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The BCAT1 CXXC Motif Provides Protection against ROS in Acute Myeloid Leukaemia Cells. Antioxidants (Basel) 2022; 11:antiox11040683. [PMID: 35453368 PMCID: PMC9030579 DOI: 10.3390/antiox11040683] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/23/2022] [Accepted: 03/28/2022] [Indexed: 01/15/2023] Open
Abstract
The cytosolic branched-chain aminotransferase (BCAT1) has received attention for its role in myeloid leukaemia development, where studies indicate metabolic adaptations due to BCAT1 up-regulation. BCAT1, like the mitochondria isoform (BCAT2), shares a conserved CXXC motif ~10 Å from the active site. This CXXC motif has been shown to act as a ‘redox-switch’ in the enzymatic regulation of the BCAT proteins, however the response to reactive oxygen species (ROS) differs between BCAT isoforms. Studies indicate that the BCAT1 CXXC motif is several orders of magnitude less sensitive to the effects of ROS compared with BCAT2. Moreover, estimation of the reduction mid-point potential of BCAT1, indicates that BCAT1 is more reductive in nature and may possess antioxidant properties. Therefore, the aim of this study was to further characterise the BCAT1 CXXC motif and evaluate its role in acute myeloid leukaemia. Our biochemical analyses show that purified wild-type (WT) BCAT1 protein could metabolise H2O2 in vitro, whereas CXXC motif mutant or WT BCAT2 could not, demonstrating for the first time a novel antioxidant role for the BCAT1 CXXC motif. Transformed U937 AML cells over-expressing WT BCAT1, showed lower levels of intracellular ROS compared with cells over-expressing the CXXC motif mutant (CXXS) or Vector Controls, indicating that the BCAT1 CXXC motif may buffer intracellular ROS, impacting on cell proliferation. U937 AML cells over-expressing WT BCAT1 displayed less cellular differentiation, as observed by a reduction of the myeloid markers; CD11b, CD14, CD68, and CD36. This finding suggests a role for the BCAT1 CXXC motif in cell development, which is an important pathological feature of myeloid leukaemia, a disease characterised by a block in myeloid differentiation. Furthermore, WT BCAT1 cells were more resistant to apoptosis compared with CXXS BCAT1 cells, an important observation given the role of ROS in apoptotic signalling and myeloid leukaemia development. Since CD36 has been shown to be Nrf2 regulated, we investigated the expression of the Nrf2 regulated gene, TrxRD1. Our data show that the expression of TrxRD1 was downregulated in transformed U937 AML cells overexpressing WT BCAT1, which taken with the reduction in CD36 implicates less Nrf2 activation. Therefore, this finding may implicate the BCAT1 CXXC motif in wider cellular redox-mediated processes. Altogether, this study provides the first evidence to suggest that the BCAT1 CXXC motif may contribute to the buffering of ROS levels inside AML cells, which may impact ROS-mediated processes in the development of myeloid leukaemia.
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Mathot E, Liberman K, Cao Dinh H, Njemini R, Bautmans I. Systematic review on the effects of physical exercise on cellular immunosenescence-related markers - An update. Exp Gerontol 2021; 149:111318. [PMID: 33794319 DOI: 10.1016/j.exger.2021.111318] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 02/25/2021] [Accepted: 03/16/2021] [Indexed: 12/14/2022]
Abstract
Immunosenescence is a remodeling of the immune system occurring with aging that leads to an increased susceptibility to auto-immunity, infections and reduced vaccination response. A growing consensus supports the view that physical exercise may counteract immunosenescence and improve the immune response. Unfortunately, evidence regarding the effects of exercise on markers of cellular immunosenescence lacked uniformity at the time of an extensive literature review in 2016. Moreover, exercise-induced effects in older adults were underrepresented compared to young adults or completely lacking, such as for senescent T-cells and apoptosis of T-lymphocytes. The aim of this systematic literature study was to collect and appraise newly available data regarding exercise-induced changes on immunosenescence-related markers of immune cells and compare this against data that was already available in 2016. Systematic reviewing of newly available data in the field of exercise immunology provides additional evidence for the effect of exercise on immunosenescence-related cellular markers. Importantly, this review provides evidence for the effect of long-term exercise on senescent T-lymphocytes in older adults. Additionally, newly retrieved evidence shows an acute exercise-induced mobilization of naïve and memory cells in older adults. In general, data regarding long-term exercise-induced effects in older adults remain scarce. Noteworthy was the high number of articles describing exercise-induced effects on regulatory T-cells. However exercise-induced effects on this cell type are still inconclusive as some articles reported an exercise-induced up- or downregulation, while others reported no effects at all. Numerous studies on Natural Killer cell counts did not provide uniformity among data that was already available. Recent data regarding dendritic cells mostly described an increase after exercise. Overall, our literature update highlights the major influence of the type and intensity of exercise on immunosenescence-related markers, especially in older adults.
