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Qu C, Zhang J, Zhang X, Du J, Su B, Li H. Value of combined detection of anti-nuclear antibody, anti-double-stranded DNA antibody and C3, C4 complements in the clinical diagnosis of systemic lupus erythematosus. Exp Ther Med 2018; 17:1390-1394. [PMID: 30680018 PMCID: PMC6327606 DOI: 10.3892/etm.2018.7072] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 11/19/2018] [Indexed: 01/22/2023] Open
Abstract
Combined detection of antinuclear antibody (ANA), anti-double-stranded DNA (ds-DNA) antibody and complements C3 and C4 in the diagnosis of systemic lupus erythematosus (SLE) was analyzed. One hundred and ninety-four patients with SLE admitted to Yantaishan Hospital of Yantai from January 2012 to December 2017 were selected as SLE group. A total of 106 patients with non-SLE rheumatic disease were selected as disease control group and 120 healthy subjects as healthy control group. The ANA and anti-ds-DNA antibodies were detected by ELISA and complement C3 and C4 were detected by rate nephelometry. The sensitivity and specificity of these four factors were also analyzed for the diagnosis of SLE. The sensitivity and specificity of ANA in diagnosing SLE were 91.75 and 79.65%, respectively; of anti-ds-DNA antibody were 67.01 and 98.23%, respectively; of complement C3 were 87.11 and 82.74%, respectively; and of complement C4 were 88.66 and 77.43%, respectively. The sensitivity and specificity of ANA and anti-ds-DNA antibody in the diagnosis of SLE were 95.36 and 96.90%, respectively; of C3 and C4 were 92.78 and 79.20%, respectively; and the sensitivity and specificity of the combination of all four indicators were 97.42 and 80.97%, respectively. The combined diagnosis of SLE with ANA, anti-ds-DNA antibody, complement C3 and C4 can play a complementary role in the diagnosis and treatment of SLE patients, and it is of great significance to the diagnosis and treatment planning of SLE patients.
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Affiliation(s)
- Changhua Qu
- Department of Clinical Laboratory, Yantaishan Hospital of Yantai, Yantai, Shandong 264000, P.R. China
| | - Juan Zhang
- Outpatient Department, Yantai Yeda Hospital, Yantai, Shandong 264000, P.R. China
| | - Xiumei Zhang
- Department of Internal Medicine, The People's Hospital of Zhangqiu Area, Zhangqiu, Shandong 250200, P.R. China
| | - Jiexin Du
- Department of Neurology, The People's Hospital of Zhangqiu Area, Zhangqiu, Shandong 250200, P.R. China
| | - Baifang Su
- Department of Science and Education, Jinan Zhangqiu District Hospital of TCM, Zhangqiu, Shandong 250200, P.R. China
| | - Hong Li
- Department of Clinical Laboratory, The Fifth People's Hospital of Jinan, Jinan, Shandong 250022, P.R. China
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DNA Damage and Deficiencies in the Mechanisms of Its Repair: Implications in the Pathogenesis of Systemic Lupus Erythematosus. J Immunol Res 2018; 2018:8214379. [PMID: 30116756 PMCID: PMC6079408 DOI: 10.1155/2018/8214379] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 05/30/2018] [Accepted: 06/13/2018] [Indexed: 12/19/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is a perplexing and potentially severe disease, the pathogenesis of which is yet to be understood. SLE is considered to be a multifactorial disease, in which genetic factors, immune dysregulation, and environmental factors, such as ultraviolet radiation, are involved. Recently, the description of novel genes conferring susceptibility to develop SLE even in their own (monogenic lupus) has raised the interest in DNA dynamics since many of these genes are linked to DNA repair. Damage to DNA induces an inflammatory response and eventually triggers an immune response, including those targeting self-antigens. We review the evidence that indicates that patients with SLE present higher levels of DNA damage than normal subjects do and that several proteins involved in the preservation of the genomic stability show polymorphisms, some of which increase the risk for SLE development. Also, the experience from animal models reinforces the connection between DNA damage and defective repair in the development of SLE-like disease including characteristic features such as anti-DNA antibodies and nephritis. Defining the role of DNA damage response in SLE pathogenesis might be strategic in the quest for novel therapies.
