Figure 5

Inhibition of trypsin-induced nuclear factor (NF)-κB activation by proteinase-activated receptor-2-inhibiting peptide (PAR2-IP) in synovial cells. Human primary synovial cells or synoviosarcoma SW982 cells were treated with trypsin and/or PAR2-IP, and the levels of phospho-p65 (p-p65), an activated NF-κB, and/or IκBα, an NF-κB inhibitor, were analyzed by western blotting. (A) Cells were incubated in serum-free DMEM medium (for primary cells) or L15 medium (for SW982 cells), and then treated with 60 nM trypsin for 15, 30, 60 and 120 minutes. (B) Cells were treated with 75 μM PAR2-IP or 60 nM trypsin alone for 30 minutes, or in combination with adding PAR2-IP first for 30 minutes and then trypsin for another 30 minutes. The relative levels of p-p65 were calculated by normalizing the band densities to that of GAPDH and setting the controls as 100%.