Formation of Deoxyguanosine Cross-Links from Calf Thymus DNA Treated with Acrolein and 4-Hydroxy-2-nonenal

• Published in: Chemical research in toxicology Vol. 23; no. 11; pp. 1701 - 1713
• Main Authors: Kozekov, Ivan D, Turesky, Robert J, Alas, Guillermo R, Harris, Constance M, Harris, Thomas M, Rizzo, Carmelo J
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 15.11.2010
• Subjects: Acrolein - chemistry; Acrolein - toxicity; Aldehydes - chemistry; Aldehydes - toxicity; Animals; Cattle; Chromatography, High Pressure Liquid; Deoxyguanosine - chemistry; DNA - chemistry; DNA Adducts - chemistry; DNA Adducts - isolation & purification; Solid Phase Extraction; Spectrometry, Mass, Electrospray Ionization; Time Factors
• ISSN: 0893-228X; 1520-5010
• DOI: 10.1021/tx100179g

Acrolein (AC) and 4-hydroxy-2-nonenal (HNE) are endogenous bis-electrophiles that arise from the oxidation of polyunsaturated fatty acids. AC is also found in high concentrations in cigarette smoke and automobile exhaust. These reactive α,β-unsaturated aldehyde (enal) covalently modify nucleic acids, to form exocyclic adducts, where the three-carbon hydroxypropano unit bridges the N1 and N 2 positions of deoxyguanosine (dG). The bifunctional nature of these enals allows them to undergo reaction with a second nucleophilic group and form DNA cross-links. These cross-linked enal adducts are likely to contribute to the genotoxic effects of both AC and HNE. We have developed a sensitive mass spectrometric method to detect cross-linked adducts of these enals in calf thymus DNA (CT DNA) treated with AC or HNE. The AC and HNE cross-linked adducts were measured by the stable isotope dilution method, employing a linear quadrupole ion trap mass spectrometer and consecutive reaction monitoring at the MS3 or MS4 scan stage. The lower limit of quantification of the cross-linked adducts is ∼1 adduct per 108 DNA bases, when 50 μg of DNA is assayed. The cross-linked adducts occur at levels that are ∼1−2% of the levels of the monomeric 1,N 2-dG adducts in CT DNA treated with either enal.