title: Influence of mitochondrial DNA level on cellular energy metabolism: implications for mitochondrial diseases.
abstract: The total amount of cellular mitochondrial DNA (mtDNA) varies widely and seems to be related to the nature and metabolic state of tissues and cells in culture. It is not known, however, whether this variation has any significance in vivo, and to which extent it regulates energy production. To better understand the importance of the cellular mtDNA level, we studied the influence of a gradual reduction of mtDNA copy number on oxidative phosphorylation in two models: (a) a control human cell line treated with different concentrations of 2', 3'-dideoxycytidine, a nucleoside analogue that inhibits mtDNA replication by interfering with mitochondrial DNA polymerase gamma, and (b) a cell line derived from a patient presenting mtDNA depletion. The two models were used to construct biochemical and phenotypic threshold curves. Our results show that oxidative phosphorylation activities are under a tight control by the amount of mtDNA in the cell, and that the full complement of mtDNA molecules are necessary to maintain a normal energy production level.
authors.affiliation: U688 INSERM-Université Victor Segalen Bordeaux2, 146 rue Léo-Saignat, 33076, Bordeaux-Cedex, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Rocher
authors.forename: Jan-Willem
authors.initials: JW
authors.lastname: Taanman
authors.forename: Denis
authors.initials: D
authors.lastname: Pierron
authors.forename: Benjamin
authors.initials: B
authors.lastname: Faustin
authors.forename: Giovani
authors.initials: G
authors.lastname: Benard
authors.forename: Rodrigue
authors.initials: R
authors.lastname: Rossignol
authors.forename: Monique
authors.initials: M
authors.lastname: Malgat
authors.forename: Laurence
authors.initials: L
authors.lastname: Pedespan
authors.forename: Thierry
authors.initials: T
authors.lastname: Letellier
mesh_terms: D000818:Animals; D002468:Cell Physiological Phenomena; D003198:Computer Simulation; D004272:DNA, Mitochondrial / Q000235:genetics*; D004734:Energy Metabolism / Q000235:genetics*; D006801:Humans; D028361:Mitochondrial Diseases / Q000235:genetics*; D008957:Models, Genetic
chemical_list: D004272:DNA, Mitochondrial