Table of Contents
Journal of Signal Transduction
Volume 2012, Article ID 982794, 17 pages
http://dx.doi.org/10.1155/2012/982794
Review Article

Reactive Oxygen Species in Skeletal Muscle Signaling

Dipartimento di Scienze Biomolecolari, Università degli Studi di Urbino “Carlo Bo”, via Saffi 2, 61029 Urbino, Italy

Received 30 June 2011; Accepted 25 August 2011

Academic Editor: Saverio Francesco Retta

Copyright © 2012 Elena Barbieri and Piero Sestili. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Generation of reactive oxygen species (ROS) is a ubiquitous phenomenon in eukaryotic cells' life. Up to the 1990s of the past century, ROS have been solely considered as toxic species resulting in oxidative stress, pathogenesis and aging. However, there is now clear evidence that ROS are not merely toxic species but also—within certain concentrations—useful signaling molecules regulating physiological processes. During intense skeletal muscle contractile activity myotubes' mitochondria generate high ROS flows: this renders skeletal muscle a tissue where ROS hold a particular relevance. According to their hormetic nature, in muscles ROS may trigger different signaling pathways leading to diverging responses, from adaptation to cell death. Whether a “positive” or “negative” response will prevail depends on many variables such as, among others, the site of ROS production, the persistence of ROS flow or target cells' antioxidant status. In this light, a specific threshold of physiological ROS concentrations above which ROS exert negative, toxic effects is hard to determine, and the concept of “physiologically compatible” levels of ROS would better fit with such a dynamic scenario. In this review these concepts will be discussed along with the most relevant signaling pathways triggered and/or affected by ROS in skeletal muscle.