scholarly journals C/EBPα initiates primitive myelopoiesis in pluripotent embryonic cells

Blood ◽  
2009 ◽  
Vol 114 (1) ◽  
pp. 40-48 ◽  
Author(s):  
Yaoyao Chen ◽  
Ricardo M. B. Costa ◽  
Nick R. Love ◽  
Ximena Soto ◽  
Martin Roth ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Embryonic Cells ◽  
Single Factor ◽  
Pluripotent Cells ◽  
Highly Active ◽  
Vertebrate Embryos ◽  
Necessary And Sufficient

Abstract The molecular mechanisms that underlie the development of primitive myeloid cells in vertebrate embryos are not well understood. Here we characterize the role of cebpa during primitive myeloid cell development in Xenopus. We show that cebpa is one of the first known hematopoietic genes expressed in the embryo. Loss- and gain-of-function studies show that it is both necessary and sufficient for the development of functional myeloid cells. In addition, we show that cebpa misexpression leads to the precocious induction of myeloid cell markers in pluripotent prospective ectodermal cells, without the cells transitioning through a general mesodermal state. Finally, we use live imaging to show that cebpa-expressing cells exhibit many attributes of terminally differentiated myeloid cells, such as highly active migratory behavior, the ability to quickly and efficiently migrate toward wounds and phagocytose bacteria, and the ability to enter the circulation. Thus, C/EPBα is the first known single factor capable of initiating an entire myelopoiesis pathway in pluripotent cells in the embryo.

Abstract 341: Protective Role of Myeloid Cell-specific Erbb3 Signaling After Transverse Aortic Constriction

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Haifeng Yin ◽  
Amanda J Lessard ◽  
Joanne T deKay ◽  
Yodit Herrmann ◽  
Michael P Robich ◽  
...  
Keyword(s):  
Heart Failure ◽  
Molecular Mechanisms ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Protective Role ◽  
Transverse Aortic Constriction ◽  
Aortic Constriction ◽  
Cardiac Progenitors ◽  
Erbb3 Signaling

Introduction: Understanding molecular mechanisms underlying cardiac hypertrophy is crucial for protecting against cardiac remodeling, or slowing down its destined pathway to heart failure. Recent studies revealed that myeloid cells play an important role in the regulation of hypertrophic remodeling. Neuregulin-1 (NRG-1) has been shown to play an essential role in the regulation of tissue-protective and pro-survival processes in response to tissue injury in the cardiovascular system. We find that NRG-1 receptors, including ErbB2 and ErbB3, are expressed and functionally active in cardiac myeloid cells. We hypothesized that the NRG-1/ErbB3 signaling in myeloid cells plays a protective role in cardiac hypertrophic remodeling. To test this hypothesis, we examined the effect of Erbb3 gene ablation in mouse myeloid cells on cardiac hypertrophic remodeling induced by pressure overload. Methods and results: Myeloid-specific ErbB3-deficient mice (ErbB3 MyeKO ) were generated by crossing Erbb3 -floxed mice with LysM-Cre transgenic mice. Cardiac hypertrophic remodeling was established in mice by transverse aortic constriction (TAC). Five days after TAC, survival was dramatically reduced in male ErbB3 MyeKO mice (20% vs. 90%, p=0.021 , MyeKO vs. MyeWT). The post-mortem examination of lung weight to body weight ratio suggested that acute pulmonary edema was developed in ERBB3 MyeKO mice. In order to determine the cellular and molecular mechanisms involved in the increased mortality in ErbB3 MyeKO males, cardiac cell populations were examined at day 3 post-TAC using flow cytometry. A significant accumulation of myeloid cells was found in control but not in ErbB3 MyeKO males. This was accompanied by increased proliferation of Sca-1 positive non-immune cells (endothelial cells and cardiac progenitors) in control but not ErbB3 MyeKO males. An antibody-based protein array analysis revealed that IGF-1 expression was significantly downregulated only in ErbB3 MyeKO males after TAC. Conclusion: Our data highlight the important role of myeloid cell-specific ErbB3 signaling in the accumulation of myeloid cells that contributes to the development of compensatory hypertrophy and the prevention of acute heart failure in male mice.

