko Nakamura
- Department of Pathophysiology, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachiouji-shi, Tokyo 192-0392, Japan
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Fujiwara Y, Kawakami Y, Shinohara Y, Ichida K. A case of hereditary xanthinuria type 1 accompanied by bilateral renal calculi. Intern Med 2012; 51:1879-84. [PMID: 22821105 DOI: 10.2169/internalmedicine.51.6891] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hereditary xanthinuria is an extremely rare purine metabolism disorder caused by a genetic abnormality in xanthine dehydrogenase. A new case of hereditary xanthinuria type 1 accompanied by bilateral renal calculi was encountered. We performed an allopurinol loading test and diagnosed classical type 1 xanthinuria. Through genetic diagnosis, we identified a mutation site in the xanthine dehydrogenase gene. Genetic analysis revealed a homozygous deletion of cytosine 2,567 in the xanthine dehydrogenase gene, and as a result, a stop codon was formed at position 928. Renal failure caused by the deposition of xanthine crystals is a known complication because xanthine is poorly soluble in water. With high fluid intake and low purine diet, no significant increase in calculi has been observed in this patient for 2 years.
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Affiliation(s)
- Yutaka Fujiwara
- Department of Endocrinology and Metabolism, KKR Sapporo Medical Center, Japan.
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27
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Stiburkova B, Krijt J, Vyletal P, Bartl J, Gerhatova E, Korinek M, Sebesta I. Novel mutations in xanthine dehydrogenase/oxidase cause severe hypouricemia: biochemical and molecular genetic analysis in two Czech families with xanthinuria type I. Clin Chim Acta 2011; 413:93-9. [PMID: 21963464 DOI: 10.1016/j.cca.2011.08.038] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 08/29/2011] [Accepted: 08/30/2011] [Indexed: 02/04/2023]
Abstract
BACKGROUND The article describes the clinical, biochemical, enzymological and molecular genetics findings in two patients from two families with xanthinuria type I. METHODS Biochemical analysis using high performance liquid chromatography, allopurinol loading test and analysis of xanthine oxidase activity in plasma and of uromodulin excretion in urine were performed. Sequencing analysis of the xanthine dehydrogenase gene and the haplotype and statistical analyses of consanguinity were performed. RESULTS Probands showed extremely low concentrations of uric acid, on seven occasions under the limit of detection. The concentration of uric acid in 38-year-old female was 15 μmol/L in serum and 0.04 mmol/L in urine. Excretion of xanthine in urine was 170 mmol/mol creatinine. The concentration of uric acid in 25-year-old male was 0.03 mmol/L in urine. Excretion of xanthine in urine was 141 mmol/mol creatinine. The allopurinol loading test confirmed xanthinuria type I. The xanthine oxidase activities in patients were 0 and 0.4 pmol/h/mL of plasma. We found three nonsense changes: p.P214QfsX4 and unpublished p.R825X and p.R881X. CONCLUSIONS We found two nonconsanguineous compound heterozygotes with xanthinuria type I caused by three nonsense changes. The methods used did not confirm consanguinity in the probands, thus there might be an unconfirmed biological relationship or mutational hotspot.
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Affiliation(s)
- Blanka Stiburkova
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Prague, Czech Republic.
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Agarwal A, Banerjee A, Banerjee UC. Xanthine oxidoreductase: a journey from purine metabolism to cardiovascular excitation-contraction coupling. Crit Rev Biotechnol 2011; 31:264-80. [PMID: 21774633 DOI: 10.3109/07388551.2010.527823] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Xanthine oxidoreductase (XOR) is a ubiquitous complex cytosolic molybdoflavoprotein which controls the rate limiting step of purine catabolism by converting xanthine to uric acid. It is known that optimum concentrations of uric acid (UA) and reactive oxygen species (ROS) are necessary for normal functioning of the body. The ability of XOR to perform detoxification reactions, and to synthesize UA and reactive oxygen species (ROS) makes it a versatile intra- and extra-cellular protective "housekeeping enzyme". It is also an important component of the innate immune system. The enzyme is a target of drugs against gout and hyperuricemia and the protein is of major interest as it is associated with ischemia reperfusion (I/R) injury, vascular disorders in diabetes, cardiovascular disorders, adipogenesis, metabolic syndrome, cancer, and many other disease conditions. Xanthine oxidoreductase in conjugation with antibodies has been shown to have an anti-tumor effect due to its ability to produce ROS, which in turn reduces the growth of cancer tissues. Apart from this, XOR in association with nitric oxide synthase also participates in myocardial excitation-contraction coupling. Although XOR was discovered over 100 years ago, its physiological and pathophysiological roles are still not clearly elucidated. In this review, various physiological and pathophysiological functional aspects of XOR and its association with various forms of cancer are discussed in detail.
