Macrophage-enriched Sectm1a promotes efficient efferocytosis to attenuate ischemia/reperfusion-induced cardiac injury
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE253579 | GEO | 2024/01/23
REPOSITORIES: GEO
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Project description:The first macrophages that seed the developing heart originate from the yolk sac during fetal life. While murine studies reveal important homeostatic and reparative functions in adults, we know little about their roles in the earliest stages of human heart development due to a lack of accessible tissue. Generation of bioengineered human cardiac microtissues from pluripotent stem cells models these first steps in cardiac tissue development, however macrophages have not been included in these studies. To bridge these gaps, we differentiated human embryonic stem cells (hESCs) into primitive LYVE1+ macrophages (hESC-macrophages; akin to yolk sac macrophages) that stably engrafted within cardiac microtissues composed of hESC-cardiomyocytes and fibroblasts to study reciprocal interactions. Engraftment induced a tissue resident macrophage gene program resembling human fetal cardiac macrophages, enriched in efferocytic pathways. Functionally, hESC-macrophages induced production and maturation of cardiomyocyte sarcomeric proteins, and enhanced contractile force, relaxation kinetics, and electrical properties. Mechanistically, the primary effect of hESC-macrophages was during the stressful events surrounding early microtissue formation, where they engaged in phosphatidylserine dependent ingestion of apoptotic cardiomyocyte cargo, which reinforced core resident macrophage identity, reduced microtissue stress and drove hESC-cardiomyocytes to become more similar to human ventricular cardiomyocytes found in early development, both transcriptionally and metabolically. Inhibiting efferocytosis of hESC-cardiomyocytes by hESC-macrophages led to increased cell stress, impaired sarcomeric protein maturation and reduced cardiac microtissue function (contraction and relaxation). Taken together, macrophage-engineered human cardiac microtissues represent a considerably improved model for human heart development, and reveal a major beneficial, yet previously unappreciated role for human primitive macrophages in enhancing cardiac tissue function.
2024-04-03 | PXD050996 | Pride
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: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 first macrophages that seed the developing heart originate from the yolk sac during fetal life. While murine studies reveal important homeostatic and reparative functions in adults, we know little about their roles in the earliest stages of human heart development due to a lack of accessible tissue. Generation of bioengineered human cardiac microtissues from pluripotent stem cells models these first steps in cardiac tissue development, however macrophages have not been included in these studies. To bridge these gaps, we differentiated human embryonic stem cells (hESCs) into primitive LYVE1+ macrophages (hESC-macrophages; akin to yolk sac macrophages) that stably engrafted within cardiac microtissues composed of hESC-cardiomyocytes and fibroblasts to study reciprocal interactions. Engraftment induced a tissue resident macrophage gene program resembling human fetal cardiac macrophages, enriched in efferocytic pathways. Functionally, hESC-macrophages induced production and maturation of cardiomyocyte sarcomeric proteins, and enhanced contractile force, relaxation kinetics, and electrical properties. Mechanistically, the primary effect of hESC-macrophages was during the stressful events surrounding early microtissue formation, where they engaged in phosphatidylserine dependent ingestion of apoptotic cardiomyocyte cargo, which reinforced core resident macrophage identity, reduced microtissue stress and drove hESC-cardiomyocytes to become more similar to human ventricular cardiomyocytes found in early development, both transcriptionally and metabolically. Inhibiting efferocytosis of hESC-cardiomyocytes by hESC-macrophages led to increased cell stress, impaired sarcomeric protein maturation and reduced cardiac microtissue function (contraction and relaxation). Taken together, macrophage-engineered human cardiac microtissues represent a considerably improved model for human heart development, and reveal a major beneficial, yet previously unappreciated role for human primitive macrophages in enhancing cardiac tissue function.
2024-04-03 | PXD050990 | Pride
Project description:Efferocytosis triggers cellular reprogramming, including the induction of mRNA transcripts which encode anti-inflammatory cytokines that promote inflammation resolution. Our current understanding of this transcriptional response is largely informed from analysis of bulk phagocyte populations; however, this precludes the resolution of heterogeneity between individual macrophages and macrophage subsets. Moreover, phagocytes may contain so called “passenger” transcripts that originate from engulfed apoptotic bodies, thus obscuring the true transcriptional reprogramming of the phagocyte. To define the transcriptional diversity during efferocytosis, we utilized single-cell mRNA sequencing after co-cultivating macrophages with apoptotic cells. Importantly, transcriptomic analyses were performed after validating the disappearance of apoptotic cell-derived RNA sequences. Our findings reveal new heterogeneity of the efferocytic response at a single-cell resolution, particularly evident between F4/80+ MHCIILO and F4/80- MHCIIHI macrophage sub-populations. After exposure to apoptotic cells, the F4/80+ MHCIILO subset significantly induced pathways associated with tissue and cellular homeostasis, while the F4/80- MHCIIHI subset downregulated these putative signaling axes. Ablation of a canonical efferocytosis receptor, MerTK, blunted efferocytic signatures and led to the escalation of cell death-associated transcriptional signatures in F4/80+ MHCIILO macrophages. Taken together, our results newly elucidate the heterogenous transcriptional response of single-cell peritoneal macrophages after exposure to apoptotic cells.
