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Sample records for macrophage scavenger receptor

  1. The macrophage scavenger receptor CD163

    DEFF Research Database (Denmark)

    Nielsen, Marianne Jensby; Madsen, Mette; Møller, Holger J

    2006-01-01

    CD163 is the monocyte/macrophage-specific receptor for haptoglobin-hemoglobin (Hp-Hb) complexes. The cytoplasmic tail of human CD163 exists as a short tail variant and two long tail variants. Reverse transcriptase-polymerase chain reaction analysis indicated that all three CD163 variants are subs......CD163 is the monocyte/macrophage-specific receptor for haptoglobin-hemoglobin (Hp-Hb) complexes. The cytoplasmic tail of human CD163 exists as a short tail variant and two long tail variants. Reverse transcriptase-polymerase chain reaction analysis indicated that all three CD163 variants...

  2. The macrophage scavenger receptor CD163

    NARCIS (Netherlands)

    Fabriek, Babs O.; Dijkstra, Christine D.; van den Berg, Timo K.

    2005-01-01

    Mature tissue macrophages form a first line of defense to recognize and eliminate potential pathogens; these specialized cells are capable of phagocytosis, degradation of self and foreign materials, establishment of cell-cell interactions, and the production of inflammatory mediators. Mature tissue

  3. Proteolytic shedding of the macrophage scavenger receptor CD163 in multiple sclerosis

    DEFF Research Database (Denmark)

    Fabriek, Babs O; Møller, Holger J; Vloet, Rianka P M

    2007-01-01

    The scavenger receptor CD163 is selectively expressed on tissue macrophages and human monocytes. CD163 has been implicated to play a role in the clearance of hemoglobin and in the regulation of cytokine production by macrophages. Membrane CD163 can be cleaved by matrix metalloproteinases (MMP...

  4. The macrophage scavenger receptor CD163 functions as an innate immune sensor for bacteria

    NARCIS (Netherlands)

    Fabriek, Babs O.; van Bruggen, Robin; Deng, Dong Mei; Ligtenberg, Antoon J. M.; Nazmi, Kamran; Schornagel, Karin; Vloet, Rianka P. M.; Dijkstra, Christine D.; van den Berg, Timo K.

    2009-01-01

    The plasma membrane glycoprotein receptor CD163 is a member of the scavenger receptor cystein-rich (SRCR) superfamily class B that is highly expressed on resident tissue macrophages in vivo. Previously, the molecule has been shown to act as a receptor for hemoglobin-haptoglobin complexes and to

  5. Alternative activation of macrophages and pulmonary fibrosis are modulated by scavenger receptor, macrophage receptor with collagenous structure.

    Science.gov (United States)

    Murthy, Shubha; Larson-Casey, Jennifer L; Ryan, Alan J; He, Chao; Kobzik, Lester; Carter, A Brent

    2015-08-01

    Alternative activation of alveolar macrophages is linked to fibrosis following exposure to asbestos. The scavenger receptor, macrophage receptor with collagenous structure (MARCO), provides innate immune defense against inhaled particles and pathogens; however, a receptor for asbestos has not been identified. We hypothesized that MARCO acts as an initial signaling receptor for asbestos, polarizes macrophages to a profibrotic M2 phenotype, and is required for the development of asbestos-induced fibrosis. Compared with normal subjects, alveolar macrophages isolated from patients with asbestosis express higher amounts of MARCO and have greater profibrotic polarization. Arginase 1 (40-fold) and IL-10 (265-fold) were higher in patients. In vivo, the genetic deletion of MARCO attenuated the profibrotic environment and pulmonary fibrosis in mice exposed to chrysotile. Moreover, alveolar macrophages from MARCO(-/-) mice polarize to an M1 phenotype, whereas wild-type mice have higher Ym1 (>3.0-fold) and nearly 7-fold more active TGF-β1 in bronchoalveolar lavage (BAL) fluid (BALF). Arg(432) and Arg(434) in domain V of MARCO are required for the polarization of macrophages to a profibrotic phenotype as mutation of these residues reduced FIZZ1 expression (17-fold) compared with cells expressing MARCO. These observations demonstrate that a macrophage membrane protein regulates the fibrotic response to lung injury and suggest a novel target for therapeutic intervention. © FASEB.

  6. Human macrophage scavenger receptors: Primary structure, expression, and localization in atherosclerotic lesions

    International Nuclear Information System (INIS)

    Matsumoto, Akiyo; Itakura, Hiroshige; Kodama, Tatsuhiko; Naito, Makoto; Takahashi, Kiyoshi; Ikemoto, Shinji; Asaoka, Hitoshi; Hayakawa, Ikuho; Kanamori, Hiroshi; Takaku, Fumimaro; Aburatani, Hiroyuki; Suzuki, Hiroshi; Kobari, Yukage; Miyai, Tatsuya; Cohen, E.H.; Wydro, R.; Housman, D.E.

    1990-01-01

    Two types of cDNAs for human macrophage scavenger receptors were cloned from a cDNA library derived from the phorbol ester-treated human monocytic cell line THP-1. The type I and type II human scavenger receptors encoded by these cDNAs are homologous (73% and 71% amino acid identity) to their previously characterized bovine counterparts and consist of six domains: cytoplasmic (I), membrane-spanning (II), spacer (III), α-helical coiled-coil (IV), collagen-like (V), and a type-specific C-terminal (VI). The receptor gene is located on human chromosome 8. The human receptors expressed in CHO-K1 cells mediated endocytosis of modified low density lipoproteins. Two mRNAs, 4.0 and 3.2 kilobases, have been detected in human liver, placenta, and brain. Immunohistochemical studies using an anti-peptide antibody which recognizes human scavenger receptors indicated the presence of the scavenger receptors in the macrophages of lipid-rich atherosclerotic lesions, suggesting the involvement of scavenger receptors in atherogenesis

  7. Transgenic mouse models to study the role of the macrophage scavenger receptor class A in atherosclerosis

    NARCIS (Netherlands)

    de Winther, M. P.; Gijbels, M. J.; van Dijk, K. W.; Havekes, L. M.; Hofker, M. H.

    2000-01-01

    Several in vivo studies have been performed on the role of the macrophage scavenger receptor class A (SR-A) in atherosclerosis using SR-A knockout mice. The results indicate both an antiatherogenic and a proatherogenic role of SR-A, depending on the nature of the animal model serving as the

  8. In vitro photodynamic effects of scavenger receptor targeted-photoactivatable nanoagents on activated macrophages.

    Science.gov (United States)

    Yi, Bong Gu; Park, Ok Kyu; Jeong, Myeong Seon; Kwon, Seung Hae; Jung, Jae In; Lee, Seongsoo; Ryoo, Sungwoo; Kim, Sung Eun; Kim, Jin Won; Moon, Won-Jin; Park, Kyeongsoon

    2017-04-01

    Scavenger receptors (SRs) expressed on the activated macrophages in inflammation sites have been considered as the most interesting and important target biomarker for targeted drug delivery, imaging and therapy. In the present study, we fabricated the scavenger receptor-A (SR-A) targeted-photoactivatable nanoagents (termed as Ce6/DS-DOCA) by entrapping chlorin e6 (Ce6) into the amphiphilic dextran sulfate-deoxycholic acid (DS-DOCA) conjugates via physically hydrophobic interactions. Insoluble Ce6 was easily encapsulated into DS-DOCA nanoparticles by a dialysis method and the loading efficiency was approximately 51.7%. The Ce6/DS-DOCA formed nano-sized self-assembled aggregates (28.8±5.6nm in diameter), confirmed by transmission electron microscope, UV/Vis and fluorescence spectrophotometer. The Ce6/DS-DOCA nanoagents could generate highly reactive singlet oxygen under laser irradiation. Also, in vitro studies showed that they were more specifically taken up by lipopolysaccharide (LPS)-induced activated macrophages (RAW 264.7) via a SR-A-mediated endocytosis, relative to by non-activated macrophages, and notably induced cell death of activated macrophages under laser irradiation. Therefore, SR-A targetable and photoactivatable Ce6/DS-DOCA nanoagents with more selective targeting to the activated macrophages will have great potential for treatment of inflammatory diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. The macrophage scavenger receptor (CD163): a double-edged sword in treatment of malignant disease

    DEFF Research Database (Denmark)

    Maniecki, Maciej Bogdan

    2009-01-01

    of inflammatory processes. The receptor is expressed by circulatory monocytes and it is highly expressed on tissue-resident macrophages. CD163 is also expressed on leukemic blast cells of AML type M4/M5 and tumor cells in malignant melanoma and breast cancer. Although circumstantial evidence of the potential...... was investigated in biopsies from bladder cancer patients. We demonstrated that CD163 mRNA expression was significantly elevated in muscle invasive tumors (T2-T4) compared with superficial tumors (Ta), and that a high level of CD163 mRNA expression in tumor biopsies was significantly associated with poor 13-year......The hemoglobin scavenger receptor CD163 is a transmembrane glycoprotein belonging to the scavenger receptor cysteine-rich (SRCR) domain family. It mediates the clearance of hemoglobin released to the circulation during intravascular hemolysis, and it is also involved in the regulation...

  10. Scavenger receptor B1 facilitates macrophage uptake of silver nanoparticles and cellular activation

    Energy Technology Data Exchange (ETDEWEB)

    Aldossari, Abdullah A.; Shannahan, Jonathan H. [The University of Colorado Anschutz Medical Campus, Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences (United States); Podila, Ramakrishna [Clemson University, Department of Physics and Astronomy (United States); Brown, Jared M., E-mail: jared.brown@ucdenver.edu [The University of Colorado Anschutz Medical Campus, Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences (United States)

    2015-07-15

    Due to increased use of silver nanoparticles (AgNPs) for their antimicrobial activity, concerns have risen regarding potential adverse human health effects. Scavenger receptor B1 (SR-B1), a major receptor for high-density lipoprotein (HDL), is expressed by macrophages and has also been reported to play a role in recognition of negatively charged particles. We, therefore, hypothesized that SR-B1 mediates macrophage uptake of AgNPs and inflammatory activation. To test this hypothesis, we exposed a mouse macrophage cell line RAW264.7 (RAW) and bone marrow-derived macrophages (BMDM) to 20 nm citrate-suspended AgNPs. To verify the role of the SR-B1 receptor, we utilized a SR-B1 inhibitor (Blt2). In vitro studies demonstrated uptake of AgNPs and HDL-coated AgNPs by macrophages which were significantly reduced following pretreatment with Blt2. Inflammatory cytokine arrays revealed that macrophages exposed to AgNPs up-regulated expression of Tnf-α, Oncostatin m (OSM), Ccl4, Il17f, Ccl7, and Ccl2, whereas Il16 was found to be down-regulated. Macrophage activation was observed following AgNP and HDL-coated AgNP exposure as measured by OSM protein production and increased surface expression of CD86. These markers of activation were reduced with Blt2 pretreatment. The in vitro findings were confirmed in vivo through pulmonary instillation of AgNPs in mice. Pulmonary instillation of AgNPs resulted in a recruitment of inflammatory cells that were reduced in SR-B1-deficient mice or following Blt2 pretreatment. This study suggests that SR-B1 plays a major role in cellular recognition of AgNPs and the induction of cell responses that could contribute to inflammation caused by AgNP exposure.

  11. Scavenger receptor B1 facilitates macrophage uptake of silver nanoparticles and cellular activation

    Science.gov (United States)

    Aldossari, Abdullah A.; Shannahan, Jonathan H.; Podila, Ramakrishna; Brown, Jared M.

    2015-07-01

    Due to increased use of silver nanoparticles (AgNPs) for their antimicrobial activity, concerns have risen regarding potential adverse human health effects. Scavenger receptor B1 (SR-B1), a major receptor for high-density lipoprotein (HDL), is expressed by macrophages and has also been reported to play a role in recognition of negatively charged particles. We, therefore, hypothesized that SR-B1 mediates macrophage uptake of AgNPs and inflammatory activation. To test this hypothesis, we exposed a mouse macrophage cell line RAW264.7 (RAW) and bone marrow-derived macrophages (BMDM) to 20 nm citrate-suspended AgNPs. To verify the role of the SR-B1 receptor, we utilized a SR-B1 inhibitor (Blt2). In vitro studies demonstrated uptake of AgNPs and HDL-coated AgNPs by macrophages which were significantly reduced following pretreatment with Blt2. Inflammatory cytokine arrays revealed that macrophages exposed to AgNPs up-regulated expression of Tnf- α, Oncostatin m (OSM), Ccl4, Il17f, Ccl7, and Ccl2, whereas Il16 was found to be down-regulated. Macrophage activation was observed following AgNP and HDL-coated AgNP exposure as measured by OSM protein production and increased surface expression of CD86. These markers of activation were reduced with Blt2 pretreatment. The in vitro findings were confirmed in vivo through pulmonary instillation of AgNPs in mice. Pulmonary instillation of AgNPs resulted in a recruitment of inflammatory cells that were reduced in SR-B1-deficient mice or following Blt2 pretreatment. This study suggests that SR-B1 plays a major role in cellular recognition of AgNPs and the induction of cell responses that could contribute to inflammation caused by AgNP exposure.

  12. Design and synthesis of a stable oxidized phospholipid mimic with specific binding recognition for macrophage scavenger receptors

    DEFF Research Database (Denmark)

    Turner, William W; Hartvigsen, Karsten; Boullier, Agnes

    2012-01-01

    Macrophage scavenger receptors appear to play a major role in the clearance of oxidized phospholipid (OxPL) products. Discrete peptide-phospholipid conjugates with the phosphatidylcholine headgroup have been shown to exhibit binding affinity for these receptors. We report the preparation of a wat...

  13. Suppression of TLR4-mediated inflammatory response by macrophage class A scavenger receptor (CD204)

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Koji; Komohara, Yoshihiro; Fujiwara, Yukio; Takemura, Kenichi [Department of Cell Pathology, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto (Japan); Lei, XiaoFeng [Department of Cell Pathology, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto (Japan); Department of Biochemistry, Showa University School of Medicine, Tokyo (Japan); Nakagawa, Takenobu [Department of Cell Pathology, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto (Japan); Sakashita, Naomi [Department of Cell Pathology, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto (Japan); Department of Human Pathology, Institute of Health Biosciences, The University of Tokushima, Tokushima (Japan); Takeya, Motohiro, E-mail: takeya@kumamoto-u.ac.jp [Department of Cell Pathology, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto (Japan)

    2011-08-05

    Highlights: {yields} We focused on the interaction between SR-A and TLR4 signaling in this study. {yields} SR-A deletion promoted NF{kappa}B activation in macrophages in septic model mouse. {yields} SR-A suppresses both MyD88-dependent and -independent TLR4 signaling in vitro. {yields} SR-A clears LPS binding to TLR4 which resulting in the suppression of TLR4 signals. -- Abstract: The class A scavenger receptor (SR-A, CD204), one of the principal receptors expressed on macrophages, has been found to regulate inflammatory response and attenuate septic endotoxemia. However, the detailed mechanism of this process has not yet been well characterized. To clarify the regulative mechanisms of lipopolysaccharide (LPS)-induced macrophage activation by SR-A, we evaluated the activation of Toll-like receptor 4 (TLR4)-mediated signaling molecules in SR-A-deficient (SR-A{sup -/-}) macrophages. In a septic shock model, the blood levels of tumor necrosis factor (TNF)-{alpha}, interleukin (IL)-6 and interferon (IFN)-{beta} were significantly increased in SR-A{sup -/-} mice compared to wild-type mice, and elevated nuclear factor kappa B (NF{kappa}B) activation was detected in SR-A{sup -/-} macrophages. SR-A deletion increased the production of pro-inflammatory cytokines, and the phosphorylation of mitogen-activated protein kinase (MAPK) and NF{kappa}B in vitro. SR-A deletion also promoted the nuclear translocation of NF{kappa}B and IFN regulatory factor (IRF)-3. In addition, a competitive binding assay with acetylated low-density lipoprotein, an SR-A-specific ligand, and anti-SR-A antibody induced significant activation of TLR4-mediated signaling molecules in wild-type macrophages but not in SR-A{sup -/-} macrophages. These results suggest that SR-A suppresses the macrophage activation by inhibiting the binding of LPS to TLR4 in a competitive manner and it plays a pivotal role in the regulation of the LPS-induced inflammatory response.

  14. Protection against inhaled oxidants through scavenging of oxidized lipids by macrophage receptors MARCO and SR-AI/II

    DEFF Research Database (Denmark)

    Dahl, Morten; Bauer, Alison K; Arredouani, Mohamed

    2007-01-01

    Alveolar macrophages (AMs) express the class A scavenger receptors (SRAs) macrophage receptor with collagenous structure (MARCO) and scavenger receptor AI/II (SRA-I/II), which recognize oxidized lipids and provide innate defense against inhaled pathogens and particles. Increased MARCO expression...... in lungs of ozone-resistant mice suggested an additional role protecting against inhaled oxidants. After ozone exposure, MARCO-/- mice showed greater lung injury than did MARCO+/+ mice. Ozone is known to generate oxidized, proinflammatory lipids in lung lining fluid, such as 5beta,6beta......-epoxycholesterol (beta-epoxide) and 1-palmitoyl-2-(9'-oxo-nonanoyl)-glycerophosphocholine (PON-GPC). Intratracheal instillation of either lipid caused substantial neutrophil influx in MARCO-/- mice, but had no effect in MARCO+/+ mice. Normal AMs showed greater uptake in vitro of beta-epoxide compared with MARCO-/- AMs...

  15. Key Role of the Scavenger Receptor MARCO in Mediating Adenovirus Infection and Subsequent Innate Responses of Macrophages.

    Science.gov (United States)

    Maler, Mareike D; Nielsen, Peter J; Stichling, Nicole; Cohen, Idan; Ruzsics, Zsolt; Wood, Connor; Engelhard, Peggy; Suomalainen, Maarit; Gyory, Ildiko; Huber, Michael; Müller-Quernheim, Joachim; Schamel, Wolfgang W A; Gordon, Siamon; Jakob, Thilo; Martin, Stefan F; Jahnen-Dechent, Willi; Greber, Urs F; Freudenberg, Marina A; Fejer, György

    2017-08-01

    The scavenger receptor MARCO is expressed in several subsets of naive tissue-resident macrophages and has been shown to participate in the recognition of various bacterial pathogens. However, the role of MARCO in antiviral defense is largely unexplored. Here, we investigated whether MARCO might be involved in the innate sensing of infection with adenovirus and recombinant adenoviral vectors by macrophages, which elicit vigorous immune responses in vivo Using cells derived from mice, we show that adenovirus infection is significantly more efficient in MARCO-positive alveolar macrophages (AMs) and in AM-like primary macrophage lines (Max Planck Institute cells) than in MARCO-negative bone marrow-derived macrophages. Using antibodies blocking ligand binding to MARCO, as well as gene-deficient and MARCO-transfected cells, we show that MARCO mediates the rapid adenovirus transduction of macrophages. By enhancing adenovirus infection, MARCO contributes to efficient innate virus recognition through the cytoplasmic DNA sensor cGAS. This leads to strong proinflammatory responses, including the production of interleukin-6 (IL-6), alpha/beta interferon, and mature IL-1α. These findings contribute to the understanding of viral pathogenesis in macrophages and may open new possibilities for the development of tools to influence the outcome of infection with adenovirus or adenovirus vectors. IMPORTANCE Macrophages play crucial roles in inflammation and defense against infection. Several macrophage subtypes have been identified with differing abilities to respond to infection with both natural adenoviruses and recombinant adenoviral vectors. Adenoviruses are important respiratory pathogens that elicit vigorous innate responses in vitro and in vivo The cell surface receptors mediating macrophage type-specific adenovirus sensing are largely unknown. The scavenger receptor MARCO is expressed on some subsets of naive tissue-resident macrophages, including lung alveolar macrophages

  16. Macrophage specific overexpression of the human macrophage scavenger receptor in transgenic mice, using a 180-kb yeast artificial chromosome, leads to enhanced foam cell formation of isolated peritoneal macrophages

    NARCIS (Netherlands)

    de Winther, M. P.; van Dijk, K. W.; van Vlijmen, B. J.; Gijbels, M. J.; Heus, J. J.; Wijers, E. R.; van den Bos, A. C.; Breuer, M.; Frants, R. R.; Havekes, L. M.; Hofker, M. H.

    1999-01-01

    Macrophage scavenger receptors class A (MSR) are thought to play an important role in atherogenesis by mediating the unrestricted uptake of modified lipoproteins by macrophages in the vessel wall leading to foam cell formation. To investigate the in vivo role of the MSR in this process, a transgenic

  17. The macrophage scavenger receptor CD163 functions as an innate immune sensor for bacteria

    NARCIS (Netherlands)

    Fabriek, B.O.; van Bruggen, R.; Deng, D.M.; Ligtenberg, A.J.M.; Nazmi, K.; Schornagel, K.; Vloet, R.P.M.; Dijkstra, C.D.; van den Berg, T.K.

    2009-01-01

    The plasma membrane glycoprotein re- ceptor CD163 is a member of the scaven- ger receptor cystein-rich (SRCR) super- family class B that is highly expressed on resident tissue macrophages in vivo. Pre- viously, the molecule has been shown to act as a receptor for hemoglobin- haptoglobin complexes

  18. Decreased immunostaining for macrophage scavenger receptor is associated with poor prognosis of prostate cancer.

    Science.gov (United States)

    Takayama, Hitoshi; Nonomura, Norio; Nishimura, Kazuo; Oka, Daizo; Shiba, Masahiro; Nakai, Yasutomo; Nakayama, Masashi; Tsujimura, Akira; Aozasa, Katsuyuki; Okuyama, Akihiko

    2009-02-01

    The aim of this study is to evaluate the expression of the macrophage scavenger receptor (MSR) in prostate needle biopsy specimens as a possible prognostic factor for prostate cancer. As MSR reportedly has a role in recognizing foreign pathogenic substances, MSR-positive inflammatory cells are often detected in solid tumours, and there is a correlation between the relative risk of prostate cancer and polymorphism of the MSR gene. MSR was evaluated by immunostaining in needle biopsies of the prostate from 135 patients who were confirmed to have prostate cancer. Among these men, 70 were treated by radical prostatectomy or by radiotherapy as definitive therapy; the other 65 were treated by hormonal therapy because of advanced disease or age. Needle-biopsy specimens were sectioned at 5 microm and immunostained with a monoclonal antibody against MSR. Six microscopic (x400) fields around the cancer foci were selected in each case for analysis. The median number of MSR-positive cells (MSR count) in each case was 24. There was an inverse correlation between the MSR count and Gleason score and clinical stage. The MSR count was lower in patients with biochemical (prostate-specific antigen, PSA) failure than that in those with no PSA failure (P or =24) than that in those with low MSR count (<24, P < 0.001). Moreover, for patients treated by definitive or hormonal therapy, the RFS rates in those with a higher MSR count were higher than in those with a lower MSR count (P < 0.001 and 0.014, respectively). Cox multivariate analysis showed that the MSR count was a prognostic factor for prostate cancer in addition to extraprostatic extension and Gleason score (P = 0.002, 0.038 and 0.011, respectively). The results of immunostaining of MSR in needle-biopsy specimens is a prognostic factor for prostate cancer.

  19. Major Vault Protein Regulates Class A Scavenger Receptor-mediated Tumor Necrosis Factor-α Synthesis and Apoptosis in Macrophages*

    Science.gov (United States)

    Ben, Jingjing; Zhang, Yan; Zhou, Rongmei; Zhang, Haiyang; Zhu, Xudong; Li, Xiaoyu; Zhang, Hanwen; Li, Nan; Zhou, Xiaodan; Bai, Hui; Yang, Qing; Li, Donghai; Xu, Yong; Chen, Qi

    2013-01-01

    Atherosclerosis is considered a disease of chronic inflammation largely initiated and perpetuated by macrophage-dependent synthesis and release of pro-inflammatory mediators. Class A scavenger receptor (SR-A) expressed on macrophages plays a key role in this process. However, how SR-A-mediated pro-inflammatory response is modulated in macrophages remains ill defined. Here through immunoprecipitation coupled with mass spectrometry, we reported major vault protein (MVP) as a novel binding partner for SR-A. The interaction between SR-A and MVP was confirmed by immunofluorescence staining and chemical cross-linking assay. Treatment of macrophages with fucoidan, a SR-A ligand, led to a marked increase in TNF-α production, which was attenuated by MVP depletion. Further analysis revealed that SR-A stimulated TNF-α synthesis in macrophages via the caveolin- instead of clathrin-mediated endocytic pathway linked to p38 and JNK, but not ERK, signaling pathways. Importantly, fucoidan invoked an enrichment of MVP in lipid raft, a caveolin-reliant membrane structure, and enhanced the interaction among SR-A, caveolin, and MVP. Finally, we demonstrated that MVP elimination ameliorated SR-A-mediated apoptosis in macrophages. As such, MVP may fine-tune SR-A activity in macrophages which contributes to the development of atherosclerosis. PMID:23703615

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Scavenger receptor-mediated recognition of maleyl bovine plasma albumin and the demaleylated protein in human monocyte macrophages

    International Nuclear Information System (INIS)

    Haberland, M.E.; Fogelman, A.M.

    1985-01-01

    Maleyl bovine plasma albumin competed on an equimolar basis with malondialdehyde low density lipoprotein (LDL) in suppressing the lysosomal hydrolysis of 125 I-labeled malondialdehyde LDL mediated by the scavenger receptor of human monocyte macrophages. Maleyl bovine plasma albumin, in which 94% of the amino groups were modified, exhibited an anodic mobility in agarose electrophoresis 1.7 times that of the native protein. Incubation of maleyl bovine plasma albumin at pH 3.5 regenerated the free amino groups and restored the protein to the same electrophoretic mobility as native albumin. Although ligands recognized by the scavenger receptor typically are anionic, the authors propose that addition of new negative charge achieved by maleylation, rather than directly forming the receptor binding site(s), induces conformational changes in albumin as a prerequisite to expression of the recognition domain(s). They conclude that the primary sequence of albumin, rather than addition of new negative charge, provides the recognition determinant(s) essential for interaction of maleyl bovine plasma albumin with the scavenger receptor

  2. Scavenger receptors in homeostasis and immunity.

    Science.gov (United States)

    Canton, Johnathan; Neculai, Dante; Grinstein, Sergio

    2013-09-01

    Scavenger receptors were originally identified by their ability to recognize and to remove modified lipoproteins; however, it is now appreciated that they carry out a striking range of functions, including pathogen clearance, lipid transport, the transport of cargo within the cell and even functioning as taste receptors. The large repertoire of ligands recognized by scavenger receptors and their broad range of functions are not only due to the wide range of receptors that constitute this family but also to their ability to partner with various co-receptors. The ability of individual scavenger receptors to associate with different co-receptors makes their responsiveness extremely versatile. This Review highlights recent insights into the structural features that determine the function of scavenger receptors and the emerging role that these receptors have in immune responses, notably in macrophage polarization and in the pathogenesis of diseases such as atherosclerosis and Alzheimer's disease.

  3. Structures of class A macrophage scavenger receptors. Electron microscopic study of flexible, multidomain, fibrous proteins and determination of the disulfide bond pattern of the scavenger receptor cysteine-rich domain.

    Science.gov (United States)

    Resnick, D; Chatterton, J E; Schwartz, K; Slayter, H; Krieger, M

    1996-10-25

    Structures of secreted forms of the human type I and II class A macrophage scavenger receptors were studied using biochemical and biophysical methods. Proteolytic analysis was used to determine the intramolecular disulfide bonds in the type I-specific scavenger receptor cysteine-rich (SRCR) domain: Cys2-Cys7, Cys3-Cys8, and Cys5-Cys6. This pattern is likely to be shared by the highly homologous domains in the many other members of the SRCR domain superfamily. Electron microscopy using rotary shadowing and negative staining showed that the type I and II receptors are extended molecules whose contour lengths are approximately 440 A. They comprised two adjacent fibrous segments, an alpha-helical coiled-coil ( approximately 230 A, including a contribution from the N-terminal spacer domain) and a collagenous triple helix ( approximately 210 A). The type I molecules also contained a C-terminal globular structure ( approximately 58 x 76 A) composed of three SRCR domains. The fibrous domains were joined by an extremely flexible hinge. The angle between these domains varied from 0 to 180 degrees and depended on the conditions of sample preparation. Unexpectedly, at physiologic pH, the prevalent angle seen using rotary shadowing was 0 degrees , resulting in a structure that is significantly more compact than previously suggested. The apparent juxtaposition of the fibrous domains at neutral pH provides a framework for future structure-function studies of these unusual multiligand receptors.

  4. Function of macrophage scavenger receptor 1 gene polymorphisms in chronic obstructive pulmonary disease with and without lung cancer in China.

    Science.gov (United States)

    Xie, Liang; Chen, Wei; Dong, Ran; He, Bin; Zhao, Kaishun; Zhang, Li; Zhou, Min; He, Ping

    2018-05-01

    The present study assessed the association between the variants of macrophage scavenger receptor (MSR)1 and chronic obstructive pulmonary disease (COPD), with or without lung cancer in China. COPD and lung cancer were previously regarded as two separate diseases. However, it has since been reported that there are close associations between COPD and lung cancer. Lung cancer may be an outcome of COPD. COPD may also coexist with lung cancer, and patients with COPD with lung cancer tend to have increased mortality. It is important to have a better understanding of the pathogenesis of COPD and the reason why it develops into lung cancer. MSR1 serves a crucial function in phagocytosis, which may be associated with the pathogenesis of COPD and lung cancer in patients with COPD. From 1 July 2015 to 20 February 2016, 100 patients with COPD and lung cancer, 100 patients with COPD without lung cancer and 100 healthy smokers were enrolled at the Shanghai Ruijin Hospital (Shanghai, China) for the genotyping of eight single-nucleotide polymorphisms (SNPs; ex3P36A_C>G, ex3S41Y_C>A, ex4V113A_T>C, ex4P174Y_G>T, ex6P275A_C>G, ex6R293×_C>T, ex10G369S_G>A and ex11H441R_A>G) via gene sequencing. The genotype frequencies of these SNPs did not significantly differ between patients with COPD with and without lung cancer, and the healthy controls. However, during DNA sequencing, the SNP rs13306550 (IVS4+3A>G) was identified in the splice donor site and was significantly associated with an increased risk of COPD compared with the healthy smokers (P=0.0053). The present study demonstrated that the variant rs13306550 was a risk factor for COPD susceptibility, but that did not influence lung cancer pathogenesis in patients with COPD. However, the mechanisms underlying the influence of rs13306550 on COPD development and progression remain to be elucidated and require further study.

  5. Artesunate Reduces Serum Lipopolysaccharide in Cecal Ligation/Puncture Mice via Enhanced LPS Internalization by Macrophages through Increased mRNA Expression of Scavenger Receptors

    Directory of Open Access Journals (Sweden)

    Bin Li

    2014-01-01

    Full Text Available Innate immunity is the first line of defense in human beings against pathogen infection; monocytes/macrophages are the primary cells of the innate immune system. Recently, macrophages/monocytes have been discovered to participate in LPS clearance, and the clearance efficiency determines the magnitude of the inflammatory response and subsequent organ injury. Previously, we reported that artesunate (AS protected sepsis mice against heat-killed E. coli challenge. Herein, we further confirmed that AS protected cecal ligation/puncture (CLP sepsis mice. Its protection on sepsis mice was related to not only reduction of pro-inflammatory cytokines and serum LPS levels but also improvement of liver function. Based on the fact that AS did not directly bind and neutralize LPS, we hypothesized that the reduction of serum LPS level might be related to enhancement of LPS internalization and subsequent detoxification. Our results showed that AS increased FITC-LPS internalization by peritoneal macrophage and liver Kupffer cell, but enhancement of LPS internalization by AS was not related to the clathrin-dependent pathway. However, AS induced mRNA expression of important scavenger receptors (SRs; SR-A and MARCO mRNA expression was upregulated, suggesting that AS enhancement of LPS internalization and inhibition of pro-inflammatory cytokines was related to changes in mRNA expression of SRs.

  6. Surfactant protein A (SP-A)-mediated clearance of Staphylococcus aureus involves binding of SP-A to the staphylococcal adhesin eap and the macrophage receptors SP-A receptor 210 and scavenger receptor class A.

    Science.gov (United States)

    Sever-Chroneos, Zvjezdana; Krupa, Agnieszka; Davis, Jeremy; Hasan, Misbah; Yang, Ching-Hui; Szeliga, Jacek; Herrmann, Mathias; Hussain, Muzafar; Geisbrecht, Brian V; Kobzik, Lester; Chroneos, Zissis C

    2011-02-11

    Staphylococcus aureus causes life-threatening pneumonia in hospitals and deadly superinfection during viral influenza. The current study investigated the role of surfactant protein A (SP-A) in opsonization and clearance of S. aureus. Previous studies showed that SP-A mediates phagocytosis via the SP-A receptor 210 (SP-R210). Here, we show that SP-R210 mediates binding and control of SP-A-opsonized S. aureus by macrophages. We determined that SP-A binds S. aureus through the extracellular adhesin Eap. Consequently, SP-A enhanced macrophage uptake of Eap-expressing (Eap(+)) but not Eap-deficient (Eap(-)) S. aureus. In a reciprocal fashion, SP-A failed to enhance uptake of Eap(+) S. aureus in peritoneal Raw264.7 macrophages with a dominant negative mutation (SP-R210(DN)) blocking surface expression of SP-R210. Accordingly, WT mice cleared infection with Eap(+) but succumbed to sublethal infection with Eap- S. aureus. However, SP-R210(DN) cells compensated by increasing non-opsonic phagocytosis of Eap(+) S. aureus via the scavenger receptor scavenger receptor class A (SR-A), while non-opsonic uptake of Eap(-) S. aureus was impaired. Macrophages express two isoforms: SP-R210(L) and SP-R210(S). The results show that WT alveolar macrophages are distinguished by expression of SP-R210(L), whereas SR-A(-/-) alveolar macrophages are deficient in SP-R210(L) expressing only SP-R210(S). Accordingly, SR-A(-/-) mice were highly susceptible to both Eap(+) and Eap(-) S. aureus. The lungs of susceptible mice generated abnormal inflammatory responses that were associated with impaired killing and persistence of S. aureus infection in the lung. In conclusion, alveolar macrophage SP-R210(L) mediates recognition and killing of SP-A-opsonized S. aureus in vivo, coordinating inflammatory responses and resolution of S. aureus pneumonia through interaction with SR-A.

  7. Is the scavenger receptor MARCO a new immune checkpoint?

    Science.gov (United States)

    Arredouani, Mohamed S

    2014-11-01

    Whereas macrophages use the scavenger receptor MARCO primarily in antimicrobial immunity by interacting with both exogenous and endogenous environments, in dendritic cells (DCs) MARCO is believed to pleiotropically link innate to adaptive immunity. MARCO exerts a significant modulatory effect on TLR-induced DC activation, thus offering novel avenues in cancer immunotherapy.

  8. Scavenger receptor AI/II truncation, lung function and COPD

    DEFF Research Database (Denmark)

    Thomsen, M; Nordestgaard, B G; Tybjaerg-Hansen, A

    2011-01-01

    The scavenger receptor A-I/II (SRA-I/II) on alveolar macrophages is involved in recognition and clearance of modified lipids and inhaled particulates. A rare variant of the SRA-I/II gene, Arg293X, truncates the distal collagen-like domain, which is essential for ligand recognition. We tested whet...

  9. Hemoglobin and heme scavenger receptors

    DEFF Research Database (Denmark)

    Nielsen, Marianne Jensby; Møller, Holger Jon; Moestrup, Søren Kragh

    2010-01-01

    Heme, the functional group of hemoglobin, myoglobin, and other hemoproteins, is a highly toxic substance when it appears in the extracellular milieu. To circumvent potential harmful effects of heme from hemoproteins released during physiological or pathological cell damage (such as hemolysis...... and rhabdomyolysis), specific high capacity scavenging systems have evolved in the mammalian organism. Two major systems, which essentially function in a similar way by means of a circulating latent plasma carrier protein that upon ligand binding is recognized by a receptor, are represented by a) the hemoglobin...

  10. High density lipoprotein stimulated migration of macrophages depends on the scavenger receptor class B, type I, PDZK1 and Akt1 and is blocked by sphingosine 1 phosphate receptor antagonists.

    Directory of Open Access Journals (Sweden)

    Aishah Al-Jarallah

    Full Text Available HDL carries biologically active lipids such as sphingosine-1-phosphate (S1P and stimulates a variety of cell signaling pathways in diverse cell types, which may contribute to its ability to protect against atherosclerosis. HDL and sphingosine-1-phosphate receptor agonists, FTY720 and SEW2871 triggered macrophage migration. HDL-, but not FTY720-stimulated migration was inhibited by an antibody against the HDL receptor, SR-BI, and an inhibitor of SR-BI mediated lipid transfer. HDL and FTY720-stimulated migration was also inhibited in macrophages lacking either SR-BI or PDZK1, an adaptor protein that binds to SR-BI's C-terminal cytoplasmic tail. Migration in response to HDL and S1P receptor agonists was inhibited by treatment of macrophages with sphingosine-1-phosphate receptor type 1 (S1PR1 antagonists and by pertussis toxin. S1PR1 activates signaling pathways including PI3K-Akt, PKC, p38 MAPK, ERK1/2 and Rho kinases. Using selective inhibitors or macrophages from gene targeted mice, we demonstrated the involvement of each of these pathways in HDL-dependent macrophage migration. These data suggest that HDL stimulates the migration of macrophages in a manner that requires the activities of the HDL receptor SR-BI as well as S1PR1 activity.

  11. The Evolution of the Scavenger Receptor Cysteine-Rich Domain of the Class A Scavenger Receptors

    Directory of Open Access Journals (Sweden)

    Nicholas eYap

    2015-07-01

    Full Text Available The class A Scavenger Receptor (cA-SR family is a group of five evolutionarily related innate immune receptors. The cA-SRs are known for their promiscuous ligand binding; as they have been shown to bind bacteria such as Streptococcus pneumoniae, and Escherichia coli, as well as different modified forms of low-density lipoprotein. Three of the five family members possess a Scavenger Receptor Cysteine Rich (SRCR domain while the remaining two receptors lack the domain. Previous work has suggested that the Macrophage Associated Receptor with COllagenous structure (MARCO shares a recent common ancestor with the non-SRCR-containing receptors; however the origin of the SRCR domain within the cA-SRs remains unknown. We hypothesize that the SRCR domains of the cA-SRs have a common origin that predates teleost fish. Using the newly available sequence data from sea lamprey and ghost shark genome projects, we have shown that MARCO shares a common ancestor with the SRCR-containing proteins. In addition, we explored the evolutionary relationships within the SRCR domain by reconstructing the ancestral SRCR domains of the cA-SRs. We identified a motif that is highly conserved between the cA-SR SRCR domains and the ancestral SRCR domain that consist of WGTVCDD. We also show that the GRAEVYY motif, a functionally important motif within MARCO, is poorly conserved in the other cA-SRs and in the reconstructed ancestral domain. Further, we identified three sites within MARCO’s SRCR domain which are under positive selection. Two of these sites lie adjacent to the conserved WGTVCDD motif, and may indicate a potential biological function for these sites. Together these findings indicate a common origin of the SRCR domain within the cA-SRs; however different selective pressures between the proteins may have caused MARCOs SRCR domain to evolve to contain different functional motifs when compared to the other SRCR-containing cA-SRs.

  12. Scavenger Receptor CD163 and Its Biological Functions

    Directory of Open Access Journals (Sweden)

    Gabriela Onofre

    2009-01-01

    Full Text Available CD163 is a member of scavenger receptor super family class B of the first subgroup. It is mapped to the region p13 on chromosome 12. Five different isoforms of CD163 have been described, which differ in the structure of their cytoplasmic domains and putative phosporylation sites. This scavenger receptor is selectively expressed on cells of monocytes and macrophages lineage exclusively. CD163 immunological function is essentially homeostatic. It also has other functions because participates in adhesion to endothelial cells, in tolerance induction and tissues regeneration. Other very important function of CD163 is the clearance of hemoglobin in its cell-free form and participation in anti-inflammation in its soluble form, exhibiting cytokine-like functions. We review the biological functions of CD163 which have been discovered until now. It seems apparent from this review that CD163 scavenger receptor can be used as biomarker in different diseases and as a valuable diagnostic parameter for prognosis of many diseases especially inflammatory disorders and sepsis.

  13. Scavenger Receptors and Resistance to Inhaled Allergens

    Science.gov (United States)

    2010-02-01

    throughput manner which will enable future studies. We plan to continue two especially interesting aspects of these studies. First, the epigenetic control...directs mod- ified proteins to antigen presentation. Eur. J. Immunol. 29: 512–521. 30. Granucci, F., F. Petralia, M. Urbano , S. Citterio, F. Di Tota, L...11 Suppl:S32-6. 50. Granucci F, Petralia F, Urbano M, Citterio S, Di Tota F, Santambrogio L, Ricciardi-Castagnoli P: The scavenger receptor MARCO

  14. Scavenger receptor AI/II truncation, lung function and COPD: a large population-based study

    DEFF Research Database (Denmark)

    Thomsen, M; Nordestgaard, B G; Tybjærg-Hansen, Anne

    2011-01-01

    The scavenger receptor A-I/II (SRA-I/II) on alveolar macrophages is involved in recognition and clearance of modified lipids and inhaled particulates. A rare variant of the SRA-I/II gene, Arg293X, truncates the distal collagen-like domain, which is essential for ligand recognition. We tested...... whether the Arg293X variant is associated with reduced lung function and risk of chronic obstructive pulmonary disease (COPD) in the general population....

  15. The Scavenger Protein Apoptosis Inhibitor of Macrophages (AIM) Potentiates the Antimicrobial Response against Mycobacterium tuberculosis by Enhancing Autophagy

    Science.gov (United States)

    Sanjurjo, Lucía; Amézaga, Núria; Vilaplana, Cristina; Cáceres, Neus; Marzo, Elena; Valeri, Marta; Cardona, Pere-Joan; Sarrias, Maria-Rosa

    2013-01-01

    Apoptosis inhibitor of macrophages (AIM), a scavenger protein secreted by tissue macrophages, is transcriptionally regulated by the nuclear receptor Liver X Receptor (LXR) and Retinoid X Receptor (RXR) heterodimer. Given that LXR exerts a protective immune response against M. tuberculosis, here we analyzed whether AIM is involved in this response. In an experimental murine model of tuberculosis, AIM serum levels peaked dramatically early after infection with M. tuberculosis, providing an in vivo biological link to the disease. We therefore studied the participation of AIM in macrophage response to M. tuberculosis in vitro. For this purpose, we used the H37Rv strain to infect THP-1 macrophages transfected to stably express AIM, thereby increasing infected macrophage survival. Furthermore, the expression of this protein enlarged foam cell formation by enhancing intracellular lipid content. Phagocytosis assays with FITC-labeled M. tuberculosis bacilli indicated that this protein was not involved in bacterial uptake; however, AIM expression decreased the number of intracellular cfus by up to 70% in bacterial killing assays, suggesting that AIM enhances macrophage mycobactericidal activity. Accordingly, M. tuberculosis-infected AIM-expressing cells upregulated the production of reactive oxygen species. Moreover, real-time PCR analysis showed increased mRNA levels of the antimicrobial peptides cathelicidin and defensin 4B. These increases were concomitant with greater cellular concentrations of the autophagy-related molecules Beclin 1 and LC3II, as well as enhanced acidification of mycobacterial phagosomes and LC3 co-localization. In summary, our data support the notion that AIM contributes to key macrophage responses to M. tuberculosis. PMID:24223991

  16. DMPD: Macrophage-stimulating protein and RON receptor tyrosine kinase: potentialregulators of macrophage inflammatory activities. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 12472665 Macrophage-stimulating protein and RON receptor tyrosine kinase: potential...:545-53. (.png) (.svg) (.html) (.csml) Show Macrophage-stimulating protein and RON receptor tyrosine kinase:...le Macrophage-stimulating protein and RON receptor tyrosine kinase: potentialregulators of macrophage inflam

  17. Receptor-Mediated Drug Delivery to Macrophages in Chemotherapy of Leishmaniasis

    Science.gov (United States)

    Mukhopadhyay, Amitabha; Chaudhuri, Gautam; Arora, Sunil K.; Sehgal, Shobha; Basu, Sandip K.

    1989-05-01

    Methotrexate coupled to maleylated bovine serum albumin was taken up efficiently through the ``scavenger'' receptors present on macrophages and led to selective killing of intracellular Leishmania mexicana amazonensis amastigotes in cultured hamster peritoneal macrophages. The drug conjugate was nearly 100 times as effective as free methotrexate in eliminating the intracellular parasites. Furthermore, in a model of experimental cutaneous leishmaniasis in hamsters, the drug conjugate brought about more than 90% reduction in the size of footpad lesions within 11 days. In contrast, the free drug at a similar concentration did not significantly affect lesion size. These studies demonstrate the potential of receptor-mediated drug delivery in the therapy of macrophage-associated diseases.

  18. Scavenger

    DEFF Research Database (Denmark)

    2009-01-01

    Scavenger is one of the cyber foraging frameworks developed in the Locusts project. It has been released as open source software at http://code.google.com/p/scavenger-cf/......Scavenger is one of the cyber foraging frameworks developed in the Locusts project. It has been released as open source software at http://code.google.com/p/scavenger-cf/...

  19. The LOX-1 Scavenger Receptor and Its Implications in the Treatment of Vascular Disease

    Directory of Open Access Journals (Sweden)

    M. W Twigg

    2012-01-01

    Full Text Available Cardiovascular disease is the leading cause of death. The disease is due to atherosclerosis which is characterized by lipid and fat accumulation in arterial blood vessel walls. A key causative event is the accumulation of oxidised low density lipoprotein particles within vascular cells, and this is mediated by scavenger receptors. One such molecule is the LOX-1 scavenger receptor that is expressed on endothelial, vascular smooth muscle, and lymphoid cells including macrophages. LOX-1 interaction with OxLDL particles stimulates atherosclerosis. LOX-1 mediates OxLDL endocytosis via a clathrin-independent internalization pathway. Transgenic animal model studies show that LOX-1 plays a significant role in atherosclerotic plaque initiation and progression. Administration of LOX-1 antibodies in cellular and animal models suggest that such intervention inhibits atherosclerosis. Antiatherogenic strategies that target LOX-1 function using gene therapy or small molecule inhibitors would be new ways to address the increasing incidence of vascular disease in many countries.

  20. Identification of the receptor scavenging hemopexin-heme complexes

    DEFF Research Database (Denmark)

    Hvidberg, Vibeke; Maniecki, Maciej B; Jacobsen, Christian

    2005-01-01

    and is suggested to facilitate cellular heme metabolism. Using a ligand-affinity approach, we purified the human hemopexin-heme receptor and identified it as the low-density lipoprotein receptor-related protein (LRP)/CD91, a receptor expressed in several cell types including macrophages, hepatocytes, neurons......, and syncytiotrophoblasts. Binding experiments, including Biacore analysis, showed that hemopexin-heme complex formation elicits the high receptor affinity. Uptake studies of radio-labeled hemopexin-heme complex in LRP/CD91-expressing COS cells and confocal microscopy of the cellular processing of fluorescent hemopexin......-heme complexes are removed by a receptor-mediated pathway showing striking similarities to the CD163-mediated haptoglobin-hemoglobin clearance in macrophages. Furthermore, the data indicate a hitherto unknown role of LRP/CD91 in inflammation....

  1. Scavenger Receptor BI Plays a Role in Facilitating Chylomicron Metabolism

    NARCIS (Netherlands)

    Out, R.; Kruijt, J.K.; Rensen, P.C.N.; Hildebrand, R.B.; Vos, P. de; Eck, M. van; Berkel, T.J.C. van

    2004-01-01

    The function of scavenger receptor class B type I (SR-BI) in mediating the selective uptake of high density lipoprotein (HDL) cholesterol esters is well established. However, the potential role of SR-BI in chylomicron and chylomicron remnant metabolism is largely unknown. In the present

  2. Genetic Variant of the Scavenger Receptor BI in Humans

    NARCIS (Netherlands)

    Vergeer, Menno; Korporaal, Suzanne J. A.; Franssen, Remco; Meurs, Illiana; Out, Ruud; Hovingh, G. Kees; Hoekstra, Menno; Sierts, Jeroen A.; Dallinga-Thie, Geesje M.; Motazacker, Mohammad Mahdi; Holleboom, Adriaan G.; van Berkel, Theo J. C.; Kastelein, John J. P.; van Eck, Miranda; Kuivenhoven, Jan Albert

    2011-01-01

    BACKGROUND In mice, the scavenger receptor class B type I (SR-BI) is essential for the delivery of high-density lipoprotein (HDL) cholesterol to the liver and steroidogenic organs. Paradoxically, elevated HDL cholesterol levels are associated with increased atherosclerosis in SR-BI-knockout mice. It

  3. Genetic variant of the scavenger receptor BI in humans

    NARCIS (Netherlands)

    Vergeer, Menno; Korporaal, Suzanne J A; Franssen, Remco; Meurs, Illiana; Out, Ruud; Hovingh, G Kees; Hoekstra, Menno; Sierts, Jeroen A; Dallinga-Thie, Geesje M; Motazacker, Mohammad Mahdi; Holleboom, Adriaan G; Van Berkel, Theo J C; Kastelein, John J P; Van Eck, Miranda; Kuivenhoven, Jan Albert

    2011-01-01

    BACKGROUND: In mice, the scavenger receptor class B type I (SR-BI) is essential for the delivery of high-density lipoprotein (HDL) cholesterol to the liver and steroidogenic organs. Paradoxically, elevated HDL cholesterol levels are associated with increased atherosclerosis in SR-BI-knockout mice.

  4. The macrophage CD163 surface glycoprotein is an erythroblast adhesion receptor

    DEFF Research Database (Denmark)

    Fabriek, Babs O; Polfliet, Machteld M J; Vloet, Rianka P M

    2007-01-01

    Erythropoiesis occurs in erythroblastic islands, where developing erythroblasts closely interact with macrophages. The adhesion molecules that govern macrophage-erythroblast contact have only been partially defined. Our previous work has implicated the rat ED2 antigen, which is highly expressed...... on the surface of macrophages in erythroblastic islands, in erythroblast binding. In particular, the monoclonal antibody ED2 was found to inhibit erythroblast binding to bone marrow macrophages. Here, we identify the ED2 antigen as the rat CD163 surface glycoprotein, a member of the group B scavenger receptor...... that it enhanced erythroid proliferation and/or survival, but did not affect differentiation. These findings identify CD163 on macrophages as an adhesion receptor for erythroblasts in erythroblastic islands, and suggest a regulatory role for CD163 during erythropoiesis....

  5. DMPD: Shaping of monocyte and macrophage function by adenosine receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17056121 Shaping of monocyte and macrophage function by adenosine receptors. Hasko ...tml) (.csml) Show Shaping of monocyte and macrophage function by adenosine receptors. PubmedID 17056121 Titl...e Shaping of monocyte and macrophage function by adenosine receptors. Authors Has

  6. The evolution of the class A scavenger receptors

    Directory of Open Access Journals (Sweden)

    Whelan Fiona J

    2012-11-01

    Full Text Available Abstract Background The class A scavenger receptors are a subclass of a diverse family of proteins defined based on their ability to bind modified lipoproteins. The 5 members of this family are strikingly variable in their protein structure and function, raising the question as to whether it is appropriate to group them as a family based on their ligand binding abilities. Results To investigate these relationships, we defined the domain architecture of each of the 5 members followed by collecting and annotating class A scavenger receptor mRNA and amino acid sequences from publicly available databases. Phylogenetic analyses, sequence alignments, and permutation tests revealed a common evolutionary ancestry of these proteins, indicating that they form a protein family. We postulate that 4 distinct gene duplication events and subsequent domain fusions, internal repeats, and deletions are responsible for the diverse protein structures and functions of this family. Despite variation in domain structure, there are highly conserved regions across all 5 members, indicating the possibility that these regions may represent key conserved functional motifs. Conclusions We have shown with significant evidence that the 5 members of the class A scavenger receptors form a protein family. We have indicated that these receptors have a common origin which may provide insight into future functional work with these proteins.

  7. Class A scavenger receptor promotes osteoclast differentiation via the enhanced expression of receptor activator of NF-{kappa}B (RANK)

    Energy Technology Data Exchange (ETDEWEB)

    Takemura, Kenichi [Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556 (Japan); Department of Orthopaedic and Neuro-Musculoskeletal Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto (Japan); Sakashita, Naomi; Fujiwara, Yukio; Komohara, Yoshihiro; Lei, XiaoFeng; Ohnishi, Koji [Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556 (Japan); Suzuki, Hiroshi [National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido (Japan); Kodama, Tatsuhiko [Department of Molecular Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo (Japan); Mizuta, Hiroshi [Department of Orthopaedic and Neuro-Musculoskeletal Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto (Japan); Takeya, Motohiro, E-mail: takeya@kumamoto-u.ac.jp [Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556 (Japan)

    2010-01-22

    Osteoclasts originate from bone marrow monocyte/macrophage lineage cells, and their differentiation depends on macrophage colony-stimulating factor (M-CSF) and receptor activator nuclear factor kappa B (RANK) ligand. Class A scavenger receptor (SR-A) is one of the principal functional molecules of macrophages, and its level of expression declines during osteoclast differentiation. To investigate the role of SR-A in osteoclastogenesis, we examined pathological changes in femoral bone and the expression levels of osteoclastogenesis-related molecules in SR-A{sup -/-} mice. The femoral osseous density of SR-A{sup -/-} mice was higher than that of SR-A{sup +/+} mice, and the number of multinucleated osteoclasts was significantly decreased. An in vitro differentiation assay revealed that the differentiation of multinucleated osteoclasts from bone marrow-derived progenitor cells is impaired in SR-A{sup -/-} mice. Elimination of SR-A did not alter the expression level of the M-CSF receptor, c-fms; however, the expression levels of RANK and RANK-related osteoclast-differentiation molecules such as nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1) and microphthalmia-associated transcription factor (MITF) significantly decreased. Furthermore, acetylated low-density lipoprotein (AcLDL), an SR-A ligand, significantly increased the expression level of RANK and MITF during osteoclast differentiation. These data indicate that SR-A promotes osteoclastogenesis via augmentation of the expression level of RANK and its related molecules.

