Defining fate potential in human ESC derived neural stem cells

: 神经干细胞（NSC）可以在体外增殖很长一段时间，同时保留了向神经细胞分化的能力。 分化成神经元、星形胶质细胞和少突胶质细胞。然而，神经干细胞的潜力有限， 产生特定的神经元类型。在体外扩增的幼稚神经干细胞主要产生GABA能中间神经元， 较少程度的谷氨酸神经元。这表明，神经干细胞，虽然多能，可能无法获得充分的 神经元类型的频谱。相反，人类胚胎干细胞（hESC）向早期神经细胞分化。 命运可以容易地偏向于各种区域特异性神经元类型 或脊髓运动神经元。我们最近报道，hESC衍生的神经后代对这种反应有反应， 区域图案线索被组织成称为神经突起（R-）的柱状神经上皮结构。 神经干细胞），并在相当详细的R-NSC特征1。我们的研究已经确定R-NSCs是一种新颖的，独特的 基于标记物表达、克隆干细胞特性、神经分化潜能和 遗传特性1，2.这些研究中最有趣的发现是R-NSCs广泛的模式化潜力 与现有的其他NSC类型相比。R-NSC能够全面分化 针对CNS 1和PNS 3衍生物，并且能够体内植入。 尽管有这些令人兴奋的初步数据，我们的研究也揭示了我们目前对 RNSC生物学。在这里，我们想通过定义内部的异质性来解决其中的一些限制。 RNSC和发展遗传策略的前瞻性分离完全模式化的R-NSC的基础上BAC 转基因BAC转基因hESC报告细胞系最近已在Studer实验室中开创， 作为R-NSC阶段、身份和功能的可靠读数。BAC转基因报告基因也将是关键的 用于探测影响R-NSC身份的外在和内在因素的功能。这些研究将提供 对神经模式的遗传和表观遗传机制的基本见解，并最终导致 新的条件下继续在体外扩增完全模式化的R-NSC -一个关键步骤， 建立稳定的可扩展的通用NSC群体。

: Neural stem cells (NSCs) can be propagated in vitro for extensive periods of time while retaining the ability to differentiate into neurons, astrocytes and oligodendrocytes. However, NSCs are limited in their potential to yield specific neuron types. Na¿ve NSCs expanded in vitro give rise primarily to GABAergic interneurons and to a lesser extent glutamate neurons. This suggests that NSCs, while multipotent, may not have access to the full spectrum of neuron types. In contrast human embryonic stem cells (hESCs) differentiated towards early neural fates can be readily biased towards various region-specific neuron types such as midbrain dopamine neurons or spinal motoneurons. We have recently reported that hESC derived neural progeny responsive to such regional patterning cues are organized into columnar neuroepithelial structures termed neural rosettes (R- NSCs) and characterized R-NSCs in considerable detail1. Our study has identified R-NSCs as novel, unique NSC stage based on marker expression, clonal stem cell properties, neural differentiation potential, and genetic identity1, 2. The most intriguing finding of these studies was the broad patterning potential of R-NSCs compared to other currently available NSC types. R-NSCs are capable of comprehensive differentiation towards CNS1 and PNS3 derivatives and capable of in vivo engraftment. Despite these exciting preliminary data our studies also revealed major gaps in our current understanding of RNSC biology. Here we would like to address some of these limitations by defining heterogeneity within RNSCs and develop genetic strategies for the prospective isolation of fully patternable R-NSCs based on BAC transgenesis. BAC transgenic hESC reporter lines have been recently pioneered in the Studer lab and will serve as reliable readout of R-NSC stage, identity and function. BAC transgenic reporters will also be critical for probing function of extrinsic and intrinsic factors affecting R-NSC identity. These studies should provide fundamental insights into the genetic and epigenetic mechanisms of neural patterning and ultimately result in novel conditions for the continued in vitro expansion of fully patternable R-NSC - a key step towards establishing a stable expandable universal NSC population.