Novel transcriptome signatures and markers defining murine macrophages at the extremes of the canonical M1 and M2 polarization spectrum
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ABSTRACT: Classically (M1) and alternatively activated (M2) macrophages play distinct roles in various physiological and disease processes. Understanding the gene transcription programs that contribute to macrophage polarization along the M1/M2 spectrum may lead to new tools to detect and therapeutically manipulate macrophage phenotype. Here, we define the M1 and M2 macrophage signature through mRNA microarray. The M1 macrophage signature was defined by 629 up-regulated and 732 down-regulated genes while the M2 macrophage signature was formed by 388 up-regulated and 425 down-regulated genes. While a subset of probes was common to both M1 and M2 cells, others were exclusive to each macrophage subset. The common M1/M2 pathways were characterized by changes in various transcriptional regulators and signaling partners, including increases in Kruppel-like Factor (Klf) 4, but decreases in Klf2. To identify M1 and M2 biomarkers that help discriminate these populations, we selected genes that were increased during M1 or M2 differentiation but decreased in the opposite population. Among top novel M1-distinct genes, we identified CD38, G-protein coupled receptor 18 (Gpr18) and Formyl peptide receptor 2 (Fpr2). Among top M2 genes, we found early growth response protein 2 (Egr2) and Myc. We validated these genes by Real-Time PCR and developed a CD38/Egr2-based flow cytometry assay that discriminates between M1 and M2 macrophages. Overall, this work defines the M1 and M2 signature and identifies several novel M1 and M2 genes that may be used to distinguish and manipulate M1 and M2 macrophages. Total RNA was prepared from bone marrow-derived macrophages of wild-type mice (n=2-3 independent mice) treated in M0, M1 or M2 conditions (n=2-3 replicates per condition originating from different mice)
Project description:Classically (M1) and alternatively activated (M2) macrophages play distinct roles in various physiological and disease processes. Understanding the gene transcription programs that contribute to macrophage polarization along the M1/M2 spectrum may lead to new tools to detect and therapeutically manipulate macrophage phenotype. Here, we define the M1 and M2 macrophage signature through mRNA microarray. The M1 macrophage signature was defined by 629 up-regulated and 732 down-regulated genes while the M2 macrophage signature was formed by 388 up-regulated and 425 down-regulated genes. While a subset of probes was common to both M1 and M2 cells, others were exclusive to each macrophage subset. The common M1/M2 pathways were characterized by changes in various transcriptional regulators and signaling partners, including increases in Kruppel-like Factor (Klf) 4, but decreases in Klf2. To identify M1 and M2 biomarkers that help discriminate these populations, we selected genes that were increased during M1 or M2 differentiation but decreased in the opposite population. Among top novel M1-distinct genes, we identified CD38, G-protein coupled receptor 18 (Gpr18) and Formyl peptide receptor 2 (Fpr2). Among top M2 genes, we found early growth response protein 2 (Egr2) and Myc. We validated these genes by Real-Time PCR and developed a CD38/Egr2-based flow cytometry assay that discriminates between M1 and M2 macrophages. Overall, this work defines the M1 and M2 signature and identifies several novel M1 and M2 genes that may be used to distinguish and manipulate M1 and M2 macrophages.
Project description:Classically activated (M1) macrophages protect from infection but can cause inflammatory disease and tissue damage while alternatively activated (M2) macrophages reduce inflammation and promote tissue repair. Modulation of macrophage phenotype may be therapeutically beneficial and requires further understanding of the molecular programs that control macrophage differentiation. A potential mechanism by which macrophages differentiate may be through microRNA (miRNA), which bind to messenger RNA and post-transcriptionally modify gene expression, cell phenotype and function. The inflammation-associated miRNA, miR-155, was rapidly up-regulated over 100-fold in M1, but not M2, macrophages. Inflammatory M1 genes and proteins iNOS, IL-1b and TNF-a were reduced up to 72% in miR-155 knockout mouse macrophages, but miR-155 deficiency did not affect expression of genes associated with M2 macrophages (e.g., Arginase-1). Additionally, a miR-155 oligonucleotide inhibitor efficiently suppressed iNOS and TNF-a gene expression in wild-type M1 macrophages. Comparative transcriptional profiling of unactivated (M0) and M1 macrophages derived from wild-type and miR-155 knockout (KO) mice revealed an M1 signature of approximately 1300 genes, half of which were dependent on miR-155. Real-Time PCR of independent datasets validated miR-155's contribution to induction of iNOS, IL-1b, TNF-a, IL-6 and IL-12, as well as suppression of miR-155 targets Inpp5d, Tspan14, Ptprj and Mafb. Overall, these data indicate that miR-155 plays an essential role in driving the differentiation and effector potential of inflammatory M1 macrophages. Total RNA was prepared from bone marrow-derived macrophages of miR-155 knockout mice (n=2 independent mice) treated in M0, M1 or M2 conditions (n=2 replicates per condition originating from different mice)
