正常及无镁诱导后神经元微环境对少突胶质前体细胞分化的影响

Influence of microenvironment of normal neurons and neurons expressing seizure-like discharge induced by free-magnesium extracellular fluid culture on the differentiation of oligodendrocyte precursor cells

目的：探讨正常神经元及痫性放电后神经元微环境对少突胶质前体细胞（oligodendrocyte precursor cell,OPC）分化的作用,从体外水平了解痫性放电对髓鞘再生的影响。方法：OPC纯化后增殖2～3 d后进行分化,分化时根据加入的神经元培养基占总培养基体积的比例分为3个层次：1/8浓度、1/4浓度、1/2浓度,每个层次再分为3组：OPC分化培养基（ODM）组、OPC分化培养基＋相应浓度诱导后神经元培养基（ODM＋INM）组、OPC分化培养基＋相应浓度正常神经元培养基（ODM＋NNM）组,采用q RTPCR检测OPC分化第3天、5天、7天血小板源性生长因子受体-α（platelet-derived growth factor receptor-alpha,PDGFRα）、环核苷酸磷酸二酯酶（cyclic neucleotide phosphodiesterase,CNPase）、髓鞘碱性蛋白（myelin basic protein,MBP）m RNA水平的相对量的差异。结果：加入1/2体积的神经元培养基对OPC分化产生明显的影响,ODM＋1/2NNM组MBP转录水平在分化第3天（P〈0.05）、第5天（P〈0.05）明显高于ODM组,在分化第7天明显低于ODM组（P〈0.05）;ODM＋1/2INM组MBP转录水平在分化第3天明显高于ODM＋1/2NNM组（P〈0.05）,在分化第5天（P〈0.05）、第7天（P〈0.05）明显低于ODM＋1/2NNM组。结论：神经元微环境对OPC分化有重要的影响作用,正常神经元微环境可以促进OPC的分化,而无镁诱导神经元痫性放电后的微环境会抑制OPC的分化。

Objective：To investigate the effect of microenvironment of normal neurons and neurons expressing seizure-like discharge induced by free-magnesium extracellular fluid culture on the differentiation of oligodendrocyte precursor cells（OPCs）,and to explore the influence of epileptic seizure on the remyelination. Methods：OPCs were purified on the 3rd day or the 4th day of proliferating phase. According to the proportion of additional neuronal medium in which neurons survived in the total medium,objects were divided into three levels：1/8,1/4,1/2;and each level was subdivided into three groups：OPC differentiation medium（ODM）group,OPC differentiation medium ＋corresponding proportion of induced seizure discharge neuron medium（ODM ＋INM） group,OPC differentiation medium ＋corresponding proportion of normal neuron medium（ODM＋NNM）group. PDGFRα,CNPase and MBP transcription expressions of oligodendrocyte cells on the 3rd day,5th day,7th day of differentiation phase were detected by q RT-PCR.Results：There were significant differences in MBP transcription expressions between ODM group and ODM＋1/2NNM group at the differentiation phase;MBP transcription expressions were higher in ODM＋1/2NNM group than in ODM group on the 3rd day（P〈0.05）and 5th day（P〈0.05）of differentiation,while lower in ODM＋1/2NNM group than in ODM group on the 7th day of differentiation（P〈 0.05）. There were also significant differences in MBP transcription expressions between ODM ＋1 /2NNM group and ODM＋1/2INM group at the differentiation phase;MBP transcription expressions were higher in ODM＋1/2INM group than in ODM＋1/2NNM group on the 3rd day of differentiation（P〈0.05）,while lower in ODM＋1/2INM group than in ODM＋1/2NNM group on the 5th day（P〈0.05）and 7th day（P〈0.05）of differentiation. Conclusion：The neuronal microenvironment has significant effect on the differentiation of OPCs. The normal neuronal microenvironment can promote OPC differentiation,and the induced seizure-like discharge neuronal microenvironment can inhibit OPC differentiation.