Llanes C, Collman R G, Hrin R, Kolson D L
Department of Neurology, University of Pennsylvania Medical Center, Philadelphia, USA.
J Neurosci Res. 1995 Dec 15;42(6):791-802. doi: 10.1002/jnr.490420608.
Acetylcholinesterase (AChE; EC 3.1.1.7) is expressed in the central nervous system in multiple molecular forms that may subserve multiple functions and may be selectively lost in neurodegenerative illnesses such as Alzheimer's disease. AChE expression has been studied in primary cultures of developing vertebrate nervous system, but investigation has been limited by the lack of a suitable human CNS surrogate cell model system for in vitro studies and the inability of primary brain cultures to provide large numbers of pure neurons. To develop an in vitro model for studies of neuronal AChE expression and function, we utilized a neuronally committed human teratocarcinoma cell line, NTera 2, that can be induced to differentiate to a post-mitotic CNS neuronal phenotype. We found that NTera 2 cells express multiple molecular forms of AChE that are similar to CNS-derived AChE isoforms in velocity sedimentation profile, anion exchange elution profile, and sensitivity to inhibitors. At least two forms of AChE are expressed (G1 and G4), similar to human and rodent brain, and induction of NTera 2 cell differentiation results in an increased G4/G1 ratio, which is characteristic of mature neurons. As in primary CNS neurons, AChE is present in NTera 2 cells in both the cytosolic fraction and in the outer membrane, and is also released in a soluble form. These observations indicate that NTera 2 cells provide a useful human model system for studies of expression of cell-associated and soluble cell-free AChE in developing and mature human neurons and for elucidating the potential role(s) of acetylcholinesterase metabolism in both normal development and neurodegenerative disease states.
乙酰胆碱酯酶（AChE；EC 3.1.1.7）在中枢神经系统中以多种分子形式表达，这些形式可能具有多种功能，并且在诸如阿尔茨海默病等神经退行性疾病中可能会选择性丧失。AChE的表达已在发育中的脊椎动物神经系统的原代培养物中进行了研究，但由于缺乏适合体外研究的人类中枢神经系统替代细胞模型系统，以及原代脑培养物无法提供大量纯神经元，相关研究受到了限制。为了开发一种用于研究神经元AChE表达和功能的体外模型，我们利用了一种已定向分化为神经元的人类畸胎瘤细胞系NTera 2，该细胞系可被诱导分化为有丝分裂后的中枢神经系统神经元表型。我们发现，NTera 2细胞表达多种AChE分子形式，这些形式在速度沉降谱、阴离子交换洗脱谱以及对抑制剂的敏感性方面与中枢神经系统来源的AChE同工型相似。至少有两种AChE形式（G1和G4）被表达，类似于人类和啮齿动物的大脑，NTera 2细胞分化的诱导导致G4/G1比值增加，这是成熟神经元的特征。与原代中枢神经系统神经元一样，AChE在NTera 2细胞的胞质部分和外膜中均有存在，并且也以可溶形式释放。这些观察结果表明，NTera 2细胞为研究发育中和成熟的人类神经元中细胞相关和可溶性无细胞AChE的表达，以及阐明乙酰胆碱酯酶代谢在正常发育和神经退行性疾病状态中的潜在作用，提供了一个有用的人类模型系统。
