scholarly journals Crosslinking of DNA and proteins induced by protein hydroperoxides

1999 ◽  
Vol 338 (3) ◽  
pp. 629-636 ◽  
Author(s):  
Silvia GEBICKI ◽  
Janusz M. GEBICKI
Keyword(s):  
Free Radicals ◽  
Oxygen Species ◽  
Metal Chelators ◽  
Strand Breaks ◽  
Biological Damage ◽  
Vigorous Agitation ◽  
Ionic Detergents ◽  
Living Organisms ◽  
Dna Strand ◽  
Hydroxyl Free Radicals

Exposure of DNA to several proteins peroxidized by radiation-generated hydroxyl free radicals resulted in formation of crosslinks between the macromolecules, detected by retardation and broadening of DNA bands in agarose gels. This technique proved suitable for the study of crosslinking of DNA with peroxidized BSA, insulin, apotransferrin and α casein, but not with several other proteins, including histones. The crosslinking depended on the presence of intact hydroperoxide groups on the protein, on their number, and on the duration of the interaction with DNA. All DNA samples tested, pBR322, pGEM, λ/HindIII and pUC18, formed crosslinks with the peroxidized BSA. Sodium chloride and formate prevented the crosslinking if present during incubation of the peroxidized protein and DNA, but had no effect once the crosslinks had formed. The gel shift of the crosslinked DNA was reversed by proteolysis, indicating that the DNA mobility change was due to attachment of protein and that the crosslinking did not induce DNA strand breaks. The metal chelators Desferal and neocuproine reduced the extent of the crosslinking, but did not prevent it. Scavengers of free radicals did not inhibit the crosslink formation. The DNA–protein complex was not disrupted by vigorous agitation, by filtration or by non-ionic detergents. These observations show that the crosslinking of DNA with proteins mediated by protein hydroperoxides is spontaneous and probably covalent, and that it may be assisted by transition metals. It is suggested that formation of such crosslinks in living organisms could account for some of the well-documented forms of biological damage induced by reactive oxygen species-induced oxidative stress.

scholarly journals The Radioprotective Effect of Procaine and Procaine-Derived Product Gerovital H3 in Lymphocytes from Young and Aged Individuals

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Anca Ungurianu ◽  
Denisa Margina ◽  
Claudia Borsa ◽  
Cristina Ionescu ◽  
Gudrun von Scheven ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Chemical Compounds ◽  
Dna Strand Breaks ◽  
Peripheral Blood Mononuclear ◽  
Strand Breaks ◽  
Young Subjects ◽  
Living Organisms ◽  
Dna Strand

Ionizing radiation induces genomic instability in living organisms, and several studies reported an ageing-dependent radiosensitivity. Chemical compounds, such as scavengers, radioprotectors, and modifiers, contribute to reducing the radiation-associated toxicity. These compounds are often antioxidants, and therefore, in order to be effective, they must be present before or during exposure to radiation. However, not all antioxidants provide radioprotection. In this study, we investigated the effects of procaine and of a procaine-based product Gerovital H3 (GH3) on the formation of endogenous and X-ray-induced DNA strand breaks in peripheral blood mononuclear cells (PBMCs) isolated from young and elderly individuals. Interestingly, GH3 showed the strongest radioprotective effects in PBMCs from young subjects, while procaine reduced the endogenous amount of DNA strand breaks more pronounced in aged individuals. Both procaine and GH3 inhibited lipid peroxidation, but procaine was more effective in inhibiting mitochondria free radicals’ generation, while GH3 showed a higher antioxidant action on macrophage-induced low-density lipoprotein oxidation. Our findings provide new insights into the mechanisms underlying the distinct effects of procaine and GH3 on DNA damage.

Stimulation of poly(ADP-ribose) synthesis by free radicals in C3H10T1/2 cells: relationship with NAD metabolism and DNA breakage

1990 ◽  
Vol 68 (3) ◽  
pp. 602-608 ◽  
Author(s):  
Dominique Lautier ◽  
Danièle Poirier ◽  
Annie Boudreau ◽  
Moulay A. Alaoui Jamali ◽  
André Castonguay ◽  
...  
Keyword(s):  
Free Radicals ◽  
Active Oxygen Species ◽  
Accurate Determination ◽  
Active Oxygen ◽  
Single Strand ◽  
Oxygen Species ◽  
Strand Breaks ◽  
Dna Breakage ◽  
Single Strand Breaks ◽  
Stimulation Of

