Establishment of basic lipidomics platforms for discovery of lipid biomarkers

Lipidomics is one of the major approaches in metabolomics, and often uses a liquid chromatography-mass spectrometer (LC-MS) to obtain profiling of lipid metabolites and to detect changing molecules statistically. However, previously reported methods have been technically insufficient in the simultaneous analysis of amphiphilic glycosphingolipids, such as gangliosides, and in the global detection of various polar metabolites from complex lipid mixtures. Here, we report on newly targeted and non-targeted methods to measure these lipid metabolites sensitively. In the targeted approach, we were able to detect individual ganglioside molecular species using the combination of reversed-phase or hydrophilic interaction liquid chromatography and ESI-MS with multiple reaction monitoring (MRM). Meanwhile, in a non-targeted approach, global analysis of various polar metabolites was possible by reverse-phased high-resolution (LC) coupled quadrapole time-of-flight MS and sensitive twodimensional (2D) profiling. Our methods will be useful for the elucidation of cancers, metabolic syndrome and nervous-system diseases, etc.; these diagnostic markers may be detectable.