Fig. 2

Leptin-induced production/expression of matrix metalloproteinase-1 (MMP-1) (a), MMP-3 (b), MMP-13 (c), interleukin-6 (IL-6) (d), nitric oxide (NO) (e), inducible nitric oxide synthase (iNOS) (f) and cyclooxygenase-2 (COX-2) (g) in cartilage from patients with osteoarthritis (OA) in subgroups stratified by suppressor of cytokine signaling-3 (SOCS-3) expression in the non-treated cartilage. Human osteoarthritic cartilage was cultured with leptin (10 μg/ml) for 42 hours. Concentrations of MMP-1, MMP-3, MMP-13 and IL-6 were measured by ELISA, NO was determined as its metabolite nitrite by the Griess reaction and iNOS and COX-2 proteins were analyzed by western blotting. The circles represent the median change in the leptin-induced effects. The whiskers represent the 95 % confidence interval of the median. Numbers of patients from whom the cartilage samples were collected are indicated. Statistical significance was calculated using the Mann–Whitney test; *p < 0.05, **p < 0.01