1. Fig. 7. Rolling neutrophils rip and drag PS+ platelet membranes in vivo.
Rolling neutrophils rip and drag PS+ platelet membranes in vivo. (A to E) C57BL mice or mice of the indicated genotype were administered appropriate fluorescence probes and then subjected to needle puncture of mesenteric vein, followed by local Thr/CRP microinjection (A and D) or gut I/R injury (B, C, and E). (A and B) Representative confocal images depicting ripping (A, top) and dragging (A, bottom, and B) of PS+ platelets [P1–3, cyan-colored cells (yellow outline)] by rolling neutrophils [N1–3, red cells (white outline)] and PS+ platelets bridging adjacent neutrophils (A, bottom) on thrombi 30′ after agonist injection (A) or in intestinal vasculature after I/R injury (B) over the indicated time frames. (A) Top: Large platelet fragments ripped from P1 and P2 by N1. Bottom: P1 (tracked by yellow arrow) dragged by N1, P2 dragged by N2, and P3 dragged by N3, culminating in neutrophil macroaggregation by bridging of N1 and N2 via P2 and of N1 and N3 via P1 and P3. (B) P2 dragged by N1-P1 rolling complex (tracked by yellow arrow). (C) Representative confocal images showing neutrophils interacting with (left) and ripping (right) PS+ platelets from lung vasculature (dotted line) after gut I/R injury. (D) Left: The number of PS+ platelets/fragments ripped or dragged by single (gray) or aggregated (white) rolling neutrophils or detached independently of neutrophils (black) from mesenteric thrombi over 2′ and 30′ after agonist injection in P-sel+/+ and P-sel−/− mice (percent of total). (D) Right: The time remaining on thrombi for neutrophil-associated PS+ fragments in P-sel+/+ mice (white and gray) and neutrophil-free PS+ fragments in P-sel−/− mice (n = 3 and 9 thrombi). (E) Confocal images depicting large PS+ platelet membrane fragments (cyan) within neutrophil aggregates (red) in mesenteric vein after gut I/R injury. (F) All the plasma from an I/R-injured or naïve donor mouse (plasma) was administered to a naïve recipient mouse (recipient) via the portal vein and then subjected to confocal microscopy. The number of aggregated neutrophils in the mesenteric veins and pulmonary circulation of excited lungs was quantified and compared to gut I/R–injured mice (I/R) (means ± SEM; n = 3). Scale bars, 10 μm (A), 50 μm (B), 10 μm (C), and 50 μm (E).
Yuping Yuan et al., Sci Transl Med 2017;9:eaam5861
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