FIGURE 4.

High-level VWF expression is a common feature of CCM disease. (A) Strong immunopositivity for VWF (shown in green) was also found in clonally expanded CCM1 ^−/− CI-huVECs. DAPI (blue) was used as nuclear counterstain. Confocal images were acquired using a 10x (NA 0.45) objective. Scale bar indicates 50 µm. (B) Immunohistochemistry demonstrated medium to strong VWF staining intensities (SI) in CCM tissue samples of hereditary cases (I-III). IV = normal brain. Representative images are shown. Open arrowhead = [SI] 4, black asterisk = [SI] 3, filled arrowhead = [SI] 2, open asterisk = [SI] 1, arrow = [SI] 0. Scale bars indicate 50 µm. The graph displays the staining intensity of normal brain vessels in the vicinity of CCMs (n = 13) and of cavernous vessel endothelia in CCM1 (n = 11), CCM2 (n = 3), and CCM3 (n = 1) probands. Bars indicate the median.