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

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• 作者：Ivan D. Kozekov ; Robert J. Turesky ; Guillermo R. Alas ; Constance M. Harris ; Thomas M. Harris ; Carmelo J. Rizzo
• 刊名：Chemical Research in Toxicology
• 出版年：2010
• 出版时间：November 15, 2010
• 年：2010
• 卷：23
• 期：11
• 页码：1701-1713
• 全文大小：549K
• 年卷期：v.23,no.11(November 15, 2010)
• ISSN：1520-5010

文摘

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 N² 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,N²-dG adducts in CT DNA treated with either enal.