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Tew DJ, Hebert JM, Schmier BJ. Discovery and properties of a monoclonal antibody targeting 8-oxoA, an oxidized adenine lesion in DNA and RNA. Redox Biol 2023; 62:102658. [PMID: 36989571 PMCID: PMC10074937 DOI: 10.1016/j.redox.2023.102658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 03/04/2023] [Indexed: 03/17/2023] Open
Abstract
8-oxoA, a major oxidation product of adenosine, is a mispairing, mutagenic lesion that arises in DNA and RNA when •OH radicals or one-electron oxidants attack the C8 adenine atom or polymerases misincorporate 8-oxo(d)ATP. The danger of 8-oxoA is underscored by the existence of dedicated cellular repair machinery that explicitly excise it from DNA, the attenuation of translation induced by 8-oxoA-mRNA or damaged ribosomes, and its potency as a TLR7 agonist. Here we present the discovery, purification, and biochemical characterization of a new mouse IgGk1 monoclonal antibody (6E4) that specifically targets 8-oxoA. Utilizing an AchE-based competitive ELISA assay, we demonstrate the selectivity of 6E4 for 8-oxoA over a plethora of canonical and chemically modified nucleosides including 8-oxoG, A, m6A, 2-oxoA, and 5-hoU. We further show the ability of 6E4 to exclusively recognize 8-oxoA in nucleoside triphosphates (8-oxoATP) and DNA/RNA oligonucleotides containing a single 8-oxoA. 6E4 also binds 8-oxoA in duplex DNA/RNA antigens where the lesion is either paired correctly or base mismatched. Our findings define the 8-oxoAde nucleobase as the critical epitope and indicate mAb 6E4 is ideally suited for a broad range of immunological applications in nucleic acid detection and quality control.
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Wallace SS. Consequences and repair of radiation-induced DNA damage: fifty years of fun questions and answers. Int J Radiat Biol 2021; 98:367-382. [PMID: 34187282 DOI: 10.1080/09553002.2021.1948141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE To summarize succinctly the 50 years of research undertaken in my laboratory and to provide an overview of my career in science. It is certainly a privilege to have been asked by Carmel Mothersill and Penny Jeggo to contribute to this special issue of the International Journal of Radiation Biology focusing on the work of women in the radiation sciences. CONCLUSION My students, post-docs and I identified and characterized a number of the enzymes that recognize and remove radiation-damaged DNA bases, the DNA glycosylases, which are the first enzymes in the Base Excision Repair (BER) pathway. Although this pathway actually evolved to repair oxidative and other endogenous DNA damages, it is also responsible for removing the vast majority of radiation-induced DNA damages including base damages, alkali-labile lesions and single strand breaks. However, because of its high efficiency, attempted BER of clustered lesions produced by ionizing radiation, can have disastrous effects on cellular DNA. We also evaluated the potential biological consequences of many of the radiation-induced DNA lesions. In addition, with collaborators, we employed computational techniques, x-ray crystallography and single molecule approaches to answer many questions at the molecular level.
