Effects of TGF-beta, GM-CSF, and PDGF on Proliferation and Expression of Cytokine and Metalloproteinase Genes in Rheumatoid Synovial Cells

Rho, Yong Gyun; Yu, Su Jin; Cheon, Hyeon Joo; Sohn, Jeong Won

Abstract

To investigate effects of cytokines on rheumatoid synovial cells, proliferation and expression of cytokine and metalloproteinase genes were studied with the primary culture of rheumatoid synovial cells which was treated with TNF-alpha, GM-CSF, TGF-alpha, PDGF and IL-B. By [3H] thymidine incorporation assay, TGF-beta and PDGF increased proliferation of synovial cells by 1.5 and 2.5 folds respectively. Cytokine gene expression was assessed by RT-PCR. Rheumatoid synovial cells expressed constitutively TGF-beta and IL-B at a high level and IL-1B, GM-CSF, and MIP-1a at a relatively low level. TGF-beta, GM-CSF and PDGF increased IL-B expression. Expression of pro-inflammatory cytokines and chemokines was increased by GM-CSF and PDGF. Both GM-CSF and PDGF increased the expression of IL-1B, GM-CSF MIP-la and IL-8. In addition, GM-CSF enhanced expression of TNF-alpha. Stromelysin and collagenase are the major proteinases responsible for destruction ot joints in rheumatoid arthritis (RA). These genes were expressed constitutivefy in rheumatoid synovial cells. In summary, PDGF and GM-CSF may piay an important role by inducing or increasing expression of IL-1B, TGF-beta and PDGF by increasing proliferation of rheumatoid synovial cells.