Research Paper Volume 13, Issue 1 pp 813—830

Carnitine promotes recovery from oxidative stress and extends lifespan in C. elegans

The long-lived mutants daf-2 and glp-1 recover from oxidative stress better than wild-type controls. (A) glp-1 worms showed faster decrease in the expression of the OSR marker gst-4::gfp. Age-matched, gst-4::gfp-expressing WT and glp-1 mutant worms were raised from L1 to L4 at 25° C to deplete germ cells in glp-1 then maintained at 20° C throughout the experiment. gst-4::gfp expression were examined with fluorescent microscope at indicated time points. Representative images were shown. (B) Data from 2 independent experiments described in (A) were normalized to the average of day-2 adulthood. Data were analyzed by two-tailed, paired student’s t-test (**, PC) daf-2 worms recovered from oxidative stress faster than wild-type controls. Age-matched worms expressing gst-4::gfp were raised at 20° C. gst-4::gfp expression was examined at indicated time points. Two independent experiments were performed. Data were normalized to the average of day-2 adulthood and analyzed by two-tailed, paired student’s t-test (*, PD) L-carnitine did not further increase lifespan of daf-2C. elegans. Age-matched wild-type or daf-2 worms were raised at 20° C throughout life with and without 10 μM L-carnitine supplement. Dead and live worms were counted every 2 or 3 days starting from day-10 of adulthood. Data from 2 experiments were pooled and analyzed by log-rank test (Supplementary Table 2). (E) L-carnitine did not further increase lifespan of glp-1 worms. Age-matched wild-type or glp-1 worms were raised at 25° C from L1 to L4 stage and then maintained at 20° C throughout life. 10 μM L-carnitine supplement was added starting from L1 stage. Dead and live worms were counted every 2 or 3 days starting from day-10 of adulthood. Data from 2 experiments were pooled and analyzed by log-rank test (Supplementary Table 2).

Figure 4. The long-lived mutants daf-2 and glp-1 recover from oxidative stress better than wild-type controls. (A) glp-1 worms showed faster decrease in the expression of the OSR marker gst-4::gfp. Age-matched, gst-4::gfp-expressing WT and glp-1 mutant worms were raised from L1 to L4 at 25° C to deplete germ cells in glp-1 then maintained at 20° C throughout the experiment. gst-4::gfp expression were examined with fluorescent microscope at indicated time points. Representative images were shown. (B) Data from 2 independent experiments described in (A) were normalized to the average of day-2 adulthood. Data were analyzed by two-tailed, paired student’s t-test (**, P<0.01). Error bars indicate standard deviation of the mean. (C) daf-2 worms recovered from oxidative stress faster than wild-type controls. Age-matched worms expressing gst-4::gfp were raised at 20° C. gst-4::gfp expression was examined at indicated time points. Two independent experiments were performed. Data were normalized to the average of day-2 adulthood and analyzed by two-tailed, paired student’s t-test (*, P<0.05. ***, P<0.001). Error bars indicate standard deviation of the mean. (D) L-carnitine did not further increase lifespan of daf-2C. elegans. Age-matched wild-type or daf-2 worms were raised at 20° C throughout life with and without 10 μM L-carnitine supplement. Dead and live worms were counted every 2 or 3 days starting from day-10 of adulthood. Data from 2 experiments were pooled and analyzed by log-rank test (Supplementary Table 2). (E) L-carnitine did not further increase lifespan of glp-1 worms. Age-matched wild-type or glp-1 worms were raised at 25° C from L1 to L4 stage and then maintained at 20° C throughout life. 10 μM L-carnitine supplement was added starting from L1 stage. Dead and live worms were counted every 2 or 3 days starting from day-10 of adulthood. Data from 2 experiments were pooled and analyzed by log-rank test (Supplementary Table 2).