Search

Aim: Plasma and serum are widely used blood-derived biofluids for metabolomics and lipidomics assays, but analytes that are present in high concentrations in blood cells cannot be evaluated in those samples and isolating serum or plasma could introduce additional variability in the data. Materials & methods: In this study, we provide a comprehensive method for quantification of the whole blood (WB) sphingolipidome, combining a single-phase extraction method with LC-high-resolution mass spectrometry. Results: We were able to quantify more than 150 sphingolipids, and when compared with paired plasma, WB contained higher concentration of most sphingolipids and individual variations were lower. These findings suggest that WB could be a better alternative to plasma, and potentially guide the evaluation of the sphingolipidome for biomarker discovery.

Therapy-induced senescence is a state of cell cycle arrest that occurs as a response to various chemotherapeutic reagents, especially ones that cause DNA damage. Senescent cells display resistance to cell death and can impair the efficacy of chemotherapeutic strategies. Since lipids can exhibit pro-survival activity, it is envisioned in this article that probing the lipidome could provide insights into novel lipids that are involved in senescence. Therefore, a tissue culture model system is established and the cellular lipidomes of senescent and proliferating cells are comparatively analyzed. Out of thousands of features detected, 17 species are identified that show significant changes in senescent cells. The majority of these species (11 out of 17) are atypical sphingolipids, 1-deoxyceramides/dihydroceramides, which are produced as a result of the utilization of alanine, instead of serine during sphingolipid biosynthesis. These lipids are depleted in senescent cells. Elevating the levels of deoxyceramides by supplementing the growth medium with metabolic precursors or by directly adding deoxyceramide result in decreased senescence, suggesting that these species might play a key role in this process., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)