中科院干细胞重点实验室金颖JBC文章

　　

生物通报道，中科院上海生命科学院/上海交大医学院健康科学研究所研究员金颖教授带领的研究小组将在最新一期的《Journal of Biological Chemistry》上发表研究成果。文章标题为：Critical roles of coactivator p300 in mouse embryonic stem cell differentiation and nanog expression.

 

胚胎干细胞(ES cells)来源于植入前胚胎囊胚期的内细胞团，具有自我更新和全能性的特点。ES细胞的自我更新和全能性特性是由细胞外信号分子和细胞内的关键转录因子共同调控的，如Oct4和Nanog等。p300是一个具有组蛋白乙酰转移酶活性的转录共激活因子，它在胚胎发育和很多生理过程中都发挥着重要的作用。但是，p300对ES细胞的全能性维持和分化过程是否具有调控功能，目前为止还没有研究报道过。

 

在金颖研究员的指导下，健康所发育生物学实验室博士生钟小敏同学对p300在小鼠ES细胞中的功能进行了探索。研究发现，在自我更新能力和全能性分子标志的表达水平上，p300基因敲除的小鼠胚胎干细胞与野生型ES细胞没有任何区别。但是在体外诱导分化时，p300的缺失使ES细胞向内中外三个胚层的分化发生了异常，并且该表型可以部分地被Nanog基因的外源过量表达所恢复。通过对Nanog基因转录调控的分析和研究，p300被证明可以直接结合在Nanog基因的转录调控区并调节其表达。进一步的研究表明，p300调控Nanog基因表达的机制可能与组蛋白的乙酰化修饰密切相关。

 

该研究工作首次证明了p300在ES细胞分化过程中的作用及其对Nanog基因的表达调控功能，为以后进一步阐明ES细胞分化的机制以及Nanog基因的作用提供了参考。这项研究工作于2009年4月发表在《生物化学杂志》 (The Journal of Biological Chemistry)上。

 

（生物通 小茜）

生物通推荐原文检索：Critical roles of coactivator p300 in mouse embryonic stem cell differentiation and nanog expression

【Abstract】

p300 is a well-known histone acetyltransferase and coactivator playing pivotal roles in many physiological processes. Despite extensive research for functions of p300 in embryogenesis and transcription regulation, its roles in regulating embryonic stem (ES) cell pluripotency are poorly understood. To address this issue, we investigated the self-renewal ability and early differentiation process in both wild-type mouse ES cells and ES cells derived from p300 knock-out (p300-/-) mice. We found that p300 ablation did not affect self-renewal capacity overtly when ES cells were maintained under undifferentiated conditions. However, the absence of p300 caused a significantly abnormal expression pattern of germ layer markers when differentiation was induced by embryoid body (EB) formation. Interestingly, the expression level of pluripotency marker Nanog, but not Oct4, was markedly lower in EBs from p300-/- ES cells, compared to that in EBs from wild-type ES cells. Exogenous expression of Nanog rescued abnormal expression of extra-embryonic endoderm marker partially, but not mesoderm and ectoderm markers. Furthermore we demonstrate that p300 was directly involved in modulating Nanog expression. Importantly, epigenetic modification of histone acetylation at the distal regulatory region of Nanog was found to be dependent on the presence of p300, which could contribute to the mechanism of regulating Nanog expression by p300. Collectively, our results show that p300 plays an important role in the differentiation process of ES cells and provide the first evidence for involvement of p300 in regulating Nanog expression during differentiation, probably through epigenetic modification of histone on Nanog.

 

学习经历

1978-1983        中国医科大学医学学士

1983-1988        北京协和医科大学/中国医学科学院基础医学研究所理学博士

1988-1994        美国北德克萨斯州大学医学中心博士后

1994-1999        美国德克萨斯大学西南医学中心博士后

 

工作简历

2000-至今        上海交通大学医学院基础医学院研究员、分子发育生物学研究室主任

2001-至今        健康科学研究所干细胞研究课题组组长

2006-至今        中国科学院干细胞生物学重点实验室主任

 

荣誊(证书,称号,会员)

International Society for Stem Cell Research会员

 

