Leptin Enhances Synthesis of Proinflammatory Mediators in Human Osteoarthritic Cartilage—Mediator Role of NO in Leptin-Induced , IL-6, and IL-8 Production
Figure 1
The effect of leptin on NO production (a), iNOS protein expression (b), PG production (c), COX-2 protein expression (d), IL-6 production (e), and IL-8 production (f) in human OA cartilage. Cartilage explants were incubated with leptin (0.1 g/mL or 10 g/mL) for 48 hours. NO production (a) was measured as nitrite accumulation in the culture medium by Griess reaction. Expression of iNOS protein (b) and COX-2 protein (d) were measured by Western blot. PG production (c) in the culture medium was measured by RIA. Concentrations of IL-6 (e), and IL-8 (f) in the culture medium were measured by ELISA. Results are expressed as pmol/mg cartilage (a), as percentages in comparison with control sample ((b) and (d)) or pg/mg cartilage ((c), (e), and (f)). Values are mean SEM. Samples were collected from 6 patients () in (a) and (c), from 3 patients () in (b) and (d), and from 7 patients () in (e) and (f). #: , *: , and **: as compared to control explants incubated in absence of exogenous leptin.
