The expression of TXNDC5 in synovial membranes, synovial fluid and blood of patients with rheumatoid arthritis / 中华风湿病学杂志

ABSTRACT

Objective To investigate the expression of thiredoxin domain containing 5 (TXNDC5) in the synovial tissues and blood samples of various arthritic conditions and autoimmune diseases to further confirm the previous findings, investigate the relations between the expression level of TXNDC5 and clinical parameters of RA. Methods The expression of TXNDC5 in the synovium was quantitatively analyzed by immunohistochemistry, real-time quantitative PCR and Western blotting. The levels of TXNDC5 in blood and synovial fluid was determined using sandwich ELISA in patients with RA, osteoarthritis (OA), systemic lupus erythematosus (SLE), ankylosing spondylitis (AS) and normal controls. One-way ANOVA, LSD test and Spearmen' s correlation were used for statistical analysis. Results Immunohistochemistry indicated that TXNDC5 expression was significantly higher in the synovial tissues of RA (100%, 40±9) than in those of OA and AS(200%,4±4). Real time PCR and western blotting confirmed the above findings (P<0.01). Sandwich-ELISA indicated significantly elevated level of TXNDC5 in the blood and synovial fluid of patients with RA (A=1.31±0.37), but not in those of OA, SLE, and AS, the healthy controls (P<0.01). The level of TXNDC5 in the blood of RA patients (A=0.8185±0.299) was positively correlated with the level of anti-CCP (r=0.350, P =0.027). Conclusion The results suggest that the pronounced increase of TXNDC5 expression may stimulate synovial pannus formation in the hypoxic environment of RA.