Detection of Lipid Peroxidation-Induced DNA Adducts Caused by 4-Oxo-2(E)-nonenal and 4-Oxo-2(E)-hexenal in Human Autopsy Tissues

Abstract

DNA adducts are produced both exogenously and endogenously via exposure to various DNA-damaging agents. Two lipid peroxidation (LPO) products, 4-oxo-2(E)-nonenal (4-ONE) and 4-oxo-2(E)-hexenal (4-OHE), induce substituted etheno-DNA adducts in cells and chemically treated animals, but the adduct levels in humans have never been reported. It is important to investigate the occurrence of 4-ONE- and 4-OHE-derived DNA adducts in humans to further understand their potential impact on human health. In this study, we conducted DNA adductome analysis of several human specimens of pulmonary DNA as well as various LPO-induced DNA adducts in 68 human autopsy tissues, including colon, heart, kidney, liver, lung, pancreas, small intestine, and spleen, by liquid chromatography tandem mass spectrometry. In the adductome analysis, DNA adducts derived from 4-ONE and 4-OHE, namely, heptanone-etheno-2'-deoxycytidine (HεdC), heptanone-etheno-2'-deoxyadenosine (HεdA), and butanone-etheno-2'-deoxycytidine (BεdC), were identified as major adducts in one human pulmonary DNA. Quantitative analysis revealed 4-ONE-derived HεdC, HεdA, and heptanone-etheno-2'-deoxyguanosine (HεdG) to be ubiquitous in various human tissues at median values of 10, 15, and 8.6 adducts per 10(8) bases, respectively. More importantly, an extremely high level (more than 100 per 10(8) bases) of these DNA adducts was observed in several cases. The level of 4-OHE-derived BεdC was highly correlated with that of HεdC (R(2) = 0.94), although BεdC was present at about a 7-fold lower concentration than HεdC. These results suggest that 4-ONE- and 4-OHE-derived DNA adducts are likely to be significant DNA adducts in human tissues, with potential for deleterious effects on human health.

Cyclooxygenase- and lipoxygenase-mediated DNA damage

“…One recent study looked at several human tissues by LC-MS/MS for Hε-DNA-adducts. Such adducts were found among several tissue types, including colon, heart, kidney, lung, pancreas, and small intestine [109]. The authors of this study also examined the levels of 8-oxo-dGuo, the most commonly found adduct, and found that there was no correlation to the levels of 8-oxo-dGuo compared to HεdCyd [109].…”

Data-Independent Mass Spectrometry Approach for Screening and Identification of DNA Adducts

“…This “pseudo-CNL” methodology was used to characterize lipid peroxidation DNA adducts in human tissues. 27–29 Numerous signals were detected; however, it is not known whether these analytes are DNA adducts or simply other compounds in the DNA digest matrix that lose 116 Da upon CID. The Turesky laboratory laid the groundwork for the linear ion trap (LIT)-MS based adductomics method.…”

DNA Damage in Rheumatoid Arthritis: An Age-Dependent Increase in the Lipid Peroxidation-Derived DNA Adduct, Heptanone-Etheno-2′-Deoxycytidine

“…The importance of lipid peroxidation-derived DNA damage in inflammatory diseases has been implied [20], and, in fact, levels of lipid peroxidation and oxidised low-density lipoprotein are highly expressed in RA patients, while a positive association between RA disease activity and lipid peroxidation has been reported [10, 15, 21]. Polyunsaturated fatty acids (PUFAs) exerting oxidative stress have been found to cause a series of α , β -unsaturated aldehydes such as acrolein, crotonaldehyde, and malondialdehyde to form lipid peroxyl radicals, which are highly DNA- and protein-reactive [7, 10, 14, 22, 23]. H ε dC has an exocyclic ring and a bulky side chain formed by deoxycytidine reacting with 4-ONE and may lead to alterations in mitochondrial function [7, 14, 22–25].…”

“…DNA damage induced by exposure to ionizing radiation, ultraviolet light, and exogenous or endogenous chemical mutagens causes DNA strand breakages, which are thought to be mutagenic, carcinogenic, and aging factors [2]. Additionally as new DNA damage, lipid peroxidation-derived DNA adducts have been recently reported in human [7], and lipid peroxidation has been also considered as a factor of the pathogenesis or the local inflammatory response of RA [4, 8–10]. Representative DNA adducts are 8-oxo-dG, 1,N 6 -etheno-2′-deoxyadenosine ( ε dA), and heptanone-etheno-2′-deoxycytidine (H ε dC); the latter two of which are direct reactive oxygen species- (ROS-) derived and lipid peroxidation-derived adducts.…”

“…Representative DNA adducts are 8-oxo-dG, 1,N 6 -etheno-2′-deoxyadenosine ( ε dA), and heptanone-etheno-2′-deoxycytidine (H ε dC); the latter two of which are direct reactive oxygen species- (ROS-) derived and lipid peroxidation-derived adducts. H ε dC is also deemed a 4-oxo-2( E- ) nonenal (4-ONE-) generated product [7]. …”