Adiponectin Inhibits LPS-Induced HMGB1 Release through an AMP Kinase and Heme Oxygenase-1-Dependent Pathway in RAW 264 Macrophage Cells

Figure 4

Effect of an HO-1 inhibitor on the anti-inflammatory action of adiponectin or IL-10 on LPS-induced HMGB1 release. Raw 264 cells were cultured as described in Figure 1 legend and were treated with dimethyl sulfoxide (DMSO, control) or ZnPP (1 μM) for 1 h before treatment with adiponectin (10 μg/mL) or IL-10 (100 ng/mL) for 18 h. Cells were then stimulated with LPS (200 ng/mL) for another 24 h. Culture medium was collected and analyzed by HMGB1 western blotting followed by quantification of the intensity of the chemiluminescent HMGB1 band. The results are expressed as means ± SE of three independent experiments ( significance compared with control; and significance compared with LPS treated cells; significance compared with LPS plus ZnPP treated cells).