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Ayudhya TI, Pellechia PJ, Dingra NN. ROS-mediated carbon monoxide and drug release from drug-conjugated carboxyboranes. Dalton Trans 2018; 47:538-543. [DOI: 10.1039/c7dt03581k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dual nature of amine carboxyboranes for combined CO and drug delivery is facilitated by ROS.
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Affiliation(s)
- T. I. Ayudhya
- Department of Chemistry
- University of Alaska
- Anchorage
- USA
| | - P. J. Pellechia
- Department of Chemistry and Biochemistry
- University of South Carolina
- Columbia
- USA
| | - N. N. Dingra
- Department of Chemistry
- University of Alaska
- Anchorage
- USA
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Akberova NI, Zhmurov AA, Nevzorova TA, Litvinov RI. An anti-DNA antibody prefers damaged dsDNA over native. J Biomol Struct Dyn 2016; 35:219-232. [PMID: 26646388 DOI: 10.1080/07391102.2015.1128979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
DNA-protein interactions, including DNA-antibody complexes, have both fundamental and practical significance. In particular, antibodies against double-stranded DNA play an important role in the pathogenesis of autoimmune diseases. Elucidation of structural mechanisms of an antigen recognition and interaction of anti-DNA antibodies provides a basis for understanding the role of DNA-containing immune complexes in human pathologies and for new treatments. Here we used Molecular Dynamic simulations of bimolecular complexes of a segment of dsDNA with a monoclonal anti-DNA antibody's Fab-fragment to obtain detailed structural and physical characteristics of the dynamic intermolecular interactions. Using a computationally modified crystal structure of a Fab-DNA complex (PDB: 3VW3), we studied in silico equilibrium Molecular Dynamics of the Fab-fragment associated with two homologous dsDNA fragments, containing or not containing dimerized thymine, a product of DNA photodamage. The Fab-fragment interactions with the thymine dimer-containing DNA was thermodynamically more stable than with the native DNA. The amino acid residues constituting a paratope and the complementary nucleotide epitopes for both Fab-DNA constructs were identified. Stacking and electrostatic interactions were shown to play the main role in the antibody-dsDNA contacts, while hydrogen bonds were less significant. The aggregate of data show that the chemically modified dsDNA (containing a covalent thymine dimer) has a higher affinity toward the antibody and forms a stronger immune complex. These findings provide a mechanistic insight into formation and properties of the pathogenic anti-DNA antibodies in autoimmune diseases, such as systemic lupus erythematosus, associated with skin photosensibilization and DNA photodamage.
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Affiliation(s)
- N I Akberova
- a Department of Biochemistry and Biotechnology, Institute of Fundamental Medicine and Biology , Kazan Federal University , 18 Kremlyovskaya St., Kazan 420111 , Russian Federation
| | - A A Zhmurov
- b Moscow Institute of Physics & Technology , 9 Institutskiy Per., Dolgoprudny, Moscow Region 141700 , Russian Federation
| | - T A Nevzorova
- a Department of Biochemistry and Biotechnology, Institute of Fundamental Medicine and Biology , Kazan Federal University , 18 Kremlyovskaya St., Kazan 420111 , Russian Federation
| | - R I Litvinov
- c Department of Cell and Developmental Biology , University of Pennsylvania Perelman School of Medicine , 1109 BRB II/III, 421 Curie Blvd., Philadelphia , PA 19104-6058 , USA
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Akberova NI, Zhmurov AA, Nevzorova TA, Litvinov RI. Molecular dynamics of immune complex of photoadduct-containing DNA with Fab-Anti-DNA antibody fragment. Mol Biol 2016. [DOI: 10.1134/s0026893316020023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Palomino GM, Bassi CL, Wastowski IJ, Xavier DJ, Lucisano-Valim YM, Crispim JCO, Rassi DM, Marques-Neto JF, Sakamoto-Hojo ET, Moreau P, Sampaio-Barros PD, Donadi EA. Patients with systemic sclerosis present increased DNA damage differentially associated with DNA repair gene polymorphisms. J Rheumatol 2014; 41:458-65. [PMID: 24488411 DOI: 10.3899/jrheum.130376] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Patients with systemic sclerosis (SSc) exhibit increased toxicity when exposed to genotoxic agents. In our study, we evaluated DNA damage and polymorphic sites in 2 DNA repair genes (XRCC1 Arg399Gln and XRCC4 Ile401Thr) in patients with SSc. METHODS A total of 177 patients were studied for DNA repair gene polymorphisms. Fifty-six of them were also evaluated for DNA damage in peripheral blood cells using the comet assay. RESULTS Compared to controls, the patients as a whole or stratified into major clinical variants (limited or diffuse