Figure 3.

PS⁺ BCMPs were procoagulant. TEM (A, left) and SEM (A, right) images of BCMPs. (B, left) Confocal microscopy images of BCMPs co-stained with lactadherin (red) and annexin V (green) with colocalization indicated in yellow. (B, right) Confocal microscopy images of BCMPs co-stained for FVa (green) and FXa (red) with colocalization indicated in yellow. (C) SEM images of fibrin production by BCMPs in the presence of recalcified MP-depleted plasma with or without lactadherin. (D) Confocal microscopy images of fibrin production (red) by BCMPs (green). The BCMP clot contains BCMPs (arrowheads) on the surface of fibers (arrows) with increased branching points. (E) Fibrin area in the microscope field of view from D calculated using Image J. ^*P < 0.05 by Student's t-test. (F) Time to attain 50% lysis of the formed fibrin clots, defined as the time elapsed from the maximal to half maximal absorption value at 405 nm (Lys 50_MA). (G) Schematic illustration of an in vivo functional assay in which wildtype mice were injected with saline or 2.5 × 10⁴/μL BCMPs and then a tail vein bleeding test was performed. The total bleeding time (H), clotting time (I), and fibrinogen levels (J) were measured (n = 6; 3 independent experiments). ^*P < 0.05 vs. Saline by Student's t-test. (K) Fluorescence microscopy images of dilated vessels in kidneys from BCMP-injected mice showing extensive fibrin deposition (arrowheads, right) compared with saline-injected mice (left). Images are representative of 6 mice in each group. (L) Fibrin area in the microscope field of view from K calculated using ImageJ. ^*P < 0.05 by Student's t-test. Abbreviations: AnnV, annexin V; BCMPs, breast cancer cell-derived microparticles; Ctrl, control; DOX, doxorubicin; Lact, lactadherin; SF, serum-free medium.