德國科研人員已成功地自人類胚胎干細(xì)胞誘導(dǎo)出大腦干細(xì)胞,。這些干細(xì)胞不僅能在培養(yǎng)皿中幾乎無限期地保存,，而且還能作為各類神經(jīng)細(xì)胞的一種取之不盡的來源,?？茖W(xué)家們還表明,，這些神經(jīng)細(xì)胞能在大腦中進(jìn)行突觸融合,。這項(xiàng)研究結(jié)果發(fā)表在最新出版的《美國國家科學(xué)院院刊》上。
多年來,，干細(xì)胞研究幾乎分裂成為兩個(gè)世界：一個(gè)是胚胎干細(xì)胞,，它是萬能的，具有無限的發(fā)展?jié)摿?；另一個(gè)是成體干細(xì)胞,，它可以從成體組織獲得，但再生和發(fā)展的能力卻有限?，F(xiàn)在，德國波恩大學(xué)科學(xué)家成功地將這兩個(gè)世界合二為一：他們誘導(dǎo)出幾乎能從人類胚胎干細(xì)胞無限再生和保存的大腦干細(xì)胞,，利用這些穩(wěn)定的干細(xì)胞系,，研究人員就能持續(xù)不斷地從體外獲取各種不同的人類神經(jīng)細(xì)胞，包括那些可挫敗帕金森氏癥的神經(jīng)細(xì)胞,。
使用這種新的細(xì)胞,，研究人員還能減少目前對(duì)胚胎干細(xì)胞的需求，胚胎干細(xì)胞是迄今為止每一個(gè)獨(dú)立細(xì)胞創(chuàng)建過程中不可或缺的基本材料,。波恩大學(xué)重構(gòu)神經(jīng)生物學(xué)教授奧利佛·布魯斯托說：“這種新的細(xì)胞,，可長(zhǎng)年累月源源不斷地供應(yīng)人類神經(jīng)細(xì)胞，而無需求助于任何胚胎干細(xì)胞的補(bǔ)充,。”
在動(dòng)物實(shí)驗(yàn)中,，研究人員找到了直接的證據(jù)證明這些人工誘導(dǎo)的神經(jīng)細(xì)胞可發(fā)揮作用。這些細(xì)胞被移植入老鼠的大腦后,，與受體大腦進(jìn)行接觸,，隨后都能發(fā)送和接受信令。研究論文的作者菲利普·科赫博士認(rèn)為,，這是自人類胚胎干細(xì)胞誘導(dǎo)出的神經(jīng)細(xì)胞能在大腦中進(jìn)行突觸融合的第一個(gè)直接證據(jù),。研究人員希望藉此取之不盡的細(xì)胞源來研究神經(jīng)退行性疾病，及可能存在于人類神經(jīng)細(xì)胞中活性成分,。
布魯斯托和他的研究團(tuán)隊(duì)是德國首個(gè)獲準(zhǔn)進(jìn)口人類胚胎干細(xì)胞的團(tuán)隊(duì),，他們?cè)谶@一熱門課題的公開討論中發(fā)揮了重要作用。布魯斯托強(qiáng)調(diào)說：“目前的研究結(jié)果已經(jīng)清晰地表明了,，胚胎干細(xì)胞和成體干細(xì)胞的研究可完美地結(jié)合起來,，這非常重要,。”（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS February 13, 2009, doi: 10.1073/pnas.0808387106
A rosette-type, self-renewing human ES cell-derived neural stem cell with potential for in vitro instruction and synaptic integration
Philipp Koch, Thoralf Opitz1, Julius A. Steinbeck1, Julia Ladewig and Oliver Brüstle2
Institute of Reconstructive Neurobiology, Life and Brain Center, University of Bonn and Hertie Foundation, D-53127 Bonn, Germany
Edited by Floyd E. Bloom, The Scripps Research Institute, La Jolla, CA, and approved January 6, 2009 (received for review September 3, 2008)
Abstract
An intriguing question in human embryonic stem cell (hESC) biology is whether these pluripotent cells can give rise to stably expandable somatic stem cells, which are still amenable to extrinsic fate instruction. Here, we present a pure population of long-term self-renewing rosette-type hESC-derived neural stem cells (lt-hESNSCs), which exhibit extensive self-renewal, clonogenicity, and stable neurogenesis. Although lt-hESNSCs show a restricted expression of regional transcription factors, they retain responsiveness to instructive cues promoting the induction of distinct subpopulations, such as ventral midbrain and spinal cord fates. Using lt-hESNSCs as a donor source for neural transplantation, we provide direct evidence that hESC-derived neurons can establish synaptic connectivity with the mammalian nervous system. Combining long-term stability, maintenance of rosette-properties and phenotypic plasticity, lt-hESNSCs may serve as useful tool to study mechanisms of human NSC self-renewal, lineage segregation, and functional in vivo integration.
