Association of metabolomic and lipidomic approaches for plasma biomarkers discovery

Metabolomics refers to the large scale detection and quantification of metabolites in a given biological condition. It is a multidisciplinary approach combining analytical chemistry, informatics and biostatistics. The challenge is to obtain a comprehensive untargeted metabolic profiles of biofluids with metabolites displaying huge differences in physicochemical properties, from polar metabolites to apolar lipids. In this respect, we have developed an analytical method based on the use of 3 orthogonal LC-HRMS systems to analyze polar to moderately apolar molecules. Different chromatographic retention mechanisms, i.e. reversed phase, hydrophilic interaction liquid chromatography (HILIC) and PentaFluroPhenylPropyl (PFPP) were performed for each samples. As a complementary approach, we have developed an analytical method for lipid profiling in plasma. This lipidomic method is based on a dedicated sample preparation procedure, LC-HRMS conditions and data processing tools. Applied to human plasma samples, more than 700 unique lipid species, i.e. unique m/z – retention time signature, can be detected and identified, including glycerophospholipids, glycerolipids, shingolipids, free fatty acids and sterols and derivatives.