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Williams JK, Smallwood MJ, Benjamin N, D'Souza RJ, Shore AC, Winyard PG, Gilchrist M. Renal nitrate clearance in chronic kidney disease. Nitric Oxide 2020; 97:16-19. [PMID: 32007629 DOI: 10.1016/j.niox.2020.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/27/2020] [Accepted: 01/29/2020] [Indexed: 12/30/2022]
Abstract
BACKGROUND Nitric oxide (NO) is rapidly oxidised in humans to nitrite and nitrate, with nitrate being present in much greater abundance. These oxidation products can be recycled back into nitric oxide via a complex entero-salivary pathway, thus preserving NO activity. Approximately 65% of circulating nitrate is excreted in the urine in 48 h, with the excretory pathway of the remainder unknown. The effect of declining renal function on nitrate clearance is unknown METHODS: Forty five subjects, 21 M, 24F, median age 69 (range 27-75 years) with renal function assessed by CKD-EPI eGFR between 9 and 89 ml/min/1.73 m2 completed the study. Following a 24 h low nitrate diet a microplate spectrophotometric method was employed to measure plasma nitrate concentration and 24 h urinary nitrate excretion were measured to determine renal nitrate clearance. RESULTS There was a strong positive correlation between urinary nitrate clearance and eGFR, (Spearman R = 0.7665, p < 0.0001) with a moderate negative correlation between plasma nitrate concentration and CKD-EPI eGFR, (Spearman's R = -0.37, p = 0.012). There was a trend between fractional excretion of nitrate and CKD-EPI eGFR (ml/min/1.73 m2) Spearman's R 0.27, p = 0.07 though this did not reach statistical significance. Plasma nitrate concentration and serum creatinine concentration were positively correlated, Spearman's R = 0.39, p = 0.008. CONCLUSIONS We have observed a strong positive association between renal nitrate clearance and renal function such that plasma nitrate rises as renal function falls. Fractional excretion of nitrate appears to decline as renal function falls. As such, urinary nitrate excretion is unlikely to be a reliable marker of endogenous NO synthesis in settings where renal function is altered.
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Affiliation(s)
- J K Williams
- NIHR Exeter Clinical Research Facility, University of Exeter Medical School, Barrack Road, EX2 5AX, UK
| | - M J Smallwood
- NIHR Exeter Clinical Research Facility, University of Exeter Medical School, Barrack Road, EX2 5AX, UK
| | - N Benjamin
- NIHR Exeter Clinical Research Facility, University of Exeter Medical School, Barrack Road, EX2 5AX, UK
| | - R J D'Souza
- NIHR Exeter Clinical Research Facility, University of Exeter Medical School, Barrack Road, EX2 5AX, UK
| | - A C Shore
- NIHR Exeter Clinical Research Facility, University of Exeter Medical School, Barrack Road, EX2 5AX, UK
| | - P G Winyard
- NIHR Exeter Clinical Research Facility, University of Exeter Medical School, Barrack Road, EX2 5AX, UK
| | - M Gilchrist
- NIHR Exeter Clinical Research Facility, University of Exeter Medical School, Barrack Road, EX2 5AX, UK.
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Szabó-Taylor KÉ, Tóth EÁ, Balogh AM, Sódar BW, Kádár L, Pálóczi K, Fekete N, Németh A, Osteikoetxea X, Vukman KV, Holub M, Pállinger É, Nagy G, Winyard PG, Buzás EI. Monocyte activation drives preservation of membrane thiols by promoting release of oxidised membrane moieties via extracellular vesicles. Free Radic Biol Med 2017; 108:56-65. [PMID: 28323130 DOI: 10.1016/j.freeradbiomed.2017.03.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 02/06/2017] [Accepted: 03/14/2017] [Indexed: 12/15/2022]
Abstract
The redox state of cellular exofacial molecules is reflected by the amount of available thiols. Furthermore, surface thiols can be considered as indicators of immune cell activation. One group of thiol containing proteins, peroxiredoxins, in particular, have been associated with inflammation. In this study, we assessed surface thiols of the U937 and Thp1 monocyte cell lines and primary monocytes in vitro upon inflammatory stimulation by irreversibly labelling the cells with a fluorescent derivative of maleimide. We also investigated exofacial thiols on circulating blood mononuclear cells in patients with rheumatoid arthritis and healthy controls. When analysing extracellular vesicles, we combined thiol labelling with the use of antibodies to specific CD markers to exclude extracellular vesicle mimicking signals from thiol containing protein aggregates. Furthermore, differential detergent lysis was applied to confirm the vesicular nature of the detected extracellular events in blood plasma. We found an increase in exofacial thiols on monocytes upon in vitro stimulation by LPS or TNF, both in primary monocytes and monocytic cell lines (p<0.0005). At the same time, newly released extracellular vesicles showed a decrease in their exofacial thiols compared with those from unstimulated cells (p<0.05). We also found a significant elevation of surface thiols on circulating monocytes in rheumatoid arthritis patients (p<0.05) and newly released extracellular vesicles of isolated CD14+ cells from rheumatoid arthritis patients had decreased thiol levels compared with healthy subjects (p<0.01). Exofacial peroxiredoxin 1 was demonstrated on the surface of primary and cultured monocytes, and the number of peroxiredoxin 1 positive extracellular vesicles was increased in rheumatoid arthritis blood plasma (p<0.05). Furthermore, an overoxidised form of peroxiredoxin was detected in extracellular vesicle-enriched preparations from blood plasma. Our data show that cell surface thiols play a protective role and reflect oxidative stress resistance state in activated immune cells. Furthermore, they support a role of extracellular vesicles in the redox regulation of human monocytes, possibly representing an antioxidant mechanism.
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Affiliation(s)
- K É Szabó-Taylor
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary.
| | - E Á Tóth
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary
| | - A M Balogh
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary
| | - B W Sódar
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary
| | - L Kádár
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary
| | - K Pálóczi
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary
| | - N Fekete
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary
| | - A Németh
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary
| | - X Osteikoetxea
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary
| | - K V Vukman
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary
| | - M Holub
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary
| | - É Pállinger
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary
| | - Gy Nagy
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary; Semmelweis University, Department of Rheumatology, 3rd Department of Internal Medicine, 1023 Budapest, Hungary
| | - P G Winyard
- University of Exeter Medical School, St Luke's Campus, Heavitree Road, Exeter EX1 2LU, United Kingdom
| | - E I Buzás
- Semmelweis University, Department of Genetics, Cell, and Immunobiology, Nagyvárad tér 4, 1089 Budapest, Hungary
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Smyth E, Solomon A, Birrell MA, Smallwood MJ, Winyard PG, Tetley TD, Emerson M. Influence of inflammation and nitric oxide upon platelet aggregation following deposition of diesel exhaust particles in the airways. Br J Pharmacol 2017; 174:2130-2139. [PMID: 28437857 PMCID: PMC5466527 DOI: 10.1111/bph.13831] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [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: 11/24/2016] [Revised: 04/07/2017] [Accepted: 04/13/2017] [Indexed: 11/27/2022] Open
Abstract
Background and Purpose Exposure to nanoparticulate pollution has been implicated in platelet‐driven thrombotic events such as myocardial infarction. Inflammation and impairment of NO bioavailability have been proposed as potential causative mechanisms. It is unclear, however, whether airways exposure to combustion‐derived nanoparticles such as diesel exhaust particles (DEP) or carbon black (CB) can augment platelet aggregation in vivo and the underlying mechanisms remain undefined. We aimed to investigate the effects of acute lung exposure to DEP and CB on platelet activation and the associated role of inflammation and endothelial‐derived NO. Experimental Approach DEP and CB were intratracheally instilled into wild‐type (WT) and eNOS−/− mice and platelet aggregation was assessed in vivo using an established model of radio‐labelled platelet thromboembolism. The underlying mechanisms were investigated by measuring inflammatory markers, NO metabolites and light transmission aggregometry. Key Results Platelet aggregation in vivo was significantly enhanced in WT and eNOS−/− mice following acute airways exposure to DEP but not CB. CB exposure, but not DEP, was associated with significant increases in pulmonary neutrophils and IL‐6 levels in the bronchoalveolar lavage fluid and plasma of WT mice. Neither DEP nor CB affected plasma nitrate/nitrite concentration and DEP‐induced human platelet aggregation was inhibited by an NO donor. Conclusions and Implications Pulmonary exposure to DEP and subsequent platelet activation may contribute to the reports of increased cardiovascular risk, associated with exposure to airborne pollution, independent of its effects on inflammation or NO bioavailability.
