MAPKs介导NMDA诱导的大鼠皮层神经元凋亡(英文)  

Involvement of MAPK pathways in NMDA-induced apoptosis of rat cortical neurons

作　　者：杨小荣[1] 孙萍[2] 秦花萍[1] 司沛沛[1] 孙雪菲[1] 张策[1] 

机构地区：[1]山西医科大学生理学系,太原030001 [2]山西医科大学第一医院营养科,太原030001

出　　处：《生理学报》2012年第6期609-616,共8页Acta Physiologica Sinica

基　　金：supported by the National Natural Science Foundation of China (No.31000481);the Natural Science Foundation of Shanxi Province,China (No.2011011040-2);the Scientific and Technological Innovation Programs of Higher Education Institutionsin Shanxi Province,China (No.20091110);the Innovative Talents Support Programs of Higher Education Institutions in Shanxi Province,China (2011)

摘　　要：NMDA诱导兴奋毒造成的神经损伤,包括细胞的凋亡和坏死。本研究旨在探讨神经元凋亡在NMDA兴奋毒所致大鼠皮层神经元死亡中的所占比例,并分析了NMDA致神经元凋亡的信号通路机制。通过使用Caspase抑制剂和测定乳酸脱氢酶活性,研究NMDA(100μmol/L,2h)兴奋毒所致的神经元凋亡;并使用MAPKs选择性抑制剂,分别采用Caspase-3活性检测,TUNEL和Annexin V染色方法,进一步观察MAPKs通路中细胞外信号调节激酶(ERK)、c-Jun N-末端激酶(JNK)和p38 MAPK三条不同途径在NMDA所致神经元凋亡中的作用。结果显示:(1)Caspase依赖的凋亡占NMDA所致细胞死亡总数的22.49%;(2)p38 MAPK抑制剂SB203580(10μmol/L)使NMDA诱导的caspase-3活性降低30.43%(P<0.05);而ERK抑制剂PD98059(20μmol/L)和JNK抑制剂SP600125(20 μmol/L)不影响caspase-3的活性;(3)SB203580(10μmol/L)使NMDA所致的TUNEL阳性细胞数减少33.10%(P<0.05);而PD98059(20μmol/L)或SP600125(20μmol/L)都没有作用;(4)Annexin V染色结果显示,SB203580(10μmol/L)使NMDA所致的早期凋亡细胞减少55.56%(P<0.05);SP600125(20μmol/L)使NMDA所致的晚期凋亡/死亡细胞减少67.59%(P<0.05);PD98059(20μmol/L)对细胞凋亡/死亡没有明显作用。以上结果表明,NMDA介导的大鼠皮层神经元死亡除坏死外,还包含有一小部分神经元凋亡;p38 MAPK途径,而非JNK和ERK途径,介导了NMDA诱导的神经元凋亡,抑制与此相关的凋亡信号通路可发挥神经保护作用;JNK途径可能介导了NMDA所致的神经元坏死而非凋亡。NMDA-induced excitotoxicity cause severe neuronal damage including apoptosis and necrosis. The present study was aimed to evaluate the proportion of NMDA-induced apoptosis of rat cortical neurons and discover signal transduction mechanism. Caspase inhibitor and lactate dehydrogenase （LDH） assay were used to study the NMDA-induced apoptosis. To explore the involved signal pathways, the primary culture of rat cortical neurons were pretreated by the inhibitors of three MAPK pathways, extracellular signal-regulated kinase （ERK）, c-Jun N-terminal kinase （JNK）, and p38 MAPK. With 2 h of NMDA treatment, cellular apoptosis was measured by caspase-3 activity, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling （TUNEL） and Annexin V staining. The results showed that： （1） Caspase-dependent apoptosis accounted for 22.49% in NMDA-induced neuronal death; （2） Pretreatment with p38 MAPK inhibitor SB203580 （10 μmol/L） significantly decreased NMDA-mediated caspase-3 activity by 30.43% （P 0.05）. However, ERK inhibitor PD98059 （20 μmol/L） or JNK inhibitor SP600125 （20 μmol/L） did not influence caspase-3 activity; （3） Pretreatment with SB203580 significantly reduced the number of NMDA-induced TUNEL-positive cells by 33.10% （P 0.05）. PD98059 （20 μmol/L） or SP600125 （20 μmol/L） did not show obvious effect; （4） Pretreatment with SB203580 （10 μmol/L） significantly reduced the number of NMDA-induced early apoptotic neurons by 55.56% （P 0.05）. Also, SP600125 （20 μmol/L） significantly decreased the amount of late apoptotic/dead cells by 67.59% （P 0.05）. There was no effect of PD98059 （20 μmol/L）. These results indicate that： （1） NMDA induces neuronal apoptosis besides necrosis; （2） p38 MAPK, but not JNK and ERK, is involved in NMDA-induced neuronal apoptosis, and inhibition of the apoptotic signaling pathway contributes to neuroprotection; （3） JNK activation might contribute to NMDA-induced neuronal necrosis rathe

关 键 词：NMDA 兴奋性神经毒 凋亡 MAPKS 

分 类 号：R331[医药卫生—人体生理学]