title: Exercise modulates liver cellular and mitochondrial proteins related to quality control signaling.
abstract: OBJECTIVE
  The effects of exercise on cardiac and skeletal muscle, including the increase on mitochondrial function, dynamics, biogenesis and autophagy signaling are well described. However, these same effects on liver mitochondria, important in the context of hepatocyte ability to mitigate drug-induced injury and obesity-related disorders, are not fully understood. Therefore, the effects of two distinct chronic exercise models (endurance training--ET and voluntary physical activity--VPA) on liver cellular and mitochondrial quality control were analyzed.
  
  
  METHODS
  Eighteen male-adult Sprague-Dawley rats were divided into sedentary (SED), ET (12-week treadmill) and VPA (12-week voluntary free wheel). Liver mitochondrial alterations were evaluated by semi-quantification of proteins involved in oxidative stress (SIRT3, p66shc, p66(Ser36)), biogenesis (citrate synthase, PGC-1α and mtTFA), dynamics (MFN1, OPA1 and DRP1) and auto(mito)phagy (Beclin-1, Bcl-2, LC3II/LC3I, p62, Parkin and PINK) signaling. Liver ultrastructural alterations were also evaluated.
  
  
  RESULTS
  Both exercise models induced beneficial alterations on liver mitochondrial morphology and increased mitochondrial biogenesis (PGC-1α and mtTFA), autophagy-related proteins (Beclin-1, LC3-II, LC3II/LC3I), and DRP1 and SIRT3 proteins. Increased citrate synthase activity and OPA1, p62 and Parkin content as well as decreased PINK protein levels were only observed after ET. VPA decreased OPA1, Beclin-1/Bcl-2, Parkin and p66(Ser36). Mitochondrial density and circularity increased in both exercised groups.
  
  
  CONCLUSIONS
  Both chronic exercise models increased proteins related with mitochondrial biogenesis and alteration proteins involved in mitochondrial dynamics and autophagy signaling, suggesting that exercise can induce liver mitochondrial adaptive remodeling and hepatocyte renewal.
authors.affiliation: CIAFEL - Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal.
authors.forename: E
authors.initials: E
authors.lastname: Santos-Alves
authors.affiliation: CIAFEL - Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal.
authors.forename: I
authors.initials: I
authors.lastname: Marques-Aleixo
authors.affiliation: Department of Physiology and Immunology, Faculty of Biology, Universitat de Barcelona, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Rizo-Roca
authors.affiliation: Department of Physiology and Immunology, Faculty of Biology, Universitat de Barcelona, Spain.
authors.forename: J R
authors.initials: JR
authors.lastname: Torrella
authors.affiliation: CNC - Centre for Neuroscience and Cell Biology, University of Coimbra, Portugal.
authors.forename: P J
authors.initials: PJ
authors.lastname: Oliveira
authors.affiliation: CIAFEL - Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Magalhães
authors.affiliation: CIAFEL - Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal. Electronic address: aascensao@fade.up.pt.
authors.forename: A
authors.initials: A
authors.lastname: Ascensão
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation / Q000502:physiology*; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000096:biosynthesis*; D018384:Oxidative Stress / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D024101:Mitochondrial Proteins
keywords: Mitochondrial plasticity; Physical activity; Quality control