Btk is a positive regulator in the TREM-1/DAP12 signaling pathway

Czech Academy of Sciences Publication Activity Database

Ormsby, Tereza; Schlecker, E.; Ferdin, J.; Tessarz, A.S.; Angelisová, Pavla; Koprulu, A.D.; Borte, M.; Warnatz, K.; Schulze, I.; Ellmeier, W.; Hořejší, Václav; Cerwenka, A.

2011-01-01

Roč. 118, č. 4 (2011), s. 936-945 ISSN 0006-4971 R&D Projects: GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50520514 Keywords : TREM-1 * DAP-12 * Btk Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.898, year: 2011

microRNA-34a-Mediated Down-Regulation of the Microglial-Enriched Triggering Receptor and Phagocytosis-Sensor TREM2 in Age-Related Macular Degeneration.

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Surjyadipta Bhattacharjee

Full Text Available The aggregation of Aβ42-peptides and the formation of drusen in age-related macular degeneration (AMD are due in part to the inability of homeostatic phagocytic mechanisms to clear self-aggregating Aβ42-peptides from the extracellular space. The triggering receptor expressed in myeloid/microglial cells-2 (TREM2, a trans-membrane-spanning, sensor-receptor of the immune-globulin/lectin-like gene superfamily is a critical component of Aβ42-peptide clearance. Here we report a significant deficit in TREM2 in AMD retina and in cytokine- or oxidatively-stressed microglial (MG cells. RT-PCR, miRNA-array, LED-Northern and Western blot studies indicated up-regulation of a microglial-enriched NF-кB-sensitive miRNA-34a coupled to a down-regulation of TREM2 in the same samples. Bioinformatics/transfection-luciferase reporter assays indicated that miRNA-34a targets the 299 nucleotide TREM2-mRNA-3'UTR, resulting in TREM2 down-regulation. C8B4-microglial cells challenged with Aβ42 were able to phagocytose these peptides, while miRNA-34a down-regulated both TREM2 and the ability of microglial-cells to phagocytose. Treatment of TNFα-stressed MG cells with phenyl-butyl nitrone (PBN, caffeic-acid phenethyl ester (CAPE, the NF-kB - [corrected] inhibitor/resveratrol analog CAY10512 or curcumin abrogated these responses. Incubation of anti-miRNA-34a (AM-34a normalized miRNA-34a abundance and restored TREM2 back to homeostatic levels. These data support five novel observations: (i that a ROS- and NF-kB - [corrected] sensitive, miRNA-34a-mediated modulation of TREM2 may in part regulate the phagocytic response; (ii that gene products encoded on two different chromosomes (miRNA-34a at chr1q36.22 and TREM2 at chr6p21.1 orchestrate a phagocytic-Aβ42-peptide clearance-system; (iii that this NF-kB-mediated-miRNA-34a-TREM2 mechanism is inducible from outside of the cell; (iv that when operating normally, this pathway can clear Aβ42 peptide monomers from the

Lymphoblast-derived integration-free iPSC line AD-TREM2-1 from a 67 year-old Alzheimer's disease patient expressing the TREM2 p.R47H variant

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Soraia Martins

2018-05-01

Full Text Available Human lymphoblast cells from a male diagnosed with Alzheimer's disease (AD expressing the TREM2 p.R47H variant were used to generate integration-free induced pluripotent stem cells (iPSCs by over-expressing episomal-based plasmids harbouring OCT4, SOX2, NANOG, LIN28, c-MYC and L-MYC. AD-TREM2–1 was defined as pluripotent based on (i expression of pluripotency-associated markers (ii embryoid body-based differentiation into cell types representative of the three germ layers and (iii the similarity between the transcriptome of the iPSC line and the human embryonic stem cell line H1 with a Pearson correlation of 0.947.

Homozygous TREM2 mutation in a family with atypical frontotemporal dementia.

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Le Ber, Isabelle; De Septenville, Anne; Guerreiro, Rita; Bras, José; Camuzat, Agnès; Caroppo, Paola; Lattante, Serena; Couarch, Philippe; Kabashi, Edor; Bouya-Ahmed, Kawtar; Dubois, Bruno; Brice, Alexis

2014-10-01

TREM2 mutations were first identified in Nasu-Hakola disease, a rare autosomal recessive disease characterized by recurrent fractures because of bone cysts and presenile dementia. Recently, homozygous and compound heterozygous TREM2 mutations were identified in rare families with frontotemporal lobar degeneration (FTLD) but without bone involvement. We identified a p.Thr66Met heterozygous mutation in a new consanguineous Italian family. Two sibs had early onset autosomal recessive FTLD without severe bone disorders. Atypical signs were present in this family: early parietal and hippocampus involvement, parkinsonism, epilepsy, and corpus callosum thickness on brain magnetic resonance imaging. This study further demonstrates the implication of TREM2 mutations in FTLD phenotypes. It illustrates the variability of bone phenotype and underlines the frequency of atypical signs in TREM2 carriers. This and previous studies evidence that TREM2 mutation screening should be limited to autosomal recessive FTLD with atypical phenotypes characterized by: (1) a very young age at onset (20-50 years); (2) early parietal and hippocampal deficits; (3) the presence of seizures and parkinsonism; (4) suggestive extensive white matter lesions and corpus callosum thickness on brain magnetic resonance imaging. Copyright © 2014 Elsevier Inc. All rights reserved.

Contribution to Alzheimer's disease risk of rare variants in TREM2, SORL1, and ABCA7 in 1779 cases and 1273 controls.

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Bellenguez, Céline; Charbonnier, Camille; Grenier-Boley, Benjamin; Quenez, Olivier; Le Guennec, Kilan; Nicolas, Gaël; Chauhan, Ganesh; Wallon, David; Rousseau, Stéphane; Richard, Anne Claire; Boland, Anne; Bourque, Guillaume; Munter, Hans Markus; Olaso, Robert; Meyer, Vincent; Rollin-Sillaire, Adeline; Pasquier, Florence; Letenneur, Luc; Redon, Richard; Dartigues, Jean-François; Tzourio, Christophe; Frebourg, Thierry; Lathrop, Mark; Deleuze, Jean-François; Hannequin, Didier; Genin, Emmanuelle; Amouyel, Philippe; Debette, Stéphanie; Lambert, Jean-Charles; Campion, Dominique

2017-11-01

We performed whole-exome and whole-genome sequencing in 927 late-onset Alzheimer disease (LOAD) cases, 852 early-onset AD (EOAD) cases, and 1273 controls from France. We assessed the evidence for gene-based association of rare variants with AD in 6 genes for which an association with such variants was previously claimed. When aggregating protein-truncating and missense-predicted damaging variants, we found exome-wide significant association between EOAD risk and rare variants in SORL1, TREM2, and ABCA7. No exome-wide significant signal was obtained in the LOAD sample, and significance of the order of 10 -6 was observed in the whole AD group for TREM2. Our study confirms previous gene-level results for TREM2, SORL1, and ABCA7 and provides a clearer insight into the classes of rare variants involved. Despite different effect sizes and varying cumulative minor allele frequencies, the rare protein-truncating and missense-predicted damaging variants in TREM2, SORL1, and ABCA7 contribute similarly to the heritability of EOAD and explain between 1.1% and 1.5% of EOAD heritability each, compared with 9.12% for APOE ε4. Copyright © 2017 Elsevier Inc. All rights reserved.

Microglia and Aging: The Role of the TREM2–DAP12 and CX3CL1-CX3CR1 Axes

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Carmen Mecca

2018-01-01

Full Text Available Depending on the species, microglial cells represent 5–20% of glial cells in the adult brain. As the innate immune effector of the brain, microglia are involved in several functions: regulation of inflammation, synaptic connectivity, programmed cell death, wiring and circuitry formation, phagocytosis of cell debris, and synaptic pruning and sculpting of postnatal neural circuits. Moreover, microglia contribute to some neurodevelopmental disorders such as Nasu-Hakola disease (NHD, and to aged-associated neurodegenerative diseases, such as Alzheimer’s disease (AD, Parkinson’s disease (PD, and others. There is evidence that human and rodent microglia may become senescent. This event determines alterations in the microglia activation status, associated with a chronic inflammation phenotype and with the loss of neuroprotective functions that lead to a greater susceptibility to the neurodegenerative diseases of aging. In the central nervous system (CNS, Triggering Receptor Expressed on Myeloid Cells 2-DNAX activation protein 12 (TREM2-DAP12 is a signaling complex expressed exclusively in microglia. As a microglial surface receptor, TREM2 interacts with DAP12 to initiate signal transduction pathways that promote microglial cell activation, phagocytosis, and microglial cell survival. Defective TREM2-DAP12 functions play a central role in the pathogenesis of several diseases. The CX3CL1 (fractalkine-CX3CR1 signaling represents the most important communication channel between neurons and microglia. The expression of CX3CL1 in neurons and of its receptor CX3CR1 in microglia determines a specific interaction, playing fundamental roles in the regulation of the maturation and function of these cells. Here, we review the role of the TREM2-DAP12 and CX3CL1-CX3CR1 axes in aged microglia and the involvement of these pathways in physiological CNS aging and in age-associated neurodegenerative diseases.

The human TREM gene cluster at 6p21.1 encodes both activating and inhibitory single IgV domain receptors and includes NKp44.

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Allcock, Richard J N; Barrow, Alexander D; Forbes, Simon; Beck, Stephan; Trowsdale, John

2003-02-01

We have characterized a cluster of single immunoglobulin variable (IgV) domain receptors centromeric of the major histocompatibility complex (MHC) on human chromosome 6. In addition to triggering receptor expressed on myeloid cells (TREM)-1 and TREM2, the cluster contains NKp44, a triggering receptor whose expression is limited to NK cells. We identified three new related genes and two gene fragments within a cluster of approximately 200 kb. Two of the three new genes lack charged residues in their transmembrane domain tails. Further, one of the genes contains two potential immunotyrosine Inhibitory motifs in its cytoplasmic tail, suggesting that it delivers inhibitory signals. The human and mouse TREM clusters appear to have diverged such that there are unique sequences in each species. Finally, each gene in the TREM cluster was expressed in a different range of cell types.

The role of TREM-2 in internalization and intracellular survival of Brucella abortus in murine macrophages.

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Wei, Pan; Lu, Qiang; Cui, Guimei; Guan, Zhenhong; Yang, Li; Sun, Changjiang; Sun, Wanchun; Peng, Qisheng

2015-02-15

Triggering receptor expressed on myeloid cells-2 (TREM-2) is a cell surface receptor primarily expressed on macrophages and dendritic cells. TREM-2 functions as a phagocytic receptor for bacteria as well as an inhibitor of Toll like receptors (TLR) induced inflammatory cytokines. However, the role of TREM-2 in Brucella intracellular growth remains unknown. To investigate whether TREM-2 is involved in Brucella intracellular survival, we chose bone marrow derived macrophages (BMDMs), in which TREM-2 is stably expressed, as cell model. Colony formation Units (CFUs) assay suggests that TREM-2 is involved in the internalization of Brucella abortus (B. abortus) by macrophages, while silencing of TREM-2 decreases intracellular survival of B. abortus. To further study the underlying mechanisms of TREM-2-mediated bacterial intracellular survival, we examined the activation of B. abortus-infected macrophages through determining the kinetics of activation of the three MAPKs, including ERK, JNK and p38, and measuring TNFα production in response to lipopolysaccharide (LPS) of Brucella (BrLPS) or B. abortus stimulation. Our data show that TREM-2 deficiency promotes activation of Brucella-infected macrophages. Moreover, our data also demonstrate that macrophage activation promotes killing of Brucella by enhancing nitric oxygen (NO), but not reactive oxygen species (ROS) production, macrophage apoptosis or cellular death. Taken together, these findings provide a novel interpretation of Brucella intracellular growth through inhibition of NO production produced by TREM-2-mediated activated macrophages. Copyright © 2014 Elsevier B.V. All rights reserved.

Study of monocyte membrane proteome perturbation during lipopolysaccharide-induced tolerance using iTRAQ-based quantitative proteomic approach

KAUST Repository

Zhang, Huoming

2010-07-02

Human monocytes\\' exposure to low-level lipopolysaccharide (LPS) induces temporary monocytic insensitivity to subsequent LPS challenge. The underlying mechanism of this phenomenon could have important clinical utilities in preventing and/or treating severe infections. In this study, we used an iTRAQ-based quantitative proteomic approach to comprehensively characterize the membrane proteomes of monocytes before and after LPS exposure. We identified a total of 1651 proteins, of which 53.6% were membrane proteins. Ninety-four percent of the proteins were quantified and 255 proteins were shown to be tightly regulated by LPS. Subcellular location analysis revealed organelle-specific response to LPS exposure: more than 90% of identified mitochondrial membrane proteins were significant downregulated, whereas the majority of proteins from other organelles such as ER, Golgi and ribosome were upregulated. Moreover, we found that the expression of most receptors potentially involved in LPS signal pathway (CD14, toll-like receptor 4, CD11/CD18 complex) were substantially decreased, while the expression of molecules involved in LPS neutralization were enhanced after LPS challenge. Together, these findings could be of significance in understanding the mechanism of LPS tolerance and provide values for designing new approaches for regulating monocytic responses in sepsis patients.

Study of monocyte membrane proteome perturbation during lipopolysaccharide-induced tolerance using iTRAQ-based quantitative proteomic approach

KAUST Repository

Zhang, Huoming; Zhao, Changqing; Li, Xin; Zhu, Yi; Gan, Chee Sian; Wang, Yong; Ravasi, Timothy; Qian, Pei-Yuan; Wong, Siew Cheng; Sze, Siu Kwan

2010-01-01

Human monocytes' exposure to low-level lipopolysaccharide (LPS) induces temporary monocytic insensitivity to subsequent LPS challenge. The underlying mechanism of this phenomenon could have important clinical utilities in preventing and/or treating severe infections. In this study, we used an iTRAQ-based quantitative proteomic approach to comprehensively characterize the membrane proteomes of monocytes before and after LPS exposure. We identified a total of 1651 proteins, of which 53.6% were membrane proteins. Ninety-four percent of the proteins were quantified and 255 proteins were shown to be tightly regulated by LPS. Subcellular location analysis revealed organelle-specific response to LPS exposure: more than 90% of identified mitochondrial membrane proteins were significant downregulated, whereas the majority of proteins from other organelles such as ER, Golgi and ribosome were upregulated. Moreover, we found that the expression of most receptors potentially involved in LPS signal pathway (CD14, toll-like receptor 4, CD11/CD18 complex) were substantially decreased, while the expression of molecules involved in LPS neutralization were enhanced after LPS challenge. Together, these findings could be of significance in understanding the mechanism of LPS tolerance and provide values for designing new approaches for regulating monocytic responses in sepsis patients.

Differential effects of malignant mesothelioma cells on THP-1 monocytes and macrophages.

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Izzi, Valerio; Chiurchiù, Valerio; D'Aquilio, Fabiola; Palumbo, Camilla; Tresoldi, Ilaria; Modesti, Andrea; Baldini, Patrizia M

2009-02-01

Malignant mesothelioma (MM) is a highly fatal tumor arising from inner body membranes, whose extensive growth is facilitated by its week immunogenicity and by its ability to blunt the immune response which should arise from the huge mass of leukocytes typically infiltrating this tumor. It has been reported that the inflammatory infiltrate found in MM tissues is characterized by a high prevalence of macrophages. Thus, in this work we evaluated the ability of human MM cells to modulate the inflammatory phenotype of human THP-1 monocytes and macrophages, a widely used in vitro model of monocyte/macrophage differentiation. Furthermore, we tested the hypothesis that the exposure to MM cells could alter the differentiation of THP-1 monocytes favoring the development of alternatively activated, tumor-supporting macrophages. Our data prove for the first time that MM cells can polarize monocytes towards an altered inflammatory phenotype and macrophages towards an immunosuppressive phenotype. Moreover, we demonstrate that monocytes cocultivated with MM cells 'keep a memory' of their encounter with the tumor which influences their differentiation to macrophages. On the whole, we provide evidence that MM cells exert distinct, cell-specific effects on monocytes and macrophages. The thorough characterization of such effects may be of a crucial importance for the rational design of new immunotherapeutic protocols.

Triggering receptor expressed on myeloid cells 2 (TREM2): a potential therapeutic target for Alzheimer disease?

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Deming, Yuetiva; Li, Zeran; Benitez, Bruno A; Cruchaga, Carlos

2018-06-20

There are currently no effective therapeutics for Alzheimer disease (AD). Clinical trials targeting amyloid beta thus far have shown very little benefit and only in the earliest stages of disease. These limitations have driven research to identify alternative therapeutic targets, one of the most promising is the triggering receptor expressed on myeloid cells 2 (TREM2). Areas covered: Here, we review the literature to-date and discuss the potentials and pitfalls for targeting TREM2 as a potential therapeutic for AD. We focus on research in animal and cell models for AD and central nervous system injury models which may help in understanding the role of TREM2 in disease. Expert opinion: Studies suggest TREM2 plays a key role in AD pathology; however, results have been conflicting about whether TREM2 is beneficial or harmful. More research is necessary before designing TREM2-targeting therapies. Successful therapeutics will most likely be administered early in disease.

Non-T cell activation linker (NTAL) negatively regulates TREM-1/DAP12-induced inflammatory cytokine production in myeloid cells

Czech Academy of Sciences Publication Activity Database

Tessarz, A.S.; Weiler, S.; Zanzinger, K.; Angelisová, Pavla; Hořejší, Václav; Cerwenka, A.

2007-01-01

Roč. 178, č. 4 (2007), s. 1991-1999 ISSN 0022-1767 R&D Projects: GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50520514 Keywords : NTAL * TREM-1 * cytokines Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.068, year: 2007

GPR84 and TREM-1 signaling contribute to the pathogenesis of reflux esophagitis.

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Abdel-Aziz, Heba; Schneider, Mathias; Neuhuber, Winfried; Kassem, Abdel Meguid; Khailah, Saleem; Müller, Jürgen; Gamaleldeen, Hadeel; Khairy, Ahmed; Khayyal, Mohamed T; Shcherbakova, Anastasiia; Efferth, Thomas; Ulrich-Merzenich, Gudrun

2015-11-24

Gastro-esophageal reflux disease (GERD) is one of the most common disorders in gastroenterology. Patients present with or without increased acid exposure indicating a non-uniform etiology. Thus the common treatment with proton pump inhibitors (PPIs) fails to control symptoms in up to 40% of patients.To further elucidate the pathophysiology of the condition and explore new treatment targets, transcriptomics, proteomics and histological methods were applied to a surgically induced sub-chronic reflux esophagitis model in Wistar rats after treatment with either omeprazole (PPI) or STW5, a herbal preparation shown to ameliorate esophagitis without affecting refluxate pH. The normal human esophageal squamous cellline HET-1A and human endoscopic biopsies were used to confirm our findings to the G-protein coupled receptor (GPR) 84 in human tissue.Both treatments reduced reflux-induced macroscopic and microscopic lesions of the esophagi as well as known pro-inflammatory cytokines. Proteomic and transcriptomic analyses identified CINC1-3, MIP-1/3α, MIG, RANTES and IL-1β as prominent mediators in GERD. Most regulated cyto-/chemokines are linked to the TREM-1 signaling pathway. The fatty acid receptor GPR84 was up-regulated in esophagitis but significantly decreased in treated groups, a finding supported by Western blot and immunohistochemistry in both rat tissue and HET-1A cells. GPR84 was also found to be significantly up-regulated in patients with grade B reflux esophagitis.The expression of GPR84 in esophageal tissue and its potential involvement in GERD are reported for the first time. IL-8 (CINC1-3) and the TREM-1 signaling pathway are proposed, besides GPR84, to play an important role in the pathogenesis of GERD.

HIV-1 Latency in Monocytes/Macrophages

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Amit Kumar

2014-04-01

Full Text Available Human immunodeficiency virus type 1 (HIV-1 targets CD4+ T cells and cells of the monocyte/macrophage lineage. HIV pathogenesis is characterized by the depletion of T lymphocytes and by the presence of a population of cells in which latency has been established called the HIV-1 reservoir. Highly active antiretroviral therapy (HAART has significantly improved the life of HIV-1 infected patients. However, complete eradication of HIV-1 from infected individuals is not possible without targeting latent sources of infection. HIV-1 establishes latent infection in resting CD4+ T cells and findings indicate that latency can also be established in the cells of monocyte/macrophage lineage. Monocyte/macrophage lineage includes among others, monocytes, macrophages and brain resident macrophages. These cells are relatively more resistant to apoptosis induced by HIV-1, thus are important stable hideouts of the virus. Much effort has been made in the direction of eliminating HIV-1 resting CD4+ T-cell reservoirs. However, it is impossible to achieve a cure for HIV-1 without considering these neglected latent reservoirs, the cells of monocyte/macrophage lineage. In this review we will describe our current understanding of the mechanism of latency in monocyte/macrophage lineage and how such cells can be specifically eliminated from the infected host.

TREM2 mutations are rare in a French cohort of patients with frontotemporal dementia.

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Lattante, Serena; Le Ber, Isabelle; Camuzat, Agnès; Dayan, Sarah; Godard, Chloé; Van Bortel, Inge; De Septenville, Anne; Ciura, Sorana; Brice, Alexis; Kabashi, Edor

2013-10-01

Homozygous mutations in TREM2 have been recently identified by exome sequencing in families presenting with frontotemporal dementia (FTD)-like phenotype. No study has evaluated the exact frequency of TREM2 mutations in cohorts of FTD patients so far. We sequenced TREM2 in 175 patients with pure FTD, mostly French, to test whether mutations could be implicated in the pathogenesis of the disease. No disease-causing mutation was identified in 175 individuals from the French cohort of FTD patients. We did not identify the polymorphism p.R47H (rs75932628), strongly associated with an increased risk of developing Alzheimer's disease. We conclude that TREM2 mutations are extremely rare in patients with pure FTD, although further investigation in larger populations is needed. Copyright © 2013 Elsevier Inc. All rights reserved.

Modulation of Hematopoietic Lineage Specification Impacts TREM2 Expression in Microglia-Like Cells Derived From Human Stem Cells.

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Amos, Peter J; Fung, Susan; Case, Amanda; Kifelew, Jerusalem; Osnis, Leah; Smith, Carole L; Green, Kevin; Naydenov, Alipi; Aloi, Macarena; Hubbard, Jesse J; Ramakrishnan, Aravind; Garden, Gwenn A; Jayadev, Suman

2017-01-01

Microglia are the primary innate immune cell type in the brain, and their dysfunction has been linked to a variety of central nervous system disorders. Human microglia are extraordinarily difficult to obtain for experimental investigation, limiting our ability to study the impact of human genetic variants on microglia functions. Previous studies have reported that microglia-like cells can be derived from human monocytes or pluripotent stem cells. Here, we describe a reproducible relatively simple method for generating microglia-like cells by first deriving embryoid body mesoderm followed by exposure to microglia relevant cytokines. Our approach is based on recent studies demonstrating that microglia originate from primitive yolk sac mesoderm distinct from peripheral macrophages that arise during definitive hematopoiesis. We hypothesized that functional microglia could be derived from human stem cells by employing BMP-4 mesodermal specification followed by exposure to microglia-relevant cytokines, M-CSF, GM-CSF, IL-34, and TGF-β. Using immunofluorescence microscopy, flow cytometry, and reverse transcription polymerase chain reaction, we observed cells with microglia morphology expressing a repertoire of markers associated with microglia: Iba1, CX3CR1, CD11b, TREM2, HexB, and P2RY12. These microglia-like cells maintain myeloid functional phenotypes including Aβ peptide phagocytosis and induction of pro-inflammatory gene expression in response to lipopolysaccharide stimulation. Addition of small molecules BIO and SB431542, previously demonstrated to drive definitive hematopoiesis, resulted in decreased surface expression of TREM2. Together, these data suggest that mesodermal lineage specification followed by cytokine exposure produces microglia-like cells in vitro from human pluripotent stem cells and that this phenotype can be modulated by factors influencing hematopoietic lineage in vitro.

Evidence of trem2 variant associated with triple risk of Alzheimer's disease.

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Zainularifeen Abduljaleel

Full Text Available Alzheimer's disease is one of the main causes of dementia among elderly individuals and leads to the neurodegeneration of different areas of the brain, resulting in memory impairments and loss of cognitive functions. Recently, a rare variant that is associated with 3-fold higher risk of Alzheimer's disease onset has been found. The rare variant discovered is a missense mutation in the loop region of exon 2 of Trem2 (rs75932628-T, Arg47His. The aim of this study was to investigate the evidence for potential structural and functional significance of Trem2 gene variant (Arg47His through molecular dynamics simulations. Our results showed the alteration caused due to the variant in TREM2 protein has significant effect on the ligand binding affinity as well as structural configuration. Based on molecular dynamics (MD simulation under salvation, the results confirmed that native form of the variant (Arg47His might be responsible for improved compactness, hence thereby improved protein folding. Protein simulation was carried out at different temperatures. At 300K, the deviation of the theoretical model of TREM2 protein increased from 2.0 Å at 10 ns. In contrast, the deviation of the Arg47His mutation was maintained at 1.2 Å until the end of the simulation (t = 10 ns, which indicated that Arg47His had reached its folded state. The mutant residue was a highly conserved region and was similar to "immunoglobulin V-set" and "immunoglobulin-like folds". Taken together, the result from this study provides a biophysical insight on how the studied variant could contribute to the genetic susceptibility to Alzheimer's disease.

The FTD-like syndrome causing TREM2 T66M mutation impairs microglia function, brain perfusion, and glucose metabolism.

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Kleinberger, Gernot; Brendel, Matthias; Mracsko, Eva; Wefers, Benedikt; Groeneweg, Linda; Xiang, Xianyuan; Focke, Carola; Deußing, Maximilian; Suárez-Calvet, Marc; Mazaheri, Fargol; Parhizkar, Samira; Pettkus, Nadine; Wurst, Wolfgang; Feederle, Regina; Bartenstein, Peter; Mueggler, Thomas; Arzberger, Thomas; Knuesel, Irene; Rominger, Axel; Haass, Christian

2017-07-03

Genetic variants in the triggering receptor expressed on myeloid cells 2 (TREM2) increase the risk for several neurodegenerative diseases including Alzheimer's disease and frontotemporal dementia (FTD). Homozygous TREM2 missense mutations, such as p.T66M, lead to the FTD-like syndrome, but how they cause pathology is unknown. Using CRISPR/Cas9 genome editing, we generated a knock-in mouse model for the disease-associated Trem2 p.T66M mutation. Consistent with a loss-of-function mutation, we observe an intracellular accumulation of immature mutant Trem2 and reduced generation of soluble Trem2 similar to patients with the homozygous p.T66M mutation. Trem2 p.T66M knock-in mice show delayed resolution of inflammation upon in vivo lipopolysaccharide stimulation and cultured macrophages display significantly reduced phagocytic activity. Immunohistochemistry together with in vivo TSPO small animal positron emission tomography (μPET) demonstrates an age-dependent reduction in microglial activity. Surprisingly, perfusion magnetic resonance imaging and FDG-μPET imaging reveal a significant reduction in cerebral blood flow and brain glucose metabolism. Thus, we demonstrate that a TREM2 loss-of-function mutation causes brain-wide metabolic alterations pointing toward a possible function of microglia in regulating brain glucose metabolism. © 2017 The Authors.

The immune receptor Trem1 cooperates with diminished DNA damage response to induce preleukemic stem cell expansion.

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Du, W; Amarachintha, S; Wilson, A; Pang, Q

2017-02-01

Fanconi anemia (FA) is an inherited bone marrow failure syndrome with extremely high risk of leukemic transformation. Here we investigate the relationship between DNA damage response (DDR) and leukemogenesis using the Fanca knockout mouse model. We found that chronic exposure of the Fanca -/- hematopoietic stem cells to DNA crosslinking agent mitomycin C in vivo leads to diminished DDR, and the emergence/expansion of pre-leukemia stem cells (pre-LSCs). Surprisingly, although genetic correction of Fanca deficiency in the pre-LSCs restores DDR and reduces genomic instability, but fails to prevent pre-LSC expansion or delay leukemia development in irradiated recipients. Furthermore, we identified transcription program underlying dysregulated DDR and cell migration, myeloid proliferation, and immune response in the Fanca -/- pre-LSCs. Forced expression of the downregulated DNA repair genes, Rad51c or Trp53i13, in the Fanca -/- pre-LSCs partially rescues DDR but has no effect on leukemia, whereas shRNA knockdown of the upregulated immune receptor genes Trem1 or Pilrb improves leukemia-related survival, but not DDR or genomic instability. Furthermore, Trem1 cooperates with diminished DDR in vivo to promote Fanca -/- pre-LSC expansion and leukemia development. Our study implicates diminishing DDR as a root cause of FA leukemogenesis, which subsequently collaborates with other signaling pathways for leukemogenic transformation.

M1 and M2 Monocytes in Rheumatoid Arthritis: A Contribution of Imbalance of M1/M2 Monocytes to Osteoclastogenesis

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Shoichi Fukui

2018-01-01

Full Text Available ObjectivesWe investigated the relationships among M1 monocytes, M2 monocytes, osteoclast (OC differentiation ability, and clinical characteristics in patients with rheumatoid arthritis (RA.MethodsPeripheral blood mononuclear cells (PBMCs were isolated from RA patients and healthy donors, and we then investigated the number of M1 monocytes or M2 monocytes by fluorescence-activated cell sorting. We also obtained and cultured CD14-positive cells from PBMCs from RA patients and healthy donors to investigate OC differentiation in vitro.ResultsForty RA patients and 20 healthy donors were included. Twenty-two patients (55% were anticitrullinated protein antibody (ACPA positive. The median M1/M2 ratio was 0.59 (0.31–1.11, interquartile range. There were no significant differences between the RA patients and healthy donors. There was a positive correlation between the M1/M2 ratio and the differentiated OC number in vitro in RA patients (ρ = 0.81, p < 0.001. The ACPA-positive patients had significantly higher M1/M2 ratios in vivo (p = 0.028 and significantly greater numbers of OCs in vitro (p = 0.005 than the ACPA-negative patients. Multivariable regression analysis revealed that the M1/M2 ratio was the sole significant contribution factor to in vitro osteoclastogenesis. RA patients with M1/M2 ratios >1 (having relatively more M1 monocytes had higher C-reactive protein and erythrocyte sedimentation rates than RA patients with M1/M2 ratios ≤1. M1-dominant monocytes in vitro produced higher concentrations of interleukin-6 upon stimulation with lipopolysaccharide than M2 monocytes.ConclusionM1/M2 monocytes imbalance strongly contributes to osteoclastogenesis of RA patients. Our findings cast M1 and M2 monocyte subsets in a new light as a new target of treatments for RA to prevent progression of osteoclastic bone destruction.

TLR4-mediated expression of Mac-1 in monocytes plays a pivotal role in monocyte adhesion to vascular endothelium.

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Seung Jin Lee

Full Text Available Toll-like receptor 4 (TLR4 is known to mediate monocyte adhesion to endothelial cells, however, its role on the expression of monocyte adhesion molecules is unclear. In the present study, we investigated the role of TLR4 on the expression of monocyte adhesion molecules, and determined the functional role of TLR4-induced adhesion molecules on monocyte adhesion to endothelial cells. When THP-1 monocytes were stimulated with Kdo2-Lipid A (KLA, a specific TLR4 agonist, Mac-1 expression was markedly increased in association with an increased adhesion of monocytes to endothelial cells. These were attenuated by anti-Mac-1 antibody, suggesting a functional role of TLR4-induced Mac-1 on monocyte adhesion to endothelial cells. In monocytes treated with MK886, a 5-lipoxygenase (LO inhibitor, both Mac-1 expression and monocyte adhesion to endothelial cells induced by KLA were markedly attenuated. Moreover, KLA increased the expression of mRNA and protein of 5-LO, suggesting a pivotal role of 5-LO on these processes. In in vivo studies, KLA increased monocyte adhesion to aortic endothelium of wild-type (WT mice, which was attenuated in WT mice treated with anti-Mac-1 antibody as well as in TLR4-deficient mice. Taken together, TLR4-mediated expression of Mac-1 in monocytes plays a pivotal role on monocyte adhesion to vascular endothelium, leading to increased foam cell formation in the development of atherosclerosis.

Investigating the role of rare heterozygous TREM2 variants in Alzheimer's disease and frontotemporal dementia

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Cuyvers, Elise; Bettens, Karolien; Philtjens, Stephanie; Van Langenhove, Tim; Gijselinck, Ilse; van der Zee, Julie; Engelborghs, Sebastiaan; Vandenbulcke, Mathieu; Van Dongen, Jasper; Geerts, Nathalie; Maes, Githa; Mattheijssens, Maria; Peeters, Karin; Cras, Patrick; Vandenberghe, Rik; De Deyn, Peter P.; Van Broeckhoven, Christine; Cruts, Marc; Sleegers, Kristel

Homozygous mutations in exon 2 of TREM2, a gene involved in Nasu-Hakola disease, can cause frontotemporal dementia (FTD). Moreover, a rare TREM2 exon 2 variant (p.R47H) was reported to increase the risk of Alzheimer's disease (AD) with an odds ratio as strong as that for APOE epsilon 4. We

Quantitative Glycoproteomic Analysis Identifies Platelet-Induced Increase of Monocyte Adhesion via the Up-Regulation of Very Late Antigen 5.

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Huang, Jiqing; Kast, Juergen

2015-08-07

Physiological stimuli, such as thrombin, or pathological stimuli, such as lysophosphatidic acid (LPA), activate platelets circulating in blood. Once activated, platelets bind to monocytes via P-selectin-PSGL-1 interactions but also release the stored contents of their granules. These platelet releasates, in addition to direct platelet binding, activate monocytes and facilitate their recruitment to atherosclerotic sites. Consequently, understanding the changes platelet releasates induce in monocyte membrane proteins is critical. We studied the glyco-proteome changes of THP-1 monocytic cells affected by LPA- or thrombin-induced platelet releasates. We employed lectin affinity chromatography combined with filter aided sample preparation to achieve high glyco- and membrane protein and protein sequence coverage. Using stable isotope labeling by amino acids in cell culture, we quantified 1715 proteins, including 852 membrane and 500 glycoproteins, identifying the up-regulation of multiple proteins involved in monocyte extracellular matrix binding and transendothelial migration. Flow cytometry indicated expression changes of integrin α5, integrin β1, PECAM-1, and PSGL-1. The observed increase in monocyte adhesion to fibronectin was determined to be mediated by the up-regulation of very late antigen 5 via a P-selectin-PSGL-1 independent mechanism. This novel aspect could be validated on CD14+ human primary monocytes, highlighting the benefits of the improved enrichment method regarding high membrane protein coverage and reliable quantification.

Leishmania infection modulates beta-1 integrin activation and alters the kinetics of monocyte spreading over fibronectin

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Figueira, Cláudio Pereira; Carvalhal, Djalma Gomes Ferrão; Almeida, Rafaela Andrade; Hermida, Micely d’ El-Rei; Touchard, Dominique; Robert, Phillipe; Pierres, Anne; Bongrand, Pierre; dos-Santos, Washington LC

2015-01-01

Contact with Leishmania leads to a decreases in mononuclear phagocyte adherence to connective tissue. In this work, we studied the early stages of bond formation between VLA4 and fibronectin, measured the kinetics of membrane alignment and the monocyte cytoplasm spreading area over a fibronectin-coated surface, and studied the expression of high affinity integrin epitope in uninfected and Leishmania-infected human monocytes. Our results show that the initial VLA4-mediated interaction of Leishmania-infected monocyte with a fibronectin-coated surface is preserved, however, the later stage, leukocyte spreading over the substrate is abrogated in Leishmania-infected cells. The median of spreading area was 72 [55–89] μm2 for uninfected and 41 [34–51] μm2 for Leishmania-infected monocyte. This cytoplasm spread was inhibited using an anti-VLA4 blocking antibody. After the initial contact with the fibronectrin-coated surface, uninfected monocyte quickly spread the cytoplasm at a 15 μm2 s−1 ratio whilst Leishmania-infected monocytes only made small contacts at a 5.5 μm2 s−1 ratio. The expression of high affinity epitope by VLA4 (from 39 ± 21% to 14 ± 3%); and LFA1 (from 37 ± 32% to 18 ± 16%) molecules was reduced in Leishmania-infected monocytes. These changes in phagocyte function may be important for parasite dissemination and distribution of lesions in leishmaniasis. PMID:26249106

The diagnostic value of CRP, IL-8, PCT, and sTREM-1 in the detection of bacterial infections in pediatric oncology patients with febrile neutropenia

NARCIS (Netherlands)

Miedema, Karin G. E.; de Bont, Eveline S. J. M.; Elferink, Rob F. M. Oude; van Vliet, Michel J.; Nijhuis, Claudi S. M. Oude; Kamps, Willem A.; Tissing, Wim J. E.

2011-01-01

In this study, we evaluated C-reactive protein (CRP), interleukin (IL)-8, procalcitonin (PCT), and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) as predictors for bacterial infection in febrile neutropenia, plus their usefulness in febrile neutropenia during chemotherapy-induced

TREM2-transduced myeloid precursors mediate nervous tissue debris clearance and facilitate recovery in an animal model of multiple sclerosis.

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Kazuya Takahashi

2007-04-01

Full Text Available BACKGROUND: In multiple sclerosis, inflammation can successfully be prevented, while promoting repair is still a major challenge. Microglial cells, the resident phagocytes of the central nervous system (CNS, are hematopoietic-derived myeloid cells and express the triggering receptor expressed on myeloid cells 2 (TREM2, an innate immune receptor. Myeloid cells are an accessible source for ex vivo gene therapy. We investigated whether myeloid precursor cells genetically modified to express TREM2 affect the disease course of experimental autoimmune encephalomyelitis (EAE, an animal model of multiple sclerosis. METHODS AND FINDINGS: EAE was induced in mice by immunization with a myelin autoantigen. Intravenous application of TREM2-transduced bone marrow-derived myeloid precursor cells at the EAE peak led to an amelioration of clinical symptoms, reduction in axonal damage, and prevention of further demyelination. TREM2-transduced myeloid cells applied intravenously migrated into the inflammatory spinal cord lesions of EAE-diseased mice, showed increased lysosomal and phagocytic activity, cleared degenerated myelin, and created an anti-inflammatory cytokine milieu within the CNS. CONCLUSIONS: Intravenously applied bone marrow-derived and TREM2-tranduced myeloid precursor cells limit tissue destruction and facilitate repair within the murine CNS by clearance of cellular debris during EAE. TREM2 is a new attractive target for promotion of repair and resolution of inflammation in multiple sclerosis and other neuroinflammatory diseases.

Suppression of inflammatory and infection responses in lung macrophages by eucalyptus oil and its constituent 1,8-cineole: Role of pattern recognition receptors TREM-1 and NLRP3, the MAP kinase regulator MKP-1, and NFκB.

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Niket Yadav

Full Text Available Eucalyptus oil (EO used in traditional medicine continues to prove useful for aroma therapy in respiratory ailments; however, there is a paucity of information on its mechanism of action and active components. In this direction, we investigated EO and its dominant constituent 1,8-cineole (eucalyptol using the murine lung alveolar macrophage (AM cell line MH-S. In an LPS-induced AM inflammation model, pre-treatment with EO significantly reduced (P ≤0.01or 0.05 the pro-inflammatory mediators TNF-α, IL-1 (α and β, and NO, albeit at a variable rate and extent; 1,8-cineole diminished IL-1 and IL-6. In a mycobacterial-infection AM model, EO pre-treatment or post-treatment significantly enhanced (P ≤0.01 the phagocytic activity and pathogen clearance. 1,8-cineole also significantly enhanced the pathogen clearance though the phagocytic activity was not significantly altered. EO or 1,8-cineole pre-treatment attenuated LPS-induced inflammatory signaling pathways at various levels accompanied by diminished inflammatory response. Among the pattern recognition receptors (PRRs involved in LPS signaling, the TREM pathway surface receptor (TREM-1 was significantly downregulated. Importantly, the pre-treatments significantly downregulated (P ≤0.01 the intracellular PRR receptor NLRP3 of the inflammasome, which is consistent with the decrease in IL-1β secretion. Of the shared downstream signaling cascade for these PRR pathways, there was significant attenuation of phosphorylation of the transcription factor NF-κB and p38 (but increased phosphorylation of the other two MAP kinases, ERK1/2 and JNK1/2. 1,8-cineole showed a similar general trend except for an opposite effect on NF-κB and JNK1/2. In this context, either pre-treatment caused a significant downregulation of MKP-1 phosphatase, a negative regulator of MAPKs. Collectively, our results demonstrate that the anti-inflammatory activity of EO and 1,8-cineole is modulated via selective downregulation

PECAM-1 polymorphism affects monocyte adhesion to endothelial cells.

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Goodman, Reyna S; Kirton, Christopher M; Oostingh, Gertie J; Schön, Michael P; Clark, Michael R; Bradley, J Andrew; Taylor, Craig J

2008-02-15

Platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) plays an important role in leukocyte-endothelial cell adhesion and transmigration. Single nucleotide polymorphisms of PECAM-1 encoding amino acid substitutions at positions 98 leucine/valine (L/V), 536 serine/asparagine (S/N), and 643 arginine/glycine (R/G) occur in strong genetic linkage resulting in two common haplotypes (LSR and VNG). These PECAM-1 polymorphisms are associated with graft-versus-host disease after hematopoietic stem cell transplantation and with cardiovascular disease, but whether they influence PECAM-1 function is unknown. We examined the effect of homozygous and heterozygous expression of the PECAM-1 LSR and VNG genotypes on the adhesive interactions of peripheral blood monocytes and activated endothelial cell monolayers under shear stress in a flow-based cell adhesion assay. There was no difference in monocyte adhesion between the two homozygous genotypes of PECAM-1 but when monocytes expressed both alleles in heterozygous form, firm adhesion of monocytes to endothelial cells was markedly increased. PECAM-1 polymorphism expressed in homozygous or heterozygous form by endothelial cells did not influence monocyte adhesion. This is, to our knowledge, the first demonstration that PECAM-1 genotype can alter the level of monocyte binding to endothelial cells and a demonstration that heterozygous expression of a polymorphic protein may lead to altered function.

Relationships between High-mobility Group Protein B1 and Triggering Receptor Expressed on Myeloid Cells Concentrations in Gingival Crevicular Fluid and Chronic Periodontitis.

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Paknejad, Mojgan; Sattari, Mandana; Roozbahani, Zohreh; Ershadi, Morteza; Mehrfard, Ali

2016-10-01

One of the inflammatory mediators which is secreted by inflammatory cells is high-mobility group protein B1 (HMGB1). Interaction of HMGB1 and toll-like receptors (TLRs) leads to increased production of inflammatory cytokines. On the other hand, it was shown that triggering receptor expressed on myeloid cells (TREM-1) also can be activated by TLRs, and its soluble form (sTREM-1) can be formed by cleaving of membrane-bound form of TREM-1 proteinases. Since there is not enough knowledge about the precise role of HMGB1 and sTREM-1 in periodontal diseases, the aim of this study was to evaluate the concentration of HMGB1 and sTREM-1 in gingival crevicular fluid (GCF) samples of patients with chronic periodontitis. Gingival crevicular fluid (GCF) samples were obtained from a total of 24 individuals with clinically healthy gingiva and 24 patients with moderate to severe chronic periodontitis. For collecting GCF samples, periopapers were placed at the entrance of the crevice and left in position for 30 seconds. Then, they were stored at -80°C. Enzyme-linked immunosorbent assay (ELISA) was used for measuring the concentration of HMGB1 and sTREM-1 in GCF samples. The concentration of HMGB1 (pchronic periodontitis group. In addition, there was a significant positive correlation between HMGB1 and sTREM-1 concentration in chronic periodontitis group (pperiodontal tissues and they can promote inflammatory process, which leads to tissue destruction.

Monocyte-lymphocyte fusion induced by the HIV-1 envelope generates functional heterokaryons with an activated monocyte-like phenotype

International Nuclear Information System (INIS)

Martínez-Méndez, David; Rivera-Toledo, Evelyn; Ortega, Enrique; Licona-Limón, Ileana; Huerta, Leonor

2017-01-01

Enveloped viruses induce cell-cell fusion when infected cells expressing viral envelope proteins interact with target cells, or through the contact of cell-free viral particles with adjoining target cells. CD4"+ T lymphocytes and cells from the monocyte-macrophage lineage express receptors for HIV envelope protein. We have previously reported that lymphoid Jurkat T cells expressing the HIV-1 envelope protein (Env) can fuse with THP-1 monocytic cells, forming heterokaryons with a predominantly myeloid phenotype. This study shows that the expression of monocytic markers in heterokaryons is stable, whereas the expression of lymphoid markers is mostly lost. Like THP-1 cells, heterokaryons exhibited FcγR-dependent phagocytic activity and showed an enhanced expression of the activation marker ICAM-1 upon stimulation with PMA. In addition, heterokaryons showed morphological changes compatible with maturation, and high expression of the differentiation marker CD11b in the absence of differentiation-inducing agents. No morphological change nor increase in CD11b expression were observed when an HIV-fusion inhibitor blocked fusion, or when THP-1 cells were cocultured with Jurkat cells expressing a non-fusogenic Env protein, showing that differentiation was not induced merely by cell-cell interaction but required cell-cell fusion. Inhibition of TLR2/TLR4 signaling by a TIRAP inhibitor greatly reduced the expression of CD11b in heterokaryons. Thus, lymphocyte-monocyte heterokaryons induced by HIV-1 Env are stable and functional, and fusion prompts a phenotype characteristic of activated monocytes via intracellular TLR2/TLR4 signaling. - Highlights: • Jurkat T cells expressing the HIV-1 envelope fuse with THP-1 monocytes. • Heterokaryons display a dominant myeloid phenotype and monocyte function. • Heterokaryons exhibit activation features in the absence of activation agents. • Activation is not due to cell-cell interaction but requires cell-cell fusion. • The

Monocyte-lymphocyte fusion induced by the HIV-1 envelope generates functional heterokaryons with an activated monocyte-like phenotype

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Martínez-Méndez, David; Rivera-Toledo, Evelyn; Ortega, Enrique; Licona-Limón, Ileana; Huerta, Leonor, E-mail: leonorhh@biomedicas.unam.mx

2017-03-01

Enveloped viruses induce cell-cell fusion when infected cells expressing viral envelope proteins interact with target cells, or through the contact of cell-free viral particles with adjoining target cells. CD4{sup +} T lymphocytes and cells from the monocyte-macrophage lineage express receptors for HIV envelope protein. We have previously reported that lymphoid Jurkat T cells expressing the HIV-1 envelope protein (Env) can fuse with THP-1 monocytic cells, forming heterokaryons with a predominantly myeloid phenotype. This study shows that the expression of monocytic markers in heterokaryons is stable, whereas the expression of lymphoid markers is mostly lost. Like THP-1 cells, heterokaryons exhibited FcγR-dependent phagocytic activity and showed an enhanced expression of the activation marker ICAM-1 upon stimulation with PMA. In addition, heterokaryons showed morphological changes compatible with maturation, and high expression of the differentiation marker CD11b in the absence of differentiation-inducing agents. No morphological change nor increase in CD11b expression were observed when an HIV-fusion inhibitor blocked fusion, or when THP-1 cells were cocultured with Jurkat cells expressing a non-fusogenic Env protein, showing that differentiation was not induced merely by cell-cell interaction but required cell-cell fusion. Inhibition of TLR2/TLR4 signaling by a TIRAP inhibitor greatly reduced the expression of CD11b in heterokaryons. Thus, lymphocyte-monocyte heterokaryons induced by HIV-1 Env are stable and functional, and fusion prompts a phenotype characteristic of activated monocytes via intracellular TLR2/TLR4 signaling. - Highlights: • Jurkat T cells expressing the HIV-1 envelope fuse with THP-1 monocytes. • Heterokaryons display a dominant myeloid phenotype and monocyte function. • Heterokaryons exhibit activation features in the absence of activation agents. • Activation is not due to cell-cell interaction but requires cell-cell fusion. • The

Sialoadhesin expressed on IFN-induced monocytes binds HIV-1 and enhances infectivity.

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Hans Rempel

2008-04-01

Full Text Available HIV-1 infection dysregulates the immune system and alters gene expression in circulating monocytes. Differential gene expression analysis of CD14(+ monocytes from subjects infected with HIV-1 revealed increased expression of sialoadhesin (Sn, CD169, Siglec 1, a cell adhesion molecule first described in a subset of macrophages activated in chronic inflammatory diseases.We analyzed sialoadhesin expression on CD14(+ monocytes by flow cytometry and found significantly higher expression in subjects with elevated viral loads compared to subjects with undetectable viral loads. In cultured CD14(+ monocytes isolated from healthy individuals, sialoadhesin expression was induced by interferon-alpha and interferon-gamma but not tumor necrosis factor-alpha. Using a stringent binding assay, sialoadhesin-expressing monocytes adsorbed HIV-1 through interaction with the sialic acid residues on the viral envelope glycoprotein gp120. Furthermore, monocytes expressing sialoadhesin facilitated HIV-1 trans infection of permissive cells, which occurred in the absence of monocyte self-infection.Increased sialoadhesin expression on CD14(+ monocytes occurred in response to HIV-1 infection with maximum expression associated with high viral load. We show that interferons induce sialoadhesin in primary CD14(+ monocytes, which is consistent with an antiviral response during viremia. Our findings suggest that circulating sialoadhesin-expressing monocytes are capable of binding HIV-1 and effectively delivering virus to target cells thereby enhancing the distribution of HIV-1. Sialoadhesin could disseminate HIV-1 to viral reservoirs during monocyte immunosurveillance or migration to sites of inflammation and then facilitate HIV-1 infection of permissive cells.

Moderate restriction of macrophage-tropic human immunodeficiency virus type 1 by SAMHD1 in monocyte-derived macrophages.

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Taya, Kahoru; Nakayama, Emi E; Shioda, Tatsuo

2014-01-01

Macrophage-tropic human immunodeficiency virus type 1 (HIV-1) strains are able to grow to high titers in human monocyte-derived macrophages. However, it was recently reported that cellular protein SAMHD1 restricts HIV-1 replication in human cells of the myeloid lineage, including monocyte-derived macrophages. Here we show that degradation of SAMHD1 in monocyte-derived macrophages was associated with moderately enhanced growth of the macrophage-tropic HIV-1 strain. SAMHD1 degradation was induced by treating target macrophages with vesicular stomatitis virus glycoprotein-pseudotyped human immunodeficiency virus type 2 (HIV-2) particles containing viral protein X. For undifferentiated monocytes, HIV-2 particle treatment allowed undifferentiated monocytes to be fully permissive for productive infection by the macrophage-tropic HIV-1 strain. In contrast, untreated monocytes were totally resistant to HIV-1 replication. These results indicated that SAMHD1 moderately restricts even a macrophage-tropic HIV-1 strain in monocyte-derived macrophages, whereas the protein potently restricts HIV-1 replication in undifferentiated monocytes.

Cytoprotection: Immune and Matrix Modulation of Tissue Repair

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2013-04-01

TREM-2 and DAP12, and tested them in THP -1 cells, a monocyte-like cell line  Initiated tests of additional antibodies for detection of TREM-2 and...interactions. The goal of Aim 2 is to develop an engineered tissue model (a “myobridge” for replacement of skeletal muscle) and use it as a test -bed to...Regulation Task 1 (Months 1–9) Develop and test stable, shear-resistant HMW-HA/fibrillar collagen hydrogels on dye-cut 2.9 mm nylon mesh rings

Zinc oxide nanoparticles induce migration and adhesion of monocytes to endothelial cells and accelerate foam cell formation

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Suzuki, Yuka; Tada-Oikawa, Saeko [Graduate School of Regional Innovation Studies, Mie University, Tsu (Japan); Ichihara, Gaku [Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya (Japan); Yabata, Masayuki; Izuoka, Kiyora [Graduate School of Regional Innovation Studies, Mie University, Tsu (Japan); Suzuki, Masako; Sakai, Kiyoshi [Nagoya City Public Health Research Institute, Nagoya (Japan); Ichihara, Sahoko, E-mail: saho@gene.mie-u.ac.jp [Graduate School of Regional Innovation Studies, Mie University, Tsu (Japan)

2014-07-01

Metal oxide nanoparticles are widely used in industry, cosmetics, and biomedicine. However, the effects of exposure to these nanoparticles on the cardiovascular system remain unknown. The present study investigated the effects of nanosized TiO{sub 2} and ZnO particles on the migration and adhesion of monocytes, which are essential processes in atherosclerogenesis, using an in vitro set-up of human umbilical vein endothelial cells (HUVECs) and human monocytic leukemia cells (THP-1). We also examined the effects of exposure to nanosized metal oxide particles on macrophage cholesterol uptake and foam cell formation. The 16-hour exposure to ZnO particles increased the level of monocyte chemotactic protein-1 (MCP-1) and induced the migration of THP-1 monocyte mediated by increased MCP-1. Exposure to ZnO particles also induced adhesion of THP-1 cells to HUVECs. Moreover, exposure to ZnO particles, but not TiO{sub 2} particles, upregulated the expression of membrane scavenger receptors of modified LDL and increased cholesterol uptake in THP-1 monocytes/macrophages. In the present study, we found that exposure to ZnO particles increased macrophage cholesterol uptake, which was mediated by an upregulation of membrane scavenger receptors of modified LDL. These results suggest that nanosized ZnO particles could potentially enhance atherosclerogenesis and accelerate foam cell formation. - Highlights: • Effects of metal oxide nanoparticles on foam cell formation were investigated. • Exposure to ZnO nanoparticles induced migration and adhesion of monocytes. • Exposure to ZnO nanoparticles increased macrophage cholesterol uptake. • Expression of membrane scavenger receptors of modified LDL was also increased. • These effects were not observed after exposure to TiO{sub 2} nanoparticles.

Global analysis of glycoproteins identifies markers of endotoxin tolerant monocytes and GPR84 as a modulator of TNFα expression.

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Müller, Mario M; Lehmann, Roland; Klassert, Tilman E; Reifenstein, Stella; Conrad, Theresia; Moore, Christoph; Kuhn, Anna; Behnert, Andrea; Guthke, Reinhard; Driesch, Dominik; Slevogt, Hortense

2017-04-12

Exposure of human monocytes to lipopolysaccharide (LPS) induces a temporary insensitivity to subsequent LPS challenges, a cellular state called endotoxin tolerance. In this study, we investigated the LPS-induced global glycoprotein expression changes of tolerant human monocytes and THP-1 cells to identify markers and glycoprotein targets capable to modulate the immunosuppressive state. Using hydrazide chemistry and LC-MS/MS analysis, we analyzed glycoprotein expression changes during a 48 h LPS time course. The cellular snapshots at different time points identified 1491 glycoproteins expressed by monocytes and THP-1 cells. Label-free quantitative analysis revealed transient or long-lasting LPS-induced expression changes of secreted or membrane-anchored glycoproteins derived from intracellular membrane coated organelles or from the plasma membrane. Monocytes and THP-1 cells demonstrated marked differences in glycoproteins differentially expressed in the tolerant state. Among the shared differentially expressed glycoproteins G protein-coupled receptor 84 (GPR84) was identified as being capable of modulating pro-inflammatory TNFα mRNA expression in the tolerant cell state when activated with its ligand Decanoic acid.

Tailored HIV-1 vectors for genetic modification of primary human dendritic cells and monocytes.

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Durand, Stéphanie; Nguyen, Xuan-Nhi; Turpin, Jocelyn; Cordeil, Stephanie; Nazaret, Nicolas; Croze, Séverine; Mahieux, Renaud; Lachuer, Joël; Legras-Lachuer, Catherine; Cimarelli, Andrea

2013-01-01

Monocyte-derived dendritic cells (MDDCs) play a key role in the regulation of the immune system and are the target of numerous gene therapy applications. The genetic modification of MDDCs is possible with human immunodeficiency virus type 1 (HIV-1)-derived lentiviral vectors (LVs) but requires high viral doses to bypass their natural resistance to viral infection, and this in turn affects their physiological properties. To date, a single viral protein is able to counter this restrictive phenotype, Vpx, a protein derived from members of the HIV-2/simian immunodeficiency virus SM lineage that counters at least two restriction factors present in myeloid cells. By tagging Vpx with a short heterologous membrane-targeting domain, we have obtained HIV-1 LVs incorporating high levels of this protein (HIV-1-Src-Vpx). These vectors efficiently transduce differentiated MDDCs and monocytes either as previously purified populations or as populations within unsorted peripheral blood mononuclear cells (PBMCs). In addition, these vectors can be efficiently pseudotyped with receptor-specific envelopes, further restricting their cellular tropism almost uniquely to MDDCs. Compared to conventional HIV-1 LVs, these novel vectors allow for an efficient genetic modification of MDDCs and, more importantly, do not cause their maturation or affect their survival, which are unwanted side effects of the transduction process. This study describes HIV-1-Src-Vpx LVs as a novel potent tool for the genetic modification of differentiated MDDCs and of circulating monocyte precursors with strong potential for a wide range of gene therapy applications.

Soluble vascular endothelial growth factor (VEGF) receptor-1 inhibits migration of human monocytic THP-1 cells in response to VEGF.

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Zhu, Cansheng; Xiong, Zhaojun; Chen, Xiaohong; Lu, Zhengqi; Zhou, Guoyu; Wang, Dunjing; Bao, Jian; Hu, Xueqiang

2011-08-01

We aimed to investigate the regulation and contribution of vascular endothelial growth factor (VEGF) and sFlt-1(1-3) to human monocytic THP-1 migration. Ad-sFlt-1/FLAG, a recombinant adenovirus carrying the human sFlt-1(1-3) (the first three extracellular domains of FLT-1, the hVEGF receptor-1) gene, was constructed. L929 cells were infected with Ad-sFlt-1/FLAG and the expression of sFlt-1 was detected by immunofluorescent assay and ELISA. Corning(®) Transwell(®) Filter Inserts containing polyethylene terephthalate (PET) membranes with pore sizes of 3 μm were used as an experimental model to simulate THP-1 migration. Five VEGF concentrations (0, 0.1, 1, 10 and 100 ng/ml), four concentrations of sFlt-1(1-3)/FLAG expression supernatants (0.1, 1, 10 and 100 ng/ml), and monocyte chemoattractant protein-1 (MCP-1, 10 ng/ml) were used to test the ability of THP-1 cells to migrate through PET membranes. The sFlt-1(1-3) gene was successfully recombined into Ad-sFlt-1/FLAG. sFlt-1(1-3) was expressed in L929 cells transfected with Ad-sFlt-1/FLAG. THP-1 cell migration increased with increasing concentrations of VEGF, while cell migration decreased with increasing concentrations of sFlt1(1-3)/FLAG. sFlt1(1-3)/FLAG had no effect on MCP-1-induced cell migration. This study demonstrated that VEGF is able to elicit a migratory response in THP-1 cells, and that sFlt-1(1-3) is an effective inhibitor of THP-1 migration towards VEGF.

Candida albicans Targets a Lipid Raft/Dectin-1 Platform to Enter Human Monocytes and Induce Antigen Specific T Cell Responses.

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Valeria de Turris

Full Text Available Several pathogens have been described to enter host cells via cholesterol-enriched membrane lipid raft microdomains. We found that disruption of lipid rafts by the cholesterol-extracting agent methyl-β-cyclodextrin or by the cholesterol-binding antifungal drug Amphotericin B strongly impairs the uptake of the fungal pathogen Candida albicans by human monocytes, suggesting a role of raft microdomains in the phagocytosis of the fungus. Time lapse confocal imaging indicated that Dectin-1, the C-type lectin receptor that recognizes Candida albicans cell wall-associated β-glucan, is recruited to lipid rafts upon Candida albicans uptake by monocytes, supporting the notion that lipid rafts act as an entry platform. Interestingly disruption of lipid raft integrity and interference with fungus uptake do not alter cytokine production by monocytes in response to Candida albicans but drastically dampen fungus specific T cell response. In conclusion, these data suggest that monocyte lipid rafts play a crucial role in the innate and adaptive immune responses to Candida albicans in humans and highlight a new and unexpected immunomodulatory function of the antifungal drug Amphotericin B.

Monocyte chemoattractant protein 1, intercellular adhesion molecule 1, and vascular cell adhesion molecule 1 in exudative age-related macular degeneration.

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Jonas, Jost B; Tao, Yong; Neumaier, Michael; Findeisen, Peter

2010-10-01

To examine intraocular concentrations of monocyte chemoattractant protein 1 (MCP-1), soluble intercellular adhesion molecule 1 (sICAM-1), soluble vascular cell adhesion molecule 1 (sVCAM-1), and vascular endothelial growth factor (VEGF) in eyes with exudative age-related macular degeneration (AMD). The investigation included a study group of 28 patients (28 eyes) with exudative AMD and a control group of 25 patients (25 eyes) with cataract. The concentrations of MCP-1, sICAM-1, sVCAM-1, and VEGF in aqueous humor samples obtained during surgery were measured using a solid-phase chemiluminescence immunoassay. The study group as compared with the control group had higher aqueous concentrations of sICAM-1 (mean [SD], 844 [2073] vs 246 [206] pg/mL, respectively; P < .001), sVCAM-1 (mean [SD], 7978 [7120] vs 2999 [1426] pg/mL, respectively; P < .001), and MCP-1 (mean [SD], 587 [338] vs 435 [221] pg/mL, respectively; P = .07). The concentration of VEGF did not vary significantly between the groups (P = .76). The MCP-1 concentration was significantly associated with macular thickness (r = 0.40; P = .004). It decreased significantly with the type of subfoveal neovascular membrane (classic membrane type, occult membrane, retinal pigment epithelium detachment) (P = .009). The concentrations of sICAM-1, sVCAM-1, and VEGF were not significantly associated with membrane type and macular thickness (P ≥ .18). Concentrations of MCP-1, sICAM-1, and sVCAM-1 are significantly associated with exudative AMD, even in the presence of normal VEGF concentrations. Intraocular MCP-1 concentrations are correlated with the subfoveal neovascular membrane type and the amount of macular edema. One may infer that MCP-1, sICAM-1, and sVCAM-1 could potentially be additional target molecules in therapy for exudative AMD.

R47H Variant of TREM2 Associated With Alzheimer Disease in a Large Late-Onset Family

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Korvatska, Olena; Leverenz, James B.; Jayadev, Suman; McMillan, Pamela; Kurtz, Irina; Guo, Xindi; Rumbaugh, Malia; Matsushita, Mark; Girirajan, Santhosh; Dorschner, Michael O.; Kiianitsa, Kostantin; Yu, Chang-En; Brkanac, Zoran; Garden, Gwenn A.; Raskind, Wendy H.; Bird, Thomas D.

