M2 marker genes are targets of Jmjd3. (A) Anti-Jmjd3 ChIP assay was performed on the indicated M2 marker promoter regions in BMDMs 48 hours after IL-4 stimulation. (B-E) BMDMs were transfected with Jmjd3 siRNA or control siRNA. The cells were then incubated with IL-4 for 6 hours (B,E) or 24 hours (C), and the expression of indicated genes was measured by quantitative RT-PCR (B,E) or, in the case of Jmjd3, also by immunoblotting (C). Gapdh was used as a loading control. The data shown in panels B and E are “fold induction” relative to that in unstimulated control siRNA-treated cells. Jmjd3 siRNA- or control siRNA-transfected BMDMs were incubated with IL-4 for 48 hours (D). Anti-H3K27me2/3 ChIP assay was performed on the promoter regions of M2 marker genes (D). (F) The schema shows that STAT6-dependent Jmjd3 induction decreases H3K27me2/3 level on M2 marker promoter regions and helps to maintain M2 marker genes in a transcriptionally active state. Data of ChIP assay and quantitative RT-PCR are representative of 3 independent experiments and are expressed as mean ± SEM. *P < .05, **P < .01 compared with unstimulated (medium alone) group (A) or control siRNA group (B,E). #P < .05 compared with control siRNA–IL-4 group (D).