FIGURE 4.

Genetic mutants of AMPK indicate that the effects of metformin on LPS-induced cytokines are independent of AMPK. AMPKα1-deficient (A–D) and AMPKβ1-deficient (E–G) BMDMs were pretreated with metformin (Met, 5 mm) for 1 h before stimulation with LPS (100 ng/ml) for 24 h. Whole cell lysates were analyzed by Western blotting for AMPKα1, pro-IL-1β, AMPKβ1, and β-actin (A, B, and E). The blots in A, B, and E are representative of three independent experiments. Supernatants were analyzed by ELISA for TNF-α (C and F) and IL-10 (D and G) production. The data in C, D, F, and G are expressed as mean ± S.E. of three independent experiments, each performed in triplicate. Ctl, control.