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Affiliation(s)
- Emelyn Mathot
- Frailty in Ageing Research group, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; Gerontology Department, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Keliane Liberman
- Frailty in Ageing Research group, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; Gerontology Department, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Hung Cao Dinh
- Frailty in Ageing Research group, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; Gerontology Department, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; Internal Medicine Department, Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam
| | - Rose Njemini
- Frailty in Ageing Research group, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; Gerontology Department, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Ivan Bautmans
- Frailty in Ageing Research group, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; Gerontology Department, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; Geriatrics Department, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium.
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Abstract
Reductive stress is defined as a condition characterized by excess accumulation of reducing equivalents (e.g., NADH, NADPH, GSH), surpassing the activity of endogenous oxidoreductases. Excessive reducing equivalents can perturb cell signaling pathways, change the formation of disulfide bonding in proteins, disturb mitochondrial homeostasis or decrease metabolism. Reductive stress is influenced by cellular antioxidant load, its flux and a subverted homeostasis that paradoxically can result in excess ROS induction. Balanced reducing equivalents and antioxidant enzymes that contribute to reductive stress can be regulated by Nrf2, typically considered as an oxidative stress induced transcription factor. Cancer cells may coordinate distinct pools of redox couples under reductive stress and these may link to biological consequences from both molecular and translational standpoints. In cancer, there is recent interest in understanding how selective induction of reductive stress may influence therapeutic management and disease progression.
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Affiliation(s)
- Leilei Zhang
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, United States.
| | - Kenneth D Tew
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, United States
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Hancock JT, Veal D. Nitric oxide, other reactive signalling compounds, redox, and reductive stress. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:819-829. [PMID: 32687173 DOI: 10.1093/jxb/eraa331] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/16/2020] [Indexed: 05/23/2023]
Abstract
Nitric oxide (NO) and other reactive nitrogen species (RNS) are key signalling molecules in plants, but they do not work in isolation. NO is produced in cells, often increased in response to stress conditions, but many other reactive compounds used in signalling are generated and accumulate spatially and temporally together. This includes the reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), and hydrogen sulfide (H2S). Here, the interactions with such other reactive molecules is briefly reviewed. Furthermore, along with ROS and H2S, NO will potentially contribute to the overall intracellular redox of the cell. However, RNS will exist in redox couples and therefore the influence of the cellular redox on such couples will be explored. In discussions of the aberrations in intracellular redox it is usually oxidation, so-called oxidative stress, which is discussed. Here, we consider the notion of reductive stress and how this may influence the signalling which may be mediated by NO. By getting a more holistic view of NO biology, the influence on cell activity of NO and other RNS can be more fully understood, and may lead to the elucidation of methods for NO-based manipulation of plant physiology, leading to better stress responses and improved crops in the future.
