1
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Therapeutic Effects of Salvianolic Acid B on Angiotensin II-Induced Atrial Fibrosis by Regulating Atrium Metabolism via Targeting AMPK/FoxO1/miR-148a-3p Axis. J Cardiovasc Transl Res 2022; 16:341-357. [PMID: 35984595 PMCID: PMC10151312 DOI: 10.1007/s12265-022-10303-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 07/29/2022] [Indexed: 10/15/2022]
Abstract
The present study highlights the effects of salvianolic acid B (Sal B) on angiotensin II (Ang II)-activated atrial fibroblasts as well as the associated potential mechanism from the metabonomics perspective. Metabolic profile analysis performed an optimal separation of the Ang II and control group, indicating a recovery impact of Sal B on Ang II-activated fibroblasts (FBs). We found that metabolite levels in the Ang II + Sal B group were reversed to normal. Moreover, 23 significant metabolites were identified. Metabolic network analysis indicated that these metabolites participated in purine metabolism and FoxO signaling pathway. We found that Sal B activated AMP-activated protein kinase (AMPK) phosphorylation, which further promoted FoxO1 activation and increased miR-148a-3p level. We further verified that Sal B modulate the abnormal AMP, phosphocreatine, glutathione (GSH), and reactive oxygen species (ROS) production in Ang II-stimulated FBs. Collectively, Sal B can protect the Ang II-activated FBs from fibrosis and oxidative stress via AMPK/FoxO1/miRNA-148a-3p axis.
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2
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Silva-Adaya D, Garza-Lombó C, Gonsebatt ME. Xenobiotic transport and metabolism in the human brain. Neurotoxicology 2021; 86:125-138. [PMID: 34371026 DOI: 10.1016/j.neuro.2021.08.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 08/02/2021] [Accepted: 08/04/2021] [Indexed: 02/06/2023]
Abstract
Organisms have metabolic pathways responsible for eliminating endogenous and exogenous toxicants. Generally, we associate the liver par excellence as the organ in charge of detoxifying the body; however, this process occurs in all tissues, including the brain. Due to the presence of the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB), the Central Nervous System (CNS) is considered a partially isolated organ, but similar to other organs, the CNS possess xenobiotic transporters and metabolic pathways associated with the elimination of xenobiotic agents. In this review, we describe the different systems related to the detoxification of xenobiotics in the CNS, providing examples in which their association with neurodegenerative processes is suspected. The CNS detoxifying systems include carrier-mediated, active efflux and receptor-mediated transport, and detoxifying systems that include phase I and phase II enzymes, as well as those enzymes in charge of neutralizing compounds such as electrophilic agents, reactive oxygen species (ROS), and free radicals, which are products of the bioactivation of xenobiotics. Moreover, we discuss the differential expression of these systems in different regions of the CNS, showing the different detoxifying needs and the composition of each region in terms of the cell type, neurotransmitter content, and the accumulation of xenobiotics and/or reactive compounds.
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Affiliation(s)
- Daniela Silva-Adaya
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico; Laboratorio Experimental de Enfermedades Neurodegenerativas, Instituto Nacional de Neurología y Neurocirugía, Mexico, 14269, Mexico
| | - Carla Garza-Lombó
- Department of Pharmacology and Toxicology, The Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 West 15th Street, NB, Indianapolis, IN, 46202, USA
| | - María E Gonsebatt
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico.
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3
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Manevski N, King L, Pitt WR, Lecomte F, Toselli F. Metabolism by Aldehyde Oxidase: Drug Design and Complementary Approaches to Challenges in Drug Discovery. J Med Chem 2019; 62:10955-10994. [PMID: 31385704 DOI: 10.1021/acs.jmedchem.9b00875] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Aldehyde oxidase (AO) catalyzes oxidations of azaheterocycles and aldehydes, amide hydrolysis, and diverse reductions. AO substrates are rare among marketed drugs, and many candidates failed due to poor pharmacokinetics, interspecies differences, and adverse effects. As most issues arise from complex and poorly understood AO biology, an effective solution is to stop or decrease AO metabolism. This perspective focuses on rational drug design approaches to modulate AO-mediated metabolism in drug discovery. AO biological aspects are also covered, as they are complementary to chemical design and important when selecting the experimental system for risk assessment. The authors' recommendation is an early consideration of AO-mediated metabolism supported by computational and in vitro experimental methods but not an automatic avoidance of AO structural flags, many of which are versatile and valuable building blocks. Preferably, consideration of AO-mediated metabolism should be part of the multiparametric drug optimization process, with the goal to improve overall drug-like properties.
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Affiliation(s)
- Nenad Manevski
- UCB Celltech , 208 Bath Road , Slough SL13WE , United Kingdom
| | - Lloyd King
- UCB Celltech , 208 Bath Road , Slough SL13WE , United Kingdom
| | - William R Pitt
- UCB Celltech , 208 Bath Road , Slough SL13WE , United Kingdom
| | - Fabien Lecomte
- UCB Celltech , 208 Bath Road , Slough SL13WE , United Kingdom
| | - Francesca Toselli
- UCB BioPharma , Chemin du Foriest 1 , 1420 Braine-l'Alleud , Belgium
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4
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Cheshmazar N, Dastmalchi S, Terao M, Garattini E, Hamzeh-Mivehroud M. Aldehyde oxidase at the crossroad of metabolism and preclinical screening. Drug Metab Rev 2019; 51:428-452. [DOI: 10.1080/03602532.2019.1667379] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Narges Cheshmazar
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Medicinal Chemistry, School of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Siavoush Dastmalchi
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Medicinal Chemistry, School of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mineko Terao
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Enrico Garattini
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Maryam Hamzeh-Mivehroud
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Medicinal Chemistry, School of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
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5
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Cortés-Puch I, Sun J, Schechter AN, Solomon SB, Park JW, Feng J, Gilliard C, Natanson C, Piknova B. Inhaled nebulized nitrite and nitrate therapy in a canine model of hypoxia-induced pulmonary hypertension. Nitric Oxide 2019; 91:1-14. [PMID: 31299340 DOI: 10.1016/j.niox.2019.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 06/17/2019] [Accepted: 07/02/2019] [Indexed: 12/12/2022]
Abstract
Dysfunction in the nitric oxide (NO) signaling pathway can lead to the development of pulmonary hypertension (PH) in mammals. Discovery of an alternative pathway to NO generation involving reduction from nitrate to nitrite and to NO has motivated the evaluation of nitrite as an alternative to inhaled NO for PH. In contrast, inhaled nitrate has not been evaluated to date, and potential benefits include a prolonged half-life and decreased risk of methemoglobinemia. In a canine model of acute hypoxia-induced PH we evaluated the effects of inhaled nitrate to reduce pulmonary arterial pressure (PAP). In a randomized controlled trial, inhaled nitrate was compared to inhaled nitrite and inhaled saline. Exhaled NO, PAP and systemic blood pressures were continuously monitored. Inhaled nitrite significantly decreased PAP and increased exhaled NO. In contrast, inhaled nitrate and inhaled saline did not decrease PAP or increase exhaled NO. Unexpectedly, we found that inhaled nitrite resulted in prolonged (>5 h) exhaled NO release, increase in nitrate venous/arterial levels and a late surge in venous nitrite levels. These findings do not support a therapeutic role for inhaled nitrate in PH but may have therapeutic implications for inhaled nitrite in various disease states.
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Affiliation(s)
- Irene Cortés-Puch
- National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD, USA; Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA; Division of Pulmonary, Critical Care and Sleep Medicine, University of California Davis, Sacramento, CA, USA
| | - Junfeng Sun
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Alan N Schechter
- National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD, USA
| | - Steven B Solomon
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Ji Won Park
- National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD, USA
| | - Jing Feng
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Cameron Gilliard
- National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD, USA; Penn State Health Milton S. Hershey Medical Center, Department of Anesthesia and Perioperative Medicine, Hershey, PA, USA
| | - Charles Natanson
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Barbora Piknova
- National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD, USA.