2016-01-01

Importance The R47H variant in the triggering receptor expressed on myeloid cells 2 gene (TREM2), a modulator of the immune response of microglia, is a strong genetic risk factor for Alzheimer disease (AD) and possibly other neurodegenerative disorders. Objective To investigate a large family with late-onset AD (LOAD), in which R47H cosegregated with 75% of cases. Design, Setting, and Participants This study includes genetic and pathologic studies of families with LOAD from 1985 to 2014. A total of 131 families with LOAD (751 individuals) were included from the University of Washington Alzheimer Disease Research Center. To identify LOAD genes/risk factors in the LOAD123 family with 21 affected members and 12 autopsies, we sequenced 4 exomes. Candidate variants were tested for cosegregation with the disease. TREM2 R47H was genotyped in an additional 130 families with LOAD. We performed clinical and neuropathological assessments of patients with and without R47H and evaluated the variant's effect on brain pathology, cellular morphology, and expression of microglial markers. Main Outcomes and Measures We assessed the effect of TREM2 genotype on age at onset and disease duration. We compared Braak and Consortium to Establish a Registry for Alzheimer's Disease scores, presence of α-synuclein and TAR DNA-binding protein 43 aggregates, and additional vascular or Parkinson pathology in TREM2 R47H carriers vs noncarriers. Microglial activation was assessed by quantitative immunohistochemistry and morphometry. Results Twelve of 16 patients with AD in the LOAD123 family carried R47H. Eleven patients with dementia had apolipoprotein E 4 (ApoE4) and R47H genotypes. We also found a rare missense variant, D353N, in a nominated AD risk gene, unc-5 homolog C (UNC5C), in 5 affected individuals in the LOAD123 family. R47H carriers demonstrated a shortened disease duration (mean [SD], 6.7 [2.8] vs 11.1 [6.6] years; 2-tailed t test; P = .04) and more frequent α-synucleinopathy. The

Effects of 17β-estradiol on the release of monocyte chemotactic protein-1 and MAPK activity in monocytes stimulated with peritoneal fluid from endometriosis patients.

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Lee, Dong-Hyung; Kim, Seung-Chul; Joo, Jong-Kil; Kim, Hwi-Gon; Na, Young-Jin; Kwak, Jong-Young; Lee, Kyu-Sup

2012-03-01

Hormones and inflammation have been implicated in the pathological process of endometriosis; therefore, we investigated the combined effects of 17β-estradiol (E2) and peritoneal fluid obtained from patients with endometriosis (ePF) or a control peritoneal fluid (cPF) obtained from patients without endometriosis on the release of monocyte chemotactic protein-1 (MCP-1) by monocytes and the role of signaling pathways. Monocytes were cultured with ePF and cPF in the presence of E2; the MCP-1 levels in the supernatants were then measured by ELISA. In addition, mitogen activated protein kinase (MAPK) activation was measured by Western blotting of phosphorylated proteins. E2 down-regulated MCP-1 release by lipopolysaccharide- or cPF-treated monocytes, but failed to suppress its release by ePF-treated monocytes. The release of MCP-1 by ePF- and cPF-treated monocytes was efficiently abrogated by p38 mitogen activated protein kinase (MAPK) inhibitors; however, the MCP-1 release by cPF-treated monocytes, but not by ePF-treated monocytes, was blocked by a MAPK kinase inhibitor. In addition, ePF and cPF induced the phosphorylation of extracellular stress regulated kinase (ERK)1/2, p38 MAPK and c-Jun N-terminal kinase (JNK). E2 decreased the phosphorylation of p38 MAPK, but not ERK1/2 in ePF-treated monocytes; however, E2 decreased the phosphorylation of p38 MAPK, ERK1/2 and JNK in cPF-treated monocytes. The ability of E2 to modulate MCP-1 production is impaired in ePF-treated monocytes, which may be related to regulation of MAPK activity. These findings suggest that the failure of E2 to suppress ePF-treated production of MCP-1 may be involved in the pathogenesis of endometriosis. © 2012 The Authors. Journal of Obstetrics and Gynaecology Research © 2012 Japan Society of Obstetrics and Gynecology.

Increased MCP-1 gene expression in monocytes of severe OSA patients and under intermittent hypoxia.

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Chuang, Li-Pang; Chen, Ning-Hung; Lin, Yuling; Ko, Wen-Shan; Pang, Jong-Hwei S

2016-03-01

Obstructive sleep apnea (OSA) is known to be a risk factor of coronary artery disease. Monocyte chemoattractant protein-1 (MCP-1), as a critical factor for monocyte infiltration, is known to play a role in the development of atherosclerosis. This study aimed to investigate the effect of intermittent hypoxia, the hallmark of OSA, on the MCP-1 expression of monocytes. Peripheral blood was sampled from 61 adults enrolled for suspected OSA. RNA was prepared from the isolated monocytes for the analysis of MCP-1. The effect of in vitro intermittent hypoxia on the regulation and function of MCP-1 was investigated on THP-1 monocytic cells and human monocytes. The mRNA and secreted protein levels were investigated by RT/real-time PCR and enzyme-linked immunosorbent assay, respectively. Monocytic MCP-1 gene expression was found to be increased significantly in severe OSA patients. In vitro intermittent hypoxia was demonstrated to increase the mRNA and protein expression levels of MCP-1 dose- and time-dependently in THP-1 monocytic cells. The MCP-1 mRNA expression in monocytes isolated from OSA patient was induced to a much higher level compared to that from normal control. Pre-treatment with inhibitor for p42/44 MAPK or p38 MAPK suppressed the activation of MCP-1 expression by intermittent hypoxia. This is the first study to demonstrate the increase of MCP-1 gene expression in monocytes of severe OSA patients. In addition, monocytic MCP-1 gene expression can be induced under intermittent hypoxia.

Abnormal monocyte recruitment and collateral artery formation in monocyte chemoattractant protein-1 deficient mice

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Voskuil, Michiel; Hoefer, Imo E.; van Royen, Niels; Hua, Jing; de Graaf, Stijn; Bode, Christoph; Buschmann, Ivo R.; Piek, Jan J.

2004-01-01

Monocyte chemoattractant protein 1 (MCP-1) has been shown to be effective for the stimulation of collateral artery formation in small and large animal models. The availability of a genetic knockout mouse enables evaluation of the importance of the role of MCP-1 in the natural course of collateral

Monocyte chemoattractant protein-1 (MCP-1 regulates macrophage cytotoxicity in abdominal aortic aneurysm.

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Qiwei Wang

Full Text Available AIMS: In abdominal aortic aneurysm (AAA, macrophages are detected in the proximity of aortic smooth muscle cells (SMCs. We have previously demonstrated in a murine model of AAA that apoptotic SMCs attract monocytes and other leukocytes by producing MCP-1. Here we tested whether infiltrating macrophages also directly contribute to SMC apoptosis. METHODS AND RESULTS: Using a SMC/RAW264.7 macrophage co-culture system, we demonstrated that MCP-1-primed RAWs caused a significantly higher level of apoptosis in SMCs as compared to control macrophages. Next, we detected an enhanced Fas ligand (FasL mRNA level and membrane FasL protein expression in MCP-1-primed RAWs. Neutralizing FasL blocked SMC apoptosis in the co-culture. In situ proximity ligation assay showed that SMCs exposed to primed macrophages contained higher levels of receptor interacting protein-1 (RIP1/Caspase 8 containing cell death complexes. Silencing RIP1 conferred apoptosis resistance to SMCs. In the mouse elastase injury model of aneurysm, aneurysm induction increased the level of RIP1/Caspase 8 containing complexes in medial SMCs. Moreover, TUNEL-positive SMCs in aneurysmal tissues were frequently surrounded by CD68(+/FasL(+ macrophages. Conversely, elastase-treated arteries from MCP-1 knockout mice display a reduction of both macrophage infiltration and FasL expression, which was accompanied by diminished apoptosis of SMCs. CONCLUSION: Our data suggest that MCP-1-primed macrophages are more cytotoxic. MCP-1 appears to modulate macrophage cytotoxicity by increasing the level of membrane bound FasL. Thus, we showed that MCP-1-primed macrophages kill SMCs through a FasL/Fas-Caspase8-RIP1 mediated mechanism.

Toxicity of nanotitanium dioxide (TiO2-NP) on human monocytes and their mitochondria.

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Ghanbary, Fatemeh; Seydi, Enaytollah; Naserzadeh, Parvaneh; Salimi, Ahmad

2018-03-01

The effect of nanotitanium dioxide (TiO 2 -NP) in human monocytes is still unknown. Therefore, an understanding of probable cytotoxicity of TiO 2 -NP on human monocytes and underlining the mechanisms involved is of significant interest. The aim of this study was to assess the cytotoxicity of TiO 2 -NP on human monocytes. Using biochemical and flow cytometry assessments, we demonstrated that addition of TiO 2 -NP at 10 μg/ml concentration to monocytes induced cytotoxicity following 12 h. The TiO 2 -NP-induced cytotoxicity on monocytes was associated with intracellular reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP) collapse, lysosomal membrane injury, lipid peroxidation, and depletion of glutathione. According to our results, TiO 2 -NP triggers oxidative stress and organelles damages in monocytes which are important cells in defense against foreign agents. Finally, our findings suggest that use of antioxidants and mitochondrial/lysosomal protective agents could be of benefit for the people in the exposure with TiO 2 -NP.

CD1 molecule expression on human monocytes induced by granulocyte-macrophage colony-stimulating factor.

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Kasinrerk, W; Baumruker, T; Majdic, O; Knapp, W; Stockinger, H

1993-01-15

In this paper we demonstrate that granulocyte-macrophage CSF (GM-CSF) specifically induces the expression of CD1 molecules, CD1a, CD1b and CD1c, upon human monocytes. CD1 molecules appeared upon monocytes on day 1 of stimulation with rGM-CSF, and expression was up-regulated until day 3. Monocytes cultured in the presence of LPS, FMLP, PMA, recombinant granulocyte-CSF, rIFN-gamma, rTNF-alpha, rIL-1 alpha, rIL-1 beta, and rIL-6 remained negative. The induction of CD1 molecules by rGM-CSF was restricted to monocytes, since no such effect was observed upon peripheral blood granulocytes, PBL, and the myeloid cell lines Monomac1, Monomac6, MV4/11, HL60, U937, THP1, KG1, and KG1A. CD1a mRNA was detectable in rGM-CSF-induced monocytes but not in those freshly isolated. SDS-PAGE and immunoblotting analyses of CD1a mAb VIT6 immunoprecipitate from lysate of rGM-CSF-activated monocytes revealed an appropriate CD1a polypeptide band of 49 kDa associated with beta 2-microglobulin. Expression of CD1 molecules on monocytes complements the distribution of these structures on accessory cells, and their specific induction by GM-CSF strengthens the suggestion that CD1 is a family of crucial structures required for interaction between accessory cells and T cells.

Age-dependent alterations of monocyte subsets and monocyte-related chemokine pathways in healthy adults

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Trautwein Christian

2010-06-01

Full Text Available Abstract Background Recent experimental approaches have unraveled essential migratory and functional differences of monocyte subpopulations in mice. In order to possibly translate these findings into human physiology and pathophysiology, human monocyte subsets need to be carefully revisited in health and disease. In analogy to murine studies, we hypothesized that human monocyte subsets dynamically change during ageing, potentially influencing their functionality and contributing to immunosenescence. Results Circulating monocyte subsets, surface marker and chemokine receptor expression were analyzed in 181 healthy volunteers (median age 42, range 18-88. Unlike the unaffected total leukocyte or total monocyte counts, non-classical CD14+CD16+ monocytes significantly increased with age, but displayed reduced HLA-DR and CX3CR1 surface expression in the elderly. Classical CD14++CD16- monocyte counts did not vary dependent on age. Serum MCP-1 (CCL2, but not MIP1α (CCL3, MIP1β (CCL4 or fractalkine (CX3CL1 concentrations increased with age. Monocyte-derived macrophages from old or young individuals did not differ with respect to cytokine release in vitro at steady state or upon LPS stimulation. Conclusions Our study demonstrates dynamic changes of circulating monocytes during ageing in humans. The expansion of the non-classical CD14+CD16+ subtype, alterations of surface protein and chemokine receptor expression as well as circulating monocyte-related chemokines possibly contribute to the preserved functionality of the monocyte pool throughout adulthood.

Microbial products activate monocytic cells through detergent-resistant membrane microdomains.

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Epelman, Slava; Berenger, Byron; Stack, Danuta; Neely, Graham G; Ma, Ling Ling; Mody, Christopher H

2008-12-01

Patients with cystic fibrosis suffer recurrent pulmonary infections that are characterized by an overactive yet ineffective and destructive inflammatory response that is associated with respiratory infections by Pseudomonas aeruginosa, a pathogen that produces a number of phlogistic molecules. To better understand this process, we used exoenzyme S (ExoS), one of the key P. aeruginosa-secreted exoproducts, which is known to stimulate cells via the Toll-like receptor (TLR) pathway. We found that ExoS induced proinflammatory cytokine production via the NF-kappaB, Erk1/2, and Src kinase pathways. Because Src kinases are concentrated within cholesterol-containing, detergent-resistant membrane microdomains (DRM) (also called lipid rafts) and DRM act as signaling platforms and amplifiers on the surface of cells, we addressed the role of DRM in ExoS signaling. ExoS bound directly to a subset of DRM and induced the phosphorylation of multiple proteins within DRM, including Src kinases. Disruption of DRM by cholesterol extraction prevented NF-kappaB and Erk 1/2 activation and TNF-alpha production in response to ExoS. Activation of monocytic cells by other TLR and Nod-like receptor agonists, such as lipoteichoic acid, lipopolysaccharide, and peptidoglycan, were also dependent on DRM, and disruption prevented TNF-alpha production. Disruption of DRM did not prevent ExoS binding but did release the Src kinase, Lyn, from the DRM fraction into the detergent-soluble fraction, a site in which Src kinases are not active. These studies show that ExoS, a TLR agonist, requires direct binding to DRM for optimal signaling, which suggests that DRM are possible therapeutic targets in cystic fibrosis.

Outer membrane vesicles from Brucella abortus promote bacterial internalization by human monocytes and modulate their innate immune response.

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Cora N Pollak

Full Text Available Outer membrane vesicles (OMVs released by some gram-negative bacteria have been shown to exert immunomodulatory effects that favor the establishment of the infection. The aim of the present study was to assess the interaction of OMVs from Brucella abortus with human epithelial cells (HeLa and monocytes (THP-1, and the potential immunomodulatory effects they may exert. Using confocal microscopy and flow cytometry, FITC-labeled OMVs were shown to be internalized by both cell types. Internalization was shown to be partially mediated by clathrin-mediated endocytosis. Pretreatment of THP-1 cells with Brucella OMVs inhibited some cytokine responses (TNF-α and IL-8 to E. coli LPS, Pam3Cys or flagellin (TLR4, TLR2 and TLR5 agonists, respectively. Similarly, pretreatment with Brucella OMVs inhibited the cytokine response of THP-1 cells to B. abortus infection. Treatment of THP-1 cells with OMVs during IFN-γ stimulation reduced significantly the inducing effect of this cytokine on MHC-II expression. OMVs induced a dose-dependent increase of ICAM-1 expression on THP-1 cells and an increased adhesion of these cells to human endothelial cells. The addition of OMVs to THP-1 cultures before the incubation with live B. abortus resulted in increased numbers of adhered and internalized bacteria as compared to cells not treated with OMVs. Overall, these results suggest that OMVs from B. abortus exert cellular effects that promote the internalization of these bacteria by human monocytes, but also downregulate the innate immune response of these cells to Brucella infection. These effects may favor the persistence of Brucella within host cells.

Myosins 1 and 6, myosin light chain kinase, actin and microtubules cooperate during antibody-mediated internalisation and trafficking of membrane-expressed viral antigens in feline infectious peritonitis virus infected monocytes.

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Dewerchin, Hannah L; Desmarets, Lowiese M; Noppe, Ytse; Nauwynck, Hans J

2014-02-12

Monocytes infected with feline infectious peritonitis virus, a coronavirus, express viral proteins in their plasma membranes. Upon binding of antibodies, these proteins are quickly internalised through a new clathrin- and caveolae-independent internalisation pathway. By doing so, the infected monocytes can escape antibody-dependent cell lysis. In the present study, we investigated which kinases and cytoskeletal proteins are of importance during internalisation and subsequent intracellular transport. The experiments showed that myosin light chain kinase (MLCK) and myosin 1 are crucial for the initiation of the internalisation. With co-localisation stainings, it was found that MLCK and myosin 1 co-localise with antigens even before internalisation started. Myosin 6 co-localised with the internalising complexes during passage through the cortical actin, were it might play a role in moving or disintegrating actin filaments, to overcome the actin barrier. One minute after internalisation started, vesicles had passed the cortical actin, co-localised with microtubules and association with myosin 6 was lost. The vesicles were further transported over the microtubules and accumulated at the microtubule organising centre after 10 to 30 min. Intracellular trafficking over microtubules was mediated by MLCK, myosin 1 and a small actin tail. Since inhibiting MLCK with ML-7 was so efficient in blocking the internalisation pathway, this target can be used for the development of a new treatment for FIPV.

The rare TREM2 R47H variant exerts only a modest effect on Alzheimer disease risk.

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Hooli, Basavaraj V; Parrado, Antonio R; Mullin, Kristina; Yip, Wai-Ki; Liu, Tian; Roehr, Johannes T; Qiao, Dandi; Jessen, Frank; Peters, Oliver; Becker, Tim; Ramirez, Alfredo; Lange, Christoph; Bertram, Lars; Tanzi, Rudolph E

2014-10-07

Recently, 2 independent studies reported that a rare missense variant, rs75932628 (R47H), in exon 2 of the gene encoding the "triggering receptor expressed on myeloid cells 2" (TREM2) significantly increases the risk of Alzheimer disease (AD) with an effect size comparable to that of the APOE ε4 allele. In this study, we attempted to replicate the association between rs75932628 and AD risk by directly genotyping rs75932628 in 2 independent Caucasian family cohorts consisting of 927 families (with 1,777 affected and 1,235 unaffected) and in 2 Caucasian case-control cohorts composed of 1,314 cases and 1,609 controls. In addition, we imputed genotypes in 3 independent Caucasian case-control cohorts containing 1,906 cases and 1,503 controls. Meta-analysis of the 2 family-based and the 5 case-control cohorts yielded a p value of 0.0029, while the overall summary estimate (using case-control data only) resulted in an odds ratio of 1.67 (95% confidence interval 0.95-2.92) for the association between the TREM2 R47H and increased AD risk. While our results serve to confirm the association between R47H and risk of AD, the observed effect on risk was substantially smaller than that previously reported. © 2014 American Academy of Neurology.

Up-regulation of endothelial monocyte chemoattractant protein-1 by coplanar PCB77 is caveolin-1-dependent

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Majkova, Zuzana; Smart, Eric; Toborek, Michal; Hennig, Bernhard

2009-01-01

Atherosclerosis, the primary cause of heart disease and stroke is initiated in the vascular endothelium, and risk factors for its development include environmental exposure to persistent organic pollutants. Caveolae are membrane microdomains involved in regulation of many signaling pathways, and in particular in endothelial cells. We tested the hypothesis that intact caveolae are required for coplanar PCB77-induced up-regulation of monocyte chemoattractant protein-1 (MCP-1), an endothelium-derived chemokine that attracts monocytes into sub-endothelial space in early stages of the atherosclerosis development. Atherosclerosis-prone LDL-R -/- mice (control) or caveolin-1 -/- /LDL-R -/- mice were treated with PCB77. PCB77 induced aortic mRNA expression and plasma protein levels of MCP-1 in control, but not caveolin-1 -/- /LDL-R -/- mice. To study the mechanism of this effect, primary endothelial cells were used. PCB77 increased MCP-1 levels in endothelial cells in a time- and concentration-dependent manner. This effect was abolished by caveolin-1 silencing using siRNA. Also, MCP-1 up-regulation by PCB77 was prevented by inhibiting p38 and c-Jun N-terminal kinase (JNK), but not ERK1/2, suggesting regulatory functions via p38 and JNK MAPK pathways. Finally, pre-treatment of endothelial cells with the aryl hydrocarbon receptor (AhR) inhibitor α-naphthoflavone (α-NF) partially blocked MCP-1 up-regulation. Thus, our data demonstrate that coplanar PCB77 can induce MCP-1 expression by endothelial cells and that this effect is mediated by AhR, as well as p 38 and JNK MAPK pathways. Intact caveolae are required for these processes both in vivo and in vitro. This further supports a key role for caveolae in vascular inflammation induced by persistent organic pollutants.

Imbalance of Circulating Monocyte Subsets and PD-1 Dysregulation in Q Fever Endocarditis: The Role of IL-10 in PD-1 Modulation

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Ka, Mignane B.; Gondois-Rey, Françoise; Capo, Christian; Textoris, Julien; Million, Mathieu; Raoult, Didier; Olive, Daniel; Mege, Jean-Louis

2014-01-01

Q fever endocarditis, a severe complication of Q fever, is associated with a defective immune response, the mechanisms of which are poorly understood. We hypothesized that Q fever immune deficiency is related to altered distribution and activation of circulating monocyte subsets. Monocyte subsets were analyzed by flow cytometry in peripheral blood mononuclear cells from patients with Q fever endocarditis and controls. The proportion of classical monocytes (CD14+CD16− monocytes) was similar in patients and controls. In contrast, the patients with Q fever endocarditis exhibited a decrease in the non-classical and intermediate subsets of monocytes (CD16+ monocytes). The altered distribution of monocyte subsets in Q fever endocarditis was associated with changes in their activation profile. Indeed, the expression of HLA-DR, a canonical activation molecule, and PD-1, a co-inhibitory molecule, was increased in intermediate monocytes. This profile was not restricted to CD16+ monocytes because CD4+ T cells also overexpressed PD-1. The mechanism leading to the overexpression of PD-1 did not require the LPS from C. burnetii but involved interleukin-10, an immunosuppressive cytokine. Indeed, the incubation of control monocytes with interleukin-10 led to a higher expression of PD-1 and neutralizing interleukin-10 prevented C. burnetii-stimulated PD-1 expression. Taken together, these results show that the immune suppression of Q fever endocarditis involves a cross-talk between monocytes and CD4+ T cells expressing PD-1. The expression of PD-1 may be useful to assess chronic immune alterations in Q fever endocarditis. PMID:25211350

The CD157-integrin partnership controls transendothelial migration and adhesion of human monocytes.

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Lo Buono, Nicola; Parrotta, Rossella; Morone, Simona; Bovino, Paola; Nacci, Giulia; Ortolan, Erika; Horenstein, Alberto L; Inzhutova, Alona; Ferrero, Enza; Funaro, Ada

2011-05-27

CD157, a member of the CD38 gene family, is an NAD-metabolizing ectoenzyme and a signaling molecule whose role in polarization, migration, and diapedesis of human granulocytes has been documented; however, the molecular events underpinning this role remain to be elucidated. This study focused on the role exerted by CD157 in monocyte migration across the endothelial lining and adhesion to extracellular matrix proteins. The results demonstrated that anti-CD157 antibodies block monocyte transmigration and adhesion to fibronectin and fibrinogen but that CD157 cross-linking is sufficient to overcome the block, suggesting an active signaling role for the molecule. Consistent with this is the observation that CD157 is prevalently located within the detergent-resistant membrane microdomains to which, upon clustering, it promotes the recruitment of β(1) and β(2) integrin, which, in turn, leads to the formation of a multimolecular complex favoring signal transduction. This functional cross-talk with integrins allows CD157 to act as a receptor despite its intrinsic structural inability to do so on its own. Intracellular signals mediated by CD157 rely on the integrin/Src/FAK (focal adhesion kinase) pathway, resulting in increased activity of the MAPK/ERK1/2 and the PI3K/Akt downstream signaling pathways, which are crucial in the control of monocyte transendothelial migration. Collectively, these findings indicate that CD157 acts as a molecular organizer of signaling-competent membrane microdomains and that it forms part of a larger molecular machine ruled by integrins. The CD157-integrin partnership provides optimal adhesion and transmigration of human monocytes.

Presence of estrogen receptors in human myeloid monocytic cells (THP-1 cell line).

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Cutolo, M; Villaggio, B; Bisso, A; Sulli, A; Coviello, D; Dayer, J M

2001-01-01

To test THP-1 cells for the presence of estrogen receptors (ER) since studies have demonstrated in vivo and in vitro, the influence of estrogens on cells involved in immune response (i.e. macrophages), and since it has been demonstrated that human myeloid monocytic THP-1 cells acquire phenotypic and functional macrophage-like features after incubation with several cytokines or pharmacological agents. Stimulation of THP-1 cells with phorbol myristate acetate (PMA) to prompt their differentiation into macrophage-like cells and evaluation of the possible induction of ER. The expression of ER was analyzed by immunocytochemical assay, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot analysis. After stimulation by PMA, the human myeloid monocytic THP-1 cells showed the presence of ER, together with markers of monocytic cell differentiation such as CD68, CD54 and HLA-DR. Estrogen effects may be exerted directly through ER on monocytes/macrophages. PMA-treated THP-1 cells may constitute a useful in vitro model to determine the effects of estrogens on macrophage-like cells and their implications in the inflammatory and immune processes.

Interaction studies reveal specific recognition of an anti-inflammatory polyphosphorhydrazone dendrimer by human monocytes.

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Ledall, Jérémy; Fruchon, Séverine; Garzoni, Matteo; Pavan, Giovanni M; Caminade, Anne-Marie; Turrin, Cédric-Olivier; Blanzat, Muriel; Poupot, Rémy

2015-11-14

Dendrimers are nano-materials with perfectly defined structure and size, and multivalency properties that confer substantial advantages for biomedical applications. Previous work has shown that phosphorus-based polyphosphorhydrazone (PPH) dendrimers capped with azabisphosphonate (ABP) end groups have immuno-modulatory and anti-inflammatory properties leading to efficient therapeutic control of inflammatory diseases in animal models. These properties are mainly prompted through activation of monocytes. Here, we disclose new insights into the molecular mechanisms underlying the anti-inflammatory activation of human monocytes by ABP-capped PPH dendrimers. Following an interdisciplinary approach, we have characterized the physicochemical and biological behavior of the lead ABP dendrimer with model and cell membranes, and compared this experimental set of data to predictive computational modelling studies. The behavior of the ABP dendrimer was compared to the one of an isosteric analog dendrimer capped with twelve azabiscarboxylate (ABC) end groups instead of twelve ABP end groups. The ABC dendrimer displayed no biological activity on human monocytes, therefore it was considered as a negative control. In detail, we show that the ABP dendrimer can bind both non-specifically and specifically to the membrane of human monocytes. The specific binding leads to the internalization of the ABP dendrimer by human monocytes. On the contrary, the ABC dendrimer only interacts non-specifically with human monocytes and is not internalized. These data indicate that the bioactive ABP dendrimer is recognized by specific receptor(s) at the surface of human monocytes.

Monocytic leukemias.

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Shaw, M T

1980-05-01

The monocytic leukemias may be subdivided into acute monocytic leukemia, acute myelomonocytic leukemia, and subacute and chronic myelomonocytic leukemia. The clinical features of acute monocytic and acute myelomonocytic leukemias are similar and are manifestations of bone marrow failure. Gingival hypertrophy and skin infiltration are more frequent in acute monocytic leukemia. Cytomorphologically the blast cells in acute monocytic leukemia may be undifferentiated or differentiated, whereas in the acute myelomonocytic variety there are mixed populations of monocytic and myeloblastic cells. Cytochemical characteristics include strongly positive reactions for nonspecific esterase, inhibited by fluoride. The functional characteristics of acute monocytic and acute myelomonocytic cells resemble those of monocytes and include glass adherence and phagocytoses, the presence of Fc receptors for IgG and C'3, and the production of colony stimulating activity. Subacute and chronic myelomonocytic leukemias are insidious and slowly progressive diseases characterized by anemia and peripheral blood monocytosis. Atypical monocytes called paramyeloid cells are characteristic. The drugs used in the treatment of acute monocytic and acute myelomonocytic leukemias include cytosine arabinoside, the anthracyclines, and VP 16-213. Drug therapy in subacute and chronic myelomonocytic leukemias is not usually indicated, although VP 16-213 has been claimed to be effective.

Heterogeneity of Bovine Peripheral Blood Monocytes

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Jamal Hussen

2017-12-01

Full Text Available Peripheral blood monocytes of several species can be divided into different subpopulations with distinct phenotypic and functional properties. Herein, we aim at reviewing published work regarding the heterogeneity of the recently characterized bovine monocyte subsets. As the heterogeneity of human blood monocytes was widely studied and reviewed, this work focuses on comparing bovine monocyte subsets with their human counterparts regarding their phenotype, adhesion and migration properties, inflammatory and antimicrobial functions, and their ability to interact with neutrophilic granulocytes. In addition, the differentiation of monocyte subsets into functionally polarized macrophages is discussed. Regarding phenotype and distribution in blood, bovine monocyte subsets share similarities with their human counterparts. However, many functional differences exist between monocyte subsets from the two species. In contrast to their pro-inflammatory functions in human, bovine non-classical monocytes show the lowest phagocytosis and reactive oxygen species generation capacity, an absent ability to produce the pro-inflammatory cytokine IL-1β after inflammasome activation, and do not have a role in the early recruitment of neutrophils into inflamed tissues. Classical and intermediate monocytes of both species also differ in their response toward major monocyte-attracting chemokines (CCL2 and CCL5 and neutrophil degranulation products (DGP in vitro. Such differences between homologous monocyte subsets also extend to the development of monocyte-derived macrophages under the influence of chemokines like CCL5 and neutrophil DGP. Whereas the latter induce the differentiation of M1-polarized macrophages in human, bovine monocyte-derived macrophages develop a mixed M1/M2 macrophage phenotype. Although only a few bovine clinical trials analyzed the correlation between changes in monocyte composition and disease, they suggest that functional differences between

Monocytes infiltrate the pancreas via the MCP-1/CCR2 pathway and differentiate into stellate cells.

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Kazuko Ino

Full Text Available Recent studies have shown that monocytes possess pluripotent plasticity. We previously reported that monocytes could differentiate into hepatic stellate cells. Although stellate cells are also present in the pancreas, their origin remains unclear. An accumulation of enhanced green fluorescent protein (EGFP(+CD45(- cells was observed in the pancreases and livers of chimeric mice, which were transplanted with a single hematopoietic stem cell isolated from EGFP-transgenic mice and treated with carbon tetrachloride (CCl4. Because the vast majority of EGFP(+CD45(- cells in the pancreas expressed stellate cell-associated antigens such as vimentin, desmin, glial fibrillary acidic protein, procollagen-I, and α-smooth muscle actin, they were characterized as pancreatic stellate cells (PaSCs. EGFP(+ PaSCs were also observed in CCl4-treated mice adoptively transferred with monocytes but not with other cell lineages isolated from EGFP-transgenic mice. The expression of monocyte chemoattractant protein-1 (MCP-1 and angiotensin II (Ang II increased in the pancreas of CCl4-treated mice and their respective receptors, C-C chemokine receptor 2 (CCR2 and Ang II type 1 receptor (AT1R, were expressed on Ly6C(high monocytes isolated from EGFP-transgenic mice. We examined the effect of an AT1R antagonist, irbesartan, which is also a CCR2 antagonist, on the migration of monocytes into the pancreas. Monocytes migrated toward MCP-1 but not Ang II in vitro. Irbesartan inhibited not only their in vitro chemotaxis but also in vivo migration of adoptively transferred monocytes from peripheral blood into the pancreas. Irbesartan treatment significantly reduced the numbers of EGFP(+F4/80(+CCR2(+ monocytic cells and EGFP(+ PaSCs in the pancreas of CCl4-treated chimeric mice receiving EGFP(+ bone marrow cells. A specific CCR2 antagonist RS504393 inhibited the occurrence of EGFP(+ PaSCs in injured mice. We propose that CCR2(+ monocytes migrate into the pancreas possibly via the

TREM-like transcript-1 protects against inflammation-associated hemorrhage by facilitating platelet aggregation in mice and humans

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Washington, A. Valance; Gibot, Sébastien; Acevedo, Ismael; Gattis, James; Quigley, Laura; Feltz, Robert; De La Mota, Alina; Schubert, Rebecca L.; Gomez-Rodriguez, Julio; Cheng, Jun; Dutra, Amalia; Pak, Evgenia; Chertov, Oleg; Rivera, Linette; Morales, Jessica; Lubkowski, Jacek; Hunter, Robert; Schwartzberg, Pamela L.; McVicar, Daniel W.

2009-01-01

Triggering receptor expressed on myeloid cells–like (TREM-like) transcript-1 (TLT-1), a type 1 single Ig domain orphan receptor specific to platelet and megakaryocyte α-granules, relocates to the platelet surface upon platelet stimulation. We found here that patients diagnosed with sepsis, in contrast to healthy individuals, had substantial levels of soluble TLT-1 (sTLT-1) in their plasma that correlated with the presence of disseminated intravascular coagulation. sTLT-1 bound to fibrinogen and augmented platelet aggregation in vitro. Furthermore, the cytoplasmic domain of TLT-1 could also bind ezrin/radixin/moesin family proteins, suggesting its ability to link fibrinogen to the platelet cytoskeleton. Accordingly, platelets of Treml1–/– mice failed to aggregate efficiently, extending tail-bleeding times. Lipopolysaccharide-treated Treml1–/– mice developed higher plasma levels of TNF and D-dimers than wild-type mice and were more likely to succumb during challenge. Finally, Treml1–/– mice were predisposed to hemorrhage associated with localized inflammatory lesions. Taken together, our findings suggest that TLT-1 plays a protective role during inflammation by dampening the inflammatory response and facilitating platelet aggregation at sites of vascular injury. Therefore, therapeutic modulation of TLT-1–mediated effects may provide clinical benefit to patients with hypercoagulatory conditions, including those associated with inflammation. PMID:19436112

The CD157-Integrin Partnership Controls Transendothelial Migration and Adhesion of Human Monocytes*

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Lo Buono, Nicola; Parrotta, Rossella; Morone, Simona; Bovino, Paola; Nacci, Giulia; Ortolan, Erika; Horenstein, Alberto L.; Inzhutova, Alona; Ferrero, Enza; Funaro, Ada

2011-01-01

CD157, a member of the CD38 gene family, is an NAD-metabolizing ectoenzyme and a signaling molecule whose role in polarization, migration, and diapedesis of human granulocytes has been documented; however, the molecular events underpinning this role remain to be elucidated. This study focused on the role exerted by CD157 in monocyte migration across the endothelial lining and adhesion to extracellular matrix proteins. The results demonstrated that anti-CD157 antibodies block monocyte transmigration and adhesion to fibronectin and fibrinogen but that CD157 cross-linking is sufficient to overcome the block, suggesting an active signaling role for the molecule. Consistent with this is the observation that CD157 is prevalently located within the detergent-resistant membrane microdomains to which, upon clustering, it promotes the recruitment of β1 and β2 integrin, which, in turn, leads to the formation of a multimolecular complex favoring signal transduction. This functional cross-talk with integrins allows CD157 to act as a receptor despite its intrinsic structural inability to do so on its own. Intracellular signals mediated by CD157 rely on the integrin/Src/FAK (focal adhesion kinase) pathway, resulting in increased activity of the MAPK/ERK1/2 and the PI3K/Akt downstream signaling pathways, which are crucial in the control of monocyte transendothelial migration. Collectively, these findings indicate that CD157 acts as a molecular organizer of signaling-competent membrane microdomains and that it forms part of a larger molecular machine ruled by integrins. The CD157-integrin partnership provides optimal adhesion and transmigration of human monocytes. PMID:21478153

EMMPRIN (CD147/basigin) mediates platelet-monocyte interactions in vivo and augments monocyte recruitment to the vascular wall.

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Schulz, C; von Brühl, M-L; Barocke, V; Cullen, P; Mayer, K; Okrojek, R; Steinhart, A; Ahmad, Z; Kremmer, E; Nieswandt, B; Frampton, J; Massberg, S; Schmidt, R

2011-05-01

Platelets play a central role in hemostasis, in inflammatory diseases such as atherosclerosis, and during thrombus formation following vascular injury. Thereby, platelets interact intensively with monocytes and enhance their recruitment to the vascular wall. To investigate the role of the extracellular matrix metalloproteinase inducer (EMMPRIN) in platelet-monocyte interactions. Isolated human monocytes were perfused in vitro over firmly adherent platelets to allow investigation of the role of EMMPRIN in platelet-monocyte interactions under flow conditions. Monocytes readily bound to surface-adherent platelets. Both antibody blockade and gene silencing of monocyte EMMPRIN substantially attenuated firm adhesion of monocytes to platelets at arterial and venous shear rates. In vivo, platelet interactions with the murine monocyte cell line ANA-1 were significantly decreased when ANA-1 cells were pretreated with EMMPRIN-silencing small interfering RNA prior to injection into wild-type mice. Using intravital microscopy, we showed that recruitment of EMMPRIN-silenced ANA-1 to the injured carotid artery was significantly reduced as compared with control cells. Further silencing of EMMPRIN resulted in significantly fewer ANA-1-platelet aggregates in the mouse circulation as determined by flow cytometry. Finally, we identified glycoprotein (GP)VI as a critical corresponding receptor on platelets that mediates interaction with monocyte EMMPRIN. Thus, blocking of GPVI inhibited the effect of EMMPRIN on firm monocyte adhesion to platelets under arterial flow conditions in vitro, and abrogated EMMPRIN-mediated platelet-monocyte aggregate formation in vivo. EMMPRIN supports platelet-monocyte interactions and promotes monocyte recruitment to the arterial wall. Therefore, EMMPRIN might represent a novel target to reduce vascular inflammation and atherosclerotic lesion development. © 2011 International Society on Thrombosis and Haemostasis.

Monocyte galactose/N-acetylgalactosamine-specific C-type lectin receptor stimulant immunotherapy of an experimental glioma. Part 1: stimulatory effects on blood monocytes and monocyte-derived cells of the brain

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Kushchayev SV

2012-09-01

Full Text Available Sergiy V Kushchayev,1 Tejas Sankar,1 Laura L Eggink,4,5 Yevgeniya S Kushchayeva,5 Philip C Wiener,1,5 J Kenneth Hoober,5,6 Jennifer Eschbacher,3 Ruolan Liu,2 Fu-Dong Shi,2 Mohammed G Abdelwahab,4 Adrienne C Scheck,4 Mark C Preul11Neurosurgery Research Laboratory, 2Neuroimmunology Laboratory, 3Department of Pathology, 4Neurooncology Research, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, 5School of Life Sciences, Arizona State University, Tempe, 6Susavion Biosciences, Inc, Tempe, AZ, USAObjectives: Immunotherapy with immunostimulants is an attractive therapy against gliomas. C-type lectin receptors specific for galactose/N-acetylgalactosamine (GCLR regulate cellular differentiation, recognition, and trafficking of monocyte-derived cells. A peptide mimetic of GCLR ligands (GCLRP was used to activate blood monocytes and populations of myeloid-derived cells against a murine glioblastoma.Methods: The ability of GCLRP to stimulate phagocytosis by human microglia and monocyte-derived cells of the brain (MDCB isolated from a human glioblastoma was initially assessed in vitro. Induction of activation markers on blood monocytes was assayed by flow cytometry after administration of GCLRP to naive mice. C57BL/6 mice underwent stereotactic intracranial implantation of GL261 glioma cells and were randomized for tumor size by magnetic resonance imaging, which was also used to assess increase in tumor size. Brain tumor tissues were analyzed using flow cytometry, histology, and enzyme-linked immunosorbent assay with respect to tumor, peritumoral area, and contralateral hemisphere regions.Results: GCLRP exhibited strong stimulatory effect on MDCBs and blood monocytes in vitro and in vivo. GCLRP was associated with an increased percentage of precursors of dendritic cells in the blood (P = 0.003, which differentiated into patrolling macrophages in tumoral (P = 0.001 and peritumoral areas (P = 0.04, rather than into dendritic cells

Gas6 Promotes Inflammatory (CCR2hiCX3CR1lo) Monocyte Recruitment in Venous Thrombosis.

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Laurance, Sandrine; Bertin, François-René; Ebrahimian, Talin; Kassim, Yusra; Rys, Ryan N; Lehoux, Stéphanie; Lemarié, Catherine A; Blostein, Mark D

2017-07-01

Coagulation and inflammation are inter-related. Gas6 (growth arrest-specific 6) promotes venous thrombosis and participates to inflammation through endothelial-innate immune cell interactions. Innate immune cells can provide the initiating stimulus for venous thrombus development. We hypothesize that Gas6 promotes monocyte recruitment during venous thrombosis. Deep venous thrombosis was induced in wild-type and Gas6-deficient (-/-) mice using 5% FeCl 3 and flow reduction in the inferior vena cava. Total monocyte depletion was achieved by injection of clodronate before deep venous thrombosis. Inflammatory monocytes were depleted using an anti-C-C chemokine receptor type 2 (CCR2) antibody. Similarly, injection of an anti-chemokine ligand 2 (CCL2) antibody induced CCL2 depletion. Flow cytometry and immunofluorescence were used to characterize the monocytes recruited to the thrombus. In vivo, absence of Gas6 was associated with a reduction of monocyte recruitment in both deep venous thrombosis models. Global monocyte depletion by clodronate leads to smaller thrombi in wild-type mice. Compared with wild type, the thrombi from Gas6 -/- mice contain less inflammatory (CCR2 hi CX 3 CR1 lo ) monocytes, consistent with a Gas6-dependent recruitment of this monocyte subset. Correspondingly, selective depletion of CCR2 hi CX 3 CR1 lo monocytes reduced the formation of venous thrombi in wild-type mice demonstrating a predominant role of the inflammatory monocytes in thrombosis. In vitro, the expression of both CCR2 and CCL2 were Gas6 dependent in monocytes and endothelial cells, respectively, impacting monocyte migration. Moreover, Gas6-dependent CCL2 expression and monocyte migration were mediated via JNK (c-Jun N-terminal kinase). This study demonstrates that Gas6 specifically promotes the recruitment of inflammatory CCR2 hi CX 3 CR1 lo monocytes through the regulation of both CCR2 and CCL2 during deep venous thrombosis. © 2017 American Heart Association, Inc.

Caracterización de la expresión de nCD64 en neutrófilos y de los niveles de s-TREM-1 y HMGB-1 en pacientes con sospecha de infección admitidos en el departamento de emergencias

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Sergio Velásquez

2013-12-01

Full Text Available Introducción. El receptor CD64, receptor soluble ‘desencadenador’ expresado en células mieloides (sTREM-1 y la proteína del grupo Box-1 de alta movilidad (HMGB-1, se han propuesto como mediadores en la sepsis. Objetivo. Evaluar el valor pronóstico de estos marcadores en pacientes con sospecha de infección, recientemente admitidos en un departamento de emergencias. Materiales y métodos. Se incluyeron en el estudio pacientes que consultaron al hospital con sospecha de infección. Se analizó la base de datos clínica, el puntaje SOFA, el puntaje APACHE II, los niveles de HMGB-1, los niveles de sTREM-1 y los niveles de nCD64. Se determinaron las concentraciones en suero de HMGB-1 y sTREM-1, usando kits de ELISA disponibles comercialmente, y la de CD64 se midió por citometría de flujo. Resultados. Se analizaron 579 pacientes con sospecha de infección al ingreso. La edad media fue de 50 años (rango intercuartílico=35-68, y 11,1 % (n=64 murieron durante el seguimiento de 28 días. El diagnóstico más frecuente en el momento del ingreso fue neumonía adquirida en la comunidad, en 23 % (n=133 de los pacientes, seguida de infección de tejidos blandos, en 16,6 % (n=96, e infección urinaria, en 15 % (n=87. Después de un análisis multivariado, no hubo asociación significativa entre ningún biomarcador y la mortalidad a los 28 días. Conclusión. Los resultados sugieren que en el contexto de un departamento de emergencias de tercer nivel de una ciudad latinoamericana típica, los tres marcadores evaluados no ofrecieron ninguna ventaja en el pronóstico de infección. La búsqueda de marcadores pronósticos más confiables en estadios tempranos de la infección aún continúa abierta.   doi: http://dx.doi.org/10.7705/biomedica.v33i4.805

Evidence for unfolded protein response activation in monocytes from individuals with alpha-1 antitrypsin deficiency.

LENUS (Irish Health Repository)

Carroll, Tomás P

2010-04-15

The hereditary disorder alpha-1 antitrypsin (AAT) deficiency results from mutations in the SERPINA1 gene and presents with emphysema in young adults and liver disease in childhood. The most common form of AAT deficiency occurs because of the Z mutation, causing the protein to fold aberrantly and accumulate in the endoplasmic reticulum (ER). This leads to ER stress and contributes significantly to the liver disease associated with the condition. In addition to hepatocytes, AAT is also synthesized by monocytes, neutrophils, and epithelial cells. In this study we show for the first time that the unfolded protein response (UPR) is activated in quiescent monocytes from ZZ individuals. Activating transcription factor 4, X-box binding protein 1, and a subset of genes involved in the UPR are increased in monocytes from ZZ compared with MM individuals. This contributes to an inflammatory phenotype with ZZ monocytes exhibiting enhanced cytokine production and activation of the NF-kappaB pathway when compared with MM monocytes. In addition, we demonstrate intracellular accumulation of AAT within the ER of ZZ monocytes. These are the first data showing that Z AAT protein accumulation induces UPR activation in peripheral blood monocytes. These findings change the current paradigm regarding lung inflammation in AAT deficiency, which up until now was derived from the protease-anti-protease hypothesis, but which now must include the exaggerated inflammatory response generated by accumulated aberrantly folded AAT in circulating blood cells.

Pannexin 1 channels mediate 'find-me' signal release and membrane permeability during apoptosis.

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Chekeni, Faraaz B; Elliott, Michael R; Sandilos, Joanna K; Walk, Scott F; Kinchen, Jason M; Lazarowski, Eduardo R; Armstrong, Allison J; Penuela, Silvia; Laird, Dale W; Salvesen, Guy S; Isakson, Brant E; Bayliss, Douglas A; Ravichandran, Kodi S

2010-10-14

Apoptotic cells release 'find-me' signals at the earliest stages of death to recruit phagocytes. The nucleotides ATP and UTP represent one class of find-me signals, but their mechanism of release is not known. Here, we identify the plasma membrane channel pannexin 1 (PANX1) as a mediator of find-me signal/nucleotide release from apoptotic cells. Pharmacological inhibition and siRNA-mediated knockdown of PANX1 led to decreased nucleotide release and monocyte recruitment by apoptotic cells. Conversely, PANX1 overexpression enhanced nucleotide release from apoptotic cells and phagocyte recruitment. Patch-clamp recordings showed that PANX1 was basally inactive, and that induction of PANX1 currents occurred only during apoptosis. Mechanistically, PANX1 itself was a target of effector caspases (caspases 3 and 7), and a specific caspase-cleavage site within PANX1 was essential for PANX1 function during apoptosis. Expression of truncated PANX1 (at the putative caspase cleavage site) resulted in a constitutively open channel. PANX1 was also important for the 'selective' plasma membrane permeability of early apoptotic cells to specific dyes. Collectively, these data identify PANX1 as a plasma membrane channel mediating the regulated release of find-me signals and selective plasma membrane permeability during apoptosis, and a new mechanism of PANX1 activation by caspases.

Mitogen-activated protein kinase phosphatase 1 (MKP-1) in macrophage biology and cardiovascular disease. A redox-regulated master controller of monocyte function and macrophage phenotype.

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Kim, Hong Seok; Asmis, Reto

2017-08-01

MAPK pathways play a critical role in the activation of monocytes and macrophages by pathogens, signaling molecules and environmental cues and in the regulation of macrophage function and plasticity. MAPK phosphatase 1 (MKP-1) has emerged as the main counter-regulator of MAPK signaling in monocytes and macrophages. Loss of MKP-1 in monocytes and macrophages in response to metabolic stress leads to dysregulation of monocyte adhesion and migration, and gives rise to dysfunctional, proatherogenic monocyte-derived macrophages. Here we review the properties of this redox-regulated dual-specificity MAPK phosphatase and the role of MKP-1 in monocyte and macrophage biology and cardiovascular diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

Alterations in calcium metabolism during human monocyte activation

International Nuclear Information System (INIS)

Scully, S.P.

1984-01-01

Human peripheral blood monocytes have been prepared from plateletpheresis residues by counterflow centrifugal elutriation in sufficient quantities to enable quantitative studies of cell calcium. Kinetic analysis of 45 Ca exchange data in resting monocytes was compatible with a model of cellular calcium containing three exchangeable calcium pools. These pools are thought to represent a putative ectocellular pool, a putative cytoplasmic chelated pool, and a putative organelle sequestered pool. Exposure of monocytes to the plant lectin Con A at a concentration that maximally simulated superoxide production caused an increase in the size and a doubling in the exchange rate of the putative cytoplasmic pool without a change in the other cellular pools. The cytoplasmic ionized calcium, [Ca]/sub i/, measured with the fluorescent probe, Quin 2 rose from a resting level of 83 nM to 165 mN within 30 sec of exposure to Con A. This increase in cytoplasmic calcium preceded the release of superoxide radicals. Calcium transport and calcium ATPase activities were identified and characterized in plasma membrane vesicles prepared from monocytes. Both activities were strictly dependent on ATP and Mg, had a Km/sub Ca/ in the submicromolar range and were stimulated by calmodulin. Thus, it seems that monocyte calcium is in a dynamic steady state that is a balance between efflux and influx rates, and that the activation of these cells results in the transition to a new steady state. The alteration in [Ca]/sub i/ that accompany the new steady state are essential for superoxide production by human monocytes

Triglyceride-rich lipoprotein regulates APOB48 receptor gene expression in human THP-1 monocytes and macrophages.

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Bermudez, Beatriz; Lopez, Sergio; Varela, Lourdes M; Ortega, Almudena; Pacheco, Yolanda M; Moreda, Wenceslao; Moreno-Luna, Rafael; Abia, Rocio; Muriana, Francisco J G

2012-02-01

The postprandial metabolism of dietary fats implies that the production of TG-rich lipoproteins (TRL) contributes to the progression of plaque development. TRL and their remnants cause rapid receptor-mediated monocyte/macrophage lipid engorgement via the cell surface apoB48 receptor (apoB48R). However, the mechanistic basis for apoB48 receptor (APOB48R) regulation by postprandial TRL in monocytes and macrophages is not well established. In this study, we investigated the effects of postprandial TRL from healthy volunteers on the expression of APOB48R mRNA and lipid uptake in human THP-1 monocytes and THP-1-derived macrophages. The expression of APOB48R mRNA was upregulated in THP-1 monocytes, but downregulated in THP-1-derived macrophages when treated with postprandial TRL (P < 0.05), in a dose- and time-dependent manner. TG and free cholesterol were dramatically increased in THP-1-derived macrophages (140 and 50%, respectively; P < 0.05) and in THP-1 monocytes (160 and 95%, respectively; P < 0.05). This lipid accumulation was severely decreased (~50%; P < 0.05) in THP-1-derived macrophages by small interfering RNA (siRNA) targeting of APOB48R. Using PPAR and retinoid X receptor (RXR) agonists, antagonists, and siRNA, our data indicate that PPARα, PPARγ, and RXRα are involved in postprandial TRL-induced APOB48R transcriptional regulation. Co-incubation with acyl-CoA synthetase or acyl-CoA:cholesterol acyltransferase inhibitors potentiated the effects of postprandial TRL on the expression of APOB48R mRNA in THP-1 monocytes and THP-1-derived macrophages. Our findings collectively suggest that APOB48R represents a molecular target of postprandial TRL via PPAR-dependent pathways in human THP-1 monocytes and macrophages and advance a potentially important link between postprandial metabolism of dietary fats and atherogenesis.

Importance of large conductance calcium-activated potassium channels (BKCa) in interleukin-1b-induced adhesion of monocytes to endothelial cells.

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Burgazli, K M; Venker, C J; Mericliler, M; Atmaca, N; Parahuleva, M; Erdogan, A

2014-01-01

The present study investigated the role of the large conductance calcium-activated potassium channels (BKCa) in interleukin-1b (IL-1b) induced inflammation. Human umbilical vein endothelial cells (HUVECs) were isolated and cultured. Endothelial cell membrane potential measurements were accomplished using the fluorescent dye DiBAC4(3). The role of BKCa was assessed using iberiotoxin, a highly selective BKCa inhibitor. Changes in the calcium intracellular calcium were investigated using Fura-2-AM imaging. Fluorescent dyes DCF-AM and DAF-AM were further used in order to measure the formation of reactive oxygen species (ROS) and nitric oxide (NO) synthesis, respectively. Endothelial cell adhesion tests were conducted with BCECF-AM adhesion assay and tritium thymidine uptake using human monocytic cells (U937). Expression of cellular adhesion molecules (ICAM-1, VCAM-1) was determined by flow cytometer. Interleukin-1b induced a BKCa dependent hyperpolarization of HUVECs. This was followed by an increase in the intracellular calcium concentration. Furthermore, IL-1b significantly increased the synthesis of NO and ROS. The increase of intracellular calcium, radicals and NO resulted in a BKCa dependent adhesion of monocytes to HUVECs. Endothelial cells treated with IL-1b expressed both ICAM-1 and VCAM-1 in significantly higher amounts as when compared to controls. It was further shown that the cellular adhesion molecules ICAM-1 and VCAM-1 were responsible for the BKCa-dependent increase in cellular adhesion. Additionally, inhibition of the NADPH oxidase with DPI led to a significant downregulation of IL-1b-induced expression of ICAM and VCAM, as well as inhibition of eNOS by L-NMMA, and intracellular calcium by BAPTA. Activation of the endothelial BKCa plays an important role in the IL-1b-induced monocyte adhesion to endothelial cells.

In vivo imaging of monocyte trafficking with 18F-fluorodeoxyglucose labeled monocytes

International Nuclear Information System (INIS)

Paik, Jin Young; Lee, Kyung Han; Han, Yu Mi; Choe, Yearn Seong; Kim, Byung Tae

2000-01-01

Since the ability to monitor in vivo monocyte trafficking would contribute to our understanding of the pathophysiology of various inflammatory disorders, we investigated the feasibility of labeling human monocytes with 18 F-FDG. Human monocytes were separated by Ficoll/Hypaque gradient and purity was assessed by flow cytometry. The influence of insulin and/or glucose on labeling efficiency was evaluated. Cell viability and activation was measured with trypan blue exclusion and hydrogen peroxide assays, respectively. Label stability was measured for up to 18 hr, and the effect of insulin pre-incubation on FDG washout was investigated. PET images were acquired in SD rats at various time points after injection of FDG labeled monocytes. Monocytes were >85% pure, and labeling efficiency was 35% for 1x106 cells after 40 min incubation with 2 mCi 18 F-FDG without insulin. Pre-incubation with 10∼100 nM insulin significantly increased FDG uptake which reached 400% of baseline levels, whereas presence of glucose or serum decreased FDG uptake. Labeled cells were >90% viable for up to 22 hr, and the labeling process did appear to significantly activate cells, Washout studies however, demonstrated gradual washout of the FDG from monocytes after initial uptake PET images of FDG labeled monocytes in SD rats showed consistent findings. Utilizing insulin effects on cellular glucose metabolism may be a feasible way of labeling monocytes with 18 F-FDG for PET imaging. However, gradual washout of FDG after initial uptake poses as a potential problem which needs to be addressed before practical application

Polarization of migrating monocytic cells is independent of PI 3-kinase activity.

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Silvia Volpe

Full Text Available BACKGROUND: Migration of mammalian cells is a complex cell type and environment specific process. Migrating hematopoietic cells assume a rapid amoeboid like movement when exposed to gradients of chemoattractants. The underlying signaling mechanisms remain controversial with respect to localization and distribution of chemotactic receptors within the plasma membrane and the role of PI 3-kinase activity in cell polarization. METHODOLOGY/PRINCIPAL FINDINGS: We present a novel model for the investigation of human leukocyte migration. Monocytic THP-1 cells transfected with the alpha(2A-adrenoceptor (alpha(2AAR display comparable signal transduction responses, such as calcium mobilization, MAP-kinase activation and chemotaxis, to the noradrenaline homologue UK 14'304 as when stimulated with CCL2, which binds to the endogenous chemokine receptor CCR2. Time-lapse video microscopy reveals that chemotactic receptors remain evenly distributed over the plasma membrane and that their internalization is not required for migration. Measurements of intramolecular fluorescence resonance energy transfer (FRET of alpha(2AAR-YFP/CFP suggest a uniform activation of the receptors over the entire plasma membrane. Nevertheless, PI 3-kinase activation is confined to the leading edge. When reverting the gradient of chemoattractant by moving the dispensing micropipette, polarized monocytes--in contrast to neutrophils--rapidly flip their polarization axis by developing a new leading edge at the previous posterior side. Flipping of the polarization axis is accompanied by re-localization of PI-3-kinase activity to the new leading edge. However, reversal of the polarization axis occurs in the absence of PI 3-kinase activation. CONCLUSIONS/SIGNIFICANCE: Accumulation and internalization of chemotactic receptors at the leading edge is dispensable for cell migration. Furthermore, uniformly distributed receptors allow the cells to rapidly reorient and adapt to changes in the

Developmental endothelial locus-1 modulates platelet-monocyte interactions and instant blood-mediated inflammatory reaction in islet transplantation.

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Kourtzelis, Ioannis; Kotlabova, Klara; Lim, Jong-Hyung; Mitroulis, Ioannis; Ferreira, Anaisa; Chen, Lan-Sun; Gercken, Bettina; Steffen, Anja; Kemter, Elisabeth; Klotzsche-von Ameln, Anne; Waskow, Claudia; Hosur, Kavita; Chatzigeorgiou, Antonios; Ludwig, Barbara; Wolf, Eckhard; Hajishengallis, George; Chavakis, Triantafyllos

2016-04-01

Platelet-monocyte interactions are strongly implicated in thrombo-inflammatory injury by actively contributing to intravascular inflammation, leukocyte recruitment to inflamed sites, and the amplification of the procoagulant response. Instant blood-mediated inflammatory reaction (IBMIR) represents thrombo-inflammatory injury elicited upon pancreatic islet transplantation (islet-Tx), thereby dramatically affecting transplant survival and function. Developmental endothelial locus-1 (Del-1) is a functionally versatile endothelial cell-derived homeostatic factor with anti-inflammatory properties, but its potential role in IBMIR has not been previously addressed. Here, we establish Del-1 as a novel inhibitor of IBMIR using a whole blood-islet model and a syngeneic murine transplantation model. Indeed, Del-1 pre-treatment of blood before addition of islets diminished coagulation activation and islet damage as assessed by C-peptide release. Consistently, intraportal islet-Tx in transgenic mice with endothelial cell-specific overexpression of Del-1 resulted in a marked decrease of monocytes and platelet-monocyte aggregates in the transplanted tissues, relative to those in wild-type recipients. Mechanistically, Del-1 decreased platelet-monocyte aggregate formation, by specifically blocking the interaction between monocyte Mac-1-integrin and platelet GPIb. Our findings reveal a hitherto unknown role of Del-1 in the regulation of platelet-monocyte interplay and the subsequent heterotypic aggregate formation in the context of IBMIR. Therefore, Del-1 may represent a novel approach to prevent or mitigate the adverse reactions mediated through thrombo-inflammatory pathways in islet-Tx and perhaps other inflammatory disorders involving platelet-leukocyte aggregate formation.

[Peptide fragments of chemokine domain of fractalkine: effect on human monocyte migration].

Science.gov (United States)

Kukhtina, N B; Aref'eva, T I; Ruleva, N Iu; Sidorova, M V; Az'muko, A A; Bespalova, Zh D; Krasnikova, T L

2012-01-01

Leukocyte chemotaxis to the area of tissue damage is mediated by chemokines. According to the primary structure, chemokines are divided into four families, fractalkine (CX3CL1) is the only one member of CX3C family and the only membrane-bound chemokine. Fractalkine molecule includes the extracellular N-terminal chemokine domain, mucin-like rod, the transmembrane and the intracellular domains. In membrane-bound state fractalkine has the properties of an adhesion molecule. Chemokine domain of fractalkine (CDF) is released from cell membrane by proteolysis, and this soluble form acts as a chemoattractant for leukocytes expressing fractalkine receptor CX3CR1. Fractalkine is involved in development of a number of pathological processes caused by inflammation, and therefore a search for fractalkine inhibitors is very important. For this purpose we identified several antigenic determinants--the fragments of CDF, and the following peptides were synthesized--P41-52 H-Leu-Glu-Thr-Arg-Gln-His-Arg-Leu-Phe-Cys-Ala-Asp-NH2, P53-60 H-Pro-Lys-Glu-Gln-Trp-Val-Lys-Asp-NH2 and P60-71 H-Asp-Ala-Met-Gln-His-Leu-Asp-Arg-Gln-Ala-Ala-Ala-NH2. The peptide effects on adhesion and migration of human peripheral blood monocytes expressing fractalkine receptors were investigated. In the presence of CDF and P41-52 we observed the increased adhesion and migration of monocytes compared with spontaneous values. Peptides P53-60 and P60-71 significantly inhibited monocyte adhesion and migration stimulated by CDF. Since the chemotactic activity of chemokines was shown to be dependent on their binding to glycosaminoglycans of the cell surface and extracellular matrix, the effect ofpeptides on the interaction of CDF with heparin was analyzed by ELISA. Peptide P41-52 competed with CDF for heparin binding, while peptides P53-60 and P60-71 had no significant activity.

The role and mechanism of KCa3.1 channels in human monocyte migration induced by palmitic acid.

