促红细胞生成素对大鼠视网膜神经元谷氨酸损伤的保护作用

The protective effect of erythropoietin on neonatal rats' retinal neurons injured by glutamic acid

目的探讨促红细胞生成素对大鼠视网膜神经元谷氨酸损伤的保护作用。方法原代培养大鼠视网膜神经元,透射电镜和LDH释放率检测评价不同浓度谷氨酸对神经元的影响,并选择损伤明显的浓度作为损伤剂量。然后细胞分组为N组(正常对照)、G组(谷氨酸损伤)、EG组(EPO+谷氨酸)、AG组(AG490+谷氨酸)、AEG组(AG490+EPO+谷氨酸)、MTT比色法比较5组神经元活力的改变。Western blot检测各组细胞Bax蛋白表达的情况。结果透射电镜显示在50μmol·L-1组出现了染色质和线粒体的改变。100μmol·L-1组改变更加明显。LDH释放率结果显示在20μmol出现了明显的细胞损害。MTT结果示EG组细胞活力高于G、AG和AEG组,G组高于AG和AEG组(P<0.01)。Western blot检测结果示,AG、AEG组Bax表达高于G组,G组高于EG组。结论 EPO对视网膜神经元谷氨酸损伤有保护作用,保护机制可能通过Jak2通路下调神经元谷氨酸损伤后Bax蛋白的表达,减少细胞凋亡从而达到视网膜神经元保护作用。

Aim To investigate the protective effect of erythropoietin（EPO ）on neonatal rats＇retinal neuronal cells injured by glutamic acid.Methods Retinal neuron cells were cultured and subjected to glutamic acid.The concentration of glutamic acid model was decided by observing the changes of neuronal cells with the releasing quantity of LDH and transmission electron microscope.Then cultured cells were divided into N group（normalcontral）,G group（glutamic acid）,EG group（EPO and glutamic acid）,AG group（AG490 and glutamic acid）,and AEG group（AG490,EPO and glutamic acid）.MTT assay was applied to detect cell viability in five groups.The expression of Bax was detected with Western blot.Results The changes of mitochondrion and chromatin occurred in 50 μmol·L-1 group and striking changes occurred in 100 μmol·L-1 group with transmission electron microscope.There was apparent damage in 20μmol·L-1 group by the releasing quantity of LDH.MTT assay indicated the cell viability of EG group was higher than that of G,AG and AEG group,while,G group cell viability was higher than that of AG and AEG group.The expression of Bax in AG and AEG group was higher than that in G group. And that in G group was higher than in EG group.Conclusions EPO pretreatment can effectively protect the neuronal cells from injuries induced by glutamic acid.Down regulation of Bax and decrease of apoptosis through Jak2 passageway may be the mechanism of protection.