scholarly journals miR-146a is a significant brake on autoimmunity, myeloproliferation, and cancer in mice

2011 ◽  
Vol 208 (6) ◽  
pp. 1189-1201 ◽  
Author(s):  
Mark P. Boldin ◽  
Konstantin D. Taganov ◽  
Dinesh S. Rao ◽  
Lili Yang ◽  
Jimmy L. Zhao ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Immune Cell ◽  
Myeloid Cell ◽  
Genetically Engineered ◽  
Biological Processes ◽  
Targeted Deletion ◽  
Genetically Engineered Mice ◽  
Immune Defects ◽  
Molecular Brake

Excessive or inappropriate activation of the immune system can be deleterious to the organism, warranting multiple molecular mechanisms to control and properly terminate immune responses. MicroRNAs (miRNAs), ∼22-nt-long noncoding RNAs, have recently emerged as key posttranscriptional regulators, controlling diverse biological processes, including responses to non-self. In this study, we examine the biological role of miR-146a using genetically engineered mice and show that targeted deletion of this gene, whose expression is strongly up-regulated after immune cell maturation and/or activation, results in several immune defects. Collectively, our findings suggest that miR-146a plays a key role as a molecular brake on inflammation, myeloid cell proliferation, and oncogenic transformation.

scholarly journals Endothelial cell-derived CD95 ligand serves as a chemokine in induction of neutrophil slow rolling and adhesion

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Liang Gao ◽  
Gülce Sila Gülcüler ◽  
Lieke Golbach ◽  
Helena Block ◽  
Alexander Zarbock ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Molecular Mechanisms ◽  
Inflammatory Diseases ◽  
Cecal Ligation ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Flow Chamber ◽  
Integrin Activation ◽  
Cd95 Ligand ◽  
Slow Rolling

Integrin activation is crucial for the regulation of leukocyte rolling, adhesion and trans-vessel migration during inflammation and occurs by engagement of myeloid cells through factors presented by inflamed vessels. However, endothelial-dependent mechanisms of myeloid cell recruitment are not fully understood. Here we show using an autoperfused flow chamber assay of whole blood neutrophils and intravital microscopy of the inflamed cremaster muscle that CD95 mediates leukocyte slow rolling, adhesion and transmigration upon binding of CD95-ligand (CD95L) that is presented by endothelial cells. In myeloid cells, CD95 triggers activation of Syk-Btk/PLCγ2/Rap1 signaling that ultimately leads to integrin activation. Excitingly, CD95-deficient myeloid cells exhibit impaired bacterial clearance in an animal model of sepsis induced by cecal ligation and puncture (CLP). Our data identify the cellular and molecular mechanisms underlying the chemoattractant effect of endothelial cell-derived CD95L in induction of neutrophil recruitment and support the use of therapeutic inhibition of CD95’s activity in inflammatory diseases.

scholarly journals Amphiregulin Aggravates Glomerulonephritis via Recruitment and Activation of Myeloid Cells

2020 ◽  
Vol 31 (9) ◽  
pp. 1996-2012 ◽  
Author(s):  
Simon Melderis ◽  
Julia Hagenstein ◽  
Matthias Tobias Warkotsch ◽  
Julien Dang ◽  
Georg Rudolf Herrnstadt ◽  
...  
Keyword(s):  
Egf Receptor ◽  
Inflammatory Diseases ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Antibody Treatment ◽  
Treatment Dose ◽  
Egfr Ligand ◽  
Significant Amelioration ◽  
M1 Phenotype