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Ma, Xiao-Zhen; Pang, Zheng-Da; Wang, Jun-Hong; Song, Zheng; Zhao, Li-Mei; Du, Xiao-Jun; Deng, Xiu-Ling

2018-05-21

Monocyte migration into diseased tissues contributes to the pathogenesis of diseases. Intermediate-conductance Ca 2+ -activated K + (K Ca 3.1) channels play an important role in cell migration. However, the role of K Ca 3.1 channels in mediating monocyte migration induced by palmitic acid (PA) is still unclear. Using cultured THP-1 cells and peripheral blood mononuclear cells from healthy subjects, we investigated the role and signaling mechanisms of K Ca 3.1 channels in mediating the migration induced by PA. Using methods of Western blotting analysis, RNA interference, cell migration assay and ELISA, we found that PA-treated monocytes exhibited increment of the protein levels of K Ca 3.1 channel and monocyte chemoattractant protein-1 (MCP-1), and the effects were reversed by co-incubation of PA with anti-TLR2/4 antibodies or by specific inhibitors of p38-MAPK, or NF-κB. In addition, PA increased monocyte migration, which was abolished by a specific K Ca 3.1 channel blocker, TRAM-34, or K Ca 3.1 small interfering RNA (siRNA). The expression and secretion of MCP-1 induced by PA was also similarly prevented by TRAM-34 and K Ca 3.1 siRNA. These results demonstrate for the first time that PA upregulates K Ca 3.1 channels through TLR2/4, p38-MAPK and NF-κB pathway to promote the expression of MCP-1, and then induce the trans-endothelial migration of monocytes. Copyright © 2018 Elsevier Inc. All rights reserved.

Synthesis of sFlt-1 by platelet-monocyte aggregates contributes to the pathogenesis of preeclampsia

Science.gov (United States)

Major, Heather D.; Cambell, Robert A.; Silver, Robert M.; Branch, D. Ware; Weyrich, Andrew S.

2014-01-01

Objective Soluble fms-like tyrosine kinase (sFlt-1) is an important mediator in the pathogenesis of preeclampsia. We sought to determine if platelet-monocyte aggregates (PMAs) produced sFlt-1 and if PMAs contributed to sFlt-1 production in preeclampsia. Study Design Case-control study of sFlt-1 release from PMAs using blood samples from women with preeclampsia matched by gestational age to pregnant controls. A third group of nonpregnant, reproductive-age women comprised an additional control group. Experiments were also performed using blood from non-pregnant women to elucidate if inducing PMAs could stimulate sFlt-1 production, and if so, to determine the necessary receptors and pathways. Results Women with preeclampsia had increased total Flt-1 concentrations in platelets and monocytes at baseline compared to pregnant controls (25 vs. 10 pg/ml, p=0.0003). sFlt-1 production was elicited from monocytes incubated with thrombin-activated platelets from non-pregnant women. sFlt-1 production was regulated at the transcriptional level by p38 and NF-κB dependent pathways. Conclusion Activated platelets in preeclampsia bind monocytes to generate sFlt-1. PMAs are a previously unrecognized source of sFlt-1 that may contribute to endothelial dysfunction and systemic inflammation commonly observed in preeclampsia. PMID:24440566

Soluble Triggering Receptor Expressed on Myeloid Cells-1 as a Novel Marker for Abdominal Sepsis.

Science.gov (United States)

Song, Xiaofei; Song, Yucheng; Zhang, Xuedong; Xue, Huanzhou

2017-07-01

The aim of the study was to investigate the concentration and diagnostic significance of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in acute abdominal conditions. Plasma specimens were obtained from 68 patients with abdominal sepsis, 60 patients with systemic inflammatory response syndrome (SIRS), and 60 healthy individuals. The sepsis group was divided into the survival and death groups according to the 28-d outcome. Plasma sTREM-1, procalcitonin (PCT), C-reactive protein (CRP), and white blood cell (WBC) count were measured. A receiver operating characteristic curve (ROC) was used to compare the diagnostic values of sTREM-1, PCT, CRP, and WBC count. In addition, the correlation between plasma sTREM-1 and the Acute Physiology and Chronic Health Evaluation (APACHE) II score in the sepsis group was assessed by Spearman correlation analysis. The plasma concentration of sTREM-1 in the sepsis group was significantly higher than that in the SIRS and healthy groups (both p sepsis vs. SIRS showed that the area under the curve of sTREM-1 (0.82) was greater than that of PCT (0.77), CRP (0.72), and WBC count (0.70). Additionally, in the sepsis group, the plasma sTREM-1 concentration correlated positively with the APACHE II score (r = 0.41; p sepsis.

Monocyte scintigraphy in rheumatoid arthritis: the dynamics of monocyte migration in immune-mediated inflammatory disease.

Directory of Open Access Journals (Sweden)

Rogier M Thurlings

2009-11-01

Full Text Available Macrophages are principal drivers of synovial inflammation in rheumatoid arthritis (RA, a prototype immune-mediated inflammatory disease. Conceivably, synovial macrophages are continuously replaced by circulating monocytes in RA. Animal studies from the 1960s suggested that macrophage replacement by monocytes is a slow process in chronic inflammatory lesions. Translation of these data into the human condition has been hampered by the lack of available techniques to analyze monocyte migration in man.We developed a technique that enabled us to analyze the migration of labelled autologous monocytes in RA patients using single photon emission computer tomography (SPECT. We isolated CD14+ monocytes by CliniMACS in 8 patients and labeled these with technetium-99m (99mTc-HMPAO. Monocytes were re-infused into the same patient. Using SPECT we calculated that a very small but specific fraction of 3.4 x 10(-3 (0.95-5.1 x 10(-3 % of re-infused monocytes migrated to the inflamed joints, being detectable within one hour after re-infusion.The results indicate monocytes migrate continuously into the inflamed synovial tissue of RA patients, but at a slow macrophage-replacement rate. This suggests that the rapid decrease in synovial macrophages that occurs after antirheumatic treatment might rather be explained by an alteration in macrophage retention than in monocyte influx and that RA might be particularly sensitive to treatments targeting inflammatory cell retention.

Detection of early atherosclerosis with radiolabeled monocyte chemoattractant protein-1 in prediabeteic Zucker rats

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Blankenberg, F.G. [Div. of Pediatric Radiology, Stanford, CA (United States); Wen, P.; Dai, M.; Zhu, D.; Panchal, S.N.; Valantine, H.A. [Division of Cardiovascular Medicine, Department of Medicine, Stanford, California (United States); Tait, J.F. [Dept. of Laboratory Medicine, Univ. of Washington, Seattle (United States); Post, A.M.; Strauss, H.W. [Div. of Nuclear Medicine, Stanford Univ., CA (United States)

2001-12-01

Background: Migration of monocytes into the arterial wall is an early finding of atherosclerosis. Monocytes are attracted to sites of vascular endothelial cell injury, the initiating event in the development of atheromatous disease, by a chemokine known as monocyte chemoattractant protein-1 (MCP-1). Injured vascular endothelial and smooth muscle cells selectively secrete MCP-1. Objective: This study was performed to determine if radiolabeled MCP-1 would co-localize at sites of monocyte/macrophage concentration in an experimental model of transplant-induced vasculopathy in diabetic animals. Materials and methods: Hearts from 3-month-old male Zucker rats, heterozygote (Lean) or homozygote (Fat) for the diabetes-associated gene fa, were transplanted into the abdomens of genetically matched recipients. Lean and Fat animals were then fed normal or high-fat diets for 90 days. Results: At 90 days significant increases (P < 0.013) of MCP-1 graft uptake were seen at imaging and confirmed on scintillation gamma well counting studies in Lean (n = 5) and Fat (n = 12) animals, regardless of diet, 400 % and 40 %, above control values, respectively. MCP-1 uptake of native and grafted hearts correlated with increased numbers of perivascular macrophages (P < 0.02), as seen by immunostaining with an antibody specific for macrophages (ED 2). Conclusion: Radiolabeled MCP-1 can detect abnormally increased numbers of perivascular mononuclear cells in native and grafted hearts in prediabetic rats. MCP-1 may be useful in the screening of diabetic children for early atherosclerotic disease. (orig.)

Detection of early atherosclerosis with radiolabeled monocyte chemoattractant protein-1 in prediabeteic Zucker rats

International Nuclear Information System (INIS)

Blankenberg, F.G.; Wen, P.; Dai, M.; Zhu, D.; Panchal, S.N.; Valantine, H.A.; Tait, J.F.; Post, A.M.; Strauss, H.W.

2001-01-01

Background: Migration of monocytes into the arterial wall is an early finding of atherosclerosis. Monocytes are attracted to sites of vascular endothelial cell injury, the initiating event in the development of atheromatous disease, by a chemokine known as monocyte chemoattractant protein-1 (MCP-1). Injured vascular endothelial and smooth muscle cells selectively secrete MCP-1. Objective: This study was performed to determine if radiolabeled MCP-1 would co-localize at sites of monocyte/macrophage concentration in an experimental model of transplant-induced vasculopathy in diabetic animals. Materials and methods: Hearts from 3-month-old male Zucker rats, heterozygote (Lean) or homozygote (Fat) for the diabetes-associated gene fa, were transplanted into the abdomens of genetically matched recipients. Lean and Fat animals were then fed normal or high-fat diets for 90 days. Results: At 90 days significant increases (P < 0.013) of MCP-1 graft uptake were seen at imaging and confirmed on scintillation gamma well counting studies in Lean (n = 5) and Fat (n = 12) animals, regardless of diet, 400 % and 40 %, above control values, respectively. MCP-1 uptake of native and grafted hearts correlated with increased numbers of perivascular macrophages (P < 0.02), as seen by immunostaining with an antibody specific for macrophages (ED 2). Conclusion: Radiolabeled MCP-1 can detect abnormally increased numbers of perivascular mononuclear cells in native and grafted hearts in prediabetic rats. MCP-1 may be useful in the screening of diabetic children for early atherosclerotic disease. (orig.)

Platelet-derived stromal cell-derived factor-1 is required for the transformation of circulating monocytes into multipotential cells.

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Noriyuki Seta

Full Text Available BACKGROUND: We previously described a primitive cell population derived from human circulating CD14(+ monocytes, named monocyte-derived multipotential cells (MOMCs, which are capable of differentiating into mesenchymal and endothelial lineages. To generate MOMCs in vitro, monocytes are required to bind to fibronectin and be exposed to soluble factor(s derived from circulating CD14(- cells. The present study was conducted to identify factors that induce MOMC differentiation. METHODS: We cultured CD14(+ monocytes on fibronectin in the presence or absence of platelets, CD14(- peripheral blood mononuclear cells, platelet-conditioned medium, or candidate MOMC differentiation factors. The transformation of monocytes into MOMCs was assessed by the presence of spindle-shaped adherent cells, CD34 expression, and the potential to differentiate in vitro into mesenchymal and endothelial lineages. RESULTS: The presence of platelets or platelet-conditioned medium was required to generate MOMCs from monocytes. A screening of candidate platelet-derived soluble factors identified stromal cell-derived factor (SDF-1 as a requirement for generating MOMCs. Blocking an interaction between SDF-1 and its receptor CXCR4 inhibited MOMC generation, further confirming SDF-1's critical role in this process. Finally, circulating MOMC precursors were found to reside in the CD14(+CXCR4(high cell population. CONCLUSION: The interaction of SDF-1 with CXCR4 is essential for the transformation of circulating monocytes into MOMCs.

Enhanced Apoptosis of Monocytes from Complication-Free Juvenile-Onset Diabetes Mellitus Type 1 May Be Ameliorated by TNF-α Inhibitors

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Jolanta Myśliwska

2014-01-01

Full Text Available Diabetes mellitus type 1 is associated with an enhanced apoptosis of different cells and tissues, accelerating occurrence of diabetic microvascular complications. The aim of our study was to determine spontaneous apoptotic potential of the monocyte subsets in juvenile-onset complication-free diabetes mellitus type 1 and to compare them with the corresponding values of the healthy. Moreover, we wanted to assess effects of TNF-R1 blocking agents and those of general TNF-α blocker (Infliximab on spontaneous apoptosis of monocytes. Sixty randomly selected DM1 patients (14.5 ± 3.2 years and 30 healthy (13.5 ± 2.8 years volunteers were enrolled in the study. Our results indicate that three monocyte subsets are distinguishable in the groups of young diabetic patients and the healthy, similarly to in the blood of adults. DM1 patients were characterized by higher values of apoptotic monocytes than the healthy. The manipulation with drugs inhibiting TNF-R1 expression diminished the pool of CD16+ apoptotic monocytes. Infliximab reduced the apoptotic CD16− cells. In conclusion, diabetes mellitus type 1 is associated with greater apoptosis of three monocyte subsets which may contribute to the development of microvascular complications. TNF-α modifiers appear to ameliorate monocyte apoptosis. They may be useful for controlling excessive monocyte apoptosis in diabetic patients.

Human monocytes undergo functional re-programming during sepsis mediated by hypoxia-inducible factor-1α.

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Shalova, Irina N; Lim, Jyue Yuan; Chittezhath, Manesh; Zinkernagel, Annelies S; Beasley, Federico; Hernández-Jiménez, Enrique; Toledano, Victor; Cubillos-Zapata, Carolina; Rapisarda, Annamaria; Chen, Jinmiao; Duan, Kaibo; Yang, Henry; Poidinger, Michael; Melillo, Giovanni; Nizet, Victor; Arnalich, Francisco; López-Collazo, Eduardo; Biswas, Subhra K

2015-03-17

Sepsis is characterized by a dysregulated inflammatory response to infection. Despite studies in mice, the cellular and molecular basis of human sepsis remains unclear and effective therapies are lacking. Blood monocytes serve as the first line of host defense and are equipped to recognize and respond to infection by triggering an immune-inflammatory response. However, the response of these cells in human sepsis and their contribution to sepsis pathogenesis is poorly understood. To investigate this, we performed a transcriptomic, functional, and mechanistic analysis of blood monocytes from patients during sepsis and after recovery. Our results revealed the functional plasticity of monocytes during human sepsis, wherein they transited from a pro-inflammatory to an immunosuppressive phenotype, while enhancing protective functions like phagocytosis, anti-microbial activity, and tissue remodeling. Mechanistically, hypoxia inducible factor-1α (HIF1α) mediated this functional re-programming of monocytes, revealing a potential mechanism for their therapeutic targeting to regulate human sepsis. Copyright © 2015 Elsevier Inc. All rights reserved.

PPD-induced monocyte mitochondrial damage is associated with a protective effect to develop tuberculosis in BCG vaccinated individuals: A cohort study.

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Marín, Diana; Marín, Nancy; Del Corral, Helena; López, Lucelly; Ramirez-Agudelo, María Elena; Rojas, Carlos A; Arbeláez, María P; García, Luis F; Rojas, Mauricio

2017-01-01

The mechanisms of mononuclear phagocyte death have been associated with the permissiveness and resistance to mycobacterial replication, but it remains unknown whether or not they help predict the risk of developing TB. To describe the factors associated with the induction of monocyte mitochondrial and membrane damage in response to PPD as well as determine if this type of damage might predict the susceptibility of developing active tuberculosis in a cohort of household contacts (HHCs) from Medellin, Colombia from 2005 to 2008. The prospective cohort study contains 2060 HHCs patients with pulmonary tuberculosis who were meticulously followed for two years. A survey of the socio-demographic, clinical, epidemiological factors and blood samples were collected. Mononuclear cell cultures were stimulated with or without PPD and the type of monocyte death was determined by the flow of cytometry, an indicator was also used for its analysis. Logistic regression was adjusted by the Generalized Estimations Equations and the survival was estimated with the Kaplan-Meier and Cox regression. Confidence intervals were used for estimating the association. 1,859 out of 2,060 blood samples of the HHCs patients analyzed showed monocyte death. In response to PPD, 83.4% underwent mitochondrial damage while 50.9% had membrane damage. The membrane damage in response to PPD was higher in children under 4 years (OR: 1.57; (95% CI: 1.1 to 2.4) and the HHCs who slept regularly in the same household has an index case of (OR: 1.54; 95% CI: 1.0 to 2.3). After adjustment by age, comorbidities, nutritional status, proximity to index case and overcrowding, the risk of developing active TB among BCG vaccinated HHCs individuals with induction of mitochondrial damage was HR = 0.19 (95% CI: 0.1 to 0.5). The induction of monocytes mitochondrial damage by PPD stimulation correlates with protection of TB disease development in BCG-vaccinated HHCs. This represents a potential tool to predict susceptibility

Synthesis of pro-inflammatory cytokines and adhesion molecules expression by the irradiated human monocyte/macrophage

International Nuclear Information System (INIS)

Pons, I.

1997-09-01

As lesions induced by ionizing radiations are essentially noticed in organs the functional and structural organisation of which depend on the highly proliferative stem cell pool, the author reports an in-vivo investigation of the effect of a gamma irradiation on the expression and secretion of pro-inflammatory cytokines par human monocytes/macrophages. In order to study the role of the cell environment in the radiation-induced inflammation, the author studied whether a co-stimulation of monocytes/macrophages by gamma irradiation, or the exposure of co-cultures of monocytes/macrophages and lymphocytes, could modulate the regulation of inflammatory cytokines. The author also studied the modulation of the expression of adhesion molecules mainly expressed by the monocyte/macrophage, and the membrane density of the CD14 receptor after irradiation of monocytes/macrophages during 24 hours, and of totally differentiated macrophages after seven days of culture

ADMA induces monocyte adhesion via activation of chemokine receptors in cultured THP-1 cells.

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Chen, Meifang; Li, Yuanjian; Yang, Tianlun; Wang, Yongjin; Bai, Yongping; Xie, Xiumei

2008-08-01

Asymmetric dimethylarginine (ADMA), an endogenous NOS inhibitor, is also an important inflammatory factor contributing to the development of atherosclerosis (AS). The present study was to test the effect of ADMA on angiotensin (Ang) II-induced monocytic adhesion. Human monocytoid cells (THP-1) or isolated peripheral blood monocyte cells (PBMCs) were incubated with Ang II (10(-6)M) or exogenous ADMA (30 microM) for 4 or 24h in the absence or presence of losartan or antioxidant PDTC. In cultured THP-1 cells, Ang II (10(-6)M) for 24h elevated the level of ADMA in the medium, upregulated the protein expression of protein arginine methyltransferase (PRMT) and decreased the activity of dimethylarginine dimethylaminohydrolase (DDAH). Both of Ang II and ADMA increased monocytic adhesion to human umbilical vein endothelial cells (HUVECs), elevated the levels of monocyte chemoattractant protein (MCP)-1, interleukin (IL)-8 and tumor necrosis factor (TNF)-alpha and upregulated CCR(2) and CXCR(2) mRNA expression, concomitantly with increase in reactive oxygen species (ROS) generation and activation of nuclear factor (NF)-kappaB. Pretreatment with losartan (10 microM) or PDTC (10 microM) abolished the effects mediated by Ang II or ADMA. In isolated PBMCs from healthy individuals, ADMA upregulated the expression of CXCR(2) mRNA, which was attenuated by losartan (10 microM), however, ADMA had no effect on surface protein expression of CCR(2). The present results suggest that ADMA may be involved in monocytic adhesion induced by Ang II via activation of chemokine receptors by ROS/NF-kappaB pathway.

ALV-J infection induces chicken monocyte death accompanied with the production of IL-1β and IL-18.

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Dai, Manman; Feng, Min; Xie, Tingting; Li, Yuanfang; Ruan, Zhuohao; Shi, Meiqing; Liao, Ming; Zhang, Xiquan

2017-11-21

Immunosuppression induced by avian leukosis virus subgroup J (ALV-J) causes serious reproduction problems and secondary infections in chickens. Given that monocytes are important precursors of immune cells including macrophages and dendritic cells, we investigated the fate of chicken monocytes after ALV-J infection. Our results indicated that most monocytes infected with ALV-J including field or laboratory strains could not successfully differentiate into macrophages due to cells death. And cells death was dependent upon viral titer and accompanied with increased IL-1β and IL-18 mRNA levels. In addition, ALV-J infection up-regulated caspase-1 and caspase-3 activity in monocytes. Collectively, we found that ALV-J could cause cell death in chicken monocytes, especially pyroptosis, which may be a significant reason for ALV-J induced immunosuppression.

Magnetic Nanoparticles Conjugated with Peptides Derived from Monocyte Chemoattractant Protein-1 as a Tool for Targeting Atherosclerosis

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Chung-Wei Kao

2018-05-01

Full Text Available Atherosclerosis is a multifactorial inflammatory disease that may progress silently for long period, and it is also widely accepted as the main cause of cardiovascular diseases. To prevent atherosclerotic plaques from generating, imaging early molecular markers and quantifying the extent of disease progression are desired. During inflammation, circulating monocytes leave the bloodstream and migrate into incipient lipid accumulation in the artery wall, following conditioning by local growth factors and proinflammatory cytokines; therefore, monocyte accumulation in the arterial wall can be observed in fatty streaks, rupture-prone plaques, and experimental atherosclerosis. In this work, we synthesized monocyte-targeting iron oxide magnetic nanoparticles (MNPs, which were incorporated with the peptides derived from the chemokine receptor C-C chemokine receptor type 2 (CCR2-binding motif of monocytes chemoattractant protein-1 (MCP-1 as a diagnostic tool for potential atherosclerosis. MCP-1-motif MNPs co-localized with monocytes in in vitro fluorescence imaging. In addition, with MNPs injection in ApoE knockout mice (ApoE KO mice, the well-characterized animal model of atherosclerosis, MNPs were found in specific organs or regions which had monocytes accumulation, especially the aorta of atherosclerosis model mice, through in vivo imaging system (IVIS imaging and magnetic resonance imaging (MRI. We also performed Oil Red O staining and Prussian Blue staining to confirm the co-localization of MCP-1-motif MNPs and atherosclerosis. The results showed the promising potential of MCP-1-motif MNPs as a diagnostic agent of atherosclerosis.

Effect and possible mechanism of monocyte-derived VEGF on monocyte-endothelial cellular adhesion after electrical burns.

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Ruan, Qiongfang; Zhao, Chaoli; Ye, Ziqing; Ruan, Jingjing; Xie, Qionghui; Xie, Weiguo

2015-06-01

One of the major obstacles in the treatment of severe electrical burns is properly handling the resulting uncontrolled inflammation. Such inflammation often causes secondary injury and necrosis, thus complicating patient outcomes. Vascular endothelial grow factor (VEGF) has emerged as an important mediator for the recruitment of monocytes to the site inflammation. This study was designed to explore the effects and possible mechanism of VEGF on monocyte-endothelial cellular adhesion. To do so, we used a cultured human monocytic cell line (THP-1) that was stimulated with serum derived from rats that had received electrical burns. Serum was obtained from rats that had received electrical burns. Both the VEGF and soluble flt-1 (sflt-1) concentrations of the serum were determined by double-antibody sandwich ELISA. The concentrations of VEGF, sflt-1, and TNF-α obtained from the cell-free cultured supernatant of THP-1 cells that had been exposed to the serum were then determined by double-antibody sandwich ELISA. Serum-stimulated THP-1 cells were added to wells with a monolayer of endothelial cells to detect the level of monocyte-endothelial cells adhesion. Finally, the state of phosphorylation of AKT was determined by Western blotting. Both in vivo and in vitro studies showed that compared to controls, the levels of VEGF were significantly increased after electrical burns. This increased was accompanied by a reduction of sflt-1 levels. Furthermore, the serum of rats that had received electrical burns was able to both activate monocytes to secrete TNF-α and enhance monocyte-endothelial cell adhesion. Treatment with the serum also resulted in an up-regulation of the phosphorylation of AKT, but had no effect on the total levels of AKT. Phosphatidylinositide 3-kinases (PI3K) inhibition decreased the number of THP-1 cells that were adhered to endothelial cells. Finally, sequestering VEGF with sflt-1 was able to reduce the effect on monocyte-endothelial cells adhesion by

Regulation of ICAM-1 in Cells of the Monocyte/Macrophage System in Microgravity

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Katrin Paulsen

2015-01-01

Full Text Available Cells of the immune system are highly sensitive to altered gravity, and the monocyte as well as the macrophage function is proven to be impaired under microgravity conditions. In our study, we investigated the surface expression of ICAM-1 protein and expression of ICAM-1 mRNA in cells of the monocyte/macrophage system in microgravity during clinostat, parabolic flight, sounding rocket, and orbital experiments. In murine BV-2 microglial cells, we detected a downregulation of ICAM-1 expression in clinorotation experiments and a rapid and reversible downregulation in the microgravity phase of parabolic flight experiments. In contrast, ICAM-1 expression increased in macrophage-like differentiated human U937 cells during the microgravity phase of parabolic flights and in long-term microgravity provided by a 2D clinostat or during the orbital SIMBOX/Shenzhou-8 mission. In nondifferentiated U937 cells, no effect of microgravity on ICAM-1 expression could be observed during parabolic flight experiments. We conclude that disturbed immune function in microgravity could be a consequence of ICAM-1 modulation in the monocyte/macrophage system, which in turn could have a strong impact on the interaction with T lymphocytes and cell migration. Thus, ICAM-1 can be considered as a rapid-reacting and sustained gravity-regulated molecule in mammalian cells.

Efficient activation of T cells by human monocyte-derived dendritic cells (HMDCs pulsed with Coxiella burnetii outer membrane protein Com1 but not by HspB-pulsed HMDCs

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Wang Xile

2011-09-01

Full Text Available Abstract Background Coxiella burnetii is an obligate intracellular bacterium and the etiologic agent of Q fever; both coxiella outer membrane protein 1 (Com1 and heat shock protein B (HspB are its major immunodominant antigens. It is not clear whether Com1 and HspB have the ability to mount immune responses against C. burnetii infection. Results The recombinant proteins Com1 and HspB were applied to pulse human monocyte-derived dendritic cells (HMDCs, and the pulsed HMDCs were used to stimulate isogenic T cells. Com1-pulsed HMDCs expressed substantially higher levels of surface molecules (CD83, CD40, CD80, CD86, CD54, and CD58 and a higher level of interleukin-12 than HspB-pulsed HMDCs. Moreover, Com1-pulsed HMDCs induced high-level proliferation and activation of CD4+ and CD8+ cells, which expressed high levels of T-cell activation marker CD69 and inflammatory cytokines IFN-γ and TNF-α. In contrast, HspB-pulsed HMDCs were unable to induce efficient T-cell proliferation and activation. Conclusions Our results demonstrate that Com1-pulsed HMDCs are able to induce efficient T-cell proliferation and drive T cells toward Th1 and Tc1 polarization; however, HspB-pulsed HMDCs are unable to do so. Unlike HspB, Com1 is a protective antigen, which was demonstrated by the adoptive transfer of Com1-pulsed bone marrow dendritic cells into naive BALB/c mice.

Increase in Peripheral Blood Intermediate Monocytes is Associated with the Development of Recent-Onset Type 1 Diabetes Mellitus in Children.

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Ren, Xiaoya; Mou, Wenjun; Su, Chang; Chen, Xi; Zhang, Hui; Cao, Bingyan; Li, Xiaoqiao; Wu, Di; Ni, Xin; Gui, Jingang; Gong, Chunxiu

2017-01-01

Monocytes play important roles in antigen presentation and cytokine production to achieve a proper immune response, and are therefore largely implicated in the development and progression of autoimmune diseases. The aim of this study was to analyze the change in the intermediate (CD14+CD16+) monocyte subset in children with recent-onset type 1 diabetes mellitus (T1DM) and its possible association with clinical parameters reflecting islet β-cell dysfunction. Compared with age- and sex-matched healthy controls, intermediate monocytes were expanded in children with T1DM, which was positively associated with hemoglobin A1C and negatively associated with serum insulin and C-peptide. Interestingly, the intermediate monocytes in T1DM patients expressed higher levels of human leukocyte antigen-DR and CD86, suggesting better antigen presentation capability. Further analysis revealed that the frequency of CD45RO+CD4+ memory T cells was increased in the T1DM patients, and the memory T cell content was well correlated with the increase in intermediate monocytes. These results suggest that expanded intermediate monocytes are a predictive factor for the poor residual islet β-cell function in children with recent-onset T1DM.

Superoxide dismutase type 1 in monocytes of chronic kidney disease patients

DEFF Research Database (Denmark)

Scholze, Alexandra; Krueger, Katharina; Diedrich, Madeleine

2011-01-01

chronic hemodialysis (HD) and 211 CKD patients, and 34 control subjects. Furthermore, we showed that different SOD1 protein species exist in human monocytes. SOD1 protein amount was significantly lower in HD (normalized SOD1 protein, 27.2 ± 2.8) compared to CKD patients (34.3 ± 2.8), or control subjects...

Measurement of the unfolded protein response (UPR) in monocytes.

LENUS (Irish Health Repository)

Carroll, Tomás P

2011-01-01

In mammalian cells, the primary function of the endoplasmic reticulum (ER) is to synthesize and assemble membrane and secreted proteins. As the main site of protein folding and posttranslational modification in the cell, the ER operates a highly conserved quality control system to ensure only correctly assembled proteins exit the ER and misfolded and unfolded proteins are retained for disposal. Any disruption in the equilibrium of the ER engages a multifaceted intracellular signaling pathway termed the unfolded protein response (UPR) to restore normal conditions in the cell. A variety of pathological conditions can induce activation of the UPR, including neurodegenerative disorders such as Parkinson\\'s disease, metabolic disorders such as atherosclerosis, and conformational disorders such as cystic fibrosis. Conformational disorders are characterized by mutations that modify the final structure of a protein and any cells that express abnormal protein risk functional impairment. The monocyte is an important and long-lived immune cell and acts as a key immunological orchestrator, dictating the intensity and duration of the host immune response. Monocytes expressing misfolded or unfolded protein may exhibit UPR activation and this can compromise the host immune system. Here, we describe in detail methods and protocols for the examination of UPR activation in peripheral blood monocytes. This guide should provide new investigators to the field with a broad understanding of the tools required to investigate the UPR in the monocyte.

Measurement of the unfolded protein response (UPR) in monocytes.

LENUS (Irish Health Repository)

Carroll, Tomas P

2012-02-01

In mammalian cells, the primary function of the endoplasmic reticulum (ER) is to synthesize and assemble membrane and secreted proteins. As the main site of protein folding and posttranslational modification in the cell, the ER operates a highly conserved quality control system to ensure only correctly assembled proteins exit the ER and misfolded and unfolded proteins are retained for disposal. Any disruption in the equilibrium of the ER engages a multifaceted intracellular signaling pathway termed the unfolded protein response (UPR) to restore normal conditions in the cell. A variety of pathological conditions can induce activation of the UPR, including neurodegenerative disorders such as Parkinson\\'s disease, metabolic disorders such as atherosclerosis, and conformational disorders such as cystic fibrosis. Conformational disorders are characterized by mutations that modify the final structure of a protein and any cells that express abnormal protein risk functional impairment. The monocyte is an important and long-lived immune cell and acts as a key immunological orchestrator, dictating the intensity and duration of the host immune response. Monocytes expressing misfolded or unfolded protein may exhibit UPR activation and this can compromise the host immune system. Here, we describe in detail methods and protocols for the examination of UPR activation in peripheral blood monocytes. This guide should provide new investigators to the field with a broad understanding of the tools required to investigate the UPR in the monocyte.

Consecutive evaluation of graphene oxide and reduced graphene oxide nanoplatelets immunotoxicity on monocytes.

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Yan, Junyan; Chen, Liliang; Huang, Chih-Ching; Lung, Shih-Chun Candice; Yang, Lingyan; Wang, Wen-Cheng; Lin, Po-Hsiung; Suo, Guangli; Lin, Chia-Hua

2017-05-01

The biocompatibilities of graphene-family nanomaterials (GFNs) should be thoroughly evaluated before their application in drug delivery and anticancer therapy. The present study aimed to consecutively assess the immunotoxicity of graphene oxide nanoplatelets (GONPs) and reduced GONPs (rGONPs) on THP-1 cells, a human acute monocytic leukemia cell line. GONPs induced the expression of antioxidative enzymes and inflammatory factors, whereas rGONPs had substantially higher cellular uptake rate, higher levels of NF-κB expression. These distinct toxic mechanisms were observed because the two nanomaterials differ in their oxidation state, which imparts different affinities for the cell membrane. Because GONPs have a higher cell membrane affinity and higher impact on membrane proteins compared with rGONPs, macrophages (THP-1a) derived from GONPs treated THP-1cells showed a severer effect on phagocytosis. By consecutive evaluation the effects of GONPs and rGONPs on THP-1 and THP-1a, we demonstrated that their surface oxidation states may cause GFNs to behave differently and cause different immunotoxic effects. Copyright © 2017 Elsevier B.V. All rights reserved.

Mycobacterium leprae upregulates IRGM expression in monocytes and monocyte-derived macrophages.

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Yang, Degang; Chen, Jia; Zhang, Linglin; Cha, Zhanshan; Han, Song; Shi, Weiwei; Ding, Ru; Ma, Lan; Xiao, Hong; Shi, Chao; Jing, Zhichun; Song, Ningjing

2014-08-01

Leprosy is caused by the infection of Mycobacterium leprae, which evokes a strong inflammatory response and leads to nerve damage. Immunity-related GTPase family M protein (IRGM) plays critical roles in controlling inflammation. The objective of the study was to investigate whether IRGM is involved in the infection of M. leprae. Levels of IRGM were assessed in M. leprae-infected CD4(+) T cells, monocytes, and monocyte-derived macrophages. Data revealed that both protein and mRNA levels of IRGM were increased in monocytes after M. leprae infection. Interestingly, monocyte-derived macrophages showed more prominent IRGM expression with M. leprae infection, whereas the bacteria did not affect IRGM in CD4(+) T cells. Furthermore, we assessed levels of IRGM in CD4(+) T cells and monocytes from 78 leprosy patients and 40 healthy controls, and observed upregulated protein level of IRGM in the monocytes from leprosy patients. Also, IRGM expression was inversely correlated with the severity of the disease. These findings suggested a close involvement of IRGM in M. leprae infection and indicated a potential mechanism of defending M. leprae infection.

HIV-1 infection and first line ART induced differential responses in mitochondria from blood lymphocytes and monocytes: the ANRS EP45 "Aging" study.

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Sophie Perrin

Full Text Available The ANRS EP45 "Aging" study investigates the cellular mechanisms involved in the accelerated aging of HIV-1 infected and treated patients. The data reported focus on mitochondria, organelles known to be involved in cell senescence.49 HIV-1 infected patients untreated with antiretroviral therapy, together with 49 seronegative age- and sex-matched control subjects and 81 HIV-1 infected and treated patients, were recruited by 3 AIDS centres (Marseille, Montpellier, Nice; France; http://clinicaltrials.gov/, NCT01038999. In more than 88% of treated patients, the viral load was 500/mm(3. ROS (reactive oxygen species production and ΔΨm (inner membrane potential were measured by flow cytometry in blood lymphocytes and monocytes (functional parameters. Three mitochondrial network quantitative morphological parameters were computed using confocal microscopy and image analysis. Three PBMC mitochondrial proteins (porin and subunits 2 and 4 of cytochrome C oxidase encoded by mtDNA or nuclear DNA, respectively were analysed by western blotting.Quantitative changes in PBMC mitochondrial proteins were not induced by either HIV-1 infection or ART. Discriminant analysis integrating functional (ROS production and ΔΨm or morphological (network volume density, fragmentation and branching parameters revealed HIV-1 infection and ART differential effects according to cell type. First line ART tended to rescue lymphocyte mitochondrial parameters altered by viral infection, but induced slight changes in monocytes. No statistical difference was found between the effects of three ART regimens on mitochondrial parameters. Correlations between functional parameters and viral load confirmed the damaging effects of HIV-1 in lymphocyte mitochondria.In patients considered to be clinically stable, mitochondria exhibited functional and morphological modifications in PBMCs resulting from either direct or indirect effects of HIV-1 infection (lymphocytes, or from first line ART

Fibroblast growth factor 23 inhibits extrarenal synthesis of 1,25-dihydroxyvitamin D in human monocytes.

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Bacchetta, Justine; Sea, Jessica L; Chun, Rene F; Lisse, Thomas S; Wesseling-Perry, Katherine; Gales, Barbara; Adams, John S; Salusky, Isidro B; Hewison, Martin

2013-01-01

Vitamin D is a potent stimulator of monocyte innate immunity, and this effect is mediated via intracrine conversion of 25-hydroxyvitamin D (25OHD) to 1,25-dihydroxyvitamin D (1,25(OH)(2) D). In the kidney, synthesis of 1,25(OH)(2) D is suppressed by fibroblast growth factor 23 (FGF23), via transcriptional suppression of the vitamin D-activating enzyme 1α-hydroxylase (CYP27B1). We hypothesized that FGF23 also suppresses CYP27B1 in monocytes, with concomitant effects on intracrine responses to 1,25(OH)(2) D. Healthy donor peripheral blood mononuclear cell monocytes (PBMCm) and peritoneal dialysate monocyte (PDm) effluent from kidney disease patients were assessed at baseline to confirm the presence of mRNA for FGF23 receptors (FGFRs), with Klotho and FGFR1 being more strongly expressed than FGFR2/3/4 in both cell types. Immunohistochemistry showed coexpression of Klotho and FGFR1 in PBMCm and PDm, with this effect being enhanced following treatment with FGF23 in PBMCm but not PDm. Treatment with FGF23 activated mitogen-activated protein kinase (MAPK) and protein kinase B (Akt) pathways in PBMCm, demonstrating functional FGFR signaling in these cells. FGF23 treatment of PBMCm and PDm decreased expression of mRNA for CYP27B1. In PBMCm this was associated with downregulation of 25OHD to 1,25(OH)(2) D metabolism, and concomitant suppression of intracrine induced 24-hydroxylase (CYP24A1) and antibacterial cathelicidin (LL37). FGF23 suppression of CYP27B1 was particularly pronounced in PBMCm treated with interleukin-15 to stimulate synthesis of 1,25(OH)(2) D. These data indicate that FGF23 can inhibit extra-renal expression of CYP27B1 and subsequent intracrine responses to 1,25(OH)(2) D in two different human monocyte models. Elevated expression of FGF23 may therefore play a crucial role in defining immune responses to vitamin D and this, in turn, may be a key determinant of infection in patients with chronic kidney disease (CKD). Copyright © 2013 American Society for

Postprandial Monocyte Activation in Individuals With Metabolic Syndrome

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Khan, Ilvira M.; Pokharel, Yashashwi; Dadu, Razvan T.; Lewis, Dorothy E.; Hoogeveen, Ron C.; Wu, Huaizhu

2016-01-01

Context: Postprandial hyperlipidemia has been suggested to contribute to atherogenesis by inducing proinflammatory changes in monocytes. Individuals with metabolic syndrome (MS), shown to have higher blood triglyceride concentration and delayed triglyceride clearance, may thus have increased risk for development of atherosclerosis. Objective: Our objective was to examine fasting levels and effects of a high-fat meal on phenotypes of monocyte subsets in individuals with obesity and MS and in healthy controls. Design, Setting, Participants, Intervention: Individuals with obesity and MS and gender- and age-matched healthy controls were recruited. Blood was collected from participants after an overnight fast (baseline) and at 3 and 5 hours after ingestion of a high-fat meal. At each time point, monocyte phenotypes were examined by multiparameter flow cytometry. Main Outcome Measures: Baseline levels of activation markers and postprandial inflammatory response in each of the three monocyte subsets were measured. Results: At baseline, individuals with obesity and MS had higher proportions of circulating lipid-laden foamy monocytes than controls, which were positively correlated with fasting triglyceride levels. Additionally, the MS group had increased counts of nonclassical monocytes, higher CD11c, CX3CR1, and human leukocyte antigen-DR levels on intermediate monocytes, and higher CCR5 and tumor necrosis factor-α levels on classical monocytes in the circulation. Postprandial triglyceride increases in both groups were paralleled by upregulation of lipid-laden foamy monocytes. MS, but not control, subjects had significant postprandial increases of CD11c and percentages of IL-1β+ and tumor necrosis factor-α+ cells in nonclassical monocytes. Conclusions: Compared to controls, individuals with obesity and MS had increased fasting and postprandial monocyte lipid accumulation and activation. PMID:27575945

Activation of Triggering Receptor Expressed on Myeloid Cells-1 on Human Neutrophils by Marburg and Ebola Viruses

National Research Council Canada - National Science Library

Mohamadzadeh, Mansour; Coberley, Sadie S; Olinger, Gene G; Kalina, Warren V; Ruthel, Gordon; Fullter, Claudette L; Swenson, Dana L; Pratt, William D; Kuhns, Douglas B; Schmaljohn, Alan L

2006-01-01

.... Here, we report that MARV and EBOV activate TREM-1 on human neutrophils, resulting in DAP12 phosphorylation, TREM-1 shedding, mobilization of intracellular calcium, secretion of proinflammatory...

Lipopolysaccharide-Elicited TSLPR Expression Enriches a Functionally Discrete Subset of Human CD14+ CD1c+ Monocytes.

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Borriello, Francesco; Iannone, Raffaella; Di Somma, Sarah; Vastolo, Viviana; Petrosino, Giuseppe; Visconte, Feliciano; Raia, Maddalena; Scalia, Giulia; Loffredo, Stefania; Varricchi, Gilda; Galdiero, Maria Rosaria; Granata, Francescopaolo; Del Vecchio, Luigi; Portella, Giuseppe; Marone, Gianni

2017-05-01

Thymic stromal lymphopoietin (TSLP) is a cytokine produced mainly by epithelial cells in response to inflammatory or microbial stimuli and binds to the TSLP receptor (TSLPR) complex, a heterodimer composed of TSLPR and IL-7 receptor α (CD127). TSLP activates multiple immune cell subsets expressing the TSLPR complex and plays a role in several models of disease. Although human monocytes express TSLPR and CD127 mRNAs in response to the TLR4 agonist LPS, their responsiveness to TSLP is poorly defined. We demonstrate that TSLP enhances human CD14 + monocyte CCL17 production in response to LPS and IL-4. Surprisingly, only a subset of CD14 + CD16 - monocytes, TSLPR + monocytes (TSLPR + mono), expresses TSLPR complex upon LPS stimulation in an NF-κB- and p38-dependent manner. Phenotypic, functional, and transcriptomic analysis revealed specific features of TSLPR + mono, including higher CCL17 and IL-10 production and increased expression of genes with important immune functions (i.e., GAS6 , ALOX15B , FCGR2B , LAIR1 ). Strikingly, TSLPR + mono express higher levels of the dendritic cell marker CD1c. This evidence led us to identify a subset of peripheral blood CD14 + CD1c + cells that expresses the highest levels of TSLPR upon LPS stimulation. The translational relevance of these findings is highlighted by the higher expression of TSLPR and CD127 mRNAs in monocytes isolated from patients with Gram-negative sepsis compared with healthy control subjects. Our results emphasize a phenotypic and functional heterogeneity in an apparently homogeneous population of human CD14 + CD16 - monocytes and prompt further ontogenetic and functional analysis of CD14 + CD1c + and LPS-activated CD14 + CD1c + TSLPR + mono. Copyright © 2017 by The American Association of Immunologists, Inc.

The proliferative human monocyte subpopulation contains osteoclast precursors

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Lari, Roya; Kitchener, Peter D; Hamilton, John A

2009-01-01

Introduction Immediate precursors of bone-resorbing osteoclasts are cells of the monocyte/macrophage lineage. Particularly during clinical conditions showing bone loss, it would appear that osteoclast precursors are mobilized from bone marrow into the circulation prior to entering tissues undergoing such loss. The observed heterogeneity of peripheral blood monocytes has led to the notion that different monocyte subpopulations may have special or restricted functions, including as osteoclast precursors. Methods Human peripheral blood monocytes were sorted based upon their degree of proliferation and cultured in macrophage colony-stimulating factor (M-CSF or CSF-1) and receptor activator of nuclear factor-kappa-B ligand (RANKL). Results The monocyte subpopulation that is capable of proliferation gave rise to significantly more multinucleated, bone-resorbing osteoclasts than the bulk of the monocytes. Conclusions Human peripheral blood osteoclast precursors reside in the proliferative monocyte subpopulation. PMID:19222861

Localization of monocyte chemotactic and activating factor (MCAF/MCP-1) in psoriasis

DEFF Research Database (Denmark)

Deleuran, M; Buhl, L; Ellingsen, T

1996-01-01

in the epidermal pustules in pustular psoriasis. In normals positive staining was observed in all the layers of the epidermis and in a few perivascular cells and blood vessels in the dermis. Where present in normal and diseased skin, eccrine ducts of sweat glands and sebaceous glands stained positive for MCAF......The monocyte chemotactic protein-1 (MCAF) also termed MCP-1, a strong chemotactic factor towards monocytes, is produced by several cell types present in the skin. The in situ presence of MCAF/MCP-1 protein in the skin has, however, not yet been established. Using immunohistochemical techniques we...... have investigated the distribution of MCAF in skin from patients with different types of psoriasis and normal healthy volunteers. We report the novel finding that psoriasis has strong positive immunostaining for MCAF located to all the layers of the epidermis, except the stratum granulosum, in pustular...

FGF23 inhibits extra-renal synthesis of 1,25-dihydroxyvitamin D in human monocytes

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Bacchetta, Justine; Sea, Jessica L; Chun, Rene F; Lisse, Thomas S; Wesseling-Perry, Katherine; Gales, Barbara; Adams, John S.; Salusky, Isidro B; Hewison, Martin

2012-01-01

Vitamin D is a potent stimulator of monocyte innate immunity, with this effect being mediated via intracrine conversion of 25-hydroxyvitamin D (25OHD) to 1,25-dihydroxyvitamin D (1,25(OH)2D). In the kidney synthesis of 1,25(OH)2D is suppressed by fibroblast growth factor 23 (FGF23), via transcriptional suppression of the vitamin D-activating enzyme 1α-hydroxylase (CYP27B1). We hypothesized that FGF23 also suppresses CYP27B1 in monocytes, with concomitant effects on intracrine responses to 1,25(OH)2D. Monocytes from healthy donor peripheral blood mononuclear cells (PBMCm) and from peritoneal dialysate effluent from kidney disease patients (PDm) were assessed at baseline to confirm the presence of mRNA for FGF23 receptors (FGFRs), with Klotho and FGFR1 being more strongly expressed than FGFR2/3/4 in both cell types. Immunohistochemistry showed co-expression of Klotho and FGFR1 in PBMCm and PDm, with this effect being enhanced following treatment with FGF23 in PBMCm but not PDm. Treatment with FGF23 activated MAP kinase (MAPK) and Akt pathways in PBMCm, demonstrating functional FGFR signaling in these cells. FGF23 treatment of PBMCm and PDm decreased expression of mRNA for CYP27B1. In PBMCm this was associated with downregulation of 25OHD to 1,25(OH)2D metabolism, and concomitant suppression of intracrine induced 24-hydroxylase (CYP24A1) and antibacterial cathelicidin (LL37). FGF23 suppression of CYP27B1 was particularly pronounced in PBMCm treated with interleukin-15 to stimulate synthesis of 1,25(OH)2D. These data indicate that FGF23 can inhibit extra-renal expression of CYP27B1 and subsequent intracrine responses to 1,25(OH)2D in two different human monocyte models. Elevated expression of FGF23 may therefore play a crucial role in defining immune responses to vitamin D and this, in turn, may be a key determinant of infection in patients with CKD. PMID:22886720

Oxidative stress induces monocyte necrosis with enrichment of cell-bound albumin and overexpression of endoplasmic reticulum and mitochondrial chaperones.

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Haiping Tang

Full Text Available In the present study, monocytes were treated with 5-azacytidine (azacytidine, gossypol or hydrogen peroxide to induce cell death through oxidative stress. A shift from apoptotic to necrotic cell death occurred when monocytes were treated with 100 µM azacytidine for more than 12 hours. Necrotic monocytes exhibited characteristics, including enrichment of cell-bound albumin and up-regulation of endoplasmic reticulum (ER- and mitochondrial-specific chaperones to protect mitochondrial integrity, which were not observed in other necrotic cells, including HUH-7, A2780, A549 and HOC1a. Our results show that the cell-bound albumin originates in the culture medium rather than from monocyte-derived hepatocytes, and that HSP60 is a potential binding partner of the cell-bound albumin. Proteomic analysis shows that HSP60 and protein disulfide isomerase are the most abundant up-regulated mitochondrial and ER-chaperones, and that both HSP60 and calreticulin are ubiquitinated in necrotic monocytes. In contrast, expression levels of the cytosolic chaperones HSP90 and HSP71 were down-regulated in the azacytidine-treated monocytes, concomitant with an increase in the levels of these chaperones in the cell culture medium. Collectively, our results demonstrates that chaperones from different organelles behave differently in necrotic monocytes, ER- and mitochondrial chaperones being retained and cytosolic and nuclear chaperones being released into the cell culture medium through the ruptured cell membrane. HSP60 may serve as a new target for development of myeloid leukemia treatment.

High-Density Lipoprotein Reduction Differentially Modulates to Classical and Nonclassical Monocyte Subpopulations in Metabolic Syndrome Patients and in LPS-Stimulated Primary Human Monocytes In Vitro

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Grün, Johanna L.; Manjarrez-Reyna, Aaron N.; Gómez-Arauz, Angélica Y.; Leon-Cabrera, Sonia; Bueno-Hernández, Nallely; Islas-Andrade, Sergio

2018-01-01

The effect of metabolic syndrome on human monocyte subpopulations has not yet been studied. Our main goal was to examine monocyte subpopulations in metabolic syndrome patients, while also identifying the risk factors that could directly influence these cells. Eighty-six subjects were divided into metabolic syndrome patients and controls. Monocyte subpopulations were quantified by flow cytometry, and interleukin- (IL-) 1β secretion levels were measured by ELISA. Primary human monocytes were cultured in low or elevated concentrations of high-density lipoprotein (HDL) and stimulated with lipopolysaccharide (LPS). The nonclassical monocyte (NCM) percentage was significantly increased in metabolic syndrome patients as compared to controls, whereas classical monocytes (CM) were reduced. Among all metabolic syndrome risk factors, HDL reduction exhibited the most important correlation with monocyte subpopulations and then was studied in vitro. Low HDL concentration reduced the CM percentage, whereas it increased the NCM percentage and IL-1β secretion in LPS-treated monocytes. The LPS effect was abolished when monocytes were cultured in elevated HDL concentrations. Concurring with in vitro results, IL-1β serum values significantly increased in metabolic syndrome patients with low HDL levels as compared to metabolic syndrome patients without HDL reduction. Our data demonstrate that HDL directly modulates monocyte subpopulations in metabolic syndrome. PMID:29850624

High-Density Lipoprotein Reduction Differentially Modulates to Classical and Nonclassical Monocyte Subpopulations in Metabolic Syndrome Patients and in LPS-Stimulated Primary Human Monocytes In Vitro

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Johanna L. Grün

2018-01-01

Full Text Available The effect of metabolic syndrome on human monocyte subpopulations has not yet been studied. Our main goal was to examine monocyte subpopulations in metabolic syndrome patients, while also identifying the risk factors that could directly influence these cells. Eighty-six subjects were divided into metabolic syndrome patients and controls. Monocyte subpopulations were quantified by flow cytometry, and interleukin- (IL- 1β secretion levels were measured by ELISA. Primary human monocytes were cultured in low or elevated concentrations of high-density lipoprotein (HDL and stimulated with lipopolysaccharide (LPS. The nonclassical monocyte (NCM percentage was significantly increased in metabolic syndrome patients as compared to controls, whereas classical monocytes (CM were reduced. Among all metabolic syndrome risk factors, HDL reduction exhibited the most important correlation with monocyte subpopulations and then was studied in vitro. Low HDL concentration reduced the CM percentage, whereas it increased the NCM percentage and IL-1β secretion in LPS-treated monocytes. The LPS effect was abolished when monocytes were cultured in elevated HDL concentrations. Concurring with in vitro results, IL-1β serum values significantly increased in metabolic syndrome patients with low HDL levels as compared to metabolic syndrome patients without HDL reduction. Our data demonstrate that HDL directly modulates monocyte subpopulations in metabolic syndrome.

Monocyte function is severely impaired by the fluorochrome calcein acetomethylester

International Nuclear Information System (INIS)

Czepluch, Frauke S.; Olieslagers, Serve J.F.; Waltenberger, Johannes

2007-01-01

For rapid chemotaxis quantification, cell prelabelling is often performed with the fluorochrome calcein acetomethylester (calcein AM). We investigated whether calcein AM-prelabelling is reliable for monocyte migration analysis. Human monocytes were either preexposed to calcein AM or unlabelled. Monocyte migration towards the potent chemoattractants transforming growth factor-β1 (TGF-β1) and N-formyl-Methionin-Leucin-Phenylalanin (fMLP) was assessed using a 48-well micro-chemotaxis chamber. For quantification, cells were visualized by light microscopy and counted. Surprisingly, random migration of calcein AM-prelabelled cells was significantly impaired compared to the unlabelled control. Accordingly, monocyte chemotaxis towards either TGF-β1 or fMLP dramatically declined. Adherence of calcein AM-labelled monocytes on plastic was also significantly decreased compared to control cells. As adhesion is regarded as an essential component of monocyte migration, the reduced migration observed in calcein AM-labelled monocytes might be explained by a fluorochrome-induced adhesion defect. Therefore, use of the fluorochrome calcein AM cannot be recommended for functional testing of monocytes

Monocytes/Macrophages Control Resolution of Transient Inflammatory Pain

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Willemen, Hanneke L. D. M.; Eijkelkamp, Niels; Carbajal, Anibal Garza; Wang, Huijing; Mack, Matthias; Zijlstra, Jitske; Heijnen, Cobi J.; Kavelaars, Annemieke

2014-01-01

Insights into mechanisms governing resolution of inflammatory pain are of great importance for many chronic pain–associated diseases. Here we investigate the role of macrophages/monocytes and the anti-inflammatory cytokine interleukin-10 (IL-10) in the resolution of transient inflammatory pain. Depletion of mice from peripheral monocytes/macrophages delayed resolution of intraplantar IL-1β- and carrageenan-induced inflammatory hyperalgesia from 1 to 3 days to >1 week. Intrathecal administration of a neutralizing IL-10 antibody also markedly delayed resolution of IL-1β- and carrageenan-induced inflammatory hyperalgesia. Recently, we showed that IL-1β- and carrageenan-induced hyperalgesia is significantly prolonged in LysM-GRK2+/− mice, which have reduced levels of G-protein-coupled receptor kinase 2 (GRK2) in LysM+ myeloid cells. Here we show that adoptive transfer of wild-type, but not of GRK2+/−, bone marrow-derived monocytes normalizes the resolution of IL-1β-induced hyperalgesia in LysM-GRK2+/− mice. Adoptive transfer of IL-10−/− bone marrow-derived monocytes failed to normalize the duration of IL-1β-induced hyperalgesia in LysM-GRK2+/− mice. Mechanistically, we show that GRK2+/− macrophages produce less IL-10 in vitro. In addition, intrathecal IL-10 administration attenuated IL-1β-induced hyperalgesia in LysM-GRK2+/− mice, whereas it had no effect in wild-type mice. Our data uncover a key role for monocytes/macrophages in promoting resolution of inflammatory hyperalgesia via a mechanism dependent on IL-10 signaling in dorsal root ganglia. Perspective We show that IL-10-producing monocytes/macrophages promote resolution of transient inflammatory hyperalgesia. Additionally, we show that reduced monocyte/macrophage GRK2 impairs resolution of hyperalgesia and reduces IL-10 production. We propose that low GRK2 expression and/or impaired IL-10 production by monocytes/macrophages represent peripheral biomarkers for the risk of developing

Transcellular lipoxygenase metabolism between monocytes and platelets

Energy Technology Data Exchange (ETDEWEB)

Bigby, T.D.; Meslier, N. (Univ. of California, San Francisco (USA))

1989-09-15

We have examined the effects of co-culture and in vitro co-stimulation on lipoxygenase metabolism in monocytes and platelets. Monocytes were obtained from the peripheral blood of normal volunteers by discontinuous gradient centrifugation and adherence to tissue culture plastic. Platelets were obtained from the platelet-rich plasma of the same donor. When 10(9) platelets and 2.5 x 10(6) monocytes were co-stimulated with 1 microM A23187, these preparations released greater quantities of 12(S)-hydroxy-10-trans-5,8,14-cis-eicosatetraenoic acid, 5(S),12-(S)dihydroxy-6,10-trans-8,14-cis-eicosatetraenoic acid, and leukotriene C4, 5(S)-hydroxy-6(R)-S-glutathionyl-7,9-trans-11,14-cis-eicosatetraenoic (LTC4) when compared with monocytes alone. Release of arachidonic acid, 5-HETE, delta 6-trans-LTB4, and delta 6-trans-12-epi-LTB4 from monocytes was decreased in the presence of platelets. A dose-response curve was constructed and revealed that the above changes became evident when the platelet number exceeded 10(7). Dual radiolabeling experiments with 3H- and 14C-arachidonic acid revealed that monocytes provided arachidonic acid, 5-HETE, and LTA4 for further metabolism by the platelet. Monocytes did not metabolize platelet intermediates detectably. In addition, as much as 1.2 microM 12(S)-hydroxy-10-trans-5,8,14-cis-eicosatetraenoic acid and 12(S)-hydroperoxy-10-trans-5,8,14-cis-eicosatetraenoic acid had no effect on monocyte lipoxygenase metabolism. Platelets were capable of converting LTA4 to LTC4, but conversion of LTA4 to LTB4 was not detected. We conclude that the monocyte and platelet lipoxygenase pathways undergo a transcellular lipoxygenase interaction that differs from the interaction of the neutrophil and platelet lipoxygenase pathways. In this interaction monocytes provide intermediate substrates for further metabolic conversion by platelets in an unidirectional manner.

FC-99 ameliorates sepsis-induced liver dysfunction by modulating monocyte/macrophage differentiation via Let-7a related monocytes apoptosis.

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Zhao, Yarong; Zhu, Haiyan; Wang, Haining; Ding, Liang; Xu, Lizhi; Chen, Dai; Shen, Sunan; Hou, Yayi; Dou, Huan

2018-03-13

The liver is a vital target for sepsis-related injury, leading to inflammatory pathogenesis, multiple organ dysfunction and high mortality rates. Monocyte-derived macrophage transformations are key events in hepatic inflammation. N 1 -[(4-methoxy)methyl]-4-methyl-1,2-benzenediamine (FC-99) previously displayed therapeutic potential on experimental sepsis. However, the underlying mechanism of this protective effect is still not clear. FC-99 treatment attenuated the liver dysfunction in septic mice that was accompanied with reduced numbers of pro-inflammatory Ly6C hi monocytes in the peripheral blood and CD11b + F4/80 lo monocyte-derived macrophages in the liver. These effects were attributed to the FC-99-induced apoptosis of CD11b + cells. In PMA-differentiated THP-1 cells, FC-99 repressed the expression of CD11b, CD14 and caspase3 and resulted in a high proportion of Annexin V + cells. Moreover, let-7a-5p expression was abrogated upon CLP stimulation in vivo , whereas it was restored by FC-99 treatment. TargetScan analysis and luciferase assays indicated that the anti-apoptotic protein BCL-XL was targeted by let-7a-5p. BCL-XL was inhibited by FC-99 in order to induce monocyte apoptosis, leading to the impaired monocyte-to-macrophage differentiation. Murine acute liver failure was generated by caecal ligation puncture surgery after FC-99 administration; Blood samples and liver tissues were collected to determine the monocyte/macrophage subsets and the induction of apoptosis. Human acute monocytic leukemia cell line (THP-1) cells were pretreated with FC-99 followed by phorbol-12-myristate-13-acetate (PMA) stimulation, in order to induce monocyte-to-macrophage differentiation. The target of FC-99 and the mechanistic analyses were conducted by microarrays, qRT-PCR validation, TargetScan algorithms and a luciferase report assay. FC-99 exhibits potential therapeutic effects on CLP-induced liver dysfunction by restoring let-7a-5p levels.

Transfecting Human Monocytes with RNA.

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Dannull, Jens; Nair, Smita K

2016-01-01

Targeting monocytes as a delivery system for drugs or nucleic acids, and thereby harnessing their natural tissue-infiltrating capacity, has become an area of intense investigation in both basic and clinical research. Herein we describe an efficient method to deliver mRNA (messenger RNA) or siRNA (small interfering RNA) into human monocytes by electroporation. This method can be applied in the laboratory to monocytes isolated via magnetic bead-based techniques, or in a clinical setting using monocytes that were collected via counterflow centrifugation elutriation using the Elutra(®) Cell Separation System. We further demonstrate that electroporation of monocytes with RNA represents a robust and highly relevant approach to modify monocytes for cell-based therapies. Last, the procedure described can readily be adapted to monocytes from different species, hence facilitating research in animal models.

Association of Canine Osteosarcoma and Monocyte Phenotype and Chemotactic Function.

