scholarly journals Defining Monocyte Differentiation into Colonic and Ileal Macrophages

2019 ◽  
Author(s):  
Mor Gross-Vered ◽  
Sébastien Trzebanski ◽  
Anat Shemer ◽  
Biana Bernshtein ◽  
Caterina Curato ◽  
...  
Keyword(s):  
Specific Gene ◽  
Monocyte Differentiation ◽  
Factors Associated ◽  
Inflammatory Conditions ◽  
Cell Ablation ◽  
Luminal Side ◽  
Barrier Tissues ◽  
Considerable Detail ◽  
Classical Monocytes ◽  
Macrophage Precursors

AbstractMonocytes are circulating short-lived macrophage precursors that are recruited on demand from the blood to sites of inflammation and challenge. In steady state, classical monocytes give rise to vasculature-resident cells that patrol the luminal side of the endothelium. In addition, classical monocytes feed macrophage compartments of selected organs, including barrier tissues, such as the skin and intestine, as well as the heart. Monocyte differentiation under conditions of inflammation has been studied in considerable detail. In contrast, monocyte differentiation under non-inflammatory conditions remains less well understood. Here we took advantage of a combination of cell ablation and precursor engraftment to investigate the generation of gut macrophages from monocytes. Collectively, we identify factors associated with the gradual adaptation of monocytes to tissue residency. Moreover, comparison of monocyte differentiation into the colon and ileum-resident macrophages revealed the graduated acquisition of gut segment-specific gene expression signatures.

scholarly journals Defining murine monocyte differentiation into colonic and ileal macrophages

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Mor Gross-Vered ◽  
Sébastien Trzebanski ◽  
Anat Shemer ◽  
Biana Bernshtein ◽  
Caterina Curato ◽  
...  
Keyword(s):  
Specific Gene ◽  
Monocyte Differentiation ◽  
Factors Associated ◽  
Inflammatory Conditions ◽  
Cell Ablation ◽  
Luminal Side ◽  
Barrier Tissues ◽  
Considerable Detail ◽  
Classical Monocytes ◽  
Macrophage Precursors

Monocytes are circulating short-lived macrophage precursors that are recruited on demand from the blood to sites of inflammation and challenge. In steady state, classical monocytes give rise to vasculature-resident cells that patrol the luminal side of the endothelium. In addition, classical monocytes feed macrophage compartments of selected organs, including barrier tissues, such as the skin and intestine, as well as the heart. Monocyte differentiation under conditions of inflammation has been studied in considerable detail. In contrast, monocyte differentiation under non-inflammatory conditions remains less well understood. Here we took advantage of a combination of cell ablation and precursor engraftment to investigate the generation of gut macrophages from monocytes. Collectively, we identify factors associated with the gradual adaptation of monocytes to tissue residency. Moreover, comparison of monocyte differentiation into the colon and ileum-resident macrophages revealed the graduated acquisition of gut segment-specific gene expression signatures.

Investigating the function of follicular subpopulations during Drosophila oogenesis through hormone-dependent enhancer-targeted cell ablation

Development ◽  
2000 ◽  
Vol 127 (3) ◽  
pp. 573-583 ◽  
Author(s):  
D.D. Han ◽  
D. Stein ◽  
L.M. Stevens
Keyword(s):  
Gene Expression ◽  
Diphtheria Toxin ◽  
Follicle Cells ◽  
Specific Gene ◽  
Border Cells ◽  
Drosophila Oogenesis ◽  
Cell Ablation ◽  
Powerful Approach ◽  
Human Estrogen Receptor

Although it is known that the establishment of polarity during Drosophila oogenesis is initiated by signalling from the oocyte to the overlying follicle cells, much less is understood about the role of specific follicular subpopulations. One powerful approach for addressing this question, toxigenic cell ablation of specific subpopulations, has not previously been applicable to studying follicular subpopulations because many of the genes and Gal4 enhancer trap insertions that are expressed in the ovary are also expressed at earlier times in development. To overcome this problem, we have utilized a fusion protein between Gal4 and the human estrogen receptor to achieve hormone-dependent, tissue-specific gene expression of UAS-linked transgenes in flies. We used this system to study the role of the polar subpopulations of follicle cells during oogenesis by expressing within them a modified form of diphtheria toxin that causes cell death. Our results confirmed previous functions ascribed to these cells, and also demonstrated a previously undescribed role for the border cells in facilitating the migration of the anterior Fasciclin III-expressing polar pair cells to the edge of the oocyte.

scholarly journals CCN1/CYR61-mediated meticulous patrolling by Ly6Clow monocytes fuels vascular inflammation

2016 ◽  
Vol 113 (33) ◽  
pp. E4847-E4856 ◽  
Author(s):  
Beat A. Imhof ◽  
Stephane Jemelin ◽  
Romain Ballet ◽  
Christian Vesin ◽  
Marc Schapira ◽  
...  
Keyword(s):  
Steady State ◽  
Vascular Inflammation ◽  
Tissue Growth ◽  
Toll Like Receptor ◽  
Inflammatory Conditions ◽  
Cytokines And Chemokines ◽  
Activated Platelets ◽  
Cysteine Rich Protein ◽  
Early Arrival ◽  
Luminal Side

