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Physics - Rheumatology

The CCL2/CCR2 Axis Enhances Vascular Cell Adhesion Molecule-1 Expression in Human Synovial Fibroblasts
Published: Wednesday, November 21, 2012
Author: Yu-Min Lin et al.

by Yu-Min Lin, Chin-Jung Hsu, Yuan-Ya Liao, Ming-Chih Chou, Chih-Hsin Tang


Chemokine ligand 2 (CCL2), also known as monocyte chemoattractant protein-1 (MCP-1), belongs to the CC chemokine family that is associated with the disease status and outcomes of osteoarthritis (OA). Here, we investigated the intracellular signaling pathways involved in CCL2-induced vascular cell adhesion molecule-1 (VCAM-1) expression in human OA synovial fibroblasts (OASFs).

Methodology/Principal Findings

Stimulation of OASFs with CCL2 induced VCAM-1 expression. CCL2-mediated VCAM-1 expression was attenuated by CCR2 inhibitor (RS102895), PKCd inhibitor (rottlerin), p38MAPK inhibitor (SB203580), and AP-1 inhibitors (curcumin and tanshinone IIA). Stimulation of cells with CCL2 increased PKCd and p38MAPK activation. Treatment of OASFs with CCL2 also increased the c-Jun phosphorylation and c-Jun binding to the AP-1 element on the VCAM-1 promoter. Moreover, CCL2-mediated CCR2, PKCd, p38MAPK, and AP-1 pathway promoted the adhesion of monocytes to the OASFs monolayer.


Our results suggest that CCL2 increases VCAM-1 expression in human OASFs via the CCR2, PKCd, p38MAPK, c-Jun, and AP-1 signaling pathway. The CCL2-induced VCAM-1 expression promoted monocytes adhesion to human OASFs.