天津医药

天津医药 ›› 2019, Vol. 47 ›› Issue (3): 235-240.doi: 10.11958/20181702

• 实验研究 • 上一篇    下一篇

U0126对谷氨酸神经毒性损伤模型大鼠的脑保护作用

赵精咪，孙莉，梁浩，程焱   

  1. 天津医科大学总医院，天津市神经病学研究所（邮编300052）
  • 收稿日期:2018-11-07 修回日期:2019-02-21 出版日期:2019-03-15 发布日期:2019-04-24
  • 通讯作者: 赵精咪 E-mail:aijianjie@yeah.net

The protective effect of U0126 on glutamate neurotoxicity in cerebral cortex

ZHAO Jing-mi,SUN Li,LIANG Hao,CHENG Yan   

  1. Tianjin Medical University General Hospital, Tianjin Neurological Institute, Tianjin 300052, China
  • Received:2018-11-07 Revised:2019-02-21 Published:2019-03-15 Online:2019-04-24
  • Contact: Jing-mi ZHAO E-mail:aijianjie@yeah.net

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摘要： 目的 探索U0126对脑组织谷氨酸神经毒性的保护作用及可能机制。方法 健康成年雄性SD大鼠皮层注射 N-甲基-D-天冬氨酸（NMDA）建立脑组织谷氨酸神经毒性模型。首先，采用不同浓度 NMDA（50、100、200mmol/L）及处理不同时间（3、6、12、24 h）筛选最佳的建模条件。根据选定的最佳条件，实验设对照组、MAPK/ERK1/2抑制剂U0126单独处理组（2 g/L）、NMDA组（200 mmol/L）、不同浓度（0.5、1、2 g/L）U0126联合NMDA处理组。各组处理24 h后处死动物，脑组织切片后行HE染色组织评价损伤；蛋白质印迹法检测损伤部位环氧合酶-2（COX-2）、诱导型一氧化氮合酶（iNOS）、Caspase-3（活化形式）及磷酸化ERK1/2（p-ERK1/2）表达水平，确定U0126在脑组织谷氨酸神经毒性损伤中的保护作用。结果 （1）NMDA以时间和浓度依赖的方式导致大鼠皮层兴奋毒性损伤，激活MAPK/ERK1/2信号通路，加重脑组织损伤，选取200 mmol/L NMDA处理24 h进行建模。（2）与对照组相比，NMDA组脑损伤部位COX-2、iNOS、Caspase-3（活化形式）、p-ERK1/2表达明显增加。U0126+NMDA处理组与NMDA组相比，COX-2、NOS、Caspase-3（活化形式）、p-ERK1/2表达水平随U0126浓度升高而降低，脑损伤的面积显著减小。结论 U0126对大鼠皮层谷氨酸神经毒性损伤具有保护作用，其机制可能与抑制ERK1/2激活及其下游的炎症、凋亡信号途径有关。

关键词: 谷氨酸, N-甲基天冬氨酸, MAP激酶激酶激酶类, 神经毒性, MAPK/ERK1/2, 环氧合酶-2, 诱导型一氧化氮合酶, Caspase-3

Abstract: Objective To investigate the protective effect and possible mechanism of U0126 on glutamate neurotoxicity in brain. Methods Glutamate neurotoxicity model was established by injecting N-methyl-D-aspartate(NMDA) into the cortex of healthy adult male SD rats. First, the optimal modeling conditions were screened using different concentrations (50, 100, 200 mmol/L) of NMDA and different treatment times (3, 6, 12, 24 h). According to the selected optimal conditions, rats were divided into the control group, MAPK / ERK1 / 2 inhibitor U0126 treatment group (2 g / L),NMDA group (200 mmol / L) and different concentrations (0.5, 1, 2 g / L) of U0126 in combination with the NMDA treatment groups. The animals were sacrificed after treatment for 24 h in each group. The brain tissue sections were stained with HE staining to evaluate the tissue damage. Western blot assay was used to detect cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), Caspase-3 (activated form) and phosphorylated ERK1 /2 (p-ERK1/2) expression levels to determine the protective effect of U0126 in glutamate neurotoxic injury in brain tissue. Results (1) NMDA induced excitotoxic damage in rat cortex in a time - and concentration-dependent manner, activated MAPK / ERK1 / 2 signaling pathway,aggravated brain tissue damage, and 200 mmol/L NMDA for 24 h was selected for modeling. (2) Compared with the control group, the expressions of COX-2, iNOS, Caspase-3 (activated form) and p-ERK1/2 increased significantly in the NMDA group. Compared with the NMDA group, the expression levels of COX-2, iNOS, Caspase-3 (activated form) and p-ERK1/2 decreased with the increased concentration of U0126 in U0126+NMDA treatment group, and the area of brain injury decreased significantly. Conclusion U0126 has a protective effect on glutamate neurotoxicity injury in rat cortex, and its mechanism may be related to the inhibition of ERK1/2 activation and downstream signaling pathways of inflammation and apoptosis.

Key words: glutamic acid, N-methylaspartate, MAP kinase kinase kinases, neurotoxicity, MAPK/ERK1/2, COX-2, iNOS, Caspase-3