Extended Data Fig. 1: Upper dermal macrophages are capillary-associated and decline in density with age.
From: Niche-specific dermal macrophage loss promotes skin capillary ageing
a, Representative images of cell expression of Ccr2-RFP and Cx3cr1-GFP in the epidermis, upper dermis, and lower dermis of 1 month old mice. b, Quantifications of cells expressing Csf1r-EGFP, Cx3cr1-GFP, or Ccr2-RFP, in the upper dermis (n = 3 mice in each group; two 500 µm2 regions per mouse; Cell number (Csf1r-EGFP vs Cx3cr1-GFP; Csf1r-EGFP vs Ccr2-RFP) was compared by one-way ANOVA and Tukey multiple comparison tests; mean ± SD). c, Visualization of CX3CR1-expressing cells in all skin layers: epidermis, upper dermis, and lower dermis (Cx3cr1-GFP;R26-mTmG) was performed during homeostatic conditions. d, Representative image of labelled upper dermal macrophages in contact with capillary superficial plexus (red) in 1 month old mice. e, Quantifications reveal most upper dermal macrophages are capillary-associated macrophages (CAMs) (n = 3 mice in total; three 500 µm2 regions per mouse; Upper dermal macrophage capillary association was compared by paired Student’s t test; mean ± SD). f, Quantifications of cells expressing Cx3cr1-GFP in the upper dermis (n = 3 mice in each group; two 500 µm2 regions per mouse; CAM density (1 vs 7-month-old) was compared by unpaired Student’s t test; mean ± SD). g, Representative optical sections of CAMs in young (1-month-old) and old (6-month-old) LysM-Cre;R26-mTmG mice. Quantifications of membrane-GFP+ cells in the upper dermis (n = 4 mice in each group; two 500 µm2 regions per mouse; CAM density (1 vs 6-month-old) was compared by unpaired Student’s t test; mean ± SD). h, Representative upper dermal optical sections from whole mount skin samples of young (1-month-old) and old (18-month-old) Csf1r-EGFP mice stained with AF647 anti-mouse CD206 (clone C068C2) antibody. Quantifications for CD206 and CSF1R co-expression in the upper dermis (n = 3 mice in each group; two 500 µm2 regions per mouse; CAM density (1 vs 18-month-old) was compared by two-way RM ANOVA and Tukey multiple comparison tests; mean ± SD). Scale bar, 50 µm.
