CTGF induces monocyte chemoattractant protein-1 expression to enhance monocyte migration in human synovial fibroblasts

► MCP-1 was highly expressed in OA synovial fibroblasts as compared with normal SFs. ► CTGF mediates the monocyte migration in OASFs by up-regulation of MCP-1 production. ► CTGF acts through the αvβ5 integrin, FAK, MEK, and ERK to induce MCP-1 activation. ► NF-κB and AP-1 are two key transcription factors of CTGF-induced MCP-1 activation.