Lipoxidation products as biomarkers of oxidative damage to proteins during lipid peroxidation reactions

Abstract

Oxidative stress is implicated in the pathogenesis of numerous disease processes including diabetes mellitus, atherosclerosis, ischaemia reperfusion injury and rheumatoid arthritis. Chemical modification of amino acids in protein during lipid peroxidation results in the formation of lipoxidation products which may serve as indicators of oxidative stress in vivo. The focus of the studies described here was initially to identify chemical modifications of protein derived exclusively from lipids in order to assess the role of lipid peroxidative damage in the pathogenesis of disease. Malondialdehye (MDA) and 4-hydroxynonenal (HNE) are well characterized oxidation products of polyunsaturated fatty acids on low-density lipoprotein (LDL) and adducts of these compounds have been detected by immunological means in atherosclerotic plaque. Thus, we first developed gas chromatography-mass spectrometry assays for the Schiff base adduct of MDA to lysine, the lysine-MDA-lysine diimine cross-link and the Michael addition product of HNE to lysine. Using these assays, we showed that the concentrations of all three compounds increased significantly in LDL during metal-catalysed oxidation in vitro. The concentration of the advanced glycation end-product N epsilon-(carboxymethyl)lysine (CML) also increased during LDL oxidation, while that of its putative carbohydrate precursor the Amadori compound N epsilon-(1-deoxyfructose-1-yl)lysine did not change, demonstrating that CML is a marker of both glycoxidation and lipoxidation reactions. These results suggest that MDA and HNE adducts to lysine residues should serve as biomarkers of lipid modification resulting from lipid peroxidation reactions, while CML may serve as a biomarker of general oxidative stress resulting from both carbohydrate and lipid oxidation reactions.

Advanced glycation end-products: a review

“…Metal catalysed oxidation of polyunsaturated fatty acids in the presence of proteins can also lead to CML formation suggesting that lipid oxidation has a role in AGE formation [46,47]. Therefore, CML could serve as a general bio-marker of oxidative stress resulting from carbohydrate and lipid oxidation reactions [48].…”

Modern Pharmacological Approaches to Therapies: Substances Tested in Animal Models of Rheumatoid Arthritis

“…In recent years, methods based on chemiluminescence and fluorescence measurements have been widely used for determination of ROS, RNS and lipid peroxidation metabolites. Fluorescent protein adducts are derivatives formed by reaction of secondary metabolites of lipid peroxidation (especially HNE and MDA) with free amino groups of proteins (Aldini et al, 2007;Requena et al, 1996). In murine and human serum, albumin protein fraction was identified as the most fluorescent fraction of proteins (Tsuchida et al, 1985).…”

Application of the accurate mass and time tag approach in studies of the human blood lipidome

“…Alternatively, isoprostanes are nonenzymatic oxidation products of arachidonic acid that have been traditionally used as indicators of oxidative stress [14] but are now being shown to have a number of biological activities [15]. Finally, reactive products of lipid peroxidation are known to accumulate on tissue proteins and negatively impact their structures and functions [16,17].…”