DNA repair pathway choice mediates somatic cell reprogramming

项目摘要 重新编程是将体细胞转化为多能干细胞。这种技术现在是例行公事 在世界各地的实验室中使用，但绝大多数重新编程的干细胞系没有 在发育上完全有能力，损害了他们在研究和治疗方面的效用。重新编程会导致 DNA损伤，这可能对所产生的细胞的质量产生持久的影响。我们的研究已经 表明在重新编程过程中的DNA损伤是由DNA复制的异常引起的。然而， DNA损伤的原因、修复机制和损伤的发育后果是 不是很清楚。这项提议的优点是，通过使用实验系统，我们能够 确定由重新编程引起的特定类型的损伤，以及 修复：我们能够区分双链断裂HR的作用和停滞的复制叉子的作用 稳定性。我们还能够区分基因组不稳定对重新编程效率的影响 转录转换不完全。我们能够通过重新编程诱导绘制基因组中的位置 损害，我们能够确定可以用来增加基因组稳定性和潜在的 提高重新编程的干细胞的发育能力。这些研究将提供一种机制 了解基因组不稳定如何抑制不同细胞状态之间的诱导转换。

Project Summary Reprogramming is the conversion of a somatic cell to a pluripotent stem cell. This technique is now routinely used in laboratories around the world, but the vast majority of reprogrammed stem cell lines are not developmentally fully competent, compromising their utility in research and therapy. Reprogramming induces DNA damage, which can have lasting consequences on the quality of the resulting cells. Our studies have shown that DNA damage during reprogramming is induced by abnormalities in DNA replication. However, the cause of DNA damage, the mechanisms of repair, and the developmental consequences of the damage are not well understood. The strength of this proposal is that with the experimental systems used, we are able to identify the specific type of damage induced by reprogramming, and the molecular mechanisms required for repair: we are able to distinguish the role of double strand break HR from the role of stalled replication fork stability. We are also able to distinguish the effect of genome instability on reprogramming efficiency from incomplete transcriptional transitions. We are able to map the sites in the genome with reprogramming-induced damage, and we are able to identify pathways that can be used to increase genome stability and potentially improve developmental competence of reprogrammed stem cells. These studies will provide a mechanistic understanding how genome instability inhibits the induced transition between different cellular states.