Science.gov (United States)

Tuohy, J L; Lascelles, B D X; Griffith, E H; Fogle, J E

2016-07-01

Monocytes/macrophages are likely key cells in immune modulation in dogs with osteosarcoma (OSA). Increased peripheral monocyte counts are negatively correlated with shorter disease-free intervals in dogs with OSA. Understanding the monocyte/macrophage's modulatory role in dogs with OSA can direct further studies in immunotherapy development for OSA. That OSA evades the immune response by down-regulating monocyte chemokine receptor expression and migratory function, and suppresses host immune responses. Eighteen dogs with OSA that have not received definitive treatment and 14 healthy age-matched controls Clinical study-expression of peripheral blood monocyte cell surface receptors, monocyte mRNA expression and cytokine secretion, monocyte chemotaxis, and survival were compared between clinical dogs with OSA and healthy control dogs. Cell surface expression of multiple chemokine receptors is significantly down-regulated in peripheral blood monocytes of dogs with OSA. The percentage expression of CCR2 (median 58%, range 2-94%) and CXCR2 expression (median 54%, range 2-92%) was higher in control dogs compared to dogs with OSA (CCR2 median 29%, range 3-45%, P = 0.0006; CXCR2 median 23%, range 0.2-52%, P = 0.0007). Prostaglandin E2 (PGE2 ) (OSA, median 347.36 pg/mL, range 103.4-1268.5; control, 136.23 pg/mL, range 69.93-542.6, P = .04) and tumor necrosis factor-alpha (TNF-α) (P = .02) levels are increased in OSA monocyte culture supernatants compared to controls. Peripheral blood monocytes of dogs with OSA exhibit decreased chemotactic function when compared to control dogs (OSA, median 1.2 directed to random migration, range 0.8-1.25; control, 1.6, range of 0.9-1.8, P = .018). Dogs with OSA have decreased monocyte chemokine receptor expression and monocyte chemotaxis, potential mechanisms by which OSA might evade the immune response. Reversal of monocyte dysfunction using immunotherapy could improve survival in dogs with OSA. Copyright © 2016 The Authors. Journal of

A role for inflammatory mediators in heterologous desensitization of CysLT1 receptor in human monocytes

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Capra, Valérie; Accomazzo, Maria Rosa; Gardoni, Fabrizio; Barbieri, Silvia; Rovati, G. Enrico

2010-01-01

Cysteinyl-leukotrienes (cysteinyl-LT) are rapidly generated at sites of inflammation and, in addition to their role in asthma, rhinitis, and other immune disorders, are increasingly regarded as significant inflammatory factors in cancer, gastrointestinal, cardiovascular diseases. We recently demonstrated that in monocyte/macrophage–like U937 cells, extracellular nucleotides heterologously desensitize CysLT1 receptor (CysLT1R)-induced Ca2+ transients. Given that monocytes express a number of other inflammatory and chemoattractant receptors, this study was aimed at characterizing transregulation between these different stimuli. We demonstrate that in U937 cells and in primary human monocytes, a series of inflammatory mediators activating Gi-coupled receptor (FPR1, BLT1) desensitize CysLT1R-induced Ca2+ response unidirectionally through activation of PKC. Conversely, PAF-R, exclusively coupled to Gq, cross-desensitizes CysLT1R without the apparent involvement of any kinase. Interestingly, Gs-coupled receptors (β2AR, H1/2R, EP2/4R) are also able to desensitize CysLT1R response through activation of PKA. Heterologous desensitization seems to affect mostly the Gi-mediated signaling of the CysLT1R. The hierarchy of desensitization among agonists may be important for leukocyte signal processing at the site of inflammation. Considering that monocytes/macrophages are likely to be the major source of cysteinyl-LT in many immunological and inflammatory processes, shedding light on how their receptors are regulated will certainly help to better understand the role of these cells in orchestrating this complex network of integrated signals. PMID:19965602

Maturation of the viral core enhances the fusion of HIV-1 particles with primary human T cells and monocyte-derived macrophages

International Nuclear Information System (INIS)

Jiang Jiyang; Aiken, Christopher

2006-01-01

HIV-1 infection requires fusion of viral and cellular membranes in a reaction catalyzed by the viral envelope proteins gp120 and gp41. We recently reported that efficient HIV-1 particle fusion with target cells is linked to maturation of the viral core by an activity of the gp41 cytoplasmic domain. Here, we show that maturation enhances the fusion of a variety of recombinant viruses bearing primary and laboratory-adapted Env proteins with primary human CD4 + T cells. Overall, HIV-1 fusion was more dependent on maturation for viruses bearing X4-tropic envelope proteins than for R5-tropic viruses. Fusion of HIV-1 with monocyte-derived macrophages was also dependent on particle maturation. We conclude that the ability to couple fusion to particle maturation is a common feature of HIV-1 Env proteins and may play an important role during HIV-1 replication in vivo

Intermediate Monocytes but Not TIE2-Expressing Monocytes Are a Sensitive Diagnostic Indicator for Colorectal Cancer

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Schauer, Dominic; Starlinger, Patrick; Reiter, Christian; Jahn, Nikolaus; Zajc, Philipp; Buchberger, Elisabeth; Bachleitner-Hofmann, Thomas; Bergmann, Michael; Stift, Anton; Gruenberger, Thomas; Brostjan, Christine

2012-01-01

We have conducted the first study to determine the diagnostic potential of the CD14++CD16+ intermediate monocytes as compared to the pro-angiogenic subset of CD14++CD16+TIE2+ TIE2-expressing monocytes (TEMs) in cancer. These monocyte populations were investigated by flow cytometry in healthy volunteers (N = 32) and in colorectal carcinoma patients with localized (N = 24) or metastatic (N = 37) disease. We further determined blood levels of cytokines associated with monocyte regulation. The results revealed the intermediate monocyte subset to be significantly elevated in colorectal cancer patients and to show the highest frequencies in localized disease. Multivariate regression analysis identified intermediate monocytes as a significant independent variable in cancer prediction. With a cut-off value at 0.37% (intermediate monocytes of total leukocytes) the diagnostic sensitivity and specificity ranged at 69% and 81%, respectively. In contrast, TEM levels were elevated in localized cancer but did not differ significantly between groups and none of the cytokines correlated with monocyte subpopulations. Of interest, in vitro analyses supported the observation that intermediate monocytes were more potently induced by primary as opposed to metastatic cancer cells which may relate to the immunosuppressive milieu established in the advanced stage of metastatic disease. In conclusion, intermediate monocytes as compared to TIE2-expressing monocytes are a more sensitive diagnostic indicator of colorectal cancer. PMID:22973451

Intermediate monocytes but not TIE2-expressing monocytes are a sensitive diagnostic indicator for colorectal cancer.

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Dominic Schauer

Full Text Available We have conducted the first study to determine the diagnostic potential of the CD14++CD16+ intermediate monocytes as compared to the pro-angiogenic subset of CD14++CD16+TIE2+ TIE2-expressing monocytes (TEMs in cancer. These monocyte populations were investigated by flow cytometry in healthy volunteers (N = 32 and in colorectal carcinoma patients with localized (N = 24 or metastatic (N = 37 disease. We further determined blood levels of cytokines associated with monocyte regulation. The results revealed the intermediate monocyte subset to be significantly elevated in colorectal cancer patients and to show the highest frequencies in localized disease. Multivariate regression analysis identified intermediate monocytes as a significant independent variable in cancer prediction. With a cut-off value at 0.37% (intermediate monocytes of total leukocytes the diagnostic sensitivity and specificity ranged at 69% and 81%, respectively. In contrast, TEM levels were elevated in localized cancer but did not differ significantly between groups and none of the cytokines correlated with monocyte subpopulations. Of interest, in vitro analyses supported the observation that intermediate monocytes were more potently induced by primary as opposed to metastatic cancer cells which may relate to the immunosuppressive milieu established in the advanced stage of metastatic disease. In conclusion, intermediate monocytes as compared to TIE2-expressing monocytes are a more sensitive diagnostic indicator of colorectal cancer.

Diagnostic Performance of Soluble Triggering Receptor Expressed on Myeloid Cells-1 in Ventilator-Associated Pneumonia of Patients with Ischemic Stroke

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Yuetian Yu

2017-01-01

Full Text Available Objective. To investigate the effect of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1 in serum, bronchoalveolar lavage fluid (BALF, endotracheal aspiration (ETA, and exhaled breath condensate (EBC samples as early biomarkers for the diagnosis of ventilator-associated pneumonia (VAP in patients with ischemic stroke. Methods. One hundred and thirty-two patients with clinically suspected VAP were enrolled in this study. Bronchoscopy was performed on the day of clinically suspected VAP. sTREM-1 levels in serum, BALF, ETA, and EBC were measured. VAP was diagnosed by quantitative cultures of BALF (≥104 cfu/mL. Results. VAP was confirmed in 76 (57.58% cases. Patients with VAP showed significantly higher sTREM-1 in BALF [32.35 (IQR, 30.08–41.72 versus 18.92 (11.89–31.72] pg/mL and in EBC [1.57 (IQR, 1.02–2.61 versus 0.41 (0.19–1.61] pg/mL than patients without VAP. The area under the curve was 0.813 (p<0.001. The optimum cut-off value for sTREM-1 in BALF was 23.61 pg/mL, yielding sensitivity and specificity of 85.5% and 73.1%. sTREM-1 in BALF had excellent correlation with that in EBC (R2 = 0.78, p<0.05. Conclusions. sTREM-1 in EBC and BALF had good diagnostic performance in differentiating patients with and without VAP.

[The effect of isoflurane on the secretion of TNF-alpha and IL-1 beta from LPS-stimulated human peripheral blood monocytes].

Science.gov (United States)

Sato, W; Enzan, K; Masaki, Y; Kayaba, M; Suzuki, M

1995-07-01

The cytokines such as tumor necrosis factor and interleukin-1 secreted from macrophages/monocytes proved to play important roles in the pathogenesis of endotoxemia, severe pancreatitis and other surgical injuries. However, it is still unclear how inhalational anesthetic agents influence the secretion of these cytokines from macrophages/monocytes. We investigated the effects of isoflurane on TNF-alpha and IL-1 beta secretions from human peripheral blood monocytes stimulated by lipopolysaccharide. TNF-alpha and IL-1 beta secretions increased after LPS stimulation and this increase was inhibited by isoflurane in dose-dependent fashion. The inhibitory action of isoflurane disappeared between 1 and 3 hours after stopping isoflurane inhalation. We concluded that isoflurane could inhibit TNF-alpha and IL-1 beta secretions from peripheral blood monocytes stimulated by LPS in a dose-dependent fashion and that the inhibitory action of isoflurane was reversible.

Interleukin 17 receptor A modulates monocyte subsets and macrophage generation in vivo.

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Shuwang Ge

Full Text Available Interleukin (IL-17A signaling via Interleukin 17 receptor A (Il17ra contributes to the inflammatory host response by inducing recruitment of innate immune cells, but also plays a role in homeostatic neutrophilic granulocyte regulation. Monocytes, the other main innate immune cell, have a longer life span and can pursue multiple differentiation pathways towards tissue macrophages. Monocytes are divided into two subpopulations by expression of the Ly6C/Gr1 surface marker in mice. We here investigated the role of Il17ra in monocyte homeostasis and macrophage generation. In Il17ra(-/- and in mixed bone marrow chimeric wt/Il17ra(-/- mice, the concentrations of circulating Il17ra(-/- Gr1(low monocytes were significantly decreased compared to wt cells. Pulmonary, splenic and resident peritoneal Il17ra(-/- macrophages were significantly fewer than of wt origin. Bone marrow progenitor and monocyte numbers were equal, but the proportion of Il17ra(-/- Gr1(low monocytes was already decreased at bone marrow level. After monocyte depletion, initial Gr1(high and Gr1(low monocyte regeneration of Il17ra(-/- and wt cells was very similar. However, Il17ra(-/- Gr1(low counts were not sustained. After labeling with either fluorescent beads or BrdU, Il17ra(-/- Gr1(high monocyte transition to Gr1(low cells was not detectable unlike wt cells. Monocyte recruitment in acute peritonitis, which is known to be largely due to Gr1(high cell migration, was unaffected in an identical environment. Unilateral ureteral obstruction induces a less acute inflammatory and fibrotic kidney injury. Compared to wt cells in the same environment, Il17ra(-/- macrophage accumulation in the kidney was decreased. In the absence of Il17ra on all myeloid cells, renal fibrosis was significantly attenuated. Our data show that Il17ra modulates Gr1(low monocyte counts and suggest defective Gr1(high to Gr1(low monocyte transition as an underlying mechanism. Lack of Il17ra altered homeostatic tissue

Induction of HO-1 in tissue macrophages and monocytes in fatal falciparum malaria and sepsis

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Liomba N

2003-11-01

Full Text Available Abstract Background As well as being inducible by haem, haemoxygenase -1 (HO-1 is also induced by interleukin-10 and an anti-inflammatory prostaglandin, 15d PGJ2, the carbon monoxide thus produced mediating the anti-inflammatory effects of these molecules. The cellular distribution of HO-1, by immunohistochemistry, in brain, lung and liver in fatal falciparum malaria, and in sepsis, is reported. Methods Wax sections were stained, at a 1:1000 dilution of primary antibody, for HO-1 in tissues collected during paediatric autopsies in Blantyre, Malawi. These comprised 37 acutely ill comatose patients, 32 of whom were diagnosed clinically as cerebral malaria and the other 5 as bacterial diseases with coma. Another 3 died unexpectedly from an alert state. Other control tissues were from Australian adults. Results Apart from its presence in splenic red pulp macrophages and microhaemorrhages, staining for HO-1 was confined to intravascular monocytes and certain tissue macrophages. Of the 32 clinically diagnosed cerebral malaria cases, 11 (category A cases had negligible histological change in the brain and absence of or scanty intravascular sequestration of parasitized erythrocytes. Of these 11 cases, eight proved at autopsy to have other pathological changes as well, and none of these eight showed HO-1 staining within the brain apart from isolated moderate staining in one case. Two of the three without another pathological diagnosis showed moderate staining of scattered monocytes in brain vessels. Six of these 11 (category A cases exhibited strong lung staining, and the Kupffer cells of nine of them were intensely stained. Of the seven (category B cases with no histological changes in the brain, but appreciable sequestered parasitised erythrocytes present, one was without staining, and the other six showed strongly staining, rare or scattered monocytes in cerebral vessels. All six lung sections not obscured by neutrophils showed strong staining of

Bone marrow chimeric mice reveal a role for CX₃CR1 in maintenance of the monocyte-derived cell population in the olfactory neuroepithelium.

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Vukovic, Jana; Blomster, Linda V; Chinnery, Holly R; Weninger, Wolfgang; Jung, Steffen; McMenamin, Paul G; Ruitenberg, Marc J

2010-10-01

Macrophages in the olfactory neuroepithelium are thought to play major roles in tissue homeostasis and repair. However, little information is available at present about possible heterogeneity of these monocyte-derived cells, their turnover rates, and the role of chemokine receptors in this process. To start addressing these issues, this study used Cx₃cr1(gfp) mice, in which the gene sequence for eGFP was knocked into the CX₃CR1 gene locus in the mutant allele. Using neuroepithelial whole-mounts from Cx₃cr1(gfp/+) mice, we show that eGFP(+) cells of monocytic origin are distributed in a loose network throughout this tissue and can be subdivided further into two immunophenotypically distinct subsets based on MHC-II glycoprotein expression. BM chimeric mice were created using Cx₃cr1(gfp/+) donors to investigate turnover of macrophages (and other monocyte-derived cells) in the olfactory neuroepithelium. Our data indicate that the monocyte-derived cell population in the olfactory neuroepithelium is actively replenished by circulating monocytes and under the experimental conditions, completely turned over within 6 months. Transplantation of Cx₃cr1(gfp/gfp) (i.e., CX₃CR1-deficient) BM partially impaired the replenishment process and resulted in an overall decline of the total monocyte-derived cell number in the olfactory epithelium. Interestingly, replenishment of the CD68(low)MHC-II(+) subset appeared minimally affected by CX₃CR1 deficiency. Taken together, the established baseline data about heterogeneity of monocyte-derived cells, their replenishment rates, and the role of CX₃CR1 provide a solid basis to further examine the importance of different monocyte subsets for neuroregeneration at this unique frontier with the external environment.

Mitochondrial functions of THP-1 monocytes following the exposure to selected natural compounds.

Science.gov (United States)

Schultze, Nadin; Wanka, Heike; Zwicker, Paula; Lindequist, Ulrike; Haertel, Beate

2017-02-15

The immune system is an important target of various xenobiotics, which may lead to severe adverse effects including immunosuppression or inappropriate immunostimulation. Mitochondrial toxicity is one possibility by which xenobiotics exert their toxic effects in cells or organs. In this study, we investigated the impact of three natural compounds, cyclosporine A (CsA), deoxynivalenol (DON) and cannabidiol (CBD) on mitochondrial functions in the THP-1 monocytic cell line. The cells were exposed for 24h to two different concentrations (IC 10 and IC 50 determined by MTT) of each compound. The cells showed concentration-dependent elevated intracellular reactive oxygen species (iROS) and induction of apoptosis (except DON) in response to the three test compounds. Mitochondrial functions were characterized by using bioenergetics profiling experiments. In THP-1 monocytes, the IC 50 of CsA decreased basal and maximal respiration as well as ATP production with an impact on spare capacity indicating a mitochondrial dysfunction. Similar reaction patterns were observed following CBD exposure. The basal respiration level and ATP-production decreased in the THP-1 cells exposed to the IC 50 of DON with no major impact on mitochondrial function. In conclusion, impaired mitochondrial function was accompanied by elevated iROS and apoptosis level in a monocytic cell line exposed to CsA and CBD. Mitochondrial dysfunction may be one explanation for the cytotoxicity of CBD and CsA also in other in immune cells. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Amelioration of Glucolipotoxicity-Induced Endoplasmic Reticulum Stress by a “Chemical Chaperone” in Human THP-1 Monocytes

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Raji Lenin

2012-01-01

Full Text Available Chronic ER stress is emerging as a trigger that imbalances a number of systemic and arterial-wall factors and promote atherosclerosis. Macrophage apoptosis within advanced atherosclerotic lesions is also known to increase the risk of atherothrombotic disease. We hypothesize that glucolipotoxicity might mediate monocyte activation and apoptosis through ER stress. Therefore, the aims of this study are (a to investigate whether glucolipotoxicity could impose ER stress and apoptosis in THP-1 human monocytes and (b to investigate whether 4-Phenyl butyric acid (PBA, a chemical chaperone could resist the glucolipotoxicity-induced ER stress and apoptosis. Cells subjected to either glucolipotoxicity or tunicamycin exhibited increased ROS generation, gene and protein (PERK, GRP-78, IRE1α, and CHOP expression of ER stress markers. In addition, these cells showed increased TRPC-6 channel expression and apoptosis as revealed by DNA damage and increased caspase-3 activity. While glucolipotoxicity/tunicamycin increased oxidative stress, ER stress, mRNA expression of TRPC-6, and programmed the THP-1 monocytes towards apoptosis, all these molecular perturbations were resisted by PBA. Since ER stress is one of the underlying causes of monocyte dysfunction in diabetes and atherosclerosis, our study emphasize that chemical chaperones such as PBA could alleviate ER stress and have potential to become novel therapeutics.

Suppression of lipin-1 expression increases monocyte chemoattractant protein-1 expression in 3T3-L1 adipocytes

International Nuclear Information System (INIS)

Takahashi, Nobuhiko; Yoshizaki, Takayuki; Hiranaka, Natsumi; Suzuki, Takeshi; Yui, Tomoo; Akanuma, Masayasu; Oka, Kazuya; Kanazawa, Kaoru; Yoshida, Mika; Naito, Sumiyoshi; Fujiya, Mikihiro; Kohgo, Yutaka; Ieko, Masahiro

2011-01-01

Highlights: ► Lipin-1 affects lipid metabolism, adipocyte differentiation, and transcription. ► Adipose lipin-1 expression is reduced in obesity. ► Lipin-1 depletion using siRNA in 3T3-L1 adipocytes increased MCP-1 expression. ► Lipin-1 is involved in adipose inflammation. -- Abstract: Lipin-1 plays a crucial role in the regulation of lipid metabolism and cell differentiation in adipocytes. Expression of adipose lipin-1 is reduced in obesity, and metabolic syndrome. However, the significance of this reduction remains unclear. This study investigated if and how reduced lipin-1 expression affected metabolism. We assessed mRNA expression levels of various genes related to adipocyte metabolism in lipin-1-depleted 3T3-L1 adipocytes by introducing its specific small interfering RNA. In lipin-1-depleted adipocytes, mRNA and protein expression levels of monocyte chemoattractant protein-1 (MCP-1) were significantly increased, although the other genes tested were not altered. The conditioned media from the cells promoted monocyte chemotaxis. The increase in MCP-1 expression was prevented by treatment with quinazoline or salicylate, inhibitors of nuclear factor-κB activation. Because MCP-1 is related to adipose inflammation and systemic insulin resistance, these results suggest that a reduction in adipose lipin-1 in obesity may exacerbate adipose inflammation and metabolism.

Suppression of lipin-1 expression increases monocyte chemoattractant protein-1 expression in 3T3-L1 adipocytes

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Nobuhiko, E-mail: ntkhs@hoku-iryo-u.ac.jp [Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510 (Japan); Yoshizaki, Takayuki [Innovation Center, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065 (Japan); Hiranaka, Natsumi; Suzuki, Takeshi [Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Yui, Tomoo; Akanuma, Masayasu; Oka, Kazuya [Department of Fixed Prosthodontics and Oral Implantology, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Kanazawa, Kaoru [Department of Dental Anesthesiology, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Yoshida, Mika; Naito, Sumiyoshi [Department of Clinical Laboratory, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Fujiya, Mikihiro; Kohgo, Yutaka [Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510 (Japan); Ieko, Masahiro [Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan)

2011-11-11

Highlights: Black-Right-Pointing-Pointer Lipin-1 affects lipid metabolism, adipocyte differentiation, and transcription. Black-Right-Pointing-Pointer Adipose lipin-1 expression is reduced in obesity. Black-Right-Pointing-Pointer Lipin-1 depletion using siRNA in 3T3-L1 adipocytes increased MCP-1 expression. Black-Right-Pointing-Pointer Lipin-1 is involved in adipose inflammation. -- Abstract: Lipin-1 plays a crucial role in the regulation of lipid metabolism and cell differentiation in adipocytes. Expression of adipose lipin-1 is reduced in obesity, and metabolic syndrome. However, the significance of this reduction remains unclear. This study investigated if and how reduced lipin-1 expression affected metabolism. We assessed mRNA expression levels of various genes related to adipocyte metabolism in lipin-1-depleted 3T3-L1 adipocytes by introducing its specific small interfering RNA. In lipin-1-depleted adipocytes, mRNA and protein expression levels of monocyte chemoattractant protein-1 (MCP-1) were significantly increased, although the other genes tested were not altered. The conditioned media from the cells promoted monocyte chemotaxis. The increase in MCP-1 expression was prevented by treatment with quinazoline or salicylate, inhibitors of nuclear factor-{kappa}B activation. Because MCP-1 is related to adipose inflammation and systemic insulin resistance, these results suggest that a reduction in adipose lipin-1 in obesity may exacerbate adipose inflammation and metabolism.

Osteopontin Prevents Monocyte Recirculation and Apoptosis

OpenAIRE

Burdo, Tricia H.; Wood, Malcolm R.; Fox, Howard S.

2007-01-01

Cells of the monocyte/macrophage lineage have been shown to be the principal targets for productive HIV-1 replication within the central nervous system. In addition, HIV-1-associated dementia (HAD) has been shown to correlate with macrophage abundance in the brain. While increased entry of monocytes into the brain is thought to initiate this process, mechanisms that prevent macrophage egress from the brain and means that prevent macrophage death may also contribute to cell accumulation. We hy...

Th1/M1 conversion to Th2/M2 responses in models of inflammation lacking cell death stimulates maturation of monocyte precursors to fibroblasts

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JoAnn eTrial

2013-09-01

Full Text Available We have demonstrated that cardiac fibrosis arises from the differentiation of monocyte-derived fibroblasts. We present here evidence that this process requires sequential Th1 and Th2 induction promoting analogous M1 (classically activated and M2 (alternatively activated macrophage polarity. Our models are 1 mice subjected to daily repetitive ischemia reperfusion (I/R without infarction and 2 the in vitro transmigration of human mononuclear leukocytes through human cardiac microvascular endothelium. In the mouse heart, leukocytes entered after I/R in response to monocyte chemoattractant protein-1 (MCP-1 which is the major cytokine induced by this protocol. Monocytes within the heart then differentiated into fibroblasts making collagen while bearing the markers of M2 macrophages. T cells were seen in these hearts as well as in the human heart with cardiomyopathy. In the in vitro model, transmigration of the leukocytes was likewise induced by MCP-1 and some monocytes matured into fibroblasts bearing M2 markers. In this model, the MCP-1 stimulus induced a transient Th1 and M1 response that developed into a predominately Th2 and M2 response. An increase in the Th2 product IL-13 was present in both the human and the mouse models, consistent with its known role in fibrosis. In these simplified models, in which there is no cell death to stimulate an anti-inflammatory response, there is nonetheless a resolution of inflammation enabling a profibrotic environment. This induces the maturation of monocyte precursors into fibroblasts.

Gene array analysis of PD-1H overexpressing monocytes reveals a pro-inflammatory profile

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Preeti Bharaj

2018-02-01

Full Text Available We have previously reported that overexpression of Programmed Death -1 Homolog (PD-1H in human monocytes leads to activation and spontaneous secretion of multiple pro inflammatory cytokines. Here we evaluate changes in monocytes gene expression after enforced PD-1H expression by gene array. The results show that there are significant alterations in 51 potential candidate genes that relate to immune response, cell adhesion and metabolism. Genes corresponding to pro-inflammatory cytokines showed the highest upregulation, 7, 3.2, 3.0, 5.8, 4.4 and 3.1 fold upregulation of TNF-α, IL-1 β, IFN-α, γ, λ and IL-27 relative to vector control. The data are in agreement with cytometric bead array analysis showing induction of proinflammatory cytokines, IL-6, IL-1β and TNF-α by PD-1H. Other genes related to inflammation, include transglutaminase 2 (TG2, NF-κB (p65 and p50 and toll like receptors (TLR 3 and 4 were upregulated 5, 4.5 and 2.5 fold, respectively. Gene set enrichment analysis (GSEA also revealed that signaling pathways related to inflammatory response, such as NFκB, AT1R, PYK2, MAPK, RELA, TNFR1, MTOR and proteasomal degradation, were significantly upregulated in response to PD-1H overexpression. We validated the results utilizing a standard inflammatory sepsis model in humanized BLT mice, finding that PD-1H expression was highly correlated with proinflammatory cytokine production. We therefore conclude that PD-1H functions to enhance monocyte activation and the induction of a pro-inflammatory gene expression profile.

Establishing porcine monocyte-derived macrophage and dendritic cell systems for studying the interaction with PRRSV-1

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Helen eSingleton

2016-06-01

Full Text Available Monocyte-derived macrophages (MoMØ and monocyte-derived dendritic cells (MoDC are two model systems well established in human and rodent systems that can be used to study the interaction of pathogens with host cells. Porcine reproductive and respiratory syndrome virus (PRRSV is known to infect myeloid cells, such as macrophages (MØ and dendritic cells (DC. Therefore, this study aimed to establish systems for the differentiation and characterization of MoMØ and MoDC for subsequent infection with PRRSV-1. M-CSF differentiated monocyte-derived macrophages (MoMØ were stimulated with activators for classical (M1 or alternative (M2 activation. GM-CSF and IL-4 generated monocyte-derived dendritic cells (MoDC were activated with the well established maturation cocktail containing PAMPs and cytokines. In addition, MoMØ and MoDC were treated with dexamethasone and IL-10, which are known immuno-suppressive reagents. Cells were characterized by morphology, phenotype and function and porcine MØ subsets highlighted some divergence from described human counterparts, while MoDC, appeared more similar to mouse and human DCs. The infection with PRRSV-1 strain Lena demonstrated different replication kinetics between MoMØ and MoDC and within subsets of each cell type. While MoMØ susceptibility was significantly increased by dexamethasone and IL-10 with an accompanying increase in CD163/CD169 expression, MoDC supported only a minimal replication of PRRSV These findings underline the high variability in the susceptibility of porcine myeloid cells towards PRRSV-1 infection.

Different Regulation of Interleukin-1 Production and Activity in Monocytes and Macrophages: Innate Memory as an Endogenous Mechanism of IL-1 Inhibition

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Mariusz P. Madej

2017-06-01

Full Text Available Production and activity of interleukin (IL-1β are kept under strict control in our body, because of its powerful inflammation-promoting capacity. Control of IL-1β production and activity allows IL-1 to exert its defensive activities without causing extensive tissue damage. Monocytes are the major producers of IL-1β during inflammation, but they are also able to produce significant amounts of IL-1 inhibitors such as IL-1Ra and the soluble form of the decoy receptor IL-1R2, in an auto-regulatory feedback loop. Here, we investigated how innate immune memory could modulate production and activity of IL-1β by human primary monocytes and monocyte-derived tissue-like/deactivated macrophages in vitro. Cells were exposed to Gram-negative (Escherichia coli and Gram-positive (Lactobacillus acidophilus bacteria for 24 h, then allowed to rest, and then re-challenged with the same stimuli. The presence of biologically active IL-1β in cell supernatants was calculated as the ratio between free IL-1β (i.e., the cytokine that is not bound/inhibited by sIL-1R2 and its receptor antagonist IL-1Ra. As expected, we observed that the responsiveness of tissue-like/deactivated macrophages to bacterial stimuli was lower than that of monocytes. After resting and re-stimulation, a memory effect was evident for the production of inflammatory cytokines, whereas production of alarm signals (chemokines was minimally affected. We observed a high variability in the innate memory response among individual donors. This is expected since innate memory largely depends on the previous history of exposure or infections, which is different in different subjects. Overall, innate memory appeared to limit the amount of active IL-1β produced by macrophages in response to a bacterial challenge, while enhancing the responsiveness of monocytes. The functional re-programming of mononuclear phagocytes through modulation of innate memory may provide innovative approaches in the management

Intermediate monocytes in ANCA vasculitis: increased surface expression of ANCA autoantigens and IL-1β secretion in response to anti-MPO antibodies.

LENUS (Irish Health Repository)

O'Brien, Eóin C

2015-01-01

ANCA vasculitis encompasses several autoimmune conditions characterised by destruction of small vessels, inflammation of the respiratory tract and glomerulonephritis. Most patients harbour autoantibodies to myeloperoxidase (MPO) or proteinase 3 (PR3). Clinical and experimental data suggest that pathogenesis is driven by ANCA-mediated activation of neutrophils and monocytes. We investigated a potential role for distinct monocyte subsets. We found that the relative proportion of intermediate monocytes is increased in patients versus control individuals, and both MPO and PR3 are preferentially expressed on these cells. We demonstrate that MPO and PR3 are expressed independently of each other on monocytes and that PR3 is not associated with CD177. MPO expression correlates with that of Fc receptor CD16 on intermediate monocytes. Monocyte subsets respond differently to antibodies directed against MPO and PR3, with anti-MPO but not anti-PR3 leading to increased IL-1β, IL-6 and IL-8 production. In concordance with the observed higher surface expression of MPO on intermediate monocytes, this subset produces the highest quantity of IL-1β in response to anti-MPO stimulation. These data suggest that monocytes, specifically, the intermediate subset, may play a role in ANCA vasculitis, and also indicate that substantial differences exist between the effect of anti-MPO and anti-PR3 antibodies on these cells.

Effects of monascin on anti-inflammation mediated by Nrf2 activation in advanced glycation end product-treated THP-1 monocytes and methylglyoxal-treated wistar rats.

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Lee, Bao-Hong; Hsu, Wei-Hsuan; Huang, Tao; Chang, Yu-Ying; Hsu, Ya-Wen; Pan, Tzu-Ming

2013-02-13

Hyperglycemia is associated with advanced glycation end products (AGEs). This study was designed to evaluate the inhibitory effects of monascin on receptor for advanced glycation end product (RAGE) signal and THP-1 monocyte inflammation after treatment with S100b, a specific ligand of RAGE. Monascin inhibited cytokine production by S100b-treated THP-1 monocytes via up-regulation of nuclear factor-erythroid 2-related factor-2 (Nrf2) and alleviated p47phox translocation to the membrane. Methylglyoxal (MG, 600 mg/kg bw) was used to induce diabetes in Wistar rats. Inhibitions of RAGE and p47phox by monascin were confirmed by peripheral blood mononuclear cells (PBMCs) of MG-induced rats. Silymarin (SM) was used as a positive control group. It was found that monascin promoted heme oxygenase-1 (HO-1) expression mediated by Nrf2. Suppressions of AGEs, tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-β) in serum of MG-induced rats were attenuated in the monascin administration group treated with retinoic acid (RA). RA treatment resulted in Nrf2 inactivation by increasing RA receptor-α (RARα) activity, suggesting that RA acts as an inhibitor of Nrf2. The results showed that monascin exerted anti-inflammatory and antioxidative effects mediated by Nrf2 to prevent the development of diseases such as type 2 diabetes caused by inflammation.

The radioactive labeling of monocytes

International Nuclear Information System (INIS)

Ensing, G.J.

1985-01-01

With the aim of studying a possible relationship between circulating monocytes and Sternberg-Reed cells investigations were started on the specific labeling of monocytes. In this thesis the literature on the pertinent data has been reviewed and a series of experiments on the monocyte labeling procedure has been described. The principles of cell labeling with radioactive compounds were discussed. 1. Total separation of the particular cell population to be labeled and subsequent labeling with a non-specific radiopharmaceutical. 2. Specific cell labeling in a mixture of cell types based on a well defined affinity of the cell under study for the radiopharmaceutical used. Next the radionuclides that can be used for cell labeling purposes were discussed with special attention for 111 In and its chelates. The principles of radiodosimetry were also discussed shortly. This section was focussed on the radiation dose the labeled cells receive because of the intracellular localized radioactivity. The radiation burden is high in comparison to amounts of radiation known to affect cell viability. A newly developed method for labeling monocytes specifically by phagocytosis of 111 In-Fe-colloid without apparent loss of cells was described in detail. (Auth.)

Glucocorticoid receptors in monocytes in type 1 diabetes mellitus

DEFF Research Database (Denmark)

Damm, P; Binder, C

1989-01-01

Glucocorticoid receptor binding characteristics were investigated in 8 males with poorly controlled Type 1 diabetes mellitus and 14 healthy males. The cell type studied was monocytes, and a method for correction for heterogeneity in glucocorticoid binding in a mononuclear leucocyte population...... or with HbA1c. In conclusion, no major abnormalities in glucocorticoid receptor binding characteristics could be demonstrated in Type 1 diabetes mellitus....... was introduced. The number of receptors and the dissociation constant KD were, respectively, 13,699 and 2.93 X 10(-8) mol/l for the control group and 15,788 and 2.75 X 10(-8) mol/l for diabetics (p greater than 0.05). In diabetics, KD correlated negatively with blood glucose (r = 0.762, p less than 0...

Curcumin as a natural regulator of monocyte chemoattractant protein-1.

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Karimian, Maryam Saberi; Pirro, Matteo; Majeed, Muhammed; Sahebkar, Amirhossein

2017-02-01

Monocyte chemoattractant/chemotactic protein-1 (MCP-1), a member of the CC chemokine family, is one of the key chemokines that regulate migration and tissue infiltration of monocytes/macrophages. Its role in the pathophysiology of several inflammatory diseases has been widely recognized, thus making MCP-1 a possible target for anti-inflammatory treatments. Curcumin (diferuloylmethane) is a natural polyphenol derived from the rhizomes of Curcuma Longa L. (turmeric). Anti-inflammatory action underlies numerous pharmacological effects of curcumin in the control and prevention of several diseases. The purpose of this review is to evaluate the effects of curcumin on the regulation of MCP-1 as a key mediator of chemotaxis and inflammation, and the biological consequences thereof. In vitro studies have shown that curcumin can decrease MCP-1 production in various cell lines. Animal studies have also revealed that curcumin can attenuate MCP-1 expression and improve a range of inflammatory diseases through multiple molecular targets and mechanisms of action. There is limited data from human clinical trials showing the decreasing effect of curcumin on MCP-1 concentrations and improvement of the course of inflammatory diseases. Most of the in vitro and animal studies confirm that curcumin exert its MCP-1-lowering and anti-inflammatory effects by down-regulating the mitogen-activated protein kinase (MAPK) and NF-κB signaling pathway. As yet, there is limited data from human clinical trials showing the effect of curcumin on MCP-1 levels and improvement of the course of inflammatory diseases. More evidence, especially from human studies, is needed to better assess the effects of curcumin on circulating MCP-1 in different human diseases and the role of this modulatory effect in the putative anti-inflammatory properties of curcumin. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mycobacterium leprae alters classical activation of human monocytes in vitro.

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Fallows, Dorothy; Peixoto, Blas; Kaplan, Gilla; Manca, Claudia

2016-01-01

Macrophages play a central role in the pathogenesis of leprosy, caused by Mycobacterium leprae. The polarized clinical presentations in leprosy are associated with differential immune activation. In tuberculoid leprosy, macrophages show a classical activation phenotype (M1), while macrophages in lepromatous disease display characteristics of alternative activation (M2). Bacille Calmette-Guérin (BCG) vaccination, which protects against leprosy, can promote sustained changes in monocyte response to unrelated pathogens and may preferentially direct monocytes towards an M1 protective phenotype. We previously reported that M. leprae can dampen the response of naïve human monocytes to a strong inducer of pro-inflammatory cytokines, such as BCG. Here, we investigated the ability of the pathogen to alter the direction of macrophage polarization and the impact of BCG vaccination on the monocyte response to M. leprae. We show that in vitro exposure of monocytes from healthy donors to M. leprae interferes with subsequent M1 polarization, indicated by lower levels of M1-associated cytokine/chemokines released and reduced expression of M1 cell surface markers. Exposure to M. leprae phenolic glycolipid (PGL) 1, instead of whole bacteria, demonstrated a similar effect on M1 cytokine/chemokine release. In addition, we found that monocytes from 10-week old BCG-vaccinated infants released higher levels of the pro-inflammatory cytokines TNF-α and IL-1β in response to M. leprae compared to those from unvaccinated infants. Exposure to M. leprae has an inhibitory effect on M1 macrophage polarization, likely mediated through PGL-1. By directing monocyte/macrophages preferentially towards M1 activation, BCG vaccination may render the cells more refractory to the inhibitory effects of subsequent M. leprae infection.

Distinct functional programming of human fetal and adult monocytes.

Science.gov (United States)

Krow-Lucal, Elisabeth R; Kim, Charles C; Burt, Trevor D; McCune, Joseph M

2014-03-20

Preterm birth affects 1 out of 9 infants in the United States and is the leading cause of long-term neurologic handicap and infant mortality, accounting for 35% of all infant deaths in 2008. Although cytokines including interferon-γ (IFN-γ), interleukin-10 (IL-10), IL-6, and IL-1 are produced in response to in utero infection and are strongly associated with preterm labor, little is known about how human fetal immune cells respond to these cytokines. We demonstrate that fetal and adult CD14(+)CD16(-) classical monocytes are distinct in terms of basal transcriptional profiles and in phosphorylation of signal transducers and activators of transcription (STATs) in response to cytokines. Fetal monocytes phosphorylate canonical and noncanonical STATs and respond more strongly to IFN-γ, IL-6, and IL-4 than adult monocytes. We demonstrate a higher ratio of SOCS3 to IL-6 receptor in adult monocytes than in fetal monocytes, potentially explaining differences in STAT phosphorylation. Additionally, IFN-γ signaling results in upregulation of antigen presentation and costimulatory machinery in adult, but not fetal, monocytes. These findings represent the first evidence that primary human fetal and adult monocytes are functionally distinct, potentially explaining how these cells respond differentially to cytokines implicated in development, in utero infections, and the pathogenesis of preterm labor.

Innate immune responses of equine monocytes cultured in equine platelet lysate.

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Naskou, Maria C; Norton, Natalie A; Copland, Ian B; Galipeau, Jacques; Peroni, John F

2018-01-01

Platelet lysate (PL) has been extensively used for the laboratory expansion of human mesenchymal stem cells (MSC) in order to avoid fetal bovine serum (FBS) which has been associated with immune-mediated host reactions and transmission of bovine-origin microbial contaminants. Before suggesting the routine use of PL for MSC culture, we wanted to further investigate whether PL alone might trigger inflammatory responses when exposed to reactive white blood cells such as monocytes. Our objectives were to evaluate the inflammatory profile of equine monocytes cultured with equine PL (ePL) and to determine if ePL can modulate the expression of inflammatory cytokines in lipopolysaccharide (LPS)-stimulated monocytes. In a first experiment, equine monocytes were isolated and incubated with donor horse serum (DHS), FBS, six individual donors ePL or pooled ePL from all horses. In a second experiment, monocytes were stimulated with E. coli LPS in the presence of 1, 5 or 10% DHS and/or pooled ePL. After 6h of incubation, cell culture supernatants were assayed via ELISA for production of the pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and Interleukin 1β (IL-1β) as well as for the anti-inflammatory Interleukin 10 (IL-10). Equine monocytes incubated with pooled ePL produced significantly less TNF-α and significantly more IL-10 than monocytes incubated in FBS. A statistically significant difference was not identified for the production of IL-1β. The second experiment showed that pooled ePL added to LPS-stimulated equine monocytes resulted in a significant reduction in TNF-α and IL-1β production. IL-10 production was not significantly upregulated by the addition of ePL to LPS-stimulated monocytes. Finally, the addition of ePL to LPS-stimulated monocytes in the presence of various concentrations of DHS resulted to statistically significant decrease of TNF-α and IL-1β compared to the control groups. This is the first study to demonstrate that ePL suppresses

Chondroitin Sulfate Inhibits Monocyte Chemoattractant Protein-1 Release From 3T3-L1 Adipocytes: A New Treatment Opportunity for Obesity-Related Inflammation?

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Thomas V Stabler

2017-08-01

Full Text Available Monocyte chemoattractant protein-1 (MCP-1 overproduction from inflamed adipose tissue is a major contributor to obesity-related metabolic syndromes. 3T3-L1 embryonic fibroblasts were cultured and differentiated into adipocytes using an established protocol. Adipocytes were treated with lipopolysaccharide (LPS to induce inflammation and thus MCP-1 release. At the same time, varying concentrations of chondroitin sulfate (CS were added in a physiologically relevant range (10-200 µg/mL to determine its impact on MCP-1 release. Chondroitin sulfate, a natural glycosaminoglycan of connective tissue including the cartilage extracellular matrix, was chosen on the basis of our previous studies demonstrating its anti-inflammatory effect on macrophages. Because the main action of MCP-1 is to induce monocyte migration, cultured THP-1 monocytes were used to test whether CS at the highest physiologically relevant concentration could inhibit cell migration induced by human recombinant MCP-1. Chondroitin sulfate (100-200 µg/mL inhibited MCP-1 release from inflamed adipocytes in a dose-dependent manner ( P  < .01, 95% confidence interval [CI]: −5.89 to −3.858 at 100 µg/mL and P  < .001, 95% CI: −6.028 to −3.996 at 200 µg/mL but had no effect on MCP-1–driven chemotaxis of THP-1 monocytes. In summary, CS could be expected to reduce macrophage infiltration into adipose tissue by reduction in adipocyte expression and release of MCP-1 and as such might reduce adipose tissue inflammation in response to pro-inflammatory stimuli such as LPS, now increasingly recognized to be relevant in vivo.

[Linezolid-induced Apoptosis through Mitochondrial Damage and Role of Superoxide Dismutase-1 in Human Monocytic Cell Line U937].

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Fujii, Satoshi; Muraoka, Sanae; Miyamoto, Atsushi; Sakurai, Koichi

2018-01-01

 Cytopenia is a major adverse event associated with linezolid therapy. The objective of this study was to examine whether the cytotoxicity of linezolid to eukaryotic cells was associated with mitochondrial dysfunction and apoptosis-like cell death in human leukemic monocyte lymphoma cell line U937. Apoptosis-like cell death was clearly observed when cells were incubated with linezolid, depending on the duration and linezolid concentration. Mitochondrial membrane potential of cells treated with linezolid collapsed in a short period of time, but the number of mitochondria did not decrease. Cytotoxicity of linezolid was relieved by the knockdown of superoxide dismutase-1 in U937 cells. On the other hand, no autophagy was observed in cells treated with linezolid. These results suggest that mitochondrial damages would be linked to the induction of apoptosis in U937 cells treated with linezolid and that its mechanism does not involve autophagy.

Platelet density per monocyte predicts adverse events in patients after percutaneous coronary intervention.

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Rutten, Bert; Roest, Mark; McClellan, Elizabeth A; Sels, Jan W; Stubbs, Andrew; Jukema, J Wouter; Doevendans, Pieter A; Waltenberger, Johannes; van Zonneveld, Anton-Jan; Pasterkamp, Gerard; De Groot, Philip G; Hoefer, Imo E

2016-01-01

Monocyte recruitment to damaged endothelium is enhanced by platelet binding to monocytes and contributes to vascular repair. Therefore, we studied whether the number of platelets per monocyte affects the recurrence of adverse events in patients after percutaneous coronary intervention (PCI). Platelet-monocytes complexes with high and low median fluorescence intensities (MFI) of the platelet marker CD42b were isolated using cell sorting. Microscopic analysis revealed that a high platelet marker MFI on monocytes corresponded with a high platelet density per monocyte while a low platelet marker MFI corresponded with a low platelet density per monocyte (3.4 ± 0.7 vs 1.4 ± 0.1 platelets per monocyte, P=0.01). Using real-time video microscopy, we observed increased recruitment of high platelet density monocytes to endothelial cells as compared with low platelet density monocytes (P=0.01). Next, we classified PCI scheduled patients (N=263) into groups with high, medium and low platelet densities per monocyte and assessed the recurrence of adverse events. After multivariate adjustment for potential confounders, we observed a 2.5-fold reduction in the recurrence of adverse events in patients with a high platelet density per monocyte as compared with a low platelet density per monocyte [hazard ratio=0.4 (95% confidence interval, 0.2-0.8), P=0.01]. We show that a high platelet density per monocyte increases monocyte recruitment to endothelial cells and predicts a reduction in the recurrence of adverse events in patients after PCI. These findings may imply that a high platelet density per monocyte protects against recurrence of adverse events.

Monocyte functions in diabetes mellitus

DEFF Research Database (Denmark)

Geisler, C; Almdal, T; Bennedsen, J

1982-01-01

The aim of this study was to investigate the functions of monocytes obtained from 14 patients with diabetes mellitus (DM) compared with those of monocytes from healthy individuals. It was found that the total number of circulating monocytes in the 14 diabetic patients was lower than that from...... for the elucidation of concomitant infections in diabetic patients are discussed....

Increase of infiltrating monocytes in the livers of patients with chronic liver diseases.

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Huang, Rui; Wu, Hongyan; Liu, Yong; Yang, Chenchen; Pan, Zhiyun; Xia, Juan; Xiong, Yali; Wang, Guiyang; Sun, Zhenhua; Chen, Jun; Yan, Xiaomin; Zhang, Zhaoping; Wu, Chao

2016-01-01

Infiltrating monocytes have been demonstrated to contribute to tissue damage in experimental models of liver injury and fibrosis. However, less is known about monocyte infiltration in the livers of patients with chronic liver diseases (CLD). In the present study, we demonstrated that CD68+ hepatic macrophages and MAC387+ infiltrating monocytes were significantly increased in the livers of CLD patients with different etiologies as compared with normal liver tissue. In addition, CLD patients with higher inflammatory grading scores had more CD68+ macrophages and MAC387+ monocytes infiltration in their livers compared to those with lower scores. Significantly more MAC387+ infiltrating monocytes were found in the liver tissue of CLD patients with higher fibrotic staging scores compared to those with lower scores. Monocyte chemoattractant protein-1 (MCP-1) expression was significantly increased in the livers of CLD patients with different etiologies. MCP-1 staining scores were significantly positively associated with the numbers of MAC387+ infiltrating monocytes in CLD patients. Taken together, our results demonstrate that infiltrating monocytes may play a pathological role in exacerbating chronic liver inflammation and fibrosis in CLD. MCP-1 may be involved in the monocyte infiltration and progression of liver inflammation and fibrosis in CLD.

Monocytes of patients with familial hypercholesterolemia show alterations in cholesterol metabolism

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Soufi Muhidien

2008-11-01

Full Text Available Abstract Background Elevated plasma cholesterol promotes the formation of atherosclerotic lesions in which monocyte-derived lipid-laden macrophages are frequently found. To analyze, if circulating monocytes already show increased lipid content and differences in lipoprotein metabolism, we compared monocytes from patients with Familial Hypercholesterolemia (FH with those from healthy individuals. Methods Cholesterol and oxidized cholesterol metabolite serum levels of FH and of healthy, gender/age matched control subjects were measured by combined gas chromatography – mass spectroscopy. Monocytes from patients with FH and from healthy subjects were isolated by antibody-assisted density centrifugation. Gene expression profiles of isolated monocytes were measured using Affymetrix HG-U 133 Plus 2.0 microarrays. We compared monocyte gene expression profiles from FH patients with healthy controls using a Welch T-test with correction for multiple testing (p Results Using microarray analysis we found in FH patients a significant up-regulation of 1,617 genes and a down-regulation of 701 genes compared to monocytes from healthy individuals. These include genes of proteins that are involved in the uptake, biosynthesis, disposition, and cellular efflux of cholesterol. In addition, plasma from FH patients contains elevated amounts of sterols and oxysterols. An increased uptake of oxidized as well as of native LDL by FH monocytes combined with a down-regulation of NPC1 and ABCA1 explains the lipid accumulation observed in these cells. Conclusion Our data demonstrate that circulating FH monocytes show differences in cell physiology that may contribute to the early onset of atherosclerosis in this disease.

Soluble membrane receptors, interleukin 6, procalcitonin and C reactive protein as prognostic markers in patients with severe sepsis and septic shock.

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Juan-Jesús Ríos-Toro

Full Text Available The objective of this study was to explore the diagnostic and prognostic value of soluble triggering receptor expressed on myeloid cell 1 (sTREM-1, soluble cluster of differentiation 14 (sCD14, soluble cluster of differentiation 163 (sCD163, interleukin-6 (IL-6, procalcitonin (PCT, and C-reactive protein (CRP serum levels for patients with severe sepsis and septic shock in an intensive care unit (ICU.Fifty patients admitted at the ICU with the diagnosis of severe sepsis or septic shock were studied. SOFA and APACHE II scores as well as serum biomarkers were measured at days 0, 2 and 5. The influence of these variables on 28-day mortality was analyzed. Twenty healthy individuals served as controls.Baseline serum concentrations of sTREM-1, sCD163, IL-6 and PCT correlated with SOFA score. Only sTREM-1 levels correlated with APACHE II score. The 28-day mortality rate for all patients was 42%. The absence of risk factors for infection, presence of septic shock, baseline values of sCD14 and decrease of PCT and IL-6 from baseline to day 5 were variables associated to mortality in the univariate analysis. The unique independent factor associated to mortality in the multivariate analysis was a decrease of PCT higher than 50% from days 0 to 5.Serum levels of sTREM-1 are correlated with the severity of sepsis. A 50% decrease of PCT was the unique variable associated with survival in the multivariate analysis.

Moderate Increase of Indoxyl Sulfate Promotes Monocyte Transition into Profibrotic Macrophages.

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Chiara Barisione

Full Text Available The uremic toxin Indoxyl-3-sulphate (IS, a ligand of Aryl hydrocarbon Receptor (AhR, raises in blood during early renal dysfunction as a consequence of tubular damage, which may be present even when eGFR is normal or only moderately reduced, and promotes cardiovascular damage and monocyte-macrophage activation. We previously found that patients with abdominal aortic aneurysms (AAAs have higher CD14+CD16+ monocyte frequency and prevalence of moderate chronic kidney disease (CKD than age-matched control subjects. Here we aimed to evaluate the IS levels in plasma from AAA patients and to investigate in vitro the effects of IS concentrations corresponding to mild-to-moderate CKD on monocyte polarization and macrophage differentiation.Free IS plasma levels, monocyte subsets and laboratory parameters were evaluated on blood from AAA patients and eGFR-matched controls. THP-1 monocytes, treated with IS 1, 10, 20 μM were evaluated for CD163 expression, AhR signaling and then induced to differentiate into macrophages by PMA. Their phenotype was evaluated both at the stage of semi-differentiated and fully differentiated macrophages. AAA and control sera were similarly used to treat THP-1 monocytes and the resulting macrophage phenotype was analyzed.IS plasma concentration correlated positively with CD14+CD16+ monocytes and was increased in AAA patients. In THP-1 cells, IS promoted CD163 expression and transition to macrophages with hallmarks of classical (IL-6, CCL2, COX2 and alternative phenotype (IL-10, PPARγ, TGF-β, TIMP-1, via AhR/Nrf2 activation. Analogously, AAA sera induced differentiation of macrophages with enhanced IL-6, MCP1, TGF-β, PPARγ and TIMP-1 expression.IS skews monocyte differentiation toward low-inflammatory, profibrotic macrophages and may contribute to sustain chronic inflammation and maladaptive vascular remodeling.

Radiation effects on cultured human monocytes and on monocyte-derived macrophages

International Nuclear Information System (INIS)

Buescher, E.S.; Gallin, J.I.

1984-01-01

Prior to administration, leukocyte transfusions are commonly irradiated with up to 5,000 R to eliminate lymphocytes and thereby prevent graft-versus-host disease in the recipient. It has been widely believed that phagocytes are resistant to this irradiation. In a recent report, it was noted that phagocyte oxidative metabolism was compromised during preparation of white cells for transfusion. As part of the effort to examine the basis for this inhibition of phagocyte function during white cell preparation, an assessment was made of the effects of irradiation on the long-lived monocytes that have been shown to persist at inflammatory foci posttransfusion. Human monocytes were irradiated for up to 3 min, receiving 2,500-5,000 R. This irradiation damaged human monocytes, significantly decreasing their in vitro survival for the first 3 wk of culture, and growth as assessed by two-dimensional cell size measurements during the first 2 wk of culture. Despite smaller cell size, total cell protein was significantly increased over time in irradiated cultures. Extracellular release of lysozyme and beta-glucuronidase per cell was not affected by irradiation, but extracellular lactate dehydrogenase (LDH) release was significantly increased after irradiation. Irradiated monocytes killed Listeria monocytogenes at a slower rate than the nonirradiated controls. Thus, the data indicate that irradiation in doses used to prevent graft-versus-host disease in leukocyte transfusion recipients has a deleterious effect on in vitro human monocyte survival and function

Labeling of autologous monocytes with 99mTc-HMPAO at very high specific radioactivity

International Nuclear Information System (INIS)

Hemert, Formijn J. van; Thurlings, Rogier; Dohmen, Serge E.; Voermans, Carlijn; Tak, Paul P.; Eck-Smit, Berthe L.F. van; Bennink, Roelof J.

2007-01-01

Rheumatoid arthritis of joints involves the accumulation of monocyte-derived macrophages in the affected synovial tissue. This process of cell migration can be portrayed scintigraphically in order to monitor noninvasive effects of therapy on the progress of the disease. Scintigraphic detection of inflammation by means of technetium 99m-hexamethylpropylene amine oxime ( 99m Tc-HMPAO)-labeled leukocytes provides a classic example. Present state-of-the-art methods in cell biology allow the isolation of cells like lymphocytes or monocytes, which are less abundant than main blood constituents but, instead, harbor particular functions like specific homing properties. To facilitate scintigraphic imaging of the cell functions involved, the relatively small population of cells must be labeled to radioactive yields as high as possible. We demonstrate that autologous monocytes isolated from 100 ml of peripheral blood can be radiolabeled to a yield of 10 (instead of 1) Bq per cell, allowing scintigraphic analysis of rheumatoid arthritis up to 20 h post injection of patients. The method is based on the instantaneous distribution of lipophilic 99m Tc-HMPAO between the hydrophobic inside of cells and the hydrophilic (aqueous) surrounding of cells, followed by decomposition of the radiopharmaceutical into compounds that are unable to cross the cellular membrane. The procedure provides a method of choice for cell-mediated scintigraphy at low availability of cells with the correct homing properties

Age Increases Monocyte Adhesion on Collagen

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Khalaji, Samira; Zondler, Lisa; Kleinjan, Fenneke; Nolte, Ulla; Mulaw, Medhanie A.; Danzer, Karin M.; Weishaupt, Jochen H.; Gottschalk, Kay-E.

2017-05-01

Adhesion of monocytes to micro-injuries on arterial walls is an important early step in the occurrence and development of degenerative atherosclerotic lesions. At these injuries, collagen is exposed to the blood stream. We are interested whether age influences monocyte adhesion to collagen under flow, and hence influences the susceptibility to arteriosclerotic lesions. Therefore, we studied adhesion and rolling of human peripheral blood monocytes from old and young individuals on collagen type I coated surface under shear flow. We find that firm adhesion of monocytes to collagen type I is elevated in old individuals. Pre-stimulation by lipopolysaccharide increases the firm adhesion of monocytes homogeneously in older individuals, but heterogeneously in young individuals. Blocking integrin αx showed that adhesion of monocytes to collagen type I is specific to the main collagen binding integrin αxβ2. Surprisingly, we find no significant age-dependent difference in gene expression of integrin αx or integrin β2. However, if all integrins are activated from the outside, no differences exist between the age groups. Altered integrin activation therefore causes the increased adhesion. Our results show that the basal increase in integrin activation in monocytes from old individuals increases monocyte adhesion to collagen and therefore the risk for arteriosclerotic plaques.

Acyclic nucleoside phosphonate antivirals activate gene expression of monocyte chemotactic protein 1 and 3.

Czech Academy of Sciences Publication Activity Database

Potměšil, Petr; Holý, Antonín; Kmoníčková, Eva; Křížková, Jana; Zídek, Zdeněk

2007-01-01

Roč. 14, č. 1 (2007), s. 59-66 ISSN 1021-7770 R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z40550506 Keywords : Acyclic nucleoside phosponate * HIV * Monocyte chemotactic protein Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.024, year: 2007

miR-582-5p is upregulated in patients with active tuberculosis and inhibits apoptosis of monocytes by targeting FOXO1.

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Yanhua Liu

Full Text Available Macrophage apoptosis is a host innate defense mechanism against tuberculosis (TB. In this study, we found that percentage of apoptotic cells in peripheral blood monocytes from patients with active TB was lower than that from healthy controls (p<0.001. To understand whether microRNAs can modulate apoptosis of monocytes, we investigated differentially expressed microRNAs in patients with active TB. miR-582-5p was mainly expressed in monocytes and was upregulated in patients with active TB. The apoptotic percentage of THP-1 cells transfected with miR-582-5p mimics was significantly lower than those transfected with negative control of microRNA mimics (p<0.001, suggesting that miR-582-5p could inhibit apoptosis of monocytes. To our knowledge, the role of miR-582-5p in regulating apoptosis of monocytes has not been reported so far. Systematic bioinformatics analysis indicated that FOXO1 might be a target gene for miR-582-5p and its 3'UTR contains potential binding sites for miR-582-5p. To determine whether miR-582-5p could influence FOXO1 expression, miR-582-5p mimics or negative control of microRNA mimics were transfected into THP-1 cells. RT-PCR and western blot analysis showed that the miR-582-5p could suppress both FOXO1 mRNA and protein expression. Co-transfection of miR-582-5p and FOXO1 3'UTR-luciferase reporter vector into cells demonstrated that significant decrease in luciferase activity was only found in reporter vector that contained a wild type sequence of FOXO1 3'UTR, suggesting that miR-582-5p could directly target FOXO1. In conclusion, miR-582-5p inhibited apoptosis of monocytes by down-regulating FOXO1 expression and might play an important role in regulating anti-M. tuberculosis directed immune responses.

Methylglyoxal-bis-guanylhydrazone inhibits osteopontin expression and differentiation in cultured human monocytes.

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Jin, Xia; Xu, Hua; McGrath, Michael S

2018-01-01

Monocyte activation and polarization play essential roles in many chronic inflammatory diseases. An imbalance of M1 and M2 macrophage activation (pro-inflammatory and alternatively activated, respectively) is believed to be a key aspect in the etiology of these diseases, thus a therapeutic approach that regulates macrophage activation could be of broad clinical relevance. Methylglyoxal-bis-guanylhydrazone (MGBG), a regulator of polyamine metabolism, has recently been shown to be concentrated in monocytes and macrophages, and interfere with HIV integration into the DNA of these cells in vitro. RNA expression analysis of monocytes from HIV+ and control donors with or without MGBG treatment revealed the only gene to be consistently down regulated by MGBG to be osteopontin (OPN). The elevated expression of this pro-inflammatory cytokine and monocyte chemoattractant is associated with various chronic inflammatory diseases. We demonstrate that MGBG is a potent inhibitor of secreted OPN (sOPN) in cultured monocytes with 50% inhibition achieved at 0.1 μM of the drug. Furthermore, inhibition of OPN RNA transcription in monocyte cultures occurs at similar concentrations of the drug. During differentiation of monocytes into macrophages in vitro, monocytes express cell surface CD16 and the cells undergo limited DNA synthesis as measured by uptake of BrdU. MGBG inhibited both activities at similar doses to those regulating OPN expression. In addition, monocyte treatment with MGBG inhibited differentiation into both M1 and M2 classes of macrophages at non-toxic doses. The inhibition of differentiation and anti-OPN effects of MGBG were specific for monocytes in that differentiated macrophages were nearly resistant to MGBG activities. Thus MGBG may have potential therapeutic utility in reducing or normalizing OPN levels and regulating monocyte activation in diseases that involve chronic inflammation.

Periodontitis-activated monocytes/macrophages cause aortic inflammation

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Miyajima, Shin-ichi; Naruse, Keiko; Kobayashi, Yasuko; Nakamura, Nobuhisa; Nishikawa, Toru; Adachi, Kei; Suzuki, Yuki; Kikuchi, Takeshi; Mitani, Akio; Mizutani, Makoto; Ohno, Norikazu; Noguchi, Toshihide; Matsubara, Tatsuaki

2014-01-01

A relationship between periodontal disease and atherosclerosis has been suggested by epidemiological studies. Ligature-induced experimental periodontitis is an adequate model for clinical periodontitis, which starts from plaque accumulation, followed by inflammation in the periodontal tissue. Here we have demonstrated using a ligature-induced periodontitis model that periodontitis activates monocytes/macrophages, which subsequently circulate in the blood and adhere to vascular endothelial cells without altering the serum TNF-α concentration. Adherent monocytes/macrophages induced NF-κB activation and VCAM-1 expression in the endothelium and increased the expression of the TNF-α signaling cascade in the aorta. Peripheral blood-derived mononuclear cells from rats with experimental periodontitis showed enhanced adhesion and increased NF-κB/VCAM-1 in cultured vascular endothelial cells. Our results suggest that periodontitis triggers the initial pathogenesis of atherosclerosis, inflammation of the vasculature, through activating monocytes/macrophages. PMID:24893991

Increased Expression of CD200 on Circulating CD11b+ Monocytes in Patients with Neovascular Age-related Macular Degeneration

DEFF Research Database (Denmark)

Singh, Amardeep; Falk, Mads K; Hviid, Thomas V F

2013-01-01

OBJECTIVE: Dysregulation of retinal microglial activity has been implicated in the pathogenesis of neovascular age-related macular degeneration. Microglia activity can be regulated through the membrane protein CD200 and its corresponding receptor, the CD200 receptor (CD200R). Because both...... with neovascular age-related macular degeneration (AMD) and 44 age-matched controls without AMD. METHODS: The participants were aged 60 years or older, had no history of immune dysfunction or cancer, and were not receiving immune-modulating therapy. All participants were subjected to a structured interview......: Patients with neovascular AMD had a higher percentage of CD11b+CD200+ monocytes and CD200+ monocytes compared with controls. Multiple regression analysis revealed that the intergroup differences observed were independent of age. Moreover, an age-related increment in CD200 expression on monocytes...

Histamine type I (H1) receptor radioligand binding studies on normal T cell subsets, B cells, and monocytes

International Nuclear Information System (INIS)

Cameron, W.; Doyle, K.; Rocklin, R.E.

