Increased BBB breakdown and loss of the BBB properties in ADAMTS13-deficient mice. (A) Representative in vivo multiphoton microscopic images (left) of IV injected FITC-dextran (MW = 40 000 Da) leakage from cortical vessels and quantification of the permeability surface (PS) product (right) of FITC-dextran in WT and Adamts13^−/− mice subjected to ischemia or sham operation. Ad^−/−, Adamts13^−/−. Scale bar = 50 μm. Values are mean ± SD. One-way ANOVA followed by Bonferroni’s multiple comparison test. n = 6 per group, *P < .05. (B) Representative images of IgG deposits (green) and CD31⁺ (white) in the peri-infarct cortical areas 14 days after stroke in WT mice. (Right) Higher magnification of the box in the center panel. Scale bar = 100 μm and 10 μm (right). (C) (Left) At 14 days after stroke, mice were given an intravascular injection of 40 000 Da FITC-labeled dextran, and brain sections were stained with CD31. (Right) Quantification of extravascular dextran fluorescence in WT and Adamts13^−/− mice subjected to stroke. Scale bar = 30 μm. Values are mean ± SD. Unpaired 2-tailed Student t test. n = 6 per group, *P < .05. (D-E) Representative images of PDGFR-β⁺ pericyte and α-SMA⁺ smooth muscle cell coverage on CD31⁺ microvessels in WT and Adamts13^−/− mice subjected to stroke. Scale bar = 50 μm (D) and 10 μm (E). (F) Immunoblots showing ZO-1, occludin, and claudin 5 levels in brain microvessels of WT and Adamts13^−/− mice subjected to stroke. (G) Quantification of collagen IV⁺ (Col IV) basement membrane coverage on CD31⁺ microvessels in WT and Adamts13^−/− mice subjected to ischemia or sham operation. Values are mean ± SD. One-way ANOVA followed by Bonferroni multiple comparison test. n = 6 per group, *P < .05. (H) Quantification of actin stress fiber formation on CD31⁺ microvessels in WT and Adamts13^−/− mice subjected to ischemia or sham operation. Values are mean ± SD. One-way ANOVA followed by Bonferroni multiple comparison test. n = 6 per group, *P < .05. (I-K) Beam-walking and tape removal tests in WT and Adamts13^−/− mice. Values are mean ± SD. Unpaired, 2-tailed Student t test. n = 8 per group, *P < .05. d, day.