skin involvement), irrespective of the underlying treatment schedule, exhibited increased DNA damage. XRCC1 (rs: 25487) and XRCC4 (rs: 28360135) allele and genotype frequencies observed in patients with SSc were not significantly different from those observed in controls; however, the XRCC1 Arg399Gln allele was associated with increased DNA damage only in healthy controls and the XRCC4 Ile401Thr allele was associated with increased DNA damage in both patients and controls. Further, the XRCC1 Arg399Gln allele was associated with the presence of antinuclear antibody and anticentromere antibody. No association was observed between these DNA repair gene polymorphic sites and clinical features of patients with SSc. CONCLUSION These results corroborate the presence of genomic instability in SSc peripheral blood cells, as evaluated by increased DNA damage, and show that polymorphic sites of the XRCC1 and XRCC4 DNA repair genes may differentially influence DNA damage and the development of autoantibodies.
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Affiliation(s)
- Gustavo Martelli Palomino
- From the Program of Basic and Applied Immunology, Faculdade de Medicina de Ribeirão Preto, University of São Paulo (FMRP-USP); Department of Basic Sciences in Health, Faculty of Medical Sciences, Federal University of Mato Grosso (UFMT); Department of Genetics, FMRP-USP; Department of Physics and Chemistry, Faculty of Pharmaceutical Sciences of Ribeirão Preto (FCFRP-USP); Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University Federal Rio Grande do Norte State (UFRN); Department of Medicine, FMRP-USP; Unit of Rheumatology, Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, (UNICAMP), Brazil; Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut des Maladies Emergentes et des Therapies Innovantes, Service de Recherches en Hemato-Immunologies, Hôpital Saint-Louis, Paris, France; Division of Rheumatology, Faculdade de Medicina, Universidade de São Paulo (FM-USP), São Paulo, Brazil
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Khan WA, Moinuddin, Habib S. Preferential recognition of catechol-estrogen modified DNA by circulating autoantibodies in cancer patients. Biochimie 2013; 95:329-35. [PMID: 23069385 DOI: 10.1016/j.biochi.2012.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 10/02/2012] [Indexed: 10/27/2022]
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8
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Khan MA, Dixit K, Uddin M, Malik A, Alam K. Role of peroxynitrite-modified H2A histone in the induction and progression of rheumatoid arthritis. Scand J Rheumatol 2012; 41:426-33. [DOI: 10.3109/03009742.2012.698300] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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10
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Raj CA, Ragavendran P, Sophia D, Rathi MA, Gopalakrishnan VK. Evaluation of in vitro antioxidant and anticancer activity of Alpinia purpurata. Chin J Nat Med 2012. [DOI: 10.1016/s1875-5364(12)60053-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Immunochemical Studies on Catechol-Estrogen Modified Plasmid: Possible Role in Rheumatoid Arthritis. J Clin Immunol 2010; 31:22-9. [DOI: 10.1007/s10875-010-9455-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Accepted: 08/17/2010] [Indexed: 11/25/2022]
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12
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Mansoor F, Ali A, Ali R. Binding of circulating SLE autoantibodies to oxygen free radical damaged chromatin. Autoimmunity 2009; 38:431-8. [PMID: 16278148 DOI: 10.1080/08916930500288596] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease characterized by various immunologic disorders, including production of autoantibodies, formation of immune complexes, decreased serum complement levels, and lymphocytopenia. One of the hallmarks of this disease is the loss of tolerance to nuclear antigens. The dominant presence of antibodies against the exposed conformational epitopes on chromatin strongly suggests that the pathogenic immune response in lupus is driven by chromatin. In the present study, the binding of SLE autoantibodies with native chromatin and oxygen free radical damaged chromatin was studied. As assessed by direct binding and inhibition ELISA, circulating SLE autoantibodies exhibited a high degree of specificity towards the reactive oxygen species (ROS)-modified chromatin in comparison to native chromatin and this binding specificity was reiterated visually by gel retardation assay. The data suggested possible role of modified chromatin in the induction of SLE autoantibodies and higher recognition of oxidatively damaged chromatin by antibodies in sera of SLE patients. It is indicated that free radical modified chromatin or nucleosomes might be the antigen for the production of circulating autoantibodies in SLE.
