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Miethe S, Rasetti-Escargueil C, Avril A, Liu Y, Chahboun S, Korkeala H, Mazuet C, Popoff MR, Pelat T, Thullier P, Sesardic D, Hust M. Development of Human-Like scFv-Fc Neutralizing Botulinum Neurotoxin E. PLoS One 2015; 10:e0139905. [PMID: 26440796 PMCID: PMC4595074 DOI: 10.1371/journal.pone.0139905] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 09/17/2015] [Indexed: 11/18/2022] Open
Abstract
Background Botulinum neurotoxins (BoNTs) are considered to be the most toxic substances known on earth and are responsible for human botulism, a life-threatening disease characterized by flaccid muscle paralysis that occurs naturally by food-poisoning or colonization of the gastrointestinal tract by BoNT-producing clostridia. BoNTs have been classified as category A agent by the Centers of Disease Control and Prevention (CDC) and are listed among the six agents with the highest risk to be used as bioweapons. Neutralizing antibodies are required for the development of effective anti-botulism therapies to deal with the potential risk of exposure. Results In this study, a macaque (Macaca fascicularis) was immunized with recombinant light chain of BoNT/E3 and an immune phage display library was constructed. After a multi-step panning, several antibody fragments (scFv, single chain fragment variable) with nanomolar affinities were isolated, that inhibited the endopeptidase activity of pure BoNT/E3 in vitro by targeting its light chain. Furthermore, three scFv were confirmed to neutralize BoNT/E3 induced paralysis in an ex vivo mouse phrenic nerve-hemidiaphragm assay. The most effective neutralization (20LD50/mL, BoNT/E3) was observed with scFv ELC18, with a minimum neutralizing concentration at 0.3 nM. Furthermore, ELC18 was highly effective in vivo when administered as an scFv-Fc construct. Complete protection of 1LD50 BoNT/E3 was observed with 1.6 ng/dose in the mouse flaccid paralysis assay. Conclusion These scFv-Fcs antibodies are the first recombinant antibodies neutralizing BoNT/E by targeting its light chain. The human-like nature of the isolated antibodies is predicting a good tolerance for further clinical development.
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Affiliation(s)
- Sebastian Miethe
- Technische Universität Braunschweig, Institut für Biochemie, Biotechnologie und Bioinformatik, Abteilung Biotechnologie, Spielmannstr. 7, 38106 Braunschweig, Germany
| | - Christine Rasetti-Escargueil
- Division of Bacteriology, National Institute for Biological Standards and Control (NIBSC), a centre of Medicines and Healthcare products Regulatory Agency, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, United Kingdom
| | - Arnaud Avril
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA), Département de Microbiologie, Unité de biotechnologie des anticorps et des toxines, 24 avenue des Maquis du Grésivaudan, B.P. 87, 38702 La Tronche Cedex, France
| | - Yvonne Liu
- Division of Bacteriology, National Institute for Biological Standards and Control (NIBSC), a centre of Medicines and Healthcare products Regulatory Agency, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, United Kingdom
| | - Siham Chahboun
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA), Département de Microbiologie, Unité de biotechnologie des anticorps et des toxines, 24 avenue des Maquis du Grésivaudan, B.P. 87, 38702 La Tronche Cedex, France
| | - Hannu Korkeala
- University of Helsinki, Faculty of Veterinary Medicine, Centre of Excellence in Microbial Food Safety Research, Department of Food Hygiene and Environmental Health, P.O. Box 66 (Agnes Sjöbergin katu 2), 00014 Helsinki University, Helsinki, Finland
| | - Christelle Mazuet
- Unité des Bactéries anaérobies et Toxines, Institut Pasteur, 25 avenue du Docteur Roux, 75015, Paris, France
| | - Michel-Robert Popoff
- Unité des Bactéries anaérobies et Toxines, Institut Pasteur, 25 avenue du Docteur Roux, 75015, Paris, France
| | - Thibaut Pelat
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA), Département de Microbiologie, Unité de biotechnologie des anticorps et des toxines, 24 avenue des Maquis du Grésivaudan, B.P. 87, 38702 La Tronche Cedex, France
| | - Philippe Thullier
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA), Département de Microbiologie, Unité de biotechnologie des anticorps et des toxines, 24 avenue des Maquis du Grésivaudan, B.P. 87, 38702 La Tronche Cedex, France
| | - Dorothea Sesardic
- Division of Bacteriology, National Institute for Biological Standards and Control (NIBSC), a centre of Medicines and Healthcare products Regulatory Agency, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, United Kingdom
