Fig. 4

An HSD activates peripheral nerve macrophages. a Representative flow cytometry dot plots showed an increase in the frequency of peripheral nerve macrophages (CD45⁺CD11b⁺F4/80⁺) at 1 and 3 months of HSD feeding. b Histograms depicted the absolute macrophage (CD45⁺CD11b⁺F4/80⁺) number, as well as those that were CD86⁺ macrophages. A quantitative analysis indicated a significant increase at 1 and 3 months of HSD feeding, and the number remained elevated after shifting HSD-fed mice to a ND, n = 6–9/group. c Histograms depicted the absolute macrophage (CD45⁺CD11b⁺F4/80⁺) number as well as those that were CD206⁺ macrophages. An HSD favored the differentiation of CD86⁺ macrophages in the nerve more than those of CD206⁺ macrophages, n = 6–9/group. d A representative flow cytometry histogram showed the percentage of Ki67⁺macrophages (CD45⁺CD11b⁺F4/80⁺) in the sciatic nerves of HSD and ND fed mice. A quantitative analysis showed that HSD did not trigger significant macrophage proliferation in nerves, n = 6–8/group. e Longitudinal sections of mouse sciatic nerves were stained with CD16/32 (FcγII/III receptor), F4/80, and DAPI, showing an increased F4/80⁺ macrophage density in HSD nerves primarily colocalized with CD16/32. f Real-time quantitative PCR showed an elevated expression of IL-1β and IL-6 in the peripheral nerves at three months of HSD feeding, n = 6–10/group. Data were combined with from male and female mice. All data was presented as mean ± SEM and analyzed with an unpaired t test, **p < 0.01, ***p < 0.001; red and green ## represents statistics for CD86⁺ or CD206⁺ macrophages, respectively