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6
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Mu X, Ji C, Wang Q, Liu K, Hao X, Zhang G, Shi X, Zhang Y, Gonzalez FJ, Wang Q, Wang Y. Non-targeted metabolomics reveals diagnostic biomarker in the tongue coating of patients with chronic gastritis. J Pharm Biomed Anal 2019; 174:541-551. [PMID: 31255854 DOI: 10.1016/j.jpba.2019.06.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 05/12/2019] [Accepted: 06/19/2019] [Indexed: 12/30/2022]
Abstract
Analysis of the properties of the tongue has been used in traditional Chinese medicine for disease diagnosis. Notably, tongue analysis, which is non-invasive and convenient compared with gastroscopy and pathological examination, can be used to assess chronic gastritis (CG). In order to find potential diagnostic biomarkers and study the metabolic mechanisms of the endogenous small molecules in the tongue coating related to CG, a non-targeted metabolomic analysis method was developed using ultra high performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry (UHPLC-Q/TOF-MS). It was performed using two different columns in positive and negative ion scanning modes separately. The stability of the samples was evaluated and the age and gender factors of the subjects were excluded to ensure the reliability of the data in this study. Finally, under the four analysis models, 130, 229, 113 and 92 differential compounds were found using multivariate statistical methods respectively. 37 potential biomarkers were putatively identified after removing the duplicate compounds and five potential diagnostic biomarkers were putatively identified by receiver operating characteristic (ROC) curve analysis, including inosine, oleamide, adenosine, N-acetylglucosamine (GlcNAc) and xanthine. The main metabolic pathways associated with CG were purine metabolism, amino acid metabolism, sphingolipid metabolism and energy metabolism, which suggested that oxygen free radicals and energy metabolism were altered in patients with CG. These results provided a potential new basis for the quantitative diagnosis and pathogenesis of CG.
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Affiliation(s)
- Xiyan Mu
- Department of Pharmaceutical Analysis, School of Pharmacy, Hebei Medical University, Shijiazhuang, PR China
| | - Chuanyuan Ji
- Hebei Province Hospital of Traditional Chinese Medicine, Shijiazhuang, PR China
| | - Qi Wang
- Department of Pharmaceutical Analysis, School of Pharmacy, Hebei Medical University, Shijiazhuang, PR China
| | - Kun Liu
- Department of Pharmaceutical Analysis, School of Pharmacy, Hebei Medical University, Shijiazhuang, PR China
| | - Xinyu Hao
- Hebei Province Hospital of Traditional Chinese Medicine, Shijiazhuang, PR China
| | - Guanhua Zhang
- Department of Pharmaceutical Analysis, School of Pharmacy, Hebei Medical University, Shijiazhuang, PR China
| | - Xiaowei Shi
- Department of Pharmaceutical Analysis, School of Pharmacy, Hebei Medical University, Shijiazhuang, PR China
| | - Yuqian Zhang
- Department of Pharmaceutical Analysis, School of Pharmacy, Hebei Medical University, Shijiazhuang, PR China
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Qiao Wang
- Department of Pharmaceutical Analysis, School of Pharmacy, Hebei Medical University, Shijiazhuang, PR China.
| | - Yangang Wang
- Hebei Province Hospital of Traditional Chinese Medicine, Shijiazhuang, PR China.
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7
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Kanemitsu T, Tsurudome Y, Kusunose N, Oda M, Matsunaga N, Koyanagi S, Ohdo S. Periodic variation in bile acids controls circadian changes in uric acid via regulation of xanthine oxidase by the orphan nuclear receptor PPARα. J Biol Chem 2017; 292:21397-21406. [PMID: 29101234 DOI: 10.1074/jbc.m117.791285] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 11/01/2017] [Indexed: 12/16/2022] Open
Abstract
Xanthine oxidase (XOD), also known as xanthine dehydrogenase, is a rate-limiting enzyme in purine nucleotide degradation, which produces uric acid. Uric acid concentrations in the blood and liver exhibit circadian oscillations in both humans and rodents; however, the underlying mechanisms remain unclear. Here, we demonstrate that XOD expression and enzymatic activity exhibit circadian oscillations in the mouse liver. We found that the orphan nuclear receptor peroxisome proliferator-activated receptor-α (PPARα) transcriptionally activated the mouse XOD gene and that bile acids suppressed XOD transactivation. The synthesis of bile acids is known to be under the control of the circadian clock, and we observed that the time-dependent accumulation of bile acids in hepatic cells interfered with the recruitment of the co-transcriptional activator p300 to PPARα, thereby repressing XOD expression. This time-dependent suppression of PPARα-mediated transactivation by bile acids caused an oscillation in the hepatic expression of XOD, which, in turn, led to circadian alterations in uric acid production. Finally, we also demonstrated that the anti-hyperuricemic effect of the XOD inhibitor febuxostat was enhanced by administering it at the time of day before hepatic XOD activity increased. These results suggest an underlying mechanism for the circadian alterations in uric acid production and also underscore the importance of selecting an appropriate time of day for administering XOD inhibitors.
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Affiliation(s)
| | | | | | | | - Naoya Matsunaga
- From the Departments of Pharmaceutics and.,Glocal Healthcare Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Satoru Koyanagi
- From the Departments of Pharmaceutics and.,Glocal Healthcare Science, Kyushu University, Fukuoka 812-8582, Japan
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8
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Kato S, Kato M, Kusano T, Nishino T. New Strategy That Delays Progression of Amyotrophic Lateral Sclerosis in G1H-G93A Transgenic Mice: Oral Administration of Xanthine Oxidoreductase Inhibitors That Are Not Substrates for the Purine Salvage Pathway. J Neuropathol Exp Neurol 2017; 75:1124-1144. [PMID: 27815397 DOI: 10.1093/jnen/nlw088] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS), Lou Gehrig's disease, is a progressive fatal neurodegenerative disease that involves both upper and lower motor neurons. We orally administered 4 xanthine oxidoreductase (XOR) inhibitors to G1H-G93A mice carrying 25 transgene copy numbers of human mutant G93A superoxide dismutase 1, from 80 days of age. Three nonpurine-analogue inhibitors (TEI-6720: Febuxostat, Y-700 and FYX-051), but not allopurinol with a purine analogue ring (pyrazolo pyrimidine ring), significantly delayed disease onset, prolonged survival and the duration of disease stages, improved clinical signs, and alleviated weight loss. Exercise testing (extension reflex, inclined plane, footprint, rotarod, and beam balance tests) showed significantly improved motor function in the G1H-G93A mice treated with these 3 inhibitors. Significant amelioration of disease was seen even when TEI-6720 or Y-700 was administered after the appearance of early signs. Histopathological evaluation in the late stage revealed that G1H-G93A mice treated with TEI-6720 had well-preserved motor neurons and fewer inclusion bodies, compared with mice treated with placebo or with allopurinol. Our results indicate that these 3 nonpurine-analogue XOR inhibitors might increase the supply of high-energy compounds via the purine salvage pathway, thereby protecting motor neurons against death. This strategy may be applicable for oral therapy of ALS patients.
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Affiliation(s)
- Shinsuke Kato
- From the Division of Neuropathology (SK) and the Division of Molecular Pathology (MK), Department of Pathology, Tottori University Faculty of Medicine, Yonago, Japan; and the Department of Biochemistry and Molecular Biology (TK, TN), Nippon Medical School, Tokyo, Japan
| | - Masako Kato
- From the Division of Neuropathology (SK) and the Division of Molecular Pathology (MK), Department of Pathology, Tottori University Faculty of Medicine, Yonago, Japan; and the Department of Biochemistry and Molecular Biology (TK, TN), Nippon Medical School, Tokyo, Japan
| | - Teruo Kusano
- From the Division of Neuropathology (SK) and the Division of Molecular Pathology (MK), Department of Pathology, Tottori University Faculty of Medicine, Yonago, Japan; and the Department of Biochemistry and Molecular Biology (TK, TN), Nippon Medical School, Tokyo, Japan
| | - Takeshi Nishino
- From the Division of Neuropathology (SK) and the Division of Molecular Pathology (MK), Department of Pathology, Tottori University Faculty of Medicine, Yonago, Japan; and the Department of Biochemistry and Molecular Biology (TK, TN), Nippon Medical School, Tokyo, Japan
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9
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Tomioka NH, Tamura Y, Takada T, Shibata S, Suzuki H, Uchida S, Hosoyamada M. Immunohistochemical and in situ hybridization study of urate transporters GLUT9/URATv1, ABCG2, and URAT1 in the murine brain. Fluids Barriers CNS 2016; 13:22. [PMID: 27955673 PMCID: PMC5154092 DOI: 10.1186/s12987-016-0046-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 11/26/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Uric acid (UA) is known to exert neuroprotective effects in the brain. However, the mechanism of UA regulation in the brain is not well characterized. In our previous study, we described that the mouse urate transporter URAT1 is localized to the cilia and apical surface of ventricular ependymal cells. To further strengthen the hypothesis that UA is transported transcellularly at the ependymal cells, we aimed to assess the distribution of other UA transporters in the murine brain. METHODS Immunostaining and highly-sensitive in situ hybridization was used to assess the distribution of UA transporters: GLUT9/URATv1, ABCG2, and URAT1. RESULTS Immunostaining for GLUT9 was observed in ependymal cells, neurons, and brain capillaries. Immunostaining for ABCG2 was observed in the choroid plexus epithelium and brain capillaries, but not in ependymal cells. These results were validated by in situ hybridization. CONCLUSIONS We propose that given their specific expression patterns in ependymal, choroid plexus epithelial, and brain capillary endothelial cells in this study, UA may be transported by these UA transporters in the murine brain. This may provide a novel strategy for targeted neuroprotection.
