Expression and significance of cyclophilin A in synovial fibroblasts from patients with rheumatoid arthritis

Abstract

To observe the expression of cyclophilin A (CyPA) and the effects of lipopolysaccharide (LPS) on CyPA expression in synovial fibroblasts (SF) from patients with rheumatoid arthritis (RA) and evaluate the potential significance of CyPA in the regulation of the onset and development of inflammation process in RA patients. SF were separated and cultured from synovial tissues of 12 patients with RA, 9 with osteoarthritis (OA) and 5 with knee trauma. The protein and mRNA expression levels of CyPA in SF were detected by Western blot (WB) and real-time quantitative polymerase chain reaction (RT-qPCR) respectively. Correlation analysis was conducted between the protein expression of CyPA in SFs and clinical parameters. Then the effects of LPS on CyPA in SF from 3 groups were detected. The expression levels of CyPA protein and mRNA in RA group were 0.86 ± 0.47 and 0.54 ± 0.22 respectively, significantly higher than those in OA group (0.40 ± 0.31 and 0.03 ± 0.02, P < 0.05) and trauma group (0.34 ± 0.21 and 0.03 ± 0.01, P < 0.05). The protein expression level of CyPA in SF of RA group had positive correlations with erythroeyte sedimentation rate (ESR), rheumatoid factor (RF) and swelling joint counts (SJC) (P < 0.05). After LPS treatment, CyPA protein and mRNA levels were 2.65 ± 1.16 and 1.82 ± 0.39 in RA SF and they were significantly higher than those in RA SF without LPS treatment (P < 0.05). The CyPA expression of SF from OA and trauma groups slightly decreased after LPS treatment.However the differences were not statistically significant (P > 0.05). The expression of CyPA is up-regulated in SF and it is positively correlated with ESR, RF and SJC in RA patients. It indicates that CyPA may be involved in the regulation of the onset and development of inflammation process of RA. And LPS may promote the expression of CyPA in SF of RA patients.