Divya Mohan1, Amy Lewis2, Mehul S Patel1, Katrina J Curtis1, Jen Y Lee2, Nicholas S Hopkinson1, Ian B Wilkinson3, Paul R Kemp2, Michael I Polkey1. 1. NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, United Kingdom. 2. Section of Molecular Medicine, National Heart and Lung Institute, Imperial College, London, United Kingdom, SW7 2AZ. 3. Clinical Pharmacology Unit, Addenbrookes Hospital, University of Cambridge, Cambridge, United Kingdom.
Abstract
INTRODUCTION: Quadriceps dysfunction is important in chronic obstructive pulmonary disease (COPD), with an associated increased proportion of type II fibers. Investigation of protein synthesis and degradation has yielded conflicting results, possibly due to study of whole biopsy samples, whereas signaling may be fiber-specific. Our objective was to develop a method for fiber-specific gene expression analysis. METHODS: 12 COPD and 6 healthy subjects underwent quadriceps biopsy. Cryosections were immunostained for type II fibers, which were separated using laser capture microdissection (LCM). Whole muscle and different fiber populations were subject to quantitative polymerase chain reaction. RESULTS: Levels of muscle-RING-finger-protein-1 and Atrogin-1 were lower in type II fibers of COPD versus healthy subjects (P = 0.02 and P = 0.03, respectively), but differences were not apparent in whole muscle or type I fibers. CONCLUSIONS: We describe a novel method for studying fiber-specific gene expression in optimum cutting temperature compound-embedded muscle specimens. LCM offers a more sensitive way to identify molecular changes in COPD muscle. Muscle Nerve 55: 902-912, 2017.
INTRODUCTION: Quadriceps dysfunction is important in chronic obstructive pulmonary disease (COPD), with an associated increased proportion of type II fibers. Investigation of protein synthesis and degradation has yielded conflicting results, possibly due to study of whole biopsy samples, whereas signaling may be fiber-specific. Our objective was to develop a method for fiber-specific gene expression analysis. METHODS: 12 COPD and 6 healthy subjects underwent quadriceps biopsy. Cryosections were immunostained for type II fibers, which were separated using laser capture microdissection (LCM). Whole muscle and different fiber populations were subject to quantitative polymerase chain reaction. RESULTS: Levels of muscle-RING-finger-protein-1 and Atrogin-1 were lower in type II fibers of COPD versus healthy subjects (P = 0.02 and P = 0.03, respectively), but differences were not apparent in whole muscle or type I fibers. CONCLUSIONS: We describe a novel method for studying fiber-specific gene expression in optimum cutting temperature compound-embedded muscle specimens. LCM offers a more sensitive way to identify molecular changes in COPD muscle. Muscle Nerve 55: 902-912, 2017.
Authors: Sara C Buttery; Divya Mohan; Marie Fisk; Nicholas S Hopkinson; Ruth Tal-Singer; Ian B Wilkinson; Michael I Polkey Journal: Eur Respir J Date: 2017-08-10 Impact factor: 16.671
Authors: Gabriela da Silva Xavier; Angeles Mondragon; Vishnou Mourougavelou; Céline Cruciani-Guglielmacci; Jessica Denom; Pedro Luis Herrera; Christophe Magnan; Guy A Rutter Journal: Diabetologia Date: 2017-03-25 Impact factor: 10.122