Figure 3. KU-55933 blocks growth factor-mediated Akt phosphorylation in differentiated but not undifferentiated SH-SY5Y cells.

A, cells were serum-starved for 6 h and treated with KU-55933 (10 µmol/L) for 1 h before treatment with insulin (100 nmol/L) for 45 min. Cells were lysed, and cell lysates were subjected to SDS-PAGE and Western blotting for the detection of phospho-Akt at Ser473 and Thr308. β-actin was the loading control. B, cells were serum-starved for 6 h and treated with KU-55933 (10 µmol/L) for 1 h before treatment with IGF-I (25 ng/mL), NGF (25 ng/mL) or BDNF (25 ng/mL) for 45 min. Cells were lysed, and cell lysates were subjected to SDS-PAGE and Western blotting for the detection of phospho-Akt at Ser473. β-actin was the loading control.