Wilkinson David G
The Francis Crick Institute, London, United Kingdom.
Front Cell Dev Biol. 2021 Nov 5;9:784039. doi: 10.3389/fcell.2021.784039. eCollection 2021.
The segregation of distinct cell populations to form sharp boundaries is crucial for stabilising tissue organisation, for example during hindbrain segmentation in craniofacial development. Two types of mechanisms have been found to underlie cell segregation: differential adhesion mediated by cadherins, and Eph receptor and ephrin signalling at the heterotypic interface which regulates cell adhesion, cortical tension and repulsion. An interplay occurs between these mechanisms since cadherins have been found to contribute to Eph-ephrin-mediated cell segregation. This may reflect that Eph receptor activation acts through multiple pathways to decrease cadherin-mediated adhesion which can drive cell segregation. However, Eph receptors mainly drive cell segregation through increased heterotypic tension or repulsion. Cadherins contribute to cell segregation by antagonising homotypic tension within each cell population. This suppression of homotypic tension increases the difference with heterotypic tension triggered by Eph receptor activation, and it is this differential tension that drives cell segregation and border sharpening.
不同细胞群体的分离以形成清晰的边界对于稳定组织结构至关重要，例如在颅面发育过程中的后脑分割期间。已发现两种机制是细胞分离的基础：钙黏蛋白介导的差异黏附，以及在异型界面处的Eph受体和ephrin信号传导，后者调节细胞黏附、皮质张力和排斥作用。这些机制之间存在相互作用，因为已发现钙黏蛋白有助于Eph-ephrin介导的细胞分离。这可能反映出Eph受体激活通过多种途径起作用，以降低钙黏蛋白介导的黏附，从而驱动细胞分离。然而，Eph受体主要通过增加异型张力或排斥来驱动细胞分离。钙黏蛋白通过拮抗每个细胞群体内的同型张力来促进细胞分离。这种对同型张力的抑制增加了与Eph受体激活引发的异型张力的差异，正是这种差异张力驱动细胞分离和边界锐化。