BackgroundRecent studies have identified the EGF receptor (EGFR) ligand amphiregulin (AREG) as an important mediator of inflammatory diseases. Both pro- and anti-inflammatory functions have been described, but the role of AREG in GN remains unknown.MethodsThe nephrotoxic nephritis model of GN was studied in AREG−/− mice after bone marrow transplantation, and in mice with myeloid cell–specific EGFR deficiency. Therapeutic utility of AREG neutralization was assessed. Furthermore, AREG's effects on renal cells and monocytes/macrophages (M/M) were analyzed. Finally, we evaluated AREG expression in human renal biopsies.ResultsRenal AREG mRNA was strongly upregulated in murine GN. Renal resident cells were the most functionally relevant source of AREG. Importantly, the observation that knockout mice showed significant amelioration of disease indicates that AREG is pathogenic in GN. AREG enhanced myeloid cell responses via inducing chemokine and colony stimulating factor 2 (CSF2) expression in kidney resident cells. Furthermore, AREG directly skewed M/M to a proinflammatory M1 phenotype and protected them from apoptosis. Consequently, anti-AREG antibody treatment dose-dependently ameliorated GN. Notably, selective abrogation of EGFR signaling in myeloid cells was sufficient to protect against nephritis. Finally, strong upregulation of AREG expression was also detected in kidneys of patients with two forms of crescentic GN.ConclusionsAREG is a proinflammatory mediator of GN via (1) enhancing renal pathogenic myeloid cell infiltration and (2) direct effects on M/M polarization, proliferation, and cytokine secretion. The AREG/EGFR axis is a potential therapeutic target for acute GN.

Activation of Triggering Receptor Expressed on Myeloid Cells-1 Protects Monocyte from Apoptosis through Regulation of Myeloid Cell Leukemia-1

2013 ◽  
Vol 118 (5) ◽  
pp. 1140-1149 ◽  
Author(s):  
MeiTing Cai ◽  
QiXing Chen ◽  
Chi Chen ◽  
XiWang Liu ◽  
JinChao Hou ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Cell Leukemia ◽  
Proinflammatory Response ◽  
Extracellular Signal Regulated Kinase ◽  
Viral Oncogene ◽  
Extracellular Signal ◽  
Monocyte Apoptosis ◽  
Oncogene Homologue

Abstract Background: Triggering receptor expressed on myeloid cells-1 (TREM-1) can amplify the proinflammatory response and may contribute to the pathogenesis of inflammatory disease such as sepsis. However, the role of TREM-1 in monocyte fate and the detailed molecular mechanisms evoked by TREM-1 are unknown. Methods: Adenoviruses overexpressing TREM-1 were constructed and transfected into a monocytic cell line. After activation of TREM-1 by agonist antibody with or without lipopolysaccharide, apoptosis was induced and assayed using flow cytometry. The signaling pathways downstream of TREM-1 were illustrated by inhibitory experiments. Proapoptotic/antiapoptotic protein levels were measured using immunoblot. In addition, the relationship between the expression levels of TREM-1 in monocytes and the magnitude of monocyte apoptosis were analyzed in septic patients. Results: Activation of TREM-1 protected monocytes from staurosporine-induced apoptosis. This characteristic was also obtained under lipopolysaccharide stimulation. The protection of TREM-1 against monocyte apoptosis was abrogated after inhibition of extracellular signal–regulated kinase or v-akt murine thymoma viral oncogene homologue signaling. Cross-linking of TREM-1 remarkably up-regulated myeloid cell leukemia-1 protein level, and inhibition of extracellular signal–regulated kinase or v-akt murine thymoma viral oncogene homologue resulted in the reduction of myeloid cell leukemia-1 expression. Inhibition of myeloid cell leukemia-1 abolished the antiapoptotic effect of TREM-1. Furthermore, in septic patients, TREM-1 levels were inversely correlated to the magnitude of apoptosis in monocyte. Conclusions: TREM-1 played an important role in apoptosis in monocytes. Activation of TREM-1 protected monocytic cells from apoptosis through activation of both extracellular signal–regulated kinase and v-akt murine thymoma viral oncogene homologue pathways and increased expression of myeloid cell leukemia-1 protein. These findings provide a novel additional mechanism for TREM-1–mediated hyperinflammatory response in monocytes.

Glial differentiation and the Gcm pathway

2007 ◽  
Vol 3 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Laurent Soustelle ◽  
Angela Giangrande
Keyword(s):  
Developmental Biology ◽  
Nervous System ◽  
Neural Development ◽  
Molecular Mechanisms ◽  
Stem Cell Differentiation ◽  
Molecular Pathways ◽  
Glial Differentiation ◽  
Cell Diversity ◽  
Necessary And Sufficient

AbstractOne of the most challenging issues in developmental biology is to understand how cell diversity is generated. The Drosophila nervous system provides a model of choice for unraveling this process. First, many neural stem cells and lineages have been identified. Second, major molecular pathways involved in neural development and associated mutations have been characterized extensively in recent years. In this review, we focus on the cellular and molecular mechanisms underlying the generation of glia. This cell population relies on the expression of gcm fate determinant, which is necessary and sufficient to induce glial differentiation. We also discuss the recently identified role of gcm genes in Drosophila melanogaster and vertebrate neurogenesis. Finally, we will consider the Gcm pathway in the context of neural stem cell differentiation.

