Mapping spatio‐temporal activation of Notch signaling during neurogenesis and gliogenesis in the developing mouse brain
Mapping spatio‐temporal activation of Notch signaling during neurogenesis and gliogenesis in the developing mouse brain
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DOI：
10.1111/j.1471-4159.2004.02470.x
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发表时间：
2004-07
影响因子：
4.7
通讯作者：
A. Tokunaga;J. Kohyama;Tetsu Yoshida;Keiko Nakao;K. Sawamoto;H. Okano
中科院分区：
文献类型：
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作者：
A. Tokunaga;J. Kohyama;Tetsu Yoshida;Keiko Nakao;K. Sawamoto;H. Okano
Notch 1在哺乳动物中枢神经系统发育中起着多种重要作用，包括维持干细胞状态以及促进神经胶质细胞的命运。然而，由于体内存在非常少量的Notch 1的活化形式，其精确的活化模式仍然未知。在这项研究中，我们使用一种特异性抗体在发育中的小鼠大脑中原位绘制了该信号通路的活性状态，该抗体识别由早老素/γ-分泌酶活性切割的Notch 1细胞内结构域的加工形式。通过使用该抗体，能够以比使用以往的Notch 1抗体更高的灵敏度检测Notch 1的活性状态。我们发现，激活的Notch 1主要是检测到的放射状胶质细胞，在心室区（VZ）的增殖前体细胞的大多数亚群的细胞核。然而，Notch 1激活在神经元碱性螺旋-环-螺旋蛋白阳性的神经元前体细胞中或在胚胎前脑的分化神经元中未检测到。有趣的是，我们发现Notch 1在围产期CNS发育过程中在星形胶质细胞谱系中被瞬时激活。总之，本方法使我们能够确定Notch信号传导激活的时间、梯度和边界。
Notch1 plays various important roles including the maintenance of the stem cell state as well as the promotion of glial fates in mammalian CNS development. However, because of the very low amount of the activated form of Notch1 present in vivo, its precise activation pattern has remained unknown. In this study, we mapped the active state of this signaling pathway in situ in the developing mouse brain using a specific antibody that recognizes the processed form of the intracellular domain of Notch1 cleaved by presenilin/γ‐secretase activity. By using this antibody, active state of Notch1 came to be detectable with a higher sensitivity than using conventional antibody against Notch1. We found that activated Notch1 was mainly detected in the nuclei of a subpopulation of radial glial cells, the majority of proliferating precursor cells in the ventricular zone (VZ). However, Notch1 activation was not detected in neuronal precursor cells positive for neuronal basic helix‐loop‐helix proteins or in differentiating neurons in the embryonic forebrain. Interestingly, we found that Notch1 was transiently activated in the astrocytic lineage during perinatal CNS development. Taken together, the present method has enabled us to determine the timing, gradients, and boundaries of the activation of Notch signaling.