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Affiliation(s)
- Naoko H. Tomioka
- Department of Human Physiology and Pathology, Faculty of Pharma-Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605 Japan
| | - Yoshifuru Tamura
- Department of Internal Medicine, Teikyo University School of Medicine, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605 Japan
| | - Tappei Takada
- Department of Pharmacy, The University of Tokyo Hospital, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655 Japan
| | - Shigeru Shibata
- Department of Internal Medicine, Teikyo University School of Medicine, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605 Japan
| | - Hiroshi Suzuki
- Department of Pharmacy, The University of Tokyo Hospital, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655 Japan
| | - Shunya Uchida
- Department of Internal Medicine, Teikyo University School of Medicine, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605 Japan
| | - Makoto Hosoyamada
- Department of Human Physiology and Pathology, Faculty of Pharma-Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605 Japan
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10
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Nitrite reduction by molybdoenzymes: a new class of nitric oxide-forming nitrite reductases. J Biol Inorg Chem 2015; 20:403-33. [DOI: 10.1007/s00775-014-1234-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 12/14/2014] [Indexed: 02/07/2023]
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Affiliation(s)
- Luisa B. Maia
- REQUIMTE/CQFB, Departamento
de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - José J. G. Moura
- REQUIMTE/CQFB, Departamento
de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
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12
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Castiglione N, Rinaldo S, Giardina G, Stelitano V, Cutruzzolà F. Nitrite and nitrite reductases: from molecular mechanisms to significance in human health and disease. Antioxid Redox Signal 2012; 17:684-716. [PMID: 22304560 DOI: 10.1089/ars.2011.4196] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Nitrite, previously considered physiologically irrelevant and a simple end product of endogenous nitric oxide (NO) metabolism, is now envisaged as a reservoir of NO to be activated in response to oxygen (O(2)) depletion. In the first part of this review, we summarize and compare the mechanisms of nitrite-dependent production of NO in selected bacteria and in eukaryotes. Bacterial nitrite reductases, which are copper or heme-containing enzymes, play an important role in the adaptation of pathogens to O(2) limitation and enable microrganisms to survive in the human body. In mammals, reduction of nitrite to NO under hypoxic conditions is carried out in tissues and blood by an array of metalloproteins, including heme-containing proteins and molybdenum enzymes. In humans, tissues play a more important role in nitrite reduction, not only because most tissues produce more NO than blood, but also because deoxyhemoglobin efficiently scavenges NO in blood. In the second part of the review, we outline the significance of nitrite in human health and disease and describe the recent advances and pitfalls of nitrite-based therapy, with special attention to its application in cardiovascular disorders, inflammation, and anti-bacterial defence. It can be concluded that nitrite (as well as nitrate-rich diet for long-term applications) may hold promise as therapeutic agent in vascular dysfunction and ischemic injury, as well as an effective compound able to promote angiogenesis.
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Affiliation(s)
- Nicoletta Castiglione
- Department of Biochemical Sciences, Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome, Italy
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13
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Al-Abbasi FA. Acrylonitrile-induced gastric toxicity in rats: the role of xanthine oxidase. Med Sci Monit 2012; 18:BR208-14. [PMID: 22648241 PMCID: PMC3560737 DOI: 10.12659/msm.882896] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 12/08/2011] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Acrylonitrile (ACN) is an extensively produced aliphatic nitrile. The gastrointestinal tract is an important target organ for ACN toxicity. The objective of the present study was to investigate the role of xanthine oxidase (XO) in ACN-induced gastric toxicity in rats. MATERIAL/METHODS We assessed the effect of ACN on oxidative stress parameters as xanthine oxidase (XO) and total xanthine dehydrogenase (XD)/ XO activity, superoxide anion (O(2)(.-)) production, reduced glutathione (GSH) levels and lipid peroxidation in gastric tissues. RESULTS A single oral dose of ACN (25 mg/kg) caused a significant enhancement in XO activity. ACN also caused a significant depletion of GSH levels, enhanced O(2)(.-) production and increased lipid peroxidation in the time-course experiment. In the dose-response experiment, ACN accelerated the conversion of XD to XO, with a significant depletion of gastric GSH in a dose-related manner. A strong negative correlation existed between the levels of GSH and the percentage enhancement in XO activity (r =-0.997). (O(2)(.-)) production and malondialdehyde (MDA) formation were significantly elevated in a dose-related manner. Pretreatment with allopurinol (50 mg/kg) significantly protected against ACN-induced rise in XO activity, depletion of GSH, and elevated production of (O(2)(.-)). However, pretreatment with diethyl maleate (DEM; 100 mg/kg) significantly aggravated the ACN-induced GSH depletion and rise in XO activity. Furthermore, DEM significantly enhanced (O(2)(.-)) and MDA production. CONCLUSIONS The present study indicates that enhancement of XO activity could be implicated in ACN-induced gastric damage in rats.
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Affiliation(s)
- Fahad A Al-Abbasi
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia.
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14
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Sharma R, Strelevitz TJ, Gao H, Clark AJ, Schildknegt K, Obach RS, Ripp SL, Spracklin DK, Tremaine LM, Vaz ADN. Deuterium Isotope Effects on Drug Pharmacokinetics. I. System-Dependent Effects of Specific Deuteration with Aldehyde Oxidase Cleared Drugs. Drug Metab Dispos 2011; 40:625-34. [DOI: 10.1124/dmd.111.042770] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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15
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Lawler JM, Kim JH, Kwak HB, Barnes WS. Redox modulation of diaphragm contractility: Interaction between DHPR and RyR channels. Free Radic Biol Med 2010; 49:1969-77. [PMID: 20920578 PMCID: PMC3005760 DOI: 10.1016/j.freeradbiomed.2010.09.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 08/28/2010] [Accepted: 09/24/2010] [Indexed: 10/19/2022]
Abstract
Previous reports indicate that reactive oxygen species (ROS) may modulate contractility in skeletal muscle. Although Ca(2+)-sensitivity of the contractile apparatus appears to be a primary site of regulation, dihydropyridine receptor (DHPR or L-type Ca(2+) channels) and calcium efflux in isolated sarcoplasmic reticulum (SR) vesicles appear to be redox sensitive as well. However, DHPR as a target is poorly understood in intact muscles at body temperature, particularly in the diaphragm, a muscle more dependent on external Ca(2+) than locomotor muscles. Previously, we reported that oxidant challenge via xanthine oxidase (XO) alters the K(+) contractures in diaphragm fiber bundles, suggestive of a role of L-type Ca(2+) channels. Contractility of isolated rat diaphragm fiber bundles revealed a biphasic response to ROS challenge that was dose and time dependent. Potentiation of twitch and low-frequency diaphragm fiber bundle contractility with 0.02 U•ml(-1) XO was reversible or partially preventable with washout, dithiothreitol, and the SOD/catalase mimetic EUK-134. The RyR antagonist ruthenium red inhibited xanthine oxidase-induced potentiation, while the RyR agonist caffeine elevated diaphragm twitch and low-frequency tension in a non-additive manner by 55% when introduced simultaneously with ROS challenge. The DHPR antagonist nitrendipine (15 μM) inhibited elevation in low-frequency diaphragm tension produced by ROS challenge. Caffeine threshold tension curves were shifted to the left with 0.02 U•ml(-1) XO, but this effect was partially reversed with 15 μM nitrendipine. These results are consistent with the hypothesis that DHPR redox state and RyR function are modulated in an interactive manner, affecting contractility in intact diaphragm fiber bundles.
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Affiliation(s)
- John M Lawler
- Department of Health and Kinesiology, Interdisciplinary Faculty of Nutrition, Texas A&M University, College Station, TX 77843-4243, USA.
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16
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den Hengst WA, Gielis JF, Lin JY, Van Schil PE, De Windt LJ, Moens AL. Lung ischemia-reperfusion injury: a molecular and clinical view on a complex pathophysiological process. Am J Physiol Heart Circ Physiol 2010; 299:H1283-99. [PMID: 20833966 DOI: 10.1152/ajpheart.00251.2010] [Citation(s) in RCA: 274] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lung ischemia-reperfusion injury remains one of the major complications after cardiac bypass surgery and lung transplantation. Due to its dual blood supply system and the availability of oxygen from alveolar ventilation, the pathogenetic mechanisms of ischemia-reperfusion injury in the lungs are more complicated than in other organs, where loss of blood flow automatically leads to hypoxia. In this review, an extensive overview is given of the molecular and cellular mechanisms that are involved in the pathogenesis of lung ischemia-reperfusion injury and the possible therapeutic strategies to reduce or prevent it. In addition, the roles of neutrophils, alveolar macrophages, cytokines, and chemokines, as well as the alterations in the cell-death related pathways, are described in detail.
