Tat-GluR6-9c抑制MLK3-MKK7-JNK信号通路对脑缺血再灌注大鼠海马CA1区神经元的保护作用  

Protective effect of GluR6-9c peptide containing TAT protein on hippocampus CA1 region neuronal cell injury in rats with ischemic brain injury through inhibiting MLK3-MKK7-JNK signal transduction pathway

作　　者：荣良群[1] 杨辉[2] 魏秀娥[1] 裴冬生 张光毅[4] 张清秀[1] 

机构地区：[1]徐州医学院第二附属医院神经内科,徐州221006 [2]徐州市第一人民医院神经外科,徐州221002 [3]江苏省肿瘤生物治疗重点实验室,徐州221004 [4]徐州医学院生物化学与分子生物学教研室,徐州221004

出　　处：《中华神经医学杂志》2013年第3期231-236,共6页Chinese Journal of Neuromedicine

基　　金：国家自然科学基金（308003091

摘　　要：目的探讨小肽Tat-GluR6-9c对混合性的谱系激酶3（MLK3）、丝裂原活化的蛋白激酶激酶7（MKK7）、c-Jun氨基末端激酶（JNK）的磷酸化水平及蛋白表达的影响，以及对海马CAl区神经元损伤的影响。方法采用4-血管阻塞方法建立大鼠全脑缺血模型，应用免疫印迹的方法分别检测小肽Tat-GluR6-9c对缺血再灌注6h时MLK3、缺血再灌注3d时JNK的磷酸化及蛋白表达水平的影响；采用免疫印迹、免疫组织化学的方法检测小肽Tat—GluR6-9c对缺血再灌注1d时MKK7的磷酸化及蛋白表达水平的影响；采用焦油紫染色方法检测缺血再灌注5d时小肽Tat-GluR6-9c对大鼠海马CAl区神经元损伤的影响。结果Tat-GluR6-9c组MLK3、MKK7及JNK磷酸化水平显著低于缺血再灌注组及对照肽组．海马CAl区神经元存活的数量明显多于缺血再灌注组及对照肽组，差异有统计学意义fP〈0．05）。结论小肽Tat-GluR6-9c能显著抑制脑缺血再灌注诱导的MLK3、MKK7及JNK的磷酸化高峰．降低海马CAl区神经元的损伤。Objective To investigate the effect of peptide Tat-GluR6-9c on phosphorylations and protein expressions of mixed-lineage kinase 3 （MLK3）, mitogen-activated protein kinase kinase 7 （MKK7） and c-Jun NH2 - terminal kinase （JNK）, and its effect on hippocampus CA1 region neuronal cell injury induced by cerebral ischemia followed by reperfusion. Methods Twenty four adult male SD rats were randomly divided into sham-operated group, ischemia-reperfusion group （I/R）, Tat-GluR6-AA treatment group and Tat-GluR6-9c treatment group （n=6）. Four-vessel occlusion method was employed to establish the cerebral ischemia models in the later 3 groups. The effects of peptide Tat-GluR6-9c on the phosphorylations and protein expressions of MLK3 （6 h after the reperfusion） and JNK （3 d after the reperfusion） were detected by Western blotting; the effects ofpeptide Tat-GluR6-9c on the phosphorylation and protein expression of MLK7 （1 d after the reperfusion） were detected by Western blotting and immunohistochemistry. Cresyl Violet （CV） staining was employed to examine the survival of CA1 pyramidal cells in the hippocampus. Results The phosphorylation ofMLK3, MKK7 and JNK in Tat-GluR6-9c treatment group was significantly less than that in I/R group and Tat-GluR6-AA treatment group （P〈0.05）. As compared with lfR group and Tat-GluR6-AA group, peptide Tat-GluR6-9c group could obviously increase the number of neuron cells （P〈0.05）. Conclusion Peptide Tat-GluR6-9c has a protective effect on neuron in CA1 region of hippocampus following cerebral ischemia-reperfusion by significantly decreasing the phosphorylations ofMLK3, MKK7 and JNK.

关 键 词：脑缺血 Tat—GluR6 9c 混合性的谱系激酶3 丝裂原活化的蛋白激酶激酶7 C-JUN氨基端激酶 

分 类 号：R285.5[医药卫生—中药学]