Pro-efferocytic nanotherapies reduce vascular inflammation without inducing anemia in a large animal model of atherosclerosis
Ontology highlight
ABSTRACT:
ORGANISM(S): Sus scrofa
PROVIDER: GSE270259 | GEO | 2024/06/24
REPOSITORIES: GEO
Similar Datasets
Project description:Fragile X Mental Retardation protein (FMRP), widely known for its role in hereditary intellectual disability, is an RNA-binding protein (RBP) that controls translation of select mRNAs. We discovered that endoplasmic reticulum (ER) stress induces phosphorylation of FMRP on a site that is known to enhance translation inhibition of FMRP-bound mRNAs. We show ER stress-induced activation of Inositol requiring enzyme-1 (IRE1), an ER-resident stress-sensing kinase/endoribonuclease, leads to FMRP phosphorylation and to suppression of macrophage cholesterol efflux and apoptotic cell clearance (efferocytosis). Conversely, FMRP-deficiency and pharmacological inhibition of IRE1 kinase activity enhances cholesterol efflux and efferocytosis, reducing atherosclerosis in mice. Our results provide mechanistic insights into how ER stress-induced IRE1 kinase activity contributes to macrophage cholesterol homeostasis and suggest IRE1 inhibition as a promising new way to counteract atherosclerosis.
2022-02-15 | PXD030594 | Pride
Project description:Macrophages can adjust their phenotype and function in response to environmental cues, such as encountering apoptotic cells or pathogens. After tissue injury or inflammation, macrophages must successively engulf and process multiple apoptotic corpses (via efferocytosis) to achieve tissue homeostasis. How macrophages may rapidly adapt their transcription to achieve continued corpse uptake is incompletely understood. Transcriptional pause/release is an evolutionarily conserved process wherein RNA polymerase II (Pol II), after initiating transcription for 20-60 nucleotides, gets ‘paused’ for seconds to hours; paused Pol II then gets ‘released’ to complete transcription to make full-length mRNA. Here we show that macrophages, within minutes of corpse encounter, use transcriptional pause/release as a mechanism to unleash a rapid transcriptional response. For human and murine macrophages, the Pol II pause/release was crucial for continued efferocytosis of corpses in vitro and in vivo. Interestingly, blocking Pol II pause/release did not impede FcR-mediated phagocytosis, yeast uptake, or bacterial phagocytosis. Integrating data from three complementary genomic approaches of PRO-seq, RNA-seq, and ATAC-seq on efferocytic macrophages at different time points, we found that Pol II pause/release controls expression of select transcription factors and downstream target genes. Further mechanistic studies on transcription factor Egr3, one of the genes prominently affected by pause/release, uncovered Egr3-related reprogramming of macrophage genes involved in cytoskeleton and corpse processing. Via lysosomal probes and a newly designed genetic fluorescent reporter, we identify a key role for pause/release in phagosome acidification during efferocytosis. Further, microglia from egr3-deficient zebrafish embryos displayed reduced phagocytosis of apoptotic neurons and fewer maturing endosomes, supporting a defect in corpse processing. Collectively, these data advance a novel concept that macrophages use Polymerase II pause/release as a mechanism to rapidly alter their transcriptional programs for efficient processing of the ingested apoptotic corpse and for successive efferocytosis.
2024-01-25 | GSE253574 | GEO
Project description:Macrophages can adjust their phenotype and function in response to environmental cues, such as encountering apoptotic cells or pathogens. After tissue injury or inflammation, macrophages must successively engulf and process multiple apoptotic corpses (via efferocytosis) to achieve tissue homeostasis. How macrophages may rapidly adapt their transcription to achieve continued corpse uptake is incompletely understood. Transcriptional pause/release is an evolutionarily conserved process wherein RNA polymerase II (Pol II), after initiating transcription for 20-60 nucleotides, gets ‘paused’ for seconds to hours; paused Pol II then gets ‘released’ to complete transcription to make full-length mRNA. Here we show that macrophages, within minutes of corpse encounter, use transcriptional pause/release as a mechanism to unleash a rapid transcriptional response. For human and murine macrophages, the Pol II pause/release was crucial for continued efferocytosis of corpses in vitro and in vivo. Interestingly, blocking Pol II pause/release did not impede FcR-mediated phagocytosis, yeast uptake, or bacterial phagocytosis. Integrating data from three complementary genomic approaches of PRO-seq, RNA-seq, and ATAC-seq on efferocytic macrophages at different time points, we found that Pol II pause/release controls expression of select transcription factors and downstream target genes. Further mechanistic studies on transcription factor Egr3, one of the genes prominently affected by pause/release, uncovered Egr3-related reprogramming of macrophage genes involved in cytoskeleton and corpse processing. Via lysosomal probes and a newly designed genetic fluorescent reporter, we identify a key role for pause/release in phagosome acidification during efferocytosis. Further, microglia from egr3-deficient zebrafish embryos displayed reduced phagocytosis of apoptotic neurons and fewer maturing endosomes, supporting a defect in corpse processing. Collectively, these data advance a novel concept that macrophages use Polymerase II pause/release as a mechanism to rapidly alter their transcriptional programs for efficient processing of the ingested apoptotic corpse and for successive efferocytosis.