  8. Innate scavenger receptor-A regulates adaptive T helper cell responses to pathogen infection

    Science.gov (United States)

    Xu, Zhipeng; Xu, Lei; Li, Wei; Jin, Xin; Song, Xian; Chen, Xiaojun; Zhu, Jifeng; Zhou, Sha; Li, Yong; Zhang, Weiwei; Dong, Xiaoxiao; Yang, Xiaowei; Liu, Feng; Bai, Hui; Chen, Qi; Su, Chuan

    2017-01-01

    The pattern recognition receptor (PRR) scavenger receptor class A (SR-A) has an important function in the pathogenesis of non-infectious diseases and in innate immune responses to pathogen infections. However, little is known about the role of SR-A in the host adaptive immune responses to pathogen infection. Here we show with mouse models of helminth Schistosoma japonicum infection and heat-inactivated Mycobacterium tuberculosis stimulation that SR-A is regulated by pathogens and suppresses IRF5 nuclear translocation by direct interaction. Reduced abundance of nuclear IRF5 shifts macrophage polarization from M1 towards M2, which subsequently switches T-helper responses from type 1 to type 2. Our study identifies a role for SR-A as an innate PRR in regulating adaptive immune responses. PMID:28695899

  9. The role of scavenger receptor B1 in infection with Mycobacterium tuberculosis in a murine model.

    Directory of Open Access Journals (Sweden)

    Georgia Schäfer

    2009-12-01

    Full Text Available The interaction between Mycobacterium tuberculosis (Mtb and host cells is complex and far from being understood. The role of the different receptor(s implicated in the recognition of Mtb in particular remains poorly defined, and those that have been found to have activity in vitro were subsequently shown to be redundant in vivo.To identify novel receptors involved in the recognition of Mtb, we screened a macrophage cDNA library and identified scavenger receptor B class 1 (SR-B1 as a receptor for mycobacteria. SR-B1 has been well-described as a lipoprotein receptor which mediates both the selective uptake of cholesteryl esters and the efflux of cholesterol, and has also recently been implicated in the recognition of other pathogens. We show here that mycobacteria can bind directly to SR-B1 on transfected cells, and that this interaction could be inhibited in the presence of a specific antibody to SR-B1, serum or LDL. We define a variety of macrophage populations, including alveolar macrophages, that express this receptor, however, no differences in the recognition and response to mycobacteria were observed in macrophages isolated from SR-B1(-/- or wild type mice in vitro. Moreover, when wild type and SR-B1(-/- animals were infected with a low dose of Mtb (100 CFU/mouse there were no alterations in survival, bacterial burdens, granuloma formation or cytokine production in the lung. However, significant reduction in the production of TNF, IFNgamma, and IL10 were observed in SR-B1(-/- mice following infection with a high dose of Mtb (1000 CFU/mouse, which marginally affected the size of inflammatory foci but did not influence bacterial burdens. Deficiency of SR-B1 also had no effect on resistance to disease under conditions of varying dietary cholesterol. We did observe, however, that the presence of high levels of cholesterol in the diet significantly enhanced the bacterial burdens in the lung, but this was independent of SR-B1.SR-B1 is involved in

  10. DMPD: Receptor tyrosine kinases and the regulation of macrophage activation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14726496 Receptor tyrosine kinases and the regulation of macrophage activation. Cor...osine kinases and the regulation of macrophage activation. PubmedID 14726496 Title Receptor tyrosine...rell PH, Morrison AC, Lutz MA. J Leukoc Biol. 2004 May;75(5):731-7. Epub 2004 Jan 14. (.png) (.svg) (.html) (.csml) Show Receptor tyr

  11. Scavenger Receptor Structure and Function in Health and Disease

    Directory of Open Access Journals (Sweden)

    Izma Abdul Zani

    2015-05-01

    Full Text Available Scavenger receptors (SRs are a ‘superfamily’ of membrane-bound receptors that were initially thought to bind and internalize modified low-density lipoprotein (LDL, though it is currently known to bind to a variety of ligands including endogenous proteins and pathogens. New family of SRs and their properties have been identified in recent years, and have now been classified into 10 eukaryote families, defined as Classes A-J. These receptors are classified according to their sequences, although in each class they are further classified based in the variations of the sequence. Their ability to bind a range of ligands is reflected on the biological functions such as clearance of modified lipoproteins and pathogens. SR members regulate pathophysiological states including atherosclerosis, pathogen infections, immune surveillance, and cancer. Here, we review our current understanding of SR structure and function implicated in health and disease.

  12. Identification of the Oxidized Low-Density Lipoprotein Scavenger Receptor CD36 in Plasma

    DEFF Research Database (Denmark)

    Handberg, Aase; Levin, Klaus; Højlund, Kurt

    2006-01-01

    BACKGROUND: Macrophage CD36 scavenges oxidized low-density lipoprotein, leading to foam cell formation, and appears to be a key proatherogenic molecule. Increased expression of CD36 has been attributed to hyperglycemia and to defective macrophage insulin signaling in insulin resistance. Premature...

  13. Drug Trafficking into Macrophages via the Endocytotic Receptor CD163

    DEFF Research Database (Denmark)

    Graversen, Jonas Heilskov; Moestrup, Søren Kragh

    2015-01-01

    for cytotoxic or phenotype-modulating drugs in the treatment of inflammatory and cancerous diseases. Such targeting of macrophages has been tried using the natural propensity of macrophages to non-specifically phagocytose circulating foreign particulate material. In addition, the specific targeting...... of macrophage-expressed receptors has been used in order to obtain a selective uptake in macrophages and reduce adverse effects of off-target delivery of drugs. CD163 is a highly expressed macrophage-specific endocytic receptor that has been studied for intracellular delivery of small molecule drugs...... to macrophages using targeted liposomes or antibody drug conjugates. This review will focus on the biology of CD163 and its potential role as a target for selective macrophage targeting compared with other macrophage targeting approaches....

  14. DMPD: Nuclear receptors in macrophages: a link between metabolism and inflammation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18022390 Nuclear receptors in macrophages: a link between metabolism and inflammati...on. Szanto A, Roszer T. FEBS Lett. 2008 Jan 9;582(1):106-16. Epub 2007 Nov 20. (.png) (.svg) (.html) (.csml) Show Nuclear... receptors in macrophages: a link between metabolism and inflammation. PubmedID 18022390 Title Nuclear

  15. Expression of scavenger receptor‐AI promotes alternative activation of murine macrophages to limit hepatic inflammation and fibrosis

    Science.gov (United States)

    Labonte, Adam C.; Sung, Sun‐Sang J.; Jennelle, Lucas T.; Dandekar, Aditya P.

    2016-01-01

    The liver maintains an immunologically tolerant environment as a result of continuous exposure to food and bacterial constituents from the digestive tract. Hepatotropic pathogens can take advantage of this niche and establish lifelong chronic infections causing hepatic fibrosis and hepatocellular carcinoma. Macrophages (Mϕ) play a critical role in regulation of immune responses to hepatic infection and regeneration of tissue. However, the factors crucial for Mϕ in limiting hepatic inflammation or resolving liver damage have not been fully understood. In this report, we demonstrate that expression of C‐type lectin receptor scavenger receptor‐AI (SR‐AI) is crucial for promoting M2‐like Mϕ activation and polarization during hepatic inflammation. Liver Mϕ uniquely up‐regulated SR‐AI during hepatotropic viral infection and displayed increased expression of alternative Mϕ activation markers, such as YM‐1, arginase‐1, and interleukin‐10 by activation of mer receptor tyrosine kinase associated with inhibition of mammalian target of rapamycin. Expression of these molecules was reduced on Mϕ obtained from livers of infected mice deficient for the gene encoding SR‐AI (msr1). Furthermore, in vitro studies using an SR‐AI‐deficient Mϕ cell line revealed impeded M2 polarization and decreased phagocytic capacity. Direct stimulation with virus was sufficient to activate M2 gene expression in the wild‐type (WT) cell line, but not in the knockdown cell line. Importantly, tissue damage and fibrosis were exacerbated in SR‐AI–/– mice following hepatic infection and adoptive transfer of WT bone‐marrow–derived Mϕ conferred protection against fibrosis in these mice. Conclusion: SR‐AI expression on liver Mϕ promotes recovery from infection‐induced tissue damage by mediating a switch to a proresolving Mϕ polarization state. (Hepatology 2017;65:32‐43). PMID:27770558

  16. Scavenger Receptors and Their Potential as Therapeutic Targets in the Treatment of Cardiovascular Disease

    Directory of Open Access Journals (Sweden)

    Sam L. Stephen

    2010-01-01

    Full Text Available Scavenger receptors act as membrane-bound and soluble proteins that bind to macromolecular complexes and pathogens. This diverse supergroup of proteins mediates binding to modified lipoprotein particles which regulate the initiation and progression of atherosclerotic plaques. In vascular tissues, scavenger receptors are implicated in regulating intracellular signaling, lipid accumulation, foam cell development, and cellular apoptosis or necrosis linked to the pathophysiology of atherosclerosis. One approach is using gene therapy to modulate scavenger receptor function in atherosclerosis. Ectopic expression of membrane-bound scavenger receptors using viral vectors can modify lipid profiles and reduce the incidence of atherosclerosis. Alternatively, expression of soluble scavenger receptors can also block plaque initiation and progression. Inhibition of scavenger receptor expression using a combined gene therapy and RNA interference strategy also holds promise for long-term therapy. Here we review our current understanding of the gene delivery by viral vectors to cells and tissues in gene therapy strategies and its application to the modulation of scavenger receptor function in atherosclerosis.

  17. The scavenger receptor MARCO modulates TLR-induced responses in dendritic cells.

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    Haydn T Kissick

    Full Text Available The scavenger receptor MARCO mediates macrophage recognition and clearance of pathogens and their polyanionic ligands. However, recent studies demonstrate MARCO expression and function in dendritic cells, suggesting MARCO might serve to bridge innate and adaptive immunity. To gain additional insight into the role of MARCO in dendritic cell activation and function, we profiled transcriptomes of mouse splenic dendritic cells obtained from MARCO deficient mice and their wild type counterparts under resting and activating conditions. In silico analysis uncovered major alterations in gene expression in MARCO deficient dendritic cells resulting in dramatic alterations in key dendritic cell-specific pathways and functions. Specifically, changes in CD209, FCGR4 and Complement factors can have major consequences on DC-mediated innate responses. Notably, these perturbations were magnified following activation with the TLR-4 agonist lipopolysaccharide. To validate our in silico data, we challenged DC's with various agonists that recognize all mouse TLRs and assessed expression of a set of immune and inflammatory marker genes. This approach identified a differential contribution of MARCO to TLR activation and validated a major role for MARCO in mounting an inflammatory response. Together, our data demonstrate that MARCO differentially affects TLR-induced DC activation and suggest targeting of MARCO could lead to different outcomes that depend on the inflammatory context encountered by DC.

  18. The novel biomarker of alternative macrophage activation, soluble mannose receptor (sMR/sCD206): Implications in multiple myeloma

    DEFF Research Database (Denmark)

    Andersen, Morten N; Andersen, Niels F; Rødgaard-Hansen, Sidsel

    2015-01-01

    Tumor-associated macrophages (TAMs) play an important role in the pathophysiology of human malignancies. They support growth of cancer cells by promoting angiogenesis, and by inhibiting tumour cell apoptosis and anti-tumor immune reactions. Several membrane proteins are well-described markers...... of human TAMs, including the haemoglobin scavenger receptor CD163 and the macrophage mannose receptor (MR/CD206). Interestingly, both CD163 and MR exist as soluble serum proteins (sCD163 and sMR) that may reflect the activation state of tissue macrophages, including TAMs. Here, we report the first data...... showed significant association with sCD163, which may indicate common origin from CD163+MR+TAMs....

  19. Novel mutations in scavenger receptor BI associated with high HDL cholesterol in humans

    NARCIS (Netherlands)

    Brunham, Liam R.; Tietjen, Ian; Bochem, Andrea E.; Singaraja, Roshni R.; Franchini, Patrick L.; Radomski, Chris; Mattice, Maryanne; Legendre, Annick; Hovingh, G. Kees; Kastelein, John J. P.; Hayden, Michael R.

    2011-01-01

    The scavenger receptor class B, member 1 (SR-BI), is a key cellular receptor for high-density lipoprotein (HDL) in mice, but its relevance to human physiology has not been well established. Recently a family was reported with a mutation in the gene encoding SR-BI and high HDL cholesterol (HDL-C).

  20. Rare variant in scavenger receptor BI raises HDL cholesterol and increases risk of coronary heart disease

    Science.gov (United States)

    Scavenger receptor BI (SR-BI) is the major receptor for high-density lipoprotein (HDL) cholesterol (HDL-C). In humans, high amounts of HDL-C in plasma are associated with a lower risk of coronary heart disease (CHD). Mice that have depleted Scarb1 (SR-BI knockout mice) have markedly elevated HDL-C l...

  1. Rare variant in scavenger receptor BI raises HDL cholesterol and increases risk of coronary heart disease

    DEFF Research Database (Denmark)

    Zanoni, Paolo; Khetarpal, Sumeet A; Larach, Daniel B

    2016-01-01

    Scavenger receptor BI (SR-BI) is the major receptor for high-density lipoprotein (HDL) cholesterol (HDL-C). In humans, high amounts of HDL-C in plasma are associated with a lower risk of coronary heart disease (CHD). Mice that have depleted Scarb1 (SR-BI knockout mice) have markedly elevated HDL-...

  2. Molecular characterization of the haptoglobin.hemoglobin receptor CD163. Ligand binding properties of the scavenger receptor cysteine-rich domain region

    DEFF Research Database (Denmark)

    Madsen, Mette; Møller, Holger J; Nielsen, Marianne Jensby

    2004-01-01

    CD163 is the macrophage receptor for endocytosis of haptoglobin.hemoglobin complexes. The extracellular region consisting of nine scavenger receptor cysteine rich (SRCR) domains also circulates in plasma as a soluble protein. By ligand binding analysis of a broad spectrum of soluble CD163...... truncation variants, the amino-terminal third of the SRCR region was shown to be crucial for the binding of haptoglobin.hemoglobin complexes. By Western blotting of the CD163 variants, a panel of ten monoclonal antibodies was mapped to SRCR domains 1, 3, 4, 6, 7, and 9, respectively. Only the two antibodies...... to CD163 demonstrated that optimal ligand binding requires physiological plasma calcium concentrations, and an immediate ligand release occurs at the low calcium concentrations measured in acidifying endosomes. In conclusion, SRCR domain 3 of CD163 is an exposed domain and a critical determinant...

  3. Dopamine receptor activation increases HIV entry into primary human macrophages.

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    Peter J Gaskill

    Full Text Available Macrophages are the primary cell type infected with HIV in the central nervous system, and infection of these cells is a major component in the development of neuropathogenesis and HIV-associated neurocognitive disorders. Within the brains of drug abusers, macrophages are exposed to increased levels of dopamine, a neurotransmitter that mediates the addictive and reinforcing effects of drugs of abuse such as cocaine and methamphetamine. In this study we examined the effects of dopamine on HIV entry into primary human macrophages. Exposure to dopamine during infection increased the entry of R5 tropic HIV into macrophages, irrespective of the concentration of the viral inoculum. The entry pathway affected was CCR5 dependent, as antagonizing CCR5 with the small molecule inhibitor TAK779 completely blocked entry. The effect was dose-dependent and had a steep threshold, only occurring above 108 M dopamine. The dopamine-mediated increase in entry required dopamine receptor activation, as it was abrogated by the pan-dopamine receptor antagonist flupenthixol, and could be mediated through both subtypes of dopamine receptors. These findings indicate that the effects of dopamine on macrophages may have a significant impact on HIV pathogenesis. They also suggest that drug-induced increases in CNS dopamine may be a common mechanism by which drugs of abuse with distinct modes of action exacerbate neuroinflammation and contribute to HIV-associated neurocognitive disorders in infected drug abusers.

  4. Dopamine Receptor Activation Increases HIV Entry into Primary Human Macrophages

    Science.gov (United States)

    Gaskill, Peter J.; Yano, Hideaki H.; Kalpana, Ganjam V.; Javitch, Jonathan A.; Berman, Joan W.

    2014-01-01

    Macrophages are the primary cell type infected with HIV in the central nervous system, and infection of these cells is a major component in the development of neuropathogenesis and HIV-associated neurocognitive disorders. Within the brains of drug abusers, macrophages are exposed to increased levels of dopamine, a neurotransmitter that mediates the addictive and reinforcing effects of drugs of abuse such as cocaine and methamphetamine. In this study we examined the effects of dopamine on HIV entry into primary human macrophages. Exposure to dopamine during infection increased the entry of R5 tropic HIV into macrophages, irrespective of the concentration of the viral inoculum. The entry pathway affected was CCR5 dependent, as antagonizing CCR5 with the small molecule inhibitor TAK779 completely blocked entry. The effect was dose-dependent and had a steep threshold, only occurring above 108 M dopamine. The dopamine-mediated increase in entry required dopamine receptor activation, as it was abrogated by the pan-dopamine receptor antagonist flupenthixol, and could be mediated through both subtypes of dopamine receptors. These findings indicate that the effects of dopamine on macrophages may have a significant impact on HIV pathogenesis. They also suggest that drug-induced increases in CNS dopamine may be a common mechanism by which drugs of abuse with distinct modes of action exacerbate neuroinflammation and contribute to HIV-associated neurocognitive disorders in infected drug abusers. PMID:25268786

  5. The scavenger receptor SSc5D physically interacts with bacteria through the SRCR-containing N-terminal domain

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    Catarina Bessa-Pereira

    2016-10-01

    Full Text Available The scavenger receptor cysteine-rich (SRCR family comprises a group of membrane-attached or secreted proteins that contain one or more modules/domains structurally similar to the membrane distal domain of type I macrophage scavenger receptor. Although no all-inclusive biological function has been ascribed to the SRCR family, some of these receptors have been shown to recognize pathogen-associated molecular patterns (PAMP of bacteria, fungi or other microbes. SSc5D is a recently described soluble SRCR receptor produced by monocytes/macrophages and T lymphocytes, consisting of an N-terminal portion which contains five SRCR modules, and a large C-terminal mucin-like domain. Towards establishing a global common role for SRCR domains, we interrogated whether the set of five SRCR domains of SSc5D displayed pattern recognition receptor (PRR properties. For that purpose, we have expressed in a mammalian expression system the N-terminal SRCR-containing moiety of SSC5D (N-SSc5D, thus excluding the mucin-like domain likely by nature to bind microorganisms, and tested the capacity of the SRCR functional groups to physically interact with bacteria. Using conventional protein-bacteria binding assays, we showed that N-SSc5D had a superior capacity to bind to E. coli strains RS218 and IHE3034 compared with that of the extracellular domains of the SRCR proteins CD5 and CD6 (sCD5 and sCD6, respectively, and similar E. coli-binding properties as Spα, a proven PRR of the SRCR family. We have further designed a more sensitive, real-time and label-free surface plasmon resonance (SPR-based assay, and examined the capacity of N-SSc5D, Spα, sCD5 and sCD6 to bind to different bacteria. We demonstrated that the N-SSc5D compares with Spα in the capacity to bind to E. coli and L. monocytogenes, and further that it can distinguish between pathogenic E. coli RS218 and IHE3034 strains and the non-pathogenic laboratory E. coli strain BL21(DE3. Our work thus advocates the

  6. [Plasma scavenger receptor BI and CD36 expression change and susceptibility of atherosclerosis in patients post liver transplantation].

    Science.gov (United States)

    Chen, Xin; Xue, Jinhong; Zhang, Shuyi; Sun, Liying; Lu, Chengzhi

    2014-02-01

    To explore the association between expression changes of plasma macrophages scavenger receptor (SR)-BI and CD36 and risk of arteriosclerosis in end-stage liver disease (ESLD) patients post liver transplantation. A total of 20 liver transplantation patients were included. Clinical data including blood pressure, blood lipid, blood glucose, incidence of new-onset cardiovascular events were obtained. Plasma macrophages scavenger receptor SR-BIand CD36 expressions were detected by polymerase chain reaction (RT-PCR) and Western-blot before and at 1 year after liver transplantation. The serum levels of TC [(5.34 ± 0.87) mmol/L vs. (4.27 ± 0.91) mmol/L], TG [(2.47 ± 0.81) mmol/L vs. (1.02 ± 0.49) mmol/L] and LDL-C [(3.36 ± 0.67) mmol/L vs. (2.14 ± 0.74) mmol/L] were significantly increased (P compared to before-transplantation levels. One patient developed non-ST segment elevation myocardial infarction and treated with percutaneous coronary intervention, another patient developed atrial fibrillation at one year after transplantation. The plasma mRNA expression of SR-BI was reduced (20.44 ± 0.60 vs. 23.12 ± 0.69, P compare with that of before the transplantation. Similarly, the plasma protein expression of SR-BIwas reduced (0.21 ± 0.13 vs. 0.64 ± 0.28, P compare with that of before the transplantation. Plasma expression changes of SR-BI and CD36 might contribute to the dyslipidemia and contribute to the atherosclerosis susceptibility after liver transplantation.

  7. Macrophage pattern recognition receptors in immunity, homeostasis and self tolerance.

    Science.gov (United States)

    Mukhopadhyay, Subhankar; Plüddemann, Annette; Gordon, Siamon

    2009-01-01

    Macrophages, a major component of innate immune defence, express a large repertoire of different classes of pattern recognition receptors and other surface antigens which determine the immunologic and homeostatic potential of these versatile cells. In the light of present knowledge ofmacrophage surface antigens, we discuss self versus nonself recognition, microbicidal effector functions and self tolerance in the innate immune system.

  8. Hepatic macrophage complement receptor clearance function following injury.

    Science.gov (United States)

    Cuddy, B G; Loegering, D J; Blumenstock, F A; Shah, D M

    1986-03-01

    Previous work has demonstrated that in vivo hepatic macrophage complement receptor clearance function is depressed following thermal injury. The present study was carried out to determine if complement receptor function depression is associated with other states of depressed host defense. Hepatic complement receptor clearance function was determined from the hepatic uptake of rat erythrocytes coated with antierythrocyte IgM (EIgM) in rats. Receptor function was determined following cannulation of a carotid artery, laparotomy plus enterotomy, hemorrhagic shock, trauma, thermal injury, acute bacteremia, acute endotoxemia, and injection of erythrocyte stroma, gelatinized lipid emulsion, or colloidal carbon. Hepatic uptake of EIgM was depressed following each of these experimental interventions except arterial cannulation. This effect was shown not to be due to a decrease in hepatic blood flow or depletion of complement and was therefore due to a depression in hepatic macrophage complement receptor clearance function. Thus, impairment of hepatic macrophage complement receptor function is associated with several states of depressed host defense.

  9. The dual role of scavenger receptor class A in development of diabetes in autoimmune NOD mice.

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    Mami Shimizu

    Full Text Available Human type 1 diabetes is an autoimmune disease that results from the autoreactive destruction of pancreatic β cells by T cells. Antigen presenting cells including dendritic cells and macrophages are required to activate and suppress antigen-specific T cells. It has been suggested that antigen uptake from live cells by dendritic cells via scavenger receptor class A (SR-A may be important. However, the role of SR-A in autoimmune disease is unknown. In this study, SR-A-/- nonobese diabetic (NOD mice showed significant attenuation of insulitis, lower levels of insulin autoantibodies, and suppression of diabetes development compared with NOD mice. We also found that diabetes progression in SR-A-/- NOD mice treated with low-dose polyinosinic-polycytidylic acid (poly(I:C was significantly accelerated compared with that in disease-resistant NOD mice treated with low-dose poly(I:C. In addition, injection of high-dose poly(I: C to mimic an acute RNA virus infection significantly accelerated diabetes development in young SR-A-/- NOD mice compared with untreated SR-A-/- NOD mice. Pathogenic cells including CD4+CD25+ activated T cells were increased more in SR-A-/- NOD mice treated with poly(I:C than in untreated SR-A-/- NOD mice. These results suggested that viral infection might accelerate diabetes development even in diabetes-resistant subjects. In conclusion, our studies demonstrated that diabetes progression was suppressed in SR-A-/- NOD mice and that acceleration of diabetes development could be induced in young mice by poly(I:C treatment even in SR-A-/- NOD mice. These results suggest that SR-A on antigen presenting cells such as dendritic cells may play an unfavorable role in the steady state and a protective role in a mild infection. Our findings imply that SR-A may be an important target for improving therapeutic strategies for type 1 diabetes.

  10. Microglial Scavenger Receptors and Their Roles in the Pathogenesis of Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Kim Wilkinson

    2012-01-01

    Full Text Available Alzheimer’s disease (AD is increasing in prevalence with the aging population. Deposition of amyloid-β (Aβ in the brain of AD patients is a hallmark of the disease and is associated with increased microglial numbers and activation state. The interaction of microglia with Aβ appears to play a dichotomous role in AD pathogenesis. On one hand, microglia can phagocytose and clear Aβ, but binding of microglia to Aβ also increases their ability to produce inflammatory cytokines, chemokines, and neurotoxic reactive oxygen species (ROS. Scavenger receptors, a group of evolutionally conserved proteins expressed on the surface of microglia act as receptors for Aβ. Of particular interest are SCARA-1 (scavenger receptor A-1, CD36, and RAGE (receptor for advanced glycation end products. SCARA-1 appears to be involved in the clearance of Aβ, while CD36 and RAGE are involved in activation of microglia by Aβ. In this review, we discuss the roles of various scavenger receptors in the interaction of microglia with Aβ and propose that these receptors play complementary, nonredundant functions in the development of AD pathology. We also discuss potential therapeutic applications for these receptors in AD.

  11. Scavenger receptors in human airway epithelial cells: role in response to double-stranded RNA.

    Directory of Open Access Journals (Sweden)

    Audrey Dieudonné

    Full Text Available Scavenger receptors and Toll-like receptors (TLRs cooperate in response to danger signals to adjust the host immune response. The TLR3 agonist double stranded (dsRNA is an efficient activator of innate signalling in bronchial epithelial cells. In this study, we aimed at defining the role played by scavenger receptors expressed by bronchial epithelial cells in the control of the innate response to dsRNA both in vitro and in vivo. Expression of several scavenger receptor involved in pathogen recognition was first evaluated in human bronchial epithelial cells in steady-state and inflammatory conditions. Their implication in the uptake of dsRNA and the subsequent cell activation was evaluated in vitro by competition with ligand of scavenger receptors including maleylated ovalbumin and by RNA silencing. The capacity of maleylated ovalbumin to modulate lung inflammation induced by dsRNA was also investigated in mice. Exposure to tumor necrosis factor-α increased expression of the scavenger receptors LOX-1 and CXCL16 and the capacity to internalize maleylated ovalbumin, whereas activation by TLR ligands did not. In contrast, the expression of SR-B1 was not modulated in these conditions. Interestingly, supplementation with maleylated ovalbumin limited dsRNA uptake and inhibited subsequent activation of bronchial epithelial cells. RNA silencing of LOX-1 and SR-B1 strongly blocked the dsRNA-induced cytokine production. Finally, administration of maleylated ovalbumin in mice inhibited the dsRNA-induced infiltration and activation of inflammatory cells in bronchoalveolar spaces and lung draining lymph nodes. Together, our data characterize the function of SR-B1 and LOX-1 in bronchial epithelial cells and their implication in dsRNA-induced responses, a finding that might be relevant during respiratory viral infections.

  12. Scavenger receptor classes A and B. Their roles in atherogenesis and the metabolism of modified LDL and HDL

    NARCIS (Netherlands)

    van Berkel, T. J.; van Eck, M.; Herijgers, N.; Fluiter, K.; Nion, S.

    2000-01-01

    Scavenger-receptor class A has been held responsible for the clearance of modified LDL from the blood circulation. However, in mice deficient in scavenger-receptor class A, the decay in vivo of acetylated LDL (t1/2 <2 min), as well as tissue distribution and liver uptake (at 5 min 77.4 +/- 4.6% of

  13. Protective or deleterious role of scavenger receptors SR-A and CD36 on host resistance to Staphylococcus aureus depends on the site of infection.

    Directory of Open Access Journals (Sweden)

    Charlène Blanchet

    Full Text Available Staphylococcus aureus is a major human opportunistic pathogen responsible for a broad spectrum of infections ranging from benign skin infection to more severe life threatening disorders (e.g. pneumonia, sepsis, particularly in intensive care patients. Scavenger receptors (SR-A and CD36 are known to be involved in S. aureus recognition by immune cells in addition to MARCO, TLR2, NOD2 and α5β1 integrin. In the present study, we further deciphered the contribution of SR-A and CD36 scavenger receptors in the control of infection of mice by S. aureus. Using double SR-A/CD36 knockout mice (S/C-KO and S. aureus strain HG001, a clinically relevant non-mutagenized strain, we showed that the absence of these two scavenger receptors was protective in peritoneal infection. In contrast, the deletion of these two receptors was detrimental in pulmonary infection following intranasal instillation. For pulmonary infection, susceptible mice (S/C-KO had more colony-forming units (CFU in their broncho-alveolar lavages fluids, associated with increased recruitment of macrophages and neutrophils. For peritoneal infection, susceptible mice (wild-type had more CFU in their blood, but recruited less macrophages and neutrophils in the peritoneal cavity than resistant mice. Exacerbated cytokine levels were often observed in the susceptible mice in the infected compartment as well as in the plasma. The exception was the enhanced compartmentalized expression of IL-1β for the resistant mice (S/C-KO after peritoneal infection. A similar mirrored susceptibility to S. aureus infection was also observed for MARCO and TLR2. Marco and tlr2 -/- mice were more resistant to peritoneal infection but more susceptible to pulmonary infection than wild type mice. In conclusion, our results show that innate immune receptors can play distinct and opposite roles depending on the site of infection. Their presence is protective for local pulmonary infection, whereas it becomes detrimental

  14. Pattern Recognition Scavenger Receptor A/CD204 Regulates Airway Inflammatory Homeostasis Following Organic Dust Extract Exposures

    Science.gov (United States)

    Poole, Jill A.; Anderson, Leigh; Gleason, Angela M.; West, William W.; Romberger, Debra J.; Wyatt, Todd A.

    2014-01-01

    Exposure to agriculture organic dusts, comprised of a diversity of pathogen-associated molecular patterns, results in chronic airway diseases. The multi-functional class A macrophage scavenger receptor (SRA)/CD204 has emerged as an important class of pattern recognition receptors with broad ligand binding ability. Our objective was to determine the role of SRA in mediating repetitive and post-inflammatory organic dust extract (ODE)-induced airway inflammation. Wild-type (WT) and SRA knockout (KO) mice were intra-nasally treated with ODE or saline daily for 3 wk and immediately euthanized or allowed to recover for 1 wk. Results show that lung histopathologic changes were increased in SRA KO mice as compared to WT following repetitive ODE exposures marked predominately by increased size and distribution of lymphoid aggregates. After a 1-wk recovery from daily ODE treatments, there was significant resolution of lung injury in WT mice, but not SRA KO animals. The increased lung histopathology induced by ODE treatment was associated with decreased accumulation of neutrophils, but greater accumulation of CD4+ T-cells. The lung cytokine milieu induced by ODE was consistent with a TH1/TH17 polarization in both WT and SRA KO mice. Overall, our data demonstrate that SRA/CD204 plays an important role in the normative inflammatory lung response to ODE as evidenced by the enhanced dust-mediated injury viewed in the absence of this receptor. PMID:24491035

  15. Differential S1P Receptor Profiles on M1- and M2-Polarized Macrophages Affect Macrophage Cytokine Production and Migration.

    Science.gov (United States)

    Müller, Jan; von Bernstorff, Wolfram; Heidecke, Claus-Dieter; Schulze, Tobias

    2017-01-01

    Introduction . Macrophages are key players in complex biological processes. In response to environmental signals, macrophages undergo polarization towards a proinflammatory (M1) or anti-inflammatory (M2) phenotype. Sphingosine 1-phosphate (S1P) is a bioactive lysophospholipid that acts via 5 G-protein coupled receptors (S1P 1-5 ) in order to influence a broad spectrum of biological processes. This study assesses S1P receptor expression on macrophages before and after M1 and M2 polarization and performs a comparative analysis of S1P signalling in the two activational states of macrophages. Methods . Bone marrow derived macrophages (BMDM) from C57 BL/6 mice were cultured under either M1- or M2-polarizing conditions. S1P-receptor expression was determined by quantitative RT-PCR. Influence of S1P on macrophage activation, migration, phagocytosis, and cytokine secretion was assessed in vitro. Results . All 5 S1P receptor subclasses were expressed in macrophages. Culture under both M1- and M2-polarizing conditions led to significant downregulation of S1P 1 . In contrast, M1-polarized macrophages significantly downregulated S1P 4 . The expression of the remaining three S1P receptors did not change. S1P increased expression of iNOS under M2-polarizing conditions. Furthermore, S1P induced chemotaxis in M1 macrophages and changed cytokine production in M2 macrophages. Phagocytosis was not affected by S1P-signalling. Discussion . The expression of different specific S1P receptor profiles may provide a possibility to selectively influence M1- or M2-polarized macrophages.

  16. The alpha-fetoprotein third domain receptor binding fragment: in search of scavenger and associated receptor targets.

    Science.gov (United States)

    Mizejewski, G J

    2015-01-01

    Recent studies have demonstrated that the carboxyterminal third domain of alpha-fetoprotein (AFP-CD) binds with various ligands and receptors. Reports within the last decade have established that AFP-CD contains a large fragment of amino acids that interact with several different receptor types. Using computer software specifically designed to identify protein-to-protein interaction at amino acid sequence docking sites, the computer searches identified several types of scavenger-associated receptors and their amino acid sequence locations on the AFP-CD polypeptide chain. The scavenger receptors (SRs) identified were CD36, CD163, Stabilin, SSC5D, SRB1 and SREC; the SR-associated receptors included the mannose, low-density lipoprotein receptors, the asialoglycoprotein receptor, and the receptor for advanced glycation endproducts (RAGE). Interestingly, some SR interaction sites were localized on the AFP-derived Growth Inhibitory Peptide (GIP) segment at amino acids #480-500. Following the detection studies, a structural subdomain analysis of both the receptor and the AFP-CD revealed the presence of epidermal growth factor (EGF) repeats, extracellular matrix-like protein regions, amino acid-rich motifs and dimerization subdomains. For the first time, it was reported that EGF-like sequence repeats were identified on each of the three domains of AFP. Thereafter, the localization of receptors on specific cell types were reviewed and their functions were discussed.

  17. The chemokine and scavenger receptor CXCL16/SR-PSOX is expressed in human vascular smooth muscle cells and is induced by interferon γ

    International Nuclear Information System (INIS)

    Wagsaeter, Dick; Olofsson, Peder S.; Norgren, Lars; Stenberg, Bjoern; Sirsjoe, Allan

    2004-01-01

    Atherosclerosis is an inflammatory disease that is characterised by the involvement of chemokines that are important for the recruitment of leukocytes and scavenger receptors that mediate foam cell formation. Several cytokines are involved in the regulation of chemokines and scavenger receptors in atherosclerosis. CXCL16 is a chemokine and scavenger receptor and found in macrophages in human atherosclerotic lesions. Using double-labelled immunohistochemistry, we identified that smooth muscle cells in human lesions express CXCL16. We then analysed the effects of IFN-γ, TNF-α, IL-12, IL-15, IL-18, and LPS on CXCL16 expression in cultured aortic smooth muscle cells. IFN-γ was the most potent CXCL16 inducer and increased mRNA, soluble form, membrane form, and total cellular levels of CXCL16. The IFN-γ induction of CXCL16 was also associated with increased uptake of oxLDL into these cells. Taken together, smooth muscle cells express CXCL16 in atherosclerotic lesions, which may play a role in the attraction of T cells to atherosclerotic lesions and contribute to the cellular internalisation of modified LDL

  18. DMPD: G-protein-coupled receptor expression, function, and signaling in macrophages. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17456803 G-protein-coupled receptor expression, function, and signaling in macropha...2007 Apr 24. (.png) (.svg) (.html) (.csml) Show G-protein-coupled receptor expression, function, and signali...ng in macrophages. PubmedID 17456803 Title G-protein-coupled receptor expression, function

  19. Loss of Function of P2X7 Receptor Scavenger Activity in Aging Mice: A Novel Model for Investigating the Early Pathogenesis of Age-Related Macular Degeneration.

    Science.gov (United States)

    Vessey, Kirstan A; Gu, Ben J; Jobling, Andrew I; Phipps, Joanna A; Greferath, Ursula; Tran, Mai X; Dixon, Michael A; Baird, Paul N; Guymer, Robyn H; Wiley, James S; Fletcher, Erica L

    2017-08-01

    Age-related macular degeneration (AMD) is a leading cause of irreversible, severe vision loss in Western countries. Recently, we identified a novel pathway involving P2X7 receptor scavenger function expressed on ocular immune cells as a risk factor for advanced AMD. In this study, we investigate the effect of loss of P2X7 receptor function on retinal structure and function during aging. P2X7-null and wild-type C57bl6J mice were investigated at 4, 12, and 18 months of age for macrophage phagocytosis activity, ocular histological changes, and retinal function. Phagocytosis activity of blood-borne macrophages decreased with age at 18 months in the wild-type mouse. Lack of P2X7 receptor function reduced phagocytosis at all ages compared to wild-type mice. At 12 months of age, P2X7-null mice had thickening of Bruchs membrane and retinal pigment epithelium dysfunction. By 18 months of age, P2X7-null mice displayed phenotypic characteristics consistent with early AMD, including Bruchs membrane thickening, retinal pigment epithelium cell loss, retinal functional deficits, and signs of subretinal inflammation. Our present study shows that loss of function of the P2X7 receptor in mice induces retinal changes representing characteristics of early AMD, providing a valuable model for investigating the role of scavenger receptor function and the immune system in the development of this age-related disease. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  20. Macrophage colony stimulating factor (M-CSF) induces Fc receptor expression on macrophages

    International Nuclear Information System (INIS)

    Magee, D.M.; Wing, E.J.; Waheed, A.; Shadduck, R.K.

    1986-01-01

    M-CSF is a glycoprotein that stimulates bone marrow progenitor cells to proliferate and differentiate into macrophages (M theta). In addition, M-CSF can modulate the function of mature M theta. In this study, the authors determined the effect of M-CSF on expression of receptors for IgG (Fc receptors). Murine resident peritoneal M theta monolayers were incubated with either M-CSF, recombinant gamma interferon (IFN), or left untreated for 48 hrs. Expression of Fc receptors was assessed by microscopy using an antibody coated sheet erythrocytes (EA) rosette assay. The results indicated that M-CSF treated M theta had significantly higher numbers of bound EA (7.1 erythrocytes/M theta), than IFN M theta (4.4), or untreated M theta (2.5) (p 51 Cr labelled EA assay, CSF M theta (16,411 cpm), IFN M theta (10,887), untreated M theta (6897) (p < 0.001). Additionally, the maximal response was noted between 10 and 500 units M-CSF. Purified anti-M-CSF IgG, when included in the cultures, ablated the enhancement of EA binding, whereas normal rabbit IgG did not. These findings indicate that M-CSF is a potent inducer of Fc receptor expression on M theta and supports other data concerning the role of M-CSF as a biological response modifier

  1. Scavenger receptors mediate the role of SUMO and Ftz-f1 in Drosophila steroidogenesis.

    Directory of Open Access Journals (Sweden)

    Ana Talamillo

    2013-04-01

    Full Text Available SUMOylation participates in ecdysteroid biosynthesis at the onset of metamorphosis in Drosophila melanogaster. Silencing the Drosophila SUMO homologue smt3 in the prothoracic gland leads to reduced lipid content, low ecdysone titers, and a block in the larval-pupal transition. Here we show that the SR-BI family of Scavenger Receptors mediates SUMO functions. Reduced levels of Snmp1 compromise lipid uptake in the prothoracic gland. In addition, overexpression of Snmp1 is able to recover lipid droplet levels in the smt3 knockdown prothoracic gland cells. Snmp1 expression depends on Ftz-f1 (an NR5A-type orphan nuclear receptor, the expression of which, in turn, depends on SUMO. Furthermore, we show by in vitro and in vivo experiments that Ftz-f1 is SUMOylated. RNAi-mediated knockdown of ftz-f1 phenocopies that of smt3 at the larval to pupal transition, thus Ftz-f1 is an interesting candidate to mediate some of the functions of SUMO at the onset of metamorphosis. Additionally, we demonstrate that the role of SUMOylation, Ftz-f1, and the Scavenger Receptors in lipid capture and mobilization is conserved in other steroidogenic tissues such as the follicle cells of the ovary. smt3 knockdown, as well as ftz-f1 or Scavenger knockdown, depleted the lipid content of the follicle cells, which could be rescued by Snmp1 overexpression. Therefore, our data provide new insights into the regulation of metamorphosis via lipid homeostasis, showing that Drosophila Smt3, Ftz-f1, and SR-BIs are part of a general mechanism for uptake of lipids such as cholesterol, required during development in steroidogenic tissues.

  2. Identification of the hemoglobin scavenger receptor/CD163 as a natural soluble protein in plasma

    DEFF Research Database (Denmark)

    Møller, Holger Jon; Peterslund, Niels Anker; Graversen, Jonas Heilskov

    2002-01-01

    enabled identification of a soluble plasma form of HbSR (sHbSR) having an electrophoretic mobility equal to that of recombinant HbSR consisting of the extracellular domain (scavenger receptor cysteine-rich 1-9). A sandwich enzyme-linked immunosorbent assay was established and used to measure the s...... a level of sHbSR above the range of healthy persons. Patients with myelomonocytic leukemias and pneumonia/sepsis exhibited the highest levels (up to 67.3 mg/L). In conclusion, sHbSR is an abundant plasma protein potentially valuable in monitoring patients with infections and myelomonocytic leukemia....

  3. The role of the class A scavenger receptors, SR-A and MARCO, in the immune system. Part 1. The structure of receptors, their ligand binding repertoires and ability to initiate intracellular signaling

    Directory of Open Access Journals (Sweden)

    Szczepan Józefowski

    2012-02-01

    Full Text Available  Recognition of pathogens by innate immune cells is mediated by pattern recognition receptors (PRR, which include scavenger receptors (SR. The class A SR, SR-A/CD204 and MARCO, are characterized by the presence of collagenous and SR cysteine-rich domains in their extracellular portions. Both receptors are expressed mainly on macrophages and dendritic cells. Thanks to their ability to bind to a wide range of polyanionic ligands, the class A SR may participate in numerous functions of these cells, such as endocytosis, and adhesion to extracellular matrix and to other cells. Among SR-A ligands are oxidized lipoproteins and β-amyloid fibrils, which link SR-A to the pathogenesis of arteriosclerosis and Alzheimer’s disease. Despite the demonstration of class A SR involvement in so many processes, the lack of selective ligands precluded reaching definite conclusions concerning their signaling abilities. Using specific receptor ligation with antibodies, we showed that SR-A and MARCO trigger intracellular signaling, modulating pro-inflammatory and microbicidal activities of macrophages. Surprisingly, despite similarities in structure and ligand binding repertoires, SR-A and MARCO exert opposite effects on interleukin-12 (IL-12 production in macrophages. SR-A ligation also stimulated H2O2 and IL-10 production, but had no effect on the release of several other cytokines. These limited effects of specific SR-A ligation contrast with generalized enhancement of immune responses observed in SR-A-deficient mice. Recent studies have revealed that many of these effects of SR-A deficiency may be caused by compensatory changes in the expression of other receptors and/or disinhibition of signal transduction from receptors belonging to the Toll/IL-1R family, rather than by the loss of the receptor function of SR-A.

  4. Lipoprotein profiles in human heterozygote carriers of a functional mutation P297S in scavenger receptor class B1

    NARCIS (Netherlands)

    Ljunggren, Stefan A.; Levels, Johannes H. M.; Hovingh, Kees; Holleboom, Adriaan G.; Vergeer, Menno; Argyri, Letta; Gkolfinopoulou, Christina; Chroni, Angeliki; Sierts, Jeroen A.; Kastelein, John J.; Kuivenhoven, Jan Albert; Lindahl, Mats; Karlsson, Helen

    2015-01-01

    The scavenger receptor class B type 1 (SR-B1) is an important HDL receptor involved in cholesterol uptake and efflux, but its physiological role in human lipoprotein metabolism is not fully understood. Heterozygous carriers of the SR-B1(P297S) mutation are characterized by increased HDL cholesterol

  5. Scavenger Receptor C Mediates Phagocytosis of White Spot Syndrome Virus and Restricts Virus Proliferation in Shrimp

    Science.gov (United States)

    Yang, Ming-Chong; Shi, Xiu-Zhen; Yang, Hui-Ting; Sun, Jie-Jie; Xu, Ling; Wang, Xian-Wei; Zhao, Xiao-Fan

    2016-01-01

    Scavenger receptors are an important class of pattern recognition receptors that play several important roles in host defense against pathogens. The class C scavenger receptors (SRCs) have only been identified in a few invertebrates, and their role in the immune response against viruses is seldom studied. In this study, we firstly identified an SRC from kuruma shrimp, Marsupenaeus japonicus, designated MjSRC, which was significantly upregulated after white spot syndrome virus (WSSV) challenge at the mRNA and protein levels in hemocytes. The quantity of WSSV increased in shrimp after knockdown of MjSRC, compared with the controls. Furthermore, overexpression of MjSRC led to enhanced WSSV elimination via phagocytosis by hemocytes. Pull-down and co-immunoprecipitation assays demonstrated the interaction between MjSRC and the WSSV envelope protein. Electron microscopy observation indicated that the colloidal gold-labeled extracellular domain of MjSRC was located on the outer surface of WSSV. MjSRC formed a trimer and was internalized into the cytoplasm after WSSV challenge, and the internalization was strongly inhibited after knockdown of Mjβ-arrestin2. Further studies found that Mjβ-arrestin2 interacted with the intracellular domain of MjSRC and induced the internalization of WSSV in a clathrin-dependent manner. WSSV were co-localized with lysosomes in hemocytes and the WSSV quantity in shrimp increased after injection of lysosome inhibitor, chloroquine. Collectively, this study demonstrated that MjSRC recognized WSSV via its extracellular domain and invoked hemocyte phagocytosis to restrict WSSV systemic infection. This is the first study to report an SRC as a pattern recognition receptor promoting phagocytosis of a virus. PMID:28027319

  6. Activated prostaglandin D2 receptors on macrophages enhance neutrophil recruitment into the lung

    Science.gov (United States)

    Jandl, Katharina; Stacher, Elvira; Bálint, Zoltán; Sturm, Eva Maria; Maric, Jovana; Peinhaupt, Miriam; Luschnig, Petra; Aringer, Ida; Fauland, Alexander; Konya, Viktoria; Dahlen, Sven-Erik; Wheelock, Craig E.; Kratky, Dagmar; Olschewski, Andrea; Marsche, Gunther; Schuligoi, Rufina; Heinemann, Akos

    2016-01-01

    Background Prostaglandin (PG) D2 is an early-phase mediator in inflammation, but its action and the roles of the 2 D-type prostanoid receptors (DPs) DP1 and DP2 (also called chemoattractant receptor–homologous molecule expressed on TH2 cells) in regulating macrophages have not been elucidated to date. Objective We investigated the role of PGD2 receptors on primary human macrophages, as well as primary murine lung macrophages, and their ability to influence neutrophil action in vitro and in vivo. Methods In vitro studies, including migration, Ca2+ flux, and cytokine secretion, were conducted with primary human monocyte-derived macrophages and neutrophils and freshly isolated murine alveolar and pulmonary interstitial macrophages. In vivo pulmonary inflammation was assessed in male BALB/c mice. Results Activation of DP1, DP2, or both receptors on human macrophages induced strong intracellular Ca2+ flux, cytokine release, and migration of macrophages. In a murine model of LPS-induced pulmonary inflammation, activation of each PGD2 receptor resulted in aggravated airway neutrophilia, tissue myeloperoxidase activity, cytokine contents, and decreased lung compliance. Selective depletion of alveolar macrophages abolished the PGD2-enhanced inflammatory response. Activation of PGD2 receptors on human macrophages enhanced the migratory capacity and prolonged the survival of neutrophils in vitro. In human lung tissue specimens both DP1 and DP2 receptors were located on alveolar macrophages along with hematopoietic PGD synthase, the rate-limiting enzyme of PGD2 synthesis. Conclusion For the first time, our results show that PGD2 markedly augments disease activity through its ability to enhance the proinflammatory actions of macrophages and subsequent neutrophil activation. PMID:26792210

  7. Serum amyloid A stimulates macrophage foam cell formation via lectin-like oxidized low-density lipoprotein receptor 1 upregulation

    International Nuclear Information System (INIS)

    Lee, Ha Young; Kim, Sang Doo; Baek, Suk-Hwan; Choi, Joon Hyuk; Cho, Kyung-Hyun; Zabel, Brian A.; Bae, Yoe-Sik

    2013-01-01

    Highlights: ► SAA induced macrophage foam cell formation. ► SAA stimulated upregulation of lectin-like oxidized low-density lipoprotein receptor 1 (LOX1). ► SAA-induced LOX1 expression and foam cell formation is mediated by JNK/NF-κB signaling. ► HDL-conjugated SAA also stimulates foam cell formation via LOX1 upregulation. ► The finding reveals a novel mechanism of action of SAA in the pathogenesis of atherosclerosis. -- Abstract: Elevated levels of serum amyloid A (SAA) is a risk factor for cardiovascular diseases, however, the role of SAA in the pathophysiology of atherosclerosis remains unclear. Here we show that SAA induced macrophage foam cell formation. SAA-stimulated foam cell formation was mediated by c-jun N-terminal kinase (JNK) signaling. Moreover, both SAA and SAA-conjugated high density lipoprotein stimulated the expression of the important scavenger receptor lectin-like oxidized low-density lipoprotein receptor 1 (LOX1) via nuclear factor-κB (NF-κB). A LOX1 antagonist carrageenan significantly blocked SAA-induced foam cell formation, indicating that SAA promotes foam cell formation via LOX1 expression. Our findings therefore suggest that SAA stimulates foam cell formation via LOX1 induction, and thus likely contributes to atherogenesis

  8. Serum amyloid A stimulates macrophage foam cell formation via lectin-like oxidized low-density lipoprotein receptor 1 upregulation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ha Young, E-mail: hayoung@skku.edu [Department of Biological Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714 (Korea, Republic of); Kim, Sang Doo [Department of Biological Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Baek, Suk-Hwan [Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of); Choi, Joon Hyuk [Department of Pathology, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of); Cho, Kyung-Hyun [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Zabel, Brian A. [Palo Alto Institute for Research and Education, Veterans Affairs Hospital, Palo Alto, CA 94304 (United States); Bae, Yoe-Sik, E-mail: yoesik@skku.edu [Department of Biological Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714 (Korea, Republic of); Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul 135-710 (Korea, Republic of)

    2013-03-29

    Highlights: ► SAA induced macrophage foam cell formation. ► SAA stimulated upregulation of lectin-like oxidized low-density lipoprotein receptor 1 (LOX1). ► SAA-induced LOX1 expression and foam cell formation is mediated by JNK/NF-κB signaling. ► HDL-conjugated SAA also stimulates foam cell formation via LOX1 upregulation. ► The finding reveals a novel mechanism of action of SAA in the pathogenesis of atherosclerosis. -- Abstract: Elevated levels of serum amyloid A (SAA) is a risk factor for cardiovascular diseases, however, the role of SAA in the pathophysiology of atherosclerosis remains unclear. Here we show that SAA induced macrophage foam cell formation. SAA-stimulated foam cell formation was mediated by c-jun N-terminal kinase (JNK) signaling. Moreover, both SAA and SAA-conjugated high density lipoprotein stimulated the expression of the important scavenger receptor lectin-like oxidized low-density lipoprotein receptor 1 (LOX1) via nuclear factor-κB (NF-κB). A LOX1 antagonist carrageenan significantly blocked SAA-induced foam cell formation, indicating that SAA promotes foam cell formation via LOX1 expression. Our findings therefore suggest that SAA stimulates foam cell formation via LOX1 induction, and thus likely contributes to atherogenesis.

  9. Comparative analysis of the internalization of the macrophage receptor sialoadhesin in human and mouse primary macrophages and cell lines.

    Science.gov (United States)

    De Schryver, Marjorie; Leemans, Annelies; Pintelon, Isabel; Cappoen, Davie; Maes, Louis; Caljon, Guy; Cos, Paul; Delputte, Peter L

    2017-06-01

    Sialoadhesin (Sn) is a surface receptor expressed on resident macrophages with the ability to bind with sialic acids. During inflammation, an upregulation of Sn is observed. Upon binding of monoclonal antibodies to Sn, the receptor becomes internalized and this has been observed in multiple species. The latter characteristic, combined with the strong upregulation of Sn on inflammatory macrophages and the fact that Sn-positive macrophages contribute to certain inflammatory diseases, makes Sn an interesting entry portal for phenotype-modulating or cytotoxic drugs. Such drugs or toxins can be linked to Sn-specific antibodies which should enable their targeted uptake by macrophages. However, the activity of such drugs depends not only on their internalization but also on the intracellular trafficking and final fate in the endolysosomal system. Although information is available for porcine Sn, the detailed mechanisms of human and mouse Sn internalization and subsequent intracellular trafficking are currently unknown. To allow development of Sn-targeted therapies, differences across species and cellular background need to be characterized in more detail. In the current report, we show that internalization of human and mouse Sn is dynamin-dependent and clathrin-mediated, both in primary macrophages and CHO cell lines expressing a recombinant Sn. In primary macrophages, internalized Sn-specific F(ab') 2 fragments are located mostly in the early endosomes. With Fc containing Sn-specific antibodies, there is a slight shift towards lysosomal localization in mouse macrophages, possibly because of an interaction with Fc receptors. Surprisingly, in CHO cell lines expressing Sn, there is a predominant lysosomal localization. Our results show that the mechanism of Sn internalization and intracellular trafficking is concurrent in the tested species. The cellular background in which Sn is expressed and the type of antibody used can affect the intracellular fate, which in turn can

  10. Macrophage ABCA2 deletion modulates intracellular cholesterol deposition, affects macrophage apoptosis, and decreases early atherosclerosis in LDL receptor knockout mice.

