1
|
Chatzinikolaou PN, Margaritelis NV, Paschalis V, Theodorou AA, Vrabas IS, Kyparos A, D'Alessandro A, Nikolaidis MG. Erythrocyte metabolism. Acta Physiol (Oxf) 2024; 240:e14081. [PMID: 38270467 DOI: 10.1111/apha.14081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 12/11/2023] [Accepted: 01/01/2024] [Indexed: 01/26/2024]
Abstract
Our aim is to present an updated overview of the erythrocyte metabolism highlighting its richness and complexity. We have manually collected and connected the available biochemical pathways and integrated them into a functional metabolic map. The focus of this map is on the main biochemical pathways consisting of glycolysis, the pentose phosphate pathway, redox metabolism, oxygen metabolism, purine/nucleoside metabolism, and membrane transport. Other recently emerging pathways are also curated, like the methionine salvage pathway, the glyoxalase system, carnitine metabolism, and the lands cycle, as well as remnants of the carboxylic acid metabolism. An additional goal of this review is to present the dynamics of erythrocyte metabolism, providing key numbers used to perform basic quantitative analyses. By synthesizing experimental and computational data, we conclude that glycolysis, pentose phosphate pathway, and redox metabolism are the foundations of erythrocyte metabolism. Additionally, the erythrocyte can sense oxygen levels and oxidative stress adjusting its mechanics, metabolism, and function. In conclusion, fine-tuning of erythrocyte metabolism controls one of the most important biological processes, that is, oxygen loading, transport, and delivery.
Collapse
Affiliation(s)
- Panagiotis N Chatzinikolaou
- Department of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, Serres, Greece
| | - Nikos V Margaritelis
- Department of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, Serres, Greece
| | - Vassilis Paschalis
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Anastasios A Theodorou
- Department of Life Sciences, School of Sciences, European University Cyprus, Nicosia, Cyprus
| | - Ioannis S Vrabas
- Department of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, Serres, Greece
| | - Antonios Kyparos
- Department of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, Serres, Greece
| | - Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Michalis G Nikolaidis
- Department of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, Serres, Greece
| |
Collapse
|
2
|
Lewis IA. Boundary flux analysis: an emerging strategy for investigating metabolic pathway activity in large cohorts. Curr Opin Biotechnol 2024; 85:103027. [PMID: 38061263 DOI: 10.1016/j.copbio.2023.103027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 11/02/2023] [Accepted: 11/15/2023] [Indexed: 02/09/2024]
Abstract
Many biological phenotypes are rooted in metabolic pathway activity rather than the concentrations of individual metabolites. Despite this, most metabolomics studies only capture steady-state metabolism - not metabolic flux. Although sophisticated metabolic flux analysis strategies have been developed, these methods are technically challenging and difficult to implement in large-cohort studies. Recently, a new boundary flux analysis (BFA) approach has emerged that captures large-scale metabolic flux phenotypes by quantifying changes in metabolite levels in the media of cultured cells. This approach is advantageous because it is relatively easy to implement yet captures complex metabolic flux phenotypes. We describe the opportunities and challenges of BFA and illustrate how it can be harnessed to investigate a wide transect of biological phenomena.
Collapse
Affiliation(s)
- Ian A Lewis
- Alberta Centre for Advanced Diagnostics, Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada.
| |
Collapse
|
3
|
Jin ES, Lee MH, Malloy CR. 13 C NMR of glutamate for monitoring the pentose phosphate pathway in myocardium. NMR IN BIOMEDICINE 2021; 34:e4533. [PMID: 33900680 DOI: 10.1002/nbm.4533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 04/05/2021] [Accepted: 04/13/2021] [Indexed: 06/12/2023]
Abstract
After administration of 13 C-labeled glucose, the activity of the pentose phosphate pathway (PPP) is often assessed by the distribution of 13 C in lactate. However, in some tissues, such as the well-oxygenated heart, the concentration of lactate may be too low for convenient analysis by NMR. Here, we examined 13 C-labeled glutamate as an alternative biomarker of the PPP in the heart. Isolated rat hearts were perfused with media containing [2,3-13 C2 ]glucose and the tissue extracts were analyzed. Metabolism of [2,3-13 C2 ]glucose yields [1,2-13 C2 ]pyruvate via glycolysis and [2,3-13 C2 ]pyruvate via the PPP. Pyruvate is in exchange with lactate or is further metabolized to glutamate through pyruvate dehydrogenase and the TCA cycle. A doublet from [4,5-13 C2 ]glutamate, indicating flux through the PPP, was readily detected in 13 C NMR of heart extracts even when the corresponding doublet from [2,3-13 C2 ]lactate was minimal. Benfotiamine, known to induce the PPP, caused an increase in production of [4,5-13 C2 ]glutamate. In rats receiving [2,3-13 C2 ]glucose, brain extracts showed well-resolved signals from both [2,3-13 C2 ]lactate and [4,5-13 C2 ]glutamate in 13 C NMR spectra. Assessment of the PPP in the brain based on glutamate had a strong linear correlation with lactate-based assessment. In summary, 13 C NMR analysis of glutamate enabled detection of the low PPP activity in isolated hearts. This analyte is an alternative to lactate for monitoring the PPP with the use of [2,3-13 C2 ]glucose.
Collapse
Affiliation(s)
- Eunsook S Jin
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Min H Lee
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Craig R Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- VA North Texas Health Care System, Dallas, Texas, USA
| |
Collapse
|
4
|
Rogers SC, Ge X, Brummet M, Lin X, Timm DD, d'Avignon A, Garbow JR, Kao J, Prakash J, Issaian A, Eisenmesser EZ, Reisz JA, D'Alessandro A, Doctor A. Quantifying dynamic range in red blood cell energetics: Evidence of progressive energy failure during storage. Transfusion 2021; 61:1586-1599. [PMID: 33830505 DOI: 10.1111/trf.16395] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 01/26/2021] [Accepted: 03/09/2021] [Indexed: 12/13/2022]
Abstract
BACKGROUND During storage, red blood cells (RBCs) undergo significant biochemical and morphologic changes, referred to collectively as the "storage lesion". It was hypothesized that these defects may arise from disrupted oxygen-based regulation of RBC energy metabolism, with resultant depowering of intrinsic antioxidant systems. STUDY DESIGN AND METHODS As a function of storage duration, the dynamic range in RBC metabolic response to three models of biochemical oxidant stress (methylene blue, hypoxanthine/xanthine oxidase, and diamide) was assessed, comparing glycolytic flux by NMR and UHPLC-MS methodologies. Blood was processed/stored under standard conditions (AS-1 additive solution) with leukoreduction. Over a 6-week period, RBC metabolic and antioxidant status were assessed at baseline and following exposure to the three biochemical oxidant models. Comparison was made of glycolytic flux (1 H-NMR tracking of [2-13 C]-glucose and metabolomic phenotyping with [1,2,3-13 C3 ] glucose), reducing equivalent (NADPH/NADP+ ) recycling, and thiol-based (GSH/GSSG) antioxidant status. RESULTS As a function of storage duration, we observed the following: (1) a reduction in baseline hexose monophosphate pathway (HMP) flux, the sole pathway responsible for the regeneration of the essential reducing equivalent NADPH; with (2) diminished stress-based dynamic range in both overall glycolytic as well as proportional HMP flux. In addition, progressive with storage duration, RBCs showed (3) constraint in reducing equivalent (NADPH) recycling capacity, (4) loss of thiol based (GSH) recycling capacity, and (5) dysregulation of metabolon assembly at the cytoplasmic domain of Band 3 membrane protein (cdB3). CONCLUSION Blood storage disturbs normal RBC metabolic control, depowering antioxidant capacity and enhancing vulnerability to oxidative injury.