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Affiliation(s)
- E Smyth
- Platelet Biology Group, National Heart and Lung Institute, Imperial College London, London, UK
| | - A Solomon
- Platelet Biology Group, National Heart and Lung Institute, Imperial College London, London, UK
| | - M A Birrell
- Respiratory Pharmacology, National Heart and Lung Institute, Imperial College London, London, UK
| | - M J Smallwood
- Inflammation Research Group, University of Exeter Medical School, Exeter, UK
| | - P G Winyard
- Inflammation Research Group, University of Exeter Medical School, Exeter, UK
| | - T D Tetley
- Lung Cell Biology Group, National Heart and Lung Institute, Imperial College London, London, UK
| | - M Emerson
- Platelet Biology Group, National Heart and Lung Institute, Imperial College London, London, UK
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McDonagh STJ, Wylie LJ, Winyard PG, Vanhatalo A, Jones AM. The Effects of Chronic Nitrate Supplementation and the Use of Strong and Weak Antibacterial Agents on Plasma Nitrite Concentration and Exercise Blood Pressure. Int J Sports Med 2015; 36:1177-85. [PMID: 26332900 DOI: 10.1055/s-0035-1554700] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Chlorhexidine-containing mouthwash (STRONG), which disturbs oral microflora, has been shown to diminish the rise in plasma nitrite concentration ([NO2-]) and attenuate the reduction in resting blood pressure (BP) typically seen after acute nitrate (NO3-) ingestion. We aimed to determine whether STRONG and weaker antiseptic agents attenuate the physiological effects of chronic NO3- supplementation using beetroot juice (BR). 12 healthy volunteers mouth-rinsed with STRONG, non-chlorhexidine mouthwash (WEAK) and deionised water (CON) 3 times a day, and ingested 70 mL BR (6.2 mmol NO3-), twice a day, for 6 days. BP (at rest and during 10 min of treadmill walking) and plasma and salivary [NO3-] and [NO2-] were measured prior to and on day 6 of supplementation. The change in salivary [NO3-] 4 h post final ingestion was higher (P<0.05) in STRONG (8.7±3.0 mM) compared to CON (6.3±0.9 mM) and WEAK (6.0±3.0 mM). In addition, the rise in plasma [NO2-] at 2 h was lower in STRONG compared with WEAK (by 89±112 nM) and CON (by 200±174 nM) and in WEAK compared with CON (all P<0.05). Changes in resting BP were not different between conditions (P>0.05). However, during treadmill walking, the increase in systolic and mean arterial BP was higher 4 h after the final nitrate bolus in STRONG compared with CON (P<0.05) but not WEAK. The results indicate that both strong and weak antibacterial agents suppress the rise in plasma [NO2-] observed following the consumption of a high NO3- diet and the former can influence the BP response during low-intensity exercise.
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Affiliation(s)
- S T J McDonagh
- Sport and Health Sciences, University of Exeter, Exeter, United Kingdom
| | - L J Wylie
- Sport and Health Sciences, University of Exeter, Exeter, United Kingdom
| | - P G Winyard
- University of Exeter Medical School, University of Exeter, Exeter, United Kingdom
| | - A Vanhatalo
- Sport and Health Sciences, University of Exeter, Exeter, United Kingdom
| | - A M Jones
- Sport and Health Sciences, University of Exeter, Exeter, United Kingdom
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Apostoli GL, Solomon A, Smallwood MJ, Winyard PG, Emerson M. Role of inorganic nitrate and nitrite in driving nitric oxide-cGMP-mediated inhibition of platelet aggregation in vitro and in vivo. J Thromb Haemost 2014; 12:1880-9. [PMID: 25163536 DOI: 10.1111/jth.12711] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [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: 03/20/2014] [Accepted: 08/20/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND Nitric oxide (NO) is a critical negative regulator of platelets that is implicated in the pathology of thrombotic diseases. Platelets generate NO, but the presence and functional significance of NO synthase (NOS) in platelets is unclear. Inorganic nitrate/nitrite is increasingly being recognized as a source of bioactive NO, although its role in modulating platelets during health and vascular dysfunction is incompletely understood. METHODS We investigated the functional significance and upstream sources of NO-cGMP signaling events in platelets by using established methods for assessing in vitro and in vivo platelet aggregation, and assessed the bioconversion of inorganic nitrate to nitrite during deficiency of endothelial NOS (eNOS). RESULTS The phosphodiesterase 5 (PDE5) inhibitor sildenafil inhibited human platelet aggregation in vitro. This inhibitory effect was abolished by a guanylyl cyclase inhibitor and NO scavengers, but unaffected by NOS inhibition. Inorganic nitrite drove cGMP-mediated inhibition of human platelet aggregation in vitro and nitrate inhibited platelet function in eNOS(-/-) mice in vivo in a model of thromboembolic radiolabeled platelet aggregation associated with an enhanced plasma nitrite concentration as compared with wild-type mice. CONCLUSIONS Platelets generate transient, endogenous cGMP signals downstream of NO that are primarily independent of NOS and may be enhanced by inhibition of PDE5. Furthermore, nitrite can generate transient NO-cGMP signals in platelets. The absence of eNOS leads to enhanced plasma nitrite levels following nitrate administration in vivo, which negatively impacts on platelet function. Our data suggest that inorganic nitrate exerts an antiplatelet effect during eNOS deficiency, and, potentially, that dietary nitrate may reduce platelet hyperactivity during endothelial dysfunction.
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Affiliation(s)
- G L Apostoli
- Platelet Biology Group, Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London, UK
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Gutowski N, Winyard PG, Szabo-Taylor K, Holley JE. POD11 Altered peroxiredoxin antioxidant enzyme expression in activated and quiescent human astrocytes. Journal of Neurology, Neurosurgery & Psychiatry 2010. [DOI: 10.1136/jnnp.2010.226340.111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Abstract
Post-translational modifications play a central role in determining the function of proteins. Such protein modifications come in a great variety of guises, and include phosphorylation, proteolysis, glycosylation, citrullination and oxidative modifications. In relation to inflammatory autoimmune diseases, some post-translational modifications appear to result in the generation of new antigens, and hence autoantibodies. Examples include: the induction of peptide immunogenicity by the spontaneous conversion of aspartic acid residues to isoaspartic acid; granzyme B-mediated cleavage of SLE autoantigens; the oxidative modification--on the surface of apoptotic cells--of lipids and proteins, rendering them immunogenic; and the presence of antibodies to oxidatively modified type II collagen and C1q in RA and SLE patients, respectively. The measurement of autoantibodies to citrullinated proteins has been verified as a very useful diagnostic tool in RA. Proteomics techniques, in principle, allow the detection of all types of in vivo protein modifications, and the increasing application of such technologies to the study of rheumatological diseases will further our understanding of autoantigenicity.
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Affiliation(s)
- P Eggleton
- Institute of Biomedical and Clinical Science, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, Devon EX1 2LU, UK
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8
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Akcay Y, Knight I, Taylor E, Aksu K, Winyard PG. Assessment of Plasma S-Nitrosothiol Concentration by Electron Paramagnetic Resonance Spectrometry and Plasma Nitrotyrosine Levels by ELISA in Behçet's Disease. EJIFCC 2007; 18:116-120. [PMID: 29593452 PMCID: PMC5869222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Y.D. Akcay
- : Department of Biochemistry, School of Medicine, Ege University, 35100 İzmir/TURKEY
| | - I.A. Knight
- : Peninsula Medical School, Institute of Biomedical & Clinical Science, St Luke’s Campus, Exeter, EX1 2LU, UK
| | - E.L. Taylor
- : Peninsula Medical School, Institute of Biomedical & Clinical Science, St Luke’s Campus, Exeter, EX1 2LU, UK
| | - K. Aksu
- : Department of Rheumatology, School of Medicine, Ege University, 35100 İzmir/TURKEY
| | - P. G. Winyard
- : Peninsula Medical School, Institute of Biomedical & Clinical Science, St Luke’s Campus, Exeter, EX1 2LU, UK
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Abstract
Oxidative stress is implicated in the pathogenesis of multiple sclerosis (MS). Defence against oxidative damage is mediated by antioxidants. Peroxiredoxin V (PRDX V) is an intracellular anti-oxidant enzyme with peroxynitrite reductase activity. It is increased during inflammation, when free radical production intensifies, and is protective in an animal model of brain injury. However, little is known about PRDX V expression in the human brain. We investigated PRDX V expression in white matter from normal human brain (n = 5) and MS patients (n = 18), using immunohistochemistry and immunoblotting. A global increase in PRDX V was evident in MS normal-appearing white matter (NAWM) but the most striking increase was in astrocytes in MS lesions. PRDX V- positive hypertrophic reactive astrocytes were seen in acute lesions where inflammation was present. Yet surprisingly, in chronic lesions (CL), where inflammation has abated and a glial scar formed, there was strong PRDX V staining of post-reactive, scar astrocytes. Furthermore, immunoblotting analysis of tissue from two MS cases confirmed a substantial increase in PRDX V expression in CL compared with NAWM from the same individual. This might indicate ongoing oxidative stress despite the absence of histologically defined inflammation. Further investigations of this phenomenon will be of interest for therapeutic targeting.
