Smooth muscle cells and fibroblasts of the coronary arteries derive from epithelial-mesenchymal transformation of the epicardium
Smooth muscle cells and fibroblasts of the coronary arteries derive from epithelial-mesenchymal transformation of the epicardium
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DOI：
10.1007/s004290050235
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发表时间：
1999-04-01
期刊：
影响因子：
--
通讯作者：
Poelmann, RE
中科院分区：
文献类型：
--
作者：
Peeters, MPFMV;Gittenberger-de Groot, AC;Poelmann, RE
先前的研究表明，有助于冠状血管形成的细胞源自背侧心中膜，然而，这些细胞在心脏发育的连续阶段中的命运仍不清楚。我们进行了一项关于血管成分的募集以及随后借助针对内皮、平滑肌细胞和成纤维细胞的免疫组织化学标记分化成成熟血管壁结构的研究。将包括鹌鹑胚胎（范围从HH15至HH18）的原始肝脏的粘附片的心外膜器官移植到鸡胚胎（范围从HH15至HH18）的心包腔中。鸡-鹌鹑嵌合体(n=16)是从内皮管形成早期(HH25)到成熟血管壁组成晚期(HH43)收获的。在HH32内皮细胞侵入心肌形成尚未分化的冠状血管之前。这些内皮细胞不伴有其他非内皮细胞。浅表心外膜层在中膜和外膜形成之前从鳞状间皮转变为长方体上皮。随后，间充质细胞的浓缩区域从向血管丛延伸的立方体衬里分层。免疫组织化学标记显示，在冠状动脉周围，这些间充质细胞分化为平滑肌细胞或成纤维细胞。我们得出的结论是，心外膜衬里的上皮间质转化输送了冠状动脉血管壁的平滑肌细胞和成纤维细胞。参与胚胎其他部位上皮转化过程的分子也在心外膜下层表达，并被认为参与诱导这一过程。
Previous research has revealed that cells contributing to coronary vascular formation are derived from the dorsal mesocardium, however, the fate of these cells during consecutive stages of heart development is still unclear. We have conducted a study regarding the recruitment of vascular components and the subsequent differentiation into mature vessel wall structures with the aid of immunohistochemical markers directed against endothelium, smooth muscle cells, and fibroblasts. The proepicardial organ including an adhering piece of primordial liver of quail embryos (ranging from HH15 to HH18) was transplanted into the pericardial cavity of chicken embryos (ranging from HH15 to HH18). The chicken-quail chimeras (n=16) were harvested from the early stage of endothelial tube formation (HH25) to the late stage of mature vessel wall composition (HH43). Before HH32 endothelial cells have invaded the myocardium to give rise to yet undifferentiated coronary vessels. These endothelial cells are not accompanied by other non-endothelial cells. The superficial epicardial layer changes from a squamous mesothelium into a cuboid epithelium preceding media and adventitia formation. Subsequently, a condensed area of mesenchymal cells delaminates from the cuboidal lining extending toward the vessel plexus. Around the coronary arteries, these mesenchymal cells differentiate into smooth muscle cells or fibroblasts as shown by immunohistochemical markers. We conclude that epithelial-mesenchymal transformation of the epicardial lining delivers the smooth muscle cells and fibroblasts of the coronary arterial vessel wall. Molecules involved in epithelial transformation processes elsewhere in the embryo are also expressed within the subepicardial layer, and are considered to participate in inducing this process.