Fig. 4
ECZeb2KO and WD-exposure interact to affect endothelial lipid metabolism. (a) Circos plot (left) showing overlap (‘common’, i.e., genes with expression changes in the same direction; turquoise) or not (‘unique’; orange) between DEGs from comparison 1 or 2 (single challenges: purple or green) and comparison 3 (combined challenge: gray). Schematic expression patterns for common or unique genes across single and combined challenges are shown next to the circos plot. Functional terms derived from the combined up- and downregulated DEGs (full list: see Supplementary Table 1 for common (top) or unique (bottom) DEGs are plotted as bubble plots representing top 10 or 30 biological processes (middle) and pathways (right) ranked according to false discovery rate (FDR). Pathways of interest are highlighted in red. Significance level in bubble plots is indicated by red dotted lines. (b) Quantitative analysis of DEGs from the functional term ‘PPAR_signaling_pathway’ showing number of genes that emerged as differentially expressed from comparison 1, 2 or 3 (left) and expression changes (expressed as log-fc) for DEGs with a ‘unique’ profile (indicated by arrowheads; right). *P < 0.05 vs. no challenge. Statistical analyses were performed according to pairwise comparisons related to single or combined challenges as indicated. Ns: not significant. (c) Schematic representation (bottom-left) shows cellular localization and function of all 72 PPAR signaling pathway genes color-coded according to their DEG status (black: not differentially expressed; purple or green: DEG from comparison 1 or 2, respectively; orange or turquoise: unique or common DEG from comparison 3). (d–h) Liver cross-sections of ECWT (d,f) or ECZeb2KO (e,g) mice after 8 weeks (w) of SD (d,e) or WD (f,g) stained for FABP4 (red) and corresponding quantification (h) of FABP4 expression plotted as area % (n = 5–15). Quantitative data are expressed as mean ± s.e.m. *: P < 0.05 vs. indicated condition by two-way ANOVA with Tukey post-hoc test. Pictures in (d–g) were taken with an EC Plan-Neofluar 10x/0.30 M27 objective on a Zeiss Axio Imager Z1 equipped with an AxiocamMRc5 and Axiovision software. Data in all panels, except for (d–h) correspond to 4w of diet exposure. VLDL: very low-density lipoprotein, RA: retinoic acid, FA: fatty acid.
