Figure 2. Activation of AMPK by OA-NO₂ does not require LKB1.

A) Phosphorylation of LKB1 Ser428 was not affected by OA-NO₂ in BAECs. Confluent BAECs were exposed to 2.5 µM OA-NO₂ for 16 h, and phosphorylated LKB1-Ser428 was detected by a phospho-specific antibody in western blots. The blot is a representative of three blots obtained from three independent experiments. Lower panels: summary data (n = 3). B) LKB1 is not required for AMPK activation by OA-NO₂. Confluent LKB1-deficient Hela-S3 cells were exposed to 2.5 µM OA-NO₂ for 16 h, and then AMPK and ACC phosphorylation were assayed as described in Materials and Methods. The blot is representative of three blots obtained from three independent experiments. Lower panels: summary data (*p<0.05 vs. control; n = 3). C) LKB1 siRNA did not abolish OA-NO₂-stimulated AMPK activation in HUVECs. HUVECs were incubated with LKB1-specific siRNA or control siRNA for 48 h and then treated with OA-NO₂ or vehicle for 16 h. After treatment, cell lysates were analyzed for LKB1 protein levels and AMPK phosphorylation at Thr172. Lower panels: summary data (*p<0.05 vs. control; n = 3).