Osmotic stressors confer age-dependent resistance to heat stress in wild-type and daf-2 Caenorhabditis elegans

Abstract

Glucose has been shown to shorten lifespan in Caenorhabditis elegans. The connection of glucose to stress resistance in C. elegans, however, appears to be complex. We have shown glucose to be protective against heat stress early in adulthood (1-day-old adults), in both wild-type (WT, N2 strain) animals and those with a mutation in the gene encoding the C. elegans insulin receptor, daf-2. The protection conferred by 1 day on high glucose continues in mid-life (7-day-old adults) for daf-2, but not for WT. Mid-life and late-life stress following 7 or 13 days on high glucose shows glucose enrichment to be neutral or detrimental for recovery from heat stress in both strains. These results were also observed for animals exposed to sorbitol instead of glucose, suggesting the osmotic stress conferred by high concentrations of carbohydrate to be the basis of the resistance to heat stress.