Fig. 5. GSK-3ß inhibitors stabilize ß-catenin and overexpression of ß-catenin increases the number of TH⁺ neurons. (A) Treatment of VM precursors with 15 µM KP or 5 µM I3M for 24 hours increased both ß-catenin and TH protein levels, as assessed by immunoblotting. ß-actin was used as a loading control. (B,C) TH immunostaining shows a twofold increase in the number of positive cells out of the total number of cells (Hoechst 33258) two days after transfection with ß-catenin, compared to transfection with an empty control vector. Statistical analysis was performed using a two-tailed unpaired t-test. Significance levels as for Fig. 1. Bar, 50 µm.