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Affiliation(s)
- Farah Mansoor
- Faculty of Medicine, Department of Biochemistry, J.N. Medical College, A.M.U, Aligarh, India
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Bassi C, Xavier D, Palomino G, Nicolucci P, Soares C, Sakamoto-Hojo E, Donadi E. Efficiency of the DNA repair and polymorphisms of the XRCC1, XRCC3 and XRCC4 DNA repair genes in systemic lupus erythematosus. Lupus 2009; 17:988-95. [PMID: 18852222 DOI: 10.1177/0961203308093461] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Impaired DNA repair efficiency in systemic lupus erythematosus (SLE) patients has been reported in some studies, mainly regarding the repair of oxidative damage, but little is known about repair kinetics towards primarily single-stranded DNA breaks. In the present study, we aimed to investigate: (a) the efficiency of SLE peripheral blood leucocytes in repairing DNA damage induced by ionizing radiation and (b) the association of DNA repair gene (XRCC1 Arg399Gln, XRCC3 Thr241Met and XRCC4 Ile401Thr) polymorphisms in SLE patients, considering the whole group, or stratified sub-groups according to clinical and laboratory features. A total of 163 SLE patients and 125 healthy controls were studied. The kinetics of DNA strand break repair was evaluated by the comet assay, and genotyping for DNA repair genes was performed by PCR-RFLP. Compared with controls, SLE leucocytes exhibited decreased efficiency of DNA repair evaluated at 30 min following irradiation. A significant association with DNA repair gene polymorphisms was not observed for the whole group of SLE patients; however, the XRCC1Arg399Gln polymorphism was associated with the presence of anti-dsDNA antibody. The concomitance of two DNA repair polymorphic sites was associated with the presence of neuropsychiatric manifestations and antiphospholipid antibody syndrome. Taken together, these results indicated that SLE leucocytes repair less efficiently the radiation-induced DNA damage, and DNA repair polymorphic sites may predispose to the development of particular clinical and laboratory features.
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Affiliation(s)
- Cl Bassi
- Department of Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Ribeirão Preto, Brazil.
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15
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Sidorenko VS, Zharkov DO. Role of base excision repair DNA glycosylases in hereditary and infectious human diseases. Mol Biol 2008. [DOI: 10.1134/s0026893308050166] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Khan WA, Habib S, Khan WA, Alam K. Enhanced binding of circulating SLE autoantibodies to catecholestrogen-copper-modified DNA. Mol Cell Biochem 2008; 315:143-50. [PMID: 18543085 DOI: 10.1007/s11010-008-9798-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Accepted: 05/23/2008] [Indexed: 01/09/2023]
Abstract
Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease characterized by circulating and tissue fixed autoantibodies reactive with self-antigens, including nucleic acid and other nuclear components. The pathways by which these autoantibodies act as a pathogenic factor remain elusive. Present study has investigated the role of estrogens in SLE etiopathogenesis. Estrogen-modified DNA [4-OHE(2)-Cu(II)-DNA] showed single- and double-strand breaks, hyperchromicity, decrease in Tm, and modification of bases. The 4-OHE(2)-Cu(II)-DNA exhibited increased binding with naturally occurring anti-DNA autoantibodies as compared to the unmodified native form (P < 0.001) as assessed by ELISA, quantitative precipitin titration, and gel retardation assay. The relative affinity of anti-DNA antibodies for modified and native DNA was in the order of 2.1 x 10(-7) M and 1.3 x 10(-6) M, respectively. The data suggested that DNA modified with 4-OHE(2) and Cu(II) may be one of the factors for the induction of circulating anti-DNA autoantibodies in SLE.
