HMGB1 contributes to platelet accumulation in venous thrombosis. (A-G) Left, Immunofluorescence staining for CD41 (red) from cross-sections of the IVC. Nuclei are counterstained with DAPI (blue); bar, 200 µm. Images representative of n = 3 experiments. Right, Quantification of platelet-covered area. Results are mean ± SEMT. (A) BoxA compared with control (n = 5 each). (B) Hmgb1^−/− fetal liver cell chimeras (n = 3) compared with Hmgb1^+/+ chimeras (n = 5). (C) Left, Immunofluorescence for CD41 in Hmgb1^−/− chimeras compared with Hmgb1^−/− chimeras receiving wild-type platelets, Hmgb1^−/− platelets, or wild-type neutrophils (n = 3 each). Right, Quantification of platelet-covered area. Dotted line indicates mean in Hmgb1^+/+ bone marrow chimeras (n = 3 each). (D) Tlr2^−/− compared with control (n = 3 each). (E) Tlr4^−/− compared with control (n = 3 each). (F) Rage^−/− compared with control (n = 5 each). (G) Myd88^−/− compared with control (n = 3 each). The Student t test was used to compare results between 2 groups, 1-way ANOVA followed by LSD–post hoc test for 3 groups.