Figure 2

Infiltration of GFP⁺ BM-cells in infarct and peri-infarct regions. (A-B) Dot plots of viable macrophages/granulocytes (CD11b⁺CD45^high, top right quadrants) and microglia (CD11b⁺CD45^dim, bottom right quadrants) in cortex from BM-chimeric unmanipulated mice and mice exposed to pMCAO. (C) Bar graph showing mean numbers of CD11b⁺CD45^dim microglia and CD11b⁺CD45^high macrophages/granulocytes in BM-chimeric mice 24 hours after pMCAO, subdivided based on expression of GFP (n = 5). Approximately 92% of of the CD45^high population were GFP⁺ . (D) Estimation and comparison of mean numbers of CD11b⁺CD45^dim microglia in non-chimeric (n = 10) versus BM-chimeric mice (n = 5) 24 hours after of pMCAO shows significantly fewer CD11b⁺CD45^dim microglial cells in irradiated mice. (E) Overview, showing distribution of infiltrating GFP⁺ BM-derived cells into infarct (IF) and peri-infarct (P-IF) regions 24 hours after pMCAO. (E-G) By 24 hours, GFP⁺ single cells (F) and vessel-associated aggregates of GFP⁺ cells (arrows in G) were observed in infarct and peri-infarct regions. Some of the vessel-associated cells were round, leukocyte-like cells (arrows) while others were elongated cells lining the vasculature (arrow heads in G and in insert). (H) Bar graph showing mean numbers of single GFP⁺ cells and vessel-associated aggregates of GFP⁺ cells in ipsi- and contralateral cortex 24 hours after surgery (n = 10). (I-P) Immunohistochemical staining of CD45.1 (I, K), CD45.2 (J, L), IgG2a (M, O) and CD45 (N, P) in ischemic tissue in BM-chimeric (I, J, M, N) and non-chimeric mice (K, L, O, P) 24 hours after pMCAO. N.D, none detected. Scale bars: 200 μm (A), 10 μm (B, C). 50 μm (I-P) *P < 0.05, **P < 0.01, and ***P < 0.001.