Collapse
Affiliation(s)
- Stephen C Rogers
- Department of Pediatrics, Divisions of Critical Care Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA.,The Center for Blood Oxygen Transport and Hemostasis, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Xia Ge
- Department of Chemistry, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
| | - Mary Brummet
- Department of Pediatrics, Divisions of Critical Care Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA.,The Center for Blood Oxygen Transport and Hemostasis, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Xue Lin
- Department of Pediatrics, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
| | - David D Timm
- Department of Pediatrics, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
| | - Andre d'Avignon
- Department of Chemistry, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
| | - Joel R Garbow
- Department of Radiology, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
| | - Jeff Kao
- Department of Chemistry, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
| | - Jaya Prakash
- Department of Pediatrics, Divisions of Critical Care Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Aaron Issaian
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Elan Z Eisenmesser
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Julie A Reisz
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Allan Doctor
- Department of Pediatrics, Divisions of Critical Care Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA.,The Center for Blood Oxygen Transport and Hemostasis, University of Maryland School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
5
|
Ch R, Rey G, Ray S, Jha PK, Driscoll PC, Dos Santos MS, Malik DM, Lach R, Weljie AM, MacRae JI, Valekunja UK, Reddy AB. Rhythmic glucose metabolism regulates the redox circadian clockwork in human red blood cells. Nat Commun 2021; 12:377. [PMID: 33452240 PMCID: PMC7810875 DOI: 10.1038/s41467-020-20479-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 12/01/2020] [Indexed: 02/07/2023] Open
Abstract
Circadian clocks coordinate mammalian behavior and physiology enabling organisms to anticipate 24-hour cycles. Transcription-translation feedback loops are thought to drive these clocks in most of mammalian cells. However, red blood cells (RBCs), which do not contain a nucleus, and cannot perform transcription or translation, nonetheless exhibit circadian redox rhythms. Here we show human RBCs display circadian regulation of glucose metabolism, which is required to sustain daily redox oscillations. We found daily rhythms of metabolite levels and flux through glycolysis and the pentose phosphate pathway (PPP). We show that inhibition of critical enzymes in either pathway abolished 24-hour rhythms in metabolic flux and redox oscillations, and determined that metabolic oscillations are necessary for redox rhythmicity. Furthermore, metabolic flux rhythms also occur in nucleated cells, and persist when the core transcriptional circadian clockwork is absent in Bmal1 knockouts. Thus, we propose that rhythmic glucose metabolism is an integral process in circadian rhythms.
Collapse
Affiliation(s)
- Ratnasekhar Ch
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
- School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK
| | - Guillaume Rey
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
- Unilabs Genetics Laboratory, 1003, Lausanne, Switzerland
| | - Sandipan Ray
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, 19104, USA
- Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502285, Telangana, India
| | - Pawan K Jha
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, 19104, USA
- Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Paul C Driscoll
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | | | - Dania M Malik
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, 19104, USA
- Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Radoslaw Lach
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
- Department of Oncology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0XZ, UK
| | - Aalim M Weljie
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, 19104, USA
- Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - James I MacRae
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Utham K Valekunja
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, 19104, USA
- Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Akhilesh B Reddy
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, 19104, USA.
- Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
- Chronobiology and Sleep institute (CSI), Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| |
Collapse
|
6
|
Guizouarn H, Allegrini B. Erythroid glucose transport in health and disease. Pflugers Arch 2020; 472:1371-1383. [PMID: 32474749 DOI: 10.1007/s00424-020-02406-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 05/15/2020] [Accepted: 05/22/2020] [Indexed: 12/14/2022]
Abstract
Glucose transport is intimately linked to red blood cell physiology. Glucose is the unique energy source for these cells, and defects in glucose metabolism or transport activity are associated with impaired red blood cell morphology and deformability leading to reduced lifespan. In vertebrate erythrocytes, glucose transport is mediated by GLUT1 (in humans) or GLUT4 transporters. These proteins also account for dehydroascorbic acid (DHA) transport through erythrocyte membrane. The peculiarities of glucose transporters and the red blood cell pathologies involving GLUT1 are summarized in the present review.
Collapse
Affiliation(s)
- Hélène Guizouarn
- Université Côte d'Azur, CNRS, Inserm, Institut de Biologie Valrose, 28 av. Valrose, 06100, Nice, France.
| | - Benoit Allegrini
- Université Côte d'Azur, CNRS, Inserm, Institut de Biologie Valrose, 28 av. Valrose, 06100, Nice, France
| |
Collapse
|
7
|
Belew GD, Di Nunzio G, Tavares L, Silva JG, Torres AN, Jones JG. Estimating pentose phosphate pathway activity from the analysis of hepatic glycogen 13 C-isotopomers derived from [U- 13 C]fructose and [U- 13 C]glucose. Magn Reson Med 2020; 84:2765-2771. [PMID: 32301167 DOI: 10.1002/mrm.28286] [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: 02/19/2020] [Revised: 03/21/2020] [Accepted: 03/25/2020] [Indexed: 12/26/2022]
Abstract
PURPOSE The pentose phosphate pathway (PPP) is an important component of hepatic intermediary metabolism. Jin et al developed an elegant 13 C-NMR method for measuring hepatic PPP flux by quantifying the distribution of glucose 13 C-isotopomers formed from [U-13 C]glycerol. We demonstrate that this approach can be extended to exogenous [U-13 C]fructose and [U-13 C]glucose precursors by 13 C-NMR analysis of glycogen. METHODS Twelve male C57BL/6 mice fed standard chow were provided a 55/45 mixture of fructose and glucose at 30% w/v in the drinking water for 18 wk. On the evening before sacrifice, the fructose component was enriched with 20% [U-13 C]fructose for 6 mice, while the glucose component was enriched with 20% [U-13 C]glucose for the remaining 6 mice. Mice were allowed to feed and drink naturally overnight, and then, euthanized. Livers were freeze-clamped and glycogen was extracted and derivatized for 13 C NMR spectroscopy. Flux of each sugar into the PPP relative to its incorporation into glycogen was quantified from selected 13 C glycogen isotopomer ratios. RESULTS Both [U-13 C]fructose and [U-13 C]glucose precursors yielded glycogen 13 C-isotopomer distributions that were characteristic of PPP activity. The fraction of [U-13 C]glucose utilized by the PPP relative to its conversion to glycogen via the direct pathway was 14 ± 1%, while that from [U-13 C]fructose relative to its conversion to glycogen via the indirect pathway was significantly lower (10 ± 1%, P = .00032). CONCLUSIONS Hepatic PPP fluxes from both [U-13 C]glucose and [U-13 C]fructose precursors were assessed by 13 C NMR analysis of glycogen 13 C-isotopomers. Glucose-6-phosphate generated via glucokinase and the direct pathway is preferentially utilized by the PPP.
