title: Depletion of the p43 mitochondrial T3 receptor in mice affects skeletal muscle development and activity.
abstract: In vertebrates, skeletal muscle myofibers display different contractile and metabolic properties associated with different mitochondrial content and activity. We have previously identified a mitochondrial triiodothyronine receptor (p43) regulating mitochondrial transcription and mitochondrial biogenesis. When overexpressed in skeletal muscle, it increases mitochondrial DNA content, stimulates mitochondrial respiration, and induces a shift in the metabolic and contractile features of muscle fibers toward a slower and more oxidative phenotype. Here we show that a p43 depletion in mice decreases mitochondrial DNA replication and respiratory chain activity in skeletal muscle in association with the induction of a more glycolytic muscle phenotype and a decrease of capillary density. In addition, p43(-/-) mice displayed a significant increase in muscle mass relative to control animals and had an improved ability to use lipids. Our findings establish that the p43 mitochondrial receptor strongly affects muscle mass and the metabolic and contractile features of myofibers and provides evidence that this receptor mediates, in part, the influence of thyroid hormone in skeletal muscle.
authors: Institut National de Recherche Agronomique (INRA), Unité Mixte de Recherche (UMR)866 Dynamique Musculaire et Métabolisme, Montpellier, France.
authors: Laurence
authors: L
authors: Pessemesse
authors: Audrey
authors: A
authors: Schlernitzauer
authors: Chamroeun
authors: C
authors: Sar
authors: Jonathan
authors: J
authors: Levin
authors: Stéphanie
authors: S
authors: Grandemange
authors: Pascal
authors: P
authors: Seyer
authors: François B
authors: FB
authors: Favier
authors: Sandra
authors: S
authors: Kaminski
authors: Gérard
authors: G
authors: Cabello
authors: Chantal
authors: C
authors: Wrutniak-Cabello
authors: François
authors: F
authors: Casas
mesh_terms: D000818:Animals; D004261:DNA Replication; D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism; D004579:Electron Transport; D006984:Hypertrophy; D050356:Lipid Metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D009119:Muscle Contraction; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism; D018482:Muscle, Skeletal / Q000098:blood supply / Q000254:growth & development* / Q000378:metabolism*; D010101:Oxygen Consumption; D010641:Phenotype; D011988:Receptors, Thyroid Hormone / Q000172:deficiency* / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial; D011988:Receptors, Thyroid Hormone