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Affiliation(s)
- J E Holley
- Institute of Biomedical and Clinical Science, Peninsula Medical School (Exeter), and Royal Devon and Exeter Hospital, Devon, UK.
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10
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Abstract
Nitric oxide (NO) is a small, highly reactive, diffusible free radical which has been implicated in many physiological and pathophysiological processes. It has either pro-apoptotic or anti-apoptotic effects on cells, depending upon a host of factors. This review outlines some of the regulatory molecules and organelles involved in the apoptotic pathways that can be influenced by the presence of NO, including p53, Bcl-2, caspases, mitochondria, and heat shock proteins. The effects of NO on the apoptosis of tumour cells are also examined.
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Affiliation(s)
- J M Tarr
- Institute of Biomedical and Clinical Science, Peninsula Medical School, Universities of Exeter and Plymouth, Exeter, Devon, EX1 2LU, UK
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11
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O'Shaughnessy MC, Vetsika EK, Inglis JJ, Carleson J, Haigh R, Kidd BL, Winyard PG. The effect of substance P on nitric oxide release in a rheumatoid arthritis model. Inflamm Res 2006; 55:236-40. [PMID: 16955242 DOI: 10.1007/s00011-006-0079-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [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: 12/01/2022] Open
Abstract
OBJECTIVE The inflammatory mediator substance P (SP) acts principally through the neurokinin (NK1) receptor. We assessed the influence of SP on production of NO and its possible role in the pathogenesis of rheumatoid arthritis (RA). METHODS The effect of SP (0.1-100 nM) on concentrations of the NO metabolite, nitrite, produced by synovial fibroblasts from RA patients was studied. For comparison, the effects of TNF-alpha (0.57 pM-5.7 nM) and IL-1beta (0.57 pM-5.7 nM) were also studied. In parallel studies, footpad inflammation was induced in NK1 receptor knock-out (KO) and wild-type (WT) mice, and swelling and NO metabolite levels were measured. RESULTS In cultured synoviocytes, SP, TNF-alpha and IL-1beta induced significantly increased nitrite concentrations. Consistent with a role for NO in SP-mediated inflammatory reactions, the plasma NO metabolite level in WT mice was significantly increased at 3 days following an injection of 10 mg/ml Mycobacterium tuberculosis, but there was no significant change in NK1 KO mice. These results were paralleled by the changes in footpad swelling in WT mice compared to NK1 KO mice. CONCLUSION SP, like TNF-alpha and IL-1beta, induces NO in both rheumatoid synoviocytes and experimental models of inflammation. Treatments directed against SP may have important and hitherto unrecognised anti-inflammatory effects.
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Affiliation(s)
- M C O'Shaughnessy
- Bone and Joint Research Unit, Barts and the London, Queen Mary's School of Medicine and Dentistry, London, EC1M 6BQ, UK
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12
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Petropoulou P, Zhang Z, Curtis MA, Johnson NW, Hughes FJ, Winyard PG. Measurement of both native and inactivated forms of alpha1 proteinase inhibitor in human inflammatory extracellular fluids. J Clin Periodontol 2003; 30:795-801. [PMID: 12956655 DOI: 10.1034/j.1600-051x.2003.00369.x] [Citation(s) in RCA: 8] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Inactivation of the elastase inhibitor, alpha1 proteinase inhibitor (alpha1PI), may be of pathogenic significance in inflammatory diseases like periodontal disease. Two key mechanisms of inactivation appear to be (a) the formation of an alpha1PI-elastase complex and (b) proteolytic cleavage by elastase or other enzymes such as metalloproteinases of host origin or enzymes of bacterial origin. Based on the different heat stabilities of the intact, complexed and proteolytically cleaved forms of alpha1PI, an enzyme-linked immunosorbent assay (ELISA) that allowed the simultaneous measurement of native and inactive forms of alpha1PI was developed. METHODS The ELISA method described employs a commercially available antibody and represents a rapid, reproducible and sensitive method for studying alpha1PI inactivation in human inflammatory diseases. The assay was applied to normal human plasma and to human extracellular fluids obtained from patients with inflammatory diseases such as adult periodontitis and rheumatoid arthritis. Samples from patients with osteoarthritis, a "non-inflammatory" joint disease, were also studied. RESULTS The findings expressed as the mean percentage (+/-SD) of the total alpha1PI that was inactivated were as follows: gingival crevicular fluid from adult periodontitis patients: 73.5+/-16.6% (n=12); normal human plasma: 8.4+/-4.9% (n=13); knee-joint synovial fluid (SF) from rheumatoid arthritis patients: 12.5+/-4.5% (n=15); plasma from rheumatoid arthritis patients: 8.0+/-1.8% (n=15); knee-joint SF from osteoarthritis patients: 8.6+/-8.2% (n=14); plasma from osteoarthritis patients: 5.7+/-4.8% (n=14). The results obtained by ELISA were in good agreement with those obtained by the semi-quantitative method of SDS-PAGE and Western blotting. CONCLUSIONS We have shown that the differential heat stability of alpha1PI may be utilised as the basis for a rapid, sensitive and reproducible ELISA assay of alpha1PI inactivation. In gingival crevicular fluid from periodontal disease patients, alpha1PI is mainly inactivated and the extent of this inactivation is much higher than in inflammatory fluids from other chronic diseases such as rheumatoid arthritis. This assay could be useful in monitoring the progression of periodontal disease.
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Affiliation(s)
- P Petropoulou
- Inflammation Research Group, Barts and The London, Queen Mary's School of Medicine and Dentistry, University of London, UK
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13
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Dai L, Claxson A, Marklund SL, Feakins R, Yousaf N, Chernajovsky Y, Winyard PG. Amelioration of antigen-induced arthritis in rats by transfer of extracellular superoxide dismutase and catalase genes. Gene Ther 2003; 10:550-8. [PMID: 12646860 DOI: 10.1038/sj.gt.3301916] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Reactive oxygen species (ROS) have been implicated in the pathogenesis of rheumatoid arthritis (RA), while antioxidant enzymes, such as extracellular superoxide dismutase (EC-SOD) and catalase, block radical-induced events. The present study tested if the ex vivo transfer of EC-SOD and catalase genes alone or in combination in the knee joint of rats with monoarticular antigen-induced arthritis (AIA) was anti-inflammatory, and examined the potential mechanisms involved. Synoviocytes isolated from female Wistar rats were immortalized with a retroviral vector SUV19.5. These cells were permanently transfected with an EC-SOD expression plasmid (pEC-SODZeo) or a catalase expression plasmid (pCatalaseZeo) to create cells overexpressing EC-SOD or catalase, as measured by RT-PCR and Western blots. The cells were engrafted in knee joints of animals at the time of the induction of AIA. Three gene transfer groups, an EC-SOD group, a catalase group and a combined therapy group (EC-SOD and catalase) were included in these experiments. Animals in the control group were engrafted with synoviocytes transfected with the plasmid pZeoSV2 without an insert. Clinical and histological assessments were performed, as well as tissue measurements of SOD, catalase and gelatinase activities. Ex vivo gene transfer of EC-SOD and catalase into rat knee joints produced about a six- to seven-fold increase in EC-SOD activity and a two- to three-fold increase in catalase activity compared with the control animals. Rats treated with cells overexpressing EC-SOD, catalase or a combination of EC-SOD and catalase showed significant suppression of knee joint swelling, decreased infiltration of inflammatory cells within the synovial membrane and reduced gelatinase activity in knee joints, compared with animals receiving cells transfected with the plasmid alone. No statistically significant difference was found between the groups treated with cells overexpressing EC-SOD, catalase or a combination of both. Gene therapy involving the local intra-articular overexpression of two antioxidant enzymes, EC-SOD and catalase, was anti-inflammatory in AIA. One mechanism appears to be the suppression of gelatinase activities by both EC-SOD and catalase.
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Affiliation(s)
- L Dai
- Bone and Joint Research Unit, Barts and The London, Queen Mary's School of Medicine and Dentistry, London, UK
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14
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Gilston V, Williams MA, Newland AC, Winyard PG. Hydrogen peroxide and tumour necrosis factor-alpha induce NF-kappaB-DNA binding in primary human T lymphocytes in addition to T cell lines. Free Radic Res 2001; 35:681-91. [PMID: 11811521 DOI: 10.1080/10715760100301201] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [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: 10/24/2022]
Abstract
Reactive oxygen intermediates (ROIs), such as hydrogen peroxide (H2O2), have been implicated as second messengers in the activation of NF-kappaB by a variety of stimuli, including tumour necrosis factor-alpha (TNF-alpha). The aim of the present study was to examine the effects of ROIs on NF-kappaB activation in primary human CD3+ T lymphocytes and human peripheral blood mononuclear cells (PBMCs). For comparison purposes, Jurkat T cells (subclones JR and JE6.1) were also investigated. Cells were incubated in the presence of either H2O2 or TNF-alpha and nuclear proteins were extracted. NF-kappaB binding was assessed by electrophoretic mobility shift assays (EMSAs). The concentration of H2O2 required to activate NF-kappaB in human primary CD3+ T lymphocytes was as low as 1 microM. In contrast, much higher concentrations of H2O2 were required to activate NF-kappaB in PBMCs and in the JR subclone of Jurkat T cells. H2O2-induced NF-kappaB activation was not observed in the JE6.1 subclone of Jurkat T cells. NF-kappaB was activated by TNF-alpha in all four cell types tested. In PBMCs and Jurkat T cells (subclones JR and JE6.1), this activation could be inhibited by pre-treatment with the antioxidants, pyrrolidine dithiocarbamate (PDTC) and N-acetyl-L-cysteine (NAC). Our results support a role for ROIs in NF-kappaB-DNA binding in human primary T lymphocytes.
