A. The effects of TSP-1, TGF-β1, CTGF and VEGF stimulation/silencing in RA-FLS on TSP-1, TGF-β1, CTGF, and VEGF proteins expression in the supernatants were determined by ELISA. RA-FLS were stimulated with CTGF (500 ng/ml), TGF-β1 (5ng/ml), TSP-1 (1,000 ng/ml) and VEGF (50 ng/ml) respectively for 48 h. Stimulation (n = 3)/silencing (n = 3) of TGF-β1 in RA-FLS resulted in significant increase/decrease in the supernatants protein expression of TSP-1, CTGF, and VEGF (p < 0.05). Stimulation (n = 3)/silencing (n = 3) of VEGF in RA-FLS leaded to similar changes of the other three protein expression in supernatants (p < 0.05). Addition(n = 3)/silencing(n = 3) of CTGF in RA-FLS caused significant up-/down-regulation in the supernatants protein expression of TSP-1 and VEGF (p < 0.05). And stimulation (n = 3)/knockdown (n = 3) of TSP-1 in RA-FLS didn’t lead to significant increase/decrease in the expression of supernatants protein TGF-β1, CTGF and VEGF. B. TSP-1, TGF-β1, CTGF and VEGF mRNA expression levels were analyzed by real-time PCR after TSP-1, TGF-β1, CTGF and VEGF stimulation/silencing. Results showed similar alterations of TSP-1, TGF-β1, CTGF and VEGF mRNA expression as demonstrated in supernatants protein regulation after TSP-1, TGF-β1, CTGF and VEGF stimulation/silencing (n = 3 respectively; p < 0.05). Results are expressed as the mean ± S.E.M. *p < 0.05, **p < 0.01, ***p < 0.001 versus Veh, #p < 0.05, ##p < 0.01, ###p < 0.001 versus Scr siRNA. Veh = vehicle control. Scr siRNA = scramble siRNA.