Experimental analyses of the function of the proepicardium using a new microsurgical procedure to induce loss-of-proepicardial-function in chick embryos
Experimental analyses of the function of the proepicardium using a new microsurgical procedure to induce loss-of-proepicardial-function in chick embryos
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DOI：
10.1002/dvdy.20487
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发表时间：
2005-08-01
影响因子：
2.5
通讯作者：
Brand, T
中科院分区：
文献类型：
--
作者：
Männer, J;Schlueter, J;Brand, T
心外膜原（PE）是一种主要的心外祖细胞群，在胚胎心脏中定植并传递心外膜、心外膜下和心内成纤维细胞以及冠状血管。最近的数据表明，pe来源的细胞在心肌发育和心脏的正常形态发生中也起着重要的调节作用。对后一个主题的研究得益于这样一个事实，即pe功能的丧失可以在鸡胚胎中实验诱导。到目前为止，有两种显微外科技术被用于制造这样的胚胎：(1)用蛋壳膜片阻断PE细胞的转移，(2)机械切除PE。然而，这两种技术都有它们的缺点。因此，我们一直在寻找消除PE的新技术。在这里，我们证明PE的光消融可以引起PE功能的丧失。在汉堡包和汉密尔顿（HH）第16期（第3天），用蛋壳窗口的方法在蛋中处理鸡胚。打开心包腔，用微移液管用1%的孟加拉玫瑰溶液对PE进行体外染色。染料的光活化是通过可见光照射操作场来完成的。术后第1天（第4天，HH期19/20）检查发现每个实验胚胎PE完全去除。第9天（HH期33/34），实验胚胎存活率为35.7%（15 / 42）。pe衍生物的发展在每个幸存者的心中都受到了损害。异常包括心外膜积液或积血，心外膜无瘤区伴室壁向外膨出，心肌薄，冠状动脉血管缺损，以及室室和心包壁之间的异常组织桥。我们的研究结果表明，光消融PE是一种诱导鸡胚胎PE功能长期丧失的有力技术。此外，我们还获得了新的数据，表明胚胎心外膜可能对心脏发育的被动机制做出了重要贡献。(c) 2005 Wiley-Liss, Inc。
The proepicardium (PE) is a primarily extracardiac progenitor cell population that colonizes the embryonic heart and delivers the epicardium, the subepicardial and intramyocardial fibroblasts, and the coronary vessels. Recent data show that PE-derived cells additionally play important regulatory roles in myocardial development and possibly in the normal morphogenesis of the heart. Research on the latter topics profits from the fact that loss-of-PE-function can be experimentally induced in chick embryos. So far, two microsurgical techniques were used to produce such embryos: (1) blocking of PE cell transfer with pieces of the eggshell membrane, and (2) mechanical excision of PE. Both of these techniques, however, have their shortcomings. We have searched, therefore, for new techniques to eliminate the PE. Here, we show that loss-of-PE-function can be induced by photoablation of the PE. Chick embryos were treated in ovo by means of a window in the eggshell at Hamburger and Hamilton (HH) stage 16 (iday 3). The pericardial coelom was opened, and the PE was externally stained with a 1% solution of Rose Bengal by means of a micropipette. Photoactivation of the dye was accomplished by illumination of the operation field with visible light. Examination on postoperative day 1 (iday 4, HH stages 19/20) disclosed complete removal of PE in every experimental embryo. On iday 9 (HH stages 33/34), the survival rate of experimental embryos was 35.7% (15 of 42). Development of the PE-derivatives was compromised in the heart of every survivor. The abnormalities encompassed hydro- or hemopericardium, epicardium-free areas with aneurysmatic outward bulging of the ventricular wall, thin myocardium, defects of the coronary vasculature, and abnormal tissue bridges between the ventricles and the pericardial wall. Our results show that photoablation of the PE is a powerful technique to induce long-lasting loss-of-PE-function in chick embryos. We have additionally obtained new data that suggest that the embryonic epicardium may make important contributions to the passive mechanics of the developing heart. (c) 2005 Wiley-Liss, Inc.