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Affiliation(s)
- V Gilston
- Bone and Joint Research Unit, St. Bartholomew's and the Royal London School of Medicine and Dentistry, UK
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15
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Davies CA, Nielsen BR, Timmins G, Hamilton L, Brooker A, Guo R, Symons MC, Winyard PG. Characterization of the radical product formed from the reaction of nitric oxide with the spin trap 3,5-dibromo-4-nitrosobenzene sulfonate. Nitric Oxide 2001; 5:116-27. [PMID: 11292361 DOI: 10.1006/niox.2001.0333] [Citation(s) in RCA: 10] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previously, 3,5-dibromo-4-nitrosobenzene sulfonate (DBNBS) has been used in combination with electron paramagnetic resonance (EPR) spectrometry to trap nitric oxide (NO(*)). The reaction between DBNBS and NO(*) yields a radical product which gives rise to an EPR signal consisting of three lines with an A(N) = 0.96 mT, but the structure of this product is unknown. A two-stage high-performance liquid chromatography fractionation was performed to isolate the radical product from the other components in the DBNBS/NO(*) reaction mixture. The fractions containing the radical product were identified by the presence of the three-line EPR signal, and then these fractions were analyzed by negative ion fast atom bombardment-mass spectrometry (FAB-MS). Collectively, the FAB-MS data suggested that the radical product is the monosodium electrostatic complex with the dianion, bis(2,6-dibromo-4-sulfophenyl) nitroxyl. Analysis of the Gaussian and Lorentzian linewidths of the EPR signal suggested that bis(2,6-dibromo-4-sulfophenyl) nitroxyl molecules may group together to form micelles. Further studies also indicated that significant amounts of nitrogen and nitrate were produced during the reaction between DBNBS and NO(*). A reaction scheme consistent with these results is presented.
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Affiliation(s)
- C A Davies
- Bone & Joint Research Unit, St Bartholomew's and the Royal London School of Medicine and Dentistry, Charterhouse Square, United Kingdom
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16
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Dai L, Lamb DJ, Leake DS, Kus ML, Jones HW, Morris CJ, Winyard PG. Evidence for oxidised low density lipoprotein in synovial fluid from rheumatoid arthritis patients. Free Radic Res 2000; 32:479-86. [PMID: 10798713 DOI: 10.1080/10715760000300481] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [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: 12/24/2022]
Abstract
The oxidative modification of human LDL has been implicated in atherosclerosis, but the mechanisms by which such modification occurs in vivo are not fully understood. In the present study, we have isolated LDL from knee-joint synovial fluid of patients with rheumatoid arthritis. We demonstrate that such LDL is oxidatively modified as evidenced by an increased negative charge, distorted particulate nature and more rapid degradation by cultured macrophages. These results indicate that formation of oxidised LDL is associated with the local inflammatory response. Because the cellular interactions in rheumatoid arthritis have analogies with those in atherogenesis, we suggest that the rheumatoid joint is a useful model of atherosclerosis in which the in vivo process of LDL oxidation may be readily studied.
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Affiliation(s)
- L Dai
- Bone and Joint Research Unit, St. Bartholomew's and the Royal London School of Medicine and Dentistry, UK
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17
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Ellis L, Gilston V, Soo CC, Morris CJ, Kidd BL, Winyard PG. Activation of the transcription factor NF-kappaB in the rat air pouch model of inflammation. Ann Rheum Dis 2000; 59:303-7. [PMID: 10733480 PMCID: PMC1753107 DOI: 10.1136/ard.59.4.303] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [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: 11/03/2022]
Abstract
OBJECTIVE To investigate the activation of NF-kappaB in the carrageenan rat air pouch model of inflammation in a time course experiment, and the effect of dexamethasone on NF-kappaB activation. METHODS Air pouch tissue treated with carrageenan (inflamed tissue) was obtained from rats killed at days 1, 2, 3, 6, 14, 21, 28 and 35 after carrageenan challenge. Tissue was also taken from non-carrageenan treated pouches (non-inflamed tissue) at day 3, and from inflamed tissues treated with dexamethasone. Tissue sections were wax embedded and stained with an "activity specific" monoclonal antibody raised against the nuclear localisation signal (NLS) of the p65 sub-unit of NF-kappaB. RESULTS Cells containing activated NF-kappaB were detected in the intimal and sub-intimal regions of the air pouches as early as day 1. There was a significant increase in cells staining for activated NF-kappaB as the inflammation progressed. Initially cells staining were more prominent in the intimal versus sub-intimal region (p<0.001 for day 1) and at later time points the pattern was reversed (p<0.001 for day 6). There was a significant reduction in the number of cells staining for activated NF-kappaB in tissue taken from dexamethasone treated rats, compared with inflamed pouches alone (p<0.001). At no time point was positive staining for activated NF-kappaB observed in blood vessels. CONCLUSIONS Activated NF-kappaB is present in the inflamed air pouch and the activation is associated with the inflammatory response to carrageenan. Treatment with dexamethasone resulted in reduced numbers of cells staining for activated NF-kappaB.
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Affiliation(s)
- L Ellis
- Bone and Joint Research Unit, St Bartholomew's and the Royal London School of Medicine and Dentistry, Charterhouse Square, London EC1M 6BQ, UK
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18
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Abstract
Several bone resorptive stimuli affect osteoclasts indirectly by modulating the production and release of osteoblastic factors. Using electrophoretic mobility shift assays, we found that not only tumour necrosis factor-alpha (TNF-alpha) but also interleukin-1beta and parathyroid hormone (PTH) caused dose and time-related increases in nuclear factor kappaB (NF-kappaB)-DNA binding in Saos-2 human osteoblastic (hOB) cells. Activation of NF-kappaB by TNF-alpha was reproduced in primary hOBs. In contrast, consistent with their previously reported lack of response to steroid hormones, Saos-2 cells did not respond to 1,25-dihydroxyvitamin D(3). We suggest that NF-kappaB activation in osteoblastic cells constitutes an important pathway in osteoblast-mediated resorptive signalling.
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Affiliation(s)
- N N Ali
- Bone and Joint Research Unit, St. Bartholomew's and the Royal London School of Medicine and Dentistry, 25-29 Ashfield Street, London, UK.
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19
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Davies CA, Perrett D, Zhang Z, Nielsen BR, Blake DR, Winyard PG. Simultaneous analysis of nitrite, nitrate and the nicotinamide nucleotides by capillary electrophoresis: application to biochemical studies and human extracellular fluids. Electrophoresis 1999; 20:2111-7. [PMID: 10451123 DOI: 10.1002/(sici)1522-2683(19990701)20:10<2111::aid-elps2111>3.0.co;2-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [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: 11/10/2022]
Abstract
A simple but rapid capillary electrophoresis method was developed for the measurement of nitrite and nitrate in human extracellular fluids and other aqueous solutions. The capabilities of the method were demonstrated by the measurement of endogenous nitrite and nitrate in plasma and serum samples from healthy volunteers, and serum and synovial fluid samples from rheumatoid arthritis patients. Furthermore, this method was used to simultaneously measure nicotinamide adenine dinucleotide, reduced (NADH), nicotinamide adenine dinucleotide (NAD+), nitrite, and nitrate, when studying the nitrite reductase activity of xanthine oxidase. The stability of nitrite was also investigated and it was found that when whole blood was spiked with nitrite and then processed, the nitrite was more stable in the plasma than in the serum. Our findings may help to explain the variations in basal nitrite concentrations reported in the literature.
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Affiliation(s)
- C A Davies
- Bone and Joint Research Unit and the Medical Unit, St Bartholomew's and the Royal London School of Medicine and Dentistry, Whitechapel, UK.
