Fig. 3.

Inhibition of adiponectin-mediated gene expression in vitro by monoclonal antibodies (mAbs). To test the ability of the mAb KH4–8 to block adiponectin function, (a) human osteoblasts and (b) human umbilical vein endothelial cells (HUVECs) were treated with adiponectin (ADIPO) or KH4–8 mAb (mAb) or both. The mAb (~120 μg/mL) and recombinant adiponectin (2.5 μg/mL) were mixed and incubated for 1 h before being used to treat cells. After 24-h treatment, the culture supernatants were collected and frozen, and interleukin-6 (IL-6) and IL-8 were measured by using enzyme-linked immunosorbent assay (ELISA) (R&D Systems, Minneapolis, MN, USA). The experiments were performed in quadruplicate. The data shown are representative of three independent experiments, and similar results were obtained with all three mAbs. Values are expressed as mean ± standard error of the mean. The expression levels of the factors were compared between groups by using the Mann–Whitney test. *P <0.05, **P <0.01 versus the untreated group, ^#P <0.05, ^##P <0.01 versus the group treated with adiponectin and mAb