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Affiliation(s)
- Willem A den Hengst
- Department of Thorax and Vascular Surgery, University of Antwerp, Antwerp, Belgium
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17
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Zweier JL, Li H, Samouilov A, Liu X. Mechanisms of nitrite reduction to nitric oxide in the heart and vessel wall. Nitric Oxide 2010; 22:83-90. [PMID: 20044016 DOI: 10.1016/j.niox.2009.12.004] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 12/10/2009] [Accepted: 12/21/2009] [Indexed: 02/07/2023]
Abstract
Nitric oxide (NO) is an important regulator of a variety of biological functions, and also has a role in the pathogenesis of cellular injury. It had been generally accepted that NO is solely generated in biological tissues by specific nitric oxide synthases (NOS) which metabolize arginine to citrulline with the formation of NO. However, over the last 15 years, nitrite-mediated NO production has been shown to be an important mechanism of NO formation in the heart and cardiovascular system. Now numerous studies have demonstrated that nitrite can be an important source rather than simply a product of NO in mammalian cells and tissues and can be a potential vasodilator drug for cardiovascular diseases. There are a variety of mechanisms of nitrite reduction to NO and it is now appreciated that this process, while enhanced under hypoxic conditions, also occurs under normoxia. Several methods, including electron paramagnetic resonance, chemiluminescence NO analyzer, and NO electrode have been utilized to measure, quantitate, and image nitrite-mediated NO formation. Results reveal that nitrite-dependent NO generation plays critical physiological and pathological roles, and is controlled by oxygen tension, pH, reducing substrates and nitrite levels. In this manuscript, we review the mechanisms of nitrite-mediated NO formation and the effects of oxygen on this process with a focus on how this occurs in the heart and vessels.
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Affiliation(s)
- Jay L Zweier
- Davis Heart and Lung Research Institute, The Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University College of Medicine, 473 West 12th Avenue, Columbus, OH 43210, USA.
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18
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Zhou SS, Li D, Sun WP, Guo M, Lun YZ, Zhou YM, Xiao FC, Jing LX, Sun SX, Zhang LB, Luo N, Bian FN, Zou W, Dong LB, Zhao ZG, Li SF, Gong XJ, Yu ZG, Sun CB, Zheng CL, Jiang DJ, Li ZN. Nicotinamide overload may play a role in the development of type 2 diabetes. World J Gastroenterol 2009; 15:5674-84. [PMID: 19960564 PMCID: PMC2789220 DOI: 10.3748/wjg.15.5674] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate whether nicotinamide overload plays a role in type 2 diabetes.
METHODS: Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of nicotinamide and N1-methylnicotinamide on glucose metabolism, plasma H2O2 levels and tissue nicotinamide adenine dinucleotide (NAD) contents of adult Sprague-Dawley rats were observed. The role of human sweat glands and rat skin in nicotinamide metabolism was investigated using sauna and burn injury, respectively.
RESULTS: Diabetic subjects had significantly higher plasma N1-methylnicotinamide levels 5 h after a 100-mg nicotinamide load than the non-diabetic subjects (0.89 ± 0.13 μmol/L vs 0.6 ± 0.13 μmol/L, P < 0.001). Cumulative doses of nicotinamide (2 g/kg) significantly increased rat plasma N1-methylnicotinamide concentrations associated with severe insulin resistance, which was mimicked by N1-methylnicotinamide. Moreover, cumulative exposure to N1-methylnicotinamide (2 g/kg) markedly reduced rat muscle and liver NAD contents and erythrocyte NAD/NADH ratio, and increased plasma H2O2 levels. Decrease in NAD/NADH ratio and increase in H2O2 generation were also observed in human erythrocytes after exposure to N1-methylnicotinamide in vitro. Sweating eliminated excessive nicotinamide (5.3-fold increase in sweat nicotinamide concentration 1 h after a 100-mg nicotinamide load). Skin damage or aldehyde oxidase inhibition with tamoxifen or olanzapine, both being notorious for impairing glucose tolerance, delayed N1-methylnicotinamide clearance.
CONCLUSION: These findings suggest that nicotinamide overload, which induced an increase in plasma N1-methylnicotinamide, associated with oxidative stress and insulin resistance, plays a role in type 2 diabetes.
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Li H, Kundu TK, Zweier JL. Characterization of the magnitude and mechanism of aldehyde oxidase-mediated nitric oxide production from nitrite. J Biol Chem 2009; 284:33850-8. [PMID: 19801639 DOI: 10.1074/jbc.m109.019125] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Aldehyde oxidase (AO) is a cytosolic enzyme with an important role in drug and xenobiotic metabolism. Although AO has structural similarity to bacterial nitrite reductases, it is unknown whether AO-catalyzed nitrite reduction can be an important source of NO. The mechanism, magnitude, and quantitative importance of AO-mediated nitrite reduction in tissues have not been reported. To investigate this pathway and its quantitative importance, EPR spectroscopy, chemiluminescence NO analyzer, and immunoassays of cGMP formation were performed. The kinetics and magnitude of AO-dependent NO formation were characterized. In the presence of typical aldehyde substrates or NADH, AO reduced nitrite to NO. Kinetics of AO-catalyzed nitrite reduction followed Michaelis-Menten kinetics under anaerobic conditions. Under physiological conditions, nitrite levels are far below its measured K(m) value in the presence of either the flavin site electron donor NADH or molybdenum site aldehyde electron donors. Under aerobic conditions with the FAD site-binding substrate, NADH, AO-mediated NO production was largely maintained, although with aldehyde substrates oxygen-dependent inhibition was seen. Oxygen tension, substrate, and pH levels were important regulators of AO-catalyzed NO generation. From kinetic data, it was determined that during ischemia hepatic, pulmonary, or myocardial AO and nitrite levels were sufficient to result in NO generation comparable to or exceeding maximal production by constitutive NO synthases. Thus, AO-catalyzed nitrite reduction can be an important source of NO generation, and its NO production will be further increased by therapeutic administration of nitrite.
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Affiliation(s)
- Haitao Li
- Center for Biomedical EPR Spectroscopy and Imaging, the Davis Heart and Lung Research Institute, Columbus, Ohio 43210-1252, USA.
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20
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Ishiyama F, Iijima K, Asanuma K, Ara N, Yoshitake J, Abe Y, Koike T, Imatani A, Ohara S, Shimosegawa T. Exogenous luminal nitric oxide exacerbates esophagus tissue damage in a reflux esophagitis model of rats. Scand J Gastroenterol 2009; 44:527-37. [PMID: 19172433 DOI: 10.1080/00365520802699260] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Cytotoxic concentrations of nitric oxide are generated luminally at the gastroesophageal junction through the entero-salivary recirculation of dietary nitrate in humans. The site of luminal nitric oxide generation shifts to the lower esophagus when gastric acid is refluxed into the esophagus. The aim of this study was to investigate the influence of persistent administration of exogenous nitric oxide on esophageal damage. MATERIAL AND METHODS 0.1% sodium nitrite and/or 1% ascorbic acid was administered in an established rat acid-refluxed esophagitis model. Co-administration of both reactants in this model is thought to induce high concentrations of nitric oxide luminally in the esophagus by an acid-catalyzed chemical reaction when refluxed gastric acid is present. The tissue damage was evaluated by a macroscopic lesion index and myeloperoxidase activity. Nitrotyrosin was assessed immunohistochemically as a footprint of peroxynitrite formation. RESULTS Co-administration of sodium nitrite and ascorbic acid induced a 4- to 5-fold increase in the esophageal damage compared with baseline reflux esophagitis, while the damage was unchanged when either of the reagents alone was given. Nitrotyrosine was strongly stained in the tissue from the co-administration. Treatment of superoxide scavengers efficiently prevented the exacerbation of esophageal damage by exogenous nitric oxide exposure, suggesting an essential role of superoxide in esophageal damage. CONCLUSIONS Exogenous luminal nitric oxide greatly exacerbated the tissue damage of reflux esophagitis. Diffusion of the luminal nitric oxide into the adjacent superoxide-enriched inflamed tissue of the esophagus could lead to the production of the highly toxic agent peroxynitrite, thus causing exacerbation of the esophageal damage.
