Figure 6. Integrated stress response (ISR) activity forms the basis to reconcile flavin adenine dinucleotide (FAD) disruption.

(a) Glycolysis, tricarboxylic acid (TCA), amino acid, fatty acid oxidation (carnitines) metabolites measured by mass spectrometry across vitamin B2-deficient diet (B2D) and FF treatments (shown as Z-score). (b) Metaboanalyst integration demonstrates B2D causes organic acidemias. (c) RNA-seq coupled with Gene Set Enrichment Analysis (GSEA) identified gene signatures altered by B2D in the liver (n = 5 independent animals/diet). (d) Change in glucose levels 30 min after pyruvate injection pre- and post-fenofibrate gavage (n = 5). (e) Amino acid, glucose metabolism, and ISR genes in B2D or B2D + FF, shown as Z-score from RNA-seq data. (f) Western blot analysis for ISR proteins in liver lysates from mice treated with B2D (4 wk total) or B2D+FF (9 wk total) and fasted overnight. (g) B2D + FF activates the ISR, increasing amino acids that restore glucose availability. Statistical significance was assessed by Mann–Whitney (a, e) and two-way ANOVA and Fisher LSD (d). Data are represented as mean ± SEM. *p<0.05, #p<0.10. Numerical data for individual panels are provided in Figure 6—source data 1. Full gel images are provided in Figure 6—source data 2.