Molecular pathogenesis of congenital heart disease mediated by neural crest and second heart field cells

摘要 心脏流出道（OFT）与相邻的主要动脉易受发育性 胚胎发育过程中的损伤导致先天性心脏病。部分原因是， 脆弱性是因为OFT的形态发生需要两个神经系统的相互作用， 嵴细胞（NCC）和相邻的第二心脏区（SHF）中胚层细胞。这发生 在胚胎咽器的动态扩张过程中。要了解这两个 并置群体，我们在谱系后进行单细胞RNA测序（scRNA-seq）， 净化，主要侧重于净捐助国。心脏NCC（CNCC）传统上被定义为 通过细胞命运进展的特定基因标记， 他们的多能性和不断变化的基因图谱。使用scRNA-seq，我们能够识别 咽器中的推定CNCC。这是通过使用早期的表达来实现的。 血管平滑肌基因，如Acta 2，作为指导。由此，我们确定了三个 小鼠胚胎日（E10.5）的CNCC群体。我们将它们称为Tbx 2和Tbx 3 (Tbx2/3）、Isl 1和Acta 2群体的基因表达差异。我们 提示Tbx 2/3和Isl 1谱系细胞可能独立进化，并有助于 咽弓动脉平滑肌细胞和OFT。这一提议被设定为 通过双谱系追踪，探索这三个种群的起源和命运轨迹， 确定基因的功能，并建立基因调控网络控制其功能。 发展我们不仅将检查NCC的变化，还将评估环境 SHF中胚层细胞，因为改变CNCC也可能影响这些祖细胞。我们 也有从小鼠胚胎中纯化的SHF中胚层细胞的scRNA-seq数据。上 另一方面，SHF所需基因的改变可能会破坏CNCC 发展作为一个具体的例子，Tbx 1，22q11.2缺失综合征的基因， 在SHF中表达，而不是CNCC，但它极大地影响了它们的功能。我们将测试这个想法 在Tbx 1无效突变胚胎中，CNCC不能从表达Sox 10的祖细胞进展 他们不能进入公平交易所。在这个项目中要研究的许多基因是 与人类先天性心脏病相关的疾病。总的来说，该计划将有助于 确定CNCC的分子方面和CNCC-SHF细胞命运的协调， 胚胎发生

ABSTRACT The cardiac outflow tract (OFT) with adjoining major arteries is susceptible to developmental insults during embryogenesis that leads to congenital heart disease. Part of the reason for their vulnerability is because the morphogenesis of the OFT requires the interaction of both neural crest cells (NCCs) and adjacent second heart field (SHF) mesoderm cells. This takes place during dynamic expansion of the embryonic pharyngeal apparatus. To understand these two juxtaposed populations, we performed single cell RNA-sequencing (scRNA-seq) after lineage purification, focusing mainly on NCCs. Cardiac NCCs (CNCCs) have traditionally been defined positionally rather than molecularly by specific gene markers of cell fate progression because of their multipotency and changing genetic profiles. Using scRNA-seq, we were able to identify putative CNCCs in the pharyngeal apparatus. This was achieved by using expression of early vascular smooth muscle genes, such as Acta2, as a guide. From this, we identified three CNCC populations at mouse embryonic day, E10.5. We refer to them as the Tbx2 and Tbx3 (Tbx2/3), Isl1 and Acta2 populations, based upon distinct expression of these genes. We suggest that the Tbx2/3 and Isl1 lineage cells may independently evolve and contribute to smooth muscle cells of the pharyngeal arch arteries and OFT, respectively. This proposal is set to explore the origin and fate trajectories of these three populations by dual lineage tracing, by determining the function of genes within, and to build gene regulatory networks controlling their development. Not only will we examine changes in NCCs but also will evaluate surrounding SHF mesoderm cells because altering CNCCs might affect these progenitor cells as well. We also have scRNA-seq data on the SHF mesoderm cells purified from mouse embryos. On the other hand, it is possible that alteration of genes required in the SHF can disrupt CNCC development. As one specific example, Tbx1, the gene for 22q11.2 deletion syndrome is expressed in the SHF but not CNCCs, but it greatly affects their function. We will test the idea that in Tbx1 null mutant embryos, CNCCs fail to progress from Sox10 expressing progenitors and are not able to enter the OFT. Many of the genes to be investigated in this program are associated with congenital heart disease in human patients. Overall, this program will help identify molecular aspects of CNCCs and the orchestration of CNCC-SHF cell fates in embryogenesis.