Fig. 6

Metabolomic signatures of NAD replacement strategies in MDX muscle. a Heatmap of ion counts for polar metabolites reaching significance (adjusted p < 0.05) in MDX muscle compared to WT controls (left column) aligned with the same metabolites identified in GSK978A-treated (center column) and NR-treated (right column) muscles after 20 weeks of treatment. b Correlation of the changes in ion abundance induced by GSK978A and (c) NR supplementation in MDX muscle after 20 weeks compared to changes driven by genotype alone. Colored points indicate metabolite ions significantly altered in at least one of the comparisons and the dashed line indicates the least-squares regression of these points. R indicates the correlation coefficient of the significant (adjusted p < 0.05) ions and p indicates the significance level of the associated Pearson’s correlation. d Volcano plot of biochemical pathways significantly altered in MDX muscle by GSK978A. Significantly altered metabolites were used to calculate pathway impact and highly affected pathways are indicated. e Total NAD content of gastrocnemius muscles harvested from contralateral limbs. Significance was determined by one-way ANOVA with Tukey’s post hoc test (**p < 0.01; ns, not significant). f Box plots of ion abundances for representative members of glycolysis (G6P, F6BP, G3P), pentose phosphate pathway (R5P), and TCA cycle (CA, SA). N = 9-12 mice per group. Whiskers represent minimum and maximum values. Significance was determined by one-way ANOVA with Tukey’s post hoc test (p values adjusted for multiple testing)