    Science.gov (United States)

    Calpe-Berdiel, Laura; Zhao, Ying; de Graauw, Marjo; Ye, Dan; van Santbrink, Peter J; Mommaas, A Mieke; Foks, Amanda; Bot, Martine; Meurs, Illiana; Kuiper, Johan; Mack, Jody T; Van Eck, Miranda; Tew, Kenneth D; van Berkel, Theo J C

    2012-08-01

    The ABCA2 transporter shares high structural homology to ABCA1, which is crucial for the removal of excess cholesterol from macrophages and, by extension, in atherosclerosis. It has been suggested that ABCA2 sequesters cholesterol inside the lysosomes, however, little is known of the macrophage-specific role of ABCA2 in regulating lipid homeostasis in vivo and in modulating susceptibility to atherosclerosis. Chimeras with dysfunctional macrophage ABCA2 were generated by transplantation of bone marrow from ABCA2 knockout (KO) mice into irradiated LDL receptor (LDLr) KO mice. Interestingly, lack of ABCA2 in macrophages resulted in a diminished lesion size in the aortic root (-24.5%) and descending thoracic aorta (-36.6%) associated with a 3-fold increase in apoptotic cells, as measured by both caspase 3 and TUNEL. Upon oxidized LDL exposure, macrophages from wildtype (WT) transplanted animals developed filipin-positive droplets in lysosomal-like compartments, corresponding to free cholesterol (FC) accumulation. In contrast, ABCA2-deficient macrophages displayed an abnormal diffuse distribution of FC over peripheral regions. The accumulation of neutral sterols in lipid droplets was increased in ABCA2-deficient macrophages, but primarily in cytoplasmic clusters and not in lysosomes. Importantly, apoptosis of oxLDL loaded macrophages lacking ABCA2 was increased 2.7-fold, probably as a consequence of the broad cellular distribution of FC. Lack of functional ABCA2 generates abnormalities in intracellular lipid distribution/trafficking in macrophages consistent with its lysosomal sequestering role, leading to an increased susceptibility to apoptosis in response to oxidized lipids and reduced atherosclerotic lesion development. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  11. Granulocyte-macrophage colony-stimulating factor primes interleukin-13 production by macrophages via protease-activated receptor-2.

    Science.gov (United States)

    Aoki, Manabu; Yamaguchi, Rui; Yamamoto, Takatoshi; Ishimaru, Yasuji; Ono, Tomomichi; Sakamoto, Arisa; Narahara, Shinji; Sugiuchi, Hiroyuki; Hirose, Eiji; Yamaguchi, Yasuo

    2015-04-01

    Chronic inflammation is often linked to the presence of type 2-polarized macrophages, which are induced by the T helper type 2 cytokines interleukin-4 and interleukin-13 (IL-13). IL-13 is a key mediator of tissue fibrosis caused by T helper type 2-based inflammation. Human neutrophil elastase (HNE) plays a pivotal role in the pathogenesis of pulmonary fibrosis. This study investigated the priming effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on IL-13 expression by macrophages stimulated with HNE. Adherent macrophages were obtained from primary cultures of human mononuclear cells. Expression of IL-13 mRNA and protein by GM-CSF-dependent macrophages was investigated after stimulation with HNE, using the polymerase chain reaction and enzyme-linked immunosorbent assay. GM-CSF had a priming effect on IL-13 mRNA and protein expression by macrophages stimulated with HNE, while this effect was not observed for various other cytokines. GM-CSF-dependent macrophages showed a significant increase in the expression of protease activated receptor-2 (PAR-2) mRNA and protein. The response of IL-13 mRNA to HNE was significantly decreased by pretreatment with alpha1-antitrypsin, a PAR-2 antibody (SAM11), or a PAR-2 antagonist (ENMD-1068). These findings suggest that stimulation with HNE can induce IL-13 production by macrophages, especially GM-CSF-dependent macrophages. Accordingly, neutrophil elastase may have a key role in fibrosis associated with chronic inflammation. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. The superoxide scavenger TEMPOL induces urokinase receptor (uPAR expression in human prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Francis Joseph

    2006-06-01

    Full Text Available Abstract There is little understanding of the effect that reactive oxygen metabolites have on cellular behavior during the processes of invasion and metastasis. These oxygen metabolites could interact with a number of targets modulating their function such as enzymes involved in basement membrane dissolution, adhesion molecules involved in motility or receptors involved in proliferation. We investigated the effect of increased scavenging of superoxide anions on the expression of the urokinase receptor (uPAR in PC-3M human prostate cancer cells. Urokinase receptor is a GPI-linked cell surface molecule which mediates multiple functions including adhesion, proliferation and pericellular proteolysis. Addition of the superoxide scavenger 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy (TEMPOL to PC-3M cultures stimulated expression of uPAR protein peaking between 48 and 72 hours. Cell surface expression of the uPAR was also increased. Surprisingly, uPAR transcript levels increased only slightly and this mild increase did not coincide with the striking degree of protein increase. This disparity indicates that the TEMPOL effect on uPAR occurs through a post-transcriptional mechanism. TEMPOL presence in PC-3M cultures reduced intracellular superoxide-type species by 75% as assayed by NBT dye conversion; however this reduction significantly diminished within hours following TEMPOL removal. The time gap between TEMPOL treatment and peak uPAR protein expression suggests that reduction of reactive oxygen metabolites in prostate cancer cells initiates a multistep pathway which requires several hours to culminate in uPAR induction. These findings reveal a novel pathway for uPAR regulation involving reactive oxygens such as superoxide anion.

  13. Liver X Receptor (LXR) activation negatively regulates visfatin expression in macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Mayi, Therese Hervee; Rigamonti, Elena [Univ Lille Nord de France, F-59000 Lille (France); INSERM UR1011, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France); Pattou, Francois [Univ Lille Nord de France, F-59000 Lille (France); Department of Endocrine Surgery, University Hospital, Lille (France); U859 Biotherapies for Diabetes, INSERM, Lille (France); Staels, Bart, E-mail: bart.staels@pasteur-lille.fr [Univ Lille Nord de France, F-59000 Lille (France); INSERM UR1011, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France); Chinetti-Gbaguidi, Giulia [Univ Lille Nord de France, F-59000 Lille (France); INSERM UR1011, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France)

    2011-01-07

    Research highlights: {yields} Synthetic LXR ligands decreased visfatin expression in human macrophages. {yields} LXR activation leads to a modest and transient decrease of NAD{sup +} concentration. {yields} LXR activation decreased PPAR{gamma}-induced visfatin in human macrophages. -- Abstract: Adipose tissue macrophages (ATM) are the major source of visfatin, a visceral fat adipokine upregulated during obesity. Also known to play a role in B cell differentiation (pre-B cell colony-enhancing factor (PBEF)) and NAD biosynthesis (nicotinamide phosphoribosyl transferase (NAMPT)), visfatin has been suggested to play a role in inflammation. Liver X Receptor (LXR) and Peroxisome Proliferator-Activated Receptor (PPAR){gamma} are nuclear receptors expressed in macrophages controlling the inflammatory response. Recently, we reported visfatin as a PPAR{gamma} target gene in human macrophages. In this study, we examined whether LXR regulates macrophage visfatin expression. Synthetic LXR ligands decreased visfatin gene expression in a LXR-dependent manner in human and murine macrophages. The decrease of visfatin mRNA was paralleled by a decrease of protein secretion. Consequently, a modest and transient decrease of NAD{sup +} concentration was observed. Interestingly, LXR activation decreased the PPAR{gamma}-induced visfatin gene and protein secretion in human macrophages. Our results identify visfatin as a gene oppositely regulated by the LXR and PPAR{gamma} pathways in human macrophages.

  14. Fcγ receptor expression on splenic macrophages in adult immune thrombocytopenia

    NARCIS (Netherlands)

    Audia, S; Santegoets, K; Laarhoven, A G; Vidarsson, G; Facy, O; Ortega-Deballon, P; Samson, M; Janikashvili, N; Saas, P; Bonnotte, B; Radstake, T R

    2017-01-01

    Splenic macrophages play a key role in immune thrombocytopenia (ITP) pathogenesis by clearing opsonized platelets. Fcγ receptors (FcγR) participate in this phenomenon, but their expression on splenic macrophages and their modulation by treatment have scarcely been studied in human ITP. We aimed to

  15. Uptake and metabolism of polymerized albumin by rat liver. Role of the scavenger receptor

    International Nuclear Information System (INIS)

    Wright, T.L.; Roll, F.J.; Jones, A.L.; Weisiger, R.A.

    1988-01-01

    Hepatitis B virus binds avidly to albumin polymers, which in turn may mediate viral attachment to liver cells. This hypothesis is critically dependent on prior results obtained using glutaraldehyde-polymerized human serum albumin as a model for naturally occurring albumin species. We used the perfused rat liver to characterize the uptake, cellular distribution, and metabolism of glutaraldehyde-polymerized human albumin. 125 I-glutaraldehyde-polymerized human albumin was efficiently removed from the perfusate by the liver (29% extraction). However, few autoradiographic grains were located over hepatic parenchymal cells (6%). Instead, most glutaraldehyde-polymerized human albumin appeared to be removed by endothelial (59%) or Kupffer (31%) cells. Hepatic uptake was strongly inhibited by formaldehyde-treated monomeric albumin, a known ligand of the endothelial scavenger receptor for chemically modified proteins. After uptake, most glutaraldehyde-polymerized human albumin was rapidly degraded and released into the perfusate (74% within 60 min). This process was blocked by chloroquine and leupeptin, suggesting that it involves lysosomal acid hydrolases. We conclude that glutaraldehyde-polymerized albumin is efficiently cleared and degraded by the endothelial scavenger pathway. Glutaraldehyde-polymerized albumin therefore appears to be a poor model for predicting the hepatic handling of naturally occurring albumin species bound to hepatitis B virions. Even if viral particles were to follow this pathway, few would enter parenchymal hepatocytes

  16. Implication of scavenger receptors in the interactions between diesel exhaust particles and immature or mature dendritic cells

    Directory of Open Access Journals (Sweden)

    Lassalle Philippe

    2009-03-01

    Full Text Available Abstract Background The exposure to pollutants such as diesel exhaust particles (DEP is associated with an increased incidence of respiratory diseases. However, the mechanisms by which DEP have an effect on human health are not completely understood. In addition to their action on macrophages and airway epithelial cells, DEP also modulate the functions of dendritic cells (DC. These professional antigen-presenting cells are able to discriminate unmodified self from non-self thanks to pattern recognition receptors such as the Toll like Receptors (TLR and Scavenger Receptors (SR. SR were originally identified by their ability to bind and internalize modified lipoproteins and microorganisms but also particles and TLR agonists. In this study, we assessed the implication of SR in the effects of DEP associated or not with TLR agonists on monocyte-derived DC (MDDC. For this, we studied the regulation of CD36, CXCL16, LOX-1, SR-A1 and SR-B1 expression on MDDC treated with DEP associated or not with TLR2, 3 and 4 ligands. Then, the capacity of SR ligands (dextran sulfate and maleylated-ovalbumin to block the effects of DEP on the function of lipopolysaccharide (LPS-activated DC has been evaluated. Results Our data demonstrate that TLR2 agonists mainly augmented CXCL16, LOX-1 and SR-B1 expression whereas DEP alone had only a weak effect. Interestingly, DEP modulated the action of TLR2 and TLR4 ligands on the expression of LOX-1 and SR-B1. Pretreatment with the SR ligand maleylated-ovalbumin but not dextran sulfate inhibited the endocytosis of DEP by MDDC. Moreover, this SR ligand blocked the effect by DEP at low dose (1 μg/ml on MDDC phenotype (a decrease of CD86 and HLA-DR expression and on the secretion of CXCL10, IL-12 and TNF-α. In contrast, the decrease of IL-12 and CXCL10 secretion and the generation of oxygen metabolite induced by DEP at 10 μg/ml was not affected by SR ligands Conclusion Our results show for the first time that the modulation of

  17. Expression analysis of G Protein-Coupled Receptors in mouse macrophages.

    Science.gov (United States)

    Lattin, Jane E; Schroder, Kate; Su, Andrew I; Walker, John R; Zhang, Jie; Wiltshire, Tim; Saijo, Kaoru; Glass, Christopher K; Hume, David A; Kellie, Stuart; Sweet, Matthew J

    2008-04-29

    Monocytes and macrophages express an extensive repertoire of G Protein-Coupled Receptors (GPCRs) that regulate inflammation and immunity. In this study we performed a systematic micro-array analysis of GPCR expression in primary mouse macrophages to identify family members that are either enriched in macrophages compared to a panel of other cell types, or are regulated by an inflammatory stimulus, the bacterial product lipopolysaccharide (LPS). Several members of the P2RY family had striking expression patterns in macrophages; P2ry6 mRNA was essentially expressed in a macrophage-specific fashion, whilst P2ry1 and P2ry5 mRNA levels were strongly down-regulated by LPS. Expression of several other GPCRs was either restricted to macrophages (e.g. Gpr84) or to both macrophages and neural tissues (e.g. P2ry12, Gpr85). The GPCR repertoire expressed by bone marrow-derived macrophages and thioglycollate-elicited peritoneal macrophages had some commonality, but there were also several GPCRs preferentially expressed by either cell population. The constitutive or regulated expression in macrophages of several GPCRs identified in this study has not previously been described. Future studies on such GPCRs and their agonists are likely to provide important insights into macrophage biology, as well as novel inflammatory pathways that could be future targets for drug discovery.

  18. Polysaccharide of Dendrobium huoshanense activates macrophages via toll-like receptor 4-mediated signaling pathways.

    Science.gov (United States)

    Xie, Song-Zi; Hao, Ran; Zha, Xue-Qiang; Pan, Li-Hua; Liu, Jian; Luo, Jian-Ping

    2016-08-01

    The present work aimed at investigating the pattern recognition receptor (PRR) and immunostimulatory mechanism of a purified Dendrobium huoshanense polysaccharide (DHP). We found that DHP could bind to the surface of macrophages and stimulate macrophages to secrete NO, TNF-α and IL-1β. To unravel the mechanism for the binding of DHP to macrophages, flow cytometry, confocal laser-scanning microscopy, affinity electrophoresis, SDS-PAGE and western blotting were employed to verify the type of PRR responsible for the recognition of DHP by RAW264.7 macrophages and peritoneal macrophages of C3H/HeN and C3H/HeJ macrophages. Results showed that toll-like receptor 4 (TLR4) was an essential receptor for macrophages to directly bind DHP. Further, the phosphorylation of ERK, JNK, Akt and p38 were observed to be time-dependently promoted by DHP, as well as the nuclear translocation of NF-κB p65. These results suggest that DHP activates macrophages via its direct binding to TLR4 to trigger TLR4 signaling pathways. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. A TNF-Regulated Recombinatorial Macrophage Immune Receptor Implicated in Granuloma Formation in Tuberculosis

    Science.gov (United States)

    Streich, Roswita; Breysach, Caroline; Raddatz, Dirk; Oniga, Septimia; Peccerella, Teresa; Findeisen, Peter; Kzhyshkowska, Julia; Gratchev, Alexei; Schweyer, Stefan; Saunders, Bernadette; Wessels, Johannes T.; Möbius, Wiebke; Keane, Joseph; Becker, Heinz; Ganser, Arnold; Neumaier, Michael; Kaminski, Wolfgang E.

    2011-01-01

    Macrophages play a central role in host defense against mycobacterial infection and anti- TNF therapy is associated with granuloma disorganization and reactivation of tuberculosis in humans. Here, we provide evidence for the presence of a T cell receptor (TCR) αβ based recombinatorial immune receptor in subpopulations of human and mouse monocytes and macrophages. In vitro, we find that the macrophage-TCRαβ induces the release of CCL2 and modulates phagocytosis. TNF blockade suppresses macrophage-TCRαβ expression. Infection of macrophages from healthy individuals with mycobacteria triggers formation of clusters that express restricted TCR Vβ repertoires. In vivo, TCRαβ bearing macrophages abundantly accumulate at the inner host-pathogen contact zone of caseous granulomas from patients with lung tuberculosis. In chimeric mouse models, deletion of the variable macrophage-TCRαβ or TNF is associated with structurally compromised granulomas of pulmonary tuberculosis even in the presence of intact T cells. These results uncover a TNF-regulated recombinatorial immune receptor in monocytes/macrophages and demonstrate its implication in granuloma formation in tuberculosis. PMID:22114556

  20. A TNF-regulated recombinatorial macrophage immune receptor implicated in granuloma formation in tuberculosis.

    Directory of Open Access Journals (Sweden)

    Alexander W Beham

    2011-11-01

    Full Text Available Macrophages play a central role in host defense against mycobacterial infection and anti- TNF therapy is associated with granuloma disorganization and reactivation of tuberculosis in humans. Here, we provide evidence for the presence of a T cell receptor (TCR αβ based recombinatorial immune receptor in subpopulations of human and mouse monocytes and macrophages. In vitro, we find that the macrophage-TCRαβ induces the release of CCL2 and modulates phagocytosis. TNF blockade suppresses macrophage-TCRαβ expression. Infection of macrophages from healthy individuals with mycobacteria triggers formation of clusters that express restricted TCR Vβ repertoires. In vivo, TCRαβ bearing macrophages abundantly accumulate at the inner host-pathogen contact zone of caseous granulomas from patients with lung tuberculosis. In chimeric mouse models, deletion of the variable macrophage-TCRαβ or TNF is associated with structurally compromised granulomas of pulmonary tuberculosis even in the presence of intact T cells. These results uncover a TNF-regulated recombinatorial immune receptor in monocytes/macrophages and demonstrate its implication in granuloma formation in tuberculosis.

  1. Cloning and characterization of SCART1, a novel scavenger receptor cysteine-rich type I transmembrane molecule

    DEFF Research Database (Denmark)

    Holm, Dorte; Fink, Dorte Rosenbek; Grønlund, Jørn

    2009-01-01

    We have cloned and characterized a novel murine transmembrane molecule, mSCART1 belonging to the scavenger receptor cysteine-rich superfamily. The cDNA encodes a polypeptide chain of 989 amino acids, organized as a type I transmembrane protein that contains eight extracellular SRCR domains followed...

  2. LDL Receptor-Related Protein-1 (LRP1 Regulates Cholesterol Accumulation in Macrophages.

    Directory of Open Access Journals (Sweden)

    Anna P Lillis

    Full Text Available Within the circulation, cholesterol is transported by lipoprotein particles and is taken up by cells when these particles associate with cellular receptors. In macrophages, excessive lipoprotein particle uptake leads to foam cell formation, which is an early event in the development of atherosclerosis. Currently, mechanisms responsible for foam cell formation are incompletely understood. To date, several macrophage receptors have been identified that contribute to the uptake of modified forms of lipoproteins leading to foam cell formation, but the in vivo contribution of the LDL receptor-related protein 1 (LRP1 to this process is not known [corrected]. To investigate the role of LRP1 in cholesterol accumulation in macrophages, we generated mice with a selective deletion of LRP1 in macrophages on an LDL receptor (LDLR-deficient background (macLRP1-/-. After feeding mice a high fat diet for 11 weeks, peritoneal macrophages isolated from Lrp+/+ mice contained significantly higher levels of total cholesterol than those from macLRP1-/- mice. Further analysis revealed that this was due to increased levels of cholesterol esters. Interestingly, macLRP1-/- mice displayed elevated plasma cholesterol and triglyceride levels resulting from accumulation of large, triglyceride-rich lipoprotein particles in the circulation. This increase did not result from an increase in hepatic VLDL biosynthesis, but rather results from a defect in catabolism of triglyceride-rich lipoprotein particles in macLRP1-/- mice. These studies reveal an important in vivo contribution of macrophage LRP1 to cholesterol homeostasis.

  3. IL-4 Receptor Alpha Signaling through Macrophages Differentially Regulates Liver Fibrosis Progression and Reversal

    Directory of Open Access Journals (Sweden)

    Shih-Yen Weng

    2018-03-01

    Full Text Available Chronic hepatitis leads to liver fibrosis and cirrhosis. Cirrhosis is a major cause of worldwide morbidity and mortality. Macrophages play a key role in fibrosis progression and reversal. However, the signals that determine fibrogenic vs fibrolytic macrophage function remain ill defined. We studied the role of interleukin-4 receptor α (IL-4Rα, a potential central switch of macrophage polarization, in liver fibrosis progression and reversal. We demonstrate that inflammatory monocyte infiltration and liver fibrogenesis were suppressed in general IL-4Rα−/− as well as in macrophage-specific IL-4Rα−/− (IL-4RαΔLysM mice. However, with deletion of IL-4RαΔLysM spontaneous fibrosis reversal was retarded. Results were replicated by pharmacological intervention using IL-4Rα-specific antisense oligonucleotides. Retarded resolution was linked to the loss of M2-type resident macrophages, which secreted MMP-12 through IL-4 and IL-13-mediated phospho-STAT6 activation. We conclude that IL-4Rα signaling regulates macrophage functional polarization in a context-dependent manner. Pharmacological targeting of macrophage polarization therefore requires disease stage-specific treatment strategies. Research in Context: Alternative (M2-type macrophage activation through IL-4Rα promotes liver inflammation and fibrosis progression but speeds up fibrosis reversal. This demonstrates context dependent, opposing roles of M2-type macrophages. During reversal IL-4Rα induces fibrolytic MMPs, especially MMP-12, through STAT6. Liver-specific antisense oligonucleotides efficiently block IL-4Rα expression and attenuate fibrosis progression. Keywords: Fibrosis, IL-4 receptor alpha, Liver, Macrophage, MMP12, Progression, Reversal

  4. Identification of Adenovirus Serotype 5 Hexon Regions That Interact with Scavenger Receptors

    Energy Technology Data Exchange (ETDEWEB)

    Khare, Reeti; Reddy, Vijay S.; Nemerow, Glen R.; Barry, Michael A. (Scripps); (Mayo)

    2012-05-04

    Most of an intravenous dose of species C adenovirus serotype 5 (Ad5) is destroyed by liver Kupffer cells. In contrast, another species C virus, Ad6, evades these cells to mediate more efficient liver gene delivery. Given that this difference in Kupffer cell interaction is mediated by the hypervariable (HVR) loops of the virus hexon protein, we genetically modified each of the seven HVRs of Ad5 with a cysteine residue to enable conditional blocking of these sites with polyethylene glycol (PEG). We show that these modifications do not affect in vitro virus transduction. In contrast, after intravenous injection, targeted PEGylation at HVRs 1, 2, 5, and 7 increased viral liver transduction up to 20-fold. Elimination or saturation of liver Kupffer cells did not significantly affect this increase in the liver transduction. In vitro, PEGylation blocked uptake of viruses via the Kupffer cell scavenger receptor SRA-II. These data suggest that HVRs 1, 2, 5, and 7 of Ad5 may be involved in Kupffer cell recognition and subsequent destruction. These data also demonstrate that this conditional genetic-chemical mutation strategy is a useful tool for investigating the interactions of viruses with host tissues.

  5. microRNA-150 inhibits the formation of macrophage foam cells through targeting adiponectin receptor 2

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jing [Department of Geratory, Linzi District People’s Hospital of Zibo City, Zibo, Shandong (China); Zhang, Suhua, E-mail: drsuhuangzhang@qq.com [Department of HealthCare, Qilu Hospital of Shandong University (Qingdao), Qingdao City, Qingdao (China)

    2016-08-05

    Transformation of macrophages into foam cells plays a critical role in the pathogenesis of atherosclerosis. The aim of this study was to determine the expression and biological roles of microRNA (miR)-150 in the formation of macrophage foam cells and to identify its functional target(s). Exposure to 50 μg/ml oxidized low-density lipoprotein (oxLDL) led to a significant upregulation of miR-150 in THP-1 macrophages. Overexpression of miR-150 inhibited oxLDL-induced lipid accumulation in THP-1 macrophages, while knockdown of miR-150 enhanced lipid accumulation. apoA-I- and HDL-mediated cholesterol efflux was increased by 66% and 43%, respectively, in miR-150-overexpressing macrophages relative to control cells. In contrast, downregulation of miR-150 significantly reduced cholesterol efflux from oxLDL-laden macrophages. Bioinformatic analysis and luciferase reporter assay revealed adiponectin receptor 2 (AdipoR2) as a direct target of miR-150. Small interfering RNA-mediated downregulation of AdipoR2 phenocopied the effects of miR-150 overexpression, reducing lipid accumulation and facilitating cholesterol efflux in oxLDL-treated THP-1 macrophages. Knockdown of AdipoR2 induced the expression of proliferator-activated receptor gamma (PPARγ), liver X receptor alpha (LXRα), ABCA1, and ABCG1. Moreover, pharmacological inhibition of PPARγ or LXRα impaired AdipoR2 silencing-induced upregulation of ABCA1 and ABCG1. Taken together, our results indicate that miR-150 can attenuate oxLDL-induced lipid accumulation in macrophages via promotion of cholesterol efflux. The suppressive effects of miR-150 on macrophage foam cell formation are mediated through targeting of AdipoR2. Delivery of miR-150 may represent a potential approach to prevent macrophage foam cell formation in atherosclerosis. -- Highlights: •miR-150 inhibits macrophage foam cell formation. •miR-150 accelerates cholesterol efflux from oxLDL-laden macrophages. •miR-150 suppresses macrophage foam cell

  6. Activation of AMPA receptor promotes TNF-α release via the ROS-cSrc-NFκB signaling cascade in RAW264.7 macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Xiu-Li [Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing (China); Ding, Fan [Office of Scientific R& D, Tsinghua University, Beijing (China); Li, Hui; Tan, Xiao-Qiu [Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing (China); Liu, Xiao [Department of Pathophysiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing (China); Cao, Ji-Min, E-mail: caojimin@126.com [Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing (China); Gao, Xue, E-mail: longlongnose@163.com [Department of Pathophysiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing (China)

    2015-05-29

    The relationship between glutamate signaling and inflammation has not been well defined. This study aimed to investigate the role of AMPA receptor (AMPAR) in the expression and release of tumor necrosis factor-alpha (TNF-α) from macrophages and the underlying mechanisms. A series of approaches, including confocal microscopy, immunofluorescency, flow cytometry, ELISA and Western blotting, were used to estimate the expression of AMPAR and downstream signaling molecules, TNF-α release and reactive oxygen species (ROS) generation in the macrophage-like RAW264.7 cells. The results demonstrated that AMPAR was expressed in RAW264.7 cells. AMPA significantly enhanced TNF-α release from RAW264.7 cells, and this effect was abolished by CNQX (AMPAR antagonist). AMPA also induced elevation of ROS production, phosphorylation of c-Src and activation of nuclear factor (NF)-κB in RAW264.7 cells. Blocking c-Src by PP2, scavenging ROS by glutathione (GSH) or inhibiting NF-κB activation by pyrrolidine dithiocarbamate (PDTC) decreased TNF-α production from RAW264.7 cells. We concluded that AMPA promotes TNF-α release in RAW264.7 macrophages likely through the following signaling cascade: AMPAR activation → ROS generation → c-Src phosphorylation → NF-κB activation → TNF-α elevation. The study suggests that AMPAR may participate in macrophage activation and inflammation. - Highlights: • AMPAR is expressed in RAW264.7 macrophages and is upregulated by AMPA stimulation. • Activation of AMPAR stimulates TNF-α release in macrophages through the ROS-cSrc-NFκB signaling cascade. • Macrophage AMPAR signaling may play an important role in inflammation.

  7. Targeting androgen receptor to suppress macrophage-induced EMT and benign prostatic hyperplasia (BPH) development.

    Science.gov (United States)

    Lu, Tianjing; Lin, Wen-Jye; Izumi, Kouji; Wang, Xiaohai; Xu, Defeng; Fang, Lei-Ya; Li, Lei; Jiang, Qi; Jin, Jie; Chang, Chawnshang

    2012-10-01

    Early studies suggested macrophages might play roles in inflammation-associated benign prostatic hyperplasia (BPH) development, yet the underlying mechanisms remain unclear. Here we first showed that CD68(+) macrophages were identified in both epithelium and the stromal area of human BPH tissues. We then established an in vitro co-culture model with prostate epithelial and macrophage cell lines to study the potential impacts of infiltrating macrophages in the BPH development and found that co-culturing prostate epithelial cells with macrophages promoted migration of macrophages. In a three-dimensional culture system, the sphere diameter of BPH-1 prostate cells was significantly increased during coculture with THP-1 macrophage cells. Mechanism dissection suggested that expression levels of epithelial-mesenchymal transition (EMT) markers, such as N-cadherin, Snail, and TGF-β2, were increased, and administration of anti-TGF-β2 neutralizing antibody during co-culture suppressed the EMT and THP-1-mediated growth of BPH-1 cells, suggesting THP-1 might go through EMT to influence the BPH development and progression. Importantly, we found that modulation of androgen receptor (AR) in BPH-1 and mPrE cells significantly increased THP-1 and RAW264.7 cell migration, respectively, and enhanced expression levels of EMT markers, suggesting that AR in prostate epithelial cells might play a role in promoting macrophage-mediated EMT in prostate epithelial cells. Silencing AR function via an AR degradation enhancer, ASC-J9, decreased the macrophage migration to BPH-1 cells and suppressed EMT marker expression. Together, these results provide the first evidence to demonstrate that prostate epithelial AR function is important for macrophage-mediated EMT and proliferation of prostate epithelial cells, which represents a previously unrecognized role of AR in the cross-talk between macrophages and prostate epithelial cells. These results may provide new insights for a new therapeutic

  8. CCR8 signaling influences Toll-like receptor 4 responses in human macrophages in inflammatory diseases.

    Science.gov (United States)

    Reimer, Martina Kvist; Brange, Charlotte; Rosendahl, Alexander

    2011-12-01

    CCR8 immunity is generally associated with Th2 responses in allergic diseases. In this study, we demonstrate for the first time a pronounced attenuated influx of macrophages in ovalbumin (OVA)-challenged CCR8 knockout mice. To explore whether macrophages in human inflamed lung tissue also were CCR8 positive, human lung tissue from patients with chronic obstructive pulmonary disease (COPD) was evaluated. Indeed, CCR8 expression was pronounced in invading monocytes/macrophages from lungs of patients with Global Initiative for Obstructive Lung Disease (GOLD) stage IV COPD. Given this expression pattern, the functional role of CCR8 on human macrophages was evaluated in vitro. Human peripheral blood monocytes expressed low levels of CCR8, while macrophage colony-stimulating factor (M-CSF)-derived human macrophages expressed significantly elevated surface levels of CCR8. Importantly, CCL1 directly regulated the expression of CD18 and CD49b and hence influenced the adhesion capacity of human macrophages. CCL1 drives chemotaxis in M-CSF-derived macrophages, and this could be completely inhibited by lipopolysaccharide (LPS). Whereas both CCL1 and LPS monotreatment inhibited spontaneous superoxide release in macrophages, CCL1 significantly induced superoxide release in the presence of LPS in a dose-dependent manner. Finally, CCL1 induced production of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) and could inhibit LPS-induced cytokine production in a dose-dependent manner. Our data demonstrate, for the first time, the presence of CCR8 on inflammatory macrophages in human COPD lung tissue. Importantly, the functional data from human macrophages suggest a potential cross talk between the CCR8 and the Toll-like receptor 4 (TLR4) pathways, both of which are present in COPD patients.

  9. TNF-alpha, produced by feline infectious peritonitis virus (FIPV)-infected macrophages, upregulates expression of type II FIPV receptor feline aminopeptidase N in feline macrophages.

    Science.gov (United States)

    Takano, Tomomi; Hohdatsu, Tsutomu; Toda, Ayako; Tanabe, Maki; Koyama, Hiroyuki

    2007-07-20

    The pathogenicity of feline infectious peritonitis virus (FIPV) is known to depend on macrophage tropism, and this macrophage infection is enhanced by mediation via anti-S antibody (antibody-dependent enhancement, ADE). In this study, we found that TNF-alpha production was increased with viral replication in macrophages inoculated with a mixture of FIPV and anti-S antibody, and demonstrated that this culture supernatant had feline PBMC apoptosis-inducing activity. We also demonstrated that the expression level of the FIPV virus receptor, feline aminopeptidase N (fAPN), was increased in macrophages of FIP cats. For upregulation of TNF-alpha and fAPN in macrophages, viral replication in macrophages is necessary, and their expressions were increased by ADE of FIPV infection. It was demonstrated that a heat-resistant fAPN-inducing factor was present in the culture supernatant of FIPV-infected macrophages, and this factor was TNF-alpha: fAPN expression was upregulated in recombinant feline TNF-alpha-treated macrophages, and FIPV infectivity was increased in these macrophages. These findings suggested that FIPV replication in macrophages increases TNF-alpha production in macrophages, and the produced TNF-alpha acts and upregulates fAPN expression, increasing FIPV sensitivity.

  10. Radical Scavenging Activity-Based and AP-1-Targeted Anti-Inflammatory Effects of Lutein in Macrophage-Like and Skin Keratinocytic Cells

    Directory of Open Access Journals (Sweden)

    Jueun Oh

    2013-01-01

    Full Text Available Lutein is a naturally occurring carotenoid with antioxidative, antitumorigenic, antiangiogenic, photoprotective, hepatoprotective, and neuroprotective properties. Although the anti-inflammatory effects of lutein have previously been described, the mechanism of its anti-inflammatory action has not been fully elucidated. Therefore, in the present study, we aimed to investigate the regulatory activity of lutein in the inflammatory responses of skin-derived keratinocytes or macrophages and to elucidate the mechanism of its inhibitory action. Lutein significantly reduced several skin inflammatory responses, including increased expression of interleukin-(IL- 6 from LPS-treated macrophages, upregulation of cyclooxygenase-(COX- 2 from interferon-γ/tumor necrosis-factor-(TNF- α-treated HaCaT cells, and the enhancement of matrix-metallopeptidase-(MMP- 9 level in UV-irradiated keratinocytes. By evaluating the intracellular signaling pathway and the nuclear transcription factor levels, we determined that lutein inhibited the activation of redox-sensitive AP-1 pathway by suppressing the activation of p38 and c-Jun-N-terminal kinase (JNK. Evaluation of the radical and ROS scavenging activities further revealed that lutein was able to act as a strong anti-oxidant. Taken together, our findings strongly suggest that lutein-mediated AP-1 suppression and anti-inflammatory activity are the result of its strong antioxidative and p38/JNK inhibitory activities. These findings can be applied for the preparation of anti-inflammatory and cosmetic remedies for inflammatory diseases of the skin.

  11. Toll-like receptor 4-positive macrophages protect mice from Pasteurella pneumotropica-induced pneumonia

    Science.gov (United States)

    Hart, Marcia L.; Mosier, Derek A.; Chapes, Stephen K.

    2003-01-01

    This study investigates Toll-like receptor 4 (TLR4)-positive macrophages in early recognition and clearance of pulmonary bacteria. TLR4 is a trans-membrane receptor that is the primary recognition molecule for lipopolysaccharide of gram-negative bacteria. The TLR4(Lps-del) mouse strains C57BL10/ScN (B10) and STOCK Abb(tm1) TLR4(Lps-del) Slc11a1(s)(B10 x C2D) are susceptible to pulmonary infections and develop pneumonia when naturally or experimentally infected by the opportunistic bacterium Pasteurella pneumotropica. Since these mice have the TLR4(Lps-del) genotype, we hypothesized that reconstitution of mice with TLR4-positive macrophages would provide resistance to this bacterium. A cultured macrophage cell line (C2D macrophages) and bone marrow cells from C2D mice were adoptively transferred to B10 and B10 x C2D mice by intraperitoneal injection. C2D macrophages increased B10 and B10 x C2D mouse resistance to P. pneumotropica. In C2D-recipient mice there was earlier transcription of tumor necrosis factor alpha and chemokines JE and macrophage inflammatory protein 2 (MIP-2) in the lungs of B10 and B10 x C2D mice, and there was earlier transcription of KC and MIP-1alpha in B10 x C2D mice. In addition, the course of inflammation following experimental Pasteurella challenge was altered in C2D recipients. C2D macrophages also protected B10 x C2D mice, which lack CD4(+) T cells. These data indicate that macrophages are critical for pulmonary immunity and can provide host resistance to P. pneumotropica. This study indicates that TLR4-positive macrophages are important for early recognition and clearance of pulmonary bacterial infections.

  12. Macrophage-to-sensory neuron crosstalk mediated by Angiotensin II type-2 receptor elicits neuropathic pain

    OpenAIRE

    Krause, Eric; Shepherd, Andrew; Mickle, Aaron; Copits, Bryan; Karlsson, Pall; Kadunganattil, Suraj; Golden, Judith; Tadinada, Satya; Mack, Madison; Haroutounian, Simon; De Kloet, Annette; Samineni, Vijay; Valtcheva, Manouela; Mcilvried, Lisa; Sheahan, Tayler

    2017-01-01

    Peripheral nerve damage initiates a complex series of cellular and structural processes that culminate in chronic neuropathic pain. Our study defines local angiotensin signaling via activation of the Angiotensin II (Ang II) type-2 receptor (AT2R) on macrophages as the critical trigger of neuropathic pain. An AT2R-selective antagonist attenuates neuropathic, but not inflammatory pain hypersensitivity in mice, and requires the cell damage-sensing ion channel transient receptor potential family-...

  13. Isolation of a macrophage receptor for proteins modified by advanced glycosylation end products

    International Nuclear Information System (INIS)

    Radoff, S.; Vlassara, H.; Cerami, A.

    1987-01-01

    The nonenzymatic reaction of glucose with protein amino groups leads to the formation of irreversible AGE, such as the recently characterized glucose-derived crosslink, [2-furoyl-4(5)-(2-furanyl)-1-H-imidazole] (FFI). These products accumulate with time in aging tissues and diabetes, and are implicated in irreversible tissue damage. The authors have recently shown that macrophages bind and degrade AGE-proteins via a specific surface receptor, which is thus selectively removing senescent macromolecules. Scatchard plot analysis of binding data has indicated 1.5 x 10 5 receptors/cell with a binding affinity (Ka) of 1.7 x 10 7 /M. They have now isolated this receptor from murine macrophage RAW 264.7 membranes, solubilized with octylglucoside/protease inhibitors, and using FFI-Sepharose affinity chromatography and FPLC. The purified receptor binds radioactive FFI-containing compounds competitively. SDS-PAGE gels under reducing conditions indicate the receptor to be composed of two polypeptides, 83 Kda and 36 Kda. Crosslinking experiments with 125 I-AGE-albumin as ligand, indicate the 83 Kda subunit to be the AGE-binding peptide. These studies further characterize a macrophage receptor which selectively recognizes time-dependent glucose-modified proteins associated with aging and diabetes

  14. Influence of ER leak on resting cytoplasmic Ca2+ and receptor-mediated Ca2+ signalling in human macrophage.

    Science.gov (United States)

    Layhadi, Janice A; Fountain, Samuel J

    2017-06-03

    Mechanisms controlling endoplasmic reticulum (ER) Ca 2+ homeostasis are important regulators of resting cytoplasmic Ca 2+ concentration ([Ca 2+ ] cyto ) and receptor-mediated Ca 2+ signalling. Here we investigate channels responsible for ER Ca 2+ leak in THP-1 macrophage and human primary macrophage. In the absence of extracellular Ca 2+ we employ ionomycin action at the plasma membrane to stimulate ER Ca 2+ leak. Under these conditions ionomycin elevates [Ca 2+ ] cyto revealing a Ca 2+ leak response which is abolished by thapsigargin. IP 3 receptors (Xestospongin C, 2-APB), ryanodine receptors (dantrolene), and translocon (anisomycin) inhibition facilitated ER Ca 2+ leak in model macrophage, with translocon inhibition also reducing resting [Ca 2+ ] cyto . In primary macrophage, translocon inhibition blocks Ca 2+ leak but does not influence resting [Ca 2+ ] cyto . We identify a role for translocon-mediated ER Ca 2+ leak in receptor-mediated Ca 2+ signalling in both model and primary human macrophage, whereby the Ca 2+ response to ADP (P2Y receptor agonist) is augmented following anisomycin treatment. In conclusion, we demonstrate a role of ER Ca 2+ leak via the translocon in controlling resting cytoplasmic Ca 2+ in model macrophage and receptor-mediated Ca 2+ signalling in model macrophage and primary macrophage. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Comparison of the effectiveness and safety between lymphocytes scavenger and IL-2 receptor blocking agent induction in living kidney transplantation

    Directory of Open Access Journals (Sweden)

    Ning-bo QIN

    2013-03-01

    Full Text Available Objective  To compare the safety of two antibody inductors, namely lymphocytes scavenger and IL-2 receptor blocking agent, in living kidney transplantation. Methods  The data of 191 patients, who received living kidney transplant in our hospital from Feb. 2007 to Jul. 2012, were retrospectively analyzed, and grouped according to the inductors they received as: a lymphocytes scavenger group (n=56, with rabbit antithymocyte immunoglobulin (rATG, 4 cases and porcine antihuman T-lymphocyte immunoglobulin (pATG, 52 cases served as the inductor; b IL -2 receptor blocking agent group (n=54, with basiliximab (40 cases and daclizumab (14 cases served as the inductor; and c control group (n=81. The incidence of rejection and infection, and the survival rate of patient/allograft within one year were then compared among the three groups. Results  Within one year after the transplantation, the incidence of acute rejection in lymphocytes scavenger group, IL-2 receptor blocking agent group and control group was 12.5%, 11.1% and 28.4%, respectively. There was a significant difference between the two inductor groups and control group (P=0.003, but no significant difference was found between the two inductor groups (P>0.05. The incidence of delayed graft function (DGF in the three groups was 8.9%, 7.4% and 13.6%, respectively, with no statistical significance (P>0.05. Also there was no significant difference among the three groups in the incidence of infection and the survival rate of patient/allograft within one year after transplantation (P>0.05. Conclusion  Both inductors may significantly reduce the incidence of acute rejection within one year without increasing the incidence of infection and other adverse events, nor affect the postoperative patient/graft survival, so they are both safe and effective.

  16. The macrophage A2B adenosine receptor regulates tissue insulin sensitivity.

    Directory of Open Access Journals (Sweden)

    Hillary Johnston-Cox

    Full Text Available High fat diet (HFD-induced type 2 diabetes continues to be an epidemic with significant risk for various pathologies. Previously, we identified the A2b adenosine receptor (A2bAR, an established regulator of inflammation, as a regulator of HFD-induced insulin resistance. In particular, HFD was associated with vast upregulation of liver A2bAR in control mice, and while mice lacking this receptor showed augmented liver inflammation and tissue insulin resistance. As the A2bAR is expressed in different tissues, here, we provide the first lead to cellular mechanism by demonstrating that the receptor's influence on tissue insulin sensitivity is mediated via its expression in macrophages. This was shown using a newly generated transgenic mouse model expressing the A2bAR gene in the macrophage lineage on an otherwise A2bAR null background. Reinstatement of macrophage A2bAR expression in A2bAR null mice fed HFD restored insulin tolerance and tissue insulin signaling to the level of control mice. The molecular mechanism for this effect involves A2bAR-mediated changes in cyclic adenosine monophosphate in macrophages, reducing the expression and release of inflammatory cytokines, which downregulate insulin receptor-2. Thus, our results illustrate that macrophage A2bAR signaling is needed and sufficient for relaying the protective effect of the A2bAR against HFD-induced tissue inflammation and insulin resistance in mice.

  17. Molecular and Functional Characterization of Mouse S5D-SRCRB: A New Group B Member of the Scavenger Receptor Cysteine-Rich Superfamily

    DEFF Research Database (Denmark)

    Miró-Julià, Cristina; Roselló, Sandra; Martínez, Vanesa G

    2011-01-01

    The scavenger receptor cysteine-rich superfamily (SRCR-SF) members are transmembrane and/or secreted receptors exhibiting one or several repeats of a cysteine-rich protein module of ∼100 aa, named scavenger receptor cysteine-rich (SRCR). Two types of SRCR domains (A or B) have been reported, which...... differ in the number of coding exons and intradomain cysteines. Although no unifying function has been reported for SRCR-SF members, recognition of pathogen-associated molecular patterns (PAMPs) was recently shown for some of them. In this article, we report the structural and functional characterization...

  18. Targeted delivery of anti-tuberculosis drugs to macrophages: targeting mannose receptors

    Science.gov (United States)

    Filatova, L. Yu; Klyachko, N. L.; Kudryashova, E. V.

    2018-04-01

    The development of systems for targeted delivery of anti-tuberculosis drugs is a challenge of modern biotechnology. Currently, these drugs are encapsulated in a variety of carriers such as liposomes, polymers, emulsions and so on. Despite successful in vitro testing of these systems, virtually no success was achieved in vivo, because of low accessibility of the foci of infection located in alveolar macrophage cells. A promising strategy for increasing the efficiency of therapeutic action of anti-tuberculosis drugs is to encapsulate the agents into mannosylated carriers targeting the mannose receptors of alveolar macrophages. The review addresses the methods for modification of drug substance carriers, such as liposomes and biodegradable polymers, with mannose residues. The use of mannosylated carriers to deliver anti-tuberculosis agents increases the drug circulation time in the blood stream and increases the drug concentration in alveolar macrophage cells. The bibliography includes 113 references.

  19. PET imaging detection of macrophages with a formyl peptide receptor antagonist

    International Nuclear Information System (INIS)

    Zhang, Yi; Kundu, Bijoy; Zhong, Min; Huang, Tao; Li, Jing; Chordia, Mahendra D.; Chen, Mei-Hua; Pan, Dongfeng; He, Jiang; Shi, Weibin

    2015-01-01

    Macrophages are a major inflammatory cell type involved in the development and progression of many important chronic inflammatory diseases. We previously found that apolipoprotein E-deficient (Apoe −/− ) mice with the C57BL/6 (B6) background develop type 2 diabetes mellitus (T2DM) and accelerated atherosclerosis when fed a Western diet and that there are increased macrophage infiltrations in pancreatic islets and aorta. The formyl peptide receptor 1 (FPR1) is abundantly expressed on the surface of macrophages. The purpose of this study was to evaluate the applicability of cinnamoyl-F-(D)L-F-(D)L-F (cFLFLF), a natural FPR1 antagonist, to detection of macrophages in the pancreatic islets and aorta. 64 Cu labeled cFLFLF and 18 F-fluorodeoxyglucose (FDG) were administered to mice with or without T2DM. Diabetic mice showed an increased 18 FDG uptake in the subcutaneous fat compared with control mice, but pancreatic uptake was minimal for either group. In contrast, diabetic mice exhibited visually noticeable more cFLFLF- 64 Cu retention in pancreas and liver than control mice. The heart and pancreas isolated from diabetic mice contained more macrophages and showed stronger PET signals than those of control mice. Flow cytometry analysis revealed the presence of macrophages but not neutrophils in pancreatic islets. Real-time PCR analysis revealed much higher FPR1 expression in pancreatic islets of diabetic over control mice. Autoradiography and immunohistochemical analysis confirmed abundant FPR1 expression in atherosclerotic lesions. Thus, 64 Cu-labeled cFLFLF peptide is a more effective PET agent for detecting macrophages compared to FDG

  20. Phagocytosis by macrophages mediated by receptors for denatured proteins - dependence on tyrosine protein kinases

    Directory of Open Access Journals (Sweden)

    M.R. Hespanhol

    2002-03-01

    Full Text Available Previous studies have demonstrated that some components of the leukocyte cell membrane, CR3 (Mac-1, CD11b/CD18 and p150/95, are able to bind to denatured proteins. Thus, it is of interest to know which effector functions of these cells can be triggered by these receptors when they interact with particles or surfaces covered with denatured proteins. In the present study we analyzed their possible role as mediators of phagocytosis of red cells covered with denatured bovine serum albumin (BSA by mouse peritoneal macrophages. We observed that a macrophages are able to recognize (bind to these red cells, b this interaction can be inhibited by denatured BSA in the fluid phase, c there is no phagocytosis of these particles by normal macrophages, d phagocytosis mediated by denatured BSA can be, however, effectively triggered in inflammatory macrophages induced by glycogen or in macrophages activated in vivo with LPS, and e this phagocytic capacity is strongly dependent on the activity of tyrosine protein kinases in its signal transduction pathway, as demonstrated by using three kinds of enzyme inhibitors (genistein, quercetin and herbimycin A.

  1. Depletion of alveolar macrophages in CD11c diphtheria toxin receptor mice produces an inflammatory response

    Science.gov (United States)

    Roberts, Lydia M; Ledvina, Hannah E; Tuladhar, Shraddha; Rana, Deepa; Steele, Shaun P; Sempowski, Gregory D; Frelinger, Jeffrey A

    2015-01-01

    Alveolar macrophages play a critical role in initiating the immune response to inhaled pathogens and have been shown to be the first cell type infected following intranasal inoculation with several pathogens, including Francisella tularensis. In an attempt to further dissect the role of alveolar macrophages in the immune response to Francisella, we selectively depleted alveolar macrophages using CD11c.DOG mice. CD11c.DOG mice express the diphtheria toxin receptor (DTR) under control of the full CD11c promoter. Because mice do not express DTR, tissue restricted expression of the primate DTR followed by treatment with diphtheria toxin (DT) has been widely used as a tool in immunology to examine the effect of acute depletion of a specific immune subset following normal development. We successfully depleted alveolar macrophages via intranasal administration of DT. However, alveolar macrophage depletion was accompanied by many other changes to the cellular composition and cytokine/chemokine milieu in the lung that potentially impact innate and adaptive immune responses. Importantly, we observed a transient influx of neutrophils in the lung and spleen. Our experience serves as a cautionary note to other researchers using DTR mice given the complex changes that occur following DT treatment that must be taken into account when analyzing data. PMID:26029367

  2. Extracellular polysaccharides produced by Ganoderma formosanum stimulate macrophage activation via multiple pattern-recognition receptors

    Directory of Open Access Journals (Sweden)

    Wang Cheng-Li

    2012-08-01

    Full Text Available Abstract Background The fungus of Ganoderma is a traditional medicine in Asia with a variety of pharmacological functions including anti-cancer activities. We have purified an extracellular heteropolysaccharide fraction, PS-F2, from the submerged mycelia culture of G. formosanum and shown that PS-F2 exhibits immunostimulatory activities. In this study, we investigated the molecular mechanisms of immunostimulation by PS-F2. Results PS-F2-stimulated TNF-α production in macrophages was significantly reduced in the presence of blocking antibodies for Dectin-1 and complement receptor 3 (CR3, laminarin, or piceatannol (a spleen tyrosine kinase inhibitor, suggesting that PS-F2 recognition by macrophages is mediated by Dectin-1 and CR3 receptors. In addition, the stimulatory effect of PS-F2 was attenuated in the bone marrow-derived macrophages from C3H/HeJ mice which lack functional Toll-like receptor 4 (TLR4. PS-F2 stimulation triggered the phosphorylation of mitogen-activated protein kinases JNK, p38, and ERK, as well as the nuclear translocation of NF-κB, which all played essential roles in activating TNF-α expression. Conclusions Our results indicate that the extracellular polysaccharides produced by G. formosanum stimulate macrophages via the engagement of multiple pattern-recognition receptors including Dectin-1, CR3 and TLR4, resulting in the activation of Syk, JNK, p38, ERK, and NK-κB and the production of TNF-α.

  3. Mannose Receptor Mediates the Immune Response to Ganoderma atrum Polysaccharides in Macrophages.

    Science.gov (United States)

    Li, Wen-Juan; Tang, Xiao-Fang; Shuai, Xiao-Xue; Jiang, Cheng-Jia; Liu, Xiang; Wang, Le-Feng; Yao, Yu-Fei; Nie, Shao-Ping; Xie, Ming-Yong

    2017-01-18

    The ability of mannose receptor (MR) to recognize the carbohydrate structures is well-established. Here, we reported that MR was crucial for the immune response to a Ganoderma atrum polysaccharide (PSG-1), as evidenced by elevation of MR in association with increase of phagocytosis and concentrations of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in normal macrophages. Elevation of MR triggered by PSG-1 also led to control lipopolysaccharide (LPS)-triggered inflammatory response via the increase of interleukin-10 (IL-10) and inhibition of phagocytosis and IL-1β. Anti-MR antibody partly attenuated PSG-1-mediated anti-inflammatory responses, while it could not affect TNF-α secretion, suggesting that another receptor was involved in PSG-1-triggered immunomodulatory effects. MR and toll-like receptor (TLR)4 coordinated the influences on the TLR4-mediated signaling cascade by the nuclear factor-κB (NF-κB) pathway in LPS-stimulated macrophages subjected to PSG-1. Collectively, immune response to PSG-1 required recognition by MR in macrophages. The NF-κB pathway served as a central role for the coordination of MR and TLR4 to elicit immune response to PSG-1.

