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Vlasenko YA, Postnikov PS, Trusova ME, Shafir A, Zhdankin VV, Yoshimura A, Yusubov MS. Synthesis of Five-Membered Iodine–Nitrogen Heterocycles from Benzimidazole-Based Iodonium Salts. J Org Chem 2018; 83:12056-12070. [DOI: 10.1021/acs.joc.8b01995] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
| | - Pavel S. Postnikov
- The Tomsk Polytechnic University, 634050 Tomsk, Russia
- University of Chemistry and Technology, 16628 Prague, Czech Republic
| | | | - Alexandr Shafir
- Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology, Tarragona, Spain
- Institute of Advanced Chemistry of Catalonia (IQAC−CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Viktor V. Zhdankin
- Department of Chemistry and Biochemistry, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
| | - Akira Yoshimura
- The Tomsk Polytechnic University, 634050 Tomsk, Russia
- Department of Chemistry and Biochemistry, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
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Napoli E, Song G, Wong S, Hagerman R, Giulivi C. Altered Bioenergetics in Primary Dermal Fibroblasts from Adult Carriers of the FMR1 Premutation Before the Onset of the Neurodegenerative Disease Fragile X-Associated Tremor/Ataxia Syndrome. THE CEREBELLUM 2017; 15:552-64. [PMID: 27089882 DOI: 10.1007/s12311-016-0779-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late onset neurodegenerative disorder, characterized by tremors, ataxia, impaired coordination, and cognitive decline. While all FXTAS individuals are carriers of a 55-200 CGG expansion at the 5'-UTR of the fragile X mental retardation gene (FMR1), also known as premutation, not all carriers develop FXTAS symptoms and some display other types of psychological/emotional disorders (e.g., autism, anxiety). The goal of this study was to investigate whether the mitochondrial dysfunction previously observed in fibroblasts from older premutation individuals (>60 years) was already present in younger (17-48 years), non-FXTAS-affected carriers and to identify the type and severity of the bioenergetic deficit. Since FXTAS affects mostly males, while females account for a small part of the FXTAS-affected population displaying less severe symptoms, only fibroblasts from males were evaluated in this study. Based on polarographic and enzymatic measurements, a generalized OXPHOS deficit was noted accompanied by increases in the matrix biomarker citrate synthase, oxidative stress (as increased mtDNA copy number and deletions), and mitochondrial network disruption/disorganization. Some of the outcomes (ATP-linked oxygen uptake, coupling, citrate synthase activity, and mitochondrial network organization) strongly correlated with the extent of the CGG expansion, with more severe deficits observed in cell lines carrying higher CGG number. Furthermore, mitochondrial outcomes can identify endophenotypes among carriers and are robust predictors of the premutation diagnosis before the onset of FXTAS, with the potential to be used as markers of prognosis and/or as readouts of pharmacological interventions.
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Affiliation(s)
- Eleonora Napoli
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, 1089 Veterinary Medicine Dr., VetMed 3B, Davis, CA, 95616, USA
| | - Gyu Song
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, 1089 Veterinary Medicine Dr., VetMed 3B, Davis, CA, 95616, USA
| | - Sarah Wong
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, 1089 Veterinary Medicine Dr., VetMed 3B, Davis, CA, 95616, USA
| | - Randi Hagerman
- Medical Investigation of Neurodevelopmental Disorders Institute (M. I. N. D.), University of California Davis, Sacramento, CA, 95817, USA.,Department of Pediatrics, University of California Medical Center, Sacramento, CA, 95817, USA
| | - Cecilia Giulivi
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, 1089 Veterinary Medicine Dr., VetMed 3B, Davis, CA, 95616, USA. .,Medical Investigation of Neurodevelopmental Disorders Institute (M. I. N. D.), University of California Davis, Sacramento, CA, 95817, USA.
