Gene expression of synovial fibroblast samples from osteoarthritis patients after cytokine and NOC-18 treatment. Synovial fibroblasts (SFs) from patients with osteoarthritis (OA) were cultured in the presence or absence of various cytokines or the nitric oxide donor (Z)-1-(2-(2-aminoethyl)-N-(2-ammonioethyl) amino)diazen-1-ium-1,2-diolate diethylenetriamine (NOC-18) for 24 hours. Relative gene expression (referred to hypoxanthine phosphoribosyl transferase) was determined by realtime PCR. The relative gene expression in the unstimulated cells for each gene is defined as 100%. (a) Tumor growth factor beta 1 (TGF-β1) stimulation (n = 6). (b) TNFα stimulation (n = 6). (c) IL-1β stimulation (n = 3). (d) IL-17 stimulation (n = 3). (e) NOC-18 stimulation (n = 3). Data shown as mean ± standard error mean. *P < 0.05, **P < 0.01, ***P < 0.0015 (paired t test). GusB, β-D-glucuronidase; HexA, hexosaminidase A subunit; HexB, hexosaminidase B subunit.