Research Paper Volume 11, Issue 15 pp 5726—5743

Figure 1. Elevated glucose metabolism suppresses paraquat-induced development arrest. (A) D-glucose but not L-glucose suppressed paraquat-induced development arrest. To synchronize eggs to the same development stage, eggs were collected from gravid worms within 2 hours. Synchronized eggs were then raised on nematode growth medium (NGM) agar plate with or without 1mM paraquat (PQ) and 1% glucose (D-gluc or L-gluc) for 4 days. Animals were imaged on plate with stereomicroscope. Representative images of 3 independent experiments were shown. (B) Quantification of animals developed to adulthood under paraquat and glucose treated conditions. C. elegans were treated as in (A) and percentage of animals reaching adulthood under indicated treatments were calculated and the mean values of 3 independent experiments (n>250) were plotted with error bars showing standard deviation (SD). P values were obtained by student’s t-test: ***, P<0.0005; ns, not significant. (C) D-glucose but not L-glucose suppressed paraquat-induced embryo lethality. Synchronized eggs from C. elegans were raised on NGM agar plate with or without paraquat (1mM) and 1% glucose (D-glucose or L-glucose). Hatching rate were calculated and the mean values of 3 independent experiments (n>300) were plotted with error bars showing the standard deviation. P values by student’s t-test: **, P<0.005; ns, not significant. (D) Dose-dependent effect of glucose on suppressing paraquat-induced developmental arrest. Synchronized eggs were raised on NGM agar plate with 1mM paraquat and indicated concentration of D-glucose for 4 days. The means of percentage of animals reaching adulthood from 3 independent experiments (n>300) were plotted, with error bars showing the standard deviation. P values by student’s t-test: *, P<0.05; **, P<0.005; *** P<0.0005; ns, not significant. (E) Glucose suppression of paraquat-induced toxicity occurred in vivo. Synchronized eggs from C. elegans were raised on NGM agar plate with 1mM paraquat without glucose for 2 days, then transferred to D-glucose plate without paraquat for indicated time points. The means of percentage of animals reaching adulthood from 3 experiments (n>250) were plotted, with error bars showing the standard deviation. P values by student’s t-test: **, P<0.005; *** P<0.0005; ns, not significant.