| | - Michael Hust
- Technische Universität Braunschweig, Institut für Biochemie, Biotechnologie und Bioinformatik, Abteilung Biotechnologie, Spielmannstr. 7, 38106 Braunschweig, Germany
- * E-mail:
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Rasetti-Escargueil C, Avril A, Chahboun S, Tierney R, Bak N, Miethe S, Mazuet C, Popoff MR, Thullier P, Hust M, Pelat T, Sesardic D. Development of human-like scFv-Fc antibodies neutralizing Botulinum toxin serotype B. MAbs 2015; 7:1161-77. [PMID: 26381852 PMCID: PMC4966489 DOI: 10.1080/19420862.2015.1082016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are responsible for human botulism, a life-threatening disease characterized by flaccid muscle paralysis that occurs naturally by food poisoning or colonization of the gastrointestinal tract by BoNT-producing clostridia. BoNTs have been classified as category A agents by the Centers for Disease Control and Prevention. To date, 7 subtypes of BoNT/B were identified showing that subtypes B1 (16 strains) and B2 (32 strains) constitute the vast majority of BoNT/B strains. Neutralizing antibodies are required for the development of anti-botulism drugs to deal with the potential risk. In this study, macaques (Macaca fascicularis) were immunized with recombinant light chain (LC) or heavy chain (HC) of BoNT/B2, followed by the construction of 2 hyper-immune phage display libraries. The best single-chain variable fragments (scFvs) isolated from each library were selected according to their affinities and cross reactivity with BoNT/B1 toxin subtype. These scFvs against LC and HC were further analyzed by assessing the inhibition of in vitro endopeptidase activity of BoNT/B1 and B2 and neutralization of BoNT/B1 and B2 toxin-induced paralysis in the mouse ex vivo phrenic nerve assay. The antibodies B2–7 (against HC) and BLC3 (against LC) were produced as scFv-Fc, and, when tested individually, neutralized BoNT/B1 and BoNT/B2 in a mouse ex vivo phrenic nerve assay. Whereas only scFv-Fc BLC3 alone protected mice against BoNT/B2-induced paralysis in vivo, when B2–7 and BLC3 were combined they exhibited potent synergistic protection. The present study provided an opportunity to assess the extent of antibody-mediated neutralization of BoNT/B1 and BoNT/B2 subtypes in ex vivo and in vitro assays, and to confirm the benefit of the synergistic effect of antibodies targeting the 2 distinct functional domains of the toxin in vivo. Notably, the framework regions of the most promising antibodies (B2–7 and BLC3) are close to the human germline sequences, which suggest that they may be well tolerated in potential clinical development.
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Affiliation(s)
- Christine Rasetti-Escargueil
- a Division of Bacteriology; National Institute for Biological Standards and Control (NIBSC), a centre of Medicines and Healthcare products Regulatory Agency ; Hertfordshire UK
| | - Arnaud Avril
- b Département des Maladies Infectieuses ; Unité Interaction Hôte-Pathogène; Institut de Recherche Biomédicale des Armées (IRBA) ; Brétigny-sur-Orge , France
| | - Siham Chahboun
- b Département des Maladies Infectieuses ; Unité Interaction Hôte-Pathogène; Institut de Recherche Biomédicale des Armées (IRBA) ; Brétigny-sur-Orge , France
| | - Rob Tierney
- a Division of Bacteriology; National Institute for Biological Standards and Control (NIBSC), a centre of Medicines and Healthcare products Regulatory Agency ; Hertfordshire UK
| | - Nicola Bak
- a Division of Bacteriology; National Institute for Biological Standards and Control (NIBSC), a centre of Medicines and Healthcare products Regulatory Agency ; Hertfordshire UK
| | - Sebastian Miethe
- c Institut für Biochemie, Biotechnologie und Bioinformatik; Technische Universität Braunschweig ; Braunschweig , Germany
| | - Christelle Mazuet
- d Unité des Bactéries anaérobies et Toxines; Institut Pasteur ; Paris , France
| | - Michel R Popoff
- d Unité des Bactéries anaérobies et Toxines; Institut Pasteur ; Paris , France
| | - Philippe Thullier
- b Département des Maladies Infectieuses ; Unité Interaction Hôte-Pathogène; Institut de Recherche Biomédicale des Armées (IRBA) ; Brétigny-sur-Orge , France
| | - Michael Hust
- c Institut für Biochemie, Biotechnologie und Bioinformatik; Technische Universität Braunschweig ; Braunschweig , Germany
| | - Thibaut Pelat
- b Département des Maladies Infectieuses ; Unité Interaction Hôte-Pathogène; Institut de Recherche Biomédicale des Armées (IRBA) ; Brétigny-sur-Orge , France
