Effect of LY294002 on Akt/GSK-3β/PDK-1 signaling and the inhibition of GSK-3β activity on PDK-1 expression. The cells were exposed to PDGF, or with increasing LY294002 concentrations of 1, 2, 5 and 20 µM for 24 h, prior to detection of the expression of (A and B) p-Akt, (C and D) GSK-3β or (E and F) PDK-1. (G and H) The cells were treated with PDGF, or with 5 µM LY294002 with/without 30 min pre-exposure to 5 µM SB216763 for 24 h, prior to the detection of PDK-1 expression. #P<0.05 and ##P<0.01 vs. cells treated with PDGF. ***P<0.001 vs. control cells. Results were pooled from three separate experiments and are presented as mean ± standard deviation. A, C and E are the representative change of p-Akt or p-GSK-3β and PDK-1 expression, respectively. The representative change of one of the three experiments is presented, as all assays exhibited identical results. Semi-quantitative analyses of p-Akt, p-GSK-3β and PDK-1 expression levels are presented in B, D, F and H, respectively. C, control; PDGF, platelet-derived growth factor; L1, L2, L5 and L10, cells treated with LY294002 at 1, 2, 5 and 20 µM following PDGF exposure; Akt, protein kinase B; GSK-3β, glycogen synthase kinase-3β; PDK-1, pyruvate dehydrogenase kinase-1; p-, phosphorylated.