Collapse
Affiliation(s)
- Getachew D Belew
- Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Giada Di Nunzio
- Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Ludgero Tavares
- Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Joao G Silva
- Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Alejandra N Torres
- Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - John G Jones
- Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal
| |
Collapse
|
8
|
Turck D, Bresson JL, Burlingame B, Dean T, Fairweather-Tait S, Heinonen M, Hirsch-Ernst KI, Mangelsdorf I, McArdle H, Naska A, Neuhäuser-Berthold M, Nowicka G, Pentieva K, Sanz Y, Siani A, Sjödin A, Stern M, Tomé D, Vinceti M, Willatts P, Engel KH, Marchelli R, Pöting A, Poulsen M, Schlatter JR, Germini A, Van Loveren H. Safety of d-ribose as a novel food pursuant to Regulation (EU) 2015/2283. EFSA J 2018; 16:e05265. [PMID: 32625902 PMCID: PMC7009719 DOI: 10.2903/j.efsa.2018.5265] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on D-ribose as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The applicant intends to market the NF as ingredient in a variety of foods, food supplements and in certain foods for specific groups. The NF is produced by fermentation using a transketolase-deficient strain of Bacillus subtilis and marketed as Bioenergy Ribose™. The information provided on the batch-to-batch variability, specifications, stability, production process and history of the organism used as a source of the NF is sufficient and does not raise safety concerns. The Panel considers that the effects observed in a subchronic toxicity study in rats could be the consequence of nutritional imbalances, but toxicological effects could not be ruled out; from this study, the Panel derived a No observed adverse effect level (NOAEL) of 3.6 g/kg body weight (bw) per day. From the human studies indicating a potential decrease in glucose levels and/or the occurrence of transient symptomatic hypoglycaemia at intakes of 10 g of d-ribose, the Panel defined 70 mg/kg bw per day as the NOAEL with respect to hypoglycaemia that can be considered applicable for adults. For children, the Panel acknowledges the lack of human data directly relevant for this population group. Based on the NOAEL derived from the subchronic toxicity study in rats, an acceptable level of intake of 36 mg/kg bw per day was defined that would also take into account the potentially increased sensitivity of certain population groups to hypoglycaemia. The Panel concludes that the NF is safe for the general population at intake levels up to 36 mg/kg bw per day and considers that the safety of the NF at the intended uses and use levels as proposed by the applicant has not been established.
Collapse
|
9
|
Jeon M, Kang HW, An S. A Mathematical Model for Enzyme Clustering in Glucose Metabolism. Sci Rep 2018; 8:2696. [PMID: 29426820 PMCID: PMC5807315 DOI: 10.1038/s41598-018-20348-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 01/17/2018] [Indexed: 01/01/2023] Open
Abstract
We have recently demonstrated that the rate-limiting enzymes in human glucose metabolism organize into cytoplasmic clusters to form a multienzyme complex, the glucosome, in at least three different sizes. Quantitative high-content imaging data support a hypothesis that the glucosome clusters regulate the direction of glucose flux between energy metabolism and building block biosynthesis in a cluster size-dependent manner. However, direct measurement of their functional contributions to cellular metabolism at subcellular levels has remained challenging. In this work, we develop a mathematical model using a system of ordinary differential equations, in which the association of the rate-limiting enzymes into multienzyme complexes is included as an essential element. We then demonstrate that our mathematical model provides a quantitative principle to simulate glucose flux at both subcellular and population levels in human cancer cells. Lastly, we use the model to simulate 2-deoxyglucose-mediated alteration of glucose flux in a population level based on subcellular high-content imaging data. Collectively, we introduce a new mathematical model for human glucose metabolism, which promotes our understanding of functional roles of differently sized multienzyme complexes in both single-cell and population levels.
Collapse
Affiliation(s)
- Miji Jeon
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD, 21250, USA
| | - Hye-Won Kang
- Department of Mathematics and Statistics, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD, 21250, USA.
| | - Songon An
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD, 21250, USA.
| |
Collapse
|
10
|
Lu W, Su X, Klein MS, Lewis IA, Fiehn O, Rabinowitz JD. Metabolite Measurement: Pitfalls to Avoid and Practices to Follow. Annu Rev Biochem 2017; 86:277-304. [PMID: 28654323 DOI: 10.1146/annurev-biochem-061516-044952] [Citation(s) in RCA: 261] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Metabolites are the small biological molecules involved in energy conversion and biosynthesis. Studying metabolism is inherently challenging due to metabolites' reactivity, structural diversity, and broad concentration range. Herein, we review the common pitfalls encountered in metabolomics and provide concrete guidelines for obtaining accurate metabolite measurements, focusing on water-soluble primary metabolites. We show how seemingly straightforward sample preparation methods can introduce systematic errors (e.g., owing to interconversion among metabolites) and how proper selection of quenching solvent (e.g., acidic acetonitrile:methanol:water) can mitigate such problems. We discuss the specific strengths, pitfalls, and best practices for each common analytical platform: liquid chromatography-mass spectrometry (LC-MS), gas chromatography-mass spectrometry (GC-MS), nuclear magnetic resonance (NMR), and enzyme assays. Together this information provides a pragmatic knowledge base for carrying out biologically informative metabolite measurements.
Collapse
Affiliation(s)
- Wenyun Lu
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Princeton, New Jersey 08544;
| | - Xiaoyang Su
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Princeton, New Jersey 08544;
| | - Matthias S Klein
- Department of Biological Science, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Ian A Lewis
- Department of Biological Science, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Oliver Fiehn
- National Institutes of Health West Coast Metabolomics Center, University of California, Davis, California 95616.,Department of Biochemistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Joshua D Rabinowitz
- Lewis Sigler Institute for Integrative Genomics and Department of Chemistry, Princeton University, Princeton, New Jersey 08544;
| |
Collapse
|
11
|
Moreno KX, Harrison CE, Merritt ME, Kovacs Z, Malloy CR, Sherry AD. Hyperpolarized δ-[1- 13 C]gluconolactone as a probe of the pentose phosphate pathway. NMR IN BIOMEDICINE 2017; 30:10.1002/nbm.3713. [PMID: 28272754 PMCID: PMC5502806 DOI: 10.1002/nbm.3713] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 12/22/2016] [Accepted: 01/23/2017] [Indexed: 05/05/2023]
Abstract
The pentose phosphate pathway (PPP) is thought to be upregulated in trauma (to produce excess NADPH) and in cancer (to provide ribose for nucleotide biosynthesis), but simple methods for detecting changes in flux through this pathway are not available. MRI of hyperpolarized 13 C-enriched metabolites offers considerable potential as a rapid, non-invasive tool for detecting changes in metabolic fluxes. In this study, hyperpolarized δ-[1-13 C]gluconolactone was used as a probe to detect flux through the oxidative portion of the pentose phosphate pathway (PPPox ) in isolated perfused mouse livers. The appearance of hyperpolarized (HP) H13 CO3- within seconds after exposure of livers to HP-δ-[1-13 C]gluconolactone demonstrates that this probe rapidly enters hepatocytes, becomes phosphorylated, and enters the PPPox pathway to produce HP-H13 CO3- after three enzyme catalyzed steps (6P-gluconolactonase, 6-phosphogluconate dehydrogenase, and carbonic anhydrase). Livers perfused with octanoate as their sole energy source show no change in production of H13 CO3- after exposure to low levels of H2 O2 , while livers perfused with glucose and insulin showed a twofold increase in H13 CO3- after exposure to peroxide. This indicates that flux through the PPPox is stimulated by H2 O2 in glucose perfused livers but not in livers perfused with octanoate alone. Subsequent perfusion of livers with non-polarized [1,2-13 C]glucose followed by 1 H NMR analysis of lactate in the perfusate verified that flux through the PPPox is indeed low in healthy livers and modestly higher in peroxide damaged livers. We conclude that hyperpolarized δ-[1-13 C]gluconolactone has the potential to serve as a metabolic imaging probe of this important biological pathway.
