Figure 10.
Inhibition of MEK1 increases the nuclear accumulation of Smad-1. Sympathetic neurons were cultured under control conditions (A, B) or in the presence of a maximally effective dose of BMP-7 (100 ng/ml) (C, D) for 2 hr. In addition, cultures were treated with BMP-7 at a concentration (10 ng/ml) close to ED50 in the presence (G, H) or absence (E, F) of PD 98059. PD 98059 (10 μm) was added 30 min before BMP-7 was maintained in the medium thereafter. Cells were immunostained with an antibody that reacts with Smad-1, and optical sections (1 μm) were obtained with a Bio-Rad confocal microscope. Phase-contrast (A, C, E, G) and fluorescence (B, D, F, H) micrographs.