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Affiliation(s)
- Susan S Wallace
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA
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Gonzalez-Hunt CP, Wadhwa M, Sanders LH. DNA damage by oxidative stress: Measurement strategies for two genomes. CURRENT OPINION IN TOXICOLOGY 2018. [DOI: 10.1016/j.cotox.2017.11.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Cadet J, Davies KJA, Medeiros MH, Di Mascio P, Wagner JR. Formation and repair of oxidatively generated damage in cellular DNA. Free Radic Biol Med 2017; 107:13-34. [PMID: 28057600 PMCID: PMC5457722 DOI: 10.1016/j.freeradbiomed.2016.12.049] [Citation(s) in RCA: 205] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Revised: 12/27/2016] [Accepted: 12/31/2016] [Indexed: 12/18/2022]
Abstract
In this review article, emphasis is placed on the critical survey of available data concerning modified nucleobase and 2-deoxyribose products that have been identified in cellular DNA following exposure to a wide variety of oxidizing species and agents including, hydroxyl radical, one-electron oxidants, singlet oxygen, hypochlorous acid and ten-eleven translocation enzymes. In addition, information is provided about the generation of secondary oxidation products of 8-oxo-7,8-dihydroguanine and nucleobase addition products with reactive aldehydes arising from the decomposition of lipid peroxides. It is worth noting that the different classes of oxidatively generated DNA damage that consist of single lesions, intra- and interstrand cross-links were unambiguously assigned and quantitatively detected on the basis of accurate measurements involving in most cases high performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry. The reported data clearly show that the frequency of DNA lesions generated upon severe oxidizing conditions, including exposure to ionizing radiation is low, at best a few modifications per 106 normal bases. Application of accurate analytical measurement methods has also allowed the determination of repair kinetics of several well-defined lesions in cellular DNA that however concerns so far only a restricted number of cases.
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Affiliation(s)
- Jean Cadet
- Département de médecine nucléaire et radiobiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada J1H 5N4.
| | - Kelvin J A Davies
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, The University of Southern California, Los Angeles, CA 90089-0191, United States; Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, CA 90089-0191, United States
| | - Marisa Hg Medeiros
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05508 000 São Paulo, SP, Brazil
| | - Paolo Di Mascio
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05508 000 São Paulo, SP, Brazil
| | - J Richard Wagner
- Département de médecine nucléaire et radiobiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada J1H 5N4
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Abstract
Oxidatively damaged DNA is implicated in various diseases, including neurodegenerative disorders, cancer, diabetes, cardiovascular and inflammatory diseases as well as aging. Several methods have been developed to detect oxidatively damaged DNA. They include chromatographic techniques, the Comet assay, (32)P-postlabelling and immunochemical methods that use antibodies to detect oxidized lesions. In this review, we discuss the detection of 8-oxo-7,8-dihydro-29-deoxyguanosine (8-oxodG), the most abundant oxidized nucleoside. This lesion is frequently used as a marker of exposure to oxidants, including environmental pollutants, as well as a potential marker of disease progression. We concentrate on studies published between the years 2000 and 2011 that used enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry to detect 8-oxodG in humans, laboratory animals and in cell lines. Oxidative damage observed in these organisms resulted from disease, exposure to environmental pollutants or from in vitro treatment with various chemical and physical factors.
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Affiliation(s)
- Pavel Rossner
- Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR, Videnska 1083, 142 20 Prague, Czech Republic.
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Maynard S, de Souza-Pinto NC, Scheibye-Knudsen M, Bohr VA. Mitochondrial base excision repair assays. Methods 2010; 51:416-25. [PMID: 20188838 PMCID: PMC2916069 DOI: 10.1016/j.ymeth.2010.02.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Accepted: 02/23/2010] [Indexed: 12/12/2022] Open
Abstract
The main source of mitochondrial DNA (mtDNA) damage is reactive oxygen species (ROS) generated during normal cellular metabolism. The main mtDNA lesions generated by ROS are base modifications, such as the ubiquitous 8-oxoguanine (8-oxoG) lesion; however, base loss and strand breaks may also occur. Many human diseases are associated with mtDNA mutations and thus maintaining mtDNA integrity is critical. All of these lesions are repaired primarily by the base excision repair (BER) pathway. It is now known that mammalian mitochondria have BER, which, similarly to nuclear BER, is catalyzed by DNA glycosylases, AP endonuclease, DNA polymerase (POLgamma in mitochondria) and DNA ligase. This article outlines procedures for measuring oxidative damage formation and BER in mitochondria, including isolation of mitochondria from tissues and cells, protocols for measuring BER enzyme activities, gene-specific repair assays, chromatographic techniques as well as current optimizations for detecting 8-oxoG lesions in cells by immunofluorescence. Throughout the assay descriptions we will include methodological considerations that may help optimize the assays in terms of resolution and repeatability.
