ERK激活对SDF-1引起的大鼠海马神经元GABA分泌抑制的影响  

ERK activation effects on GABA secretion inhibition induced by SDF-1 in hippocampal neurons of rats

作　　者：张紫娟[1] 郭美霞[2] 邢莹[3] 

机构地区：[1]河南中医学院基础医学院,郑州450046 [2]新乡医学院三全学院,河南新乡453003 [3]郑州大学医学院生理学教研室,郑州450003

出　　处：《中国应用生理学杂志》2015年第5期443-447,共5页Chinese Journal of Applied Physiology

基　　金：国家自然科学基金资助项目(31000514)

摘　　要：目的:观察细胞外调节激酶(ERK)信号通路激活对基质细胞衍生因子(SDF-1)引起离体培养的大鼠海马神经元γ-氨基丁酸(GABA)分泌的影响。方法:新生SD大鼠海马神经元离体培养,Western blot法观察ERK1/2信号通路的磷酸化水平;ELISA法和RT-PCR技术检测ERK1/2特异性阻断剂PD98059作用于离体培养的海马神经元后GABA分泌的改变;谷氨酸脱羧酶(GAD65/67)和γ-氨基丁酸转运体(GAT)的蛋白表达量及GAD65和GAT-1 mRNA表达水平。结果:SDF-1作用于海马神经元可引起ERK1/2磷酸化水平明显升高,同时加用CXCR4受体阻断剂AMD3100,可阻断SDF1引起的ERK1/2激活;SDF-1可明显抑制离体培养的海马神经元GABA的分泌,同时加用ERK1/2特异性抑制剂PD98059,可部分逆转SDF-1对GABA分泌的抑制作用;SDF-1作用于离体培养的海马神经元,可抑制谷氨酸脱羧酶GAD65和GABA转运体GAT-1 mRNA的生成;ERK抑制剂PD98059可有效翻转SDF-1的作用。Western blot结果发现SDF-1可抑制海马神经元GAT-1和GAD65/67蛋白的表达,加用ERK1/2抑制剂可部分恢复GAT-1和GAD65/67蛋白合成。结论:SDF1作用于离体培养的海马神经元CXCR4,通过激活ERK1/2信号通路进而抑制GAD蛋白表达,可能是其介导GABA分泌抑制的通路之一。Objective： To investigate the effect of extracellular regulating kinase （ERK） signaling pathway on the secretion of 7-aminobu- tyric acid（GABA） in cultured rat hippocampal neurons induced by stromal cell derived factor-1 （SDF-1 ）. Methods： The hippocampal neurons of newborn SD rats were cultured and identified in vitro; the phosphorylation level of ERK1/2 was examined by Western blot; ELISA was used to detect the effect of PD98059, a ERK1/2 specific blocker on GABA secretion of cultured hippocampal neurons and Western blot were adopted to measure the protein expression levels of glutamate deearboxylase （GAD65/67） and gamma aminobutyric acid transporter （GAT） ; after blocking ERK1/2 signaling pathway with PD98059; RT-PCR was used to detect the mRNA expression levels of GAT-1 and GAD65 after treated with PD98059. Results： The levels of ERK1/2 phosphorylation were increased significantly by SDF1 acting on hippocampal neurons, and CX- CR4 receptor blocker AMD3100,could inhibit SDF-1 induced ERK1/2 activation; SDF-1 could inhibit the secretion of GABA in cultured hip- pocampal neurons, and ERK1/2 specific inhibitor PD98059, could partly reverse the inhibition of GABA secretion by SDF-1. The effects of SDF-1 on cultured hippocampal neurons was to decrease the mRNA genesis of glutamic acid decarboxylase GAD65 and GABA transporter GAT- 1, besides, ERK inhibitor PD98059 could effectively flip the effect of SDF-1. The results of Western blot showed that SDF-1 could inhibit the protein expression of GAT-1 and GAD65/67 in hippocampal neurons and the inhibition of GAT-1 and GAD65/67 protein expression could be partially restored by ERK1/2 blocker. Conclusion： SDF-1 acts on the CXCR4 of hippocampal neurons in vitro, and inhibits the expression of GAD by activating the ERK1/2 signaling pathway, and this may represent one possible pathway of GABA secretion inhibition.

关 键 词：海马神经元 γ-氨基丁酸 细胞外调节激酶 基质细胞衍生因子-1 大鼠 

分 类 号：R338.2[医药卫生—人体生理学]