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This Article Full Text Full Text (PDF) All Versions of this Article: 295/4/R1263    most recent 90455.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Dupont-Versteegden, E. E. Articles by Peterson, C. A. PubMed PubMed Citation Articles by Dupont-Versteegden, E. E. Articles by Peterson, C. A.

EXERCISE AND RESPIRATORY PHYSIOLOGY

Identification of cold-shock protein RBM3 as a possible regulator of skeletal muscle size through expression profiling

¹Department of Rehabilitation Sciences, Division of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington; ²Department of Biostatistics, ³College of Public Health, and ⁴Department of Information Technology, University of Arkansas for Medical Sciences, Little Rock, Arkansas; ⁵Department of Biostatistics, University of Wisconsin, Milwaukee, Wisconsin; and ⁶College of Health Sciences, University of Kentucky, Lexington, Kentucky

Submitted 28 May 2008 ; accepted in final form 15 August 2008

Changes in gene expression associated with skeletal muscle atrophy due to aging are distinct from those due to disuse, suggesting that the response of old muscle to inactivity may be altered. The goal of this study was to identify changes in muscle gene expression that may contribute to loss of adaptability of old muscle. Muscle atrophy was induced in young adult (6-mo) and old (32-mo) male Brown Norway/F344 rats by 2 wk of hindlimb suspension (HS), and soleus muscles were analyzed by cDNA microarrays. Overall, similar changes in gene expression with HS were observed in young and old muscles for genes encoding proteins involved in protein folding (heat shock proteins), muscle structure, and contraction, extracellular matrix, and nucleic acid binding. More genes encoding transport and receptor proteins were differentially expressed in the soleus muscle from young rats, while in soleus muscle from old rats more genes that encoded ribosomal proteins were upregulated. The gene encoding the cold-shock protein RNA-binding motif protein-3 (RBM3) was induced most highly with HS in muscle from old rats, verified by real-time RT-PCR, while no difference with age was observed. The cold-inducible RNA-binding protein (Cirp) gene was also overexpressed with HS, whereas cold-shock protein Y-box-binding protein-1 was not. A time course analysis of RBM3 mRNA abundance during HS showed that upregulation occurred after apoptotic nuclei and markers of protein degradation increased. We conclude that a cold-shock response may be part of a compensatory mechanism in muscles undergoing atrophy to preserve remaining muscle mass and that RBM3 may be a therapeutic target to prevent muscle loss.

aging; microarray; Cirp; atrophy