Reactivating regulatory programs for regeneration

项目摘要/摘要 人类的心脏损伤，如心脏病发作，会导致无法弥补的损害和终身的心脏并发症。 开发诱导心脏修复的翻译策略仅限于实验室可访问的模型 比如斑马鱼和老鼠。使用斑马鱼，它可以在严重受伤后再生它们的心脏， 我们先前已经证明，神经脊来源的心肌细胞促进损伤诱导的心肌细胞增殖。 损伤后通过重新激活发育基因网络来包围心肌细胞。重要的是，基因 去除神经沟来源的心肌细胞会导致再生失败和巨大的疤痕。现在知道了 神经沟来源的心肌细胞和重新激活发育网络的重要性，许多 这些网络在受伤后是如何重新部署的，以及这些网络是否会 受伤后，在人们的心中保持沉默。我们目前的假设是，人类的神经脊源自 心肌细胞在损伤后不能重新部署发育基因网络，因此不能 诱导修复机制。直到最近，评估人类来源的心脏组织的基因调控动力学 是不可能的。现在，来自人类多能干细胞的自组装心脏器官已经 为探索人类衍生组织中的心脏修复提供了一条新的途径；然而，这些心脏模型 不含来源于神经脊的心肌细胞。在这里，我们建议(I)评估动态染色质 用单细胞ATAC-SEQ解开关键成分的斑马鱼再生心脏景观 重新激活控制斑马鱼心脏再生的发育程序所必需的，(Ii) 在人类来源的心脏损伤模型中，使用一种 多组学方法，最后，(3)使用基于CRISPR的下一代功能基因组学筛查来识别 负责“修复损伤”的人类神经脊源性心肌细胞的基因回路。最终，我们的 目标是将来自斑马鱼修复电路的基因调控网络信息与我们人类衍生的 筛查以确定潜在干预的最佳目标，使用任何相关的驾驶治疗方式 损伤后的在体心脏修复。

PROJECT SUMMARY/ABSTRACT Human cardiac injury, such as a heart attack, leads to irreparable damage and life-long heart complications. Developing translational strategies for inducing heart repair has been limited to laboratory accessible models such as the zebrafish and mouse. Using the zebrafish, which can regenerate their heart after substantial injury, we have previously shown that neural crest-derived cardiomyocytes promote injury-induced proliferation of surrounding cardiomyocytes by re-activating developmental gene networks after injury. Importantly, genetic ablation of neural crest-derived cardiomyocytes leads to a failure of regeneration and a large scar. Now knowing the importance of neural crest-derived cardiomyocytes and re-activating developmental networks, many questions remained unanswered on how these networks are re-deployed after injury and if these networks remain silenced in human hearts after injury. Our current hypothesis is that human neural crest-derived cardiomyocytes are unable to redeploy developmental gene networks after injury and are therefore unable to induce repair mechanisms. Until recently, assessing gene regulatory dynamics in human-derived cardiac tissues was not possible. Now, self-assembling cardiac organoids derived from human pluripotent stem cells have presented a new avenue for exploring cardiac repair in human-derived tissues; however, these cardioid models do not contain cardiomyocytes derived from neural crest. Here, we propose to (i) assess the dynamic chromatin landscapes of the regenerating zebrafish heart using single cell ATAC-seq to unravel critical components necessary for re-activating developmental programs that control cardiac regeneration in the zebrafish, (ii) interrogate the reactivation of developmental programs in a human-derived cardioid model after injury using a multiomics approach, and finally, (iii) use next-generation CRISPR-based functional genomics screens to identify gene circuits responsible for “repair impairment” of human neural crest-derived cardiomyocytes. Ultimately, our goal is to combine gene regulatory network information from zebrafish repair circuits and our human-derived screen to identify optimal targets for potential intervention using any relevant therapeutic modality for driving cardiac repair in vivo post-injury.