  4. Macrophage galactose-type C-type lectin receptor for DC targeting of antitumor glycopeptide vaccines

    DEFF Research Database (Denmark)

    Nuti, M; Zizzari, I; Napoletano, C

    2011-01-01

    e13528 Background: Dendritic cells (DCs) are the most potent antigen presenting cells and are employed in cancer vaccination. Several receptors are being studied in order to identif strategies to increase DCs activating capacity. The C-type lectin macrophage galactose type C-type lectin (MGL...... of IFNg and IL-2 secretion by both CD8 and CD4 T cells. CONCLUSIONS: These results demonstrate that MGL engagement profoundly affects DC plasticity inducing and directing a Th1 immune response. Moreover, MGL receptor expressed on human DC can be targeted by glycopeptide based vaccines with adjuvant...

  5. DMPD: Molecular mechanisms of macrophage activation and deactivation bylipopolysaccharide: roles of the receptor complex. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14609719 Molecular mechanisms of macrophage activation and deactivation bylipopolys...acol Ther. 2003 Nov;100(2):171-94. (.png) (.svg) (.html) (.csml) Show Molecular mechanisms of macrophage act...medID 14609719 Title Molecular mechanisms of macrophage activation and deactivation bylipopolysaccharide: ro

  6. Histone Deacetylase 7 Promotes Toll-like Receptor 4-dependent Proinflammatory Gene Expression in Macrophages*

    Science.gov (United States)

    Shakespear, Melanie R.; Hohenhaus, Daniel M.; Kelly, Greg M.; Kamal, Nabilah A.; Gupta, Praveer; Labzin, Larisa I.; Schroder, Kate; Garceau, Valerie; Barbero, Sheila; Iyer, Abishek; Hume, David A.; Reid, Robert C.; Irvine, Katharine M.; Fairlie, David P.; Sweet, Matthew J.

    2013-01-01

    Broad-spectrum inhibitors of histone deacetylases (HDACs) constrain Toll-like receptor (TLR)-inducible production of key proinflammatory mediators. Here we investigated HDAC-dependent inflammatory responses in mouse macrophages. Of the classical Hdacs, Hdac7 was expressed at elevated levels in inflammatory macrophages (thioglycollate-elicited peritoneal macrophages) as compared with bone marrow-derived macrophages and the RAW264 cell line. Overexpression of a specific, alternatively spliced isoform of Hdac7 lacking the N-terminal 22 amino acids (Hdac7-u), but not the Refseq Hdac7 (Hdac7-s), promoted LPS-inducible expression of Hdac-dependent genes (Edn1, Il-12p40, and Il-6) in RAW264 cells. A novel class IIa-selective HDAC inhibitor reduced recombinant human HDAC7 enzyme activity as well as TLR-induced production of inflammatory mediators in thioglycollate-elicited peritoneal macrophages. Both LPS and Hdac7-u up-regulated the activity of the Edn1 promoter in an HDAC-dependent fashion in RAW264 cells. A hypoxia-inducible factor (HIF) 1 binding site in this promoter was required for HDAC-dependent TLR-inducible promoter activity and for Hdac7- and HIF-1α-mediated trans-activation. Coimmunoprecipitation assays showed that both Hdac7-u and Hdac7-s interacted with HIF-1α, whereas only Hdac7-s interacted with the transcriptional repressor CtBP1. Thus, Hdac7-u positively regulates HIF-1α-dependent TLR signaling in macrophages, whereas an interaction with CtBP1 likely prevents Hdac7-s from exerting this effect. Hdac7 may represent a potential inflammatory disease target. PMID:23853092

  7. Histone deacetylase 7 promotes Toll-like receptor 4-dependent proinflammatory gene expression in macrophages.

    Science.gov (United States)

    Shakespear, Melanie R; Hohenhaus, Daniel M; Kelly, Greg M; Kamal, Nabilah A; Gupta, Praveer; Labzin, Larisa I; Schroder, Kate; Garceau, Valerie; Barbero, Sheila; Iyer, Abishek; Hume, David A; Reid, Robert C; Irvine, Katharine M; Fairlie, David P; Sweet, Matthew J

    2013-08-30

    Broad-spectrum inhibitors of histone deacetylases (HDACs) constrain Toll-like receptor (TLR)-inducible production of key proinflammatory mediators. Here we investigated HDAC-dependent inflammatory responses in mouse macrophages. Of the classical Hdacs, Hdac7 was expressed at elevated levels in inflammatory macrophages (thioglycollate-elicited peritoneal macrophages) as compared with bone marrow-derived macrophages and the RAW264 cell line. Overexpression of a specific, alternatively spliced isoform of Hdac7 lacking the N-terminal 22 amino acids (Hdac7-u), but not the Refseq Hdac7 (Hdac7-s), promoted LPS-inducible expression of Hdac-dependent genes (Edn1, Il-12p40, and Il-6) in RAW264 cells. A novel class IIa-selective HDAC inhibitor reduced recombinant human HDAC7 enzyme activity as well as TLR-induced production of inflammatory mediators in thioglycollate-elicited peritoneal macrophages. Both LPS and Hdac7-u up-regulated the activity of the Edn1 promoter in an HDAC-dependent fashion in RAW264 cells. A hypoxia-inducible factor (HIF) 1 binding site in this promoter was required for HDAC-dependent TLR-inducible promoter activity and for Hdac7- and HIF-1α-mediated trans-activation. Coimmunoprecipitation assays showed that both Hdac7-u and Hdac7-s interacted with HIF-1α, whereas only Hdac7-s interacted with the transcriptional repressor CtBP1. Thus, Hdac7-u positively regulates HIF-1α-dependent TLR signaling in macrophages, whereas an interaction with CtBP1 likely prevents Hdac7-s from exerting this effect. Hdac7 may represent a potential inflammatory disease target.

  8. CD163: a signal receptor scavenging haptoglobin-hemoglobin complexes from plasma

    DEFF Research Database (Denmark)

    Graversen, Jonas Heilskov; Madsen, Mette; Moestrup, Søren K

    2002-01-01

    as the endocytic receptor binding hemoglobin (Hb) in complex with the plasma protein haptoglobin (Hp). This specific receptor-ligand interaction leading to removal from plasma of the Hp-Hb complex-but not free Hp or Hb-now explains the depletion of circulating Hp in individuals with increased intravascular...

  9. Intravascular optical imaging of high-risk plaques in vivo by targeting macrophage mannose receptors

    Science.gov (United States)

    Kim, Ji Bak; Park, Kyeongsoon; Ryu, Jiheun; Lee, Jae Joong; Lee, Min Woo; Cho, Han Saem; Nam, Hyeong Soo; Park, Ok Kyu; Song, Joon Woo; Kim, Tae Shik; Oh, Dong Joo; Gweon, Daegab; Oh, Wang-Yuhl; Yoo, Hongki; Kim, Jin Won

    2016-03-01

    Macrophages mediate atheroma expansion and disruption, and denote high-risk arterial plaques. Therefore, they are substantially gaining importance as a diagnostic imaging target for the detection of rupture-prone plaques. Here, we developed an injectable near-infrared fluorescence (NIRF) probe by chemically conjugating thiolated glycol chitosan with cholesteryl chloroformate, NIRF dye (cyanine 5.5 or 7), and maleimide-polyethylene glycol-mannose as mannose receptor binding ligands to specifically target a subset of macrophages abundant in high-risk plaques. This probe showed high affinity to mannose receptors, low toxicity, and allowed the direct visualization of plaque macrophages in murine carotid atheroma. After the scale-up of the MMR-NIRF probe, the administration of the probe facilitated in vivo intravascular imaging of plaque inflammation in coronary-sized vessels of atheromatous rabbits using a custom-built dual-modal optical coherence tomography (OCT)-NIRF catheter-based imaging system. This novel imaging approach represents a potential imaging strategy enabling the identification of high-risk plaques in vivo and holds promise for future clinical implications.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Mechanism of interleukin-13 production by granulocyte-macrophage colony-stimulating factor-dependent macrophages via protease-activated receptor-2.

    Science.gov (United States)

    Yamaguchi, Rui; Yamamoto, Takatoshi; Sakamoto, Arisa; Ishimaru, Yasuji; Narahara, Shinji; Sugiuchi, Hiroyuki; Hirose, Eiji; Yamaguchi, Yasuo

    2015-06-01

    Granulocyte-macrophage colony-stimulating factor (GM-CSF) promotes classically activated M1 macrophages. GM-CSF upregulates protease-activated receptor-2 (PAR-2) protein expression and activation of PAR-2 by human neutrophil elastase (HNE) regulates cytokine production. This study investigated the mechanism of PAR-2-mediated interleukin (IL)-13 production by GM-CSF-dependent macrophages stimulated with HNE. Adherent macrophages were obtained from primary cultures of human mononuclear cells. After stimulation with HNE to activate the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway, IL-13 mRNA and protein levels were assessed by the reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. PAR-2 protein was detected in GM-CSF-dependent macrophages by Western blotting. Unexpectedly, PD98059 (an ERK1 inhibitor) increased IL-13 production, even at higher concentrations. Interestingly, U0126 (an ERK1/2 inhibitor) reduced IL-13 production in a concentration-dependent manner. Neither SB203580 (a p38alpha/p38beta inhibitor) nor BIRB796 (a p38gamma/p38delta inhibitor) affected IL-13 production, while TMB-8 (a calcium chelator) diminished IL-13 production. Stimulation with HNE promoted the production of IL-13 (a Th2 cytokine) by GM-CSF-dependent M1 macrophages. PAR-2-mediated IL-13 production may be dependent on the Ca(2+)/ERK2 signaling pathway. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Macrophage colony-stimulating factor, CSF-1, and its proto-oncogene-encoded receptor

    International Nuclear Information System (INIS)

    Sherr, C.J.; Rettenmier, C.W.; Roussel, M.F.

    1988-01-01

    The macrophage colony-stimulating factor, CSF-1, or M-CSF, is one of a family of hematopoietic growth factors that stimulates the proliferation of monocytes, macrophages, and their committed bone marrow progenitors. Unlike pluripotent hemopoietins such as granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3 or multi-CSF), which affect the growth of myeloid cells of several different hematopoietic lineages, CSF-1 acts only on cells of the mononuclear phagocyte series to stimulate their growth and enhance their survival. Retroviral transduction of the feline c-fms gene in the Susan McDonough and Hardy Zuckerman-5 (HZ-5) strains of feline sarcoma virus (FeSV) led to genetic alterations that endowed the recombined viral oncogene (v-fms) with the ability to transform cells in culture morphologically and to induce firbrosarcomas and hematopoietic neoplasms in susceptible animals. The v-fms oncogene product differs from the normal CSF-1 receptor in certain of its cardinal biochemical properties, most notably in exhibiting constitutively high basal levels of tyrosine kinase activity in the absence of its ligand. Comparative studies of the c-fms and v-fms genes coupled with analyses of engineered mutants and receptor chimeras have begun to pinpoint pertinent genetic alterations in the normal receptor gene that unmask its latent oncogenic potential. In addition, the availability of biologically active c-fms, v-fms, and CSF-1 cDNAs has allowed these genes to be mobilized and expressed in naive cells, thereby facilitating assays for receptor coupling with downstream components of the mitogenic pathway in diverse cell types

  13. Imaging and measuring the biophysical properties of Fc gamma receptors on single macrophages using atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Mi [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Lianqing, E-mail: lqliu@sia.cn [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Xi, Ning [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong (China); Wang, Yuechao [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Xiao, Xiubin [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China); Zhang, Weijing, E-mail: zhangwj3072@163.com [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China)

    2013-09-06

    Highlights: •Nanoscale cellular ultra-structures of macrophages were observed. •The binding affinities of FcγRs were measured directly on macrophages. •The nanoscale distributions of FcγRs were mapped on macrophages. -- Abstract: Fc gamma receptors (FcγR), widely expressed on effector cells (e.g., NK cells, macrophages), play an important role in clinical cancer immunotherapy. The binding of FcγRs to the Fc portions of antibodies that are attached to the target cells can activate the antibody-dependent cell-mediated cytotoxicity (ADCC) killing mechanism which leads to the lysis of target cells. In this work, we used atomic force microscopy (AFM) to observe the cellular ultra-structures and measure the biophysical properties (affinity and distribution) of FcγRs on single macrophages in aqueous environments. AFM imaging was used to obtain the topographies of macrophages, revealing the nanoscale cellular fine structures. For molecular interaction recognition, antibody molecules were attached onto AFM tips via a heterobifunctional polyethylene glycol (PEG) crosslinker. With AFM single-molecule force spectroscopy, the binding affinities of FcγRs were quantitatively measured on single macrophages. Adhesion force mapping method was used to localize the FcγRs, revealing the nanoscale distribution of FcγRs on local areas of macrophages. The experimental results can improve our understanding of FcγRs on macrophages; the established approach will facilitate further research on physiological activities involved in antibody-based immunotherapy.

  14. Bacteria binding by DMBT1/SAG/gp-340 is confined to the VEVLXXXXW motif in its scavenger receptor cysteine-rich domains

    DEFF Research Database (Denmark)

    Bikker, Floris J; Ligtenberg, Antoon J M; End, Caroline

    2004-01-01

    The scavenger receptor cysteine-rich (SRCR) proteins form an archaic group of metazoan proteins characterized by the presence of SRCR domains. These proteins are classified in group A and B based on the number of conserved cysteine residues in their SRCR domains, i.e. six for group A and eight fo...

  15. In vivo regulation of scavenger receptor BI and the selective uptake of high density lipoprotein cholesteryl esters in rat liver parenchymal and Kupffer cells

    NARCIS (Netherlands)

    Fluiter, K.; van der Westhuijzen, D. R.; van Berkel, T. J.

    1998-01-01

    High density lipoprotein cholesteryl esters (HDL-CE) are selectively taken up by liver parenchymal cells without parallel apolipoprotein uptake. This selective uptake route forms an important step in the so-called reverse cholesterol transport. Scavenger receptor BI (SR-BI) is the only known HDL

  16. Scavenger Receptor Class B Type I Mediates Biliary Cholesterol Secretion Independent of ATP-Binding Cassette Transporter g5/g8 in Mice

    NARCIS (Netherlands)

    Wiersma, Harmen; Gatti, Alberto; Nijstad, Niels; Elferink, Ronald P. J. Oude; Kuipers, Folkert; Tietge, Uwe J. F.

    2009-01-01

    Scavenger receptor class B type I (SR-BI) mediates selective uptake of cholesterol from high-density lipoprotein (HDL) particles by the liver and influences biliary cholesterol secretion. However, it is not dear, if this effect is direct or indirect. The aim of this study was to determine the impact

  17. Effect of human scavenger receptor class A overexpression in bone marrow-derived cells on cholesterol levels and atherosclerosis in ApoE-deficient mice

    NARCIS (Netherlands)

    van Eck, M.; de Winther, M. P.; Herijgers, N.; Havekes, L. M.; Hofker, M. H.; Groot, P. H.; van Berkel, T. J.

    2000-01-01

    In the arterial wall, scavenger receptor class A (SRA) is implicated in pathological lipid deposition. In contrast, in the liver, SRA is suggested to remove modified lipoproteins from the circulation, thereby protecting the body from their pathological action. The role of SRA on bone marrow-derived

  18. Effect of human scavenger receptor class A overexpression in bone marrow-derived cells on cholesterol levels and atherosclerosis in apoE-deficient mice

    NARCIS (Netherlands)

    Eck, M. van; Winther, M.P.J. de; Herijgers, N.; Havekes, L.M.; Hofker, M.H.; Groot, P.H.E.; Berkel, T.J.C. van

    2000-01-01

    In the arterial wall, scavenger receptor class A (SRA) is implicated in pathological lipid deposition. In contrast, in the liver, SRA is suggested to remove modified lipoproteins from the circulation, thereby protecting the body from their pathological action. The role of SRA on bone marrow-derived

  19. VEGF receptor blockade markedly reduces retinal microglia/macrophage infiltration into laser-induced CNV.

    Directory of Open Access Journals (Sweden)

    Hu Huang

    Full Text Available Although blocking VEGF has a positive effect in wet age-related macular degeneration (AMD, the effect of blocking its receptors remains unclear. This was an investigation of the effect of VEGF receptor (VEGFR 1 and/or 2 blockade on retinal microglia/macrophage infiltration in laser-induced choroidal neovascularization (CNV, a model of wet AMD. CNV lesions were isolated by laser capture microdissection at 3, 7, and 14 days after laser and analyzed by RT-PCR and immunofluorescence staining for mRNA and protein expression, respectively. Neutralizing antibodies for VEGFR1 or R2 and the microglia inhibitor minocycline were injected intraperitoneally (IP. Anti-CD11b, CD45 and Iba1 antibodies were used to confirm the cell identity of retinal microglia/macrophage, in the RPE/choroidal flat mounts or retinal cross sections. CD11b(+, CD45(+ or Iba1(+ cells were counted. mRNA of VEGFR1 and its three ligands, PlGF, VEGF-A (VEGF and VEGF-B, were expressed at all stages, but VEGFR2 were detected only in the late stage. PlGF and VEGF proteins were expressed at 3 and 7 days after laser. Anti-VEGFR1 (MF1 delivered IP 3 days after laser inhibited infiltration of leukocyte populations, largely retinal microglia/macrophage to CNV, while anti-VEGFR2 (DC101 had no effect. At 14 days after laser, both MF1 and DC101 antibodies markedly inhibited retinal microglia/macrophage infiltration into CNV. Therefore, VEGFR1 and R2 play differential roles in the pathogenesis of CNV: VEGFR1 plays a dominant role at 3 days after laser; but both receptors play pivotal roles at 14 days after laser. In vivo imaging demonstrated accumulation of GFP-expressing microglia into CNV in both CX3CR1(gfp/gfp and CX3CR1(gfp/+ mice. Minocycline treatment caused a significant increase in lectin(+ cells in the sub-retinal space anterior to CNV and a decrease in dextran-perfused neovessels compared to controls. Targeting the chemoattractant molecules that regulate trafficking of retinal microglia/macrophage

  20. Scavenger receptor-mediated endocytosis by sinusoidal cells in rat bone marrow

    International Nuclear Information System (INIS)

    Geoffroy, J.S.

    1987-01-01

    Endocytosis of serum albumin by sinusoidal endothelial cells in rat bone marrow was investigated initially at the ultrastructural level with subsequent biochemical investigation of the specificity mediating this event. Bovine serum albumin adsorbed to 20nm colloidal gold particles (AuBSA) was chosen as the electron microscopic probe. Morphological data strongly suggested that a receptor was involved in uptake of AuBSA. Confirmation of receptor involvement in the uptake of AuBSA by marrow sinusoidal endothelial cells was achieved utilizing an in situ isolated hind limb perfusion protocol in conjunction with unlabeled, radiolabeled, and radio-/colloidal gold labeled probes. The major findings of competition and saturation experiments were: (1) endocytosis of AuBSA was mediated by a receptor for modified/treated serum albumin; (2) endocytosis of formaldehyde-treated serum albumin was mediated by a binding site which may be the same or closely related to the site responsible for the uptake of AuBSA; and (3) endocytosis of native untreated albumin was not mediated by receptor and probably represents fluid-phase pinocitosis

  1. Scavenger receptor class B member 1 protein: hepatic regulation and its effects on lipids, reverse cholesterol transport, and atherosclerosis

    Directory of Open Access Journals (Sweden)

    Kent AP

    2011-04-01

    Full Text Available Anthony P Kent, Ioannis M StylianouDepartment of Medicine and Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA, USAAbstract: Scavenger receptor class B member 1 (SR-BI, also known as SCARB1 is the primary receptor for the selective uptake of cholesterol from high-density lipoprotein (HDL. SR-BI is present in several key tissues; however, its presence and function in the liver is deemed the most relevant for protection against atherosclerosis. Cholesterol is transferred from HDL via SR-BI to the liver, which ultimately results in the excretion of cholesterol via bile and feces in what is known as the reverse cholesterol transport pathway. Much of our knowledge of SR-BI hepatic function and regulation is derived from mouse models and in vitro characterization. Multiple independent regulatory mechanisms of SR-BI have been discovered that operate at the transcriptional and post-transcriptional levels. In this review we summarize the critical discoveries relating to hepatic SR-BI cholesterol metabolism, atherosclerosis, and regulation of SR-BI, as well as alternative functions that may indirectly affect atherosclerosis.Keywords: SR-BI, SCARB1, lipids, atherosclerosis, CAD, mouse models

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

    Science.gov (United States)

    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.

  3. A macrophage activation switch (MAcS)-index for assessment of monocyte/macrophage activation

    DEFF Research Database (Denmark)

    Maniecki, Maciej Bogdan; Lauridsen, Mette; Knudsen, Troels Bygum

    2008-01-01

    , simplified by the M1-M2 dichotomy of classically activated (M1), pro-inflammatory cells and alternatively activated (M2), anti-inflammatory cells. Macrophages, however, display a large degree of flexibility and are able to switch between activation states (1). The hemoglobin scavenger receptor CD163...... is expressed exclusively on monocytes and macrophages, and its expression is strongly induced by anti-inflammatory stimuli like IL10 and glucocorticoid, making CD163 an ideal M2 macrophage marker (2). Furthermore a soluble variant of CD163 (sCD163) is shed from the cell surface to plasma by protease mediated.......058-5139) (panti-inflammatory state.   CONCLUSION: We present a CD163-derived macrophage activation switch (MAcS)-index, which seems able to differentiate between (predominantly) pro-inflammatory and anti-inflammatory macrophage activation. The index needs...

  4. Characterization of a novel human scavenger receptor cysteine-rich molecule SCART1 expressed by lymphocytes

    DEFF Research Database (Denmark)

    Holm, D.; Fink, D. R.; Steffensen, M. A.

    2013-01-01

    a member of the SRCR superfamily, mSCART1, which primarily is expressed on a large subset of γδ T cells in mice. Here we report the cloning and characterization of human SCART1 (hSCART1) mainly expressed by CD4(+) and CD8(+) T lymphocytes. The hSCART1 gene maps to chromosome 10, region q26.3, a region...... domain. Shorter splice forms have also been isolated. Quantitative real-time PCR analysis on human blood-fractions has shown that hSCART1 is expressed primarily by CD4(+) and CD8(+) T lymphocytes with either αβ or γδ T cell receptors, and real-time PCR on 22 different human tissues showed high expression...... that the protein plays a role in the immune system, perhaps as a co-receptor on αβ and γδ T cells....

  5. CCR8 Signaling Influences Toll-Like Receptor 4 Responses in Human Macrophages in Inflammatory Diseases ▿

    Science.gov (United States)

    Kvist Reimer, Martina; Brange, Charlotte; Rosendahl, Alexander

    2011-01-01

    CCR8 immunity is generally associated with Th2 responses in allergic diseases. In this study, we demonstrate for the first time a pronounced attenuated influx of macrophages in ovalbumin (OVA)-challenged CCR8 knockout mice. To explore whether macrophages in human inflamed lung tissue also were CCR8 positive, human lung tissue from patients with chronic obstructive pulmonary disease (COPD) was evaluated. Indeed, CCR8 expression was pronounced in invading monocytes/macrophages from lungs of patients with Global Initiative for Obstructive Lung Disease (GOLD) stage IV COPD. Given this expression pattern, the functional role of CCR8 on human macrophages was evaluated in vitro. Human peripheral blood monocytes expressed low levels of CCR8, while macrophage colony-stimulating factor (M-CSF)-derived human macrophages expressed significantly elevated surface levels of CCR8. Importantly, CCL1 directly regulated the expression of CD18 and CD49b and hence influenced the adhesion capacity of human macrophages. CCL1 drives chemotaxis in M-CSF-derived macrophages, and this could be completely inhibited by lipopolysaccharide (LPS). Whereas both CCL1 and LPS monotreatment inhibited spontaneous superoxide release in macrophages, CCL1 significantly induced superoxide release in the presence of LPS in a dose-dependent manner. Finally, CCL1 induced production of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) and could inhibit LPS-induced cytokine production in a dose-dependent manner. Our data demonstrate, for the first time, the presence of CCR8 on inflammatory macrophages in human COPD lung tissue. Importantly, the functional data from human macrophages suggest a potential cross talk between the CCR8 and the Toll-like receptor 4 (TLR4) pathways, both of which are present in COPD patients. PMID:21976223

  6. Conserved Bacterial-Binding Peptides of the Scavenger-Like Human Lymphocyte Receptor CD6 Protect From Mouse Experimental Sepsis

    Directory of Open Access Journals (Sweden)

    Mario Martínez-Florensa

    2018-04-01

    Full Text Available Sepsis is an unmet clinical need constituting one of the most important causes of death worldwide, a fact aggravated by the appearance of multidrug resistant strains due to indiscriminate use of antibiotics. Host innate immune receptors involved in pathogen-associated molecular patterns (PAMPs recognition represent a source of broad-spectrum therapies alternative or adjunctive to antibiotics. Among the few members of the ancient and highly conserved scavenger receptor cysteine-rich superfamily (SRCR-SF sharing bacterial-binding properties there is CD6, a lymphocyte-specific surface receptor. Here, we analyze the bacterial-binding properties of three conserved short peptides (11-mer mapping at extracellular SRCR domains of human CD6 (CD6.PD1, GTVEVRLEASW; CD6.PD2 GRVEMLEHGEW; and CD6.PD3, GQVEVHFRGVW. All peptides show high binding affinity for PAMPs from Gram-negative (lipopolysaccharide; Kd from 3.5 to 3,000 nM and Gram-positive (lipoteichoic acid; Kd from 36 to 680 nM bacteria. The CD6.PD3 peptide possesses broad bacterial-agglutination properties and improved survival of mice undergoing polymicrobial sepsis in a dose- and time-dependent manner. Accordingly, CD6.PD3 triggers a decrease in serum levels of both pro-inflammatory cytokines and bacterial load. Interestingly, CD6.PD3 shows additive survival effects on septic mice when combined with Imipenem/Cilastatin. These results illustrate the therapeutic potential of peptides retaining the bacterial-binding properties of native CD6.

  7. Porphyromonas gulae Activates Unprimed and Gamma Interferon-Primed Macrophages via the Pattern Recognition Receptors Toll-Like Receptor 2 (TLR2), TLR4, and NOD2

    Science.gov (United States)

    Holden, James A.; O'Brien-Simpson, Neil M.; Lenzo, Jason C.; Orth, Rebecca K. H.; Mansell, Ashley

    2017-01-01

    ABSTRACT Porphyromonas gulae is an anaerobic, Gram-negative coccobacillus that has been associated with periodontal disease in companion animals. The aims of this study were to analyze the ligation of pattern recognition receptors by P. gulae and the subsequent activation of macrophages. Exposure of HEK cells transfected with Toll-like receptors (TLRs) or NOD-like receptors to P. gulae resulted in the ligation of TLR2, TLR4, and NOD2. The effects of this engagement of receptors were investigated by measuring the synthesis of nitric oxide (NO), CD86 expression, and inflammatory cytokine production by wild-type, TLR2−/−, and TLR4−/− macrophages. The addition of P. gulae to unprimed and gamma interferon (IFN-γ)-primed (M1 phenotype) macrophages significantly increased the surface expression of CD86, but only M1 macrophages produced nitric oxide. P. gulae-induced expression of CD86 on unprimed macrophages was dependent on both TLR2 and TLR4, but CD86 expression and NO production in M1 macrophages were only TLR2 dependent. P. gulae induced an increase in secretion of interleukin-1α (IL-1α), IL-1β, IL-6, IL-12p70, IL-13, tumor necrosis factor alpha (TNF-α), granulocyte colony-stimulating factor (G-CSF), monocyte chemoattractant protein 1 (MCP-1), and macrophage inflammatory protein 1α (MIP-1α) by M1 macrophages compared to that by unprimed controls. Among these cytokines, secretion of IL-6 and TNF-α by M1 macrophages was dependent on either TLR2 or TLR4. Our data indicate that TLR2 and TLR4 are important for P. gulae activation of unprimed macrophages and that activation and effector functions induced in M1 macrophages by P. gulae are mainly dependent on TLR2. In conclusion, P. gulae induces a strong TLR2-dependent inflammatory M1 macrophage response which may be important in establishing the chronic inflammation associated with periodontal disease in companion animals. PMID:28630066

  8. Porphyromonas gulae Activates Unprimed and Gamma Interferon-Primed Macrophages via the Pattern Recognition Receptors Toll-Like Receptor 2 (TLR2), TLR4, and NOD2.

    Science.gov (United States)

    Holden, James A; O'Brien-Simpson, Neil M; Lenzo, Jason C; Orth, Rebecca K H; Mansell, Ashley; Reynolds, Eric C

    2017-09-01

    Porphyromonas gulae is an anaerobic, Gram-negative coccobacillus that has been associated with periodontal disease in companion animals. The aims of this study were to analyze the ligation of pattern recognition receptors by P. gulae and the subsequent activation of macrophages. Exposure of HEK cells transfected with Toll-like receptors (TLRs) or NOD-like receptors to P. gulae resulted in the ligation of TLR2, TLR4, and NOD2. The effects of this engagement of receptors were investigated by measuring the synthesis of nitric oxide (NO), CD86 expression, and inflammatory cytokine production by wild-type, TLR2 -/- , and TLR4 -/- macrophages. The addition of P. gulae to unprimed and gamma interferon (IFN-γ)-primed (M1 phenotype) macrophages significantly increased the surface expression of CD86, but only M1 macrophages produced nitric oxide. P. gulae- induced expression of CD86 on unprimed macrophages was dependent on both TLR2 and TLR4, but CD86 expression and NO production in M1 macrophages were only TLR2 dependent. P. gulae induced an increase in secretion of interleukin-1α (IL-1α), IL-1β, IL-6, IL-12p70, IL-13, tumor necrosis factor alpha (TNF-α), granulocyte colony-stimulating factor (G-CSF), monocyte chemoattractant protein 1 (MCP-1), and macrophage inflammatory protein 1α (MIP-1α) by M1 macrophages compared to that by unprimed controls. Among these cytokines, secretion of IL-6 and TNF-α by M1 macrophages was dependent on either TLR2 or TLR4. Our data indicate that TLR2 and TLR4 are important for P. gulae activation of unprimed macrophages and that activation and effector functions induced in M1 macrophages by P. gulae are mainly dependent on TLR2. In conclusion, P. gulae induces a strong TLR2-dependent inflammatory M1 macrophage response which may be important in establishing the chronic inflammation associated with periodontal disease in companion animals. Copyright © 2017 American Society for Microbiology.

  9. The scavenger receptor repertoire in six cnidarian species and its putative role in cnidarian-dinoflagellate symbiosis

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    Emilie F. Neubauer

    2016-11-01

    Full Text Available Many cnidarians engage in a mutualism with endosymbiotic photosynthetic dinoflagellates that forms the basis of the coral reef ecosystem. Interpartner interaction and regulation includes involvement of the host innate immune system. Basal metazoans, including cnidarians have diverse and complex innate immune repertoires that are just beginning to be described. Scavenger receptors (SR are a diverse superfamily of innate immunity genes that recognize a broad array of microbial ligands and participate in phagocytosis of invading microbes. The superfamily includes subclades named SR-A through SR-I that are categorized based on the arrangement of sequence domains including the scavenger receptor cysteine rich (SRCR, the C-type lectin (CTLD and the CD36 domains. Previous functional and gene expression studies on cnidarian-dinoflagellate symbiosis have implicated SR-like proteins in interpartner communication and regulation. In this study, we characterized the SR repertoire from a combination of genomic and transcriptomic resources from six cnidarian species in the Class Anthozoa. We combined these bioinformatic analyses with functional experiments using the SR inhibitor fucoidan to explore a role for SRs in cnidarian symbiosis and immunity. Bioinformatic searches revealed a large diversity of SR-like genes that resembled SR-As, SR-Bs, SR-Es and SR-Is. SRCRs, CTLDs and CD36 domains were identified in multiple sequences in combinations that were highly homologous to vertebrate SRs as well as in proteins with novel domain combinations. Phylogenetic analyses of CD36 domains of the SR-B-like sequences from a diversity of metazoans grouped cnidarian with bilaterian sequences separate from other basal metazoans. All cnidarian sequences grouped together with moderate support in a subclade separately from bilaterian sequences. Functional experiments were carried out on the sea anemone Aiptasia pallida that engages in a symbiosis with Symbiodinium minutum

  10. Murine macrophage response from peritoneal cavity requires signals mediated by chemokine receptor CCR-2 during Staphylococcus aureus infection.

    Science.gov (United States)

    Nandi, Ajeya; Bishayi, Biswadev

    2016-02-01

    C-C chemokine receptor-2 (CCR-2) is a cognate receptor for monocyte chemotactic protein-1 (MCP-1), and recent studies revealed that MCP-1-CCR-2 signaling is involved in several inflammatory diseases characterized by macrophage infiltration. Currently, there is no study on the involvement of CCR-2 in the killing of S. aureus by macrophages of Swiss albino mice, and its substantial role in host defense against S. aureus infection in murine macrophages is still unclear. Therefore, the present study was aimed to investigate the functional and interactive role of CCR-2 and MCP-1 in regulating peritoneal macrophage responses with respect to acute S. aureus infection. We found that phagocytosis of S. aureus can serve as an important stimulus for MCP-1 production by peritoneal macrophages, which is dependent directly or indirectly on cytokines, reactive oxygen species and nitric oxide. Neutralization of CCR-2 in macrophages leads to increased production of IL-10 and decreased production of IFN-γ and IL-6. In CCR-2 blocked macrophages, pretreatment with specific blocker of NF-κB or p38-MAPK causes elevation in MCP-1 level and subsequent downregulation of CCR-2 itself. We speculate that CCR-2 is involved in S. aureus-induced MCP-1 production via NF-κB or p38-MAPK signaling. We also hypothesized that unnaturally high level of MCP-1 that build up upon CCR-2 neutralization might allow promiscuous binding to one or more other chemokine receptors, a situation that would not occur in CCR-2 non-neutralized condition. This may be the plausible explanation for such observed Th-2 response in CCR-2 blocked macrophages infected with S. aureus in the present study.

  11. Salivary agglutinin, which binds Streptococcus mutans and Helicobacter pylori, is the lung scavenger receptor cysteine-rich protein gp-340.

    Science.gov (United States)

    Prakobphol, A; Xu, F; Hoang, V M; Larsson, T; Bergstrom, J; Johansson, I; Frängsmyr, L; Holmskov, U; Leffler, H; Nilsson, C; Borén, T; Wright, J R; Strömberg, N; Fisher, S J

    2000-12-22

    Salivary agglutinin is a high molecular mass component of human saliva that binds Streptococcus mutans, an oral bacterium implicated in dental caries. To study its protein sequence, we isolated the agglutinin from human parotid saliva. After trypsin digestion, a portion was analyzed by matrix-assisted laser/desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), which gave the molecular mass of 14 unique peptides. The remainder of the digest was subjected to high performance liquid chromatography, and the separated peptides were analyzed by MALDI-TOF/post-source decay; the spectra gave the sequences of five peptides. The molecular mass and peptide sequence information showed that salivary agglutinin peptides were identical to sequences in lung (lavage) gp-340, a member of the scavenger receptor cysteine-rich protein family. Immunoblotting with antibodies that specifically recognized either lung gp-340 or the agglutinin confirmed that the salivary agglutinin was gp-340. Immunoblotting with an antibody specific to the sialyl Le(x) carbohydrate epitope detected expression on the salivary but not the lung glycoprotein, possible evidence of different glycoforms. The salivary agglutinin also interacted with Helicobacter pylori, implicated in gastritis and peptic ulcer disease, Streptococcus agalactiae, implicated in neonatal meningitis, and several oral commensal streptococci. These results identify the salivary agglutinin as gp-340 and suggest it binds bacteria that are important determinants of either the oral ecology or systemic diseases.

  12. Serum lipoproteins attenuate macrophage activation and Toll-Like Receptor stimulation by bacterial lipoproteins

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    James Richard W

    2010-09-01

    Full Text Available Abstract Background Chlamydia trachomatis was previously shown to express a lipoprotein, the macrophage infectivity potentiator (Mip, exposed at the bacterial surface, and able to stimulate human primary monocytes/macrophages through Toll Like Receptor (TLR2/TLR1/TLR6, and CD14. In PMA-differentiated THP-1 cells the proinflammatory activity of Mip was significantly higher in the absence than in the presence of serum. The present study aims to investigate the ability of different serum factors to attenuate Mip proinflammatory activity in PMA-differentiated THP-1 cells and in primary human differentiated macrophages. The study was also extend to another lipoprotein, the Borrelia burgdorferi outer surface protein (OspA. The proinflammatory activity was studied through Tumor Necrosis Factor alpha (TNF-α and Interleukin (IL-8 release. Finally, TLR1/2 human embryonic kidney-293 (HEK-293 transfected cells were used to test the ability of the serum factors to inhibit Mip and OspA proinflammatory activity. Results In the absence of any serum and in the presence of 10% delipidated FBS, production of Mip-induced TNF-α and IL-8 in PMA-differentiated THP-1 cells were similar whereas they were significantly decreased in the presence of 10% FBS suggesting an inhibiting role of lipids present in FBS. In the presence of 10% human serum, the concentrations of TNF-α and IL-8 were 2 to 5 times lower than in the presence of 10% FBS suggesting the presence of more potent inhibitor(s in human serum than in FBS. Similar results were obtained in primary human differentiated macrophages. Different lipid components of human serum were then tested (total lipoproteins, HDL, LDL, VLDL, triglyceride emulsion, apolipoprotein (apoA-I, B, E2, and E3. The most efficient inhibitors were LDL, VLDL, and apoB that reduced the mean concentration of TNF-α release in Mip-induced macrophages to 24, 20, and 2%, respectively (p Conclusions These results demonstrated the ability of

  13. 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

  14. Vertebrate scavenger receptor class B member 2 (SCARB2: comparative studies of a major lysosomal membrane glycoprotein

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    Roger Stephen Holmes

    2012-06-01

    Full Text Available Scavenger receptor class B member 2 (SCARB2 (also LIMP-2, CD36L2 or LGP85 is a major lysosomal membrane glycoprotein involved in endosomal and lysosomal biogenesis and maintenance. SCARB2 acts as a receptor for the lysosomal mannose-6-phosphate independent targeting of β-glucuronidase and enterovirus 71 and influences Parkinson’s disease and epilepsy. Genetic deficiency of this protein causes deafness and peripheral neuropathy in mice as well as myoclonic epilepsy and nephrotic syndrome in humans. Comparative SCARB2 amino acid sequences and structures and SCARB2 gene locations were examined using data from several vertebrate genome projects. Vertebrate SCARB2 sequences shared 43-100% identity as compared with 30-36% sequence identities with other CD36-like superfamily members, SCARB1 and CD36. At least 10 N-glycosylation sites were conserved among most vertebrate SCARB2 proteins examined. Sequence alignments, key amino acid residues and conserved predicted secondary structures were examined, including cytoplasmic, transmembrane and external lysosomal membrane sequences: cysteine disulfide residues, thrombospondin (THP1 binding sites and 16 proline and 20 glycine conserved residues, which may contribute to short loop formation within the exomembrane SCARB2 sequences. Vertebrate SCARB2 genes contained 12 coding exons. The human SCARB2 gene contained a CpG island (CpG100, ten microRNA-binding sites and several transcription factor binding sites (including PPARA which may contribute to a higher level (2.4 times average of gene expression. Phylogenetic analyses examined the relationships and potential evolutionary origins of the vertebrate SCARB2 gene with vertebrate SCARB1 and CD36 genes. These suggested that SCARB2 originated from duplications of the CD36 gene in an ancestral genome forming three vertebrate CD36 gene family members: SCARB1, SCARB2 and CD36.

  15. Mycobacterium avium MAV2052 protein induces apoptosis in murine macrophage cells through Toll-like receptor 4.

    Science.gov (United States)

    Lee, Kang-In; Choi, Han-Gyu; Son, Yeo-Jin; Whang, Jake; Kim, Kwangwook; Jeon, Heat Sal; Park, Hye-Soo; Back, Yong Woo; Choi, Seunga; Kim, Seong-Woo; Choi, Chul Hee; Kim, Hwa-Jung

    2016-04-01

    Mycobacterium avium and its sonic extracts induce apoptosis in macrophages. However, little is known about the M. avium components regulating macrophage apoptosis. In this study, using multidimensional fractionation, we identified MAV2052 protein, which induced macrophage apoptosis in M. avium culture filtrates. The recombinant MAV2052 induced macrophage apoptosis in a caspase-dependent manner. The loss of mitochondrial transmembrane potential (ΔΨm), mitochondrial translocation of Bax, and release of cytochrome c from mitochondria were observed in macrophages treated with MAV2052. Further, reactive oxygen species (ROS) production was required for the apoptosis induced by MAV2052. In addition, ROS and mitogen-activated protein kinases were involved in MAV2052-mediated TNF-α and IL-6 production. ROS-mediated activation of apoptosis signal-regulating kinase 1 (ASK1)-JNK pathway was a major signaling pathway for MAV2052-induced apoptosis. Moreover, MAV2052 bound to Toll-like receptor (TLR) 4 molecule and MAV2052-induced ROS production, ΔΨm loss, and apoptosis were all significantly reduced in TLR4(-/-) macrophages. Altogether, our results suggest that MAV2052 induces apoptotic cell death through TLR4 dependent ROS production and JNK pathway in murine macrophages.

  16. Involvement of macrophage migration inhibitory factor and its receptor (CD74) in human breast cancer.

    Science.gov (United States)

    Richard, Vincent; Kindt, Nadège; Decaestecker, Christine; Gabius, Hans-Joachim; Laurent, Guy; Noël, Jean-Christophe; Saussez, Sven

    2014-08-01

    Macrophage migration inhibitory factor (MIF) and its receptor CD74 appear to be involved in tumorigenesis. We evaluated, by immunohistochemical staining, the tissue expression and distribution of MIF and CD74 in serial sections of human invasive breast cancer tumor specimens. The serum MIF level was also determined in breast cancer patients. We showed a significant increase in serum MIF average levels in breast cancer patients compared to healthy individuals. MIF tissue expression, quantified by a modified Allred score, was strongly increased in carcinoma compared to tumor-free specimens, in the cancer cells and in the peritumoral stroma, with fibroblasts the most intensely stained. We did not find any significant correlation with histoprognostic factors, except for a significant inverse correlation between tumor size and MIF stromal positivity. CD74 staining was heterogeneous and significantly decreased in cancer cells but increased in the surrounding stroma, namely in lymphocytes, macrophages and vessel endothelium. There was no significant variation according to classical histoprognostic factors, except that CD74 stromal expression was significantly correlated with triple-negative receptor (TRN) status and the absence of estrogen receptors. In conclusion, our data support the concept of a functional role of MIF in human breast cancer. In addition to auto- and paracrine effects on cancer cells, MIF could contribute to shape the tumor microenvironment leading to immunomodulation and angiogenesis. Interfering with MIF effects in breast tumors in a therapeutic perspective remains an attractive but complex challenge. Level of co-expression of MIF and CD74 could be a surrogate marker for efficacy of anti-angiogenic drugs, particularly in TRN breast cancer tumor.

  17. Tumor-associated macrophages in glioblastoma multiforme-a suitable target for somatostatin receptor-based imaging and therapy?

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    Constantin Lapa

    Full Text Available Glioblastoma multiforme (GBM is the most common primary brain tumor in adults. Tumor-associated macrophages (TAM have been shown to promote malignant growth and to correlate with poor prognosis. [1,4,7,10-tetraazacyclododecane-NN',N″,N'″-tetraacetic acid]-d-Phe1,Tyr3-octreotate (DOTATATE labeled with Gallium-68 selectively binds to somatostatin receptor 2A (SSTR2A which is specifically expressed and up-regulated in activated macrophages. On the other hand, the role of SSTR2A expression on the cell surface of glioma cells has not been fully elucidated yet. The aim of this study was to non-invasively assess SSTR2A expression of both glioma cells as well as macrophages in GBM.15 samples of patient-derived GBM were stained immunohistochemically for macrophage infiltration (CD68, proliferative activity (Ki67 as well as expression of SSTR2A. Anti-CD45 staining was performed to distinguish between resident microglia and tumor-infiltrating macrophages. In a subcohort, positron emission tomography (PET imaging using 68Ga-DOTATATE was performed and the semiquantitatively evaluated tracer uptake was compared to the results of immunohistochemistry.The amount of microglia/macrophages ranged from 50% in the tumor samples with the vast majority being resident microglial cells. A strong SSTR2A immunostaining was observed in endothelial cells of proliferating vessels, in neurons and neuropile. Only faint immunostaining was identified on isolated microglial and tumor cells. Somatostatin receptor imaging revealed areas of increased tracer accumulation in every patient. However, retention of the tracer did not correlate with immunohistochemical staining patterns.SSTR2A seems not to be overexpressed in GBM samples tested, neither on the cell surface of resident microglia or infiltrating macrophages, nor on the surface of tumor cells. These data suggest that somatostatin receptor directed imaging and treatment strategies are less promising in GBM.

  18. Inhibition of transglutaminase 2 reduces efferocytosis in human macrophages: Role of CD14 and SR-AI receptors.

    Science.gov (United States)

    Eligini, S; Fiorelli, S; Tremoli, E; Colli, S

    2016-10-01

    Transglutaminase 2 (TGM2), a member of the transglutaminase family of enzymes, is a multifunctional protein involved in numerous events spanning from cell differentiation, to signal transduction, apoptosis, and wound healing. It is expressed in a variety of cells, macrophages included. Macrophage TGM2 promotes the clearance of apoptotic cells (efferocytosis) and emerging evidence suggests that defective efferocytosis contributes to the consequences of inflammation-associated diseases, including atherosclerotic lesion progression and its sequelae. Of interest, active TGM2 identified in human atherosclerotic lesions plays critical roles in plaque stability through effects on matrix cross-linking and TGFβ activity. This study explores the mechanisms by which TGM2 controls efferocytosis in human macrophages. Herein we show that TGM2 increases progressively during monocyte differentiation towards macrophages and controls their efferocytic potential as well as morphology and viability. Two experimental approaches that took advantage of the inhibition of TGM2 activity and protein silencing give proof that TGM2 reduction significantly impairs macrophage efferocytosis. Among the mechanisms involved we highlighted a role of the receptors CD14 and SR-AI whose levels were markedly reduced by TGM2 inhibition. Conversely, CD36 receptor and αvβ3 integrin levels were not influenced. Of note, lipid accumulation and IL-10 secretion were reduced in macrophages displaying defective efferocytosis. Overall, our data define a crucial role of TGM2 activity during macrophage differentiation via mechanisms involving CD14 and SR-AI receptors and show that TGM2 inhibition triggers a pro-inflammatory phenotype. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

  19. Inflammation induced mTORC2-Akt-mTORC1 signaling promotes macrophage foam cell formation.

    Science.gov (United States)

    Banerjee, Dipanjan; Sinha, Archana; Saikia, Sudeshna; Gogoi, Bhaskarjyoti; Rathore, Arvind K; Das, Anindhya Sundar; Pal, Durba; Buragohain, Alak K; Dasgupta, Suman

    2018-06-05

    The transformation of macrophages into lipid loaded foam cells is a critical and early event in the pathogenesis of atherosclerosis. Several recent reports highlighted that induction of TLR4 signaling promotes macrophage foam cell formation; however, the underlying molecular mechanisms have not been clearly elucidated. Here, we found that the TLR4 mediated inflammatory signaling communicated with mTORC2-Akt-mTORC1 metabolic cascade in macrophage and thereby promoting lipid uptake and foam cell formation. Mechanistically, LPS treatment markedly upregulates TLR4 mediated inflammatory pathway which by activating mTORC2 induces Akt phosphorylation at serine 473 and that aggravate mTORC1 dependent scavenger receptors expression and consequent lipid accumulation in THP-1 macrophages. Inhibition of mTORC2 either by silencing Rictor expression or inhibiting its association with mTOR notably prevents LPS induced Akt activation, scavenger receptors expression and macrophage lipid accumulation. Although suppression of mTORC1 expression by genetic knockdown of Raptor did not produce any significant change in Akt S473 phosphorylation, however, incubation with Akt activator in Rictor silenced cells failed to promote scavenger receptors expression and macrophage foam cell formation. Thus, present research explored the signaling pathway involved in inflammation induced macrophage foam cells formation and therefore, targeting this pathway might be useful for preventing macrophage foam cell formation. Copyright © 2018 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  20. Triamcinolone acetonide activates an anti-inflammatory and folate receptor-positive macrophage that prevents osteophytosis in vivo.

    Science.gov (United States)

    Siebelt, Michiel; Korthagen, Nicoline; Wei, Wu; Groen, Harald; Bastiaansen-Jenniskens, Yvonne; Müller, Christina; Waarsing, Jan Hendrik; de Jong, Marion; Weinans, Harrie

    2015-12-05

    Triamcinolone acetonide (TA) is used for osteoarthritis management to reduce pain, and pre-clinical studies have shown that TA limits osteophyte formation. Osteophyte formation is known to be facilitated by synovial macrophage activation. TA injections might influence macrophage activation and subsequently reduce osteophytosis. Although widely applied in clinical care, the mechanism through which TA exerts this effect remains unknown. In this animal study, we investigated the in vivo effects of TA injections on macrophage activation, osteophyte development and joint degeneration. Furthermore, in vitro macrophage differentiation experiments were conducted to further explain working mechanisms of TA effects found in vivo. Osteoarthritis was induced in rat knees using papain injections and a running protocol. Untreated and TA-treated animals were longitudinally monitored for 12 weeks with in vivo micro-computed tomography (μCT) to measure subchondral bone changes. Synovial macrophage activation was measured in vivo using folate receptor β (FRβ)-targeted single-photon emission computed tomography/computed tomography. Articular cartilage was analyzed at 6 and 12 weeks with ex vivo contrast-enhanced μCT and histology. To further explain the outcomes of our in vivo study, TA on macrophages was also studied in vitro. These cultured macrophages were either M1- or M2-activated, and they were analyzed using fluorescence-activated cell sorting for CD163 and FRβ expression as well as for messenger RNA (mRNA) expression of interleukin (IL)-10. Our in vivo study showed that intra-articular injections with TA strongly enhanced FRβ(+) macrophage activation. Despite stimulated macrophage activation, osteophyte formation was fully prevented. There was no beneficial effect of TA against cartilage degradation or subchondral bone sclerosis. In vitro macrophage cultures showed that TA strongly induced monocyte differentiation towards CD163(+) and FRβ(+) macrophages. Furthermore

  1. A macrophage inflammatory protein homolog encoded by guinea pig cytomegalovirus signals via CC chemokine receptor 1

    International Nuclear Information System (INIS)

    Penfold, Mark; Miao Zhenhua; Wang Yu; Haggerty, Shannon; Schleiss, Mark R.

    2003-01-01

    Cytomegaloviruses encode homologs of cellular immune effector proteins, including chemokines (CKs) and CK receptor-like G protein-coupled receptors (GPCRs). Sequence of the guinea pig cytomegalovirus (GPCMV) genome identified an open reading frame (ORF) which predicted a 101 amino acid (aa) protein with homology to the macrophage inflammatory protein (MIP) subfamily of CC (β) CKs, designated GPCMV-MIP. To assess functionality of this CK, recombinant GPCMV-MIP was expressed in HEK293 cells and assayed for its ability to bind to and functionally interact with a variety of GPCRs. Specific signaling was observed with the hCCR1 receptor, which could be blocked with hMIP -1α in competition experiments. Migration assays revealed that GPCMV-MIP was able to induce chemotaxis in hCCR1-L1.2 cells. Antisera raised against a GST-MIP fusion protein immunoprecipitated species of ∼12 and 10 kDa from GPCMV-inoculated tissue culture lysates, and convalescent antiserum from GPCMV-infected animals was immunoreactive with GST-MIP by ELISA assay. These results represent the first substantive in vitro characterization of a functional CC CK encoded by a cytomegalovirus

  2. PET Imaging of Macrophage Mannose Receptor-Expressing Macrophages in Tumor Stroma Using 18F-Radiolabeled Camelid Single-Domain Antibody Fragments.

