FIGURE 3.

Orm is induced by both proinflammatory and metabolic signals. A, TNFα induces the three Orm isoforms in 3T3-L1 adipocytes. Differentiated adipocytes were treated with TNFα (10 ng/ml) for 15 h. mRNA levels of each isoform of Orm, TNFα, and adiponectin (AdipoQ) were analyzed by Q-PCR. mRNA levels of TNFα and adiponectin (AdipoQ) were used as controls for the effect of TNFα. B, metabolic signals induce the three Orm isoforms. Differentiated adipocytes were preincubated in low glucose (Glc; 5.5 mm) media for 24 h and then treated with a series of concentrations of insulin (10 or 100 nm) in the presence or absence of high glucose (Glc; 25 mm) challenge. C, effect of palmitate (Pal; 500 μm) on Orm mRNA expression in 3T3-L1 adipocytes. D, secretion of ORM is promoted by metabolic and inflammatory signals in adipocytes. Differentiated adipocytes were preincubated in low glucose (Glc; 5.5 mm) containing DMEM supplemented with 0.2% bovine serum albumin. After 24 h, culture media were chased with fresh media, and the cells were treated with insulin (Ins; 100 nm), TNFα (10 ng/ml) or high glucose (25 mm) for additional 24 h. Secretion of ORM was evaluated by Western blot analysis with the cell-conditioned media. Ctl, control.