Figure 3.

C15 Dampens Wound Leukocyte Recruitment and Skews Macrophage Phenotype

Four 4 mm excisional wounds were made to the dorsal skin of Sv129Ev mice. Vehicle or C15 (100 pg/wound) in 30% Pluronic gel was administered directly into the wound immediately after wounding.

(A–C) Representative micrographs and quantification of neutrophil (Ly6G⁺ cell, brown) (A), mast cell (toluidine blue⁺ cell, blue) (B), and monocyte-macrophage (F4/80⁺ cell, brown) (C) recruitment to wound granulation tissue up to 14 days after wounding.

(D) Macrophage immunostaining through the midpoint of day 7 wounds. Red arrows indicate wound edges, and green lines mark the edge of the macrophage-dense area.

(E) Quantification of the distance that macrophages extend beyond the wound margin into the surrounding tissue.

(F) Schematic showing macrophage distribution around vehicle- and C15-treated day 7 wounds and corresponding photos of macrophage morphology.

(G) Quantification and representative photos of Prussian blue⁺ iron-loaded cells within the wound.

(H) Quantification and representative photos of TNF-α expression (brown).

(I) Characterization of macrophage phenotype within day 7 C15- and vehicle-treated wounds. Ym1 and Arg1 are M2 markers, and iNOS is an M1 macrophage marker.

Data are expressed as means ± SEM; there were four to eight wounds per treatment group. ^∗p < 0.05 and ^∗∗p < 0.01 relative to vehicle-treated wounds. The following abbreviation is used: FOV, field of view.