We have studied the effect of H2O2 and O2− produced by xanthine and xanthine oxidase on NAD catabolism, poly(ADP-ribose) synthesis, and production of DNA single-strand breaks in C3H10T1/2 cells. The results show a correlation between the induction of DNA single-strand breaks, the decrease of NAD pool, and the accumulation of polymer. New techniques, based on affinity chromatography and reversed-phase high pressure liquid chromatography, have allowed an accurate determination of polymer contents and showed a 20-fold stimulation of polymer biosynthesis induced by active oxygen species. Inhibition experiments performed with 3-aminobenzamide have shown that the decrease in NAD levels after exposure of cells to active oxygen species was caused by stimulation of poly(ADP-ribosyl)ation and of another cellular process.Key words: poly(ADP-ribose), free radicals, C3H10T1/2 cells, DNA breakage, NAD catabolism.

Oxygen free radicals and disorders of pregnancy

2001 ◽  
Vol 12 (4) ◽  
pp. 273-298 ◽  
Author(s):  
Irina A Buhimschi ◽  
Carl P Weiner
Keyword(s):  
Reactive Oxygen Species ◽  
Free Radicals ◽  
Free Radical ◽  
Oxygen Radicals ◽  
Oxygen Free Radicals ◽  
Energy State ◽  
Oxygen Species ◽  
Chemical Bonds ◽  
Physiological Processes ◽  
Living Organisms

Oxygen radicals and reactive oxygen species are normal attributes of aerobic life. In most molecules, the electrons are paired and, with the exception of hydrogen, the four outer most pairs of each atom form chemical bonds. Electrons are in a relatively stable energy state when paired. A free radical is a molecule with an unpaired electron. Free radicals of oxygen are of particular importance to living organisms in which they are involved in the genesis of a wide array of diseases and physiological processes (e.g. life span and ageing).

scholarly journals Assessment of genotoxicity and depuration of anthracene in the juvenile coastal fish Trachinotus carolinus using the comet assay

2013 ◽  
Vol 61 (4) ◽  
pp. 215-222 ◽  
Author(s):  
Fabio Matsu Hasue ◽  
Maria José de Arruda Campos Rocha Passos ◽  
Thaís da Cruz Alves dos Santos ◽  
Arthur José da Silva Rocha ◽  
Caroline Patrício Vignardi ◽  
...  
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Aquatic Organisms ◽  
Dna Strand Breaks ◽  
Time Dependent ◽  
Clean Water ◽  
Oxygen Species ◽  
Coastal Fish ◽  
Strand Breaks ◽  
Dna Strand

In the environment, anthracene is characterized as being persistent, bioaccumulative and toxic to aquatic organisms. Biotransformation of xenobiotic substances, such as anthracene, produces reactive oxygen species that may induce DNA strand breaks. The aim of the present study was to evaluate the DNA damage in juvenile T. carolinus exposed to different concentrations (8, 16 and 32 µg.L-1) of anthracene for 24 h in the dark then subsequently allowed to depurate in clean water for different periods of time (48, 96 or 144 h) using the comet assay. Our results show that anthracene is genotoxic to T. carolinus and that DNA damage was dose- and depuration/time- dependent. Anthracenegenotoxicity was observed in all experimental concentrations. Depuration seemed to be more efficient in fish exposed to thelowest anthracene concentration and maintained in clean water for 96 h.

scholarly journals Lipocalin produced by myelofibrosis cells affects the fate of both hematopoietic and marrow microenvironmental cells

Blood ◽  
2015 ◽  
Vol 126 (8) ◽  
pp. 972-982 ◽  
Author(s):  
Min Lu ◽  
Lijuan Xia ◽  
Yen-Chun Liu ◽  
Tsivia Hochman ◽  
Laetizia Bizzari ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Dna Strand Breaks ◽  
Oxygen Species ◽  
Strand Breaks ◽  
Cd34 Cells ◽  
Key Points ◽  
Dna Strand

Key Points LCN2 acts to generate reactive oxygen species, leading to increased DNA strand breaks and apoptosis in normal CD34+ cells. LCN2 promotes the generation of osteoblasts but diminishes adipogenesis, resembling the composition of the MF marrow microenvironment.