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Affiliation(s)
- Fumitake Ishiyama
- Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
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21
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Corpas FJ, Palma JM, Sandalio LM, Valderrama R, Barroso JB, Del Río LA. Peroxisomal xanthine oxidoreductase: characterization of the enzyme from pea (Pisum sativum L.) leaves. JOURNAL OF PLANT PHYSIOLOGY 2008; 165:1319-30. [PMID: 18538891 DOI: 10.1016/j.jplph.2008.04.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Revised: 04/04/2008] [Accepted: 04/04/2008] [Indexed: 05/26/2023]
Abstract
The presence and properties of the enzyme xanthine oxidoreductase (XOR) in peroxisomes from pea (Pisum sativum L.) leaves were studied using biochemical and immunological methods. The activity analysis showed that, in leaf peroxisomes, the superoxide-generating XOR form, xanthine oxidase (XOD), was predominant over the xanthine dehydrogenase form (XDH), with a XDH/XOD ratio of 0.5. However, in crude extracts of pea leaves, the XDH form was more abundant, with a XDH/XOD ratio of 1.6. The native molecular mass of the peroxisomal XOR determined by polyacrylamide gel electrophoresis was 290 kDa. Using western blot assays, we identified an immunoreactive band of 59 kDa that was not affected by the reducing reagent DTT or endogenous proteases. The analysis of pea leaves by electron microscopy immunogold labeling with affinity-purified antibodies against rat XOD confirmed that this enzyme was localized in the matrix of peroxisomes, as well as in chloroplasts and cytosol. In pea plants subjected to abiotic stress by cadmium, the activity of the peroxisomal XOR was reduced, whereas its protein level expression increased. The results confirmed that leaf peroxisomes contain XOR, and suggest that this peroxisomal metalloflavoprotein enzyme is involved in the mechanism of response of pea plants to abiotic stress by heavy metals.
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Affiliation(s)
- Francisco J Corpas
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, CSIC, Apartado, Granada, Spain.
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22
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Li H, Cui H, Kundu TK, Alzawahra W, Zweier JL. Nitric oxide production from nitrite occurs primarily in tissues not in the blood: critical role of xanthine oxidase and aldehyde oxidase. J Biol Chem 2008; 283:17855-63. [PMID: 18424432 DOI: 10.1074/jbc.m801785200] [Citation(s) in RCA: 210] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recent studies have shown that nitrite is an important storage form and source of NO in biological systems. Controversy remains, however, regarding whether NO formation from nitrite occurs primarily in tissues or in blood. Questions also remain regarding the mechanism, magnitude, and contributions of several alternative pathways of nitrite-dependent NO generation in biological systems. To characterize the mechanism and magnitude of NO generation from nitrite, electron paramagnetic resonance spectroscopy, chemiluminescence NO analyzer, and immunoassays of cGMP formation were performed. The addition of nitrite triggered a large amount of NO generation in tissues such as heart and liver, but only trace NO production in blood. Carbon monoxide increased NO release from blood, suggesting that hemoglobin acts to scavenge NO not to generate it. Administration of the xanthine oxidase (XO) inhibitor oxypurinol or aldehyde oxidase (AO) inhibitor raloxifene significantly decreased NO generation from nitrite in heart or liver. NO formation rates increased dramatically with decreasing pH or with decreased oxygen tension. Isolated enzyme studies further confirm that XO and AO, but not hemoglobin, are critical nitrite reductases. Overall, NO generation from nitrite mainly occurs in tissues not in the blood, with XO and AO playing critical roles in nitrite reduction, and this process is regulated by pH, oxygen tension, nitrite, and reducing substrate concentrations.
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Affiliation(s)
- Haitao Li
- Center for Biomedical EPR Spectroscopy and Imaging, Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH 43210, USA.
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23
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Osborne PG, Hashimoto M. Brain ECF antioxidant interactions in hamsters during arousal from hibernation. Behav Brain Res 2007; 178:115-22. [PMID: 17207864 DOI: 10.1016/j.bbr.2006.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 12/06/2006] [Accepted: 12/08/2006] [Indexed: 12/25/2022]
Abstract
Warming from hibernation to cenothermia involves intense metabolic activity and large fluxes in regional blood flow and volume. During this transition, levels of the antioxidants, ascorbate (AA), urate and glutathione (GSH) in brain tissue, extracellular fluid (ECF) and plasma change substantially. Striatal ECF was sampled and manipulated using very slow perfusion microdialysis to examine the mechanisms that influence the changing profile of striatal ECF AA, urate and GSH levels during arousal from hibernation to cenothermia in Syrian hamsters (Mesocricetus auratus). Omission of glucose from the perfusate had no effect upon the respective decrease, increase and transient increase in striatal ECF levels of AA, GSH and urate observed during arousal from hibernation to cenothermia. In contrast, inhibition of xanthine dehydrogenase/oxidase (XOR) activity by reverse dialysis with oxypurinol, itself a free radical scavenger, decreased ECF urate and preserved ECF AA levels. This suggests that some ECF AA is oxidized by free radical products of XOR flux and/or by other free radical producing processes activated during the transition from hibernation to cenothermia. Local supplementation of ECF AA, GSH and cystiene had no effect upon the profile of transient increase of ECF urate observed during arousal from hibernation. The production of free radicals by XOR and the disappearance of AA from the ECF continues for at least 2h immediately after the hamster has attained cenothermia. The hamster, immediately after arousal from hibernation, can be utilized as a natural model to study free radical production and effective scavenging at cenothermia.
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Affiliation(s)
- Peter G Osborne
- Institute of Life Sciences, National Taitung University, Taitung 950, Taiwan.
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Nishimura M, Naito S. Tissue-specific mRNA expression profiles of human phase I metabolizing enzymes except for cytochrome P450 and phase II metabolizing enzymes. Drug Metab Pharmacokinet 2006; 21:357-74. [PMID: 17072089 DOI: 10.2133/dmpk.21.357] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Pairs of forward and reverse primers and TaqMan probes specific to each of 52 human phase I metabolizing enzymes (alcohol dehydrogenase, aldehyde dehydrogenase, aldehyde oxidase, dihydropyrimidine dehydrogenase, epoxide hydrolase, esterase, flavin-containing monooxygenase, monoamine oxidase, prostaglandin endoperoxide synthase, quinone oxidoreductase, and xanthene dehydrogenase) and 48 human phase II metabolizing enzymes (acetyltransferase, acyl-CoA:amino acid N-acyltransferase, UDP-glucuronosyltransferase, glutathione S-transferase, methyltransferase, and sulfotransferase) were prepared. The mRNA expression level of each target enzyme was analyzed in total RNA from single and pooled specimens of various human tissues (adrenal gland, bone marrow, brain, colon, heart, kidney, liver, lung, pancreas, peripheral leukocytes, placenta, prostate, salivary gland, skeletal muscle, small intestine, spinal cord, spleen, stomach, testis, thymus, thyroid gland, trachea, and uterus) by real-time reverse transcription PCR using an ABI PRISM 7700 Sequence Detection System. Further, individual differences in the mRNA expression of representative human phase I and II metabolizing enzymes in the liver were also evaluated. The mRNA expression profiles of the above phase I and phase II metabolizing enzymes in 23 different human tissues were used to identify the tissues exhibiting high transcriptional activity for these enzymes. These results are expected to be valuable in establishing drug metabolism-mediated screening systems for new chemical entities in new drug development and in research concerning the clinical diagnosis of disease.
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Affiliation(s)
- Masuhiro Nishimura
- Division of Pharmacology, Drug Safety and Metabolism, Otsuka Pharmaceutical Factory Inc, Naruto, Tokushima, Japan.
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Kitamura S, Sugihara K, Ohta S. Drug-Metabolizing Ability of Molybdenum Hydroxylases. Drug Metab Pharmacokinet 2006; 21:83-98. [PMID: 16702728 DOI: 10.2133/dmpk.21.83] [Citation(s) in RCA: 176] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Molybdenum hydroxylases, which include aldehyde oxidase and xanthine oxidoreductase, are involved in the metabolism of some medicines in humans. They exhibit oxidase activity towards various heterocyclic compounds and aldehydes. The liver cytosol of various mammals also exhibits a significant reductase activity toward nitro, sulfoxide, N-oxide and other moieties, catalyzed by aldehyde oxidase. There is considerable variability of aldehyde oxidase activity in liver cytosol of mammals: humans show the highest activity, rats and mice show low activity, and dogs have no detectable activity. On the other hand, xanthine oxidoreductase activity is present widely among species. Interindividual variation of aldehyde oxidase activity is present in humans. Drug-drug interactions associated with aldehyde oxidase and xanthine oxidoreductase are of potential clinical significance. Drug metabolizing ability of molybdenum hydroxylases and the variation of the activity are described in this review.
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Affiliation(s)
- Shigeyuki Kitamura
- Graduate School of Biomedical Sciences, Hiroshima University, Kasumi, Japan.