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20
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Nazhat NB, Saadalla-Nazhat RA, Fairburn K, Jones P, Blake DR, Nielsen BR, Symons MC, Winyard PG. Nitrite determination in human plasma and synovial fluid using reactions of nitric oxide with 3, 5-dibromo-4-nitrosobenzenesulphonate (DBNBS). Biochim Biophys Acta 1999; 1427:276-86. [PMID: 10216244 DOI: 10.1016/s0304-4165(99)00026-4] [Citation(s) in RCA: 9] [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: 10/17/2022]
Abstract
DBNBS (3,5-dibromo-4-nitrosobenzenesulphonate) reacts with nitric oxide (NO) produced from nitrite ions in acid solution to give a radical with a characteristic electron spin resonance spectrum, attributable to a 'DBNBS-NO' product, and comprising a triplet with alphaN=0.96 mT. This is identical with the spectrum obtained when NO, introduced from the gas phase, reacts with DBNBS. Under certain conditions, an additional signal is observed, attributable to oxidation of DBNBS to the radical cation, DBNBS*+ (a triplet with alphaN=1.32 mT). Conditions are described for the determination of nitrite, which avoid this DBNBS oxidation. The height of the low-field signal from the DBNBS-NO product is directly proportional to the nitrite concentration up to about 0.08 mM nitrite. The method has been applied to the measurement of nitrite concentrations in whole blood, plasma and synovial fluid taken from rheumatoid arthritis patients. In order to avoid the oxidation of DBNBS when analysing biological samples of this type, it is necessary to treat the specimen by ultrafiltration as soon as possible after collection and before addition of DBNBS.
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Affiliation(s)
- N B Nazhat
- Inflammation Research Group, St Bartholomew's and the Royal London School of Medicine and Dentistry, 25-29 Ashfield Street, London E1 2AD, UK
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21
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Zhang Z, Naughton D, Winyard PG, Benjamin N, Blake DR, Symons MC. Generation of nitric oxide by a nitrite reductase activity of xanthine oxidase: a potential pathway for nitric oxide formation in the absence of nitric oxide synthase activity. Biochem Biophys Res Commun 1998; 249:767-72. [PMID: 9731211 DOI: 10.1006/bbrc.1998.9226] [Citation(s) in RCA: 192] [Impact Index Per Article: 7.4] [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: 11/22/2022]
Abstract
Nitric oxide (NO) synthesis is well-known to result from the oxidation of L-arginine by a family of NO synthases (NOS). However, under hypoxic conditions this mechanism of NO synthesis may be impaired and NO is formed by a NOS independent mechanism. This study was designed to examine the reduction of nitrite to NO by xanthine oxidase (XO) under hypoxia, because the bacterial nitrate/nitrite reductases have structural similarity to XO. We found that both purified and tissue containing XO catalyze the reduction of nitrite to NO, as demonstrated using a chemiluminescent NO meter. This redox reaction requires NADH as an electron donor, and is oxygen independent. The inhibitory profiles suggest that reduction of nitrite takes place at the molybdenum center of XO whilst NADH is oxidized at the FAD center. Heparin binding of XO caused an increase in the catalysis of nitrite reduction. The XO-catalyzed generation of NO may be important in redistribution of blood flow to ischaemic tissue as a supplement to NOS, since both nitrite and NADH have been shown to be elevated in hypoxic tissue.
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Affiliation(s)
- Z Zhang
- Bone and Joint Research Unit, Royal London School of Medicine and Dentistry, United Kingdom.
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22
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Jones HW, Bailey R, Zhang Z, Dunne KA, Blake DR, Cox NL, Morris CJ, Winyard PG. Inactivation of antithrombin III in synovial fluid from patients with rheumatoid arthritis. Ann Rheum Dis 1998; 57:162-5. [PMID: 9640132 PMCID: PMC1752544 DOI: 10.1136/ard.57.3.162] [Citation(s) in RCA: 7] [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: 11/04/2022]
Abstract
OBJECTIVE To investigate the thrombin inhibitory capacity of antithrombin III in the inflamed human joint. METHODS Thrombin inhibitory capacity was measured, using a kinetic spectophotometric method, in matched plasma and synovial fluid samples of patients with rheumatoid arthritis (n = 22) and osteoarthritis (n = 16), together with normal control plasma samples (n = 13). In the same samples, the concentration of antithrombin III was also determined by the method of radial immunodiffusion. The combination of these measurements allowed the calculation of the specific thrombin inhibitory capacity of these samples. RESULTS An increased concentration of antithrombin III in rheumatoid compared with osteoarthritic synovial fluid was noted (p < 0.05). However, there was a significant depression in the specific activity of antithrombin III in rheumatoid synovial fluid when compared with matched plasma samples (p < 0.001) or with osteoarthritic synovial fluid (p < 0.05). CONCLUSION In rheumatoid synovial fluid the thrombin inhibitory capacity of antithrombin III is disproportionately depressed relative to the concentration of antithrombin III, indicating the inactivation of antithrombin III in the rheumatoid joint.
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Affiliation(s)
- H W Jones
- Department of Rheumatology, Royal Hampshire County Hospital, Winchester
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23
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Zhang Z, Blake DR, Stevens CR, Kanczler JM, Winyard PG, Symons MC, Benboubetra M, Harrison R. A reappraisal of xanthine dehydrogenase and oxidase in hypoxic reperfusion injury: the role of NADH as an electron donor. Free Radic Res 1998; 28:151-64. [PMID: 9645392 DOI: 10.3109/10715769809065801] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.0] [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: 11/13/2022]
Abstract
Xanthine oxidase (XO) is conventionally known as a generator of reactive oxygen species (ROS) which contribute to hypoxic-reperfusion injury in tissues. However, this role for human XO is disputed due to its distinctive lack of activity towards xanthine, and the failure of allopurinol to suppress reperfusion injury. In this paper, we have employed native gel electrophoresis together with activity staining to investigate the role human xanthine dehydrogenase (XD) and XO in hypoxic reperfusion injury. This approach has provided information which cannot be obtained by conventional spectrophotometric assays. We found that both XD and XO of human umbilical vein endothelial cells (HUVECs) and lymphoblastic leukaemic cells (CEMs) catalysed ROS generation by oxidising NADH, but not hypoxanthine. The conversion of XD to XO was observed in both HUVECs and CEMs in response to hypoxia, although the level of conversion varied. Purified human milk XD generated ROS more efficiently in the presence of NADH than in the presence of hypoxanthine. This NADH oxidising activity was blocked by the FAD site inhibitor, diphenyleneiodonium (DPI), but was not suppressible by the molybdenum site inhibitor, allopurinol. However, in the presence of both DPI and allopurinol the activities of XD/XO were completely blocked with either NADH or hypoxanthine as substrates. We conclude that both human XD and XO can oxidise NADH to generate ROS. Therefore, the conversion of XD to XO is not necessary for post-ischaemic ROS generation. The hypoxic-reperfusion injury hypothesis should be reappraised to take into account the important role played by XD and XO in oxidising NADH to yield ROS.
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Affiliation(s)
- Z Zhang
- Bone and Joint Research Unit, St Bartholomew's and the Royal London School of Medicine and Dentistry, University of London, UK.
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24
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Edmonds SE, Winyard PG, Guo R, Kidd B, Merry P, Langrish-Smith A, Hansen C, Ramm S, Blake DR. Putative analgesic activity of repeated oral doses of vitamin E in the treatment of rheumatoid arthritis. Results of a prospective placebo controlled double blind trial. Ann Rheum Dis 1997; 56:649-55. [PMID: 9462166 PMCID: PMC1752293 DOI: 10.1136/ard.56.11.649] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.4] [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: 02/06/2023]
Abstract
OBJECTIVE Vitamin E, the most potent naturally occurring lipid soluble antioxidant has been suggested to possess both anti-inflammatory and analgesic activity in humans. This double blind and randomised study used a broad spectrum of clinical and laboratory parameters to investigate whether there was any additional anti-inflammatory or analgesic effects, or both, of orally administered alpha-tocopherol in rheumatoid arthritis patients who were already receiving anti-rheumatic drugs. METHODS Forty two patients were enrolled and treated with alpha-tocopherol (n = 20) at a dose of 600 mg twice a day (2 x 2 capsules) or with placebo (n = 22) for 12 weeks. The following parameters were measured: (1) Three clinical indices of inflammation--the Ritchie articular index, the duration of morning stiffness, and the number of swollen joints; (2) three measures of pain--pain in the morning, pain in the evening, and pain after chosen activity; (3) haematological and biochemical measures of inflammatory activity; (4) assays for the oxidative modification of proteins and lipids. RESULTS All laboratory measures of inflammatory activity and oxidative modification were unchanged. Furthermore, the clinical indices of inflammation were not influenced by the treatment. However, the pain parameters were significantly decreased after vitamin E treatment when compared with placebo. CONCLUSION The results provide preliminary evidence that vitamin E may exert a small but significant analgesic activity independent of a peripheral anti-inflammatory effect, but which complements standard anti-inflammatory treatment.
