Low Wnt/β-catenin signaling determines leaky vessels in the subfornical organ and affects water homeostasis in mice
- University Hospital Frankfurt, Germany
- Université libre de Bruxelles, Belgium
- Max-Planck-Institute for Molecular Biomedicine, Germany
- Kyoto University, Japan
Abstract
The circumventricular organs (CVOs) in the central nervous system (CNS) lack a vascular blood-brain barrier (BBB), creating communication sites for sensory or secretory neurons, involved in body homeostasis. Wnt/β-catenin signaling is essential for BBB development and maintenance in endothelial cells (ECs) in most CNS vessels. Here we show that in mouse development, as well as in adult mouse and zebrafish, CVO ECs rendered Wnt-reporter negative, suggesting low level pathway activity. Characterization of the subfornical organ (SFO) vasculature revealed heterogenous claudin-5 (Cldn5) and Plvap/Meca32 expression indicative for tight and leaky vessels, respectively. Dominant, EC-specific β-catenin transcription in mice, converted phenotypically leaky into BBB-like vessels, by augmenting Cldn5+ vessels, stabilizing junctions and by reducing Plvap/Meca32+ and fenestrated vessels, resulting in decreased tracer permeability. Endothelial tightening augmented neuronal activity in the SFO of water restricted mice. Hence, regulating the SFO vessel barrier may influence neuronal function in the context of water homeostasis.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files. Source data files are provided for Figures 4F-H, 5C, 6B, 7D, 8E-F, 9C as well as in Figure 4-figure supplement 1C, Figure 4-figure supplement 3D, Figure 8-figure supplement 1B. Raw data for all quantifications are provided in a separated MS Excel documents.
Article and author information
Author details
Benoit Vanhollebeke
Funding
Horizon 2020 Framework Programme (BtRAIN)
- Raoul F V Germano
- Benoit Vanhollebeke
- Stefan Liebner
Deutsche Forschungsgemeinschaft (LI 911/5-1)
- Fabienne Benz
- Ralf H Adams
- Sylvaine Guérit
- Stefan Liebner
Landes-Offensive zur Entwicklung Wissenschaftlich- ökonomischer Exzellenz Program of the Center for Personalized Translational Epilepsy Research (TP8)
- Stefan Liebner
Goethe University Frankfurt - Line A
- Sylvaine Guérit
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Elisabetta Dejana, FIRC Institute of Molecular Oncology, Italy
Ethics
Animal experimentation: Animals were housed under standard conditions and fed ad libitum. All experimental protocols, handling and use of mice were approved by the Regierungspräsidium Darmstadt, Germany (FK/1052 and FK/1108). All animal handling was performed to minimize suffering.
Version history
- Received: November 21, 2018
- Accepted: March 28, 2019
- Accepted Manuscript published: April 1, 2019 (version 1)
- Version of Record published: April 24, 2019 (version 2)
Copyright
© 2019, Benz et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 4,394
- views
-
- 701
- downloads
-
- 56
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Low Wnt/β-catenin signaling determines leaky vessels in the subfornical organ and affects water homeostasis in mice
eLife 8:e43818.
https://doi.org/10.7554/eLife.43818
Further reading
-
- Developmental Biology
- Structural Biology and Molecular Biophysics
The receptor tyrosine kinase ROR2 mediates noncanonical WNT5A signaling to orchestrate tissue morphogenetic processes, and dysfunction of the pathway causes Robinow syndrome, brachydactyly B, and metastatic diseases. The domain(s) and mechanisms required for ROR2 function, however, remain unclear. We solved the crystal structure of the extracellular cysteine-rich (CRD) and Kringle (Kr) domains of ROR2 and found that, unlike other CRDs, the ROR2 CRD lacks the signature hydrophobic pocket that binds lipids/lipid-modified proteins, such as WNTs, suggesting a novel mechanism of ligand reception. Functionally, we showed that the ROR2 CRD, but not other domains, is required and minimally sufficient to promote WNT5A signaling, and Robinow mutations in the CRD and the adjacent Kr impair ROR2 secretion and function. Moreover, using function-activating and -perturbing antibodies against the Frizzled (FZ) family of WNT receptors, we demonstrate the involvement of FZ in WNT5A-ROR signaling. Thus, ROR2 acts via its CRD to potentiate the function of a receptor super-complex that includes FZ to transduce WNT5A signals.
-
- Cell Biology
- Developmental Biology
The generation of distinct cell fates during development depends on asymmetric cell division of progenitor cells. In the central and peripheral nervous system of Drosophila, progenitor cells respectively called neuroblasts or sensory organ precursors use PAR polarity during mitosis to control cell fate determination in their daughter cells. How polarity and the cell cycle are coupled, and how the cell cycle machinery regulates PAR protein function and cell fate determination is poorly understood. Here, we generate an analog sensitive allele of CDK1 and reveal that its partial inhibition weakens but does not abolish apical polarity in embryonic and larval neuroblasts and leads to defects in polarisation of fate determinants. We describe a novel in vivo phosphorylation of Bazooka, the Drosophila homolog of PAR-3, on Serine180, a consensus CDK phosphorylation site. In some tissular contexts, phosphorylation of Serine180 occurs in asymmetrically dividing cells but not in their symmetrically dividing neighbours. In neuroblasts, Serine180 phosphomutants disrupt the timing of basal polarisation. Serine180 phosphomutants also affect the specification and binary cell fate determination of sensory organ precursors as well as Baz localisation during their asymmetric cell divisions. Finally, we show that CDK1 phosphorylates Serine-S180 and an equivalent Serine on human PAR-3 in vitro.
