Related Experiment Videos
Increased expression of extracellular matrix metalloproteinase inducer in rheumatoid synovium
Y T Konttinen1, T F Li, J Mandelin
1Department of Anatomy, University of Helsinki, Finland.
Objective:
To investigate the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) in the synovial membrane of patients with rheumatoid arthritis (RA) and osteoarthritis (OA).
Methods:
Mouse monoclonal antibody against human EMMPRIN was applied according to an avidin-biotin-peroxidase complex method to reveal EMMPRIN expression. Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR) were performed to check for the presence of EMMPRIN protein and messenger RNA (mRNA).
Results:
EMMPRIN immunoreactivity was more intense in RA than in OA synovial membrane (P < 0.01). EMMPRIN staining was more widespread in RA than in OA, especially in association with macrophage infiltrates. RT-PCR of synovial membrane samples disclosed the presence of EMMPRIN mRNA. Nucleotide sequencing of the PCR amplification products confirmed the identity of the amplified bands. Immunoblot analysis revealed 55-kd glycosylated EMMPRIN bands, which were particularly prominent in RA samples.
Conclusion:
The expression of EMMPRIN is upregulated in the rheumatoid synovial membrane. EMMPRIN can induce local production of at least MMPs 1, 2, and 3, and can thereby play a role in joint destruction in RA.