Fig. 6: Transplantation of human S100A8⁺ immune cells induce BAT aging and thermogenic decline in mice.

a, b Representative flow cytometry plots and quantification of frequencies of S100A8⁺ immune cells (a) and T cells (b) in peripheral blood cells from young and old normal healthy donors (all males; Young: n = 9, Old: n = 13). c Correlation of S100a8 with p21 (Kras) expression in human whole blood cells based on data from the Genotype Tissue Expression (GTEx) database. d Schematic diagram of experimental processes of transplantation of human S100A8⁺ or S100A8⁻ immune cells into NOD-SCID mice. This diagram was created with BioRender.com. e Serum concentration of TNF and IL-6 in transplanted mice (n = 5). f Representative flow cytometry plots and quantification of frequencies of human CD45⁺ immune cells in the SVFs of BAT from transplanted mice (n = 5). g Representative images of TH and human CD45 staining in the BAT of transplanted mice. Scale bar, 100 μm. h Representative immunoblots of UCP1, P16, and P21 in the BAT of transplanted mice (n = 5). i SA-β-gal staining of BAT and its frozen sections of transplanted mice. j Representative infrared thermal images of BAT of transplanted mice subjected to cold stimulation for 6 h (n = 5). k Core body temperature of transplanted mice under cold stimulation (n = 5). Data shown are representative of three independent experiments with similar results. n indicates the number of biologically independent samples examined. Data are shown as the mean ± SEM. Statistical differences were supposed to be significant when P < 0.05. Statistical analysis was performed by two-way ANOVA (k), or unpaired two-tailed Student’s t test (a, b, e–h). Source data are provided as a Source Data File.