Project description:Recent studies suggest the presence of both âclassically activatedâ M1 and âalternatively activatedâ M2 macrophages in human atherosclerotic tissue, yet due to the lack of validated markers the reported localization patterns of these macrophage phenotypes within plaques are ambiguous. In the present study, we searched for markers that indisputably can identify differentiated M1 and M2 macrophages independently of stimuli that affect the activation status of the two subpopulations. We used these validated markers to assess the presence of M1 and M2 macrophages in different zones of human carotid artery atherosclerotic plaques obtained from 12 patients. Using microarray and qPCR technology we show that the frequently used macrophage subpopulation markers MCP-1 and CD206 do not discriminate between M1 and M2 macrophages. However, we confirm the subtype specificity of the classical M2 marker CD163 and we report that the genes INHBA and DSP (both M1) and SEPP1 and MARCKS (both M2) are highly suitable for macrophage phenotyping. mRNA expression of the pan-macrophage marker CD68 in the shoulder zones of the plaques and in adjacent tissue segments correlated positively with mRNA expression levels of SEPP1, MARCKS and CD163 (r=0.86, 0.94 and 0.96, and r= 0.86, 0.98 and 0.69, respectively) but not with the expression of the M1 markers DSP and INHBA. In contrast, mRNA expression of CD68 in the core of the plaques correlated positively with expression of DSP and INHBA (r=0.73 and 0.49) but not with SEPP1, MARCKS and CD163. These findings suggest that M1 macrophages predominate in the core of human carotid atherosclerotic plaques while M2 macrophages prevail at the periphery of the plaque. Keywords: Expression profiling by array Monocytes from healthy volunteers were differentiated into M1 and M2 macrophages by incubation with granulocyte-macrophage colony-stimulating factor (GM-CSF) or macrophage colony-stimulating factor (M-CSF), respectively. After 5 days cells were exposed to oxidized LDL. Total RNA was isolated and subjected to gene expression profiling.
Project description:Human blood monocytes were differentiated over six days with either 100 ng/ml M-CSF or 1 umol/l CXCL4 In atherosclerotic arteries, blood monocytes differentiate to macrophages in the presence of growth factors like macrophage colony-stimulation factor (MCSF) and chemokines like platelet factor 4 (CXCL4). To compare the gene expression signature of CXCL4-induced macrophages with MCSF-induced macrophages or macrophages polarized with IFN-γ/LPS (M1) or IL-4 (M2), we cultured primary human peripheral blood monocytes for six days. mRNA expression was measured by Affymetrix gene chips and differences were analyzed by Local Pooled Error test, Profile of Complex Functionality and Gene Set Enrichment Analysis. 375 genes were differentially expressed between MCSF- and CXCL4-induced macrophages, 206 of them overexpressed in CXCL4 macrophages coding for genes implicated in the inflammatory/immune response, antigen processing/presentation, and lipid metabolism. CXCL4-induced macrophages overexpressed some M1 and M2 genes and the corresponding cytokines at the protein level, however, their transcriptome clustered with neither M1 nor M2 transcriptomes. They almost completely lost the ability to phagocytose zymosan beads. Genes linked to atherosclerosis were not consistently up- or downregulated. Scavenger receptors showed lower and cholesterol efflux transporters higher expression in CXCL4- than MCSF-induced macrophages, resulting in lower LDL content. We conclude that CXCL4 induces a unique macrophage transcriptome distinct from known macrophage types, defining a new macrophage differentiation that we propose to call M4. two MCSF samples and two CXCL4 samples
Project description:The global change of the miR expression profile during atherosclerosis is due to the infiltration of different types of leukocytes into the arterail vessel wall in addition to disease-specific regulation in vascular cells. Monocyte-derived macrophage accumulation in the subintimal region is critical in the formation of atherosclerotic plaques. It is currently unknown which miRs are involved in the atherogenic macrophage response. The comparison of the miR expression profile in LPS/Interferon-gamma activated mouse macrophages with the miR expression in the normal aortic vessel wall was performed to detect macrophage-enriched miRs. This screening may help to identify macrophage-enriched miRs in atherosclerotic vessels that may play a role in the macrophage function during atherogenesis. Bone marrow cells were harvested from femura of 6-8 week old female C57BL/6 mice, re-suspended in DMEM-F12/10% FCS/10% L929-conditioned medium, and cultured for 7 days to differentiate into primary macrophages. F4/80 and CD11b expression was determined by flow cytometry to confirm the macrophage phenotype. Macrophages were stimulated with LPS (100ng/ml, 14 hours) and INF-g (10ng/ml, 6 hours) and the M1 polarization was verified by quantification of mannose receptor C type 1 (MRC1), arginase II (ArgII), inducible nitric oxide synthase (iNOS), and arginase I (ArgI) by qRT-PCR. Total RNA (M1-type macrophages and aorta tissue) was isolated using mirVana microRNA Isolation Kit.
