Fig. 2

The saturated VLCFA C26:0 activates the JNK stress kinase pathway but not TLR-mediated NFκB signalling. A Reporter Jurkat E6-1-NFκB::eGFP-TLR2/1, Jurkat E6-1-NFκB::eGFP-TLR2/6 and Jurkat E6-1-NFκB::eGFP-TLR4/CD14 cells, as well as reporter THP-1 E6-1-NFκB::eGFP-TLR4/CD14 cells were incubated with either the cognate TLR ligands flagellin, LPS, PAM3CSK4 or MALP2 or saturated LCFA (C16:0), saturated VLCFAs (C24:0, C26:0) or mono-unsaturated LCFA (C18:1) as indicated. After 24 h, eGFP expression was assessed by flow cytometry. The heatmap represents mean fold change to vehicle of 2 replicates. B–G Primary human macrophages derived from healthy control donors (n = 2–4) were treated with either the solvent ethanol (vehicle), C16:0 (100 µM), C26:0 (100 µM) or LPS (100 ng/ml) for the indicated time. Immunoblotting was performed on cell lysates analysing the levels of B–D phosphorylated and total NFκB-p65 or E–G phosphorylated and total JNK1 (46 kDa)/JNK2 (55 kDa). H Macrophages derived from 3 healthy control donors were incubated with either C26:0 (100 µM), the CD36 inhibitor (CD36i) sulfosuccinimidyl oleate (100 µM) or both compounds for 24 h prior to immunoblotting for phosphorylated and total JNK1/JNK2. Values are shown as the mean fold change to vehicle control and error bars indicate standard deviation. One-way ANOVA and Fisher’s LSD multiple comparison test were performed in B–G. Paired two-way Student’s t-test was performed in H. *p < 0.05; **p < 0.01; ***p < 0.001; ns not significant