Inflammation is characterized by the recruitment of leukocytes from the bloodstream. The rapid arrival of neutrophils is followed by a wave of inflammatory lymphocyte antigen 6 complex (Ly6C)-positive monocytes. In contrast Ly6Clow monocytes survey the endothelium in the steady state, but their role in inflammation is still unclear. Here, using confocal intravital microscopy, we show that upon Toll-like receptor 7/8 (TLR7/8)-mediated inflammation of mesenteric veins, platelet activation drives the rapid mobilization of Ly6Clow monocytes to the luminal side of the endothelium. After repeatedly interacting with platelets, Ly6Clow monocytes commit to a meticulous patrolling of the endothelial wall and orchestrate the subsequent arrival and extravasation of neutrophils through the production of proinflammatory cytokines and chemokines. At a molecular level, we show that cysteine-rich protein 61 (CYR61)/CYR61 connective tissue growth factor nephroblastoma overexpressed 1 (CCN1) protein is released by activated platelets and enables the recruitment of Ly6Clow monocytes upon vascular inflammation. In addition endothelium-bound CCN1 sustains the adequate patrolling of Ly6Clow monocytes both in the steady state and under inflammatory conditions. Blocking CCN1 or platelets with specific antibodies impaired the early arrival of Ly6Clow monocytes and abolished the recruitment of neutrophils. These results refine the leukocyte recruitment cascade model by introducing endothelium-bound CCN1 as an inflammation mediator and by demonstrating a role for platelets and patrolling Ly6Clow monocytes in acute vascular inflammation.

scholarly journals Monocyte Subsets Are Differentially Lost from the Circulation during Acute Inflammation Induced by Human Experimental Endotoxemia

2017 ◽  
Vol 9 (5) ◽  
pp. 464-474 ◽  
Author(s):  
Tamar Tak ◽  
Roger van Groenendael ◽  
Peter Pickkers ◽  
Leo Koenderman
Keyword(s):  
Acute Inflammation ◽  
Human Monocyte ◽  
Monocyte Subset ◽  
Monocyte Subsets ◽  
Human Endotoxemia ◽  
Cd38 Expression ◽  
Inflammatory Conditions ◽  
Endotoxemia Model ◽  
Differentiation Status ◽  
Classical Monocytes

Three human monocyte subsets are recognized with different functions in the immune system: CD14++/CD16- classical monocytes (CM), CD14++/CD16+ intermediate monocytes (IM) and CD14+/CD16++ non-classical monocytes (NCM). Increased IM and NCM percentages have been reported under inflammatory conditions, yet little is known about monocyte subsets at the onset of inflammation. The human endotoxemia model is uniquely capable of studying the first phases of acute inflammation induced by intravenous injection of 2 ng/kg bodyweight lipopolysaccharide (LPS) into healthy volunteers. After that, monocyte subset counts, activation/differentiation status and chemokine levels were studied over 24 h. The numbers of all subsets were decreased by >95% after LPS injection. CM numbers recovered first (3- 6 h), followed by IM (6-8 h) and NCM numbers (8-24 h). Similarly, increased monocyte counts were observed first in CM (8 h), followed by IM and NCM (24 h). Monocytes did not display a clear activated phenotype (minor increase in CD11b and CD38 expression). Plasma levels of CCL2, CCL4 and CX3CL1 closely resembled the cell numbers of CM, IM and NCM, respectively. Our study provides critical insights into the earliest stages of acute inflammation and emphasizes the necessity to stain for different monocyte subsets when studying the role of monocytes in disease, as neither function nor kinetics of the subsets overlap.

scholarly journals Prevalence, Risk Factors, and Management of Stroke in Patients with COVID-19 Infection: A Review

2021 ◽  
pp. 10-17
Author(s):  
Sidra Shahid Mubasher ◽  
Humera Batool ◽  
Emen Udo Kierian ◽  
Khatja Batool
Keyword(s):  
Risk Factors ◽  
Older Patients ◽  
Care Center ◽  
Prothrombotic State ◽  
Stroke Patients ◽  
Stroke Incidence ◽  
Health Care Center ◽  
Factors Associated ◽  
Inflammatory Conditions ◽  
History Of

In the current pandemic, it is imperative to comprehend and advance a search forward to explore the pathogenesis of stroke in COVID-19 infected patients. In this review, we have discussed the prevalence of stroke in COVID-19 infected patients and different risk factors associated with the stroke in COVID-19. We also presented a comprehensive review on management of Stroke Patients during the COVID-19 pandemic. The COVID-19 positive patients with stroke should be treated in a designated COVID-19 health care center as per the guidelines. Study also showed that older patients with a history of cardiovascular diseases, prothrombotic state, smoking, and infection significantly had a higher likelihood of stroke incidence. The study revealed that effective treatment of COVID-19 and reduction of the inflammatory conditions may seem to be the way forward to minimize the symptomatic stroke associated with COVID-19 infection, and rehabilitation of Stroke patients should be optimal during a pandemic.