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Affiliation(s)
- Scott Maynard
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD 21236, USA
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Maatouk I, Bouaïcha N, Plessis MJ, Périn F. Optimization of the32P-Postlabeling/Thin Layer Chromatography Assay (32P-TLC) for In Vitro Detection of 8-Oxo-Deoxyguanosine as a Biomarker of Oxidative DNA Damage. Toxicol Mech Methods 2008; 16:313-22. [PMID: 20021030 DOI: 10.1080/15376520600616909] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Marrot L, Meunier JR. Skin DNA photodamage and its biological consequences. J Am Acad Dermatol 2008; 58:S139-48. [PMID: 18410800 DOI: 10.1016/j.jaad.2007.12.007] [Citation(s) in RCA: 213] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Revised: 12/05/2007] [Accepted: 12/07/2007] [Indexed: 12/25/2022]
Abstract
It is well established that ultraviolet (UV) radiation from sunlight damages skin cells' DNA. Wavelengths in the UVB range are absorbed by DNA and can induce mutagenic lesions such as pyrimidine dimers. On the other hand, genotoxic effects of solar UVA are mainly mediated by the activation of endogenous photosensitizers resulting in the generation of a local oxidative stress. Exogenous chemicals, such as drugs like psoralens or fluoroquinolones, sometimes amplify UV-induced harmful effects. DNA damage can lead to mutations and genetic instability. This is one of the reasons why sunlight overexposure increases the risk of skin cancer. But DNA photolesions can also be involved in other skin-specific responses to UV radiation: erythema, immunosuppression, and melanogenesis are examples reported in the literature. The aim of this short review is to summarize the general knowledge in the field of UV-induced DNA damage. Besides the biological consequences of DNA photolesions, this article also deals with technologies used for their detection and shows how helpful such approaches can be to assess photoprotection provided by sunscreens.
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Affiliation(s)
- Laurent Marrot
- L'Oréal Advanced Research, Life Science Research, Investigative Toxicology Department, Genotoxicity Group, Aulnay-sous-Bois, France.
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Pilger A, Rüdiger HW. 8-Hydroxy-2'-deoxyguanosine as a marker of oxidative DNA damage related to occupational and environmental exposures. Int Arch Occup Environ Health 2006; 80:1-15. [PMID: 16685565 DOI: 10.1007/s00420-006-0106-7] [Citation(s) in RCA: 233] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2005] [Accepted: 03/23/2006] [Indexed: 11/26/2022]
Abstract
Oxidative DNA damage is considered to play an important role in pathophysiological processes, ageing and cancer. So far major interest has been on measuring 8-hydroxy-2'-deoxyguanosine (8-OHdG), the preferred methods relying on HPLC or GC-mass spectrometry. The high biological relevance of 8-OHdG is due to its ability to induce G-->T transversions, which are among the most frequent somatic mutations found in human cancers. Effects of workplace exposures on the level of white blood cell 8-OHdG or urinary 8-OHdG have been reported with controversial results. Exposures examined include asbestos, azo-dyes, benzene, fine particulate matter (PM(2.5)), glassworks, polycyclic aromatic hydrocarbons (PAHs), rubber manufacturing, silica, metals, styrene, toluene and xylenes. The available data indicate that there is still a lack of well established dose-response relations between occupational or environmental exposures and the induction of 8-OHdG. Smoking has been most consistently identified as a confounder for 8-OHdG, but various occupational studies did not reveal higher levels of 8-OHdG in smokers. Despite the conflicting results, the reported studies show promise for 8-OHdG as a biomarker of oxidative stress associated with chemical exposure. However, there are critical aspects related to the analytical challenge, artifactual production of 8-OHdG, inter- and intra-individual variation, confounding factors and inter-laboratory differences, implying that further work is needed to reach a consensus on the background level of 8-OHdG.
