Ski overexpression up-regulates ^ser780pRb in rat Schwann cells and in epithelial cells and promotes TGFβ-independent Ski and ^ser780pRb cytoplasmic colocalization and the proliferation of rat Schwann cells and epithelial cells. (A and B) Western blot analysis of Ski and ^ser780pRb (pRb) in rat Schwann cells (A) and WB-F344 cells (B) kept in growing medium and infected with a control or a Ski-overexpressing (Ski+) lentivirus. (C and D) Images of single confocal sections of Ski (red) and ^ser780pRb (pRb; green) coimmunostaining in rat Schwann cells (C) and WB-F344 cells (D) both infected with a Ski+ adenovirus and cultured in DM or treated with TGFβ. Arrows indicate examples of the colocalization (appears yellow) of Ski and ^ser780pRb. Insets are magnifications of the regions outlined by boxes. (E and F) Percentage of BrdU-labeled rat Schwann cells (E) and WB-F344 cells (F) infected with a control or a Ski+ lentivirus and cultured in DM or treated with TGFβ. (G) SMA (green) and Ski (red) coimmunostaining and DAPI labeling (blue) in TGFβ-treated WB-F344 cells infected with a control or a Ski+ lentivirus. (H) Western blot analysis of SMA in lysates of WB-F344 cells infected with a control or a Ski+ lentivirus and cultured in DM or treated with TGFβ. (A, B, and H) β-Actin of GAPDH was used as loading control. Statistical analyses were performed using two-tailed t tests on at least three independent experiments. Error bars represent SEM. *, P < 0.05; **, P < 0.01; ***, P < 0.001.