title: High-resolution lipidomics coupled with rapid fixation reveals novel ischemia-induced signaling in the rat neurolipidome.
abstract: The field of lipidomics has evolved vastly since its creation 15 years ago. Advancements in mass spectrometry have allowed for the identification of hundreds of intact lipids and lipid mediators. However, because of the release of fatty acids from the phospholipid membrane in the brain caused by ischemia, identifying the neurolipidome has been challenging. Microwave fixation has been shown to reduce the ischemia-induced release of several lipid mediators. Therefore, this study aimed to develop a method combining high-resolution tandem mass spectrometry (MS/MS), high-energy head-focused microwave fixation and statistical modeling, allowing for the measurement of intact lipids and lipid mediators in order to eliminate the ischemia-induced release of fatty acids and identify the rat neurolipidome. In this study, we demonstrated the ischemia-induced production of bioactive lipid mediators, and the reduction in variability using microwave fixation in combination with liquid chromatography (LC)-MS/MS. We have also illustrated for the first time that microwave fixation eliminates the alterations in intact lipid species following ischemia. While many phospholipid species were unchanged by ischemia, other intact lipid classes, such as diacylglycerol, were lower in concentration following microwave fixation compared to ischemia.
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Marc-Olivier
authors.initials: MO
authors.lastname: Trépanier
authors.affiliation: Metabolomx, Mountain View, California, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Eiden
authors.affiliation: Lipid Biology, Nestlé Institute of Health Sciences, Lausanne, Switzerland.
authors.forename: Delphine
authors.initials: D
authors.lastname: Morin-Rivron
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Bazinet
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.|Lipid Biology, Nestlé Institute of Health Sciences, Lausanne, Switzerland.
authors.forename: Mojgan
authors.initials: M
authors.lastname: Masoodi
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000378:metabolism / Q000503:physiopathology*; D002518:Ceramides / Q000378:metabolism; D004075:Diglycerides / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D007249:Inflammation / Q000139:chemically induced / Q000503:physiopathology; D050356:Lipid Metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D008872:Microwaves; D009474:Neurons / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D015398:Signal Transduction
chemical_list: D002518:Ceramides; D004075:Diglycerides; D005227:Fatty Acids; D008070:Lipopolysaccharides; D010743:Phospholipids
keywords: bioactive lipids; ischemia; lipidomics; microwave fixation; phospholipids