    Science.gov (United States)

    Blykers, Anneleen; Schoonooghe, Steve; Xavier, Catarina; D'hoe, Kevin; Laoui, Damya; D'Huyvetter, Matthias; Vaneycken, Ilse; Cleeren, Frederik; Bormans, Guy; Heemskerk, Johannes; Raes, Geert; De Baetselier, Patrick; Lahoutte, Tony; Devoogdt, Nick; Van Ginderachter, Jo A; Caveliers, Vicky

    2015-08-01

    Tumor-associated macrophages constitute a major component of the stroma of solid tumors, encompassing distinct subpopulations with different characteristics and functions. We aimed to identify M2-oriented tumor-supporting macrophages within the tumor microenvironment as indicators of cancer progression and prognosis, using PET imaging. This can be realized by designing (18)F-labeled camelid single-domain antibody fragments (sdAbs) specifically targeting the macrophage mannose receptor (MMR), which has been identified as an important biomarker on this cell population. Cross-reactive anti-MMR sdAbs were generated after immunization of an alpaca with the extracellular domains of both human and mouse MMR. The lead binder was chosen on the basis of comparisons of binding affinity and in vivo pharmacokinetics. The PET tracer (18)F-fluorobenzoate (FB)-anti-MMR sdAb was developed using the prosthetic group N-succinimidyl-4-(18)F-fluorobenzoate ((18)F-SFB), and its biodistribution, tumor-targeting potential, and specificity in terms of macrophage and MMR targeting were evaluated in mouse tumor models. Four sdAbs were selected after affinity screening, but only 2 were found to be cross-reactive for human and mouse MMR. The lead anti-MMR 3.49 sdAb, bearing an affinity of 12 and 1.8 nM for mouse and human MMR, respectively, was chosen for its favorable in vivo biodistribution profile and tumor-targeting capacity. (18)F-FB-anti-MMR 3.49 sdAb was synthesized with a 5%-10% radiochemical yield using an automated and optimized protocol. In vivo biodistribution analyses showed fast clearance via the kidneys and retention in MMR-expressing organs and tumor. The kidney retention of the fluorinated sdAb was 20-fold lower than a (99m)Tc-labeled counterpart. Compared with MMR- and C-C chemokine receptor 2-deficient mice, significantly higher uptake was observed in tumors grown in wild-type mice, demonstrating the specificity of the (18)F tracer for MMR and macrophages, respectively. Anti

  3. Comparative studies of vertebrate scavenger receptor class B type 1: a high-density lipoprotein binding protein

    Directory of Open Access Journals (Sweden)

    Holmes RS

    2012-06-01

    Full Text Available Roger S Holmes,1,2 Laura A Cox11Department of Genetics and Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA; 2School of Biomolecular and Physical Sciences, Griffith University, Nathan, Queensland, AustraliaAbstract: Scavenger receptor class B type 1 protein (SCARB1 plays an essential role in cholesterol homeostasis and functions in binding high density lipoprotein cholesterol (HDL in liver and other tissues of the body. SCARB1 also functions in lymphocyte homeostasis and in the uptake of hepatitis C virus (HCV by the liver. A genetic deficiency of this protein results in autoimmune disorders and significant changes in blood cholesterol phenotype. Comparative SCARB1 amino acid sequences and structures and SCARB1 gene locations were examined using data from several vertebrate genome projects. Vertebrate SCARB1 sequences shared 50%–99% identity as compared with 28%–31% sequence identities with other CD36-like superfamily members, ie, SCARB2 and SCARB3 (also called CD36. At least eight N-glycosylation sites were conserved among most of the vertebrate SCARB1 proteins examined. Sequence alignments, key amino acid residues, and conserved predicted secondary structures were also studied, including: cytoplasmic, transmembrane, and exoplasmic sequences; conserved N-terminal and C-terminal transmembrane glycines which participate in oligomer formation; conserved cystine disulfides and a free SH residue which participates in lipid transport; carboxyl terminal PDZ-binding domain sequences (Ala507-Arg/Lys508-Leu509; and 30 conserved proline and 18 conserved glycine residues, which may contribute to short loop formation within the exoplasmic HDL-binding sequence. Vertebrate SCARB1 genes usually contained 12 coding exons. The human SCARB1 gene contained CpG islands, micro RNA binding sites, and several transcription factor binding sites (including PPARG which may contribute to the high level (13.7 times

  4. Curcumin Modulates Macrophage Polarization Through the Inhibition of the Toll-Like Receptor 4 Expression and its Signaling Pathways

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    Yaoyao Zhou

    2015-05-01

    Full Text Available Background: Curcumin, the active ingredient in curcuma rhizomes, has a wide range of therapeutic effects. However, its atheroprotective activity in human acute monocytic leukemia THP-1 cells remains unclear. We investigated the activity and molecular mechanism of action of curcumin in polarized macrophages. Methods: Phorbol myristate acetate (PMA-treated THP-1 cells were differentiated to macrophages, which were further polarized to M1 cells by lipopolysaccharide (LPS; 1 µg/ml and interferon (IFN-γ (20 ng/ml and treated with varying curcumin concentrations. [3H]thymidine (3H-TdR incorporation assays were utilized to measure curcumin-induced growth inhibition. The expression of tumor necrosis factor-a (TNF-a, interleukin (IL-6, and IL-12B (p40 were measured by quantitative real-time polymerase chain reaction (PCR and enzyme-linked immunosorbent assay (ELISA. Macrophage polarization and its mechanism were evaluated by flow cytometry and western blot. Additionally, toll-like receptor 4 (TLR4 small interfering RNA and mitogen-activated protein kinase (MAPK inhibitors were used to further confirm the molecular mechanism of curcumin on macrophage polarization. Results: Curcumin dose-dependently inhibited M1 macrophage polarization and the production of TNF-a, IL-6, and IL-12B (p40. It also decreased TLR4 expression, which regulates M1 macrophage polarization. Furthermore, curcumin significantly inhibited the phosphorylation of ERK, JNK, p38, and nuclear factor (NF-γB. In contrast, SiTLR4 in combination with p-JNK, p-ERK, and p-p38 inhibition reduced the effect of curcumin on polarization. Conclusions: Curcumin can modulate macrophage polarization through TLR4-mediated signaling pathway inhibition, indicating that its effect on macrophage polarization is related to its anti-inflammatory and atheroprotective effects. Our data suggest that curcumin could be used as a therapeutic agent in atherosclerosis.

  5. alpha-MSH and its receptors in regulation of tumor necrosis factor-alpha production by human monocyte/macrophages.

    Science.gov (United States)

    Taherzadeh, S; Sharma, S; Chhajlani, V; Gantz, I; Rajora, N; Demitri, M T; Kelly, L; Zhao, H; Ichiyama, T; Catania, A; Lipton, J M

    1999-05-01

    The hypothesis that macrophages contain an autocrine circuit based on melanocortin [ACTH and alpha-melanocyte-stimulating hormone (alpha-MSH)] peptides has major implications for neuroimmunomodulation research and inflammation therapy. To test this hypothesis, cells of the THP-1 human monocyte/macrophage line were stimulated with lipopolysaccharide (LPS) in the presence and absence of alpha-MSH. The inflammatory cytokine tumor necrosis factor (TNF)-alpha was inhibited in relation to alpha-MSH concentration. Similar inhibitory effects on TNF-alpha were observed with ACTH peptides that contain the alpha-MSH amino acid sequence and act on melanocortin receptors. Nuclease protection assays indicated that expression of the human melanocortin-1 receptor subtype (hMC-1R) occurs in THP-1 cells; Southern blots of RT-PCR product revealed that additional subtypes, hMC-3R and hMC-5R, also occur. Incubation of resting macrophages with antibody to hMC-1R increased TNF-alpha concentration; the antibody also markedly reduced the inhibitory influence of alpha-MSH on TNF-alpha in macrophages treated with LPS. These results in cells known to produce alpha-MSH at rest and to increase secretion of the peptide when challenged are consistent with an endogenous regulatory circuit based on melanocortin peptides and their receptors. Targeting of this neuroimmunomodulatory circuit in inflammatory diseases in which myelomonocytic cells are prominent should be beneficial.

  6. Macrophage heterogeneity and cholesterol homeostasis: classically-activated macrophages are associated with reduced cholesterol accumulation following treatment with oxidized LDL.

    Science.gov (United States)

    Chu, Eugene M; Tai, Daven C; Beer, Jennifer L; Hill, John S

    2013-02-01

    Macrophages are centrally involved during atherosclerosis development and are the predominant cell type that accumulates cholesterol in the plaque. Macrophages however, are heterogeneous in nature reflecting a variety of microenvironments and different phenotypes may be more prone to contribute towards atherosclerosis progression. Using primary human monocyte-derived macrophages, we sought to evaluate one aspect of atherogenic potential of different macrophage phenotypes by determining their propensity to associate with and accumulate oxidized low density lipoprotein (oxLDL). Classically-activated macrophages treated simultaneously with interferon γ (IFNγ) and tumor necrosis factor α (TNFα) associated with less oxLDL and accumulated less cholesterol compared to untreated controls. The combined treatment of IFNγ and TNFα reduced the mRNA expression of CD36 and the expression of both cell surface CD36 and macrophage scavenger receptor 1 (MSR1) protein. Under oxLDL loaded conditions, IFNγ and TNFα did not reduce macrophage protein expression of the transcription factor peroxisome proliferator-actived receptor γ (PPARγ) which is known to positively regulate CD36 expression. However, macrophages treated with IFNγ attenuated the ability of the PPARγ-specific agonist rosiglitazone from upregulating cell surface CD36 protein expression. Our results demonstrate that the observed reduction of cholesterol accumulation in macrophages treated with IFNγ and TNFα following oxLDL treatment was due at least in part to reduced cell surface CD36 and MSR1 protein expression. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Porcine sialoadhesin (CD169/Siglec-1 is an endocytic receptor that allows targeted delivery of toxins and antigens to macrophages.

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    Peter L Delputte

    Full Text Available Sialoadhesin is exclusively expressed on specific subpopulations of macrophages. Since sialoadhesin-positive macrophages are involved in inflammatory autoimmune diseases, such as multiple sclerosis, and potentially in the generation of immune responses, targeted delivery of drugs, toxins or antigens via sialoadhesin-specific immunoconjugates may prove a useful therapeutic strategy. Originally, sialoadhesin was characterized as a lymphocyte adhesion molecule, though recently its involvement in internalization of sialic acid carrying pathogens was shown, suggesting that sialoadhesin is an endocytic receptor. In this report, we show that porcine sialoadhesin-specific antibodies and F(ab'₂ fragments trigger sialoadhesin internalization, both in primary porcine macrophages and in cells expressing recombinant porcine sialoadhesin. Using chemical inhibitors, double immunofluorescence stainings and dominant-negative constructs, porcine sialoadhesin internalization was shown to be clathrin- and Eps15-dependent and to result in targeting to early endosomes but not lysosomes. Besides characterizing the sialoadhesin endocytosis mechanism, two sialoadhesin-specific immunoconjugates were evaluated. We observed that porcine sialoadhesin-specific immunotoxins efficiently kill sialoadhesin-expressing macrophages. Furthermore, porcine sialoadhesin-specific albumin immunoconjugates were shown to be internalized in macrophages and immunization with these immunoconjugates resulted in a rapid and robust induction of albumin-specific antibodies, this compared to immunization with albumin alone. Together, these data expand sialoadhesin functionality and show that it can function as an endocytic receptor, a feature that cannot only be misused by sialic acid carrying pathogens, but that may also be used for specific targeting of toxins or antigens to sialoadhesin-expressing macrophages.

  8. Investigation of genetic variation in scavenger receptor class B, member 1 (SCARB1) and association with serum carotenoids

    Science.gov (United States)

    McKay, Gareth J; Loane, Edward; Nolan, John M; Patterson, Christopher C; Meyers, Kristin J; Mares, Julie A; Yonova-Doing, Ekaterina; Hammond, Christopher J; Beatty, Stephen; Silvestri, Giuliana

    2013-01-01

    Objective To investigate association of scavenger receptor class B, member 1 (SCARB1) genetic variants with serum carotenoid levels of lutein (L) and zeaxanthin (Z) and macular pigment optical density (MPOD). Design A cross-sectional study of healthy adults aged 20-70. Participants 302 participants recruited following local advertisement. Methods MPOD was measured by customized heterochromatic flicker photometry. Fasting blood samples were taken for serum L and Z measurement by HPLC and lipoprotein analysis by spectrophotometric assay. Forty-seven single nucleotide polymorphisms (SNPs) across SCARB1 were genotyped using Sequenom technology. Association analyses were performed using PLINK to compare allele and haplotype means, with adjustment for potential confounding and correction for multiple comparisons by permutation testing. Replication analysis was performed in the TwinsUK and CAREDS cohorts. Main outcome measures Odds ratios (ORs) for macular pigment optical density area, serum lutein and zeaxanthin concentrations associated with genetic variations in SCARB1 and interactions between SCARB1 and sex. Results Following multiple regression analysis with adjustment for age, body mass index, sex, high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), triglycerides, smoking, dietary L and Z levels, 5 SNPs were significantly associated with serum L concentration and 1 SNP with MPOD (P<0.01). Only the association between rs11057841 and serum L withstood correction for multiple comparisons by permutation testing (P<0.01) and replicated in the TwinsUK cohort (P=0.014). Independent replication was also observed in the CAREDS cohort with rs10846744 (P=2×10−4), a SNP in high linkage disequilibrium with rs11057841 (r2=0.93). No significant interactions by sex were found. Haplotype analysis revealed no stronger association than obtained with single SNP analyses. Conclusions Our study has identified association between rs11057841 and

  9. Oxidized LDL Induces Alternative Macrophage Phenotype through Activation of CD36 and PAFR

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    Francisco J. Rios

    2013-01-01

    Full Text Available OxLDL is recognized by macrophage scavenger receptors, including CD36; we have recently found that Platelet-Activating Factor Receptor (PAFR is also involved. Since PAFR in macrophages is associated with suppressor function, we examined the effect of oxLDL on macrophage phenotype. It was found that the presence of oxLDL during macrophage differentiation induced high mRNA levels to IL-10, mannose receptor, PPARγ and arginase-1 and low levels of IL-12 and iNOS. When human THP-1 macrophages were pre-treated with oxLDL then stimulated with LPS, the production of IL-10 and TGF-β significantly increased, whereas that of IL-6 and IL-8 decreased. In murine TG-elicited macrophages, this protocol significantly reduced NO, iNOS and COX2 expression. Thus, oxLDL induced macrophage differentiation and activation towards the alternatively activated M2-phenotype. In murine macrophages, oxLDL induced TGF-β, arginase-1 and IL-10 mRNA expression, which were significantly reduced by pre-treatment with PAFR antagonists (WEB and CV or with antibodies to CD36. The mRNA expression of IL-12, RANTES and CXCL2 were not affected. We showed that this profile of macrophage activation is dependent on the engagement of both CD36 and PAFR. We conclude that oxLDL induces alternative macrophage activation by mechanisms involving CD36 and PAFR.

  10. Decreased expression of liver X receptor-α in macrophages infected with Chlamydia pneumoniae in human atherosclerotic arteries in situ.

    Science.gov (United States)

    Bobryshev, Yuri V; Orekhov, Alexander N; Killingsworth, Murray C; Lu, Jinhua

    2011-01-01

    In in vitro experiments, Chlamydia pneumoniae has been shown to infect macrophages and to accelerate foam cell formation. It has been hypothesized that the C. pneumoniae infection affects foam cell formation by suppressing the expression of liver X receptors (LXR), but whether such an event occurs in human atherosclerosis is not known. In this study we examined carotid artery segments, obtained by endarterectomy, in which the presence of C. pneumoniae was confirmed by both polymerase chain reaction and immunohistochemistry. The expression of LXR-α in macrophages infected with C. pneumoniae and macrophages that were not infected was compared using a quantitative immunohistochemical analysis. The analysis revealed a 2.2-fold reduction in the expression of LXR-α in C. pneumoniae-infected cells around the lipid cores in atherosclerotic plaques. In the cytoplasm of laser-capture microdissected cells that were immunopositive for C. pneumoniae, electron microscopy demonstrated the presence of structures with the appearance of elementary, reticulate and aberrant bodies of C. pneumoniae. We conclude that LXR-α expression is reduced in C. pneumoniae-infected macrophages in human atherosclerotic lesions which supports the hypothesis that C. pneumoniae infection might suppress LXR expression in macrophages transforming into foam cells. Copyright © 2011 S. Karger AG, Basel.

  11. Proteinase activated receptor 1 mediated fibrosis in a mouse model of liver injury: a role for bone marrow derived macrophages.

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    Yiannis N Kallis

    Full Text Available Liver fibrosis results from the co-ordinated actions of myofibroblasts and macrophages, a proportion of which are of bone marrow origin. The functional effect of such bone marrow-derived cells on liver fibrosis is unclear. We examine whether changing bone marrow genotype can down-regulate the liver's fibrotic response to injury and investigate mechanisms involved. Proteinase activated receptor 1 (PAR1 is up-regulated in fibrotic liver disease in humans, and deficiency of PAR1 is associated with reduced liver fibrosis in rodent models. In this study, recipient mice received bone marrow transplantation from PAR1-deficient or wild-type donors prior to carbon tetrachloride-induced liver fibrosis. Bone marrow transplantation alone from PAR1-deficient mice was able to confer significant reductions in hepatic collagen content and activated myofibroblast expansion on wild-type recipients. This effect was associated with a decrease in hepatic scar-associated macrophages and a reduction in macrophage recruitment from the bone marrow. In vitro, PAR1 signalling on bone marrow-derived macrophages directly induced their chemotaxis but did not stimulate proliferation. These data suggest that the bone marrow can modulate the fibrotic response of the liver to recurrent injury. PAR1 signalling can contribute to this response by mechanisms that include the regulation of macrophage recruitment.

  12. Scavenger Receptor Class B, Type I, a CD36 Related Protein in Macrobrachium nipponense: Characterization, RNA Interference, and Expression Analysis with Different Dietary Lipid Sources

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    Zhili Ding

    2016-01-01

    Full Text Available The scavenger receptor class B, type I (SR-BI, is a member of the CD36 superfamily comprising transmembrane proteins involved in mammalian and fish lipid homeostasis regulation. We hypothesize that this receptor plays an important role in Macrobrachium nipponense lipid metabolism. However, little attention has been paid to SR-BI in commercial crustaceans. In the present study, we report a cDNA encoding M. nipponense scavenger receptor class B, type I (designated as MnSR-BI, obtained from a hepatopancreas cDNA library. The complete MnSR-BI coding sequence was 1545 bp, encoding 514 amino acid peptides. The MnSR-BI primary structure consisted of a CD36 domain that contained two transmembrane regions at the N- and C-terminals of the protein. SR-BI mRNA expression was specifically detected in muscle, gill, ovum, intestine, hepatopancreas, stomach, and ovary tissues. Furthermore, its expression in the hepatopancreas was regulated by dietary lipid sources, with prawns fed soybean and linseed oils exhibiting higher expression levels. RNAi-based SR-BI silencing resulted in the suppression of its expression in the hepatopancreas and variation in the expression of lipid metabolism-related genes. This is the first report of SR-BI in freshwater prawns and provides the basis for further studies on SR-BI in crustaceans.

  13. Orphan Nuclear Receptor ERRα Controls Macrophage Metabolic Signaling and A20 Expression to Negatively Regulate TLR-Induced Inflammation.

    Science.gov (United States)

    Yuk, Jae-Min; Kim, Tae Sung; Kim, Soo Yeon; Lee, Hye-Mi; Han, Jeongsu; Dufour, Catherine Rosa; Kim, Jin Kyung; Jin, Hyo Sun; Yang, Chul-Su; Park, Ki-Sun; Lee, Chul-Ho; Kim, Jin-Man; Kweon, Gi Ryang; Choi, Hueng-Sik; Vanacker, Jean-Marc; Moore, David D; Giguère, Vincent; Jo, Eun-Kyeong

    2015-07-21

    The orphan nuclear receptor estrogen-related receptor α (ERRα; NR3B1) is a key metabolic regulator, but its function in regulating inflammation remains largely unknown. Here, we demonstrate that ERRα negatively regulates Toll-like receptor (TLR)-induced inflammation by promoting Tnfaip3 transcription and fine-tuning of metabolic reprogramming in macrophages. ERRα-deficient (Esrra(-/-)) mice showed increased susceptibility to endotoxin-induced septic shock, leading to more severe pro-inflammatory responses than control mice. ERRα regulated macrophage inflammatory responses by directly binding the promoter region of Tnfaip3, a deubiquitinating enzyme in TLR signaling. In addition, Esrra(-/-) macrophages showed an increased glycolysis, but impaired mitochondrial respiratory function and biogenesis. Further, ERRα was required for the regulation of NF-κB signaling by controlling p65 acetylation via maintenance of NAD(+) levels and sirtuin 1 activation. These findings unravel a previously unappreciated role for ERRα as a negative regulator of TLR-induced inflammatory responses through inducing Tnfaip3 transcription and controlling the metabolic reprogramming. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Mitofusin 2 decreases intracellular lipids in macrophages by regulating peroxisome proliferator-activated receptor

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chun; Ge, Beihai [Department of Cardiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030 (China); He, Chao [Department of Cardiology, China Three Gorges University, Yichang 433000 (China); Zhang, Yi; Liu, Xiaowen [Department of Cardiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030 (China); Liu, Kejian [Department of Cardiology, The First Affiliated Hospital of Medical College, Shihezi University (China); Qian, Cuiping; Zhang, Yu; Peng, Wenzhong [Department of Cardiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030 (China); Guo, Xiaomei, E-mail: xmguo@tjh.tjmu.edu.cn [Department of Cardiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030 (China)

    2014-07-18

    Highlights: • Mfn2 decreases cellular lipid accumulation by activating cholesterol transporters. • PPARγ is involved in the Mfn2-mediated increase of cholesterol transporter expressions. • Inactivation of ERK1/2 and p38 is involved in Mfn2-induced PPARγ expression. - Abstract: Mitofusin 2 (Mfn2) inhibits atherosclerotic plaque formation, but the underlying mechanism remains elusive. This study aims to reveal how Mfn2 functions in the atherosclerosis. Mfn2 expression was found to be significantly reduced in arterial atherosclerotic lesions of both mice and human compared with healthy counterparts. Here, we observed that Mfn2 increased cellular cholesterol transporter expression in macrophages by upregulating peroxisome proliferator-activated receptor-γ, an effect achieved at least partially by inhibiting extracellular signal-regulated kinase1/2 (ERK1/2) and p38 mitogen-activated protein kinases (MAPKs) pathway. These findings provide insights into potential mechanisms of Mfn2-mediated alterations in cholesterol transporter expression, which may have significant implications for the treatment of atherosclerotic heart disease.

  15. Mitofusin 2 decreases intracellular lipids in macrophages by regulating peroxisome proliferator-activated receptor

    International Nuclear Information System (INIS)

    Liu, Chun; Ge, Beihai; He, Chao; Zhang, Yi; Liu, Xiaowen; Liu, Kejian; Qian, Cuiping; Zhang, Yu; Peng, Wenzhong; Guo, Xiaomei

    2014-01-01

    Highlights: • Mfn2 decreases cellular lipid accumulation by activating cholesterol transporters. • PPARγ is involved in the Mfn2-mediated increase of cholesterol transporter expressions. • Inactivation of ERK1/2 and p38 is involved in Mfn2-induced PPARγ expression. - Abstract: Mitofusin 2 (Mfn2) inhibits atherosclerotic plaque formation, but the underlying mechanism remains elusive. This study aims to reveal how Mfn2 functions in the atherosclerosis. Mfn2 expression was found to be significantly reduced in arterial atherosclerotic lesions of both mice and human compared with healthy counterparts. Here, we observed that Mfn2 increased cellular cholesterol transporter expression in macrophages by upregulating peroxisome proliferator-activated receptor-γ, an effect achieved at least partially by inhibiting extracellular signal-regulated kinase1/2 (ERK1/2) and p38 mitogen-activated protein kinases (MAPKs) pathway. These findings provide insights into potential mechanisms of Mfn2-mediated alterations in cholesterol transporter expression, which may have significant implications for the treatment of atherosclerotic heart disease

  16. Genetic Variation in the Scavenger Receptor MARCO and Its Association with Chronic Obstructive Pulmonary Disease and Lung Infection in 10,604 Individuals

    DEFF Research Database (Denmark)

    Thomsen, Mette; Nordestgaard, Børge G; Kobzik, Lester

    2013-01-01

    Background: MARCO (macrophage receptor with collagenous structure) is a dominant receptor for unopsonized particles and bacteria in the lungs. Reduced function of this receptor due to genetic variation may be associated with susceptibility to chronic obstructive pulmonary disease (COPD) and lung...... infection. Objectives: To identify novel genetic variants in MARCO that are associated with reduced lung function, or increased risk of COPD or lung infection. Methods: We first screened 760 individuals with extreme lung phenotypes in a large general population study to identify novel variants in the MARCO...... the entire cohort for these variants, we found low minor allele frequencies ranging from 0.005 to 5%. None of the individual MARCO genotypes were associated with reduced lung function, or risk of COPD or lung infection. H101Q heterozygotes had an increased odds ratio for sepsis of 2.2 (95% CI: 1...

  17. Hypoxic stress up-regulates the expression of Toll-like receptor 4 in macrophages via hypoxia-inducible factor.

    Science.gov (United States)

    Kim, So Young; Choi, Yong Jun; Joung, Sun Myung; Lee, Byung Ho; Jung, Yi-Sook; Lee, Joo Young

    2010-04-01

    Toll-like receptors (TLRs) are germline-encoded innate immune receptors that recognize invading micro-organisms and induce immune and inflammatory responses. Deregulation of TLRs is known to be closely linked to various immune disorders and inflammatory diseases. Cells at sites of inflammation are exposed to hypoxic stress, which further aggravates inflammatory processes. We have examined if hypoxic stress modulates the TLR activity of macrophages. Hypoxia and CoCl(2) (a hypoxia mimetic) enhanced the expression of TLR4 messenger RNA and protein in macrophages (RAW264.7 cells), whereas the messenger RNA of other TLRs was not increased. To determine the underlying mechanism, we investigated the role of hypoxia-inducible factor 1 (HIF-1) in the regulation of TLR4 expression. Knockdown of HIF-1alpha expression by small interfering RNA inhibited hypoxia-induced and CoCl(2)-induced TLR4 expression in macrophages, while over-expression of HIF-1alpha potentiated TLR4 expression. Chromatin immunoprecipitation assays revealed that HIF-1alpha binds to the TLR4 promoter region under hypoxic conditions. In addition, deletion or mutation of a putative HIF-1-binding motif in the TLR4 promoter greatly attenuated HIF-1alpha-induced TLR4 promoter reporter expression. Up-regulation of TLR4 expression by hypoxic stress enhanced the response of macrophages to lipopolysaccharide, resulting in increased expression of cyclooxygenase-2, interleukin-6, regulated on activation normal T cell expressed and secreted, and interferon-inducible protein-10. These results demonstrate that TLR4 expression in macrophages is up-regulated via HIF-1 in response to hypoxic stress, suggesting that hypoxic stress at sites of inflammation enhances susceptibility to subsequent infection and inflammatory signals by up-regulating TLR4.

  18. P2Y6 receptor potentiates pro-inflammatory responses in macrophages and exhibits differential roles in atherosclerotic lesion development.

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    Ricardo A Garcia

    Full Text Available BACKGROUND: P2Y(6, a purinergic receptor for UDP, is enriched in atherosclerotic lesions and is implicated in pro-inflammatory responses of key vascular cell types and macrophages. Evidence for its involvement in atherogenesis, however, has been lacking. Here we use cell-based studies and three murine models of atherogenesis to evaluate the impact of P2Y(6 deficiency on atherosclerosis. METHODOLOGY/PRINCIPAL FINDINGS: Cell-based studies in 1321N1 astrocytoma cells, which lack functional P2Y(6 receptors, showed that exogenous expression of P2Y(6 induces a robust, receptor- and agonist-dependent secretion of inflammatory mediators IL-8, IL-6, MCP-1 and GRO1. P2Y(6-mediated inflammatory responses were also observed, albeit to a lesser extent, in macrophages endogenously expressing P2Y(6 and in acute peritonitis models of inflammation. To evaluate the role of P2Y(6 in atherosclerotic lesion development, we used P2Y(6-deficient mice in three mouse models of atherosclerosis. A 43% reduction in aortic arch plaque was observed in high fat-fed LDLR knockout mice lacking P2Y(6 receptors in bone marrow-derived cells. In contrast, no effect on lesion development was observed in fat-fed whole body P2Y(6xLDLR double knockout mice. Interestingly, in a model of enhanced vascular inflammation using angiotensin II, P2Y(6 deficiency enhanced formation of aneurysms and exhibited a trend towards increased atherosclerosis in the aorta of LDLR knockout mice. CONCLUSIONS: P2Y(6 receptor augments pro-inflammatory responses in macrophages and exhibits a pro-atherogenic role in hematopoietic cells. However, the overall impact of whole body P2Y(6 deficiency on atherosclerosis appears to be modest and could reflect additional roles of P2Y(6 in vascular disease pathophysiologies, such as aneurysm formation.

  19. Scavenger receptor class B type I (SR-BI) in pig enterocytes: trafficking from the brush border to lipid droplets during fat absorption

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Niels-Christiansen, Lise-Lotte W; Immerdal, Lissi

    2003-01-01

    BACKGROUND: Scavenger receptor class B type I (SR-BI) is known to mediate cellular uptake of cholesterol from high density lipoprotein particles and is particularly abundant in liver and steroidogenic tissues. In addition, SR-BI expression in the enterocyte brush border has also been reported...... but its role in the small intestine remains unclear. AIM AND METHODS: To gain insight into the possible function of pig SR-BI during uptake of dietary fat, its localisation in enterocytes was studied in the fasting state and during fat absorption by immunogold electron microscopy and subcellular...... fat, SR-BI is endocytosed from the enterocyte brush border and accumulates in cytoplasmic lipid droplets. Internalisation of the receptor occurs mainly by clathrin coated pits rather than by a caveolae/lipid raft based mechanism....

  20. Bovine Viral Diarrhea Virus Type 2 Impairs Macrophage Responsiveness to Toll-Like Receptor Ligation with the Exception of Toll-Like Receptor 7.

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    Robert G Schaut

    Full Text Available Bovine viral diarrhea virus (BVDV is a member of the Flaviviridae family. BVDV isolates are classified into two biotypes based on the development of cytopathic (cp or non-cytopathic (ncp effects in epithelial cell culture. BVDV isolates are further separated into species, BVDV1 and 2, based on genetic differences. Symptoms of BVDV infection range from subclinical to severe, depending on strain virulence, and may involve multiple organ systems and induction of a generalized immunosuppression. During BVDV-induced immune suppression, macrophages, critical to innate immunity, may have altered pathogen recognition receptor (PRR signaling, including signaling through toll-like receptors (TLRs. Comparison of BVDV 2 strains with different biotypes and virulence levels is valuable to determining if there are differences in host macrophage cellular responses between viral phenotypes. The current study demonstrates that cytopathic (cp, noncytopathic (ncp, high (hv or low virulence (lv BVDV2 infection of bovine monocyte-derived macrophages (MDMΦ result in differential expression of pro-inflammatory cytokines compared to uninfected MDMΦ. A hallmark of cp BVDV2 infection is IL-6 production. In response to TLR2 or 4 ligation, as might be observed during secondary bacterial infection, cytokine secretion was markedly decreased in BVDV2-infected MDMΦ, compared to non-infected MDMΦ. Macrophages were hyporesponsive to viral TLR3 or TLR8 ligation. However, TLR7 stimulation of BVDV2-infected MDMΦ induced cytokine secretion, unlike results observed for other TLRs. Together, these data suggest that BVDV2 infection modulated mRNA responses and induced a suppression of proinflammatory cytokine protein responses to TLR ligation in MDMΦ with the exception of TLR7 ligation. It is likely that there are distinct differences in TLR pathways modulated following BVDV2 infection, which have implications for macrophage responses to secondary infections.

  1. Peroxisome Proliferator-Activated Receptor γ Induces the Expression of Tissue Factor Pathway Inhibitor-1 (TFPI-1 in Human Macrophages

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    G. Chinetti-Gbaguidi

    2016-01-01

    Full Text Available Tissue factor (TF is the initiator of the blood coagulation cascade after interaction with the activated factor VII (FVIIa. Moreover, the TF/FVIIa complex also activates intracellular signalling pathways leading to the production of inflammatory cytokines. The TF/FVIIa complex is inhibited by the tissue factor pathway inhibitor-1 (TFPI-1. Peroxisome proliferator-activated receptor gamma (PPARγ is a transcription factor that, together with PPARα and PPARβ/δ, controls macrophage functions. However, whether PPARγ activation modulates the expression of TFP1-1 in human macrophages is not known. Here we report that PPARγ activation increases the expression of TFPI-1 in human macrophages in vitro as well as in vivo in circulating peripheral blood mononuclear cells. The induction of TFPI-1 expression by PPARγ ligands, an effect shared by the activation of PPARα and PPARβ/δ, occurs also in proinflammatory M1 and in anti-inflammatory M2 polarized macrophages. As a functional consequence, treatment with PPARγ ligands significantly reduces the inflammatory response induced by FVIIa, as measured by variations in the IL-8, MMP-2, and MCP-1 expression. These data identify a novel role for PPARγ in the control of TF the pathway.

  2. Genomewide effects of peroxisome proliferator-activated receptor gamma in macrophages and dendritic cells--revealing complexity through systems biology.

    Science.gov (United States)

    Cuaranta-Monroy, Ixchelt; Kiss, Mate; Simandi, Zoltan; Nagy, Laszlo

    2015-09-01

    Systems biology approaches have become indispensable tools in biomedical and basic research. These data integrating bioinformatic methods gained prominence after high-throughput technologies became available to investigate complex cellular processes, such as transcriptional regulation and protein-protein interactions, on a scale that had not been studied before. Immunology is one of the medical fields that systems biology impacted profoundly due to the plasticity of cell types involved and the accessibility of a wide range of experimental models. In this review, we summarize the most important recent genomewide studies exploring the function of peroxisome proliferator-activated receptor γ in macrophages and dendritic cells. PPARγ ChIP-seq experiments were performed in adipocytes derived from embryonic stem cells to complement the existing data sets and to provide comparators to macrophage data. Finally, lists of regulated genes generated from such experiments were analysed with bioinformatics and system biology approaches. We show that genomewide studies utilizing high-throughput data acquisition methods made it possible to gain deeper insights into the role of PPARγ in these immune cell types. We also demonstrate that analysis and visualization of data using network-based approaches can be used to identify novel genes and functions regulated by the receptor. The example of PPARγ in macrophages and dendritic cells highlights the crucial importance of systems biology approaches in establishing novel cellular functions for long-known signaling pathways. © 2015 Stichting European Society for Clinical Investigation Journal Foundation.

  3. Toll like receptor 4 (TLR4) mediates the stimulating activities of chitosan oligosaccharide on macrophages.

    Science.gov (United States)

    Zhang, Pei; Liu, Weizhi; Peng, Yanfei; Han, Baoqin; Yang, Yan

    2014-11-01

    The in vivo and in vitro immunostimulating properties of chitosan oligosaccharide (COS) prepared by enzymatic hydrolysis of chitosan and the mechanisms mediating the effects were investigated. Our data showed that the highly active chitosanase isolated could hydrolyze chitosan to the polymerization degree of 3-8. The resulting COS was an efficient immunostimulator. COS markedly enhanced the proliferation and neutral red phagocytosis by RAW 264.7 macrophages. The production of nitric oxide (NO) and tumor necrosis factor alpha (TNF-α) by macrophages was significantly increased after incubation with COS. Oral administration of COS in mice could increase spleen index and serum immunoglobin G (IgG) contents. COS was labeled with FITC to study the pinocytosis by macrophages. Results showed that FITC-COS was phagocyted by macrophages and anti-murine TLR4 antibody completely blocked FITC-COS pinocytosis. RT-PCR indicated that COS treatment of macrophages significantly increased TLR4 and inducible nitric oxide synthase (iNOS) mRNA levels. When cells were pretreated with anti-murine TLR4 antibody, the effect of COS on TLR4 and iNOS mRNA induction was decreased. COS-induced NO secretion by macrophages was also markedly decreased by anti-murine TLR4 antibody pretreatment. In conclusion, the present study revealed that COS possesses potent immune-stimulating properties by activating TLR4 on macrophages. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Cross Talk between inhibitory immunoreceptor Tyrosine-Based Activation Motif-Signaling and Toll-Like Receptor Pathways in Macrophages and Dendritic Cells

    Czech Academy of Sciences Publication Activity Database

    Hirsch, Ivan; Janovec, Václav; Stranska, R.; Bendriss-Vermare, N.

    2017-01-01

    Roč. 8, Apr 7 (2017), č. článku 394. ISSN 1664-3224 Institutional support: RVO:61388963 Keywords : plasmacytoid dendritic cell * conventional dendritic cells * macrophage * toll-like receptors * regulatory receptors Subject RIV: EC - Immunology OBOR OECD: Immunology Impact factor: 6.429, year: 2016 http://journal.frontiersin.org/article/10.3389/fimmu.2017.00394/full

  5. Thromboxane A{sub 2} receptor signaling promotes liver tissue repair after toxic injury through the enhancement of macrophage recruitment

    Energy Technology Data Exchange (ETDEWEB)

    Minamino, Tsutomu [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Departments of Gastroenterology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Ito, Yoshiya [Departments of Surgery, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Ohkubo, Hirotoki [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Departments of Surgery, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Hosono, Kanako; Suzuki, Tatsunori [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Sato, Takehito [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Departments of Gastroenterology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Ae, Takako; Shibuya, Akitaka [Departments of Gastroenterology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Sakagami, Hiroyuki [Departments of Anatomy, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Narumiya, Shuh [Department of Pharmacology, Kyoto University School of Medicine, Kyoto, 606-8315 (Japan); Koizumi, Wasaburo [Departments of Gastroenterology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Majima, Masataka, E-mail: mmajima@med.kitasato-u.ac.jp [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan)

    2012-02-15

    It is thought that thromboxane A{sub 2} (TxA{sub 2}) contributes to the progression of inflammation during acute hepatic injury; however, it is still unknown whether TxA{sub 2} is involved in liver repair. The objective of the present study was to examine the role of TxA{sub 2} receptor (TP) signaling in liver injury and repair in response to toxic injury. Carbon tetrachloride (CCl{sub 4}) was used to induce liver injury in TP knockout (TP{sup −/−}) mice and wild-type (WT) mice. In WT mice, serum levels of alanine aminotransferase (ALT) and the size of the necrotic area peaked at 24 and 48 h, respectively, and then declined. In TP{sup −/−} mice, the changes in ALT levels were similar to WT mice, but liver regeneration was impaired as evidenced by remained elevated levels of hepatic necrosis and by delayed hepatocyte proliferation, which was associated with the reduced expression of growth factors including interleukin-6 (IL-6), tumor necrosis factor alpha (TNFα), and hepatocyte growth factor (HGF). In TP{sup −/−} mice, the accumulation of hepatic CD11b{sup +}/F4/80{sup +} macrophages in injured livers was attenuated, and the hepatic expression of monocyte chemoattractant protein-1 (MCP-1/CCL2) and its receptor, the C―C chemokine receptor (CCR2), was reduced compared to WT. Additionally, the application of the TP receptor agonist, U-46619, enhanced the expression of MCP-1/CCL2 and CCR2 in peritoneal macrophages, which was associated with increased levels of IL-6, TNFα and HGF. These results suggested that TP receptor signaling facilitates liver recovery following CCl{sub 4}-induced hepatotoxicity by affecting the expression of hepatotrophic growth factors, and through the recruitment of macrophages mediated by MCP-1/CCL2-CCR2 expression. -- Highlights: ► TP enhances liver regeneration by CCl{sub 4}. ► TP accumulates macrophages. ► TP up-regulates MCP-1.

  6. TAM receptor-dependent regulation of SOCS3 and MAPKs contributes to proinflammatory cytokine downregulation following chronic NOD2 stimulation of human macrophages.

    Science.gov (United States)

    Zheng, Shasha; Hedl, Matija; Abraham, Clara

    2015-02-15

    Microbial-induced cytokine regulation is critical to intestinal immune homeostasis. Acute stimulation of nucleotide-binding oligomerization domain 2 (NOD2), the Crohn's disease-associated sensor of bacterial peptidoglycan, induces cytokines. However, cytokines are attenuated after chronic NOD2 and pattern recognition receptor stimulation of macrophages; similar attenuation is observed in intestinal macrophages. The role of Tyro3, Axl, and Mer (TAM) receptors in regulating chronic pattern recognition receptor stimulation and NOD2-induced outcomes has not been examined. Moreover, TAM receptors have been relatively less investigated in human macrophages. Whereas TAM receptors did not downregulate acute NOD2-induced cytokines in primary human macrophages, they were essential for downregulating signaling and proinflammatory cytokine secretion after chronic NOD2 and TLR4 stimulation. Axl and Mer were similarly required in mice for cytokine downregulation after chronic NOD2 stimulation in vivo and in intestinal tissues. Consistently, TAM expression was increased in human intestinal myeloid-derived cells. Chronic NOD2 stimulation led to IL-10- and TGF-β-dependent TAM upregulation in human macrophages, which, in turn, upregulated suppressor of cytokine signaling 3 expression. Restoring suppressor of cytokine signaling 3 expression under TAM knockdown conditions restored chronic NOD2-mediated proinflammatory cytokine downregulation. In contrast to the upregulated proinflammatory cytokines, attenuated IL-10 secretion was maintained in TAM-deficient macrophages upon chronic NOD2 stimulation. The level of MAPK activation in TAM-deficient macrophages after chronic NOD2 stimulation was insufficient to upregulate IL-10 secretion; however, full restoration of MAPK activation under these conditions restored c-Fos, c-Jun, musculoaponeurotic fibrosarcoma oncogene homolog K, and PU.1 binding to the IL-10 promoter and IL-10 secretion. Therefore, TAM receptors are critical for

  7. Interleukin-10 increases reverse cholesterol transport in macrophages through its bidirectional interaction with liver X receptor α

    International Nuclear Information System (INIS)

    Halvorsen, Bente; Holm, Sverre; Yndestad, Arne; Scholz, Hanne; Sagen, Ellen Lund; Nebb, Hilde; Holven, Kirsten B.; Dahl, Tuva B.; Aukrust, Pål

    2014-01-01

    Highlights: • IL-10 promotes reverse cholesterol efflux from lipid loaded macrophages. • IL-10 increases the expression of ABCA-1 and ABCG-1. • IL-10 exhibits cross-talk with the nuclear receptor LXRα. - Abstract: Interleukin (IL)-10 is a prototypical anti-inflammatory cytokine that has been shown to attenuate atherosclerosis development. In addition to its anti-inflammatory properties, the anti-atherogenic effect of IL-10 has recently also been suggested to reflect a complex effect of IL-10 on lipid metabolism in macrophages. In the present study we examined the effects of IL-10 on cholesterol efflux mechanism in lipid-loaded THP-1 macrophages. Our main findings were: (i) IL-10 significantly enhanced cholesterol efflux induced by fetal-calf serum, high-density lipoprotein (HDL) 2 and apolipoprotein A-1. (ii) The IL-10-mediated effects on cholesterol efflux were accompanied by an increased IL-10-mediated expression of the ATP-binding cassette transporters ABCA1 and ABCG1, that was further enhanced when the cells were co-activated with the liver X receptor (LXR)α agonist (22R)-hydroxycholesterol. (iii) The effect of LXRα activation on the IL-10-mediated effects on the ATP-binding cassette transporters seems to include enhancing effects on the IL-10 receptor 1 (IL10R1) expression and interaction with STAT-3 signaling. (iv) These enhancing effects on ABCA1 and ABCG1 was not seen when the cells were stimulated with the IL-10 family members IL-22 and IL-24. This study suggests that the anti-atherogenic properties of IL-10 may include enhancing effects on cholesterol efflux mechanism that involves cross-talk with LXRα activation

  8. Interleukin-10 increases reverse cholesterol transport in macrophages through its bidirectional interaction with liver X receptor α

    Energy Technology Data Exchange (ETDEWEB)

    Halvorsen, Bente, E-mail: Bente.Halvorsen@rr-research.no [Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo (Norway); Institute of Clinical Medicine, University of Oslo, Oslo (Norway); K.G. Jebsen Inflammation Research Center, University of Oslo, Oslo (Norway); Holm, Sverre [Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo (Norway); Yndestad, Arne [Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo (Norway); Institute of Clinical Medicine, University of Oslo, Oslo (Norway); K.G. Jebsen Inflammation Research Center, University of Oslo, Oslo (Norway); Scholz, Hanne [Section for Transplantation, Institute for Surgical Research, Oslo University Hospital Rikshospitalet, Oslo (Norway); Sagen, Ellen Lund [Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo (Norway); Nebb, Hilde [Department of Nutrition, Institute for Basic Medical Sciences, University of Oslo, Oslo (Norway); Institute of Clinical Medicine, University of Oslo, Oslo (Norway); Holven, Kirsten B. [Department of Nutrition, Institute for Basic Medical Sciences, University of Oslo, Oslo (Norway); Dahl, Tuva B. [Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo (Norway); Institute of Clinical Medicine, University of Oslo, Oslo (Norway); Aukrust, Pål [Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo (Norway); Section of Clinical Immunology and Infectious Diseases, Oslo University Hospital Rikshospitalet, Oslo (Norway); Institute of Clinical Medicine, University of Oslo, Oslo (Norway); K.G. Jebsen Inflammation Research Center, University of Oslo, Oslo (Norway)

    2014-08-08

    Highlights: • IL-10 promotes reverse cholesterol efflux from lipid loaded macrophages. • IL-10 increases the expression of ABCA-1 and ABCG-1. • IL-10 exhibits cross-talk with the nuclear receptor LXRα. - Abstract: Interleukin (IL)-10 is a prototypical anti-inflammatory cytokine that has been shown to attenuate atherosclerosis development. In addition to its anti-inflammatory properties, the anti-atherogenic effect of IL-10 has recently also been suggested to reflect a complex effect of IL-10 on lipid metabolism in macrophages. In the present study we examined the effects of IL-10 on cholesterol efflux mechanism in lipid-loaded THP-1 macrophages. Our main findings were: (i) IL-10 significantly enhanced cholesterol efflux induced by fetal-calf serum, high-density lipoprotein (HDL){sub 2} and apolipoprotein A-1. (ii) The IL-10-mediated effects on cholesterol efflux were accompanied by an increased IL-10-mediated expression of the ATP-binding cassette transporters ABCA1 and ABCG1, that was further enhanced when the cells were co-activated with the liver X receptor (LXR)α agonist (22R)-hydroxycholesterol. (iii) The effect of LXRα activation on the IL-10-mediated effects on the ATP-binding cassette transporters seems to include enhancing effects on the IL-10 receptor 1 (IL10R1) expression and interaction with STAT-3 signaling. (iv) These enhancing effects on ABCA1 and ABCG1 was not seen when the cells were stimulated with the IL-10 family members IL-22 and IL-24. This study suggests that the anti-atherogenic properties of IL-10 may include enhancing effects on cholesterol efflux mechanism that involves cross-talk with LXRα activation.

  9. Alternatively Activated (M2) Macrophage Phenotype Is Inducible by Endothelin-1 in Cultured Human Macrophages.

    Science.gov (United States)

    Soldano, Stefano; Pizzorni, Carmen; Paolino, Sabrina; Trombetta, Amelia Chiara; Montagna, Paola; Brizzolara, Renata; Ruaro, Barbara; Sulli, Alberto; Cutolo, Maurizio

    2016-01-01

    Alternatively activated (M2) macrophages are phenotypically characterized by the expression of specific markers, mainly macrophage scavenger receptors (CD204 and CD163) and mannose receptor-1 (CD206), and participate in the fibrotic process by over-producing pro-fibrotic molecules, such as transforming growth factor-beta1 (TGFbeta1) and metalloproteinase (MMP)-9. Endothelin-1 (ET-1) is implicated in the fibrotic process, exerting its pro-fibrotic effects through the interaction with its receptors (ETA and ETB). The study investigated the possible role of ET-1 in inducing the transition from cultured human macrophages into M2 cells. Cultured human monocytes (THP-1 cell line) were activated into macrophages (M0 macrophages) with phorbol myristate acetate and subsequently maintained in growth medium (M0-controls) or treated with either ET-1 (100nM) or interleukin-4 (IL-4, 10ng/mL, M2 inducer) for 72 hours. Similarly, primary cultures of human peripheral blood monocyte (PBM)-derived macrophages obtained from healthy subjects, were maintained in growth medium (untreated cells) or treated with ET-1 or IL-4 for 6 days. Both M0 and PBM-derived macrophages were pre-treated with ET receptor antagonist (ETA/BRA, bosentan 10-5M) for 1 hour before ET-1 stimulation. Protein and gene expression of CD204, CD206, CD163, TGFbeta1 were analysed by immunocytochemistry, Western blotting and quantitative real time polymerase chain reaction (qRT-PCR). Gene expression of interleukin(IL)-10 and macrophage derived chemokine (CCL-22) was evaluated by qRT-PCR. MMP-9 production was investigated by gel zymography. ET-1 significantly increased the expression of M2 phenotype markers CD204, CD206, CD163, IL-10 and CCL-22, and the production of MMP-9 in both cultures of M0 and PBM-derived macrophages compared to M0-controls and untreated cells. In cultured PBM-derived macrophages, ET-1 increased TGFbeta1 protein and gene expression compared to untreated cells. The ET-1-mediated effects were

  10. PPARγ regulates the expression of cholesterol metabolism genes in alveolar macrophages

    International Nuclear Information System (INIS)

    Baker, Anna D.; Malur, Anagha; Barna, Barbara P.; Kavuru, Mani S.; Malur, Achut G.; Thomassen, Mary Jane

    2010-01-01

    Peroxisome proliferator-activated receptor-gamma (PPARγ) is a nuclear transcription factor involved in lipid metabolism that is constitutively expressed in the alveolar macrophages of healthy individuals. PPARγ has recently been implicated in the catabolism of surfactant by alveolar macrophages, specifically the cholesterol component of surfactant while the mechanism remains unclear. Studies from other tissue macrophages have shown that PPARγ regulates cholesterol influx, efflux, and metabolism. PPARγ promotes cholesterol efflux through the liver X receptor-alpha (LXRα) and ATP-binding cassette G1 (ABCG1). We have recently shown that macrophage-specific PPARγ knockout (PPARγ KO) mice accumulate cholesterol-laden alveolar macrophages that exhibit decreased expression of LXRα and ABCG1 and reduced cholesterol efflux. We hypothesized that in addition to the dysregulation of these cholesterol efflux genes, the expression of genes involved in cholesterol synthesis and influx was also dysregulated and that replacement of PPARγ would restore regulation of these genes. To investigate this hypothesis, we have utilized a Lentivirus expression system (Lenti-PPARγ) to restore PPARγ expression in the alveolar macrophages of PPARγ KO mice. Our results show that the alveolar macrophages of PPARγ KO mice have decreased expression of key cholesterol synthesis genes and increased expression of cholesterol receptors CD36 and scavenger receptor A-I (SRA-I). The replacement of PPARγ (1) induced transcription of LXRα and ABCG1; (2) corrected suppressed expression of cholesterol synthesis genes; and (3) enhanced the expression of scavenger receptors CD36. These results suggest that PPARγ regulates cholesterol metabolism in alveolar macrophages.

  11. PPAR{gamma} regulates the expression of cholesterol metabolism genes in alveolar macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Anna D.; Malur, Anagha; Barna, Barbara P.; Kavuru, Mani S. [Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, East Carolina University (United States); Malur, Achut G. [Department of Microbiology and Immunology, East Carolina University (United States); Thomassen, Mary Jane, E-mail: thomassenm@ecu.edu [Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, East Carolina University (United States); Department of Microbiology and Immunology, East Carolina University (United States)

    2010-03-19

    Peroxisome proliferator-activated receptor-gamma (PPAR{gamma}) is a nuclear transcription factor involved in lipid metabolism that is constitutively expressed in the alveolar macrophages of healthy individuals. PPAR{gamma} has recently been implicated in the catabolism of surfactant by alveolar macrophages, specifically the cholesterol component of surfactant while the mechanism remains unclear. Studies from other tissue macrophages have shown that PPAR{gamma} regulates cholesterol influx, efflux, and metabolism. PPAR{gamma} promotes cholesterol efflux through the liver X receptor-alpha (LXR{alpha}) and ATP-binding cassette G1 (ABCG1). We have recently shown that macrophage-specific PPAR{gamma} knockout (PPAR{gamma} KO) mice accumulate cholesterol-laden alveolar macrophages that exhibit decreased expression of LXR{alpha} and ABCG1 and reduced cholesterol efflux. We hypothesized that in addition to the dysregulation of these cholesterol efflux genes, the expression of genes involved in cholesterol synthesis and influx was also dysregulated and that replacement of PPAR{gamma} would restore regulation of these genes. To investigate this hypothesis, we have utilized a Lentivirus expression system (Lenti-PPAR{gamma}) to restore PPAR{gamma} expression in the alveolar macrophages of PPAR{gamma} KO mice. Our results show that the alveolar macrophages of PPAR{gamma} KO mice have decreased expression of key cholesterol synthesis genes and increased expression of cholesterol receptors CD36 and scavenger receptor A-I (SRA-I). The replacement of PPAR{gamma} (1) induced transcription of LXR{alpha} and ABCG1; (2) corrected suppressed expression of cholesterol synthesis genes; and (3) enhanced the expression of scavenger receptors CD36. These results suggest that PPAR{gamma} regulates cholesterol metabolism in alveolar macrophages.

  12. The in vitro GcMAF effects on endocannabinoid system transcriptionomics, receptor formation, and cell activity of autism-derived macrophages

    OpenAIRE

    Siniscalco, Dario; Bradstreet, James Jeffrey; Cirillo, Alessandra; Antonucci, Nicola

    2014-01-01

    Background Immune system dysregulation is well-recognized in autism and thought to be part of the etiology of this disorder. The endocannabinoid system is a key regulator of the immune system via the cannabinoid receptor type 2 (CB2R) which is highly expressed on macrophages and microglial cells. We have previously published significant differences in peripheral blood mononuclear cell CB2R gene expression in the autism population. The use of the Gc protein-derived Macrophage Activating Factor...

  13. DMPD: Toll like receptors and autoimmunity: a critical appraisal. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17959357 Toll like receptors and autoimmunity: a critical appraisal. Papadimitraki ...ml) Show Toll like receptors and autoimmunity: a critical appraisal. PubmedID 17959357 Title Toll like receptors and auto

  14. Identification of the bacteria-binding peptide domain on salivary agglutinin (gp-340/DMBT1), a member of the scavenger receptor cysteine-rich superfamily

    DEFF Research Database (Denmark)

    Bikker, Floris J; Ligtenberg, Antoon J M; Nazmi, Kamran

    2002-01-01

    Salivary agglutinin is encoded by DMBT1 and identical to gp-340, a member of the scavenger receptor cysteine-rich (SRCR) superfamily. Salivary agglutinin/DMBT1 is known for its Streptococcus mutans agglutinating properties. This 300-400 kDa glycoprotein is composed of conserved peptide motifs: 14...... containing exclusively SRCR and SID domains that binds to S. mutans. To define more closely the S. mutans-binding domain, consensus-based peptides of the SRCR domains and SIDs were designed and synthesized. Only one of the SRCR peptides, designated SRCRP2, and none of the SID peptides bound to S. mutans....... Strikingly, this peptide was also able to induce agglutination of S. mutans and a number of other bacteria. The repeated presence of this peptide in the native molecule endows agglutinin/DMBT1 with a general bacterial binding feature with a multivalent character. Moreover, our studies demonstrate...

