Fig. 8

Leukocyte transmigration actively contributes to BSCB disruption. a Representative images of LPS-induced leukocytes (labeled by Alexa Fluor 700-conjugated GR-1) adhered to the lumen of vessels (labeled by 150 kDa FITC-dextran). Scale bar = 200 μm. b Quantification of activated leukocytes in the lumen of the dSV 12 h after LPS injection (n = 6 mice). c Representative images of BSCB leakage (white arrow) induced by LPS-activated leukocytes at 12 h (n = 4 independent experiments). Scale bar = 200 μm. d Representative immunofluorescence images of TJs in small vessels 24 h after LPS injection or application of SB225002 4 h post-SCI. Scale bar = 5 μm. e–g Quantification of gap density at TJs in (d). (e) Claudin-5; (f) occludin; (g) ZO-1 (n = 5 mice, a total of 114, 121, 118, 167 vessels). h Time-lapse imaging of barrier leakage in the epicenter after acute SCI with SB225002 application. Scale bar = 200 μm. i Quantification of the integrated fluorescence intensity of 40 kDa TRITC-dextran extravasated from the dAV in (h). Data from the ctrl group were replotted from Fig. 5h (n = 9 mice, or n = 6 in the ctrl group). Data are presented as the mean ± SEM; *P < 0.05, **P < 0.01, ****P < 0.0001; nested, the Mann–Whitney test (b); one-way ANOVA (e–g); general estimated Equation (i)