Fig. 4.

Both AKT and cdc2 inhibitors inhibit Cd-induced vimentin phosphorylation at Ser³⁹ and Ser⁵⁵, α-SMA activation, ECM accumulation, and collagen secretion. A; after 24 h of serum starvation, primary lung fibroblasts (n = 5) were pretreated with the MEK 1 inhibitor PD 985059 (PD; 20 μM), the PKC inhibitor G06983 (G0; 250 nM), the AKT inhibitor LY294002 (LY; 20 μM), the cdc2 inhibitor Roscovitine (RO; 10 μM) only, or combination of AKT and cdc2 inhibitors (LY + RO) 1 h before 20 μM CdCl₂ treatment for 3 h and then allowed to recover for 48 h. The soluble collagen levels were evaluated by Sircol collagen assay. Horizontal bars indicate the mean values. **P < 0.01 vs. control. Cells were also treated with TGF-β (2 ng/ml) for 48 h as a positive control. B and C: cells were pretreated with inhibitor shown as above before 20 μM CdCl₂ treatment for 2 h (B) or 3 h and then allowed to recover for 48 h (C), followed by immunoblot analysis for indicated antibodies. The results shown in A–C are representative of those from 3 independent experiments.