Table of Contents
ISRN Obesity
Volume 2012 (2012), Article ID 647348, 14 pages
http://dx.doi.org/10.5402/2012/647348
Research Article

Docosahexaenoic Acid Protects Muscle Cells from Palmitate-Induced Atrophy

Division of Exercise Physiology, School of Medicine, West Virginia University, Morgantown, WV 26506-9227, USA

Received 6 July 2012; Accepted 29 August 2012

Academic Editors: K. Abberton and E. Rodríguez Rodríguez

Copyright © 2012 Randall W. Bryner et al. 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

Background. Accumulation of free fatty acids leads to lipid-toxicity-associated skeletal muscle atrophy. Palmitate treatment reduces myoblast and myotube growth and causes apoptosis in vitro. It is not known if omega-3 fatty acids will protect muscle cells against palmitate toxicity. Therefore, we examined the effects of docosahexaenoic acid (DHA) on skeletal muscle growth. Methods. Mouse myoblasts (C2C12) were differentiated to myotubes, and then treated with 0 or 0.5 mM palmitic acid or 0 or 0.1 mM DHA. Results. Intramyocellular lipid was increased in palmitate-treated cells but was prevented by DHA-palmitate cotreatment. Total AMPK increased in DHA+ palmitate-treated compared to palmitate only cells. RpS6 phosphorylation decreased after palmitate (−55%) and this was blunted by DHA+ palmitate (−35%) treatment. Palmitate treatment decreased PGC1 protein expression by 69%, but was increased 165% with DHA+ palmitate ( ) versus palmitate alone. While palmitate induced 25% and 90% atrophy in myotubes (after 48 hours and 96 hours, resp.), DHA+ palmitate treatment caused myotube hypertrophy of ~50% and 100% after 48 and 96 hours, respectively. Conclusion. These data show that DHA is protective against palmitate-induced atrophy. Although DHA did not activate the AMPK pathway, DHA treatment restored growth-signaling (i.e., rpS6) and rescued palmitate-induced muscle atrophy.