Fig 1: Platelets internalize protein S100A8 from coactivated neutrophils. A, To determine the source of platelet S100A8/A9 in patients with STEMI, isolated quiescent platelets (top), quiescent platelets coincubated with neutrophils without (middle) and with activation by 30-nM TRAP-6 (thrombin-related activating peptide-6; bottom) were incubated for 2 h before fixation and staining. Blue color: 4′,6-diamidino-2-phenylindole (DAPI) stain; green color: CD41 (cluster of differentiation); red color: S100A8. Quiescent platelets harbor no S100A8. Staining for S100A8 is primarily observed in neutrophils but also in smaller released neutrophil microparticles. Activation of platelets with TRAP-6 leads to greater release of S100A8 from neutrophils and increased S100A8/CD41 costaining. B, Quantification of costaining: 0.01% of 1247 events in quiescent platelets, 5% of 6925 events with quiescent platelets and neutrophils, and 43% of 23 053 events in activated platelets with neutrophils. Event numbers represent 3 replicate fields of view per condition. C, Three-dimensional imaging confirms the internalization of S100A8 into platelets when interacting with neutrophils under activating conditions. D, Neutrophils were stimulated with 1 µmol/L N-formyl-methionyl-leucyl-phenylalanine (fMLP) for 30 minutes, and the protein releasate was analyzed by Western blot. fMLP-stimulated neutrophil releasate was separated by size-exclusion chromatography (SEC), and S100A9 abundance was determined by Western blot. Vesicle marker elution profiles were determined by dot blot.
Fig 2: Erythromyeloid progenitors (EMPs) migrate to establish an IBA1+ population in cerebral organoids. (a) Schematic drawing depicting the introduction of EMPs to ORGs and subsequent experiments. (b) Immunohistological staining of IBA1+ cells colonizing a TUJ1 stained cORG at 120 days in vitro (DIV). (c,d) Immunohistological stainings of adjacent sections of an ORG 35 DIV, five days after incorporation of EMPs. TBR2+ and DCX+ cells show the formation of cortical loops, while CD41 shows the locus of incorporation and IBA1, the cells migrating from the locus to the vicinity of the nascent cortical loops. (e) A population of IBA1+ cells in taking different morphologies at 120 DIV. (f) Maturation of a cortical loop, as shown by immunostaining of SATB2 at 120 DIV. (g) A 3D reconstruction of an IBA1+ cell and its processes closely intertwined with TUJ1+ neurons at 66 DIV. (h) Detection and quantification of different morphology types of IBA1+ cells in organoids 35, 66 and 120 DIV, using the artificial intelligence platform by Aiforia. The Y-axis presents the portion of the respective morphology type in all the detected IBA1+ cells. The bars represent the mean (+/- SEM) percentage of three organoids for the 35 DIV group (one batch), six for 66 (DIV (one batch) and nine for 120 DIV (two batches), Tukey test, significance *** p < 0.001, ** p < 0.01, * p < 0.05 compared to 35 DIV, ## indicate similarly significance compared to 66 DIV; (i) Representative orthogonal projection images of all the quantified morphology types, imaged from a single section of an organoid at 120 DIV. All results presented here come from organoids of the iPCS line MBE2968, while the qualitative results in panels (b,e–g,i) was replicated using the other three lines, MAD6, BIONi010-C-2 and Ctrl8 c2.
Fig 3: CD41 and fibrin immunostaining of native, decellularized and recellularized veins.a-c) CD41 immunostaining of cryosections. Asterisk indicates the lumen. Native and decellularized veins stain negative (a and b), whereas c) shows continuous CD41 staining of luminal side after recellularization.d-f) Fibrin immunostaining of cryosections. Asterisk indicates the lumen. Native and decellularized veins stain negative (d and e), whereas f) shows continuous staining for fibrin along the luminal surface following recellularization.
Fig 4: Hypoxia induced eRNA stimulates collagen accumulation, leucocyte infiltration and activation in cardiomyocytes.(a) MT staining (Collagen stained purple whereas tissue was stained pink); immunohistochemistry/immunofluorescence analysis of (b) a-SMA, (c) PECAM-1, (d) NE, (e) CD11/CD18 and (f) CD41 in myocardial tissue sections have been presented with higher magnification images in the subset. Magnification of the images in subset is 40X. Images were acquired at 20X and 40X resolution. DAPI (blue) was used as a nuclear stain. Data are representative of three independent times with three mice per experiment. (Scale bar: 50 µm).
Fig 5: The body of L-PRF consists of a dense and porous fibrin matrix with platelet aggregations. (A–G) L-PRF was prepared from healthy donors, and immunostaining and confocal imaging for CD41 (platelets, in green) and fibrin (in red) was performed on the face and body region of the clots. A DAPI counterstain (in blue) visualizes the nuclei of leukocytes in the face area. (A,B) Tile scan images taken at the level of the face (A) area and the main body (B) of an L-PRF clot. (C) Optical slice (0.34 µm thickness) from the area in (B) illustrating the fibrin fibers (red) and platelets (green). (D,F) Maximum intensity projection and (E,G) 3D representation of a CD41 (in green) and fibrin (in red) stained section at the edge (D,E) and center (F,G) of an L-PRF clot. L-PRF is a compact structure and has a porous fibrin matrix that contains platelets, and the density of the fibrin fibers was higher around platelet aggregates. (H,I) Ultrastructural SEM analysis of an L-PRF clot illustrates the fibrin fibers, red blood cells, platelets, and leukocytes on the surface of an L-PRF clot. Scale bar: in (A,B) = 200 µm; in (C) = 50 µm; in (D,F) = 20 µm; in (H) = 20 µm; in (I) = 10 µm.
Supplier Page from Abcam for Anti-CD41 antibody [M148]