Vinculin controls endothelial cell junction dynamics during vascular lumen formation

Blood vessel morphogenesis is driven by coordinated endothelial cell behaviors. Active remodeling of cell cell junctions promotes cellular plasticity while preserving vascular integrity. Here, we analyze the dynamics of endothelial adherens junctions during lumen formation in angiogenic sprouts in vivo. Live imaging in zebra fish reveals that lumen expansion is accompanied by the formation of transient finger-shaped junctions. Junctional fingers are positively regulated by blood pressure, whereas flow inhibition prevents their formation. Using fluorescent reporters, we show that junctional fingers contain the mechanotransduction protein vinculin. Furthermore, genetic deletion of vinculin prevents finger formation, a junctional defect that could be rescued by transient endothelial expression of vinculin. Our findings suggest a mechanism whereby lumen expansion leads to an increase in junctional tension, triggering recruitment of vinculin and formation of junctional fingers. We propose that endothelial cells employ force-dependent junctional remodeling to counteract external forces in order to maintain vascular integrity during sprouting angiogenesis.

Automated summary

Blood vessel morphogenesis is driven by coordinated endothelial cell behaviors. Active remodeling of cell-cell junctions promotes cellular plasticity while preserving vascular integrity. Lumen expansion in angiogenic sprouts is accompanied by the formation of transient finger-shaped junctions. Blood pressure positively regulates the formation of junctional fingers, while flow inhibition prevents their formation. Mechanotransduction protein vinculin is recruited to junctional fingers, and its genetic deletion prevents finger formation. Endothelial cells employ force-dependent junctional remodeling to counteract external forces and maintain vascular integrity during sprouting angiogenesis.