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26
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Atmani D, Baghiani A, Harrison R, Benboubetra M. NADH oxidation and superoxide production by caprine milk xanthine oxidoreductase. Int Dairy J 2005. [DOI: 10.1016/j.idairyj.2004.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Ueda O, Sugihara K, Ohta S, Kitamura S. INVOLVEMENT OF MOLYBDENUM HYDROXYLASES IN REDUCTIVE METABOLISM OF NITRO POLYCYCLIC AROMATIC HYDROCARBONS IN MAMMALIAN SKIN. Drug Metab Dispos 2005; 33:1312-8. [PMID: 15932950 DOI: 10.1124/dmd.105.005306] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Molybdenum hydroxylases, aldehyde oxidase and xanthine oxidoreductase, were shown to be involved in the nitroreduction of 2-nitrofluorene (NF), 1-nitropyrene, and 4-nitrobiphenyl, environmental pollutants, in the skin of various mammalian species. NF was reduced to 2-aminofluorene by hamster skin cytosol in the presence of 2-hydroxypyrimidine, 4-hydroxypyrimidine, N(1)-methylnicotinamide, or benzaldehyde, but not hypoxanthine or xanthine. Inhibitors of aldehyde oxidase markedly inhibited these nitroreductase activities, but oxypurinol, an inhibitor of xanthine oxidoreductase, had little effect. In DEAE column chromatography of hamster skin cytosol, the major fraction exhibiting nitroreductase activity also showed aldehyde oxidase activity. 2-Hydroxypyrimidine-linked nitroreductase activities of skin cytosol from rabbits and guinea pigs were also inhibited by an inhibitor of aldehyde oxidase. In contrast, nitroreductase activities of skin cytosols of rats and mice were markedly inhibited by oxypurinol. When aldehyde oxidase activity was estimated in skin cytosol of various mammals using benzaldehyde oxidase activity as a marker, considerable variability of the activity was found. The highest activity was observed with hamsters, and the lowest activity with rats. On the other hand, the highest xanthine oxidoreductase activity was observed with rats, and the lowest activity with rabbits. These skin cytosols of various mammals also exhibited significant 2-hydroxypyrimidine-linked nitroreductase activities toward 1-nitropyrene and 4-nitrobiphenyl catalyzed by aldehyde oxidase and xanthine oxidoreductase. Thus, NF was mainly reduced by aldehyde oxidase and xanthine oxidoreductase in skins of animals. However, the contributions of these two molybdenum hydroxylases were considerably different among animal species.
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Affiliation(s)
- Osamu Ueda
- Hiroshima University,Graduate School of Biomedical Sciences, Minami-ku, Hiroshima 734-8551, Japan
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Rooseboom M, Commandeur JNM, Vermeulen NPE. Enzyme-catalyzed activation of anticancer prodrugs. Pharmacol Rev 2004; 56:53-102. [PMID: 15001663 DOI: 10.1124/pr.56.1.3] [Citation(s) in RCA: 370] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The rationale fo the development of prodrugs relies upon delivery of higher concentrations of a drug to target cells compared to administration of the drug itself. In the last decades, numerous prodrugs that are enzymatically activated into anti-cancer agents have been developed. This review describes the most important enzymes involved in prodrug activation notably with respect to tissue distribution, up-regulation in tumor cells and turnover rates. The following endogenous enzymes are discussed: aldehyde oxidase, amino acid oxidase, cytochrome P450 reductase, DT-diaphorase, cytochrome P450, tyrosinase, thymidylate synthase, thymidine phosphorylase, glutathione S-transferase, deoxycytidine kinase, carboxylesterase, alkaline phosphatase, beta-glucuronidase and cysteine conjugate beta-lyase. In relation to each of these enzymes, several prodrugs are discussed regarding organ- or tumor-selective activation of clinically relevant prodrugs of 5-fluorouracil, axazaphosphorines (cyclophosphamide, ifosfamide, and trofosfamide), paclitaxel, etoposide, anthracyclines (doxorubicin, daunorubicin, epirubicin), mercaptopurine, thioguanine, cisplatin, melphalan, and other important prodrugs such as menadione, mitomycin C, tirapazamine, 5-(aziridin-1-yl)-2,4-dinitrobenzamide, ganciclovir, irinotecan, dacarbazine, and amifostine. In addition to endogenous enzymes, a number of nonendogenous enzymes, used in antibody-, gene-, and virus-directed enzyme prodrug therapies, are described. It is concluded that the development of prodrugs has been relatively successful; however, all prodrugs lack a complete selectivity. Therefore, more work is needed to explore the differences between tumor and nontumor cells and to develop optimal substrates in terms of substrate affinity and enzyme turnover rates fo prodrug-activating enzymes resulting in more rapid and selective cleavage of the prodrug inside the tumor cells.
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Affiliation(s)
- Martijn Rooseboom
- Leiden/Amsterdam Center for Drug Research (L.A.C.D.R.), Division of Molecular Toxicology, Department of Pharmacochemistry, Vrije Universiteit Amsterdam, De Boelelaan 1083, Amsterdam, The Netherlands.
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Silva FMD, Silveira RJ, Hallal ALDLC, Wilhelm Filho D, Cardoso JJDD, Leão LEV. Efeito da ventilação com diferentes frações inspiradas de oxigênio e do alopurinol na isquemia-reperfusão pulmonar em ratos. Rev Col Bras Cir 2004. [DOI: 10.1590/s0100-69912004000500005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJETIVO: Avaliar o efeito da ventilação associada a frações inspiradas de oxigênio a 0,21 e 1,00 e do alopurinol (antioxidante) na isquemia-reperfusão pulmonar. MÉTODO: Foram utilizados 60 ratos Wistar, distribuídos aleatoriamente em seis grupos. O grupo 1 foi o controle; no grupo 2 os animais foram ventilados durante a isquemia-reperfusão pulmonar com FiO2 de 0,21; e no grupo 3, com FiO2 de 1,00. Os três grupos restantes 1A, 2A e 3A foram medicados com 100 mg/kg de alopurinol no pré-operatório e submetidos a procedimentos semelhantes aos grupos 1, 2 e 3, respectivamente. O modelo utilizado foi de isquemia-reperfusão normotérmica, in situ. O tempo de isquemia foi de 30 minutos, e o de reperfusão, de 10 minutos. Como parâmetros de avaliação foram utilizados a pressão arterial média sistêmica (PAM), a relação da pressão parcial de oxigênio/fração inspirada de oxigênio (PaO2/FiO2), a dosagem das substâncias reativas ao ácido tiobarbitúrico (TBARS) no tecido pulmonar e a relação entre peso pulmonar úmido e peso pulmonar seco. RESULTADOS: Em relação à PAM, ocorreu diminuição significante (p<0,05) entre os grupos 3 x 1, 2 x 2A e 3 x 3A. Na PaO2/FiO2 ocorreu diminuição significante (p<0,05) entre os grupos 3 x 2 e 3 x 3A. Nas TBARS ocorreu diminuição significante (p<0,05) entre os grupos 3 x 3A. Na relação peso pulmonar úmido/seco ocorreu aumento significante (p<0,05) entre os grupos 3 x 2, 2 x 2A e 3 x 3A. CONCLUSÕES: A ventilação com oxigênio a 21%, quando comparada à ventilação com oxigênio a 100%, apresentou diminuição menos acentuada da PAM, melhor relação entre PaO2/FiO2, e menor edema pulmonar. O uso de alopurinol no pré-operatório mostrou uma diminuição menos acentuada da PAM, melhor relação entre PaO2/FiO2, menor produção de TBARS e menor edema pulmonar, quando comparado aos resultados dos grupos que não o utilizaram.
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Affiliation(s)
- Fábio May da Silva
- Universidade Federal de São Paulo; Secretaria Estadual de Saúde de Santa Catarina
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Martin HM, Hancock JT, Salisbury V, Harrison R. Role of xanthine oxidoreductase as an antimicrobial agent. Infect Immun 2004; 72:4933-9. [PMID: 15321984 PMCID: PMC517476 DOI: 10.1128/iai.72.9.4933-4939.2004] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Hannah M Martin
- Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, United Kingdom
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31
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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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Gayle J, Jones SL, Argenzio RA, Blikslager AT. Neutrophils increase paracellular permeability of restituted ischemic-injured porcine ileum. Surgery 2002; 132:461-70. [PMID: 12324760 DOI: 10.1067/msy.2002.125320] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND We have previously shown minimal evidence of neutrophil infiltration during early reperfusion of porcine ischemic ileum. However, we noted marked neutrophil infiltration 6 to 18 hours after ischemia during mucosal repair. We postulated such neutrophil infiltration would disrupt restituting epithelium. METHODS Pigs were pretreated with anti-CD11/CD18 monoclonal antibody, superoxide dismutase-polyethylene glycol, or saline solution before inducing 1 hour of ischemia. Pigs recovered for up to 18 hours, after which mucosal repair was assessed. RESULTS One hour of ischemia induced loss of 19 +/- 7% of the villous epithelial surface area. Epithelial restitution covered the mucosal defect within 2 hours, although full recovery of mucosal barrier function required 6 hours. By 18 hours, a significant decrease in transepithelial electrical resistance and increase in transmucosal mannitol flux was noted despite the continued presence of complete epithelial coverage. Accumulation of neutrophils within restituting epithelium was noted on histologic examination, associated with electron-microscopic evidence of widened paracellular spaces. Pretreatment with anti-CD11/CD18 monoclonal antibody and superoxide dismutase-polyethylene glycol significantly reduced neutrophil infiltration and normalized transepithelial electrical resistance and mannitol fluxes. CONCLUSIONS Mucosal inflammation during epithelial repair resulted in increased paracellular permeability as neutrophils traversed restituted epithelium. Blocking neutrophil adhesion or scavenging superoxide prevented mucosal dysfunction in recovering tissue.