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Affiliation(s)
- John T Hancock
- Department of Applied Sciences, University of the West of England, Bristol, UK
| | - David Veal
- Department of Applied Sciences, University of the West of England, Bristol, UK
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5
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Quiles JL, Sánchez-González C, Vera-Ramírez L, Giampieri F, Navarro-Hortal MD, Xiao J, Llopis J, Battino M, Varela-López A. Reductive Stress, Bioactive Compounds, Redox-Active Metals, and Dormant Tumor Cell Biology to Develop Redox-Based Tools for the Treatment of Cancer. Antioxid Redox Signal 2020; 33:860-881. [PMID: 32064905 DOI: 10.1089/ars.2020.8051] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Significance: Cancer is related to redox biology from many points of view, such as initiation and promotion, metabolism and growth, invasion and metastasis, vascularization, or through the interaction with the immune system. In addition, this extremely complex relationship depends on the redox homeostasis of each cellular compartment, which might be used to fight cancer. Recent Advances: New ways of modulating specific and little explored aspects of redox biology have been revealed, as well as new delivery methods or uses of previously known treatments against cancer. Here, we review the latest experimental evidence regarding redox biology in cancer treatment and analyze its potential impact in the development of improved and more effective antineoplastic therapies. Critical Issues: A critical issue that deserves particular attention is the understanding that both extremes of redox biology (i.e., oxidative stress [OS] and reductive stress) might be useful or harmful in relation to cancer prevention and treatment. Future Directions: Additional research is needed to understand how to selectively induce reductive or OS adequately to avoid cancer proliferation or to induce cancer cell death.
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Affiliation(s)
- José L Quiles
- Department of Physiology, Institute of Nutrition and Food Technology "José Mataix Verdú", Biomedical Research Center, University of Granada, Granada, Spain.,College of Food Science and Technology, Northwest University, Xi'an, China
| | - Cristina Sánchez-González
- Department of Physiology, Institute of Nutrition and Food Technology "José Mataix Verdú", Biomedical Research Center, University of Granada, Granada, Spain
| | - Laura Vera-Ramírez
- Department of Genomic Medicine, GENYO: Centre for Genomics and Oncology (Pfizer-University of Granada and Andalusian Regional Government), Granada, Spain
| | - Francesca Giampieri
- College of Food Science and Technology, Northwest University, Xi'an, China.,Department of Clinical Sciences, Università Politecnica delle Marche, Ancona, Italy
| | - M Dolores Navarro-Hortal
- Department of Physiology, Institute of Nutrition and Food Technology "José Mataix Verdú", Biomedical Research Center, University of Granada, Granada, Spain
| | - Jianbo Xiao
- International Research Center for Food Nutrition and Safety, Jiangsu University, Zhenjiang, China
| | - Juan Llopis
- Department of Physiology, Institute of Nutrition and Food Technology "José Mataix Verdú", Biomedical Research Center, University of Granada, Granada, Spain
| | - Maurizio Battino
- Department of Clinical Sciences, Università Politecnica delle Marche, Ancona, Italy.,International Research Center for Food Nutrition and Safety, Jiangsu University, Zhenjiang, China.,Nutrition and Food Science Group, Department of Analytical and Food Chemistry, CITACA, CACTI, University of Vigo, Vigo, Spain
| | - Alfonso Varela-López
- Department of Physiology, Institute of Nutrition and Food Technology "José Mataix Verdú", Biomedical Research Center, University of Granada, Granada, Spain
