Urokinase-type plasminogen activator, receptor, and inhibitor correlating with gelatinase-B (MMP-9) contribute to inflammation in gouty arthritis of the knee.
OBJECTIVE
To determine the possible role of the plasminogen activator (PA)/plasmin system in gouty arthritis.


METHODS
We compared the antigenic values of urokinase-type PA (uPA), soluble uPA receptor (suPAR), and PA inhibitor type-1 (PAI-1) and the levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 in 63 synovial fluid (SF) samples from knee joints of 38 patients with gouty arthritis and 20 SF samples from knee joints of 20 patients with osteoarthritis (OA).


RESULTS
The increases of uPA, suPAR, and PAI-1 antigenic values in SF were associated with increased levels of latent MMP-9 (pro-MMP-9) (p < 0.001, p < 0.001, p < 0.001, respectively) in gouty arthritis, whereas a correlation was not observed between uPA, suPAR, and PAI-1 antigenic values and MMP-2 levels. Increased uPA, suPAR, and PAI-1 antigenic values in gouty arthritis SF were also correlated to each other (p < 0.001, p < 0.001, p < 0.001). In gouty arthritis SF, no significant relations were observed between uPA and suPAR antigenic values and leukocyte, neutrophil, or monocyte counts, while increased values of PAI-1 corresponded closely with increased leukocyte and neutrophil counts (p = 0.005, p = 0.004). Significantly higher values of the uPA, suPAR, and PAI-1 (p < 0.001, p < 0.001, p = 0.012) appeared in SF of gouty arthritis than in SF from patients with OA.


CONCLUSIONS
These results show a correlation of the PA/plasmin system and MMP-9 in SF from patients with gouty arthritis, resulting in increased PA catalytic activity and contributing to inflammation in gouty arthritis.
Chu
Shu-Chen
SC
Institute of Biochemistry, School of Medicine, Chung Shan Medical University, Taiwan.
Yang
Shun-Fa
SF
Lue
Ko-Huang
KH
Hsieh
Yih-Shou
YS
Hsiao
Tang-Yan
TY
Lu
Ko-Hsiu
KH
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006073:Gout / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D006801:Humans; D007719:Knee Joint / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000276:immunology / Q000378:metabolism*; D008875:Middle Aged; D017395:Plasminogen Activator Inhibitor 1 / Q000276:immunology / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000276:immunology / Q000378:metabolism*; D055293:Receptors, Urokinase Plasminogen Activator; D013582:Synovial Fluid / Q000276:immunology / Q000378:metabolism*; D014568:Urokinase-Type Plasminogen Activator / Q000276:immunology / Q000378:metabolism*
C524898:PLAUR protein, human; D017395:Plasminogen Activator Inhibitor 1; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator; D020780:Matrix Metalloproteinase 9