Figure 3

Peptide treatment inhibited MMP and sPLA₂ gene expression in IL-1β induced RA SF. Cells were pretreated with the peptide (phospholipase inhibitor from python (PIP)-18), secretory phospholipase A₂ (sPLA₂) inhibitor (LY315920) or matrix metalloproteinase inhibitor (MMP-II) at 5 μM for one hour, and incubated with hrIL-1β (10 ng/ml) for 24 hours before isolating total RNA. Relative mRNA expression levels were determined by real-time PCR analyses, normalized to internal GAPD values, and plotted relative to control samples treated with vehicle (0.5% dimethyl sulfoxide). Gene-specific real-time analysis was performed for all seven mRNA targets, sPLA2, MMP-1, -2, -3, -9, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. Results shown are the mean ± standard deviation of fold inductions from three independent experiments with a pool of rheumatoid arthritis (RA) synovial fibroblast (SF) cultures obtained from five RA patients.