Ahmed Sohail
Institute of Medical Biology, 8A Biomedical Grove, #06-06 Immunos, Singapore 138648, Singapore.
J Cell Biochem. 2009 Jan 1;106(1):1-6. doi: 10.1002/jcb.21972.
A stem cell has three important features. Firstly, the ability of self-renewal: making identical copies of itself. Secondly, multipotency, generating all the major cell lineages of the host tissue (in the case of embryonic stem cells-pluripotency). Thirdly, the ability to generate/regenerate tissues. Thus, the study of stem cells will help unravel the complexity of tissue development and organisation, and will also have important clinical applications. Neural stem cells (NSCs) are present during embryonic development and in certain regions of the adult central nervous system (CNS). Mobilizing adult NSCs to promote repair of injured or diseased CNS is a promising approach. Since NSCs may give rise to brain tumor, they represent in vitro models for anti-cancer drug screening. To facilitate the use of NSCs in clinical scenarios, we need to explore the biology of these cells in greater details. One clear goal is to be able to definitively identify and purify NSCs. The neurosphere-forming assay is robust and reflects the behavior of NSCs. Clonal analysis where single cells give rise to neurospheres need to be used to follow the self-renewal and multipotency characteristics of NSCs. Neurosphere formation in combination with other markers of NSC behavior such as active Notch signaling represents the state of the art to follow these cells. Many issues connected with NSC biology need to be explored to provide a platform for clinical applications. Important future directions that are highlighted in this review are; identification of markers for NSCs, the use of NSCs in high-throughput screens and the modelling of the central nervous development. There is no doubt that the study of NSCs is crucial if we are to tackle the diseases of the CNS such as Parkinson's and Alzheimer's.
干细胞具有三个重要特征。其一，自我更新能力：能够自我复制出相同的细胞。其二，多能性，可产生宿主组织的所有主要细胞谱系（胚胎干细胞则具有多能性）。其三，生成/再生组织的能力。因此，对干细胞的研究将有助于揭示组织发育和组织构成的复杂性，并且还将具有重要的临床应用价值。神经干细胞（NSCs）在胚胎发育期间以及成体中枢神经系统（CNS）的某些区域中存在。动员成体神经干细胞以促进受损或患病中枢神经系统的修复是一种很有前景的方法。由于神经干细胞可能引发脑肿瘤，它们可作为抗癌药物筛选的体外模型。为了便于在临床场景中使用神经干细胞，我们需要更深入地探究这些细胞的生物学特性。一个明确的目标是能够确切地识别和纯化神经干细胞。神经球形成试验可靠且能反映神经干细胞的行为。需要采用单细胞形成神经球的克隆分析来追踪神经干细胞的自我更新和多能性特征。神经球形成与神经干细胞行为的其他标志物（如活跃的Notch信号）相结合代表了追踪这些细胞的最新技术水平。为了提供临床应用平台，许多与神经干细胞生物学相关的问题有待探索。本综述中强调的重要未来方向包括：神经干细胞标志物的鉴定、神经干细胞在高通量筛选中的应用以及中枢神经系统发育的建模。毫无疑问，如果我们要攻克帕金森氏症和阿尔茨海默氏症等中枢神经系统疾病，神经干细胞的研究至关重要。
