FIG. 2.

Effect of DPP4 on insulin-stimulated Akt phosphorylation in adipocytes and skeletal muscle cells. Differentiated human adipocytes (A and B) and skeletal muscle cells (C and D) were treated with the indicated amounts of DPP4 without and with concomitant administration of a specific DPP4 inhibitor for 24 h. After stimulation with insulin (100 nmol/L, 10 min), the cells were lysed and 5–10 μg of total lysates were resolved by SDS-PAGE and blotted to polyvinylidene fluoride membranes. Membranes were blocked with 5% milk in TBS containing 0.1% Tween 20 and incubated overnight with p-Akt antibody. After incubation with the appropriate HRP-coupled secondary antibody, the signal was detected by enhanced chemiluminescence. Signals were analyzed on a LUMI Imager Work Station (Boehringer). Data are actin normalized mean values ± SEM (n = 3–8). Representative Western blots are presented. For A, lanes were excised from a single Western blot and displayed in the presented order. Basal (white bars); insulin-stimulated (black bars). *Significantly different from insulin-stimulated control or indicated situation. ns, not significant.