Apical Restriction of the Planar Cell Polarity Component VANGL in Pancreatic Ducts Is Required to Maintain Epithelial Integrity

Cell polarity is essential for the architecture and function of numerous epithelial tissues. Here, we show that apical restriction of planar cell polarity (PCP) components is necessary for the maintenance of epithelial integrity. Using the mammalian pancreas as a model, we find that components of the core PCP pathway, such as the transmembrane protein Van Gogh-like (VANGL), become apically restricted over a period of several days. Expansion of VANGL localization to the basolateral membranes of progenitors leads to their death and disruption of the epithelial integrity. VANGL basolateral expansion does not affect apico-basal polarity but acts in the cells where Vangl is mislocalized by reducing Dishevelled and its downstream target ROCK. This reduction in ROCK activity culminates in progenitor cell egression, death, and eventually pancreatic hypoplasia. Thus, precise spatiotemporal modulation of VANGL-dependent PCP signaling is crucial for proper pancreatic morphogenesis. [Display omitted] •PCP components are restricted to apical junctions during pancreas development•The core PCP protein VANGL is planar polarized along the duct•Ectopic basolateral expansion of VANGL cell autonomously downregulates DVL and ROCK•Decreased ROCK activity leads to cell egression, apoptosis, and pancreatic hypoplasia Flasse et al. show that the PCP protein VANGL is polarized both along the apico-basal and planar axis in pancreatic ductal cells. VANGL apical restriction rather than its planar polarization is required for progenitor survival. This discriminates the importance of apical tethering of a PCP protein from its planar polarization.