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DNA strand breaks and base modifications induced by cholesterol hydroperoxides
Graziella E Ronsein1, Mauricio Cesar Bof de Oliveira, Marisa H G Medeiros
1Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo-SP, Brazil. ronsein@iq.usp.br
Free Radical Research
|October 15, 2010
Summary
Cholesterol hydroperoxides (ChOOH) cause DNA damage, including strand breaks and base modifications, particularly in the presence of copper ions. This finding highlights the role of lipid peroxidation in DNA damage and potential mutations.
Area of Science:
- Biochemistry
- Molecular Biology
- Oxidative Stress Research
Background:
- Cholesterol (Ch) oxidation generates hydroperoxides (ChOOH) that can spread oxidative stress.
- Lipid peroxidation is implicated in cellular damage and disease processes.
Purpose of the Study:
- To investigate the DNA-damaging potential of cholesterol hydroperoxides (ChOOH).
- To evaluate ChOOH-induced DNA strand breaks and base modifications in a plasmid DNA model.
- To analyze the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) resulting from ChOOH exposure.
Main Methods:
- Plasmid DNA incubation with ChOOH and copper ions (Cu2+).
- Assessment of DNA strand breaks and base modifications using DNA repair enzymes (Fpg and Endo III).
- High-performance liquid chromatography coupled with tandem mass spectrometry (HPLC/MS/MS) for 8-oxodGuo detection.
Main Results:
- ChOOH induced DNA strand breaks in a time- and concentration-dependent manner in the presence of Cu2+.
- Purine and pyrimidine base modifications in DNA were observed after ChOOH treatment.
- HPLC/MS/MS confirmed the oxidation of 2'-deoxyguanosine (dGuo) to 8-oxodGuo, indicating DNA oxidation.
Conclusions:
- Cholesterol hydroperoxides are capable of inducing significant DNA damage.
- The findings support the contribution of lipid peroxidation to DNA modifications and mutations.
- This study elucidates a mechanism linking cholesterol oxidation to genotoxicity.
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