鱼藤酮对星形胶质细胞谷氨酸摄取功能的影响

Effects of rotenone on glutamate uptaking in primary cultured astrocytes

目的研究鱼藤酮对原代培养星形胶质细胞谷氨酸转运功能的影响。方法应用HPLC荧光法检测鱼藤酮染毒星形胶质细胞胞外Glu浓度,同位素标记法检测Glu摄取能力,采用RT-PCR与Western blot技术观察谷氨酸转运体基因及蛋白表达。结果鱼藤酮染毒星形胶质细胞胞外Glu浓度明显升高,Glu摄取能力显著降低,谷氨酸/天冬氨酸转运体(glutamate/aspartate transporter,GLAST)基因和蛋白表达均明显降低,而谷氨酸转运体-1(glutamatetransporter-1,GLT-1)蛋白表达升高。结论鱼藤酮可显著降低星形胶质细胞谷氨酸摄取功能,引起胞外Glu浓度升高;GLAST表达下调可能是鱼藤酮诱导胞外谷氨酸含量增加的主要原因之一,而GLT-1上调可能为神经细胞自我保护机制,以限制谷氨酸的神经毒作用。

Objective To study the effects of rotenone on glutamate uptaking in primary cultured astrocytes.Methods The extracellular glutamate was detected by high performance liquid chromatography（HPLC）,the uptaking ability of glutamate was detected with isotope lebeling method and the mRNA and protein expression of glutamate transporter were detected using RTPCR and Western blot,respectively.Results It was showed that the extracellular rotenone level was obviously risen,shown the uptaking function of astrocyte to glutamate was decreased,Meanwhile,the expression of GLAST（glutamate/aspartate transporter）mRNA and protein also decreased significantly in 1.0 and 2.0 μmol/L rotenone exposed groups,but the expression of glutamate transporter-1（GLT-1）enhanced obviously.Conclusions It was suggested that rotenone might reduce the uptaking ability of astrocyte to glutamate,induce the extracellular level of Glu risen,the down-regulation of GLAST may be the main reason of elevated extracellular Glu level induced by rotenone,while the increased expression of GLT-1 might represent a self-protective mechanism by nerve cells for limiting the neurotoxicity by Glu.