Thrombin receptor mediated signals induce expressions of interleukin 6 and granulocyte colony stimulating factor via NF-κB activation in synovial fibroblasts

OBJECTIVE To clarify the mechanism of thrombin receptor mediated signal transduction and the induction of cytokines by thrombin stimulation in rheumatoid synovial fibroblasts. METHODS Cytokines were measured by enzyme linked immunosorbent assay (ELISA) in the supernatants of cultured rheumatoid synovial fibroblasts stimulated by thrombin. To assess the mechanism of thrombin receptor mediated signal transduction in the rheumatoid synovial fibroblasts, electrophoretic mobility gel shift assay (EMSA), immunoglobulin κ-chloramphenicol acetyltransferase (CAT) assay, and immunostaining for NF-κB subunit molecule was performed. RESULTS Thrombin stimulation activated the inducible transcription factor NF-κB, and then induced subsequent expressions of interleukin 6 (IL6) and granulocyte colony stimulating factor (G-CSF) in the cells. CONCLUSION Thrombin receptor mediated signal transduction could induce the expressions of IL6 and G-CSF, and increase inflammatory events in the cavum articulare via NF-κB activation.