Ligand-insensitive PPARγ controls progressive or reinforcing macrophage polarization as an epigenomic ratchet of transcriptional memory
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE115505 | GEO | 2018/06/20
REPOSITORIES: GEO
Similar Datasets
Project description:Macrophages polarize into distinct phenotypes in response to complex environmental cues. We found that the nuclear receptor PPARγ drove robust phenotypic changes in macrophages upon repeated stimulation with interleukin (IL)-4. The functions of PPARγ on macrophage polarization in this setting were independent of ligand binding. Ligand-insensitive PPARγ bound DNA and recruited the coactivator P300 and the architectural protein RAD21. This established a permissive chromatin environment that conferred transcriptional memory by facilitating the binding of the transcriptional regulator STAT6 and RNA polymerase II, leading to robust production of enhancer and mRNAs upon IL-4 re-stimulation. Ligand-insensitive PPARγ binding controlled the expression of an extracellular matrix remodeling-related gene network in macrophages. Expression of these genes increased during muscle regeneration in a mouse model of injury, and this increase coincided with the detection of IL-4 and PPARγ in the affected tissue. Thus, a predominantly ligand-insensitive PPARγ:RXR cistrome regulates progressive and/or reinforcing macrophage polarization.
| S-EPMC6197058 | biostudies-literature
Project description:Macrophages change their phenotype in response to complex (reinforcing or opposing) environmental cues. The molecular components providing the epigenomic basis of progressive or reinforcing polarization are largely unknown. Here we show that the normally ligand-activated nuclear receptor, Peroxisome Proliferator-Activated Receptor gamma (PPARγ), is a predominantly ligand-insensitive, epigenomic driver of a robust phenotypic change in macrophages uniquely upon repeated/reinforcing IL-4 stimulation. Ligand-insensitive PPARγ recruits P300, RAD21 and establishes a permissive chromatin environment, conferring transcriptional memory by facilitating the binding of STAT6 and RNAPII leading to more robust eRNA production upon IL-4 restimulation. PPARγ-mediated transcriptional memory allows the progressive, functional transition of macrophages upon repeated cytokine exposure by controlling the expression of an extracellular matrix remodeling related gene network, also expressed in macrophages from a mouse model of muscle regeneration and show progressive upregulation during the course of regeneration after muscle injury, coinciding with the appearance of IL-4 and PPARγ. Collectively, in contrast to the current prevailing view, alternative polarization gives rise to a predominantly ligand-insensitive PPARγ:RXR cistrome, regulating progressive/reinforcing macrophage polarization.
2018-06-20 | GSE115504 | GEO
Project description:Macrophages change their phenotype in response to complex (reinforcing or opposing) environmental cues. The molecular components providing the epigenomic basis of progressive or reinforcing polarization are largely unknown. Here we show that the normally ligand-activated nuclear receptor, Peroxisome Proliferator-Activated Receptor gamma (PPARγ), is a predominantly ligand-insensitive, epigenomic driver of a robust phenotypic change in macrophages uniquely upon repeated/reinforcing IL-4 stimulation. Ligand-insensitive PPARγ recruits P300, RAD21 and establishes a permissive chromatin environment, conferring transcriptional memory by facilitating the binding of STAT6 and RNAPII leading to more robust eRNA production upon IL-4 restimulation. PPARγ-mediated transcriptional memory allows the progressive, functional transition of macrophages upon repeated cytokine exposure by controlling the expression of an extracellular matrix remodeling related gene network, also expressed in macrophages from a mouse model of muscle regeneration and show progressive upregulation during the course of regeneration after muscle injury, coinciding with the appearance of IL-4 and PPARγ. Collectively, in contrast to the current prevailing view, alternative polarization gives rise to a predominantly ligand-insensitive PPARγ:RXR cistrome, regulating progressive/reinforcing macrophage polarization.
