Figure 1.

Glucose uptake in rat L6 myoblasts and in murine muscle incubated with ABA: effect of AMPK inhibition and LANCL2 silencing. (a) Serum-starved rat L6 myoblasts were: (i) pre-incubated for 30 min without (control) or with the AMPK inhibitor dorsomorphin (1 µM), or (ii) transiently transfected with scramble (siRNA-SCR) or LANCL2-targeting siRNA (siRNA-L2), then incubated without (control) or with 100 nM ABA, without or with 1 µM dorsomorphin, for 30 min and uptake of the fluorescent glucose analog 2-NBDG was measured after 10 min incubation with the dye. Results are expressed as fluorescence relative to control (mean ± SD from at least 3 experiments; *p = 0.001 relative to control, ^#p = 0.002 relative to ABA, **p = 0.001 relative to siRNA-SCR without ABA, ^$p = 0.002 relative to siRNA-SCR + ABA). Inset: a representative Western blot of LANCL2 expression in siRNA-SCR vs. siRNA-L2 cells. (b) Ligand Tracer analysis of FDG uptake by L6 cells stably infected with a scramble (shRNA-SCR, upper panel) or with a LANCL2-targeting shRNA (shRNA-L2, lower panel). Cells were pre-incubated with or without 100 nM ABA for 1 hour before being placed in the Ligand Tracer device. Cytochalasin B and Phloretin were added at time zero of the Ligand Tracer analysis (cyto-phlo). Representative traces are shown on the left and mean ± SD values from 3 experiments are shown on the right. Inset: a representative Western blot of LANCL2 expression in shRNA-SCR vs. shRNA-L2 cells. *p < 0.03 relative to control. (c) Freshly isolated samples of femoral quadriceps (~100 mg) were pre-incubated, or not (control) with 1 microM dorsomorphin (Dorso) and then time-activity curves of FDG uptake were recorded, in the absence (control) and in the presence of 100 nM ABA. Representative curves are shown on the left and central panel (without and with Dorso, respectively) and the mean ± SD from 3 experiments is shown on the right panel. *p = 0.007 relative to control, #p = 0.007 relative to ABA.