Figure 7. Knockdown of Sirt1 reduces Cdk2/Cyc E and Cdk2/Rb complex formation.

Representative western blots showing levels of acetylated Cdk2 (a), acetylated Rb (b), Cdk2/Cyc E (d) and Rb/Cdk2 complexes (e), and acetylated FoxO3a (g) in NX and HX white matter (P18), in the presence or absence of Sirt1 (n=3 brains for each group, for each treatment). Graphs represent percentages of proliferating BrdU⁺ cells in control cultures and after knockdown of Cdk2 (c) or FoxO3a (h) and Olig2⁺ cells after knockdown of Cdk2 (f) or FoxO3a (i) in NX and HX cultures. Knockdown of Cdk2 reduces the percentage of proliferating cells and elevates Olig2⁺ cells in NX and HX cultures as compared with control cultures. However, knockdown of FoxO3a increases BrdU⁺ cells and reduces Olig2⁺ cells in NX and HX cultures. Histograms show mean±s.e.m. Three cultures per condition.