Maldi mass spectrometric imaging of cardiolipin and its oxidation products directly from tissue sections in a lung oxidative damage model.
Sparvero-LJ; Amoscato-A; Pitt-B; Kagan-V
Toxicologist 2012 Mar; 126(Suppl 1):254
Molecular understanding of lipid functions and signaling mechanisms has created the need for tissue selective assessment for localization of phospholipids and their oxidation products while maintaining tissue integrity. Cardiolipin (CL) is a mitochondria-specific anionic phospholipid that plays key roles in normal mitochondrial functions but also in cell death pathways. The molecular diversity of endogenous CL in some tissues and the low abundance of its individual species, particularly oxidized derivatives, makes in situ analysis challenging. Current Mass Spectrometry protocols using lung homogenates (LC-MS) have greatly enhanced our ability to explore molecular species of CL and its oxidized products. However location-specific information on oxidation cannot be determined from homogenates. Assuming that oxidative lipidomics analysis of acute lung injury will directly benefit from MALDI-MS imaging, we assessed possible advantages of this frontier technology in characterization of structural lipid changes in the lung. MALDI-MS imaging was performed on thin lung sections from both na´ve mice and ones receiving glucose oxidase (GOX) intratracheally as a model of oxidative injury. Scanning was at the diameter of the laser beam (20 microns), and each location scanned generated a complete mass spectrum that correlated with tissue location. A strong increase in oxidative degradation products of CL was observed by MALDI-MS imaging. Light microscopy confirms the preservation of tissue structure (without fixation). Serial sections were homogenized and analyzed by LC-MS to confirm the CL species identified by MALDI-MS imaging. Assignment to an anatomical region suspected to be injured (e.g. airways) has been achieved.
Lipid-peroxidation; Phospholipids; Oxidative-phosphorylation; Oxidative-processes; Lipids; Molecular-biology; Analytical-instruments; Analytical-models; Analytical-processes; Laboratory-equipment; Laboratory-techniques; Biochemical-analysis; Cell-alteration; Cell-damage; Cell-function; Chromatographic-analysis; Liquid-chromatography; Mass-spectrometry; Oxidation; Laboratory-animals; Lung-tissue; Microscopic-analysis
The Toxicologist. Society of Toxicology 51st Annual Meeting and ToxExpo, March 11-15, 2012, San Francisco, California
University of Pittsburgh at Pittsburgh