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Cancer Cell death Cell cycle Cytoskeleton Exo/endocytosis Differentiation Division Organelles Signalling Stem cells Trafficking
Cell Biology International (2007) 31, 546–553 (Printed in Great Britain)
A reducing redox environment promotes C2C12 myogenesis: Implications for regeneration in aged muscle
Jason M. Hansena, Markus Klassa, Craig Harrisb and Marie Csetea*
aDepartment of Anesthesiology, School of Medicine, Emory University, 1462 Clifton Road NE, Suite 420, Atlanta, GA 30322, USA
bToxicology Program, Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA


Abstract

Intracellular redox potential of skeletal muscle becomes progressively more oxidized with aging, negatively impacting regenerative ability. We examined the effects of oxidizing redox potential on terminal differentiation of cultured C2C12 myoblasts. Redox potentials were manipulated by changing the culture O2 environment, by free radical scavenging, or addition of H2O2. Intracellular reactive oxygen species (ROS) production was higher in 20% environmental O2 and in this condition, redox potential became progressively oxidized compared to cultures in 6% O2. Treatment with a ROS trapping agent (phenyl-N-tert-butylnitrone, PBN) caused reducing redox potentials and enhanced C2C12 differentiation, while addition of 25 micromolar H2O2 to cells in 20% O2 dramatically slowed differentiation. Under these most oxidative conditions, quantitative PCR showed a significant decrease in myogenic basic helix–loop–helix transcription factor expression compared to cultures treated with PBN or grown in 6% O2. Thus, oxidative intracellular environments impair myoblast differentiation, while reducing environments favor myogenesis.


Key words: C2C12 myoblast, Muscle aging, Myoblast, Myogenin, Redox potential.

*Corresponding author. Tel.: +1 404 712 2588; fax: +1 404 712 2585.


Received 7 December 2005/13 November 2006; accepted 29 November 2006

doi:10.1016/j.cellbi.2006.11.027


ISSN Print: 1065-6995
ISSN Electronic: 1095-8355
Published by Portland Press Limited on behalf of the International Federation for Cell Biology (IFCB)