Collapse
Affiliation(s)
- Karlos X. Moreno
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX 75390
| | - Crystal E. Harrison
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX 75390
| | - Matthew E. Merritt
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX 75390
- Dept of Radiology, UT Southwestern Medical Center, Dallas, TX 75390
| | - Zoltan Kovacs
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX 75390
| | - Craig R. Malloy
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX 75390
- Dept of Radiology, UT Southwestern Medical Center, Dallas, TX 75390
- Dept of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390
- VA North Texas Health Care System, Dallas, TX 75216
| | - A. Dean Sherry
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX 75390
- Dept of Radiology, UT Southwestern Medical Center, Dallas, TX 75390
- Dept of Chemistry, University of Texas at Dallas, Richardson, TX 75083
- Corresponding Author: A. Dean Sherry; Advanced Imaging Research Center; 5323 Harry Hines Blvd, Dallas, TX 75390; telephone: +1 (214) 645-2730, fax: +1 (214) 645-2744; ; URL: http://www8.utsouthwestern.edu/utsw/home/research/AIRC/index.html
| |
Collapse
|
12
|
Kohnhorst CL, Kyoung M, Jeon M, Schmitt DL, Kennedy EL, Ramirez J, Bracey SM, Luu BT, Russell SJ, An S. Identification of a multienzyme complex for glucose metabolism in living cells. J Biol Chem 2017; 292:9191-9203. [PMID: 28424264 DOI: 10.1074/jbc.m117.783050] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 04/17/2017] [Indexed: 01/05/2023] Open
Abstract
Sequential metabolic enzymes in glucose metabolism have long been hypothesized to form multienzyme complexes that regulate glucose flux in living cells. However, it has been challenging to directly observe these complexes and their functional roles in living systems. In this work, we have used wide-field and confocal fluorescence microscopy to investigate the spatial organization of metabolic enzymes participating in glucose metabolism in human cells. We provide compelling evidence that human liver-type phosphofructokinase 1 (PFKL), which catalyzes a bottleneck step of glycolysis, forms various sizes of cytoplasmic clusters in human cancer cells, independent of protein expression levels and of the choice of fluorescent tags. We also report that these PFKL clusters colocalize with other rate-limiting enzymes in both glycolysis and gluconeogenesis, supporting the formation of multienzyme complexes. Subsequent biophysical characterizations with fluorescence recovery after photobleaching and FRET corroborate the formation of multienzyme metabolic complexes in living cells, which appears to be controlled by post-translational acetylation on PFKL. Importantly, quantitative high-content imaging assays indicated that the direction of glucose flux between glycolysis, the pentose phosphate pathway, and serine biosynthesis seems to be spatially regulated by the multienzyme complexes in a cluster-size-dependent manner. Collectively, our results reveal a functionally relevant, multienzyme metabolic complex for glucose metabolism in living human cells.
Collapse
Affiliation(s)
- Casey L Kohnhorst
- From the Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250
| | - Minjoung Kyoung
- From the Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250
| | - Miji Jeon
- From the Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250
| | - Danielle L Schmitt
- From the Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250
| | - Erin L Kennedy
- From the Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250
| | - Julio Ramirez
- From the Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250
| | - Syrena M Bracey
- From the Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250
| | - Bao Tran Luu
- From the Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250
| | - Sarah J Russell
- From the Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250
| | - Songon An
- From the Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250
| |
Collapse
|
13
|
Slaninova V, Krafcikova M, Perez-Gomez R, Steffal P, Trantirek L, Bray SJ, Krejci A. Notch stimulates growth by direct regulation of genes involved in the control of glycolysis and the tricarboxylic acid cycle. Open Biol 2016; 6:150155. [PMID: 26887408 PMCID: PMC4772804 DOI: 10.1098/rsob.150155] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Glycolytic shift is a characteristic feature of rapidly proliferating cells, such as cells during development and during immune response or cancer cells, as well as of stem cells. It results in increased glycolysis uncoupled from mitochondrial respiration, also known as the Warburg effect. Notch signalling is active in contexts where cells undergo glycolytic shift. We decided to test whether metabolic genes are direct transcriptional targets of Notch signalling and whether upregulation of metabolic genes can help Notch to induce tissue growth under physiological conditions and in conditions of Notch-induced hyperplasia. We show that genes mediating cellular metabolic changes towards the Warburg effect are direct transcriptional targets of Notch signalling. They include genes encoding proteins involved in glucose uptake, glycolysis, lactate to pyruvate conversion and repression of the tricarboxylic acid cycle. The direct transcriptional upregulation of metabolic genes is PI3K/Akt independent and occurs not only in cells with overactivated Notch but also in cells with endogenous levels of Notch signalling and in vivo. Even a short pulse of Notch activity is able to elicit long-lasting metabolic changes resembling the Warburg effect. Loss of Notch signalling in Drosophila wing discs as well as in human microvascular cells leads to downregulation of glycolytic genes. Notch-driven tissue overgrowth can be rescued by downregulation of genes for glucose metabolism. Notch activity is able to support growth of wing during nutrient-deprivation conditions, independent of the growth of the rest of the body. Notch is active in situations that involve metabolic reprogramming, and the direct regulation of metabolic genes may be a common mechanism that helps Notch to exert its effects in target tissues.
