Figure 3. Macrophages promote angiogenesis in response to obesity-like stromal cells.

(A, B) Mammary glands from NOD/SCID mice humanized with SVF/CCL2 cells demonstrated significantly increased CD31⁺ cells after 4 weeks compared with glands humanized with SVF/EV cells as quantified by immunofluorescence (A) and flow cytometry (B). Glands from 3 mice were utilized for each time point. (C) Matrigel plugs were implanted under the flank of Mac-SCID mice. Those containing SVF/CCL2 cells recruited significantly increased numbers of F4/80⁺ macrophages and CD31⁺ endothelial cells than plugs containing SVF/EV cells. In mice treated with diphtheria toxin (DT), both F4/80⁺ macrophages and CD31⁺ endothelial cells were significantly decreased in plugs containing either SVF/CCL2 or SVF/EV cells compared with plugs from vehicle treated mice. (D) At 2 weeks following humanization, DT treatment decreased both CD11b⁺ and CD31⁺ cells compared with glands from vehicle-treated mice. Four weeks following humanization and DT administration, no significant changes in CD11b⁺ cells were observed, and only DT-treated SVF/CCL2 glands demonstrated significantly reduced CD31⁺ cells compared with those from vehicle-treated mice. Mice received DT or vehicle at 24 hours and 48 hours following humanization. Glands were collected at 2 or 4 weeks following DT administration (n=5 mice/group). Two Matrigel plugs were injected subcutaneously in each mouse. Data denoted as a fold change from vehicle treated mice in each condition. Original magnification (A) 200x; bar=100μm.