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Postnikov PS, Guselnikova OA, Yusubov MS, Yoshimura A, Nemykin VN, Zhdankin VV. Preparation and X-ray Structural Study of Dibenziodolium Derivatives. J Org Chem 2015; 80:5783-8. [DOI: 10.1021/acs.joc.5b00741] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | | | - Mekhman S. Yusubov
- The Tomsk Polytechnic University, 634050 Tomsk, Russia
- The Siberian State Medical University 634050 Tomsk, Russia
| | - Akira Yoshimura
- Department
of Chemistry and Biochemistry, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
| | - Victor N. Nemykin
- Department
of Chemistry and Biochemistry, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
| | - Viktor V. Zhdankin
- Department
of Chemistry and Biochemistry, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
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Francischetti IMB, Gordon E, Bizzarro B, Gera N, Andrade BB, Oliveira F, Ma D, Assumpção TCF, Ribeiro JMC, Pena M, Qi CF, Diouf A, Moretz SE, Long CA, Ackerman HC, Pierce SK, Sá-Nunes A, Waisberg M. Tempol, an intracellular antioxidant, inhibits tissue factor expression, attenuates dendritic cell function, and is partially protective in a murine model of cerebral malaria. PLoS One 2014; 9:e87140. [PMID: 24586264 PMCID: PMC3938406 DOI: 10.1371/journal.pone.0087140] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 12/18/2013] [Indexed: 01/19/2023] Open
Abstract
Background The role of intracellular radical oxygen species (ROS) in pathogenesis of cerebral malaria (CM) remains incompletely understood. Methods and Findings We undertook testing Tempol—a superoxide dismutase (SOD) mimetic and pleiotropic intracellular antioxidant—in cells relevant to malaria pathogenesis in the context of coagulation and inflammation. Tempol was also tested in a murine model of CM induced by Plasmodium berghei Anka infection. Tempol was found to prevent transcription and functional expression of procoagulant tissue factor in endothelial cells (ECs) stimulated by lipopolysaccharide (LPS). This effect was accompanied by inhibition of IL-6, IL-8, and monocyte chemoattractant protein (MCP-1) production. Tempol also attenuated platelet aggregation and human promyelocytic leukemia HL60 cells oxidative burst. In dendritic cells, Tempol inhibited LPS-induced production of TNF-α, IL-6, and IL-12p70, downregulated expression of co-stimulatory molecules, and prevented antigen-dependent lymphocyte proliferation. Notably, Tempol (20 mg/kg) partially increased the survival of mice with CM. Mechanistically, treated mice had lowered plasma levels of MCP-1, suggesting that Tempol downmodulates EC function and vascular inflammation. Tempol also diminished blood brain barrier permeability associated with CM when started at day 4 post infection but not at day 1, suggesting that ROS production is tightly regulated. Other antioxidants—such as α-phenyl N-tertiary-butyl nitrone (PBN; a spin trap), MnTe-2-PyP and MnTBAP (Mn-phorphyrin), Mitoquinone (MitoQ) and Mitotempo (mitochondrial antioxidants), M30 (an iron chelator), and epigallocatechin gallate (EGCG; polyphenol from green tea) did not improve survival. By contrast, these compounds (except PBN) inhibited Plasmodium falciparum growth in culture with different IC50s. Knockout mice for SOD1 or phagocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (gp91phox–/–) or mice treated with inhibitors of SOD (diethyldithiocarbamate) or NADPH oxidase (diphenyleneiodonium) did not show protection or exacerbation for CM. Conclusion Results with Tempol suggest that intracellular ROS contribute, in part, to CM pathogenesis. Therapeutic targeting of intracellular ROS in CM is discussed.