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Affiliation(s)
- Amit Agarwal
- Department of Pharmaceutical Technology (Biotechnology), National Institute of Pharmaceutical Education and Research, Punjab, India
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Interaction between eye pigment genes and tau-induced neurodegeneration in Drosophila melanogaster. Genetics 2010; 186:435-42. [PMID: 20592261 DOI: 10.1534/genetics.110.119545] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Null mutations in the genes white and brown, but not scarlet, enhance a rough eye phenotype in a Drosophila melanogaster model of tauopathy; however, adding rosy mutations suppresses these effects. Interaction with nucleotide-derived pigments or increased lysosomal dysregulation are potential mechanisms. Finally, tau toxicity correlates with increased GSK-3β activity, but not with tau phosphorylation at Ser202/Thr205.
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Wang S, Yan J, Wang J, Chen J, Zhang T, Zhao Y, Xue M. Synthesis of some 5-phenylisoxazole-3-carboxylic acid derivatives as potent xanthine oxidase inhibitors. Eur J Med Chem 2010; 45:2663-70. [PMID: 20189693 DOI: 10.1016/j.ejmech.2010.02.013] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Revised: 02/01/2010] [Accepted: 02/04/2010] [Indexed: 12/17/2022]
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Lespade L, Bercion S. Theoretical study of the mechanism of inhibition of xanthine oxidase by flavonoids and gallic acid derivatives. J Phys Chem B 2010; 114:921-8. [PMID: 20030406 DOI: 10.1021/jp9041809] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Xanthine oxidase is a flavoprotein enzyme which catalyzes the oxidative hydroxylation of purine substrates. Because of its availability, it has become a model for structural molybdoenzymes in general. The enzyme is a well-established target of drugs against gout and hyperuricemia and exists in two forms: oxidase and deshydrogenase. In some pathologies, its level increases in oxidase form, being the source of free radicals which can cause damage to surrounding tissues. It is important to understand the mechanisms of the enzyme inhibition to help in the search of new inhibitors. The main active center is a molybdopterin buried in a cavity. Theoretical calculations can be of some help for distinguishing the important aspects in the inhibition: attraction inside the cavity and anchorage. In this paper, the molybdopterin molecule geometry has been optimized by ab initio with the DFT method and the results have been shown to be very similar to the X-ray coordinates. In order to evaluate the attraction inside the cavity, the electrostatic potential between the charged molybdopterin molecule and two series of inhibitors, some flavonoids, and some gallic acid derivatives have been calculated using the multipolar development supplied by the Gaussian package. The good concordance between the electrostatic force and IC(50) indicates that the attraction is an important factor in the inhibition and must be taken into account in the designing of new drugs.
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Affiliation(s)
- Laure Lespade
- Institut des Sciences Moléculaires, Université de Bordeaux 1, 351 cours de la Libération, 33405 Talence, France.
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Michel TM, Camara S, Tatschner T, Frangou S, Sheldrick AJ, Riederer P, Grünblatt E. Increased xanthine oxidase in the thalamus and putamen in depression. World J Biol Psychiatry 2010; 11:314-20. [PMID: 20218795 DOI: 10.3109/15622970802123695] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A growing body of literature suggests persistent and selective structural changes in the cortico-limbic-thalamic-striatal system in patients with recurrent depressive disorder (DD). Oxidative stress is thought to play a key role in these processes. So far, the main scientific focus has been on antioxidant enzymes in this context. For the first time, this proof of concept study examines the activity of the free radicals producing the enzyme, xanthine oxidase (XO), directly in the cortico-limbic-thalamic-striatal system of patients with recurrent depression. The activity of XO was ascertained in the cortico-limbic-thalamic-striatal regions in post-mortem brain tissue of patients with recurrent depressive episodes and individuals without any neurological or psychiatric history (7/7). We measured the XO activity in following brain areas: hippocampus, regio entorhinalis, thalamus, putamen and caudate nucleus. In this study, we report a significant increase of XO activity in the thalamus and the putamen of patients with depression. Our findings contribute to the growing body of evidence suggesting that oxidative stress plays a pivotal role in certain brain areas in recurrent depressive disorder.
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Affiliation(s)
- Tanja Maria Michel
- Neurochemistry Laboratory, Department of Psychiatry and Psychotherapy, University of Würzburg, Würzburg, Germany.
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Establishment and characterization of a new hypoxia-resistant cancer cell line, OCUM-12/Hypo, derived from a scirrhous gastric carcinoma. Br J Cancer 2010; 102:898-907. [PMID: 20145613 PMCID: PMC2833244 DOI: 10.1038/sj.bjc.6605543] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Background: Many kinds of solid tumour have heterogeneously a hypoxic environment. Tumour hypoxia reported to be associated with more aggressive tumour phenotypes such as high metastatic ability and resistance to various anti-cancer therapies which may lead to a poorer prognosis. However, the mechanisms by which hypoxia affects the aggressive phenotypes remain unclear. Methods: We established a scirrhous gastric carcinoma cell line (OCUM-12) from ascites associated with scirrhous gastric carcinoma, and a hypoxia-resistant cancer cell line (OCUM-12/Hypo) was cloned from OCUM-12 cells by continuous exposure to 1% oxygen. Results: Histologic findings from orthotopic tumours derived from parent OCUM-12 cells and daughter OCUM-12/Hypo cells revealed poorly differentiated adenocarcinoma with extensive fibrosis that resembled human scirrhous gastric cancer. Necrotic lesions were frequently detected in the OCUM-12 tumours but were rarely found in the OCUM-12/Hypo tumours, although both types had multiple hypoxic loci. Apoptosis rate of OCUM-12 cells was increased to 24.7% at 1% O2, whereas that of OCUM-12/Hypo was 5.6%. The OCUM-12/Hypo orthotopic models developed multiple metastases to the peritoneum and lymph nodes, but the OCUM-12 models did not. OCUM-12/Hypo cells showed epithelial-to-mesenchymal transition and high migratory and invasive activities in comparison with OCUM-12 cells. The mRNA expression levels of both E-cadherin and zonula occludens ZO-1 and ZO-2 decreased in OCUM-12/Hypo cells, and that of vimentin, Snail-1, Slug/Snail-2, Twist, ZEB-1, ZEB-2, matrix metalloproteinase-1 (MMP-1), and MMP-2 were increased in OCUM-12/Hypo cells. Conclusion: OCUM-12 and OCUM-12/Hypo may be useful for the elucidation of disease progression associated with scirrhous gastric cancer in the setting of chronic hypoxia.
