Fig 1.
Human skeletal muscle transcriptomics reveals substantial metabolic reprogramming.
(A) Volcano plot with significantly up and downregulated genes of septic and control patient skeletal muscle gene expression. (B) Barplot of differentially expressed solute carriers. (C) Clustermap of differentially expressed genes in one of six specified pathways. Patient identifiers are on the left most part of the figure, and gene classifiers are at the top portion of the figure. (D) Metabolic map of differentially expressed genes. All displayed genes have an adjusted p<0.05 from differential gene expression analysis.
Fig 2.
Murine model of sepsis, cecal ligation and puncture, induces weight and activity loss, widespread inflammation, and significant reduction in energy expenditure.
Photos of degree of ligation (A), superficial suture (B), and internal suture (C) during CLP. (D) Survival curve for degree of mortality. (E) Body weight during CLP challenge. (F) Plasma cytokines in septic and sham control animals. Metabolic cage data showing reduction in activity (G), water intake (H), VO2 (I), and VCO2 (J). Dark bars along the x-axis indicate the animal’s dark cycle. Asterisk in F indicates p-value from student’s t test < 0.05 between sepsis and sham groups.
Fig 3.
Plasma metabolomics demonstrates high degree of metabolic reprogramming at the systemic level.
(A) Principal components analysis of plasma metabolomics. (B) Volcano plot, with differentially expressed metabolites (adjusted p<0.05) in red if downregulated, and blue if upregulated in septic mice. (C) Metabolites in the NAD Biosynthetic pathway. (D) Clustermap of all differentially expressed metabolites. Select differentially expressed metabolites related to inflammation/stress (E), carnitines (F), and amino acid metabolism (G). A metabolic map and associated bar plot of key metabolites in the tricarboxylic acid (TCA) cycle and related pathways (H), and in the urea cycle (I). * indicates a benjamani-hochberg adjusted p<0.05, ** indicated <0.01 for septic vs. sham animals.
Fig 4.
Shared and tissue-specific metabolic responses to sepsis.
(A) Clustering heatmap shown for all measured intra-tissue metabolites in septic and sham control mice. Chord plot demonstrating significant correlations (p<0.05 for spearman rho correlation) of metabolites between seven tissues in sham (B) and septic (C) mice. Red lines indicate positive correlations, blue lines indicate negative correlations. The line thickness is dictated by the number of metabolites shared between tissues.
Fig 5.
Sepsis induces global redox and energetic stress in tissues.
(A) Tissue energy state ratios of ADP to ATP and AMP to ATP. (B) Redox ratios of reduced glutathione to glutathione disulfide (2GSH:GSSG) and (C), lactate to pyruvate. Asterisk indicates p<0.05 from a student’s t test between septic and sham animals.
Fig 6.
Stable isotope tracing with U-13C5-Glutamine reveals muscle-liver glutamine reprogramming.
Fully labeled tracer enrichment for [1,2,3,4,5,6,6-2H7]-glucose (A), and [U-13C5]-glutamine (B) during the final ten minutes of the tracer infusion study. Whole body turnover of glucose (C) and glutamine (D). Fractional contribution of glutamine to glutathione (E), and to three intermediates of the TCA cycle (F). p<0.05 is deemed significant from a student’s t test between septic and sham animals.