Fig. 8

IL-6 produced by hADSCs causes an infiltration of the proangiogenic and immunosuppressive M2 macrophages and increases the number of blood vessels. The immunofluorescence analysis of the muscles collected 7 days after the artery ligation and the administration of hADSCs with human IL-6 blocking antibody (hADSCs + anti IL-6) and the control group (PBS⁻). The representative images of M2 macrophages (F4/80⁺ (red)/CD206⁺ (green)) (a, b, c) and blood vessels CD31⁺ (green) (d, e, f). After the administration of IL-6 producing hADSCs the increased infiltration of M2 macrophages (b) and the increase of blood vessels (e) were observed. After blocking of the IL-6 secreted by hADSCs in vivo no macrophage infiltration or increase in the number of blood vessels was observed (c, f). The number of capillaries (CD31⁺) (h) and the total area of F4/80 macrophages (g) counted in collected muscles 7 days after the administration of hADSC, hADSCs with siltuximab and PBS. n = 5; 5 muscles per group were analyzed; 5 (for the total area of F4/80) or 10 (for the number of capillaries) pictures of each muscle were taken. ***p < 0.001 evaluated with Kruskal-Wallis one-way analysis of variance and multiple comparison of mean ranks for all groups. Nuclei stained with DAPI (blue), scale bars = 50 μm