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George J, Struthers AD. Role of urate, xanthine oxidase and the effects of allopurinol in vascular oxidative stress. Vasc Health Risk Manag 2009; 5:265-72. [PMID: 19436671 PMCID: PMC2672460 DOI: 10.2147/vhrm.s4265] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Oxidative stress plays an important role in the progression of vascular endothelial dysfunction. The two major systems generating vascular oxidative stress are the NADPH oxidase and the xanthine oxidase pathways. Allopurinol, a xanthine oxidase inhibitor, has been in clinical use for over 40 years in the treatment of chronic gout. Allopurinol has also been shown to improve endothelial dysfunction, reduce oxidative stress burden and improve myocardial efficiency by reducing oxygen consumption in smaller mechanistic studies involving various cohorts at risk of cardiovascular events. This article aims to explain the role of xanthine oxidase in vascular oxidative stress and to explore the mechanisms by which allopurinol is thought to improve vascular and myocardial indices.
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Affiliation(s)
- Jacob George
- Division of Medicine and Therapeutics, Ninewells Hospital and Medical School, Dundee, UK.
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Linder N, Martelin E, Lundin M, Louhimo J, Nordling S, Haglund C, Lundin J. Xanthine oxidoreductase - clinical significance in colorectal cancer and in vitro expression of the protein in human colon cancer cells. Eur J Cancer 2008; 45:648-55. [PMID: 19112016 DOI: 10.1016/j.ejca.2008.10.036] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Revised: 10/02/2008] [Accepted: 10/15/2008] [Indexed: 11/27/2022]
Abstract
Xanthine oxidoreductase (XOR) is a key enzyme in degradation of DNA and RNA, and has previously been shown to be decreased in aggressive breast and gastric cancer. In this study, XOR expression was assessed in tissue microarray specimens of 478 patients with colorectal cancer and related to clinical parameters. In addition, we performed in vitro studies of XOR activity, protein and mRNA in colon cancer cells (Caco-2). Results from the tissue expression analyses show that XOR was decreased in 62% and undetectable in 22% of the tumours as compared to normal tissue. Loss of XOR was associated with poor grade of differentiation (p=0.006) and advanced Dukes stage (p=0.03). In multivariate survival analysis, XOR was a prognostic factor (p=0.008), independent of Dukes stage, histological grade, age and tumour location. The in vitro analyses show that XOR is not measurable in undifferentiated Caco-2 cells, but appears and increases with differentiation. We conclude that XOR expression is associated with histological grade of differentiation and extent of disease in colorectal cancer, and it provides significant prognostic information independently of established factors.
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Affiliation(s)
- Nina Linder
- Department of Oncology, Institute of Clinical Medicine, University of Helsinki, Haartmaninkatu 4, PO Box 105, 00029 Helsinki, Finland
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Mittal A, Phillips ARJ, Loveday B, Windsor JA. The potential role for xanthine oxidase inhibition in major intra-abdominal surgery. World J Surg 2008; 32:288-95. [PMID: 18074171 DOI: 10.1007/s00268-007-9336-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND Xanthine oxidase (XO) is a cytosolic metalloflavoprotein that has been implicated in the pathogenesis of a wide spectrum of diseases, and is thought to be the most important source of oxygen-free radicals and cell damage during re-oxygenation of hypoxic tissues. Clinical studies have already shown that XO inhibition is safe and effective for the treatment of gout, tumour-lysis syndrome, and to reduce complications such as post-operative arrhythmias, myocardial infarction and mortality in cardiovascular surgery. Here, we review the evidence from two decades of animal studies that have investigated the effects of XO inhibition during intra-abdominal surgery. MATERIALS AND METHODS A search of the Ovid MEDLINE database from 1950 through January 2007 was carried out using the following search terms: xanthine oxidase, allopurinol, ischemia, reperfusion, intestine, bowel, and general surgery. RESULTS The inhibition of XO has been shown to reduce oxidative stress, neutrophil priming, damage to intestinal mucosa due to ischemia reperfusion injuries, intestinal anastomotic dehiscence, bacterial translocation, adhesion formation, distant organ injury and mortality. CONCLUSIONS Despite this evidence which very strongly suggests a likely clinically beneficial role for XO inhibition in the elective and acute operative setting, it is surprising that such an approach has not been investigated in general surgery. There is now sufficient evidence to justify dedicated studies to determine the clinical benefits, dosing and duration of XO inhibition before and after gastrointestinal surgery.
