Gelatinase activity in synovial fluid and synovium obtained from healthy and osteoarthritic joints of dogs.
OBJECTIVE
To determine matrix metalloproteinase (MMP) activity in synovial fluid (SF) obtained from the joints of dogs with degenerative joint disease (DJD) secondary to various underlying conditions.


METHODS
35 samples of SF obtained from 18 clinically normal (control) dogs and 34 samples of SF obtained from 17 dogs with DJD; dogs with DJD were from 2 populations (client-owned dogs and research dogs that had DJD secondary to the lysosomal storage disease mucopolysaccharidosis VII).


METHODS
MMP activity in samples of SF was semiquantitatively examined by use of gelatin or casein zymography. Western blot analysis was performed by use of antibodies for MMP-2 and MMP-9. In addition, in situ MMP activity was observed in sections of synovial membrane obtained from healthy and osteoarthritic joints.


RESULTS
Samples of SF from osteoarthritic joints had higher MMP-2 activity and dramatically increased MMP-9 activity, compared with values for healthy joints. Substrate-overlay analyses indicated minimal gelatin-degrading activity in synoviocytes obtained from control dogs, whereas greater activity was seen in osteoarthritic synoviocytes, with additional activity in the underlying tissue.


CONCLUSIONS
Higher MMP-2 activity and dramatic increases in MMP-9 activity were associated with the osteoarthritic state, even though MMP-2 activity was detected in healthy joints. This study expands information on MMP production in SF of osteoarthritic joints in other species and documents the similarity of MMP activity patterns regardless of the cause of DJD.
Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104-6044, USA.
Susan W
SW
Volk
Amy S
AS
Kapatkin
Mark E
ME
Haskins
Raquel M
RM
Walton
Marina
M
D'Angelo
D000818:Animals; D004283:Dog Diseases / Q000201:enzymology*; D004285:Dogs; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D016538:Mucopolysaccharidosis VII / Q000201:enzymology / Q000662:veterinary; D010003:Osteoarthritis / Q000201:enzymology / Q000209:etiology / Q000662:veterinary*; D012016:Reference Values; D013582:Synovial Fluid / Q000201:enzymology*; D013583:Synovial Membrane / Q000201:enzymology*
D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9