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Affiliation(s)
- Ivo M. B. Francischetti
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- * E-mail: (IMBF); (MW)
| | - Emile Gordon
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Bruna Bizzarro
- Laboratory of Experimental Immunology, Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Nidhi Gera
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Bruno B. Andrade
- Laboratory of Parasitic Diseases, NIAID/NIH, Bethesda, Maryland, United States of America
| | - Fabiano Oliveira
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Dongying Ma
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Teresa C. F. Assumpção
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - José M. C. Ribeiro
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Mirna Pena
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Chen-Feng Qi
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Samuel E. Moretz
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Carole A. Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Hans C. Ackerman
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Susan K. Pierce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Anderson Sá-Nunes
- Laboratory of Experimental Immunology, Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Michael Waisberg
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- University of Virginia, Department of Pathology, Charlottesville, Virginia, United States of America
- * E-mail: (IMBF); (MW)
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van den Broek NMA, Ciapaite J, Nicolay K, Prompers JJ. Comparison of in vivo postexercise phosphocreatine recovery and resting ATP synthesis flux for the assessment of skeletal muscle mitochondrial function. Am J Physiol Cell Physiol 2010; 299:C1136-43. [PMID: 20668212 DOI: 10.1152/ajpcell.00200.2010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
(31)P magnetic resonance spectroscopy (MRS) has been used to assess skeletal muscle mitochondrial function in vivo by measuring 1) phosphocreatine (PCr) recovery after exercise or 2) resting ATP synthesis flux with saturation transfer (ST). In this study, we compared both parameters in a rat model of mitochondrial dysfunction with the aim of establishing the most appropriate method for the assessment of in vivo muscle mitochondrial function. Mitochondrial dysfunction was induced in adult Wistar rats by daily subcutaneous injections with the complex I inhibitor diphenyleneiodonium (DPI) for 2 wk. In vivo (31)P MRS measurements were supplemented by in vitro measurements of oxygen consumption in isolated mitochondria. Two weeks of DPI treatment induced mitochondrial dysfunction, as evidenced by a 20% lower maximal ADP-stimulated oxygen consumption rate in isolated mitochondria from DPI-treated rats oxidizing pyruvate plus malate. This was paralleled by a 46% decrease in in vivo oxidative capacity, determined from postexercise PCr recovery. Interestingly, no significant difference in resting, ST-based ATP synthesis flux was observed between DPI-treated rats and controls. These results show that PCr recovery after exercise has a more direct relationship with skeletal muscle mitochondrial function than the ATP synthesis flux measured with (31)P ST MRS in the resting state.
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Affiliation(s)
- N M A van den Broek
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
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Selemidis S, Sobey CG, Wingler K, Schmidt HH, Drummond GR. NADPH oxidases in the vasculature: Molecular features, roles in disease and pharmacological inhibition. Pharmacol Ther 2008; 120:254-91. [DOI: 10.1016/j.pharmthera.2008.08.005] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 08/06/2008] [Indexed: 02/07/2023]
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Masamune A, Watanabe T, Kikuta K, Satoh K, Shimosegawa T. NADPH oxidase plays a crucial role in the activation of pancreatic stellate cells. Am J Physiol Gastrointest Liver Physiol 2008; 294:G99-G108. [PMID: 17962358 DOI: 10.1152/ajpgi.00272.2007] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Activated pancreatic stellate cells (PSCs) play an important role in pancreatic fibrosis and inflammation, where oxidative stress is implicated in the pathogenesis. NADPH oxidase might be a source of reactive oxygen species (ROS) in the injured pancreas. This study aimed to clarify the expression and regulation of cell functions by NADPH oxidase in PSCs. PSCs were isolated from rat and human pancreas tissues. Expression of NADPH oxidase was assessed by reverse transcription-PCR and immunostaining. Intracellular ROS production was assessed using 2',7'-dichlorofluorescin diacetate. The effects of diphenylene iodonium (DPI) and apocynin, inhibitors of NADPH oxidase, on key parameters of PSC activation were evaluated in vitro. In vivo, DPI (at 1 mg.kg body wt(-1).day(-1)) was administered in drinking water to 10-wk-old male Wistar Bonn/Kobori rats for 10 wk and to rats with chronic pancreatitis induced by dibutyltin dichloride (DBTC). PSCs expressed key components of NADPH oxidase (p22(phox), p47(phox), NOX1, gp91(phox)/NOX2, NOX4, and NOX activator 1). PDGF-BB, IL-1beta, and angiotensin II induced ROS production, which was abolished by DPI and apocynin. DPI inhibited PDGF-induced proliferation, IL-1beta-induced chemokine production, and expression of alpha-smooth muscle actin and collagen. DPI inhibited transformation of freshly isolated cells to a myofibroblast-like phenotype. In addition, DPI inhibited the development of pancreatic fibrosis in Wistar Bonn/Kobori rats and in rats with DBTC-induced chronic pancreatitis. In conclusion, PSCs express NADPH oxidase to generate ROS, which mediates key cell functions and activation of PSCs. NADPH oxidase might be a potential target for the treatment of pancreatic fibrosis.
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Affiliation(s)
- Atsushi Masamune
- Div. of Gastroenterology, Tohoku Univ. Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574 Japan.
