Quantitative evaluation of a high resolution lipidomics platform

Abstract

Given the general importance of lipids in health and disease, there is a need for efficient technology that broadly profiles and quantitates the lipid composition of complex mixtures. In this study, we developed and quantitatively evaluated a platform that simultaneously profiles both lipids and polar metabolites from the same sample. This method was achieved by using a methyl tert-butyl ether (MTBE) extraction and employing two liquid chromatography methods coupled with high resolution mass spectrometry (LC-HRMS). This workflow enabled detection and semi-quantitation of over 300 polar metabolites as well as over 300 lipids with comprehensive coverage of diverse chemical classes. Using cultured mammalian cells as an example, we report the quantitative properties of the platform including the sensitivity and linear range. The lipidomics strategy was further applied to characterize changes to lipid metabolism upon treatment with metformin to human ovarian cancer cells. Of the 256 detected lipids, 99 lipids (39%) significantly increased, 11 lipids (4%) were significantly reduced and 146 lipids (57%) remain unchanged in metformin-treated cells. Stable isotope tracing of carbon into lipids using [13C6]-glucose further measured the contribution of de novo fatty acid synthesis to the total fatty acid pool. In summary, the platform enabled the semi-quantitative assessment of hundreds of lipid species and associated carbon incorporation from glucose in a high throughput manner.