Fig. 1: Analysis of proteome profiling uncovered ferroptosis as a biological process affected by 20 µM 1,4 dihydroxy quininib in OMM2.5 cells.

A Heatmap chart depicting all the differentially expressed proteins between 0.5% DMSO and 20 µM 1,4 dihydroxy quininib (Q7) treated OMM2.5 cells after 4, 8 or 24 h of treatment. The heat maps show n = 4 for each time point with the respective colour scale located below each figure. The blue and red refer to down-regulated and upregulated proteins, respectively. The 4 h heat map (left panel) represents 66 differentially expressed proteins where 41 proteins are upregulated and 25 proteins are downregulated. The 8 h heat map (middle panel) represents 164 differentially expressed proteins where 72 proteins are upregulated and 92 proteins are downregulated. The 24 h heat map (right panel) represents 95 differentially expressed proteins where 49 proteins are upregulated and 46 proteins are downregulated. B Venn diagram analyses showing the unique and shared downregulated proteins between 0.5% DMSO and 20 µM Q7 treated OMM2.5 cells at 4, 8 and 24 h (upper panel), the unique and shared upregulated proteins between 0.5% DMSO and 20 µM Q7 treated OMM2.5 cells at 4, 8 and 24 h (middle panel), and the total amount of unique and shared differentially expressed proteins between 0.5% DMSO and 20 µM Q7 treated OMM2.5 cells at 4, 8 and 24 h (lower panel). C Volcano plots depicting the differentially expressed proteins between 0.5% DMSO and 20 µM Q7 treated OMM2.5 cells at 4 h (left panel), 8 h (middle panel) and 24 h (right panel). The proteins highlighted in red represent the proteins with a Student’s T-Test Difference ≥ 0.5. The proteins highlighted in blue represent those with a Student’s T-Test Difference ≤ − 0.5. The most consistently upregulated protein after 4, 8 or 24 h of treatment is heme oxygenase 1 (HO-1). D–H Gene ontology (GO) classification of proteomic data for differentially expressed proteins between 0.5% DMSO and 20 µM Q7-treated OMM2.5 cells after 8 h (D, E) and 24 h (F, G) of treatment. D KEGG pathway analysis of significantly upregulated proteins in 20 µM Q7-treated vs 0.5% DMSO-treated OMM2.5 cells after 8 h of treatment, showing the most enriched categories in biological process. E Protein-protein interaction network showing the significantly upregulated proteins in 20 µM Q7-treated vs 0.5% DMSO-treated OMM2.5 cells associated to ferroptosis, after 8 h of treatment. F KEGG pathway analysis of significantly upregulated proteins in 20 µM Q7-treated vs 0.5% DMSO-treated OMM2.5 cells after 24 h of treatment, showing the most enriched categories in biological process. G Protein-protein interaction network showing the significantly upregulated proteins in 20 µM Q7-treated vs 0.5% DMSO-treated OMM2.5 cells associated to ferroptosis, after 24 h of treatment. The panel also shows upregulated (red nodes) and downregulated (blue node) proteins associated to fluid shear stress and atherosclerosis process. HO-1 upregulation is common to both pathways. (H) DAVID pathway analysis displaying significantly upregulated proteins at 8 h (red stars) and 24 h (red triangles) in 20 µM Q7-treated vs 0.5% DMSO-treated OMM2.5 cells in ferroptosis process. Image obtained from KEGG [102]. Q7 = 1,4-dihydroxy quininib; HMOX1 = HO-1; h = hours.