title: Mitochondrial efficiency is increased in axenically cultured Caenorhabditis elegans.
abstract: Culturing Caenorhabditis elegans in axenic medium leads to a twofold increase in lifespan and considering the similar phenotypical traits with dietary restricted animals, it is referred to as axenic dietary restriction (ADR). The free radical theory of aging has suggested a pivotal role for mitochondria in the aging process and previous findings established that culture in axenic medium increases metabolic rate. We asked whether axenic culture induces changes in mitochondrial functionality of C. elegans. We show that ADR induces increased electron transport chain (ETC) capacity, enhanced coupling efficiency and reduced leakiness of the mitochondria of young adult worms but not a decrease of ROS production capacity and in vivo H2O2 levels. The age-dependent increase in leak respiration and decrease in coupling efficiency is repressed under ADR conditions. Although ADR mitochondria experience a decrease in ETC capacity with age, they succeed to maintain highly efficient and well-coupled function compared to fully fed controls. This might be mediated by combination of a limited increase in supercomplex abundance and decreased individual CIV abundance, facilitating electron transport and ultimately leading to increased mitochondrial efficiency.
authors.affiliation: Department of Biology, Ghent University, Proeftuinstraat 86, 9000 Gent, Belgium.
authors.forename: Natascha
authors.initials: N
authors.lastname: Castelein
authors.affiliation: Faculty of Chemistry, Technische Universität Darmstadt, Petersenstr. 22, 64287 Darmstadt, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Muschol
authors.affiliation: Department of Biology, Ghent University, Proeftuinstraat 86, 9000 Gent, Belgium.
authors.forename: Ineke
authors.initials: I
authors.lastname: Dhondt
authors.affiliation: Department of Biology, Ghent University, Proeftuinstraat 86, 9000 Gent, Belgium.
authors.forename: Huaihan
authors.initials: H
authors.lastname: Cai
authors.affiliation: Laboratory of Cell Biology & Histology, Dept. Veterinary Sciences, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; Cell Systems and Cellular Imaging (CSI), Department Molecular Technology, Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Winnok H
authors.initials: WH
authors.lastname: De Vos
authors.affiliation: Faculty of Chemistry, Technische Universität Darmstadt, Petersenstr. 22, 64287 Darmstadt, Germany.
authors.forename: Norbert A
authors.initials: NA
authors.lastname: Dencher
authors.affiliation: Department of Biology, Ghent University, Proeftuinstraat 86, 9000 Gent, Belgium. Electronic address: Bart.Braeckman@UGent.be.
authors.forename: Bart P
authors.initials: BP
authors.lastname: Braeckman
mesh_terms: D000367:Age Factors; D000375:Aging / Q000378:metabolism*; D000818:Animals; D061245:Axenic Culture; D017173:Caenorhabditis elegans / Q000254:growth & development / Q000378:metabolism*; D031204:Caloric Restriction; D045222:Electron Transport Chain Complex Proteins / Q000378:metabolism; D004734:Energy Metabolism; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000378:metabolism*; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D045222:Electron Transport Chain Complex Proteins; D017382:Reactive Oxygen Species
keywords: Axenic; Bioenergetics; Caenorhabditis elegans; Dietary restriction; Mitochondria; ROS