Collapse
Affiliation(s)
- Vera Slaninova
- Faculty of Science, University of South Bohemia, Branisovska 31, 37005 Ceske Budejovice, Czech Republic Institute of Entomology, Biology Centre, Czech Academy of Sciences, 37005 Ceske Budejovice, Czech Republic
| | - Michaela Krafcikova
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Raquel Perez-Gomez
- Faculty of Science, University of South Bohemia, Branisovska 31, 37005 Ceske Budejovice, Czech Republic
| | - Pavel Steffal
- Faculty of Science, University of South Bohemia, Branisovska 31, 37005 Ceske Budejovice, Czech Republic
| | - Lukas Trantirek
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Sarah J Bray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Alena Krejci
- Faculty of Science, University of South Bohemia, Branisovska 31, 37005 Ceske Budejovice, Czech Republic Institute of Entomology, Biology Centre, Czech Academy of Sciences, 37005 Ceske Budejovice, Czech Republic
| |
Collapse
|
14
|
Fan TWM, Lane AN. Applications of NMR spectroscopy to systems biochemistry. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2016; 92-93:18-53. [PMID: 26952191 PMCID: PMC4850081 DOI: 10.1016/j.pnmrs.2016.01.005] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 01/26/2016] [Accepted: 01/28/2016] [Indexed: 05/05/2023]
Abstract
The past decades of advancements in NMR have made it a very powerful tool for metabolic research. Despite its limitations in sensitivity relative to mass spectrometric techniques, NMR has a number of unparalleled advantages for metabolic studies, most notably the rigor and versatility in structure elucidation, isotope-filtered selection of molecules, and analysis of positional isotopomer distributions in complex mixtures afforded by multinuclear and multidimensional experiments. In addition, NMR has the capacity for spatially selective in vivo imaging and dynamical analysis of metabolism in tissues of living organisms. In conjunction with the use of stable isotope tracers, NMR is a method of choice for exploring the dynamics and compartmentation of metabolic pathways and networks, for which our current understanding is grossly insufficient. In this review, we describe how various direct and isotope-edited 1D and 2D NMR methods can be employed to profile metabolites and their isotopomer distributions by stable isotope-resolved metabolomic (SIRM) analysis. We also highlight the importance of sample preparation methods including rapid cryoquenching, efficient extraction, and chemoselective derivatization to facilitate robust and reproducible NMR-based metabolomic analysis. We further illustrate how NMR has been applied in vitro, ex vivo, or in vivo in various stable isotope tracer-based metabolic studies, to gain systematic and novel metabolic insights in different biological systems, including human subjects. The pathway and network knowledge generated from NMR- and MS-based tracing of isotopically enriched substrates will be invaluable for directing functional analysis of other 'omics data to achieve understanding of regulation of biochemical systems, as demonstrated in a case study. Future developments in NMR technologies and reagents to enhance both detection sensitivity and resolution should further empower NMR in systems biochemical research.
Collapse
Affiliation(s)
- Teresa W-M Fan
- Department of Toxicology and Cancer Biology, University of Kentucky, 789 S. Limestone St., Lexington, KY 40536, United States.
| | - Andrew N Lane
- Department of Toxicology and Cancer Biology, University of Kentucky, 789 S. Limestone St., Lexington, KY 40536, United States.
| |
Collapse
|
15
|
Lane AN, Fan TWM. Regulation of mammalian nucleotide metabolism and biosynthesis. Nucleic Acids Res 2015; 43:2466-85. [PMID: 25628363 PMCID: PMC4344498 DOI: 10.1093/nar/gkv047] [Citation(s) in RCA: 544] [Impact Index Per Article: 60.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Revised: 12/21/2014] [Accepted: 01/12/2015] [Indexed: 12/25/2022] Open
Abstract
Nucleotides are required for a wide variety of biological processes and are constantly synthesized de novo in all cells. When cells proliferate, increased nucleotide synthesis is necessary for DNA replication and for RNA production to support protein synthesis at different stages of the cell cycle, during which these events are regulated at multiple levels. Therefore the synthesis of the precursor nucleotides is also strongly regulated at multiple levels. Nucleotide synthesis is an energy intensive process that uses multiple metabolic pathways across different cell compartments and several sources of carbon and nitrogen. The processes are regulated at the transcription level by a set of master transcription factors but also at the enzyme level by allosteric regulation and feedback inhibition. Here we review the cellular demands of nucleotide biosynthesis, their metabolic pathways and mechanisms of regulation during the cell cycle. The use of stable isotope tracers for delineating the biosynthetic routes of the multiple intersecting pathways and how these are quantitatively controlled under different conditions is also highlighted. Moreover, the importance of nucleotide synthesis for cell viability is discussed and how this may lead to potential new approaches to drug development in diseases such as cancer.
Collapse
Affiliation(s)
- Andrew N Lane
- Graduate Center of Toxicology and Markey Cancer Center, University of Kentucky, Biopharm Complex, 789 S. Limestone St, Lexington, KY 40536, USA
| | - Teresa W-M Fan
- Graduate Center of Toxicology and Markey Cancer Center, University of Kentucky, Biopharm Complex, 789 S. Limestone St, Lexington, KY 40536, USA
| |
Collapse
|
16
|
Tavares LC, Jarak I, Nogueira FN, Oliveira PJ, Carvalho RA. Metabolic evaluations of cancer metabolism by NMR-based stable isotope tracer methodologies. Eur J Clin Invest 2015; 45 Suppl 1:37-43. [PMID: 25524585 DOI: 10.1111/eci.12358] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Cancer cells are widely recognized for being able to adapt their metabolism towards converting available nutrients into biomass to increase proliferation rates. MATERIALS AND METHODS We will review a series of nuclear magnetic resonance (NMR)-based stable isotope tracer methodologies for probing cancer metabolism. RESULTS The monitoring of such adaptations is of the utmost importance to unravel cancer metabolism and tumour growth. Several major metabolic targets have been recognized as promising foci and have been addressed by multiple studies in recent years. In this work are presented strategies to quantify glycolysis, pentose phosphate pathway, Krebs cycle turnover and de novo lipogenesis by NMR isotopomer analysis. CONCLUSIONS Being able to adequately define the interplay between metabolic pathways allows the monitoring of their prevalence in tissues and such information is critical for an accurate knowledge of the metabolic distinctive nature of tumours towards devising more efficient antitumorigenic strategies. Discussed methodologies are currently available in the literature, but to date, no single review has compiled all their possible uses, particularly in an interdependent perspective.
Collapse
Affiliation(s)
- Ludgero C Tavares
- Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal; Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | | | | | | | | |
Collapse
|
17
|
Therapeutic properties of VO(dmpp)2 as assessed by in vitro and in vivo studies in type 2 diabetic GK rats. J Inorg Biochem 2014; 131:115-22. [DOI: 10.1016/j.jinorgbio.2013.11.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/15/2013] [Accepted: 11/17/2013] [Indexed: 01/28/2023]
|
18
|
Sickle hemoglobin disturbs normal coupling among erythrocyte O2 content, glycolysis, and antioxidant capacity. Blood 2013; 121:1651-62. [PMID: 23297128 DOI: 10.1182/blood-2012-02-414037] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Energy metabolism in RBCs is characterized by O2-responsive variations in flux through the Embden Meyerhof pathway (EMP) or the hexose monophosphate pathway (HMP). Therefore, the generation of ATP, NADH, and 2,3-DPG (EMP) or NADPH (HMP) shift with RBC O2 content because of competition between deoxyhemoglobin and key EMP enzymes for binding to the cytoplasmic domain of the Band 3 membrane protein (cdB3). Enzyme inactivation by cdB3 sequestration in oxygenated RBCs favors HMP flux and NADPH generation (maximizing glutathione-based antioxidant systems). We tested the hypothesis that sickle hemoglobin disrupts cdB3-based regulatory protein complex assembly, creating vulnerability to oxidative stress. In RBCs from patients with sickle cell anemia, we demonstrate in the present study constrained HMP flux, NADPH, and glutathione recycling and reduced resilience to oxidative stress manifested by membrane protein oxidation and membrane fragility. Using a novel, inverted membrane-on-bead model, we illustrate abnormal (O2-dependent) association of sickle hemoglobin to RBC membrane that interferes with sequestration/inactivation of the EMP enzyme GAPDH. This finding was confirmed by immunofluorescent imaging during RBC O2 loading/unloading. Moreover, selective inhibition of inappropriately dispersed GAPDH rescues antioxidant capacity. Such disturbance of cdB3-based linkage between O2 gradients and RBC metabolism suggests a novel mechanism by which hypoxia may influence the sickle cell anemia phenotype.