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Affiliation(s)
- S E Edmonds
- Inflammation Research Group, St Bartholomew's School of Medicine and Dentistry, London
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25
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Blake DR, Stevens CR, Sahinoglu T, Ellis G, Gaffney K, Edmonds S, Benboubetra M, Harrison R, Jawed S, Kanczler J, Millar TM, Winyard PG, Zhang Z. Xanthine oxidase: four roles for the enzyme in rheumatoid pathology. Biochem Soc Trans 1997; 25:812-6. [PMID: 9388551 DOI: 10.1042/bst0250812] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- D R Blake
- Bone and Joint Research Unit, St Bartholomew's London, U.K
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26
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Zhang Z, Naughton DP, Blake DR, Benjamin N, Stevens CR, Winyard PG, Symons MC, Harrison R. Human xanthine oxidase converts nitrite ions into nitric oxide (NO). Biochem Soc Trans 1997; 25:524S. [PMID: 9388740 DOI: 10.1042/bst025524s] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Z Zhang
- Bone and Joint Research Unit, St. Bartholomew's, London, UK
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27
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Gilston V, Jones HW, Soo CC, Coumbe A, Blades S, Kaltschmidt C, Baeuerle PA, Morris CJ, Blake DR, Winyard PG. NF-kappa B activation in human knee-joint synovial tissue during the early stage of joint inflammation. Biochem Soc Trans 1997; 25:518S. [PMID: 9388734 DOI: 10.1042/bst025518s] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- V Gilston
- Inflammation Research Group, St. Bartholomew's, London, UK
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28
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Dai L, Zhang Z, Winyard PG, Gaffney K, Jones H, Blake DR, Morris CJ. A modified form of low-density lipoprotein with increased electronegative charge is present in rheumatoid arthritis synovial fluid. Free Radic Biol Med 1997; 22:705-10. [PMID: 9013133 DOI: 10.1016/s0891-5849(96)00389-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Reactive oxygen species (ROS) are pro-inflammatory factors in the pathogenesis of rheumatoid arthritis. During inflammation, the amount of low-density lipoprotein (LDL) in the inflamed joint is increased. LDL is known to be susceptible to oxidation by ROS. Oxidized LDL may serve as a mediator for joint damage, further exacerbating the inflammatory process. LDL isolated from synovial fluid and plasma from individual patients (paired samples) with rheumatoid arthritis or osteoarthritis was characterized by crossed immunoelectrophoresis. On analysis by this technique, synovial fluid LDL from most patients with rheumatoid arthritis contained two peaks: one corresponding to normal plasma native LDL, and the other having an increased electrophoretic mobility associated with oxidized LDL. Paired plasma LDL samples contained native LDL alone, as did paired synovial fluid and plasma LDL from patients with osteoarthritis. Thus, in addition to native LDL, a second form of LDL was shown to be present in rheumatoid synovial fluid, which had properties consistent with those of oxidized LDL.
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Affiliation(s)
- L Dai
- Inflammation Research Group, London Hospital Medical College, University of London, UK
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29
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Abstract
Monocyte adhesion to the arterial wall is a key event in the atherosclerotic process. We studied the interactions between human coronary arterial intimal smooth muscle cells (SMCs) and monocytes by examining (i) whether SMCs mediate monocyte adhesion when stimulated by oxidatively modified low density lipoprotein (LDL) or by the cytokines TNF alpha and IL-1, and (ii) the role of the adhesion molecules VCAM-1 and ICAM-1 (vascular cell and intercellular adhesion molecule, respectively) in this process. Preincubation of SMCs with both TNF alpha and IL-1 caused a significant 2-fold increase in VCAM-1 and ICAM-1 expression and a more than 9-fold increase in monocyte adhesion. The latter was significantly inhibited (by 1/3) by neutralising antibodies to VCAM-1 and ICAM-1. Modified LDL also induced a significant 3-fold increase in monocyte adhesion to SMCs, but did not induce VCAM-1 or ICAM-1 expression, nor was this adhesion inhibited by neutralising antibodies to VCAM-1 or ICAM-1. Oxidatively modified LDL, like the proinflammatory cytokines TNF alpha and IL-1, has the ability to enhance monocyte adhesion to human SMCs in vitro. LDL-induced monocyte adhesion to SMCs is distinct from that induced by TNF alpha and IL-1 in its lack of dependence on the classical adhesion pathways involving smooth muscle VCAM-1 and ICAM-1. SMCs are identified as a new cell population which may play an active role in recruiting monocytes to the arterial intima and atherosclerotic plaque.
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Affiliation(s)
- S A Thorne
- Cardiac Department, Royal London Hospital, UK
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30
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Dai L, Winyard PG, Zhang Z, Blake DR, Morris CJ. Ascorbate promotes low density lipoprotein oxidation in the presence of ferritin. Biochim Biophys Acta 1996; 1304:223-8. [PMID: 8982268 DOI: 10.1016/s0005-2760(96)00121-x] [Citation(s) in RCA: 12] [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: 02/03/2023]
Abstract
Whilst catalytic iron has been implicated in the development of atherosclerosis by initiating low density lipoprotein (LDL) oxidation, the source of such iron remains uncertain. Here, we show that LDL oxidation in the presence of ferritin was stimulated by ascorbate (15-60 microM), whilst this effect was inhibited by the iron chelator desferrioxamine. Ascorbate also showed an antioxidant activity at high concentrations (125-250 microM). Our results suggest that the combination of ascorbate with ferritin may supply free iron for LDL oxidation in vivo.
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Affiliation(s)
- L Dai
- Inflammation Research Group, St Bartholomew's School of Medicine and Dentistry, London, UK
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31
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Abstract
OBJECTIVE To investigate the possibility that synovial cells might respond to thrombin in the inflamed human joint, using immunohistochemical detection of thrombin receptors. METHODS Frozen sections of synovial membrane from 20 patients with rheumatoid arthritis, 16 with osteoarthritis, and four normal controls were stained using a monoclonal antibody to the human thrombin receptor. Sections were also double stained for both receptors and non-specific esterase. RESULTS Receptor positive cells were present in rheumatoid synovia, with some cells also staining positively for non-specific esterase. In contrast, both osteoarthritic and normal synovia contained very few cells expressing receptors. CONCLUSIONS Thrombin may mediate important pathological changes during chronic inflammatory joint disease.
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Affiliation(s)
- R Morris
- Inflammation Research Group, St Bartholomew's, London, United Kingdom
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32
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Marok R, Winyard PG, Coumbe A, Kus ML, Gaffney K, Blades S, Mapp PI, Morris CJ, Blake DR, Kaltschmidt C, Baeuerle PA. Activation of the transcription factor nuclear factor-kappaB in human inflamed synovial tissue. Arthritis Rheum 1996; 39:583-91. [PMID: 8630106 DOI: 10.1002/art.1780390407] [Citation(s) in RCA: 244] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE The transcription factor nuclear factor kappaB (NF-kappaB) has been implicated in the inflammatory response and is known to be activated by a process involving reactive oxygen intermediates. The purpose of the present study was to demonstrate the presence and distribution of activated NF-kappaB in synovium samples from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and from autopsy subjects with no known history of arthritis. METHODS Immunohistochemical staining was performed using both polyclonal and monoclonal "activity-specific" antibodies to the Rel-A (p65) subunit of NF-kappaB (anti-Rel-A nuclear location sequences). Histologic features of inflammation were also scored. RESULTS Both antibodies demonstrated positive staining of synovial tissue, with a cellular distribution that was nuclear. The staining was associated with specific cell types within the tissue, in particular, type A synoviocytes and vascular endothelium. Notably, lymphoid aggregates were unstained. Using the monoclonal antibody, a further study was carried out to investigate the distribution of staining in tissues from patients with different disease activities and clinical diagnoses, as well as in normal control tissue obtained at autopsy. Patients with acute RA more commonly showed vessel staining (P = 0.05) and, conversely, showed less frequent staining of the synovial lining (P < 0.005) compared with OA patients. Synovial tissue from controls exhibited either no staining or only weak staining in the synovial lining. CONCLUSION The activation of NF-kappaB in vascular endothelium and type A synovial lining cells is a feature of synovial tissue from both RA and OA patients. The distribution of this staining appears to be related to the clinical diagnosis.
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Affiliation(s)
- R Marok
- London Hospital Medical College, University of London, UK
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33
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Abstract
Peroxynitrite (ONOO-) has recently been implicated in connective tissue destruction in vivo. We have studied the effect of ONOO- on the activity of tissue inhibitor of metalloproteinase-1 (TIMP-1) in vitro. The inactivation of TIMP-1 by ONOO- was dose dependent with 50 microM ONOO- reducing the inhibitory activity of TIMP-1 towards gelatinase-A by 50%. High concentrations of ONOO- (500 microM-5 mM) caused protein fragmentation whilst lower concentrations (<250 microM) inactivated TIMP-1 without altering the molecular weight. Inactivation could be blocked by ONOO- scavengers but not by hydroxyl radical scavengers. Our results show that ONOO- is capable of inactivating TIMP-1, a process which could potentiate metalloproteinase-mediated tissue breakdown.
