VWF active conformation enhances endocytosis by macrophage. (A-H) wt-rVWF (5 μg/mL) was perfused over PMA-stimulated THP-1 macrophages in the absence (A-D) or presence (E-H) of botrocetin (1.6 U/mL). Perfusion was performed for 15 minutes at 5 dynes/cm2. Nuclei were stained with 4,6-diamidino-2-phenylindole (blue), actin was stained with AlexaFluor 488–conjugated phalloidin (green), and VWF was detected with primary rabbit anti-human VWF antibody followed by tetramethyl rhodamine iso-thiocyanate–conjugated goat anti-rat IgG antibody (red). Original magnification is ×100. (I) VWF internalization was quantified with ImageJ as the percentage of surface covered by red spots (VWF staining) per number of cells per field. Data represent mean ± SEM. *P < .05.
