Early detection of skeletal muscle bioenergetic deficit by magnetic resonance spectroscopy in cigarette smoke-exposed mice

PLoS One. 2020 Jun 22;15(6):e0234606. doi: 10.1371/journal.pone.0234606. eCollection 2020.

Abstract

Skeletal muscle dysfunction is a common complication and an important prognostic factor in patients with chronic obstructive pulmonary disease (COPD). It is associated with intrinsic muscular abnormalities of the lower extremities, but it is not known whether there is an easy way to predict its presence. Using a mouse model of chronic cigarette smoke exposure, we tested the hypothesis that magnetic resonance spectroscopy allows us to detect muscle bioenergetic deficit in early stages of lung disease. We employed this technique to evaluate the synthesis rate of adenosine triphosphate (ATP) and characterize concomitant mitochondrial dynamics patterns in the gastrocnemius muscle of emphysematous mice. The fibers type composition and citrate synthase (CtS) and cytochrome c oxidase subunit IV (COX4) enzymatic activities were evaluated. We found that the rate of ATP synthesis was reduced in the distal skeletal muscle of mice exposed to cigarette smoke. Emphysematous mice showed a significant reduction in body weight gain, in the cross-sectional area of the total fiber and in the COX4 to CtS activity ratio, due to a significant increase in CtS activity of the gastrocnemius muscle. Taken together, these data support the hypothesis that in the early stage of lung disease, we can detect a decrease in ATP synthesis in skeletal muscle, partly caused by high oxidative mitochondrial enzyme activity. These findings may be relevant to predict the presence of skeletal bioenergetic deficit in the early stage of lung disease besides placing the mitochondria as a potential therapeutic target for the treatment of COPD comorbidities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / biosynthesis
  • Adenosine Triphosphate / deficiency
  • Animals
  • Energy Metabolism*
  • Lung Diseases / diagnosis
  • Magnetic Resonance Spectroscopy / methods
  • Mice
  • Mitochondria / metabolism
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / physiopathology*
  • Nicotiana / adverse effects
  • Pulmonary Disease, Chronic Obstructive / diagnosis
  • Smoke / adverse effects*

Substances

  • Smoke
  • Adenosine Triphosphate

Associated data

  • figshare/10.6084/m9.figshare.10048418.v1

Grants and funding

This study was supported in part by a Spanish Society of Pulmonology and Thoracic Surgery Grant (SPR - SEPAR 2014 and EB - SEPAR 2018); Instituto de Salud Carlos III – Acción Estratégica en Salud (GPB - AES 13/01909, GBP - 16/01783, EB - 18/00075); Fundación Catalana de Pneumología (EB - FUCAP) 2016 and EB - Unrestricted grant from Fondazione Internazionale Menarini 2018 (Spain). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.