Fig. 3.
t-PA colocalizes with VWF in WP bodies.
Preconfluent HUVECs were pretreated with control medium (panels A and B), VEGF (40 ng/mL) and ATRA (10−6 M) (panels C and D), and sodium butyrate (NaBut; 3 mM) (panels E and F). The cells were then processed for double-label indirect immunofluorescence. Identical fields are shown for t-PA (FITC channel; panels A, C, and E) and VWF (Texas Red channel; panels B, D, and F). WP bodies are identified as rod-shaped granules that stain with anti-VWF antibodies. The proportion of t-PA–positive cells was markedly increased in response to VEGF/ATRA and NaBut. t-PA was always colocalized with VWF in WP bodies, with no evidence for an alternative storage pool. The bar represents 20 μm.
