Fig. 2

ST2 expression in endothelial cells, microglia, and macrophages in the ischemic brain early after experimental stroke. (A-B) ST2 expression on ECs and microglia/macrophages was elevated after tMCAO. (A) Top: Representative gating strategy for CD31⁺Ly6G⁻ EC, CD31⁻Ly6G⁻CD11b⁺CD45^intermediate microglia, and CD31⁻Ly6G⁻CD11b⁺F4/80⁺CD45^high macrophages in the brain 3d after tMCAO. Bottom: Histograms showing ST2 expression on ECs, macrophages, and microglia in sham and stroke brains. (B) Quantification of the percentage of ST2⁺ ECs, macrophages, or microglia in sham or ischemic brains. (C) ST2 staining (magenta) in the ischemic brains from WT and ST2 KO mice 3d after tMCAO. Cell nuclei are counterstained with DAPI (blue). (D) Co-immunostaining of ST2 (magenta) and Iba1 (green) in the peri-infarct area of WT mice 3d after tMCAO. Areas in the white insets are enlarged. (E) Co-immunostaining of ST2 (magenta) and CD31 (green) in the brain of CCR2-RFP reporter mice 3d after tMCAO. Areas in the white inset were enlarged and reconstructed in 3D. White arrows: ST2 expression in CD31⁺ ECs. Yellow arrows: ST2 expression in CCR2⁺ infiltrating macrophages. (F) Immunostaining of IL-33 and quantification of the number of IL-33⁺ cells and intensity of IL-33 staining in the peri-infarct area of WT and ST2 KO mice 3d following tMCAO. *P < 0.05. Two-tailed Student’s t test (B) or Welch’s t test (F)