Fig. 1: Lenalidomide promotes M2 macrophages polarization.

a, b qRT-PCR analysis for expression of macrophage M2 phenotype genes in RAW264.7 (a) and BMDMs (b) with lenalidomide treatment for 4 h, IL13 (10 ng/ml) was used as positive control (n = 3). c, d Western blotting analysis for expression of Arg1 and Ym1 in RAW264.7 (c) and BMDMs (d) with lenalidomide treatment for 4 h. GAPDH or β-actin was the loading control (n = 3). e Flow cytometry analysis of the percentage of M2 phenotype (CD206⁺ cells) in RAW264.7 cells with lenalidomide (25 nM) treatment for 4 h. IL13 (10 ng/ml) was used as positive control (n = 3). f Flow cytometry analysis of the percentage of M2 phenotype (CD206⁺F4/80⁺ cells) in BMDMs with lenalidomide (25 nM) treatment for 4 h (n = 3). Cells were gated at F4/80⁺ cells. g, h BMDMs were pretreated with LPS (50 ng/ml) for 24 h and then administrated with lenalidomide (25 nM) for additional 4 h. qRT-PCR was carried out to analyze mRNA level of macrophage M1 phenotype genes (n = 3) (g). Flow cytometry analysis was carried out to characterize the percentage of M1 phenotype (CD86⁺F4/80⁺ cells), cells were gated at F4/80⁺ cells (n = 3) (h). Data are presented as means ± SEM; *P < 0.05, **P < 0.01, ***P < 0.001 versus untreated control