High-throughput measurement of lipid turnover rates using 15T FTICR mass spectrometry

Abstract

Alteration in lipid dynamics is highly associated with various diseases including diabetes and atherosclerosis. Measuring in vivo lipid turnover rates at the molecular level can provide insight for better understanding of disease metabolism. The extensive occurrence of isomeric and isobaric lipids is a major bottleneck for studying lipid dynamics on a global scale by mass spectrometry (MS). An ultra-high resolution mass spectrometer is a promising solution to distinguish lipid isobars. In this presentation, we investigated the performance of Fourier Transform-Ion Cyclotron Resonance (FT-ICR) MS in the highthroughput measurement of lipid turnover rates in HeLa cell using partial deuterium oxide (D2O) labeling. HeLa cells were cultured in 5% (mol/mol) D2O enriched media and harvested at 8 different labeling times (0, 3, 6, 12, 18, 24, 36, and 48 hr). Lipid extracts from HeLa cell were separated by Ultra-Performance liquid chromatography and analyzed by ultra-high resolution 15T FT-ICR mass spectrometer for differentiation of lipid isobars. High-throughput determination of lipid turnover rates was performed on a global scale by employing our in-house built software. As a result, 424 and 192 lipids were identified at the species level in positive and negative ion mode, respectively. Turnover rates of 48 lipids covering 12 lipid subclasses were obtained in the range 0.0048 to 0.15 hr^(−1).