  15. Endocytosis via galactose receptors in vivo. Ligand size directs uptake by hepatocytes and/or liver macrophages

    International Nuclear Information System (INIS)

    Schlepper-Schaefer, J.; Huelsmann, D.; Djovkar, A.; Meyer, H.E.; Herbertz, L.; Kolb, H.; Kolb-Bachofen, V.

    1986-01-01

    The intrahepatic binding and uptake of variously sized ligands with terminal galactosyl residues is rat liver was followed. The ligands were administered to prefixed livers in binding studies and in vivo and in situ (serum-free perfused livers) in uptake studies. Gold sols with different particle diameters were prepared: 5 nm (Au 5 ), 17 nm (Au 17 ), 50 nm (Au 50 ) and coated with galactose exposing glycoproteins (asialofetuin (ASF) or lactosylated BSA (LacBSA)). Electron microscopy of mildly prefixed livers perfused with LacBSA-Au 5 in serum-free medium showed ligand binding to liver macrophages, hepatocytes and endothelial cells. Ligands bound to prefixed cell surfaces reflect the initial distribution of receptor activity: pre-aggregated clusters of ligands are found on liver macrophages, single particles statistically distributed on hepatocytes and pre-aggregated clusters of particles restricted to coated pits on endothelial cells. Ligand binding is prevented in the presence of 80 mM N-acetylgalactosamine (GalNAc), while N-acetylglucosamine (GlcNAc) is without effect. Electron microscopy of livers after ligand injection into the tail vein shows that in vivo uptake of electron-dense galactose particles by liver cells is size-dependent. In vivo uptake by liver macrophages is mediated by galactose-specific recognition as shown by inhibition with GalNAc

  16. Lower Squalene Epoxidase and Higher Scavenger Receptor Class B Type 1 Protein Levels Are Involved in Reduced Serum Cholesterol Levels in Stroke-Prone Spontaneously Hypertensive Rats.

    Science.gov (United States)

    Michihara, Akihiro; Mido, Mayuko; Matsuoka, Hiroshi; Mizutani, Yurika

    2015-01-01

    A lower serum cholesterol level was recently shown to be one of the causes of stroke in an epidemiological study. Spontaneously hypertensive rats stroke-prone (SHRSP) have lower serum cholesterol levels than normotensive Wistar-Kyoto rats (WKY). To elucidate the mechanisms responsible for the lower serum cholesterol levels in SHRSP, we determined whether the amounts of cholesterol biosynthetic enzymes or the receptor and transporter involved in cholesterol uptake and efflux in the liver were altered in SHRSP. When the mRNA levels of seven cholesterol biosynthetic enzymes were measured using real-time polymerase chain reaction (PCR), farnesyl pyrophosphate synthase and squalene epoxidase (SQE) levels in the liver of SHRSP were significantly lower than those in WKY. SQE protein levels were significantly reduced in tissues other than the brain of SHRSP. No significant differences were observed in low-density lipoprotein (LDL) receptor (uptake of serum LDL-cholesterol) or ATP-binding cassette transporter A1 (efflux of cholesterol from the liver/formation of high-density lipoprotein (HDL)) protein levels in the liver and testis between SHRSP and WKY, whereas scavenger receptor class B type 1 (SRB1: uptake of serum HDL-cholesterol) protein levels were higher in the livers of SHRSP. These results indicated that the lower protein levels of SQE and higher protein levels of SRB1 in the liver were involved in the reduced serum cholesterol levels in SHRSP.

  17. Understanding the Mysterious M2 Macrophage through Activation Markers and Effector Mechanisms

    Science.gov (United States)

    Rőszer, Tamás

    2015-01-01

    The alternatively activated or M2 macrophages are immune cells with high phenotypic heterogeneity and are governing functions at the interface of immunity, tissue homeostasis, metabolism, and endocrine signaling. Today the M2 macrophages are identified based on the expression pattern of a set of M2 markers. These markers are transmembrane glycoproteins, scavenger receptors, enzymes, growth factors, hormones, cytokines, and cytokine receptors with diverse and often yet unexplored functions. This review discusses whether these M2 markers can be reliably used to identify M2 macrophages and define their functional subdivisions. Also, it provides an update on the novel signals of the tissue environment and the neuroendocrine system which shape the M2 activation. The possible evolutionary roots of the M2 macrophage functions are also discussed. PMID:26089604

  18. Streptococcus gordonii induces nitric oxide production through its lipoproteins stimulating Toll-like receptor 2 in murine macrophages.

    Science.gov (United States)

    Kim, Hyun Young; Baik, Jung Eun; Ahn, Ki Bum; Seo, Ho Seong; Yun, Cheol-Heui; Han, Seung Hyun

    2017-02-01

    Streptococcus gordonii, a Gram-positive commensal in the oral cavity, is an opportunistic pathogen that can cause endodontic and systemic infections resulting in infective endocarditis. Lipoteichoic acid (LTA) and lipoprotein are major virulence factors of Gram-positive bacteria that are preferentially recognized by Toll-like receptor 2 (TLR2) on immune cells. In the present study, we investigated the effect of S. gordonii LTA and lipoprotein on the production of the representative inflammatory mediator nitric oxide (NO) by the mouse macrophages. Heat-killed S. gordonii wild-type and an LTA-deficient mutant (ΔltaS) but not a lipoprotein-deficient mutant (Δlgt) induced NO production in mouse primary macrophages and the cell line, RAW 264.7. S. gordonii wild-type and ΔltaS also induced the expression of inducible NO synthase (iNOS) at the mRNA and protein levels. In contrast, the Δlgt mutant showed little effect under the same condition. Furthermore, S. gordonii wild-type and ΔltaS induced NF-κB activation, STAT1 phosphorylation, and IFN-β expression, which are important for the induction of iNOS gene expression, with little activation by Δlgt. S. gordonii wild-type and ΔltaS showed an increased adherence and internalization to RAW 264.7 cells compared to Δlgt. In addition, S. gordonii wild-type and ΔltaS, but not Δlgt, substantially increased TLR2 activation while none of these induced NO production in TLR2-deficient macrophages. Triton X-114-extracted lipoproteins from S. gordonii were sufficient to induce NO production. Collectively, we suggest that lipoprotein is an essential cell wall component of S. gordonii to induce NO production in macrophages through TLR2 triggering NF-κB and STAT1 activation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Involvement of proton-sensing receptor TDAG8 in the anti-inflammatory actions of dexamethasone in peritoneal macrophages

    International Nuclear Information System (INIS)

    He, Xiao-dong; Tobo, Masayuki; Mogi, Chihiro; Nakakura, Takashi; Komachi, Mayumi; Murata, Naoya; Takano, Mutsumi; Tomura, Hideaki; Sato, Koichi; Okajima, Fumikazu

    2011-01-01

    Highlights: ► Glucocorticoid (GC) induced the expression of proton-sensing TDAG8 in macrophages. ► GC enhanced acidic pH-induced cAMP accumulation and inhibition of TNF-α production. ► The enhancement of the GC-induced actions was lost by TDAG8 deficiency. ► GC-induced anti-inflammatory actions are partly mediated by TDAG8 expression. -- Abstract: Dexamethasone (DEX), a potent glucocorticoid, increased the expression of T-cell death associated gene 8 (TDAG8), a proton-sensing G protein-coupled receptor, which is associated with the enhancement of acidic pH-induced cAMP accumulation, in peritoneal macrophages. We explored the role of increased TDAG8 expression in the anti-inflammatory actions of DEX. The treatment of macrophages with either DEX or acidic pH induced the cell death of macrophages; however, the cell death was not affected by TDAG8 deficiency. While DEX inhibited lipopolysaccharide-induced production of tumor necrosis factor-α, an inflammatory cytokine, which was independent of TDAG8, at neutral pH, the glucocorticoid enhanced the acidic pH-induced inhibition of tumor necrosis factor-α production in a manner dependent on TDAG8. In conclusion, the DEX-induced increase in TDAG8 expression is in part involved in the glucocorticoid-induced anti-inflammatory actions through the inhibition of inflammatory cytokine production under the acidic pH environment. On the other hand, the role of TDAG8 in the DEX-induced cell death is questionable.

  20. Involvement of proton-sensing receptor TDAG8 in the anti-inflammatory actions of dexamethasone in peritoneal macrophages

    Energy Technology Data Exchange (ETDEWEB)

    He, Xiao-dong; Tobo, Masayuki; Mogi, Chihiro; Nakakura, Takashi; Komachi, Mayumi; Murata, Naoya; Takano, Mutsumi; Tomura, Hideaki; Sato, Koichi [Laboratory of Signal Transduction, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512 (Japan); Okajima, Fumikazu, E-mail: fokajima@showa.gunma-u.ac.jp [Laboratory of Signal Transduction, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512 (Japan)

    2011-12-02

    Highlights: Black-Right-Pointing-Pointer Glucocorticoid (GC) induced the expression of proton-sensing TDAG8 in macrophages. Black-Right-Pointing-Pointer GC enhanced acidic pH-induced cAMP accumulation and inhibition of TNF-{alpha} production. Black-Right-Pointing-Pointer The enhancement of the GC-induced actions was lost by TDAG8 deficiency. Black-Right-Pointing-Pointer GC-induced anti-inflammatory actions are partly mediated by TDAG8 expression. -- Abstract: Dexamethasone (DEX), a potent glucocorticoid, increased the expression of T-cell death associated gene 8 (TDAG8), a proton-sensing G protein-coupled receptor, which is associated with the enhancement of acidic pH-induced cAMP accumulation, in peritoneal macrophages. We explored the role of increased TDAG8 expression in the anti-inflammatory actions of DEX. The treatment of macrophages with either DEX or acidic pH induced the cell death of macrophages; however, the cell death was not affected by TDAG8 deficiency. While DEX inhibited lipopolysaccharide-induced production of tumor necrosis factor-{alpha}, an inflammatory cytokine, which was independent of TDAG8, at neutral pH, the glucocorticoid enhanced the acidic pH-induced inhibition of tumor necrosis factor-{alpha} production in a manner dependent on TDAG8. In conclusion, the DEX-induced increase in TDAG8 expression is in part involved in the glucocorticoid-induced anti-inflammatory actions through the inhibition of inflammatory cytokine production under the acidic pH environment. On the other hand, the role of TDAG8 in the DEX-induced cell death is questionable.

  1. Affinity purification of human granulocyte macrophage colony-stimulating factor receptor alpha-chain. Demonstration of binding by photoaffinity labeling

    International Nuclear Information System (INIS)

    Chiba, S.; Shibuya, K.; Miyazono, K.; Tojo, A.; Oka, Y.; Miyagawa, K.; Takaku, F.

    1990-01-01

    The human granulocyte macrophage colony-stimulating factor (GM-CSF) receptor alpha-chain, a low affinity component of the receptor, was solubilized and affinity-purified from human placenta using biotinylated GM-CSF. Scatchard analysis of 125 I-GM-CSF binding to the placental membrane extract disclosed that the GM-CSF receptor had a dissociation constant (Kd) of 0.5-0.8 nM, corresponding to the Kd value of the GM-CSF receptor alpha-chain on the intact placental membrane. Affinity labeling of the solubilized protein using a photoreactive cross-linking agent, N-hydroxysuccinimidyl-4-azidobenzoate (HSAB), demonstrated a single specific band of 70-95 kDa representing a ligand-receptor complex. Approximately 2 g of the placental membrane extract was subjected to a biotinylated GM-CSF-fixed streptavidin-agarose column, resulting in a single major band at 70 kDa on a silver-stained sodium dodecyl sulfate gel. The radioiodination for the purified material disclosed that the purified protein had an approximate molecular mass of 70 kDa and a pI of 6.6. Binding activity of the purified material was demonstrated by photoaffinity labeling using HSAB- 125 I-GM-CSF, producing a similar specific band at 70-95 kDa as was demonstrated for the crude protein

  2. Salivary agglutinin and lung scavenger receptor cysteine-rich glycoprotein 340 have broad anti-influenza activities and interactions with surfactant protein D that vary according to donor source and sialylation

    DEFF Research Database (Denmark)

    Hartshorn, Kevan L.; Ligtenberg, Antoon; White, Mitchell R.

    2006-01-01

    We previously found that scavenger receptor cysteine-rich gp-340 (glycoprotein-340), isolated from lung or saliva, directly inhibits human IAVs (influenza A viruses). We now show that salivary gp-340 has broad antiviral activity against human, equine and porcine IAV strains. Although lung...

  3. Toll- like receptors expressed on embryonic macrophages couple inflammatory signals to iron metabolism during early ontogenesis

    Czech Academy of Sciences Publication Activity Database

    Balounová, Jana; Vavrochová, Tereza; Benešová, Martina; Ballek, Ondřej; Kolář, Michal; Filipp, Dominik

    2014-01-01

    Roč. 44, č. 5 (2014), s. 1491-1502 ISSN 0014-2980 R&D Projects: GA AV ČR IAA500520707 Institutional support: RVO:68378050 Keywords : Embryo nic macrophages * Ferroportin * Gene expression microarray * Iron metabolism * TLR stimulation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.034, year: 2014

  4. Modeling receptor-mediated endocytosis of polymer-functionalized iron oxide nanoparticles by human macrophages

    Czech Academy of Sciences Publication Activity Database

    Lunov, O.; Zablotskyy, Vitaliy A.; Syrovets, T.; Röcker, C.; Tron, K.; Nienhaus, G.U.; Simmet, T.

    2011-01-01

    Roč. 32, č. 2 (2011), s. 547-555 ISSN 0142-9612 Institutional research plan: CEZ:AV0Z10100522 Keywords : macrophage * nanoparticle * bioabsorption * modeling * antisense * MRI (magnetic resonance imaging) Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.404, year: 2011 http://www.sciencedirect.com/science/article/pii/S014296121001149X

  5. Toll- like receptors expressed on embryonic macrophages couple inflammatory signals to iron metabolism during early ontogenesis

    Czech Academy of Sciences Publication Activity Database

    Balounová, Jana; Vavrochová, Tereza; Benešová, Martina; Ballek, Ondřej; Kolář, Michal; Filipp, Dominik

    2014-01-01

    Roč. 44, č. 5 (2014), s. 1491-1502 ISSN 0014-2980 R&D Projects: GA AV ČR IAA500520707 Institutional support: RVO:68378050 Keywords : Embryonic macrophages * Ferroportin * Gene expression microarray * Iron metabolism * TLR stimulation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.034, year: 2014

  6. Epigenetic regulation of macrophage function

    NARCIS (Netherlands)

    Hoeksema, M.A.

    2016-01-01

    Atherosclerosis is a lipid-driven chronic inflammatory disorder with a key role for macrophages in all disease stages. Macrophages are involved as scavengers of lipids, regulate inflammation, attract other immune cells and contribute to the resolution of inflammation, fibrosis and plaque stability.

  7. TmSR-C, scavenger receptor class C, plays a pivotal role in antifungal and antibacterial immunity in the coleopteran insect Tenebrio molitor.

    Science.gov (United States)

    Kim, Soo Gon; Jo, Yong Hun; Seong, Jeong Hwan; Park, Ki Beom; Noh, Mi Young; Cho, Jun Ho; Ko, Hye Jin; Kim, Chang Eun; Tindwa, Hamisi; Patnaik, Bharat Bhusan; Bang, In Seok; Lee, Yong Seok; Han, Yeon Soo

    2017-10-01

    Scavenger receptors (SRs) constitute a family of membrane-bound receptors that bind to multiple ligands. The SR family of proteins is involved in removing cellular debris, oxidized low-density lipoproteins, and pathogens. Specifically, class C scavenger receptors (SR-C) have also been reported to be involved in phagocytosis of gram-positive and -negative bacteria in Drosophila and viruses in shrimp. However, reports are unavailable regarding the role of SR-C in antifungal immune mechanisms in insects. In this study, a full-length Tenebrio molitor SR-C (TmSR-C) sequence was obtained by 5'- and 3'-Rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). The TmSR-C full-length cDNA comprised 1671 bp with 5'- and 3'-untranslated regions of 23- and 107-bp, respectively. TmSR-C encodes a putative protein of 556 amino acid residues that is constitutively expressed in all tissues of late instar larvae and 2-day-old adults, with the highest transcript levels observed in hemocytes of larvae and adults. TmSR-C mRNA showed a 2.5-fold and 3-fold increase at 24 and 6 h after infection with Candida albicans and β-glucan, respectively. Immunoassay with TmSR-C polyclonal antibody showed induction of the putative protein in the cytosols of hemocytes at 3 h after inoculation of C. albicans. RNA interference (RNAi)-based gene silencing and phagocytosis assays were used to understand the role of TmSR-C in antifungal immunity. Silencing of TmSR-C transcripts reduced the survivability of late instar larvae at 2 days post-inoculation of C. albicans, Escherichia coli, or Staphylococcus aureus. Furthermore, in TmSR-C-silenced larvae, there was a decline in the rate of microorganism phagocytosis. Taken together, results of this study suggest that TmSR-C plays a pivotal role in phagocytosing not only fungi but also gram-negative and -positive bacteria in T. molitor. Copyright © 2017. Published by Elsevier Ltd.

  8. DMPD: Is HIV infection a TNF receptor signalling-driven disease? [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18178131 Is HIV infection a TNF receptor signalling-driven disease? Herbein G, Khan... KA. Trends Immunol. 2008 Feb;29(2):61-7. (.png) (.svg) (.html) (.csml) Show Is HIV infection a TNF receptor signalling-driven dise...ase? PubmedID 18178131 Title Is HIV infection a TNF receptor signalling-driven diseas

  9. DMPD: Toll-like receptors regulation of viral infection and disease. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18280610 Toll-like receptors regulation of viral infection and disease. Thompson JM...how Toll-like receptors regulation of viral infection and disease. PubmedID 18280610 Title Toll-like recepto...rs regulation of viral infection and disease. Authors Thompson JM, Iwasaki A. Pub

  10. DMPD: The Toll-like receptors: analysis by forward genetic methods. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16001129 The Toll-like receptors: analysis by forward genetic methods. Beutler B. I...mmunogenetics. 2005 Jul;57(6):385-92. (.png) (.svg) (.html) (.csml) Show The Toll-like receptors: analysis by forwar...d genetic methods. PubmedID 16001129 Title The Toll-like receptors: analysis by forward genetic meth

  11. DMPD: NOD-like receptors (NLRs): bona fide intracellular microbial sensors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18585455 NOD-like receptors (NLRs): bona fide intracellular microbial sensors. Shaw...tml) (.csml) Show NOD-like receptors (NLRs): bona fide intracellular microbial sensors. PubmedID 18585455 Ti...tle NOD-like receptors (NLRs): bona fide intracellular microbial sensors. Authors

  12. DMPD: TGF-beta signaling from receptors to the nucleus. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 10611754 TGF-beta signaling from receptors to the nucleus. Roberts AB. Microbes Inf...ect. 1999 Dec;1(15):1265-73. (.png) (.svg) (.html) (.csml) Show TGF-beta signaling from receptors to the nucleus.... PubmedID 10611754 Title TGF-beta signaling from receptors to the nucleus. Authors Roberts AB. Publicat

  13. DMPD: Viral recognition by Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17336545 Viral recognition by Toll-like receptors. Barton GM. Semin Immunol. 2007 F...eb;19(1):33-40. Epub 2007 Mar 2. (.png) (.svg) (.html) (.csml) Show Viral recognition by Toll-like receptors.... PubmedID 17336545 Title Viral recognition by Toll-like receptors. Authors Barton GM. Publication Semin Imm

  14. DMPD: Modulation of Toll-interleukin 1 receptor mediated signaling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15662540 Modulation of Toll-interleukin 1 receptor mediated signaling. Li X, Qin J.... J Mol Med. 2005 Apr;83(4):258-66. Epub 2005 Jan 21. (.png) (.svg) (.html) (.csml) Show Modulation of Toll-i...nterleukin 1 receptor mediated signaling. PubmedID 15662540 Title Modulation of Toll-interleukin 1 receptor

  15. DMPD: Endogenous ligands of Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15178705 Endogenous ligands of Toll-like receptors. Tsan MF, Gao B. J Leukoc Biol. ...2004 Sep;76(3):514-9. Epub 2004 Jun 3. (.png) (.svg) (.html) (.csml) Show Endogenous ligands of Toll-like re...ceptors. PubmedID 15178705 Title Endogenous ligands of Toll-like receptors. Authors Tsan MF, Gao B. Publicat

  16. DMPD: Role of Toll-like receptor responses for sepsis pathogenesis. [Dynamic Macrophage Pathway CSML Database

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    Full Text Available 18086373 Role of Toll-like receptor responses for sepsis pathogenesis. Weighardt H,... of Toll-like receptor responses for sepsis pathogenesis. PubmedID 18086373 Title Role of Toll-like receptor... responses for sepsis pathogenesis. Authors Weighardt H, Holzmann B. Publication

  17. DMPD: Signals and receptors involved in recruitment of inflammatory cells. [Dynamic Macrophage Pathway CSML Database

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    Full Text Available 7744810 Signals and receptors involved in recruitment of inflammatory cells. Ben-Ba...ow Signals and receptors involved in recruitment of inflammatory cells. PubmedID 7744810 Title Signals and receptors involved in recr...uitment of inflammatory cells. Authors Ben-Baruch A, Mic

  18. DMPD: Lysophospholipid receptors: signaling and biology. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15189145 Lysophospholipid receptors: signaling and biology. Ishii I, Fukushima N, Y...e X, Chun J. Annu Rev Biochem. 2004;73:321-54. (.png) (.svg) (.html) (.csml) Show Lysophospholipid receptors...: signaling and biology. PubmedID 15189145 Title Lysophospholipid receptors: signaling and biology. Authors

  19. DMPD: C-type lectin receptors in antifungal immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18160296 C-type lectin receptors in antifungal immunity. Willment JA, Brown GD. Tre...nds Microbiol. 2008 Jan;16(1):27-32. Epub 2007 Dec 21. (.png) (.svg) (.html) (.csml) Show C-type lectin receptors in antifun...gal immunity. PubmedID 18160296 Title C-type lectin receptors in antifungal immunity. Author

  20. DMPD: LPS-binding proteins and receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 9665271 LPS-binding proteins and receptors. Fenton MJ, Golenbock DT. J Leukoc Biol.... 1998 Jul;64(1):25-32. (.png) (.svg) (.html) (.csml) Show LPS-binding proteins and receptors. PubmedID 9665271 Title LPS-binding prot...eins and receptors. Authors Fenton MJ, Golenbock DT. Publication J Leukoc Biol. 199

  1. Cholesteryl ester hydroperoxides increase macrophage CD36 gene expression via PPARα

    International Nuclear Information System (INIS)

    Jedidi, Iness; Couturier, Martine; Therond, Patrice; Gardes-Albert, Monique; Legrand, Alain; Barouki, Robert; Bonnefont-Rousselot, Dominique; Aggerbeck, Martine

    2006-01-01

    The uptake of oxidized LDL by macrophages is a key event in the development of atherosclerosis. The scavenger receptor CD36 is one major receptor that internalizes oxidized LDL. In differentiated human macrophages, we compared the regulation of CD36 expression by copper-oxidized LDL or their products. Only oxidized derivatives of cholesteryl ester (CEOOH) increased the amount of CD36 mRNA (2.5-fold). Both oxidized LDL and CEOOH treatment increased two to fourfold the transcription of promoters containing peroxisome-proliferator-activated-receptor responsive elements (PPRE) in the presence of PPARα or γ. Electrophoretic-mobility-shift-assays with nuclear extracts prepared from macrophages treated by either oxidized LDL or CEOOH showed increased binding of PPARα to the CD36 gene promoter PPRE. In conclusion, CEOOH present in oxidized LDL increase CD36 gene expression in a pathway involving PPARα

  2. The Scavenger Receptor SSc5D Physically Interacts with Bacteria through the SRCR-Containing N-Terminal Domain

    Czech Academy of Sciences Publication Activity Database

    Pereira, C.B.; Bocková, Markéta; Santos, R.F.; Santos, A. M.; de Araujo, M.M.; Oliveira, L.; Homola, Jiří; Carmo, A.M.

    2016-01-01

    Roč. 7, October (2016), č. článku 416. ISSN 1664-3224 R&D Projects: GA ČR(CZ) GBP205/12/G118 Grant - others:AV ČR(CZ) AP1101 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:67985882 Keywords : Pattern recognition receptors * Bacteria * Surface plasmon resonance Subject RIV: BH - Optics, Masers, Lasers Impact factor: 6.429, year: 2016

  3. Functional expression of P2X family receptors in macrophages is affected by microenvironment in mouse T cell acute lymphoblastic leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shayan; Feng, Wenli; Yang, Xiao; Yang, Wanzhu; Ru, Yongxin; Liao, Jinfeng; Wang, Lina; Lin, Yongmin; Ren, Qian [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020 (China); Zheng, Guoguang, E-mail: zhengggtjchn@aliyun.com [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020 (China); Center for Stem Cell Medicine, Chinese Academy of Medical Sciences, Beijing 100730 (China)

    2014-04-18

    Highlights: • We study the impact of leukemic microenvironment on P2X family receptors in Mφs. • Bone marrow and spleen Mφs are studied in Notch1-induced mouse leukemia model. • Increased expression of P2X7R is found in Mφs during the development of leukemia. • Elevated P2X7R-mediated calcium response is found in Mφs at late stage of leukemia. • More apoptotic Mφs are found in bone marrow and spleen at late stage of leukemia. - Abstract: Nucleotides are important players in intercellular signaling communication network. P2X family receptors (P2XRs) are ATP-gated plasma membrane ion channels with diverse biological functions. Macrophages are important components in the microenvironment of hematopoiesis participating in both physiological and pathological processes. However, the role of P2XRs in macrophages in leukemia has not been established. Here we investigated expression pattern and functions of P2XRs in macrophages from bone marrow (BM) and spleen of Notch1-induced T-ALL mice. Real-time PCR showed that P2XRs except P2X5R were expressed in BM and spleen macrophages. Furthermore, with the development of leukemia, the expression of P2X7R increased in both BM and spleen macrophages whereas expression of P2X1R increased in spleen macrophages. Live cell imaging recoding the Ca{sup 2+} response demonstrated that P2X7R expressed in macrophages was functional. TUNEL and electron microscopy analysis found that apoptotic macrophages were frequently observed in BM and spleen at late stage of leukemia, which was partly contributed by the activation of overexpressed P2X7R. Our results suggested that the intercellular communication mediated by nucleotides might orchestrate in the pathological process of leukemia and could be a potential target for the treatment of leukemia.

  4. Functional expression of P2X family receptors in macrophages is affected by microenvironment in mouse T cell acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Chen, Shayan; Feng, Wenli; Yang, Xiao; Yang, Wanzhu; Ru, Yongxin; Liao, Jinfeng; Wang, Lina; Lin, Yongmin; Ren, Qian; Zheng, Guoguang

    2014-01-01

    Highlights: • We study the impact of leukemic microenvironment on P2X family receptors in Mφs. • Bone marrow and spleen Mφs are studied in Notch1-induced mouse leukemia model. • Increased expression of P2X7R is found in Mφs during the development of leukemia. • Elevated P2X7R-mediated calcium response is found in Mφs at late stage of leukemia. • More apoptotic Mφs are found in bone marrow and spleen at late stage of leukemia. - Abstract: Nucleotides are important players in intercellular signaling communication network. P2X family receptors (P2XRs) are ATP-gated plasma membrane ion channels with diverse biological functions. Macrophages are important components in the microenvironment of hematopoiesis participating in both physiological and pathological processes. However, the role of P2XRs in macrophages in leukemia has not been established. Here we investigated expression pattern and functions of P2XRs in macrophages from bone marrow (BM) and spleen of Notch1-induced T-ALL mice. Real-time PCR showed that P2XRs except P2X5R were expressed in BM and spleen macrophages. Furthermore, with the development of leukemia, the expression of P2X7R increased in both BM and spleen macrophages whereas expression of P2X1R increased in spleen macrophages. Live cell imaging recoding the Ca 2+ response demonstrated that P2X7R expressed in macrophages was functional. TUNEL and electron microscopy analysis found that apoptotic macrophages were frequently observed in BM and spleen at late stage of leukemia, which was partly contributed by the activation of overexpressed P2X7R. Our results suggested that the intercellular communication mediated by nucleotides might orchestrate in the pathological process of leukemia and could be a potential target for the treatment of leukemia

  5. Exogenous oxidants activate nuclear factor kappa B through Toll-like receptor 4 stimulation to maintain inflammatory phenotype in macrophage.

    Science.gov (United States)

    Zhang, Yan; Igwe, Orisa J

    2018-01-01

    Disturbances in redox equilibrium in tissue can lead to inflammatory state, which is a mediatory factor in many human diseases. The mechanism(s) by which exogenous oxidants may activate an inflammatory response is not fully understood. Emerging evidence suggests that oxidant-induced Toll-like receptor 4 (TLR4) activation plays a major role in "sterile" inflammation. In the present study, we used murine macrophage RAW-Blue cells, which are chromosomally integrated with secreted embryonic alkaline phosphatase (SEAP) inducible by NF-κB. We confirmed the expression of TLR4 mRNA and protein in RAW-Blue cells by RT-PCR and Western blot, respectively. We showed that oxidants increased intracellular reactive oxygen species production and lipid peroxidation, which resulted in decreased intracellular total antioxidant capacity. Consistent with the actions of TLR4-specific agonist LPS-EK, exogenous oxidants increased transcriptional activity of NF-κB p65 with subsequent release of NF-κB reporter gene SEAP. These effects were blocked by pretreatment with TLR4 neutralizing pAb and TLR4 signaling inhibitor CLI-095. In addition, oxidants decreased the expression of IκBα with enhanced phosphorylation at the Tyr42 residue. Finally, oxidants and LPS-EK increased TNFα production, but did not affect IL-10 production, which may cause imbalance between pro- and anti-inflammatory processes, which CLI-095 inhibited. For biological relevance, we confirmed that oxidants increased release of TNFα and IL-6 in primary macrophages derived from TLR4-WT and TLR4-KO mice. Our results support the involvement of TLR4 mediated oxidant-induced inflammatory phenotype through NF-κB activation in macrophages. Thus exogenous oxidants may play a role in activating inflammatory phenotypes that propagate and maintain chronic disease states. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Nucleotide-oligomerizing domain-1 (NOD1) receptor activation induces pro-inflammatory responses and autophagy in human alveolar macrophages.

    Science.gov (United States)

    Juárez, Esmeralda; Carranza, Claudia; Hernández-Sánchez, Fernando; Loyola, Elva; Escobedo, Dante; León-Contreras, Juan Carlos; Hernández-Pando, Rogelio; Torres, Martha; Sada, Eduardo

    2014-09-25

    Nucleotide-binding oligomerizing domain-1 (NOD1) is a cytoplasmic receptor involved in recognizing bacterial peptidoglycan fragments that localize to the cytosol. NOD1 activation triggers inflammation, antimicrobial mechanisms and autophagy in both epithelial cells and murine macrophages. NOD1 mediates intracellular pathogen clearance in the lungs of mice; however, little is known about NOD1's role in human alveolar macrophages (AMs) or its involvement in Mycobacterium tuberculosis (Mtb) infection. AMs, monocytes (MNs), and monocyte-derived macrophages (MDMs) from healthy subjects were assayed for NOD1 expression. Cells were stimulated with the NOD1 ligand Tri-DAP and cytokine production and autophagy were assessed. Cells were infected with Mtb and treated with Tri-DAP post-infection. CFUs counting determined growth control, and autophagy protein recruitment to pathogen localization sites was analyzed by immunoelectron microscopy. NOD1 was expressed in AMs, MDMs and to a lesser extent MNs. Tri-DAP stimulation induced NOD1 up-regulation and a significant production of IL1β, IL6, IL8, and TNFα in AMs and MDMs; however, the level of NOD1-dependent response in MNs was limited. Autophagy activity determined by expression of proteins Atg9, LC3, IRGM and p62 degradation was induced in a NOD1-dependent manner in AMs and MDMs but not in MNs. Infected AMs could be activated by stimulation with Tri-DAP to control the intracellular growth of Mtb. In addition, recruitment of NOD1 and the autophagy proteins IRGM and LC3 to the Mtb localization site was observed in infected AMs after treatment with Tri-DAP. NOD1 is involved in AM and MDM innate responses, which include proinflammatory cytokines and autophagy, with potential implications in the killing of Mtb in humans.

  7. Entry of porcine reproductive and respiratory syndrome virus into porcine alveolar macrophages via receptor-mediated endocytosis.

    Science.gov (United States)

    Nauwynck, H J; Duan, X; Favoreel, H W; Van Oostveldt, P; Pensaert, M B

    1999-02-01

    Porcine alveolar macrophages (AMphi) are the dominant cell type that supports the replication of porcine reproductive and respiratory syndrome virus (PRRSV) in vivo and in vitro. In order to determine the characteristics of the virus-receptor interaction, the attachment of PRRSV to cells was examined by using biotinylated virus in a series of flow cytometric assays. PRRSV bound specifically to AMphi in a dose-dependent manner. Binding of PRRSV to AMphi increased gradually and reached a maximum within 60 min at 4 degrees C. By confocal microscopy, it was shown that different degrees of PRRSV binding exist and that entry is by endocytosis. Virus uptake in vesicles is a clathrin-dependent process, as it was blocked by the addition of cytochalasin D and co-localization of PRRSV and clathrin was found. Furthermore, by the use of two weak bases, NH4Cl and chloroquine, it was demonstrated that PRRSV uses a low pH-dependent entry pathway. In the presence of these reagents, input virions accumulated in large vacuoles, indicating that uncoating was prevented. These results indicate that PRRSV entry into AMphi involves attachment to a specific virus receptor(s) followed by a process of endocytosis, by which virions are taken into the cell within vesicles by a clathrin-dependent pathway. A subsequent drop in pH is required for proper virus replication.

  8. Characterization and molecular features of the cell surface receptor for human granulocyte-macrophage colony-stimulating factor

    International Nuclear Information System (INIS)

    Chiba, S.; Tojo, A.; Kitamura, T.; Urabe, A.; Miyazono, K.; Takaku, F.

    1990-01-01

    The receptors for human granulocyte-macrophage colony-stimulating factor (GM-CSF) on the surfaces of normal and leukemic myeloid cells were characterized using 125I-labeled bacterially synthesized GM-CSF. The binding was rapid, specific, time dependent, and saturable. Scatchard analysis of the 125I-GM-CSF binding to peripheral blood neutrophils indicated the presence of a single class of binding site (Kd = 99 +/- 21 pM; 2,304 +/- 953 sites/cell). However, for peripheral blood monocytes and two GM-CSF-responsive myeloid cell lines (U-937 and TF-1), the Scatchard plots were biphasic curvilinear, which were best fit by curves derived from two binding site model: one with high affinity (Kd1 = 10-40 pM) and the other with low affinity (Kd2 = 0.9-2.0 nM). For U-937 cells, the number of high-affinity receptors was 1,058 +/- 402 sites/cell and that of low-affinity receptors was estimated to be 10,834 +/- 2,396 sites/cell. Cross-linking studies yielded three major bands with molecular masses of 150 kDa, 115 kDa, and 95 kDa, which were displaced by an excess amount of unlabeled GM-CSF, suggesting 135-kDa, 100-kDa, and 80-kDa species for the individual components of the human GM-CSF receptor. These bands comigrated for different cell types including peripheral blood neutrophils, U-937 cells and TF-1 cells. In experiments using U-937 cells, only the latter two bands appeared to be labeled in a dose-dependent manner in a low-affinity state. These results suggest that the human GM-CSF receptor possibly forms a multichain complex

  9. Specific Kv1.3 blockade modulates key cholesterol-metabolism-associated molecules in human macrophages exposed to ox-LDL.

    Science.gov (United States)

    Yang, Yong; Wang, Yan-Fu; Yang, Xiao-Fang; Wang, Zhao-Hui; Lian, Yi-Tian; Yang, Ying; Li, Xiao-Wei; Gao, Xiang; Chen, Jian; Shu, Yan-Wen; Cheng, Long-Xian; Liao, Yu-Hua; Liu, Kun

    2013-01-01

    Cholesterol-metabolism-associated molecules, including scavenger receptor class A (SR-A), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), CD36, ACAT1, ABCA1, ABCG1, and scavenger receptor class B type I, can modulate cholesterol metabolism in the transformation from macrophages to foam cells. Voltage-gated potassium channel Kv1.3 has increasingly been demonstrated to play an important role in the modulation of macrophage function. Here, we investigate the role of Kv1.3 in modulating cholesterol-metabolism-associated molecules in human acute monocytic leukemia cell-derived macrophages (THP-1 macrophages) and human monocyte-derived macrophages exposed to oxidized LDL (ox-LDL). Human Kv1.3 and Kv1.5 channels (hKv1.3 and hKv1.5) are expressed in macrophages and form a heteromultimeric channel. The hKv1.3-E314 antibody that we had generated as a specific hKv1.3 blocker inhibited outward delayed rectifier potassium currents, whereas the hKv1.5-E313 antibody that we had generated as a specific hKv1.5 blocker failed. Accordingly, the hKv1.3-E314 antibody reduced percentage of cholesterol ester and enhanced apoA-I-mediated cholesterol efflux in THP-1 macrophages and human monocyte-derived macrophages exposed to ox-LDL. The hKv1.3-E314 antibody downregulated SR-A, LOX-1, and ACAT1 expression and upregulated ABCA1 expression in THP-1 macrophages and human monocyte-derived macrophages. Our results reveal that specific Kv1.3 blockade represents a novel strategy modulating cholesterol metabolism in macrophages, which benefits the treatment of atherosclerotic lesions.

  10. Specific Kv1.3 blockade modulates key cholesterol-metabolism-associated molecules in human macrophages exposed to ox-LDL[S

    Science.gov (United States)

    Yang, Yong; Wang, Yan-Fu; Yang, Xiao-Fang; Wang, Zhao-Hui; Lian, Yi-Tian; Yang, Ying; Li, Xiao-Wei; Gao, Xiang; Chen, Jian; Shu, Yan-Wen; Cheng, Long-Xian; Liao, Yu-Hua; Liu, Kun

    2013-01-01

    Cholesterol-metabolism-associated molecules, including scavenger receptor class A (SR-A), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), CD36, ACAT1, ABCA1, ABCG1, and scavenger receptor class B type I, can modulate cholesterol metabolism in the transformation from macrophages to foam cells. Voltage-gated potassium channel Kv1.3 has increasingly been demonstrated to play an important role in the modulation of macrophage function. Here, we investigate the role of Kv1.3 in modulating cholesterol-metabolism-associated molecules in human acute monocytic leukemia cell-derived macrophages (THP-1 macrophages) and human monocyte-derived macrophages exposed to oxidized LDL (ox-LDL). Human Kv1.3 and Kv1.5 channels (hKv1.3 and hKv1.5) are expressed in macrophages and form a heteromultimeric channel. The hKv1.3-E314 antibody that we had generated as a specific hKv1.3 blocker inhibited outward delayed rectifier potassium currents, whereas the hKv1.5-E313 antibody that we had generated as a specific hKv1.5 blocker failed. Accordingly, the hKv1.3-E314 antibody reduced percentage of cholesterol ester and enhanced apoA-I-mediated cholesterol efflux in THP-1 macrophages and human monocyte-derived macrophages exposed to ox-LDL. The hKv1.3-E314 antibody downregulated SR-A, LOX-1, and ACAT1 expression and upregulated ABCA1 expression in THP-1 macrophages and human monocyte-derived macrophages. Our results reveal that specific Kv1.3 blockade represents a novel strategy modulating cholesterol metabolism in macrophages, which benefits the treatment of atherosclerotic lesions. PMID:23099443

  11. DMPD: Toll-like receptors and Type I interferons. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available m. 2007 May 25;282(21):15319-23. Epub 2007 Mar 29. (.png) (.svg) (.html) (.csml) Show Toll-like receptors and Type I interferons. Pub...medID 17395581 Title Toll-like receptors and Type I interferons. Authors Uematsu S,

  12. Toll-like receptor 4 is involved in the cell cycle modulation and required for effective human cytomegalovirus infection in THP-1 macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Arcangeletti, Maria-Cristina, E-mail: mariacristina.arcangeletti@unipr.it [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy); Germini, Diego; Rodighiero, Isabella [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy); Mirandola, Prisco [Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma (Italy); De Conto, Flora; Medici, Maria-Cristina [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy); Gatti, Rita [Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma (Italy); Chezzi, Carlo; Calderaro, Adriana [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy)

    2013-05-25

    Suitable host cell metabolic conditions are fundamental for the effective development of the human cytomegalovirus (HCMV) lytic cycle. Indeed, several studies have demonstrated the ability of this virus to interfere with cell cycle regulation, mainly by blocking proliferating cells in G1 or G1/S. In the present study, we demonstrate that HCMV deregulates the cell cycle of THP-1 macrophages (a cell line irreversibly arrested in G0) by pushing them into S and G2 phases. Moreover, we show that HCMV infection of THP-1 macrophages leads to Toll-like receptor 4 (TLR4) activation. Since various studies have indicated TLR4 to be involved in promoting cell proliferation, here we investigate the possible role of TLR4 in the observed HCMV-induced cell cycle perturbation. Our data strongly support TLR4 as a mediator of HCMV-triggered cell cycle activation in THP-1 macrophages favouring, in turn, the development of an efficient viral lytic cycle. - Highlights: ► We studied HCMV infection impact on THP-1 macrophage cell cycle. ► We analysed the role played by Toll-like receptor (TLR) 4 upon HCMV infection. ► HCMV pushes THP-1 macrophages (i.e. resting cells) to re-enter the cell cycle. ► TLR4 pathway inhibition strongly affects the effectiveness of HCMV replication. ► TLR4 pathway inhibition significantly decreases HCMV-induced cell cycle re-entry.

  13. Oxidised LDL internalisation by the LOX-1 scavenger receptor is dependent on a novel cytoplasmic motif and is regulated by dynamin-2.

    Science.gov (United States)

    Murphy, Jane E; Vohra, Ravinder S; Dunn, Sarah; Holloway, Zoe G; Monaco, Anthony P; Homer-Vanniasinkam, Shervanthi; Walker, John H; Ponnambalam, Sreenivasan

    2008-07-01

    The LOX-1 scavenger receptor recognises pro-atherogenic oxidised low-density lipoprotein (OxLDL) particles and is implicated in atherosclerotic plaque formation, but this mechanism is not well understood. Here we show evidence for a novel clathrin-independent and cytosolic-signal-dependent pathway that regulates LOX-1-mediated OxLDL internalisation. Cell surface labelling in the absence or presence of OxLDL ligand showed that LOX-1 is constitutively internalised from the plasma membrane and its half-life is not altered upon ligand binding and trafficking. We show that LOX-1-mediated OxLDL uptake is disrupted by overexpression of dominant-negative dynamin-2 but unaffected by CHC17 or mu2 (AP2) depletion. Site-directed mutagenesis revealed a conserved and novel cytoplasmic tripeptide motif (DDL) that regulates LOX-1-mediated endocytosis of OxLDL. Taken together, these findings indicate that LOX-1 is internalised by a clathrin-independent and dynamin-2-dependent pathway and is thus likely to mediate OxLDL trafficking in vascular tissues.

  14. Cholesterol trafficking and raft-like membrane domain composition mediate scavenger receptor class B type 1-dependent lipid sensing in intestinal epithelial cells.

    Science.gov (United States)

    Morel, Etienne; Ghezzal, Sara; Lucchi, Géraldine; Truntzer, Caroline; Pais de Barros, Jean-Paul; Simon-Plas, Françoise; Demignot, Sylvie; Mineo, Chieko; Shaul, Philip W; Leturque, Armelle; Rousset, Monique; Carrière, Véronique

    2018-02-01

    Scavenger receptor Class B type 1 (SR-B1) is a lipid transporter and sensor. In intestinal epithelial cells, SR-B1-dependent lipid sensing is associated with SR-B1 recruitment in raft-like/ detergent-resistant membrane domains and interaction of its C-terminal transmembrane domain with plasma membrane cholesterol. To clarify the initiating events occurring during lipid sensing by SR-B1, we analyzed cholesterol trafficking and raft-like domain composition in intestinal epithelial cells expressing wild-type SR-B1 or the mutated form SR-B1-Q445A, defective in membrane cholesterol binding and signal initiation. These features of SR-B1 were found to influence both apical cholesterol efflux and intracellular cholesterol trafficking from plasma membrane to lipid droplets, and the lipid composition of raft-like domains. Lipidomic analysis revealed likely participation of d18:0/16:0 sphingomyelin and 16:0/0:0 lysophosphatidylethanolamine in lipid sensing by SR-B1. Proteomic analysis identified proteins, whose abundance changed in raft-like domains during lipid sensing, and these included molecules linked to lipid raft dynamics and signal transduction. These findings provide new insights into the role of SR-B1 in cellular cholesterol homeostasis and suggest molecular links between SR-B1-dependent lipid sensing and cell cholesterol and lipid droplet dynamics. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Tachykinins activate guinea-pig alveolar macrophages: involvement of NK2 and NK1 receptors.

    OpenAIRE

    Brunelleschi, S.; Vanni, L.; Ledda, F.; Giotti, A.; Maggi, C. A.; Fantozzi, R.

    1990-01-01

    1. The effects of substance P (SP), neurokinin A (NKA) and neurokinin B (NKB) were evaluated on superoxide anion (O2-.) production by guinea-pig alveolar macrophages (AM). 2. SP dose-dependently (ED50 = 0.7 nM) evoked O2-. production from guinea-pig AM; the N-terminal heptapeptide, SP(1-7), was ineffective. In the presence of thiorphan (10(-5) M), an enkephalinase inhibitor, the stimulating effects of SP were not significantly modified. NKA and NKB were both able to induce O2-. production fro...

  16. Extra-epitopic hepatitis C virus polymorphisms confer resistance to broadly neutralizing antibodies by modulating binding to scavenger receptor B1.

    Science.gov (United States)

    El-Diwany, Ramy; Cohen, Valerie J; Mankowski, Madeleine C; Wasilewski, Lisa N; Brady, Jillian K; Snider, Anna E; Osburn, William O; Murrell, Ben; Ray, Stuart C; Bailey, Justin R

    2017-02-01

    Broadly-neutralizing monoclonal antibodies (bNAbs) may guide vaccine development for highly variable viruses including hepatitis C virus (HCV), since they target conserved viral epitopes that could serve as vaccine antigens. However, HCV resistance to bNAbs could reduce the efficacy of a vaccine. HC33.4 and AR4A are two of the most potent anti-HCV human bNAbs characterized to date, binding to highly conserved epitopes near the amino- and carboxy-terminus of HCV envelope (E2) protein, respectively. Given their distinct epitopes, it was surprising that these bNAbs showed similar neutralization profiles across a panel of natural HCV isolates, suggesting that some viral polymorphisms may confer resistance to both bNAbs. To investigate this resistance, we developed a large, diverse panel of natural HCV envelope variants and a novel computational method to identify bNAb resistance polymorphisms in envelope proteins (E1 and E2). By measuring neutralization of a panel of HCV pseudoparticles by 10 μg/mL of each bNAb, we identified E1E2 variants with resistance to one or both bNAbs, despite 100% conservation of the AR4A binding epitope across the panel. We discovered polymorphisms outside of either binding epitope that modulate resistance to both bNAbs by altering E2 binding to the HCV co-receptor, scavenger receptor B1 (SR-B1). This study is focused on a mode of neutralization escape not addressed by conventional analysis of epitope conservation, highlighting the contribution of extra-epitopic polymorphisms to bNAb resistance and presenting a novel mechanism by which HCV might persist even in the face of an antibody response targeting multiple conserved epitopes.

  17. Substance P enhances tissue factor release from granulocyte-macrophage colony-stimulating factor-dependent macrophages via the p22phox/β-arrestin 2/Rho A signaling pathway.

    Science.gov (United States)

    Yamaguchi, Rui; Yamamoto, Takatoshi; Sakamoto, Arisa; Ishimaru, Yasuji; Narahara, Shinji; Sugiuchi, Hiroyuki; Yamaguchi, Yasuo

    2016-03-01

    Granulocyte-macrophage colony stimulating factor (GM-CSF) induces procoagulant activity of macrophages. Tissue factor (TF) is a membrane-bound glycoprotein and substance P (SP) is a pro-inflammatory neuropeptide involved in the formation of membrane blebs. This study investigated the role of SP in TF release by GM-CSF-dependent macrophages. SP significantly decreased TF levels in whole-cell lysates of GM-CSF-dependent macrophages. TF was detected in the culture supernatant by enzyme-linked immunosorbent assay after stimulation of macrophages by SP. Aprepitant (an SP/neurokinin 1 receptor antagonist) reduced TF release from macrophages stimulated with SP. Pretreatment of macrophages with a radical scavenger(pyrrolidinedithiocarbamate) also limited the decrease of TF in whole-cell lysates after stimulation with SP. A protein kinase C inhibitor (rottlerin) partially blocked this macrophage response to SP, while it was significantly inhibited by a ROCK inhibitor (Y-27632) or a dynamin inhibitor (dinasore). An Akt inhibitor (perifosine) also partially blocked this response. Furthermore, siRNA targeting p22phox, β-arrestin 2, or Rho A, blunted the release of TF from macrophages stimulated with SP. In other experiments, visceral adipocytes derived from cryopreserved preadipocytes were found to produce SP. In conclusion, SP enhances the release of TF from macrophages via the p22phox/β-arrestin 2/Rho A signaling pathway. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Mining microarray datasets in nutrition: expression of the GPR120 (n-3 fatty acid receptor/sensor) gene is down-regulated in human adipocytes by macrophage secretions.

    Science.gov (United States)

    Trayhurn, Paul; Denyer, Gareth

    2012-01-01

    Microarray datasets are a rich source of information in nutritional investigation. Targeted mining of microarray data following initial, non-biased bioinformatic analysis can provide key insight into specific genes and metabolic processes of interest. Microarrays from human adipocytes were examined to explore the effects of macrophage secretions on the expression of the G-protein-coupled receptor (GPR) genes that encode fatty acid receptors/sensors. Exposure of the adipocytes to macrophage-conditioned medium for 4 or 24 h had no effect on GPR40 and GPR43 expression, but there was a marked stimulation of GPR84 expression (receptor for medium-chain fatty acids), the mRNA level increasing 13·5-fold at 24 h relative to unconditioned medium. Importantly, expression of GPR120, which encodes an n-3 PUFA receptor/sensor, was strongly inhibited by the conditioned medium (15-fold decrease in mRNA at 24 h). Macrophage secretions have major effects on the expression of fatty acid receptor/sensor genes in human adipocytes, which may lead to an augmentation of the inflammatory response in adipose tissue in obesity.

  19. Probiotic Bacteria Alter Pattern-Recognition Receptor Expression and Cytokine Profile in a Human Macrophage Model Challenged with Candida albicans and Lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Victor H. Matsubara

    2017-11-01

    Full Text Available Probiotics are live microorganisms that confer benefits to the host health. The infection rate of potentially pathogenic organisms such as Candida albicans, the most common agent associated with mucosal candidiasis, can be reduced by probiotics. However, the mechanisms by which the probiotics interfere with the immune system are largely unknown. We evaluated the effect of probiotic bacteria on C. albicans challenged human macrophages. Macrophages were pretreated with lactobacilli alone (Lactobacillus rhamnosus LR32, Lactobacillus casei L324m, or Lactobacillus acidophilus NCFM or associated with Escherichia coli lipopolysaccharide (LPS, followed by the challenge with C. albicans or LPS in a co-culture assay. The expression of pattern-recognition receptors genes (CLE7A, TLR2, and TLR4 was determined by RT-qPCR, and dectin-1 reduced levels were confirmed by flow cytometry. The cytokine profile was determined by ELISA using the macrophage cell supernatant. Overall probiotic lactobacilli down-regulated the transcription of CLEC7A (p < 0.05, resulting in the decreased expression of dectin-1 on probiotic pretreated macrophages. The tested Lactobacillus species down-regulated TLR4, and increased TLR2 mRNA levels in macrophages challenged with C. albicans. The cytokines profile of macrophages challenged with C. albicans or LPS were altered by the probiotics, which generally led to increased levels of IL-10 and IL-1β, and reduction of IL-12 production by macrophages (p < 0.05. Our data suggest that probiotic lactobacilli impair the recognition of PAMPs by macrophages, and alter the production of pro/anti-inflammatory cytokines, thus modulating inflammation.

  20. Proteomic Analysis of ABCA1-Null Macrophages Reveals a Role for Stomatin-Like Protein-2 in Raft Composition and Toll-Like Receptor Signaling.