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9
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Abstract
Because cell proliferation is subject to checkpoint-mediated regulation of the cell cycle, pharmacophores that target cell cycle checkpoints have been used clinically to treat human hyperproliferative disorders. It is shown here that the flavoprotein inhibitor diphenyleneiodionium can block cell proliferation by targeting of cell cycle checkpoints. Brief exposure of mitotically arrested cells to diphenyleneiodonium induces a loss of the mitotic cell morphology, and this corresponds with a decrease in the levels of the mitotic markers MPM2 and phospho-histone H3, as well as a loss of centrosome maturation, spindle disassembly, and redistribution of the chromatin remodeling helicase ATRX. Surprisingly, this mitotic exit resulted in a tetraploidization that persisted long after drug release. Analogously, brief exposure to diphenyleneiodonium also caused prolonged arrest in G(1) phase. By contrast, diphenyleneiodonium exposure did not abrogate S phase, although it did result in a subsequent block of G(2) cell cycle progression. This indicates that diphenyleneiodonium selectively targets components of the cell cycle, thereby either causing cell cycle arrest, or checkpoint override followed by cell cycle arrest. These irreversible effects of diphenyleneiodonium on the cell cycle may underlie its potent antiproliferative activity.
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Affiliation(s)
- Robin M Scaife
- Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, Centre for Medical Research, The University of Western Australia.
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Giannesini B, Cozzone PJ, Bendahan D. In vivo MR investigation of skeletal muscle function in small animals. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2004; 17:210-8. [PMID: 15592946 DOI: 10.1007/s10334-004-0080-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2004] [Revised: 10/26/2004] [Accepted: 10/26/2004] [Indexed: 11/30/2022]
Abstract
In vivo 31P-MRS investigations have been widely used in small animals to study skeletal muscle function under normal and pathological conditions. Paradoxically in these studies, the benefit provided by 31P-MRS in terms of non-invasiveness is lost because of the utilization of experimental setups that integrate invasive devices for inducing muscle contractions and for measuring mechanical performance. These traditional methodologies, which require surgical preparations, have obvious limitations regarding repeatability in the same animal. The purpose of this review is to highlight the technical aspects of the in vivo MR investigations of skeletal muscle function in small animal models. We will more particularly address the issue related to the invasiveness of different procedures used so far in order to show finally that a further step into non-invasiveness can be achieved, in particular with the support of muscle functional 1H-MRI.
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Affiliation(s)
- B Giannesini
- Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS 6612, Faculté de Médecine de Marseille, 27 Boulevard Jean Moulin, 13005, Marseille, France
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Kono H, Rusyn I, Uesugi T, Yamashina S, Connor HD, Dikalova A, Mason RP, Thurman RG. Diphenyleneiodonium sulfate, an NADPH oxidase inhibitor, prevents early alcohol-induced liver injury in the rat. Am J Physiol Gastrointest Liver Physiol 2001; 280:G1005-12. [PMID: 11292610 DOI: 10.1152/ajpgi.2001.280.5.g1005] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The oxidant source in alcohol-induced liver disease remains unclear. NADPH oxidase (mainly in liver Kupffer cells and infiltrating neutrophils) could be a potential free radical source. We aimed to determine if NADPH oxidase inhibitor diphenyleneiodonium sulfate (DPI) affects nuclear factor-kappaB (NF-kappaB) activation, liver tumor necrosis factor-alpha (TNF-alpha) mRNA expression, and early alcohol-induced liver injury in rats. Male Wistar rats were fed high-fat liquid diets with or without ethanol (10-16 g. kg(-1). day(-1)) continuously for up to 4 wk, using the Tsukamoto-French intragastric enteral feeding protocol. DPI or saline vehicle was administered by subcutaneous injection for 4 wk. Mean urine ethanol concentrations were similar between the ethanol- and ethanol plus DPI-treated groups. Enteral ethanol feeding caused severe fat accumulation, mild inflammation, and necrosis in the liver (pathology score, 4.3 +/- 0.3). In contrast, DPI significantly blunted these changes (pathology score, 0.8 +/- 0.4). Enteral ethanol administration for 4 wk also significantly increased free radical adduct formation, NF-kappaB activity, and TNF-alpha expression in the liver. DPI almost completely blunted these parameters. These results indicate that DPI prevents early alcohol-induced liver injury, most likely by inhibiting free radical formation via NADPH oxidase, thereby preventing NF-kappaB activation and TNF-alpha mRNA expression in the liver.