Asbestos causes DNA strand breaks in cultured pulmonary epithelial cells: role of iron-catalyzed free radicals

1995 ◽  
Vol 268 (3) ◽  
pp. L471-L480 ◽  
Author(s):  
D. W. Kamp ◽  
V. A. Israbian ◽  
S. E. Preusen ◽  
C. X. Zhang ◽  
S. A. Weitzman
Keyword(s):  
Dna Damage ◽  
Free Radicals ◽  
Free Radical ◽  
Phytic Acid ◽  
Dna Strand Breaks ◽  
Alveolar Type ◽  
Strand Breaks ◽  
Mineral Dusts ◽  
Dna Strand ◽  
Dose Dependent

Asbestos causes pulmonary fibrosis and various malignancies by mechanisms that remain uncertain. Reactive oxygen species in part cause asbestos toxicity. However, it is not known whether asbestos-induced free radical production causes alveolar epithelial cell (AEC) cytotoxicity by inducing DNA strand breaks (DNA-SB). We tested the hypothesis that asbestos-induced AEC injury in vitro is due to iron-catalyzed free radical generation, which in turn causes DNA-SB. We found that amosite asbestos damages cultured human pulmonary epithelial-like cells (WI-26 cells) as assessed by 51Cr release and that an iron chelator, phytic acid (500 microM), attenuates these effects. A role for iron causing these effects was supported by the observation that ferric chloride-treated phytic acid did not diminish WI-26 cell injury. Production of hydroxyl radical-like species (.OH) was assessed based upon the .OH-dependent formation of formaldehyde (HCHO) in the presence of dimethyl sulfoxide. A variety of mineral dusts induced significant levels of .OH formation (nmol HCHO at 30 min: carbonyl iron, 85 +/- 21; amosite asbestos, 14 +/- 2; chrysotile asbestos, 7 +/- 1; titanium dioxide, 2.5 +/- 0.5). Phytic acid significantly diminished the asbestos-induced .OH production. DNA damage to AEC was assessed by the alkaline unwinding, ethidium bromide fluorometric technique. Hydrogen peroxide caused dose-dependent DNA-SB in WI-26 cells after a 30-min exposure period [50% effective dose (ED50): 5 microM] that was similar to other cell lines. Amosite asbestos induced dose-dependent DNA-SB in WI-26, A549, and primary isolated rat alveolar type II cells maintained in culture for 7-10 days (alveolar type I-like). Lower doses of amosite (0.5-5 micrograms/ml or 0.25-2.5 micrograms/cm2) caused significant WI-26 cell DNA-SB after prolonged exposure periods (> or = 2 days). Phytic acid ameliorated DNA damage in all three cultured AEC. There was a direct correlation between mineral dust-induced .OH production at 30 min and DNA-SB in WI-26 cells at 4 h (P < 0.0005). These data suggest that mineral dusts can be directly genotoxic to relevant target cells of asbestos, AEC. Furthermore, these results provide additional support for the premise that iron-catalyzed free radicals mediate asbestos-induced pulmonary toxicity.

scholarly journals 3′-Phosphodiesterase and 3′→5′ Exonuclease Activities of Yeast Apn2 Protein and Requirement of These Activities for Repair of Oxidative DNA Damage

2001 ◽  
Vol 21 (5) ◽  
pp. 1656-1661 ◽  
Author(s):  
Ildiko Unk ◽  
Lajos Haracska ◽  
Satya Prakash ◽  
Louise Prakash
Keyword(s):  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Dna Polymerases ◽  
Oxygen Species ◽  
Genetic Studies ◽  
Strand Breaks ◽  
Abasic Sites ◽  
Dna Damaging Agents ◽  
End Groups ◽  
Dna Strand

ABSTRACT In Saccharomyces cerevisiae, the AP endonucleases encoded by the APN1 and APN2 genes provide alternate pathways for the removal of abasic sites. Oxidative DNA-damaging agents, such as H2O2, produce DNA strand breaks which contain 3′-phosphate or 3′-phosphoglycolate termini. Such 3′ termini are inhibitory to synthesis by DNA polymerases. Here, we show that purified yeast Apn2 protein contains 3′-phosphodiesterase and 3′→5′ exonuclease activities, and mutation of the active-site residue Glu59 to Ala in Apn2 inactivates both these activities. Consistent with these biochemical observations, genetic studies indicate the involvement of APN2 in the repair of H2O2-induced DNA damage in a pathway alternate to APN1, and the Ala59 mutation inactivates this function of Apn2. From these results, we conclude that the ability of Apn2 to remove 3′-end groups from DNA is paramount for the repair of strand breaks arising from the reaction of DNA with reactive oxygen species.

scholarly journals Dissociations of free radicals to generate protons, electrophiles or nucleophiles: role in DNA strand breaks

2021 ◽  
Author(s):  
John C. Walton
Keyword(s):  
Free Radicals ◽  
Dna Strand Breaks ◽  
Strand Breaks ◽  
Radical Generation ◽  
Dna Strand

The concept behind the research described in this article was that of marrying the ‘soft’ methods of radical generation with the effectiveness and flexibility of nucleophile/electrophile synthetic procedures.

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