OP44 - Systems biology of oxidative stress: first insights in lipid oxidation and protein modification cross-talks

Abstract

Recent research indicates that oxidative stress (OS) affects all levels of cellular organization and induce perturbation in gene expression, epigenetic regulation, mRNA and protein levels, and cellular metabolism. Oxidative modifications of proteins and lipids represent another level of complexity in cellular regulation supported by numerous studies demonstrating how these modifications regulate gene expression and cellular signaling pathways. However, it is almost impossible to specify the input and (patho)physiological consequences of OS using data from a single modification level. Nowadays, it is clear that only a holistic approach, as suggested by systems biology, will provide an integrated view on OS-related cellular regulation and pathologies by considering all known OS determinants, identifying new ones, and establishing functional links among them. As a first effort to study OS via redox systems biology, we applied a multi-omics approach to characterize the impact of OS on cardiomyocytes (CM) using a dynamic model of nitrosative stress. Reactive carbonylated lipids, hydroxylated and truncated phospholipids, nitrated fatty acids, and oxysterols were quantified relative to a control in CM lipid extracts after 15, 30, 70 min, and 16 h of OS. Simultaneously, the protein fraction was analyzed for a wide range of post-translational modifications, such as phosphorylation, carbonylation, cysteine oxidation, and nitrosylation. Omics data were combined and supported by biochemical and microscopy studies on oxidation dynamics, spatial distribution, and functional effects. Thus, the combination of lipidomics, data-driven proteomics, and systems biology integration allowed the identification of more than 200 proteins modified by reactive lipid peroxidation products of which many were involved in calcium signaling pathways, regulation of actin cytoskeleton, focal adhesion, and phosphatidylinositol signaling system. Biochemical and microscopy studies further confirmed OS-derived impairment of Ca-signaling and cytoskeletal protein distribution.