Fig. 4.

Cyr61 secretion induced by IL-6. a, b Extracellular protein levels of Cyr61 in culture supernatants of IL-6-treated RA-FLSs measured by western blotting. b IL-6 (20 ng/mL). c, d FLSs stimulated by extracellular Cyr61 (100 ng/mL) for indicated time periods. c Protein levels were determined by western blotting. d The mRNA levels of Cyr61 were determined through real time polymerase chain reaction. e–h The mRNA levels of Cyr61, MMP1, 2, and GAPDH induced by IL-6 (20 ng/mL) and extracellular Cyr61 protein (100 ng/mL) for 2 h. e, f The mRNA levels were determined by reverse-transcription polymerase chain reaction. g, h The mRNA levels were determined through real time polymerase chain reaction. Data are representative of at least three independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001