Department of Molecular Embryology, Institute of Anatomy and Cell Biology, University of Freiburg, Albertstr. 17, 79104 Freiburg, Germany.
Histochem Cell Biol. 2012 Sep;138(3):503-14. doi: 10.1007/s00418-012-0971-y. Epub 2012 Jun 6.
The dermomyotome is the dorsal compartment of the somite which gives rise to multiple cell fates including skeletal muscle, connective tissue, and endothelia. It consists of a pseudostratified, roughly rectangular epithelial sheet, the margins of which are called the dermomyotomal lips. The dermomyotomal lips are blastema-like epithelial growth zones, which continuously give rise to resident dermomyotomal cells and emigrating muscle precursor cells, which populate the subjacent myotomal compartment. Wnt signaling has been shown to regulate both dermomyotome formation and maintenance of the dermomyotomal lips. Whereas the epithelialization of the dermomyotome is regulated via canonical, β-catenin-dependent Wnt signaling, the downstream signaling mechanisms suppressing epithelial-mesenchymal transition (EMT) in the mature dermomyotomal lips have been unknown. Here, we present evidence that dermomyotomal lip sustainment is differentially regulated. Whereas the dorsomedial dermomyotomal lip is maintained by canonical Wnt signaling, development of the ventrolateral dermomyotomal lip is regulated by non-canonical, PCP-like Wnt signaling. We discuss our results in the light of the different developmental prerequisites in the dorsomedial and ventrolateral lips, respectively, thus providing a new perspective on the regulation of dermomyotomal EMT.
皮肌节是体节的背侧隔室，它产生多种细胞命运，包括骨骼肌、结缔组织和内皮细胞。它由一个假复层的、大致矩形的上皮片组成，其边缘称为皮肌节唇。皮肌节唇是类似于胚基的上皮生长带，不断产生常驻皮肌节细胞和迁移的肌肉前体细胞，这些细胞填充在下一个肌节隔室中。已经表明 Wnt 信号调节皮肌节的形成和皮肌节唇的维持。虽然皮肌节的上皮化是通过经典的β-catenin 依赖的 Wnt 信号调节的，但成熟皮肌节唇中抑制上皮-间充质转化 (EMT) 的下游信号机制尚不清楚。在这里，我们提供了证据表明皮肌节唇的维持是有差异调节的。虽然背侧皮肌节唇是通过经典的 Wnt 信号维持的，但是腹侧皮肌节唇的发育是由非经典的、PCP 样的 Wnt 信号调节的。我们根据背侧和腹侧唇的不同发育前提条件讨论了我们的结果，从而为皮肌节 EMT 的调节提供了新的视角。
