Following clodronate treatment, Kupffer cells start repopulating the liver from day 7, the number of young platelets decreases while the total platelet count increases and upon desialylation, and CD41-YFP platelets accumulate predominantly on Kupffer cells . (A ) SD-IVM of the mouse liver right after injection of fluorescently labeled albumin. Kupffer cells were stained using fluorescently labeled anti-F4/80 antibody. Scale bar is 33 µm. (B) Mice were treated with a single dose of i.v. clodronate liposomes to deplete Kupffer cells. Kupffer cell repopulation was quantified as the F4/80-positive area over time. Data represent means ± SEM (n ≥ 5 mice per group). (C) Quantification of the CD41⁺ Thiazole Orange^hi young platelet population in the blood from control mice and mice on day 5 after Kupffer cell (KC) depletion. Data represent means ± SEM (n = 5 mice per group). (D) Total platelet count was analyzed using flow cytometry of blood from control mice and mice on day 5 after Kupffer cell depletion. Data represent means ± SEM (n = 5 mice per group). (E) Galactose exposure as measured by RCA-FITC binding to control and “old” platelets on day 3 after in vivo labeling. Data represent means ± SEM (n = 7 mice per group). (F) SD-IVM of the liver of CD41-YFP^ki/+ mice treated with 50 mU sialidase. Representative still images obtained at the indicated time points. Kupffer cells and endothelial cells were stained using fluorescently labeled anti-F4/80 and anti-CD31 antibody, respectively. Scale bars are 46 µm. (G) Colocalization of platelets with Kupffer cells, endothelial cells (ECs), and hepatocytes (Hep) was quantified at the 20-min time point after sialidase treatment using Imaris software. Data represent means ± SEM (n = 5 mice per group). Unpaired two-tailed t test (C–E) and one-way ANOVA with post-hoc testing (G) were used to determine statistical significance. *, P < 0.05; ***, P < 0.001. Results from all experiments shown are representative of at least three independent experiments.