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Matrix metalloproteinase 13 (collagenase 3) in human rheumatoid synovium
O Lindy1, Y T Konttinen, T Sorsa
1University of Helsinki, Finland.
Objective:
To show the eventual presence and extent of production of matrix metalloproteinase 13 (MMP-13, or collagenase 3) in rheumatoid synovial tissue samples and extracts, and to assess the inhibition characteristics of recombinant MMP-13.
Methods:
Immunohistochemical avidin-biotin-peroxidase complex staining/morphometry was used to analyze MMP-13-positive cells in situ. Neutral salt extraction of synovial tissue, electrophoresis of the extract in different buffer systems, and Western blotting were also used. The inhibitory properties of doxycycline, clodronate, pamidronate, and D-penicillamine for recombinant enzyme were determined with a soluble type II collagen assay.
Results:
MMP-13 was detected in fibroblast- and macrophage-like mononuclear cells in the synovial lining and stroma and in vascular endothelial cells. The overall expression of MMP-13 in these cells in the synovial stroma was high in rheumatoid arthritis (86 +/- 12%) compared with osteoarthritis (17 +/- 5%) patient samples (P = 0.0027). In a high-pH native electrophoresis gel, immunoreactivity to anti-MMP-1 and anti-MMP-13 were clearly separated, with anti-MMP-13-immunoreactive material migrating faster than anti-MMP-1-immunoreactive material. Finally, in contrast to MMP-1 and MMP-8, MMP-13 was found to be relatively resistant to the inhibitory effects of doxycycline and clodronate in vitro.
Conclusion:
Due to its localization in synovial tissue, its substrate profile, increased expression, and relative resistance to known MMP inhibitors, MMP-13 is suggested to play a major role in the pathogenesis of tissue destruction in rheumatoid arthritis.
Insights
Matrix metalloproteinase 13 (MMP-13) is highly expressed in rheumatoid arthritis synovial tissue. MMP-13 plays a key role in rheumatoid arthritis pathogenesis and tissue destruction.
Area of Science:
- Rheumatology
- Biochemistry
- Immunology
Background:
- Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by joint destruction.
- Matrix metalloproteinases (MMPs) are implicated in extracellular matrix degradation in RA.
- MMP-13 (collagenase 3) role in RA pathogenesis requires further elucidation.
Purpose of the Study:
- To investigate the presence and extent of MMP-13 production in rheumatoid synovial tissue.
- To characterize the inhibitory properties of various compounds against recombinant MMP-13.
Main Methods:
- Immunohistochemistry and morphometry to detect MMP-13-positive cells in synovial tissue.
- Western blotting and electrophoresis to analyze MMP-13 expression and characteristics.
- In vitro enzyme assays to assess inhibition by doxycycline, clodronate, pamidronate, and D-penicillamine.
Main Results:
- MMP-13 was detected in fibroblast-like, macrophage-like, and endothelial cells within RA synovial tissue.
- MMP-13 expression was significantly higher in RA (86%) compared to osteoarthritis (17%) samples.
- MMP-13 demonstrated relative resistance to inhibition by doxycycline and clodronate in vitro.
Conclusions:
- MMP-13's localization, increased expression in RA, and resistance to inhibitors suggest a significant role in RA-driven tissue destruction.
- Targeting MMP-13 may offer a therapeutic strategy for rheumatoid arthritis.