Identification of self-replicating multipotent progenitors in the embryonic nervous system by high Notch activity and Hes5 expression
Identification of self-replicating multipotent progenitors in the embryonic nervous system by high Notch activity and Hes5 expression
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DOI：
10.1111/j.1460-9568.2007.05370.x
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发表时间：
2007-02-01
影响因子：
3.4
通讯作者：
Taylor, Verdon
中科院分区：
文献类型：
--
作者：
Basak, Onur;Taylor, Verdon
在哺乳动物大脑发育过程中，由于缺乏特异性标记物，从其他祖细胞中辨别神经干细胞一直受到阻碍。识别引导哺乳动物神经发生的祖细胞池和信号通路对于理解控制神经系统发育的复杂机制至关重要。Notch信号在哺乳动物神经系统的发育中起着至关重要的作用，通过维持多能性神经干细胞并调节其命运。为了原位鉴定假定的神经干细胞，我们产生了表达绿色荧光蛋白（GFP）的转基因小鼠，并报道了发育中的中枢神经系统中Notch信号活动。这里我们展示了这些小鼠神经管内祖细胞的细分。我们从神经管中纯化祖细胞，发现notch报告活性最高的细胞具有自我更新能力和多能性，而缺乏Hes5表达的细胞在体外不能形成神经球。通过标记蛋白共表达和细胞分选，我们发现胚胎神经管所有轴向水平的神经上皮细胞和一些放射状胶质细胞都显示活跃的Notch信号。然而，发育中的端脑和分化中的Islet1/2-和lim1阳性运动神经元的thbr2阳性基底祖细胞不表达Hes5-GFP。定量分析表明，Hes5表达比相关基因Hes1表达与神经干细胞电位的相关性更强。因此，Notch活性通过Hes5识别具有干细胞特性的多能祖细胞，并将不同的祖细胞细分为确定的池。
Discrimination of neural stem cells from other progenitors in the developing mammalian brain has been hampered by the lack of specific markers. Identifying the progenitor pools and signalling pathways that guide mammalian neurogenesis are central to understanding the complex mechanisms that govern development of the nervous system. Notch signalling plays a pivotal role in the development of the mammalian nervous system by maintaining multipotent neural stem cells and regulating their fate. In order to identify putative neural stem cells in situ, we generated transgenic mice that express Green Fluorescent Protein (GFP) and report Notch signalling activity in the developing CNS. Here we show the subdivision of progenitors within the neural tube of these mice. We purify progenitors from the neural tube and show that cells with the highest levels of Notch-reporter activity have self-renewal capability and multipotency, whereas those lacking Hes5 expression do not form neurospheres in vitro. Using marker protein co-expression and cell sorting, we show that both neuroepithelial cells as well as some radial glia at all axial levels of the embryonic neural tube display active Notch signalling. However, Tbr2-positive basal progenitors of the developing telencephalon and differentiating Islet1/2- and Lim1-positive motor neurons outside the ventricular zone do not express Hes5-GFP. Quantitative analysis showed that Hes5 expression correlates better with neural stem cell potential than expression of the related gene Hes1. Thus, Notch activity through Hes5 identifies multipotent progenitors with stem cell properties and subdivides the different progenitors into defined pools.