Fig. 9.

Dominant-negative Akt induced caspase activation in primary cultures of immature oligodendrocytes in the presence of HRG β1. Oligodendrocyte progenitor cells were mock-infected or infected with 10 MOI of a control adenovirus (Ad.RSV.alphos) or an adenovirus expressing AA-Akt the presence of 150 ng/ml HRG β1. Oligodendrocyte precursors were grown in the presence of PDGF/bFGF for 24 hr; growth factors were then removed, HRG β1 was added to the media, and adenovirus infection was performed. After 48 hr infection in the presence of HRG β1, the virus was removed, and cells were cultured in DMEM plus HRG β1 for an additional 20–24 hr before caspase inhibitor staining. A total of 1000 cells were counted, and the caspase-positive cells were expressed as a percentage of total number of cells visualized by DAPI staining. Data are the mean of a representative experiment made in duplicate. Data are shown as mean ± SEM (n = 2); *p < 0.05.