Fig. 2: Bioenergetic stress induces oxidative cellular damage.
From: Bioenergetic stress potentiates antimicrobial resistance and persistence
a ATP synthase activity (left, p < 0.0001; pF1 p < 0.0001, pNOX p < 0.0001) and NADH production rates (right, p < 0.0001; pF1 p < 0.0001, pNOX p < 0.0001) predicted by genome-scale metabolic modeling using the iML1515 model of E. coli metabolism63 (n ≥ 10,000 flux samples for all model simulations). b Predicted respiratory (O2 utilization, left, p < 0.0001; pF1 p < 0.0001, pNOX p < 0.0001) and glycolytic (hexokinase, right, p < 0.0001; pF1 p < 0.0001, pNOX p < 0.0001) activities. c Predicted intracellular H2O2 production (p < 0.0001; pF1 p < 0.0001, pNOX p < 0.0001), catalase activity (p < 0.0001; pF1 p < 0.0001, pNOX p < 0.0001), superoxide production (p < 0.0001; pF1 p < 0.0001, pNOX p < 0.0001), and superoxide dismutase activity rates (p < 0.0001; pF1 p < 0.0001, pNOX p < 0.0001). Statistical testing for modeling data by the Kruskal-Wallis test with Dunn’s multiple comparisons test versus pEmpty. Error bars depict median flux distributions ± interquartile ranges. d Integrated H2O2 production by catalase and peroxidase-deficient ΔahpCF ΔkatE ΔkatG (ΔHPX) cells expressing pEmpty, pF1, or pNOX measured using a highly specific horseradish peroxidase and Amplex Red assay64 (left). Integrated H2O2 at mid-exponential phase (OD600 ≈ 0.5; right). Statistical testing by one-way ANOVA (p < 0.0001) with Šídák’s multiple comparisons test versus pEmpty (pF1 p < 0.0001, pNOX p < 0.0001). e Carbonylated proteins in exponential phase pEmpty, pF1, (p = 0.0011) and pNOX (p = 0.0164) cells as determined by ELISA. Statistical testing by one-way ANOVA (p = 00019) with Dunnett’s multiple comparisons test versus pEmpty. f Oxidized deoxyguanosine (8-oxo-dG) in exponential phase pEmpty, pF1, (p = 0.0001) and pNOX (p < 0.0001) cells as determined by ELISA. Statistical testing by one-way ANOVA (p < 0.0001) with Dunnett’s multiple comparisons test versus pEmpty. All experiments performed in MOPS-rich media. n = 4 for all experiments. All experimental data represent biological replicates (independent cultures) and are depicted as mean ± SEM. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001, ****p ≤ 0.0001. Non-significant comparisons not shown. Source data are provided within the ‘Source Data.xlsx’ file.
