Evaluation of collagenase activity, matrix metalloproteinase-8, and matrix metalloproteinase-13 in horses with chronic obstructive pulmonary disease.
OBJECTIVE
To determine collagenase activity and evaluate matrix metalloproteinase (MMP)-8 and MMP-13 in horses with chronic obstructive pulmonary disease (COPD).


METHODS
12 horses with COPD and 12 healthy control horses.


METHODS
Collagenase activity was determined by use of an assay for degradation of type-I collagen. Western immunoblot analysis was used to identify interstitial collagenases MMP-8 and MMP-13 in tracheal epithelial lining fluid (TELF). Immunocytochemistry and in situ hybridization were used to determine cellular expression of these 2 collagenases in cells in bronchoalveolar lavage fluid (BALF).


RESULTS
Collagenase activity was approximately 7 times higher in samples obtained from horses with COPD, compared with control horses. During stabling, horses with COPD had significantly higher collagenase activity than after being maintained on summer pasture, when activity was similar to that of control horses. Immunoreactivity of MMP-8 and MMP-13 was significantly increased in TELF of horses with COPD, compared with healthy horses. In TELF, a positive correlation was detected between immunoreactivity of MMP-8 and MMP-13 and the amount of degradation of type-I collagen. Macrophages and epithelial cells were the major cellular sources of MMP-8 and MMP-13.


CONCLUSIONS
Increased collagenase activity in TELF indicates active ongoing disease and, thus, may reflect lung tissue changes in horses with COPD. Measurements of collagenase activity and MMP immunoreactivity may provide additional diagnostic tools to identify the active phase of chronic lung disease.
Raulo
S M
SM
Department of Clinical Veterinary Sciences, Faculty of Veterinary Medicine, Helsinki University, Finland.
Sorsa
T A
TA
Kiili
M T
MT
Maisi
P S
PS
D000818:Animals; D015153:Blotting, Western / Q000662:veterinary; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D003094:Collagen / Q000378:metabolism; D017364:Collagenases / Q000096:biosynthesis / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D005260:Female; D006734:Horse Diseases / Q000201:enzymology* / Q000473:pathology; D006736:Horses; D007150:Immunohistochemistry / Q000662:veterinary; D017403:In Situ Hybridization / Q000662:veterinary; D008297:Male; D053509:Matrix Metalloproteinase 13; D020784:Matrix Metalloproteinase 8 / Q000096:biosynthesis / Q000378:metabolism*; D009504:Neutrophils / Q000201:enzymology; D029424:Pulmonary Disease, Chronic Obstructive / Q000201:enzymology / Q000473:pathology / Q000662:veterinary*; D018709:Statistics, Nonparametric; D014132:Trachea / Q000201:enzymology
D003094:Collagen; D017364:Collagenases; D053509:Matrix Metalloproteinase 13; D020784:Matrix Metalloproteinase 8