1986-01-01

A single, specific binding site for [ 3 H]pyrilamine on normal human T helper, T suppressor, B cells, and monocytes was documented. The binding of the radioligand to its receptor is reversible with cold H 1 antagonist, saturates at 40 to 60 nM, and binding equilibrium is achieved in 2 to 4 min. Using a computer program (Ligand), the authors calculated the dissociation constants, binding capacities, and numbers of receptors per cell for each of the different cell types. Monocytes were found to have the highest affinity for [ 3 H]pyrilamine, followed by T helper cells, B cells and T suppressor cells (K/sub D/ = 44.6 +/- 49.4 nM). T suppressor cells were found to express the higher number of H 1 receptors per cell followed by B cells, T helper cells, and monocytes. The binding affinity for [ 3 H]pyrilamine increased over a 48-hr period, whereas the number of receptors per T cell was essentially unchanged. In contrast, T cells stimulated with Con A or PHA were shown to have a greater than fourfold increase in the number of receptors per cell, whereas the binding affinity for [ 3 H]pyrilamine decreased over the 48-hr period. Although the function of H 1 receptors on T cells, B cells, and monocytes has not been completely defined, this receptor has the potential of playing an important role in the modulating the immune response

Intriguing interplay between feline infectious peritonitis virus and its receptors during entry in primary feline monocytes.

Science.gov (United States)

Van Hamme, Evelien; Desmarets, Lowiese; Dewerchin, Hannah L; Nauwynck, Hans J

2011-09-01

Two potential receptors have been described for the feline infectious peritonitis virus (FIPV): feline aminopeptidase N (fAPN) and feline dendritic cell-specific intercellular adhesion molecule grabbing non-integrin (fDC-SIGN). In cell lines, fAPN serves as a receptor for serotype II, but not for serotype I FIPV. The role of fAPN in infection of in vivo target cells, monocytes, is not yet confirmed. Both serotype I and II FIPVs use fDC-SIGN for infection of monocyte-derived cells but how is not known. In this study, the role of fAPN and fDC-SIGN was studied at different stages in FIPV infection of monocytes. First, the effects of blocking the potential receptor(s) were studied for the processes of attachment and infection. Secondly, the level of co-localization of FIPV and the receptors was determined. It was found that FIPV I binding and infection were not affected by blocking fAPN while blocking fDC-SIGN reduced FIPV I binding to 36% and practically completely inhibited infection. Accordingly, 66% of bound FIPV I particles co-localized with fDC-SIGN. Blocking fAPN reduced FIPV II binding by 53% and infection by 80%. Further, 60% of bound FIPV II co-localized with fAPN. fDC-SIGN was not involved in FIPV II binding but infection was reduced with 64% when fDC-SIGN was blocked. In conclusion, FIPV I infection of monocytes depends on fDC-SIGN. Most FIPV I particles already interact with fDC-SIGN at the plasma membrane. For FIPV II, both fAPN and fDC-SIGN are involved in infection with only fAPN playing a receptor role at the plasma membrane. Copyright © 2011 Elsevier B.V. All rights reserved.

Fc receptors for mouse IgG1 on human monocytes: polymorphism and role in antibody-induced T cell proliferation.

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Tax, W J; Hermes, F F; Willems, R W; Capel, P J; Koene, R A

1984-09-01

In previous studies, it was shown that there is polymorphism in the mitogenic effect of mouse IgG1 monoclonal antibodies against the T3 antigen of human T cells. This polymorphism implies that IgG1 anti-T3 antibodies are not mitogenic for T cells from 30% of healthy individuals. The present results demonstrate that this polymorphism is caused by polymorphism of an Fc receptor for mouse IgG1, present on human monocytes. The Fc receptor for murine IgG1 could be detected by a newly developed rosetting assay on monocytes from all individuals responsive to the mitogenic effect of IgG1 anti-T3 antibodies. This Fc receptor was not detectable on monocytes from those individuals exhibiting no mitogenic responses to IgG1 anti-T3 monoclonal antibodies. Cross-linking of T3 antigens appears to be essential for antibody-induced mitosis of T cells, because mononuclear cells that did not proliferate in response to WT 31 (an IgG1 antibody against T3 antigen) showed a proliferative response to Sepharose beads coated with WT 31. The Fc receptor--if functionally present--may be involved in the cross-linking of T3 antigens through anti-T3 antibodies. Further evidence for the involvement of this Fc receptor in antibody-induced T cell proliferation was provided by inhibition studies. Immune complexes containing IgG1 antibodies were able to inhibit the proliferative response to IgG1 anti-T3 antibodies. This inhibition by immune complexes appears to be mediated through the monocyte Fc receptor for mouse IgG1. These findings are important for the interpretation of previously described inhibitory effects of anti-T cell monoclonal antibodies on T cell proliferation, and show that such inhibitory effects may be monocyte-mediated (via immune complexes) rather than caused by a direct involvement of the respective T cell antigens in T cell mitosis. The Fc receptor for mouse IgG1 plays a role in antibody-induced T cell proliferation. Its polymorphism may have important implications for the

Lipopolysaccharide regulated protein expression is only partly impaired in monocytes from patients with type I diabetes

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Abke Sabine

2006-03-01

Full Text Available Abstract Background Monocytes play an important role in innate immunity and atherosclerosis. A disturbed secretion of cytokines in lipopolysaccharide (LPS activated monocytes from type 1 diabetes (T1D patients has been described and may contribute to the impaired inflammatory response in these individuals. In the present study the influence of LPS on five different proteins with a function in immunity and atherosclerosis was analyzed in monocytes from controls and T1D patients. Methods Monocytes were isolated from controls and T1D patients and the LPS-stimulated increase of IL-6, CXCL8, monocyte chemotactic protein 1 (CCL2, MCP-1 and superoxide dismutase (SOD 2, as well as the LPS-mediated decrease of apolipoprotein E (Apo E in primary human monocytes from controls and T1D patients was determined. Results CCL2 and IL-6 secretion in response to LPS was found significantly reduced in monocytes from T1D patients when compared to controls whereas basal CCL2 release was similar in control and T1D cells. In contrast, CXCL8 and apolipoprotein E secretion and SOD 2 expression upon LPS stimulation is similar from T1D and control monocytes. Conclusion These data indicate that LPS-mediated protein expression is only partly disturbed in monocytes from T1D patients. Reduced secretion of IL-6 and CCL2 in activated monocytes of these patients may contribute to an impaired inflammatory response and vascular disease.

A distinguishing gene signature shared by tumor-infiltrating Tie2-expressing monocytes, blood "resident" monocytes, and embryonic macrophages suggests common functions and developmental relationships.

Science.gov (United States)

Pucci, Ferdinando; Venneri, Mary Anna; Biziato, Daniela; Nonis, Alessandro; Moi, Davide; Sica, Antonio; Di Serio, Clelia; Naldini, Luigi; De Palma, Michele

2009-07-23

We previously showed that Tie2-expressing monocytes (TEMs) have nonredundant proangiogenic activity in tumors. Here, we compared the gene expression profile of tumor-infiltrating TEMs with that of tumor-associated macrophages (TAMs), spleen-derived Gr1(+)Cd11b(+) neutrophils/myeloid-derived suppressor cells, circulating "inflammatory" and "resident" monocytes, and tumor-derived endothelial cells (ECs) by quantitative polymerase chain reaction-based gene arrays. TEMs sharply differed from ECs and Gr1(+)Cd11b(+) cells but were highly related to TAMs. Nevertheless, several genes were differentially expressed between TEMs and TAMs, highlighting a TEM signature consistent with enhanced proangiogenic/tissue-remodeling activity and lower proinflammatory activity. We validated these findings in models of oncogenesis and transgenic mice expressing a microRNA-regulated Tie2-GFP reporter. Remarkably, resident monocytes and TEMs on one hand, and inflammatory monocytes and TAMs on the other hand, expressed coordinated gene expression profiles, suggesting that the 2 blood monocyte subsets are committed to distinct extravascular fates in the tumor microenvironment. We further showed that a prominent proportion of embryonic/fetal macrophages, which participate in tissue morphogenesis, expressed distinguishing TEM genes. It is tempting to speculate that Tie2(+) embryonic/fetal macrophages, resident blood monocytes, and tumor-infiltrating TEMs represent distinct developmental stages of a TEM lineage committed to execute physiologic proangiogenic and tissue-remodeling programs, which can be co-opted by tumors.

EFFECTS OF SECRETABLE PLACENTAL FACTORS UPON SECRETION OF CYTOKINES BY THP-1 MONOCYTE-LIKE CELLS

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Ya. S. Onokhina

2013-01-01

Full Text Available Abstract. Мonocytes in feto-placental circulation are exposed to factors secreted by placental tissue. These factors influence monocyte functions in pregnancy. In present study, an in vitro model (monocyte-like THP-1 cells was used for assessing effects of soluble placental factors obtained from women with physiological pregnancies, or preeclampsia cases. The following effects of placental factors were revealed: increased secretion of VEGF by THP-1 cells along with decreased secretion of IL-6, IL-8 and MCP-1 under the influence of placental factors from the I. trimester of pregnancy in comparison with III. trimester. Secretion of IL-6 and MCP-1 by THP-1 cells was increased, and secretion of soluble TNFRII was decreased upon co-cultivation with soluble placental factors from the women with preeclampsia, as compared with placental products from physiological pregnancies.The work is supported by grants ГК № 02.740.11.0711 from Ministry of Education and Science, and НШ-3594.2010.7 grant from the President of Russian Federation.

Transcriptome analysis of monocyte-HIV interactions

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Tran Huyen

2010-06-01

Full Text Available Abstract Background During HIV infection and/or antiretroviral therapy (ART, monocytes and macrophages exhibit a wide range of dysfunctions which contribute significantly to HIV pathogenesis and therapy-associated complications. Nevertheless, the molecular components which contribute to these dysfunctions remain elusive. We therefore applied a parallel approach of genome-wide microarray analysis and focused gene expression profiling on monocytes from patients in different stages of HIV infection and/or ART to further characterise these dysfunctions. Results Processes involved in apoptosis, cell cycle, lipid metabolism, proteasome function, protein trafficking and transcriptional regulation were identified as areas of monocyte dysfunction during HIV infection. Individual genes potentially contributing to these monocyte dysfunctions included several novel factors. One of these is the adipocytokine NAMPT/visfatin, which we show to be capable of inhibiting HIV at an early step in its life cycle. Roughly half of all genes identified were restored to control levels under ART, while the others represented a persistent dysregulation. Additionally, several candidate biomarkers (in particular CCL1 and CYP2C19 for the development of the abacavir hypersensitivity reaction were suggested. Conclusions Previously described areas of monocyte dysfunction during HIV infection were confirmed, and novel themes were identified. Furthermore, individual genes associated with these dysfunctions and with ART-associated disorders were pinpointed. These genes form a useful basis for further functional studies concerning the contribution of monocytes/macrophages to HIV pathogenesis. One such gene, NAMPT/visfatin, represents a possible novel restriction factor for HIV. Background Both macrophages and T lymphocyte subsets express the CD4 receptor and either the CXCR4 and/or the CCR5 coreceptor which confer susceptibility to infection with the Human Immunodeficiency Virus

Phagocytosis of haemozoin (malarial pigment enhances metalloproteinase-9 activity in human adherent monocytes: Role of IL-1beta and 15-HETE

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Giribaldi Giuliana

2008-08-01

Full Text Available Abstract Background It has been shown previously that human monocytes fed with haemozoin (HZ or trophozoite-parasitized RBCs displayed increased matrix metalloproteinase-9 (MMP-9 enzyme activity and protein/mRNA expression and increased TNF production, and showed higher matrix invasion ability. The present study utilized the same experimental model to analyse the effect of phagocytosis of: HZ, delipidized HZ, beta-haematin (lipid-free synthetic HZ and trophozoites on production of IL-1beta and MMP-9 activity and expression. The second aim was to find out which component of HZ was responsible for the effects. Methods Native HZ freshly isolated from Plasmodium falciparum (Palo Alto strain, Mycoplasma-free, delipidized HZ, beta-haematin (lipid-free synthetic HZ, trophozoites and control meals such as opsonized non-parasitized RBCs and inert latex particles, were fed to human monocytes. The production of IL-1beta by differently fed monocytes, in presence or absence of specific MMP-9 inhibitor or anti-hIL-1beta antibodies, was quantified in supernatants by ELISA. Expression of IL-1beta was analysed by quantitative real-time RT-PCR. MMP-9 activity and protein expression were quantified by gelatin zymography and Western blotting. Results Monocytes fed with HZ or trophozoite-parasitized RBCs generated increased amounts of IL-1beta and enhanced enzyme activity (in cell supernatants and protein/mRNA expression (in cell lysates of monocyte MMP-9. The latter appears to be causally related to enhanced IL-1beta production, as enhancement of both expression and enzyme activity were abrogated by anti-hIL-1beta Abs. Upregulation of IL-1beta and MMP-9 were absent in monocytes fed with beta-haematin or delipidized HZ, indicating a role for HZ-attached or HZ-generated lipid components. 15-HETE (15(S,R-hydroxy-6,8,11,13-eicosatetraenoic acid a potent lipoperoxidation derivative generated by HZ from arachidonic acid via haem-catalysis was identified as one mediator

Modulation of the expression of chondroitin sulfate proteoglycan in stimulated human monocytes

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Uhlin-Hansen, L.; Eskeland, T.; Kolset, S.O.

1989-01-01

Proteoglycan biosynthesis was studied in human monocytes and monocyte-derived macrophages (MDM) after exposure to typical activators of the monocyte/macrophage system: interferon-gamma (IFN-gamma), lipopolysaccharide (LPS), and phorbol 12-myristate 13-acetate (PMA). By morphological examination, both monocytes and MDM were stimulated by these activators. Treatment with IFN-gamma resulted in a slight decrease in the expression of [35S]chondroitin sulfate proteoglycan (CSPG) in both monocytes and MDM, whereas LPS treatment increased the [35S]CSPG expression 1.8 and 2.2 times, respectively. PMA, in contrast, decreased the CSPG expression 0.4 times in monocytes, whereas MDM were stimulated to increase the biosynthesis 1.9 times. An increase in the sulfate density of the chondroitin sulfate chains was evident following differentiation of monocytes into MDM due to the expression of disulfated disaccharide units of the chondroitin sulfate E type (CS-E). However, monocytes exposed to PMA did also express disaccharides of the chondroitin sulfate E type. Furthermore, the expression of CS-E in MDM was increased 2 times following PMA treatment. An inactive phorbol ester, phorbol 12,13-diacetate, did not affect the expression of CS-E in either monocytes or MDM when compared with control cultures, suggesting that protein kinase C-dependent signal pathways may be involved in the regulation of sulfation of CSPG. Exposure to LPS or IFN-gamma did not lead to any changes in the sulfation of the chondroitin sulfate chains

miR-582-5p is upregulated in patients with active tuberculosis and inhibits apoptosis of monocytes by targeting FOXO1.

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Liu, Yanhua; Jiang, Jing; Wang, Xinjing; Zhai, Fei; Cheng, Xiaoxing

2013-01-01

Macrophage apoptosis is a host innate defense mechanism against tuberculosis (TB). In this study, we found that percentage of apoptotic cells in peripheral blood monocytes from patients with active TB was lower than that from healthy controls (pmicroRNAs can modulate apoptosis of monocytes, we investigated differentially expressed microRNAs in patients with active TB. miR-582-5p was mainly expressed in monocytes and was upregulated in patients with active TB. The apoptotic percentage of THP-1 cells transfected with miR-582-5p mimics was significantly lower than those transfected with negative control of microRNA mimics (pmicroRNA mimics were transfected into THP-1 cells. RT-PCR and western blot analysis showed that the miR-582-5p could suppress both FOXO1 mRNA and protein expression. Co-transfection of miR-582-5p and FOXO1 3'UTR-luciferase reporter vector into cells demonstrated that significant decrease in luciferase activity was only found in reporter vector that contained a wild type sequence of FOXO1 3'UTR, suggesting that miR-582-5p could directly target FOXO1. In conclusion, miR-582-5p inhibited apoptosis of monocytes by down-regulating FOXO1 expression and might play an important role in regulating anti-M. tuberculosis directed immune responses.

Shear Stress Enhances Chemokine Secretion from Chlamydia pneumoniae-infected Monocytes.

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Evani, Shankar J; Dallo, Shatha F; Murthy, Ashlesh K; Ramasubramanian, Anand K

2013-09-01

Chlamydia pneumoniae is a common respiratory pathogen that is considered a highly likely risk factor for atherosclerosis. C. pneumoniae is disseminated from the lung into systemic circulation via infected monocytes and lodges at the atherosclerotic sites. During transit, C. pneumoniae -infected monocytes in circulation are subjected to shear stress due to blood flow. The effect of mechanical stimuli on infected monocytes is largely understudied in the context of C. pneumoniae infection and inflammation. We hypothesized that fluid shear stress alters the inflammatory response of C. pneumoniae -infected monocytes and contributes to immune cell recruitment to the site of tissue damage. Using an in vitro model of blood flow, we determined that a physiological shear stress of 7.5 dyn/cm 2 for 1 h on C. pneumoniae -infected monocytes enhances the production of several chemokines, which in turn is correlated with the recruitment of significantly large number of monocytes. Taken together, these results suggest synergistic interaction between mechanical and chemical factors in C. pneumoniae infection and associated inflammation.

Monocyte transferrin-iron uptake in hereditary hemochromatosis

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Sizemore, D.J.; Bassett, M.L.

1984-01-01

Transferrin-iron uptake by peripheral blood monocytes was studied in vitro to test the hypothesis that the relative paucity of mononuclear phagocyte iron loading in hereditary hemochromatosis results from a defect in uptake of iron from transferrin. Monocytes from nine control subjects and 17 patients with hemochromatosis were cultured in the presence of 59Fe-labelled human transferrin. There was no difference in 59Fe uptake between monocytes from control subjects and monocytes from patients with hemochromatosis who had been treated by phlebotomy and who had normal body iron stores. However, 59Fe uptake by monocytes from iron-loaded patients with hemochromatosis was significantly reduced compared with either control subjects or treated hemochromatosis patients. It is likely that this was a secondary effect of iron loading since iron uptake by monocytes from treated hemochromatosis patients was normal. Assuming that monocytes in culture reflect mononuclear phagocyte iron metabolism in vivo, this study suggests that the relative paucity of mononuclear phagocyte iron loading in hemochromatosis is not related to an abnormality in transferrin-iron uptake by these cells

[Role of phosphoinositide 3 kinase/protein kinase B signal pathway in monocyte-endothelial adhesion induced by serum of rats with electrical burn].

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Ruan, Qiongfang; Zhao, Chaoli; Ye, Ziqing; Zhang, Weidong; Xie, Qionghui; Xie, Weiguo

2014-06-01

irregular though the membrane was complete at PCH 3; cellular size became irregular and cell membrane and cytoplasm were swollen at PCH 6; cell membrane was disrupted with death of cells at PCH 24. The contents of TNF-α in culture supernatant in normal serum group at PCH 24 and in burn serum group at PCH 3, 6, 24 were respectively (38.5 ± 1.4), (75.1 ± 1.5), (91.5 ± 1.8), (117.0 ± 1.4) pg/mL (F = 1 415.306, P THP-1 cells adherent to endothelial cells were respectively (231 ± 45), (280 ± 47), (703 ± 169), (335 ± 85) per 100-time field; (219 ± 49), (235 ± 21), (562 ± 123), (226 ± 29) per 100-time field (with F values respectively 25.630 and 18.975, P values below 0.01). The number of THP-1 cells adhered to EA.hy926 cells was significantly more in burn serum group than in normal serum group at PCH 3 and 6 (with t values respectively 6.189 and 6.601, P values below 0.01). The number of THP-1 cells adherent to EA.hy926 cells was significantly fewer in burn serum+inhibitor group than in burn serum group at PCH 3 and 6 (with t values respectively 6.821 and 6.465, P values below 0.01). The serum of rats suffering from electrical burn can induce the monocytes to secrete TNF-α, thus enhancing monocyte-endothelial cell adhesion, but it can be inhibited by blocking PI3K/Akt signal pathway.

IL-4 induces cAMP and cGMP in human monocytic cells

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B. Dugas

1995-01-01

Full Text Available Human monocytes, preincubated with IFN-γ respond to IL-4 by a cGMP increase through activation of an inducible NO synthase. Here, IL-4 was found to induce an accumulation of cGMP (1 – 3 min and cAMP (20 – 25 min in unstimulated monocytes. This was impaired with NOS inhibitors, but also with EGTA and calcium/calmodulin inhibitors. These results suggest that: (1 IL-4 may stimulate different NOS isoforms in resting and IFN-γ activated monocytes, and (2 cAMP accumulation may be partially dependent on the NO pathway. By RT-PCR, a type III constitutive NOS mRNA was detected in U937 monocytic cells. IL-4 also increased the [Ca2+]i in these cells. Different NOS may thus be expressed in monocytic cells depending on their differentiation and the signals they receive.

Supernatants from oral epithelial cells and gingival fibroblasts modulate human immunodeficiency virus type 1 promoter activation induced by periodontopathogens in monocytes/macrophages.

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González, O A; Ebersole, J L; Huang, C B

2010-04-01

Bacterial and host cell products during coinfections of Human Immunodeficiency Virus type 1-positive (HIV-1(+)) patients regulate HIV-1 recrudescence in latently infected cells (e.g. T cells, monocytes/macrophages), impacting highly active antiretroviral therapy (HAART) failure and progression of acquired immunodeficiency syndrome. A high frequency of oral opportunistic infections (e.g. periodontitis) in HIV-1(+) patients has been demonstrated; however, their potential to impact HIV-1 exacerbation is unclear. We sought to determine the ability of supernatants derived from oral epithelial cells (OKF4) and human gingival fibroblasts (Gin-4) challenged with periodontal pathogens, to modulate the HIV-1 promoter activation in monocytes/macrophages. BF24 monocytes/macrophages transfected with the HIV-1 promoter driving the expression of chloramphenicol acetyltransferase (CAT) were stimulated with Porphyromonas gingivalis, Fusobacterium nucleatum, or Treponema denticola in the presence of supernatants from OKF4 or Gin4 cells either unstimulated or previously pulsed with bacteria. CAT levels were determined by enzyme-linked immunosorbent assay and cytokine production was evaluated by Luminex beadlyte assays. OKF4 and Gin4 supernatants enhanced HIV-1 promoter activation particularly related to F. nucleatum challenge. An additive effect was observed in HIV-1 promoter activation when monocytes/macrophages were simultaneously stimulated with gingival cell supernatants and bacterial extracts. OKF4 cells produced higher levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukins -6 and -8 in response to F. nucleatum and P. gingivalis. Preincubation of OKF4 supernatants with anti-GM-CSF reduced the additive effect in periodontopathogen-induced HIV-1 promoter activation. These results suggest that soluble mediators produced by gingival resident cells in response to periodontopathogens could contribute to HIV-1 promoter activation in monocytes

Kruppel-like factor 2 (KLF2) regulates proinflammatory activation of monocytes

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Das, Hiranmoy; Kumar, Ajay; Lin, Zhiyong; Patino, Willmar D.; Hwang, Paul M.; Feinberg, Mark W.; Majumder, Pradip K.; Jain, Mukesh K.

2006-01-01

The mechanisms regulating activation of monocytes remain incompletely understood. Herein we provide evidence that Kruppel-like factor 2 (KLF2) inhibits proinflammatory activation of monocytes. In vitro, KLF2 expression in monocytes is reduced by cytokine activation or differentiation. Consistent with this observation, KLF2 expression in circulating monocytes is reduced in patients with chronic inflammatory conditions such as coronary artery disease. Adenoviral overexpression of KLF2 inhibits the LPS-mediated induction of proinflammatory factors, cytokines, and chemokines and reduces phagocytosis. Conversely, short interfering RNA-mediated reduction in KLF2 increased inflammatory gene expression. Reconstitution of immunodeficient mice with KLF2-overexpressing monocytes significantly reduced carrageenan-induced acute paw edema formation. Mechanistically, KLF2 inhibits the transcriptional activity of both NF-κB and activator protein 1, in part by means of recruitment of transcriptional coactivator p300/CBP-associated factor. These observations identify KLF2 as a novel negative regulator of monocytic activation. PMID:16617118

Peripheral blood monocyte subsets predict antiviral response in chronic hepatitis C.

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Rodríguez-Muñoz, Y; Martín-Vílchez, S; López-Rodríguez, R; Hernández-Bartolomé, A; Trapero-Marugán, M; Borque, M J; Moreno-Otero, R; Sanz-Cameno, P

2011-10-01

Hepatitis C virus infection evolves into chronic progressive liver disease in a significant percentage of patients. Monocytes constitute a diverse group of myeloid cells that mediate innate and adaptive immune response. In addition to proinflammatory CD16+ monocytes, a Tie-2+ subgroup - Tie-2 expressing monocytes (TEMs) - that has robust proangiogenic potential has been recently defined. To study the heterogeneity of peripheral blood monocytes in chronic hepatitis C (CHC) patients and to examine their proposed pathophysiological roles on disease progression and response to antiviral therapy. We studied CD16+ and Tie-2+ peripheral monocyte subpopulations in 21 healthy subjects and 39 CHC patients in various stages of disease and responses to antiviral treatment using flow cytometry. Expression profiles of proangiogenic and tissue remodelling factors in monocyte supernatants were measured using ELISA and protein arrays. Intrahepatic expression of CD14, CD31 and Tie-2 was analysed using immunofluorescence. Increases of certain peripheral monocyte subsets were observed in the blood of CHC patients, wherein those cells with proinflammatory (CD16+) or proangiogenic (TEMs) potential expanded (P TEMs were significantly increased in nonresponders, particularly those with lower CD16 expression. In addition, many angiogenic factors were differentially expressed by peripheral monocytes from control or CHC patients, such as angiopoietin-1 and angiogenin (P TEMs were distinguished within portal infiltrates of CHC patients. These findings suggest for the first time the relevance of peripheral monocytes phenotypes for the achievement of response to treatment. Hence, the study of monocyte subset regulation might effect improved CHC prognoses and adjuvant therapies. © 2011 Blackwell Publishing Ltd.

Oxidative Mechanisms of Monocyte-Mediated Cytotoxicity

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Weiss, Stephen J.; Lobuglio, Albert F.; Kessler, Howard B.

1980-01-01

Human monocytes stimulated with phorbol myristate acetate were able to rapidly destroy autologous erythrocyte targets. Monocyte-mediated cytotoxicity was related to phorbol myristate acetate concentration and monocyte number. Purified preparations of lymphocytes were incapable of mediating erythrocyte lysis in this system. The ability of phorbol myristate acetate-stimulated monocytes to lyse erythrocyte targets was markedly impaired by catalase or superoxide dismutase but not by heat-inactivated enzymes or albumin. Despite a simultaneous requirement for superoxide anion and hydrogen peroxide in the cytotoxic event, a variety of hydroxyl radical and singlet oxygen scavengers did not effect cytolysis. However, tryptophan significantly inhibited cytotoxicity. The myeloperoxidase inhibitor cyanide enhanced erythrocyte destruction, whereas azide reduced it modestly. The inability of cyanide to reduce cytotoxicity coupled with the protective effect of superoxide dismutase suggests that cytotoxicity is independent of the classic myeloperoxidase system. We conclude that monocytes, stimulated with phorbol myristate acetate, generate superoxide anion and hydrogen peroxide, which together play an integral role in this cytotoxic mechanism.

Susceptibility and response of human blood monocyte subsets to primary dengue virus infection.

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Kok Loon Wong

Full Text Available Human blood monocytes play a central role in dengue infections and form the majority of virus infected cells in the blood. Human blood monocytes are heterogeneous and divided into CD16(- and CD16(+ subsets. Monocyte subsets play distinct roles during disease, but it is not currently known if monocyte subsets differentially contribute to dengue protection and pathogenesis. Here, we compared the susceptibility and response of the human CD16(- and CD16(+ blood monocyte subsets to primary dengue virus in vitro. We found that both monocyte subsets were equally susceptible to dengue virus (DENV2 NGC, and capable of supporting the initial production of new infective virus particles. Both monocyte subsets produced anti-viral factors, including IFN-α, CXCL10 and TRAIL. However, CD16(+ monocytes were the major producers of inflammatory cytokines and chemokines in response to dengue virus, including IL-1β, TNF-α, IL-6, CCL2, 3 and 4. The susceptibility of both monocyte subsets to infection was increased after IL-4 treatment, but this increase was more profound for the CD16(+ monocyte subset, particularly at early time points after virus exposure. These findings reveal the differential role that monocyte subsets might play during dengue disease.

Monoclonal antibody OKM5 inhibits the in vitro binding of Plasmodium falciparum-infected erythrocytes to monocytes, endothelial, and C32 melanoma cells

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Barnwell, J.W.; Ockenhouse, C.F.; Knowles, D.M. II

1985-01-01

Plasmodium falciparum-infected erythrocytes bind in vitro to human endothelial cells, monocytes, and a certain melanoma cell line. Evidence suggests that this interaction is mediated by similar mechanisms which lead to the sequestration of parasitized erythrocytes in vivo through their attachment to endothelial cells of small blood vessels. They show here the monoclonal antibody OKM5, previously shown to react with the membranes of endothelial cells, monocyte,s and platelets, also reacts with the C32 melanoma cell line which also binds P. falciparum-infected erythrocytes. At relatively low concentrations, OKM5 inhibits and reverses the in vitro adherence of infected erythrocytes to target cells. As with monocytes, OKM5 antibody recognizes an 125 I-labeled protein of approximately 88 Kd on the surface of C32 melanoma cells. It seems likely, therefore, that the 88 Kd polypeptide plays a role in cytoadherence, possibly as the receptor or part of a receptor for a ligand on the surface of infected erythrocytes

Olopatadine Suppresses the Migration of THP-1 Monocytes Induced by S100A12 Protein

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2006-01-01

Full Text Available Olopatadine hydrochloride (olopatadine is an antiallergic drug with histamine H 1 receptor antagonistic activity. Recently, olopatadine has been shown to bind to S100A12 which is a member of the S100 family of calcium-binding proteins, and exerts multiple proinflammatory activities including chemotaxis for monocytes and neutrophils. In this study, we examined the possibility that the interaction of olopatadine with S100A12 inhibits the proinflammatory effects of S100A12. Pretreatment of olopatadine with S100A12 reduced migration of THP-1, a monocyte cell line, induced by S100A12 alone, but did not affect recombinant human regulated upon activation, normal T cell expressed and secreted (RANTES-induced migration. Amlexanox, which also binds to S100A12, inhibited the THP-1 migration induced by S100A12. However, ketotifen, another histamine H 1 receptor antagonist, had little effect on the activity of S100A12. These results suggest that olopatadine has a new mechanism of action, that is, suppression of the function of S100A12, in addition to histamine H 1 receptor antagonistic activity.

Monocyte matrix metalloproteinase production in Type 2 diabetes and controls – a cross sectional study

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Davies Isabel R

2003-03-01

Full Text Available Abstract Background Coronary plaque rupture may result from localised over expression of matrix metalloproteinases (MMPs within the plaque by infiltrating monocyte – macrophages. As MMP expression can be promoted by the modified lipoproteins, oxidative stress and hyperglycaemia that characterises Type 2 diabetes, we hypothesised that peripheral monocytes in these patients, exposed to these factors in vivo, would demonstrate increased MMP production compared to controls. Methods We examined peripheral venous monocyte expression of MMP and tissue inhibitor of metalloproteinase-1 (TIMP-1 in 18 controls and 22 subjects with Type 2 diabetes and no previous cardiovascular complications. Results No significant difference in MMP-1, 3 or 9 or TIMP-1 production was observed between control and diabetes groups. Conclusions Monocyte MMP-1, 3, and 9, and TIMP-1, production are not abnormal in Type 2 diabetes. This data cannot be extrapolated to monocyte – macrophage behaviour in the vessel wall, but it does suggest MMP and TIMP-1 expression prior to monocyte infiltration and transformation are not abnormal in Type 2 diabetes.

Effects of Platelets on Platelet Concentrate Product on the Activation of Human Peripheral Blood Monocyte Cells

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N Sadat Razavi Hoseini

2016-02-01

Full Text Available Introduction: Monocytes can interact with platelets due to their surface molecules such as P-selectin glycoprotein ligand-1 (PSGL-1, and form monocyte-platelet complex. In the present study, the effects of platelets interaction of platelet concentrates (PCs and peripheral blood monocytes were investigated in vitro as a model to predict the probable interactions of these cells and consequently activation of monocytes. Methods: In this experimental study, units of whole blood and PCs were prepared from Tehran Blood Transfusion Center. After isolation of monocytes from the whole blood, these cells were treated with PC- derived platelets. The activation of monocytes was assessed before and after treatment by the analysis of the respiratory burst of monocytes using dihydrorhodamine 123 (DHR-123. The study data were analyzed using the non-parametric test of Wilcoxon. Results: The purity of monocytes was determined as 86.1±2 using NycoPrep method. The respiratory burst of monocytes was increased after exposure with platelets. In fact, the difference was significant when platelets were used on the 5th day of storage (P=0.001. Conclusions: The study findings revealed that platelets have an efficient capacity to stimulate and activate monocytes. The possible involvement of molecules in the interaction of platelet-monocyte demand to be further studied in future.

Outside-in HLA class I signaling regulates ICAM-1 clustering and endothelial cell-monocyte interactions via mTOR in transplant antibody-mediated rejection.

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Salehi, Sahar; Sosa, Rebecca A; Jin, Yi-Ping; Kageyama, Shoichi; Fishbein, Michael C; Rozengurt, Enrique; Kupiec-Weglinski, Jerzy W; Reed, Elaine F

2018-05-01

Antibody-mediated rejection (AMR) resulting in transplant allograft vasculopathy (TAV) is the major obstacle for long-term survival of solid organ transplants. AMR is caused by donor-specific antibodies to HLA, which contribute to TAV by initiating outside-in signaling transduction pathways that elicit monocyte recruitment to activated endothelium. Mechanistic target of rapamycin (mTOR) inhibitors can attenuate TAV; therefore, we sought to understand the mechanistic underpinnings of mTOR signaling in HLA class I Ab-mediated endothelial cell activation and monocyte recruitment. We used an in vitro model to assess monocyte binding to HLA I Ab-activated endothelial cells and found mTOR inhibition reduced ezrin/radixin/moesin (ERM) phosphorylation, intercellular adhesion molecule 1 (ICAM-1) clustering, and monocyte firm adhesion to HLA I Ab-activated endothelium. Further, in a mouse model of AMR, in which C57BL/6. RAG1 -/- recipients of BALB/c cardiac allografts were passively transferred with donor-specific MHC I antibodies, mTOR inhibition significantly reduced vascular injury, ERM phosphorylation, and macrophage infiltration of the allograft. Taken together, these studies indicate mTOR inhibition suppresses ERM phosphorylation in endothelial cells, which impedes ICAM-1 clustering in response to HLA class I Ab and prevents macrophage infiltration into cardiac allografts. These findings indicate a novel therapeutic application for mTOR inhibitors to disrupt endothelial cell-monocyte interactions during AMR. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

Glucose transporter expression differs between bovine monocyte and macrophage subsets and is influenced by milk production.

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Eger, M; Hussen, J; Koy, M; Dänicke, S; Schuberth, H-J; Breves, G

2016-03-01

The peripartal period of dairy cows is characterized by negative energy balance and higher incidences of infectious diseases such as mastitis or metritis. With the onset of lactation, milk production is prioritized and large amounts of glucose are transported into the mammary gland. Decreased overall energy availability might impair the function of monocytes acting as key innate immune cells, which give rise to macrophages and dendritic cells and link innate and adaptive immunity. Information on glucose requirements of bovine immune cells is rare. Therefore, this study aims to evaluate glucose transporter expression of the 3 bovine monocyte subsets (classical, intermediate, and nonclassical monocytes) and monocyte-derived macrophages and to identify influences of the peripartal period. Blood samples were either collected from nonpregnant healthy cows or from 16 peripartal German Holstein cows at d -14, +7, and +21 relative to parturition. Quantitative real-time PCR was applied to determine mRNA expression of glucose transporters (GLUT) 1, GLUT3, and GLUT4 in monocyte subsets and monocyte-derived macrophages. The low GLUT1 and GLUT3 expression in nonclassical monocytes was unaltered during differentiation into macrophages, whereas in classical and intermediate monocytes GLUT expression was downregulated. Alternatively activated M2 macrophages consumed more glucose compared with classically activated M1 macrophages. The GLUT4 mRNA was only detectable in unstimulated macrophages. Neither monocytes nor macrophages were insulin responsive. In the peripartum period, monocyte GLUT1 and GLUT3 expression and the GLUT3/GLUT1 ratio were negatively correlated with lactose production. The high-affinity GLUT3 transporter appears to be the predominant glucose transporter on bovine monocytes and macrophages, especially in the peripartal period when blood glucose levels decline. Glucose transporter expression in monocytes is downregulated as a function of lactose production, which

Minocycline Inhibition of Monocyte Activation Correlates with Neuronal Protection in SIV NeuroAIDS

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Campbell, Jennifer H.; Burdo, Tricia H.; Autissier, Patrick; Bombardier, Jeffrey P.; Westmoreland, Susan V.; Soulas, Caroline; González, R. Gilberto; Ratai, Eva-Maria; Williams, Kenneth C.

2011-01-01

Background Minocycline is a tetracycline antibiotic that has been proposed as a potential conjunctive therapy for HIV-1 associated cognitive disorders. Precise mechanism(s) of minocycline's functions are not well defined. Methods Fourteen rhesus macaques were SIV infected and neuronal metabolites measured by proton magnetic resonance spectroscopy (1H MRS). Seven received minocycline (4 mg/kg) daily starting at day 28 post-infection (pi). Monocyte expansion and activation were assessed by flow cytometry, cell traffic to lymph nodes, CD16 regulation, viral replication, and cytokine production were studied. Results Minocycline treatment decreased plasma virus and pro-inflammatory CD14+CD16+ and CD14loCD16+ monocytes, and reduced their expression of CD11b, CD163, CD64, CCR2 and HLA-DR. There was reduced recruitment of monocyte/macrophages and productively infected cells in axillary lymph nodes. There was an inverse correlation between brain NAA/Cr (neuronal injury) and circulating CD14+CD16+ and CD14loCD16+ monocytes. Minocycline treatment in vitro reduced SIV replication CD16 expression on activated CD14+CD16+ monocytes, and IL-6 production by monocytes following LPS stimulation. Conclusion Neuroprotective effects of minocycline are due in part to reduction of activated monocytes, monocyte traffic. Mechanisms for these effects include CD16 regulation, reduced viral replication, and inhibited immune activation. PMID:21494695

A first-in-man safety and pharmacokinetics study of nangibotide, a new modulator of innate immune response through TREM-1 receptor inhibition.

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Cuvier, V; Lorch, U; Witte, S; Olivier, A; Gibot, S; Delor, I; Garaud, J J; Derive, M; Magguilli-Salcedo, M

2018-06-08

The peptide nangibotide is the first clinical-stage agent targeting the immunoreceptor TREM-1 (Triggering Receptor Expressed on Myeloid cells-1) and is being investigated as a novel therapy for acute inflammatory disorders such as septic shock. This first-in-man, randomised, double-blind, ascending dose, placebo-controlled Phase I study evaluated the safety, tolerability, and pharmacokinetics of nangibotide. 27 healthy subjects (aged 18-45 years) were randomised into eight groups. Nangibotide was administered as a single continuous intravenous infusion. The first two groups received a single I.V. dose of 1 and 10 mg, respectively, over 15 min. Subsequent groups were randomised in a product: placebo 3:1 ratio at doses ranging from 0.03 to 6 mg/kg/h over 7 h 45 min, preceded by a 15-minute loading dose of up to 5 mg/kg. Nangibotide was safe and well tolerated up to the highest dose tested. There were only few adverse events and they were mild in severity and considered unrelated to treatment. Nangibotide displayed dose-proportional PK properties, with a clearance of 6.6 L/kg/h for a subject of 70 kg and a 3 min effective half-life, which are compatible with extensive enzymatic metabolism in blood. Central and peripheral volumes of distribution were 16.7 L and 15.9 L respectively, indicating limited distribution of the drug mainly in blood and interstitial fluid. No circulating anti-drug antibodies were detectable up to 28 days after administration. The novel immunomodulator nangibotide displayed favourable safety and PK profiles at all doses, including expected pharmacologically active doses, and warrants further clinical development. This article is protected by copyright. All rights reserved.

Single-Cell RNA-Seq Reveals the Transcriptional Landscape and Heterogeneity of Aortic Macrophages in Murine Atherosclerosis.

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Cochain, Clément; Vafadarnejad, Ehsan; Arampatzi, Panagiota; Jaroslav, Pelisek; Winkels, Holger; Ley, Klaus; Wolf, Dennis; Saliba, Antoine-Emmanuel; Zernecke, Alma

2018-03-15

Rationale: It is assumed that atherosclerotic arteries contain several macrophage subsets endowed with specific functions. The precise identity of these subsets is poorly characterized as they ha ve been defined by the expression of a restricted number of markers. Objective: We have applied single-cell RNA-seq as an unbiased profiling strategy to interrogate and classify aortic macrophage heterogeneity at the single-cell level in atherosclerosis. Methods and Results: We performed single-cell RNA sequencing of total aortic CD45 + cells extracted from the non-diseased (chow fed) and atherosclerotic (11 weeks of high fat diet) aorta of Ldlr -/- mice. Unsupervised clustering singled out 13 distinct aortic cell clusters. Among the myeloid cell populations, Resident-like macrophages with a gene expression profile similar to aortic resident macrophages were found in healthy and diseased aortae, whereas monocytes, monocyte-derived dendritic cells (MoDC), and two populations of macrophages were almost exclusively detectable in atherosclerotic aortae, comprising Inflammatory macrophages showing enrichment in I l1b , and previously undescribed TREM2 hi macrophages. Differential gene expression and gene ontology enrichment analyses revealed specific gene expression patterns distinguishing these three macrophage subsets and MoDC, and uncovered putative functions of each cell type. Notably, TREM2 hi macrophages appeared to be endowed with specialized functions in lipid metabolism and catabolism, and presented a gene expression signature reminiscent of osteoclasts, suggesting a role in lesion calcification. TREM2 expression was moreover detected in human lesional macrophages. Importantly, these macrophage populations were present also in advanced atherosclerosis and in Apoe -/- aortae, indicating relevance of our findings in different stages of atherosclerosis and mouse models. Conclusions: These data unprecedentedly uncovered the transcriptional landscape and phenotypic

Lipopolysaccharide induces autotaxin expression in human monocytic THP-1 cells

International Nuclear Information System (INIS)

Li Song; Zhang Junjie

2009-01-01

Autotaxin (ATX) is a secreted enzyme with lysophospholipase D (lysoPLD) activity, which converts lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA), a bioactive phospholipid involved in numerous biological activities, including cell proliferation, differentiation, and migration. In the present study, we found that bacterial lipopolysaccharide (LPS), a well-known initiator of the inflammatory response, induced ATX expression in monocytic THP-1 cells. The activation of PKR, JNK, and p38 MAPK was required for the ATX induction. The LPS-induced ATX in THP-1 cells was characterized as the β isoform. In the presence of LPC, ATX could promote the migrations of THP-1 and Jurkat cells, which was inhibited by pertussis toxin (PTX), an inhibitor of Gi-mediated LPA receptor signaling. In summary, LPS induces ATX expression in THP-1 cells via a PKR, JNK and p38 MAPK-mediated mechanism, and the ATX induction is likely to enhance immune cell migration in proinflammatory response by regulating LPA levels in the microenvironment.

Induction of autophagy is essential for monocyte-macrophage differentiation

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Zhang, Yan; Morgan, Michael J.; Chen, Kun; Choksi, Swati; Liu, Zheng-gang

2012-01-01

Monocytes are programmed to undergo apoptosis in the absence of stimulation. Stimuli that promote monocyte-macrophage differentiation not only cause cellular changes, but also prevent the default apoptosis of monocytes. In the present study, we demonstrate that autophagy is induced when monocytes are triggered to differentiate and that the induction of autophagy is pivotal for the survival and differentiation of monocytes. We also show that inhibition of autophagy results in apoptosis of cell...

SAMHD1 controls cell cycle status, apoptosis and HIV-1 infection in monocytic THP-1 cells

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Bonifati, Serena; Daly, Michele B.; St Gelais, Corine; Kim, Sun Hee; Hollenbaugh, Joseph A.; Shepard, Caitlin; Kennedy, Edward M.; Kim, Dong-Hyun; Schinazi, Raymond F.; Kim, Baek; Wu, Li

2016-01-01

SAMHD1 limits HIV-1 infection in non-dividing myeloid cells by decreasing intracellular dNTP pools. HIV-1 restriction by SAMHD1 in these cells likely prevents activation of antiviral immune responses and modulates viral pathogenesis, thus highlighting a critical role of SAMHD1 in HIV-1 physiopathology. Here, we explored the function of SAMHD1 in regulating cell proliferation, cell cycle progression and apoptosis in monocytic THP-1 cells. Using the CRISPR/Cas9 technology, we generated THP-1 cells with stable SAMHD1 knockout. We found that silencing of SAMHD1 in cycling cells stimulates cell proliferation, redistributes cell cycle population in the G_1/G_0 phase and reduces apoptosis. These alterations correlated with increased dNTP levels and more efficient HIV-1 infection in dividing SAMHD1 knockout cells relative to control. Our results suggest that SAMHD1, through its dNTPase activity, affects cell proliferation, cell cycle distribution and apoptosis, and emphasize a key role of SAMHD1 in the interplay between cell cycle regulation and HIV-1 infection.

SAMHD1 controls cell cycle status, apoptosis and HIV-1 infection in monocytic THP-1 cells

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Bonifati, Serena [Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH (United States); Daly, Michele B. [Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA (United States); St Gelais, Corine; Kim, Sun Hee [Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH (United States); Hollenbaugh, Joseph A.; Shepard, Caitlin [Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA (United States); Kennedy, Edward M. [Department of Molecular Genetics and Microbiology, Duke University, Durham, NC (United States); Kim, Dong-Hyun [Department of Pharmacy, School of Pharmacy, Kyung-Hee University, Seoul (Korea, Republic of); Schinazi, Raymond F. [Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA (United States); Kim, Baek, E-mail: baek.kim@emory.edu [Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA (United States); Department of Pharmacy, School of Pharmacy, Kyung-Hee University, Seoul (Korea, Republic of); Wu, Li, E-mail: wu.840@osu.edu [Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH (United States)

2016-08-15

SAMHD1 limits HIV-1 infection in non-dividing myeloid cells by decreasing intracellular dNTP pools. HIV-1 restriction by SAMHD1 in these cells likely prevents activation of antiviral immune responses and modulates viral pathogenesis, thus highlighting a critical role of SAMHD1 in HIV-1 physiopathology. Here, we explored the function of SAMHD1 in regulating cell proliferation, cell cycle progression and apoptosis in monocytic THP-1 cells. Using the CRISPR/Cas9 technology, we generated THP-1 cells with stable SAMHD1 knockout. We found that silencing of SAMHD1 in cycling cells stimulates cell proliferation, redistributes cell cycle population in the G{sub 1}/G{sub 0} phase and reduces apoptosis. These alterations correlated with increased dNTP levels and more efficient HIV-1 infection in dividing SAMHD1 knockout cells relative to control. Our results suggest that SAMHD1, through its dNTPase activity, affects cell proliferation, cell cycle distribution and apoptosis, and emphasize a key role of SAMHD1 in the interplay between cell cycle regulation and HIV-1 infection.

Terbinafine stimulates the pro-inflammatory responses in human monocytic THP-1 cells through an ERK signaling pathway.

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Mizuno, Katsuhiko; Fukami, Tatsuki; Toyoda, Yasuyuki; Nakajima, Miki; Yokoi, Tsuyoshi

2010-10-23

Oral antifungal terbinafine has been reported to cause liver injury with inflammatory responses in a small percentage of patients. However the underlying mechanism remains unknown. To examine the inflammatory reactions, we investigated whether terbinafine and other antifungal drugs increase the release of pro-inflammatory cytokines using human monocytic cells. Dose- and time-dependent changes in the mRNA expression levels and the release of interleukin (IL)-8 and tumor necrosis factor (TNF)α from human monocytic THP-1 and HL-60 cells with antifungal drugs were measured. Effects of terbinafine on the phosphorylation of extracellular signal-regulated kinase (ERK)1/2, p38 mitogen-activated protein (MAP) kinase and c-Jun N-terminal kinase (JNK)1/2 were investigated. The release of IL-8 and TNFα from THP-1 and HL-60 cells was significantly increased by treatment with terbinafine but not by fluconazole, suggesting that terbinafine can stimulate monocytes and increase the pro-inflammatory cytokine release. Terbinafine also significantly increased the phosphorylation of ERK1/2 and p38 MAP kinase in THP-1 cells. Pretreatment with a MAP kinase/ERK kinase (MEK)1/2 inhibitor U0126 significantly suppressed the increase of IL-8 and TNFα levels by terbinafine treatment in THP-1 cells, but p38 MAPK inhibitor SB203580 did not. These results suggested that an ERK1/2 pathway plays an important role in the release of IL-8 and TNFα in THP-1 cells treated with terbinafine. The release of inflammatory mediators by terbinafine might be one of the mechanisms underlying immune-mediated liver injury. This in vitro method may be useful to predict adverse inflammatory reactions that lead to drug-induced liver injury. Copyright © 2010 Elsevier Inc. All rights reserved.

Prion protein induced signaling cascades in monocytes

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Krebs, Bjarne; Dorner-Ciossek, Cornelia; Schmalzbauer, Ruediger; Vassallo, Neville; Herms, Jochen; Kretzschmar, Hans A.

2006-01-01

Prion proteins play a central role in transmission and pathogenesis of transmissible spongiform encephalopathies. The cellular prion protein (PrP C ), whose physiological function remains elusive, is anchored to the surface of a variety of cell types including neurons and cells of the lymphoreticular system. In this study, we investigated the response of a mouse monocyte/macrophage cell line to exposure with PrP C fusion proteins synthesized with a human Fc-tag. PrP C fusion proteins showed an attachment to the surface of monocyte/macrophages in nanomolar concentrations. This was accompanied by an increase of cellular tyrosine phosphorylation as a result of activated signaling pathways. Detailed investigations exhibited activation of downstream pathways through a stimulation with PrP fusion proteins, which include phosphorylation of ERK 1,2 and Akt kinase. Macrophages opsonize and present antigenic structures, contact lymphocytes, and deliver cytokines. The findings reported here may become the basis of understanding the molecular function of PrP C in monocytes and macrophages

Altered monocyte activation markers in Tourette’s syndrome: a case–control study

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Matz Judith

2012-05-01

Full Text Available Abstract Background Infections and immunological processes are likely to be involved in the pathogenesis of Tourette’s syndrome (TS. To determine possible common underlying immunological mechanisms, we focused on innate immunity and studied markers of inflammation, monocytes, and monocyte-derived cytokines. Methods In a cross-sectional study, we used current methods to determine the number of monocytes and levels of C-reactive protein (CRP in 46 children, adolescents, and adult patients suffering from TS and in 43 healthy controls matched for age and sex. Tumor necrosis factor alpha (TNF-alpha, interleukin 6 (IL-6, soluble CD14 (sCD14, IL1-receptor antagonist (IL1-ra, and serum neopterin were detected by immunoassays. Results We found that CRP and neopterin levels and the number of monocytes were significantly higher in TS patients than in healthy controls. Serum concentrations of TNF-alpha, sIL1-ra, and sCD14 were significantly lower in TS patients. All measured values were within normal ranges and often close to detection limits. Conclusions The present results point to a monocyte dysregulation in TS. This possible dysbalance in innate immunity could predispose to infections or autoimmune reactions.

THP-1 monocytes but not macrophages as a potential alternative for CD34+ dendritic cells to identify chemical skin sensitizers

International Nuclear Information System (INIS)

Lambrechts, Nathalie; Verstraelen, Sandra; Lodewyckx, Hanne; Felicio, Ana; Hooyberghs, Jef; Witters, Hilda; Tendeloo, Viggo van; Cauwenberge, Paul van; Nelissen, Inge; Heuvel, Rosette van den; Schoeters, Greet

2009-01-01

Early detection of the sensitizing potential of chemicals is an emerging issue for chemical, pharmaceutical and cosmetic industries. In our institute, an in vitro classification model for prediction of chemical-induced skin sensitization based on gene expression signatures in human CD34 + progenitor-derived dendritic cells (DC) has been developed. This primary cell model is able to closely mimic the induction phase of sensitization by Langerhans cells in the skin, but it has drawbacks, such as the availability of cord blood. The aim of this study was to investigate whether human in vitro cultured THP-1 monocytes or macrophages display a similar expression profile for 13 predictive gene markers previously identified in DC and whether they also possess a discriminating capacity towards skin sensitizers and non-sensitizers based on these marker genes. To this end, the cell models were exposed to 5 skin sensitizers (ammonium hexachloroplatinate IV, 1-chloro-2,4-dinitrobenzene, eugenol, para-phenylenediamine, and tetramethylthiuram disulfide) and 5 non-sensitizers (L-glutamic acid, methyl salicylate, sodium dodecyl sulfate, tributyltin chloride, and zinc sulfate) for 6, 10, and 24 h, and mRNA expression of the 13 genes was analyzed using real-time RT-PCR. The transcriptional response of 7 out of 13 genes in THP-1 monocytes was significantly correlated with DC, whereas only 2 out of 13 genes in THP-1 macrophages. After a cross-validation of a discriminant analysis of the gene expression profiles in the THP-1 monocytes, this cell model demonstrated to also have a capacity to distinguish skin sensitizers from non-sensitizers. However, the DC model was superior to the monocyte model for discrimination of (non-)sensitizing chemicals.

HLA class I antibodies trigger increased adherence of monocytes to endothelial cells by eliciting an increase in endothelial P-selectin and, depending on subclass, by engaging FcγRs1

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Valenzuela, Nicole M; Mulder, Arend; Reed, Elaine F

2013-01-01

Antibody-mediated rejection of solid organ transplants is characterized by intragraft macrophages. It is incompletely understood how donor specific antibody binding to graft endothelium promotes monocyte adhesion, and what, if any, contribution is made by the Fc region of the antibody. We investigated the mechanisms underlying monocyte recruitment by HLA class I antibody-activated endothelium. We used a panel of murine monoclonal antibodies of different subclasses to crosslink HLA I on human aortic, venous and microvascular endothelial cells, and measured the binding of human monocytic cell lines and peripheral blood monocytes. Both anti-HLA I murine IgG1 and mIgG2a induced endothelial P-selectin, which was required for monocyte adhesion to endothelium irrespective of subclass. Mouse IgG2a but not mIgG1 could bind human FcγRs. Accordingly, HLA I mIgG2a but not mIgG1 treatment of endothelial cells significantly augmented recruitment, predominantly through FcγRI, and, to a lesser extent, FcγRIIa. Moreover, HLA I mIgG2a promoted firm adhesion of monocytes to ICAM-1 through Mac-1, which may explain the prominence of monocytes during antibody mediated rejection. We confirmed these observations using human HLA allele specific monoclonal antibodies and IgG purified from transplant patient sera. HLA I antibodies universally elicit endothelial exocytosis leading to monocyte adherence, implying that P-selectin is a putative therapeutic target to prevent macrophage infiltration during antibody-mediated rejection. Importantly, the subclass of donor specific antibody may influence its pathogenesis. These results imply that hIgG1 and hIgG3 should have a greater capacity to trigger monocyte infiltration into the graft than IgG2 or IgG4 due to enhancement by FcγR interactions. PMID:23690477

Monocyte Subsets in Schistosomiasis Patients with Periportal Fibrosis

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Jamille Souza Fernandes

2014-01-01

Full Text Available A major issue with Schistosoma mansoni infection is the development of periportal fibrosis, which is predominantly caused by the host immune response to egg antigens. Experimental studies have pointed to the participation of monocytes in the pathogenesis of liver fibrosis. The aim of this study was to characterize the subsets of monocytes in individuals with different degrees of periportal fibrosis secondary to schistosomiasis. Monocytes were classified into classical (CD14++CD16−, intermediate (CD14++CD16+, and nonclassical (CD14+CD16++. The expressions of monocyte markers and cytokines were assessed using flow cytometry. The frequency of classical monocytes was higher than the other subsets. The expression of HLA-DR, IL-6, TNF-α, and TGF-β was higher in monocytes from individuals with moderate to severe fibrosis as compared to other groups. Although no differences were observed in receptors expression (IL-4R and IL-10R between groups of patients, the expression of IL-12 was lower in monocytes from individuals with moderate to severe fibrosis, suggesting a protective role of this cytokine in the development of fibrosis. Our data support the hypothesis that the three different monocyte populations participate in the immunopathogenesis of periportal fibrosis, since they express high levels of proinflammatory and profibrotic cytokines and low levels of regulatory markers.

Human CD68 promoter GFP transgenic mice allow analysis of monocyte to macrophage differentiation in vivo.

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Iqbal, Asif J; McNeill, Eileen; Kapellos, Theodore S; Regan-Komito, Daniel; Norman, Sophie; Burd, Sarah; Smart, Nicola; Machemer, Daniel E W; Stylianou, Elena; McShane, Helen; Channon, Keith M; Chawla, Ajay; Greaves, David R

2014-10-09

The recruitment of monocytes and their differentiation into macrophages at sites of inflammation are key events in determining the outcome of the inflammatory response and initiating the return to tissue homeostasis. To study monocyte trafficking and macrophage differentiation in vivo, we have generated a novel transgenic reporter mouse expressing a green fluorescent protein (GFP) under the control of the human CD68 promoter. CD68-GFP mice express high levels of GFP in both monocyte and embryo-derived tissue resident macrophages in adult animals. The human CD68 promoter drives GFP expression in all CD115(+) monocytes of adult blood, spleen, and bone marrow; we took advantage of this to directly compare the trafficking of bone marrow-derived CD68-GFP monocytes to that of CX3CR1(GFP) monocytes in vivo using a sterile zymosan peritonitis model. Unlike CX3CR1(GFP) monocytes, which downregulate GFP expression on differentiation into macrophages in this model, CD68-GFP monocytes retain high-level GFP expression for 72 hours after differentiation into macrophages, allowing continued cell tracking during resolution of inflammation. In summary, this novel CD68-GFP transgenic reporter mouse line represents a powerful resource for analyzing monocyte mobilization and monocyte trafficking as well as studying the fate of recruited monocytes in models of acute and chronic inflammation. © 2014 by The American Society of Hematology.

Niacin results in reduced monocyte adhesion in patients with type 2 diabetes mellitus.

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Tavintharan, S; Woon, K; Pek, L T; Jauhar, N; Dong, X; Lim, S C; Sum, C F

2011-03-01

Patients with type 2 diabetes have increased expression of cell adhesion molecules (CAMs). CAMs and monocyte adhesion mediate essential processes in atherogenesis. It remains unclear if monocytes from patients on niacin have reduced adhesion function. We studied the variation of monocyte adhesion in patients with type 2 diabetes and low HDL-cholesterol, taking either extended release niacin (Niaspan®, Abbott Laboratories) or controls not on niacin. Biochemical parameters including adiponectin, CAMs and fresh monocytes from whole blood for adhesion assays, were studied at baseline and 12-weeks. Niacin 1500 mg daily raised HDL-cholesterol from 0.8 mmol/l (95% CI: 0.7-0.9) to 0.9 mmol/l (95% CI: 0.8-1.1), p=0.10, and significantly reduced PECAM-1 by 24.9% (95% CI: 10.9-39.0; p<0.05), increased adiponectin by 30.5% (95% CI: 14.1-47.0; p<0.05), with monocyte adhesion reduced by 9.2% (95%CI: 0.7-17.7; p<0.05) in endothelial cells treated in basal conditions, and 7.8% (95% CI: 3.1-12.5; p<0.05) after TNF-α stimulation. Monocytes isolated from patients on niacin had reduced adhesion to endothelial cells. Our findings suggest niacin has broad range of effects apart from lipid-modification, and these could be important in cardiovascular risk reduction. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Activated human mast cells induce LOX-1-specific scavenger receptor expression in human monocyte-derived macrophages.

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Mervi Alanne-Kinnunen

Full Text Available Activated mast cells in atherosclerotic lesions degranulate and release bioactive compounds capable of regulating atherogenesis. Here we examined the ability of activated human primary mast cells to regulate the expression of the major scavenger receptors in cultured human primary monocyte-derived macrophages (HMDMs.Components released by immunologically activated human primary mast cells induced a transient expression of lectin-like oxidized LDL receptor (LOX-1 mRNA in HMDMs, while the expression of two other scavenger receptors, MSR1 and CD36, remained unaffected. The LOX-1-inducing secretory components were identified as histamine, tumor necrosis factor alpha (TNF-α, and transforming growth factor beta (TGF-β1, which exhibited a synergistic effect on LOX-1 mRNA expression. Histamine induced a transient expression of LOX-1 protein. Mast cell -induced increase in LOX-1 expression was not associated with increased uptake of oxidized LDL by the macrophages.Mast cell-derived histamine, TNF-α, and TGF-β1 act in concert to induce a transient increase in LOX-1 expression in human primary monocyte-derived macrophages. The LOX-1-inducing activity potentially endows mast cells a hitherto unrecognized role in the regulation of innate immune reactions in atherogenesis.

Kaempferol impedes IL-32-induced monocyte-macrophage differentiation.

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Nam, Sun-Young; Jeong, Hyun-Ja; Kim, Hyung-Min

2017-08-25

Kaempferol possesses a wide range of therapeutic properties, including antioxidant, anti-inflammatory, and anticancer properties. The present study sought to evaluate the effects and possible pharmacological mechanisms of kaempferol on interleukin (IL)-32-induced monocyte-macrophage differentiation. In this study, we performed flow cytometry assay, immunocytochemical staining, quantitative real-time PCR, enzyme-linked immuno sorbent assay, caspase-1 assay, and Western blotting to observe the effects and underlying mechanisms of kaempferol using the human monocyte cell line THP-1. The flow cytometry, immunocytochemical staining, and real-time PCR results show that kaempferol attenuated IL-32-induced monocyte differentiation to product macrophage-like cells. Kaempferol decreased the production and mRNA expression of pro-inflammatory cytokines, in this case thymic stromal lymphopoietin (TSLP), IL-1β, tumor necrosis factor (TNF)-α, and IL-8. Furthermore, kaempferol inhibited the IL-32-induced activation of p38 and nuclear factor-κB in a dose-dependent manner in THP-1 cells. Kaempferol also ameliorated the lipopolysaccharide-induced production of the inflammatory mediators TSLP, IL-1β, TNF-α, IL-8, and nitric oxide of macrophage-like cells differentiated by IL-32. In brief, our findings may provide new mechanistic insights into the anti-inflammatory effects of kaempferol. Copyright © 2017 Elsevier B.V. All rights reserved.