| | - Dorothea Sesardic
- a Division of Bacteriology; National Institute for Biological Standards and Control (NIBSC), a centre of Medicines and Healthcare products Regulatory Agency ; Hertfordshire UK
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Miethe S, Rasetti-Escargueil C, Liu Y, Chahboun S, Pelat T, Avril A, Frenzel A, Schirrmann T, Thullier P, Sesardic D, Hust M. Development of neutralizing scFv-Fc against botulinum neurotoxin A light chain from a macaque immune library. MAbs 2014; 6:446-59. [PMID: 24492304 PMCID: PMC3984333 DOI: 10.4161/mabs.27773] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Botulinum toxins (BoNTs) are among the most toxic substances on earth, with serotype A toxin being the most toxic substance known. They are responsible for human botulism, a disease characterized by flaccid muscle paralysis that occurs naturally through food poisoning or the colonization of the gastrointestinal tract by BoNT-producing clostridia. BoNT has been classified as a category A agent by the Centers for Disease Control, and it is one of six agents with the highest potential risk of use as bioweapons. Human or human-like neutralizing antibodies are thus required for the development of anti-botulinum toxin drugs to deal with this possibility. In this study, Macaca fascicularis was hyperimmunized with a recombinant light chain of BoNT/A. An immune phage display library was constructed and, after multistep panning, several scFv with nanomolar affinities that inhibited the endopeptidase activity of BoNT/A1 in vitro as scFv-Fc, with a molar ratio (ab binding site:toxin) of up to 1:1, were isolated. The neutralization of BoNT/A-induced paralysis by the SEM120-IID5, SEM120-IIIC1 and SEM120-IIIC4 antibodies was demonstrated in mouse phrenic nerve-hemidiaphragm preparations with the holotoxin. The neutralization observed is the strongest ever measured in the phrenic nerve-hemidiaphragm assay for BoNT/A1 for a monoclonal antibody. Several scFv-Fc inhibiting the endopeptidase activity of botulinum neurotoxin A were isolated. For SEM120-IID5, SEM120-IIIC1, and SEM120-IIIC4, inhibitory effects in vitro and protection against the toxin ex vivo were observed. The human-like nature of these antibodies makes them promising lead candidates for further development of immunotherapeutics for this disease.
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Affiliation(s)
- Sebastian Miethe
- Technische Universität Braunschweig; Institut für Biochemie, Biotechnologie, und Bioinformatik; Abteilung Biotechnologie; Braunschweig, Germany
| | - Christine Rasetti-Escargueil
- National Institute for Biological Standards and Control (NIBSC); Medicines and Healthcare Products Regulatory Agency; Division of Bacteriology; Potters Bar, UK
| | - Yvonne Liu
- National Institute for Biological Standards and Control (NIBSC); Medicines and Healthcare Products Regulatory Agency; Division of Bacteriology; Potters Bar, UK
| | - Siham Chahboun
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA); Département de Microbiologie; Unité de biotechnologie des anticorps et des toxines ; La Tronche Cedex, France
| | - Thibaut Pelat
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA); Département de Microbiologie; Unité de biotechnologie des anticorps et des toxines ; La Tronche Cedex, France
| | - Arnaud Avril
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA); Département de Microbiologie; Unité de biotechnologie des anticorps et des toxines ; La Tronche Cedex, France
| | - André Frenzel
- Technische Universität Braunschweig; Institut für Biochemie, Biotechnologie, und Bioinformatik; Abteilung Biotechnologie; Braunschweig, Germany
| | - Thomas Schirrmann
- Technische Universität Braunschweig; Institut für Biochemie, Biotechnologie, und Bioinformatik; Abteilung Biotechnologie; Braunschweig, Germany
| | - Philippe Thullier
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA); Département de Microbiologie; Unité de biotechnologie des anticorps et des toxines ; La Tronche Cedex, France
| | - Dorothea Sesardic
- National Institute for Biological Standards and Control (NIBSC); Medicines and Healthcare Products Regulatory Agency; Division of Bacteriology; Potters Bar, UK
| | - Michael Hust
- Technische Universität Braunschweig; Institut für Biochemie, Biotechnologie, und Bioinformatik; Abteilung Biotechnologie; Braunschweig, Germany
