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Journal of Biomedicine and Biotechnology
Volume 2012 (2012), Article ID 704061, 12 pages
http://dx.doi.org/10.1155/2012/704061
Research Article

Influences of Desmin and Keratin 19 on Passive Biomechanical Properties of Mouse Skeletal Muscle

1Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
2Departments of Orthopaedic Surgery and Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
3Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
4Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD 21201, USA

Received 28 May 2011; Accepted 10 September 2011

Academic Editor: J.-P. Jin

Copyright © 2012 Sameer B. Shah 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

In skeletal muscle fibers, forces must be transmitted between the plasma membrane and the intracellular contractile lattice, and within this lattice between adjacent myofibrils. Based on their prevalence, biomechanical properties and localization, desmin and keratin intermediate filaments (IFs) are likely to participate in structural connectivity and force transmission. We examined the passive load-bearing response of single fibers from the extensor digitorum longus (EDL) muscles of young (3 months) and aged (10 months) wild-type, desmin-null, K19-null, and desmin/K19 double-null mice. Though fibers are more compliant in all mutant genotypes compared to wild-type, the structural response of each genotype is distinct, suggesting multiple mechanisms by which desmin and keratin influence the biomechanical properties of myofibers. This work provides additional insight into the influences of IFs on structure-function relationships in skeletal muscle. It may also have implications for understanding the progression of desminopathies and other IF-related myopathies.