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Affiliation(s)
- Anubhav Mittal
- Department of Surgery, Faculty of Medicine and Health Sciences, University of Auckland, Level 12 Support Building, Auckland City Hospital, Park Rd, Grafton, Auckland, New Zealand.
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Abstract
OBJECTIVE Xanthine oxidase (XO) catalyzes the oxidation of endogenous and exogenous purines and pyrimidines. In this study, we speculated that individual variations in XO activity are caused by genetic variations in the XO gene. METHODS To investigate the genetic variations in XO in 96 Japanese participants, denaturing high-performance liquid chromatography was used. To assess the effects of these variations on enzymatic activity, wild-type XO and 21 types of variant XO--including those in the database and those just discovered--were transiently expressed in COS-7 cells. RESULTS Three nonsynonymous single nucleotide polymorphisms, including 514G>A (Gly172Arg), 3326A>C (Asp1109Thr), and 3662A>G (His1221Arg) were identified in Japanese participants. Functional characterization of 21 XO variants showed a deficiency in enzyme activity in two variants (Arg149Cys and Thr910Lys); low activity (intrinsic clearance, CLint: 22-69% compared with the wild-type) in six variants (Pro555Ser, Arg607Gln, Thr623Ile, Asn909Lys, Pro1150Arg, and Cys1318Tyr); and high activity (CLint: approximately two-fold higher than that in the wild-type) in two variants (Ile703Val and His1221Arg). CONCLUSION These results suggest that several single nucleotide polymorphisms in the XO gene are involved in individual variations in XO activity. In addition, such findings will be useful to identify xanthinuria patients.
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Peretz H, Naamati MS, Levartovsky D, Lagziel A, Shani E, Horn I, Shalev H, Landau D. Identification and characterization of the first mutation (Arg776Cys) in the C-terminal domain of the Human Molybdenum Cofactor Sulfurase (HMCS) associated with type II classical xanthinuria. Mol Genet Metab 2007; 91:23-9. [PMID: 17368066 DOI: 10.1016/j.ymgme.2007.02.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Revised: 02/06/2007] [Accepted: 02/06/2007] [Indexed: 11/28/2022]
Abstract
Classical xanthinuria type II is an autosomal recessive disorder characterized by deficiency of xanthine dehydrogenase and aldehyde oxidase activities due to lack of a common sulfido-olybdenum cofactor (MoCo). Two mutations, both in the N-terminal domain of the Human Molybdenum Cofactor Sulfurase (HMCS), were reported in patients with type II xanthinuria. Whereas the N-terminal domain of HMCS was demonstrated to have cysteine desulfurase activity, the C-terminal domain hypothetically transfers the sulfur to the MoCo. We describe the first mutation in the C-terminal domain of HMCS identified in a Bedouin-Arab child presenting with urolithiasis and in an asymptomatic Jewish female. Patients were diagnosed with type II xanthinuria by homozygosity mapping and/or allopurinol loading test. The Bedouin-Arab child was homozygous for a c.2326C>T (p.Arg776Cys) mutation, while the female patient was compound heterozygous for this and a novel c.1034insA (p.Gln347fsStop379) mutation in the N-terminal domain of HMCS. Cosegregation of the homozygous mutant genotype with hypouricemia and hypouricosuria was demonstrated in the Bedouin family. Haplotype analysis indicated that p.Arg776Cys is a recurrent mutation. Arg776 together with six surrounding amino acid residues were found fully conserved and predicted to be buried in homologous eukaryotic MoCo sulfurases. Moreover, Arg776 is conserved in a diversity of eukaryotic and prokaryotic proteins that posses a domain homologous to the C-terminal domain of HMCS. Our findings suggest that Arg776 is essential for a core structure of the C-terminal domain of the HMCS and identification of a mutation at this site may contribute clarifying the mechanism of MoCo sulfuration.
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Affiliation(s)
- Hava Peretz
- Clinical Biochemistry Laboratory, Sourasky Medical Center, Tel Aviv, Israel.
