Objective: To analyze synovial membrane of patients with rheumatoid arthritis (RA) for the expression of unknown matrix metalloproteinases (MMP).
Methods: Degenerate oligonucleotides corresponding to highly conserved regions of the MMP gene family and the rapid amplification of cDNA ends (RACE) method have been used to search for new members of this gene family. MMP gene expression has been characterized by Northern blot analysis.
Results: We cloned a MMP cDNA from the synovial membrane that is completely identical to the recently published collagenase 3 cDNA derived from a human breast cancer cDNA library (Freije, et al: J Biol Chem 1994;269:16766-73). Collagenase 3 is expressed in parallel with interstitial collagenase and stromelysin 1 in RA and osteoarthritis (OA). Collagenase 3 gene expression was not detected in several normal human tissues.
Conclusion: The expression of collagenase 3 in the synovial membrane in RA and OA suggests its involvement in articular tissue degradation.