Research Paper Volume 11, Issue 15 pp 5726—5743

Conserved roles of glucose in suppressing reactive oxygen species-induced cell death and animal survival

Figure 4. ROS/SKN-1-dependent lifespan extension and stress resistance are suppressed by glucose supplementation. (A) Glucose suppressed the extended lifespan of mitochondrial respiration mutant isp-1. N2 WT and isp-1 mutant animals were raised at 20°C on NGM agar plate supplemented with or without 0.5% glucose from hatching. 50μM 5-Fluoro-2′-deoxyuridine (FUDR) was added at L4 stage to prevent progenies from growing. Survival was examined every 2 days until all animals died. Data were collected from 2 independent experiments (n> 140) and plotted and statistically analyzed with Prism software. P values by Log-rank test: isp-1 vs. WT, P<0.0001; isp-1+glucose vs. WT+glucose: not significant. (B) Glucose suppressed the extended lifespan of germline-less mutant glp-1. Lifespan assay of N2 WT and glp-1 mutant animals were conducted as in (A) except that worms where raised at 25°C from L1 for 24 hours. Data from 2 independent trials (n>120) were pooled and plotted by using Prism software. P values by Log-rank test: glp-1 vs. WT, P<0.0001; glp-1+glucose vs. WT+glucose: not significant. (C) Glucose suppressed the extended lifespan of paraquat-treated C. elegans. Synchronized eggs were raised on control NGM plate, plates with either 1mM paraquat or 0.5% glucose, or both. Young adult worms were transferred to new plates for lifespan assay similar to (A). Data from 2 independent trials (n>120) were pooled and plotted by using Prism software. P values by Log-rank test: PQ vs. WT, P<0.0001; PQ+glucose vs. WT+glucose: not significant. (D) The hydrogen peroxide resistance of germline-less mutant (glp-1) was abrogated by glucose. N2 WT and the temperature sensitive glp-1 mutant animals growing with or without 0.5% glucose were raised under non-permissive temperature (25°C) from L1 stage for 24 hours, then shifted back to 20°C until day-1 adulthood. Animals were then incubated with 5mM of H2O2 in water for indicated time points. Survival rates of the means of 3 independent experiments were plotted for each time point, with error bars showing standard deviation (SD). P value by student’s t-test: *, P<0.05. (E) Resistance to infection of germline-less mutant (glp-1) were abrogated by glucose. N2 WT and the temperature sensitive glp-1 mutant animals growing with and without 0.5% glucose were raised at non-permissive temperature (25°C) from L1 stage for 24 hours, then shifted back to 20°C. Animals were then fed Salmonella typhimurium on agar plate for indicated time points and survival rate of the mean values of 3 independent experiments were plotted, with error bars indicating standard deviation (SD). P value by student’s t-test: *, P<0.05; **, P<0.005.