Fig. 2: CAMs are required to clear vascular damage and preserve skin capillaries during ageing.
From: Niche-specific dermal macrophage loss promotes skin capillary ageing
a, Schematic of laser-induced capillary clotting (top). Bottom, time-lapse imaging of Csf1reGFPR26mTmG mice after clot formation (yellow lightning bolt, 940 nm, 1 s). b, Laser-induced clot formation in 10-month-old mice. The yellow arrowheads indicate extraluminal vascular debris. The dotted white box highlights third harmonic optical z-series, pseudocoloured to visualize RBC movement in recovering capillaries. c, Clot recovery in 10-month-old mice. Quantification of reperfusion at days 1 and 7 after clotting in regions with CAMs (<75 µm) versus without CAMs (>75 µm) is shown. n = 16 clots per group; 3 mice. Statistical analysis was performed using two-way RM-ANOVA with Fisher’s test. Data are mean ± s.d. d, Imaging of clot repair after simultaneous laser ablation of CAMs (red lightning bolt) and capillary clotting in Csf1reGFP mice (940 nm, 1 s). e, Quantification of reperfusion in CAM-ablated versus control regions at days 1 and 7. n = 19 (CAM ablated) and 16 (control) clots; 3 mice total. Statistical analysis was performed using two-way RM-ANOVA with Fisher’s test. Data are mean ± s.d. f, Repeated imaging of capillary clot recovery in Cx3cr1creERRac1fl/fl and Cx3cr1creERRac1fl/+ mice. CAMs (green), capillaries (red) and RBCs (white) are visualized. g, Quantification of perivascular RBC debris at day 3. n = 52 (Rac1fl/+) and 48 (Rac1fl/fl) clots; 3 mice per group. Statistical analysis was performed using unpaired t-tests. Data are mean ± s.d. h, Capillary reperfusion at days 1, 3 and 7. n = 67 (Rac1fl/+) and 82 (Rac1fl/fl) clots; 3 mice per group. Statistical analysis was performed using two-way RM-ANOVA with Tukey’s test. i, Sequential revisits over 3 months show pruning of individual capillaries (yellow arrowheads). j,k, Quantification of homeostatic capillary loss 3 months after tamoxifen administration. n = 4 (Rac1fl/+) and n = 5 (Rac1fl/fl) mice; two 500 µm2 regions per mouse. Statistical analysis was performed using unpaired t-tests (j) and two-way RM-ANOVA with Fisher’s test (k). Data are mean ± s.d. Scale bars, 50 µm.
