INIFTA   05425
INSTITUTO DE INVESTIGACIONES FISICO-QUIMICAS TEORICAS Y APLICADAS
Unidad Ejecutora - UE
capítulos de libros
Título:
Lipid peroxidation
Autor/es:
ANGEL CATALA
Libro:
Principles of Free Radical Biomedicine
Editorial:
Nova Science Publishers
Referencias:
Lugar: Hauppauge, New York 11787-3619, USA; Año: 2011; p. 1 - 12
Resumen:
The onset of lipid peroxidation within cellular membranes is associated with changes in their physicochemical properties and with the impairment of protein functions located in the membrane environment. Polyunsaturated fatty acids (PUFAs) and their metabolites have a diversity of physiological roles including: energy provision, membrane structure, cell signaling and regulation of gene expression. Lipids containing polyunsaturated fatty acids are prone to free radical–initiated oxidation and can contribute in chain reactions that increase injure to biomolecules. Lipid peroxidation, which leads to lipid hydroperoxide generation often, occurs in response to oxidative stress. Hydroperoxides are generally reduced to their subsequent alcohols by glutathione peroxidases. Nevertheless, these enzymes are diminished in certain diseases resulting in a transitory augment of lipid hydroperoxides that favors their degradation into several compounds, including hydroxy-alkenals. The best known of these are: 4-hydroxy-2-nonenal (4-HNE) and 4-hydroxy-2-hexenal (4-HHE), which originate from lipid peroxidation of n-6 and n-3 fatty acids, respectively. Compared to free radicals, these aldehydes are moderately stable and can spread within or even escape from the cell and attack targets distant from the site of the original event. These aldehydes display great reactivity with biomolecules, such as proteins, DNA, and phospholipids, generating a diversity of intra- and intermolecular covalent adducts. At the membrane level, proteins and amino lipids can be covalently modified by hydoxy-alkenals, damaging membrane structure. In addition these aldehydes can act as bioactive molecules in physiological and/or pathological events. Besides this chapter  intended to provide an appropriate outline of recognized effects of hydroxy-alkenals and oxidized phospholipids on cell signaling, from their intracellular production, to their action as intracellular messenger, up to their influence on transcription factors and gene expression.