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Affiliation(s)
- H Kono
- Laboratory of Hepatobiology and Toxicology, Department of Pharmacology, University of North Carolina, Mary Ellen Jones Bldg., Chapel Hill, NC 27599-7365, USA
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Are Plants Stacked Neutrophiles? Comparison of Pathogen-Induced Oxidative Burst in Plants and Mammals. ACTA ACUST UNITED AC 2000. [DOI: 10.1007/978-3-642-57203-6_9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Tracey I, Dunn JF, Radda GK. A 31P-magnetic resonance spectroscopy and biochemical study of the mo(vbr) mouse: potential model for the mitochondrial encephalomyopathies. Muscle Nerve 1997; 20:1352-9. [PMID: 9342151 DOI: 10.1002/(sici)1097-4598(199711)20:11<1352::aid-mus2>3.0.co;2-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
31P-magnetic resonance spectroscopy (31P-MRS) provides new biochemical information on mitochondrial disorders affecting brain and muscle. To elucidate the mechanisms of mitochondrial abnormalities, however, animal models are needed. We assessed the mo(vbr) (mottled viable brindled) mouse for its value in studying (1) energetics of a mitochondrial disorder and (2) 31P-MRS changes associated with mitochondrial abnormalities in vivo. The maximal activity of succinate-cytochrome c reductase was significantly reduced in mo(vbr) muscle compared to controls, whereas cytochrome oxidase activity was only reduced in mo(vbr) brain. 31P-MRS of mo(vbr) brain showed an increased pH, but no changes in any metabolite ratios. The phosphocreatine (PCr) recovery rate after exercise was reduced in muscles from mo(vbr) mice, indicating impairment of oxidative metabolism. We conclude that mo(vbr) brain and muscle tissue have biochemical abnormalities consistent with mitochondrial impairment. The PCr recovery rate, measured by 31P-MRS, was sensitive to the muscle abnormality. This strain is best described as having chronic mitochondrial dysfunction.
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Affiliation(s)
- I Tracey
- Department of Biochemistry, Oxford University, United Kingdom
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Affiliation(s)
- Peter J. Stang
- Department of Chemistry, University of Minnesota-Duluth, Duluth, Minnesota 55812
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Abstract
31Phosphorus nuclear magnetic resonance spectroscopy was used to examine skeletal muscle in 29 patients with mitochondrial myopathy, 9 male and 20 female. Gastrocnemius was investigated in 15 patients and 30 normal subjects and finger flexor muscle (flexor digitorum superficialis, fds) in 24 patients and 35 normal controls. Both muscles were studied in 10 of the patients. Results were abnormal (outside the full range of normal values) in all but 2 patients. In 86% of patients (25/29) abnormalities were detected in resting muscle. In most cases there was a low phosphocreatine/ATP ratio, high calculated free [ADP] and low phosphorylation potential. At rest, abnormality was detected with equal ease in fds and gastrocnemius. Exercise and recovery increased the sensitivity of MRS in detecting abnormal metabolism. Finger flexion was better tolerated by patients than plantar flexion and gave bigger changes in metabolite concentrations and intracellular pH. Thus, results from fds were more easily differentiated from normal. Exercise duration was significantly shorter than in controls while phosphocreatine depletion was more rapid than normal, consistent with a shortfall in mitochondrial ATP synthesis. Nearly all patients (25/27, 93%) showed abnormalities during recovery from exercise. [ADP] was high during exercise and its recovery was delayed, providing increased drive for oxidative phosphorylation. Phosphocreatine resynthesis during recovery (which reflects oxidative ATP synthesis) was slow both in absolute terms and in relation to [ADP]. Recovery of intracellular pH after exercise was significantly more rapid than normal, consistent with an upregulation of proton efflux.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D J Taylor
- MRC Biochemical and Clinical Magnetic Resonance Unit, John Radcliffe Hospital, Oxford, UK
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Vijayasarathy C, Giger U, Prociuk U, Patterson DF, Breitschwerdt EB, Avadhani NG. Canine mitochondrial myopathy associated with reduced mitochondrial mRNA and altered cytochrome c oxidase activities in fibroblasts and skeletal muscle. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART A, PHYSIOLOGY 1994; 109:887-94. [PMID: 7530157 DOI: 10.1016/0300-9629(94)90236-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Skeletal muscle and fibroblast biopsies obtained from a normal dog and an old English sheep dog with exertional myopathy and lactic acidosis were examined for mitochondrial enzyme activities and mitochondrially coded mRNAs. The fibroblast cultures of the affected dog showed reduced cytochrome c oxidase (COX) I+II mRNA content (25% of control) and COX enzyme activities (23% of control). The skeletal muscle of the affected dog was similarly affected and showed not only decreased COX I+II mRNA content, but also decreased ATPase6 mRNA level. Apart from COX enzyme activity (62% of control), the oligomycin sensitive ATPase and NADH-Ferricyanide reductase activities were also reduced in the skeletal muscle of the affected dog (12-20% of control). These results suggest that a mitochondrial dysfunction may be the causative factor of the exertional metabolic myopathy with lactic acidosis in this affected old English sheep dog. These animals may serve as an excellent model for mitochondrial myopathies.