2024-01-25 | GSE253577 | GEO
Project description:Macrophages can adjust their phenotype and function in response to environmental cues, such as encountering apoptotic cells or pathogens. After tissue injury or inflammation, macrophages must successively engulf and process multiple apoptotic corpses (via efferocytosis) to achieve tissue homeostasis. How macrophages may rapidly adapt their transcription to achieve continued corpse uptake is incompletely understood. Transcriptional pause/release is an evolutionarily conserved process wherein RNA polymerase II (Pol II), after initiating transcription for 20-60 nucleotides, gets ‘paused’ for seconds to hours; paused Pol II then gets ‘released’ to complete transcription to make full-length mRNA. Here we show that macrophages, within minutes of corpse encounter, use transcriptional pause/release as a mechanism to unleash a rapid transcriptional response. For human and murine macrophages, the Pol II pause/release was crucial for continued efferocytosis of corpses in vitro and in vivo. Interestingly, blocking Pol II pause/release did not impede FcR-mediated phagocytosis, yeast uptake, or bacterial phagocytosis. Integrating data from three complementary genomic approaches of PRO-seq, RNA-seq, and ATAC-seq on efferocytic macrophages at different time points, we found that Pol II pause/release controls expression of select transcription factors and downstream target genes. Further mechanistic studies on transcription factor Egr3, one of the genes prominently affected by pause/release, uncovered Egr3-related reprogramming of macrophage genes involved in cytoskeleton and corpse processing. Via lysosomal probes and a newly designed genetic fluorescent reporter, we identify a key role for pause/release in phagosome acidification during efferocytosis. Further, microglia from egr3-deficient zebrafish embryos displayed reduced phagocytosis of apoptotic neurons and fewer maturing endosomes, supporting a defect in corpse processing. Collectively, these data advance a novel concept that macrophages use Polymerase II pause/release as a mechanism to rapidly alter their transcriptional programs for efficient processing of the ingested apoptotic corpse and for successive efferocytosis.
2024-01-25 | GSE253576 | GEO
Project description:Efficient clearance and degradation of apoptotic cardiomyocytes by macrophages (termed efferocytosis) are critical for inflammation resolution and restoration of cardiac function after myocardial ischemia/reperfusion (I/R). Here, we define secreted and transmembrane protein 1a (Sectm1a), a cardiac macrophage-enriched gene, as a modulator of macrophage efferocytosis in I/R hearts. Upon myocardial I/R, Sectm1a-KO mice exhibit impaired macrophage efferocytosis, leading to massive accumulation of apoptotic cardiomyocytes, cardiac inflammation, fibrosis, and consequently, exaggerated cardiac dysfunction. By contrast, therapeutic administration of recombinant SECTM1A protein significantly enhances macrophage efferocytosis and improves cardiac function. Mechanistically, SECTM1A can elicit autocrine effects on the activation of glucocorticoid-induced TNF receptor (GITR) at the surface of macrophages, leading to the upregulation of liver X receptor alpha (LXRα) and its downstream efferocytosis-related genes and lysosomal enzyme genes. Our study suggests that Sectm1a-mediated activation of Gitr/LXRα axis could be a promising approach to enhance macrophage efferocytosis for the treatment of myocardial I/R injury.
2024-01-23 | GSE253579 | GEO
Project description:Macrophages are a functionally heterogeneous cell population, critical for the clearance of apoptotic cells. Apoptotic cells have so far been regarded as cells with homogeneous characteristics, often neglecting their original cell lineage identity. Contrary to this, we have observed that the identities of apoptotic cells matter, since they diversify the profile of efferocytic macrophages in vitro and in mouse models of tissue damage. Apoptotic neutrophils trigger a tissue remodeling macrophage signature, while T cells and hepatocytes respectively do not change or promote a tolerogenic macrophage response. Accordingly, the in vivo transfer of macrophages fed with apoptotic neutrophils, but not the transfer of macrophages fed with other apoptotic cells, promotes tissue remodeling. Finally, using a mouse model of parasite-induced tissue pathology, we found that the presence of specific apoptotic cells while simultaneously engaging select phagocytic receptors, i.e. AXL and MERTK by apoptotic neutrophils, diversifies macrophage function. These data reveal that the identity of an apoptotic cell should not be neglected since it drives macrophage transcriptomic and functional heterogeneity.
