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: Clara Fermoselle, Roberto Rabinovich, Pilar Ausín, Ester Puig-Vilanova, Carlos Coronell, Francisco Sanchez, Josep Roca, Joaquim Gea, Esther Barreiro
• Journal: The European respiratory journal (Eur Respir J) Vol. 40 Issue 4 Pg. 851-62 (Oct 2012) ISSN: 1399-3003 [Electronic] England
• PMID: 22408199 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Muscle Proteins

Topics

• Aged
• Case-Control Studies
• Extremities
• Humans
• Inflammation (metabolism)
• Male
• Middle Aged
• Muscle Proteins (metabolism)
• Muscle, Skeletal (metabolism, physiopathology)
• Muscular Atrophy (complications, metabolism, physiopathology)
• Oxidation-Reduction
• Oxidative Stress (physiology)
• Pulmonary Disease, Chronic Obstructive (complications, metabolism, physiopathology)
• Quadriceps Muscle (metabolism, physiopathology)