UHPLC-MS-based untargeted metabolomic strategy to reveal the metabolic differences between cisplatin first- and second-generation apoptotic bodies from HK-2 cells

During the process of programmed cell death (apoptosis), the disassembly of apoptotic cells gives rise to apoptotic bodies (ABs) which play an important role in the pathogenesis of different diseases. ABs from renal human proximal tubular cells HK-2 on na & iuml;ve cells was not always the same: ABs directly generated after exposure of human proximal tubular epithelial HK-2 cells to chemotherapeutic agent cisplatin (1st generation ABs) triggered apoptosis and inhibited cell proliferation, whereas ABs induced by 1st generation ABs (2nd generation ABs) enhanced HK-2 cell proliferation. To shed light on the mechanisms involved in these disparate ABs' effects, a study of the changes in the metabolome of 1st and 2nd generation ABs produced by HK-2 cells in the cisplatin setting was performed by a reversed-phase ultra-high-performance liquid chromatography-mass spectrometry (RP-UHPLC-MS) untargeted metabolomic approach. Thus, ABs fluid and extracellular fluid from 1st and 2nd generation ABs were analyzed to obtain as much information as possible of the metabolites of these extracellular vesicles. Principal components analysis and partial least square discriminant analysis were conducted to find the statistically significant differences between both groups. A good clustering of each group was observed and variable importance in the projection values were selected to choose the molecular features which were identified according to the Metabolomics Standard Initiative (MSI) guidelines. Finally, the biological relevance of the achieved results was discussed.