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Kundu TK, Hille R, Velayutham M, Zweier JL. Characterization of superoxide production from aldehyde oxidase: an important source of oxidants in biological tissues. Arch Biochem Biophys 2007; 460:113-21. [PMID: 17353002 PMCID: PMC4073616 DOI: 10.1016/j.abb.2006.12.032] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Revised: 12/27/2006] [Accepted: 12/29/2006] [Indexed: 01/02/2023]
Abstract
Aldehyde oxidase, a molybdoflavoenzyme that plays an important role in aldehyde biotransformation, requires oxygen as substrate and produces reduced oxygen species. However, little information is available regarding its importance in cellular redox stress. Therefore, studies were undertaken to characterize its superoxide and hydrogen peroxide production. Aldehyde oxidase was purified to >98% purity and exhibited a single band at approximately 290 kDa on native polyacrylamide gradient gel electrophoresis. Superoxide generation was measured and quantitated by cytochrome c reduction and EPR spin trapping with p-dimethyl aminocinnamaldehyde as reducing substrate. Prominent superoxide generation was observed with an initial rate of 295 nmol min(-1) mg(-1). Electrochemical measurements of oxygen consumption and hydrogen peroxide formation yielded values of 650 and 355 nmol min(-1) mg(-1). In view of the ubiquitous distribution of aldehydes in tissues, aldehyde oxidase can be an important basal source of superoxide that would be enhanced in disease settings where cellular aldehyde levels are increased.
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Affiliation(s)
- Tapan Kumar Kundu
- Center for Biomedical EPR Spectroscopy and Imaging, the Davis Heart and Lung Research Institute, and the Division of Cardiovascular Medicine, the Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH 43210
| | - Russ Hille
- Center for Biomedical EPR Spectroscopy and Imaging, the Davis Heart and Lung Research Institute, and the Division of Cardiovascular Medicine, the Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH 43210
- Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH 43210
| | - Murugesan Velayutham
- Center for Biomedical EPR Spectroscopy and Imaging, the Davis Heart and Lung Research Institute, and the Division of Cardiovascular Medicine, the Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH 43210
| | - Jay L. Zweier
- Center for Biomedical EPR Spectroscopy and Imaging, the Davis Heart and Lung Research Institute, and the Division of Cardiovascular Medicine, the Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH 43210
- Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH 43210
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Hewinson J, Stevens CR, Millar TM. Vascular physiology and pathology of circulating xanthine oxidoreductase: from nucleotide sequence to functional enzyme. Redox Rep 2005; 9:71-9. [PMID: 15231061 DOI: 10.1179/135100004225004797] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The evolutionarily conserved, cofactor-dependent, enzyme xanthine oxidoreductase exists in both cell-associated and circulatory forms. The exact role of the circulating form is not known; however, several putative physiological and pathological functions have been suggested that range from purine catabolism to a mediator of acute respiratory distress syndrome. Regulation of gene expression, cofactor synthesis and insertion, post-translational conversion, entry into the circulation, and putative physiological and pathological roles for human circulating xanthine oxidoreductase are discussed.
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Abstract
In aerobic cells, free radicals are constantly produced mostly as reactive oxygen species. Once produced, free radicals are removed by antioxidant defenses including enzyme catalase, glutathione peroxidase, and superoxide dismutase. Reactive oxygen species, including nitric oxide and related species, commonly exert a series of useful physiological effects. However, imbalance between prooxidant and antioxidant defenses in favor of prooxidants results in oxidative stress associated with the oxidative modification of biomolecules such as lipids, proteins, and nucleic acids. Alone or in combination with primary ethiological factors, free radicals are involved in a pathogenesis of more than a hundred diseases. This chapter reviews the basic science of some of the potential sources and characteristics of free radicals, as well as antioxidant enzymes. Special attention is paid to the role of free radicals in the pathogenesis of atherosclerosis and immunology-mediated inflammatory reaction.
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Affiliation(s)
- Vidosava B Djordjević
- Institute for Biochemistry, Faculty of Medicine, University of Nis, Serbia and Montenegro USA
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Kurosaki M, Terao M, Barzago MM, Bastone A, Bernardinello D, Salmona M, Garattini E. The aldehyde oxidase gene cluster in mice and rats. Aldehyde oxidase homologue 3, a novel member of the molybdo-flavoenzyme family with selective expression in the olfactory mucosa. J Biol Chem 2004; 279:50482-98. [PMID: 15383531 DOI: 10.1074/jbc.m408734200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammalian molybdo-flavoenzymes are oxidases requiring FAD and molybdopterin (molybdenum cofactor) for their catalytic activity. This family of proteins was thought to consist of four members, xanthine oxidoreductase, aldehyde oxidase 1 (AOX1), and the aldehyde oxidase homologues 1 and 2 (AOH1 and AOH2, respectively). Whereas the first two enzymes are present in humans and various other mammalian species, the last two proteins have been described only in mice. Here, we report on the identification, in both mice and rats, of a novel molybdo-flavoenzyme, AOH3. In addition, we have cloned the cDNAs coding for rat AOH1 and AOH2, demonstrating that this animal species has the same complement of molybdo-flavoproteins as the mouse. The AOH3 cDNA is characterized by remarkable similarity to AOX1, AOH1, AOH2, and xanthine oxidoreductase cDNAs. Mouse AOH3 is selectively expressed in Bowman's glands of the olfactory mucosa, although small amounts of the corresponding mRNA are present also in the skin. In the former location, two alternatively spliced forms of the AOH3 transcript with different 3'-untranslated regions were identified. The general properties of AOH3 were determined by purification of mouse AOH3 from the olfactory mucosa. The enzyme possesses aldehyde oxidase activity and oxidizes, albeit with low efficiency, exogenous substrates that are recognized by AOH1 and AOX1. The Aoh3 gene maps to mouse chromosome 1 band c1 and rat chromosome 7 in close proximity to the Aox1, Aoh1, and Aoh2 loci and has an exon/intron structure almost identical to that of the other molybdo-flavoenzyme genes in the two species.
