C. elegans as model for the study of high glucose- mediated life span reduction

Diabetes. 2009 Nov;58(11):2450-6. doi: 10.2337/db09-0567. Epub 2009 Aug 12.

Abstract

Objective: Establishing Caenorhabditis elegans as a model for glucose toxicity-mediated life span reduction.

Research design and methods: C. elegans were maintained to achieve glucose concentrations resembling the hyperglycemic conditions in diabetic patients. The effects of high glucose on life span, glyoxalase-1 activity, advanced glycation end products (AGEs), and reactive oxygen species (ROS) formation and on mitochondrial function were studied.

Results: High glucose conditions reduced mean life span from 18.5 + or - 0.4 to 16.5 + or - 0.6 days and maximum life span from 25.9 + or - 0.4 to 23.2 + or - 0.4 days, independent of glucose effects on cuticle or bacterial metabolization of glucose. The formation of methylglyoxal-modified mitochondrial proteins and ROS was significantly increased by high glucose conditions and reduced by mitochondrial uncoupling and complex IIIQo inhibition. Overexpression of the methylglyoxal-detoxifying enzyme glyoxalase-1 attenuated the life-shortening effect of glucose by reducing AGE accumulation (by 65%) and ROS formation (by 50%) and restored mean (16.5 + or - 0.6 to 20.6 + or - 0.4 days) and maximum life span (23.2 + or - 0.4 to 27.7 + or - 2.3 days). In contrast, inhibition of glyoxalase-1 by RNAi further reduced mean (16.5 + or - 0.6 to 13.9 + or - 0.7 days) and maximum life span (23.2 + or - 0.4 to 20.3 + or - 1.1 days). The life span reduction by glyoxalase-1 inhibition was independent from the insulin signaling pathway because high glucose conditions also affected daf-2 knockdown animals in a similar manner.

Conclusions: C. elegans is a suitable model organism to study glucose toxicity, in which high glucose conditions limit the life span by increasing ROS formation and AGE modification of mitochondrial proteins in a daf-2 independent manner. Most importantly, glucose toxicity can be prevented by improving glyoxalase-1-dependent methylglyoxal detoxification or preventing mitochondrial dysfunction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans / growth & development
  • Caenorhabditis elegans / metabolism*
  • Caenorhabditis elegans / ultrastructure
  • Disease Models, Animal
  • Glucose / toxicity*
  • Humans
  • Hyperglycemia / metabolism*
  • Life Expectancy / trends
  • Longevity / physiology*
  • Microscopy, Electron, Scanning
  • Mitochondria / metabolism
  • Reactive Oxygen Species / metabolism

Substances

  • Reactive Oxygen Species
  • Glucose