Time study of VWF. Interrupted cyclic strain triggers thrombotic events reflected in the increase of VWF. (A) Confocal images of HUVECs unstretched, stretched for 6 hours at 10% on a flat membrane, stretched for 24 hours at 10%, and interrupted stretch at 10%. DAPI in blue, F-actin in red, and VWF in green; all membranes used were flat. Objective, original magnification ×40; scale bar, 20 μm. The arrow represents the direction of the uniaxial cyclic stretch. Z-stack sum projection. (B) Frequency distribution of VWF expression (intensity of fluorescence I [AU]) for 1 representative experiment. Frequency distribution at the top: unstretched (light blue), stretched for 6 hours at 10% (magenta), and stretched for 24 hours at 10% (orange). Frequency distribution at the bottom: unstretched (light blue), stretched for 24 hours at 10% (orange), and interrupted stretch at 10% (yellow). (C) Relative VWF protein expression fold change (bar graph) and interquartile range (dot graph). Mean ± SD values of unstretched, N = 4 independent experiments; stretched for 6 hours at 10%, N = 3 independent experiments; stretched for 24 hours at 10%, N = 3 independent experiments; and interrupted 10% stretch, N = 4 independent experiments. n = 9000 cells; ∗∗∗∗P < .0001. Every black dot represents 1 independent experiment.