Stimulated monocyte IL-6 secretion predicts survival of patients with head and neck squamous cell carcinoma

International Nuclear Information System (INIS)

Heimdal, John-Helge; Kross, Kenneth; Klementsen, Beate; Olofsson, Jan; Aarstad, Hans Jørgen

2008-01-01

This study was performed in order to determine whether monocyte in vitro function is associated with presence, stage and prognosis of head and neck squamous cell carcinoma (HNSCC) disease. Prospective study describing outcome, after at least five years observation, of patients treated for HNSCC disease in relation to their monocyte function. Sixty-five patients with newly diagnosed HNSCC and eighteen control patients were studied. Monocyte responsiveness was assessed by measuring levels of monocyte in vitro interleukin (IL)-6 and monocyte chemotactic peptide (MCP)-1 secretion after 24 hours of endotoxin stimulation in cultures supplied either with 20% autologous serum (AS) or serum free medium (SFM). Survival, and if relevant, cause of death, was determined at least 5 years following primary diagnosis. All patients, as a group, had higher in vitro monocyte responsiveness in terms of IL-6 (AS) (t = 2.03; p < 0.05) and MCP-1 (SFM) (t = 2.49; p < 0.05) compared to controls. Increased in vitro monocyte IL-6 endotoxin responsiveness under the SFM condition was associated with decreased survival rate (Hazard ratio (HR) = 2.27; Confidence interval (CI) = 1.05–4.88; p < 0.05). The predictive value of monocyte responsiveness, as measured by IL-6, was also retained when adjusted for age, gender and disease stage of patients (HR = 2.67; CI = 1.03–6.92; p < 0.05). With respect to MCP-1, low endotoxin-stimulated responsiveness (AS), analysed by Kaplan-Meier method, predicted decreased survival (χ = 4.0; p < 0.05). In HNSCC patients, changed monocyte in vitro response to endotoxin, as measured by increased IL-6 (SFM) and decreased MCP-1 (AS) responsiveness, are negative prognostic factors

Monocytes with angiogenic potential are selectively induced by liver resection and accumulate near the site of liver regeneration.

Science.gov (United States)

Schauer, Dominic; Starlinger, Patrick; Zajc, Philipp; Alidzanovic, Lejla; Maier, Thomas; Buchberger, Elisabeth; Pop, Lorand; Gruenberger, Birgit; Gruenberger, Thomas; Brostjan, Christine

2014-10-30

Monocytes reportedly contribute to liver regeneration. Three subsets have been identified to date: classical, intermediate, non-classical monocytes. The intermediate population and a subtype expressing TIE2 (TEMs) were suggested to promote angiogenesis. In a clinical setting, we investigated which monocyte subsets are regulated after liver resection and correlate with postoperative liver function. In 38 patients monocyte subsets were evaluated in blood and subhepatic wound fluid by flow cytometry before and 1-3 days after resection of colorectal liver metastases. The monocyte-regulating cytokines macrophage colony stimulating factor (M-CSF), transforming growth factor beta 1 (TGFβ1), and angiopoietin 2 (ANG-2) were measured in patient plasma by ELISA. C-reactive protein (CRP) and liver function parameters were retrieved from routine hospital analyses. On post-operative day (POD) 1 blood monocytes shifted to significantly elevated levels of intermediate monocytes. In wound fluid, a delayed surge in intermediate monocytes was detected by POD 3. Furthermore, TEMs were highly enriched in wound fluid as compared to circulation. CRP and M-CSF levels were substantially increased in patient blood after surgery and correlated significantly with the frequency of intermediate monocytes. In addition, liver function parameters showed a significant association with intermediate monocyte levels on POD 3. The reportedly pro-angiogenic subsets of monocytes are selectively increased upon liver resection and accumulate next to the site of liver regeneration. As previously proposed by in vitro experiments, the release of CRP and M-CSF may trigger the induction of intermediate monocytes. The correlation with liver parameters points to a functional involvement of these monocyte populations in liver regeneration which warrants further investigation.

Monocyte Trafficking, Engraftment, and Delivery of Nanoparticles and an Exogenous Gene into the Acutely Inflamed Brain Tissue - Evaluations on Monocyte-Based Delivery System for the Central Nervous System.

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Hsin-I Tong

Full Text Available The ability of monocytes and monocyte-derived macrophages (MDM to travel towards chemotactic gradient, traverse tissue barriers, and accumulate precisely at diseased sites makes them attractive candidates as drug carriers and therapeutic gene delivery vehicles targeting the brain, where treatments are often hampered by the blockade of the blood brain barrier (BBB. This study was designed to fully establish an optimized cell-based delivery system using monocytes and MDM, by evaluating their homing efficiency, engraftment potential, as well as carriage and delivery ability to transport nano-scaled particles and exogenous genes into the brain, following the non-invasive intravenous (IV cell adoptive transfer in an acute neuroinflammation mouse model induced by intracranial injection of Escherichia coli lipopolysaccharides. We demonstrated that freshly isolated monocytes had superior inflamed-brain homing ability over MDM cultured in the presence of macrophage colony stimulating factor. In addition, brain trafficking of IV infused monocytes was positively correlated with the number of adoptive transferred cells, and could be further enhanced by transient disruption of the BBB with IV administration of Mannitol, Bradykinin or Serotonin right before cell infusion. A small portion of transmigrated cells was detected to differentiate into IBA-1 positive cells with microglia morphology in the brain. Finally, with the use of superparamagnetic iron oxide nanoparticles SHP30, the ability of nanoscale agent-carriage monocytes to enter the inflamed brain region was validated. In addition, lentiviral vector DHIV-101 was used to introduce green fluorescent protein (GFP gene into monocytes, and the exogenous GFP gene was detected in the brain at 48 hours following IV infusion of the transduced monocytes. All together, our study has set up the optimized conditions for the more-in-depth tests and development of monocyte-mediated delivery, and our data supported

Expansion of CD14+CD16+ monocytes producing TNF-α in complication-free diabetes type 1 juvenile onset patients.

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Myśliwska, Jolanta; Smardzewski, Marcin; Marek-Trzonkowska, Natalia; Myśliwiec, Małgorzata; Raczyńska, Krystyna

2012-10-01

We concentrated on the complication-free phase of juvenile onset type 1 diabetes mellitus (T1DM) searching for associations between concentration of inflammatory factors TNF-α, CRP and VEGF and two monocyte subsets the CD14(++)CD16(-) and CD14(+)CD16(+). We analysed a randomly selected group of 150 patients without complications (disease duration 2.74 ± 2.51 years) at the start of the project and 5 years later. They were compared with 24 patients with retinopathy (6.53 ± 3.39 years of disease) and 30 healthy volunteers. Our results indicate that in the complication-free period the concentration of TNF-α significantly increased and continued to increase after retinopathy was established. After 5 years the percentage and absolute number of CD14(+)CD16(+) monocytes doubled in complication-free patients. Our study indicates that the size of CD14(+)CD16(+) monocyte subset may be used alternatively to CRP values as an indicator of inflammation grade. Our results imply the necessity of trials using anti-TNF-α therapy in the complication-free phase of the disease. Copyright © 2012 Elsevier Ltd. All rights reserved.

Stimulated monocyte IL-6 secretion predicts survival of patients with head and neck squamous cell carcinoma

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Olofsson Jan

2008-01-01

Full Text Available Abstract Background This study was performed in order to determine whether monocyte in vitro function is associated with presence, stage and prognosis of head and neck squamous cell carcinoma (HNSCC disease. Methods Prospective study describing outcome, after at least five years observation, of patients treated for HNSCC disease in relation to their monocyte function. Sixty-five patients with newly diagnosed HNSCC and eighteen control patients were studied. Monocyte responsiveness was assessed by measuring levels of monocyte in vitro interleukin (IL-6 and monocyte chemotactic peptide (MCP-1 secretion after 24 hours of endotoxin stimulation in cultures supplied either with 20% autologous serum (AS or serum free medium (SFM. Survival, and if relevant, cause of death, was determined at least 5 years following primary diagnosis. Results All patients, as a group, had higher in vitro monocyte responsiveness in terms of IL-6 (AS (t = 2.03; p t = 2.49; p in vitro monocyte IL-6 endotoxin responsiveness under the SFM condition was associated with decreased survival rate (Hazard ratio (HR = 2.27; Confidence interval (CI = 1.05–4.88; p p p Conclusion In HNSCC patients, changed monocyte in vitro response to endotoxin, as measured by increased IL-6 (SFM and decreased MCP-1 (AS responsiveness, are negative prognostic factors.

Membrane microparticles and diseases.

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Wu, Z-H; Ji, C-L; Li, H; Qiu, G-X; Gao, C-J; Weng, X-S

2013-09-01

Membrane microparticles (MPs) are plasma membrane-derived vesicles shed by various types of activated or apoptotic cells including platelets, monocytes, endothelial cells, red blood cells, and granulocytes. MPs are being increasingly recognized as important regulators of cell-to-cell interactions. Recent evidences suggest they may play important functions not only in homeostasis but also in the pathogenesis of a number of diseases such as vascular diseases, cancer, infectious diseases and diabetes mellitus. Accordingly, inhibiting the production of MPs may serve as a novel therapeutic strategy for these diseases. Here we review recent advances on the mechanism underlying the generation of MPs and the role of MPs in vascular diseases, cancer, diabetes, inflammation, and pathogen infection.

Galectin-2 induces a proinflammatory, anti-arteriogenic phenotype in monocytes and macrophages.

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Cansu Yıldırım

Full Text Available Galectin-2 is a monocyte-expressed carbohydrate-binding lectin, for which increased expression is genetically determined and associated with decreased collateral arteriogenesis in obstructive coronary artery disease patients. The inhibiting effect of galectin-2 on arteriogenesis was confirmed in vivo, but the mechanism is largely unknown. In this study we aimed to explore the effects of galectin-2 on monocyte/macrophage phenotype in vitro and vivo, and to identify the receptor by which galectin-2 exerts these effects. We now show that the binding of galectin-2 to different circulating human monocyte subsets is dependent on monocyte surface expression levels of CD14. The high affinity binding is blocked by an anti-CD14 antibody but not by carbohydrates, indicating a specific protein-protein interaction. Galectin-2 binding to human monocytes modulated their transcriptome by inducing proinflammatory cytokines and inhibiting pro-arteriogenic factors, while attenuating monocyte migration. Using specific knock-out mice, we show that galectin-2 acts through the CD14/toll-like receptor (TLR-4 pathway. Furthermore, galectin-2 skews human macrophages to a M1-like proinflammatory phenotype, characterized by a reduced motility and expression of an anti-arteriogenic cytokine/growth factor repertoire. This is accompanied by a switch in surface protein expression to CD40-high and CD206-low (M1. In a murine model we show that galectin-2 administration, known to attenuate arteriogenesis, leads to increased numbers of CD40-positive (M1 and reduced numbers of CD206-positive (M2 macrophages surrounding actively remodeling collateral arteries. In conclusion galectin-2 is the first endogenous CD14/TLR4 ligand that induces a proinflammatory, non-arteriogenic phenotype in monocytes/macrophages. Interference with CD14-Galectin-2 interaction may provide a new intervention strategy to stimulate growth of collateral arteries in genetically compromised cardiovascular

Regulatory NK cells mediated between immunosuppressive monocytes and dysfunctional T cells in chronic HBV infection.

Science.gov (United States)

Li, Haijun; Zhai, Naicui; Wang, Zhongfeng; Song, Hongxiao; Yang, Yang; Cui, An; Li, Tianyang; Wang, Guangyi; Niu, Junqi; Crispe, Ian Nicholas; Su, Lishan; Tu, Zhengkun

2017-09-12

HBV infection represents a major health problem worldwide, but the immunological mechanisms by which HBV causes chronic persistent infection remain only partly understood. Recently, cell subsets with suppressive features have been recognised among monocytes and natural killer (NK) cells. Here we examine the effects of HBV on monocytes and NK cells. Monocytes and NK cells derived from chronic HBV-infected patients and healthy controls were purified and characterised for phenotype, gene expression and cytokines secretion by flow cytometry, quantitative real-time (qRT)-PCR, ELISA and western blotting. Culture and coculture of monocytes and NK cells were used to determine NK cell activation, using intracellular cytokines staining. In chronic HBV infection, monocytes express higher levels of PD-L1, HLA-E, interleukin (IL)-10 and TGF-β, and NK cells express higher levels of PD-1, CD94 and IL-10, compared with healthy individuals. HBV employs hepatitis B surface antigen (HBsAg) to induce suppressive monocytes with HLA-E, PD-L1, IL-10 and TGF-β expression via the MyD88/NFκB signalling pathway. HBV-treated monocytes induce NK cells to produce IL-10, via PD-L1 and HLA-E signals. Such NK cells inhibit autologous T cell activation. Our findings reveal an immunosuppressive cascade, in which HBV generates suppressive monocytes, which initiate regulatory NK cells differentiation resulting in T cell inhibition. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

[Changes of monocyte and monocyte-platelet aggregates in different subgroups of thrombotic events in patients with acute myocardial infarction during PCI].

Science.gov (United States)

Wang, Sheng; Sun, Cuifang; Liao, Wang; Wu, Zhongwei; Wang, Yudai; Huang, Xiuxian; Lu, Sijia; Dong, Xiaoli; Shuai, Fujie; Li, Bin

2017-07-01

Objective To investigate the impact of thrombotic events on the alterations of monocyte and monocyte-platelet aggregates (MPAs) in patients with acute myocardial infarction (AMI) during percutaneous coronary intervention (PCI). Methods Blood was collected before PCI for flow cytometry. Monocyte subsets and MPAs were detected by four-color platform (CDl4-APC, CDl6-PE-Cy7, CD86-PE and CD41-Alexa Fluor R 488). According to the expression of the platelet surface marker CD41, the number of monocyte subsets and MPAs was analyzed using the fluorescent microspheres of absolute counting tube. The Wilcoxon rank sum test and receiver operating characteristic (ROC) curve analysis were performed. Results CD14 + CD16 ++ monocytes in intraprocedural thrombotic events (IPTE) group were significantly fewer than those in non-IPTE group, and the percentage in total mononuclear cells decreased. Compared with non-IPTE group, MPA binding ratio and monocyte subset MPA binding ratio were significantly higher in IPTE group. ROC analysis showed that MPA binding ratio and subgroup MPA binding ratio had a better predictive value for IPTE in patients with AMI. Conclusion The CD14 + CD16 ++ monocytes in IPTE group were significantly fewer than those in the non-IPTE group. MPA binding ratio and MPA binding ratio of monocyte subsets were significantly higher in the IPTE group than in the non-IPTE group, so they have a good predictive value for IPTE in patients with AMI.

The role of monocytes and T cells in 1,25-dihydroxyvitamin D3 mediated inhibition of B cell function in vitro

DEFF Research Database (Denmark)

Müller, K; Heilmann, C; Poulsen, L K

1991-01-01

1,25-Dihydroxyvitamin D3 (1,25-(OH)2D3) inhibits immunoglobulin production by human mononuclear cells (MNC) in vitro. The present study was undertaken to evaluate the role of T cells and monocytes in 1,25-(OH)2D3 induced suppression of B cell functions. The synthetic vitamin D3 analogue MC 903...... was examined in parallel. 1,25-(OH)2D3 and MC 903 showed a dose-related inhibition of IgM, IgG and IgA plaque-forming cells in poke-weed mitogen (PWM) activated cultures of MNC. This effect was most likely mediated through impairment of T cell and monocyte functions. First, the inhibitory effect was seen after...

Differential regulation of TNF-α and IL-1β production from endotoxin stimulated human monocytes by phosphodiesterase inhibitors

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K. L. Molnar-Kimber

1992-01-01

Full Text Available The effect of selective PDE-I (vinpocetine, PDE-III (milrinone, CI-930, PDE-IV (rolipram, nitroquazone, and PDE-V (zaprinast isozyme inhibitors on TNF-α and IL-1β production from LPS stimulated human monocytes was investigated. The PDE-IV inhibitors caused a concentration dependent inhibition of TNF-α production, but only partially inhibited IL-1β at high concentrations. High concentrations of the PDE-III inhibitors weakly inhibited TNF-α, but had no effect on IL-1β production. PDE-V inhibition was associated with an augmentation of cytokine secretion. Studies with combinations of PDE isozyme inhibitors indicated that PDE-III and PDE-V inhibitors modulate rolipram's suppression of TNF production in an additive manner. These data confirm that TNF-α and IL-1β production from LPS stimulated human monocytes are differentially regulated, and suggest that PDE-IV inhibitors have the potential to suppress TNF levels in man.

Ursodeoxycholic acid inhibits TNFα-induced IL-8 release from monocytes.

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O'Dwyer, Aoife M; Lajczak, Natalia K; Keyes, Jennifer A; Ward, Joseph B; Greene, Catherine M; Keely, Stephen J

2016-08-01

Monocytes are critical to the pathogenesis of inflammatory bowel disease (IBD) as they infiltrate the mucosa and release cytokines that drive the inflammatory response. Ursodeoxycholic acid (UDCA), a naturally occurring bile acid with anti-inflammatory actions, has been proposed as a potential new therapy for IBD. However, its effects on monocyte function are not yet known. Primary monocytes from healthy volunteers or cultured U937 monocytes were treated with either the proinflammatory cytokine, TNFα (5 ng/ml) or the bacterial endotoxin, lipopolysaccharide (LPS; 1 μg/ml) for 24 h, in the absence or presence of UDCA (25-100 μM). IL-8 release into the supernatant was measured by ELISA. mRNA levels were quantified by qPCR and changes in cell signaling proteins were determined by Western blotting. Toxicity was assessed by measuring lactate dehydrogenase (LDH) release. UDCA treatment significantly attenuated TNFα-, but not LPS-driven, release of IL-8 from both primary and cultured monocytes. UDCA inhibition of TNFα-driven responses was associated with reduced IL-8 mRNA expression. Both TNFα and LPS stimulated NFκB activation in monocytes, while IL-8 release in response to both cytokines was attenuated by an NFκB inhibitor, BMS-345541. Interestingly, UDCA inhibited TNFα-, but not LPS-stimulated, NFκB activation. Finally, TNFα, but not LPS, induced phosphorylation of TNF receptor associated factor (TRAF2), while UDCA cotreatment attenuated this response. We conclude that UDCA specifically inhibits TNFα-induced IL-8 release from monocytes by inhibiting TRAF2 activation. Since such actions would serve to dampen mucosal immune responses in vivo, our data support the therapeutic potential of UDCA for IBD. Copyright © 2016 the American Physiological Society.

Stimulation of monocytes by placental microparticles involves Toll-like receptors and nuclear factor kappa-light-chain-enhancer of activated B cells

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Marianne Simone Joerger-Messerli

2014-04-01

Full Text Available Human pregnancy is accompanied by a mild systemic inflammatory response, which includes the activation of monocytes circulating in maternal blood. This response is exaggerated in preeclampsia, a placental-dependent disorder specific to human pregnancies. We and others showed that placental syncytiotrophoblast membrane microparticles (STBM generated in vitro from normal placentas stimulated peripheral blood monocytes, which suggests a contribution of STBM to the systemic maternal inflammation. Here, we analyzed the inflammatory potential of STBM prepared from preeclamptic placentas on primary monocytes and investigated the mode of action in vitro.STBM generated in vitro by placental villous explants of normal or preeclamptic placentas were co-incubated with human peripheral blood monocytes. In some cases, inhibitors of specific cellular functions or signaling pathways were used. The analysis of the monocytic response was performed by flow cytometry, enzyme-linked immunoassays, real-time PCR and fluorescence microscopy.STBM derived from preeclamptic placentas up-regulated the cell surface expression of CD54, and stimulated the secretion of the pro-inflammatory interleukin (IL-6 and IL-8 in a similar, dose-dependent manner as did STBM prepared from normal placentas. STBM bound to the cell surface of monocytes, but phagocytosis was not necessary for activation. STBM-induced cytokine secretion was impaired in the presence of inhibitors of toll-like receptor (TLR signaling or when nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB activation was blocked.Our results suggest that the inflammatory reaction in monocytes may be initiated by the interaction of STBM with TLRs, which in turn signal through NF-κB to mediate the transcription of genes coding for pro-inflammatory factors.

Genome-wide association study identifies single nucleotide polymorphism in DYRK1A associated with replication of HIV-1 in monocyte-derived macrophages.

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Sebastiaan M Bol

2011-02-01

Full Text Available HIV-1 infected macrophages play an important role in rendering resting T cells permissive for infection, in spreading HIV-1 to T cells, and in the pathogenesis of AIDS dementia. During highly active anti-retroviral treatment (HAART, macrophages keep producing virus because tissue penetration of antiretrovirals is suboptimal and the efficacy of some is reduced. Thus, to cure HIV-1 infection with antiretrovirals we will also need to efficiently inhibit viral replication in macrophages. The majority of the current drugs block the action of viral enzymes, whereas there is an abundance of yet unidentified host factors that could be targeted. We here present results from a genome-wide association study identifying novel genetic polymorphisms that affect in vitro HIV-1 replication in macrophages.Monocyte-derived macrophages from 393 blood donors were infected with HIV-1 and viral replication was determined using Gag p24 antigen levels. Genomic DNA from individuals with macrophages that had relatively low (n = 96 or high (n = 96 p24 production was used for SNP genotyping with the Illumina 610 Quad beadchip. A total of 494,656 SNPs that passed quality control were tested for association with HIV-1 replication in macrophages, using linear regression. We found a strong association between in vitro HIV-1 replication in monocyte-derived macrophages and SNP rs12483205 in DYRK1A (p = 2.16 × 10(-5. While the association was not genome-wide significant (p<1 × 10(-7, we could replicate this association using monocyte-derived macrophages from an independent group of 31 individuals (p = 0.0034. Combined analysis of the initial and replication cohort increased the strength of the association (p = 4.84 × 10(-6. In addition, we found this SNP to be associated with HIV-1 disease progression in vivo in two independent cohort studies (p = 0.035 and p = 0.0048.These findings suggest that the kinase DYRK1A is involved in the replication of HIV-1, in vitro in macrophages

Radiation-Induced Thymidine Phosphorylase Upregulation in Rectal Cancer Is Mediated by Tumor-Associated Macrophages by Monocyte Chemoattractant Protein-1 From Cancer Cells

International Nuclear Information System (INIS)

Kim, Tae-Dong; Li Ge; Song, Kyoung-Sub; Kim, Jin-Man; Kim, Jun-Sang; Kim, Jong-Seok; Yun, Eun-Jin; Park, Jong-Il; Park, Hae-Duck; Hwang, Byung-Doo; Lim, Kyu; Yoon, Wan-Hee

2009-01-01

Purpose: The mechanisms of thymidine phosphorylase (TP) regulation induced by radiation therapy (XRT) in various tumors are poorly understood. We investigated the effect and mechanisms of preoperative XRT on TP expression in rectal cancer tissues. Methods and Materials: TP expression and CD68 and monocyte chemoattractant protein-1 (MCP-1) levels in rectal cancer tissues and cancer cell lines were evaluated before and after XRT in Western blotting, immunohistochemistry, enzyme-linked immunoassay, and reverse transcription-polymerase chain reaction studies. Isolated peripheral blood monocytes were used in the study of chemotaxis under the influence of MCP-1 released by irradiated colon cancer cells. Results: Expression of TP was significantly elevated by 9 Gy of XRT in most rectal cancer tissues but not by higher doses of XRT. In keeping with the close correlation of the increase in both TP expression and the number of tumor-associated macrophages (TAMs), anti-TP immunoreactivity was found in the CD68-positive TAMs and not the neoplastic cells. Expression of MCP-1 was increased in most cases after XRT, and this increase was strongly correlated with TP expression. However, this increase in MCP-1 expression occurred in tumor cells and not stromal cells. The XRT upregulated MCP-1 mRNA and also triggered the release of MCP-1 protein from cultured colon cancer cells. The supernatant of irradiated colon cancer cells showed strong chemotactic activity for monocyte migration, but this activity was completely abolished by neutralizing antibody. Conclusions: Use of XRT induces MCP-1 expression in cancer cells, which causes circulating monocytes to be recruited into TAMs, which then upregulate TP expression in rectal cancer tissues

Dexamethasone Suppresses Oxysterol-Induced Differentiation of Monocytic Cells

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Yonghae Son

2016-01-01

Full Text Available Oxysterol like 27-hydroxycholesterol (27OHChol has been reported to induce differentiation of monocytic cells into a mature dendritic cell phenotype. We examined whether dexamethasone (Dx affects 27OHChol-induced differentiation using THP-1 cells. Treatment of monocytic cells with Dx resulted in almost complete inhibition of transcription and surface expression of CD80, CD83, and CD88 induced by 27OHChol. Elevated surface levels of MHC class I and II molecules induced by 27OHChol were reduced to basal levels by treatment with Dx. A decreased endocytosis ability caused by 27OHChol was recovered by Dx. We also examined effects of Dx on expression of CD molecules involved in atherosclerosis. Increased levels of surface protein and transcription of CD105, CD137, and CD166 by treatment with 27OHChol were significantly inhibited by cotreatment with Dx. These results indicate that Dx inhibits 27OHChol-induced differentiation of monocytic cells into a mature dendritic cell phenotype and expression of CD molecules whose levels are associated with atherosclerosis. In addition, we examined phosphorylation of AKT induced by 27OHChol and effect of Dx, where cotreatment with Dx inhibited the phosphorylation of AKT. The current study reports that Dx regulates oxysterol-mediated dendritic cell differentiation of monocytic cells.

Platelet-derived growth factor (PDGF-BB-mediated induction of monocyte chemoattractant protein 1 in human astrocytes: implications for HIV-associated neuroinflammation

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Bethel-Brown Crystal

2012-12-01

Full Text Available Abstract Chemokine (C-C motif ligand 2, also known as monocyte chemoattractant protein 1 (MCP-1 is an important factor for the pathogenesis of HIV-associated neurocognitive disorders (HAND. The mechanisms of MCP-1-mediated neuropathogenesis, in part, revolve around its neuroinflammatory role and the recruitment of monocytes into the central nervous system (CNS via the disrupted blood-brain barrier (BBB. We have previously demonstrated that HIV-1/HIV-1 Tat upregulate platelet-derived growth factor (PDGF-BB, a known cerebrovascular permeant; subsequently, the present study was aimed at exploring the regulation of MCP-1 by PDGF-BB in astrocytes with implications in HAND. Specifically, the data herein demonstrate that exposure of human astrocytes to HIV-1 LAI elevated PDGF-B and MCP-1 levels. Furthermore, treating astrocytes with the human recombinant PDGF-BB protein significantly increased the production and release of MCP-1 at both the RNA and protein levels. MCP-1 induction was regulated by activation of extracellular-signal-regulated kinase (ERK1/2, c-Jun N-terminal kinase (JNK and p38 mitogen-activated protein (MAP kinases and phosphatidylinositol 3-kinase (PI3K/Akt pathways and the downstream transcription factor, nuclear factor κB (NFκB. Chromatin immunoprecipitation (ChIP assays demonstrated increased binding of NFκB to the human MCP-1 promoter following PDGF-BB exposure. Conditioned media from PDGF-BB-treated astrocytes increased monocyte transmigration through human brain microvascular endothelial cells (HBMECs, an effect that was blocked by STI-571, a tyrosine kinase inhibitor (PDGF receptor (PDGF-R blocker. PDGF-BB-mediated release of MCP-1 was critical for increased permeability in an in vitro BBB model as evidenced by blocking antibody assays. Since MCP-1 is linked to disease severity, understanding its modulation by PDGF-BB could aid in understanding the proinflammatory responses in HAND. These results suggest that astrocyte

Strenuous physical exercise adversely affects monocyte chemotaxis

DEFF Research Database (Denmark)

Czepluch, Frauke S; Barres, Romain; Caidahl, Kenneth

2011-01-01

Physical exercise is important for proper cardiovascular function and disease prevention, but it may influence the immune system. We evaluated the effect of strenuous exercise on monocyte chemotaxis. Monocytes were isolated from blood of 13 young, healthy, sedentary individuals participating...... in a three-week training program which consisted of repeated exercise bouts. Monocyte chemotaxis and serological biomarkers were investigated at baseline, after three weeks training and after four weeks recovery. Chemotaxis towards vascular endothelial growth factor-A (VEGF-A) and transforming growth factor...

Recruitment of classical monocytes can be inhibited by disturbing heteromers of neutrophil HNP1 and platelet CCL5

NARCIS (Netherlands)

Alard, Jean-Eric; Ortega-Gomez, Almudena; Wichapong, Kanin; Bongiovanni, Dario; Horckmans, Michael; Megens, Remco T. A.; Leoni, Giovanna; Ferraro, Bartolo; Rossaint, Jan; Paulin, Nicole; Ng, Judy; Ippel, Hans; Suylen, Dennis; Hinkel, Rabea; Blanchet, Xavier; Gaillard, Fanny; D'Amico, Michele; von Hundelshausen, Phillipp; Zarbock, Alexander; Scheiermann, Christoph; Hackeng, Tilman M.; Steffens, Sabine; Kupatt, Christian; Nicolaes, Gerry A. F.; Weber, Christian; Soehnlein, Oliver

2015-01-01

In acute and chronic inflammation, neutrophils and platelets, both of which promote monocyte recruitment, are often activated simultaneously. We investigated how secretory products of neutrophils and platelets synergize to enhance the recruitment of monocytes. We found that neutrophil-borne human

Protective role of klotho protein on epithelial cells upon co-culture with activated or senescent monocytes

Energy Technology Data Exchange (ETDEWEB)

Mytych, Jennifer, E-mail: jennifermytych@gmail.com [Institute of Applied Biotechnology and Basic Sciences, University of Rzeszow, Werynia 502, 36-100 Kolbuszowa (Poland); Centre of Applied Biotechnology and Basic Sciences, University of Rzeszow, Werynia 502, 36-100 Kolbuszowa (Poland); Wos, Izabela; Solek, Przemyslaw; Koziorowski, Marek [Institute of Applied Biotechnology and Basic Sciences, University of Rzeszow, Werynia 502, 36-100 Kolbuszowa (Poland); Centre of Applied Biotechnology and Basic Sciences, University of Rzeszow, Werynia 502, 36-100 Kolbuszowa (Poland)

2017-01-15

Monocytes ensure proper functioning and maintenance of epithelial cells, while good condition of monocytes is a key factor of these interactions. Although, it was shown that in some circumstances, a population of altered monocytes may appear, there is no data regarding their effect on epithelial cells. In this study, using direct co-culture model with LPS-activated and Dox-induced senescent THP-1 monocytes, we reported for the first time ROS-induced DNA damage, reduced metabolic activity, proliferation inhibition and cell cycle arrest followed by p16-, p21- and p27-mediated DNA damage response pathways activation, premature senescence and apoptosis induction in HeLa cells. Also, we show that klotho protein possessing anti-aging and anti-inflammatory characteristics reduced cytotoxic and genotoxic events by inhibition of insulin/IGF-IR and downregulation of TRF1 and TRF2 proteins. Therefore, klotho protein could be considered as a protective factor against changes caused by altered monocytes in epithelial cells. - Highlights: • Activated and senescent THP-1 monocytes induced cyto- and genotoxicity in HeLa cells. • Altered monocytes provoked oxidative and nitrosative stress-induced DNA damage. • DNA damage activated DDR pathways and lead to premature senescence and apoptosis. • Klotho reduced ROS/RNS-mediated toxicity through insulin/IGF-IR pathway inhibition. • Klotho protects HeLa cells from cyto- and genotoxicity induced by altered monocytes.

Protective role of klotho protein on epithelial cells upon co-culture with activated or senescent monocytes

International Nuclear Information System (INIS)

Mytych, Jennifer; Wos, Izabela; Solek, Przemyslaw; Koziorowski, Marek

2017-01-01

Monocytes ensure proper functioning and maintenance of epithelial cells, while good condition of monocytes is a key factor of these interactions. Although, it was shown that in some circumstances, a population of altered monocytes may appear, there is no data regarding their effect on epithelial cells. In this study, using direct co-culture model with LPS-activated and Dox-induced senescent THP-1 monocytes, we reported for the first time ROS-induced DNA damage, reduced metabolic activity, proliferation inhibition and cell cycle arrest followed by p16-, p21- and p27-mediated DNA damage response pathways activation, premature senescence and apoptosis induction in HeLa cells. Also, we show that klotho protein possessing anti-aging and anti-inflammatory characteristics reduced cytotoxic and genotoxic events by inhibition of insulin/IGF-IR and downregulation of TRF1 and TRF2 proteins. Therefore, klotho protein could be considered as a protective factor against changes caused by altered monocytes in epithelial cells. - Highlights: • Activated and senescent THP-1 monocytes induced cyto- and genotoxicity in HeLa cells. • Altered monocytes provoked oxidative and nitrosative stress-induced DNA damage. • DNA damage activated DDR pathways and lead to premature senescence and apoptosis. • Klotho reduced ROS/RNS-mediated toxicity through insulin/IGF-IR pathway inhibition. • Klotho protects HeLa cells from cyto- and genotoxicity induced by altered monocytes.

Statins attenuate polymethylmethacrylate-mediated monocyte activation.

LENUS (Irish Health Repository)

Laing, Alan J

2012-02-03

BACKGROUND: Periprosthetic osteolysis precipitates aseptic loosening of components, increases the risk of periprosthetic fracture and, through massive bone loss, complicates revision surgery and ultimately is the primary cause for failure of joint arthroplasty. The anti-inflammatory properties of HMG-CoA reductase inhibitors belonging to the statin family are well recognized. We investigated a possible role for status in initiating the first stage of the osteolytic cycle, namely monocytic activation. METHODS: We used an in vitro model of the human monocyte\\/macrophage inflammatory response to poly-methylmethacrylate (PMMA) particles after pretreat-ing cells with cerivastatin, a potent member of the statin family. Cell activation based upon production of TNF-alpha and MCP-1 cytokines was analyzed and the intracellular Raf-MEK-ERK signal transduction pathway was evaluated using western blot analysis, to identify its role in cell activation and in any cerivastatin effects observed. RESULTS: We found that pretreatment with cerivastatin significantly abrogates the production of inflammatory cytokines TNF-alpha and MCP-1 by human monocytes in response to polymethylmethacrylate particle activation. This inflammatory activation and attenuation appear to be mediated through the intracellular Raf-MEK-ERK pathway. INTERPRETATION: We propose that by intervening at the upstream activation stage, subsequent osteoclast activation and osteolysis can be suppressed. We believe that the anti-inflammatory properties of statins may potentially play a prophylactic role in the setting of aseptic loosening, and in so doing increase implant longevity.

PGC-1-related coactivator (PRC) negatively regulates endothelial adhesion of monocytes via inhibition of NF κB activity

Energy Technology Data Exchange (ETDEWEB)

Chengye, Zhan; Daixing, Zhou, E-mail: dxzhou7246@hotmail.com; Qiang, Zhong; Shusheng, Li

2013-09-13

Highlights: •First time to display that LPS downregulate the expression of PRC. •First time to show that PRC inhibits the induction of VCAM-1 and E-selectin. •First time to show that PRC inhibit monocytes attachment to endothelial cells. •First time to display that PRC inhibits transcriptional activity of NF-κB. •PRC protects the respiration rate and suppresses the glycolysis rate against LPS. -- Abstract: PGC-1-related coactivator (PRC) is a growth-regulated transcriptional cofactor known to activate many of the nuclear genes specifying mitochondrial respiratory function. Endothelial dysfunction is a prominent feature found in many inflammatory diseases. Adhesion molecules, such as VCAM-1, mediate the attachment of monocytes to endothelial cells, thereby playing an important role in endothelial inflammation. The effects of PRC in regards to endothelial inflammation remain unknown. In this study, our findings show that PRC can be inhibited by the inflammatory cytokine LPS in cultured human umbilical vein endothelial cells (HUVECs). In the presence of LPS, the expression of endothelial cell adhesion molecular, such as VCAM1 and E-selectin, is found to be increased. These effects can be negated by overexpression of PRC. Importantly, monocyte adhesion to endothelial cells caused by LPS is significantly attenuated by PRC. In addition, overexpression of PRC protects mitochondrial metabolic function and suppresses the rate of glycolysis against LPS. It is also found that overexpression of PRC decreases the transcriptional activity of NF-κB. These findings suggest that PRC is a negative regulator of endothelial inflammation.

Effects of peritoneal fluid from endometriosis patients on the release of monocyte-specific chemokines by leukocytes.

Science.gov (United States)

Na, Yong-Jin; Lee, Dong-Hyung; Kim, Seung-Chul; Joo, Jong-Kil; Wang, Ji-Won; Jin, Jun-O; Kwak, Jong-Young; Lee, Kyu-Sup

2011-06-01

Chemokines have been implicated in the pathological process of endometriosis. We compared the effects of peritoneal fluid obtained from patients with endometriosis (ePF) and controls without endometriosis (cPF) on the release of monocyte-specific CC chemokines such as monocyte chemotactic protein-1 (MCP-1), regulated upon activation normal T cell expressed and secreted (RANTES), and macrophage inflammatory protein-1α (MIP-1α) by neutrophils, monocytes, and T cells. Moreover, we evaluated the correlation between the levels of chemokines in ePF and their release by these cells. Cells were obtained from healthy young volunteers and cultured with ePF (n = 12) or cPF (n = 8). The chemokine levels in the ePF and the supernatants of cultured cells with ePF were then measured by ELISA. There was a positive correlation between the levels of MCP-1 and MIP-1α in ePF. The addition of ePF to the cell cultures failed to increase the release of MCP-1, RANTES, and MIP-1α when compared to cPF, but the levels of RANTES in ePF were positively correlated with the release of RANTES by ePF-treated monocytes and T cells. Moreover, there was a positive correlation between the levels of RANTES and MIP-1α released by neutrophils and between the levels of MCP-1 and MIP-1α released by T cells. Finally, the levels of RANTES released by monocyte-derived macrophages and monocytes cultured with ePF were positively correlated. These findings suggest that monocytes, neutrophils, and T cells release differential levels of MCP-1, RANTES, and MIP-1α in response to stimulation with ePF.

Blood Monocyte Subsets and Selected Cardiovascular Risk Markers in Rheumatoid Arthritis of Short Duration in relation to Disease Activity

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Ewa Klimek

2014-01-01

Full Text Available Objectives. To evaluate blood monocyte subsets and functional monocyte properties in patients with rheumatoid arthritis (RA of short duration in the context of cardiovascular (CV risk and disease activity. Methods. We studied conventional markers of CV risk, intima media thickness (IMT, and blood monocyte subsets in 27 patients aged 41 ± 10 years with RA of short duration (median 12 months and 22 healthy controls. The RA subjects were divided into low (DAS28: 2.6–5.1 and high (DAS28 > 5.1 disease activity. Results. RA patients exhibited increased levels of intermediate (CD14++CD16+ monocytes with decreased CD45RA expression compared to controls, increased counts of classical (CD14++CD16− monocytes, and decreased percentages of nonclassical (CD14+CD16++ monocytes. Patients with high disease activity had lower HLA DR expression on classical monocytes compared to low disease activity patients. There were no differences in monocyte subsets between subjects with DAS > 5.1 and DAS ≤ 5.1. There were no significant intergroup differences in IMT and the majority of classical CV risk factors. Conclusions. Patients with RA of short duration show alteration in peripheral blood monocyte subsets despite the fact that there is no evidence of subclinical atherosclerosis. Disease activity assessed with DAS28 was associated with impaired functional properties but not with a shift in monocyte subpopulations.

Pro-inflammatory capacity of classically activated monocytes relates positively to muscle mass and strength.

Science.gov (United States)

Beenakker, Karel G M; Westendorp, Rudi G J; de Craen, Anton J M; Slagboom, Pieternella E; van Heemst, Diana; Maier, Andrea B

2013-08-01

In mice, monocytes that exhibit a pro-inflammatory profile enter muscle tissue after muscle injury and are crucial for clearance of necrotic tissue and stimulation of muscle progenitor cell proliferation and differentiation. The aim of this study was to test if pro-inflammatory capacity of classically activated (M1) monocytes relates to muscle mass and strength in humans. This study included 191 male and 195 female subjects (mean age 64.2 years (SD 6.4) and 61.9 ± 6.4, respectively) of the Leiden Longevity Study. Pro-inflammatory capacity of M1 monocytes was assessed by ex vivo stimulation of whole blood with Toll-like receptor (TLR) 4 agonist lipopolysaccharide (LPS) and TLR-2/1 agonist tripalmitoyl-S-glycerylcysteine (Pam₃Cys-SK₄), both M1 phenotype activators. Cytokines that stimulate M1 monocyte response (IFN-γ and GM-CSF) as well as cytokines that are secreted by M1 monocytes (IL-6, TNF-α, IL-12, and IL-1β) were measured. Analyses were adjusted for age, height, and body fat mass. Upon stimulation with LPS, the cytokine production capacity of INF-γ, GM-CSF, and TNF-α was significantly positively associated with lean body mass, appendicular lean mass and handgrip strength in men, but not in women. Upon stimulation with Pam₃Cys-SK₄, IL-6; TNF-α; and Il-1β were significantly positively associated with lean body mass and appendicular lean in women, but not in men. Taken together, this study shows that higher pro-inflammatory capacity of M1 monocytes upon stimulation is associated with muscle characteristics and sex dependent. © 2013 John Wiley & Sons Ltd and the Anatomical Society.

Phenotypic heterogeneity of peripheral monocytes in healthy dogs.

Science.gov (United States)

Gibbons, Natalie; Goulart, Michelle R; Chang, Yu-Mei; Efstathiou, Konstantinos; Purcell, Robert; Wu, Ying; Peters, Laureen M; Turmaine, Mark; Szladovits, Balazs; Garden, Oliver A

2017-08-01

Monocytes are key cells of the innate immune system. Their phenotypic and functional roles have been investigated in humans, mice and other animals, such as the rat, pig and cow. To date, detailed phenotypic analysis of monocytes has not been undertaken in dogs. Two important surface markers in human monocytes are CD14 and MHC class II (MHC II). By flow cytometry, we demonstrated that canine monocytes can be subdivided into three separate populations: CD14 pos MHC II neg , CD14 pos MHC II pos and CD14 neg MHC II pos . Both light and transmission electron microscopy confirmed the monocytic identity of all three populations. The CD14 pos MHC II neg population could be distinguished on an ultrastructural level by their smaller size, the presence of more numerous, larger granules, and more pseudopodia than both of the other populations. Copyright © 2017 Elsevier B.V. All rights reserved.

Adding exercise to rosuvastatin treatment: influence on C-reactive protein, monocyte toll-like receptor 4 expression, and inflammatory monocyte (CD14+CD16+) population.

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Coen, Paul M; Flynn, Michael G; Markofski, Melissa M; Pence, Brandt D; Hannemann, Robert E

2010-12-01

Statin treatment and exercise training can reduce markers of inflammation when administered separately. The purpose of this study was to determine the effect of rosuvastatin treatment and the addition of exercise training on circulating markers of inflammation including C-reactive protein (CRP), monocyte toll-like receptor 4 (TLR4) expression, and CD14+CD16+ monocyte population size. Thirty-three hypercholesterolemic and physically inactive subjects were randomly assigned to rosuvastatin (R) or rosuvastatin/exercise (RE) groups. A third group of physically active hypercholesterolemic subjects served as a control (AC). The R and RE groups received rosuvastatin treatment (10 mg/d) for 20 weeks. From week 10 to week 20, the RE group also participated in an exercise training program (3d/wk). Measurements were made at baseline (Pre), week 10 (Mid), and week 20 (Post), and included TLR4 expression on CD14+ monocytes and CD14+CD16+ monocyte population size as determined by 3-color flow cytometry. Serum CRP was quantified by enzyme-linked immunosorbent assay. TLR4 expression on CD14+ monocytes was higher in the R group at week 20. When treatment groups (R and RE) were combined, serum CRP was lower across time. Furthermore, serum CRP and inflammatory monocyte population size were lower in the RE group compared with the R group at the Post time point. When all groups (R, RE, and AC) were combined, TLR4 expression was greater on inflammatory monocytes (CD14+CD16+) compared with classic monocytes (CD14+CD16⁻) at all time points. In conclusion, rosuvastatin may influence monocyte inflammatory response by increasing TLR4 expression on circulating monocytes. The addition of exercise training to rosuvastatin treatment further lowered CRP and reduced the size of the inflammatory monocyte population, suggesting an additive anti-inflammatory effect of exercise. Copyright © 2010 Elsevier Inc. All rights reserved.

Involvement of JNK and NF-κB pathways in lipopolysaccharide (LPS)-induced BAG3 expression in human monocytic cells.

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Wang, Hua-Qin; Meng, Xin; Liu, Bao-Qin; Li, Chao; Gao, Yan-Yan; Niu, Xiao-Fang; Li, Ning; Guan, Yifu; Du, Zhen-Xian

2012-01-01

Lipopolysaccharide (LPS) is an outer-membrane glycolipid component of Gram-negative bacteria known for its fervent ability to activate monocytic cells and for its potent proinflammatory capabilities. Bcl-2-associated athanogene 3 (BAG3) is a survival protein that has been shown to be stimulated during cell response to stressful conditions, such as exposure to high temperature, heavy metals, proteasome inhibition, and human immunodeficiency virus 1 (HIV-1) infection. In addition, BAG3 regulates replication of Varicella-Zoster Virus (VZV) and Herpes Simplex Virus (HSV) replication, suggesting that BAG3 could participate in the host response to infection. In the current study, we found that LPS increased the expression of BAG3 in a dose- and time-dependent manner. Actinomycin D completely blocked the LPS-induced BAG3 accumulation, as well as LPS activated the proximal promoter of BAG3 gene, supported that the induction by LPS occurred at the level of gene transcription. LPS-induced BAG3 expression was blocked by JNK or NF-κB inhibition, suggesting that JNK and NF-κB pathways participated in BAG3 induction by LPS. In addition, we also found that induction of BAG3 was implicated in monocytic cell adhesion to extracellular matrix induced by LPS. Overall, the data support that BAG3 is induced by LPS via JNK and NF-κB-dependent signals, and involved in monocytic cell-extracellular matrix interaction, suggesting that BAG3 may have a role in the host response to LPS stimulation. Copyright © 2011 Elsevier Inc. All rights reserved.

Chemical dampening of Ly6C(hi) monocytes in the periphery produces anti-depressant effects in mice.

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Zheng, Xiao; Ma, Sijing; Kang, An; Wu, Mengqiu; Wang, Lin; Wang, Qiong; Wang, Guangji; Hao, Haiping

2016-01-19

The involvement of systemic immunity in depression pathogenesis promises a periphery-targeting paradigm in novel anti-depressant discovery. However, relatively little is known about druggable targets in the periphery for mental and behavioral control. Here we report that targeting Ly6C(hi) monocytes in blood can serve as a strategy for anti-depressant purpose. A natural compound, ginsenoside Rg1 (Rg1), was firstly validated as a periphery-restricted chemical probe. Rg1 selectively suppressed Ly6C(hi) monocytes recruitment to the inflamed mice brain. The proinflammatory potential of Ly6C(hi) monocytes to activate astrocytes was abrogated by Rg1, which led to a blunted feedback release of CCL2 to recruit the peripheral monocytes. In vitro study demonstrated that Rg1 pretreatment on activated THP-1 monocytes retarded their ability to trigger CCL2 secretion from co-cultured U251 MG astrocytes. CCL2-triggered p38/MAPK and PI3K/Akt activation were involved in the action of Rg1. Importantly, in mice models, we found that dampening Ly6C(hi) monocytes at the periphery ameliorated depression-like behavior induced by neuroinflammation or chronic social defeat stress. Together, our work unravels that blood Ly6C(hi) monocytes may serve as the target to enable remote intervention on the depressed brain, and identifies Rg1 as a lead compound for designing drugs targeting peripheral CCL2 signals.

[Binding of the antileukemia drug Escherichia coli L-asparaginase to the plasma membrane of normal human mononuclear cells].

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Mercado-Vianco, L; Arenas-Díaz, G

1999-06-01

To demonstrate that the enzyme L-asparaginase from Escherichia coli (EcA) binds to the plasma membranes of normal human lymphocytes and monocytes. Lymphocytes and monocytes were isolated from heparinized blood samples which came from healthy volunteer donors. The cells were incubated with EcA to detect a possible binding of the enzyme to the mononuclear cells by indirect immunofluorescence using confocal microscopy. Meanwhile, ultracentrifugation was used to obtain the erythrocyte ghost microsomal fraction (P100) which was then analyzed by Western blotting to determine if EcA binds the lipid bilayer unspecifically. For the immunoassays, monospecific polyclonal antibodies were obtained from ascitic tumors developed in mice immunized with commercial L-asparaginase. EcA bins the lymphocyte and monocyte plasma membranes. In monocytes, there occurs a capping phenomenon, that is, the accumulation of fluorescent marker in one region. The image analyzer highlights it clearly at a depth of 3.8 microns. This binding would be unspecific, that is, there is no mediation of a specific receptor that binds EcA. This arises from the ability of the enzyme to bind to the membranes of erythrocyte ghost, as evidenced by the ability of the molecule to associate with a hydrophobic medium. The antibodies against EcA obtained from ascitic tumours developed in mice do not show cross reactivity with Na+/K+ ATPase, aspartate aminotransferase, nor with extracts of blood cells, which would make it a specific tool for the detection of EcA in whole cells and in homogenates electrotransfered to nitrocellulose membranes. L-asparaginase from E. coli behaves as a lipoprotein due to its ability to insert itself into hydrophobic environments, in which it resembles an isozyme present in T. pyriformis. The binding of this enzyme to lymphocytes and monocytes, demonstrated in this work, would permit the modification of the antileukemic treatment injecting doses of EcA bound to patient's own isolated immune

Functional role of monocytes and macrophages for the inflammatory response in acute liver injury

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Henning W Zimmermann

2012-10-01

Full Text Available Different etiologies such as drug toxicity, acute viral hepatitis B or acetaminophen poisoning can cause acute liver injury (ALI or even acute liver failure (ALF. Excessive cell death of hepatocytes in the liver is known to result in a strong hepatic inflammation. Experimental murine models of liver injury highlighted the importance of hepatic macrophages, so-called Kupffer cells, for initiating and driving this inflammatory response by releasing proinflammatory cytokines and chemokines including tumor necrosis factor (TNF, interleukin-6 (IL-6, IL-1-beta or monocyte chemoattractant protein 1 (MCP-1, CCL2 as well as activating other non-parenchymal liver cells, e.g. endothelial or hepatic stellate cells (HSC. Many of these proinflammatory mediators can trigger hepatocytic cell death pathways, e.g. via caspase activation, but also activate protective signaling pathways, e.g. via nuclear factor kappa B (NF-kB. Recent studies in mice demonstrated that these macrophage actions largely depend on the recruitment of monocytes into the liver, namely of the inflammatory Ly6c+ (Gr1+ monocyte subset as precursors of tissue macrophages. The chemokine receptor CCR2 and its ligand MCP-1/CCL2 promote monocyte subset infiltration upon liver injury. In contrast, the chemokine receptor CX3CR1 and its ligand fractalkine (CX3CL1 are important negative regulators of monocyte infiltration by controlling their survival and differentiation into functionally diverse macrophage subsets upon injury. The recently identified cellular and molecular pathways for monocyte subset recruitment, macrophage differentiation and interactions with other hepatic cell types in the injured liver may therefore represent interesting novel targets for future therapeutic approaches in ALF.

Ureaplasma isolates stimulate pro-inflammatory CC chemokines and matrix metalloproteinase-9 in neonatal and adult monocytes

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Silwedel, Christine; Fehrholz, Markus; Henrich, Birgit; Waaga-Gasser, Ana Maria; Claus, Heike; Speer, Christian P.

2018-01-01

Being generally regarded as commensal bacteria, the pro-inflammatory capacity of Ureaplasma species has long been debated. Recently, we confirmed Ureaplasma–driven pro-inflammatory cytokine responses and a disturbance of cytokine equilibrium in primary human monocytes in vitro. The present study addressed the expression of CC chemokines and matrix metalloproteinase-9 (MMP-9) in purified term neonatal and adult monocytes stimulated with serovar 8 of Ureaplasma urealyticum (Uu) and serovar 3 of U. parvum (Up). Using qRT-PCR and multi-analyte immunoassay, we assessed mRNA and protein expression of the monocyte chemotactic proteins 1 and 3 (MCP-1/3), the macrophage inflammatory proteins 1α and 1β (MIP-1α/β) as well as MMP-9. For the most part, both isolates stimulated mRNA expression of all given chemokines and MMP-9 in cord blood and adult monocytes (pUreaplasma isolates in vitro, adding to our previous data. Findings from co-stimulated cells indicate that Ureaplasma may modulate monocyte immune responses to a second stimulus. PMID:29558521

Enhancement of proinflammatory and procoagulant responses to silica particles by monocyte-endothelial cell interactions

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Liu Xin

2012-09-01

Full Text Available Abstract Background Inorganic particles, such as drug carriers or contrast agents, are often introduced into the vascular system. Many key components of the in vivo vascular environment include monocyte-endothelial cell interactions, which are important in the initiation of cardiovascular disease. To better understand the effect of particles on vascular function, the present study explored the direct biological effects of particles on human umbilical vein endothelial cells (HUVECs and monocytes (THP-1 cells. In addition, the integrated effects and possible mechanism of particle-mediated monocyte-endothelial cell interactions were investigated using a coculture model of HUVECs and THP-1 cells. Fe3O4 and SiO2 particles were chosen as the test materials in the present study. Results The cell viability data from an MTS assay showed that exposure to Fe3O4 or SiO2 particles at concentrations of 200 μg/mL and above significantly decreased the cell viability of HUVECs, but no significant loss in viability was observed in the THP-1 cells. TEM images indicated that with the accumulation of SiO2 particles in the cells, the size, structure and morphology of the lysosomes significantly changed in HUVECs, whereas the lysosomes of THP-1 cells were not altered. Our results showed that reactive oxygen species (ROS generation; the production of interleukin (IL-6, IL-8, monocyte chemoattractant protein 1 (MCP-1, tumor necrosis factor (TNF-α and IL-1β; and the expression of CD106, CD62E and tissue factor in HUVECs and monocytes were significantly enhanced to a greater degree in the SiO2-particle-activated cocultures compared with the individual cell types alone. In contrast, exposure to Fe3O4 particles had no impact on the activation of monocytes or endothelial cells in monoculture or coculture. Moreover, using treatment with the supernatants of SiO2-particle-stimulated monocytes or HUVECs, we found that the enhancement of proinflammatory response by SiO2

Increased C-C chemokine receptor 2 gene expression in monocytes of severe obstructive sleep apnea patients and under intermittent hypoxia.

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Chuang, Li-Pang; Chen, Ning-Hung; Lin, Shih-Wei; Chang, Ying-Ling; Liao, Hsiang-Ruei; Lin, Yu-Sheng; Chao, I-Ju; Lin, Yuling; Pang, Jong-Hwei S

2014-01-01

Obstructive sleep apnea (OSA) is known to be a risk factor of coronary artery disease. The chemotaxis and adhesion of monocytes to the endothelium in the early atherosclerosis is important. This study aimed to investigate the effect of intermittent hypoxia, the hallmark of OSA, on the chemotaxis and adhesion of monocytes. Peripheral blood was sampled from 54 adults enrolled for suspected OSA. RNA was prepared from the isolated monocytes for the analysis of C-C chemokine receptor 2 (CCR2). The effect of intermittent hypoxia on the regulation and function of CCR2 was investigated on THP-1 monocytic cells and monocytes. The mRNA and protein expression levels were investigated by RT/real-time PCR and western blot analysis, respectively. Transwell filter migration assay and cell adhesion assay were performed to study the chemotaxis and adhesion of monocytes. Monocytic CCR2 gene expression was found to be increased in severe OSA patients and higher levels were detected after sleep. Intermittent hypoxia increased the CCR2 expression in THP-1 monocytic cells even in the presence of TNF-α and CRP. Intermittent hypoxia also promoted the MCP-1-mediated chemotaxis and adhesion of monocytes to endothelial cells. Furthermore, inhibitor for p42/44 MAPK or p38 MAPK suppressed the activation of monocytic CCR2 expression by intermittent hypoxia. This is the first study to demonstrate the increase of CCR2 gene expression in monocytes of severe OSA patients. Monocytic CCR2 gene expression can be induced under intermittent hypoxia which contributes to the chemotaxis and adhesion of monocytes.

Diagnostic Performance of Soluble Triggering Receptor Expressed on Myeloid Cells-1 in Ventilator-Associated Pneumonia of Patients with Ischemic Stroke.

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Yu, Yuetian; Zhu, Cheng; Liu, Chunyan; Gao, Yuan; Yin, Rong; Cao, Jianguo

2017-01-01

Objective . To investigate the effect of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in serum, bronchoalveolar lavage fluid (BALF), endotracheal aspiration (ETA), and exhaled breath condensate (EBC) samples as early biomarkers for the diagnosis of ventilator-associated pneumonia (VAP) in patients with ischemic stroke. Methods . One hundred and thirty-two patients with clinically suspected VAP were enrolled in this study. Bronchoscopy was performed on the day of clinically suspected VAP. sTREM-1 levels in serum, BALF, ETA, and EBC were measured. VAP was diagnosed by quantitative cultures of BALF (≥10 4  cfu/mL). Results . VAP was confirmed in 76 (57.58%) cases. Patients with VAP showed significantly higher sTREM-1 in BALF [32.35 (IQR, 30.08-41.72) versus 18.92 (11.89-31.72)] pg/mL and in EBC [1.57 (IQR, 1.02-2.61) versus 0.41 (0.19-1.61)] pg/mL than patients without VAP. The area under the curve was 0.813 ( p VAP.

Genome-Wide Association Study Identifies Single Nucleotide Polymorphism in DYRK1A Associated with Replication of HIV-1 in Monocyte-Derived Macrophages

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Bol, Sebastiaan M.; Moerland, Perry D.; Limou, Sophie; van Remmerden, Yvonne; Coulonges, Cédric; van Manen, Daniëlle; Herbeck, Joshua T.; Fellay, Jacques; Sieberer, Margit; Sietzema, Jantine G.; van 't Slot, Ruben; Martinson, Jeremy; Zagury, Jean-François; Schuitemaker, Hanneke; van 't Wout, Angélique B.

2011-01-01

Background HIV-1 infected macrophages play an important role in rendering resting T cells permissive for infection, in spreading HIV-1 to T cells, and in the pathogenesis of AIDS dementia. During highly active anti-retroviral treatment (HAART), macrophages keep producing virus because tissue penetration of antiretrovirals is suboptimal and the efficacy of some is reduced. Thus, to cure HIV-1 infection with antiretrovirals we will also need to efficiently inhibit viral replication in macrophages. The majority of the current drugs block the action of viral enzymes, whereas there is an abundance of yet unidentified host factors that could be targeted. We here present results from a genome-wide association study identifying novel genetic polymorphisms that affect in vitro HIV-1 replication in macrophages. Methodology/Principal Findings Monocyte-derived macrophages from 393 blood donors were infected with HIV-1 and viral replication was determined using Gag p24 antigen levels. Genomic DNA from individuals with macrophages that had relatively low (n = 96) or high (n = 96) p24 production was used for SNP genotyping with the Illumina 610 Quad beadchip. A total of 494,656 SNPs that passed quality control were tested for association with HIV-1 replication in macrophages, using linear regression. We found a strong association between in vitro HIV-1 replication in monocyte-derived macrophages and SNP rs12483205 in DYRK1A (p = 2.16×10−5). While the association was not genome-wide significant (p<1×10−7), we could replicate this association using monocyte-derived macrophages from an independent group of 31 individuals (p = 0.0034). Combined analysis of the initial and replication cohort increased the strength of the association (p = 4.84×10−6). In addition, we found this SNP to be associated with HIV-1 disease progression in vivo in two independent cohort studies (p = 0.035 and p = 0.0048). Conclusions/Significance These findings suggest that

CD16+ Monocytes and Skewed Macrophage Polarization toward M2 Type Hallmark Heart Transplant Acute Cellular Rejection.

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van den Bosch, Thierry P P; Caliskan, Kadir; Kraaij, Marina D; Constantinescu, Alina A; Manintveld, Olivier C; Leenen, Pieter J M; von der Thüsen, Jan H; Clahsen-van Groningen, Marian C; Baan, Carla C; Rowshani, Ajda T

2017-01-01

During acute heart transplant rejection, infiltration of lymphocytes and monocytes is followed by endothelial injury and eventually myocardial fibrosis. To date, no information is available on monocyte-macrophage-related cellular shifts and their polarization status during rejection. Here, we aimed to define and correlate monocyte-macrophage endomyocardial tissue profiles obtained at rejection and time points prior to rejection, with corresponding serial blood samples in 25 heart transplant recipients experiencing acute cellular rejection. Additionally, 33 healthy individuals served as control. Using histology, immunohistochemistry, confocal laser scan microscopy, and digital imaging expression of CD14, CD16, CD56, CD68, CD80, and CD163 were explored to define monocyte and macrophage tissue profiles during rejection. Fibrosis was investigated using Sirius Red stainings of rejection, non-rejection, and 1-year biopsies. Expression of co-stimulatory and migration-related molecules on circulating monocytes, and production potential for pro- and anti-inflammatory cytokines were studied using flow cytometry. At tissue level, striking CD16+ monocyte infiltration was observed during rejection ( p  rejection compared to barely present CD68+CD80+ M1 macrophages. Rejection was associated with severe fibrosis in 1-year biopsies ( p  rejection status, decreased frequencies of circulating CD16+ monocytes were found in patients compared to healthy individuals. Rejection was reflected by significantly increased CD54 and HLA-DR expression on CD16+ monocytes with retained cytokine production potential. CD16+ monocytes and M2 macrophages hallmark the correlates of heart transplant acute cellular rejection on tissue level and seem to be associated with fibrosis in the long term.

