Inhibition of STAT6 and PPARγ impacts microglia alternative activation induced by IL-4 and RvD1. BV-2 cells were treated with leflunomide (10 μM) or GW9662 (1 μM) 30 minutes prior to administration of RvD1 (100 nM) and then stimulated with IL-4 (10 ng/ml) for 24 hours. Immunofluorescence assay for Arg1 (A) and Ym1 (B) indicated that the induction of Arg1 and Ym1 by RvD1 and IL-4 was disappeared when blocking STAT6 or PPARγ signaling pathway. Scale bars indicate 20 μm. (C) The protein levels of Arg1 and Ym1 were measured by Western blot. A representative result from three independent experiments is shown. Quantification for Arg1 and Ym1 was normalized by β-actin. Data are presented as mean ± SEM for three independent experiments. Asterisks indicate statistically significant difference (*P < 0.05, **P < 0.01).