Increased Synoviolin (SYN) expression in the synovial fibroblasts from collagen-induced arthritis (CIA) mice. (a) Test of the specificity of anti-SYN antibody. HEK 293 cells were transfected with (lane 1) or without (lane 2) SYN expression plasmids. Lysates from the transfected cells were analyzed by SDS-PAGE and Western blotting using sera from the mice immunized with GST (glutathione S-transferase)-SYN fusion protein (top panel). The same membrane was reprobed with anti-actin (bottom panel). (b) Analysis of the protein expression of SYN in mouse synovial fibroblasts. Mouse synovial fibroblasts were isolated from each of three normal or CIA mice. Cells were lysed and subjected to SDS-PAGE and Western blotting using anti-SYN polyclonal antibodies (top panel). The same membrane was reprobed with anti-actin antibody (bottom panel). (c) Quantification of SYN expression. The densities of each band in (b) were analyzed, and the ratio of SYN/(10-1 actin) was used. Error bars represent three different CIA or normal mice. Statistic analysis indicates that the expression of SYN is significantly increased (p < 0.001).