Benwell, C. | Search bioRxiv

bioRxiv2025

Neuropilin 2 stabilises adherens junctions and protects against endothelial activation by promoting the interaction between VE cadherin and p120 catenin

The mechanosensing properties of endothelial cell-cell junctions are essential for vascular beds to respond to the mechanical forces exerted by blood flow. In states of disturbed flow, endothelial cells (ECs) become activated and transition to a pro-inflammatory, atheroprone phenotype. Here, we investigated the role of transmembrane glycoprotein neuropilin 2 (NRP2) in maintaining adherens junction integrity using cultured immortalised mouse ECs and a genetically modified mouse model to demonstrate the effects of an endothelial-specific deletion of Nrp2 in vivo. We reveal that, akin to its ortholog, Nrp1, Nrp2 exists as a constituent of adherens junctions, maintaining surface availability of VE cadherin by promoting its interaction with p120 catenin. As a consequence, endothelial knockout mice (Nrp2flfl.ECKO) display hyperpermeable retinal vasculature during development. Nrp2 depletion was subsequently found to activate key pro-inflammatory cytokines and adhesion molecules known to participate in the progression of atherogenesis, in addition to increased immune cell attachment aortic plaque development. These findings describe a role for Nrp2 in maintaining junctional signalling in ECs, protecting against endothelial activation during a state of vascular disease.

cell biology↗

bioRxiv2023

Together, Neuropilin 1 and Neuropilin 2 direct α5 integrin trafficking through GTPase-activating-protein p120RasGAP in endothelial cells to promote fibronectin fibrillogenesis

Integrin trafficking to and from membrane adhesions is a crucial mechanism that dictates many aspects of a cells behaviour, including motility, polarisation, and invasion. In endothelial cells (ECs), the intracellular traffic of 5 integrin is regulated by both neuropilin 1 (NRP1) and neuropilin 2 (NRP2), yet the redundancies in function between these co-receptors remain unclear. Moreover, the endocytic complexes that participate in NRP-directed traffic remain poorly annotated. Using label-free quantitative mass spectrometry of 5 integrin associations in ECs we identify 5 trafficking pathways that depend on NRP1, NRP2, or both NRPs. We identify a trafficking pathway that depends on both NRPs: one that impinges on the GTPase-activating protein p120RasGAP. This pathway promotes the recycling of 5 integrin from early endosomes. Mechanistically, p120RasGAP enables transit of endocytosed 5 integrin-NRP1-NRP2 complexes to Rab11+ recycling endosomes, promoting cell polarisation and fibronectin (FN) fibrillogenesis. Silencing of both NRP receptors, or p120RasGAP, results in the accumulation of 5 integrin in early endosomes, a loss of 5 integrin from surface adhesions, and attenuated EC polarisation. Importantly, endothelial-specific deletion of both NRP1 and NRP2 in the postnatal retina recapitulated our in vitro findings, severely impairing FN fibrillogenesis and polarised sprouting. Our data assign an essential role for p120RasGAP during integrin traffic in ECs and support a hypothesis that NRP receptors can co-traffic internalised cargoes.

cell biology↗