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Affiliation(s)
- J'mai Gayle
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA
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Picchiottino C, Lee PC. Differential development of aldehyde dehydrogenase in fore- and glandular stomach in postnatal rats. Exp Biol Med (Maywood) 2002; 227:554-8. [PMID: 12094021 DOI: 10.1177/153537020222700721] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Many foods contain the unsaturated aldehyde, hexadienal (HX). Human exposure is thus unavoidable. HX feeding to rodents caused cancers only in the forestomach. Aldehyde dehydrogenases (ALDH) are key enzymes in the metabolism of aldehydes. We examined the distribution of ALDH using HX as the substrate (HXDH) along the GI tract of adolescent rats and found that their stomachs have high levels of HXDH activity and the enzyme preferred HX > 9-cis-retinal > acetyl aldehyde > formyl aldehyde. We also followed the postnatal development of the stomach. At birth, the forestomach represented 40-50% of the total stomach weight. Both fore- and glandular stomach gained weight, with the glandular portion gaining at a faster rate. By 21 days, the forestomach was 24-28% of the total weight and decreased slightly to an adult level of 22-24%. Gastric HXDH is low from birth to 14 days of age. HXDH activity increased thereafter, reaching higher levels at 21 days and peaking around 30-36 days of age. The activity then decreased to the adult level. The fore- and glandular stomach had the same level of HXDH activity in the newborn and at 7 and 14 days of age. At weaning, HXDH activity was higher (3x) in the forestomach than in the glandular stomach. In adults, the forestomach still had 2x the HXDH activity compared to the glandular stomach. Zymograms showed similar isozyme patterns of HXDH but with different ratios of the three major forms between the forestomach and the glandular stomach. Results indicate a differential development of HXDH between the fore- and glandular stomach that might be related to the higher sensitivity of the forestomach to HX feeding.
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Affiliation(s)
- Christa Picchiottino
- Gastroenterology Division, Department of Pediatrics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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Kalgutkar AS, Dalvie DK, Castagnoli N, Taylor TJ. Interactions of nitrogen-containing xenobiotics with monoamine oxidase (MAO) isozymes A and B: SAR studies on MAO substrates and inhibitors. Chem Res Toxicol 2001; 14:1139-62. [PMID: 11559028 DOI: 10.1021/tx010073b] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- A S Kalgutkar
- Pharmacokinetics, Dynamics, and Metabolism Department, Pfizer Global Research and Development, Groton, Connecticut 06340, USA.
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35
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Morita Y, Sawada M, Seno H, Takaishi S, Fukuzawa H, Miyake N, Hiai H, Chiba T. Identification of xanthine dehydrogenase/xanthine oxidase as a rat Paneth cell zinc-binding protein. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1540:43-9. [PMID: 11476893 DOI: 10.1016/s0167-4889(01)00118-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Paneth cells are zinc-containing cells localized in small intestinal crypts, but their function has not been fully elucidated. Previously, we showed that an intravenous injection of diphenylthiocarbazone (dithizone), a zinc chelator, induced selective killing of Paneth cells, and purified a zinc-binding protein in Paneth cells. In the present study, we further characterized one of these proteins, named zinc-binding protein of Paneth cells (ZBPP)-1. Partial amino acid sequences of ZBPP-1 showed identity with rat xanthine dehydrogenase (XD)/xanthine oxidase (XO). Anti-rat XD antibody (Ab) recognized ZBPP-1, and conversely anti ZBPP-1 Ab recognized 85 kDa fragment of rat XD in Western blotting. Messenger RNA and protein levels of XD were consistent with our previous data on the fluctuation of Paneth cell population after dithizone injection. Thus, ZBPP-1 is an 85 kDa fragment of XD/XO in Paneth cells. XD/XO in Paneth cells may play important roles in intestinal function.
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Affiliation(s)
- Y Morita
- Department of Internal Medicine, Graduate School of Medicine, Kyoto University, Japan
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36
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Lawler JM, Hu Z. Interaction of nitric oxide and reactive oxygen species on rat diaphragm contractility. ACTA PHYSIOLOGICA SCANDINAVICA 2000; 169:229-36. [PMID: 10886037 DOI: 10.1046/j.1365-201x.2000.00733.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Growing evidence indicates that reactive oxygen species (ROS) as well as nitric oxide (NO) have a profound influence on contractile function of skeletal muscle possibly through modulation of excitation-contraction coupling. We hypothesized that if NO and xanthine oxidase (XO) interact at key sites in excitation-contraction coupling, the effects of XO with nitric oxide synthase (NOS) inhibitors and NO donors on contractile function of the unfatigued diaphragm would not be additive. Diaphragm fibre bundles were extracted from 4-month Fischer-344 rats and placed in Krebs solution bubbled with 95% O2, 5% CO2. Baseline twitch tension, tension at 20 Hz (low-frequency), and maximal tetanic tension (Po) at 120 Hz were then measured (PRE). In Experiment 1 diaphragm fibre bundles were exposed to Krebs with 200 microM hypoxanthine as a control (CON); 0.02 U mL-1 XO + 200 microM hypoxanthine; 1 mM of the NOS inhibitor N-nitro-L-arginine (L-NNA) or L-NNA + XO. Five minutes were allowed for equilibration, and a second set of contractile measures was taken (POST). In Experiment 2 we exposed diaphragm fibre bundles to one of the following four solutions: CON, XO, 100 microM of the NO donor sodium nitroprusside (SNP) and XO + SNP, and evaluated contractile function as described above. In Experiment 3 we tested to determine if peroxynitrite production from the reaction of superoxide anion and NO affected the above results for SNP using 30 microM ebselen as a peroxynitrite quencher. Xanthine oxidase resulted in a significant potentiation of diaphragm twitch tension and tension at 20 Hz (+29%) without affecting Po. L-NNA also significantly increased 20 Hz tension but did not alter Po. However, the combination of XO + L-NNA did not further increase low-frequency contractility. Sodium nitroprusside alone did not affect diaphragm contractility, but did attenuate XO-induced potentiation in the XO + SNP group. Ebselen did not alter the impact of SNP on XO in the diaphragm. These data support the hypothesis that XO and NO interact or compete at similar sites of action that modulate contractility of the unfatigued diaphragm.
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Affiliation(s)
- J M Lawler
- Redox Biology Laboratory, Human Performance Laboratories, Department of Health and Kinesiology, Texas A & M University, College Station, Texas 77843-4243, USA
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Moriwaki Y, Yamamoto T, Yamakita J, Takahashi S, Tsutsumi Z, Higashino K. Effect of interferon-gamma on purine catabolic and salvage enzyme activities in rats. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1427:385-91. [PMID: 10350654 DOI: 10.1016/s0304-4165(99)00038-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To determine whether interferon-gamma affects rat purine catabolic and salvage enzyme activities, rats were injected with interferon-gamma (600000 U/kg, i.p.) and, similarly to a vehicle-injected control group, killed before or after injection at 6, 12, and 24 h. Organ homogenates were prepared and enzymatic reactions with substrates were carried out, after which the products were measured either chromatographically or spectrophotometrically. Western and Northern blotting also were performed. In contrast to the vehicle-injected rats, interferon-gamma-injected rats showed a significant rise in xanthine oxidoreductase activity in the liver, while enzyme activity was unchanged in the spleen, kidney, and lung. Western analysis of hepatic xanthine oxidoreductase showed an increased concentration of this protein 12 and 24 h after interferon-gamma injection. Northern analysis disclosed an enhanced mRNA expression coding for this enzyme, peaking 12 h after injection. Contrastingly, the activities of adenosine deaminase, purine nucleoside phosphorylase, hypoxanthine guanine phosphoribosyltransferase, and adenine phosphoribosyltransferase were not affected by interferon-gamma in any organ tested. While interferon-gamma causes an increased hepatic biosynthesis of xanthine oxidoreductase, the physiologic role of this enzyme induction remains undetermined.
