Annals of Biomedical Engineering

, Volume 43, Issue 9, pp 2036–2046

Cathepsins in Rotator Cuff Tendinopathy: Identification in Human Chronic Tears and Temporal Induction in a Rat Model

  • Song P. Seto
  • Akia N. Parks
  • Yongzhi Qiu
  • Louis J. Soslowsky
  • Spero Karas
  • Manu O. Platt
  • Johnna S. Temenoff
Article

DOI: 10.1007/s10439-014-1245-8

Cite this article as:
Seto, S.P., Parks, A.N., Qiu, Y. et al. Ann Biomed Eng (2015) 43: 2036. doi:10.1007/s10439-014-1245-8

Abstract

While overuse of the supraspinatus tendon is a leading factor in rotator cuff injury, the underlying biochemical changes have not been fully elucidated. In this study, torn human rotator cuff (supraspinatus) tendon tissue was analyzed for the presence of active cathepsin proteases with multiplex cysteine cathepsin zymography. In addition, an overuse injury to supraspinatus tendons was induced through downhill running in an established rat model. Histological analysis demonstrated that structural damage occurred by 8 weeks of overuse compared to control rats in the region of tendon insertion into bone. In both 4- and 8-week overuse groups, via zymography, there was approximately a 180% increase in cathepsin L activity at the insertion region compared to the controls, while no difference was found in the midsubstance area. Additionally, an over 400% increase in cathepsin K activity was observed for the insertion region of the 4-week overused tendons. More cathepsin K and L immunostaining was observed at the insertion region of the overuse groups compared to controls. These results provide important information on a yet unexplored mechanism for tendon degeneration that may operate alone or in conjunction with other proteases to contribute to chronic tendinopathy.

Keywords

Supraspinatus tendon Proteases Tendon tear Cathepsins 

Abbreviations

MMP

Matrix metalloproteinase

OCT

Optimum cutting temperature

H&E

Hematoxylin and eosin

SDS

Sodium dodecyl sulfate

Copyright information

© Biomedical Engineering Society 2015

Authors and Affiliations

  • Song P. Seto
    • 1
  • Akia N. Parks
    • 1
  • Yongzhi Qiu
    • 1
  • Louis J. Soslowsky
    • 2
  • Spero Karas
    • 3
  • Manu O. Platt
    • 1
    • 4
  • Johnna S. Temenoff
    • 1
    • 4
    • 5
  1. 1.W.H. Coulter Department of Biomedical EngineeringGeorgia Institute of Technology and Emory UniversityAtlantaUSA
  2. 2.McKay Orthopaedic Research LaboratoryUniversity of PennsylvaniaPhiladelphiaUSA
  3. 3.Department of OrthopaedicsEmory UniversityAtlantaUSA
  4. 4.Petit Institute for Bioengineering and BioscienceGeorgia Institute of TechnologyAtlantaUSA
  5. 5.W.H. Coulter Department of Biomedical EngineeringGeorgia Tech/Emory UniversityAtlantaUSA

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