Figure 1

Induction of cyclooxidase-2 (COX-2) and matrix metalloproteinase-1 (MMP-1) expression by trypsin in human primary cells. Human primary cells were cultured as described in Materials and Methods. COX-2 and MMP-1 expression levels after trypsin treatment were analyzed by western blotting. Chondrocytes (A) and synovial cells (B) were treated with 30 nM trypsin in serum-free DMEM for different time periods as indicated. (C) Primary synovial cells were treated with various concentrations of trpsin for 8 hours.