Fig. 5. Intracellular Lp-PLA2 is responsible for ferroptosis suppression by regulating phospholipid compositions.
a Western blot analysis to confirm the presence of Lp-PLA2 in the pellet and supernatant after ectopic expression of Lp-PLA2 in Hs746T cells. b Western blot analysis to confirm the presence of Lp-PLA2 in the cytoplasm and plasma membrane after ectopic expression of Lp-PLA2 in Hs746T cells. c Lipid peroxidation levels in Hs746T cells treated with RSL3 and/or 2 μM darapladib for 0.5 h and cultured in FBS-deficient medium. Lipid oxidative potential was assessed by flow cytometry and microscopy using C11-BODIPY581/591. The data are presented as the means ± SDs (n = 3 independent experiments with, the significance of the results was assessed using a two-tailed Student’s t test). d, e LDH levels of WT and PLA2G7 KO cells treated with RSL3 in the absence of serum for 24 h. The data are presented as the means ± SDs (d: n = 8, e: n = 4 independent experiments with, the significance of the results was assessed using a two-tailed Student’s t test (d) or one-sided Wilcoxon rank-sum test (e)). f, g Lipidomic analysis acquired from the UPLC/QTOF MS spectra of WT and PLA2G7 KO H1299 cells. Each value in the heatmap is a coloured representation of a calculated Z score (f). Lipids are presented as the total numbers of carbon atoms, double bonds, and fatty acyl chains. n = 8 independent experiments. A volcano plot of lipid classes showing the log2(fold change) and –log10(p) values in the control versus PLA2G7 KO H1299 cells is presented (f). FFA free fatty acid, Cer ceramide, SM sphingomyelin, lysoPC lysophosphatidylcholine, lysoPE lysophosphatidylethanolamine, lysoPG lysophosphatidylglycerol, lysoPI lysophosphatidylinositol, lysoPS lysophosphatidylserine, PC phosphatidylcholine, PE phosphatidylethanolamine, PG phosphatidylglycerol, PI phosphatidylinositol, PS phosphatidylserine. Exact p values provided as source data. Source data are provided as a source data file.