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所率干细胞研究组与上海新华医院的陈方教授合作，从孕妇产前诊断的羊水细胞中高效快速地建立了诱导多能干细胞。
博士生李春亮等在金颖的指导下发现羊水细胞中一部分特殊类群（即高表达NESTIN, VIMENTIN and GATA4,不表达OCT4, SOX2, NANOG and TRA-1-60）在病毒介导的四因子诱导下，感染后第二天发生形态上的剧烈变化，第四天出现人胚胎干细胞类似形态的克隆，第六天可以机械法挑选后进行建系。经过统计发现，AKP阳性的未分化克隆形成率最高可达到1.525%，有趣的是，当减少因子C-MYC后，三因子同样可以在第四天诱导出iPS克隆，只是AKP阳性的未分化克隆形成率稍低，从三个独立的病人样本中，均能够稳定高效的诱导出iPS细胞，提示这群细胞高效发生重编程具有普遍性。对建立的八株人类诱导多能干细胞进行进一步的鉴定发现，这些细胞能够长期在体外稳定传代并保持46XX核型，维持自我更新，蛋白和mRNA水平高表达全能性的标志基因，如OCT4, NANOG, SOX2, SSEA4, TRA-1-60等，AKP染色呈强阳性，甲基化PCR联合测序法对OCT4的启动子进行分析后发现，在未分化的iPS细胞和阳性对照人胚胎干细胞中，OCT4的启动子呈现低甲基化，而在供体羊水细胞和阴性对照人包皮成纤维细胞中则呈现高度甲基化。STR分析结果证明这些诱导多能干细胞的确来自于对应供体的羊水细胞，有趣的是，全基因组表达谱扫描结果提示，研究人员所得到的羊水细胞在表达谱相关性上和人胚胎干细胞非常相似，correlation coefficient达到0.8866，这可能是它高效被重编程的原因之一。诱导多能干细胞的主要应用是分化和细胞移植，研究人员尝试了体外和体内的分化实验，在悬浮类胚体和实验中，科学家能得到典型的中、外、内胚层形态细胞，RT-PCR检测到了各个胚层标志物的表达，定向诱导向神经外胚层的分化中，诱导35天后，研究人员得到了高纯度的神经前体细胞。在体内畸胎瘤实验中，注射未分化的诱导多能干细胞到免疫缺陷小鼠三个月以后能够得到良性的畸胎瘤，切片分析能找到形态典型的肌肉，肠管，神经上皮，软骨，肺上皮等三胚层来源组织或者细胞，而对照细胞即起始羊水细胞注射的各组均未发现畸胎瘤。
综上所述，该项研究第一次发现孕妇产前诊断的羊水细胞中高效快速建立了诱导多能干细胞，重编程所发生所需要的时间（6天）为人类诱导多能干细胞相关报道最短，减少了在这个过程中细胞发生变异的可能。也为重编程的机制研究以及基于新型技术探讨重编程的研究提供了理想的细胞来源。
该成果于8月13日在线发表于国际权威杂志Human Molecular Genetics。（生物谷Bioon.com）
金颖老师参加干细胞讲座
生物谷推荐原始出处：
Human Molecular Genetics, doi:10.1093/hmg/ddp386
Pluripotency can be rapidly and efficiently induced in human amniotic fluid-derived cells
Chunliang Li1,4,#, Junmei Zhou5,6,#, Guilai Shi1,4, Yu Ma1,2, Ying Yang1,4, Junjie Gu1,2, Hongyao Yu1,4, Shibo Jin1,2, Zhe Wei1,4, Fang Chen5,6 and Ying Jin1,2,3,*
1 Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences/Shanghai JiaoTong University School of Medicine; 225 South Chongqing Road, Shanghai, 200025, China 2 Shanghai Stem Cell Institute, Shanghai JiaoTong University School of Medicine, Shanghai, China 3 Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai JiaoTong University School of Medicine, Shanghai, China 4 Graduate School of Chinese Academy of Sciences, Beijing, China 5 Department of Urology, Shanghai Children's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China 6 Tissue Engineering Laboratory, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai JiaoTong University School of Medicine, Shanghai, China
Direct reprogramming of human somatic cells into pluripotency has broad implications in generating patient-specific induced pluripotent stem (iPS) cells for disease modeling and cellular replacement therapies. However, the low efficiency and safety issues associated with generation of human iPS cells have limited their usage in clinical settings. Cell types can significantly influence reprogramming efficiency and kinetics. To date, human iPS cells have been obtained only from a few cell types. Here, we report for the first time rapid and efficient generation of iPS cells from human amniotic fluid-derived cells (hAFDCs) via ectopic expression of four human factors: OCT4/SOX2/KLF4/C-MYC. Significantly, typical single iPS cell colonies can be picked up six days after viral infection with high efificiency. Eight iPS cell lines have been derived. They can be continuously propagated in vitro and express pluripotency markers such as AKP, OCT4, SOX2, SSEA4, TRA-1-60 and TRA-1-81, maintaining the normal karyotype. Transgenes are completely inactivated and the endogenous OCT4 promoter is adequately demethylated in the established iPS cell lines. Moreover, various cells and tissues from all three germ layers are found in embryoid bodies and teratomas respectively. In addition, microarray analysis demonstrates a high correlation coefficient between hAFDC-iPS cells and human embryonic stem cells, but a low correlation coefficient between hAFDCs and hAFDC-iPS cells. Taken together, these data identify an ideal human somatic cell resource for rapid and efficient generation of iPS cells, allowing us to establish human iPS cells using more advanced approaches and possibly to establish disease- or patient-specific iPS cells.