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Affiliation(s)
- Wahid Ali Khan
- Department of Biochemistry, J. N. Medical College, A. M. U., Aligarh, 202002, India
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Alam K, Jabeen S. Immunogenicity of mitochondrial DNA modified by hydroxyl radical. Cell Immunol 2007; 247:12-7. [PMID: 17716639 DOI: 10.1016/j.cellimm.2007.06.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Revised: 06/27/2007] [Accepted: 06/28/2007] [Indexed: 12/19/2022]
Abstract
Mitochondria consume about 90 percent of oxygen used by the body, and are a particularly rich source of reactive oxygen species (ROS). In this research communication mitochondrial DNA (mtDNA) was isolated from fresh goat liver and modified in vitro by hydroxyl radical generated from UV irradiation (254 nm) of hydrogen peroxide. As a consequence of hydroxyl radical modification, mtDNA showed hyperchromicity and sensitivity to nuclease S1 digestion as compared to control mtDNA. Animals immunized with mtDNA and ROS-modified mtDNA induced antibodies as detected by direct binding and competition ELISA. The data suggest that immunogenicity of mtDNA got augmented after treatment with hydroxyl radical. IgG isolated from immune sera showed specificity for respective immunogen and cross-reaction with other nucleic acids. Binding of induced antibodies with array of antigens clearly indicates their polyspecific nature. Moreover, the polyspecificity exhibited by induced antibodies is unique in view of similar multiple antigen binding properties of naturally occurring anti-DNA antibodies derived from SLE patients.
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MESH Headings
- Animals
- Antibody Specificity/immunology
- Antigen-Antibody Reactions/immunology
- Autoantibodies/blood
- Autoantibodies/chemistry
- Autoantibodies/immunology
- DNA Damage/immunology
- DNA, Mitochondrial/chemistry
- DNA, Mitochondrial/immunology
- DNA, Mitochondrial/radiation effects
- Enzyme-Linked Immunosorbent Assay/methods
- Female
- Goats
- Humans
- Hydrogen Peroxide/chemistry
- Hydrogen Peroxide/radiation effects
- Hydroxyl Radical/chemistry
- Hydroxyl Radical/immunology
- Hydroxyl Radical/toxicity
- Immune Sera/chemistry
- Immune Sera/immunology
- Immunoglobulin G/blood
- Immunoglobulin G/chemistry
- Immunoglobulin G/immunology
- In Vitro Techniques
- Lupus Erythematosus, Systemic/blood
- Lupus Erythematosus, Systemic/etiology
- Lupus Erythematosus, Systemic/immunology
- Mitochondria, Liver/chemistry
- Mitochondria, Liver/metabolism
- Nucleic Acid Conformation/radiation effects
- Nucleic Acid Denaturation/radiation effects
- Rabbits
- Spectrophotometry, Ultraviolet
- Ultraviolet Rays
- Vaccination/methods
- Vaccines, Synthetic/chemistry
- Vaccines, Synthetic/immunology
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Affiliation(s)
- Khurshid Alam
- Department of Biochemistry, Faculty of Medicine, J.N. Medical College, A.M.U., Aligarh 202 002, India.
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Khan WA, Alam K. Catechol-estrogen modified DNA: a better antigen for cancer autoantibody. Arch Biochem Biophys 2007; 465:293-300. [PMID: 17632072 DOI: 10.1016/j.abb.2007.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Revised: 06/10/2007] [Accepted: 06/12/2007] [Indexed: 11/20/2022]
Abstract
Estrogens are known mutagenic and carcinogenic risk factors. Non-enzymatic oxidation of catechol-estrogens in the presence of copper is reported to generate reactive oxygen species (ROS) that can cause DNA damage. We show that DNA modification in the presence of 4-hydroxyestradiol (4-OHE(2)) and copper (Cu-II) results in single and double strand breaks, base modification, hyperchromicity and change in ellipticity. Modified DNA (4-OHE(2)-Cu(II)-DNA) was highly immunogenic in experimental animals. Induced anti-4-OHE(2)-Cu(II)-DNA antibodies were effectively used as a probe for detecting oxidative lesions in human genomic DNA and for the estimation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in the urine of cancer patients. Circulating antibodies from cancer patients showed high binding to 4-OHE(2)-Cu(II)-DNA as compared to native DNA. Our results imply that interaction of catechol-estrogen and copper leads to the production of potent ROS, capable of causing DNA damage, thus playing an important role in carcinogenesis. The modified DNA presents unique epitopes which may be one of the factors for autoantibody induction in cancer.
