Journal Article

WNK1 collaborates with TGF-β in endothelial cell junction turnover and angiogenesis

Earnest, Svetlana, Wichaidit, Chonlarat, Cobb, Melanie H., Plumber, Sakina, Barry, David M., Binns, Derk, Jaykumar, Ankita B., Grzemska, Magdalena, Goldsmith, Elizabeth J., Cleaver, Ondine

2022

Overview

Angiogenesis is essential for growth of new blood vessels, remodeling existing vessels, and repair of damaged vessels, and these require reorganization of endothelial cell–cell junctions through a partial endothelial–mesenchymal transition. Homozygous disruption of the gene encoding the protein kinase WNK1 results in lethality in mice near embryonic day (E) 12 due to impaired angiogenesis. This angiogenesis defect can be rescued by endothelial-specific expression of an activated form of the WNK1 substrate kinase OSR1. We show that inhibition of WNK1 kinase activity not only prevents sprouting of endothelial cells from aortic slices but also vessel extension in inhibitortreated embryos ex vivo. Mutations affecting TGF-β signaling also result in abnormal vascular development beginning by E10 and, ultimately, embryonic lethality. Previously, we demonstrated cross-talk of WNK1 with TGF-β–regulated SMAD signaling, and OSR1 was identified as a component of the TGF-β interactome. However, molecular events jointly regulated by TGF-β and WNK1/OSR1 have not been delineated. Here, we show that inhibition of WNK1 promotes TGF-β–dependent degradation of the tyrosine kinase receptor AXL, which is involved in TGF-β–mediated cell migration and angiogenesis. We also show that interaction between OSR1 and occludin, a protein associated with endothelial tight junctions, is an essential step to enable tight junction turnover. Furthermore, we show that these phenomena are WNK1 dependent, and sensitive to TGF-β. These findings demonstrate intimate connections between WNK1/OSR1 and multiple TGF-β–sensitive molecules controlling angiogenesis and suggest that WNK1 may modulate many TGF-β–regulated functions.

• Publisher: National Academy of Sciences
• Subject: Angiogenesis / Animals / Aorta / Axl protein / Axl Receptor Tyrosine Kinase / Biological Sciences / Blood vessels / Cell Biology / Cell junctions / Cell migration / Crosstalk / Embryogenesis / Endothelial cells / Endothelial Cells - metabolism / Intercellular Junctions - metabolism / Kinases / Lethality / Mesenchyme / Mice / Mutation / Neovascularization, Physiologic - genetics / Neovascularization, Physiologic - physiology / Protein-tyrosine kinase receptors / Proteins / Proteolysis / Proto-Oncogene Proteins - metabolism / Receptor Protein-Tyrosine Kinases - metabolism / Signaling / Smad protein / Substrate inhibition / Tight junctions / Transforming Growth Factor beta - metabolism / Transforming growth factor-b / Tyrosine / WNK Lysine-Deficient Protein Kinase 1 - genetics / WNK Lysine-Deficient Protein Kinase 1 - metabolism