title: FoxO-dependent atrogenes vary among catabolic conditions and play a key role in muscle atrophy induced by hindlimb suspension.
abstract: Muscle atrophy is a debilitating condition that affects a high percentage of the population with a negative impact on quality of life. Dissecting the molecular level of the atrophy process, and the similarities/dissimilarities among different catabolic conditions, is a necessary step for designing specific countermeasures to attenuate/prevent muscle loss. The FoxO family transcription factors represent one of the most important regulators of atrophy programme stimulating the expression of many atrophy-related genes. The findings of the present study clearly indicate that the signalling network controlling the atrophy programme is specific for each catabolic condition.
  
  
  
  Muscle atrophy is a complex process that is in common with many different catabolic diseases including disuse/inactivity and ageing. The signalling pathways that control the atrophy programme in the different disuse/inactivity conditions have not yet been completely dissected. The inhibition of FoxO is considered to only partially spare muscle mass after denervation. The present study aimed: (i) to determine the involvement of FoxOs in hindlimb suspension disuse model; (ii) to define whether the molecular events of protein breakdown are shared among different unloaded muscles; and finally (iii) to compare the data obtained in this model with another model of inactivity such as denervation. Both wild-type and muscle-specific FoxO1,3,4 knockout (FoxO1,3,4-/-) mice were unloaded for 3 and 14 days and muscles were characterized by functional, morphological, biochemical and molecular assays. The data obtained show that FoxOs are required for muscle loss and force drop during unloading. Moreover, we found that FoxO-dependent atrogenes vary in different unloaded muscles and that they diverge from denervation. The findings of the present study clearly indicate that the signalling network that controls the atrophy programme is specific for each catabolic condition.
authors: Department of Molecular Medicine, University of Pavia, Pavia, Italy.|Interuniversity Institute of Myology, University of Pavia, Pavia, Italy.
authors: Lorenza
authors: L
authors: Brocca
authors: Department of Biomedical Sciences, University of Padova, Padova, Italy.
authors: Luana
authors: L
authors: Toniolo
authors: Department of Biomedical Sciences, University of Padova, Padova, Italy.
authors: Carlo
authors: 0000-0001-8080-361X
authors: C
authors: Reggiani
authors: Department of Molecular Medicine, University of Pavia, Pavia, Italy.|Interdipartimental Centre for Biology and Sport Medicine, University of Pavia, Pavia, Italy.|Fondazione Salvatore Maugeri (IRCCS) , Scientific Institute of Pavia, Pavia, Italy.
authors: Roberto
authors: R
authors: Bottinelli
authors: Department of Biomedical Sciences, University of Padova, Padova, Italy.|Venetian Institute of Molecular Medicine, Padova, Italy.
authors: Marco
authors: M
authors: Sandri
authors: Department of Molecular Medicine, University of Pavia, Pavia, Italy.|Interuniversity Institute of Myology, University of Pavia, Pavia, Italy.|Interdipartimental Centre for Biology and Sport Medicine, University of Pavia, Pavia, Italy.
authors: Maria Antonietta
authors: 0000-0002-1653-1266
authors: MA
authors: Pellegrino
mesh_terms: D000818:Animals; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D019417:Hindlimb Suspension / Q000009:adverse effects; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000473:pathology; D009133:Muscular Atrophy / Q000209:etiology / Q000378:metabolism*
chemical_list: D051858:Forkhead Transcription Factors
keywords: atrogenes regulation; muscle atrophy; muscle disuse