We showed previously that the attachment of synovial fibroblasts (SFs) to laminin-111 (LM-111) in the presence of TGF-ß induces significant expression of the matrix metalloproteinase (MMP)-3. Here we go on to investigate the regulation of additional MMPs and their specific tissue inhibitors of matrix proteases (TIMPs). Changes in steady state mRNA levels encoding TIMPs and MMPs were investigated by quantitative RT-PCR. Production of MMPs was monitored by a multiplexed immunoarray. Signal transduction pathways were studied by immunoblotting. Attachment of SFs to LM-111 in the presence of TGF-ß induced significant increases in MMP-3 mRNA (12.35-fold, p<0.001) and protein (mean 62 ng/mL, 6-fold, p<0.008) and in expression of MMP-10 mRNA (11.68-fold, p<0.05) and protein (54 ng/mL, 20-fold, p≥0.02). All other TIMPs and MMPs investigated failed to show this LM-111-facilitated TGF-ß response. No phosphorylation of NFκB was observed. We conclude that co-stimulation of SFs by LM-111 together with TGF-ß suffices to induce significant expression of MMP-3 and MMP-10 by SFs and that this induction is independent of NFκB phosphorylation.
- synovial fibroblast