Fig. 1

IL-4 promotes cellular expansion and beige commitment of adipocyte precursors (APs). A Schematic of IL-4 induced priming of APs. APs isolated from scWAT were cultured in vitro. IL-4 was added into the growth medium one day after cell seeding and cells were harvested for analysis on the indicated days B The cell proliferation rate of APs cultured in IL-4 containing media (n = 3). C The beige adipogenic markers (Pgc1-α, Pparg, Ear2, and Tmem26) mRNA levels were examined by qPCR in APs (n = 3). Longer incubation of APs with IL-4 induces higher expression levels of markers. D mRNA expression levels of the white adipogenic markers (Zfp423 and Asc1) and the brown adipogenic markers (Ebf2 and Pdk4) were analyzed by qPCR in APs (n = 3). E The mRNA levels of Ucp1, Ap2, and Pgc1-α genes were measured by quantitative PCR (qPCR) in differentiated adipocytes (n = 3). When APs were pre-incubated with IL-4 for four days before the induction of differentiation, the expressions of beige and adipogenic markers in differentiated adipocytes increased to a significantly greater extent than those in control cells. F The protein levels of UCP1 were examined by western blotting in differentiated adipocytes. Pre-incubation of APs with IL-4 leads to higher levels of UCP1 expression in differentiated adipocytes. Biological triplicates for each condition were examined. The quantified signal intensities in the western blotting are presented as a bar graph (n = 3). MDI refers to the induction of differentiation by an adipogenic cocktail. Data are presented as mean ± SEM. *** p < 0.005, **p < 0.01, *p < 0.05