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Affiliation(s)
- Wahid Ali Khan
- Department of Biochemistry, J. N. Medical College, A. M. U., Aligarh 202002, India
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Abstract
Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease in which anti-double-stranded DNA antibody is a classic autoantibody that characterizes SLE. A role for oestrogens in the pathogenesis of SLE has been suspected for many years but the exact patho-aetiology remains elusive. In this study, the binding of SLE autoantibodies with native and 4-OHE(2)-NO-modified plasmid DNA were assessed. Binding specificity of antibodies was analysed by direct binding and inhibition enzyme-linked immunosorbent assay, quantitative precipitin titration and gel retardation assay. Anti-DNA IgG from SLE sera, purified on Protein A-Agarose matrix, exhibited increased recognition of 4-OHE(2)-NO-DNA than native DNA (P < 0.001). Gel retardation assay further substantiated the enhanced recognition of modified DNA by anti-DNA autoantibodies. The affinity of anti-DNA antibodies for modified polymer was found to be high as calculated by using Langmuir plot. DNA modified by 4-OHE(2)-NO presents unique neo-epitopes that might be one of the factor in antigen-driven induction of SLE autoantibodies.
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Affiliation(s)
- W A Khan
- Department of Biochemistry, Faculty of Medicine, J. N. Medical College, AMU, Aligarh, India.
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Khan F, Siddiqui AA, Ali R. Measurement and significance of 3-nitrotyrosine in systemic lupus erythematosus. Scand J Immunol 2006; 64:507-14. [PMID: 17032243 DOI: 10.1111/j.1365-3083.2006.01794.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nitration of free and protein associated tyrosine represents, in vivo, a mechanism that can severely compromise the cell function. The detection of 3-nitrotyrosine (3-NT) in pathological tissues is suggestive of the occurrence of nitrating pathways and has been identified as a marker of inflammation and a stable end product of increased reactive nitrogen intermediate production. Protein nitration occurs in many disease conditions including systemic lupus erythematosus (SLE). In this study we show that the level of both free and protein bound 3-NT, which is produced by reactive nitrogen species (RNS)-dependent oxidative damage, is elevated in patients with SLE and that there is a possible role of RNS-modified epitopes in the aetiology of the disease. Commercially available poly L-tyrosine was exposed to nitrating species, inducing nitration in tyrosine residues. Immunoglobulin-G (IgG) purified on Protein-A-Sepharose matrix from 24 SLE patients was studied for their recognition of native and nitrated poly L-tyrosine by direct binding and competition enzyme-linked immunosorbent assay (ELISA). The formation of immune complex between SLE IgG and nitrated poly L-tyrosine was visualized by gel retardation assay. Free 3-NT in patients' sera was detected and quantitated by high performance liquid chromatography whereas protein-bound 3-NT was analysed by Western blotting and the concentration was calculated by sandwich ELISA. The concentration of free 3-NT was found to be 1.4 +/- 0.09 microm whereas the concentration of protein bound 3-NT was 96.52 +/- 21.12 microm nitrated bovine serum albumin equivalents/mg protein, which was significantly higher when compared with healthy controls. Elevated level of 3-NT was observed in SLE patients using two different techniques, when compared with healthy subjects confirms the overproduction of RNS in the pathogenesis of human SLE.
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Affiliation(s)
- F Khan
- Department of Biochemistry, Faculty of Medicine, Aligarh M.University, Aligarh, UP, India.