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Affiliation(s)
- E R Frears
- The inflammation Research Group, London Hospital Medical College, University of London, UK
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34
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Thorne SA, Abbot SE, Winyard PG, Blake DR, Mills PG. Extent of oxidative modification of low density lipoprotein determines the degree of cytotoxicity to human coronary artery cells. Heart 1996; 75:11-6. [PMID: 8624864 PMCID: PMC484214 DOI: 10.1136/hrt.75.1.11] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
OBJECTIVE To assess whether the extent of LDL oxidation influences its cytotoxic effects, thus contributing to its atherogenic potential. DESIGN AND SETTING The effects of native and modified LDL on cultured human coronary artery smooth muscle cells (SMC) and endothelial cells (ECs) were investigated. MAIN OUTCOME MEASURES Four indices of cytotoxicity were studied: (i) chromium-51 release; (ii) 5-bromo-2'-deoxyuridine (BrDUrd) uptake; (iii) morphological appearance; and (iv) EC migration. RESULTS (i) Minimally modified (mm) LDL (400 micrograms/ml) causes significant 51Cr release; the cytotoxic effect was significantly greater for copper oxidised (ox) LDL (400 micrograms/ml). Native LDL had no effect. (ii) BrDUrd uptake studies showed significant inhibition of cell proliferation by 100 micrograms/ml of oxLDL and to a lesser extent by mmLDL; native LDL had no effect. (iii) Morphological appearance was not altered by native LDL. Changes in cell morphology were induced by mmLDL (400 micrograms/ml), and were more pronounced with oxLDL in concentrations of > or = 200 micrograms/ml. (iv) EC migration was significantly inhibited by oxLDL (100 micrograms/ml), but not by native or mmLDL. CONCLUSION The extent of oxidation of LDL determined its cytotoxicity to coronary artery cells. Native LDL had no cytotoxic effect. In contrast, oxLDL and to a lesser extent mmLDL caused cytotoxicity at concentrations to which cells in vivo might be exposed. This may contribute to the atherogenicity of modified LDL by enhancing cellular injury and inflammation, and by inhibiting re-endothelialisation of areas of coronary artery damaged during the atherogenic process.
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Affiliation(s)
- S A Thorne
- Cardiac Department, Royal London Hospital
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35
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Affiliation(s)
- P G Winyard
- Inflammation Research Group, St. Bartholomew's, London, United Kingdom
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36
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Roselaar SE, Nazhat NB, Winyard PG, Jones P, Cunningham J, Blake DR. Detection of oxidants in uremic plasma by electron spin resonance spectroscopy. Kidney Int 1995; 48:199-206. [PMID: 7564078 DOI: 10.1038/ki.1995.285] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.8] [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: 01/26/2023]
Abstract
Depletion of antioxidants and the presence of products of free radical damage in plasma suggest that oxidative stress is increased in uremia. We have developed an application of electron spin resonance spectroscopy, and used this method to show that a stable oxidizing component or components of plasma accumulate in uremia. No oxidizing activity was detectable in plasma from subjects with normal renal function. The oxidant was detected by its capacity to oxidize the spin trap 3,5-dibromo-4-nitrosobenzene sulphonate (DBNBS). The oxidant was dialyzable from plasma, had an upper molecular weight limit of about 3,000 Daltons and was stable over many months. Physiological plasma concentrations of vitamin C, a water soluble congener of vitamin E and reduced glutathione were unable to inhibit the oxidizing capacity of uremic plasma. Thus, uremia is associated with accumulation of an endogenous oxidizing activity at much higher concentrations than in subjects with normal renal function.
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Affiliation(s)
- S E Roselaar
- Department of Nephrology, London Hospital Medical College, University of London, United Kingdom
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37
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Abstract
Oxidatively modified LDL (oLDL) is thought to play a key role in the pathogenesis of atherosclerosis. We have studied Cu(2+)-induced peroxidation reactions of LDL and have elucidated the sequence of events which subsequently occur within LDL particles by 1H-NMR spectroscopy. Studies of chloroform/methanol extracts show that LDL arachidonate is oxidised by Cu2+ at a higher rate and to a greater extent than linoleate, giving isomeric hydroperoxides with predominantly trans,trans double-bonds, whilst only cis,trans isomers were detected as intrinsic hydroperoxides in control LDL samples. These intrinsic hydroperoxides were not degraded during peroxidation, suggesting that they are not involved in the initiation of Cu(2+)-induced peroxidation. Aldehydes arising from the decomposition of hydroperoxides were also detected, as well as saturated fatty acids which were released into the external aqueous medium. Decomposition pathways of the two major isomeric hydroperoxides are discussed. Cu(2+)-induced oxidation of LDL cholesterol appears to occur only after hydroperoxide breakdown, with esterified cholesterol being oxidised to a greater extent than free cholesterol. Phospholipid hydrolysis appeared to parallel the peroxidation of arachidonic acid, and the released lysophosphatidylcholine may become associated with apoB. These results suggest that hydroperoxide breakdown (probably in phospholipids) may be a key event in the peroxidation process, leading to the oxidation of cholesterol and propagation into the core of LDL.
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Affiliation(s)
- J K Lodge
- Department of Chemistry, Birkbeck College, University of London, UK
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38
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Chidwick K, Whichelow CE, Zhang Z, Fairburn K, Sachs JA, Blake DR, Winyard PG. Relationship between alpha 1-antitrypsin inactivation and tumor necrosis factor alpha concentration in the synovial fluid of patients with rheumatoid arthritis. Arthritis Rheum 1994; 37:1723-6. [PMID: 7986217 DOI: 10.1002/art.1780371203] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To examine the relationship between alpha 1-antitrypsin (alpha 1AT) specific activity and tumor necrosis factor alpha (TNF alpha) concentration in synovial fluid from 48 patients with rheumatoid arthritis. METHODS The specific activity of alpha 1AT was calculated from the measurement of alpha 1AT concentration (by rocket immunoelectrophoresis) and elastase inhibitory capacity. TNF alpha was detected by enzyme-linked immunosorbent assay. RESULTS TNF alpha concentrations correlated with the extent of alpha 1AT inactivation. CONCLUSION Our findings are consistent with a role of elastase in TNF alpha release within the inflamed joint.
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Affiliation(s)
- K Chidwick
- London Hospital Medical College, University of London, UK
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39
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Blake DR, Winyard PG, Marok R. The contribution of hypoxia-reperfusion injury to inflammatory synovitis: the influence of reactive oxygen intermediates on the transcriptional control of inflammation. Ann N Y Acad Sci 1994; 723:308-17. [PMID: 8030874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- D R Blake
- Inflammation Research Group, London Hospital Medical College, University of London, United Kingdom
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40
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Zhang Z, Winyard PG, Chidwick K, Murphy G, Wardell M, Carrell RW, Blake DR. Proteolysis of human native and oxidised alpha 1-proteinase inhibitor by matrilysin and stromelysin. Biochim Biophys Acta 1994; 1199:224-8. [PMID: 8123672 DOI: 10.1016/0304-4165(94)90119-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Matrilysin is shown to rapidly inactivate alpha 1PI, an inhibitor of elastase, by cleaving the Pro357-Met358 peptide bond of its reactive centre. The rate of inactivation of alpha 1PI by matrilysin is four times higher than stromelysin. Matrilysin cleaves oxidised alpha 1PI at the Phe352-Leu353 bond, whilst stromelysin cleaves oxidised alpha 1PI at the Met358-Ser359 bond. We conclude that matrilysin is a potent serpinase which could play a role in inflammatory tissue damage by proteolytically inactivating alpha 1PI.
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Affiliation(s)
- Z Zhang
- Inflammation Research Group, London Hospital Medical College, University of London, UK
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41
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Abstract
7,8-Dihydro-8-oxo-2'-deoxyguanosine (8-oxodG) is present in DNA isolated from human and murine cells. Other studies have reported artificially elevated levels in DNA extracted using phenol-based methods. This report shows that DNA, isolated by different methods, with or without the use of a phenol reagent, contains similar levels of 8-oxodG. This, taken with other studies of human tissues which show varying levels of 8-oxodG, indicates that, with due care in the extraction procedure, biologically significant amounts of this altered base are present in mammalian DNA.
