β淀粉样蛋白25-35诱导的大鼠嗜铬细胞瘤细胞凋亡过程中核因子кB激活的调控

目的 探讨β淀粉样蛋白(amyloid-β,Aβ)25-35诱导的大鼠嗜铬细胞瘤细胞(PC12)凋亡过程中核因子кB(nuclear factor кB,NF-кB)的活化与蛋白激酶B(Akt)和糖原合成酶激酶3β(glycogen synthase kinase 3β,GSK-3β)之间的关系.方法 用Aβ(25-35)诱导PC12细胞凋亡,并分析在此过程中Akt、GSK-3β以及NF-кB的活性变化.在Aβ(25-35)诱导PC12细胞凋亡过程中,分别阻断Akt通路和GSK-3β通路,测定细胞活性以及Akt、GSK-3β、NF-кB的关系.结果 Aβ(25-35)诱导细胞凋亡过程中,细胞凋亡率与Aβ(25-35)的用量呈现剂量依赖关系,用0、5、10、20、40μmol/L Aβ(25-35)处理PC12细胞48 h后,细胞的凋亡率分别为(3.01±0.03)%、(3.08±0.03)%、(25.32±0.76)%、(42.88±0.60)%、(60.85±2.39)%.与对照组比较,Aβ(25-35)诱导细胞凋亡过程中NF-кB被激活,而Akt、GSK-3β的活性则均受到抑制.用渥曼青霉素(wortmannin)抑制Akt的活性可引起NF-кB活性的下降.GSK-3β活性上升.用GSK-3β的特异性抑制剂氯化锂(LiC1)抑制其活性,则NF-кB活性同样下降.而对Akt的活性无显著影响.结论 Akt和GSK-3β都是NF-кB的上游调节因子,他们共同调控Aβ(25-35)诱导的PC12细胞凋亡过程中NF-кB的活化.这些结果有助于更好地理解阿尔茨海默病的发病机制,并对其防治提供新的思路.

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

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.