6C), suggesting that Klf10 may inhibit IL-12p40 by binding directly to the CACCC site of the promoter. ChIP assays were performed to determine whether Klf10 was recruited to the CACCC Belnacasan molecular weight element of IL-12p40 promoter. Semi-qPCR and qPCR results verify that Klf10 can bind to the CACCC site of the IL-12p40 promoter (Fig. 6D and E). Therefore, we demonstrate that Klf10 inhibited the transcriptional activity of IL-12p40 by

binding directly to the CACCC site of the IL12p40 promoter. Macrophages are important mediators in immune responses to inflammation. The remarkable plasticity of macrophages has recently been the subject of intense investigation. M-CSF and GM-CSF are mediators involved in the regulation of macrophage heterogeneity. Macrophages induced by GM-CSF and stimulated with IFN-γ and LPS are characterized by a high expression of inflammatory cytokines and iNOS. By contrast, macrophages induced by M-CSF and then stimulated with IL-4 are responsible for the resolution of inflammation. Controlling the expression of inflammatory factors is critical in maintaining the antiinflammatory state in M-CSF-induced macrophages. KLFs are important zinc finger transcription factors that can regulate the transcriptional activity of target genes, thereby affecting their expression. So far, Klf4 has been demonstrated to be critical during macrophage differentiation. Klf4 is expressed in a monocyte-restricted

and stage-specific pattern during myelopoiesis [23]. Recent studies identified Klf4 as a key regulator in M2 macrophage polarization [5]. Klf4 is also related to macrophage activation. selleck Klf4 overexpression can induce macrophage activation marker iNOS and inhibit TGF-β1 and Smad3 signaling [25]. Klf10, initially identified and named as TGF-β inducible early gene 1 in human osteoblasts [26], has been reported to have a critical role in T-cell biology [28, 29]. In this study, we demonstrated that Klf10 functions as a specific repressor to IL-12p40 in M-BMMs,

whereas the expression of other cytokines, such as TNF-α and IL-10, were not obviously affected. 17-DMAG (Alvespimycin) HCl IL-12p40 is a subunit shared by IL-12p70 and IL-23, and its regulation is important for both innate and adaptive immunity. IL-10 can suppress IL-12 by inhibiting the transcription of its encoding genes [43]. TGF-β is also an inhibitor of IL-12 production through the reduction of the stability of IL-12 p40 mRNA [35]. Type I interferons, such as IFN-α and IFN-β, can also inhibit the production of IL-12 [33]. However, the aforementioned cytokines that regulate IL-12p40 were unaffected by Klf10 in our results. In addition, some transcription factors, such as IRF5, IRF8, C/EBP α, and C/EBP β, regulate the expression of IL-12p40. We found that the expression of these factors was not obviously affected in Klf10-deficient mice (data not shown). Therefore, Klf10 may directly regulate the expression of IL-12p40 in transcriptional levels.