2020-08-22 | GSE156234 | GEO
Project description:Apoptotic cell clearance (efferocytosis), a process essential for organismal homeostasis, is performed by phagocytes that inhabit a wide range of environments, including physiologic hypoxia. Here, we find macrophages, the predominant tissue-resident phagocyte, display enhanced efferocytosis under chronic hypoxia, characterized by increased internalization and accelerated degradation of apoptotic cells. Analysis of mRNA and protein programs revealed that chronic hypoxia induces two distinct but complimentary states in macrophages. The first, ‘primed’ state consists of concomitant induction of transcriptional and translational programs broadly associated with metabolism in apoptotic cell-naïve macrophages that persist during efferocytosis. The second, ‘poised’ state consists of transcription, but not translation, of phagocyte function programs in apoptotic cell-naïve macrophages that are subsequently translated during efferocytosis. We discovered that one such primed state consists of the efficient flux of glucose into a noncanonical pentose phosphate pathway (PPP) loop, whereby PPP-derived intermediates cycle back through the PPP to enhance production of NADPH. Mechanistically, we found that PPP-derived NADPH directly supports enhanced efferocytosis under chronic hypoxia via its role in phagolysosomal maturation, while simultaneously maintaining cellular redox homeostasis. Thus, macrophages adapt to chronic hypoxia by adopting states that both support cell fitness and ensure ability to rapidly and safely perform essential homeostatic functions.
2022-12-30 | GSE192969 | GEO
Project description:The first macrophages that seed the developing heart originate from the yolk sac during fetal life. While murine studies reveal important homeostatic and reparative functions in adults, we know little about their roles in the earliest stages of human heart development due to a lack of accessible tissue. Generation of bioengineered human cardiac microtissues from pluripotent stem cells models these first steps in cardiac tissue development, however macrophages have not been included in these studies. To bridge these gaps, we differentiated human embryonic stem cells (hESCs) into primitive LYVE1+ macrophages (hESC-macrophages; akin to yolk sac macrophages) that stably engrafted within cardiac microtissues composed of hESC-cardiomyocytes and fibroblasts to study reciprocal interactions. Engraftment induced a tissue resident macrophage gene program resembling human fetal cardiac macrophages, enriched in efferocytic pathways. Functionally, hESC-macrophages induced production and maturation of cardiomyocyte sarcomeric proteins, and enhanced contractile force, relaxation kinetics, and electrical properties. Mechanistically, the primary effect of hESC-macrophages was during early microtissue formation, where they engaged in phosphatidylserine dependent ingestion of apoptotic cardiomyocyte cargo, which reinforced core resident macrophage identity, reduced microtissue stress and drove hESC-cardiomyocytes to become more similar to human ventricular cardiomyocytes found in early development, both transcriptionally and metabolically. Inhibiting efferocytosis of hESC-cardiomyocytes by hESC-macrophages led to increased cell stress, impaired sarcomeric protein maturation and reduced cardiac microtissue function (contraction and relaxation). Taken together, macrophage-engineered human cardiac microtissues represent a considerably improved model for human heart development, and reveal a major beneficial, yet previously unappreciated role for human primitive macrophages in enhancing cardiac tissue function.
2024-04-02 | GSE261628 | GEO
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:We performed a FACS-based genome-wide CRISPR knockout screen in primary murine macrophages to identify regulators of efferocytosis, the phagocytic clearance of dying cells. The screen identified known and novel regulators of macrophage efferocytosis. More broadly, the screen approach can be applied to interrogate complex functional phenotypes in primary macrophages.
2022-11-23 | GSE212008 | GEO
Project description:Clearance of apoptotic cancer cells by macrophages, known as efferocytosis, fuels the bone-metastatic growth of prostate cancer cells via pro-inflammatory and immunosuppressive mechanisms that are still unclear. In this study, single-cell transcriptomics of bone marrow macrophages undergoing efferocytosis of apoptotic prostate cancer cells revealed a significant enrichment of a cellular response to hypoxia. Here we show that efferocytic macrophages promote HIF-1α stabilization under normoxic conditions through interaction with phosphorylated STAT3. Inflammatory cytokine gene expression analysis of efferocytic HIF-1α-mutant macrophages revealed a reduced expression of the pro-tumorigenic Mif. Furthermore, stabilization of HIF-1α using the HIF-prolyl-hydroxylase inhibitor, Roxadustat, enhanced MIF expression in macrophages. Finally, macrophages treated with recombinant MIF protein activated NF-κB (p65) signaling increased the expression of pro-inflammatory cytokines. Altogether, these findings suggest that the clearance of apoptotic cancer cell by tumor-associated macrophages triggers p-STAT3/HIF-1α/MIF signaling to enhance tumor-promoting inflammation in bone, suggesting this axis as a target for metastatic prostate cancer.
2022-12-14 | GSE180638 | GEO