Analysis of intracellular lipid hydroperoxide-mediated oxidative stress by stable isotope dilution LC-MS

摘要

Oxidative stress represents one of the major cellular responses toxic insults and environmental agents such as viruses and mycotoxins. During oxidative stress there is a decrease in the amount of intracellular glutathione (GSH), increases in GSSG with a concomitant increase in reactive oxygen species (ROS) as well as increased activity of cyclooxygenase -2 and lipoxygenases (LOXs) involved in lipid peroxidation. This can overwhelm protective mechanisms and increase ROS-mediated modifications to GSH, proteins, DNA, and lipids. The resulting lipid hydroperoxides undergo further biotransformations or homolytic decomposition to bifunctional electrophiles such as 4-oxo-2(E)-nonenal (ONE) that also covalently modify GSH, DNA, and proteins. Two macrophage/monocyte cell lines were used to explore how endogenous lipid peroxidation effects cellular redox status and protective detoxification pathways.