Project description:Macrophage phenotypic and functional heterogeneity derives from tissue-specific transcriptional signatures shaped by the local microenvironment. Most studies addressing the molecular basis for macrophage heterogeneity have focused on murine cells, while the factors controlling the functional specialization of human macrophages are less known. M-CSF drives the generation of human monocyte-derived macrophages with a potent anti-inflammatory activity upon stimulation. We now report that knock-down of MAFB impairs the acquisition of the anti-inflammatory profile of human macrophages, identify the MAFB-dependent gene signature in human macrophages and illustrate the co-expression of MAFB and MAFB-target genes in CD163+ tissue-resident and tumor associated macrophages. The contribution of MAFB to the homeostatic/anti-inflammatory macrophage profile is further supported by the skewed polarization of monocyte-derived macrophages from Multicentric Carpo Tarsal Osteolysis (OMIM#166300), a pathology caused by mutations in the MAFB gene. Our results demonstrate that MAFB critically determines the acquisition of the anti-inflammatory transcriptional and functional profiles of human macrophages.
Project description:Macrophage phenotypic and functional heterogeneity derives from tissue-specific transcriptional signatures shaped by the local microenvironment. Most studies addressing the molecular basis for macrophage heterogeneity have focused on murine cells, while the factors controlling the functional specialization of human macrophages are less known. M-CSF drives the generation of human monocyte-derived macrophages with a potent anti-inflammatory activity upon stimulation. We now report that knock-down of MAFB impairs the acquisition of the anti-inflammatory profile of human macrophages, identify the MAFB-dependent gene signature in human macrophages and illustrate the co-expression of MAFB and MAFB-target genes in CD163+ tissue-resident and tumor associated macrophages. The contribution of MAFB to the homeostatic/anti-inflammatory macrophage profile is further supported by the skewed polarization of monocyte-derived macrophages from Multicentric Carpo Tarsal Osteolysis (OMIM#166300), a pathology caused by mutations in the MAFB gene. Our results demonstrate that MAFB critically determines the acquisition of the anti-inflammatory transcriptional and functional profiles of human macrophages.
Project description:Analysis of the role of transcriptions factors MAF and MAFB on the phenotypic profles of human M-CSF-derived macrophages. Methods: Human Peripheral Blood Mononuclear Cells (PBMC) were isolated from buffy coats from donors over a Lymphoprep gradient according to standard procedures. Monocytes were purified from PBMC by magnetic cell sorting using anti-CD14 microbeads (>95% CD14+ cells). Monocytes (0.5 x 106 cells/ml, >95% CD14+ cells) were cultured in RPMI 1640 supplemented with 10% fetal bovine serum (FBS) for 7 days in the presence of 10 ng/ml M-CSF to generate M-CSF-polarized macrophages (M-MØ). Macrophages were differentiated from peripheral blood monocytes from 3 healthy donors with M-CSF (M-MØ) to generate anti-inflammatory M-MØ. Macrophages were transfected with either Control siRNA or MAFB-specific siRNA or MAF-specific siRNA for 24h and global gene expression was analysed by RNA-Seq.
Project description:Macrophage phenotypic and functional heterogeneity derives from tissue-specific transcriptional signatures shaped by the local microenvironment. Most studies addressing the molecular basis for macrophage heterogeneity have focused on murine cells, while the factors controlling the functional specialization of human macrophages are less known. M-CSF drives the generation of human monocyte-derived macrophages with a potent anti-inflammatory activity upon stimulation. The contribution of MAFB to the homeostatic/anti-inflammatory macrophage profile is further supported by the skewed polarization of monocyte-derived macrophages from Multicentric Carpo Tarsal Osteolysis (OMIM#166300), a pathology caused by mutations in the MAFB gene.
