3月22日，國際學(xué)術(shù)期刊Cell Research在線發(fā)表了中科院上海生命科學(xué)研究院/上海交大醫(yī)學(xué)院健康所,、中科院干細(xì)胞生物學(xué)重點實驗室楊黃恬研究組和上海生命科學(xué)研究院生化與細(xì)胞所肖磊研究組合作的最新研究成果,。本項研究建立了全新的大鼠胚胎干細(xì)胞（rat embryonic stem cells, rESCs）體外分化體系，并在國際上率先證實rESCs可以在體外分化為具有功能性的心肌細(xì)胞,。
大鼠是最早被用于科學(xué)研究的實驗動物,。與最為常用的模式生物小鼠相比，大鼠具有許多獨特的優(yōu)勢,，如生理特征與藥物反應(yīng)性與人更為接近等,，因而長期廣泛地應(yīng)用于行為學(xué)、生理學(xué)和藥理學(xué)以及毒性測試等實驗,。大鼠疾病模型也已成功應(yīng)用于心臟衰竭,，高血壓，糖尿病,，神經(jīng)性疾病等的研究,。然而由于缺乏類似于小鼠的胚胎干細(xì)胞系，大鼠在實驗研究中的應(yīng)用受到了極大地限制,。2008年,，Austin Smith和Qi-long Ying研究組通過應(yīng)用特殊的無血清培養(yǎng)系統(tǒng)，成功建立了真正的具有多能性的rESCs,。然而,，目前rESCs體外分化仍非常困難。
楊黃恬研究員的博士研究生曹楠在肖磊研究組廖婧博士建立的rESCs系基礎(chǔ)上，通過系統(tǒng)的篩選和摸索,，結(jié)合使用條件性培養(yǎng)基以及特定的信號通路抑制劑,，建立了可同時分化至內(nèi)、中,、外三胚層的rESCs體外分化模型,，并成功獲得了具有典型大鼠胚胎心肌細(xì)胞形態(tài)和肌絲結(jié)構(gòu)特征的心肌細(xì)胞，該分化系統(tǒng)時序表達(dá)中胚層,、心肌前體細(xì)胞和心肌細(xì)胞的標(biāo)志性基因,，分化的細(xì)胞包括了三種主要的心肌細(xì)胞類型：心室肌細(xì)胞、心房肌細(xì)胞以及竇房結(jié)細(xì)胞,，且分化的心肌細(xì)胞對b-腎上腺素受體激動劑Isoproterenol和乙酰膽堿激動劑Carbachol也顯現(xiàn)與大鼠胚胎心肌細(xì)胞類似的反應(yīng),。
該項研究建立的rESCs體外分化模型為研究心臟發(fā)生、發(fā)育的分子機制,、心肌細(xì)胞藥物毒性檢測和促進心肌細(xì)胞分化,、改善心肌細(xì)胞收縮和心電功能的化合物篩選提供了新的工具，也為進一步開展細(xì)胞治療研究提供了新途徑,。
該項研究工作得到了國家科技部,、農(nóng)業(yè)部、國家自然科學(xué)基金委和中國科學(xué)院的支持,。（生物谷Bioon.com）
生物谷推薦原文出處：
Cell Research , (22 March 2011) | doi:10.1038/cr.2011.48
In vitro differentiation of rat embryonic stem cells into functional cardiomyocytes
Nan Cao, Jing Liao, Zumei Liu, Wenmin Zhu, Jia Wang, Lijun Liu, Lili Yu, Ping Xu, Chun Cui, Lei Xiao and Huang-Tian Yang
AbstractThe recent breakthrough in the generation of rat embryonic stem cells (rESCs) opens the door to application of gene targeting to create models for the study of human diseases. In addition, the in vitro differentiation system from rESCs into derivatives of three germ layers will serve as a powerful tool and resource for the investigation of mammalian development, cell function, tissue repair, and drug discovery. However, these uses have been limited by the difficulty of in vitro differentiation. The aims of this study were to establish an in vitro differentiation system from rESCs and to investigate whether rESCs are capable of forming terminal-differentiated cardiomyocytes. Using newly established rESCs, we found that embryoid body (EB)-based method used in mouse ESC (mESC) differentiation failed to work for the serum-free cultivated rESCs. We then developed a protocol by combination of three chemical inhibitors and feeder-conditioned medium. Under this condition, rESCs formed EBs, propagated and differentiated into three embryonic germ layers. Moreover, rESC-formed EBs could differentiate into spontaneously beating cardiomyocytes after plating. Analyses of molecular, structural, and functional properties revealed that rESC-derived cardiomyocytes were similar to those derived from fetal rat hearts and mESCs. In conclusion, we successfully developed an in vitro differentiation system for rESCs through which functional myocytes were generated and displayed phenotypes of rat fetal cardiomyocytes. This unique cellular system will provide a new approach to study the early development and cardiac function, and serve as an important tool in pharmacological testing and cell therapy.