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Affiliation(s)
- G Harris
- London Hospital Medical College, University of London, UK
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42
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Chidwick K, Zhang Z, Stanworth DR, Asmar G, Blake DR, Winyard PG. Mechanisms of alpha 1-antitrypsin inactivation in arthritic joints: comment on the article by Abbink et al. Arthritis Rheum 1994; 37:150-1. [PMID: 8129760 DOI: 10.1002/art.1780370129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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43
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Affiliation(s)
- R Morris
- Inflammation Research Group, London Hospital Medical College, United Kingdom
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44
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Bashir S, Harris G, Denman MA, Blake DR, Winyard PG. Oxidative DNA damage and cellular sensitivity to oxidative stress in human autoimmune diseases. Ann Rheum Dis 1993; 52:659-66. [PMID: 8239761 PMCID: PMC1005143 DOI: 10.1136/ard.52.9.659] [Citation(s) in RCA: 195] [Impact Index Per Article: 6.3] [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: 01/29/2023]
Abstract
OBJECTIVES To estimate the extent of genomic DNA damage and killing of lymphocytes by reactive oxygen intermediates in autoimmune diseases. METHODS 8-Oxo-7-hydrodeoxyguanosine (8-oxodG), a promutagenic DNA lesion induced by reactive oxygen intermediates, was measured by high performance liquid chromatography, coupled with electrochemical detection, in hydrolysates of DNA which had been extracted from lymphocyte and polymorphonuclear leucocyte fractions of human blood. In addition, human primary blood lymphocytes stimulated by concanavalin A were assayed for cytotoxicity induced by hydrogen peroxide on day 0, by assessing cell proliferation during seven days of culture. RESULTS Constitutive 8-oxodG was detectable (mean (2 SEM) moles 8-oxodG/10(6) moles deoxyguanosine) in DNA isolated from normal human blood lymphocytes (68 (8), n = 26) and polymorphonuclear leucocytes (118 (24), n = 24). Lymphocyte DNA from donors with the following inflammatory autoimmune diseases contained significantly higher levels of 8-oxodG than that from healthy donors: rheumatoid arthritis (98 (16)), systemic lupus erythematosus (137 (28)), vasculitis (100 (32)), and Behçet's disease (92 (19)). Lymphocyte 8-oxodG levels in non-autoimmune controls and patients with scleroderma were not significantly different from those of healthy controls. The levels of 8-oxodG were significantly higher in the DNA from normal polymorphonuclear leucocytes than in paired DNA samples from normal lymphocytes, but there were no differences between levels of 8-oxodG in polymorphonuclear leucocytes from normal subjects and the patients studied. Levels of 8-oxodG did not correlate with disease duration, disease severity, or age. Lymphocytes from patients with systemic lupus erythematosus and rheumatoid arthritis, but not those with scleroderma, also showed cellular hypersensitivity to the toxic effects of hydrogen peroxide. CONCLUSION There was increased genomic DNA damage, and increased susceptibility to cytotoxic killing by hydrogen peroxide, in lymphocytes from patients with certain autoimmune diseases. These results might be explained by defective repair of DNA damage or by increased production of reactive oxygen intermediates in inflammation. Although more direct studies are needed, the evidence available favours the former explanation.
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Affiliation(s)
- S Bashir
- Inflammation Research Group, London Hospital Medical College, University of London, United Kingdom
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45
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Winyard PG, Tatzber F, Esterbauer H, Kus ML, Blake DR, Morris CJ. Presence of foam cells containing oxidised low density lipoprotein in the synovial membrane from patients with rheumatoid arthritis. Ann Rheum Dis 1993; 52:677-80. [PMID: 8239763 PMCID: PMC1005146 DOI: 10.1136/ard.52.9.677] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.4] [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: 01/29/2023]
Abstract
OBJECTIVE Increased concentrations of lipid peroxidation products have been described in the serum and synovial fluid from patients with rheumatoid arthritis. A large proportion of the unsaturated lipids in human extracellular fluids is a component of low density lipoprotein (LDL). The oxidative modification of LDL, and its subsequent uptake by macrophages, has been implicated in the pathogenesis of atherosclerosis, but not of rheumatoid arthritis. This study aimed to assess whether oxidatively modified LDL was present in the rheumatoid synovium. METHODS A polyclonal antiserum raised in rabbits against oxidised LDL (o-LDL) was used to perform an immunohistochemical study of a series of synovial biopsy specimens from patients with rheumatoid arthritis. RESULTS Collections of positively stained macrophages, arranged in a linear fashion and with the morphological characteristics of foam cells--that is, 'fatty streaks', were identified around blood vessels within the intimal connective tissue. In addition, scattered, positively stained foam cells were present in association with deposits of fibrin. These staining patterns were absent from control synovial membranes (traumatic knee injuries). CONCLUSIONS The findings in all rheumatoid patients studied suggest that atherosclerosis and rheumatoid arthritis have analogous pathogenetic features.
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Affiliation(s)
- P G Winyard
- Inflammation Research Group, London Hospital Medical College, University of London, United Kingdom
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46
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Abstract
In recent years it has become increasingly apparent that, in man, free radicals play a role in a variety of normal regulatory systems, the deregulation of which may play an important role in inflammation. As examples, we discuss the second messenger roles of: NO in the regulation of vascular tone, O2.- in fibroblast proliferation and H2O2 in the activation of transcription factors such as NF kappa B. Other control mechanisms, the physiological function of which may be perturbed in inflammation, include: the oxidative modification of low density lipoprotein, the oxidative inactivation of alpha-1-protease inhibitor, DNA damage/repair and heat shock protein synthesis. At sites of inflammation, increased free radical activity is associated with the activation of the neutrophil NADPH oxidase and/or the uncoupling of a variety of redox systems, including endothelial cell xanthine dehydrogenase. Although free radicals, thus produced, have the capacity to mediate tissue destruction, either alone or in concert with proteases, we argue that disturbances in the second messenger and regulatory activities of free radicals may also contribute significantly to the inflammatory process.
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Affiliation(s)
- V R Winrow
- ARC Bone and Joint Research Unit, London Hospital Medical College
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47
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Fairburn K, Stevens CR, Winyard PG, Kus M, Ward RJ, Cunningham J, Zaidi M, Blake DR. Oxidative stress and its control: a pathogenetic role in inflammatory joint disease. Biochem Soc Trans 1993; 21:371-5. [PMID: 8359499 DOI: 10.1042/bst0210371] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- K Fairburn
- Inflammation Research Group, London Hospital Medical College, U.K
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48
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Abstract
alpha 1-Antitrypsin (alpha 1AT) is known to be oxidised by reactive oxygen species both in vitro and in vivo, leading to its inactivation. We report here that synovial fluid (SF) alpha 1AT is inactivated during exercise of the knee-joints of rheumatoid arthritis (RA) patients. Sequential SF sampling from exercised RA patients showed a marked decrease in the mean activity of alpha 1AT after exercise with no change in the molecular forms of alpha 1AT. No such inactivation was found in the control (continuously resting) RA patients. We suggest that oxidation may contribute to alpha 1AT inactivation as a consequence of 'hypoxic-reperfusion' injury after exercise of the inflamed joint.
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Affiliation(s)
- Z Zhang
- London Hospital Medical College, University of London, UK
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49
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Edmonds SE, Blake DR, Morris CJ, Winyard PG. An imaginative approach to synovitis--the role of hypoxic reperfusion damage in arthritis. J Rheumatol Suppl 1993; 37:26-31. [PMID: 8501748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The rheumatoid joint is hypoxic. The loss of the physiologic defense mechanism, reflex muscle inhibition, allows the generation of high intraarticular pressures, particularly during exercise. Hypoxia alters the biochemistry of the synovium and encourages the production of reactive oxygen species (ROS) on reperfusion of blood. In excess, ROS damage tissues, and the products of oxidative damage are detectable in rheumatoid synovial fluid. In addition to damaging proteins, carbohydrates and lipids, cellular and structural damage also occurs.
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Affiliation(s)
- S E Edmonds
- Bone and Joint Research Unit, London Hospital Medical College, UK
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50
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Fairburn K, Grootveld M, Ward RJ, Abiuka C, Kus M, Williams RB, Winyard PG, Blake DR. Alpha-tocopherol, lipids and lipoproteins in knee-joint synovial fluid and serum from patients with inflammatory joint disease. Clin Sci (Lond) 1992; 83:657-64. [PMID: 1336435 DOI: 10.1042/cs0830657] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [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: 12/26/2022]
Abstract
1. We have determined the antioxidant status of synovial fluid and serum of patients with inflammatory joint disease in terms of the biologically active lipid-soluble antioxidant, alpha-tocopherol. Synovial fluid concentrations of alpha-tocopherol were significantly lower relative to those of paired serum samples (P < 0.001). Serum levels of alpha-tocopherol in these patients did not differ significantly from those in control serum. 2. Lower concentrations of cholesterol, triacylglycerol and low-density lipoprotein were also observed in patients' synovial fluid compared with matched serum samples. However, multiple regression analysis of the data indicated that there remained a significant depletion of alpha-tocopherol, which was largely independent of these co-variables, in inflammatory synovial fluid. These findings are consistent with the consumption of alpha-tocopherol within the inflamed joint via its role in terminating the process of lipid peroxidation. 3. Nuclear magnetic resonance spectroscopic analysis of matched inflammatory synovial fluid and serum confirmed lower concentrations of triacylglycerol in synovial fluid together with evidence of a shortened mean triacylglycerol chain length. The latter metabolic difference suggests an increased utilization of triacylglycerols for energy within the inflamed joint.
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Affiliation(s)
- K Fairburn
- Inflammation Research Group, London Hospital Medical College, U.K
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