Cyclic Loading Inhibits Expression of MMP-3 but Not MMP-1 in an In Vitro Rabbit Flexor Tendon Model

Details

• Personal Author:
  Asundi KR ; Rempel DM
• Description:
  Background. Gene expression analysis is useful for assessing cellular behavior and may improve our understanding of the initial cellular response to mechanical load leading to tendon degeneration. This study assessed gene expression of MMP-1 and MMP-3, genes associated with matrix degradation, in tendons exposed to cyclic loads within physiologic range. Methods. Six flexor tendons from each of ten New Zealand White rabbits were harvested and randomly assigned to one of the following six groups: load deprived for 18 h; cyclically loaded for 18 h to a peak stress of 2 MPa; 3 MPa; 4 MPa; 5 MPa; or snap frozen in liquid nitrogen. MMP-1, MMP-3 and 18 s mRNA expression was measured by qRT-PCR. Findings. No significant differences in MMP-1 mRNA expression levels were found between loading groups. MMP-3 expression was significantly inhibited (57%) in tendons cyclically loaded to a peak stress of 4 MPa in comparison to load deprived tendons, however, when peak stress was increased to 5 MPa, expression was no longer significantly lower compared to stress shielded tendons. Interpretation. The results suggest a 'U' shape relationship between load and MMP-3 expression. The lack of change in MMP-1 expression with loading was unexpected as inhibition of MMP-1 in response to mechanical load has been demonstrated in previous studies. In conclusion, we demonstrate that MMP-3 expression is modulated by cyclic load and is sensitive to load magnitude. MMP-1 mRNA expression is not significantly modulated by cyclic load in this model. [Description provided by NIOSH]
• Subjects:
  Biomechanical Phenomena Engineering Environmental Monitoring Ergonomics Genetics Laboratories Musculoskeletal Diseases Musculoskeletal System Nervous System Occupational Health Risk Assessment Risk Factors Safety

  More +
• Keywords:
  Author Keywords: Tendinopathy Biological-effects Biological-function Biomechanical-engineering Biomechanical-modeling Biomechanics Cell-biology Cellular-reactions Control-technology Dynamic Tissue Loading Engineering-controls Exposure-assessment Exposure-levels Exposure-methods Genetic-factors Injury-prevention Laboratory-animals Laboratory-testing Matrix Metalloproteinase Mechanics Musculoskeletal-system Musculoskeletal-system-disorders Neurological-reactions Organ Culture Overuse Injury Physiological-effects Physiological-measurements Physiological-response Quantitative-analysis Repetitive-work Risk-analysis Risk-factors Statistical-analysis

  More +
• ISSN:
  0268-0033
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  California ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  117-121
• Volume:
  23
• Issue:
  1
• NIOSHTIC Number:
  nn:20037280
• Citation:
  Clin Biomech 2008 Jan; 23(1):117-121
• Contact Point Address:
  Dr. David Rempel, Department of Bioengineering, University of California, Berkeley, 1301 South 46th Street, Building 163, Richmond, CA 94804
• Email:
  david.rempel@ucsf.edu
• Federal Fiscal Year:
  2008
• Performing Organization:
  University of California, Berkeley
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Clinical Biomechanics
• End Date:
  20250630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:b086c3db50c2423fcf4ac7d1a4ce505495111b8d6296b443a19197b343d2797d2c55fc901e52ec3149619d92d91e31356994a71901087239b1de11092ea82443
• Download URL:
  https://stacks.cdc.gov/view/cdc/188396/cdc_188396_DS1.pdf
• File Type:
  [PDF - 155.76 KB ]