Detailed quantification of cardiac ventricular myocardial architecture in the embryonic and fetal mouse heart by application of structure tensor analysis to high resolution episcopic microscopic data.
Detailed quantification of cardiac ventricular myocardial architecture in the embryonic and fetal mouse heart by application of structure tensor analysis to high resolution episcopic microscopic data.
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DOI：
10.3389/fcell.2022.1000684
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发表时间：
2022
影响因子：
5.5
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中科院分区：
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哺乳动物的心脏是胚胎发生过程中最先形成并发挥作用的器官之一，它从一个简单的管子发展成为一个能够有效地将血液泵送到身体其他部位的复杂器官。胚胎发育过程中致密心肌的逐渐生长伴随着其结构复杂性和组织的变化。然而，心肌结构在胚胎发生过程中如何发育仍知之甚少。迄今为止，心脏发育的分析主要集中于使用选定的二维组织学切片的定性描述。高分辨率落射显微镜（HREM）是一种新颖的显微成像技术，能够获得心脏的高分辨率三维图像并对心脏发育进行详细的定量分析。在这项工作中，我们通过应用于心脏 HREM 图像的结构张量分析，对野生型小鼠（从 E14.5 到 E18.5）心肌结构的发育进行了详细表征。我们的结果表明，即使在 E14.5，肌细胞也已经对齐，显示其螺旋角从心内膜中的正角逐渐变化到心外膜中的负角。而且，心肌组织化程度随着心肌的生长而逐渐增加。然而，心肌结构的发育是异质的，表现出心室、心室壁以及心肌层之间的区域差异，心内膜和心外膜之间的生长模式不同。我们还发现，左心室中圆周排列的肌细胞的百分比随着胎龄的增加而显着增加。最后，我们发现 LV 内的分数各向异性 (FA) 随着胎龄逐渐增加，而 RV 内的 FA 保持不变。
The mammalian heart, which is one of the first organs to form and function during embryogenesis, develops from a simple tube into a complex organ able to efficiently pump blood towards the rest of the body. The progressive growth of the compact myocardium during embryonic development is accompanied by changes in its structural complexity and organisation. However, how myocardial myoarchitecture develops during embryogenesis remain poorly understood. To date, analysis of heart development has focused mainly on qualitative descriptions using selected 2D histological sections. High resolution episcopic microscopy (HREM) is a novel microscopic imaging technique that enables to obtain high-resolution three-dimensional images of the heart and perform detailed quantitative analyses of heart development. In this work, we performed a detailed characterization of the development of myocardial architecture in wildtype mice, from E14.5 to E18.5, by means of structure tensor analysis applied to HREM images of the heart. Our results shows that even at E14.5, myocytes are already aligned, showing a gradual change in their helical angle from positive angulation in the endocardium towards negative angulation in the epicardium. Moreover, there is gradual increase in the degree of myocardial organisation concomitant with myocardial growth. However, the development of the myoarchitecture is heterogeneous showing regional differences between ventricles, ventricular walls as well as between myocardial layers, with different growth patterning between the endocardium and epicardium. We also found that the percentage of circumferentially arranged myocytes within the LV significantly increases with gestational age. Finally, we found that fractional anisotropy (FA) within the LV gradually increases with gestational age, while the FA within RV remains unchanged.