Upregulation of α-skeletal muscle actin and myosin heavy polypeptide gene products in degenerating rotator cuff muscles

✍ Scribed by Bruno Fuchs; Matthias Zumstein; Felix Regenfelder; Patrick Steinmann; Thomas Fuchs; Knut Husmann; Jens Hellermann; Bernhard Jost; Jürg Hodler; Walter Born; C. Gerber

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 191 KB
• Volume: 26
• Category: Article
• ISSN: 0736-0266
• DOI: 10.1002/jor.20577

✦ Synopsis

Abstract

Impaired function of shoulder muscles, resulting from rotator cuff tears, is associated with abnormal deposition of fat in muscle tissue, but corresponding cellular and molecular mechanisms, likely reflected by altered gene expression profiles, are largely unknown. Here, an analysis of muscle gene expression was carried out by semiquantitative RT‐PCR in total RNA extracts of supraspinatus biopsies collected from 60 patients prior to shoulder surgery. A significant increase of α‐skeletal muscle actin (p = 0.0115) and of myosin heavy polypeptide 1 (p = 0.0147) gene transcripts was observed in parallel with progressive fat deposition in the muscle, assessed on parasagittal T1‐weighted turbo‐spin‐echo magnetic resonance images according to Goutallier. Upregulation of α‐skeletal muscle actin and of myosin heavy polypeptide‐1 has been reported to be associated with increased muscle tissue metabolism and oxidative stress. The findings of the present study, therefore, challenge the hypothesis that increased fat deposition in rotator cuff muscle after injury reflects muscle degeneration. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1007–1011, 2008