Elkabetz Y, Studer L
Developmental Biology Program, Division of Neurosurgery, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
Cold Spring Harb Symp Quant Biol. 2008;73:377-87. doi: 10.1101/sqb.2008.73.052. Epub 2009 Feb 9.
Neural stem cells (NSCs) are defined by their ability to self-renew while retaining differentiation potential toward the three main central nervous system (CNS) lineages: neurons, astrocytes, and oligodendrocytes. A less appreciated fact about isolated NSCs is their narrow repertoire for generating specific neuron types, which are generally limited to a few region-specific subtypes such as GABAergic and glutamatergic neurons. Recent studies in human embryonic stem cells have identified a novel neural stem cell stage at which cells exhibit plasticity toward generating a broad range of neuron types in response to appropriate developmental signals. Such rosette-stage NSCs (R-NSCs) are also distinct from other NSC populations by their specific cytoarchitecture, gene expression, and extrinsic growth requirements. Here, we discuss the properties of R-NSCs within the context of NSC biology and define some of the key questions for future investigation. R-NSCs may represent the first example of a NSC population capable of recreating the full cellular diversity of the developing CNS, with implications for both basic stem cell biology and translational applications in regenerative medicine and drug discovery.
神经干细胞（NSCs）的定义是，它们能够自我更新，同时保持向中枢神经系统（CNS）的三种主要谱系分化的潜力，这三种谱系分别是神经元、星形胶质细胞和少突胶质细胞。关于分离出的神经干细胞，一个不太为人所知的事实是，它们生成特定神经元类型的能力有限，通常仅限于少数几种区域特异性亚型，如γ-氨基丁酸能神经元和谷氨酸能神经元。最近对人类胚胎干细胞的研究发现了一种新的神经干细胞阶段，在此阶段，细胞在适当的发育信号作用下，对生成广泛的神经元类型表现出可塑性。这种玫瑰花结阶段的神经干细胞（R-NSCs）在细胞结构、基因表达和外在生长需求方面也与其他神经干细胞群体不同。在这里，我们在神经干细胞生物学的背景下讨论R-NSCs的特性，并确定一些未来研究的关键问题。R-NSCs可能代表了一种神经干细胞群体的首个例子，这种群体能够重现发育中的中枢神经系统的全部细胞多样性，这对基础干细胞生物学以及再生医学和药物发现中的转化应用都有重要意义。
