School of Biological Sciences Research Seminar Series: ‘The challenges of measuring oxidized phospholipids and understanding their biological effects’

Prof Corinne Spickett,  School of Life & Health Sciences, Aston University

Hosted by Dr David Leake

Phospholipids are essential components of cell membranes, and are transported within the body in lipoproteins. Unsaturated phospholipids can be oxidized enzymatically or by oxidizing agents produced adventitiously, for example during inflammation. The resulting oxidized phospholipids (oxPLs) have biological and signalling effects, many of which are considered detrimental. OxPLs can be considered as “damage-associated molecular patterns” and interact with several immune receptors, including toll-like receptors. The outcomes can be inflammatory or anti-inflammatory, depending on the oxidized phospholipid, cell type and concentration. Therefore to understand the contributions of oxPLs, it is necessary to have sensitive and specific methods of identifying different oxidized species. This is challenging as low density lipoprotein contains more than 350 different native lipid species, cell membranes are similarly complex, and oxidation increases the complexity further. We have been developing “ox-lipidomic” mass spectrometry approaches to facilitate identification of individual oxPLs in complex samples such as plasma, ascites and cell extracts. Furthermore, some oxidized lipid breakdown products are reactive and form adducts with proteins by a process called lipoxidation. This is thought to be an additional mechanism by which oxPLs can influence cell signalling in pathophysiology, and can also be analysed by advanced mass spectrometry techniques.