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Affiliation(s)
- C Vijayasarathy
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104
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Mitochondrial Diseases: Noninvasive Approaches. ACTA ACUST UNITED AC 1994. [DOI: 10.1016/b978-0-12-152517-0.50009-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2023]
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Abstract
Skeletal muscle of seven hypothyroid patients was investigated in the resting state and during exercise and recovery using 31P magnetic resonance spectroscopy. The bioenergetics and intracellular pH of the hypothyroid muscle were thus evaluated and compared with results from normal muscle and muscle of patients with mitochondrial myopathy. In resting hypothyroid muscle there were significant elevations in the concentration ratios of phosphocreatine/ATP and inorganic phosphate/ATP, while phosphocreatine/inorganic phosphate and intracellular pH were lower than normal. In exercising hypothyroid muscle, energy stores were depleted more rapidly and acidification began later than in normal muscle. Recovery of phosphocreatine to the pre-exercise value was normal, but intracellular pH recovered slowly. The data suggest that in the hypothyroid state, glycogen breakdown in skeletal muscle was delayed thereby limiting the substrate supply for both glycolytic and oxidative production of ATP at the beginning of exercise. There was no evidence for a decrease in the oxidative capacity of the muscle of our patients, but elevated ADP may have stimulated oxidative metabolism and helped to compensate for low mitochondrial content. The low intracellular pH in resting muscle and the slow pH recovery after exercise imply that proton handling was abnormal in the hypothyroid muscle.
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Affiliation(s)
- D J Taylor
- MRC Biochemical and Clinical Magnetic Resonance Unit, John Radcliffe Hospital, Headington, Oxford, UK
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Byrne E, Morgan Hughes JA. Prolonged aerobic exercise: physiological studies in rat gastrocnemius with additional observations on the effects of acute mitochondrial blockade. J Neurol Sci 1989; 92:215-27. [PMID: 2809619 DOI: 10.1016/0022-510x(89)90138-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Protracted low frequency (1 and 5 Hz) stimulation of rat gastrocnemius in vivo leads to fatigue and fall out of glycolytic fibres with the development of a stable twitch response with continuation of the stimulus train. This model was used to examine the physiological effects of acute mitochondrial blockade on oxidative fibre function with the injection of a mitochondrial uncoupler (dinitrophenol) and a site I inhibitor (diphenyleneiodonium) intraarterially after a stable twitch response had developed. Dinitrophenol leads to progressive failure of contractility, closely followed by action potential failure and electrically silent contracture: external work accelerated this sequence but it also developed in resting muscle suggesting that DNP lead to active ATP hydrolysis and a more severe energy depletion than that encountered in human disease states. Diphenyleneiodonium also leads to progressive twitch tension and action potential failure but contracture was late and inconstant, considerable recovery in twitch parameters was seen with rest and restimulation lead to pathological fatiguability of twitch tension. This model has some similarity to human mitochondriopathies with pathological fatiguability. This acute model should allow ready testing of any therapeutic approaches which bypass respiratory chain blocks.
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Affiliation(s)
- E Byrne
- Institute of Neurology, Queen Square, London, U.K
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