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Affiliation(s)
- Mami Kurosaki
- Laboratory of Molecular Biology, Centro Catullo e Daniela Borgomainerio, Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
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Ivanov NV, Trani M, Edmondson DE. High-level expression and characterization of a highly functional Comamonas acidovorans xanthine dehydrogenase in Pseudomonas aeruginosa. Protein Expr Purif 2004; 37:72-82. [PMID: 15294283 DOI: 10.1016/j.pep.2004.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2004] [Revised: 03/22/2004] [Indexed: 10/26/2022]
Abstract
An improved procedure is described for the high-level expression of Comamonas acidovorans XDH in Pseudomonas aeruginosa PAO1-LAC. The level of functional expression (56 mg protein/L culture) is found to be 7-fold higher than that observed in Escherichia coli and 30-fold higher than that induced in C. acidovorans. Co-expression of the xdhC gene is required for maximal level of functional expression. Comparison of purified preparations of XDH expressed in the absence of xdhC (XDH(AB)) with that expressed in its presence (XDH(ABC)) shows the increased level of activity due to the level of Mo incorporation. The Fe and FAD contents of expressed enzymes are independent of xdhC co-expression. Electron paramagnetic resonance spectroscopy, circular dichroism spectroscopy, metal analysis, and kinetic properties of recombinant purified XDH(ABC) are identical with those exhibited by the native enzyme. This expression system should serve as a valuable tool for further biophysical and mechanistic investigations of xanthine dehydrogenase by site-directed mutagenesis. A method is also described to evaluate the suitability of P. aeruginosa and other organisms as potential expression hosts for five different sources of xdh genes.
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Fukunari A, Okamoto K, Nishino T, Eger BT, Pai EF, Kamezawa M, Yamada I, Kato N. Y-700 [1-[3-Cyano-4-(2,2-dimethylpropoxy)phenyl]-1H-pyrazole-4-carboxylic acid]: a potent xanthine oxidoreductase inhibitor with hepatic excretion. J Pharmacol Exp Ther 2004; 311:519-28. [PMID: 15190124 DOI: 10.1124/jpet.104.070433] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Y-700 (1-[3-Cyano-4-(2,2-dimethylpropoxy)phenyl]-1H-pyrazole-4-carboxylic acid) is a newly synthesized inhibitor of xanthine oxidoreductase (XOR). Steady-state kinetics with the bovine milk enzyme indicated a mixed type inhibition with K(i) and K(i) ' values of 0.6 and 3.2 nM, respectively. Titration experiments showed that Y-700 bound tightly both to the active sulfo-form and to the inactive desulfo-form of the enzyme with K(d) values of 0.9 and 2.8 nM, respectively. X-ray crystallographic analysis of the enzyme-inhibitor complex revealed that Y-700 closely interacts with the channel leading to the molybdenum-pterin active site but does not directly coordinate to the molybdenum ion. In oxonate-treated rats, orally administered Y-700 (1-10 mg/kg) dose dependently lowered plasma urate levels. At a dose of 10 mg/kg, the hypouricemic action of Y-700 was more potent and of longer duration than that of 4-hydroxypyrazolo(3,4-d)pyrimidine, whereas its action was approximately equivalent to that of 2-(3-cyano-4-isobutoxyphenyl)-4-methyl-5-thiazolecarboxylic acid, a nonpurine inhibitor of XOR. In normal rats, orally administered Y-700 (0.3-3 mg/kg) dose dependently reduced the urinary excretion of urate and allantoin, accompanied by an increase in the excretion of hypoxanthine and xanthine. Y-700 (1 mg/kg) was absorbed rapidly by the oral route with high bioavailability (84.1%). Y-700 was hardly excreted via the kidneys but was mainly cleared via the liver. These results suggest that Y-700 will be a promising candidate for the treatment of hyperuricemia and other diseases in which XOR may be involved.
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Affiliation(s)
- Atsushi Fukunari
- Discovery Technology Laboratory, Pharmaceuticals Research Unit, Mitsubishi Pharma Corporation, 1000 Kamoshida-cho, Aoba-ku, Yokohama 227-0033, Japan.
