DeVeale Brian, Bausch-Fluck Damaris, Seaberg Raewyn, Runciman Susan, Akbarian Vahe, Karpowicz Phillip, Yoon Charles, Song Hannah, Leeder Rachel, Zandstra Peter W, Wollscheid Bernd, van der Kooy Derek
Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
Stem Cells. 2014 Jan;32(1):258-68. doi: 10.1002/stem.1550.
The composition of cell-surface proteins changes during lineage specification, altering cellular responses to their milieu. The changes that characterize maturation of early neural stem cells (NSCs) remain poorly understood. Here we use mass spectrometry-based cell surface capture technology to profile the cell surface of early NSCs and demonstrate functional requirements for several enriched molecules. Primitive NSCs arise from embryonic stem cells upon removal of Transforming growth factor-β signaling, while definitive NSCs arise from primitive NSCs upon Lif removal and FGF addition. In vivo aggregation assays revealed that N-cadherin upregulation is sufficient for the initial exclusion of definitive NSCs from pluripotent ectoderm, while c-kit signaling limits progeny of primitive NSCs. Furthermore, we implicate EphA4 in primitive NSC survival signaling and Erbb2 as being required for NSC proliferation. This work elucidates several key mediators of NSC function whose relevance is confirmed on forebrain-derived populations and identifies a host of other candidates that may regulate NSCs.
细胞表面蛋白的组成在细胞谱系特化过程中发生变化，从而改变细胞对其周围环境的反应。早期神经干细胞（NSCs）成熟过程中的特征性变化仍知之甚少。在这里，我们使用基于质谱的细胞表面捕获技术来分析早期神经干细胞的细胞表面，并证明了几种富集分子的功能需求。去除转化生长因子-β信号后，原始神经干细胞从胚胎干细胞产生，而去除白血病抑制因子（Lif）并添加成纤维细胞生长因子（FGF）后，定型神经干细胞从原始神经干细胞产生。体内聚集试验表明，N-钙黏蛋白的上调足以使定型神经干细胞最初从多能外胚层中排除，而c-kit信号传导限制了原始神经干细胞的后代。此外，我们发现EphA4参与原始神经干细胞的存活信号传导，而Erbb2是神经干细胞增殖所必需的。这项工作阐明了神经干细胞功能的几个关键介质，其相关性在前脑来源的群体中得到证实，并鉴定了许多可能调节神经干细胞的其他候选物。
