IGF-1经PI3K/Akt依赖性途径保护苯妥英诱导的小脑颗粒神经元凋亡

目的　观察胰岛素样生长因子 1 (insulin likegrowfactor 1, IGF 1)对苯妥英(100μmol·L-1 )处理的大鼠小脑颗粒神经元 (cerebellargranularneurons, CGNs)存活率的影响,并探讨其与PI3K/Akt通路的关系。方法　体外培养 8的小脑颗粒神经元,同时给予 100μmol·L-1苯妥英和μmol·L-1 IGF 1, 48h后行凋亡分析,观察IGF 1对苯妥英诱导的小脑颗粒神经元的保护作用;采用PI3K/Akt通路特异性抑制剂LY294002(50μmol·L-1 )预先与小脑颗粒神经元孵育 30min,再加 1μmol·L-1 IGF 1和 100μmol·L-1苯妥英共孵育 48h,测定神经元存活率,观察IGF 1与PI3KAkt通路的关系;Westernblot法检测苯妥因处理不同时间小脑颗粒神经元内磷酸化Akt水平及总Akt的表达量,并观察IGF 1对磷酸化Akt水平的影响,进一步探讨IGF 1的作用是否经PI3K/Akt通路。结果　①1μmol·L-1 IGF 1可明显抑制 100μmol·L-1苯妥英引起的小脑颗粒神经元的凋亡明显提高小脑颗粒神经元的存活率,使其凋亡特征消失。②PI3K/Akt通路特异性抑制剂LY294002可取消IGF 1的保护作用。③苯妥英使小脑颗粒神经元内磷酸化Akt水平明显降低,但不影响总Akt表达量。④IGF 1可明显恢复被苯妥英抑制的磷酸化Akt的水平。结论　IGF 1保护苯妥英诱导的小脑颗粒神经元凋亡,这种

IGF-1 protection against cerebellar granule neurons apoptosis induced by diphenylhydantoin through a PI3K/Akt dependent pathway

Aim To investigate the effects of insulin like grow th factor1(IGF-1) on apoptosis of cerebellar granule neurons(CGNs) induced by dip henylhydantoin (DPH) and its possible relationship with PI3K/Akt.Methods Rat cerebellar granule neurons(CGNs), primarily cultured for 8 days, w ere co-incubated with 100 μmol·L -1 DPH and 1 μmol·L -1 IGF-1 fo r 48 h and then submitted to apoptotic analysis. CGNs, pretreated with 100 μmol ·L -1 DPH and 1 μmol·L -1 IGF-1 for 48 h, were incubated with LY29 4002, a specific inhibitor of PI3K for 30 minutes, and then performed cell viabi lity assays to explore the relationship of IGF-1 with PI3K/Akt pathway. Western blotting was employed to further study whether Akt was involved in the apoptoti c effect of DPH and the protection of IGF-1. Results 1 μmol·L -1 IGF-1 demonstrated significant protective effects on apoptosis of CGNs t reated with DPH, which could be abolished by LY294002, a specific inhibitor of P I3K/Akt pathway. IGF-1 also upregulated the activity of Akt in CGNs, which was markedly decreased by DPH.Conclusions IGF-1 blocked the DPH-i nduced apoptosis of CGNs possibly through a PI3K/Akt dependent pathway.