title: Exercise-induced modulation of calcineurin activity parallels the time course of myofibre transitions.
abstract: This study establishes a causal link between the limitation of myofibre transitions and modulation of calcineurin activity, during different exercise paradigms. We have designed a new swimming-based training protocol in order to draw a comparison between a high frequency and amplitude exercise (swimming) and low frequency and amplitude exercise (running). We initially analysed the time course of muscle adaptations to a 6- or 12-week swimming- or running-based training exercise program, on two muscles of the mouse calf, the slow-twitch soleus and the fast-twitch plantaris. The magnitude of exercise-induced muscle plasticity proved to be dependent on both the muscle type and the exercise paradigm. In contrast to the running-based training which generated a continuous increase of the slow phenotype throughout a 12-week training program, swimming induced transitions to a slower phenotype which ended after 6 weeks of training. We then compared the time course of the exercise-induced changes in calcineurin activity during muscle adaptation to training. Both exercises induced an initial activation followed by the inhibition of calcineurin. In the muscles of animals submitted to a 12-week swimming-based training, this inhibition was concomitant with the end of myofibre transition. Calcineurin inhibition was a consequence of the inhibition of its catalytic subunit gene expression on one hand, and of the expression increase of the modulatory calcineurin interacting proteins 1 gene (MCIP1), on the other. The present study provides the first experimental cues for an interpretation of muscle phenotypic variation control.
authors.affiliation: Université Paris Descartes, Centre Universitaire des Saints-Pères, Laboratoire de Neurobiologie des Réseaux Sensorimoteurs, UMR 7060 CNRS, Equipe Biologie du Développement et de la Différenciation Neuromusculaire, Paris Cedex, France.
authors.forename: Clément
authors.initials: C
authors.lastname: Grondard
authors.forename: Olivier
authors.initials: O
authors.lastname: Biondi
authors.forename: Claude
authors.initials: C
authors.lastname: Pariset
authors.forename: Philippe
authors.initials: P
authors.lastname: Lopes
authors.forename: Séverine
authors.initials: S
authors.lastname: Deforges
authors.forename: Sylvie
authors.initials: S
authors.lastname: Lécolle
authors.forename: Bruno Della
authors.initials: BD
authors.lastname: Gaspera
authors.forename: Claude-Louis
authors.initials: CL
authors.lastname: Gallien
authors.forename: Christophe
authors.initials: C
authors.lastname: Chanoine
authors.forename: Frédéric
authors.initials: F
authors.lastname: Charbonnier
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D019703:Calcineurin / Q000235:genetics / Q000502:physiology*; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D005080:Exercise Test; D007150:Immunohistochemistry; D019344:Lactic Acid / Q000097:blood; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D009043:Motor Activity; D009046:Motor Neurons / Q000378:metabolism; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism*; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D020033:Protein Isoforms; D016760:Proto-Oncogene Proteins c-fos / Q000276:immunology; D012333:RNA, Messenger / Q000378:metabolism; D012420:Running; D013550:Swimming; D013997:Time Factors
chemical_list: D020033:Protein Isoforms; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; C519276:myosin heavy chain-1, mouse; D019344:Lactic Acid; D002795:Choline O-Acetyltransferase; C120817:calcineurin phosphatase; D019703:Calcineurin; D010744:Phosphoric Monoester Hydrolases; D018995:Myosin Heavy Chains