Reactivation and reprogramming of spinal progenitors into a unique neuro-regenerative state

脊髓损伤后，神经连接被切断，受伤处附近的神经细胞死亡，导致永久性残疾。在哺乳动物中，脊髓中的干细胞不能替代失去的神经细胞。然而，在斑马鱼中，这些干细胞在受伤后产生新的神经细胞，帮助修复过程。因此，斑马鱼模型为阐明成功再生的必要步骤提供了机会。我们之前已经证明，脊髓干细胞激活的机制是再生过程中所特有的，而不仅仅是发育的重演。在这里，我们提出了一个基因组学项目，在该项目中，我们比较了斑马鱼不同发育阶段和修复过程操作后损伤脊髓干细胞的基因调控和基因活性。通过这种方式，我们可以通过计算梳理出关键的细胞程序，这些程序与从休眠状态重新激活和重新编程脊髓干细胞以取代失去的神经细胞有关。最后，我们将利用CRISPR/Cas9技术确认关键基因及其调控元件的功能重要性。因此，我们希望对成功再生所特有的基因调控程序做出根本性的重要观察。与此同时，在实现丢失的神经细胞的替换中确定的分子步骤将为哺乳动物的治疗努力提供蓝图，以克服干细胞的低效重编程，从而成功地替换那里的神经细胞。

After a spinal cord injury, nerve connections are severed and nerve cells near the injury die, leading to permanent disabilities. In mammals, stem cells in the spinal cord fail to replace lost nerve cells. However, in zebrafish these stem cells generate new nerve cells after injury that aid the repair process. Thus, the zebrafish model offers an opportunity to elucidate the necessary steps for successful regeneration. We have previously shown that spinal stem cells activate mechanisms that are unique to the regeneration process and not a mere recapitulation of development. Here, we propose a genomics project in which we compare gene regulation and gene activity in injured spinal stem cells at different developmental stages and after manipulations of repair processes in zebrafish. In this way we can computationally tease out crucial cellular programmes that are related to reactivation from a dormant state and reprograming of spinal stem cells to replace lost nerve cells. Finally, we will confirm the functional importance of pivotal genes and their regulatory elements using CRISPR/Cas9 technology. Thus we hope to make fundamentally important observations on gene-regulatory programmes that are specific to successful regeneration. At the same time, the identified molecular steps in achieving replacement of lost nerve cells will serve as a blueprint for therapeutic efforts in mammals to overcome the inefficient reprogramming of stem cells to successful replacement of nerve cells there.