CypA expression in synovial tissues and CypA secretion from FLS of CIA mice. (a) Representative western blots of CypA levels in the lysates obtained from synovial tissues of control and CIA mice. Protein levels of CypA were normalized to GAPDH and the data are expressed as the percentage of control values. Three separate experiments (n = 3 mice in each) were performed (control: 100.0 ± 4.4%, CIA: 668.0 ± 22.24%). (b) Representative photographs showing immunohistochemical staining of CypA in synovial tissues of control and CIA mice (left and middle panel, respectively; n = 4 mice in each group). Right panel (negative control) showing immunohistochemical staining of CypA in synovial tissues of CIA mice according to the method described above, except that the primary antibody was omitted. (c,d) Representative western blots of CypA in the conditioned medium (c: top panel) and in the cell lysates (d) of FLS culture treated with vehicle and LPS (100 ng/mL for 24 h). β-actin was used as an internal control. Densitometric analysis was performed on protein bands and the data are expressed as the percentage of vehicle values. Each bar indicates mean ± S.E.M. (n = 5) *P < 0.05, significantly different from vehicle (c: bottom panel). Three separate experiments (n = 2 dishes in each) were performed (vehicle: 100.0 ± 1.0%, LPS: 104.9 ± 1.9%) (d).