relation: http://d-scholarship-dev.library.pitt.edu/18778/ title: Oxidative lipidomics of hyperoxic acute lung injury: Mass spectrometric characterization of cardiolipin and phosphatidylserine peroxidation creator: Tyurina, YY creator: Tyurin, VA creator: Kaynar, M creator: Kapralova, VI creator: Wasserloos, K creator: Li, J creator: Mosher, M creator: Wright, L creator: Wipf, P creator: Watkins, S creator: Pitt, BR creator: Kagan, VE description: Reactive oxygen species have been shown to play a significant role in hyperoxia-induced acute lung injury, in part, by inducing apoptosis of pulmonary endothelium. However, the signaling roles of phospholipid oxidation products in pulmonary endothelial apoptosis have not been studied. Using an oxidative lipidomics approach, we identified individual molecular species of phospholipids involved in the apoptosis-associated peroxidation process in a hyperoxic lung. C57BL/6 mice were killed 72 h after exposure to hyperoxia (100% oxygen). We found that hyperoxia-induced apoptosis (documented by activation of caspase-3 and -7 and histochemical terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling staining of pulmonary endothelium) was accompanied by nonrandom oxidation of pulmonary lipids. Two anionic phospholipids, mitochondria-specific cardiolipin (CL) and extramitochondrial phosphatidylserine (PS), were the two major oxidized phospholipids in hyperoxic lung. Using electrospray ionization mass spectrometry, we identified several oxygenation products in CL and PS. Quantitative assessments revealed a significant decrease of CL and PS molecular species containing C18:2, C20:4, C22:5, and C22:6 fatty acids. Similarly, exposure of mouse pulmonary endothelial cells (MLEC) to hyperoxia (95% oxygen; 72 h) resulted in activation of caspase-3 and -7 and significantly decreased the content of CL molecular species containing C18:2 and C20:4 as well as PS molecular species containing C22:5 and C22:6. Oxygenated molecular species were found in the same two anionic phospholipids, CL and PS, in MLEC exposed to hyperoxia. Treatment of MLEC with a mitochondria-targeted radical scavenger, a conjugate of hemi-gramicidin S with nitroxide, XJB-5-131, resulted in significantly lower oxidation of both CL and PS and a decrease in hyperoxia-induced changes in caspase-3 and -7 activation. We speculate that cytochrome c driven oxidation of CL and PS is associated with the signaling role of these oxygenated species participating in the execution of apoptosis and clearance of pulmonary endothelial cells, thus contributing to hyperoxic lung injury. Copyright © 2010 the American Physiological Society. date: 2010-07-01 type: Article type: PeerReviewed format: text/plain language: en rights: attached identifier: http://d-scholarship-dev.library.pitt.edu/18778/1/licence.txt identifier: Tyurina, YY and Tyurin, VA and Kaynar, M and Kapralova, VI and Wasserloos, K and Li, J and Mosher, M and Wright, L and Wipf, P and Watkins, S and Pitt, BR and Kagan, VE (2010) Oxidative lipidomics of hyperoxic acute lung injury: Mass spectrometric characterization of cardiolipin and phosphatidylserine peroxidation. American Journal of Physiology - Lung Cellular and Molecular Physiology, 299 (1). ISSN 1040-0605 relation: 10.1152/ajplung.00035.2010