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Peres A, Da Silva IM, Santos M, Beretta Â, Andrade VM, RomãO PRT, Dorneles GP. DNA damage in mononuclear cells following maximal exercise in sedentary and physically active lean and obese men. Eur J Sport Sci 2020; 21:1073-1082. [DOI: 10.1080/17461391.2020.1801850] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Alessandra Peres
- Cellular and Molecular Immunology Lab, Federal University of Health Sciences of Porto Alegre (UFCSPA). Porto Alegre, Brazil
| | - Igor M. Da Silva
- Cellular and Molecular Immunology Lab, Federal University of Health Sciences of Porto Alegre (UFCSPA). Porto Alegre, Brazil
| | - Maeli Santos
- Cellular and Molecular Immunology Lab, Federal University of Health Sciences of Porto Alegre (UFCSPA). Porto Alegre, Brazil
| | - Ângela Beretta
- Laboratory of Molecular and Celular Biology, Graduate Programme of Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciúma, SC, Brazil
| | - Vanessa Moraes Andrade
- Laboratory of Molecular and Celular Biology, Graduate Programme of Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciúma, SC, Brazil
| | - Pedro R. T. RomãO
- Cellular and Molecular Immunology Lab, Federal University of Health Sciences of Porto Alegre (UFCSPA). Porto Alegre, Brazil
| | - Gilson P. Dorneles
- Cellular and Molecular Immunology Lab, Federal University of Health Sciences of Porto Alegre (UFCSPA). Porto Alegre, Brazil
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Torreggiani A, Tinti A, Jurasekova Z, Capdevila M, Saracino M, Di Foggia M. Structural Lesions of Proteins Connected to Lipid Membrane Damages Caused by Radical Stress: Assessment by Biomimetic Systems and Raman Spectroscopy. Biomolecules 2019; 9:E794. [PMID: 31783702 PMCID: PMC6995617 DOI: 10.3390/biom9120794] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/25/2019] [Accepted: 11/27/2019] [Indexed: 12/16/2022] Open
Abstract
Model systems constituted by proteins and unsaturated lipid vesicles were used to gain more insight into the effects of the propagation of an initial radical damage on protein to the lipid compartment. The latter is based on liposome technology and allows measuring the trans unsaturated fatty acid content as a result of free radical stress on proteins. Two kinds of sulfur-containing proteins were chosen to connect their chemical reactivity with membrane lipid transformation, serum albumins and metallothioneins. Biomimetic systems based on radiation chemistry were used to mimic the protein exposure to different kinds of free radical stress and Raman spectroscopy to shed light on protein structural changes caused by the free radical attack. Among the amino acid residues, Cys is one of the most sensitive residues towards the attack of free radicals, thus suggesting that metal-Cys clusters are good interceptors of reactive species in metallothioneins, together with disulfides moieties in serum albumins. Met is another important site of the attack, in particular under reductive conditions. Tyr and Phe are sensitive to radical stress too, leading to electron transfer reactions or radical-induced modifications of their structures. Finally, modifications in protein folding take place depending on reactive species attacking the protein.
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Affiliation(s)
| | - Anna Tinti
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, via Belmeloro 8/2, 40126 Bologna, Italy; (A.T.); (M.D.F.)
| | - Zuzana Jurasekova
- Department of Biophysics, Faculty of Science, P.J. Safarik University, Jesenna 5, 04001 Kosice, Slovakia;
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P. J. Safarik University, Jesenna 5, 04001 Kosice, Slovakia
| | - Mercè Capdevila
- Departament de Quimica, Facultat de ciencies, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia, Spain;
| | - Michela Saracino
- Istituto I.S.O.F. (C.N.R.), via P. Gobetti 101, 40129 Bologna, Italy;
| | - Michele Di Foggia
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, via Belmeloro 8/2, 40126 Bologna, Italy; (A.T.); (M.D.F.)
