摘要目的 探讨孤儿核受体NR4A1表达对氧-葡萄糖剥夺(oxy gen-glucose deprivation,OGD)诱导培养大鼠小脑颗粒神经元凋亡的影响及其可能机制.方法 大鼠小脑颗粒细胞原代培养7～8 d后给予OGD处理.应用四甲基偶氮唑蓝法检测细胞活性,流式细胞术检测细胞凋亡率,蛋白质印迹法检测NR4A1、胱天蛋白酶-3和细胞色素c蛋白表达,实时定量聚合酶链反应检测NR4A1mRNA表达.用编码NR4A1的慢病毒载体转染大鼠小脑颗粒神经元,并检测转染大鼠小脑颗粒神经元OGD后凋亡率以及细胞色素c和胱天蛋白酶-3表达.结果 随着OGD时间的延长,培养大鼠小脑颗粒神经元活性显著性降低,凋亡率显著性增高,NR4A1 mRNA和蛋白以及胱天蛋白酶-3和细胞色素c蛋白表达均显著性上调.转染NR4A1的大鼠小脑颗粒神经元过表达NR4A1,OGD后凋亡率显著性降低,胱天蛋白酶-3和细胞色素c蛋白表达显著性下调.结论 NR4A1过表达能通过下调胱天蛋白酶-3和细胞色素c表达减少OGD诱导的大鼠小脑颗粒神经元凋亡.

abstractsObjective To investigate the effect of orphan nuclear receptor NR4A1 expression on oxygenglucose deprivation (OGD)-induced apoptosis in cultured rat cerebellar granule neurons and its possible mechanisms.Methods Primary rat cerebellar granule neurons were cultured for 7 to 8 days,and then treated with OGD.The activity of cultured rat cerebellar granule neurons was assessed by methyl thiazolyl tetrazolium (MTT) assay,apoptosis was detected with flow cytometry,the expressions of NR4A1,caspase-3 and cytochrome c were determined by Western blot analysis,NR4A1 mRNA expression was detected with real-time polymerase chain reaction.The rat cerebellar granule neurons were transfected with lentiviral vector-encoding rat NR4A1.The apoptotic rates and expressions of caspase-3 and cytochrome c in rat cerebellar granule neurons transfected with NR4A1 were detected after OGD.Results The activity of rat cerebellar granule neurons decreased significantly,the apoptotic rate increased significantly,the expressions of NR4A1 mRNA and protein as well as caspase-3 and cytochrome c incrased significantly along with the OGD time.NR4A1 was overexpressed,apoptosis rate was significantly reduced in rat cerebellar granule neurons transfected with NR4A1.The expressions of caspase-3 and cytochrome c were significantly reduced in the rat cerebellar granule neurons transfected with NR4A1 after OGD.Conclusions NR4A1 overexpression may reduce OGD-induced apoptosis in rat cerebellar granule neurons by downregulating the expressions of caspase-3 and cytochrome c.