Utilization of Military-Relevant Muscle Injury Models to Identify Pharmacological Treatment Strategies

Abstract

This study was designed to characterize critical molecules involved in skeletal muscle response to ischemia-reperfusion (I/R) and blunt trauma injury in order to identify strategies for pharmacological intervention. For I/R injury, a tourniquet was applied to rat hind limbs for 3 h. Extensor digitorum longus (EDL) muscles from the healthy and I/R leg were harvested 2 h post-reperfusion for analysis. For the blunt trauma model, mice were anesthetized, the tibialis anterior (TA) muscle was exposed, and injury was induced by applying a steel probe (cooled to -20 C) to the belly of the TA muscle. Muscle samples were collected from the healthy and injured leg 3, 10, 24, 48, and 72 h post-injury. Quantitative Real Time Polymerase Chain Reaction (qRT-PCR), immunoblotting, and immunohistochemistry were used to quantify/localize analytes of interest. I/R resulted in a significant (p<0.05) upregulation of MT (4.7- fold) and MMP-9 (2.6- fold) mRNA, with no change in MMP-2. Blunt trauma/freeze injury resulted in an upregulation of mRNA expression at 3h, 10h, 24h, 48h, and 72h, respectively for MT (2.15-, 3.43-, 4.23-, 3.50-, 1.2 (n.s.)- fold), MMP-2 (1.25-(n.s), 1.28-(n.s), 1.07-(n.s), 1.84- and 1.86-fold), and MMP-3 (4.70-, 67.68-, 40.04-, 24.29, and 14.0-fold). Protein levels of MT and MMP-2 also increased several-fold post-injury with a decrease in the active form of MMP-3. We conclude that MT production is related to injury-induced oxidative-stress, which affects extracellular matrix integrity, explaining our observed increase in the MMPs. Thus, oxidative mediated extracellular matrix disruption is a potential mechanism for skeletal muscle proteolysis post-injury.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 2008
Accession Number
ADA505798

Entities

People

  • Brian R. Barnes
  • Bruce T. Liang
  • Edward J. Zambraski
  • Eric R. Szelenyi
  • Maria L. Urso
  • Robert O. Nicholson
  • Thomas J. Walters

Organizations

  • United States Army Research Institute of Environmental Medicine

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Aneurysm
  • Chemical Reactions
  • Chemical Synthesis
  • Chemistry
  • Health Services
  • Immunohistochemistry
  • Medical Personnel
  • Molecules
  • Muscle Cells
  • Muscle Fibers
  • Muscles
  • Oxidative Stress
  • Polymerase Chain Reaction
  • Skeletal Muscle
  • Tissues
  • Vascular Diseases

Fields of Study

  • Biology
  • Chemistry

Readers

  • Molecular Biology and Genetics
  • Trauma Surgery or Emergency Medicine.