Epigenetic control of functional maintenance and differentiation capacity of USSC

USSC功能维持和分化能力的表观遗传控制

• 批准号: 55928575
• 负责人: Professor Dr. Markus G. Uhrberg
• 金额: --
• 依托单位: Institut für Transplantationsdiagnostik und Zelltherapeutika (ITZ)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/55928575?language=en
• 关键词: Epigenetic; control; functional; maintenance; differentiation

Recent evidence suggests that expression of Dlk1 distinguishes between two types of cord bloodderived stem cells, namely Dlk1+ USSC that have the potential to differentiate to the osteogenic lineage and Dlk1- CB-MSC, which have mainly adipogenic differentiation potential. Dlk1 is part of the imprinted dlk1-dio3 locus, which was recently associated with incomplete epigenetic reprogramming and impaired differentiation potential in murine induced pluripotent stem (iPS) cells. In the first part of the project, we aim to dissect the epigenetic basis for the regulation of Dlk1 in the context of the extended dlk1-dio3 locus. High-density tiling arrays covering the complete locus in sense and antisense direction will be used for comparative analysis of DNA methylation and histone modifications in cord blood-derived somatic stem and iPS cells. Analysis of other components of the Dlk1-Dio3 locus such as miRNAs, snoRNAs, and large non-coding RNAs will add to a comprehensive picture of the regulation of DLK1 in stem cells. In the second part of the project we will explore the potential for epigenetic reprogramming of USSC using epigenetic modifiers. In this context, we have already shown that Dlk1+ USSC can be reproducibly converted to Dlk1- cells that adopt a sphere-like phenotype (spheUSSC) and can be differentiated to adipocytes with high efficiency. Importantly, spheUSSC can be propagated to large cell numbers without further treatment with epigenetic modifiers. We will further characterize the differentiation potential of spheUSSC, their suitability for induction of pluripotency by exogenous factors and their potential for “trophic activity”. Finally, we will further elucidate the potential for directed epigenetic reprogramming of USSC using novel combinations of epigenetic drugs.

最近的证据表明，Dlk1的表达可以区分两种类型的脐带血来源干细胞，即具有向成骨谱系分化潜力的Dlk1+ USSC和主要具有成脂分化潜力的Dlk1- CB-MSC。Dlk1是印迹Dlk1 -dio3位点的一部分，最近与小鼠诱导多能干细胞的不完全表观遗传重编程和分化潜力受损有关。在项目的第一部分，我们的目标是剖析Dlk1在扩展的Dlk1 -dio3位点的背景下调控的表观遗传学基础。在脐带血源性体细胞干细胞和诱导多能干细胞中，将采用覆盖完整正义和反义位点的高密度平铺阵列，对DNA甲基化和组蛋白修饰进行比较分析。分析DLK1 - dio3位点的其他成分，如mirna、snorna和大型非编码rna，将增加对干细胞中DLK1调控的全面了解。在项目的第二部分，我们将探索利用表观遗传修饰剂对USSC进行表观遗传重编程的潜力。在这种情况下，我们已经证明Dlk1+ USSC可以重复地转化为采用球形表型的Dlk1-细胞（spheUSSC），并且可以高效地分化为脂肪细胞。重要的是，spheUSSC可以在没有表观遗传修饰剂的情况下繁殖到大量细胞。我们将进一步描述spheUSSC的分化潜力，它们对外源因子诱导多能性的适用性以及它们的“营养活性”潜力。最后，我们将进一步阐明使用新型表观遗传药物组合对USSC进行定向表观遗传重编程的潜力。