Abstract 641: The Role of Interleukin-23 in the Development of Atherosclerosis

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Aliia Fatkhullina ◽  
Iuliia Peshkova ◽  
Ekaterina Koltsova
Keyword(s):  
T Cells ◽  
Cell Function ◽  
Inflammatory Diseases ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Chronic Inflammatory Disease ◽  
Lymphoid Cells ◽  
Efficient Manner ◽  
Mediators Of Inflammation

Atherosclerosis is lipid-driven chronic inflammatory disease of the arterial wall mediated by innate and adaptive immune responses. Inflammation promotes the development atherosclerotic plaques. Cytokines are soluble mediators of inflammation and important players in the pathogenesis of atherosclerosis. IL-23, a cytokine of IL-6/IL-12 cytokines superfamily is produced by myeloid cells and regulates the production of IL-17 and IL-22 by T helper IL-17 producing (Th17) cells, innate lymphoid cells of type 3 (ILC3) and gamma delta T cells in various auto-inflammatory diseases. IL-23R expression was also detected on myeloid cells but its role in regulation of myeloid cell function is not well defined. The level of IL-23 was shown to be upregulated in cardiovascular pathologies. Therefore, we decided to address the role of IL-23 in atherosclerosis using Il23p19 and Il23(R) receptor deficient mice. Surprisingly, atherosclerosis prone, Ldlr -/- mice transplanted with Il23p19 -/- or Il23r -/- bone marrow and fed with Western diet (WD) for 14 weeks demonstrated acceleration of atherosclerosis progression, which was characterized by increased accumulation of various hematopoietic cells in the aortas. Analysis of cytokine production unexpectedly revealed no changes in IL-17A and IFN-gamma production among CD4 T cells in the aortas. This effect was specific to aortas, as IL-17A production in the intestine of Il23p19 -/- mice was reduced, similarly to previously published observations. On the other hand, macrophages from Il23p19 -/- mice were able to uptake oxLDL in more efficient manner compared to wt controls, suggesting the regulatory role of IL-23 in foam cells formation. We also found enhanced inflammatory gene expression in aortas of Il23p19 -/- -> Ldlr -/- and Il23r -/- -> Ldlr -/- mice compared to wt controls. Overall our data suggest IL-17 independent atheroprotective role of IL-23.

Abstract 590: Loss of Myeloid Cell Prostaglandin E Receptor 4 Does Not Alter Diabetes-Accelerated Atherosclerosis in a Murine Model of Type 1 Diabetes

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Sara N Vallerie ◽  
Farah Kramer ◽  
Jenny E Kanter ◽  
Shelley Barnhart ◽  
Richard M Breyer ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Mouse Model ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Prostaglandin E ◽  
Lesion Area ◽  
Accelerated Atherosclerosis ◽  
Anti Inflammatory

