1.Nuclear factor кB activation co-regulated by protein kinase B and glycogen synthase kinase 3β during amyloid-β 25-35 -induced apoptosis in rat pheochromocytoma cells
Yumei LI ; Linping CHENG ; Sijun REN ; Yongping DENG ; Shengqiang CHEN
Chinese Journal of Geriatrics 2010;29(7):597-600
Objective To investigate the relationships of nuclear factor кB (NF-кB) activation with protein kinase B (Akt) and glycogen synthase kinase 3β (GSK-3β) during amyloid-β (Aβ) (25-35) -induced apoptosis in pheochromocytoma cells (PC12 cells) of rats. Methods Apoptosis in PC12 cells was induced by A(25-35). The activities of Akt, GSK-3β and NF-кB were analyzed in this process. The Akt and GSK-3β pathways were blocked by their specific inhibitors, respectively, and the relationships of Akt and, GSK-3β with NF-кB during Aβ(25-35)-induced apoptosis in PC12 cells were determined. Results Aβ(25-35) induced apoptosis was in a dose-dependent manner. With 0, 5, 10, 20 μmol/L and 40 μmol/L Aβ(25-35) treaing for 48 h, the apoptosis rates of PC12 cells were (3. 01 ± 0.03)%, (3.08 ±0.03)%, (25.32 ± 0.76)%, ( 42.88 ± 0.60 )% and ( 60.85 ± 2.39 )% , respectively. Compared to control, both Akt and GSK-3β were suppressed during apoptosis, at meantime NF-кB was activated. The inhibited Akt activity by wortmannin leaded to decreased NF-кB activatity and increased GSK-3β activatity. Suppression of GSK-3β with its specific inhibitor LiCl caused the decreased activation of NF-кB too, but it had no significant influence on Akt activity. Conclusions These results suggest that both Akt and GSK-3β are upstream regulators of NF-кB. They co-regulate the activation of NF-кB during Aβ(25-35)-induced apoptosis in PC12 cells. This study contributes to the theoretical base for the pathogenesis of Alzheimer disease (AD) , and provides a new idea to AD prevention and therapy.