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8
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Wadley AJ, Keane G, Cullen T, James L, Vautrinot J, Davies M, Hussey B, Hunter DJ, Mastana S, Holliday A, Petersen SV, Bishop NC, Lindley MR, Coles SJ. Characterization of extracellular redox enzyme concentrations in response to exercise in humans. J Appl Physiol (1985) 2019; 127:858-866. [PMID: 31246554 DOI: 10.1152/japplphysiol.00340.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Redox enzymes modulate intracellular redox balance and are secreted in response to cellular oxidative stress, potentially modulating systemic inflammation. Both aerobic and resistance exercise are known to cause acute systemic oxidative stress and inflammation; however, how redox enzyme concentrations alter in extracellular fluids following bouts of either type of exercise is unknown. Recreationally active men (n = 26, mean ± SD: age 28 ± 8 yr) took part in either: 1) two separate energy-matched cycling bouts: one of moderate intensity (MOD) and a bout of high intensity interval exercise (HIIE) or 2) an eccentric-based resistance exercise protocol (RES). Alterations in plasma (study 1) and serum (study 2) peroxiredoxin (PRDX)-2, PRDX-4, superoxide dismutase-3 (SOD3), thioredoxin (TRX-1), TRX-reductase and interleukin (IL)-6 were assessed before and at various timepoints after exercise. There was a significant increase in SOD3 (+1.5 ng/mL) and PRDX-4 (+5.9 ng/mL) concentration following HIIE only, peaking at 30- and 60-min post-exercise respectively. TRX-R decreased immediately and 60 min following HIIE (-7.3 ng/mL) and MOD (-8.6 ng/mL), respectively. In non-resistance trained men, no significant changes in redox enzyme concentrations were observed up to 48 h following RES, despite significant muscle damage. IL-6 concentration increased in response to all trials, however there was no significant relationship between absolute or exercise-induced changes in redox enzyme concentrations. These results collectively suggest that HIIE, but not MOD or RES increase the extracellular concentration of PRDX-4 and SOD3. Exercise-induced changes in redox enzyme concentrations do not appear to directly relate to systemic changes in IL-6 concentration.NEW & NOTEWORTHY Two studies were conducted to characterize changes in redox enzyme concentrations after single bouts of exercise to investigate the emerging association between extracellular redox enzymes and inflammation. We provide evidence that SOD3 and PRDX-4 concentration increased following high-intensity aerobic but not eccentric-based resistance exercise. Changes were not associated with IL-6. The results provide a platform to investigate the utility of SOD3 and PRDX-4 as biomarkers of oxidative stress following exercise.
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Affiliation(s)
- Alex J Wadley
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom.,University Hospitals of Leicester NHS Trust, Leicester, United Kingdom
| | - Gary Keane
- Institute of Science and the Environment, University of Worcester, Worcestershire, United Kingdom
| | - Tom Cullen
- Centre for Sport, Exercise, and Life Sciences, Coventry University, Coventry, United Kingdom
| | - Lynsey James
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom.,Translational Chemical Biology Research Group, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Jordan Vautrinot
- Institute of Science and the Environment, University of Worcester, Worcestershire, United Kingdom
| | - Matthew Davies
- Institute of Sport and Exercise Sciences, University of Worcester, Worcestershire, United Kingdom
| | - Bethan Hussey
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom.,Translational Chemical Biology Research Group, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - David J Hunter
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom.,Translational Chemical Biology Research Group, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Sarabjit Mastana
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom.,Translational Chemical Biology Research Group, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Adrian Holliday
- Institute of Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, United Kingdom
| | | | - Nicolette C Bishop
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom.,University Hospitals of Leicester NHS Trust, Leicester, United Kingdom
| | - Martin R Lindley
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom.,Translational Chemical Biology Research Group, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Steven J Coles
- Institute of Science and the Environment, University of Worcester, Worcestershire, United Kingdom
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Tomàs Giner M, Jiménez-Martí E, Bofill Arasa R, Tinti A, Di Foggia M, Chatgilialoglu C, Torreggiani A. Analysis of the soybean metallothionein system under free radical stress: protein modification connected to lipid membrane damage. Metallomics 2018; 10:1792-1804. [PMID: 30398507 DOI: 10.1039/c8mt00164b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Metallothioneins are small Cys-rich peptides capable of coordinating metal ions, and proposed to be involved in radical stress. The four Zn(ii)-GmMT complexes of soybean (Glycine max) were recombinantly synthesised and exposed to oxidative (HO˙) and reductive (H˙ atoms and eaq-) stress conditions. Gamma-irradiation was used to simulate the endogenous formation of the reactive species in both aqueous solutions and unsaturated lipid vesicle suspensions, a biomimetic model that showed that tandem protein/lipid damage occurs, in particular under reductive radical stress. This is due to the formation of diffusible sulphur-centred radicals, which migrate from the aqueous phase to the lipid bilayer and are thus able to transform the cis double bond of the oleate moiety into the trans isomer. Among the amino acid residues present in GmMTs, Cys is one of the most sensitive residues towards the attack of free radicals, thus suggesting metal-clusters to be good interceptors of free radicals. Also Met, Tyr and Phe residues are sensitive amino acid sites of attack under both oxidative and reductive conditions. The modification of the Zn(ii)-GmMT complexes, in particular isoform 2, was monitored by Raman spectroscopy and mass spectrometry. Free radical stress on the Zn(ii)-GmMT complexes is able to induce significant structural changes such as partial deconstruction and/or rearrangement of the metal clusters, but not the complete demetallation of the proteins nor breaking of the backbone, thus confirming their capability to act as protectors under free radical stress conditions.
