Fig. 1: Western-style diet is associated with RvT deficiency and increased disease pathology.

Wild-type C57BL/6 mice were fed chow or Western-style diet. K/BxN serum-induced arthritis was initiated at 11 weeks and sustained by giving three weekly boosters. a Disease progression was measured using a 26-point clinical score. n = 3 per group; Statistical differences were evaluated using 2-way ANOVA for clinical scores. Mice were culled at 16 weeks, A.U. = arbitrary units. b knee joints were collected and Safranin O staining intensity assessed. Mean gray intensity was calculated using ImageJ software. n = 3 per group. c Aortas were isolated and lipid content assessed using Oil-Red O staining. Aortic lipid content was calculated using ImageJ software. n = 3 per group. d Lipid mediators were identified and quantified in aortic sections using targeted LC-MS/MS profiling. n = 6 per group from two separate experiments. e Wild-type C57BL/6 mice were fed chow or Western-style diet. K/BxN serum-induced arthritis was initiated at 11 weeks. Six days later plasma was collected and, lipid mediators were identified and quantified using targeted LC-MS/MS profiling. n = 7 per group from two separate experiments. Statistical differences were evaluated using linear regression. Unless specified, error bars, mean ± s.e.m.; Statistical differences were evaluated using unpaired t-test. f, g WT (circles) and ApoE−/− (triangles) mice with prolonged arthritis were fed a standard chow diet or WD for 11 weeks. Aortas and plasma were harvested and lipid load in the aortas was determined using oil-red O. Plasma RvT1 and RvT4 concentrations were measured using LC-MS/MS profiling. RvT concentrations were then correlated with aortic lipid content. Statistical differences were evaluated using linear regression. Dashed lines = 95% confidence interval. n = 12 mice from three separate experiments.