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Sesardic D, Rasetti-Escargueil C, Chahboun S, Hust M, Liu Y, Pelat T, Helmsing S, Mérens A, Jones R, Thullier P. Preliminary results of the AntiBotABE project: Identification of neutralizing scFvs antibodies against botulinum toxins A and B. Toxicon 2013. [DOI: 10.1016/j.toxicon.2012.07.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Chahboun S, Hust M, Liu Y, Pelat T, Miethe S, Helmsing S, Jones RG, Sesardic D, Thullier P. Isolation of a nanomolar scFv inhibiting the endopeptidase activity of botulinum toxin A, by single-round panning of an immune phage-displayed library of macaque origin. BMC Biotechnol 2011; 11:113. [PMID: 22111995 PMCID: PMC3252318 DOI: 10.1186/1472-6750-11-113] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Accepted: 11/23/2011] [Indexed: 01/06/2023] Open
Abstract
Background Botulinum neurotoxin A (BoNT/A), mainly represented by subtype A1, is the most toxic substance known. It causes naturally-occurring food poisoning, and is among the biological agents at the highest risk of being weaponized. Several antibodies neutralizing BoNT/A by targeting its heavy chain (BoNT/A-H) have been isolated in the past. For the first time however, an IgG (4LCA) recently isolated by hybridoma technology and targeting the BoNT/A light chain (BoNT/A-L), was shown to inhibit BoNT/A endopeptidase activity and protect in vivo against BoNT/A. In the present study, a phage-displayed library was constructed from a macaque (Macaca fascicularis) hyper-immunized with BoNTA/L in order to isolate scFvs inhibiting BoNT/A endopeptidase activity for clinical use. Results Diversity of the scFvs constituting the library was limited due to the frequent presence, within the genes intended to be part of the library, of restriction sites utilized for its construction. After screening with several rounds of increasing stringency, as is usual with phage technology, the library got overwhelmed by phagemids encoding incomplete scFvs. The screening was successfully re-performed with a single round of high stringency. In particular, one of the isolated scFvs, 2H8, bound BoNT/A1 with a 3.3 nM affinity and effectively inhibited BoNT/A1 endopeptidase activity. The sequence encoding 2H8 was 88% identical to human germline genes and its average G-score was -0.72, quantifying the high human-like quality of 2H8. Conclusions The presence of restrictions sites within many of the sequences that were to be part of the library did not prevent the isolation of an scFv, 2H8, by an adapted panning strategy. ScFv 2H8 inhibited toxin endopeptidase activity in vitro and possessed human-like quality required for clinical development. More generally, the construction and screening of phage-displayed libraries built from hyper-immunized non-human primates is an efficient solution to isolate antibody fragments with therapeutic potential.
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Affiliation(s)
- Siham Chahboun
- Unité de Biotechnologie des Anticorps, et des Toxines, Département de Microbiologie, Institut de Recherche Biomédicale des Armées (IRBA-CRSSA), 24 Avenue des Maquis du Grésivaudan, BP 87, 38702 La Tronche Cedex, France.
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Thullier P, Chahboun S, Pelat T. A comparison of human and macaque (Macaca mulatta) immunoglobulin germline V regions and its implications for antibody engineering. MAbs 2010; 2:528-38. [PMID: 20562531 PMCID: PMC2958574 DOI: 10.4161/mabs.2.5.12545] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 05/30/2010] [Indexed: 01/08/2023] Open
Abstract
Seventy-five V regions encoded by the sequenced genome of one Macaca mulatta specimen have been identified by homology, and paired with similar human counterparts. When the human V region of each pair presented no allelic polymorphism, it was directly compared with its homolog. This was the case for 37 pairs, and percents of identity ranged between 84 to 97%. When the human V region presented allelic polymorphism, this polymorphism was found to be significantly smaller (p<0.0001, p<0.0001, p = 0.03 for IGHV, IGLV, IGKV regions respectively), 4.2-fold on average, than the differences observed between human and macaque V regions. Similar results were obtained when analysing framework regions (FRs) only. These results, in agreement with others, demonstrate the existence of differences between human and macaque V regions, confirm the need for the humanization of macaque V regions intended for therapeutic use and call into question the validity of patents relying on the "undistinguishable" character of human and macaque V regions or FRs.
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Affiliation(s)
- Philippe Thullier
- Département de Biologie des Agents Transmissibles, Centre de Recherche du Service de Santé des Armées, La Tronche, France.
