title: Does oxidative stress modulate limb muscle atrophy in severe COPD patients?
abstract: Oxidative stress may differentially regulate protein loss within peripheral muscles of severe chronic obstructive pulmonary disease (COPD) patients exhibiting different body composition. Oxidation levels of proteins, myosin heavy chain (MyHC) and myonuclei, superoxide anion, antioxidants, actin, creatine kinase, carbonic anhydrase-3, ubiquitin-proteasome system, redox-signalling pathways, inflammation and muscle structure, and damage were quantified in limb muscles of severe COPD patients with and without muscle wasting, and in sedentary controls. Compared with controls, in the quadriceps of muscle-wasted COPD patients, levels of protein carbonylation, oxidation of MyHC and myonuclei, superoxide anion production, superoxide dismutase, total protein ubiquinitation, E2(14k), atrogin-1, FoxO1 and p65 were higher, while content of MyHC, creatine kinase, carbonic anhydrase-3, myogenin, and fast-twitch fibre size were decreased. Importantly, in nonwasted COPD patients, where MyHC was more oxidised than in controls, its content was preserved. Muscle inflammation and glutathione levels did not differ between patients and controls. In all patients, muscle structure abnormalities were increased, while muscle force and exercise capacity were reduced. In severe COPD, while muscle oxidative stress increases regardless of their body composition, protein ubiquitination and loss of MyHC were enhanced only in patients exhibiting muscle atrophy. Oxidative stress does not seem to directly modulate muscle protein loss in these patients.
authors.affiliation: Pulmonology Dept, Muscle and Respiratory System Research Unit, IMIM-Hospital del Mar, Health and Experimental Sciences Dept, Universitat Pompeu Fabra, PRBB, Barcelona, Spain.
authors.forename: Clara
authors.initials: C
authors.lastname: Fermoselle
authors.forename: Roberto
authors.initials: R
authors.lastname: Rabinovich
authors.forename: Pilar
authors.initials: P
authors.lastname: Ausín
authors.forename: Ester
authors.initials: E
authors.lastname: Puig-Vilanova
authors.forename: Carlos
authors.initials: C
authors.lastname: Coronell
authors.forename: Francisco
authors.initials: F
authors.lastname: Sanchez
authors.forename: Josep
authors.initials: J
authors.lastname: Roca
authors.forename: Joaquim
authors.initials: J
authors.lastname: Gea
authors.forename: Esther
authors.initials: E
authors.lastname: Barreiro
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D005121:Extremities; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000503:physiopathology; D009133:Muscular Atrophy / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D052097:Quadriceps Muscle / Q000378:metabolism / Q000503:physiopathology
chemical_list: D009124:Muscle Proteins