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Berry CE, Hare JM. Xanthine oxidoreductase and cardiovascular disease: molecular mechanisms and pathophysiological implications. J Physiol 2003; 555:589-606. [PMID: 14694147 PMCID: PMC1664875 DOI: 10.1113/jphysiol.2003.055913] [Citation(s) in RCA: 621] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
There is substantial evidence that oxidative stress participates in the pathophysiology of cardiovascular disease. Biochemical, molecular and pharmacological studies further implicate xanthine oxidoreductase (XOR) as a source of reactive oxygen species in the cardiovascular system. XOR is a member of the molybdoenzyme family and is best known for its catalytic role in purine degradation, metabolizing hypoxanthine and xanthine to uric acid with concomitant generation of superoxide. Gene expression of XOR is regulated by oxygen tension, cytokines and glucocorticoids. XOR requires molybdopterin, iron-sulphur centres, and FAD as cofactors and has two interconvertible forms, xanthine oxidase and xanthine dehydrogenase, which transfer electrons from xanthine to oxygen and NAD(+), respectively, yielding superoxide, hydrogen peroxide and NADH. Additionally, XOR can generate superoxide via NADH oxidase activity and can produce nitric oxide via nitrate and nitrite reductase activities. While a role for XOR beyond purine metabolism was first suggested in ischaemia-reperfusion injury, there is growing awareness that it also participates in endothelial dysfunction, hypertension and heart failure. Importantly, the XOR inhibitors allopurinol and oxypurinol attenuate dysfunction caused by XOR in these disease states. Attention to the broader range of XOR bioactivity in the cardiovascular system has prompted initiation of several randomised clinical outcome trials, particularly for congestive heart failure. Here we review XOR gene structure and regulation, protein structure, enzymology, tissue distribution and pathophysiological role in cardiovascular disease with an emphasis on heart failure.
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Affiliation(s)
- Cristine E Berry
- The Johns Hopkins Hospital School of Medicine, Cardiology Division, 600 N Wolfe Street, Carnegie 568, Baltimore, MD 21287, USA
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Yamamoto T, Moriwaki Y, Takahashi S, Tsutsumi Z, Tuneyoshi K, Matsui K, Cheng J, Hada T. Identification of a new point mutation in the human molybdenum cofactor sulferase gene that is responsible for xanthinuria type II. Metabolism 2003; 52:1501-4. [PMID: 14624414 DOI: 10.1016/s0026-0495(03)00272-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A 43-year-old xanthinuric female was referred to our department because of hypouricemia. Routine laboratory data showed hypouricemia, a high level of plasma oxypurines, decreased urinary uric acid excretion, and increased urinary oxypurine excretion, with xanthine dehydrogenase activity in the duodenal mucosa below the limits of detection. In addition, allopurinol was not metabolized. From these findings, the patient was diagnosed with xanthinuria type II. To investigate the properties of xanthine dehydrogenase/xanthine oxidase (XDH/XO) deficiency, a cDNA sequence encoding XDH/XO, aldehyde oxidase (AO), and molybdenum cofactor sulferase (MCS), as well as immunoblotting analysis for XDH/XO protein, obtained from duodenal mucosa samples were performed. The XDH/XO cDNA and AO cDNA sequences of the xanthinuric patient were consistent with previously reported ones, whereas the MCS cDNA sequence revealed a point mutation of G to C in nucleotide 466, which changed codon 156 from GCC (Ala) to CCC (Pro). In addition, the MCS genomic DNA sequence including the site of the mutation revealed the same, suggesting that the xanthinuric patient was homozygous for this mutation. Such findings have not been previously reported for patients with xanthinuria type II.
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Affiliation(s)
- Tetsuya Yamamoto
- Department of Internal Medicine, Hyogo College of Medicine, Hyogo, Japan
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Aposhian HV, Zakharyan RA, Avram MD, Kopplin MJ, Wollenberg ML. Oxidation and detoxification of trivalent arsenic species. Toxicol Appl Pharmacol 2003; 193:1-8. [PMID: 14613711 DOI: 10.1016/s0041-008x(03)00324-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Arsenic compounds with a +3 oxidation state are more toxic than analogous compounds with a +5 oxidation state, for example, arsenite versus arsenate, monomethylarsonous acid (MMA(III)) versus monomethylarsonic acid (MMA(V)), and dimethylarsinous acid (DMA(III)) versus dimethylarsinic acid (DMA(V)). It is no longer believed that the methylation of arsenite is the beginning of a methylation-mediated detoxication pathway. The oxidation of these +3 compounds to their less toxic +5 analogs by hydrogen peroxide needs investigation and consideration as a potential mechanism for detoxification. Xanthine oxidase uses oxygen to oxidize hypoxanthine to xanthine to uric acid. Hydrogen peroxide and reactive oxygen are also products. The oxidation of +3 arsenicals by the hydrogen peroxide produced in the xanthine oxidase reaction was blocked by catalase or allopurinol but not by scavengers of the hydroxy radical, e.g., mannitol or potassium iodide. Melatonin, the singlet oxygen radical scavenger, did not inhibit the oxidation. The production of H2O2 by xanthine oxidase may be an important route for decreasing the toxicity of trivalent arsenic species by oxidizing them to their less toxic pentavalent analogs. In addition, there are many other reactions that produce hydrogen peroxide in the cell. Although chemists have used hydrogen peroxide for the oxidation of arsenite to arsenate to purify water, we are not aware of any published account of its potential importance in the detoxification of trivalent arsenicals in biological systems. At present, this oxidation of the +3 oxidation state arsenicals is based on evidence from in vitro experiments. In vivo experiments are needed to substantiate the role and importance of H2O2 in arsenic detoxication in mammals.
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Affiliation(s)
- H Vasken Aposhian
- Department of Molecular and Cellular Biology, The University of Arizona, Tucson, AZ 85721, USA.
