Determination of changes in sphingolipid content in β-cells and isolated extracellular vesicles after sustained hyperglycemia using ToF-SIMS spectrometry

ToF-SIMS (Time of Flight - Secondary Ion Mass Spectrometry) is a nondestructive and direct technique for the analysis of molecules <1000 Da, e.g. lipids. Hyperglycemia (HG) is a state of increased glucose concentration. HG produces metabolic changes in pancreatic β cells, and modulates extracellular vesicles (EVs) release. Here, HG-induced changes in the composition of sphingolipids were analyzed.
Pancreatic β-cells were cultured in normoglycemic, medium hyperglycemia (HG) and HG conditions (5, 11, 25 mM of D-glucose). Low-pressure filtration dialysis and ultracentrifugation were used to separate smal and large EVs. TOF-SIMS equipped with the Bi3+ gun was used.
We compared the levels of sphingolipids. Significant differences in peak intensities characteristic for individual lipids between different populations of EVs and parental cells were revealed. The experiments showed the enrichment of EVs with specific lipids in relation to parental cells.