2018-06-20 | GSE115502 | GEO
Project description:Macrophages change their phenotype in response to complex (reinforcing or opposing) environmental cues. The molecular components providing the epigenomic basis of progressive or reinforcing polarization are largely unknown. Here we show that the normally ligand-activated nuclear receptor, Peroxisome Proliferator-Activated Receptor gamma (PPARγ), is a predominantly ligand-insensitive, epigenomic driver of a robust phenotypic change in macrophages uniquely upon repeated/reinforcing IL-4 stimulation. Ligand-insensitive PPARγ recruits P300, RAD21 and establishes a permissive chromatin environment, conferring transcriptional memory by facilitating the binding of STAT6 and RNAPII leading to more robust eRNA production upon IL-4 restimulation. PPARγ-mediated transcriptional memory allows the progressive, functional transition of macrophages upon repeated cytokine exposure by controlling the expression of an extracellular matrix remodeling related gene network, also expressed in macrophages from a mouse model of muscle regeneration and show progressive upregulation during the course of regeneration after muscle injury, coinciding with the appearance of IL-4 and PPARγ. Collectively, in contrast to the current prevailing view, alternative polarization gives rise to a predominantly ligand-insensitive PPARγ:RXR cistrome, regulating progressive/reinforcing macrophage polarization.
2018-06-20 | GSE115085 | GEO
Project description:Macrophages change their phenotype in response to complex (reinforcing or opposing) environmental cues. The molecular components providing the epigenomic basis of progressive or reinforcing polarization are largely unknown. Here we show that the normally ligand-activated nuclear receptor, Peroxisome Proliferator-Activated Receptor gamma (PPARγ), is a predominantly ligand-insensitive, epigenomic driver of a robust phenotypic change in macrophages uniquely upon repeated/reinforcing IL-4 stimulation. Ligand-insensitive PPARγ recruits P300, RAD21 and establishes a permissive chromatin environment, conferring transcriptional memory by facilitating the binding of STAT6 and RNAPII leading to more robust eRNA production upon IL-4 restimulation. PPARγ-mediated transcriptional memory allows the progressive, functional transition of macrophages upon repeated cytokine exposure by controlling the expression of an extracellular matrix remodeling related gene network, also expressed in macrophages from a mouse model of muscle regeneration and show progressive upregulation during the course of regeneration after muscle injury, coinciding with the appearance of IL-4 and PPARγ. Collectively, in contrast to the current prevailing view, alternative polarization gives rise to a predominantly ligand-insensitive PPARγ:RXR cistrome, regulating progressive/reinforcing macrophage polarization.
2018-06-20 | GSE115083 | GEO
Project description:Ligand-insensitive PPARγ controls progressive or reinforcing macrophage polarization as an epigenomic ratchet of transcriptional memory
| PRJNA476688 | ENA
Project description:Stimulation of macrophages with interferon-γ (IFN-γ) and interleukin 4 (IL-4) triggers distinct and opposing activation programs. During mixed infections or cancer, macrophages are often exposed to both cytokines, but how these two programs influence each other remains unclear. We found that IFN-γ and IL-4 mutually inhibited the epigenomic and transcriptional changes induced by each cytokine alone. Computational and functional analyses revealed the genomic bases for gene-specific cross-repression. For instance, while binding motifs for the transcription factors STAT1 and IRF1 were associated with robust and IL-4-resistant responses to IFN-γ, their coexistence with binding sites for auxiliary transcription factors such as AP-1 generated vulnerability to IL-4-mediated inhibition. These data provide a core mechanistic framework for the integration of signals that control macrophage activation in complex environmental conditions.
