Involvement of JNK signaling in IL4-induced M2 macrophage polarization

It has been generally accepted that alternatively activated macrophages (M2), which can be induced by type 2 cytokines such as IL-4, is responsible for tissue repair. However, the function of JNK in IL-4-induced M2 macrophage polarization remains unclear. Here, we demonstrated that M0 macrophages can be polarized into M2 status in response to IL-4 stimulation with the increased expression of the M2-specific molecular markers. We also found that IL-4 induced higher expression of JNK and transcription factor c-Myc in M2 macrophages. Our Q-PCR and Western blot results showed that JNK increased the expression of c-Myc and M2 markers Arg1, Mrc1. We also demonstrated c-Myc was the downstream of IL-4-JNK pathway. Further, the depletion of c-Myc, Arg1 and Mrc1 could inhibit the migration ability of M2 macrophages. Taken together, our data establishes a new role for JNK signaling in IL-4-induced alternative activation of macrophages and may provide a novel strategy for immune therapy.