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Garattini E, Mendel R, Romão MJ, Wright R, Terao M. Mammalian molybdo-flavoenzymes, an expanding family of proteins: structure, genetics, regulation, function and pathophysiology. Biochem J 2003; 372:15-32. [PMID: 12578558 PMCID: PMC1223366 DOI: 10.1042/bj20030121] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2003] [Revised: 02/04/2003] [Accepted: 02/10/2003] [Indexed: 12/11/2022]
Abstract
The molybdo-flavoenzymes are structurally related proteins that require a molybdopterin cofactor and FAD for their catalytic activity. In mammals, four enzymes are known: xanthine oxidoreductase, aldehyde oxidase and two recently described mouse proteins known as aldehyde oxidase homologue 1 and aldehyde oxidase homologue 2. The present review article summarizes current knowledge on the structure, enzymology, genetics, regulation and pathophysiology of mammalian molybdo-flavoenzymes. Molybdo-flavoenzymes are structurally complex oxidoreductases with an equally complex mechanism of catalysis. Our knowledge has greatly increased due to the recent crystallization of two xanthine oxidoreductases and the determination of the amino acid sequences of many members of the family. The evolution of molybdo-flavoenzymes can now be traced, given the availability of the structures of the corresponding genes in many organisms. The genes coding for molybdo-flavoenzymes are expressed in a cell-specific fashion and are controlled by endogenous and exogenous stimuli. The recent cloning of the genes involved in the biosynthesis of the molybdenum cofactor has increased our knowledge on the assembly of the apo-forms of molybdo-flavoproteins into the corresponding holo-forms. Xanthine oxidoreductase is the key enzyme in the catabolism of purines, although recent data suggest that the physiological function of this enzyme is more complex than previously assumed. The enzyme has been implicated in such diverse pathological situations as organ ischaemia, inflammation and infection. At present, very little is known about the pathophysiological relevance of aldehyde oxidase, aldehyde oxidase homologue 1 and aldehyde oxidase homologue 2, which do not as yet have an accepted endogenous substrate.
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Affiliation(s)
- Enrico Garattini
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri, via Eritrea 62, 20157 Milan, Italy.
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Okamoto K, Eger BT, Nishino T, Kondo S, Pai EF, Nishino T. An extremely potent inhibitor of xanthine oxidoreductase. Crystal structure of the enzyme-inhibitor complex and mechanism of inhibition. J Biol Chem 2003; 278:1848-55. [PMID: 12421831 DOI: 10.1074/jbc.m208307200] [Citation(s) in RCA: 301] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
TEI-6720 (2-(3-cyano-4-isobutoxyphenyl)-4-methyl-5-thiazolecarboxylic acid) is an extremely potent inhibitor of xanthine oxidoreductase. Steady state kinetics measurements exhibit mixed type inhibition with K(i) and K(i)' values of 1.2 +/- 0.05 x 10(-10) m and 9 +/- 0.05 x 10(-10) m, respectively. Fluorescence-monitored titration experiments showed that TEI-6720 bound very tightly to both the active and the inactive desulfo-form of the enzyme. The dissociation constant determined for the desulfo-form was 2 +/- 0.03 x 10(-9) m; for the active form, the corresponding number was too low to allow accurate measurements. The crystal structure of the active sulfo-form of milk xanthine dehydrogenase complexed with TEI-6720 and determined at 2.8-A resolution revealed the inhibitor molecule bound in a long, narrow channel leading to the molybdenum-pterin active site of the enzyme. It filled up most of the channel and the immediate environment of the cofactor, very effectively inhibiting the activity of the enzyme through the prevention of substrate binding. Although the inhibitor did not directly coordinate to the molybdenum ion, numerous hydrogen bonds as well as hydrophobic interactions with the protein matrix were observed, most of which are also used in substrate recognition.
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Affiliation(s)
- Ken Okamoto
- Department of Biochemistry and Molecular Biology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-0022, Japan
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Abstract
Xanthine oxidoreductase (XOR) is a complex molybdoflavoenzyme, present in milk and many other tissues, which has been studied for over 100 years. While it is generally recognized as a key enzyme in purine catabolism, its structural complexity and specialized tissue distribution suggest other functions that have never been fully identified. The publication, just over 20 years ago, of a hypothesis implicating XOR in ischemia-reperfusion injury focused research attention on the enzyme and its ability to generate reactive oxygen species (ROS). Since that time a great deal more information has been obtained concerning the tissue distribution, structure, and enzymology of XOR, particularly the human enzyme. XOR is subject to both pre- and post-translational control by a range of mechanisms in response to hormones, cytokines, and oxygen tension. Of special interest has been the finding that XOR can catalyze the reduction of nitrates and nitrites to nitric oxide (NO), acting as a source of both NO and peroxynitrite. The concept of a widely distributed and highly regulated enzyme capable of generating both ROS and NO is intriguing in both physiological and pathological contexts. The details of these recent findings, their pathophysiological implications, and the requirements for future research are addressed in this review.
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Affiliation(s)
- Roger Harrison
- Department of Biology and Biochemistry, University of Bath, Bath, UK.
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