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Affiliation(s)
- A Pilger
- Division of Occupational Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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Maatouk I, Bouaïcha N, Plessis MJ, Périn F. Detection by 32P-postlabelling of 8-oxo-7,8-dihydro-2′-deoxyguanosine in DNA as biomarker of microcystin-LR- and nodularin-induced DNA damage in vitro in primary cultured rat hepatocytes and in vivo in rat liver. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2004; 564:9-20. [PMID: 15474406 DOI: 10.1016/j.mrgentox.2004.06.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2004] [Revised: 06/01/2004] [Accepted: 06/25/2004] [Indexed: 12/14/2022]
Abstract
Microcystin-LR (MCYST-LR) and nodularin (NOD) produced by cyanobacteria are potent and specific hepatotoxins. The induction of free-radical formation, reduction of glutathione levels and induction of DNA damage are three major events found in rat hepatocytes treated with these hepatotoxins. However, the mechanism of MCYST-LR- and NOD-mediated induction of oxidative DNA damage has not been fully elucidated. The objective of this study was to determine whether MCYST-LR and NOD increase the formation of a DNA oxidative damage marker such as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) in vitro in primary rat hepatocytes and in vivo in rat liver cells. Rat hepatocytes were exposed to MCYST-LR or NOD at low doses (2 and 10 ng/ml), at which there is no evidence of morphologically apparent cytotoxic effects, as well as an induced dose- and time-dependent formation of 8-oxo-dG. Moreover, MCYST-LR treatment of rats (50 microg/kg, ip) resulted in a significant increase of 8-oxo-dG in liver DNA, at 24 h after treatment before decreasing at 48 h. However, NOD-induced DNA damage was increased both at 24 and 48 h, in contrast to the MCYST-LR-induced effect. The effects on this oxidative DNA damage marker indicates that MCYST-LR and NOD do evoke oxidative stress, which may contribute, at least in part, to their liver toxicity and carcinogenicity during long-term exposure.
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Affiliation(s)
- Imed Maatouk
- Laboratoire Raymond Latarjet, Institut Curie-Section Recherche, Bâtiment 112, Centre Universitaire, 91405 Orsay Cedex, France
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11
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Mohsin Ali M, Kurisu S, Yoshioka Y, Terato H, Ohyama Y, Kubo K, Ide H. Detection of endonuclease III- and 8-oxoguanine glycosylase-sensitive base modifications in gamma-irradiated DNA and cells by the aldehyde reactive probe (ARP) assay. JOURNAL OF RADIATION RESEARCH 2004; 45:229-237. [PMID: 15304965 DOI: 10.1269/jrr.45.229] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Ionizing radiation generates diverse DNA lesions that differentially induce cell death and mutations. In the present study, calf thymus DNA (400 microg/ml) and HeLa cells were irradiated by (60)Co gamma-rays, and abasic (AP) sites and endonuclease (Endo)III- and 8-oxoguanine glycosylase (hOGG1)-sensitive base modifications in DNA were quantitated by the aldehyde reactive probe (ARP) assay. The irradiation of calf thymus DNA in phosphate buffer generated 91 Endo III- and 100 hOGG1-sensitive base modifications and 110 AP sites per 10(6) base pairs (bp) per Gy. The yield of the lesions in Tris buffer was 41- to 91-fold lower than that in phosphate, demonstrating a radioprotective effect of Tris. The HeLa cell chromosomal DNA contained 12 Endo III- and 3.8 hOGG1-sensitive base modifications and less than 1 AP sites per 10(6) bp as endogenous damage, and their level was increased by irradiation. The yields of the damage at 1 Gy (roughly equivalent to the lethal dose of HeLa cells [1.6-1.8 Gy]) were 0.13 Endo III, 0.091 hOGG1, and 0.065 AP sites per 10(6) bp, showing that irradiation with a lethal dose brought about only a marginal increase in base damage relative to an endogenous one. A comparison of the present data with those reported for DNA strand breaks supports the primary importance of double-strand breaks and clustered lesions as lethal damages formed by ionizing radiation.
