Akt phosphorylation is decreased by AChR antibodies in myotubes but not in myoblasts. Immortalized human muscle cells (LHCN) were differentiated over 7 days (D7) or kept as myoblasts (D0). AChR monoclonal antibodies (mAb 198 or mAb 155) or isotype control (IgG2a) were added 48 h before the analysis. The cells were stimulated with insulin or not (Unstimulated) and the proteins were extracted and analyzed via a Western Blot. A representative image of the Western Blot result is shown in panel A. The ratio between pAkt and total Akt band intensities is represented in graphs for myoblasts (B) and myotubes at D7 (C). In each group, the sample size was n = 5–7 from three independent experiments. Asterisks represent significance given by an ANOVA analysis versus the control condition (Dunnett’s post test). Mean ± SEM is represented. ***p < 0.001; **p < 0.01; *p < 0.05.