Collapse
|
19
|
Marin-Valencia I, Cho SK, Rakheja D, Hatanpaa KJ, Kapur P, Mashimo T, Jindal A, Vemireddy V, Good LB, Raisanen J, Sun X, Mickey B, Choi C, Takahashi M, Togao O, Pascual JM, DeBerardinis RJ, Maher EA, Malloy CR, Bachoo RM. Glucose metabolism via the pentose phosphate pathway, glycolysis and Krebs cycle in an orthotopic mouse model of human brain tumors. NMR IN BIOMEDICINE 2012; 25:1177-86. [PMID: 22383401 PMCID: PMC3670098 DOI: 10.1002/nbm.2787] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 12/29/2011] [Accepted: 01/03/2012] [Indexed: 05/05/2023]
Abstract
It has been hypothesized that increased flux through the pentose phosphate pathway (PPP) is required to support the metabolic demands of rapid malignant cell growth. Using orthotopic mouse models of human glioblastoma (GBM) and renal cell carcinoma metastatic to brain, we estimated the activity of the PPP relative to glycolysis by infusing [1,2-(13) C(2) ]glucose. The [3-(13) C]lactate/[2,3-(13) C(2) ]lactate ratio was similar for both the GBM and brain metastasis and their respective surrounding brains (GBM, 0.197 ± 0.011 and 0.195 ± 0.033, respectively (p = 1); metastasis: 0.126 and 0.119 ± 0.033, respectively). This suggests that the rate of glycolysis is significantly greater than the PPP flux in these tumors, and that the PPP flux into the lactate pool is similar in both tumors. Remarkably, (13) C-(13) C coupling was observed in molecules derived from Krebs cycle intermediates in both tumor types, denoting glucose oxidation. In the renal cell carcinoma, in contrast with GBM, (13) C multiplets of γ-aminobutyric acid (GABA) differed from its precursor glutamate, suggesting that GABA did not derive from a common glutamate precursor pool. In addition, the orthotopic renal tumor, the patient's primary renal mass and brain metastasis were all strongly immunopositive for the 67-kDa isoform of glutamate decarboxylase, as were 84% of tumors on a renal cell carcinoma tissue microarray of the same histology, suggesting that GABA synthesis is cell autonomous in at least a subset of renal cell carcinomas. Taken together, these data demonstrate that (13) C-labeled glucose can be used in orthotopic mouse models to study tumor metabolism in vivo and to ascertain new metabolic targets for cancer diagnosis and therapy.
Collapse
Affiliation(s)
- Isaac Marin-Valencia
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Division of Pediatric Neurology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Steve K. Cho
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Annette G. Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Dinesh Rakheja
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Kimmo J. Hatanpaa
- Annette G. Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Payal Kapur
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Tomoyuki Mashimo
- Annette G. Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Ashish Jindal
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Vamsidhara Vemireddy
- Annette G. Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Levi B. Good
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Jack Raisanen
- Annette G. Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Xiankai Sun
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Bruce Mickey
- Annette G. Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Neurological Surgery, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Changho Choi
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Masaya Takahashi
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Osamu Togao
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Juan M. Pascual
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Division of Pediatric Neurology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Ralph J. DeBerardinis
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Elizabeth A. Maher
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Annette G. Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Craig R. Malloy
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Medical Service, Veterans Affairs North Texas Healthcare System, Lancaster, Texas 75216
- Corresponding authors: Robert M. Bachoo, MD, PhD, Department of Neurology, Annette G. Strauss Center for Neuro-Onoclogy, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75235, ; Craig Malloy, M.D., Mary Nell and Ralph B. Rogers Magnetic Resonance Center, 5323 Harry Hines Blvd., Dallas,TX 75390-8568.,
| | - Robert M. Bachoo
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Annette G. Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Corresponding authors: Robert M. Bachoo, MD, PhD, Department of Neurology, Annette G. Strauss Center for Neuro-Onoclogy, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75235, ; Craig Malloy, M.D., Mary Nell and Ralph B. Rogers Magnetic Resonance Center, 5323 Harry Hines Blvd., Dallas,TX 75390-8568.,
| |
Collapse
|
20
|
Metelo AM, Pérez-Carro R, Castro MMCA, López-Larrubia P. VO(dmpp)2 normalizes pre-diabetic parameters as assessed by in vivo magnetic resonance imaging and spectroscopy. J Inorg Biochem 2012; 115:44-9. [PMID: 22922310 DOI: 10.1016/j.jinorgbio.2012.06.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 06/01/2012] [Accepted: 06/05/2012] [Indexed: 01/19/2023]
Abstract
Type 2 diabetes mellitus has been associated with obesity, metabolic syndrome, cardiovascular diseases and cancer. Attempts have been made for early diagnosis and finding effective drugs to prevent severe consequences and ameliorate the symptoms of this disorder. In this work, the pharmacological properties of VO(dmpp)(2), [bis(1,2-dimethyl-3-hydroxy-4-pyridinonato)oxovanadium(IV)], were in vivo evaluated. For 4 weeks fatty Zucker rats were subjected to a daily dose of VO(dmpp)(2) (44 μmol/kg) and their metabolic profile was followed by assessing different biological parameters at established time points: body weight, subcutaneous fat width and hepatic triglyceride content determined by magnetic resonance imaging and spectroscopy, respectively. A glucose tolerance test was performed at the end of the experiment. After treatment, treated obese rats presented a weight significantly lower than the non-treated obese animals (359.0±11.1 vs. 433.5±6.2g, P<0.05), a thinner subcutaneous fat width, and a statistically significant decrease in hepatic triglyceride content (5.41±0.59 vs. 21.03±1.40%, P<0.0005). Additionally, the glucose intolerant profile of fatty Zucker rats was completely reversed in treated animals (102.3±2.1 vs. 172.4±1.3 mg/100 mL; P<0.0005). These results reinforce the therapeutic action of VO(dmpp)(2) which shows particular effects on lipid metabolism.
