Cells of BM origin populate the vascular endothelium in mice with PMCAO treated with G-CSF/SCF. (A-C) Images from Z-stacks, where sections from G-CSF/SCF–treated PMCAO mice were immunostained with CD31, a specific marker of vascular endothelium, and GFP to track the bone marrow origin. The side panels demonstrate the colocalization of the 2 markers (endothelial marker and GFP) in several cells of the vascular wall. (D,E) demonstrates colocalization of GFP with the von Willebrand factor in vascular endothelium shown in red. (F) One level of a Z-series with side panels demonstrating that a GFP⁺ cell lining the lumen of a capillary (*) is also labeled with red dots representing the antibody staining for VE-cadherin, another specific endothelial cell marker. (G) Colocalization of BRDU (red dots over labeled nuclei) with GFP in a luminal cell lining a capillary (*). Arrow points to the colocalization of the red and green in the main panel as well as in the side panels. Arrows point to BRDU⁺ nuclei that do not belong to GFP⁺ cells. The images are a single level taken out of a Z-series, where the section was optically sliced into 0.5-μm–thin sections and iterative restoration was perfomed using Volocity 4.0 software. Objective, 40×; numeric aperture, 0.6 (A-E); and objective, 63×; numeric aperture, 0.7 (F). Scale bar equals 25 μm (A-C), 10 μm (D-F), and 16 μm (G).