| S-EPMC5524187 | biostudies-literature
Project description:Macrophages are pleiotropic cells capable of performing a broad spectrum of functions. Macrophage phenotypes are classified along a continuum between the extremes of proinflammatory M1 macrophages and anti-inflammatory M2 macrophages. The seemingly opposing functions of M1 and M2 macrophages must be tightly regulated for an effective and proper response to foreign molecules or damaged tissue. Excessive activation of either M1 or M2 macrophages contributes to the pathology of many diseases. Emodin is a Chinese herb-derived compound and has shown potential to inhibit inflammation in various settings. In this study, we tested the ability of emodin to modulate the macrophage response to both M1 and M2 stimuli. Primary mouse macrophages were stimulated with LPS/IFNγ or IL4 with or without emodin, and the effects of emodin on gene transcription, cell signaling pathways, and histone modifications were examined by a variety of approaches, including microarray, quantitative real-time PCR, Western blotting, chromatin immunoprecipitation, and functional assays. We found that emodin bidirectionally tunes the induction of LPS/IFNγ- and IL4-responsive genes through inhibiting NFκB/IRF5/STAT1 signaling and IRF4/STAT6 signaling, respectively. Thereby, emodin modulates macrophage phagocytosis, migration, and NO production. Furthermore, emodin inhibited the removal of H3K27 trimethylation (H3K27m3) marks and the addition of H3K27 acetylation (H3K27ac) marks on genes required for M1 or M2 polarization of macrophages. In conclusion, our data suggest that emodin is uniquely able to suppress the excessive response of macrophages to both M1 and M2 stimuli and therefore has the potential to restore macrophage homeostasis in various pathologies.
| S-EPMC4882421 | biostudies-literature
Project description:BackgroundSchisandrin B (Sch B), the main ingredient of Schisandra chinensis, displays many bioactivities. This study aimed to identify the drug target of Sch B against liver fibrosis and describe the related molecular mechanisms.MethodsThe effects of Sch B on liver fibrosis and macrophage polarization was investigated in vivo and in vitro. Furthermore, we analyzed the regulatory effect of Sch B on peroxisome proliferator-activated receptor gamma (PPARγ).ResultsOur data showed that Sch B dramatically alleviated liver inflammation and fibrosis and inhibited macrophage activation via PPARγ. Sch B binds with PPARγ by molecular docking. Immunofluorescence double staining showed that PPARγ was mainly expressed in macrophages rather than hepatic stellate cells (HSCs) in liver fibrosis. Importantly, Sch B strongly inhibited macrophage polarization in fibrotic livers compared with the model group. Further, the results revealed that Sch B efficiently inhibited macrophage polarization and also decreased the levels of inflammatory cytokines in vitro. Knockdown of PPARγ by small interfering RNA (siRNA) inhibited the effect of Sch B on macrophage polarization. Mechanistically, Sch B regulated macrophage polarization through inhibition of the nuclear factor (NF)-κB signaling pathway via PPARγ both in vivo and in vitro.ConclusionsThese results suggested that Sch B alleviated carbon tetrachloride (CCl4)-induced liver inflammation and fibrosis by inhibiting macrophage polarization via targeting PPARγ.
| S-EPMC8573433 | biostudies-literature
Project description:Naringin exhibited various pharmacological activities. However, its biological function and underlying mechanism in regulating macrophage polarization remain elusive. This study aimed to investigate the regulatory network between naringin and macrophage polarization in sepsis-induced intestinal injury. Cecal ligation and puncture (CLP) was used to establish the animal model of sepsis. Chromatin immunoprecipitation and a luciferase reporter assay were used to determine the interplay between peroxisome proliferator-activated receptor γ (PPARγ) and miR-21 promoter, as well as miR-21 and its target genes. Naringin enhanced the overall survival of septic mice and alleviated the CLP-induced inflammatory response and intestinal damage. This was accompanied by the increased expression of PPARγ in the intestines and the stimulation of ileal macrophages toward the M2 phenotype. Furthermore, in lipopolysaccharide-stimulated bone marrow-derived macrophages, naringin stimulated M2 polarization. Mechanistically, PPARγ inhibition attenuated the promotion of M2 polarization caused by naringin, and the naringin/PPARγ regulatory work was compromised by miR-21 inhibition. The present study suggested that naringin promoted M2 polarization via the PPARγ/miR-21 axis, thus relieving sepsis-induced intestinal injury. This study provides novel insights into the mechanism by which naringin alleviated sepsis-induced intestinal injury through regulation of macrophage polarization.
| S-EPMC8463290 | biostudies-literature