Collapse
Affiliation(s)
- Ana M Metelo
- Instituto Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Madrid, Spain
| | | | | | | |
Collapse
|
21
|
Fan TWM, Tan J, McKinney MM, Lane AN. Stable Isotope Resolved Metabolomics Analysis of Ribonucleotide and RNA Metabolism in Human Lung Cancer Cells. Metabolomics 2012; 8:517-527. [PMID: 26146495 PMCID: PMC4486296 DOI: 10.1007/s11306-011-0337-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We have developed a simple NMR-based method to determine the turnover of nucleotides and incorporation into RNA by stable isotope resolved metabolomics (SIRM) in A549 lung cancer cells. This method requires no chemical degradation of the nucleotides or chromatography. During cell growth, the free ribonucleotide pool is rapidly replaced by de novo synthesized nucleotides. Using [U-13C]-glucose and [U-13C,15N]-glutamine as tracers, we showed that virtually all of the carbons in the nucleotide riboses were derived from glucose, whereas glutamine was preferentially utilized over glucose for pyrimidine ring biosynthesis, via the synthesis of Asp through the Krebs cycle. Incorporation of the glutamine amido nitrogen into the N3 and N9 positions of the purine rings was also demonstrated by proton-detected 15N NMR. The incorporation of 13C from glucose into total RNA was measured and shown to be a major sink for the nucleotides during cell proliferation. This method was applied to determine the metabolic action of an anti-cancer selenium agent (methylseleninic acid or MSA) on A549 cells. We found that MSA inhibited nucleotide turnover and incorporation into RNA, implicating an important role of nucleotide metabolism in the toxic action of MSA on cancer cells.
Collapse
Affiliation(s)
- Teresa W-M. Fan
- Department of Chemistry, University of Louisville, 2210 S. Brook St, Rm 348 John W. Shumaker Research, Building, Louisville, KY 40292, USA
- Center for Regulatory Environmental Analytical Metabolomics, 2210 S. Brook St., Louisville, KY 40292, USA
- JG Brown Cancer Center, Clinical Translational Research Building, 505 S. Hancock St., Louisville, KY 40202, USA
| | - Jinlian Tan
- JG Brown Cancer Center, Clinical Translational Research Building, 505 S. Hancock St., Louisville, KY 40202, USA
| | - Martin M. McKinney
- Department of Medicine, Clinical Translational Research Building, 505 S. Hancock St., Louisville, KY 40202, USA
| | - Andrew N. Lane
- Department of Chemistry, University of Louisville, 2210 S. Brook St, Rm 348 John W. Shumaker Research, Building, Louisville, KY 40292, USA
- Center for Regulatory Environmental Analytical Metabolomics, 2210 S. Brook St., Louisville, KY 40292, USA
- JG Brown Cancer Center, Clinical Translational Research Building, 505 S. Hancock St., Louisville, KY 40202, USA
- Department of Medicine, Clinical Translational Research Building, 505 S. Hancock St., Louisville, KY 40202, USA
| |
Collapse
|
22
|
Abstract
We have determined the time course of [U-(13)C]-glucose utilization and transformations in SCID mice via bolus injection of the tracer in the tail vein. Incorporation of (13)C into metabolites extracted from mouse blood plasma and several tissues (lung, heart, brain, liver, kidney, and skeletal muscle) were profiled by NMR and GC-MS, which helped ascertain optimal sampling times for different target tissues. We found that the time for overall optimal (13)C incorporation into tissue was 15-20 min but with substantial differences in (13)C labeling patterns of various organs that reflected their specific metabolism. Using this stable isotope resolved metabolomics (SIRM) approach, we have compared the (13)C metabolite profile of the lungs in the same mouse with or without an orthotopic lung tumor xenograft established from human PC14PE6 lung adenocarcinoma cells. The (13)C metabolite profile shows considerable differences in [U-(13)C]-glucose transformations between the two lung tissues, demonstrating the feasibility of applying SIRM to investigate metabolic networks of human cancer xenograft in the mouse model.
Collapse
Affiliation(s)
- Teresa W.-M. Fan
- Department of Chemistry, University of Louisville, 2210 S. Brook St, Rm 348 John W. Shumaker Research Building, Louisville, KY 40292, USA
- Department of Medicine, James Graham Brown Cancer Center, Clinical Translational Research Building, 505 S. Hancock St., Louisville, KY 40202, USA
- Center for Regulatory Environmental Metabolomics, University of Louisville, 2210 S. Brook St., Louisville, KY 40292, USA
| | - Andrew N. Lane
- Department of Chemistry, University of Louisville, 2210 S. Brook St, Rm 348 John W. Shumaker Research Building, Louisville, KY 40292, USA
- Department of Medicine, James Graham Brown Cancer Center, Clinical Translational Research Building, 505 S. Hancock St., Louisville, KY 40202, USA
- Center for Regulatory Environmental Metabolomics, University of Louisville, 2210 S. Brook St., Louisville, KY 40292, USA
| | - Richard M. Higashi
- Department of Chemistry, University of Louisville, 2210 S. Brook St, Rm 348 John W. Shumaker Research Building, Louisville, KY 40292, USA
- Center for Regulatory Environmental Metabolomics, University of Louisville, 2210 S. Brook St., Louisville, KY 40292, USA
| | - Jun Yan
- Department of Medicine, James Graham Brown Cancer Center, Clinical Translational Research Building, 505 S. Hancock St., Louisville, KY 40202, USA
| |
Collapse
|
23
|
Bothwell JHF, Griffin JL. An introduction to biological nuclear magnetic resonance spectroscopy. Biol Rev Camb Philos Soc 2010; 86:493-510. [PMID: 20969720 DOI: 10.1111/j.1469-185x.2010.00157.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful analytical techniques available to biology. This review is an introduction to the potential of this method and is aimed at readers who have little or no experience in acquiring or analyzing NMR spectra. We focus on spectroscopic applications of the magnetic resonance effect, rather than imaging ones, and explain how various aspects of the NMR phenomenon make it a versatile tool with which to address a number of biological problems. Using detailed examples, we discuss the use of (1) H NMR spectroscopy in mixture analysis and metabolomics, the use of (13) C NMR spectroscopy in tracking isotopomers and determining the flux through metabolic pathways ('fluxomics') and the use of (31) P NMR spectroscopy in monitoring ATP generation and intracellular pH homeotasis in vivo. Further examples demonstrate how NMR spectroscopy can be used to probe the physical environment of a cell by measuring diffusion and the tumbling rates of individual metabolites and how it can determine macromolecular structures by measuring the bonds and distances which separate individual atoms. We finish by outlining some of the key challenges which remain in NMR spectroscopy and we highlight how recent advances-such as increased magnet field strengths, cryogenic cooling, microprobes and hyperpolarisation-are opening new avenues for today's biological NMR spectroscopists.
Collapse
Affiliation(s)
- John H F Bothwell
- Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast, UK.
| | | |
Collapse
|
24
|
Role of band 3 in regulating metabolic flux of red blood cells. Proc Natl Acad Sci U S A 2009; 106:18515-20. [PMID: 19846781 DOI: 10.1073/pnas.0905999106] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Deoxygenation elevates glycolytic flux and lowers pentose phosphate pathway (PPP) activity in mammalian erythrocytes. The membrane anion transport protein (band 3 or AE1) is thought to facilitate this process by binding glycolytic enzymes (GEs) and inhibiting their activity in an oxygen-dependent manner. However, this regulatory mechanism has not been demonstrated under physiological conditions. In this study, we introduce a (1)H-(13)C NMR technique for measuring metabolic fluxes in intact cells. The role of band 3 in mediating the oxygenated/deoxygenated metabolic transition was examined by treating cells with pervanadate, a reagent that prevents the GE-band 3 complex from forming. We report that pervanadate suppresses oxygen-dependent changes in glycolytic and PPP fluxes. Moreover, these metabolic alterations were not attributable to modulation of bisphosphoglycerate mutase, direct inhibition of GEs by pervanadate, or oxidation, which are the major side effects of pervanadate treatment. These data provide direct evidence supporting the role of band 3 in mediating oxygen-regulated metabolic transitions.
