Figure 5.

Altered metabolism in Prdm16^csp1/wt cardiac tissue. (A) Normalized central carbon metabolite counts are presented as log2 value of the mean of normalized peak area ratio Prdm16^csp1/wt/controls of males, females, and combination of both sexes. In female Prdm16^csp1/wt LV tissue, broad suppression of several metabolic pathways was observed. In male Prdm16^csp1/wt LV tissue, a similar but less pronounced reduction was detected. Statistical analysis of individual metabolites was performed with non-parametric Wilcoxon Rank Sum test, * indicates P < 0.05. (B) Univariate analysis reveals in cardiac tissue of Prdm16^csp1/wt mice significant reduction of the amino acid, glycolysis, glycerol, and tricarboxylic acid cycle (TCA) metabolism using combined male and female data. Divergent metabolism of male and female animals was observed for amino acid metabolism, glycolysis, and TCA cycle. (C) Lipid analysis was performed with LC-MS using the lipidizer kit (Sciex). Global lipid analysis and evaluation as log2 value of the intensity ratio Prdm16^csp1/wt/controls reveal normal levels for most lipid classes. Strongest regulation was observed for triacylglycerol (TAG) in male Prdm16^csp1/wt hearts. The number (n) of validly detected lipids per class is indicated. (D) Selected neutral lipids and sphingolipids critical for the heart, lipids altered in Prdm16^csp1/wt mice, and lipids previously associated with heart function (^†Tham et al.,^{24  ‡}Wittenbecher et al.²⁵) are presented for Prdm16^csp1/wt cardiac tissue of both sexes and in combination. Values for phospholipids are available in Supplementary material online, Figure SIX in the Data Supplement. Analysed biological replicates for all metabolic analysis are n = 4–6. (E) Signalling activity of the mitogen-activated protein kinase (MAPK) and mTOR pathway was assessed with the Milliplex phosphoprotein magnetic bead system and revealed diminished phosphorylation of insulin receptor (Insr_Tyr1162-1163), phosphatase and tensin homologue (Pten_Ser380), and Akt serine/threonine kinase 2 (Akt_Ser473) in female Prdm16^csp1/wt mice. Analysed biological replicates for all metabolic analysis are n = 4–6. Statistical analysis of selected lipids was performed with non-parametric Wilcoxon Sum Rank test, * indicates P < 0.05. Colouring indicates reduction (red) or increase (blue) of the log2 of ratio by −0.2 or 0.2, respectively.