（封面圖片：Yu-Fen Chou等科學家發(fā)現(xiàn)多能干細胞存在多個基態(tài),，每一個基態(tài)都具有自身獨特的分子和生物學特性。在封面圖中,，作者用不同色彩的環(huán)表示不同的干細胞狀態(tài),，這些環(huán)互相聯(lián)結(jié)。細胞能從一個態(tài)轉(zhuǎn)化為下一個確定的態(tài),，這導致了世系分化以及胚胎發(fā)生,，以上過程通過中間的胚胎輻射出的路徑表達。）
干細胞具有多能性,，這是一種維持細胞自我更新以及產(chǎn)生三胚層衍生組織的能力,。長久以來科學家們一直認為，干細胞多能性是一種單一的高階基態(tài),，并且隨著細胞分化的開始而逐步喪失,。而在2008年10月31日出版的《細胞》（Cell）上,，來自美國麻省綜合醫(yī)院的Yu-Fen Chou等科學家認為，事實上存在多個這樣的基態(tài),，每一個基態(tài)都具有自身獨特的分子和生物學特性,。
在本期的封面文章中，研究小組證明了干細胞能從一個態(tài)轉(zhuǎn)化到另一個態(tài),，而以上過程很大程度上取決于細胞生長因子微環(huán)境,。多能干細胞系（pluripotent stem cell line）能由囊胚產(chǎn)生，這一部分最終得到胚胎干細胞系（embryonic stem cell line,，ES cell line）,，而另一部分多能干細胞來自于上胚層，這部分最終得到上胚層干細胞系（epiblast stem cell line,，EpiSCs line）,。而ES細胞以及EpiSCs細胞在結(jié)合維持其多能狀態(tài)的生長因子時表現(xiàn)出極大的差異。這兩種干細胞種類的分子以及功能上的差別證明,，組織來源和生長因子環(huán)境或許對于決定干細胞類型非常重要,。
此外，科學家研究了組織來源以及生長因子是如何影響干細胞多能狀態(tài)的,。研究小組證實能從小鼠囊胚得到具有獨特功能和分子特性的新干細胞系,，并且生長因子培養(yǎng)環(huán)境和細胞間相互作用在確定獨特且穩(wěn)定的干細胞基態(tài)方面具有至關重要的作用。（生物谷Bioon.com）
生物谷推薦原始出處：
Cell,，Volume 135, Issue 3, 449-461, 31 October 2008,，Yu-Fen Chou, Niels Geijsen
The Growth Factor Environment Defines Distinct Pluripotent Ground States in Novel Blastocyst-Derived Stem Cells
Yu-Fen Chou1,7,Hsu-Hsin Chen1,7,Maureen Eijpe2,7,Akiko Yabuuchi3,Joshua G. Chenoweth4,Paul Tesar5,Jun Lu6,Ronald D.G. McKay4andNiels Geijsen1,,
1 Harvard Stem Cell Institute, Massachusetts General Hospital, Center for Regenerative Medicine, CPZN 4256, 185 Cambridge Street, Boston, MA 02114, USA
2 Erasmus Medical Centre, Department of Cell Biology, Dr. Molewaterplein 50, 3015 GE, Rotterdam, The Netherlands
3 Division of Pediatric Hematology/Oncology, Children's Hospital Boston, One Blackfan Circle, Boston, MA, 02115, USA
4 Laboratory of Molecular Biology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
5 Department of Genetics, Case Western Reserve University, 2109 Adelbert Road BRB-725, Cleveland, OH 44106, USA
6 The Broad Institute of Harvard University and Massachusetts Institute of Technology, Cambridge, MA 02141, USA
7 These authors contributed equally to this work
SUMMARY
Pluripotent stem cell lines can be derived from blastocyst embryos, which yield embryonic stem cell lines (ES cells), as well as the postimplantation epiblast, which gives rise to epiblast stem cell lines (EpiSCs). Remarkably, ES cells and EpiSCs display profound differences in the combination of growth factors that maintain their pluripotent state. Molecular and functional differences between these two stem cell types demonstrate that the tissue of origin and/or the growth factor milieu may be important determinants of the stem cell identity. We explored how developmental stage of the tissue of origin and culture growth factor conditions affect the stem cell pluripotent state. Our findings indicate that novel stem cell lines, with unique functional and molecular properties, can be generated from murine blastocyst embryos. We demonstrate that the culture growth factor environment and cell-cell interaction play a critical role in defining several unique and stable stem cell ground states.
