Kotani Masaharu, Osanai Taka, Tajima Youichi, Kato Hiroko, Imada Masato, Kaneda Hideki, Kubo Hideo, Sakuraba Hitoshi
Department of Clinical Genetics, Tokyo Metropolitan Institute of Medical Science, Tokyo Metropolitan Organization for Medical Research, Tokyo, Japan.
J Neurosci Res. 2002 Mar 1;67(5):595-606. doi: 10.1002/jnr.10150.
P19 embryonic carcinoma (EC) cells are one of the simplest systems for analyzing the neuronal differentiation. To identify the membrane-associated molecules on the neuronal cells involved in the early neuronal differentiation in mice, we generated two monoclonal antibodies, SKY-1 and SKY-2, by immunizing rats with a membrane fraction of the neuronally committed P19 EC cells as an antigen. SKY-1 and SKY-2 recognized the carbohydrate moiety of a 90 kDa protein (RANDAM-1) and the polypeptide core of a 40 kDa protein (RANDAM-2), respectively. In the P19 EC cells, the expression of RANDAM-1 was colocalized to a part of Nestin-positive cells, whereas that of RANDAM-2 was observed in most Nestin-positive cells as well as beta-III-tubulin positive neurons. In the embryonic and adult brain of mice, RANDAM-1 was expressed at embryonic day 8.5 (E8.5), and the localization of antigen was restricted on the neuroepithelium and choroid plexus. The RANDAM-2 expression commenced at E6.0, and the antigen was distributed not only on the neuroepithelium of embryonic brain but on the neurons of adult brain. Collectively, it was concluded that RANDAM-1 is a stage specific antigen to express on the neural stem cells, and RANDAM-2 is constitutively expressed on both the neural stem cells and differentiated neuronal cells in mouse central nervous system (CNS).
P19胚胎癌细胞是用于分析神经元分化的最简单系统之一。为了鉴定参与小鼠早期神经元分化的神经元细胞上的膜相关分子，我们以神经元定向的P19胚胎癌细胞的膜部分作为抗原免疫大鼠，产生了两种单克隆抗体SKY-1和SKY-2。SKY-1和SKY-2分别识别一种90 kDa蛋白质（RANDAM-1）的碳水化合物部分和一种40 kDa蛋白质（RANDAM-2）的多肽核心。在P19胚胎癌细胞中，RANDAM-1的表达与部分巢蛋白阳性细胞共定位，而RANDAM-2的表达在大多数巢蛋白阳性细胞以及β-III-微管蛋白阳性神经元中都能观察到。在小鼠的胚胎和成年大脑中，RANDAM-1在胚胎第8.5天（E8.5）表达，抗原定位局限于神经上皮和脉络丛。RANDAM-2的表达在E6.0开始，抗原不仅分布在胚胎脑的神经上皮上，还分布在成年脑的神经元上。总的来说，得出的结论是，RANDAM-1是在神经干细胞上表达的阶段特异性抗原，而RANDAM-2在小鼠中枢神经系统（CNS）的神经干细胞和分化的神经元细胞上都持续表达。
