Exendin-4通过拮抗钙超载改善Aβ_(31-35)诱导的HT22海马神经细胞per1基因异常表达

Exendin-4 improves abnormal expression of the per1 gene induced by Aβ_(31-35) via antagonizing calcium overload in HT22 cells

目的:探讨Exendin-4对Aβ_(31-35)所致的HT22神经细胞per1基因异常表达的影响及可能作用机制。方法:本研究采用海马神经细胞HT22作为实验对象。以1%血清饥饿1 h来诱导细胞同步化(CT0)。MTT实验检测细胞存活率;倒置显微镜下观察细胞形态变化;Real-time PCR检测各CT时间per1基因的表达变化;选择per1表达差异最显著的CT时间点,采用流式细胞术检测细胞内钙离子浓度的变化情况。结果:(1)Exendin-4可以明显提高Aβ_(31-35)所致的HT22细胞存活率的下降;(2)镜下观察可见,经Exendin-4预处理后部分改善了Aβ_(31-35)对细胞的损伤作用,细胞形态有所恢复;(3)Aβ_(31-35)使per1基因在CT16时各处理组的相对表达量明显不同;与对照组相比,Aβ_(31-35)使per1基因表达量明显升高;经Exendin-4预处理后,per1基因的表达得到一定程度的恢复,差异具有统计学意义;(4)在CT16时各处理组细胞荧光强度值明显不同,与对照组相比,Aβ_(31-35)使细胞荧光强度明显增强;经Exendin-4预处理后,细胞荧光强度值明显降低,差异具有统计学意义,此结果与加入尼莫地平的结果类似。加入尼莫地平预处理后,检测各个CT时间per1基因表达变化,与Exendin-4预处理组得到的结果类似。结论:Exendin-4通过拮抗钙超载改善Aβ_(31-35)诱导的HT22海马神经细胞per1基因的异常表达。

Objective： To investigate the mechanism of Exendin-4 against amyloid 13-protein （Aβ31-35） induced the abnormal expression of perl gene in HT22 cells. Methods： HT22 cells were used as the experimental object. Cells were synchronized to G0/G1 phase by 1% serum starvation for 1 h （CTO）. Cell survival rate was detected by MTT assay; Morphological changes were observed under an inverted microscope; perl gene expression in different CT times was examined by Real-time PCR; the intracellular calcium concentration at the CT time of perl expression difference was analyzed by flow cytometry. Results： （1） Exendin-4 significantly improved the decrease of survival rate induced by Aβ31-35 ; （2） The cytotoxicity of Aβ31-35 could be attenuated after Exendin-4 pretreatment, the cellular morphological recovered; （3） At CT16, Aβ31-35 significantly increased the expression ofperl gene; Compared with Aβ31-35 group, perl gene expression partially recovered after Exendin-4 pretreatment; （4） At CT16, compared with control group, Aβ31-35 enhanced cell fluorescence intensity obviously; after pretreatment with Exendin4, the cell fluorescence intensity decreased significandy, which were similar to those in nimodipine group. After pretreatment with nimodipine, the expression of perl gene was consistent with Exendin-4 pretreatment group at different CT times. Conclusion： Exendin-4 improves the abnormal expression of perl gene induced by Aβ31-35 via antagonizing calcium overload in HT22 cells.