Fig. 7.

Time course of activation of Erk1/2 and Rsk1 as well as phosphorylation of Bad after administration of TGF-β1 in the cultured rat hippocampal cells. A, B, Representative blots of P-Erk1/2, P-Rsk1 (Thr³⁶⁰/Ser³⁶⁴), P-Bad (Ser¹¹²), Bad and α-tubulin and the semiquantification of the blots. TGF-β1 (10 ng/ml) was added to the hippocampal cells on the seventh day of culture. To block MAPK signaling, U0126 (20 μm) was added 2 hr before the exposure of TGF-β1. Controls received vehicle only. The cells were harvested in a lysis buffer at 15 and 30 min (A) as well as 1, 8, and 24 hr (B) after adding TGF-β1. Thirty micrograms of total protein from each group were loaded to SDS-polyacrylamide gel. Blots were representative of three independent cultures. The ratio of IOD from P-Erk1/2, P-Rsk1, and P-Bad signals to α-tubulin signals was calculated. The ratios obtained from vehicle-treated controls (either 30 min or 24 hr) were normalized to 100%, and the data were given as means ± SD of the percentage of the corresponding control. *p < 0.05; **p < 0.01; ***p < 0.001, compared with vehicle-treated control (30 min);^#p < 0.05;^##p < 0.01;^###p < 0.001 compared with vehicle-treated control (24 hr).