Cxc12 chemokine signaling regulates synchronous development of coronary vessels and myocardium

项目摘要 冠状动脉血管在维持持续的氧气供应方面起着重要作用。 以及对心脏的营养。冠心病是心肌梗死的主要原因， 心力衰竭，它仍然是世界范围内死亡的主要原因。尽管它的 重要的是，调节冠状动脉心肌血管形成的机制仍然是 我们的知识有很大的差距。我们观察到，在斑马鱼心脏发育过程中，冠状动脉 血管与特定的皮质心肌细胞亚群密切相关 以转录因子GATA4为标志。GATA4+心肌细胞跟随冠脉病变轨迹 当内皮细胞出现在幼年斑马鱼心脏的表面时。 此外，我们的初步数据表明，Cxcl12b趋化因子的表达是一个关键的 斑马鱼冠状动脉发育过程中的血管生成因子在扩张中增加 GATA4+心肌细胞。此外，GATA4+心肌细胞与冠状动脉 心脏血管缺乏Cxcr4a，Cxcl12b的受体。重要的是，成年的cxcr4a突变体 斑马鱼在心脏受伤后不能再生。我们假设心脏发育发生在 由时间上不同的机制调节的两个阶段：新形成的冠状动脉 内皮细胞在出现阶段提供有益的提示，如旁分泌因子。 引导gata4+心肌细胞出现，而在扩张期，cxcl12b Gata4+心肌细胞表达增加以吸引冠脉，而冠脉是 它们的形态发生/发育和再生。我们建议1)确定有多新 冠状动脉通过分析引导GATA4+心肌细胞填充心室 从编码分泌分子的RNAseq中鉴定差异表达的候选基因 (例如CXCR4、ERBB4)使用CRISPR突变鱼线和新的外植体培养系统；2) 确定冠状动脉如何影响形态发生和Gata4+的再生能力 心肌扩张过程中的心肌细胞多色克隆分析 操纵CXCL12-CXCR4趋化因子信号转导。我们将进一步确定cxcl12b如何 表达受低氧和Gata4的调节。我们提议的研究将揭示潜在的 冠心病的发展原因。此外，还阐明了其作用机制。 斑马鱼潜在的心肌血管化将揭示潜在的治疗方法 人类的方法。

Project Summary The coronary vasculature plays essential roles in maintaining a continuous supply of oxygen and nutrients to the heart. Coronary heart disease is a major cause of myocardial infarction and heart failure, which continues to be the leading cause of mortality worldwide. Despite its importance, the mechanisms that regulate coronary vascularization of the myocardium remain a major gap in our knowledge. We observed that during zebrafish heart development, coronary vessels form a close association with a specific subpopulation of cortical cardiomyocytes marked by the transcription factor Gata4. gata4+ cardiomyocytes follow the tracks of coronary endothelial cells when they emerge onto the surface of the juvenile zebrafish hearts. Furthermore, our preliminary data suggest that expression of the Cxcl12b chemokine, a critical angiogenic factor during zebrafish coronary vessel development, is increased in expanding gata4+ cardiomyocytes. Moreover, gata4+ cardiomyocytes fail to associate with coronary vessels in hearts lacking Cxcr4a, the receptor for Cxcl12b. Importantly, adult cxcr4a mutant zebrafish fail to regenerate after heart injury. We hypothesize that heart development occurs in two phases that are regulated by temporally distinct mechanisms: newly formed coronary endothelial cells provide instructive cues, such as paracrine factors, during the emerging phase to guide gata4+ cardiomyocytes when they emerge, while during the expanding phase, cxcl12b expression increases in gata4+ cardiomyocytes to attract coronary vessels that are essential for their morphogenesis/development and regeneration. We propose to 1) To determine how new coronary vessels guide gata4+ cardiomyocytes to populate the heart ventricle by analyzing differentially expressed candidate genes identified from RNAseq encoding secreted molecules (e.g. cxcr4, erbb4) using CRISPR mutant fish lines and a novel explant culture system; 2) To determine how coronary vessels affect morphogenesis and the regenerative capacity of gata4+ cardiomyocytes during myocardial expansion using multicolor clonal analysis and by manipulating Cxcl12-Cxcr4 chemokine signaling. We will further determine how cxcl12b expression is regulated by hypoxia and Gata4. Our proposed study will reveal potential developmental causes of coronary heart diseases. Furthermore, elucidation of the mechanisms underlying myocardial vascularization in zebrafish will shed light on potential therapeutic approaches for humans.