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Affiliation(s)
- Mireia Tomàs Giner
- Dep. Genètica, Facultat de Biologia, Univ. Barcelona, Av. Diagonal 645, 08028 Barcelona, Catalonia, Spain.
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10
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Wadley AJ, Morgan RG, Heesom KJ, Hole PS, Coles SJ. Detecting intracellular thiol redox state in leukaemia and heterogeneous immune cell populations: An optimised protocol for digital flow cytometers. MethodsX 2018; 5:1473-1483. [PMID: 30505701 PMCID: PMC6251017 DOI: 10.1016/j.mex.2018.10.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 10/15/2018] [Indexed: 12/04/2022] Open
Abstract
Flow cytometric methods for detecting and quantifying reduced intracellular thiol content using fluorescein-5-maleimide (F5M) in viable eukaryotic cells date back to 1983 (Durand and Olive [1]). There has been little development in these methodologies since that time, a period that has witnessed huge technological advances, particularly with the emergence of digital multi-parameter flow cytometric systems. Concurrent advancement in our understanding of redox regulation within eukaryotic cellular systems has also followed, whereby it is now accepted that cysteine thiols partake in redox reactions, which regulate protein activity and function (Groitl and Jakob (2014), Won et al. (2012)). Moreover, we are at the dawn of a new era in redox biology whereby the importance of ‘reductive stress’ in eukaryotic cellular systems is gathering momentum (Wadley et al. (2018) [4]). It is therefore critical that methods be continually advanced to better understand these concepts in more detail at the cellular level. Flow cytometry is a powerful technique that may be used for this purpose. Henceforth we have rejuvenated these methods to address modern scientific questions. In this paper, essential detail is provided on: The adaption of a protocol initially described by Durand and Olive [1] for use with modern digital flow cytometer configurations. Here we provide optimal conditions for labelling intracellular thiols with F5M for detection using digital flow cytometers. Our modifications avoid the use of methanol fixation thus preserving cell viability in single cell suspension cultures. Demonstration that flow cytometry can detect the gain and loss of reduced intracellular thiols in cells exposed to physiological doses of hydrogen peroxide mediated by glucose oxidase (Hole et al. (2013) [5]). Validation of F5M protein labelling by coupling method to confocal microscopy and downstream proteomics, thus permitting a powerful experimental platform for potential use with next generation flow cytometry e.g. CyTOF (Lin and Maecker (2018) [6]).
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Affiliation(s)
- Alex J Wadley
- School of Science and the Environment, University of Worcester, Worcester, UK.,School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Rhys G Morgan
- School of Life Sciences, University of Sussex, John Maynard Smith Building, Brighton, UK
| | - Kate J Heesom
- Bristol Proteomics Facility, University of Bristol, Bristol, UK
| | - Paul S Hole
- Institute of Cancer and Genetics, Cardiff University School of Medicine, Cardiff, UK
| | - Steven J Coles
- School of Science and the Environment, University of Worcester, Worcester, UK
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