Fig. 5: Netrin-1 controls BBB integrity.

a, b Quantification of cadaverine content in P67 brains, 30 min after i.v. cadaverine injection. Ntn1 gene deletion was induced by tamoxifen injection between P60 and P64, n = 4 Ntn1^fl/fl, n = 4 Ntn1iko, n = 5 Robo4^+l+ and n = 4 Robo4^+l− brains. Each dot represents one mouse. Western blot (c) and quantification (d) of brain protein extracts, n = 7 Ntn1^fl/fl and n = 10 Ntn1iko brains. Each dot represents one mouse. One control mouse was set as 1. Western blot (e) and quantification (f) of mouse brain ECs treated with scrambled CTRL or Unc5B siRNA for 48 h and treated with recombinant mouse Netrin-1 (500 ng/ml) or not (−) for the indicated times. Each dot represents one independent experiment, n = 4 independent experiment. g CTRL IgG or Unc5B immunoprecipitation of brain protein extracts and Western blot for LRP6. h quantification of LRP6 pulldown with Unc5B, n = 3 Ntn1^fl/fl and n = 6 Ntn1iko brains. Each dot represents one mouse. One control mouse was set as 1. Western blot (i) and quantification (j) of mouse brain ECs treated with recombinant mouse Netrin-1 (500 ng/ml) or not (−) for the indicated times. Each dot represents one independent experiment, n = 4 independent experiment. Western blot (k) and quantification (l) of mouse brain ECs treated with CTRL DMSO or FAK inhibitor (5 uM) for 30 min followed by recombinant mouse Netrin-1 treatment (500 ng/ml) or not (−) for 1 h. Each dot represents one independent experiment, n = 3 independent experiment (pFAK-Y397(/β-actin): exact p-value between DMSO + Netrin1 (1 h) and FAKi + Netrin1 (1 h) = 0.000031). All data are shown as mean ± SEM. NS non-significant. Two-sided Mann–Whitney U test was performed for statistical analysis between two groups. ANOVA followed by Bonferroni’s multiple comparisons test was performed for statistical analysis between multiple groups. Source data are provided as a Source Data file.