Nonclassical Ly6C− Monocytes Drive the Development of Inflammatory Arthritis in Mice

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Alexander V. Misharin

2014-10-01

Full Text Available Different subsets and/or polarized phenotypes of monocytes and macrophages may play distinct roles during the development and resolution of inflammation. Here, we demonstrate in a murine model of rheumatoid arthritis that nonclassical Ly6C− monocytes are required for the initiation and progression of sterile joint inflammation. Moreover, nonclassical Ly6C− monocytes differentiate into inflammatory macrophages (M1, which drive disease pathogenesis and display plasticity during the resolution phase. During the development of arthritis, these cells polarize toward an alternatively activated phenotype (M2, promoting the resolution of joint inflammation. The influx of Ly6C− monocytes and their subsequent classical and then alternative activation occurs without changes in synovial tissue-resident macrophages, which express markers of M2 polarization throughout the course of the arthritis and attenuate joint inflammation during the initiation phase. These data suggest that circulating Ly6C− monocytes recruited to the joint upon injury orchestrate the development and resolution of autoimmune joint inflammation.

Palmitate and insulin synergistically induce IL-6 expression in human monocytes

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Lumpkin Charles K

2010-11-01

Full Text Available Abstract Background Insulin resistance is associated with a proinflammatory state that promotes the development of complications such as type 2 diabetes mellitus (T2DM and atherosclerosis. The metabolic stimuli that initiate and propagate proinflammatory cytokine production and the cellular origin of proinflammatory cytokines in insulin resistance have not been fully elucidated. Circulating proinflammatory monocytes show signs of enhanced inflammation in obese, insulin resistant subjects and are thus a potential source of proinflammatory cytokine production. The specific, circulating metabolic factors that might stimulate monocyte inflammation in insulin resistant subjects are poorly characterized. We have examined whether saturated nonesterified fatty acids (NEFA and insulin, which increase in concentration with developing insulin resistance, can trigger the production of interleukin (IL-6 and tumor necrosis factor (TNF-α in human monocytes. Methods Messenger RNA and protein levels of the proinflammatory cytokines IL-6 and TNF-α were measured by quantitative real-time PCR (qRT-PCR and Luminex bioassays. Student's t-test was used with a significance level of p Results Esterification of palmitate with coenzyme A (CoA was necessary, while β-oxidation and ceramide biosynthesis were not required, for the induction of IL-6 and TNF-α in THP-1 monocytes. Monocytes incubated with insulin and palmitate together produced more IL-6 mRNA and protein, and more TNF-α protein, compared to monocytes incubated with palmitate alone. Incubation of monocytes with insulin alone did not affect the production of IL-6 or TNF-α. Both PI3K-Akt and MEK/ERK signalling pathways are important for cytokine induction by palmitate. MEK/ERK signalling is necessary for synergistic induction of IL-6 by palmitate and insulin. Conclusions High levels of saturated NEFA, such as palmitate, when combined with hyperinsulinemia, may activate human monocytes to produce

Monocyte enrichment from leukapheresis products by using the Elutra cell separator.

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Kim, Sinyoung; Kim, Hyun Ok; Baek, Eun-Jung; Choi, Youjeong; Kim, Han-Soo; Lee, Min-Geul

2007-12-01

Dendritic cells (DCs), used in clinical trials for cancer immunotherapy, require processing on an expanded scale to conform to current good manufacturing practice guidelines. This study evaluated a large-scale monocyte enrichment procedure with a commercially available cell separator (Elutra, Gambro BCT) and analyzed the capacity of enriched monocytes to differentiate into DCs. Mononuclear cells were collected in two patients with malignant melanoma and seven healthy donors by leukapheresis. Continuous-counterflow elutriation with the Elutra was performed to enrich and purify monocytes from leukapheresis products. Purity and recovery of enriched monocytes were analyzed by flow cytometry. DCs were generated from the elutriated monocytes and characterized by phenotypic surface marker and stimulatory capacity in an allogeneic mixed lymphocyte reaction. In the leukapheresis products, the total MNC count was 7.3 x 10(9) +/- 0.7 x 10(9) and the mean percentage of CD14+ monocytes was 16.5 +/- 3.8 percent, which increased to 68.9 +/- 7.4 percent after elutriation with the Elutra. The mean monocyte recovery was 94.3 percent. Elutriated monocytes were successfully cultured into phenotypically and functionally mature DCs. These results indicate that the Elutra cell separator allows for fast and easy enrichment of monocytes within a closed system. Furthermore, these monocytes can be differentiated into functionally mature DCs. Compared to plastic adherence and immunomagnetic selection methods, the elutriation procedure is inexpensive, efficient, and very effective.

Human monocytes undergo excessive apoptosis following temozolomide activating the ATM/ATR pathway while dendritic cells and macrophages are resistant.

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Martina Bauer

Full Text Available Immunodeficiency is a severe therapy-limiting side effect of anticancer chemotherapy resulting from sensitivity of immunocompetent cells to DNA damaging agents. A central role in the immune system is played by monocytes that differentiate into macrophages and dendritic cells (DCs. In this study we compared human monocytes isolated from peripheral blood and cytokine matured macrophages and DCs derived from them and assessed the mechanism of toxicity of the DNA methylating anticancer drug temozolomide (TMZ in these cell populations. We observed that monocytes, but not DCs and macrophages, were highly sensitive to the killing effect of TMZ. Studies on DNA damage and repair revealed that the initial DNA incision was efficient in monocytes while the re-ligation step of base excision repair (BER can not be accomplished, resulting in an accumulation of DNA single-strand breaks (SSBs. Furthermore, monocytes accumulated DNA double-strand breaks (DSBs following TMZ treatment, while DCs and macrophages were able to repair DSBs. Monocytes lack the DNA repair proteins XRCC1, ligase IIIα and PARP-1 whose expression is restored during differentiation into macrophages and DCs following treatment with GM-CSF and GM-CSF plus IL-4, respectively. These proteins play a key role both in BER and DSB repair by B-NHEJ, which explains the accumulation of DNA breaks in monocytes following TMZ treatment. Although TMZ provoked an upregulation of XRCC1 and ligase IIIα, BER was not enhanced likely because PARP-1 was not upregulated. Accordingly, inhibition of PARP-1 did not sensitize monocytes, but monocyte-derived DCs in which strong PARP activation was observed. TMZ induced in monocytes the DNA damage response pathways ATM-Chk2 and ATR-Chk1 resulting in p53 activation. Finally, upon activation of the Fas-receptor and the mitochondrial pathway apoptosis was executed in a caspase-dependent manner. The downregulation of DNA repair in monocytes, resulting in their selective

Elevated levels of peripheral blood CD14(bright) CD16+ and CD14(dim) CD16+ monocytes may contribute to the development of retinopathy in patients with juvenile onset type 1 diabetes.

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Ryba-Stanisławowska, Monika; Myśliwska, Jolanta; Juhas, Ulana; Myśliwiec, Małgorzata

2015-09-01

The study aimed to analyze the CD14(bright) CD16(+) and CD14(dim) CD16(+) monocyte subsets in juvenile-onset complication-free diabetes mellitus type 1 in the context of their association with microvascular complications. 61 children with type 1 diabetes and 30 healthy individuals were enrolled in a study. CD14(bright) CD16(+) and CD14(dim) CD16(+) monocytes were quantified in peripheral blood by means of flow cytometry. At the time of sampling blood glucose concentration was taken along with biochemical measurement of renal function, CRP and glycosylated hemoglobin. The Spearman's correlations were used to compare the relationship between CD16(+) monocyte subsets and the clinical parameters that can predict the development of microangiopathies. The flow cytometric analysis of monocyte subsets in peripheral blood of analyzed subjects revealed that the numbers of CD14(bright) CD16(+) and CD14(dim) CD16(+) monocytes were significantly higher in patients with type 1 diabetes than in the healthy individuals. As to the relationship between CD16(+) monocyte subsets and the clinical parameters that can predict development of microangiopathies, it was shown that both CD16(+) subsets were associated with increased risk of retinopathy development, defined as retinopathy development value. Elevated levels of intermediate CD14(bright) CD16(+) and non-classical CD14(dim) CD16(+) monocytes predict development of diabetic retinopathy in patients with type 1 diabetes. © 2015 APMIS. Published by John Wiley & Sons Ltd.

MONOCYTES AND MACROPHAGES IN PREGNANCY AND PREECLAMPSIA

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Marijke M Faas

2014-06-01

Full Text Available Preeclampsia is an important complication in pregnancy, characterized byhypertension and proteinuria in the second half of pregnancy. Generalizedactivation of the inflammatory response is thought to play a role in thepathogenesis of preeclampsia. Monocytes may play a central role in thisinflammatory response. Monocytes are short lived cells, that mature in thecirculation and invade into tissues upon an inflammatory stimulus anddevelop into macrophages. Macrophages are abundantly present in theendometrium and play a role in implantation and placentation in normalpregnancy. In preeclampsia, these macrophages appear to be present in largernumbers and are also activated. In the present review we focused on the roleof monocytes and macrophages in the pathophysiology of preeclampsia.

Extracellular Histones Increase Tissue Factor Activity and Enhance Thrombin Generation by Human Blood Monocytes.

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Gould, Travis J; Lysov, Zakhar; Swystun, Laura L; Dwivedi, Dhruva J; Zarychanski, Ryan; Fox-Robichaud, Alison E; Liaw, Patricia C

2016-12-01

Sepsis is characterized by systemic activation of inflammatory and coagulation pathways in response to infection. Recently, it was demonstrated that histones released into the circulation by dying/activated cells may contribute to sepsis pathology. Although the ability of extracellular histones to modulate the procoagulant activities of several cell types has been investigated, the influence of histones on the hemostatic functions of circulating monocytes is unknown. To address this, we investigated the ability of histones to modulate the procoagulant potential of THP-1 cells and peripheral blood monocytes, and examined the effects of plasmas obtained from septic patients to induce a procoagulant phenotype on monocytic cells. Tissue factor (TF) activity assays were performed on histone-treated THP-1 cells and blood monocytes. Exposure of monocytic cells to histones resulted in increases in TF activity, TF antigen, and phosphatidylserine exposure. Histones modulate the procoagulant activity via engagement of Toll-like receptors 2 and 4, and this effect was abrogated with inhibitory antibodies. Increased TF activity of histone-treated cells corresponded to enhanced thrombin generation in plasma determined by calibrated automated thrombography. Finally, TF activity was increased on monocytes exposed to plasma from septic patients, an effect that was attenuated in plasma from patients receiving unfractionated heparin (UFH). Our studies suggest that increased levels of extracellular histones found in sepsis contribute to dysregulated coagulation by increasing TF activity of monocytes. These procoagulant effects can be partially ameliorated in sepsis patients receiving UFH, thereby identifying extracellular histones as a potential therapeutic target for sepsis treatment.

Humanised IgG1 antibody variants targeting membrane-bound carcinoembryonic antigen by antibody-dependent cellular cytotoxicity and phagocytosis.

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Ashraf, S Q; Umana, P; Mössner, E; Ntouroupi, T; Brünker, P; Schmidt, C; Wilding, J L; Mortensen, N J; Bodmer, W F

2009-11-17

The effect of glycoengineering a membrane specific anti-carcinoembryonic antigen (CEA) (this paper uses the original term CEA for the formally designated CEACAM5) antibody (PR1A3) on its ability to enhance killing of colorectal cancer (CRC) cell lines by human immune effector cells was assessed. In vivo efficacy of the antibody was also tested. The antibody was modified using EBNA cells cotransfected with beta-1,4-N-acetylglucosaminyltransferase III and the humanised hPR1A3 antibody genes. The resulting alteration of the Fc segment glycosylation pattern enhances the antibody's binding affinity to the FcgammaRIIIa receptor on human immune effector cells but does not alter the antibody's binding capacity. Antibody-dependent cellular cytotoxicity (ADCC) is inhibited in the presence of anti-FcgammaRIII blocking antibodies. This glycovariant of hPR1A3 enhances ADCC 10-fold relative to the parent unmodified antibody using either unfractionated peripheral blood mononuclear or natural killer (NK) cells and CEA-positive CRC cells as targets. NK cells are far more potent in eliciting ADCC than either freshly isolated monocytes or granulocytes. Flow cytometry and automated fluorescent microscopy have been used to show that both versions of hPR1A3 can induce antibody-dependent cellular phagocytosis (ADCP) by monocyte-derived macrophages. However, the glycovariant antibody did not mediate enhanced ADCP. This may be explained by the relatively low expression of FcgammaRIIIa on cultured macrophages. In vivo studies show the efficacy of glycoengineered humanised IgG1 PR1A3 in significantly improving survival in a CRC metastatic murine model. The greatly enhanced in vitro ADCC activity of the glycoengineered version of hPR1A3 is likely to be clinically beneficial.

CD14CD16 Monocyte Subset Levels in Heart Failure Patients

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Chiara Barisione

2010-01-01

Full Text Available Our aim was to define the distribution of monocyte subsets in a cohort of congestive heart failure (CHF patients, to verify whether increased severity of CHF is linked to the expansion of specific monocyte subsets, and finally to investigate the relationship between monocyte subset relative frequencies, laboratory parameters of inflammation, and monocyte ACE expression.

Adropin Contributes to Anti-Atherosclerosis by Suppressing Monocyte-Endothelial Cell Adhesion and Smooth Muscle Cell Proliferation

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Kengo Sato

2018-04-01

Full Text Available Adropin, a peptide hormone expressed in liver and brain, is known to improve insulin resistance and endothelial dysfunction. Serum levels of adropin are negatively associated with the severity of coronary artery disease. However, it remains unknown whether adropin could modulate atherogenesis. We assessed the effects of adropin on inflammatory molecule expression and human THP1 monocyte adhesion in human umbilical vein endothelial cells (HUVECs, foam cell formation in THP1 monocyte-derived macrophages, and the migration and proliferation of human aortic smooth muscle cells (HASMCs in vitro and atherogenesis in Apoe−/− mice in vivo. Adropin was expressed in THP1 monocytes, their derived macrophages, HASMCs, and HUVECs. Adropin suppressed tumor necrosis factor α-induced THP1 monocyte adhesion to HUVECs, which was associated with vascular cell adhesion molecule 1 and intercellular adhesion molecule 1 downregulation in HUVECs. Adropin shifted the phenotype to anti-inflammatory M2 rather than pro-inflammatory M1 via peroxisome proliferator-activated receptor γ upregulation during monocyte differentiation into macrophages. Adropin had no significant effects on oxidized low-density lipoprotein-induced foam cell formation in macrophages. In HASMCs, adropin suppressed the migration and proliferation without inducing apoptosis via ERK1/2 and Bax downregulation and phosphoinositide 3-kinase/Akt/Bcl2 upregulation. Chronic administration of adropin to Apoe−/− mice attenuated the development of atherosclerotic lesions in the aorta, with reduced the intra-plaque monocyte/macrophage infiltration and smooth muscle cell content. Thus, adropin could serve as a novel therapeutic target in atherosclerosis and related diseases.

Molecular Mechanisms That Underlie the Dynamic Adaptation of Innate Monocyte Memory to Varying Stimulant Strength of TLR Ligands.

Science.gov (United States)

Yuan, Ruoxi; Geng, Shuo; Li, Liwu

2016-01-01

In adaptation to rising stimulant strength, innate monocytes can be dynamically programed to preferentially express either pro- or anti-inflammatory mediators. Such dynamic innate adaptation or programing may bear profound relevance in host health and disease. However, molecular mechanisms that govern innate adaptation to varying strength of stimulants are not well understood. Using lipopolysaccharide (LPS), the model stimulant of toll-like-receptor 4 (TLR4), we reported that the expressions of pro-inflammatory mediators are preferentially sustained in monocytes adapted by lower doses of LPS, and suppressed/tolerized in monocytes adapted by higher doses of LPS. Mechanistically, monocytes adapted by super-low dose LPS exhibited higher levels of transcription factor, interferon regulatory factor 5 (IRF5), and reduced levels of transcriptional modulator B lymphocyte-induced maturation protein-1 (Blimp-1). Intriguingly, the inflammatory monocyte adaptation by super-low dose LPS is dependent upon TRAM/TRIF but not MyD88. Similar to LPS, we also observed biphasic inflammatory adaptation and tolerance in monocytes challenged with varying dosages of TLR7 agonist. In sharp contrast, rising doses of TLR3 agonist preferentially caused inflammatory adaptation without inducing tolerance. At the molecular level, the differential regulation of IRF5 and Blimp-1 coincides with unique monocyte adaptation dynamics by TLR4/7 and TLR3 agonists. Our study provides novel clue toward the understanding of monocyte adaptation and memory toward distinct TLR ligands.

Estradiol coupling to human monocyte nitric oxide release is dependent on intracellular calcium transients: evidence for an estrogen surface receptor.

Science.gov (United States)

Stefano, G B; Prevot, V; Beauvillain, J C; Fimiani, C; Welters, I; Cadet, P; Breton, C; Pestel, J; Salzet, M; Bilfinger, T V

1999-10-01

We tested the hypothesis that estrogen acutely stimulates constitutive NO synthase (cNOS) activity in human peripheral monocytes by acting on an estrogen surface receptor. NO release was measured in real time with an amperometric probe. 17beta-estradiol exposure to monocytes stimulated NO release within seconds in a concentration-dependent manner, whereas 17alpha-estradiol had no effect. 17beta-estradiol conjugated to BSA (E2-BSA) also stimulated NO release, suggesting mediation by a membrane surface receptor. Tamoxifen, an estrogen receptor inhibitor, antagonized the action of both 17beta-estradiol and E2-BSA, whereas ICI 182,780, a selective inhibitor of the nuclear estrogen receptor, had no effect. We further showed, using a dual emission microfluorometry in a calcium-free medium, that the 17beta-estradiol-stimulated release of monocyte NO was dependent on the initial stimulation of intracellular calcium transients in a tamoxifen-sensitive process. Leeching out the intracellular calcium stores abolished the effect of 17beta-estradiol on NO release. RT-PCR analysis of RNA obtained from the cells revealed a strong estrogen receptor-alpha amplification signal and a weak beta signal. Taken together, a physiological dose of estrogen acutely stimulates NO release from human monocytes via the activation of an estrogen surface receptor that is coupled to increases in intracellular calcium.

Urine Epidermal Growth Factor, Monocyte Chemoattractant Protein-1 or Their Ratio as Biomarkers for Interstitial Fibrosis and Tubular Atrophy in Primary Glomerulonephritis

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Supanat Worawichawong

2016-12-01

Full Text Available Background/Aims: The degree of tubular atrophy and interstitial fibrosis (IFTA is an important prognostic factor in glomerulonephritis. Imbalance between pro-inflammatory cytokines such as monocyte chemoattractant protein- 1 (MCP-1 and protective cytokines such as epidermal growth factor (EGF likely determine IFTA severity. In separate studies, elevated MCP-1 and decreased EGF have been shown to be associated with IFTA severity. In this study, we aim to evaluate the predictive value of urinary EGF/MCP-1 ratio compared to each biomarker individually for moderate to severe IFTA in primary glomerulonephritis (GN. Methods: Urine samples were collected at biopsy from primary GN (IgA nephropathy, focal and segmental glomerulosclerosis, minimal change disease, membranous nephropathy. MCP-1 and EGF were analyzed by enzyme-linked immunosorbent assay. Results: EGF, MCP-1 and EGF/MCP-1 ratio from primary GN, all correlated with IFTA (n=58. By univariate analysis, glomerular filtration rate, EGF, and EGF/MCP-1 ratio were associated with IFTA. By multivariate analysis, only EGF/MCP-1 ratio was independently associated with IFTA. EGF/MCP-1 ratio had a sensitivity of 88% and specificity of 74 % for IFTA. EGF/MCP-1 had good discrimination for IFTA (AUC=0.85, but the improvement over EGF alone was not significant. Conclusion: EGF/MCP-1 ratio is independently associated IFTA severity in primary glomerulonephritis, but the ability of EGF/MCP-1 ratio to discriminate moderate to severe IFTA may not be much better than EGF alone.

Differential induction from X-irradiated human peripheral blood monocytes to dendritic cells

International Nuclear Information System (INIS)

Yoshino, Hironori; Takahashi, Kenji; Monzen, Satoru; Kashiwakura, Ikuo

2008-01-01

Dendritic cells (DCs) are a type of antigen-presenting cell which plays an essential role in the immune system. To clarify the influences of ionizing radiation on the differentiation to DCs, we focused on human peripheral blood monocytes and investigated whether X-irradiated monocytes can differentiate into DCs. The non-irradiated monocytes and 5 Gy-irradiated monocytes were induced into immature DCs (iDCs) and mature DCs (mDCs) with appropriate cytokine stimulation, and the induced cells from each monocyte expressed each DC-expressing surface antigen such as CD40, CD86 and HLA-DR. However, the expression levels of CD40 and CD86 on the iDCs derived from the 5 Gy-irradiated monocytes were higher than those of iDCs derived from non-irradiated monocytes. Furthermore, the mDCs derived from 5 Gy-irradiated monocytes had significantly less ability to stimulate allogeneic T cells in comparison to the mDCs derived from non-irradiated monocytes. There were no significant differences in the phagocytotic activity of the iDCs and cytokines detected in the supernatants conditioned by the DCs from the non-irradiated and irradiated monocytes. These results suggest that human monocytes which are exposed to ionizing radiation can thus differentiate into DCs, but there is a tendency that X-irradiation leads to an impairment of the function of DCs. (author)

CD14(hi)CD16+ monocytes phagocytose antibody-opsonised Plasmodium falciparum infected erythrocytes more efficiently than other monocyte subsets, and require CD16 and complement to do so.

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Zhou, Jingling; Feng, Gaoqian; Beeson, James; Hogarth, P Mark; Rogerson, Stephen J; Yan, Yan; Jaworowski, Anthony

2015-07-07

With more than 600,000 deaths from malaria, mainly of children under five years old and caused by infection with Plasmodium falciparum, comes an urgent need for an effective anti-malaria vaccine. Limited details on the mechanisms of protective immunity are a barrier to vaccine development. Antibodies play an important role in immunity to malaria and monocytes are key effectors in antibody-mediated protection by phagocytosing antibody-opsonised infected erythrocytes (IE). Eliciting antibodies that enhance phagocytosis of IE is therefore an important potential component of an effective vaccine, requiring robust assays to determine the ability of elicited antibodies to stimulate this in vivo. The mechanisms by which monocytes ingest IE and the nature of the monocytes which do so are unknown. Purified trophozoite-stage P. falciparum IE were stained with ethidium bromide, opsonised with anti-erythrocyte antibodies and incubated with fresh whole blood. Phagocytosis of IE and TNF production by individual monocyte subsets was measured by flow cytometry. Ingestion of IE was confirmed by imaging flow cytometry. CD14(hi)CD16+ monocytes phagocytosed antibody-opsonised IE and produced TNF more efficiently than CD14(hi)CD16- and CD14(lo)CD16+ monocytes. Blocking experiments showed that Fcγ receptor IIIa (CD16) but not Fcγ receptor IIa (CD32a) or Fcγ receptor I (CD64) was necessary for phagocytosis. CD14(hi)CD16+ monocytes ingested antibody-opsonised IE when peripheral blood mononuclear cells were reconstituted with autologous serum but not heat-inactivated autologous serum. Antibody-opsonised IE were rapidly opsonised with complement component C3 in serum (t1/2 = 2-3 minutes) and phagocytosis of antibody-opsonised IE was inhibited in a dose-dependent manner by an inhibitor of C3 activation, compstatin. Compared to other monocyte subsets, CD14(hi)CD16+ monocytes expressed the highest levels of complement receptor 4 (CD11c) and activated complement receptor 3 (CD11b) subunits

Inhibition of the differentiation of monocyte-derived dendritic cells by human gingival fibroblasts.

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Sylvie Séguier

Full Text Available We investigated whether gingival fibroblasts (GFs can modulate the differentiation and/or maturation of monocyte-derived dendritic cells (DCs and analyzed soluble factors that may be involved in this immune modulation. Experiments were performed using human monocytes in co-culture with human GFs in Transwell® chambers or using monocyte cultures treated with conditioned media (CM from GFs of four donors. The four CM and supernatants from cell culture were assayed by ELISA for cytokines involved in the differentiation of dendritic cells, such as IL-6, VEGF, TGFβ1, IL-13 and IL-10. The maturation of monocyte-derived DCs induced by LPS in presence of CM was also studied. Cell surface phenotype markers were analyzed by flow cytometry. In co-cultures, GFs inhibited the differentiation of monocyte-derived DCs and the strength of this blockade correlated with the GF/monocyte ratio. Conditioned media from GFs showed similar effects, suggesting the involvement of soluble factors produced by GFs. This inhibition was associated with a lower stimulatory activity in MLR of DCs generated with GFs or its CM. Neutralizing antibodies against IL-6 and VEGF significantly (P<0.05 inhibited the inhibitory effect of CM on the differentiation of monocytes-derived DCs and in a dose dependent manner. Our data suggest that IL-6 is the main factor responsible for the inhibition of DCs differentiation mediated by GFs but that VEGF is also involved and constitutes an additional mechanism.

Development of pro-inflammatory phenotype in monocytes after engulfing Hb-activated platelets in hemolytic disorders.

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Singhal, Rashi; Chawla, Sheetal; Rathore, Deepak K; Bhasym, Angika; Annarapu, Gowtham K; Sharma, Vandana; Seth, Tulika; Guchhait, Prasenjit

2017-02-01

Monocytes and macrophage combat infections and maintain homeostatic balance by engulfing microbes and apoptotic cells, and releasing inflammatory cytokines. Studies have described that these cells develop anti-inflammatory properties upon recycling the free-hemoglobin (Hb) in hemolytic conditions. While investigating the phenotype of monocytes in two hemolytic disorders-paroxysmal nocturnal hemoglobinuria (PNH) and sickle cell disease (SCD), we observed a high number of pro-inflammatory (CD14 + CD16 hi ) monocytes in these patients. We further investigated in vitro the phenotype of these monocytes and found an estimated 55% of CD14 + cells were transformed into the CD14 + CD16 hi subset after engulfing Hb-activated platelets. The CD14 + CD16 hi monocytes, which were positive for both intracellular Hb and CD42b (platelet marker), secreted significant amounts of TNF-α and IL-1β, unlike monocytes treated with only free Hb, which secreted more IL-10. We have shown recently the presence of a high number of Hb-bound hyperactive platelets in patients with both diseases, and further investigated if the monocytes engulfed these activated platelets in vivo. As expected, we found 95% of CD14 + CD16 hi monocytes with both intracellular Hb and CD42b in both diseases, and they expressed high TNF-α. Furthermore our data showed that these monocytes whether from patients or developed in vitro after treatment with Hb-activated platelets, secreted significant amounts of tissue factor. Besides, these CD14 + CD16 hi monocytes displayed significantly decreased phagocytosis of E. coli. Our study therefore suggests that this alteration of monocyte phenotype may play a role in the increased propensity to pro-inflammatory/coagulant complications observed in these hemolytic disorders-PNH and SCD. Copyright © 2016 Elsevier Inc. All rights reserved.

PU.1 is essential for CD11c expression in CD8(+/CD8(- lymphoid and monocyte-derived dendritic cells during GM-CSF or FLT3L-induced differentiation.

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Xue-Jun Zhu

Full Text Available Dendritic cells (DCs regulate innate and acquired immunity through their roles as antigen-presenting cells. Specific subsets of mature DCs, including monocyte-derived and lymphoid-derived DCs, can be distinguished based on distinct immunophenotypes and functional properties. The leukocyte integrin, CD11c, is considered a specific marker for DCs and it is expressed by all DC subsets. We created a strain of mice in which DCs and their progenitors could be lineage traced based on activity of the CD11c proximal promoter. Surprisingly, we observed levels of CD11c promoter activity that were similar in DCs and in other mature leukocytes, including monocytes, granulocytes, and lymphocytes. We sought to identify DNA elements and transcription factors that regulate DC-associated expression of CD11c. The ets transcription factor, PU.1, is a key regulator of DC development, and expression of PU.1 varies in different DC subsets. GM-CSF increased monocyte-derived DCs in mice and from mouse bone marrow cultured in vitro, but it did not increase CD8(+ lymphoid-derived DCs or B220(+ plasmacytoid DCs. FLT3L increased both monocyte-derived DCs and lymphoid-derived DCs from mouse bone marrow cultured in vitro. GM-CSF increased the 5.3 Kb CD11c proximal promoter activity in monocyte-derived DCs and CD8(+ lymphoid-derived DCs, but not in B220(+ plasmacytoid DCs. In contrast, FLT3L increased the CD11c proximal promoter activity in both monocyte-derived DCs and B220(+ plasmacytoid DCs. We used shRNA gene knockdown and chromatin immunoprecipitation to demonstrate that PU.1 is required for the effects of GM-CSF or FLT3L on monocyte-derived DCs. We conclude that both GM-CSF and FLT3L act through PU.1 to activate the 5.3 Kb CD11c proximal promoter in DCs and to induce differentiation of monocyte-derived DCs. We also confirm that the CD11c proximal promoter is not sufficient to direct lineage specificity of CD11c expression, and that additional DNA elements are required

Lactic acid delays the inflammatory response of human monocytes

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Peter, Katrin, E-mail: katrin.peter@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); Rehli, Michael, E-mail: michael.rehli@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); RCI Regensburg Center for Interventional Immunology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); Singer, Katrin, E-mail: katrin.singer@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); Renner-Sattler, Kathrin, E-mail: kathrin.renner-sattler@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); Kreutz, Marina, E-mail: marina.kreutz@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); RCI Regensburg Center for Interventional Immunology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany)

2015-02-13

Lactic acid (LA) accumulates under inflammatory conditions, e.g. in wounds or tumors, and influences local immune cell functions. We previously noted inhibitory effects of LA on glycolysis and TNF secretion of human LPS-stimulated monocytes. Here, we globally analyze the influence of LA on gene expression during monocyte activation. To separate LA-specific from lactate- or pH-effects, monocytes were treated for one or four hours with LPS in the presence of physiological concentrations of LA, sodium lactate (NaL) or acidic pH. Analyses of global gene expression profiles revealed striking effects of LA during the early stimulation phase. Up-regulation of most LPS-induced genes was significantly delayed in the presence of LA, while this inhibitory effect was attenuated in acidified samples and not detected after incubation with NaL. LA targets included genes encoding for important monocyte effector proteins like cytokines (e.g. TNF and IL-23) or chemokines (e.g. CCL2 and CCL7). LA effects were validated for several targets by quantitative RT-PCR and/or ELISA. Further analysis of LPS-signaling pathways revealed that LA delayed the phosphorylation of protein kinase B (AKT) as well as the degradation of IκBα. Consistently, the LPS-induced nuclear accumulation of NFκB was also diminished in response to LA. These results indicate that the broad effect of LA on gene expression and function of human monocytes is at least partially caused by its interference with immediate signal transduction events after activation. This mechanism might contribute to monocyte suppression in the tumor environment. - Highlights: • Lactic acid broadly delays LPS-induced gene expression in human monocytes. • Expression of important monocyte effector molecules is affected by lactic acid. • Interference of lactic acid with TLR signaling causes the delayed gene expression. • The profound effect of lactic acid might contribute to immune suppression in tumors.

Lactic acid delays the inflammatory response of human monocytes

International Nuclear Information System (INIS)

Peter, Katrin; Rehli, Michael; Singer, Katrin; Renner-Sattler, Kathrin; Kreutz, Marina

2015-01-01

Lactic acid (LA) accumulates under inflammatory conditions, e.g. in wounds or tumors, and influences local immune cell functions. We previously noted inhibitory effects of LA on glycolysis and TNF secretion of human LPS-stimulated monocytes. Here, we globally analyze the influence of LA on gene expression during monocyte activation. To separate LA-specific from lactate- or pH-effects, monocytes were treated for one or four hours with LPS in the presence of physiological concentrations of LA, sodium lactate (NaL) or acidic pH. Analyses of global gene expression profiles revealed striking effects of LA during the early stimulation phase. Up-regulation of most LPS-induced genes was significantly delayed in the presence of LA, while this inhibitory effect was attenuated in acidified samples and not detected after incubation with NaL. LA targets included genes encoding for important monocyte effector proteins like cytokines (e.g. TNF and IL-23) or chemokines (e.g. CCL2 and CCL7). LA effects were validated for several targets by quantitative RT-PCR and/or ELISA. Further analysis of LPS-signaling pathways revealed that LA delayed the phosphorylation of protein kinase B (AKT) as well as the degradation of IκBα. Consistently, the LPS-induced nuclear accumulation of NFκB was also diminished in response to LA. These results indicate that the broad effect of LA on gene expression and function of human monocytes is at least partially caused by its interference with immediate signal transduction events after activation. This mechanism might contribute to monocyte suppression in the tumor environment. - Highlights: • Lactic acid broadly delays LPS-induced gene expression in human monocytes. • Expression of important monocyte effector molecules is affected by lactic acid. • Interference of lactic acid with TLR signaling causes the delayed gene expression. • The profound effect of lactic acid might contribute to immune suppression in tumors

Deciphering the transcriptional circuitry of microRNA genes expressed during human monocytic differentiation

KAUST Repository

Schmeier, Sebastian; MacPherson, Cameron R; Essack, Magbubah; Kaur, Mandeep; Schaefer, Ulf; Suzuki, Harukazu; Hayashizaki, Yoshihide; Bajic, Vladimir B.

2009-01-01

Background: Macrophages are immune cells involved in various biological processes including host defence, homeostasis, differentiation, and organogenesis. Disruption of macrophage biology has been linked to increased pathogen infection, inflammation and malignant diseases. Differential gene expression observed in monocytic differentiation is primarily regulated by interacting transcription factors (TFs). Current research suggests that microRNAs (miRNAs) degrade and repress translation of mRNA, but also may target genes involved in differentiation. We focus on getting insights into the transcriptional circuitry regulating miRNA genes expressed during monocytic differentiation. Results: We computationally analysed the transcriptional circuitry of miRNA genes during monocytic differentiation using in vitro time-course expression data for TFs and miRNAs. A set of TF?miRNA associations was derived from predicted TF binding sites in promoter regions of miRNA genes. Time-lagged expression correlation analysis was utilised to evaluate the TF?miRNA associations. Our analysis identified 12 TFs that potentially play a central role in regulating miRNAs throughout the differentiation process. Six of these 12 TFs (ATF2, E2F3, HOXA4, NFE2L1, SP3, and YY1) have not previously been described to be important for monocytic differentiation. The remaining six TFs are CEBPB, CREB1, ELK1, NFE2L2, RUNX1, and USF2. For several miRNAs (miR-21, miR-155, miR-424, and miR-17-92), we show how their inferred transcriptional regulation impacts monocytic differentiation. Conclusions: The study demonstrates that miRNAs and their transcriptional regulatory control are integral molecular mechanisms during differentiation. Furthermore, it is the first study to decipher on a large-scale, how miRNAs are controlled by TFs during human monocytic differentiation. Subsequently, we have identified 12 candidate key controllers of miRNAs during this differentiation process. 2009 Schmeier et al; licensee Bio

Deciphering the transcriptional circuitry of microRNA genes expressed during human monocytic differentiation

KAUST Repository

Schmeier, Sebastian

2009-12-10

Background: Macrophages are immune cells involved in various biological processes including host defence, homeostasis, differentiation, and organogenesis. Disruption of macrophage biology has been linked to increased pathogen infection, inflammation and malignant diseases. Differential gene expression observed in monocytic differentiation is primarily regulated by interacting transcription factors (TFs). Current research suggests that microRNAs (miRNAs) degrade and repress translation of mRNA, but also may target genes involved in differentiation. We focus on getting insights into the transcriptional circuitry regulating miRNA genes expressed during monocytic differentiation. Results: We computationally analysed the transcriptional circuitry of miRNA genes during monocytic differentiation using in vitro time-course expression data for TFs and miRNAs. A set of TF?miRNA associations was derived from predicted TF binding sites in promoter regions of miRNA genes. Time-lagged expression correlation analysis was utilised to evaluate the TF?miRNA associations. Our analysis identified 12 TFs that potentially play a central role in regulating miRNAs throughout the differentiation process. Six of these 12 TFs (ATF2, E2F3, HOXA4, NFE2L1, SP3, and YY1) have not previously been described to be important for monocytic differentiation. The remaining six TFs are CEBPB, CREB1, ELK1, NFE2L2, RUNX1, and USF2. For several miRNAs (miR-21, miR-155, miR-424, and miR-17-92), we show how their inferred transcriptional regulation impacts monocytic differentiation. Conclusions: The study demonstrates that miRNAs and their transcriptional regulatory control are integral molecular mechanisms during differentiation. Furthermore, it is the first study to decipher on a large-scale, how miRNAs are controlled by TFs during human monocytic differentiation. Subsequently, we have identified 12 candidate key controllers of miRNAs during this differentiation process. 2009 Schmeier et al; licensee Bio

Activation of farnesoid X receptor downregulates monocyte chemoattractant protein-1 in murine macrophage

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Li, Liangpeng; Zhang, Qian; Peng, Jiahe; Jiang, Chanjui; Zhang, Yan; Shen, Lili; Dong, Jinyu; Wang, Yongchao; Jiang, Yu, E-mail: yujiang0207@163.com

2015-11-27

Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily, which plays important roles in bile acids/lipid homeostasis and inflammation. Monocyte chemoattractant protein-1 (MCP-1) contributes to macrophage infiltration into body tissues during inflammation. Here we investigated whether FXR can regulate MCP-1 expression in murine macrophage. FXR activation down regulate MCP-1 mRNA and protein levels in ANA-1 and Raw264.7 cells. Luciferase reporter assay, Gel shift and Chromatin immunoprecipitation assays have revealed that the activated FXR bind to the FXR element located in −738 bp ∼  −723 bp in MCP-1 promoter. These results suggested that FXR may serve as a novel target for regulating MCP-1 levels for the inflammation related diseases therapies. - Highlights: • FXR is expressed in murine macrophage cell line. • FXR down regulates MCP-1 expression. • FXR binds to the DR4 in MCP-1 promoter.

Phenotypic and functional modulation of porcine monocyte-derived ...

African Journals Online (AJOL)

Jane

2011-08-08

Aug 8, 2011 ... monocyte-derived dendritic cells for foot-and-mouth disease virus. Hai-yan Shen1# ... tissues, to migrate to secondary lymphoid organs and to provide the ... innate and adaptive immune responses mentioned earlier led us to ...

Whole blood flow cytometric analysis of Ureaplasma-stimulated monocytes from pregnant women.

Science.gov (United States)

Friedland, Yael D; Lee-Pullen, Tracey F; Nathan, Elizabeth; Watts, Rory; Keelan, Jeffrey A; Payne, Matthew S; Ireland, Demelza J

2015-06-01

We hypothesised that circulating monocytes of women with vaginal colonisation with Ureaplasma spp., genital microorganisms known to cause inflammation-driven preterm birth, would elicit a tolerised cytokine response to subsequent in vitro Ureaplasma parvum serovar 3 (UpSV3) stimulation. Using multi-parameter flow cytometry, we found no differences with regard to maternal colonisation status in the frequency of TNF-α-, IL-6-, IL-8- and IL-1β-expressing monocytes in response to subsequent UpSV3 stimulation (P > 0.10 for all cytokines). We conclude that vaginal Ureaplasma spp. colonisation does not specifically tolerise monocytes of pregnant women towards decreased responses to subsequent stimulation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Effects of transforming growth factor-beta on long-term human cord blood monocyte cultures

International Nuclear Information System (INIS)

Orcel, P.; Bielakoff, J.; De Vernejoul, M.C.

1990-01-01

Transforming growth factor-beta (TGF-beta) modulates growth and differentiation in many cell types and is abundant in bone matrix. We recently showed that human cord blood monocytes cultured in the presence of 1,25(OH)2D3 acquire some features of osteoclast precursors. Since TGF-beta has been shown to influence bone resorption in organ culture, we have studied the effect of TGF-beta (1-1,000 pg/ml) on cord blood monocyte cultures. These cells were cultured on plastic substrate during 3 weeks in the presence of 20% horse serum and 10(-9) M 1,25(OH)2D3. TGF-beta, from a concentration of 10 pg/ml in the culture medium, decreased in a dose dependent manner the formation of multinucleated cells. At a concentration of TGF-beta of 1 ng/ml, the multinucleated cells were reduced to 2.1% +/- 0.3%, compared to 19.3% +/- 1.5% in control cultures. TGF-beta inhibited in a dose-dependent manner the proliferation of cord blood monocytes as assessed by 3H-thymidine incorporation at 7 and 14 days of culture. The fusion index was also decreased by 3 weeks of treatment with TGF-beta. Indomethacin did not reverse the inhibitory effects of TGF-beta. The expression of the osteoclastic phenotype was assessed using two different antibodies: 23C6, a monoclonal antibody directed against the vitronectin receptor, which is highly expressed by osteoclasts but not by adult monocytes, and an antibody to HLA-DR, which is not present on osteoclast. TGF-beta decreased the expression of HLA-DR and increased in a dose-dependent manner the proportion of 23C6-labeled cells; these results suggest that TGF-beta could modulate a differentiation effect to the osteoclastic phenotype. However, when cord blood monocytes were cultured on devitalized rat calvariae prelabeled with 45Ca, TGF-beta did not induce any 45Ca release from bone cultured with monocytes

Membrane compartment of Can1 (MCC): specialized functional microdomain of the yeast plasma membrane

OpenAIRE

Doudová, Lenka

2017-01-01

Membrane compartment of Can1 (MCC): specialized functional microdomain of the yeast plasma membrane Yeast plasma membrane is divided into several different compartments. Membrane compartment of Can1 is specific for its protein and lipid composition, furthermore it creates furrow-like invaginations on the plasma membrane. These invaginations are made by multiprotein complexes called eisosomes, which are located in the cytosolic side of MCCs. It was established that this domain plays an importa...

Specific Depletion of Ly6Chi Inflammatory Monocytes Prevents Immunopathology in Experimental Cerebral Malaria

Science.gov (United States)

Kuepper, Janina M.; Biswas, Aindrila; Djie-Maletz, Andrea; Limmer, Andreas; van Rooijen, Nico; Mack, Matthias; Hoerauf, Achim; Dunay, Ildiko Rita

2015-01-01

Plasmodium berghei ANKA (PbA) infection of C57BL/6 mice leads to experimental cerebral malaria (ECM) that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb), we depleted in vivo Ly6Chi inflammatory monocytes (by anti-CCR2), Ly6G+ neutrophils (by anti-Ly6G) or both cell types (by anti-Gr1) during infection with Ovalbumin-transgenic PbA parasites (PbTg). Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6Chi inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6Chi inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes. PMID:25884830

Functional role of CD11c+ monocytes in atherogenesis associated with hypercholesterolemia

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Monocyte activation and migration into the arterial wall are key events in atherogenesis associated with hypercholesterolemia. CD11c/CD18, a beta2 integrin expressed on human monocytes and a subset of mouse monocytes, has been shown to play a distinct role in human monocyte adhesion on endothelial c...

HCMV Reprogramming of Infected Monocyte Survival and Differentiation: A Goldilocks Phenomenon

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Emily V. Stevenson

2014-02-01

Full Text Available The wide range of disease pathologies seen in multiple organ sites associated with human cytomegalovirus (HCMV infection results from the systemic hematogenous dissemination of the virus, which is mediated predominately by infected monocytes. In addition to their role in viral spread, infected monocytes are also known to play a key role in viral latency and life-long persistence. However, in order to utilize infected monocytes for viral spread and persistence, HCMV must overcome a number of monocyte biological hurdles, including their naturally short lifespan and their inability to support viral gene expression and replication. Our laboratory has shown that HCMV is able to manipulate the biology of infected monocytes in order to overcome these biological hurdles by inducing the survival and differentiation of infected monocytes into long-lived macrophages capable of supporting viral gene expression and replication. In this current review, we describe the unique aspects of how HCMV promotes monocyte survival and differentiation by inducing a “finely-tuned” macrophage cell type following infection. Specifically, we describe the induction of a uniquely polarized macrophage subset from infected monocytes, which we argue is the ideal cellular environment for the initiation of viral gene expression and replication and, ultimately, viral spread and persistence within the infected host.

The role of TREM2 R47H as a risk factor for Alzheimer's disease, frontotemporal lobar degeneration, amyotrophic lateral sclerosis, and Parkinson's disease

DEFF Research Database (Denmark)

Lill, Christina M; Rengmark, Aina; Pihlstrøm, Lasse

2015-01-01

A rare variant in TREM2 (p.R47H, rs75932628) was recently reported to increase the risk of Alzheimer's disease (AD) and, subsequently, other neurodegenerative diseases, i.e. frontotemporal lobar degeneration (FTLD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). Here we......) and total-tau protein levels in the cerebrospinal fluid (CSF) of 828 individuals with AD or mild cognitive impairment. Our data show that rs75932628 is highly significantly associated with the risk of AD across 24,086 AD cases and 148,993 controls of European descent (odds ratio or OR = 2.71, P = 4.67 × 10......(-25)). No consistent evidence for association was found between this marker and the risk of FTLD (OR = 2.24, P = .0113 across 2673 cases/9283 controls), PD (OR = 1.36, P = .0767 across 8311 cases/79,938 controls) and ALS (OR = 1.41, P = .198 across 5544 cases/7072 controls). Furthermore, carriers of the rs75932628...

IL-2 induction of IL-1 beta mRNA expression in monocytes. Regulation by agents that block second messenger pathways

DEFF Research Database (Denmark)

Kovacs, E J; Brock, B; Varesio, L

1989-01-01

We have previously shown that in mixed cultures of PBL incubation with human rIL-2 induces the rapid expression of IL-1 alpha and IL-1 beta mRNA. Because studies have demonstrated that IL-2R can be expressed on the surface of human peripheral blood monocytes, we chose to investigate whether IL-1 ...

Maturation and demise of human primary monocytes by carbon nanotubes

Science.gov (United States)

De Nicola, Milena; Mirabile Gattia, Daniele; Traversa, Enrico; Ghibelli, Lina

2013-06-01

The possibility of exploiting carbon nanotubes (CNT) in biomedical practices requires thorough analysis of the chemical or bulk effects they may exert on the immune system, the complex network that recognizes and eliminates foreign particles. In particular, the phagocytosing ability of cells belonging to the monocyte/macrophage lineage may render these immune cells an ideal toxicological target of pristine CNT, which may form aggregates of size exceeding monocyte/macrophage phagocytosing plasticity. To shed light on this issue, we analyzed the effects that pristine multi-walled CNT (MWCNT) without metal or biological impurities exert on survival and activation of freshly explanted human peripheral blood monocytes, analyzing in parallel the non-phagocytosing lymphocytes, and using graphite as control carbon material. MWCNT (diameter 10-50 nm, length up to 10 μm) exert two different toxic effects on mononuclear leukocytes: a minor apoptogenic effect (on lymphocytes > monocytes), and a major, apoptosis-independent effect that exclusively and deeply affect monocyte homeostasis. Analysis of monocyte number, adhesion, redox equilibrium, and the differentiation markers CD14 and CD11b reveals that MWCNT cause the selective disappearance of phagocytosis-competent monocytes by mechanisms related to the presence of large nanoparticle aggregates, suggesting phenomena of bulk toxicity possibly consisting of frustrated phagocytosis. At the same time, MWCNT stimulate adhesion of the phagocytosis-incompetent monocytes, and their differentiation toward a peculiar maturation asset. These observations point out novel mechanisms of CNT toxicity, renewing concerns that they may impair the innate immune system deranging the inflammatory responses.

Maturation and demise of human primary monocytes by carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

De Nicola, Milena, E-mail: milena.de.nicola@uniroma2.it [University of Rome ' Tor Vergata' , Department of Biology (Italy); Mirabile Gattia, Daniele, E-mail: daniele.mirabile@enea.it [UTTMAT, ENEA-C.R. Casaccia (Italy); Traversa, Enrico, E-mail: Enrico.Traversa@kaust.edu.sa [King Abdullah University of Science and Technology (KAUST), Division of Physical Science and Engineering (Saudi Arabia); Ghibelli, Lina, E-mail: ghibelli@uniroma2.it [University of Rome ' Tor Vergata' , Department of Biology (Italy)

2013-06-15

The possibility of exploiting carbon nanotubes (CNT) in biomedical practices requires thorough analysis of the chemical or bulk effects they may exert on the immune system, the complex network that recognizes and eliminates foreign particles. In particular, the phagocytosing ability of cells belonging to the monocyte/macrophage lineage may render these immune cells an ideal toxicological target of pristine CNT, which may form aggregates of size exceeding monocyte/macrophage phagocytosing plasticity. To shed light on this issue, we analyzed the effects that pristine multi-walled CNT (MWCNT) without metal or biological impurities exert on survival and activation of freshly explanted human peripheral blood monocytes, analyzing in parallel the non-phagocytosing lymphocytes, and using graphite as control carbon material. MWCNT (diameter 10-50 nm, length up to 10 {mu}m) exert two different toxic effects on mononuclear leukocytes: a minor apoptogenic effect (on lymphocytes > monocytes), and a major, apoptosis-independent effect that exclusively and deeply affect monocyte homeostasis. Analysis of monocyte number, adhesion, redox equilibrium, and the differentiation markers CD14 and CD11b reveals that MWCNT cause the selective disappearance of phagocytosis-competent monocytes by mechanisms related to the presence of large nanoparticle aggregates, suggesting phenomena of bulk toxicity possibly consisting of frustrated phagocytosis. At the same time, MWCNT stimulate adhesion of the phagocytosis-incompetent monocytes, and their differentiation toward a peculiar maturation asset. These observations point out novel mechanisms of CNT toxicity, renewing concerns that they may impair the innate immune system deranging the inflammatory responses.

Maturation and demise of human primary monocytes by carbon nanotubes

International Nuclear Information System (INIS)

De Nicola, Milena; Mirabile Gattia, Daniele; Traversa, Enrico; Ghibelli, Lina

2013-01-01

The possibility of exploiting carbon nanotubes (CNT) in biomedical practices requires thorough analysis of the chemical or bulk effects they may exert on the immune system, the complex network that recognizes and eliminates foreign particles. In particular, the phagocytosing ability of cells belonging to the monocyte/macrophage lineage may render these immune cells an ideal toxicological target of pristine CNT, which may form aggregates of size exceeding monocyte/macrophage phagocytosing plasticity. To shed light on this issue, we analyzed the effects that pristine multi-walled CNT (MWCNT) without metal or biological impurities exert on survival and activation of freshly explanted human peripheral blood monocytes, analyzing in parallel the non-phagocytosing lymphocytes, and using graphite as control carbon material. MWCNT (diameter 10–50 nm, length up to 10 μm) exert two different toxic effects on mononuclear leukocytes: a minor apoptogenic effect (on lymphocytes > monocytes), and a major, apoptosis-independent effect that exclusively and deeply affect monocyte homeostasis. Analysis of monocyte number, adhesion, redox equilibrium, and the differentiation markers CD14 and CD11b reveals that MWCNT cause the selective disappearance of phagocytosis-competent monocytes by mechanisms related to the presence of large nanoparticle aggregates, suggesting phenomena of bulk toxicity possibly consisting of frustrated phagocytosis. At the same time, MWCNT stimulate adhesion of the phagocytosis-incompetent monocytes, and their differentiation toward a peculiar maturation asset. These observations point out novel mechanisms of CNT toxicity, renewing concerns that they may impair the innate immune system deranging the inflammatory responses.

Maturation and demise of human primary monocytes by carbon nanotubes

KAUST Repository

De Nicola, Milena D.

2013-05-17

The possibility of exploiting carbon nanotubes (CNT) in biomedical practices requires thorough analysis of the chemical or bulk effects they may exert on the immune system, the complex network that recognizes and eliminates foreign particles. In particular, the phagocytosing ability of cells belonging to the monocyte/macrophage lineage may render these immune cells an ideal toxicological target of pristine CNT, which may form aggregates of size exceeding monocyte/macrophage phagocytosing plasticity. To shed light on this issue, we analyzed the effects that pristine multi-walled CNT (MWCNT) without metal or biological impurities exert on survival and activation of freshly explanted human peripheral blood monocytes, analyzing in parallel the non-phagocytosing lymphocytes, and using graphite as control carbon material. MWCNT (diameter 10-50 nm, length up to 10 μm) exert two different toxic effects on mononuclear leukocytes: a minor apoptogenic effect (on lymphocytes > monocytes), and a major, apoptosis-independent effect that exclusively and deeply affect monocyte homeostasis. Analysis of monocyte number, adhesion, redox equilibrium, and the differentiation markers CD14 and CD11b reveals that MWCNT cause the selective disappearance of phagocytosis-competent monocytes by mechanisms related to the presence of large nanoparticle aggregates, suggesting phenomena of bulk toxicity possibly consisting of frustrated phagocytosis. At the same time, MWCNT stimulate adhesion of the phagocytosis-incompetent monocytes, and their differentiation toward a peculiar maturation asset. These observations point out novel mechanisms of CNT toxicity, renewing concerns that they may impair the innate immune system deranging the inflammatory responses. © 2013 Springer Science+Business Media Dordrecht.

The continuum of monocyte phenotypes: Experimental evidence and prognostic utility in assessing cardiovascular risk.

Science.gov (United States)

Cignarella, Andrea; Tedesco, Serena; Cappellari, Roberta; Fadini, Gian Paolo

2018-03-30

The monocyte-macrophage cell lineage represents a major player in innate immunity, and is involved in many physiologic and pathologic conditions. Particularly, monocyte-macrophages play a very important role in atherosclerosis and cardiovascular disease. Monocyte heterogeneity is well recognized but the biologic and clinical meaning of the various monocyte subtypes is not entirely understood. Traditionally, monocytes can be divided in classical, intermediate, and nonclassical based on expression of the surface antigens CD14 and CD16. While macrophage diversity is now well recognized to organize as a continuum, monocyte subsets have long been considered as separated entities. However, mounting evidence obtained by tracking the ontology of human monocytes help clarifying that monocytes mature from classical to nonclassical ones, through an intermediate phenotype. This concept is therefore best depicted as a continuum, whereas the subdivision into discrete CD14/CD16 subsets appears an oversimplification. In this review, we discuss the evidence supporting the existence of a monocyte continuum along with the technical challenges of monocyte characterization. In particular, we describe the advantage of considering monocytes along a continuous distribution for the evaluation of cardiovascular risk. We make the point that small transition along the monocyte continuum better reflects cardiovascular risk than a simplified analysis of discrete monocyte subsets. Recognizing the monocyte continuum can be helpful to model other pathophysiologic conditions where these cells are involved. ©2018 Society for Leukocyte Biology.

Molecular mechanisms that underlie the dynamic adaptation of innate monocyte memory to varying stimulant strength of TLR ligands

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Ruoxi Yuan

2016-11-01

Full Text Available In adaptation to rising stimulant strength, innate monocytes can be dynamically programmed to preferentially express either pro- or anti-inflammatory mediators. Such dynamic innate adaptation or programming may bear profound relevance in host health and disease. However, molecular mechanisms that govern innate adaptation to varying strength of stimulants are not well understood. Using lipopolysaccharide (LPS, the model stimulant of Toll-Like-Receptor 4 (TLR4, we reported that the expressions of pro-inflammatory mediators are preferentially sustained in monocytes adapted by lower doses of LPS, and suppressed/tolerized in monocytes adapted by higher doses of LPS. Mechanistically, monocytes adapted by super-low dose LPS exhibited higher levels of transcription factor IRF5 and reduced levels of transcriptional modulator BLIMP-1. Intriguingly, the inflammatory monocyte adaptation by super-low dose LPS is dependent upon TRAM/TRIF but not MyD88. Similar to LPS, we also observed biphasic inflammatory adaptation and tolerance in monocytes challenged with varying dosages of TLR7 agonist. In sharp contrast, rising doses of TLR3 agonist preferentially caused inflammatory adaptation without inducing tolerance. At the molecular level, the differential regulation of IRF5 and Blimp-1 coincides with unique monocyte adaptation dynamics by TLR4/7 and TLR3 agonists. Our study provides novel clue toward the understanding of monocyte adaptation and memory toward distinct TLR ligands.

Differential oxidative stress induced by dengue virus in monocytes from human neonates, adult and elderly individuals.

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Nereida Valero

Full Text Available Changes in immune response during lifespan of man are well known. These changes involve decreased neonatal and elderly immune response. In addition, it has been shown a relationship between immune and oxidative mechanisms, suggesting that altered immune response could be associated to altered oxidative response. Increased expression of nitric oxide (NO has been documented in dengue and in monocyte cultures infected with different types of dengue virus. However, there is no information about the age-dependent NO oxidative response in humans infected by dengue virus. In this study, monocyte cultures from neonatal, elderly and adult individuals (n = 10 each group were infected with different dengue virus types (DENV- 1 to 4 and oxidative/antioxidative responses and apoptosis were measured at days 1 and 3 of culture. Increased production of NO, lipid peroxidation and enzymatic and nonenzymatic anti-oxidative responses in dengue infected monocyte cultures were observed. However, neonatal and elderly monocytes had lower values of studied parameters when compared to those in adult-derived cultures. Apoptosis was present in infected monocytes with higher values at day 3 of culture. This reduced oxidant/antioxidant response of neonatal and elderly monocytes could be relevant in the pathogenesis of dengue disease.

Neutrophil glycoprotein Mo1 is an integral membrane protein of plasma membranes and specific granules

International Nuclear Information System (INIS)

Stevenson, K.B.; Nauseef, W.M.; Clark, R.A.

1987-01-01

The glucoprotein Mo1 has previously been demonstrated to be on the cell surface and in the specific granule fraction of neutrophils and to be translocated to the cell surface during degranulation. It is not known, however, whether Mo1 is an integral membrane protein or a soluble, intragranular constituent loosely associated with the specific granule membrane. Purified neutrophils were disrupted by nitrogen cavitation and separated on Percoll density gradients into four fractions enriched for azurophilic granules, specific granules, plasma membrane, and cytosol, respectively. The glycoproteins in these fractions were labeled with 3 H-borohydride reduction, extracted with Triton X-114, and immunoprecipitated with 60.3, an anti-Mo1 monoclonal antibody. Mo1 was detected only in the specific granule and plasma membrane fractions and partitioned exclusively into the detergent-rich fraction consistent with Mo1 being an integral membrane protein. In addition, treatment of specific granule membranes with a high salt, high urea buffer to remove adsorbed or peripheral proteins failed to dissociate Mo1. These data support the hypothesis that Mo1 is an integral membrane protein of plasma and specific granule membranes in human neutrophils

Death of Monocytes through Oxidative Burst of Macrophages and Neutrophils: Killing in Trans.

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Viviane Ponath

Full Text Available Monocytes and their descendants, macrophages, play a key role in the defence against pathogens. They also contribute to the pathogenesis of inflammatory diseases. Therefore, a mechanism maintaining a balance in the monocyte/macrophage population must be postulated. Our previous studies have shown that monocytes are impaired in DNA repair, rendering them vulnerable to genotoxic stress while monocyte-derived macrophages are DNA repair competent and genotoxic stress-resistant. Based on these findings, we hypothesized that monocytes can be selectively killed by reactive oxygen species (ROS produced by activated macrophages. We also wished to know whether monocytes and macrophages are protected against their own ROS produced following activation. To this end, we studied the effect of the ROS burst on DNA integrity, cell death and differentiation potential of monocytes. We show that monocytes, but not macrophages, stimulated for ROS production by phorbol-12-myristate-13-acetate (PMA undergo apoptosis, despite similar levels of initial DNA damage. Following co-cultivation with ROS producing macrophages, monocytes displayed oxidative DNA damage, accumulating DNA single-strand breaks and a high incidence of apoptosis, reducing their ability to give rise to new macrophages. Killing of monocytes by activated macrophages, termed killing in trans, was abolished by ROS scavenging and was also observed in monocytes co-cultivated with ROS producing activated granulocytes. The data revealed that monocytes, which are impaired in the repair of oxidised DNA lesions, are vulnerable to their own ROS and ROS produced by macrophages and granulocytes and support the hypothesis that this is a mechanism regulating the amount of monocytes and macrophages in a ROS-enriched inflammatory environment.

Decreased glucose uptake by hyperglycemia is regulated by different mechanisms in human cancer cells and monocytes

International Nuclear Information System (INIS)

Kim, Chae Kyun; Chung, June Key; Lee, Yong Jin; Hong, Mee Kyoung; Jeong, Jae Min; Lee, Dong Soo; Lee, Myung Chul

2002-01-01

To clarify the difference in glucose uptake between human cancer cells and monocytes, we studied ( 18 F) fluorodeoxyglucose (FDG) uptake in three human colon cancer cell lines (SNU-C2A, SNU-C4, SNU-C5), one human lung cancer cell line (NCI-H522), and human peripheral blood monocytes. The FDG uptake of both cancer cells and monocytes was increased in glucose-free medium, but decreased in the medium containing 16.7 mM glucose (hyperglycemic). The level of Glut1 mRNA decreased in human colon cancer cells and NCI-H522 under hyperglycemic condition. Glut1 protein expression was also decreased in the four human cancer cell lines under hyperglycemic condition, whereas it was consistently undetectable in monocytes. SNU-C2A, SNU-C4 and NCI-H522 showed a similar level of hexokinase activity (7.5-10.8 mU/mg), while SNU-C5 and moncytes showed lower range of hexokinase activity (4.3-6.5 mU/mg). These data suggest that glucose uptake is regulated by different mechanisms in human cancer cells and monocytes

The effect of metformin on monocyte secretory function in simvastatin-treated patients with impaired fasting glucose.

Science.gov (United States)

Krysiak, Robert; Okopien, Bogusław

2013-01-01

This study was designed to investigate whether metformin affects monocyte secretory function in patients with impaired fasting glucose receiving chronic statin therapy. The study included 48 patients with impaired fasting glucose treated for at least three months with simvastatin (40 mg daily). These patients were randomized to either metformin (3 g daily) or placebo, which was administered together with simvastatin for 90 days. Plasma lipids, glucose homeostasis markers, monocyte cytokine release and plasma C-reactive protein levels were determined before randomization and at the end of the treatment. Compared to placebo, metformin reduced monocyte release of tumor necrosis factor-α, interleukin-1β, interleukin-6, monocyte chemoattractant protein-1 and interleukin-8, as well as decreased plasma C-reactive protein levels, which were accompanied by an improvement in insulin sensitivity. The obtained results suggest that metformin may inhibit monocyte secretory function and reduce systemic inflammation in statin-treated patients with prediabetes. Impaired fasting glucose patients with high cardiovascular risk may receive the greatest benefits from concomitant treatment with a statin and metformin. Copyright © 2013 Elsevier Inc. All rights reserved.

Infiltration Pattern of Blood Monocytes into the Central Nervous System during Experimental Herpes Simplex Virus Encephalitis.

