a, The descending thoracic aorta or the inner curvature of aortic arches were isolated and prepared en face from wild-type mice and stained for PLXND1, PECAM-1 and DAPI. Quantification of PLXND1 levels was performed by fluorescence intensity measurement using ImageJ; 4–6 images were taken of tissue collected from n = 4 mice. Data are mean ± s.e.m. Scale bar, 20 μm. b, The descending thoracic aorta was isolated and prepared en face from Plxnd1iECKO mice and stained for PLXND1 expression to assess the specificity of the PLXND1 immunostain. n = 3 mice all showed similar results. c, The descending thoracic aorta or the inner curvature of aortic arches were isolated and prepared en face from wild-type mice and stained for SEMA3E and PECAM-1 expression and with DAPI. Quantification of SEMA3E levels was performed by fluorescence intensity measurement using ImageJ; 4–6 images were taken using tissue collected from n = 3 mice. Data are mean ± s.e.m. P values were obtained using two-tailed Student’s t-test using GraphPad Prism. *P < 0.05. Scale bar, 20 μm. d, Mouse ECs were exposed to shear stress for the indicated times or left as static controls before immunoprecipitating PLXND1 and analysing its association with the junctional mechanosensory complex (PECAM, VE-cadherin and VEGFR2) as well as PI3K/p85. n = 3 independent experiments. Source data