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Affiliation(s)
- Mohammed Mohsin Ali
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan
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12
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Jensen A, Calvayrac G, Karahalil B, Bohr VA, Stevnsner T. Mammalian 8-oxoguanine DNA glycosylase 1 incises 8-oxoadenine opposite cytosine in nuclei and mitochondria, while a different glycosylase incises 8-oxoadenine opposite guanine in nuclei. J Biol Chem 2003; 278:19541-8. [PMID: 12644468 DOI: 10.1074/jbc.m301504200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cells are continuously exposed to oxidative species, which cause several types of oxidative DNA lesions. Repair of some of these lesions has been well characterized but little is known about the repair of many DNA lesions. The oxidized adenine base, 7,8-dihydro-8-oxoadenine (8-oxoA), is a relatively common DNA lesion, which is believed to be mutagenic in mammalian cells. This study investigates repair of 8-oxoA in nuclear and mitochondrial mammalian extracts. In nuclei, 8-oxoA:C and 8-oxoA:G base pairs are recognized and cleaved; in contrast, only 8-oxoA:C base pairs are cleaved in mitochondria. High stability of the DNA helix increased the efficiency of incision of 8-oxoA, and the efficiency decreased at DNA bends and condensed regions of the helix. Using liver extracts from mice knocked out for 8-oxoguanine DNA glycosylase 1 (OGG1), we demonstrated that OGG1 is the only glycosylase that incises 8-oxoA, when base-paired with cytosine in mitochondria and nuclei, but a different enzyme incises 8-oxoA when base-paired with guanine in the nucleus. Consistent with this result, a covalent DNA-protein complex was trapped using purified human OGG1 or human nuclear or mitochondrial extracts with a DNA substrate containing an 8-oxoA:C base pair.
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Affiliation(s)
- Anne Jensen
- Danish Center for Molecular Gerontology, Department of Molecular Biology, University of Aarhus, DK-8000 Aarhus C, Denmark
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Seedhouse CH, Margison GP, Hendry JH, Hajeer A, Embleton MJ. Anti-8-oxo-2'-deoxyguanosine phage antibodies: isolation, characterization, and relationship to disease states. Biochem Biophys Res Commun 2001; 280:595-604. [PMID: 11162561 DOI: 10.1006/bbrc.2000.4170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We have used human single chain Fv (scFv) phage display antibody libraries to isolate recombinant antibodies against the DNA adduct 8-oxo-2'-deoxyguanosine (8-oxodG). One of these scFvs (175G) bound to several 8-oxodG-containing oligonucleotides whilst demonstrating no cross-reactivity with G-containing control oligonucleotides, and bound to 8-oxodG lesions introduced into DNA by treatment with methylene blue and white light. In addition, 175G inhibited the cleavage of an 8-oxodG-containing oligonucleotide by the Escherichia coli enzyme formamidopyrimidine-DNA glycosylase (Fpg). The nucleotide sequence of the 175G V(H) gene segment was 98% homologous to the published V(H) sequence of a human hybridoma derived from a patient with systemic lupus erythematosus (SLE). Sera from two SLE patients bound to damaged DNA, and this binding could be inhibited by 175G. The use of human scFv phage display libraries has thus produced a unique reagent with specificity for 8-oxodG, which may have a role in damage detection and quantitation and in modifying DNA repair activity. 175G also offers support to the hypothesis that SLE might be associated with oxidative damage to DNA.
