Quantitative profiling of differentially expressed oxylipins in ADSCs under proinflammatory cytokine stimulation

Mesenchymal stem cells (MSCs) have been proved to have anti-inflammatory capabilities, but the mechanisms are still under investigation. Recently, oxylipins have been identified as being related to the immuno-regulation function of MSCs, but the MSC-derived oxylipins, especially under the stimulation of versatile pro-inflammatory cytokines, have never been comprehensively analyzed. In the present research, a UPLC-MS/MS method was employed to identify and quantify the oxylipin profiles of adipose-derived mesenchymal stem cells (ADSCs) under cytokine stimulation (IL-1 beta, TNF-alpha, IFN-gamma and TNF-alpha + IFN-gamma). The differentially produced oxylipins between experimental groups were analyzed and compared. The elevated level of lipoxygenase-15 (LOX-15) mRNA was further verified by qRT-PCR analysis. From the targeted 71 oxylipins, we detected and quantified 57 oxylipins, while 14 were not detected. Distinctive from other cytokines, ADSCs activated by the combination of IFN-gamma and TNF-alpha up-regulated LOX-15 products 7-HDHA and 15-HEPE, which were metabolized from docosahexaenoic acid (DHA) and eicosapentaenoic acid, respectively, and involved in the pro-resolution phase of inflammation. The results reported here make a first step towards a comprehensive characterization of MSC-derived oxylipins under differential proinflammatory cytokine stimulation. The findings may lay a fundamental foundation for MSC-based therapies and further determine ways to optimize the therapeutic potential of MSCs.