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Khan F, Khan F, Siddiqui AA, Ali R. Plasmid DNA acquires immunogenicity on exposure to singlet oxygen. BIOCHEMISTRY (MOSCOW) 2006; 71:871-8. [PMID: 16978150 DOI: 10.1134/s0006297906080086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In the present study, the effect of singlet oxygen (1O2) (generated by ultraviolet (UV) irradiation of methylene blue) on plasmid DNA has been analyzed by UV spectroscopy, fluorescence spectroscopy, and S1 nuclease digestibility. Both native and 1O2-modified plasmid DNA were treated with a number of restriction enzymes to map out the sites damaged by 1O2. It was also observed that, on exposure to 1O2, native plasmid DNA that is non-immunogenic acquired the ability to elicit an immune response in experimental animals. However, the induced antibodies exhibited appreciable cross reactivity with various polynucleotides and nucleic acids. The data indicate that the antibodies, though cross-reactive, preferentially bind 1O2-modified epitopes on plasmid DNA. Gel retardation assay further substantiated the enhanced recognition of 1O2-modified plasmid DNA over the native form. The antibodies developed were then subjected to competition ELISA with sera from various diseases such as systemic lupus erythematosus, rheumatoid arthritis, and cancer. These results suggest that upon exposure of DNA to 1O2, neo-epitopes are generated, which may be one of the factors for the induction of circulating autoantibodies in the three diseases.
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Affiliation(s)
- Fozia Khan
- Department of Biochemistry, Faculty of Medicine, J. N. Medical College, A. M. U. Aligarh, 202002, India.
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Khan F, Ali R. Antibodies against nitric oxide damaged poly L-tyrosine and 3-nitrotyrosine levels in systemic lupus erythematosus. BMB Rep 2006; 39:189-96. [PMID: 16584635 DOI: 10.5483/bmbrep.2006.39.2.189] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Alterations in the amino acid structure or sequence can generate neo-epitopes from self-proteins causing autoaggressive immune attack. Reactive nitrogen species are an important factor that induces post-translational modification of proteins by cellular reduction and oxidation mechanism; cysteinyl-nitrosylation or tyrosine nitration leading to potentially pathogenic pathways. It was thought of interest to investigate the immunogenicity of nitrated poly L-tyrosine vis-á-vis its possible role in the induction of antibodies in systemic lupus erythematosus (SLE). Commercially available poly L-tyrosine was exposed to nitrating species and the damage was monitored by UV spectroscopy and alkaline gel electrophoresis. The results indicated the formation of 3-nitrotyrosine. Nitrated poly L-tyrosine induced higher titre antibodies as compared to the native form. Nitrated poly L-tyrosine was recognized by the autoantibodies present in the sera of patients suffering from SLE by enzyme immunoassays and band shift assay. The possible role of nitrated self-proteins has been discussed in the production of circulating anti-DNA antibodies in SLE.
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Affiliation(s)
- Fozia Khan
- Department of Biochemistry, Faculty of Medicine, A.M.U. Aligarh-202002, UP, India
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Waris G, Ahsan H. Reactive oxygen species: role in the development of cancer and various chronic conditions. J Carcinog 2006; 5:14. [PMID: 16689993 PMCID: PMC1479806 DOI: 10.1186/1477-3163-5-14] [Citation(s) in RCA: 920] [Impact Index Per Article: 51.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Accepted: 05/11/2006] [Indexed: 12/12/2022] Open
Abstract
Oxygen derived species such as superoxide radical, hydrogen peroxide, singlet oxygen and hydroxyl radical are well known to be cytotoxic and have been implicated in the etiology of a wide array of human diseases, including cancer. Various carcinogens may also partly exert their effect by generating reactive oxygen species (ROS) during their metabolism. Oxidative damage to cellular DNA can lead to mutations and may, therefore, play an important role in the initiation and progression of multistage carcinogenesis. The changes in DNA such as base modification, rearrangement of DNA sequence, miscoding of DNA lesion, gene duplication and the activation of oncogenes may be involved in the initiation of various cancers. Elevated levels of ROS and down regulation of ROS scavengers and antioxidant enzymes are associated with various human diseases including various cancers. ROS are also implicated in diabtes and neurodegenerative diseases. ROS influences central cellular processes such as proliferation a, apoptosis, senescence which are implicated in the development of cancer. Understanding the role of ROS as key mediators in signaling cascades may provide various opportunities for pharmacological intervention.
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Affiliation(s)
- Gulam Waris
- Moores UCSD Cancer Center, University of California at San Diego, La Jolla, CA 92093, USA
| | - Haseeb Ahsan
- Department of Dermatology, University of Wisconsin – Madison, Medical Science Center, Madison, WI 53706, USA
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