1. Fig. 6. Rolling neutrophils extract membranes from fragile remnant PS+ platelets.
Rolling neutrophils extract membranes from fragile remnant PS+ platelets. (A) Fluorescence and DIC images depicting the level of filamentous actin (phalloidin) in remnant PS+ human platelets (annexin V). (B and C) DIC images demonstrate remnant platelet membrane deformation and detachment (B), quantification of platelet detachment, and calculated drag forces at the indicated shear rates (C) (means ± SEM) (n = 9). (D and E) Representative scanning electron microscopy (SEM) images depicting the size of membrane fragments (MFs) pulled by neutrophils from spread remnant platelets (D) and the integrity of PS+ and PS− platelet membranes after neutrophil perfusion (E). (F and G) Representative fluorescence images depict the ripping and dragging of remnant PS+ platelets (green) by rolling neutrophils (*, red) from nonspread platelets (F) (ripped platelet, yellow dotted circles and white arrows; dragged platelet, yellow and white dotted circles and white arrows) over the indicated time frames and percent of total PS+ platelets being ripped or dragged (means ± SEM) (n = 3) (G). (H to M) Confocal and SEM images depicting the ripping of remnant PS+ platelet membranes by rolling neutrophils (*, red) from nonspread platelets (green) (H) over the indicated time frames (yellow and white circles and yellow arrows) and spread platelets (J to M), platelet membrane wrapping (I and J, white arrows), and bridging adjacent neutrophils (K and L, white arrows). (M) Representative fluorescence image depicting the extensive surface coating of aggregating neutrophils (hollow and unlabeled) by remnant PS+ platelet membranes (fluorescent) after perfusion over spread PS+ platelets. Scale bars, 3.8 μm (D, left), 1 μm (D, middle), 2 μm (D, right), 2.5 μm (E, left), 2 μm (E, right), 10 μm (F), 10 μm (H), 1 μm (J), 2 μm (K, left), 1 μm (K, right), and 10 μm (M). 2D, two-dimensional.
Yuping Yuan et al., Sci Transl Med 2017;9:eaam5861
Published by AAAS