Figure 6.

Adoptive transfer of BMP4-treated M2 promotes beige fat biogenesis and improves energy expenditure in mice. Eight-week-old male C57BL/6J mice housed at 22°C were adoptive transferred with 5 × 10⁶ M2 macrophages or BMP4-activated M2 macrophages into each side of scWAT twice a week. Mice were examined after 2 weeks. (A) Flow cytometry analysis for the percentage of M1 macrophages (CD45⁺CD11c⁺F4/80⁺) and M2 macrophages (CD45⁺CD206⁺F4/80⁺) in scWAT transferred with macropahges. (B) Representative scWATs after transfer experiment. (C) Western blot analysis of UCP1 protein expression in scWAT. Relative gray intensity of bands from three individual experiments was quantified using Image J software. (D) Real-time PCR analysis for mRNA abundance of UCP1 and other markers for brown adipocytes, including Cidea, PRDM16, PGC1α, and UCP1. (E) Real-time PCR analysis for mRNA abundance of genes related to angiogenesis. (F) Whole-body oxygen consumption of three groups of mice were monitored in metabolic cage and calculated. (G) Daily food intake of mice during the period of adoptive transferred with M2 macrophages. (H) Body weight of mice in three groups maintained on chow diet after 2 weeks of adoptive transfer. Student’s test was used and data are presented as mean ± SD *P < 0.05; **P < 0.01; ***P < 0.001. n = 5 mice per group.