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Affiliation(s)
- C H Seedhouse
- Department of Immunology, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Wilmslow Road, Manchester, M20 4BX, United Kingdom
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Carr AC, Frei B. Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans. Am J Clin Nutr 1999; 69:1086-107. [PMID: 10357726 DOI: 10.1093/ajcn/69.6.1086] [Citation(s) in RCA: 461] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The current recommended dietary allowance (RDA) for vitamin C for adult nonsmoking men and women is 60 mg/d, which is based on a mean requirement of 46 mg/d to prevent the deficiency disease scurvy. However, recent scientific evidence indicates that an increased intake of vitamin C is associated with a reduced risk of chronic diseases such as cancer, cardiovascular disease, and cataract, probably through antioxidant mechanisms. It is likely that the amount of vitamin C required to prevent scurvy is not sufficient to optimally protect against these diseases. Because the RDA is defined as "the average daily dietary intake level that is sufficient to meet the nutrient requirement of nearly all healthy individuals in a group," it is appropriate to reevaluate the RDA for vitamin C. Therefore, we reviewed the biochemical, clinical, and epidemiologic evidence to date for a role of vitamin C in chronic disease prevention. The totality of the reviewed data suggests that an intake of 90-100 mg vitamin C/d is required for optimum reduction of chronic disease risk in nonsmoking men and women. This amount is about twice the amount on which the current RDA for vitamin C is based, suggesting a new RDA of 120 mg vitamin C/d.
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Affiliation(s)
- A C Carr
- Linus Pauling Institute, Oregon State University, Corvallis 97331, USA
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Jones GD, Dickinson L, Lunec J, Routledge MN. SVPD-post-labeling detection of oxidative damage negates the problem of adventitious oxidative effects during 32P-labeling. Carcinogenesis 1999; 20:503-7. [PMID: 10190569 DOI: 10.1093/carcin/20.3.503] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The exploitation of oxidative DNA lesions as biomarkers of oxidative stress in vivo requires techniques that allow for the precise and valid measurement of oxidative damage to DNA. Previously, endogenous levels of the oxidative lesion 8-hydroxy-2'-deoxyguanosine (8-HO-dG) in rat tissues determined by a micrococcal nuclease/calf spleen phosphodiesterase-based 32P-post-labeling protocol were found to be at least 10-fold higher than those determined by HPLC with electrochemical detection. This was attributed to the adventitious oxidation of the normal nucleotides (dGp) occurring during the labeling stage of the postlabeling protocol, which could only be prevented by the introduction of additional chromatographic steps to remove the unmodified species prior to labeling. In the present study we report that an alternative snake venom phosphodiesterase-based 32P-post-labeling procedure (SVPD-postlabeling) negates the problem of adventitious oxidative damage during labeling by virtue of a unique digestion strategy. In SVPD-post-labeling, digestion yields certain lesions (thymine glycols, phosphoglycolates and abasic sites) as damage-containing dimer species which are ready substrates for labeling. In contrast, the undamaged DNA is recovered as mononucleoside species (dN) which are not substrates for labeling and so remain undetected. Furthermore, even if the mononucleosides are oxidized during labeling, they will not contribute to the level of damage detected. Indeed, we demonstrate that neither the external gamma-irradiation of the digested DNA samples nor increasing the incubation time of the labeling reaction alters the levels of damage detected by SVPD-post-labeling. The negation of adventitious oxidative effects during labeling deems that an optimized SVPD-post-labeling procedure should be well-suited for the biomonitoring of endogenous oxidative stress in vivo.
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Affiliation(s)
- G D Jones
- Biomolecular Damage Group, Centre for Mechanisms of Human Toxicity, University of Leicester, UK.
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16
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Salles B, Rodrigo G, Li RY, Calsou P. DNA damage excision repair in microplate wells with chemiluminescence detection: development and perspectives. Biochimie 1999; 81:53-8. [PMID: 10214910 DOI: 10.1016/s0300-9084(99)80038-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The development of in vitro repair assays with human cell-free extracts led to new insights on the mechanism of excision of DNA damage which consists of incision/excision and repair synthesis/ligation. We have adapted the repair synthesis reaction with cells extracts incubated with damaged plasmid DNA performed in liquid phase to solid phase by DNA adsorption into microplate wells. Since cells extracts are repair competent in base excision and nucleotide excision repair, all types of substrate DNA lesions were detected with chemiluminescence measurement after incorporation of biotin-deoxynucleotide during the repair synthesis step. Derivatives of our initial 3D-assay (DNA damage detection) have been set up to: i) screen antioxidative compounds and NER inhibitors; ii) capture genomic DNA (3D(Cell)-assay) that allows detection of alkylated base and consequently determines the kinetics of the cellular repair; and iii) immunodetect the repair proteins in an ELISA reaction (3D(Rec)-assay). The 3D derived assays are presented and discussed.