主要成果

        1. 成功地建立起胚胎干细胞水平研究蛋白质和蛋白质-DNA之间相互作用的技术平台。利用亲和纯化及酵母双杂交等技术筛选出多个与胚胎干细胞全能性因子Oct-3/4相互作用的蛋白质，通过质谱分析发现一个新的蛋白因子Wwp2，Wwp2专一性地与Oct-3/4作用，是Oct-4的E3泛素化连接酶。利用染色质免疫沉淀等方法发现并研究了Oct-3/4的新的下游基因及Oct-3/4对基因表达调控的分子机制。

        2. 建立正常受精及孤雌激活胚胎来源的小鼠ES细胞系，为体外研究ES细胞增殖分化提供了良好的模型；而孤雌干细胞系又有助于基因组印迹及表观遗传在发育中的作用机制的研究。

        3. 建立了人的胚胎干细胞系并实现无滋养层培养和人胚胎干细胞向神经细胞的定向诱导分化。

 

近期主要论文

 

Li C, Yang Y, Gu J, Ma Y, Jin Y. Derivation and transcriptional profiling analysis of pluripotent stem cell lines from rat blastocysts. Cell Res. 2009 Feb;19(2):173-86.

 

Zhong X, Jin Y. Critical roles of coactivator p300 in mouse embryonic stem cell differentiation and nanog expression. J Biol Chem. 2009 Jan 16. [Epub ahead of print]

 

Zhang Z, Liao B, Xu M, Jin Y*. (2007) Posttranslation Modification of POU domain transcription factor Oct-4 by SUMO-1. FASEB Journal. 21:3042-3051.

 

Hui Li, Zhihong Zhang, Beibei Wang, Junmei Zhang, Yingming Zhao, Ying Jin. The Wwp2-mediated Ubiquitination of the RNA Polymerase II Large Subunit in Mouse Embryonic Pluripotent Stem Cells. Mol Cell Biol. 2007 Aug;27(15):5296-305.

 

Wang, B.B., Lu, R, Wang, W.C., Jin Y*.(2006) Inducible and reversible suppression of Npm1 gene expression using stably integrated small interfering RNA vector in mouse embryonic stem cells. Biochemical and Biophysical Research Communications. 8;347(4):1129-1137

 

Sun BW, Yang AC, Feng Y, Sun YJ, Zhu Y, Zhang Y, Jiang H, Li CL, Gao FR, Zhang ZH, Wang WC, Kong XY, Jin G, Fu SJ, Jin Y. Temporal and parental-specific expression of imprinted genes in a newly derived Chinese human embryonic stem cell line and embryoid bodies. Hum Mol Genet. 2006 Jan 1;15(1):65-75.

 

Jiang, H., Sun, B.W., Wang, W.C., Zhang, Z.H., Gao, F.R., Shi, G.L., Cui, B., Kong, X.Y., He, Z., Ding, X.Y., Kuang, Y., Fei, J., Sun, Y.J., Feng, Y*., Jin, Y.* (2007) Activation of paternally expressed imprinted genes in newly derived germline-competent mouse parthenogenetic embryonic stem cell lines. Cell Research 17：792-803

 

Xu, H.M., Liao, B., Zhang, Q.J., Wang, B.B., Li, H., Zhong, X.M., Sheng, H.Z., Zhao, Y.X., Zhao, Y.M., Jin, Y*. (2004) Wwp2, an E3 ubiquitin ligase that targets transcription factor Oct-4 for ubiquitination. Journal of Biological Chemistry 279(22): 23495-503

 

Bucher, K., Sofroniew, M.V., Pannell, R., Impey, H., Smith, A.J.H., Torres,E.M.,Dunnett, S.B., Jin, Y., Baer, R. And Rabbits, T.H. The T cell oncogene Tal2 is necessary for normal development of the mouse brain. Dev Biol. 2000 Nov 15;227(2):533-44.

 

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Tsan, J.T., Wang, Z., Jin, Y., Hwang, L.-Y., Bash, R.O., and Baer, R. (1997)Mammalian cells as hosts for two-hybrid studies of protein-protein interaction.In The Yeast Two-hybrid System (Bartel, P.L., and Fields S., Eds.), Oxford University Press, pp. 217-232.