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Monge C, Beraud N, Tepp K, Pelloux S, Chahboun S, Kaambre T, Kadaja L, Roosimaa M, Piirsoo A, Tourneur Y, Kuznetsov AV, Saks V, Seppet E. Comparative analysis of the bioenergetics of adult cardiomyocytes and nonbeating HL-1 cells: respiratory chain activities, glycolytic enzyme profiles, and metabolic fluxes. Can J Physiol Pharmacol 2009; 87:318-26. [PMID: 19370085 DOI: 10.1139/y09-018] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Comparative analysis of the bioenergetic parameters of adult rat cardiomyocytes (CM) and HL-1 cells with very different structure but similar cardiac phenotype was carried out with the aim of revealing the importance of the cell structure for regulation of its energy fluxes. Confocal microscopic analysis showed very different mitochondrial arrangement in these cells. The cytochrome content per milligram of cell protein was decreased in HL-1 cells by a factor of 7 compared with CM. In parallel, the respiratory chain complex activities were decreased by 4-8 times in the HL-1 cells. On the contrary, the activities of glycolytic enzymes, hexokinase (HK), and pyruvate kinase (PK) were increased in HL-1 cells, and these cells effectively transformed glucose into lactate. At the same time, the creatine kinase (CK) activity was significantly decreased in HL-1 cells. In conclusion, the results of this study comply with the assumption that in contrast to CM in which oxidative phosphorylation is a predominant provider of ATP and the CK system is a main carrier of energy from mitochondria to ATPases, in HL-1 cells the energy metabolism is based mostly on the glycolytic reactions coupled to oxidative phosphorylation through HK.
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Affiliation(s)
- Claire Monge
- INSERM U884, Laboratory of Fundamental and Applied Bioenergetics, Joseph Fourier University, Grenoble, France
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Chahboun S, Tallineau C, Pontcharraud R, Guettier A, Piriou A. Polyunsaturated fatty acid profiles and alpha-tocopherol levels in plasma and whole blood incubated with copper. Evidence of inhibition of lipoperoxidation in plasma by hemolysate. Biochim Biophys Acta 1990; 1042:324-9. [PMID: 2306484 DOI: 10.1016/0005-2760(90)90160-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Polyunsaturated fatty acid (PUFA) profiles and alpha-tocopherol levels were studied in human plasma and whole blood incubated with copper under air or nitrogen. In plasma, both PUFAs and alpha-tocopherol disappeared. The results were completely different in whole blood: (i) in plasma, while alpha-tocopherol decreased in the same manner as in plasma incubated alone, profiles of PUFA were only slightly modified. So, in spite of the absence of alpha-tocopherol, lipoperoxidation was not very marked. That is why the release of a protective factor from erythrocytes during hemolysis was under consideration. This was confirmed by the complete inhibition of degradation of PUFAs in plasma when hemolysate was added; (ii) In erythrocytes, no modification in PUFA profiles could be detected while alpha-tocopherol decreased slightly. Thus, not only do erythrocytes resist the copper-dependent oxidative stress in an incredible manner, but they also seem to protect plasma at the time of hemolysis.
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Affiliation(s)
- S Chahboun
- Laboratoire de Biochimie et de Toxicologie, Faculté de Médecine et de Pharmacie, Poitiers, France
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Piriou A, Tallineau C, Chahboun S, Pontcharraud R, Guillard O. Copper-induced lipid peroxidation and hemolysis in whole blood: evidence for a lack of correlation. Toxicology 1987; 47:351-61. [PMID: 3424389 DOI: 10.1016/0300-483x(87)90064-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
In order to establish a possible relationship between hemolytic and peroxidant activities of copper ions, lipid peroxidation was studied in plasma and whole blood incubated for 24 h with different concentrations of copper. The lipid peroxidation was investigated by the determination of thiobarbituric acid-reactive species, conjugated dienes and fluorescent lipid chromophores. The copper-induced lipoperoxidation was clearly demonstrated in plasma incubated with high concentrations of copper (12.10(-4) and 20.10(-4) M); in whole blood, all the lipoperoxidation products were increased in the plasma, while the fluorescent lipid chromophores remained unchanged in red cells. With a copper concentration similar to that found in acute copper intoxication (4.10(-4) M) no lipoperoxidation was observed and yet hemolysis occurred, reduced glutathione (GSH) decreased dramatically and methemoglobin (MetHb) increased. From these results, we assume that, despite its prooxidant activity and its capacity to produce lipoperoxidation, it has not been proven that copper ions at pathophysiological concentrations induce hemolysis by an oxidative mechanism.
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Affiliation(s)
- A Piriou
- Laboratoire de Biochimie et de Toxicologie, Faculté de Médecine et de Pharmacie, Poiters, France
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