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Affiliation(s)
- B Salles
- Institut de Pharmacologie et de Biologie Structurale, CNRS UPR 9062, Toulouse, France
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17
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Rink SM, Shen JC, Loeb LA. Creation of RNA molecules that recognize the oxidative lesion 7,8-dihydro-8-hydroxy-2'-deoxyguanosine (8-oxodG) in DNA. Proc Natl Acad Sci U S A 1998; 95:11619-24. [PMID: 9751715 PMCID: PMC21690 DOI: 10.1073/pnas.95.20.11619] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/1998] [Accepted: 08/05/1998] [Indexed: 11/18/2022] Open
Abstract
We used in vitro evolution to obtain RNA molecules that specifically recognize and bind with high affinity to the oxidative lesion 7, 8-dihydro-8-hydroxy-2'-deoxyguanosine (8-oxodG) in DNA. A pool of approximately 10(15) RNA molecules containing a random insert of 45 nucleotides in length was subject to 10 successive rounds of chromatographic enrichment using an 8-oxodG affinity matrix, reverse transcription, PCR amplification, and RNA synthesis. Selected RNA molecules bind to 8-oxodG located at the 3' terminus (Kd = 270 nM) or in the center (Kd = 2.8 microM) of a 19-nt strand of DNA, with no detectable affinity for the corresponding dG-containing DNA sequences. These 8-oxodG-binding RNAs will be used to monitor levels of 8-oxodG in DNA from biological sources and should provide a unique method for evaluating oxygen-mediated DNA damage. This approach should be applicable for the creation of RNA molecules that can bind to and identify the different modifications of DNA produced by a variety of environmental agents.
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Affiliation(s)
- S M Rink
- The Joseph Gottstein Memorial Cancer Research Laboratory, Departments of Pathology and Biochemistry, University of Washington School of Medicine, Seattle, WA 98195-7705, USA
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Cooke MS, Herbert KE, Butler PC, Lunec J. Further evidence for a possible role of conformation in the immunogenicity and antigenicity of the oxidative DNA lesion, 8-oxo-2'deoxyguanosine. Free Radic Res 1998; 28:459-69. [PMID: 9702526 DOI: 10.3109/10715769809066883] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Damage to DNA by reactive oxygen species is acknowledged to be an important factor in a number of pathological conditions, including ageing and carcinogenesis. As a consequence, the development of methods for the sensitive detection and quantitation of oxidative DNA lesions has been of paramount importance. The oxidatively modified base product which has achieved most attention is 8-oxodeoxyguanosine (8-oxodG) and is a recognised marker of oxidative DNA damage. Although both polyclonal and monoclonal antibodies have previously been raised to 8-oxodG these have, for the most part failed to recognise this lesion within the DNA polymer. We have, through dilution cloning, produced a monoclonal antibody which appears to preferentially recognise 8-oxodG over deoxyguanosine (dG) in single-stranded oxidatively modified DNA. Such discrimination was not apparent when the DNA was double-stranded. Previous work has shown that 8-oxodG favours the syn glycosidic conformation due to steric repulsion, whereas dG assumes the anti. We present initial data that appear to support the postulate that it is these differences in conformation, in addition to structural recognition of the lesion itself, which are responsible for the discrimination, by our antibody of 8-oxodG over dG in single-stranded DNA.
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Affiliation(s)
- M S Cooke
- Division of Chemical Pathology, Centre for Mechanisms of Human Toxicity, University of Leicester, UK.
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