To identify suitable promoters for expressing exogenous genes in arthritic joints, the constitutive, simian virus 40 (SV 40) and IL-1 or metal inducible, human stromelysin and metallothionein (MT) gene promoters were tested for their activity in chondrocytes and synovial fibroblasts. Transient transfection with plasmids containing the reporter chloramphenicol acetyltransferase (CAT) gene attached to these promoters showed that SV40, stromelysin and MT promoters drove CAT expression with different strengths in primary bovine chondrocytes. The MTI-F and MT-IG gene promoters were also functional in human chondrocytes. The SV40, IL-1 inducible stromelysin-1 and MT-IG driven CAT activity was also detectable in human synoviocytes. Therefore, chondrocytes and synoviocytes have the trans-acting factors necessary for transcription from the respective promoters which may be conserved in bovine and human cells. These promoters could be useful for expressing potentially therapeutic anti-inflammatory and anti-erosive genes in arthritic joints.