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Rafik Menasria

Full Text Available The kinetics and distribution of infiltrating blood monocytes into the central nervous system and their involvement in the cerebral immune response together with resident macrophages, namely microglia, were evaluated in experimental herpes simplex virus 1 (HSV-1 encephalitis (HSE. To distinguish microglia from blood monocyte-derived macrophages, chimeras were generated by conditioning C57BL/6 recipient mice with chemotherapy regimen followed by transplantation of bone morrow-derived cells that expressed the green fluorescent protein. Mice were infected intranasally with a sub-lethal dose of HSV-1 (1.2 x 10(6 plaque forming units. Brains were harvested prior to and on days 4, 6, 8 and 10 post-infection for flow cytometry and immunohistochemistry analysis. The amounts of neutrophils (P < 0.05 and "Ly6C hi" inflammatory monocytes (P < 0.001 significantly increased in the CNS compared to non-infected controls on day 6 post-infection, which corresponded to more severe clinical signs of HSE. Levels decreased on day 8 for both leukocytes subpopulations (P < 0.05 for inflammatory monocytes compared to non-infected controls to reach baseline levels on day 10 following infection. The percentage of "Ly6C low" patrolling monocytes significantly increased (P < 0.01 at a later time point (day 8, which correlated with the resolution phase of HSE. Histological analysis demonstrated that blood leukocytes colonized mostly the olfactory bulb and the brainstem, which corresponded to regions where HSV-1 particles were detected. Furthermore, infiltrating cells from the monocytic lineage could differentiate into activated local tissue macrophages that express the microglia marker, ionized calcium-binding adaptor molecule 1. The lack of albumin detection in the brain parenchyma of infected mice showed that the infiltration of blood leukocytes was not necessarily related to a breakdown of the blood-brain barrier but could be the result of a functional recruitment. Thus

Functional contribution of elevated circulating and hepatic non-classical CD14CD16 monocytes to inflammation and human liver fibrosis.

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Henning W Zimmermann

Full Text Available BACKGROUND: Monocyte-derived macrophages critically perpetuate inflammatory responses after liver injury as a prerequisite for organ fibrosis. Experimental murine models identified an essential role for the CCR2-dependent infiltration of classical Gr1/Ly6C(+ monocytes in hepatic fibrosis. Moreover, the monocyte-related chemokine receptors CCR1 and CCR5 were recently recognized as important fibrosis modulators in mice. In humans, monocytes consist of classical CD14(+CD16(- and non-classical CD14(+CD16(+ cells. We aimed at investigating the relevance of monocyte subpopulations for human liver fibrosis, and hypothesized that 'non-classical' monocytes critically exert inflammatory as well as profibrogenic functions in patients during liver disease progression. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed circulating monocyte subsets from freshly drawn blood samples of 226 patients with chronic liver disease (CLD and 184 healthy controls by FACS analysis. Circulating monocytes were significantly expanded in CLD-patients compared to controls with a marked increase of the non-classical CD14(+CD16(+ subset that showed an activated phenotype in patients and correlated with proinflammatory cytokines and clinical progression. Correspondingly, CD14(+CD16(+ macrophages massively accumulated in fibrotic/cirrhotic livers, as evidenced by immunofluorescence and FACS. Ligands of monocyte-related chemokine receptors CCR2, CCR1 and CCR5 were expressed at higher levels in fibrotic and cirrhotic livers, while CCL3 and CCL4 were also systemically elevated in CLD-patients. Isolated monocyte/macrophage subpopulations were functionally characterized regarding cytokine/chemokine expression and interactions with primary human hepatic stellate cells (HSC in vitro. CD14(+CD16(+ monocytes released abundant proinflammatory cytokines. Furthermore, CD14(+CD16(+, but not CD14(+CD16(- monocytes could directly activate collagen-producing HSC. CONCLUSIONS/SIGNIFICANCE: Our data

DMPD: Differential responses of human monocytes and macrophages to IL-4 and IL-13. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 10534111 Differential responses of human monocytes and macrophages to IL-4 and IL-1...):575-8. (.png) (.svg) (.html) (.csml) Show Differential responses of human monocytes and macrophages to IL-...4 and IL-13. PubmedID 10534111 Title Differential responses of human monocytes an

Reduction of Monocyte Chemoattractant Protein-1 and Interleukin-8 Levels by Ticlopidine in TNF-α Stimulated Human Umbilical Vein Endothelial Cells

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Chaur-Jong Hu

2009-01-01

Full Text Available Atherosclerosis and its associated complications represent major causes of morbidity and mortality in the industrialized or Western countries. Monocyte chemoattractant protein-1 (MCP-1 is critical for the initiating and developing of atherosclerotic lesions. Interleukin-8 (IL-8, a CXC chemokine, stimulates neutrophil chemotaxis. Ticlopidine is one of the antiplatelet drugs used to prevent thrombus formation relevant to the pathophysiology of atherothrombosis. In this study, we found that ticlopidine dose-dependently decreased the mRNA and protein levels of TNF-α-stimulated MCP-1, IL-8, and vascular cell adhesion molecule-1 (VCAM-1 in human umbilical vein endothelial cells (HUVECs. Ticlopidine declined U937 cells adhesion and chemotaxis as compared to TNF-α stimulated alone. Furthermore, the inhibitory effects were neither due to decreased HUVEC viability, nor through NF-kB inhibition. These results suggest that ticlopidine decreased TNF-α induced MCP-1, IL-8, and VCAM-1 levels in HUVECs, and monocyte adhesion. Therefore, the data provide additional therapeutic machinery of ticlopidine in treatment and prevention of atherosclerosis.

Properties of human blood monocytes. I. CD91 expression and log orthogonal light scatter provide a robust method to identify monocytes that is more accurate than CD14 expression.

Science.gov (United States)

Hudig, Dorothy; Hunter, Kenneth W; Diamond, W John; Redelman, Doug

2014-03-01

This study was designed to improve identification of human blood monocytes by using antibodies to molecules that occur consistently on all stages of monocyte development and differentiation. We examined blood samples from 200 healthy adults without clinically diagnosed immunological abnormalities by flow cytometry (FCM) with multiple combinations of antibodies and with a hematology analyzer (Beckman LH750). CD91 (α2 -macroglobulin receptor) was expressed only by monocytes and to a consistent level among subjects [mean median fluorescence intensity (MFI) = 16.2 ± 3.2]. Notably, only 85.7 ± 5.82% of the CD91(+) monocytes expressed high levels of the classical monocyte marker CD14, with some CD91(+) CD16(+) cells having negligible CD14, indicating that substantial FCM under-counts will occur when monocytes are identified by high CD14. CD33 (receptor for sialyl conjugates) was co-expressed with CD91 on monocytes but CD33 expression varied by nearly ten-fold among subjects (mean MFI = 17.4 ± 7.7). In comparison to FCM analyses, the hematology analyzer systematically over-counted monocytes and eosinophils while lymphocyte and neutrophil differential values generally agreed with FCM methods. CD91 is a better marker to identify monocytes than CD14 or CD33. Furthermore, FCM (with anti-CD91) identifies monocytes better than a currently used clinical CBC instrument. Use of anti-CD91 together with anti-CD14 and anti-CD16 supports the identification of the diagnostically significant monocyte populations with variable expression of CD14 and CD16. Copyright © 2013 Clinical Cytometry Society.

Edaravone attenuates monocyte adhesion to endothelial cells induced by oxidized low-density lipoprotein

International Nuclear Information System (INIS)

Li, Zhijuan; Cheng, Jianxin; Wang, Liping

2015-01-01

Oxidized low-density lipoprotein (oxLDL) plays a vital role in recruitment of monocytes to endothelial cells, which is important during early stages of atherosclerosis development. Edaravone, a potent and novel scavenger of free radicals inhibiting hydroxyl radicals, has been clinically used to reduce the neuronal damage following ischemic stroke. In the present study, Edaravone was revealed to markedly reduce oxLDL-induced monocyte adhesion to human umbilical vein endothelial cells (HUVECs). The inhibitory mechanism of Edaravone was associated with suppression of the chemokine MCP-1 and adhesion molecule VCAM-1 and ICAM-1 expression. In addition, luciferase reporter assay results revealed that administration of Edaravone attenuated the increase in NF-κB transcriptional activity induced by oxLDL. Notably, it's also shown that Edaravone treatment blocked oxLDL induced p65 nuclear translocation in HUVECs. Results indicate that Edaravone negatively regulates endothelial inflammation. - Highlights: • Edaravone reduces oxLDL-induced monocyte adhesion to HUVECs. • Edaravone attenuates oxLDL-induced expression of MCP-1, VCAM-1, and ICAM-1. • Edaravone reduces NF-κB transcriptional activity and p65 nuclear translocation.

CD14+ monocytes promote the immunosuppressive effect of human umbilical cord matrix stem cells

International Nuclear Information System (INIS)

Wang, Ding; Chen, Ke; Du, Wei Ting; Han, Zhi-Bo; Ren, He; Chi, Ying

2010-01-01

Here, the effect of CD14 + monocytes on human umbilical cord matrix stem cell (hUC-MSC)-mediated immunosuppression was studied in vitro. hUC-MSCs exerted a potent inhibitory effect on the proliferation and interferon-γ (IFN-γ) secretion capacities of CD4 + and CD8 + T cells in response to anti-CD3/CD28 stimulation. Transwell co-culture system revealed that the suppressive effect was primarily mediated by soluble factors. Addition of prostaglandin synthesis inhibitors (indomethacin or NS-398) almost completely abrogated the immunosuppression activity of hUC-MSCs, identifying prostaglandin E 2 (PGE 2 ) as an important soluble mediator. CD14 + monocytes were found to be able to enhance significantly the immunosuppressive effect of hUC-MSCs in a dose-dependent fashion. Moreover, the inflammatory cytokine IL-1β, either exogenously added or produced by CD14 + monocytes in culture, could trigger expression of high levels of PGE 2 by hUC-MSCs, whereas inclusion of the IL-1 receptor antagonist (IL-1RA) in the culture down-regulated not only PGE 2 expression, but also reversed the promotional effect of CD14 + monocytes and partially restored CD4 + and CD8 + T cell proliferation and IFN-γ secretion. Our data demonstrate an important role of monocytes in the hUC-MSC-induced immunomodulation, which may have important implications in future efforts to explore the clinical potentials of hUC-MSCs.

Dopamine Increases CD14+CD16+ Monocyte Migration and Adhesion in the Context of Substance Abuse and HIV Neuropathogenesis

Science.gov (United States)

Coley, Jacqueline S.; Calderon, Tina M.; Gaskill, Peter J.; Eugenin, Eliseo A.; Berman, Joan W.

2015-01-01

Drug abuse is a major comorbidity of HIV infection and cognitive disorders are often more severe in the drug abusing HIV infected population. CD14+CD16+ monocytes, a mature subpopulation of peripheral blood monocytes, are key mediators of HIV neuropathogenesis. Infected CD14+CD16+ monocyte transmigration across the blood brain barrier mediates HIV entry into the brain and establishes a viral reservoir within the CNS. Despite successful antiretroviral therapy, continued influx of CD14+CD16+ monocytes, both infected and uninfected, contributes to chronic neuroinflammation and the development of HIV associated neurocognitive disorders (HAND). Drug abuse increases extracellular dopamine in the CNS. Once in the brain, CD14+CD16+ monocytes can be exposed to extracellular dopamine due to drug abuse. The direct effects of dopamine on CD14+CD16+ monocytes and their contribution to HIV neuropathogenesis are not known. In this study, we showed that CD14+CD16+ monocytes express mRNA for all five dopamine receptors by qRT-PCR and D1R, D5R and D4R surface protein by flow cytometry. Dopamine and the D1-like dopamine receptor agonist, SKF38393, increased CD14+CD16+ monocyte migration that was characterized as chemokinesis. To determine whether dopamine affected cell motility and adhesion, live cell imaging was used to monitor the accumulation of CD14+CD16+ monocytes on the surface of a tissue culture dish. Dopamine increased the number and the rate at which CD14+CD16+ monocytes in suspension settled to the dish surface. In a spreading assay, dopamine increased the area of CD14+CD16+ monocytes during the early stages of cell adhesion. In addition, adhesion assays showed that the overall total number of adherent CD14+CD16+ monocytes increased in the presence of dopamine. These data suggest that elevated extracellular dopamine in the CNS of HIV infected drug abusers contributes to HIV neuropathogenesis by increasing the accumulation of CD14+CD16+ monocytes in dopamine rich brain

The CD14+CD16+ inflammatory monocyte subset displays increased mitochondrial activity and effector function during acute Plasmodium vivax malaria.

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Lis R V Antonelli

2014-09-01

Full Text Available Infection with Plasmodium vivax results in strong activation of monocytes, which are important components of both the systemic inflammatory response and parasite control. The overall goal of this study was to define the role of monocytes during P. vivax malaria. Here, we demonstrate that P. vivax-infected patients display significant increase in circulating monocytes, which were defined as CD14(+CD16- (classical, CD14(+CD16(+ (inflammatory, and CD14loCD16(+ (patrolling cells. While the classical and inflammatory monocytes were found to be the primary source of pro-inflammatory cytokines, the CD16(+ cells, in particular the CD14(+CD16(+ monocytes, expressed the highest levels of activation markers, which included chemokine receptors and adhesion molecules. Morphologically, CD14(+ were distinguished from CD14lo monocytes by displaying larger and more active mitochondria. CD14(+CD16(+ monocytes were more efficient in phagocytizing P. vivax-infected reticulocytes, which induced them to produce high levels of intracellular TNF-α and reactive oxygen species. Importantly, antibodies specific for ICAM-1, PECAM-1 or LFA-1 efficiently blocked the phagocytosis of infected reticulocytes by monocytes. Hence, our results provide key information on the mechanism by which CD14(+CD16(+ cells control parasite burden, supporting the hypothesis that they play a role in resistance to P. vivax infection.

Obese Mexican American children have elevated MCP-1, TNF-alpha, monocyte concentration, and dyslipidemia

Science.gov (United States)

Obesity is an independent risk factor for chronic disease. The prevalence of obesity is especially high among Mexican American children. Peripheral blood monocytes are altered with obesity contributing to elevated systemic inflammation and increased risk of chronic disease. In addition, obesity alte...

The acute monocytic leukemias: multidisciplinary studies in 45 patients.

Science.gov (United States)

Straus, D J; Mertelsmann, R; Koziner, B; McKenzie, S; de Harven, E; Arlin, Z A; Kempin, S; Broxmeyer, H; Moore, M A; Menendez-Botet, C J; Gee, T S; Clarkson, B D

1980-11-01

The clinical and laboratory features of 37 patients with variants of acute monocytic leukemia are described. Three of these 37 patients who had extensive extramedullary leukemic tissue infiltration are examples of true histiocytic "lymphomas." Three additional patients with undifferentiated leukemias, one patient with refractory anemia with excess of blasts, one patient with chronic myelomonocytic leukemia, one patient with B-lymphocyte diffuse "histiocytic" lymphoma and one patient with "null" cell, terminal deoxynucleotidyl transferase-positive lymphoblastic lymphoma had bone marrow cells with monocytic features. Another patient had dual populations of lymphoid and monocytoid leukemic cells. The true monocytic leukemias, acute monocytic leukemia (AMOL) and acute myelomonocytic leukemia (AMMOL), are closely related to acute myelocytic leukemia (AML) morphologically and by their response to chemotherapy. like AML, the leukemic cells from the AMMOL and AMOL patients form leukemic clusters in semisolid media. Cytochemical staining of leukemic cells for nonspecific esterases, presence of Fc receptor on the cell surface, phagocytic ability, low TdT activity, presence of surface "ruffles" and "ridges" on scanning EM, elevations of serum lysozyme, and clinical manifestations of leukemic tissue infiltration are features which accompanied monocytic differentiation in these cases.

Specific depletion of Ly6C(hi) inflammatory monocytes prevents immunopathology in experimental cerebral malaria.

Science.gov (United States)

Schumak, Beatrix; Klocke, Katrin; Kuepper, Janina M; Biswas, Aindrila; Djie-Maletz, Andrea; Limmer, Andreas; van Rooijen, Nico; Mack, Matthias; Hoerauf, Achim; Dunay, Ildiko Rita

2015-01-01

Plasmodium berghei ANKA (PbA) infection of C57BL/6 mice leads to experimental cerebral malaria (ECM) that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb), we depleted in vivo Ly6C(hi) inflammatory monocytes (by anti-CCR2), Ly6G+ neutrophils (by anti-Ly6G) or both cell types (by anti-Gr1) during infection with Ovalbumin-transgenic PbA parasites (PbTg). Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6C(hi) inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6C(hi) inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes.

Chronic Inhibition of PDE5 Limits Pro-Inflammatory Monocyte-Macrophage Polarization in Streptozotocin-Induced Diabetic Mice.

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Venneri, Mary Anna; Giannetta, Elisa; Panio, Giuseppe; De Gaetano, Rita; Gianfrilli, Daniele; Pofi, Riccardo; Masciarelli, Silvia; Fazi, Francesco; Pellegrini, Manuela; Lenzi, Andrea; Naro, Fabio; Isidori, Andrea M

2015-01-01

Diabetes mellitus is characterized by changes in endothelial cells that alter monocyte recruitment, increase classic (M1-type) tissue macrophage infiltration and lead to self-sustained inflammation. Our and other groups recently showed that chronic inhibition of phosphodiesterase-5 (PDE5i) affects circulating cytokine levels in patients with diabetes; whether PDE5i also affects circulating monocytes and tissue inflammatory cell infiltration remains to be established. Using murine streptozotocin (STZ)-induced diabetes and in human vitro cell-cell adhesion models we show that chronic hyperglycemia induces changes in myeloid and endothelial cells that alter monocyte recruitment and lead to self-sustained inflammation. Continuous PDE5i with sildenafil (SILD) expanded tissue anti-inflammatory TIE2-expressing monocytes (TEMs), which are known to limit inflammation and promote tissue repair. Specifically, SILD: 1) normalizes the frequency of circulating pro-inflammatory monocytes triggered by hyperglycemia (53.7 ± 7.9% of CD11b+Gr-1+ cells in STZ vs. 30.4 ± 8.3% in STZ+SILD and 27.1 ± 1.6% in CTRL, PTEMs (30.9 ± 3.6% in STZ+SILD vs. 6.9 ± 2.7% in STZ, P TEMs are defective in chronic hyperglycemia and that SILD normalizes their levels by facilitating the shift from classic (M1-like) to alternative (M2-like)/TEM macrophage polarization. Restoration of tissue TEMs with PDE5i could represent an additional pharmacological tool to prevent end-organ diabetic complications.

Production of inflammatory cytokines by peripheral blood monocytes in chronic alcoholism: relationship with ethanol intake and liver disease.

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Laso, Francisco Javier; Vaquero, José Miguel; Almeida, Julia; Marcos, Miguel; Orfao, Alberto

2007-09-01

Controversial results have been reported about the effects of alcoholism on the functionality of monocytes. In the present study we analyze the effects of chronic alcoholism on the intracellular production of inflammatory cytokines by peripheral blood (PB) monocytes. Spontaneous and in vitro-stimulated production of interleukin (IL) 1alpha (TNFalpha) by PB monocytes was analyzed at the single level by flow cytometry in chronic alcoholics without liver disease and active ethanol (EtOH) intake (AWLD group), as well as in patients with alcohol liver cirrhosis (ALC group), who were either actively drinking (ALCET group) or with alcohol withdrawal (ALCAW group). A significantly increased spontaneous production of IL1beta, IL6, IL12, and TNFalpha was observed on PB monocytes among AWLD individuals. Conversely, circulating monocytes form ALCET patients showed an abnormally low spontaneous and stimulated production of inflammatory cytokines. No significant changes were observed in ALCAW group as regards production of IL1beta, IL6, IL12, and TNFalpha. Our results show an altered pattern of production of inflammatory cytokines in PB monocytes from chronic alcoholic patients, the exact abnormalities observed depending on both the status of EtOH intake and the existence of alcoholic liver disease. Copyright 2007 Clinical Cytometry Society.

Soya-cerebroside, an extract of Cordyceps militaris, suppresses monocyte migration and prevents cartilage degradation in inflammatory animal models

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Liu, Shan-Chi; Chiu, Ching-Peng; Tsai, Chun-Hao; Hung, Chun-Yin; Li, Te-Mao; Wu, Yang-Chang; Tang, Chih-Hsin

2017-01-01

Pathophysiological events that modulate the progression of structural changes in osteoarthritis (OA) include the secretion of inflammatory molecules, such as proinflammatory cytokines. Interleukin-1beta (IL-1β) is the prototypical inflammatory cytokine that activates OA synovial cells to release cytokines and chemokines in support of the inflammatory response. The monocyte chemoattractant protein-1 (MCP-1/CCL2) is one of the key chemokines that regulate migration and infiltration of monocytes in response to inflammation. We show in this study that IL-1β-induced MCP-1 expression and monocyte migration in OA synovial fibroblasts (OASFs) is effectively inhibited by soya-cerebroside, an extract of Cordyceps militaris. We found that soya-cerebroside up-regulated of microRNA (miR)-432 expression via inhibiting AMPK and AKT signaling pathways in OASFs. Soya-cerebroside also effectively decreased monocyte infiltration and prevented cartilage degradation in a rat inflammatory model. Our findings are the first to demonstrate that soya-cerebroside inhibits monocyte/macrophage infiltration into synoviocytes, attenuating synovial inflammation and preventing cartilage damage by reducing MCP-1 expression in vitro and in vivo. Taken together, we suggest a novel therapeutic strategy based on the use of soya-cerebroside for the management of OA. PMID:28225075

Effects of acute exercise on monocyte subpopulations in metabolic syndrome patients.

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Wonner, Ralph; Wallner, Stefan; Orsó, Evelyn; Schmitz, Gerd

2016-06-10

Acute exercise induces numerous changes in peripheral blood, e.g. counts of leukocytes. CD16 pos monocytes, which play a role in the pathogenesis of arteriosclerosis and the metabolic syndrome (MetS), are among the blood cells with the highest fold increase through exercise. So far no studies have investigated the effect of exercise on the blood cell composition of patients with MetS. Blood cell counts, a wide panel of laboratory tests, as well as lipid and protein content of monocytes and granulocytes were determined in healthy subjects, persons with metabolic risk and MetS patients before and after one minute of exercise at 400 W. Leukocyte counts increased significantly in all groups with CD14 pos CD16 pos monocytes showing the highest fold-change. In MetS patients the fold increase was smaller. They had a higher resting level of CD14 pos CD16 pos monocytes and a lower basal ratio of CD16 neg /CD16 pos monocytes. A similar ratio of these cells was induced in control and risk subjects after exercise. However, absolute counts of mobilized pro-inflammatory monocytes did not differ significantly. Furthermore, we detected a decrease in protein content of monocytes in controls, but not in MetS patients. As strenuous exercise is able to mobilize the same amount of pro-inflammatory monocytes in MetS patients as in healthy persons, the elevated basal level of these cells in MetS patients is likely to be caused by enhanced maturation rather than chronic mobilization. The removal of these monocytes from the endothelium might be part of the beneficial effect of exercise on vascular disease. © 2016 International Clinical Cytometry Society. © 2016 International Clinical Cytometry Society.

Functional relevance of protein glycosylation to the pro-inflammatory effects of extracellular matrix metalloproteinase inducer (EMMPRIN) on monocytes/macrophages.

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Ge, Heng; Yuan, Wei; Liu, Jidong; He, Qing; Ding, Song; Pu, Jun; He, Ben

2015-01-01

Extracellular matrix metalloproteinase inducer (EMMPRIN) is an important pro-inflammatory protein involved in the cellular functions of monocytes/macrophages. We have hypothesized that high-level heterogeneousness of protein glycosylation of EMMPRIN may have functional relevance to its biological effects and affect the inflammatory activity of monocytes/macrophages. The glycosylation patterns of EMMPRIN expressed by monocytes/macrophages (THP-1 cells) in response to different extracellular stimuli were observed, and the structures of different glycosylation forms were identified. After the purification of highly- and less-glycosylated proteins respectively, the impacts of different glycosylation forms on the pro-inflammatory effects of EMMPRIN were examined in various aspects, such as cell adhesion to endothelial cells, cell migrations, cytokine expression, and activation of inflammatory signalling pathway. 1) It was mainly the highly-glycosylated form of EMMPRIN (HG-EMMPRIN) that increased after being exposed to inflammatory signals (PMA and H2O2). 2) Glycosylation of EMMPRIN in monocytes/macrophages led to N-linked-glycans being added to the protein, with the HG form containing complex-type glycans and the less-glycosylated form (LG) the simple type. 3) Only the HG-EMMPRIN but not the LG-EMMPRIN exhibited pro-inflammatory effects and stimulated inflammatory activities of the monocytes/macrophages (i.e., activation of ERK1/2 and NF-κB pathway, enhanced monocyte-endothelium adhesion, cell migration and matrix metalloproteinase -9 expression). Post-transcriptional glycosylation represents an important mechanism that determines the biological effects of EMMPRIN in monocytes/macrophages. Glycosylation of EMMPRIN may serve as a potential target for regulating the inflammatory activities of monocytes/macrophages.

Functional relevance of protein glycosylation to the pro-inflammatory effects of extracellular matrix metalloproteinase inducer (EMMPRIN on monocytes/macrophages.

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Heng Ge

Full Text Available Extracellular matrix metalloproteinase inducer (EMMPRIN is an important pro-inflammatory protein involved in the cellular functions of monocytes/macrophages. We have hypothesized that high-level heterogeneousness of protein glycosylation of EMMPRIN may have functional relevance to its biological effects and affect the inflammatory activity of monocytes/macrophages.The glycosylation patterns of EMMPRIN expressed by monocytes/macrophages (THP-1 cells in response to different extracellular stimuli were observed, and the structures of different glycosylation forms were identified. After the purification of highly- and less-glycosylated proteins respectively, the impacts of different glycosylation forms on the pro-inflammatory effects of EMMPRIN were examined in various aspects, such as cell adhesion to endothelial cells, cell migrations, cytokine expression, and activation of inflammatory signalling pathway.1 It was mainly the highly-glycosylated form of EMMPRIN (HG-EMMPRIN that increased after being exposed to inflammatory signals (PMA and H2O2. 2 Glycosylation of EMMPRIN in monocytes/macrophages led to N-linked-glycans being added to the protein, with the HG form containing complex-type glycans and the less-glycosylated form (LG the simple type. 3 Only the HG-EMMPRIN but not the LG-EMMPRIN exhibited pro-inflammatory effects and stimulated inflammatory activities of the monocytes/macrophages (i.e., activation of ERK1/2 and NF-κB pathway, enhanced monocyte-endothelium adhesion, cell migration and matrix metalloproteinase -9 expression.Post-transcriptional glycosylation represents an important mechanism that determines the biological effects of EMMPRIN in monocytes/macrophages. Glycosylation of EMMPRIN may serve as a potential target for regulating the inflammatory activities of monocytes/macrophages.

A human coronavirus responsible for the common cold massively kills dendritic cells but not monocytes.

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Mesel-Lemoine, Mariana; Millet, Jean; Vidalain, Pierre-Olivier; Law, Helen; Vabret, Astrid; Lorin, Valérie; Escriou, Nicolas; Albert, Matthew L; Nal, Béatrice; Tangy, Frédéric

2012-07-01

Human coronaviruses are associated with upper respiratory tract infections that occasionally spread to the lungs and other organs. Although airway epithelial cells represent an important target for infection, the respiratory epithelium is also composed of an elaborate network of dendritic cells (DCs) that are essential sentinels of the immune system, sensing pathogens and presenting foreign antigens to T lymphocytes. In this report, we show that in vitro infection by human coronavirus 229E (HCoV-229E) induces massive cytopathic effects in DCs, including the formation of large syncytia and cell death within only few hours. In contrast, monocytes are much more resistant to infection and cytopathic effects despite similar expression levels of CD13, the membrane receptor for HCoV-229E. While the differentiation of monocytes into DCs in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4 requires 5 days, only 24 h are sufficient for these cytokines to sensitize monocytes to cell death and cytopathic effects when infected by HCoV-229E. Cell death induced by HCoV-229E is independent of TRAIL, FasL, tumor necrosis factor alpha, and caspase activity, indicating that viral replication is directly responsible for the observed cytopathic effects. The consequence of DC death at the early stage of HCoV-229E infection may have an impact on the early control of viral dissemination and on the establishment of long-lasting immune memory, since people can be reinfected multiple times by HCoV-229E.

The glial scar-monocyte interplay: a pivotal resolution phase in spinal cord repair.

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Ravid Shechter

Full Text Available The inflammatory response in the injured spinal cord, an immune privileged site, has been mainly associated with the poor prognosis. However, recent data demonstrated that, in fact, some leukocytes, namely monocytes, are pivotal for repair due to their alternative anti-inflammatory phenotype. Given the pro-inflammatory milieu within the traumatized spinal cord, known to skew monocytes towards a classical phenotype, a pertinent question is how parenchymal-invading monocytes acquire resolving properties essential for healing, under such unfavorable conditions. In light of the spatial association between resolving (interleukin (IL-10 producing monocytes and the glial scar matrix chondroitin sulfate proteoglycan (CSPG, in this study we examined the mutual relationship between these two components. By inhibiting the de novo production of CSPG following spinal cord injury, we demonstrated that this extracellular matrix, mainly known for its ability to inhibit axonal growth, serves as a critical template skewing the entering monocytes towards the resolving phenotype. In vitro cell culture studies demonstrated that this matrix alone is sufficient to induce such monocyte polarization. Reciprocal conditional ablation of the monocyte-derived macrophages concentrated at the lesion margins, using diphtheria toxin, revealed that these cells have scar matrix-resolving properties. Replenishment of monocytic cell populations to the ablated mice demonstrated that this extracellular remodeling ability of the infiltrating monocytes requires their expression of the matrix-degrading enzyme, matrix metalloproteinase 13 (MMP-13, a property that was found here to be crucial for functional recovery. Altogether, this study demonstrates that the glial scar-matrix, a known obstacle to regeneration, is a critical component skewing the encountering monocytes towards a resolving phenotype. In an apparent feedback loop, monocytes were found to regulate scar resolution. This

Polychlorinated biphenyl-induced VCAM-1 expression is attenuated in aortic endothelial cells isolated from caveolin-1 deficient mice

International Nuclear Information System (INIS)

Han, Sung Gu; Eum, Sung Yong; Toborek, Michal; Smart, Eric; Hennig, Bernhard

2010-01-01

Exposure to environmental contaminants, such as polychlorinated biphenyls (PCBs), is a risk factor for the development of cardiovascular diseases such as atherosclerosis. Vascular cell adhesion molecule-1 (VCAM-1) is a critical mediator for adhesion and uptake of monocytes across the endothelium in the early stages of atherosclerosis development. The upregulation of VCAM-1 by PCBs may be dependent on functional membrane domains called caveolae. Caveolae are particularly abundant in endothelial cell membranes and involved in trafficking and signal transduction. The objective of this study was to investigate the role of caveolae in PCB-induced endothelial cell dysfunction. Primary mouse aortic endothelial cells (MAECs) isolated from caveolin-1-deficient mice and background C57BL/6 mice were treated with coplanar PCBs, such as PCB77 and PCB126. In addition, siRNA gene silencing technique was used to knockdown caveolin-1 in porcine vascular endothelial cells. In MAECs with functional caveolae, VCAM-1 protein levels were increased after exposure to both coplanar PCBs, whereas expression levels of VCAM-1 were not significantly altered in cells deficient of caveolin-1. Furthermore, PCB-induced monocyte adhesion was attenuated in caveolin-1-deficient MAECs. Similarly, siRNA silencing of caveolin-1 in porcine endothelial cells confirmed the caveolin-1-dependent VCAM-1 expression. Treatment of cells with PCB77 and PCB126 resulted in phosphorylation of extracellular signal-regulated kinase-1/2 (ERK1/2), and pharmacological inhibition of ERK1/2 diminished the observed PCB-induced increase in monocyte adhesion. These findings suggest that coplanar PCBs induce adhesion molecule expression, such as VCAM-1, in endothelial cells, and that this response is regulated by caveolin-1 and functional caveolae. Our data demonstrate a critical role of functional caveolae in the activation and dysfunction of endothelial cells by coplanar PCBs.

Decreased glucose uptake by hyperglycemia is regulated by different mechanisms in human cancer cells and monocytes

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Kim, Chae Kyun; Chung, June Key; Lee, Yong Jin; Hong, Mee Kyoung; Jeong, Jae Min; Lee, Dong Soo; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

2002-04-01

To clarify the difference in glucose uptake between human cancer cells and monocytes, we studied ({sup 18}F) fluorodeoxyglucose (FDG) uptake in three human colon cancer cell lines (SNU-C2A, SNU-C4, SNU-C5), one human lung cancer cell line (NCI-H522), and human peripheral blood monocytes. The FDG uptake of both cancer cells and monocytes was increased in glucose-free medium, but decreased in the medium containing 16.7 mM glucose (hyperglycemic). The level of Glut1 mRNA decreased in human colon cancer cells and NCI-H522 under hyperglycemic condition. Glut1 protein expression was also decreased in the four human cancer cell lines under hyperglycemic condition, whereas it was consistently undetectable in monocytes. SNU-C2A, SNU-C4 and NCI-H522 showed a similar level of hexokinase activity (7.5-10.8 mU/mg), while SNU-C5 and moncytes showed lower range of hexokinase activity (4.3-6.5 mU/mg). These data suggest that glucose uptake is regulated by different mechanisms in human cancer cells and monocytes.

Comprehensive exploration of the effects of miRNA SNPs on monocyte gene expression.

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Nicolas Greliche

Full Text Available We aimed to assess whether pri-miRNA SNPs (miSNPs could influence monocyte gene expression, either through marginal association or by interacting with polymorphisms located in 3'UTR regions (3utrSNPs. We then conducted a genome-wide search for marginal miSNPs effects and pairwise miSNPs × 3utrSNPs interactions in a sample of 1,467 individuals for which genome-wide monocyte expression and genotype data were available. Statistical associations that survived multiple testing correction were tested for replication in an independent sample of 758 individuals with both monocyte gene expression and genotype data. In both studies, the hsa-mir-1279 rs1463335 was found to modulate in cis the expression of LYZ and in trans the expression of CNTN6, CTRC, COPZ2, KRT9, LRRFIP1, NOD1, PCDHA6, ST5 and TRAF3IP2 genes, supporting the role of hsa-mir-1279 as a regulator of several genes in monocytes. In addition, we identified two robust miSNPs × 3utrSNPs interactions, one involving HLA-DPB1 rs1042448 and hsa-mir-219-1 rs107822, the second the H1F0 rs1894644 and hsa-mir-659 rs5750504, modulating the expression of the associated genes.As some of the aforementioned genes have previously been reported to reside at disease-associated loci, our findings provide novel arguments supporting the hypothesis that the genetic variability of miRNAs could also contribute to the susceptibility to human diseases.

Glycoengineering of therapeutic antibodies enhances monocyte/macrophage-mediated phagocytosis and cytotoxicity.

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Herter, Sylvia; Birk, Martina C; Klein, Christian; Gerdes, Christian; Umana, Pablo; Bacac, Marina

2014-03-01

Therapeutic Abs possess several clinically relevant mechanisms of action including perturbation of tumor cell signaling, activation of complement-dependent cytotoxicity, Ab-dependent cellular cytotoxicity (ADCC), Ab-dependent cellular phagocytosis (ADCP), and induction of adaptive immunity. In view of the important role of phagocytic lineage cells in the mechanism of action of therapeutic Abs, we analyzed FcγR receptor-dependent effector functions of monocytes and macrophages triggered by glycoengineered (GE) Abs (having enhanced FcγRIIIa [CD16a] binding affinity) versus their wild-type (WT) counterparts under different experimental conditions. We first defined the precise FcγR repertoire on classical and nonclassical intermediate monocytes--M1 and M2c macrophage populations. We further show that WT and GE Abs display comparable binding and induce similar effector functions (ADCC and ADCP) in the absence of nonspecific, endogenous IgGs. However, in the presence of these IgGs (i.e., in a situation that more closely mimics physiologic conditions), GE Abs display significantly superior binding and promote stronger monocyte and macrophage activity. These data show that in addition to enhancing CD16a-dependent NK cell cytotoxicity, glycoengineering also enhances monocyte and macrophage phagocytic and cytotoxic activities through enhanced binding to CD16a under conditions that more closely resemble the physiologic setting.

Vitamin d-directed rheostatic regulation of monocyte antibacterial responses

DEFF Research Database (Denmark)

Adams, John S; Ren, Songyang; Liu, Philip T

2009-01-01

The active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)(2)D) enhances innate immunity by inducing the cathelicidin antimicrobial peptide (hCAP). In monocytes/macrophages, this occurs primarily in response to activation of TLR, that induce expression of the vitamin D receptor and localized...... synthesis of 1,25(OH)(2)D from precursor 25-hydroxyvitamin D(3) (25OHD). To clarify the relationship between vitamin D and innate immunity, we assessed changes in hCAP expression in vivo and ex vivo in human subjects attending a bone clinic (n = 50). Of these, 38% were vitamin D-insufficient (...) and received supplementation with vitamin D (50,000 IU vitamin D(2) twice weekly for 5 wk). Baseline 25OHD status or vitamin D supplementation had no effect on circulating levels of hCAP. Therefore, ex vivo changes in hCAP for each subject were assessed using peripheral blood monocytes cultured with 10...

The expression of cholesterol metabolism genes in monocytes from HIV-infected subjects suggests intracellular cholesterol accumulation.

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Feeney, Eoin R; McAuley, Nuala; O'Halloran, Jane A; Rock, Clare; Low, Justin; Satchell, Claudette S; Lambert, John S; Sheehan, Gerald J; Mallon, Patrick W G

2013-02-15

Human immunodeficiency virus (HIV) infection is associated with increased cardiovascular risk and reduced high-density lipoprotein cholesterol (HDL-c). In vitro, HIV impairs monocyte-macrophage cholesterol efflux, a major determinant of circulating HDL-c, by increasing ABCA1 degradation, with compensatory upregulation of ABCA1 messenger RNA (mRNA). We examined expression of genes involved in cholesterol uptake, metabolism, and efflux in monocytes from 22 HIV-positive subjects on antiretroviral therapy (ART-Treated), 30 untreated HIV-positive subjects (ART-Naive), and 22 HIV-negative controls (HIV-Neg). HDL-c was lower and expression of ABCA1 mRNA was higher in ART-Naive subjects than in both ART-Treated and HIV-Neg subjects (both P ART-Treated and ART-Naive subjects than in HIV-Neg controls. In vivo, increased monocyte ABCA1 expression in untreated HIV-infected patients and normalization of ABCA1 expression with virological suppression by ART supports direct HIV-induced impairment of cholesterol efflux previously demonstrated in vitro. However, decreased expression of cholesterol sensing, uptake, and synthesis genes in both untreated and treated HIV infection suggests that both HIV and ART affect monocyte cholesterol metabolism in a pattern consistent with accumulation of intramonocyte cholesterol.

Monocyte-Derived Signals Activate Human Natural Killer Cells in Response to Leishmania Parasites

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Messlinger, Helena; Sebald, Heidi; Heger, Lukas; Dudziak, Diana; Bogdan, Christian; Schleicher, Ulrike

2018-01-01

Activated natural killer (NK) cells release interferon (IFN)-γ, which is crucial for the control of intracellular pathogens such as Leishmania. In contrast to experimental murine leishmaniasis, the human NK cell response to Leishmania is still poorly characterized. Here, we investigated the interaction of human blood NK cells with promastigotes of different Leishmania species (Leishmania major, Leishmania mexicana, Leishmania infantum, and Leishmania donovani). When peripheral blood mononuclear cells or purified NK cells and monocytes (all derived from healthy blood donors from Germany without a history of leishmaniasis) were exposed to promastigotes, NK cells showed increased surface expression of the activation marker CD69. The extent of this effect varied depending on the Leishmania species; differences between dermotropic and viscerotropic L. infantum strains were not observed. Upregulation of CD69 required direct contact between monocytes and Leishmania and was partly inhibitable by anti-interleukin (IL)-18. Unexpectedly, IL-18 was undetectable in most of the supernatants (SNs) of monocyte/parasite cocultures. Confocal fluorescence microscopy of non-permeabilized cells revealed that Leishmania-infected monocytes trans-presented IL-18 to NK cells. Native, but not heat-treated SNs of monocyte/Leishmania cocultures also induced CD69 on NK cells, indicating the involvement of a soluble heat-labile factor other than IL-18. A role for the NK cell-activating cytokines IL-1β, IL-2, IL-12, IL-15, IL-21, and IFN-α/β was excluded. The increase of CD69 was not paralleled by NK cell IFN-γ production or enhanced cytotoxicity. However, prior exposure of NK cells to Leishmania parasites synergistically increased their IFN-γ release in response to IL-12, which was dependent on endogenous IL-18. CD1c+ dendritic cells were identified as possible source of Leishmania-induced IL-12. Finally, we observed that direct contact between Leishmania and NK cells reduced the

Monocyte-Derived Signals Activate Human Natural Killer Cells in Response to Leishmania Parasites

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Helena Messlinger

2018-01-01

Full Text Available Activated natural killer (NK cells release interferon (IFN-γ, which is crucial for the control of intracellular pathogens such as Leishmania. In contrast to experimental murine leishmaniasis, the human NK cell response to Leishmania is still poorly characterized. Here, we investigated the interaction of human blood NK cells with promastigotes of different Leishmania species (Leishmania major, Leishmania mexicana, Leishmania infantum, and Leishmania donovani. When peripheral blood mononuclear cells or purified NK cells and monocytes (all derived from healthy blood donors from Germany without a history of leishmaniasis were exposed to promastigotes, NK cells showed increased surface expression of the activation marker CD69. The extent of this effect varied depending on the Leishmania species; differences between dermotropic and viscerotropic L. infantum strains were not observed. Upregulation of CD69 required direct contact between monocytes and Leishmania and was partly inhibitable by anti-interleukin (IL-18. Unexpectedly, IL-18 was undetectable in most of the supernatants (SNs of monocyte/parasite cocultures. Confocal fluorescence microscopy of non-permeabilized cells revealed that Leishmania-infected monocytes trans-presented IL-18 to NK cells. Native, but not heat-treated SNs of monocyte/Leishmania cocultures also induced CD69 on NK cells, indicating the involvement of a soluble heat-labile factor other than IL-18. A role for the NK cell-activating cytokines IL-1β, IL-2, IL-12, IL-15, IL-21, and IFN-α/β was excluded. The increase of CD69 was not paralleled by NK cell IFN-γ production or enhanced cytotoxicity. However, prior exposure of NK cells to Leishmania parasites synergistically increased their IFN-γ release in response to IL-12, which was dependent on endogenous IL-18. CD1c+ dendritic cells were identified as possible source of Leishmania-induced IL-12. Finally, we observed that direct contact between Leishmania and NK cells

HIV/SIV infection primes monocytes and dendritic cells for apoptosis.

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Mireille Laforge

2011-06-01

Full Text Available Subversion or exacerbation of antigen-presenting cells (APC death modulates host/pathogen equilibrium. We demonstrated during in vitro differentiation of monocyte-derived macrophages and monocyte-derived dendritic cells (DCs that HIV sensitizes the cells to undergo apoptosis in response to TRAIL and FasL, respectively. In addition, we found that HIV-1 increased the levels of pro-apoptotic Bax and Bak molecules and decreased the levels of anti-apoptotic Mcl-1 and FLIP proteins. To assess the relevance of these observations in the context of an experimental model of HIV infection, we investigated the death of APC during pathogenic SIV-infection in rhesus macaques (RMs. We demonstrated increased apoptosis, during the acute phase, of both peripheral blood DCs and monocytes (CD14(+ from SIV(+RMs, associated with a dysregulation in the balance of pro- and anti-apoptotic molecules. Caspase-inhibitor and death receptors antagonists prevented apoptosis of APCs from SIV(+RMs. Furthermore, increased levels of FasL in the sera of pathogenic SIV(+RMs were detected, compared to non-pathogenic SIV infection of African green monkey. We suggest that inappropriate apoptosis of antigen-presenting cells may contribute to dysregulation of cellular immunity early in the process of HIV/SIV infection.

Edaravone attenuates monocyte adhesion to endothelial cells induced by oxidized low-density lipoprotein

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Li, Zhijuan, E-mail: zjlee038@163.com; Cheng, Jianxin; Wang, Liping

2015-10-30

Oxidized low-density lipoprotein (oxLDL) plays a vital role in recruitment of monocytes to endothelial cells, which is important during early stages of atherosclerosis development. Edaravone, a potent and novel scavenger of free radicals inhibiting hydroxyl radicals, has been clinically used to reduce the neuronal damage following ischemic stroke. In the present study, Edaravone was revealed to markedly reduce oxLDL-induced monocyte adhesion to human umbilical vein endothelial cells (HUVECs). The inhibitory mechanism of Edaravone was associated with suppression of the chemokine MCP-1 and adhesion molecule VCAM-1 and ICAM-1 expression. In addition, luciferase reporter assay results revealed that administration of Edaravone attenuated the increase in NF-κB transcriptional activity induced by oxLDL. Notably, it's also shown that Edaravone treatment blocked oxLDL induced p65 nuclear translocation in HUVECs. Results indicate that Edaravone negatively regulates endothelial inflammation. - Highlights: • Edaravone reduces oxLDL-induced monocyte adhesion to HUVECs. • Edaravone attenuates oxLDL-induced expression of MCP-1, VCAM-1, and ICAM-1. • Edaravone reduces NF-κB transcriptional activity and p65 nuclear translocation.

Specific depletion of Ly6C(hi inflammatory monocytes prevents immunopathology in experimental cerebral malaria.

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Beatrix Schumak

Full Text Available Plasmodium berghei ANKA (PbA infection of C57BL/6 mice leads to experimental cerebral malaria (ECM that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb, we depleted in vivo Ly6C(hi inflammatory monocytes (by anti-CCR2, Ly6G+ neutrophils (by anti-Ly6G or both cell types (by anti-Gr1 during infection with Ovalbumin-transgenic PbA parasites (PbTg. Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6C(hi inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6C(hi inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes.

CD14{sup +} monocytes promote the immunosuppressive effect of human umbilical cord matrix stem cells

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Wang, Ding, E-mail: qqhewd@gmail.com [The State Key Laboratory of Experimental Hematology, Institute of Hematology and Hospital of Blood Diseases, Chinese Academy of Medical Sciences and Peking Union of Medical College, 288 Nanjing Road, Tianjin 300020 (China); TEDA Life and Technology Research Center, Institute of Hematology, Chinese Academy of Medical Sciences, TEDA, Tianjin (China); Chen, Ke, E-mail: chenke_59@hotmail.com [The State Key Laboratory of Experimental Hematology, Institute of Hematology and Hospital of Blood Diseases, Chinese Academy of Medical Sciences and Peking Union of Medical College, 288 Nanjing Road, Tianjin 300020 (China); TEDA Life and Technology Research Center, Institute of Hematology, Chinese Academy of Medical Sciences, TEDA, Tianjin (China); Du, Wei Ting, E-mail: duwtpumc@yahoo.com.cn [The State Key Laboratory of Experimental Hematology, Institute of Hematology and Hospital of Blood Diseases, Chinese Academy of Medical Sciences and Peking Union of Medical College, 288 Nanjing Road, Tianjin 300020 (China); Han, Zhi-Bo, E-mail: zhibohan@hotmail.com [The State Key Laboratory of Experimental Hematology, Institute of Hematology and Hospital of Blood Diseases, Chinese Academy of Medical Sciences and Peking Union of Medical College, 288 Nanjing Road, Tianjin 300020 (China); TEDA Life and Technology Research Center, Institute of Hematology, Chinese Academy of Medical Sciences, TEDA, Tianjin (China); Ren, He, E-mail: knifesharp2000@hotmail.com [National Engineering Research Center of Cell Products, AmCellGene Co. Ltd, TEDA, Tianjin (China); Chi, Ying, E-mail: caizhuying@hotmail.com [The State Key Laboratory of Experimental Hematology, Institute of Hematology and Hospital of Blood Diseases, Chinese Academy of Medical Sciences and Peking Union of Medical College, 288 Nanjing Road, Tianjin 300020 (China); TEDA Life and Technology Research Center, Institute of Hematology, Chinese Academy of Medical Sciences, TEDA, Tianjin (China); and others

2010-09-10

Here, the effect of CD14{sup +} monocytes on human umbilical cord matrix stem cell (hUC-MSC)-mediated immunosuppression was studied in vitro. hUC-MSCs exerted a potent inhibitory effect on the proliferation and interferon-{gamma} (IFN-{gamma}) secretion capacities of CD4{sup +} and CD8{sup +} T cells in response to anti-CD3/CD28 stimulation. Transwell co-culture system revealed that the suppressive effect was primarily mediated by soluble factors. Addition of prostaglandin synthesis inhibitors (indomethacin or NS-398) almost completely abrogated the immunosuppression activity of hUC-MSCs, identifying prostaglandin E{sub 2} (PGE{sub 2}) as an important soluble mediator. CD14{sup +} monocytes were found to be able to enhance significantly the immunosuppressive effect of hUC-MSCs in a dose-dependent fashion. Moreover, the inflammatory cytokine IL-1{beta}, either exogenously added or produced by CD14{sup +} monocytes in culture, could trigger expression of high levels of PGE{sub 2} by hUC-MSCs, whereas inclusion of the IL-1 receptor antagonist (IL-1RA) in the culture down-regulated not only PGE{sub 2} expression, but also reversed the promotional effect of CD14{sup +} monocytes and partially restored CD4{sup +} and CD8{sup +} T cell proliferation and IFN-{gamma} secretion. Our data demonstrate an important role of monocytes in the hUC-MSC-induced immunomodulation, which may have important implications in future efforts to explore the clinical potentials of hUC-MSCs.

Biocompatibility studies of polyacrylonitrile membranes modified with carboxylated polyetherimide

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Senthilkumar, S.; Rajesh, S.; Jayalakshmi, A.; Mohan, D., E-mail: mohantarun@gmail.com

2013-10-15

Poly (ether-imide) (PEI) was carboxylated and used as the hydrophilic modification agent for the preparation of polyacrylonitrile (PAN) membranes. Membranes were prepared with different blend compositions of PAN and CPEI by diffusion induced precipitation. The modified membranes were characterized by thermo gravimetric analysis (TGA), mechanical analysis, scanning electron microscopy (SEM) and contact angle measurement to understand the influence of CPEI on the properties of the membranes. The biocompatibility studies exhibited reduced plasma protein adsorption, platelet adhesion and thrombus formation on the modified membrane surface. The complete blood count (CBC) results of CPEI incorporated membranes showed stable CBC values and significant decrease in the complement activation were also observed. In addition to good cytocompatibility, monocytes cultured on these modified membranes exhibited improved functional profiles in 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Thus it could be concluded that PAN/CPEI membranes with excellent biocompatibility can be useful for hemodialysis. Highlights: • Carboxylated PEI was prepared and utilized as hydrophilic modification agent. • CPEI incorporated into PAN to improved biocompatibility and cyto compatibility • Biocompatibility of membranes was correlated with morphology and hydrophilicity. • Antifouling studies of the PAN/CPEI membranes was studied by BSA as model foulant.

ROCK1-directed basement membrane positioning coordinates epithelial tissue polarity.

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Daley, William P; Gervais, Elise M; Centanni, Samuel W; Gulfo, Kathryn M; Nelson, Deirdre A; Larsen, Melinda

2012-01-01

The basement membrane is crucial for epithelial tissue organization and function. However, the mechanisms by which basement membrane is restricted to the basal periphery of epithelial tissues and the basement membrane-mediated signals that regulate coordinated tissue organization are not well defined. Here, we report that Rho kinase (ROCK) controls coordinated tissue organization by restricting basement membrane to the epithelial basal periphery in developing mouse submandibular salivary glands, and that ROCK inhibition results in accumulation of ectopic basement membrane throughout the epithelial compartment. ROCK-regulated restriction of PAR-1b (MARK2) localization in the outer basal epithelial cell layer is required for basement membrane positioning at the tissue periphery. PAR-1b is specifically required for basement membrane deposition, as inhibition of PAR-1b kinase activity prevents basement membrane deposition and disrupts overall tissue organization, and suppression of PAR-1b together with ROCK inhibition prevents interior accumulations of basement membrane. Conversely, ectopic overexpression of wild-type PAR-1b results in ectopic interior basement membrane deposition. Significantly, culture of salivary epithelial cells on exogenous basement membrane rescues epithelial organization in the presence of ROCK1 or PAR-1b inhibition, and this basement membrane-mediated rescue requires functional integrin β1 to maintain epithelial cell-cell adhesions. Taken together, these studies indicate that ROCK1/PAR-1b-dependent regulation of basement membrane placement is required for the coordination of tissue polarity and the elaboration of tissue structure in the developing submandibular salivary gland.

STAT3 activation in monocytes accelerates liver cancer progression

International Nuclear Information System (INIS)

Wu, Wen-Yong; Li, Jun; Wu, Zheng-Sheng; Zhang, Chang-Le; Meng, Xiang-Ling

2011-01-01

Signal transducer and activator of transcription 3 (STAT3) is an important transcription factor ubiquitously expressed in different cell types. STAT3 plays an essential role in cell survival, proliferation, and differentiation. Aberrantly hyper-activated STAT3 signaling in cancer cells and in the tumor microenvironment has been detected in a wide variety of human cancers and is considered an important factor for cancer initiation, development, and progression. However, the role of STAT3 activation in monocytes in the development of HCC has not been well understood. Immunohistochemical analysis of phosphorylated STAT3 was performed on tissue microarray from HCC patients. Using a co-culture system in vivo, HCC cell growth was determined by the MTT assay. In vivo experiments were conducted with mice given diethylinitrosamine (DEN), which induces HCC was used to investigate the role of STAT3 expression in monocytes on tumor growth. Real-time PCR was used to determine the expression of cell proliferation and cell arrest associated genes in the tumor and nontumor tissue from liver. Phosphorylated STAT3 was found in human hepatocellular carcinoma tissue samples and was expressed in tumor cells and also in monocytes. Phosphorylated STAT3 expression in monocyte was significantly correlated to advanced clinical stage of HCC and a poor prognosis. Using a co-culture system in vivo, monocytes promoted HCC cell growth via the IL-6/STAT3 signaling pathway. The STAT3 inhibitor, NSC 74859, significantly suppressed tumor growth in vivo in mice with diethylinitrosamine (DEN)-induced HCC. In this animal model, blockade of STAT3 with NSC 74859 induced tumor cell apoptosis, while inhibiting both tumor cells and monocytes proliferation. Furthermore, NSC 74859 treatment suppressed cancer associated inflammation in DEN-induce HCC. Our data suggest constitutively activated STAT3 monocytes promote liver tumorigenesis in clinical patients and animal experiments. Thus, STAT3 in tumor

Immortalized porcine mesenchymal cells derived from nasal mucosa, lungs, lymph nodes, spleen and bone marrow retain their stemness properties and trigger the expression of siglec-1 in co-cultured blood monocytic cells.

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Garba, Abubakar; Desmarets, Lowiese M B; Acar, Delphine D; Devriendt, Bert; Nauwynck, Hans J

2017-01-01

Mesenchymal stromal cells have been isolated from different sources. They are multipotent cells capable of differentiating into many different cell types, including osteocytes, chondrocytes and adipocytes. They possess a therapeutic potential in the management of immune disorders and the repair of damaged tissues. Previous work in our laboratory showed an increase of the percentages of CD172a+, CD14+, CD163+, Siglec-1+, CD4+ and CD8+ hematopoietic cells, when co-cultured with immortalized mesenchymal cells derived from bone marrow. The present work aimed to demonstrate the stemness properties of SV40-immortalized mesenchymal cells derived from nasal mucosa, lungs, spleen, lymph nodes and red bone marrow and their immunomodulatory effect on blood monocytes. Mesenchymal cells from nasal mucosa, lungs, spleen, lymph nodes and red bone marrow were isolated and successfully immortalized using simian virus 40 large T antigen (SV40LT) and later, co-cultured with blood monocytes, in order to examine their differentiation stage (expression of Siglec-1). Flow cytometric analysis revealed that the five mesenchymal cell lines were positive for mesenchymal cell markers CD105, CD44, CD90 and CD29, but lacked the expression of myeloid cell markers CD16 and CD11b. Growth analysis of the cells demonstrated that bone marrow derived-mesenchymal cells proliferated faster compared with those derived from the other tissues. All five mesenchymal cell lines co-cultured with blood monocytes for 1, 2 and 7 days triggered the expression of siglec-1 in the monocytes. In contrast, no siglec-1+ cells were observed in monocyte cultures without mesenchymal cell lines. Mesenchymal cells isolated from nasal mucosa, lungs, spleen, lymph nodes and bone marrow were successfully immortalized and these cell lines retained their stemness properties and displayed immunomodulatory effects on blood monocytes.

Expression profiling feline peripheral blood monocytes identifies a transcriptional signature associated with type two diabetes mellitus.

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O'Leary, Caroline A; Sedhom, Mamdouh; Reeve-Johnson, Mia; Mallyon, John; Irvine, Katharine M

2017-04-01

Diabetes mellitus is a common disease of cats and is similar to type 2 diabetes (T2D) in humans, especially with respect to the role of obesity-induced insulin resistance, glucose toxicity, decreased number of pancreatic β-cells and pancreatic amyloid deposition. Cats have thus been proposed as a valuable translational model of T2D. In humans, inflammation associated with adipose tissue is believed to be central to T2D development, and peripheral blood monocytes (PBM) are important in the inflammatory cascade which leads to insulin resistance and β-cell failure. PBM may thus provide a useful window to study the pathogenesis of diabetes mellitus in cats, however feline monocytes are poorly characterised. In this study, we used the Affymetrix Feline 1.0ST array to profile peripheral blood monocytes from 3 domestic cats with T2D and 3 cats with normal glucose tolerance. Feline monocytes were enriched for genes expressed in human monocytes, and, despite heterogeneous gene expression, we identified a T2D-associated expression signature associated with cell cycle perturbations, DNA repair and the unfolded protein response, oxidative phosphorylation and inflammatory responses. Our data provide novel insights into the feline monocyte transcriptome, and support the hypothesis that inflammatory monocytes contribute to T2D pathogenesis in cats as well as in humans. Copyright © 2017 Elsevier B.V. All rights reserved.

The Role of Monocyte Percentage in Osteoporosis in Male Rheumatic Diseases.

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Su, Yu-Jih; Chen, Chao Tung; Tsai, Nai-Wen; Huang, Chih-Cheng; Wang, Hung-Chen; Kung, Chia-Te; Lin, Wei-Che; Cheng, Ben-Chung; Su, Chih-Min; Hsiao, Sheng-Yuan; Lu, Cheng-Hsien

2017-11-01

Osteoporosis is easily overlooked in male patients, especially in the field of rheumatic diseases mostly prevalent with female patients, and its link to pathogenesis is still lacking. Attenuated monocyte apoptosis from a transcriptome-wide expression study illustrates the role of monocytes in osteoporosis. This study tested the hypothesis that the monocyte percentage among leukocytes could be a biomarker of osteoporosis in rheumatic diseases. Eighty-seven males with rheumatic diseases were evaluated in rheumatology outpatient clinics for bone mineral density (BMD) and surrogate markers, such as routine peripheral blood parameters and autoantibodies. From the total number of 87 patients included in this study, only 15 met the criteria for diagnosis of osteoporosis. Both age and monocyte percentage remained independently associated with the presence of osteoporosis. Steroid dose (equivalent prednisolone dose) was negatively associated with BMD of the hip area and platelet counts were negatively associated with BMD and T score of the spine area. Besides age, monocyte percentage meets the major requirements for osteoporosis in male rheumatic diseases. A higher monocyte percentage in male rheumatic disease patients, aged over 50 years in this study, and BMD study should be considered in order to reduce the risk of osteoporosis-related fractures.

Differential Modulation of Annexin I Binding Sites on Monocytes and Neutrophils

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H. S. Euzger

1999-01-01

Full Text Available Specific binding sites for the anti-inflammatory protein annexin I have been detected on the surface of human monocytes and polymorphonuclear leukocytes (PMN. These binding sites are proteinaceous in nature and are sensitive to cleavage by the proteolytic enzymes trypsin, collagenase, elastase and cathepsin G. When monocytes and PMN were isolated independently from peripheral blood, only the monocytes exhibited constitutive annexin I binding. However PMN acquired the capacity to bind annexin I following co-culture with monocytes. PMN incubation with sodium azide, but not protease inhibitors, partially blocked this process. A similar increase in annexin I binding capacity was also detected in PMN following adhesion to endothelial monolayers. We propose that a juxtacrine activation rather than a cleavage-mediated transfer is involved in this process. Removal of annexin I binding sites from monocytes with elastase rendered monocytes functionally insensitive to full length annexin I or to the annexin I-derived pharmacophore, peptide Ac2-26, assessed as suppression of the respiratory burst. These data indicate that the annexin I binding site on phagocytic cells may have an important function in the feedback control of the inflammatory response and their loss through cleavage could potentiate such responses.

Studies on the production of endogenous pyrogen by rabbit monocytes: the role of calcium and cyclic nucleotides.

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Sigal, S L; Duff, G W; Atkins, E

1985-01-01

Rabbit monocytes stimulated with endotoxin produced endogenous pyrogen, even under conditions of high or low extracellular calcium concentrations. Maximal production occurred when the concentration was in the near-physiological range. Prolonged incubation of cells with a calcium chelator prevented subsequent activation with endotoxin, an effect which was rapidly reversible by re-addition of calcium but not other cations. Addition of small amounts of lanthanum, which acts as a calcium channel blocker, prevented the restoration of pyrogen production, indicating that entry of the added calcium into the monocyte was required. Incorporation of a calcium ionophore into the cell membrane did not stimulate pyrogen production, and no measurable influx or efflux of calcium occurred during stimulation with endotoxin. These observations suggest that a slowly exchangeable calcium pool is necessary for the production of endogenous pyrogen, but that a rise in intracellular calcium is not by itself a necessary or sufficient stimulus. This stands in contrast to other biological systems in which Ca2+ directly couples stimulus and hormone secretion. Incubation of cells with agents shown to increase cyclic 3',5' AMP or cyclic 3',5' GMP levels in monocytes similarly did not stimulate pyrogen production or modulate its production by endotoxin stimulation. Thus, cyclic nucleotides also did not play a detectable role as intracellular messengers in this system. Future work is required to define more clearly the mechanism for the production of endogenous pyrogen, given its marked effects on the immune system through lymphocyte activation and temperature regulation.