Nectin proteins are expressed at early stages of nephrogenesis and play a role in renal epithelial cell morphogenesis

摘要

The effect of nectins on junctional formation has been documented in vitro and in vivo, but the role of nectins in the kidney during three-dimensional epithelial cell morphogenesis has not been studied. In the developing murine kidney at the tip of each terminal branch of the ureteric bud, there is a coinduc-tion event between the metanephric mesenchyme and the ureteric bud tip. Induced mesenchymal cells undergo a mes-enchymal-to-epithelial transition (MET) to become the epithelial cells of the renal vesicle with a classic polarized structure with TJs, AJs, and segregated apical and basolateral markers (5, 6, 12, 26). MET is accompanied by the upregulation of a variety of epithelial markers, including ion channels, E-cad-herin, ZO-1, and occludin (6, 14, 38). The role of the nectin proteins in this MET has not been defined.