Reactivating regulatory programs for regeneration

项目总结/摘要 人类心脏损伤，如心脏病发作，会导致无法弥补的损害和终身心脏并发症。 开发诱导心脏修复的转化策略仅限于实验室可获得的模型 比如斑马鱼和老鼠。利用能够在严重损伤后再生心脏的斑马鱼， 我们先前已经表明，神经嵴来源的心肌细胞促进损伤诱导的心肌细胞增殖， 通过在损伤后重新激活发育基因网络来保护周围的心肌细胞。重要的是，遗传 神经嵴衍生的心肌细胞的消融导致再生失败和大的疤痕。现在知道 神经嵴衍生的心肌细胞和重新激活发育网络的重要性，许多 关于这些网络在受伤后如何重新部署以及这些网络是否 在受伤后仍然保持沉默。我们目前的假设是，人类神经嵴源性 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，评估人源性心脏组织中的基因调控动力学 不可能现在，来自人类多能干细胞的自组装心脏类器官已经 提出了一种新的途径，探索心脏修复在人类来源的组织，但是，这些心脏模型， 不含来源于神经嵴的心肌细胞。在这里，我们建议（i）评估动态染色质 使用单细胞ATAC-seq的再生斑马鱼心脏的景观，以解开关键组件 重新激活控制斑马鱼心脏再生的发育程序所必需的，（ii） 在人源性心脏模型中，使用 多组学方法，最后，（iii）使用下一代基于CRISPR的功能基因组学筛选， 基因电路负责人类神经嵴衍生心肌细胞的“修复损伤”。最终，我们 我们的目标是将来自斑马鱼修复回路的联合收割机基因调控网络信息与我们的人类衍生的 筛选以确定潜在干预的最佳目标，使用任何相关的治疗方式， 损伤后的体内心脏修复。

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.