ERK1/2阻滞剂U0126抑制高频磁刺激引起的星形胶质细胞迁移

The Inhibitory Effects of ERK Inhibitor-U0126 on High Frequency Magnetic Stimulation-induced Astrocyte Migration

目的:目的:研究不同剂量U0126对高频磁刺激促进星形胶质细胞迁移作用的影响,为选择合适的阻滞剂量提供依据。方法:24只SD大鼠制作为脊髓损伤模型,按U0126浓度随机分为对照组(0mg/kg)、低剂量组(0.1mg/kg)、中剂量组(0.2mg/kg)及高剂量组(0.4mg/kg)各6只,U0126注射24h后4组均每日给予磁刺激,频率10Hz、强度1.52T,刺激量30脉冲,于第14天,大鼠处死,采用图像分析系统观察胶质纤维酸性蛋白(GFAP)、微管相关蛋白-2(MAP-2)和细胞外信号调节激酶1/2(ERK1/2)的表达及脊髓损伤空洞体积的变化。结果:与对照组比较,低、中及高剂量组脊髓损伤空洞体积随着U0126剂量的增加逐渐增大,GFAP、ERK1/2的阳性表达逐渐减弱(均P<0.05),高剂量组与低剂量组间差异有显著性(P<0.05);中剂量组差异不明显。4组病灶区域MAP-2均呈阴性表达。结论:不同剂量的U0126可抑制磁刺激引起的星形胶质细胞的迁移。0.2mg/kg既可以完全抑制EPK信号通路,又可以减少U0126的用量,因此是一个较合适的剂量。

Objective：To select a suitable dose of U0126 by investigating the inhibitory effects of different doses of U0126 on high frequency magnetic stimulation-induced astrocyte migration.Methods：Twenty-four adult healthy SD rats were injected with 0.5 mL of 1% ethidium bromide（EB）in PBS into spinal cord dorsal funiculus on the left side at T10-11 level to make local spinal cord injury models,and randomly divided into four groups.The rats in four groups were exposed to magnetic stimulation（10 Hz,1.52 T,30 pulses）at the following doses of U0126 respectively：0 mg/kg（control group）,0.1 mg/kg（low-dose group）,0.2 mg/kg（middle-dose group）,0.4 mg/kg（high-dose group）.On the 14th h after stimulation,the rats were sacrificed and the expression of glial fibrillary acidic protein（GFAP）,microtubule associated protein-2（MAP-2）,extracellular signal-regulated kinase1/2（ERK1/2）and the volume of spinal cord injured holes were analyzed with immunohistochemistry technique.Quantitative analysis of the expression of GFAP,MAP-2 and ERK1/2 was performed with the image analysis system.Results：With the increase of U0126 dose,the volume of spinal cord injured hole was increased on the 14th h（P0.05）.In the lesion area,the expression of GFAP and ERK1/2 could be detected,while MAP2 was undetectable.Significant difference was revealed in the expression of GFAP and ERK1/2 among the four groups,and their expression level was significantly lower in U0126 groups than that in control group（P0.05）,while the middle-dose group had similar effect with the high-dose group.Conclusion：Different doses of U0126 could reverse the astrocyte migration induced by high frequency magnetic stimulation,and 0.2 mg/kg was the suitable dose.