Diabetes is associated with an increased risk of cardiovascular disease, largely due to increased atherosclerosis. Our studies have suggested myeloid cell prostaglandin E 2 (PGE 2 ) production as a possible mediator of diabetes-accelerated atherosclerosis in a virally-induced mouse model of type 1 diabetes. Prostaglandin E Receptor 4 (EP4; Ptger4 ) is a major PGE 2 receptor in myeloid cells. We hypothesized that generation of a mouse model of myeloid cell-targeted EP4-deficiency would allow us to test the role of myeloid EP4 in diabetes-accelerated atherosclerosis. Thus, we generated a Ptger4 flox/flox LysM-Cre tg/tg mouse model. Peritoneal macrophages isolated from these myeloid cell EP4-deficient (EP4 M-/- ) mice expressed <90% Ptger4 mRNA compared to LysM-Cre tg/tg controls (n=10; p<0.0001). To analyze the role of myeloid cell EP4 in diabetes-accelerated atherosclerosis, we transplanted bone marrow from EP4 M-/- mice and littermate controls into lethally irradiated Ldlr -/- RIP-LCMV mice (the model of type 1 diabetes) and, after 7 weeks of recovery, induced diabetes by viral infection and fed the mice a low-fat semi-purified diet for an additional 12 weeks. Diabetic EP4 M-/- mice had similar blood glucose (568 ± 15 vs. 569 ± 15 mg/dl), blood cholesterol (531 ± 29 vs. 510 ± 37 mg/dl), and plasma triglycerides (249 ± 49 vs. 247 ± 44 mg/dl) as diabetic controls (n=15 all groups; mean ± SEM). At the endpoint, aortas were harvested for lesion area quantification. Diabetic EP4 M-/- and diabetic wild type mice had similar lesion area (1.9% ± 0.2 vs. 1.7% ± 0.2), which were both increased (p < 0.01; n=9-15) as compared to their non-diabetic controls. Additionally, we analyzed the role of EP4 in inflammatory activation of myeloid cells ex vivo. EP4-deficiency had no significant effect on basal or lipopolysaccharide (LPS)-induced inflammatory gene expression in the absence of PGE 2 . Pretreatment of the cells with PGE 2 (10 nM) followed by LPS stimulation resulted in a significant reduction of Tnfa and Il6 mRNA compared to LPS alone, and this anti-inflammatory effect of PGE 2 was completely blocked in EP4-deficient cells. These results suggest that myeloid cell EP4 mediates anti-inflammatory actions of PGE 2 but that it is not involved in diabetes-accelerated atherosclerosis.

scholarly journals Essential role of spi-1–like (spi-1l) in zebrafish myeloid cell differentiation

Blood ◽  
2009 ◽  
Vol 113 (9) ◽  
pp. 2038-2046 ◽  
Author(s):  
Alex Bukrinsky ◽  
Kevin J. P. Griffin ◽  
Yan Zhao ◽  
Shuo Lin ◽  
Utpal Banerjee
Keyword(s):  
Functional Analysis ◽  
Transcription Factor ◽  
Cell Differentiation ◽  
Essential Role ◽  
Critical Role ◽  
Myeloid Cell ◽  
Myeloid Differentiation ◽  
Adult Kidney ◽  
Necessary And Sufficient

The ETS protein Spi-1/Pu.1 plays a pivotal and widespread role throughout hematopoiesis in many species. This study describes the identification, characterization, and functional analysis of a new zebrafish spi transcription factor spi-1–like (spi-1l) that is expressed in primitive myeloid cells, erythro-myelo progenitor cells, and in the adult kidney. Spi-1l functions genetically downstream of etsrp, scl, and spi-1/pu.1 in myeloid differentiation. Spi-1l is coexpressed in a subset of spi-1/pu.1 cells and its function is necessary and sufficient for macrophage and granulocyte differentiation. These results establish a critical role for spi-1l in zebrafish myeloid cell differentiation.

scholarly journals Myeloid Cells in the Tumor Microenvironment: Modulation of Tumor Angiogenesis and Tumor Inflammation

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Michael C. Schmid ◽  
Judith A. Varner
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Angiogenesis ◽  
Malignant Tumors ◽  
Critical Role ◽  
Myeloid Cells ◽  
Suppressor Cells ◽  
Myeloid Cell ◽  
Promote Tumor Growth ◽  
Bone Marrow Derived Cells

Myeloid cells are a heterogeneous population of bone marrow-derived cells that play a critical role during growth and metastasis of malignant tumors. Tumors exhibit significant myeloid cell infiltrates, which are actively recruited to the tumor microenvironment. Myeloid cells promote tumor growth by stimulating tumor angiogenesis, suppressing tumor immunity, and promoting metastasis to distinct sites. In this review, we discuss the role of myeloid cells in promoting tumor angiogenesis. Furthermore, we describe a subset of myeloid cells with immunosuppressive activity (known as myeloid-derived suppressor cells). Finally, we will comment on the mechanisms regulating myeloid cell recruitment to the tumor microenvironment and on the potential of myeloid cells as new targets for cancer therapy.

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