title: The failure to extend lifespan via disruption of complex II is linked to preservation of dynamic control of energy metabolism.
abstract: A decrease in mitochondrial electron transport chain (ETC) activity results in an extended lifespan in Caenorhabditis elegans. This longevity has only been reported when complexes I, III and IV genes are silenced, but not genes of complex II. We now have suppressed each complex II subunit in turn and have confirmed that in no case is lifespan extended. Animals with impaired complex II function exhibit similar metabolic changes to those observed following suppression of complexes I, III and IV genes, but the magnitude of the changes is smaller. Furthermore, an inverse correlation exists between mitochondrial membrane potential and ATP levels (r(2)=0.82), which strongly suggests that dynamic allocation of energy resources is maintained. In contrast, suppression of genes from complexes I, III and IV, results in a metabolic crisis with an associated stress response and loss of metabolic flexibility. Thus, the maintenance of a normal metabolism at a moderately decreased level does not alter normal lifespan, whereas metabolic crisis and induction of a stress response is linked to lifespan extension.
authors: School of Biological Sciences, University of Queensland, St Lucia 4072, Brisbane, Australia.
authors: Jujiao
authors: J
authors: Kuang
authors: Paul R
authors: PR
authors: Ebert
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D042967:Electron Transport Complex I / Q000235:genetics / Q000378:metabolism; D042963:Electron Transport Complex II / Q000235:genetics* / Q000378:metabolism*; D014450:Electron Transport Complex III / Q000235:genetics / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism; D004734:Energy Metabolism; D005786:Gene Expression Regulation; D020868:Gene Silencing; D008020:Life Support Care; D053078:Membrane Potential, Mitochondrial; D013312:Stress, Physiological
chemical_list: D000255:Adenosine Triphosphate; D042963:Electron Transport Complex II; D003576:Electron Transport Complex IV; D042967:Electron Transport Complex I; D014450:Electron Transport Complex III