2024-02-16 | E-MTAB-13780 | biostudies-arrayexpress
Project description:Macrophages are a functionally heterogeneous cell population, critical for the clearance of apoptotic cells. Apoptotic cells have so far been regarded as cells with homogeneous characteristics, often neglecting their original cell lineage identity. Contrary to this, we have observed that the identities of apoptotic cells matter, since they diversify the profile of efferocytic macrophages in vitro and in mouse models of tissue damage. Apoptotic neutrophils trigger a tissue remodeling macrophage signature, while T cells and hepatocytes respectively do not change or promote a tolerogenic macrophage response. Accordingly, the in vivo transfer of macrophages fed with apoptotic neutrophils, but not the transfer of macrophages fed with other apoptotic cells, promotes tissue remodeling. Finally, using a mouse model of parasite-induced tissue pathology, we found that the presence of specific apoptotic cells while simultaneously engaging select phagocytic receptors, i.e. AXL and MERTK by apoptotic neutrophils, diversifies macrophage function. These data reveal that the identity of an apoptotic cell should not be neglected since it drives macrophage transcriptomic and functional heterogeneity.
2024-02-16 | E-MTAB-13753 | biostudies-arrayexpress
Project description:Macrophages rely on tightly integrated metabolic rewiring to clear dying neighboring cells by efferocytosis during homeostasis and disease. Here, we reveal that glutaminase (GLS) 1-mediated glutaminolysis is critical to promote apoptotic cell clearance by macrophages during homeostasis in mice. In addition, impaired macrophage glutaminolysis exacerbates atherosclerosis, a condition during which efficient apoptotic cell debris clearance is critical to limit disease progression. Gls1 expression strongly correlates with atherosclerotic plaque necrosis in patients with cardiovascular diseases. High-throughput transcriptional and metabolic profiling revealed that macrophage efferocytic capacity relies on a non-canonical transaminase pathway, independent from the traditional requirement of glutamate dehydrogenase (GLUD1) to fuel ɑ-ketogulatrate-dependent immunometabolism. This pathway is necessary to meet the unique requirements of efferocytosis for cellular detoxification and high energy cytoskeletal rearrangements. Thus, we uncovered a novel role for non-canonical glutamine metabolism for efficient clearance of dying cells and maintenance of tissue homeostasis during health and disease in mouse and humans
2021-12-31 | GSE183176 | GEO
Project description:Defects in apoptotic cell clearance, or efferocytosis, can cause inflammatory diseases and prevent tissue repair due in part, to a key role of efferocytosis in inducing a pro-repair transcriptional program in phagocytic cells like macrophages. While the cellular machinery and metabolic pathways involved in efferocytosis have been characterized, the precise efferocytic response of macrophages is dependent on the identity and macromolecular cues of apoptotic cells, and the complex tissue microenvironment in which efferocytosis occurs. Here, we find that macrophages undergoing active efferocytosis in mid-stage mouse skin wounds in vivo display a pro-repair gene program, while efferocytosis of apoptotic skin fibroblasts in vitro induces an immature/inflammatory transcription response. These data provide a resource for understanding how the skin wound niche influences macrophage efferocytosis and will be useful for future investigations that define the role of efferocytosis during tissue repair
2024-08-06 | GSE273754 | GEO
Project description:Inflammation is a physiopathological process triggered by infection or tissue damage. Immune system initiates coordinated sequential steps in response to these danger signals. Once the threat has been contained inflammation has to be subsequently shut down. Inflammation resolution is initiated by the reprogramming of pro-inflammatory macrophages toward a pro-resolving profile. This reprogramming is induced in particular by the non-phlogistic engulfment of apoptotic cells, mostly apoptotic neutrophils, a process called efferocytosis. As a matter of fact, macrophages are an essential linchpin regulating both inflammation triggering and sustaining and inflammation resolution. This duality can be achieved through the tremendous plasticity of these innate immune cells. Indeed, depending on microenvironmental signals (cytokines, efferocytosis, growth factors…) macrophages can adopt numerous diverse and sometimes antagonistic phenotypes. The mechanisms governing these transitions remain relatively scattered especially in human. With this project we propose to explore the mechanisms involved in human macrophage reprogramming toward a pro-resolving profile after efferocytosis. The stakes are high due to the estimated prevalence of chronic inflammatory diseases in Western society is 5 to 7%. Chronic inflammation is a burden to patient due to life-long debilitating illness and increased mortality and is also a burden to society due to high costs for therapy and care. Finding new therapies to limit chronic inflammation establishment and persistence is thus a highly valuable goal.
2021-12-01 | E-MTAB-8885 | biostudies-arrayexpress