Project description:The global change of the miR expression profile during atherosclerosis is due to the infiltration of different types of leukocytes into the arterial vessel wall in addition to disease-specific regulation in vascular cells. Monocyte-derived macrophage accumulation in the subintimal region is critical in the formation of atherosclerotic plaques. It is currently unknown which miRs are involved in the atherogenic macrophage response. The comparison of the miR expression profile in LPS/Interferon-gamma activated mouse macrophages with the miR expression in the unstimulated mouse macrophages was performed to detect M1-type macrophage-enriched miRs. This screening combined with our miR profiling in atherosclerotic vessels may help to identify M1-type macrophage-enriched miRs in atherosclerotic vessels that may play a role in the macrophage function during atherogenesis. Bone marrow cells were harvested from femura of 6- to 8-week-old female C57BL/6 mice, re-suspended in DMEM-F12/10% FCS/10% L929-conditioned medium, and cultured for 7 days to differentiate into primary macrophages. F4/80 and CD11b expression was determined by flow cytometry to confirm the macrophage phenotype. Macrophages were stimulated with LPS (100ng/ml, 14 hours) and INF-g (10ng/ml, 6 hours), and the M1 polarization was verified by quantification of mannose receptor C type 1 (MRC1), arginase II (ArgII), inducible nitric oxide synthase (iNOS), and arginase I (ArgI) by qRT-PCR. Total RNA (M1-type and unstimulated (MФ) macrophages) was isolated using the mirVana microRNA Isolation Kit.
Project description:Macrophages have distinct characteristics depending on their microenvironment. We performed proteomic analysis between M1 and M2 macrophages and found that cellular metabolism is the key regulator of macrophage function. We used microarray to support proteomic data between M1 and M2 macrophages. M1 macrophages are obtained using cell sorting of CD45+MHCII+CD8a-F4/80+ population from C57BL/6J bone marrow cell derived heterogenous cells under GM-CSF conditioning for 7 days. M2 macrophages are differentiated with 20% L929 cell supernatant for 7 days and sorted from CD45+F4/80+CD11b+ population.
Project description:Analysis of the effects of CNI-1493 treatment on M1 and M2 polarized macrophages. The purpose of this microarray is to identify genes that may be differentially expressed in M1 or M2 macrophages after treatment with CNI-1493. CNI-1493 is a known inhibitor of M1 macrophages but details of its molecular mechanism are unknown. The effect of CNI-1493 on M2 macrophages has yet to be explored, but we hypothesize that CNI-1493 treatment will attenuate pro-tumor properties of M2 macrophages. We demonstrate with this array that known macrophage markers are unchanged after treatment with CNI-1493, indicating that CNI-1493 does not change the macrophage phenotype on a transcriptional level. Additionally, no candidate genes to suggest how CNI-1493 may attenuate the pro-tumor effects of M2 macrophages are readily identifiable. Total RNA extracted from M1 or M2 macrophages after polarization with GM-CSF (25ng/ml) or M-CSF (25ng/ml) for 7 days, followed by addition of IFN-γ (20ng/ml) and LPS (100ng/ml) or IL-4 (40ng/ml) for 18 hours, respectively, from CD14+ human PBMCs, and treated with CNI-1493 (200nM)
Project description:Monocytes mature to macrophages in the presence of the lineage determining cytokine M-CSF. They can be further polarized into M1 or M2 macrophages with distinct functional properties. We used microarrays to detail the global programme of gene expression underlying macrophage maturation and polarization and identified distinct classes of up-regulated genes during this process. Experiment Overall Design: Freshly isolated monocytes were cultured in the presence of M-CSF for 7 days, and then polarized to M1 or M2 cells. The study includes Monocytes at day 0, macrophages at day 3 and 7, M1 and m2 polarized macrophages.
Project description:Decline in tissue NAD levels during aging has been linked to aging-associated diseases, such as age-related metabolic disease, physical decline, and Alzheimers disease. However, the mechanism for aging-associated NAD decline remains unclear. Here we report that pro-inflammatory M1 macrophages, but not naive or M2 macrophages, highly express the NAD consuming enzyme CD38 and have enhanced CD38-dependent NADase activity. Furthermore, we show that aging is associated with enhanced inflammation due to increased senescent cells, and the accumulation of CD38 positive M1 macrophages in visceral white adipose tissue. We also find that inflammatory cytokines found in the supernatant from senescent cells (Senescence associated secretory proteins, SASP) induces macrophages to proliferate and express CD38. As senescent cells progressively accumulate in adipose tissue during aging, these results highlight a new causal link between visceral tissue senescence and tissue NAD decline during aging and may present a novel therapeutic opportunity to maintain NAD levels during aging.