PD-L1 expression on nonclassical monocytes reveals their origin and immunoregulatory function

2019 ◽  
Vol 4 (36) ◽  
pp. eaar3054 ◽  
Author(s):  
Mariaelvy Bianchini ◽  
Johan Duchêne ◽  
Donato Santovito ◽  
Maximilian J. Schloss ◽  
Maximilien Evrard ◽  
...  
Keyword(s):  
Two Photon Microscopy ◽  
T Cell Apoptosis ◽  
Two Photon ◽  
Inflammatory Conditions ◽  
Checkpoint Molecule ◽  
Health And Disease ◽  
And Function ◽  
Classical Monocytes ◽  
Shed Light

The role of nonclassical monocytes (NCMs) in health and disease is emerging, but their location and function within tissues remain poorly explored. Imaging of NCMs has been limited by the lack of an established single NCM marker. Here, we characterize the immune checkpoint molecule PD-L1 (CD274) as an unequivocal marker for tracking NCMs in circulation and pinpoint their compartmentalized distribution in tissues by two-photon microscopy. Visualization of PD-L1+ NCMs in relation to bone marrow vasculature reveals that conversion of classical monocytes into NCMs requires contact with endosteal vessels. Furthermore, PD-L1+ NCMs are present in tertiary lymphoid organs (TLOs) under inflammatory conditions in both mice and humans, and NCMs exhibit a PD-L1–dependent immunomodulatory function that promotes T cell apoptosis within TLOs. Our findings establish an unambiguous tool for the investigation of NCMs and shed light on their origin and function.

Three Dimensional structure and organization of diploid chromosomes by optical section microscopy

1987 ◽  
Vol 45 ◽  
pp. 633-635
Author(s):  
David A. Agard ◽  
Yasushi Hiraoka ◽  
John W. Sedat
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Developmental State ◽  
Mitotic Cell ◽  
Biological Properties ◽  
Dimensional Structure ◽  
Specific Gene ◽  
Three Dimensional Structure ◽  
Complementary Techniques ◽  
Dynamic Structures

In an effort to understand the complex relationship between structure and biological function within the nucleus, we have embarked on a program to examine the three-dimensional structure and organization of Drosophila melanogaster embryonic chromosomes. Our overall goal is to determine how DNA and proteins are organized into complex and highly dynamic structures (chromosomes) and how these chromosomes are arranged in three dimensional space within the cell nucleus. Futher, we hope to be able to correlate structual data with such fundamental biological properties as stage in the mitotic cell cycle, developmental state and transcription at specific gene loci.Towards this end, we have been developing methodologies for the three-dimensional analysis of non-crystalline biological specimens using optical and electron microscopy. We feel that the combination of these two complementary techniques allows an unprecedented look at the structural organization of cellular components ranging in size from 100A to 100 microns.

Stain contamination and embedding in electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 50-53
Author(s):  
Hilton H. Mollenhauer
Keyword(s):  
Electron Microscopy ◽  
Information Retrieval ◽  
Epoxy Resins ◽  
Image Contrast ◽  
Sample Preservation ◽  
Factors Associated ◽  
Amount Of Information ◽  
Electron Microscopical ◽  
Contrast Information

Many factors (e.g., resolution of microscope, type of tissue, and preparation of sample) affect electron microscopical images and alter the amount of information that can be retrieved from a specimen. Of interest in this report are those factors associated with the evaluation of epoxy embedded tissues. In this context, informational retrieval is dependant, in part, on the ability to “see” sample detail (e.g., contrast) and, in part, on tue quality of sample preservation. Two aspects of this problem will be discussed: 1) epoxy resins and their effect on image contrast, information retrieval, and sample preservation; and 2) the interaction between some stains commonly used for enhancing contrast and information retrieval.

High-resolution observations of metastable γ’ precipitation in Al-15at.%Ag

1996 ◽  
Vol 54 ◽  
pp. 1004-1005
Author(s):  
N. V. Larcher ◽  
I. G. Solorzano
Keyword(s):  
Discontinuous Precipitation ◽  
Equilibrium Phase ◽  
Quantitative Description ◽  
Present Contribution ◽  
Α Phase ◽  
The Matrix ◽  
Aging Sequence ◽  
Matrix Precipitation ◽  
Considerable Detail ◽  
Kinetics Of

It is currently well established that, for an Al-Ag alloy quenched from the α phase and aged within the metastable solvus, the aging sequence is: supersaturated α → GP zones → γ’ → γ (Ag2Al). While GP zones and plate-shaped γ’ are metastable phases, continuously distributed in the matrix, formation of the equilibrium phase γ takes place at grain boundaries by discontinuous precipitation (DP). The crystal structure of both γ’ and γ is hep with the following orientation relationship with respect to the fee α matrix: {0001}γ′,γ // {111}α, <1120>γ′,γ, // <110>α.The mechanisms and kinetics of continuous matrix precipitation (CMP) in dilute Al-Ag alloys have been studied in considerable detail. The quantitative description of DP kinetics, however, has received less attention. The present contribution reports the microstructural evolution resulting from aging an Al-Ag alloy with Ag content higher than those previously reported in the literature, focusing the observations of γ' plate-shaped metastable precipitates.

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