Collapse
|
25
|
Faneca H, Figueiredo V, Tomaz I, Gonçalves G, Avecilla F, Pedroso de Lima M, Geraldes CF, Pessoa JC, Castro MMC. Vanadium compounds as therapeutic agents: Some chemical and biochemical studies. J Inorg Biochem 2009; 103:601-8. [DOI: 10.1016/j.jinorgbio.2008.11.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Revised: 11/06/2008] [Accepted: 11/10/2008] [Indexed: 11/27/2022]
|
26
|
Kleijn RJ, van Winden WA, Ras C, van Gulik WM, Schipper D, Heijnen JJ. 13C-labeled gluconate tracing as a direct and accurate method for determining the pentose phosphate pathway split ratio in Penicillium chrysogenum. Appl Environ Microbiol 2006; 72:4743-54. [PMID: 16820467 PMCID: PMC1489366 DOI: 10.1128/aem.02955-05] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study we developed a new method for accurately determining the pentose phosphate pathway (PPP) split ratio, an important metabolic parameter in the primary metabolism of a cell. This method is based on simultaneous feeding of unlabeled glucose and trace amounts of [U-13C]gluconate, followed by measurement of the mass isotopomers of the intracellular metabolites surrounding the 6-phosphogluconate node. The gluconate tracer method was used with a penicillin G-producing chemostat culture of the filamentous fungus Penicillium chrysogenum. For comparison, a 13C-labeling-based metabolic flux analysis (MFA) was performed for glycolysis and the PPP of P. chrysogenum. For the first time mass isotopomer measurements of 13C-labeled primary metabolites are reported for P. chrysogenum and used for a 13C-based MFA. Estimation of the PPP split ratio of P. chrysogenum at a growth rate of 0.02 h(-1) yielded comparable values for the gluconate tracer method and the 13C-based MFA method, 51.8% and 51.1%, respectively. A sensitivity analysis of the estimated PPP split ratios showed that the 95% confidence interval was almost threefold smaller for the gluconate tracer method than for the 13C-based MFA method (40.0 to 63.5% and 46.0 to 56.5%, respectively). From these results we concluded that the gluconate tracer method permits accurate determination of the PPP split ratio but provides no information about the remaining cellular metabolism, while the 13C-based MFA method permits estimation of multiple fluxes but provides a less accurate estimate of the PPP split ratio.
Collapse
Affiliation(s)
- Roelco J Kleijn
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.
| | | | | | | | | | | |
Collapse
|
27
|
Jones JG, Barosa C, Gomes F, Carina Mendes A, Delgado TC, Diogo L, Garcia P, Bastos M, Barros L, Fagulha A, Baptista C, Carvalheiro M, Madalena Caldeira M. NMR Derivatives for Quantification of 2H and 13C‐Enrichment of Human Glucuronide from Metabolic Tracers. J Carbohydr Chem 2006. [DOI: 10.1080/07328300600732840] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- John G. Jones
- a NMR Research Unit, Department of Biochemistry and Center for Neurosciences and Cell Biology , University of Coimbra , Coimbra, Portugal
| | - Cristina Barosa
- a NMR Research Unit, Department of Biochemistry and Center for Neurosciences and Cell Biology , University of Coimbra , Coimbra, Portugal
| | - Filipe Gomes
- b Department of Chemistry , University of Coimbra , Coimbra, Portugal
| | - Ana Carina Mendes
- b Department of Chemistry , University of Coimbra , Coimbra, Portugal
| | - Teresa C. Delgado
- a NMR Research Unit, Department of Biochemistry and Center for Neurosciences and Cell Biology , University of Coimbra , Coimbra, Portugal
| | - Luisa Diogo
- c Pediatrics Hospital of Coimbra , Coimbra, Portugal
| | - Paula Garcia
- c Pediatrics Hospital of Coimbra , Coimbra, Portugal
| | - Margarida Bastos
- d Department of Endocrinology , University Hospital of Coimbra , Coimbra, Portugal
| | - Luisa Barros
- d Department of Endocrinology , University Hospital of Coimbra , Coimbra, Portugal
| | - Ana Fagulha
- d Department of Endocrinology , University Hospital of Coimbra , Coimbra, Portugal
| | - Carla Baptista
- d Department of Endocrinology , University Hospital of Coimbra , Coimbra, Portugal
| | - Manuela Carvalheiro
- d Department of Endocrinology , University Hospital of Coimbra , Coimbra, Portugal
| | | |
Collapse
|
28
|
Delgado TC, Tomaz AI, Correia I, Costa Pessoa J, Jones JG, Geraldes CFGC, Castro MMCA. Uptake and metabolic effects of insulin mimetic oxovanadium compounds in human erythrocytes. J Inorg Biochem 2005; 99:2328-39. [PMID: 16226808 DOI: 10.1016/j.jinorgbio.2005.08.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Revised: 08/01/2005] [Accepted: 08/26/2005] [Indexed: 11/26/2022]
Abstract
The uptake of the oxidation products of two oxovanadium(IV) compounds, [N,N'-ethylenebis(pyridoxylaminato)]oxovanadium(IV), V(IV)O(Rpyr(2)en), and bis-[3-hydroxy-1,2-dimethyl-4-pyridinonato]oxovanadium(IV), V(IV)O(dmpp)(2), by human erythrocytes was studied using (51)V and (1)H NMR and EPR spectroscopy. V(IV)O(Rpyr(2)en) in aerobic aqueous solution is oxidized to its V(V) counterpart and the neutral form slowly enters the cells by passive diffusion. In aerobic conditions, V(IV)O(dmpp)(2) originates V(V) complexes of 1:1 and 1:2 stoichiometry. The neutral 1:1 species is taken up by erythrocytes through passive diffusion in a temperature-dependent process; its depletion from the extracellular medium promotes the dissociation of the negatively charged 1:2 species, and the protonation of the negatively charged 1:1 species. The identity of these complexes is not maintained inside the cells, and the intracellular EPR spectra suggest N(2)O(2) or NO(3) intracellular coordinating environments. The oxidative stress induced by the oxovanadium compounds in erythrocytes was not significant at 1mM concentration, but was increased by both vanadate and oxidized V(IV)O(dmpp)(2) at 5mM. Only 1mM oxidized V(IV)O(dmpp)(2) significantly stimulated erythrocytes glucose intake (0.75+/-0.13 against 0.37+/-0.17mM/h found for the control, p<0.05).
Collapse
Affiliation(s)
- Teresa C Delgado
- Department of Biochemistry, Center of NMR Spectroscopy and Center for Neurosciences and Cell Biology, University of Coimbra, P.O. Box 3126, 3001-401 Coimbra, Portugal
| | | | | | | | | | | | | |
Collapse
|