Metabolic Profiling and Quantification of Sphingolipids by Liquid Chromatography-Tandem Mass Spectrometry

A precise, robust, and specific liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) method was developed for profiling and quantifying glucosyl sphingosine (GS), glucosylceramide (GC), ceramide (Cer), lactosylceramide (LacCer) and sulfatide lipid species in a variety of mouse tissues. The linear response ranges of these species were 0.05-25 ng. The major GC species identified in visceral tissues of mice were GCs with N-acyl chains of C24-1, C24, C22, C16 lengths, but the qualitative and quantitative profiles differed among tissues. GC levels in spleen were approximately 3-5 times higher than in liver and lung. Brain differed from visceral tissues in that galactosylceramides (GalCer) were the predominant monohexosylceramide species identified. A silica column used in hydrophobic interaction liquid chromatography (HILIC) mode was capable of differentiating GC and GalCer. The analysis of mouse brain samples revealed that GC accounted for only 0.3% of the total monohexosylceramides. Cer and LacCer were also profiled and quantified in mouse brain, lung, liver and spleen. Application of these methods greatly facilitated a range of targeted sphingolipidomic investigations and will permit a better understanding of the function and mechanism of these diverse molecular species in various disease animal models, including Gaucher disease.