    Science.gov (United States)

    Chowdhury, Saiful M; Zhu, Xuewei; Aloor, Jim J; Azzam, Kathleen M; Gabor, Kristin A; Ge, William; Addo, Kezia A; Tomer, Kenneth B; Parks, John S; Fessler, Michael B

    2015-07-01

    Lipid raft membrane microdomains organize signaling by many prototypical receptors, including the Toll-like receptors (TLRs) of the innate immune system. Raft-localization of proteins is widely thought to be regulated by raft cholesterol levels, but this is largely on the basis of studies that have manipulated cell cholesterol using crude and poorly specific chemical tools, such as β-cyclodextrins. To date, there has been no proteome-scale investigation of whether endogenous regulators of intracellular cholesterol trafficking, such as the ATP binding cassette (ABC)A1 lipid efflux transporter, regulate targeting of proteins to rafts. Abca1(-/-) macrophages have cholesterol-laden rafts that have been reported to contain increased levels of select proteins, including TLR4, the lipopolysaccharide receptor. Here, using quantitative proteomic profiling, we identified 383 proteins in raft isolates from Abca1(+/+) and Abca1(-/-) macrophages. ABCA1 deletion induced wide-ranging changes to the raft proteome. Remarkably, many of these changes were similar to those seen in Abca1(+/+) macrophages after lipopolysaccharide exposure. Stomatin-like protein (SLP)-2, a member of the stomatin-prohibitin-flotillin-HflK/C family of membrane scaffolding proteins, was robustly and specifically increased in Abca1(-/-) rafts. Pursuing SLP-2 function, we found that rafts of SLP-2-silenced macrophages had markedly abnormal composition. SLP-2 silencing did not compromise ABCA1-dependent cholesterol efflux but reduced macrophage responsiveness to multiple TLR ligands. This was associated with reduced raft levels of the TLR co-receptor, CD14, and defective lipopolysaccharide-induced recruitment of the common TLR adaptor, MyD88, to rafts. Taken together, we show that the lipid transporter ABCA1 regulates the protein repertoire of rafts and identify SLP-2 as an ABCA1-dependent regulator of raft composition and of the innate immune response. © 2015 by The American Society for Biochemistry and

  1. Proteomic Analysis of ABCA1-Null Macrophages Reveals a Role for Stomatin-Like Protein-2 in Raft Composition and Toll-Like Receptor Signaling*

    Science.gov (United States)

    Chowdhury, Saiful M.; Zhu, Xuewei; Aloor, Jim J.; Azzam, Kathleen M.; Gabor, Kristin A.; Ge, William; Addo, Kezia A.; Tomer, Kenneth B.; Parks, John S.; Fessler, Michael B.

    2015-01-01

    Lipid raft membrane microdomains organize signaling by many prototypical receptors, including the Toll-like receptors (TLRs) of the innate immune system. Raft-localization of proteins is widely thought to be regulated by raft cholesterol levels, but this is largely on the basis of studies that have manipulated cell cholesterol using crude and poorly specific chemical tools, such as β-cyclodextrins. To date, there has been no proteome-scale investigation of whether endogenous regulators of intracellular cholesterol trafficking, such as the ATP binding cassette (ABC)A1 lipid efflux transporter, regulate targeting of proteins to rafts. Abca1−/− macrophages have cholesterol-laden rafts that have been reported to contain increased levels of select proteins, including TLR4, the lipopolysaccharide receptor. Here, using quantitative proteomic profiling, we identified 383 proteins in raft isolates from Abca1+/+ and Abca1−/− macrophages. ABCA1 deletion induced wide-ranging changes to the raft proteome. Remarkably, many of these changes were similar to those seen in Abca1+/+ macrophages after lipopolysaccharide exposure. Stomatin-like protein (SLP)-2, a member of the stomatin-prohibitin-flotillin-HflK/C family of membrane scaffolding proteins, was robustly and specifically increased in Abca1−/− rafts. Pursuing SLP-2 function, we found that rafts of SLP-2-silenced macrophages had markedly abnormal composition. SLP-2 silencing did not compromise ABCA1-dependent cholesterol efflux but reduced macrophage responsiveness to multiple TLR ligands. This was associated with reduced raft levels of the TLR co-receptor, CD14, and defective lipopolysaccharide-induced recruitment of the common TLR adaptor, MyD88, to rafts. Taken together, we show that the lipid transporter ABCA1 regulates the protein repertoire of rafts and identify SLP-2 as an ABCA1-dependent regulator of raft composition and of the innate immune response. PMID:25910759

  2. Cholesterol efflux from THP-1 macrophages is impaired by the fatty acid component from lipoprotein hydrolysis by lipoprotein lipase.

    Science.gov (United States)

    Yang, Yanbo; Thyagarajan, Narmadaa; Coady, Breanne M; Brown, Robert J

    2014-09-05

    Lipoprotein lipase (LPL) is an extracellular lipase that primarily hydrolyzes triglycerides within circulating lipoproteins. Macrophage LPL contributes to atherogenesis, but the mechanisms behind it are poorly understood. We hypothesized that the products of lipoprotein hydrolysis generated by LPL promote atherogenesis by inhibiting the cholesterol efflux ability by macrophages. To test this hypothesis, we treated human THP-1 macrophages with total lipoproteins that were hydrolyzed by LPL and we found significantly reduced transcript levels for the cholesterol transporters ATP binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor BI. These decreases were likely due to significant reductions for the nuclear receptors liver-X-receptor-α, peroxisome proliferator activated receptor (PPAR)-α, and PPAR-γ. We prepared a mixture of free fatty acids (FFA) that represented the ratios of FFA species within lipoprotein hydrolysis products, and we found that the FFA mixture also significantly reduced cholesterol transporters and nuclear receptors. Finally, we tested the efflux of cholesterol from THP-1 macrophages to apolipoprotein A-I, and we found that the treatment of THP-1 macrophages with the FFA mixture significantly attenuated cholesterol efflux. Overall, these data show that the FFA component of lipoprotein hydrolysis products generated by LPL may promote atherogenesis by inhibiting cholesterol efflux, which partially explains the pro-atherogenic role of macrophage LPL. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Triamcinolone acetonide activates an anti-inflammatory and folate receptor-positive macrophage that prevents osteophytosis in vivo

    NARCIS (Netherlands)

    Siebelt, Michiel; Korthagen, Nicoline; Wei, Wu; Groen, Harald; Bastiaansen-Jenniskens, Yvonne; Müller, Christina; Waarsing, Jan Hendrik; de Jong, Marion; Weinans, Harrie

    2015-01-01

    INTRODUCTION: Triamcinolone acetonide (TA) is used for osteoarthritis management to reduce pain, and pre-clinical studies have shown that TA limits osteophyte formation. Osteophyte formation is known to be facilitated by synovial macrophage activation. TA injections might influence macrophage

  4. Macrophage colony-stimulating factor and its receptor signaling augment glycated albumin-induced retinal microglial inflammation in vitro

    Directory of Open Access Journals (Sweden)

    Jiang Chun H

    2011-01-01

    Full Text Available Abstract Background Microglial activation and the proinflammatory response are controlled by a complex regulatory network. Among the various candidates, macrophage colony-stimulating factor (M-CSF is considered an important cytokine. The up-regulation of M-CSF and its receptor CSF-1R has been reported in brain disease, as well as in diabetic complications; however, the mechanism is unclear. An elevated level of glycated albumin (GA is a characteristic of diabetes; thus, it may be involved in monocyte/macrophage-associated diabetic complications. Results The basal level of expression of M-CSF/CSF-1R was examined in retinal microglial cells in vitro. Immunofluorescence, real-time PCR, immunoprecipitation, and Western blot analyses revealed the up-regulation of CSF-1R in GA-treated microglial cells. We also detected increased expression and release of M-CSF, suggesting that the cytokine is produced by activated microglia via autocrine signaling. Using an enzyme-linked immunosorbent assay, we found that GA affects microglial activation by stimulating the release of tumor necrosis factor-α and interleukin-1β. Furthermore, the neutralization of M-CSF or CSF-1R with antibodies suppressed the proinflammatory response. Conversely, this proinflammatory response was augmented by the administration of M-CSF. Conclusions We conclude that GA induces microglial activation via the release of proinflammatory cytokines, which may contribute to the inflammatory pathogenesis of diabetic retinopathy. The increased microglial expression of M-CSF/CSF-1R not only is a response to microglial activation in diabetic retinopathy but also augments the microglial inflammation responsible for the diabetic microenvironment.

  5. Cyclooxygenase-2 induction in macrophages is modulated by docosahexaenoic acid via interactions with free fatty acid receptor 4 (FFA4).

    Science.gov (United States)

    Li, Xinzhi; Yu, Ying; Funk, Colin D

    2013-12-01

    Cyclooxygenase-2 (COX-2)-derived prostaglandins are implicated in numerous inflammatory disorders. The purpose of these studies was to examine previously unexplored interactions between COX-2 induction and docosahexaenoic acid (DHA) via the free fatty acid receptor 4 (FFA4) signaling pathway in murine RAW 264.7 cells and peritoneal macrophages challenged with lipopolysaccharide (LPS). DHA dose (IC50=18 μM)- and time-dependently reduced COX-2 expression, without affecting COX-1. DHA (25 μM for 24 h) decreased LPS-induced prostaglandin E2 (PGE2) synthesis by 81%, primarily through reducing COX-2 (60%), as well as down-regulating microsomal prostaglandin E synthase-1 (46%), but independently of peroxisome proliferator-activated receptors. FFA4 knockdown abrogated DHA effects on COX-2 induction, PGE2 production, and interleukin 6 (IL-6) gene expression. In the presence of inhibitors of eicosanoid metabolism via COX-2, 12/15-lipoxygenase and CYP450s (rofecoxib (1 μM), PD146176 (2 μM), or MS-PPOH (20 μM)), DHA was still effective in attenuating COX-2 induction. Moreover, Toll-like receptor 4 signaling via Akt/JNK phosphorylation and p65 nuclear translocation was repressed by DHA-activated FFA4 coupling with β-arrestin 2, which was reversed by FFA4 knockdown. These data support DHA modulation of COX-2 expression and activity, in part, via FFA4, which provides a new mechanistic explanation for some of the anti-inflammatory effects of DHA.

  6. Macrophage-related serum biomarkers soluble CD163 (sCD163) and soluble mannose receptor (sMR) to differentiate mild liver fibrosis from cirrhosis in patients with chronic hepatitis C

    DEFF Research Database (Denmark)

    Andersen, E S; Rødgaard-Hansen, S; Moessner, B

    2014-01-01

    Macrophages regulate the fibrotic process in chronic liver disease. The aim of the present pilot study was to evaluate two new macrophage-specific serum biomarkers [soluble CD163 (sCD163) and soluble mannose receptor (sMR, sCD206)] as potential fibrosis markers in patients chronically infected wi...

  7. Cholesterol efflux from THP-1 macrophages is impaired by the fatty acid component from lipoprotein hydrolysis by lipoprotein lipase

    International Nuclear Information System (INIS)

    Yang, Yanbo; Thyagarajan, Narmadaa; Coady, Breanne M.; Brown, Robert J.

    2014-01-01

    Highlights: • Lipoprotein hydrolysis products were produced by lipoprotein lipase. • Hydrolysis products lowers expression of macrophage cholesterol transporters. • Hydrolysis products reduces expression of select nuclear receptors. • Fatty acid products lowers cholesterol transporters and select nuclear receptors. • Fatty acid products reduces cholesterol efflux from macrophages. - Abstract: Lipoprotein lipase (LPL) is an extracellular lipase that primarily hydrolyzes triglycerides within circulating lipoproteins. Macrophage LPL contributes to atherogenesis, but the mechanisms behind it are poorly understood. We hypothesized that the products of lipoprotein hydrolysis generated by LPL promote atherogenesis by inhibiting the cholesterol efflux ability by macrophages. To test this hypothesis, we treated human THP-1 macrophages with total lipoproteins that were hydrolyzed by LPL and we found significantly reduced transcript levels for the cholesterol transporters ATP binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor BI. These decreases were likely due to significant reductions for the nuclear receptors liver-X-receptor-α, peroxisome proliferator activated receptor (PPAR)-α, and PPAR-γ. We prepared a mixture of free fatty acids (FFA) that represented the ratios of FFA species within lipoprotein hydrolysis products, and we found that the FFA mixture also significantly reduced cholesterol transporters and nuclear receptors. Finally, we tested the efflux of cholesterol from THP-1 macrophages to apolipoprotein A-I, and we found that the treatment of THP-1 macrophages with the FFA mixture significantly attenuated cholesterol efflux. Overall, these data show that the FFA component of lipoprotein hydrolysis products generated by LPL may promote atherogenesis by inhibiting cholesterol efflux, which partially explains the pro-atherogenic role of macrophage LPL

  8. Cholesterol efflux from THP-1 macrophages is impaired by the fatty acid component from lipoprotein hydrolysis by lipoprotein lipase

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yanbo; Thyagarajan, Narmadaa; Coady, Breanne M.; Brown, Robert J., E-mail: rbrown@mun.ca

    2014-09-05

    Highlights: • Lipoprotein hydrolysis products were produced by lipoprotein lipase. • Hydrolysis products lowers expression of macrophage cholesterol transporters. • Hydrolysis products reduces expression of select nuclear receptors. • Fatty acid products lowers cholesterol transporters and select nuclear receptors. • Fatty acid products reduces cholesterol efflux from macrophages. - Abstract: Lipoprotein lipase (LPL) is an extracellular lipase that primarily hydrolyzes triglycerides within circulating lipoproteins. Macrophage LPL contributes to atherogenesis, but the mechanisms behind it are poorly understood. We hypothesized that the products of lipoprotein hydrolysis generated by LPL promote atherogenesis by inhibiting the cholesterol efflux ability by macrophages. To test this hypothesis, we treated human THP-1 macrophages with total lipoproteins that were hydrolyzed by LPL and we found significantly reduced transcript levels for the cholesterol transporters ATP binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor BI. These decreases were likely due to significant reductions for the nuclear receptors liver-X-receptor-α, peroxisome proliferator activated receptor (PPAR)-α, and PPAR-γ. We prepared a mixture of free fatty acids (FFA) that represented the ratios of FFA species within lipoprotein hydrolysis products, and we found that the FFA mixture also significantly reduced cholesterol transporters and nuclear receptors. Finally, we tested the efflux of cholesterol from THP-1 macrophages to apolipoprotein A-I, and we found that the treatment of THP-1 macrophages with the FFA mixture significantly attenuated cholesterol efflux. Overall, these data show that the FFA component of lipoprotein hydrolysis products generated by LPL may promote atherogenesis by inhibiting cholesterol efflux, which partially explains the pro-atherogenic role of macrophage LPL.

  9. Increased DNA methylation of scavenger receptor class B type I contributes to inhibitory effects of prenatal caffeine ingestion on cholesterol uptake and steroidogenesis in fetal adrenals

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Dong-Mei; He, Zheng; Ma, Liang-Peng; Wang, Lin-Long [Department of Pharmacology, Wuhan University School of Basic Medical Sciences, Wuhan 430071 (China); Ping, Jie, E-mail: pingjie@whu.edu.cn [Department of Pharmacology, Wuhan University School of Basic Medical Sciences, Wuhan 430071 (China); Hubei Provincial Key Laboratory of Developmentally Originated Diseases, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China); Wang, Hui [Department of Pharmacology, Wuhan University School of Basic Medical Sciences, Wuhan 430071 (China); Hubei Provincial Key Laboratory of Developmentally Originated Diseases, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China)

    2015-06-01

    Steroid hormones synthesized from cholesterol in the fetal adrenal are crucial for fetal development. We have observed the inhibited fetal adrenal corticosterone synthesis and increased intrauterine growth retardation (IUGR) rate in rats under prenatal caffeine ingestion. The aim of this study is to evaluate the effects of prenatal caffeine ingestion on cholesterol supply in fetal adrenal steroidogenesis in rats and explore the underlying epigenetic mechanisms. Pregnant Wistar rats were treated with 60 mg/kg·d caffeine from gestational day (GD) 7 to GD17. Histological changes of fetal adrenals and increased IUGR rates were observed in the caffeine group. There were significantly decreased steroid hormone contents and cholesterol supply in caffeine-treated fetal adrenals. Data from the gene expression array suggested that prenatal caffeine ingestion caused increased expression of genes related to DNA methylation and decreased expression of genes related to cholesterol uptake. The following conjoint analysis of DNA methylation array with these differentially expressed genes suggested that scavenger receptor class B type I (SR-BI) may play an important role in caffeine-induced cholesterol supply deficiency. Moreover, real-time RT-PCR and immunohistochemical detection certified the inhibitory effects of caffeine on both mRNA expression and protein expression of SR-BI in the fetal adrenal. And the increased DNA methylation frequency in the proximal promoter of SR-BI was confirmed by bisulfite-sequencing PCR. In conclusion, prenatal caffeine ingestion can induce DNA hypermethylation of the SR-BI promoter in the rat fetal adrenal. These effects may lead to decreased SR-BI expression and cholesterol uptake, which inhibits steroidogenesis in the fetal adrenal. - Highlights: • Prenatal caffeine ingestion inhibits steroid hormone production in the fetal adrenal. • Prenatal caffeine ingestion inhibits cholesterol uptake in the fetal adrenal. • Prenatal caffeine

  10. Increased DNA methylation of scavenger receptor class B type I contributes to inhibitory effects of prenatal caffeine ingestion on cholesterol uptake and steroidogenesis in fetal adrenals

    International Nuclear Information System (INIS)

    Wu, Dong-Mei; He, Zheng; Ma, Liang-Peng; Wang, Lin-Long; Ping, Jie; Wang, Hui

    2015-01-01

    Steroid hormones synthesized from cholesterol in the fetal adrenal are crucial for fetal development. We have observed the inhibited fetal adrenal corticosterone synthesis and increased intrauterine growth retardation (IUGR) rate in rats under prenatal caffeine ingestion. The aim of this study is to evaluate the effects of prenatal caffeine ingestion on cholesterol supply in fetal adrenal steroidogenesis in rats and explore the underlying epigenetic mechanisms. Pregnant Wistar rats were treated with 60 mg/kg·d caffeine from gestational day (GD) 7 to GD17. Histological changes of fetal adrenals and increased IUGR rates were observed in the caffeine group. There were significantly decreased steroid hormone contents and cholesterol supply in caffeine-treated fetal adrenals. Data from the gene expression array suggested that prenatal caffeine ingestion caused increased expression of genes related to DNA methylation and decreased expression of genes related to cholesterol uptake. The following conjoint analysis of DNA methylation array with these differentially expressed genes suggested that scavenger receptor class B type I (SR-BI) may play an important role in caffeine-induced cholesterol supply deficiency. Moreover, real-time RT-PCR and immunohistochemical detection certified the inhibitory effects of caffeine on both mRNA expression and protein expression of SR-BI in the fetal adrenal. And the increased DNA methylation frequency in the proximal promoter of SR-BI was confirmed by bisulfite-sequencing PCR. In conclusion, prenatal caffeine ingestion can induce DNA hypermethylation of the SR-BI promoter in the rat fetal adrenal. These effects may lead to decreased SR-BI expression and cholesterol uptake, which inhibits steroidogenesis in the fetal adrenal. - Highlights: • Prenatal caffeine ingestion inhibits steroid hormone production in the fetal adrenal. • Prenatal caffeine ingestion inhibits cholesterol uptake in the fetal adrenal. • Prenatal caffeine

  11. Scavenger Receptor B1 is a Potential Biomarker of Human Nasopharyngeal Carcinoma and Its Growth is Inhibited by HDL-mimetic Nanoparticles

    Science.gov (United States)

    Zheng, Ying; Liu, Yanyan; Jin, Honglin; Pan, Shaotao; Qian, Yuan; Huang, Chuan; Zeng, Yixin; Luo, Qingming; Zeng, Musheng; Zhang, Zhihong

    2013-01-01

    Nasopharyngeal carcinoma (NPC) is a very regional malignant head and neck cancer that has attracted widespread attention for its unique etiology, epidemiology and therapeutic options. To achieve high cure rates in NPC patients, theranostic approaches are actively being pursued and improved efforts remain desirable in identifying novel biomarkers and establishing effective therapeutic approaches with low long-term toxicities. Here, we discovered that the scavenger receptor class B type I (SR-B1) was overexpressed in all investigated NPC cell lines and 75% of NPC biopsies, demonstrating that SR-B1 is a potential biomarker of NPC. Additional functional analysis showed that SR-B1 has great effect on cell motility while showing no significant impact on cell proliferation. As high-density lipoproteins (HDL) exhibit strong binding affinities to SR-B1 and HDL mimetic peptides are reportedly capable of inhibiting tumor growth, we further examined the SR-B1 targeting ability of a highly biocompatible HDL-mimicking peptide-phospholipid scaffold (HPPS) nanocarrier and investigated its therapeutic effect on NPC. Results show that NPC cells with higher SR-B1 expression have superior ability in taking up the core constituents of HPPS. Moreover, HPPS inhibited the motility and colony formation of 5-8F cells, and significantly suppressed the NPC cell growth in nude mice without inducing tumor cell necrosis or apoptosis. These results indicate that HPPS is not only a NPC-targeting nanocarrier but also an effective anti-NPC drug. Together, the identification of SR-B1 as a potential biomarker and the use of HPPS as an effective anti-NPC agent may shed new light on the diagnosis and therapeutics of NPC. PMID:23843895

  12. Mycobacterium leprae Activates Toll-Like Receptor-4 Signaling and Expression on Macrophages Depending on Previous Bacillus Calmette-Guerin Vaccination.

    Science.gov (United States)

    Polycarpou, Anastasia; Holland, Martin J; Karageorgiou, Ioannis; Eddaoudi, Ayad; Walker, Stephen L; Willcocks, Sam; Lockwood, Diana N J

    2016-01-01

    Toll-like receptor (TLR)-1 and TLR2 have been shown to be receptors for Mycobacterium leprae (M. leprae), yet it is unclear whether M. leprae can signal through alternative TLRs. Other mycobacterial species possess ligands for TLR4 and genetic association studies in human populations suggest that people with TLR4 polymorphisms may be protected against leprosy. Using human embryonic kidney (HEK)-293 cells co-transfected with TLR4, we demonstrate that M. leprae activates TLR4. We used human macrophages to show that M. leprae stimulation of cytokine production is diminished if pre-treated with TLR4 neutralizing antibody. TLR4 protein expression was up-regulated on macrophages derived from non-bacillus Calmette-Guerin (BCG) vaccinated healthy volunteers after incubation with M. leprae, whereas it was down-regulated in macrophages derived from BCG-vaccinated donors. Finally, pre-treatment of macrophages derived from BCG-naive donors with BCG reversed the effect of M. leprae on TLR4 expression. This may be a newly described phenomenon by which BCG vaccination stimulates "non-specific" protection to the human immune system.

  13. Postprandial phase time influences the uptake of TAG from postprandial TAG-rich lipoproteins by THP-1 macrophages.

    Science.gov (United States)

    Cabello-Moruno, Rosana; Sinausia, Laura; Botham, Kathleen M; Montero, Emilio; Avella, Michael; Perona, Javier S

    2014-11-14

    Postprandial TAG-rich lipoproteins (TRL) can be taken up by macrophages, leading to the formation of foam cells, probably via receptor-mediated pathways. The present study was conducted to investigate whether the postprandial time point at which TRL are collected modulates this process. A meal containing refined olive oil was given to nine healthy young men and TRL were isolated from their serum at 2, 4 and 6 h postprandially. The lipid class and apoB compositions of TRL were determined by HPLC and SDS-PAGE, respectively. The accumulation of lipids in macrophages was determined after the incubation of THP-1 macrophages with TRL. The gene expression of candidate receptors was measured by real-time PCR. The highest concentrations of TAG, apoB48 and apoB100 in TRL were observed at 2 h after the consumption of the test meal. However, excessive intracellular TAG accumulation in THP-1 macrophages was observed in response to incubation with TRL isolated at 4 h, when their particle size (estimated as the TAG:apoB ratio) was intermediate. The abundance of mRNA transcripts in macrophages in response to incubation with TRL was down-regulated for LDL receptor (LDLR), slightly up-regulated for VLDL receptor and remained unaltered for LDLR-related protein, but no effect of the postprandial time point was observed. In contrast, the mRNA expression of scavenger receptors SRB1, SRA2 and CD36 was higher when cells were incubated with TRL isolated at 4 h after the consumption of the test meal. In conclusion, TRL led to excessive intracellular TAG accumulation in THP-1 macrophages, which was greater when cells were incubated with intermediate-sized postprandial TRL isolated at 4 h and was associated with a significant increase in the mRNA expression of scavenger receptors.

  14. Cervical Cancer Cell Supernatants Induce a Phenotypic Switch from U937-Derived Macrophage-Activated M1 State into M2-Like Suppressor Phenotype with Change in Toll-Like Receptor Profile

    Directory of Open Access Journals (Sweden)

    Karina Sánchez-Reyes

    2014-01-01

    Full Text Available Cervical cancer (CC is the second most common cancer among women worldwide. Infection with human papillomavirus (HPV is the main risk factor for developing CC. Macrophages are important immune effector cells; they can be differentiated into two phenotypes, identified as M1 (classically activated and M2 (alternatively activated. Macrophage polarization exerts profound effects on the Toll-like receptor (TLR profile. In this study, we evaluated whether the supernatant of human CC cells HeLa, SiHa, and C-33A induces a shift of M1 macrophage toward M2 macrophage in U937-derived macrophages. Results. The results showed that soluble factors secreted by CC cells induce a change in the immunophenotype of macrophages from macrophage M1 into macrophage M2. U937-derived macrophages M1 released proinflammatory cytokines and nitric oxide; however, when these cells were treated with the supernatant of CC cell lines, we observed a turnover of M1 toward M2. These cells increased CD163 and IL-10 expression. The expression of TLR-3, -7, and -9 is increased when the macrophages were treated with the supernatant of CC cells. Conclusions. Our result strongly suggests that CC cells may, through the secretion of soluble factors, induce a change of immunophenotype M1 into M2 macrophages.

  15. Rab20 regulates phagosome maturation in RAW264 macrophages during Fc gamma receptor-mediated phagocytosis.

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    Youhei Egami

    Full Text Available Rab20, a member of the Rab GTPase family, is known to be involved in membrane trafficking, however its implication in FcγR-mediated phagocytosis is unclear. We examined the spatiotemporal localization of Rab20 during phagocytosis of IgG-opsonized erythrocytes (IgG-Es in RAW264 macrophages. By the live-cell imaging of fluorescent protein-fused Rab20, it was shown that Rab20 was transiently associated with the phagosomal membranes. During the early stage of phagosome formation, Rab20 was not localized on the membranes of phagocytic cups, but was gradually recruited to the newly formed phagosomes. Although Rab20 was colocalized with Rab5 to some extent, the association of Rab20 with the phagosomes persisted even after the loss of Rab5 from the phagosomal membranes. Then, Rab20 was colocalized with Rab7 and Lamp1, late endosomal/lysosomal markers, on the internalized phagosomes. Moreover, our analysis of Rab20 mutant expression revealed that the maturation of phagosomes was significantly delayed in cells expressing the GDP-bound mutant Rab20-T19N. These data suggest that Rab20 is an important component of phagosome and regulates the phagosome maturation during FcγR-mediated phagocytosis.

  16. Extracellular hemoglobin polarizes the macrophage proteome toward Hb-clearance, enhanced antioxidant capacity and suppressed HLA class 2 expression.

    OpenAIRE

    Kaempfer Theresa; Duerst Elena; Gehrig Peter; Roschitzki Bernd; Rutishauser Dorothea; Grossmann Jonas; Schoedon Gabriele; Vallelian Florence; Schaer Dominik J

    2011-01-01

    Peripheral blood monocytes and macrophages are the only cell population with a proven hemoglobin (Hb) clearance capacity through the CD163 scavenger receptor pathway. Hb detoxification and related adaptive cellular responses are assumed to be essential processes to maintaining tissue homeostasis and promoting wound healing in injured tissues. Using a dual platform mass spectrometry analysis with MALDI TOF/TOF and LTQ Orbitrap instruments combined with isobaric tag for relative and absolute qu...

  17. Activation of nucleotide-binding domain-like receptor containing protein 3 inflammasome in dendritic cells and macrophages by Streptococcus sanguinis.

    Science.gov (United States)

    Saeki, Ayumi; Suzuki, Toshihiko; Hasebe, Akira; Kamezaki, Ryousuke; Fujita, Mari; Nakazawa, Futoshi; Shibata, Ken-Ichiro

    2017-03-01

    Streptococcus sanguinis is frequently isolated from the blood of patients with infective endocarditis and contributes to the pathology of this disease through induction of interleukin (IL)-1β responsible for the development of the disease. However, the mechanism of IL-1β induction remains unknown. In this study, S. sanguinis activated a murine dendritic cell (DC) to induce IL-1β and this activity was attenuated by silencing the mRNAs of nucleotide-binding domain-like receptor containing protein 3 (NLRP3) and caspase-1. S. sanguinis induced IL-1β production in murine bone marrow-derived macrophage, but this activity was significantly reduced in bone marrow-derived macrophages from NLRP3-, apoptosis-associated speck-like protein containing a caspase-recruitment domain-, and caspase-1-deficient mice. DC phagocytosed S. sanguinis cells, followed by the release of adenosine triphosphate (ATP). The ATP-degradating enzyme attenuated the release of ATP and IL-1β. The inhibitors for ATP receptor reduced IL-1β release in DC. These results strongly suggest that S. sanguinis has the activity to induce IL-1β through the NLRP3 inflammasome in macrophage and DC and interaction of purinergic receptors with ATP released is involved in expression of the activity. © 2016 John Wiley & Sons Ltd.

  18. Dual inhibition of Ang-2 and VEGF receptors normalizes tumor vasculature and prolongs survival in glioblastoma by altering macrophages

    Science.gov (United States)

    Peterson, Teresa E.; Kirkpatrick, Nathaniel D.; Huang, Yuhui; Farrar, Christian T.; Marijt, Koen A.; Kloepper, Jonas; Datta, Meenal; Amoozgar, Zohreh; Seano, Giorgio; Jung, Keehoon; Kamoun, Walid S.; Vardam, Trupti; Snuderl, Matija; Goveia, Jermaine; Chatterjee, Sampurna; Batista, Ana; Muzikansky, Alona; Leow, Ching Ching; Xu, Lei; Batchelor, Tracy T.; Duda, Dan G.; Fukumura, Dai; Jain, Rakesh K.

    2016-01-01

    Glioblastomas (GBMs) rapidly become refractory to anti-VEGF therapies. We previously demonstrated that ectopic overexpression of angiopoietin-2 (Ang-2) compromises the benefits of anti-VEGF receptor (VEGFR) treatment in murine GBM models and that circulating Ang-2 levels in GBM patients rebound after an initial decrease following cediranib (a pan-VEGFR tyrosine kinase inhibitor) administration. Here we tested whether dual inhibition of VEGFR/Ang-2 could improve survival in two orthotopic models of GBM, Gl261 and U87. Dual therapy using cediranib and MEDI3617 (an anti–Ang-2–neutralizing antibody) improved survival over each therapy alone by delaying Gl261 growth and increasing U87 necrosis, effectively reducing viable tumor burden. Consistent with their vascular-modulating function, the dual therapies enhanced morphological normalization of vessels. Dual therapy also led to changes in tumor-associated macrophages (TAMs). Inhibition of TAM recruitment using an anti–colony-stimulating factor-1 antibody compromised the survival benefit of dual therapy. Thus, dual inhibition of VEGFR/Ang-2 prolongs survival in preclinical GBM models by reducing tumor burden, improving normalization, and altering TAMs. This approach may represent a potential therapeutic strategy to overcome the limitations of anti-VEGFR monotherapy in GBM patients by integrating the complementary effects of anti-Ang2 treatment on vessels and immune cells. PMID:27044097

  19. Characterization of immortalized MARCO and SR-AI/II-deficient murine alveolar macrophage cell lines

    Directory of Open Access Journals (Sweden)

    Imrich Amy

    2008-05-01

    Full Text Available Abstract Background Alveolar macrophages (AM avidly bind and ingest unopsonized inhaled particles and bacteria through class A scavenger receptors (SRAs MARCO and SR-AI/II. Studies to characterize the function of these SRAs have used AMs from MARCO or SR-AI/II null mice, but this approach is limited by the relatively low yield of AMs. Moreover, studies using both MARCO and SR-AI/II-deficient (MS-/- mice have not been reported yet. Hence, we sought to develop continuous cell lines from primary alveolar macrophages from MS-/- mice. Results We used in vitro infection of the primary AMs with the J2 retrovirus carrying the v-raf and v-myc oncogenes. Following initial isolation in media supplemented with murine macrophage colony-stimulating factor (M-CSF, we subcloned three AM cell lines, designated ZK-1, ZK-2 and ZK-6. These cell lines grow well in RPMI-1640-10% FBS in the absence of M-CSF. These adherent but trypsin-sensitive cell lines have a doubling time of approximately 14 hours, exhibit typical macrophage morphology, and express macrophage-associated cell surface Mac-1 (CD11b and F4/80 antigens. The cell lines show robust Fc-receptor dependent phagocytosis of opsonized red blood cells. Similar to freshly isolated AMs from MS-/- mice, the cell lines exhibit decreased phagocytosis of unopsonized titanium dioxide (TiO2, fluorescent latex beads and bacteria (Staphylococcus aureus compared with the primary AMs from wild type (WT C57BL/6 mice. Conclusion Our results indicated that three contiguous murine alveolar macrophage cell lines with MS-/- (ZK1, ZK2 and ZK6 were established successfully. These cell lines demonstrated macrophage morphology and functional activity. Interestingly, similar to freshly isolated AMs from MS-/- mice, the cell lines have a reduced, but not absent, ability to bind and ingest particles, with an altered pattern of blockade by scavenger receptor inhibitors. These cell lines will facilitate in vitro studies to further define

  20. Inhibition of EMMPRIN and MMP-9 Expression by Epigallocatechin-3-Gallate through 67-kDa Laminin Receptor in PMA-Induced Macrophages.

    Science.gov (United States)

    Wang, Qi-Ming; Wang, Hao; Li, Ya-Fei; Xie, Zhi-Yong; Ma, Yao; Yan, Jian-Jun; Gao, Yi Fan Wei; Wang, Ze-Mu; Wang, Lian-Sheng

    2016-01-01

    It is well documented that overexpression of EMMPRIN (extracellular matrix metalloproteinase inducer) and MMPs (matrix metalloproteinases) by monocytes/macrophages plays an important role in atherosclerotic plaque rupture. Green tea polyphenol epigallocatechin-3-gallate (EGCG) has a variety of pharmacological properties and exerts cardiovascular protective effects. Recently, the 67-kD laminin receptor (67LR) has been identified as a cell surface receptor of EGCG. The aim of the present study was to evaluate the effects of EGCG on the expression of EMMPRIN and MMP-9 in PMA-induced macrophages, and the potential mechanisms underlying its effects. Human monocytic THP-1 cells were induced to differentiate into macrophages with phorbol 12-myristate 13-acetate (PMA). Protein expression and MMP-9 activity were assayed by Western blot and Gelatin zymography, respectively. Real-time PCR was used to examine EMMPRIN and MMP-9 mRNA expression. We showed that EGCG (10-50µmol/L) significantly inhibited the expression of EMMPRIN and MMP-9 and activation of extracellular signal-regulated kinase 1/2 (ERK1/2), p38 and c-Jun N-terminal kinase (JNK) in PMA-induced macrophages. Downregulation of EMMPRIN by gene silencing hindered PMA-induced MMP-9 secretion and expression, indicating an important role of EMMPRIN in the inhibition of MMP-9 by EGCG. Moreover, 67LR was involved in EGCG-mediated suppression of EMMPRIN and MMP-9 expression. Anti-67LR antibody treatment led to abrogation of the inhibitory action of EGCG on the expression of EMMPRIN and MMP-9 and activation of ERK1/2, p38, and JNK. Our results indicate that EGCG restrains EMMPRIN and MMP-9 expression via 67LR in PMA-induced macrophages, which also suggests that EGCG may be a possible therapeutic agent for stabilizing atherosclerotic plaque. © 2016 The Author(s) Published by S. Karger AG, Basel.

  1. Inhibition of EMMPRIN and MMP-9 Expression by Epigallocatechin-3-Gallate through 67-kDa Laminin Receptor in PMA-Induced Macrophages

    Directory of Open Access Journals (Sweden)

    Qi-Ming Wang

    2016-11-01

    Full Text Available Background/Aims: It is well documented that overexpression of EMMPRIN (extracellular matrix metalloproteinase inducer and MMPs (matrix metalloproteinases by monocytes/macrophages plays an important role in atherosclerotic plaque rupture. Green tea polyphenol epigallocatechin-3-gallate (EGCG has a variety of pharmacological properties and exerts cardiovascular protective effects. Recently, the 67-kD laminin receptor (67LR has been identified as a cell surface receptor of EGCG. The aim of the present study was to evaluate the effects of EGCG on the expression of EMMPRIN and MMP-9 in PMA-induced macrophages, and the potential mechanisms underlying its effects. Methods: Human monocytic THP-1 cells were induced to differentiate into macrophages with phorbol 12-myristate 13-acetate (PMA. Protein expression and MMP-9 activity were assayed by Western blot and Gelatin zymography, respectively. Real-time PCR was used to examine EMMPRIN and MMP-9 mRNA expression. Results: We showed that EGCG (10-50µmol/L significantly inhibited the expression of EMMPRIN and MMP-9 and activation of extracellular signal-regulated kinase 1/2 (ERK1/2, p38 and c-Jun N-terminal kinase (JNK in PMA-induced macrophages. Downregulation of EMMPRIN by gene silencing hindered PMA-induced MMP-9 secretion and expression, indicating an important role of EMMPRIN in the inhibition of MMP-9 by EGCG. Moreover, 67LR was involved in EGCG-mediated suppression of EMMPRIN and MMP-9 expression. Anti-67LR antibody treatment led to abrogation of the inhibitory action of EGCG on the expression of EMMPRIN and MMP-9 and activation of ERK1/2, p38, and JNK. Conclusion: Our results indicate that EGCG restrains EMMPRIN and MMP-9 expression via 67LR in PMA-induced macrophages, which also suggests that EGCG may be a possible therapeutic agent for stabilizing atherosclerotic plaque.

  2. Activation of α-7 nicotinic acetylcholine receptor reduces ischemic stroke injury through reduction of pro-inflammatory macrophages and oxidative stress.

    Directory of Open Access Journals (Sweden)

    Zhenying Han

    Full Text Available Activation of α-7 nicotinic acetylcholine receptor (α-7 nAchR has a neuro-protective effect on ischemic and hemorrhagic stroke. However, the underlying mechanism is not completely understood. We hypothesized that α-7 nAchR agonist protects brain injury after ischemic stroke through reduction of pro-inflammatory macrophages (M1 and oxidative stress. C57BL/6 mice were treated with PHA568487 (PHA, α-7 nAchR agonist, methyllycaconitine (MLA, nAchR antagonist, or saline immediately and 24 hours after permanent occlusion of the distal middle cerebral artery (pMCAO. Behavior test, lesion volume, CD68(+, M1 (CD11b(+/Iba1(+ and M2 (CD206/Iba1+ microglia/macrophages, and phosphorylated p65 component of NF-kB in microglia/macrophages were quantified using histological stained sections. The expression of M1 and M2 marker genes, anti-oxidant genes and nicotinamide adenine dinucleotide phosphate (NADPH oxidase were quantified using real-time RT-PCR. Compared to the saline-treated mice, PHA mice had fewer behavior deficits 3 and 7 days after pMCAO, and smaller lesion volume, fewer CD68(+ and M1 macrophages, and more M2 macrophages 3 and 14 days after pMCAO, whereas MLA's effects were mostly the opposite in several analyses. PHA increased anti-oxidant genes and NADPH oxidase expression associated with decreased phosphorylation of NF-kB p65 in microglia/macrophages. Thus, reduction of inflammatory response and oxidative stress play roles in α-7 nAchR neuro-protective effect.

  3. Fcγ receptor I alpha chain (CD64) expression in macrophages is critical for the onset of meningitis by Escherichia coli K1.

    Science.gov (United States)

    Mittal, Rahul; Sukumaran, Sunil K; Selvaraj, Suresh K; Wooster, David G; Babu, M Madan; Schreiber, Alan D; Verbeek, J Sjef; Prasadarao, Nemani V

    2010-11-18

    Neonatal meningitis due to Escherichia coli K1 is a serious illness with unchanged morbidity and mortality rates for the last few decades. The lack of a comprehensive understanding of the mechanisms involved in the development of meningitis contributes to this poor outcome. Here, we demonstrate that depletion of macrophages in newborn mice renders the animals resistant to E. coli K1 induced meningitis. The entry of E. coli K1 into macrophages requires the interaction of outer membrane protein A (OmpA) of E. coli K1 with the alpha chain of Fcγ receptor I (FcγRIa, CD64) for which IgG opsonization is not necessary. Overexpression of full-length but not C-terminal truncated FcγRIa in COS-1 cells permits E. coli K1 to enter the cells. Moreover, OmpA binding to FcγRIa prevents the recruitment of the γ-chain and induces a different pattern of tyrosine phosphorylation of macrophage proteins compared to IgG2a induced phosphorylation. Of note, FcγRIa(-/-) mice are resistant to E. coli infection due to accelerated clearance of bacteria from circulation, which in turn was the result of increased expression of CR3 on macrophages. Reintroduction of human FcγRIa in mouse FcγRIa(-/-) macrophages in vitro increased bacterial survival by suppressing the expression of CR3. Adoptive transfer of wild type macrophages into FcγRIa(-/-) mice restored susceptibility to E. coli infection. Together, these results show that the interaction of FcγRI alpha chain with OmpA plays a key role in the development of neonatal meningitis by E. coli K1.

  4. Divergence of macrophage phagocytic and antimicrobial programs in leprosy.

    Science.gov (United States)

    Montoya, Dennis; Cruz, Daniel; Teles, Rosane M B; Lee, Delphine J; Ochoa, Maria Teresa; Krutzik, Stephan R; Chun, Rene; Schenk, Mirjam; Zhang, Xiaoran; Ferguson, Benjamin G; Burdick, Anne E; Sarno, Euzenir N; Rea, Thomas H; Hewison, Martin; Adams, John S; Cheng, Genhong; Modlin, Robert L

    2009-10-22

    Effective innate immunity against many microbial pathogens requires macrophage programs that upregulate phagocytosis and direct antimicrobial pathways, two functions generally assumed to be coordinately regulated. We investigated the regulation of these key functions in human blood-derived macrophages. Interleukin-10 (IL-10) induced the phagocytic pathway, including the C-type lectin CD209 and scavenger receptors, resulting in phagocytosis of mycobacteria and oxidized low-density lipoprotein. IL-15 induced the vitamin D-dependent antimicrobial pathway and CD209, yet the cells were less phagocytic. The differential regulation of macrophage functional programs was confirmed by analysis of leprosy lesions: the macrophage phagocytosis pathway was prominent in the clinically progressive, multibacillary form of the disease, whereas the vitamin D-dependent antimicrobial pathway predominated in the self-limited form and in patients undergoing reversal reactions from the multibacillary to the self-limited form. These data indicate that macrophage programs for phagocytosis and antimicrobial responses are distinct and differentially regulated in innate immunity to bacterial infections.

  5. Peroxynitrite scavenging by flavonids.

    NARCIS (Netherlands)

    Haenen, G.R.M.M.; Paquay, J.B.G.; Korthouwer, R.E.M.; Bast, A.

    1997-01-01

    The peroxynitrite scavenging activity of a series of structurally related flavonoids was tested. It was found that flavonoids are excellent scavengers of peroxynitrite. Compared to the known peroxynitrite scavenger ebselen, the most active flavonoids proved to be 10 times more effective. Indications

  6. Ocimum basilicum ethanolic extract decreases cholesterol synthesis and lipid accumulation in human macrophages.

    Science.gov (United States)

    Bravo, Elena; Amrani, Souliman; Aziz, Mohammed; Harnafi, Hicham; Napolitano, Mariarosaria

    2008-12-01

    Macrophage lipid accumulation induced by low density lipoproteins (LDL) plays a pivotal role in atherosclerotic plaque development. Previous work showed that Ocimum basilicum extract, used as hypocholesterolemic agent by traditional medicine in Morocco, has hypolipidemic activity in rat acute hyperlipimidemia. This study investigated the effects of ethanolic extract of O. basilicum on lipid accumulation in human macrophages. As modification of LDL increase atherogenicity of the particles we evaluated the effects of the extract on LDL oxidation. The extract caused a dose-related increase of LDL-resistance to Cu(2+)-induced oxidation. Furthermore, at the dose of 60 microg/ml, significantly decreases the accumulation of macrophage lipid droplets induced by modified LDL evaluated as by red-oil staining. Cholesterol esterification and triacylglycerol synthesis in the cells were not affected. Macrophage treatment with 60 microg/ml, but not 20 microg/ml, of the extract reduced newly synthesized unesterified cholesterol by about 60% and decreased scavenger receptors activity by about 20-30%, evaluated by the internalization of cholesterol carried by [(3)H]CE-aggregated-LDL. The results suggest that O. basilicum ethanolic extract has the capability to reduce foam cell formation through the reduction of cholesterol synthesis and the modulation of the activity of surface scavenger receptors.

  7. Serum levels of TWEAK and scavenger receptor CD163 in type 1 diabetes mellitus: relationship with cardiovascular risk factors. a case-control study.

    Directory of Open Access Journals (Sweden)

    Gemma Llauradó

    Full Text Available OBJECTIVE: To test the usefulness of serum concentrations of tumor necrosis factor-like weak inducer of apoptosis (sTWEAK and soluble scavenger receptor CD163 (sCD163 as markers of subtle inflammation in patients with type 1 diabetes mellitus (T1DM without clinical cardiovascular (CV disease and to evaluate their relationship with arterial stiffness (AS. METHODS: Sixty-eight patients with T1DM and 68 age and sex-matched, healthy subjects were evaluated. Anthropometrical variables and CV risk factors were recorded. Serum concentrations of sTWEAK and sCD163 were measured. AS was assessed by aortic pulse wave velocity (aPWV. All statistical analyses were stratified by gender. RESULTS: T1DM patients showed lower serum concentrations of sTWEAK (Men: 1636.5 (1146.3-3754.8 pg/mL vs. 765.9 (650.4-1097.1 pg/mL; p<0.001. Women: 1401.0 (788.0-2422.2 pg/mL vs. 830.1 (562.6-1175.9 pg/mL; p = 0.011 compared with their respective controls. Additionally, T1DM men had higher serum concentrations of sCD163 (285.0 (247.7-357.1 ng/mL vs. 224.8 (193.3-296.5 ng/mL; p = 0.012 compared with their respective controls. sTWEAK correlated negatively with aPWV in men (r = -0.443; p<0.001. However, this association disappeared after adjusting for potential confounders. In men, the best multiple linear regression model showed that the independent predictors of sTWEAK were T1DM and WHR (R(2 = 0.640; p<0.001. In women, T1DM and SBP were the independent predictors for sTWEAK (R(2 = 0.231; p = 0.001. CONCLUSION: sTWEAK is decreased in T1DM patients compared with age and sex-matched healthy subjects after adjusting for classic CV risk factors, although sTWEAK levels may be partially influenced by some of them. Additionally, T1DM men have higher serum concentrations of sCD163. These results point out an association between the inflammatory system and CV risk in T1DM.

  8. The Activin A-Peroxisome Proliferator-Activated Receptor Gamma Axis Contributes to the Transcriptome of GM-CSF-Conditioned Human Macrophages.

    Science.gov (United States)

    Nieto, Concha; Bragado, Rafael; Municio, Cristina; Sierra-Filardi, Elena; Alonso, Bárbara; Escribese, María M; Domínguez-Andrés, Jorge; Ardavín, Carlos; Castrillo, Antonio; Vega, Miguel A; Puig-Kröger, Amaya; Corbí, Angel L

    2018-01-01

    GM-CSF promotes the functional maturation of lung alveolar macrophages (A-MØ), whose differentiation is dependent on the peroxisome proliferator-activated receptor gamma (PPARγ) transcription factor. In fact, blockade of GM-CSF-initiated signaling or deletion of the PPARγ-encoding gene PPARG leads to functionally defective A-MØ and the onset of pulmonary alveolar proteinosis. In vitro , macrophages generated in the presence of GM-CSF display potent proinflammatory, immunogenic and tumor growth-limiting activities. Since GM-CSF upregulates PPARγ expression, we hypothesized that PPARγ might contribute to the gene signature and functional profile of human GM-CSF-conditioned macrophages. To verify this hypothesis, PPARγ expression and activity was assessed in human monocyte-derived macrophages generated in the presence of GM-CSF [proinflammatory GM-CSF-conditioned human monocyte-derived macrophages (GM-MØ)] or M-CSF (anti-inflammatory M-MØ), as well as in ex vivo isolated human A-MØ. GM-MØ showed higher PPARγ expression than M-MØ, and the expression of PPARγ in GM-MØ was found to largely depend on activin A. Ligand-induced activation of PPARγ also resulted in distinct transcriptional and functional outcomes in GM-MØ and M-MØ. Moreover, and in the absence of exogenous activating ligands, PPARγ knockdown significantly altered the GM-MØ transcriptome, causing a global upregulation of proinflammatory genes and significantly modulating the expression of genes involved in cell proliferation and migration. Similar effects were observed in ex vivo isolated human A-MØ, where PPARγ silencing led to enhanced expression of genes coding for growth factors and chemokines and downregulation of cell surface pathogen receptors. Therefore, PPARγ shapes the transcriptome of GM-CSF-dependent human macrophages ( in vitro derived GM-MØ and ex vivo isolated A-MØ) in the absence of exogenous activating ligands, and its expression is primarily regulated by activin A

  9. Cloning of gp-340, a putative opsonin receptor for lung surfactant protein D

    DEFF Research Database (Denmark)

    Holmskov, U; Mollenhauer, J; Madsen, J

    1999-01-01

    in a soluble form and in association with the membranes of alveolar macrophages. The primary structure of gp-340 has been established by molecular cloning, which yielded a 7,686-bp cDNA sequence encoding a polypeptide chain of 2, 413 amino acids. The domain organization features 13 scavenger receptor cysteine...... in a way that suggested capping, whereas other macrophages showed strong intracellular staining within the phagosome/phagolysosome compartments. In some macrophages, SP-D and gp-340 were located in the same cellular compartment. Immunoreactive gp-340 was also found in epithelial cells of the small...

  10. AMP-Activated Protein Kinase Interacts with the Peroxisome Proliferator-Activated Receptor Delta to Induce Genes Affecting Fatty Acid Oxidation in Human Macrophages.

    Directory of Open Access Journals (Sweden)

    Marina Kemmerer

    Full Text Available AMP-activated protein kinase (AMPK maintains energy homeostasis by suppressing cellular ATP-consuming processes and activating catabolic, ATP-producing pathways such as fatty acid oxidation (FAO. The transcription factor peroxisome proliferator-activated receptor δ (PPARδ also affects fatty acid metabolism, stimulating the expression of genes involved in FAO. To question the interplay of AMPK and PPARδ in human macrophages we transduced primary human macrophages with lentiviral particles encoding for the constitutively active AMPKα1 catalytic subunit, followed by microarray expression analysis after treatment with the PPARδ agonist GW501516. Microarray analysis showed that co-activation of AMPK and PPARδ increased expression of FAO genes, which were validated by quantitative PCR. Induction of these FAO-associated genes was also observed upon infecting macrophages with an adenovirus coding for AMPKγ1 regulatory subunit carrying an activating R70Q mutation. The pharmacological AMPK activator A-769662 increased expression of several FAO genes in a PPARδ- and AMPK-dependent manner. Although GW501516 significantly increased FAO and reduced the triglyceride amount in very low density lipoproteins (VLDL-loaded foam cells, AMPK activation failed to potentiate this effect, suggesting that increased expression of fatty acid catabolic genes alone may be not sufficient to prevent macrophage lipid overload.

  11. Pharmacological Inhibition of Macrophage Toll-like Receptor 4/Nuclear Factor-kappa B Alleviates Rhabdomyolysis-induced Acute Kidney Injury.

    Science.gov (United States)

    Huang, Rong-Shuang; Zhou, Jiao-Jiao; Feng, Yu-Ying; Shi, Min; Guo, Fan; Gou, Shen-Ju; Salerno, Stephen; Ma, Liang; Fu, Ping

    2017-09-20

    Acute kidney injury (AKI) is the most common and life-threatening systemic complication of rhabdomyolysis. Inflammation plays an important role in the development of rhabdomyolysis-induced AKI. This study aimed to investigate the kidney model of AKI caused by rhabdomyolysis to verify the role of macrophage Toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-κB) signaling pathway. C57BL/6 mice were injected with a 50% glycerin solution at bilateral back limbs to induce rhabdomyolysis, and CLI-095 or pyrrolidine dithiocarbamate (PDTC) was intraperitoneally injected at 0.5 h before molding. Serum creatinine levels, creatine kinase, the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6, and hematoxylin and eosin stainings of kidney tissues were tested. The infiltration of macrophage, mRNA levels, and protein expression of TLR4 and NF-κB were investigated by immunofluorescence double-staining techniques, reverse transcriptase-quantitative polymerase chain reaction, and Western blotting, respectively. In vitro, macrophage RAW264.7 was stimulated by ferrous myoglobin; the cytokines, TLR4 and NF-κB expressions were also detected. In an in vivo study, using CLI-095 or PDTC to block TLR4/NF-κB, functional and histologic results showed that the inhibition of TLR4 or NF-κB alleviated glycerol-induced renal damages (P rhabdomyolysis-induced AKI by the regulation of proinflammatory cytokine production and macrophage infiltration.

  12. The in vitro GcMAF effects on endocannabinoid system transcriptionomics, receptor formation, and cell activity of autism-derived macrophages

    Science.gov (United States)

    2014-01-01

    Background Immune system dysregulation is well-recognized in autism and thought to be part of the etiology of this disorder. The endocannabinoid system is a key regulator of the immune system via the cannabinoid receptor type 2 (CB2R) which is highly expressed on macrophages and microglial cells. We have previously published significant differences in peripheral blood mononuclear cell CB2R gene expression in the autism population. The use of the Gc protein-derived Macrophage Activating Factor (GcMAF), an endogenous glycosylated vitamin D binding protein responsible for macrophage cell activation has demonstrated positive effects in the treatment of autistic children. In this current study, we investigated the in vitro effects of GcMAF treatment on the endocannabinoid system gene expression, as well as cellular activation in blood monocyte-derived macrophages (BMDMs) from autistic patients compared to age-matched healthy developing controls. Methods To achieve these goals, we used biomolecular, biochemical and immunocytochemical methods. Results GcMAF treatment was able to normalize the observed differences in dysregulated gene expression of the endocannabinoid system of the autism group. GcMAF also down-regulated the over-activation of BMDMs from autistic children. Conclusions This study presents the first observations of GcMAF effects on the transcriptionomics of the endocannabinoid system and expression of CB2R protein. These data point to a potential nexus between endocannabinoids, vitamin D and its transporter proteins, and the immune dysregulations observed with autism. PMID:24739187

  13. The Nuclear Orphan Receptor NR4A1 is Involved in the Apoptotic Pathway Induced by LPS and Simvastatin in RAW 264.7 Macrophages.

