Intercellular Signalling in Cardiovascular Development and Disease Laboratory, Centro Nacional de Investigaciones Cardiovasculares (CNIC); Ciber de Enfermedades Cardiovasculares.
Intercellular Signalling in Cardiovascular Development and Disease Laboratory, Centro Nacional de Investigaciones Cardiovasculares (CNIC); Ciber de Enfermedades Cardiovasculares;
J Vis Exp. 2022 Jul 27(185). doi: 10.3791/64207.
The study of the cellular and molecular mechanisms underlying the development of the mammalian heart is essential to address human congenital heart disease. The development of the primitive cardiac valves involves the epithelial-to-mesenchymal transition (EMT) of endocardial cells from the atrioventricular canal (AVC) and outflow tract (OFT) regions of the heart in response to local inductive myocardial and endocardial signals. Once the cells delaminate and invade the extracellular matrix (cardiac jelly) located between the endocardium and the myocardium, the primitive endocardial cushions (EC) are formed. This process implies that the endocardium has to fill the gaps left by the delaminated cells and has to reorganize itself to converge (narrow) or extend (lengthen) along an axis. Current research has implicated the planar cell polarity (PCP) pathway in regulating the subcellular localization of the factors involved in this process. Classically, the initial phases of cardiac valve development have been studied in cross-sections of embryonic hearts or in ex vivo AVC or OFT explants cultured on collagen gels. These approaches allow the analysis of apico-basal polarity but do not allow the analysis of cell behavior within the plane of the epithelium or of the morphological changes of migrating cells. Here, we show an experimental approach that allows the visualization of the endocardium at valvulogenic regions as a planar field of cells. This experimental approach provides the opportunity to study PCP, planar topology, and intercellular communication within the endocardium of the OFT and AVC during valve development. Deciphering new cellular mechanisms involved in cardiac valve morphogenesis may contribute to understanding congenital heart disease associated with endocardial cushion defects.
研究哺乳动物心脏发育的细胞和分子机制对于解决人类先天性心脏病至关重要。原始心瓣膜的发育涉及心内膜细胞从房室管（AVC）和心脏流出道（OFT）区域的上皮-间充质转化（EMT），以响应局部诱导的心肌和心内膜信号。一旦细胞分层并侵入位于心内膜和心肌之间的细胞外基质（心胶质），原始心内膜垫（EC）就会形成。这个过程意味着心内膜必须填补分层细胞留下的间隙，并重新组织自己，沿着一个轴汇聚（变窄）或延伸（延长）。目前的研究表明，平面细胞极性（PCP）途径在调节参与该过程的因子的亚细胞定位中起作用。经典地，心脏瓣膜发育的初始阶段已在胚胎心脏的横切片或在胶原凝胶上培养的离体 AVC 或 OFT 外植体中进行了研究。这些方法允许分析顶端-基底极性，但不允许分析上皮层内细胞的行为或迁移细胞的形态变化。在这里，我们展示了一种实验方法，该方法允许将心瓣膜形成区域的心内膜可视化作为一个平面细胞场。这种实验方法提供了研究 PCP、平面拓扑和 OFT 和 AVC 心内膜中细胞间通讯的机会，在瓣膜发育过程中。解析心脏瓣膜形态发生中涉及的新细胞机制可能有助于理解与心内膜垫缺陷相关的先天性心脏病。
