During lung development, proper epithelial cell arrangements are critical for the formation of an arborized network of tubes. Each tube requires a lumen, the diameter of which must be tightly regulated to enable optimal lung function. Lung branching and lumen morphogenesis require close epithelial cell-cell contacts that are maintained as a result of adherens junctions, tight junctions and by intact apical-basal (A/B) polarity. However, the molecular mechanisms that maintain epithelial cohesion and lumen diameter in the mammalian lung are unknown. Here we show that Scribble, a protein implicated in planar cell polarity (PCP) signalling, is necessary for normal lung morphogenesis. Lungs of the Scrib mouse mutant Circletail (Crc) are abnormally shaped with fewer airways, and these airways often lack a visible, 'open' lumen. Mechanistically we show that Scrib genetically interacts with the core PCP gene Vangl2 in the developing lung and that the distribution of PCP pathway proteins and Rho mediated cytoskeletal modification is perturbed in Scrib(Crc/Crc) lungs. However A/B polarity, which is disrupted in Drosophila Scrib mutants, is largely unaffected. Notably, we find that Scrib mediates functions not attributed to other PCP proteins in the lung. Specifically, Scrib localises to both adherens and tight junctions of lung epithelia and knockdown of Scrib in lung explants and organotypic cultures leads to reduced cohesion of lung epithelial cells. Live imaging of Scrib knockdown lungs shows that Scrib does not affect bud bifurcation, as previously shown for the PCP protein Celsr1, but is required to maintain epithelial cohesion. To understand the mechanism leading to reduced cell-cell association, we show that Scrib associates with β-catenin in embryonic lung and the sub-cellular distribution of adherens and tight junction proteins is perturbed in mutant lung epithelia. Our data reveal that Scrib is required for normal lung epithelial organisation and lumen morphogenesis by maintaining cell-cell contacts. Thus we reveal novel and important roles for Scrib in lung development operating via the PCP pathway, and in regulating junctional complexes and cell cohesion.

译文

在肺发育过程中,适当的上皮细胞排列对于管的树状网络的形成至关重要。每个管都需要一个管腔,必须严格调节其直径以实现最佳的肺功能。肺分支和管腔形态发生需要紧密的上皮细胞-细胞接触,这些接触是粘附连接,紧密连接和完整的顶基 (a/B) 极性的结果。然而,维持哺乳动物肺上皮内聚和管腔直径的分子机制尚不清楚。在这里,我们显示Scribble (一种与平面细胞极性 (PCP) 信号有关的蛋白质) 对于正常的肺形态发生是必需的。Scrib小鼠突变体Circletail (Crc) 的肺形状异常,气道较少,并且这些气道通常缺乏可见的 “开放” 腔。从机制上讲,我们表明Scrib与发育中的肺中的核心PCP基因Vangl2发生遗传相互作用,并且在Scrib(Crc/Crc) 肺中PCP途径蛋白和Rho介导的细胞骨架修饰的分布受到干扰。然而,在果蝇Scrib突变体中被破坏的A/B极性在很大程度上不受影响。值得注意的是,我们发现Scrib介导的功能不归因于肺中的其他PCP蛋白。具体来说,Scrib定位于肺上皮的粘附和紧密连接以及肺外植体和器官型培养物中Scrib的敲除导致肺上皮细胞的凝聚力降低。Scrib敲低肺的实时成像表明,Scrib不影响芽分叉,如先前对PCP蛋白Celsr1所示,但是维持上皮凝聚力所必需的。为了了解导致细胞-细胞关联减少的机制,我们显示Scrib与胚胎肺中的 β-catenin缔合,并且粘附和紧密连接蛋白的亚细胞分布在突变的肺上皮中受到干扰。我们的数据表明,通过维持细胞与细胞的接触,正常的肺上皮组织和管腔形态发生需要Scrib。因此,我们揭示了Scrib在通过PCP途径运作的肺发育中以及在调节连接复合物和细胞凝聚力方面的新的重要作用。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录