Project description:The direct communication between our central nervous and inflammatory signalling systems is a well-recognised, yet poorly understood relationship. To increase our understanding of this relationship, we examined the metabolism of serotonin and its precursor tryptophan in macrophages under inflammatory settings. Both are involved in inflammatory signalling and known to play a major role in mood regulation. Tryptophan depletion by macrophages during inflammation can consequently result in a reduction of serotonin systemically and has been suggested to cause depression. Increased understanding of this system could help overcome the problem of treatment resistant depressed patients. To this end, we treated primary human monocyte derived macrophages with a range of anti-depressant/anti-inflammatory drugs and analysed their transcriptional profile under various inflammatory conditions. In addition to the classic endotoxic driver of inflammation, LPS, we also used IFNα which is a constitutive cytokine shown to directly induce depression when administered in high doses. The anti-depressant drugs were not found to have any significant effects on macrophage inflammatory signalling. However, the anti-inflammatories drugs were found to alter components of the serotonin/tryptophan metabolism pathways. This study increases our understanding of the intricacies of immune/mood cross-talk and offers into developing anti-inflammatories as co-treatment for depression. We treated human primary macrophage cells with anti-inflammatory or anti-depressant drugs and analysed their transcriptional effects during inf.lammatory signaling within the context of tryptophan metabolism/kynurenic metabolism.
Project description:MafB is a member of the large Maf family of transcription factors that share similar basic region/leucine zipper DNA binding motifs and N-terminal activation domains.Although it is well known that MafB is specifically expressed in macrophages, characterization of the null mutant phenotype in these tissues has not been previously reported. To investigate suspected MafB functions macrophages, we generated mafB/green fluorescent protein (GFP) knock-in null mutant mice. MafB deficiency was found to dramatically suppress F4/80 expression in nonadherent macrophages. To investigate detail function of MafB in nonadherent macrophages, we performed microarray analysis. Macrophages were derived from day 14.5 fetal livers of mafB- /- and WT mice. Suspensions of single fetal liver cells were prepared by mechanical disruption . A total of 106 cells in suspension were centrifuged at 1,200 rpm for 5 min, and the cell pellet was resuspended in Dulbeccoâs modified Eagleâs medium supplemented with 10% fetal calf serum (heat inactivated), streptomycin and penicillin (100 units/ml), and macrophage colony-stimulating factor (M-CSF) (10 ng/ml) and then seeded either onto a nonadhesive dishes coated with hydrophilic polymers (Hydrocell; Cell Seed, Tokyo). The culture medium was not changed throughout the experiment. M-CSF (final concentration, 10 ng/ml) was added every day from day 4 onwards. One, 2, 4, and 6 days after seeding, the cells were harvested and analyzed by flow cytometry. After 6 day culture, macrophages of Mafb-/- and WT were use microarray analysis .
Project description:HDL infusion reduces atherosclerosis in animal models and is being evaluated as a treatment in humans. While some studies have shown anti-inflammatory effects of HDL in macrophages, others have reported pro-inflammatory effects and there is no consensus on underlying mechanisms. Transcriptional profiling reveals that HDL-mediated cholesterol efflux leads to both pro- and anti-inflammatory effects in LPS-stimulated macrophages. While early anti-inflammatory effects reflect reduced TLR4 levels, late anti-inflammatory effects are due to reduced interferon receptor signaling. Pro-inflammatory effects occur late and are ER stress responses mediated by IRE1a/ASK1/p38 MAPK signaling under conditions of marked cholesterol depletion. rHDL infusions in hypercholesterolemic atherosclerotic mice produced moderate anti-inflammatory effects in lesional macrophages without pro-inflammatory gene expression changes suggesting a beneficial therapeutic effect of HDL in vivo.
Project description:We report that colonic lamina propria anti-inflammatory macrophages from Il10rb-/- (KO) mice at 12 weeks possessed significantly high levels of proinflammatory transcripts compared to the ones from Il10rb+/- (het) controls. While the transcriptional profile between macrophages from KO and het mice was comparable at 1 weeks and did not possess significant levels of proinflammatory transcripts, we show that the macrophages from KO mice were enriched for proinflammatory transcripts at 3 weeks compared to the ones from 3 week old het controls. These data indicate that the anti-inflammatory signature of colonic lamina propria macrophages from Il10rb-/- mice is compromized at 3 weeks.