Cellular redox signalling is mediated by the post-translational modification of proteins by reactive oxygen/nitrogen species or the products derived from their reactions. In the case of oxidized lipids, several receptor-dependent and -independent mechanisms are now emerging. At low concentrations, adaptation to oxidative stress in the vasculature appears to be mediated by induction of antioxidant defences, including the synthesis of the intracellular antioxidant glutathione. At high concentrations apoptosis occurs through mechanisms that have yet to be defined in detail. Recent studies have revealed a mechanism through which electrophilic lipids, formed as the reaction products of oxidation, orchestrate these adaptive responses in the vasculature. Using a proteomics approach, we have identified a subset of proteins in cells that we term the electrophile-responsive proteome. Electrophilic modification of thiol groups in these proteins can initiate cell signalling events through the transcriptional activation of genes regulated by consensus sequences for the antioxidant response element found in their promoter regions. The insights gained from our understanding of the biology of these mechanisms will be discussed in the context of cardiovascular disease.
- redox signalling
- thiol group
44th International Conference on the Bioscience of Lipids, a meeting held at Keble College, Oxford, 7–11 September 2003
Abbreviations used: ROS, reactive oxygen species, RNS, reactive nitrogen species; LDL, low-density lipoprotein; oxLDL, oxidized low-density lipoprotein; PUFA, polyunsaturated fatty acid; PG, prostaglandin; 15d-PGJ2, 15-deoxy- δ12,14-PGJ2; HNE, 4-hydroxynonenal; NOS, nitric oxide synthase; GCL, glutamate–cysteine ligase; ARE, antioxidant response element; Nrf2, nuclear factor-erythroid-2-related factor; Keap-1, Kelch-like erythroid-cell-derived protein with CNC homology (ECH)-associated protein-1.
- © 2004 Biochemical Society