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Affiliation(s)
- Y Moriwaki
- Third Department of Internal Medicine, Hyogo College of Medicine, Mukogawa-cho 1-1, Nishinomiya, Hyogo 663-8501, Japan
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38
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Yoshihara S, Ohta S. Involvement of hepatic aldehyde oxidase in conversion of 1-methyl-4-phenyl-2,3-dihydropyridinium (MPDP+) to 1-methyl-4-phenyl-5,6-dihydro-2-pyridone. Arch Biochem Biophys 1998; 360:93-8. [PMID: 9826433 DOI: 10.1006/abbi.1998.0925] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To obtain direct evidence of the involvement of aldehyde oxidase (AO), a cytosolic molybdoflavoenzyme, in the metabolism of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), we investigated the in vitro metabolism of MPTP and the two-electron-oxidized 1-methyl-4-phenyl-2,3-dihydropyridinium species (MPDP+) by using mouse liver enzyme preparations. Incubation of MPTP with mitochondrial fraction gave exclusively 1-methyl-4-phenylpyridinium (MPP+); this reaction was inhibited by deprenyl, a monoamine oxidase (MAO)-B inhibitor, and KCN. When the mitochondrial fraction was combined with the cytosolic fraction, MPP+ formation was markedly decreased, while a large amount of 1-methyl-4-phenyl-5, 6-dihydro-2-pyridone (MPTP lactam) was newly formed. Incubation of MPDP+ with the cytosolic fraction led to rapid formation of MPTP lactam with concomitant disappearance of the substrate. The cytosol-dependent formation of MPTP lactam was inhibited by known AO inhibitors, such as menadione, norharman, and KCN. The activity of cytosol in MPTP lactam formation was completely duplicated by purified mouse liver AO. These results indicate that AO catalyzes the metabolic conversion of MPDP+, produced from MPTP by MAO-B, to MPTP lactam. This metabolic pathway might be an important detoxification route, averting the formation of toxic MPP+.
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Affiliation(s)
- S Yoshihara
- Institute of Pharmaceutical Sciences, Hiroshima University School of Medicine, 1-2-3 Kasumi, Hiroshima, Minami-ku, 734-8551, Japan.
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Moriwaki Y, Yamamoto T, Yamakita J, Takahashi S, Tsutsumi Z, Higashino K. Zonal distribution of allopurinol-oxidizing enzymes in rat liver. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 431:47-50. [PMID: 9598029 DOI: 10.1007/978-1-4615-5381-6_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We describe an enzymatic histochemical localization of two allopurinol-oxidizing enzymes, xanthine oxidase and aldehyde oxidase in rat hepatic tissues. This method is based on the tetrazolium salt procedures by use of a tissue protectant, polyvinyl alcohol, with tetra-nitro BT as the final electron acceptor. The present study demonstrated that both oxidases are present in the cytoplasm of hepatic cells. However, the distribution of the enzymes was uneven, being seen mainly in the pericentral rather than the periportal area. When allopurinol was used as a substrate, the specific staining by xanthine oxidase was more prominent than that of aldehyde oxidase. The results suggested that xanthine oxidase is more effective in oxidizing allopurinol than aldehyde oxidase.
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Affiliation(s)
- Y Moriwaki
- Third Department of Internal Medicine, Hyogo College of Medicine Mukogawa-cho 1-1, Japan
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40
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Moriwaki Y, Yamamoto T, Yamakita J, Takahashi S, Higashino K. Comparative localization of aldehyde oxidase and xanthine oxidoreductase activity in rat tissues. THE HISTOCHEMICAL JOURNAL 1998; 30:69-74. [PMID: 10192546 DOI: 10.1023/a:1003222831002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The distribution of aldehyde oxidase activity was evaluated in unfixed cryostat sections from tissues of male Wistar rats using a tissue protectant, polyvinyl alcohol, with Tetranitro BT as a final electron acceptor. The distribution of aldehyde oxidase activity was compared with that of xanthine oxidoreductase. The enzyme histochemical method demonstrated aldehyde oxidase activity in the epithelium of the tongue, renal tubules and bronchioles, as well as in the cytoplasm of liver cells. Such activity was not detected in oesophagus, stomach, spleen, adrenal glands, small or large intestine or skeletal and heart muscle fibres. In contrast, xanthine oxidoreductase activity was demonstrated in the tongue, renal tubules, bronchioles, oesophageal, gastric, small and large intestinal epithelial cells, adrenal glands, spleen and liver cytoplasm but not in skeletal and heart muscle fibres. The significance of the ubiquitous distribution of aldehyde oxidase activity, especially in surface epithelial cells from various tissues, except for the gastrointestinal tract, is unclear. However, aldehyde oxidase may possess some physiological activity other than in the metabolism of N-heterocyclics or of certain drugs.
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Affiliation(s)
- Y Moriwaki
- Third Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan
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41
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Zhao G, al-Mehdi AB, Fisher AB. Anoxia-reoxygenation versus ischemia in isolated rat lungs. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:L1112-7. [PMID: 9435564 DOI: 10.1152/ajplung.1997.273.6.l1112] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Oxidant generation in anoxia-reoxygenation and ischemia-reperfusion was compared in isolated rat lungs. Anoxia-reoxygenation was produced by N2 ventilation followed by O2 ventilation. After anoxia, lung ATP content was decreased by 59%. Oxygenated ischemia was produced by discontinuing perfusion while ventilation with O2 was maintained. With anoxia-reoxygenation, oxidant generation, evaluated by oxidation of dichlorodihydrofluorescein (H2DCF) to fluorescent dichlorofluorescein, increased 3.6-fold, lung thiobarbituric acid reactive substances (TBARS) increased 342%, conjugated dienes increased 285%, and protein carbonyl content increased 46%. Pretreatment of lungs with 100 microM allopurinol inhibited the reoxygenation-mediated increase in lung fluorescence by 75% and TBARS by 69%. Oxygenated ischemia resulted in an approximately eightfold increase in lung H2DCF oxidation and a fourfold increase in TBARS, but allopurinol had no effect. On the other hand, 100 microM diphenyliodonium (DPI) inhibited the ischemia-mediated increase in lung fluorescence by 69% and lung TBARS by 70%, but it had no effect on the increase with anoxia-reoxygenation. Therefore, both ischemia-reperfusion and anoxia-reoxygenation result in oxidant generation by the lung, but a comparison of results with a xanthine oxidase inhibitor (allopurinol) and a flavoprotein inhibitor (DPI) indicate that the pathways for oxidant generation are distinctly different.
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Affiliation(s)
- G Zhao
- Institute for Environmental Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104, USA
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Castagnoli N, Rimoldi JM, Bloomquist J, Castagnoli KP. Potential metabolic bioactivation pathways involving cyclic tertiary amines and azaarenes. Chem Res Toxicol 1997; 10:924-40. [PMID: 9305573 DOI: 10.1021/tx970096j] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A major theme explored in this review is the MAO-and cytochrome P450-catalyzed alpha-carbon oxidations of selected cyclic tertiary amines to give iminium metabolites that undergo further chemical modifications to form known or potentially toxic products. The most dramatic illustration of this type of bioactivation process is the conversion of the parkinsonian-inducing neurotoxin MPTP (23) by brain MAO-B to the iminium (dihydropyridinium) metabolite 24 which is oxidized further to the pyridinium species MPP+ (25). The selective destruction of nigrostriatal neurons by MPP+ is dependent on a unique sequence of events (transport into the nerve terminals by the dopamine transporter, localization in the inner mitochondrial membrane by electromotive forces, and inhibition of complex I of the mitochondrial electron transport chain) that, fortunately, are unlikely to be encountered with many substances. A second example of a well-documented metabolic bioactivation sequence involves the highly toxic pyrrolizidine alkaloids (102). These compounds undergo cytochrome P450-catalyzed alpha-carbon oxidation which converts the 3-pyrrolinyl moiety present in the parent alkaloids into a pyrrolyl-containing metabolite (105). The presence of labile functional groups results in the spontaneous conversion of 105 to reactive electrophilic products (106 and 108) that undergo Michael addition reactions with nucleophiles on biomacromolecules leading to a variety of toxic outcomes. Less clearly defined are the potential contributions to neurodegenerative processes that may be mediated by low-level, long term exposure to less potent toxins. Examples of potential proneurotoxins are the endogenously formed tetrahydroisoquinolines (such as 40-50) and tetrahydro-beta-carbolines (such as 54) that may be biotransformed to neurotoxic isoquinolinium (such as 51) and beta-carbolinium (such as 52) species in the brain. A similar argument can be made for 4-piperidinols (compounds that are at the same oxidation state as the tetrahydropyridines) which may be metabolized via iminium intermediates to amino enols that spontaneously convert to dihydropyridinium species and hence to pyridinium metabolites (67-->68-->69-->70-->71, Scheme 10). This type of reaction sequence has been well documented with the parkinsonian-inducing neuroleptic agent haloperidol (72) which is metabolized in humans, baboons, and rodents to the pyridinium species HPP+ (75), a potent inhibitor of mitochondrial respiration. Finally, an appreciation of the alpha-carbon oxidations of fully reduced azacycles such as (S)-nicotine (61) and phencyclidine (82) to chemically reactive metabolites that form covalent adducts with proteins, including the enzymes that are responsible for their formation, may prove of toxicological importance when attempting to account for the effects of chronic abuse of these potent drugs.1
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Affiliation(s)
- N Castagnoli
- Department of Chemistry and Entomology, Virginia Tech, Blacksburg 24061-0212, USA.
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