Nature：一种新的多功能胚胎干细胞被发现
生物谷报道：人类胚胎干细胞在治疗方面有潜在的重要性，因为它们有多种功能，如果给予适当条件的话，它们能够分化成几乎任何类型的细胞。影响关于它们的研究工作的进展的一个障碍是，人类与小鼠胚胎干细胞之间存在令人困惑的差别。现在，独立工作的两个小组生成了一种新的多功能胚胎干细胞。这种名为EpiSC 的细胞分离自被植入胚胎的小鼠以及大鼠胚胎。研究人员表示，它们比现有的小鼠ES 细胞更像人类ES 细胞，从而有望为了解人类细胞如何生长与分化提供一条没有争议的新模式。这项研究结果发表在最新一期的《自然》杂志上。
由美国国家神经疾病和中风研究院的RonaldMcKay 和英国牛津大学的同事领导的研究小组，将小鼠作为研究对象；而由英国剑桥大学的Roger Pedersen 和Ludovic Vallier 率领的科学家则用大鼠进行了试验。
McKay 指出，“这是多能性细胞的一个新类型”，意味着它能够发育成任何种类的身体组织。他解释说，传统的小鼠ES 细胞并不能让我们获取有关人类的大量信息，这是因为小鼠细胞要“更加原始”。例如，小鼠细胞需要生长因子LIF（白血病抑制因子），然而与其他干细胞一样，人类ES 细胞在抑制上述因子的情况下才能更好地发育。如今，McKay 研究小组发现了一种与人类干细胞类似的小鼠干细胞。在将胚胎植入小鼠子宫5 天半后，研究人员从外胚层———小鼠胚胎最内部的细胞———中分离出EpiSC。与人类ES 细胞类似，EpiSC 不能在LIF存在的前提下很好地生长，同时它们的基因表达以及细胞表面标记的模式也与人类相同。McKay 表示，这些细胞代表了一个更高级的发育阶段，即传统小鼠ES 细胞与已经开始分化的细胞之间的一个“缺失的环节”。他强调：“大多数人都认为你不可能在胚胎移植后获得多能性细胞系。”
Pedersen 则表示，大鼠的EpiSC 与小鼠的类似，他同时预测，科学家将能够从“大部分甚至所有的哺乳动物中”获取此类细胞。他说，从这些干细胞发育出的细胞系作用很大，将成为人类ES 细胞加速发育为组织的一个模型，从而用于病患的治疗。
EpiSCs的发现应能为加快人类胚胎干细胞在研究（最终也许还包括治疗）中的应用提供一个重要的实验模型。这项研究表明，科学家能够培育出包括源自人类在内的新的ES 细胞系，它们“最终将更加适用于分化的目标”。
原文出处：
Nature Volume 448 Number 7150
Derivation of pluripotent epiblast stem cells from mammalian embryos p191
I. Gabrielle M. Brons, Lucy E. Smithers, Matthew W. B. Trotter, Peter Rugg-Gunn, Bowen Sun, Susana M. Chuva de Sousa Lopes, Sarah K. Howlett, Amanda Clarkson, Lars Ahrlund-Richter, Roger A. Pedersen & Ludovic Vallier
doi:10.1038/nature05950
First paragraph | Full Text | PDF (666K) | Supplementary information
See also: Editor's summary
New cell lines from mouse epiblast share defining features with human embryonic stem cells p196
Paul J. Tesar, Josh G. Chenoweth, Frances A. Brook, Timothy J. Davies, Edward P. Evans, David L. Mack, Richard L. Gardner & Ronald D. G. McKay
doi:10.1038/nature05972
First paragraph | Full Text | PDF (589K) | Supplementary information
See also: Editor's summary
作者简介：
Ronald D.G. McKay, Ph.D., Senior Investigator
Dr. McKay received a B.Sc. in 1971 and a Ph.D. in 1974 from University of Edinburgh, where he studied under the tutelage of Edwin Southern examining DNA organization and chromosome structure. He received postdoctoral training at University of Oxford working with Walter Bodner examining restriction fragment length polymorphism (RFLPs). In 1978 he became a senior staff investigator at Cold Spring Harbor Laboratory concentrating on two areas: the interaction of SV40 T-antigen with the specific binding site at the viral origin of replication and the molecular organization of the nervous system. Joining the MIT faculty in 1984, Dr. McKay continued to examine different aspects of neuronal organization in the nervous system. In 1993 he came to NINDS as chief of the Laboratory of Molecular biology. His laboratory is studying stem cell differentiation.
Research Interests:
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The identification of stem cells in the fetal and adult mammalian brain has many scientific and clinical consequences. We have evidence for a common stem cell generating the central and peripheral nervous system (CNS + PNS). This cell can be obtained in large numbers and provides an ideal system to analyze the pathways that control fate choice. We are working on contact dependent and soluble signals that control the proliferation and differentiation of stem cells. Similar mechanisms regulate differentiation in fetal and adult stem cells. It is important to determine if stem cells give rise to functional neurons. We have shown that stem cells can generate synaptically active neurons. |
Selected Recent Publications:
· Cameron HA, McKay RDG (2001) Adult Neurogenesis Produces a Large Pool of New Granule Cells in the Dentate Gyrus, J Comp Neurol 435, 406-417.
· Lumelsky N, Blondel O, Laeng P, Velasco I, Ravin R, McKay RDG (2001) Differentiation of Embroyonic Stem Cells to Insulin-secreting Structures Similar to Pancreatic Islets, Science 292, 1389-1394.
· Lee S-H, Lumelsky N, Studer L, Auerbach J, McKay RDG (2000) Efficient generation of midbrain and hindbrain neurons from embryonic stem cells., Nat. Biotech. 18, 675-679.
· Vicario-Abejon C, Collin C, McKay RDG. (2000) Hippocampal stem cells differentiate into excitatory and inhibitory neurons., Eur J Neurosci. 12, 677-88.
· Brustle O, Jones K, Learish R, Karram K, Choudhary K, Wiestler OD, Duncan ID, McKay RDG.. (1999) Embryonic stem cell-derived glial precursors: a source of myelinating transplants., Science 285, 754-6.
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