Establishment and Maintenance of the Pluripotent State

摘要 多能干细胞可以产生体内所有类型的细胞，因此具有巨大的潜力， 再生医学，并为发育生物学和药理学的研究提供了一个强大的工具。 将体细胞直接转化为多能（诱导多能干细胞：iPS）细胞的进展提供了一种新的方法， 这是产生大量定制干细胞的有吸引力的途径。在以下方面取得了显著进展： 有效地产生iPS细胞，包括整合免费线，然而，详细的机制见解， 仍然缺乏多能性的建立、随后的维持和有效退出。 在过去的四年里，我们的项目团队为实现更好的 对这些的理解（Smith等，Nature 2012，14; Ziller等，Nature 2013，14; Gifford等，Cell 2013; Tsankov等人Nature 2015; Liao等人Nature Genetics 2015; Cacchiarelli等人Cell in 2015等）。作为 预计结果将有助于确定需要进一步实验的领域， 向我们提出了一系列新的挥之不去的问题，这些问题对我们理解人类多能性至关重要。 我们在更大的计划项目（过去和未来）框架内的目标将为以下方面提供重要的见解： 这一目标将对人类重编程和多能性领域产生广泛影响。 在接下来的几年里，我们将应用一个复杂的，最近工程DNMT 1敲除/诱导救援人类 ES细胞系，以解决人类干细胞生物学的基本问题，重点是幼稚与 准备好的国家我们将应用单细胞技术和分析的最新进展， 对人类多能性生物学的深入了解。最后，我们将使用我们最近开发和表征的 人类次级重编程系统的定义和研究的最关键点之一（最终 过渡）在重编程过程中也是最不了解的。

Abstract Pluripotent stem cells can give rise to all cell types in the body and have therefore enormous potential for regenerative medicine, and provide a powerful tool for studies in developmental biology and pharmacology. Advances in transforming somatic cells directly into pluripotent (induced pluripotent stem: iPS) cells provide an attractive avenue for generating large numbers of customized stem cells. Notable progress has been made to efficiently generate iPS cells, including integration-free lines, however, detailed mechanistic insights regarding the establishment, subsequent maintenance and efficient exit from pluripotency are still lacking. Over the past four years our program project team has made significant contributions towards a better understanding of these (Smith et al. Nature 2012,14; Ziller et al. Nature 2013,14; Gifford et al. Cell 2013; Tsankov et al. Nature 2015; Liao et al. Nature Genetics 2015; Cacchiarelli et al Cell in 2015 and more). As would be expected the results have helped pinpoint areas that need further experimentation and also presented us with a new set of lingering questions that are central to our understanding of human pluripotency. Our aims in the framework of the larger program project (past and future) will provide crucial insights towards this end and as a result will have a broad impact on the fields of human reprogramming and pluripotency. Over the next years, we will apply a complex, recently engineered DNMT1 knockout/inducible rescue human ES cell line to address fundamental questions in human stem cell biology with a focus on the naïve versus primed states. We will apply the latest advances in single cell technology and analysis to gain unprecedented insights into the biology of human pluripotency. Lastly, we will use our recently developed and characterized human secondary reprogramming system to define and study one of the most critical points (the final transition) in the reprogramming process that is also the least understood.