Efferocytosis Fuels Requirements of Fatty Acid Oxidation and the Electron Transport Chain to Polarize Macrophages for Tissue Repair
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE121681 | GEO | 2018/12/27
REPOSITORIES: GEO
Similar Datasets
Project description: Not available
| S-EPMC6471613 | biostudies-literature
Project description:Efferocytosis Fuels Requirements of Fatty Acid Oxidation and the Electron Transport Chain to Polarize Macrophages for Tissue Repair
| PRJNA498080 | ENA
Project description:Efferocytosis fuels malignant pleural effusion through TIMP1
| PRJNA723335 | ENA
Project description: Not available
| S-EPMC6699831 | biostudies-literature
Project description:Malignant Pleural Effusion (MPE) results from the capacity of several human cancers to metastasize to the pleural cavity. The median survival is 3-12 months and no effective treatments are currently available. Immune-based therapies have failed until now, reflecting our insufficient understanding of the basic immunological mechanisms leading to MPE progression. Here, we show that phagocytosis of apoptotic cells in the pleural cavity fuels the progression of MPE. We found that efferocytosis through the receptor tyrosine kinases AXL and MERTK in macrophages led to the production of IL-10. Using single cell RNA-Seq, we revealed that IL-10 is indeed produced by four distinct pleural cavity macrophage subpopulations characterized by different metabolic states and cell chemotaxis properties. In turn, IL-10 acts on dendritic cells (DCs) inducing the production of tissue inhibitor of metalloproteinases 1 (TIMP1). Genetic ablation of AXL and MERTK in macrophages or IL-10 receptor in DCs or TIMP1 significantly reduced MPE progression. Taken together, our results delineate an inflammatory cascade – from the clearance of apoptotic cells by macrophages, to production of IL-10, to induction of TIMP1 in DCs – that facilitates MPE progression. This inflammatory cascade offers a series of targets for therapies which aim at preventing or treating MPE.
2021-08-24 | GSE172455 | 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
Project description:Although tumor growth requires the mitochondrial electron transport chain (ETC), the relative contribution of Complex I (CI) and II (CII), the gatekeepers for initiating electron flow, remains unclear. Here, we report that loss of CII, but not CI, reduces melanoma tumor growth by increasing antigen presentation and T cell-mediated killing. This is driven by succinate-mediated transcriptional and epigenetic activation of major histocompatibility complex I-antigen processing and presentation (MHC-APP) genes that is independent of interferon signaling. Furthermore, knock-out of MCJ, to promote electron entry preferentially via CI, provides proof-of-concept of ETC rewiring to achieve anti-tumor responses without side effects associated with an overall reduction in mitochondrial respiration in non-cancer cells. Our results hold therapeutic potential for tumors that have reduced MHC-APP expression, a common mechanism of cancer immunoevasion.
2024-05-01 | GSE235311 | GEO
Project description:The NLRP3 inflammasome is linked to sterile and pathogen-dependent inflammation, and its dysregulation underlies many chronic diseases. Mitochondria have been implicated as regulators of NLRP3 inflammasome through multiple mechanisms including generation of mitochondrial ROS. Here we report that mitochondrial electron transport chain (ETC) complexes I, II, III and V inhibitors all prevent NLRP3 inflammasome activation. Ectopic expression of Saccharomyces cerevisiae NADH dehydrogenase (NDI1) or Ciona intestinalis alternative oxidase (AOX), which can respectively complement the functional loss of mitochondrial complex I or III, without generation of ROS, rescued NLRP3 inflammasome activation in the absence of endogenous mitochondrial complex I or complex III function. Metabolomics revealed phosphocreatine (PCr), which can sustain ATP levels, as a common metabolite that is diminished by mitochondrial ETC inhibitors. PCr depletion decreased ATP levels and NLRP3 inflammasome activation. Thus, mitochondrial ETC sustains NLRP3 inflammasome activation through PCr-dependent generation of ATP but a ROS independent mechanism.
2022-03-09 | GSE197606 | GEO
Project description:Poor wound healing due to dysregulated tissue repair responses can exacerbate and prolong disease. Successful tissue repair is critically dependent on the timely clearance of apoptotic cells by macrophages in a process termed efferocytosis. Mechanisms and factors that link these two fundamental processes are therefore of great interest. Herein, we observed that a subset of 12-lipoxygenase (ALOX12)-expressing macrophages upregulate the production of host protective autacoids termed maresin conjugates in tissue regeneration (MCTR) during efferocytosis. MCTRs in turn play autocrine and paracrine functions in enhancing the ability of both ALOX12-positive and surrounding ALOX12-negative macrophages to uptake apoptotic cells. These effects of ALOX12-positive macrophages and MCTRs in regulating apoptotic cells clearance was also observed at sites of high apoptotic cell burden in mouse and flatworm models, as the formation of these mediators was upregulated and abrogation of related ALOX activity in mice reduced the ability of macrophages to clear apoptotic cells. Furthermore, add-back of MCTRs rapidly enhanced the efferocytosis capability of macrophages in mice and planarian flatworms. Mechanistic studies in macrophages revealed that MCTRs modulated Rac1 signalling and glycolytic metabolism, two pathways crucial for effective efferocytosis, and enhanced efferocytosis-induced WNT ligand production. Inhibition of Rac1 abrogated the ability of MCTRs to enhance glucose uptake and efferocytosis in vitro, while inhibiting either Rac1, glycolysis, or WNT ligand production prevented MCTR-mediated enhancement of apoptotic cell clearance and tissue regeneration. Taken together, our findings identify a central role for ALOX12-expressing macrophages in the regulation of efferocytosis and tissue repair via the local formation of MCTRs.
2023-12-12 | PXD038390 | Pride
Project description:The efficient clearance of dead and dying cells, also known as efferocytosis, is critical to maintain tissue homeostasis. In the bone marrow microenvironment (BMME), this role is primarily fulfilled by professional bone marrow macrophages, but recent work has shown that mesenchymal stromal cells (MSCs) act as a non-professional phagocyte within the BMME. However, little is known about the mechanism and impact of efferocytosis on MSCs in the BMME and on their function. To investigate this, we performed flow cytometric analysis of neutrophil uptake by ST2 cells, a murine bone marrow-derived stromal cell line, and in murine primary bone marrow-derived stromal cells. Transcriptional analysis showed that MSCs possess the necessary receptors and internal processing machinery to conduct efferocytosis, with Axl and Tyro3 serving as the main receptors, while MerTK was not expressed. Moreover, the expression of these receptors was modulated by efferocytic behavior, regardless of apoptotic target. MSCs derived from human bone marrow also demonstrated efferocytic behavior, showing that MSC efferocytosis is conserved. In all MSCs, efferocytosis impaired osteoblastic differentiation. Transcriptional analysis and functional assays identified downregulation in MSC mitochondrial function upon efferocytosis. Experimentally, efferocytosis induced mitochondrial fission in MSCs. Pharmacologic inhibition of mitochondrial fission in MSCs not only decreased efferocytic activity but also rescued osteoblastic differentiation, demonstrating that efferocytosis-mediated mitochondrial remodeling plays a critical role in regulating MSC differentiation. This work describes a novel function of MSCs as non-professional phagocytes within the BMME and demonstrates that efferocytosis by MSCs plays a key role in directing mitochondrial remodeling and MSC differentiation. Efferocytosis by MSCs may therefore be a novel mechanism of dysfunction and senescence. Since our data in human MSCs show that MSC efferocytosis is conserved, the consequences of MSC efferocytosis may impact the behavior of these cells in the human skeleton, including osteoporosis in aging.
2023-07-14 | GSE223279 | GEO