Cell-Extracellular Matrix Interactions Play Multiple Essential Roles in Aortic Arch Development.
Cell-Extracellular Matrix Interactions Play Multiple Essential Roles in Aortic Arch Development.
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细胞-细胞外基质相互作用在主动脉弓发育中起着多种重要作用。
DOI：
10.1161/circresaha.120.318200
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发表时间：
2021-02-05
影响因子：
20.1
通讯作者：
Astrof S
中科院分区：
文献类型：
--
作者：
Warkala M;Chen D;Ramirez A;Jubran A;Schonning M;Wang X;Zhao H;Astrof S
第四咽弓动脉（PAA）的形态发生缺陷会导致致命的出生缺陷。了解PAA形成的调控基因和机制将为先天性心脏病的病因学和治疗提供重要的见解。细胞-ECM相互作用在PAA及其衍生物、主动脉弓动脉（AAA）及其主要分支的形态发生中起重要作用;然而，它们的具体功能还不清楚。以前，我们证明了整合素α5β1和纤连蛋白（Fn 1）在Isl 1谱系中表达调节PAA的形成。本研究的目的是研究整合素α5β1和Fn 1调节AAA形态发生的细胞机制。使用时间谱系追踪，整体共聚焦成像，和定量分析的第二心脏领域（SHF）和内皮细胞（EC）的动态，我们表明，大多数PAA EC祖细胞出现E7.5在SHF和有助于咽弓内皮E7.5和E9.5之间。因此，SHF衍生的EC在咽弓形成一个均匀的小血管丛，其通过35体节重塑成PAA。血管丛的重塑是由依赖于咽部ECM微环境的信号协调的，其对于内皮是外在的。Isl 1谱系中整合素α5β1或Fn 1的条件性消融表明ECM的信号传导在多个步骤调节AAA形态发生：1）SHF衍生的EC在咽弓中的积累，2）第4弓中均匀EC丛重塑为PAA;和3）邻近PAA内皮的神经嵴衍生细胞分化为血管平滑肌细胞。PAA的形成是一个多步骤的过程，需要SHF衍生的EC对咽弓的动态贡献，内皮丛重塑成PAA，以及PAA重塑成AAA及其主要分支。由整合素α5β1和Fn 1调节的细胞-ECM相互作用在这些发育阶段的每一个中都起着重要作用。AAA形态发生对新生儿存活至关重要;然而，AAA发生的细胞机制尚未完全了解。使用谱系追踪，我们证明了时间和定量差异的贡献的SHF的PAA内皮细胞，可以解释，至少部分地，差分敏感性的第4 PAA的扰动。我们发现，由Fn 1和整合素α5β1介导的细胞-ECM相互作用在PAA发展的多个步骤中发挥多效性和细胞类型特异性功能。最初，Fn 1和整合素α5β1调节咽弓中SHF衍生的内皮祖细胞的积累。在第四弓中形成小血管后，Fn 1和整合素α5β1以内皮非细胞自主的方式调节血管重塑进入第四PAA。此外，与它们在PAA形成中的作用无关，Fn 1和整合素α5β1通过介导神经嵴来源的细胞分化为血管平滑肌细胞来调节4th PAA的稳定性。整合素α5β1和Fn 1在咽中胚层和神经嵴中的组合表达对于后一过程至关重要。我们工作的意义在于确定PAA形成的细胞动力学基础，以及在AAA形态发生的多个步骤中细胞-ECM相互作用的复杂时间和细胞类型特异性作用。
Defects in the morphogenesis of the 4th pharyngeal arch arteries (PAAs) give rise to lethal birth defects. Understanding genes and mechanisms regulating PAA formation will provide important insights into the etiology and treatments for congenital heart disease. Cell-ECM interactions play essential roles in the morphogenesis of PAAs and their derivatives, the aortic arch artery (AAA) and its major branches; however, their specific functions are not well-understood. Previously, we demonstrated that integrin α5β1 and fibronectin (Fn1) expressed in the Isl1 lineages regulate PAA formation. The objective of the current studies was to investigate cellular mechanisms by which integrin α5β1 and Fn1 regulate AAA morphogenesis. Using temporal lineage tracing, whole-mount confocal imaging, and quantitative analysis of the second heart field (SHF) and endothelial cell (EC) dynamics, we show that the majority of PAA EC progenitors arise by E7.5 in the SHF and contribute to pharyngeal arch endothelium between E7.5 and E9.5. Consequently, SHF-derived ECs in the pharyngeal arches form a uniform plexus of small blood vessels, which remodels into the PAAs by 35 somites. The remodeling of the vascular plexus is orchestrated by signals dependent on the pharyngeal ECM microenvironment, extrinsic to the endothelium. Conditional ablation of integrin α5β1 or Fn1 in the Isl1 lineages showed that signaling by the ECM regulates AAA morphogenesis at multiple steps: 1) accumulation of SHF-derived ECs in the pharyngeal arches, 2) remodeling of the uniform EC plexus in the 4th arches into the PAAs; and 3) differentiation of neural crest-derived cells adjacent to the PAA endothelium into vascular smooth muscle cells. PAA formation is a multi-step process entailing dynamic contribution of SHF-derived ECs to pharyngeal arches, the remodeling of endothelial plexus into the PAAs, and the remodeling of the PAAs into the AAA and its major branches. Cell-ECM interactions regulated by integrin α5β1 and Fn1 play essential roles at each of these developmental stages. AAA morphogenesis is critical for neonatal survival; however, cellular mechanisms underlying AAA development are not well-understood. Using lineage tracing, we demonstrate temporal and quantitative differences in the contribution of the SHF to the PAA endothelium that can explain, at least in part, the differential sensitivity of the 4th PAAs to perturbations. We show that cell-ECM interactions mediated by Fn1 and integrin α5β1 play pleiotropic and cell-type-specific functions at multiple steps of PAA development. Initially, Fn1 and integrin α5β1 regulate the accrual of SHF-derived endothelial progenitors in the pharyngeal arches. Following the formation of small blood vessels in the 4th arch, Fn1 and integrin α5β1 regulate blood vessel remodeling into the 4th PAA in an endothelial non-cell-autonomous manner. In addition, and independent of their roles in PAA formation, Fn1 and integrin α5β1 regulate 4th PAA stability by mediating the differentiation of neural crest-derived cells into vascular smooth muscle cells. Combinatorial expression of integrin α5β1 and Fn1 in the pharyngeal mesoderm and the neural crest is critical for this latter process. The significance of our work lies in identifying cellular dynamics underlying PAA formation, and intricate temporal and cell-type-specific roles of cell-ECM interactions in AAA morphogenesis at multiple steps of its formation and remodeling.