Evaluation of tartrate-resistant acid phosphatase and cathepsin K in ruptured cranial cruciate ligaments in dogs.
OBJECTIVE
To determine localization of tartrate-resistant acid phosphatase (TRAP) and cathepsin K in ruptured and healthy cranial cruciate ligaments (CCL) in dogs.


METHODS
30 dogs with ruptured CCL, 8 aged dogs without ruptured CCL, and 9 young dogs without ruptured CCL.


METHODS
The CCL was examined histologically and cells containing TRAP and cathepsin K were identified histochemically and immunohistochemically, respectively.


RESULTS
Cathepsin K and TRAP were detected within the same cells, principally within the epiligamentous region and to a lesser extent in the core region of ruptured CCL. Numbers of cells containing TRAP and cathepsin K were significantly greater in ruptured CCL, compared with CCL from young or aged dogs, and numbers of such cells were greater in CCL from aged dogs, compared with those of young dogs. In aged dogs, small numbers of cells containing TRAP and cathepsin K were seen in intact CCL associated with ligament fascicles in which there was chondroid transformation of ligament fibroblasts and disruption of the extracellular matrix.


CONCLUSIONS
Ruptured CCL contain greater numbers of cells with the proteinases TRAP and cathepsin K than CCL from healthy, young, or aged dogs. Results suggest that cell-signaling pathways that regulate expression of these proteinases may form part of the mechanism that leads to upregulation of collagenolytic ligament remodeling and progressive structural failure of the CCL over time.
Muir
Peter
P
Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706, USA.
Hayashi
Kei
K
Manley
Paul A
PA
Colopy
Sara A
SA
Hao
Zhengling
Z
D000135:Acid Phosphatase / Q000378:metabolism*; D000375:Aging / Q000502:physiology; D000818:Animals; D056657:Cathepsin K; D002403:Cathepsins / Q000378:metabolism*; D004283:Dog Diseases / Q000201:enzymology*; D004285:Dogs; D005260:Female; D006614:Hindlimb / Q000201:enzymology / Q000293:injuries*; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism*; D007596:Joints / Q000201:enzymology / Q000293:injuries; D008022:Ligaments / Q000201:enzymology* / Q000293:injuries*; D008297:Male; D012421:Rupture / Q000201:enzymology* / Q000662:veterinary*; D000071681:Tartrate-Resistant Acid Phosphatase
D007527:Isoenzymes; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D002403:Cathepsins; D056657:Cathepsin K