Sheridan K M, Maltese W A
Hood Research Program, Weis Center for Research, Pennsylvania State University College of Medicine, Danville 17822-2616, USA.
J Mol Neurosci. 1998 Apr;10(2):121-8. doi: 10.1007/BF02737123.
Postmitotic NT2N cells, which are derived from human NT2 teratocarcinoma cells by treatment with retinoic acid (RA) and mitotic inhibitors, are viewed as a good in vitro model for mature neurons of the human central nervous system. Although NT2N cells exhibit many morphological and biochemical characteristics of neurons, the expression of key protein components involved in regulated exocytosis have not been firmly established. Here we show by immunoblot analysis that mature morphologically differentiated NT2N cells contain readily detectable quantities of the synaptic vesicle-associated proteins, synaptobrevin, synapsin, and synaptophysin. They also express the presynaptic plasma membrane protein, SNAP-25, and a Rab GTPase implicated in the control of Ca(2+)-dependent exocytosis, Rab3A. These proteins were not detected in untreated NT2 cells or cells exposed to RA for only 6 d. The induction of an array of proteins known to be involved in the docking and fusion of synaptic vesicles with the plasma membrane provides further support for the validity of NT2N cells as a model for human cortical neurons and suggests that these cells may be useful for in vitro molecular studies of the Ca(2+)-regulated exocytic pathway in nerve terminals.
有丝分裂后NT2N细胞由人NT2畸胎瘤细胞经视黄酸（RA）和有丝分裂抑制剂处理后获得，被视为研究人类中枢神经系统成熟神经元的良好体外模型。尽管NT2N细胞表现出神经元的许多形态和生化特征，但参与调节性胞吐作用的关键蛋白成分的表达尚未得到确凿证实。在此，我们通过免疫印迹分析表明，形态学上成熟分化的NT2N细胞含有易于检测到的突触小泡相关蛋白，如突触囊泡蛋白、突触素和突触素I。它们还表达突触前质膜蛋白SNAP-25以及一种与Ca(2+)依赖性胞吐作用控制有关的Rab GTP酶Rab3A。在未处理的NT2细胞或仅暴露于RA 6天的细胞中未检测到这些蛋白。一系列已知参与突触小泡与质膜对接和融合的蛋白的诱导，进一步支持了NT2N细胞作为人类皮质神经元模型的有效性，并表明这些细胞可能有助于对神经末梢中Ca(2+)调节的胞吐途径进行体外分子研究。
