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Printable Handouts
Navigable Slide Index
- Introduction
- Oxidatively generated damage to DNA
- Reactive oxygen and nitrogen species: reactivity
- Oxidatively generated damage to DNA
- Oxidatively damaged nucleic acids: general objectives
- Oxidatively generated damage to DNA: outlines
- Oxidatively generated base damage: current situation
- Oxidative chemistry of guanine
- Formation of singlet oxygen
- 1O2 oxidation reactions of guanine
- Chemical reactions of 1O2 with isolated DNA
- 1O2 oxidation of cellular DNA damage
- OH radical reactions of the guanine moiety
- Guanine radical cations: reactions
- Nucleophilic reactions _x000B_of the guanine radical cation
- Formation of a guanine-lysine cross-link: one-electron oxidation reaction
- Guanine radical cation: other nucleophilic reactions
- Guanine radical cations: reactions
- Reactions of oxidizing G(-H)• guanine radical
- Measurement of oxidized DNA bases: aims
- Oxidized base damage in cellular DNA: current situation
- Measurement of oxidized DNA bases: approaches
- Measurement of oxidized DNA bases: assays involving separation of the targeted lesion
- Measurement of oxidized DNA bases: drawbacks in chromatographic methods
- Measurement of oxidized DNA bases: requirements for chromatographic methods
- Measurement of oxidized DNA bases: selected recent aspects
- HPLC-MS/MS measurements of oxidized bases and nucleosides
- HPLC-MS/MS analysis in the MRM mode
- HPLC-MS/MS of oxidized nucleosides: separation - detection – quantification
- Measurement of oxidized DNA bases: selected recent aspects
- g-ray induced DNA damage in human monocytes-lesions /109 DNA bases/ Gy
- Hydroxyl radical-mediated thymine damage in cellular DNA
- Enzymatic and radical oxidation of 5-methylcytosine
- Conclusions and perspectives
- Formation of clustered damage in cells: radical oxidation at C4
- Formation of clustered DNA damage (1)
- Formation of clustered DNA damage (2)
- Measurement of oxidized DNA bases: selected recent aspects
- Oxidative reactions to cellular DNA by UV radiation
- Oxidative reactions mediated by UVA radiation
- UVA-induced oxidation reactions to DNA: early observations
- UVA-induced DNA damage in human cells
- UVA-induced base damage in human skin
- Measurement of oxidized DNA bases: selected recent aspects
- Measurement of low levels of oxidized bases in cellular DNA
- The comet assay
- Comet assay-modified methods aimed at detecting base damage
- Comet assay associated with DNA glycosylases (Fpg)
- Comet assay measurements of damage in g-irradiated THP1 monocytes
- Improved modified comet assay
- DNA damage classes in g–irradiated THP-1 cells
- Oxidatively damaged cellular DNA: ESCODD
- Concluding remarks & perspectives
- Acknowledgments (1)
- Acknowledgments (2)
Topics Covered
- Oxidative stress and cellular oxidants
- Nucleobase degradation pathways induced by hydroxyl radical, singlet oxygen and one-electron oxidants
- Oxidatively generated damage to cellular DNA: single and tandem lesions
- Epigenetic marks: enzymatic oxidation of 5-methycytosine
- Measurement of oxidized bases: chromatographic and enzymatic assays
- Base oxidation products formed in cellular DNA upon exposure to ionizing radiations and UVA component of solar light
Talk Citation
Cadet, J. (2020, February 27). Oxidatively generated damage to DNA: mechanistic aspects and formation in cells [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved December 27, 2024, from https://doi.org/10.69645/GMDB6163.Export Citation (RIS)
Publication History
Financial Disclosures
- Professor Cadet has no commercial/financial matters to disclose.
A selection of talks on Biochemistry
Transcript
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0:00
The presentation is entitled "Oxidatively Generated
Damage to DNA: Mechanistic Aspects and Formation in Cells".
The survey provides up to date insight into
major oxidative degradation pathways of nucleobases in both isolated and cellular DNA.
0:23
Let me start with a few general considerations on the generation of
oxidative processes and their chemical and biochemical implications.
Superoxide radical is usually produced endogenously
through the respiration burst and the metabolism of xenobiotics.
These poorly reactive species can be converted into
hydrogen peroxide either by spontaneous or enzymatic dismutation.
Hydrogen peroxide can migrate within the cells,
since also it is not very reactive,
and in the presence of metal transition,
it can be converted into the highly reactive hydroxyl radical.
Hydroxyl radical can be produced as
an indirect effect of hydrogen radiation, for example.
Hydrogen radiation also can ionize, substrates as well as type one photosensitizer.
Photosensitization for type two mechanism can lead to the generation of a singlet oxygen.
All these reactive species and processes can damage DNA,
leading to the formation of different classes of lesions such as modified bases,
a basic site, single and double strand breaks,
DNA-protein cross-link, and also aldehyde adducts to aminobase.
As immediate or delayed consequences,
this modification can lead to lethality,
mutagenesis, carcinogenesis, and also aging.
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