    Science.gov (United States)

    Kim, Yong Chan; Song, Seok Bean; Lee, Sang Kyu; Park, Sang Min; Kim, Young Sang

    2014-04-01

    Macrophage death plays a role in several physiological and inflammatory pathologies such as sepsis and arthritis. In our previous work, we showed that simvastatin triggers cell death in LPS-activated RAW 264.7 mouse macrophage cells through both caspase-dependent and independent apoptotic pathways. Here, we show that the nuclear orphan receptor NR4A1 is involved in a caspase-independent apoptotic process induced by LPS and simvastatin. Simvastatin-induced NR4A1 expression in RAW 264.7 macrophages and ectopic expression of a dominant-negative mutant form of NR4A1 effectively suppressed both DNA fragmentation and the disruption of mitochondrial membrane potential (MMP) during LPS- and simvastatin-induced apoptosis. Furthermore, apoptosis was accompanied by Bcl-2-associated X protein (Bax) translocation to the mitochondria. Our findings suggest that NR4A1 expression and mitochondrial translocation of Bax are related to simvastatin-induced apoptosis in LPS-activated RAW 264.7 macrophages.

  14. The in vitro GcMAF effects on endocannabinoid system transcriptionomics, receptor formation, and cell activity of autism-derived macrophages.

    Science.gov (United States)

    Siniscalco, Dario; Bradstreet, James Jeffrey; Cirillo, Alessandra; Antonucci, Nicola

    2014-04-17

    Immune system dysregulation is well-recognized in autism and thought to be part of the etiology of this disorder. The endocannabinoid system is a key regulator of the immune system via the cannabinoid receptor type 2 (CB2R) which is highly expressed on macrophages and microglial cells. We have previously published significant differences in peripheral blood mononuclear cell CB2R gene expression in the autism population. The use of the Gc protein-derived Macrophage Activating Factor (GcMAF), an endogenous glycosylated vitamin D binding protein responsible for macrophage cell activation has demonstrated positive effects in the treatment of autistic children. In this current study, we investigated the in vitro effects of GcMAF treatment on the endocannabinoid system gene expression, as well as cellular activation in blood monocyte-derived macrophages (BMDMs) from autistic patients compared to age-matched healthy developing controls. To achieve these goals, we used biomolecular, biochemical and immunocytochemical methods. GcMAF treatment was able to normalize the observed differences in dysregulated gene expression of the endocannabinoid system of the autism group. GcMAF also down-regulated the over-activation of BMDMs from autistic children. This study presents the first observations of GcMAF effects on the transcriptionomics of the endocannabinoid system and expression of CB2R protein. These data point to a potential nexus between endocannabinoids, vitamin D and its transporter proteins, and the immune dysregulations observed with autism.

  15. Fluid-Phase Pinocytosis of Native Low Density Lipoprotein Promotes Murine M-CSF Differentiated Macrophage Foam Cell Formation

    Science.gov (United States)

    Xu, Qing; Bohnacker, Thomas; Wymann, Matthias P.; Kruth, Howard S.

    2013-01-01

    During atherosclerosis, low-density lipoprotein (LDL)-derived cholesterol accumulates in macrophages to form foam cells. Macrophage uptake of LDL promotes foam cell formation but the mechanism mediating this process is not clear. The present study investigates the mechanism of LDL uptake for macrophage colony-stimulating factor (M-CSF)-differentiated murine bone marrow-derived macrophages. LDL receptor-null (LDLR−/−) macrophages incubated with LDL showed non-saturable accumulation of cholesterol that did not down-regulate for the 24 h examined. Incubation of LDLR−/− macrophages with increasing concentrations of 125I-LDL showed non-saturable macrophage LDL uptake. A 20-fold excess of unlabeled LDL had no effect on 125I-LDL uptake by wild-type macrophages and genetic deletion of the macrophage scavenger receptors CD36 and SRA did not affect 125I-LDL uptake, showing that LDL uptake occurred by fluid-phase pinocytosis independently of receptors. Cholesterol accumulation was inhibited approximately 50% in wild-type and LDLR−/− mice treated with LY294002 or wortmannin, inhibitors of all classes of phosphoinositide 3-kinases (PI3K). Time-lapse, phase-contrast microscopy showed that macropinocytosis, an important fluid-phase uptake pathway in macrophages, was blocked almost completely by PI3K inhibition with wortmannin. Pharmacological inhibition of the class I PI3K isoforms alpha, beta, gamma or delta did not affect macrophage LDL-derived cholesterol accumulation or macropinocytosis. Furthermore, macrophages from mice expressing kinase-dead class I PI3K beta, gamma or delta isoforms showed no decrease in cholesterol accumulation or macropinocytosis when compared with wild-type macrophages. Thus, non-class I PI3K isoforms mediated macropinocytosis in these macrophages. Further characterization of the components necessary for LDL uptake, cholesterol accumulation, and macropinocytosis identified dynamin, microtubules, actin, and vacuolar type H(+)-ATPase as

  16. Fibroblast growth factor receptor 1 activation in mammary tumor cells promotes macrophage recruitment in a CX3CL1-dependent manner.

    Directory of Open Access Journals (Sweden)

    Johanna R Reed

    Full Text Available Tumor formation is an extensive process requiring complex interactions that involve both tumor cell-intrinsic pathways and soluble mediators within the microenvironment. Tumor cells exploit the intrinsic functions of many soluble molecules, including chemokines and their receptors, to regulate pro-tumorigenic phenotypes that are required for growth and progression of the primary tumor. Previous studies have shown that activation of inducible FGFR1 (iFGFR1 in mammary epithelial cells resulted in increased proliferation, migration, and invasion in vitro and tumor formation in vivo. These studies also demonstrated that iFGFR1 activation stimulated recruitment of macrophages to the epithelium where macrophages contributed to iFGFR1-mediated epithelial cell proliferation and angiogenesis. The studies presented here further utilize this model to identify the mechanisms that regulate FGFR1-induced macrophage recruitment. Results from this study elucidate a novel role for the inflammatory chemokine CX3CL1 in FGFR1-induced macrophage migration. Specifically, we illustrate that activation of both the inducible FGFR1 construct in mouse mammary epithelial cells and endogenous FGFR in the triple negative breast cancer cell line, HS578T, leads to expression of the chemokine CX3CL1. Furthermore, we demonstrate that FGFR-induced CX3CL1 is sufficient to recruit CX3CR1-expressing macrophages in vitro. Finally, blocking CX3CR1 in vivo leads to decreased iFGFR1-induced macrophage recruitment, which correlates with decreased angiogenesis. While CX3CL1 is a known target of FGF signaling in the wound healing environment, these studies demonstrate that FGFR activation also leads to induction of CX3CL1 in a tumor setting. Furthermore, these results define a novel role for CX3CL1 in promoting macrophage recruitment during mammary tumor formation, suggesting that the CX3CL1/CX3CR1 axis may represent a potential therapeutic approach for targeting breast cancers associated

  17. Impact of Silver and Iron Nanoparticle Exposure on Cholesterol Uptake by Macrophages

    Directory of Open Access Journals (Sweden)

    Jonathan H. Shannahan

    2015-01-01

    Full Text Available Macrophages are central to the development of atherosclerosis by absorbing lipids, promoting inflammation, and increasing plaque deposition. Nanoparticles (NPs are becoming increasingly common in biomedical applications thereby increasing exposure to the immune and vascular systems. This project investigated the influence of NPs on macrophage function and specifically cholesterol uptake. Macrophages were exposed to 20 nm silver NPs (AgNPs, 110 nm AgNPs, or 20 nm Fe3O4 NPs for 2 h and NP uptake, cytotoxicity, and subsequent uptake of fluorescently labeled cholesterol were assessed. Macrophage uptake of NPs did not induce cytotoxicity at concentrations utilized (25 μg/mL; however, macrophage exposure to 20 nm AgNPs reduced subsequent uptake of cholesterol. Further, we assessed the impact of a cholesterol-rich environment on macrophage function following NP exposure. In these sets of experiments, macrophages internalized NPs, exhibited no cytotoxicity, and altered cholesterol uptake. Alterations in the expression of scavenger receptor-B1 following NP exposure, which likely influences cholesterol uptake, were observed. Overall, NPs alter cholesterol uptake, which may have implications in the progression of vascular or immune mediated diseases. Therefore, for the safe development of NPs for biomedical applications, it is necessary to understand their impact on cellular function and biological interactions in underlying disease environments.

  18. Novel keto-phospholipids are generated by monocytes and macrophages, detected in cystic fibrosis, and activate peroxisome proliferator-activated receptor-γ.

    Science.gov (United States)

    Hammond, Victoria J; Morgan, Alwena H; Lauder, Sarah; Thomas, Christopher P; Brown, Sarah; Freeman, Bruce A; Lloyd, Clare M; Davies, Jane; Bush, Andrew; Levonen, Anna-Liisa; Kansanen, Emilia; Villacorta, Luis; Chen, Y Eugene; Porter, Ned; Garcia-Diaz, Yoel M; Schopfer, Francisco J; O'Donnell, Valerie B

    2012-12-07

    12/15-Lipoxygenases (LOXs) in monocytes and macrophages generate novel phospholipid-esterified eicosanoids. Here, we report the generation of two additional families of related lipids comprising 15-ketoeicosatetraenoic acid (KETE) attached to four phosphatidylethanolamines (PEs). The lipids are generated basally by 15-LOX in IL-4-stimulated monocytes, are elevated on calcium mobilization, and are detected at increased levels in bronchoalveolar lavage fluid from cystic fibrosis patients (3.6 ng/ml of lavage). Murine peritoneal macrophages generate 12-KETE-PEs, which are absent in 12/15-LOX-deficient mice. Inhibition of 15-prostaglandin dehydrogenase prevents their formation from exogenous 15-hydroxyeicosatetraenoic acid-PE in human monocytes. Both human and murine cells also generated analogous hydroperoxyeicosatetraenoic acid-PEs. The electrophilic reactivity of KETE-PEs is shown by their Michael addition to glutathione and cysteine. Lastly, both 15-hydroxyeicosatetraenoic acid-PE and 15-KETE-PE activated peroxisome proliferator-activated receptor-γ reporter activity in macrophages in a dose-dependent manner. In summary, we demonstrate novel peroxisome proliferator-activated receptor-γ-activating oxidized phospholipids generated enzymatically by LOX and 15-prostaglandin dehydrogenase in primary monocytic cells and in a human Th2-related lung disease. The lipids are a new family of bioactive mediators from the 12/15-LOX pathway that may contribute to its known anti-inflammatory actions in vivo.

  19. Differential effect on TCR:CD3 stimulation of a 90-kD glycoprotein (gp90/Mac-2BP), a member of the scavenger receptor cysteine-rich domain protein family

    DEFF Research Database (Denmark)

    Silvestri, B; Calderazzo, F; Coppola, V

    1998-01-01

    We studied the effects of a 90-kD glycoprotein (gp90/Mac-2BP) belonging to the scavenger receptor family, present in normal serum and at increased levels in inflammatory disease and cancer patients, on some T cell function parameters. Whereas the lymphocyte proliferative response to non-specific ......We studied the effects of a 90-kD glycoprotein (gp90/Mac-2BP) belonging to the scavenger receptor family, present in normal serum and at increased levels in inflammatory disease and cancer patients, on some T cell function parameters. Whereas the lymphocyte proliferative response to non......-specific mitogens such as phytohaemagglutinin (PHA) and concanavalin A (Con A), but not pokeweed mitogen (PWM), was strongly reduced, probably due to the lectin-binding properties of gp90/Mac-2BP, the response to T cell receptor (TCR) agonists such as superantigens and allogeneic cells was potentiated. When...... lymphocytes were stimulated with different anti-TCR:CD3 MoAbs, both in soluble and solid-phase form, gp90/Mac-2BP was able to down-regulate the proliferative response to anti-CD3 MoAb, whereas the response to anti-TCR alphabeta MoAb was enhanced. A similar differential effect was observed when a MoAb against...

  20. Phagocytosis of cholesteryl ester is amplified in diabetic mouse macrophages and is largely mediated by CD36 and SR-A.

    Directory of Open Access Journals (Sweden)

    Christopher B Guest

    Full Text Available Type 2 diabetes (T2D is associated with accelerated atherosclerosis, which accounts for approximately 75% of all diabetes-related deaths. Here we investigate the link between diabetes and macrophage cholesteryl ester accumulation. When diabetic (db/db mice are given cholesteryl ester intraperitoneally (IP, peritoneal macrophages (PerMPhis recovered from these animals showed a 58% increase in intracellular cholesteryl ester accumulation over PerMPhis from heterozygote control (db/+ mice. Notably, PerMPhi fluid-phase endocytosis and large particle phagocytosis was equivalent in db/+and db/db mice. However, IP administration of CD36 and SR-A blocking antibodies led to 37% and 25% reductions in cholesteryl ester accumulation in PerMPhi. Finally, in order to determine if these scavenger receptors (SRs were part of the mechanism responsible for the increased accumulation of cholesteryl esters observed in the diabetic mouse macrophages, receptor expression was quantified by flow cytometry. Importantly, db/db PerMPhis showed a 43% increase in CD36 expression and an 80% increase in SR-A expression. Taken together, these data indicate that direct cholesteryl ester accumulation in mouse macrophages is mediated by CD36 and SR-A, and the magnitude of accumulation is increased in db/db macrophages due to increased scavenger receptor expression.

  1. Differential cell reaction upon Toll-like receptor 4 and 9 activation in human alveolar and lung interstitial macrophages

    Directory of Open Access Journals (Sweden)

    Meyerhans Andreas

    2010-09-01

    Full Text Available Abstract Background Investigations on pulmonary macrophages (MΦ mostly focus on alveolar MΦ (AM as a well-defined cell population. Characteristics of MΦ in the interstitium, referred to as lung interstitial MΦ (IM, are rather ill-defined. In this study we therefore aimed to elucidate differences between AM and IM obtained from human lung tissue. Methods Human AM and IM were isolated from human non-tumor lung tissue from patients undergoing lung resection. Cell morphology was visualized using either light, electron or confocal microscopy. Phagocytic activity was analyzed by flow cytometry as well as confocal microscopy. Surface marker expression was measured by flow cytometry. Toll-like receptor (TLR expression patterns as well as cytokine expression upon TLR4 or TLR9 stimulation were assessed by real time RT-PCR and cytokine protein production was measured using a fluorescent bead-based immunoassay. Results IM were found to be smaller and morphologically more heterogeneous than AM, whereas phagocytic activity was similar in both cell types. HLA-DR expression was markedly higher in IM compared to AM. Although analysis of TLR expression profiles revealed no differences between the two cell populations, AM and IM clearly varied in cell reaction upon activation. Both MΦ populations were markedly activated by LPS as well as DNA isolated from attenuated mycobacterial strains (M. bovis H37Ra and BCG. Whereas AM expressed higher amounts of inflammatory cytokines upon activation, IM were more efficient in producing immunoregulatory cytokines, such as IL10, IL1ra, and IL6. Conclusion AM appear to be more effective as a non-specific first line of defence against inhaled pathogens, whereas IM show a more pronounced regulatory function. These dissimilarities should be taken into consideration in future studies on the role of human lung MΦ in the inflammatory response.

  2. Ablation of the Leptin receptor in Myeloid Cells Impairs Pulmonary Clearance of Streptococcus Pneumoniae and Alveolar Macrophage Bactericidal Function.

    Science.gov (United States)

    Mancuso, Peter; Curtis, Jeffrey L; Freeman, Christine M; Peters-Golden, Marc; Weinberg, Jason B; Myers, Martin G

    2018-03-22

    Leptin is a pleiotropic hormone produced by white adipose tissue that regulates appetite and many physiologic functions including the immune response to infection. Genetic leptin deficiency in humans and mice impairs host defenses against respiratory tract infections. Since leptin deficiency is associated with obesity and other metabolic abnormalities, we generated mice that lack the leptin receptor (LepRb) in cells of the myeloid linage (LysM-LepRb-KO) to evaluate its impact in lean metabolically normal mice in a murine model of pneumococcal pneumonia. We observed higher lung and spleen bacterial burdens in LysM-LepRb-KO mice following an intratracheal challenge with S. pneumoniae. Although numbers of leukocytes recovered from bronchoalveolar lavage fluid did not differ between groups, we did observe higher levels of pulmonary IL-13 and TNFα in LysM-LepRb-KO mice 48 h post-infection. Phagocytosis and killing of ingested S. pneumoniae were also impaired in alveolar macrophages (AM)s from LysM-LepRb-KO mice in vitro, and was associated with reduced LTB4 and enhanced PGE2 synthesis in vitro. Pretreatment of AMs with LTB4 and the cyclooxygenase inhibitor, indomethacin, restored phagocytosis but not bacterial killing in vitro. These results, confirm our previous observations in leptin-deficient (ob/ob) and fasted mice, and demonstrate that decreased leptin action, as opposed to metabolic irregularities associated with obesity or starvation, are responsible for the defective host defense against pneumococcal pneumonia. They also provide novel targets for therapeutic intervention in humans with bacterial pneumonia.

  3. Human decidual macrophages and NK cells differentially express Toll-like receptors and display distinct cytokine profiles upon TLR stimulation.

    Directory of Open Access Journals (Sweden)

    Marion eDuriez

    2014-07-01

    Full Text Available Maternofetal pathogen transmission is partially controlled at the level of the maternal uterine mucosa at the fetal implantation site (the decidua basalis, where maternal and fetal cells are in close contact. Toll-like receptors (TLRs may play an important role in initiating rapid immune responses against pathogens in the decidua basalis, however the tolerant microenvironment should be preserved in order to allow fetal development. Here we investigated the expression and functionality of TLRs expressed by decidual macrophages (dMs and NK cells (dNKs, the major decidual immune cell populations.We report for the first time that both human dMs and dNK cells express mRNAs encoding TLRs 1-9, albeit with a higher expression level in dMs. TLR2, TLR3 and TLR4 protein expression checked by flow cytometry was positive for both dMs and dNK cells. In vitro treatment of primary dMs and dNK cells with specific TLR2, TLR3, TLR4, TLR7/8 and TLR9 agonists enhanced their secretion of pro- and anti-inflammatory cytokines, as well as cytokines and chemokines involved in immune cell crosstalk. Only dNK cells released IFN-γ, whereas only dMs released IL-1β, IL-10 and IL-12. TLR9 activation of dMs resulted in a distinct pattern of cytokine expression compared to the other TLRs. The cytokine profiles expressed by dMs and dNK cells upon TLR activation are compatible with maintenance of the fetotolerant immune environment during initiation of immune responses to pathogens at the maternofetal interface.

  4. Macrophage colony-stimulating factor receptor marks and regulates a fetal myeloid-primed B-cell progenitor in mice.

    Science.gov (United States)

    Zriwil, Alya; Böiers, Charlotta; Wittmann, Lilian; Green, Joanna C A; Woll, Petter S; Jacobsen, Sten Eirik W; Sitnicka, Ewa

    2016-07-14

    Although it is well established that unique B-cell lineages develop through distinct regulatory mechanisms during embryonic development, much less is understood about the differences between embryonic and adult B-cell progenitor cells, likely to underpin the genetics and biology of infant and childhood PreB acute lymphoblastic leukemia (PreB-ALL), initiated by distinct leukemia-initiating translocations during embryonic development. Herein, we establish that a distinct subset of the earliest CD19(+) B-cell progenitors emerging in the E13.5 mouse fetal liver express the colony-stimulating factor-1 receptor (CSF1R), previously thought to be expressed, and play a lineage-restricted role in development of myeloid lineages, and macrophages in particular. These early embryonic CSF1R(+)CD19(+) ProB cells also express multiple other myeloid genes and, in line with this, possess residual myeloid as well as B-cell, but not T-cell lineage potential. Notably, these CSF1R(+) myeloid-primed ProB cells are uniquely present in a narrow window of embryonic fetal liver hematopoiesis and do not persist in adult bone marrow. Moreover, analysis of CSF1R-deficient mice establishes a distinct role of CSF1R in fetal B-lymphopoiesis. CSF1R(+) myeloid-primed embryonic ProB cells are relevant for infant and childhood PreB-ALLs, which frequently have a bi-phenotypic B-myeloid phenotype, and in which CSF1R-rearrangements have recently been reported. © 2016 by The American Society of Hematology.

  5. Dysregulation of Macrophage Activation Profiles by Engineered Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kodali, Vamsi; Littke, Matthew H.; Tilton, Susan C.; Teeguarden, Justin G.; Shi, Liang; Frevert, Charles W.; Wang, Wei; Pounds, Joel G.; Thrall, Brian D.

    2013-08-27

    Although the potential human health impacts from exposure to engineered nanoparticles (ENPs) are uncertain, past epidemiological studies have established correlations between exposure to ambient air pollution particulates and the incidence of pneumonia and lung infections. Using amorphous silica and superparamagnetic iron oxide (SPIO) as model high production volume ENPs, we examined how macrophage activation by bacterial lipopolysaccharide (LPS) or the lung pathogen Streptococcus pneumoniae is altered by ENP pretreatment. Neither silica nor SPIO treatment elicited direct cytotoxic or pro-inflammatory effects in bone marrow-derived macrophages. However, pretreatment of macrophages with SPIO caused extensive reprogramming of nearly 500 genes regulated in response to LPS challenge, hallmarked by exaggerated activation of oxidative stress response pathways and suppressed activation of both pro- and anti-inflammatory pathways. Silica pretreatment altered regulation of only 67 genes, but there was strong correlation with gene sets affected by SPIO. Macrophages exposed to SPIO displayed a phenotype suggesting an impaired ability to transition from an M1 to M2-like activation state, characterized by suppressed IL-10 induction, enhanced TNFα production, and diminished phagocytic activity toward S. pneumoniae. Studies in macrophages deficient in scavenger receptor A (SR-A) showed SR-A participates in cell uptake of both the ENPs and S. pneumonia and co-regulates the anti-inflammatory IL-10 pathway. Thus, mechanisms for dysregulation of innate immunity exist by virtue that common receptor recognition pathways are used by some ENPs and pathogenic bacteria, although the extent of transcriptional reprogramming of macrophage function depends on the physicochemical properties of the ENP after internalization. Our results also illustrate that biological effects of ENPs may be indirectly manifested only after challenging normal cell function. Finally, nanotoxicology screening

  6. Adenosine A1, A2a, A2B, and A3 receptors in hematopoiesis. 2. Expression of receptor mRNA in resting and lipopolysaccharide-activated mouse RAW 264.7 macrophages

    Czech Academy of Sciences Publication Activity Database

    Štreitová, Denisa; Hofer, Michal; Holá, Jiřina; Vacek, Antonín; Pospíšil, Milan

    2010-01-01

    Roč. 59, č. 1 (2010), s. 139-144 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA305/06/0015; GA ČR(CZ) GA305/08/0158 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : adenosine receptors * macrophage * mRNA expression Subject RIV: BO - Biophysics Impact factor: 1.646, year: 2010

  7. Induction of experimental autoimmune encephalomyelitis in C57BL/6 mice deficient in either the chemokine macrophage inflammatory protein-1alpha or its CCR5 receptor

    DEFF Research Database (Denmark)

    Tran, E H; Kuziel, W A; Owens, T

    2000-01-01

    -type mice in Th1 cytokine gene expression, the kinetics and severity of disease, and infiltration of the central nervous system by lymphocytes, macrophages and granulocytes. RNase protection assays showed comparable accumulation of mRNA for the chemokines interferon-inducible protein-10, RANTES, macrophage...... and its CCR5 receptor in the induction of EAE by immunizing C57BL / 6 mice deficient in either MIP-1alpha or CCR5 with myelin oligodendrocyte glycoprotein (MOG). We found that MIP-1alpha-deficient mice were fully susceptible to MOG-induced EAE. These knockout animals were indistinguishable from wild...... chemoattractant protein-1, MIP-1beta, MIP-2, lymphotactin and T cell activation gene-3 during the course of the disease. CCR5-deficient mice were also susceptible to disease induction by MOG. The dispensability of MIP-1alpha and CCR5 for MOG-induced EAE in C57BL / 6 mice supports the idea that differential...

  8. Effects of P-MAPA immunomodulator on Toll-like receptor 2, ROS, nitric oxide, MAPKp38 and IKK in PBMC and macrophages from dogs with visceral leishmaniasis.

    Science.gov (United States)

    Melo, L M; Perosso, J; Almeida, B F M; Silva, K L O; Somenzari, M A; de Lima, V M F

    2014-02-01

    Leishmania (L.) chagasi is the etiologic agent of visceral leishmaniasis (VL) that can be transmitted to humans and dogs. VL in Brazil represents a serious public health problem; therefore, it is important to study new alternatives to treat infected dogs. In dogs, the therapeutic arsenal against canine VL is limited. The immunomodulator protein aggregate magnesium-ammonium phospholinoleate-palmitoleate anhydride (P-MAPA) improves immunocompetence when the immune system is impaired, but its dependence on Toll-like receptors (TLRs) and the mechanisms involved in immune response remain unclear. The in vitro action of P-MAPA on the expression of TLR2 and TLR4, reactive oxygen species (ROS), nitric oxide (NO) and p38 mitogen-activated protein kinase (p38 MAPK) and IKK phosphorylation was studied in mononuclear cells from peripheral blood and macrophages from healthy and Leishmania-infected dogs. The PBMC or macrophages were isolated and cultured with different concentrations of P-MAPA (20,100 and 200 μg/ml) in a humid environment at 37°C with 5% CO(2). Observation revealed that Leishmania-infected dogs showed a decrease in TLR2 in macrophages compared with healthy dogs and in induction with P-MAPA. ROS were increased in PBMCs from Leishmania spp.-infected dogs compared with healthy dogs and P-MAPA improved ROS production. NO production was increased in culture supernatant from macrophages stimulated by P-MAPA in both healthy and Leishmania spp. infected dogs. Treatment of macrophages from healthy dogs with immunomodulatory P-MAPA induced p38 MAPK and IKK phosphorylation, suggesting signal transduction by this pathway. These findings suggest that P-MAPA has potential as a therapeutic drug in the treatment of canine visceral leishmaniasis. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Cell Elasticity Determines Macrophage Function

    Science.gov (United States)

    Patel, Naimish R.; Bole, Medhavi; Chen, Cheng; Hardin, Charles C.; Kho, Alvin T.; Mih, Justin; Deng, Linhong; Butler, James; Tschumperlin, Daniel; Fredberg, Jeffrey J.; Krishnan, Ramaswamy; Koziel, Henry

    2012-01-01

    Macrophages serve to maintain organ homeostasis in response to challenges from injury, inflammation, malignancy, particulate exposure, or infection. Until now, receptor ligation has been understood as being the central mechanism that regulates macrophage function. Using macrophages of different origins and species, we report that macrophage elasticity is a major determinant of innate macrophage function. Macrophage elasticity is modulated not only by classical biologic activators such as LPS and IFN-γ, but to an equal extent by substrate rigidity and substrate stretch. Macrophage elasticity is dependent upon actin polymerization and small rhoGTPase activation, but functional effects of elasticity are not predicted by examination of gene expression profiles alone. Taken together, these data demonstrate an unanticipated role for cell elasticity as a common pathway by which mechanical and biologic factors determine macrophage function. PMID:23028423

  10. Cell elasticity determines macrophage function.

    Directory of Open Access Journals (Sweden)

    Naimish R Patel

    Full Text Available Macrophages serve to maintain organ homeostasis in response to challenges from injury, inflammation, malignancy, particulate exposure, or infection. Until now, receptor ligation has been understood as being the central mechanism that regulates macrophage function. Using macrophages of different origins and species, we report that macrophage elasticity is a major determinant of innate macrophage function. Macrophage elasticity is modulated not only by classical biologic activators such as LPS and IFN-γ, but to an equal extent by substrate rigidity and substrate stretch. Macrophage elasticity is dependent upon actin polymerization and small rhoGTPase activation, but functional effects of elasticity are not predicted by examination of gene expression profiles alone. Taken together, these data demonstrate an unanticipated role for cell elasticity as a common pathway by which mechanical and biologic factors determine macrophage function.

  11. DMPD: Toll-like receptor 3: a link between toll-like receptor, interferon and viruses. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15031527 Toll-like receptor 3: a link between toll-like receptor, interferon and virus... (.csml) Show Toll-like receptor 3: a link between toll-like receptor, interferon and viruses. PubmedID 1503...1527 Title Toll-like receptor 3: a link between toll-like receptor, interferon and virus

  12. The promotion of mandibular defect healing by the targeting of S1P receptors and the recruitment of alternatively activated macrophages.

    Science.gov (United States)

    Das, Anusuya; Segar, Claire E; Hughley, Brian B; Bowers, Daniel T; Botchwey, Edward A

    2013-12-01

    Endogenous signals originating at the site of injury are involved in the paracrine recruitment, proliferation, and differentiation of circulating progenitor and diverse inflammatory cell types. Here, we investigate a strategy to exploit endogenous cell recruitment mechanisms to regenerate injured bone by local targeting and activation of sphingosine-1-phosphate (S1P) receptors. A mandibular defect model was selected for evaluating regeneration of bone following trauma or congenital disease. The particular challenges of mandibular reconstruction are inherent in the complex anatomy and function of the bone given that the area is highly vascularized and in close proximity to muscle. Nanofibers composed of poly(DL-lactide-co-glycolide) (PLAGA) and polycaprolactone (PCL) were used to delivery FTY720, a targeted agonist of S1P receptors 1 and 3. In vitro culture of bone progenitor cells on drug-loaded constructs significantly enhanced SDF1α mediated chemotaxis of bone marrow mononuclear cells. In vivo results show that local delivery of FTY720 from composite nanofibers enhanced blood vessel ingrowth and increased recruitment of M2 alternatively activated macrophages, leading to significant osseous tissue ingrowth into critical sized defects after 12 weeks of treatment. These results demonstrate that local activation of S1P receptors is a regenerative cue resulting in recruitment of wound healing or anti-inflammatory macrophages and bone healing. Use of such small molecule therapy can provide an alternative to biological factors for the clinical treatment of critical size craniofacial defects. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Impaired clearance of influenza A virus in obese, leptin receptor deficient mice is independent of leptin signaling in the lung epithelium and macrophages.

    Directory of Open Access Journals (Sweden)

    Kathryn A Radigan

    Full Text Available During the recent H1N1 outbreak, obese patients had worsened lung injury and increased mortality. We used a murine model of influenza A pneumonia to test the hypothesis that leptin receptor deficiency might explain the enhanced mortality in obese patients.We infected wild-type, obese mice globally deficient in the leptin receptor (db/db and non-obese mice with tissue specific deletion of the leptin receptor in the lung epithelium (SPC-Cre/LepR fl/fl or macrophages and alveolar type II cells (LysM-Cre/Lepr fl/fl with influenza A virus (A/WSN/33 [H1N1] (500 and 1500 pfu/mouse and measured mortality, viral clearance and several markers of lung injury severity.The clearance of influenza A virus from the lungs of mice was impaired in obese mice globally deficient in the leptin receptor (db/db compared to normal weight wild-type mice. In contrast, non-obese, SP-C-Cre+/+/LepR fl/fl and LysM-Cre+/+/LepR fl/fl had improved viral clearance after influenza A infection. In obese mice, mortality was increased compared with wild-type mice, while the SP-C-Cre+/+/LepR fl/fl and LysM-Cre+/+/LepR fl/fl mice exhibited improved survival.Global loss of the leptin receptor results in reduced viral clearance and worse outcomes following influenza A infection. These findings are not the result of the loss of leptin signaling in lung epithelial cells or macrophages. Our results suggest that factors associated with obesity or with leptin signaling in non-myeloid populations such as natural killer and T cells may be associated with worsened outcomes following influenza A infection.

  14. Macrophage sub-populations and the lipoxin A4 receptor implicate active inflammation during equine tendon repair.

    Directory of Open Access Journals (Sweden)

    Stephanie Georgina Dakin

    Full Text Available Macrophages (Mφ orchestrate inflammatory and reparatory processes in injured connective tissues but their role during different phases of tendon healing is not known. We investigated the contribution of different Mφ subsets in an equine model of naturally occurring tendon injury. Post mortem tissues were harvested from normal (uninjured, sub-acute (3-6 weeks post injury and chronically injured (>3 months post injury superficial digital flexor tendons. To determine if inflammation was present in injured tendons, Mφ sub-populations were quantified based on surface antigen expression of CD172a (pan Mφ, CD14(highCD206(low (pro-inflammatory M1Mφ, and CD206(high (anti-inflammatory M2Mφ to assess potential polarised phenotypes. In addition, the Lipoxin A(4 receptor (FPR2/ALX was used as marker for resolving inflammation. Normal tendons were negative for both Mφ and FPR2/ALX. In contrast, M1Mφ predominated in sub-acute injury, whereas a potential phenotype-switch to M2Mφ polarity was seen in chronic injury. Furthermore, FPR2/ALX expression by tenocytes was significantly upregulated in sub-acute but not chronic injury. Expression of the FPR2/ALX ligand Annexin A1 was also significantly increased in sub-acute and chronic injuries in contrast to low level expression in normal tendons. The combination of reduced FPR2/ALX expression and persistence of the M2Mφ phenotype in chronic injury suggests a potential mechanism for incomplete resolution of inflammation after tendon injury. To investigate the effect of pro-inflammatory mediators on lipoxin A(4 (LXA(4 production and FPR2/ALX expression in vitro, normal tendon explants were stimulated with interleukin-1 beta and prostaglandin E(2. Stimulation with either mediator induced LXA(4 release and maximal upregulation of FPR2/ALX expression after 72 hours. Taken together, our data suggests that although tenocytes are capable of mounting a protective mechanism to counteract inflammatory stimuli, this

  15. In vitro and in vivo Analysis of the Binding of the C Terminus of the HDL Receptor Scavenger Receptor Class B type I (SR-BI) to the PDZ1 Domain of its Cytoplasmic Adaptor Protein PDZK1

    Energy Technology Data Exchange (ETDEWEB)

    O Kocher; G Birrane; K Tsukamoto; S Fenske; A Yesilaltay; R Pal; K Daniels; J Ladias; M Krieger

    2011-12-31

    The PDZ1 domain of the four PDZ domain-containing protein PDZK1 has been reported to bind the C terminus of the HDL receptor scavenger receptor class B, type I (SR-BI), and to control hepatic SR-BI expression and function. We generated wild-type (WT) and mutant murine PDZ1 domains, the mutants bearing single amino acid substitutions in their carboxylate binding loop (Lys(14)-Xaa(4)-Asn(19)-Tyr-Gly-Phe-Phe-Leu(24)), and measured their binding affinity for a 7-residue peptide corresponding to the C terminus of SR-BI ((503)VLQEAKL(509)). The Y20A and G21Y substitutions abrogated all binding activity. Surprisingly, binding affinities (K(d)) of the K14A and F22A mutants were 3.2 and 4.0 ?M, respectively, similar to 2.6 ?M measured for the WT PDZ1. To understand these findings, we determined the high resolution structure of WT PDZ1 bound to a 5-residue sequence from the C-terminal SR-BI ((505)QEAKL(509)) using x-ray crystallography. In addition, we incorporated the K14A and Y20A substitutions into full-length PDZK1 liver-specific transgenes and expressed them in WT and PDZK1 knock-out mice. In WT mice, the transgenes did not alter endogenous hepatic SR-BI protein expression (intracellular distribution or amount) or lipoprotein metabolism (total plasma cholesterol, lipoprotein size distribution). In PDZK1 knock-out mice, as expected, the K14A mutant behaved like wild-type PDZK1 and completely corrected their hepatic SR-BI and plasma lipoprotein abnormalities. Unexpectedly, the 10-20-fold overexpressed Y20A mutant also substantially, but not completely, corrected these abnormalities. The results suggest that there may be an additional site(s) within PDZK1 that bind(s) SR-BI and mediate(s) productive SR-BI-PDZK1 interaction previously attributed exclusively to the canonical binding of the C-terminal SR-BI to PDZ1.

  16. Botanical Scavenger Hunt

    Science.gov (United States)

    Walker-Livingston, Wendy

    2009-01-01

    Why not combine the use of technology with the excitement of a scavenger hunt that moves middle-level students out into the "wilds" of their school campus to classify plants? In the lesson plan described here, students embark on a botanical scavenger hunt and then document their findings using a digital camera. This project was designed to allow…

  17. The scavenger endothelial cell: a new player in homeostasis and immunity.

    Science.gov (United States)

    Sørensen, Karen Kristine; McCourt, Peter; Berg, Trond; Crossley, Clive; Le Couteur, David; Wake, Kenjiro; Smedsrød, Bård

    2012-12-15

    To maintain homeostasis, the animal body is equipped with a powerful system to remove circulating waste. This review presents evidence that the scavenger endothelial cell (SEC) is responsible for the clearance of blood-borne waste macromolecules in vertebrates. SECs express pattern-recognition endocytosis receptors (mannose and scavenger receptors), and in mammals, the endocytic Fc gamma-receptor IIb2. This cell type has an endocytic machinery capable of super-efficient uptake and degradation of physiological and foreign waste material, including all major classes of biological macromolecules. In terrestrial vertebrates, most SECs line the wall of the liver sinusoid. In phylogenetically older vertebrates, SECs reside instead in heart, kidney, or gills. SECs, thus, by virtue of their efficient nonphagocytic elimination of physiological and microbial substances, play a critical role in the innate immunity of vertebrates. In major invertebrate phyla, including insects, the same function is carried out by nephrocytes. The concept of a dual-cell principle of waste clearance is introduced to emphasize that professional phagocytes (macrophages in vertebrates; hemocytes in invertebrates) eliminate larger particles (>0.5 μm) by phagocytosis, whereas soluble macromolecules and smaller particles are eliminated efficiently and preferentially by clathrin-mediated endocytosis in nonphagocytic SECs in vertebrates or nephrocytes in invertebrates. Including these cells as important players in immunology and physiology provides an additional basis for understanding host defense and tissue homeostasis.

  18. Beta 2-adrenergic receptor agonists are novel regulators of macrophage activation in diabetic renal and cardiovascular complications.

    Science.gov (United States)

    Noh, Hyunjin; Yu, Mi Ra; Kim, Hyun Joo; Lee, Ji Hye; Park, Byoung-Won; Wu, I-Hsien; Matsumoto, Motonobu; King, George L

    2017-07-01

    Macrophage activation is increased in diabetes and correlated with the onset and progression of vascular complications. To identify drugs that could inhibit macrophage activation, we developed a cell-based assay and screened a 1,040 compound library for anti-inflammatory effects. Beta2-adrenergic receptor (β2AR) agonists were identified as the most potent inhibitors of phorbol myristate acetate-induced tumor necrosis factor-α production in rat bone marrow macrophages. In peripheral blood mononuclear cells isolated from streptozotocin-induced diabetic rats, β2AR agonists inhibited diabetes-induced tumor necrosis factor-α production, which was prevented by co-treatment with a selective β2AR blocker. To clarify the underlying mechanisms, THP-1 cells and bone marrow macrophages were exposed to high glucose. High glucose reduced β-arrestin2, a negative regulator of NF-κB activation, and its interaction with IκBα. This subsequently enhanced phosphorylation of IκBα and activation of NF-κB. The β2AR agonists enhanced β-arrestin2 and its interaction with IκBα, leading to downregulation of NF-κB. A siRNA specific for β-arrestin2 reversed β2AR agonist-mediated inhibition of NF-κB activation and inflammatory cytokine production. Treatment of Zucker diabetic fatty rats with a β2AR agonist for 12 weeks attenuated monocyte activation as well as pro-inflammatory and pro-fibrotic responses in the kidneys and heart. Thus, β2AR agonists might have protective effects against diabetic renal and cardiovascular complications. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  19. Cyclic GMP-dependent protein kinase II is necessary for macrophage M1 polarization and phagocytosis via toll-like receptor 2.

    Science.gov (United States)

    Liao, Wei-Ting; You, Huey-Ling; Li, Changgui; Chang, Jan-Gowth; Chang, Shun-Jen; Chen, Chung-Jen

    2015-05-01

    Cyclic GMP-dependent protein kinase II (cGKII; PRKG2) phosphorylates a variety of biological targets and has been identified as a gout-susceptible gene. However, the regulatory role of cGKII in triggering gout disease has yet to be clarified. Thus, we plan to explore the specific function of cGKII in macrophages related to gout disease. By using cGKII gene knockdown method, we detected macrophage M1/M2 polarization, phagocytosis, and their responses to stimulation by monosodium urate (MSU). cGKII was highly expressed in M1 phenotype, but not in M2, and cGKII knockdown significantly inhibited macrophage M1 polarization by decreasing M1 chemokine markers (CXCL10 and CCL2) and downregulating phagocytosis function. We further identified that cGKII-associated phagocytosis was mediated by upregulating toll-like receptor 2 (TLR2) expression, but not by TLR4. Mimicking gout condition by MSU treatments, we found that MSU alone induced cGKII and TLR2 expression with increased M1 polarization markers and phagocytosis activity. It means that cGKII knockdown significantly inhibited this MSU-induced cGKII-TLR2-phagocytosis axis. Our study showed that cGKII plays a key role in M1 polarization, especially in TLR2-mediated phagocytosis under MSU exposure. The findings provide evidence for the possible role of cGKII as an inflammation exciter in gout disease. Gout-susceptible gene cGKII is necessary for macrophage M1 polarization. cGKII regulates M1 phagocytosis function via TLR2. Monosodium urate treatments increase cGKII expression and related function. This study reveals the role of cGKII in enhancing gouty inflammatory responses.

  20. HIV-1 Nef induces proinflammatory state in macrophages through its acidic cluster domain: involvement of TNF alpha receptor associated factor 2.

    Directory of Open Access Journals (Sweden)

    Giorgio Mangino

    Full Text Available BACKGROUND: HIV-1 Nef is a virulence factor that plays multiple roles during HIV replication. Recently, it has been described that Nef intersects the CD40 signalling in macrophages, leading to modification in the pattern of secreted factors that appear able to recruit, activate and render T lymphocytes susceptible to HIV infection. The engagement of CD40 by CD40L induces the activation of different signalling cascades that require the recruitment of specific tumor necrosis factor receptor-associated factors (i.e. TRAFs. We hypothesized that TRAFs might be involved in the rapid activation of NF-κB, MAPKs and IRF-3 that were previously described in Nef-treated macrophages to induce the synthesis and secretion of proinflammatory cytokines, chemokines and IFNβ to activate STAT1, -2 and -3. METHODOLOGY/PRINCIPAL FINDINGS: Searching for possible TRAF binding sites on Nef, we found a TRAF2 consensus binding site in the AQEEEE sequence encompassing the conserved four-glutamate acidic cluster. Here we show that all the signalling effects we observed in Nef treated macrophages depend on the integrity of the acidic cluster. In addition, Nef was able to interact in vitro with TRAF2, but not TRAF6, and this interaction involved the acidic cluster. Finally silencing experiments in THP-1 monocytic cells indicate that both TRAF2 and, surprisingly, TRAF6 are required for the Nef-induced tyrosine phosphorylation of STAT1 and STAT2. CONCLUSIONS: Results reported here revealed TRAF2 as a new possible cellular interactor of Nef and highlighted that in monocytes/macrophages this viral protein is able to manipulate both the TRAF/NF-κB and TRAF/IRF-3 signalling axes, thereby inducing the synthesis of proinflammatory cytokines and chemokines as well as IFNβ.

  1. Molecular cloning of a second subunit of the receptor for human granulocyte - macrophage colony-stimulating factor (GM-CSF): Reconstitution of a high-affinity GM-CSF receptor

    International Nuclear Information System (INIS)

    Hayashida, Kazuhiro; Kitamura, Toshio; Gorman, D.M.; Miyajima, Atsushi; Arai, Kenichi; Yokota, Takashi

    1990-01-01

    Using the mouse interleukin 3 (IL-3) receptor cDNA as a probe, the authors obtained a monologous cDNA (KH97) from a cDNA library of a human hemopoietic cell line, TF-1. The protein encoded by the KH97 cDNA has 56% amino acid sequence identity with the mouse IL-3 receptor and retains features common to the family of cytokine receptors. Fibroblasts transfected with the KH97 cDNA expressed a protein of 120 kDa but did not bind any human cytokines, including IL-3 and granulocyte - macrophage colony-stimulating factor (GM-CSF). Interestingly, cotransfection of cDNAs for KH97 and the low-affinity human GM-CSF receptor in fibroblasts resulted in formation of a high-affinity receptor for GM-CSF. The dissociation rate of GM-CSF from the reconstituted high-affinity receptor was slower than that from the low-affinity site, whereas the association rate was unchanged. Cross-linking of 125 I-labeled GM-CSF to fibroblasts cotransfected with both cDNAs revealed the same cross-linking patterns as in TF-1 cells - i.e., two major proteins of 80 and 120 kDa which correspond to the low-affinity GM-CSF receptor and the KH97 protein, respectively. These results indicate that the high-affinity GM-CSF receptor is composed of at least two components in a manner analogous to the IL-2 receptor. They therefore propose to designate the low-affinity GM-CSF receptor and the KH97 protein as the α and β subunits of the GM-CSF receptor, respectively

  2. The effects of dietary fatty acids on the postprandial triglyceride-rich lipoprotein/apoB48 receptor axis in human monocyte/macrophage cells.

    Science.gov (United States)

    Varela, Lourdes M; Ortega-Gomez, Almudena; Lopez, Sergio; Abia, Rocio; Muriana, Francisco J G; Bermudez, Beatriz

    2013-12-01

    Intestinally produced triglyceride-rich lipoproteins (TRL) play an important role in the progression of atherosclerosis. In this study, we investigated the relevance of monounsaturated fatty acid (MUFA) and saturated fatty acid (SFA) in postprandial TRL in affecting the transcriptional activity of the apolipoprotein-B48 receptor (ApoB48R) and its functionality in human monocyte/macrophage cells. Healthy male volunteers were administered four standardized high-fat meals containing butter, high-palmitic sunflower oil, olive oil (ROO) or a mixture of vegetable and fish oils (50 g/m(2) body surface area) to obtain a panel of postprandial TRL with gradual MUFA oleic acid-to-SFA palmitic acid ratios. The increase in this ratio was linearly associated with a decrease of ApoB48R up-regulation and lipid accumulation in THP-1 and primary monocytes. ApoB48R mRNA levels and intracellular triglycerides were also lower in the monocytes from volunteers after the ingestion of the ROO meal when compared to the ingestion of the butter meal. In THP-1 macrophages, the increase in the MUFA oleic acid-to-SFA palmitic acid ratio in the postprandial TRL was linearly correlated with an increase in ApoB48R down-regulation and a decrease in lipid accumulation. We also revealed that the nuclear receptor transcription factors PPARα, PPARβ/δ, and PPARγ and the PPAR-RXR transcriptional complex were involved in sensing the proportion of MUFA oleic acid and SFA palmitic acid, and these were also involved in adjusting the transcriptional activity of ApoB48R. The results of this study support the notion that MUFA-rich dietary fats may prevent excessive lipid accumulation in monocyte/macrophage cells by targeting the postprandial TRL/ApoB48R axis. © 2013.

  3. Loss of Macrophage Low-Density Lipoprotein Receptor-Related Protein 1 Confers Resistance to the Antiatherogenic Effects of Tumor Necrosis Factor-α Inhibition.

    Science.gov (United States)

    Zhu, Lin; Giunzioni, Ilaria; Tavori, Hagai; Covarrubias, Roman; Ding, Lei; Zhang, Youmin; Ormseth, Michelle; Major, Amy S; Stafford, John M; Linton, MacRae F; Fazio, Sergio

    2016-08-01

    Antiatherosclerotic effects of tumor necrosis factor-α (TNF-α) blockade in patients with systemic inflammatory states are not conclusively demonstrated, which suggests that effects depend on the cause of inflammation. Macrophage LRP1 (low-density lipoprotein receptor-related protein 1) and apoE contribute to inflammation through different pathways. We studied the antiatherosclerosis effects of TNF-α blockade in hyperlipidemic mice lacking either LRP1 (MΦLRP1(-/-)) or apoE from macrophages. Lethally irradiated low-density lipoprotein receptor (LDLR)(-/-) mice were reconstituted with bone marrow from either wild-type, MΦLRP1(-/-), apoE(-/-) or apoE(-/-)/MΦLRP1(-/-)(DKO) mice, and then treated with the TNF-α inhibitor adalimumab while fed a Western-type diet. Adalimumab reduced plasma TNF-α concentration, suppressed blood ly6C(hi) monocyte levels and their migration into the lesion, and reduced lesion cellularity and inflammation in both wild-type→LDLR(-/-) and apoE(-/-)→LDLR(-/-) mice. Overall, adalimumab reduced lesion burden by 52% to 57% in these mice. Adalimumab reduced TNF-α and blood ly6C(hi) monocyte levels in MΦLRP1(-/-)→LDLR(-/-) and DKO→LDLR(-/-) mice, but it did not suppress ly6C(hi) monocyte migration into the lesion or atherosclerosis progression. Our results show that TNF-α blockade exerts antiatherosclerotic effects that are dependent on the presence of macrophage LRP1. © 2016 American Heart Association, Inc.

  4. The scavenger activity of the human P2X7 receptor differs from P2X7 pore function by insensitivity to antagonists, genetic variation and sodium concentration: Relevance to inflammatory brain diseases.

    Science.gov (United States)

    Ou, Amber; Gu, Ben J; Wiley, James S

    2018-04-01

    Activation of P2X7 receptors is widely recognised to initiate proinflammatory responses. However P2X7 also has a dual function as a scavenger receptor which is active in the absence of ATP and plasma proteins and may be important in central nervous system (CNS) diseases. Here, we investigated both P2X7 pore formation and its phagocytic function in fresh human monocytes (as a model of microglia) by measuring ATP-induced ethidium dye uptake and fluorescent bead uptake respectively. This was studied in monocytes expressing various polymorphic variants as well as in the presence of different P2X7 antagonists and ionic media. P2X7-mediated phagocytosis was found to account for about half of Latrunculin (or Cytochalasin D)-sensitive bead engulfment by fresh human monocytes. Monocytes harbouring P2X7 Ala348Thr or Glu496Ala polymorphic variants showed increase or loss of ethidium uptake respectively, but these changes in pore formation did not always correspond to the changes in phagocytosis of YG beads. Unlike pore function, P2X7-mediated phagocytosis was not affected by three potent selective P2X7 antagonists and remained identical in Na + and K + media. Taken together, our results show that P2X7 is a scavenger receptor with important function in the CNS but its phagocytic function has features distinct from its pore function. Both P2X7 pore formation and P2X7-mediated phagocytosis should be considered in the design of new P2X7 antagonists for the treatment of CNS diseases. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Inhibition of the NLRP3 inflammasome attenuates foam cell formation of THP-1 macrophages by suppressing ox-LDL uptake and promoting cholesterol efflux.

    Science.gov (United States)

    Chen, Liang; Yao, Qiying; Xu, Siwei; Wang, Hongyan; Qu, Peng

    2018-01-01

    The NOD-like receptor family, pyrin domain-containing protein 3 (NLRP3) inflammasome plays an important role in the development of atherosclerosis. The activated NLRP3 inflammasome has been reported to promote macrophage foam cell formation, but not all studies have obtained the same result, and how NLRP3 inflammasome is involved in the formation of foam cells remains elusive. We used selective NLRP3 inflammasome inhibitors and NLRP3-deficient THP-1 cells to assess the effect of NLRP3 inflammasome inhibition on macrophage foam cell formation, oxidized low-density lipoprotein (ox-LDL) uptake, esterification, and cholesterol efflux, as well as the expression of associated proteins. Inhibition of the NLRP3 inflammasome attenuated foam cell formation, diminished ox-LDL uptake, and promoted cholesterol efflux from THP-1 macrophages. Moreover, it downregulated CD36, acyl coenzyme A: cholesterol acyltransferase-1 and neutral cholesterol ester hydrolase expression; upregulated ATP-binding cassette transporter A1 (ABCA1) and scavenger receptor class B type I (SR-BI) expression; but had no effect on the expression of scavenger receptor class A and ATP-binding cassette transporter G1. Collectively, our findings show that inhibition of the NLRP3 inflammasome decreases foam cell formation of THP-1 macrophages via suppression of ox-LDL uptake and enhancement of cholesterol efflux, which may be due to downregulation of CD36 expression and upregulation of ABCA1 and SR-BI expression, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. A new IRAK-M-mediated mechanism implicated in the anti-inflammatory effect of nicotine via α7 nicotinic receptors in human macrophages.

    Directory of Open Access Journals (Sweden)

    Maria C Maldifassi

    Full Text Available Nicotine stimulation of α7 nicotinic acetylcholine receptor (α7 nAChR powerfully inhibits pro-inflammatory cytokine production in lipopolysaccharide (LPS-stimulated macrophages and in experimental models of endotoxemia. A signaling pathway downstream from the α7 nAChRs, which involves the collaboration of JAK2/STAT3 and NF-κB to interfere with signaling by Toll-like receptors (TLRs, has been implicated in this anti-inflammatory effect of nicotine. Here, we identifiy an alternative mechanism involving interleukin-1 receptor-associated kinase M (IRAK-M, a negative regulator of innate TLR-mediated immune responses. Our data show that nicotine up-regulates IRAK-M expression at the mRNA and protein level in human macrophages, and that this effect is secondary to α7 nAChR activation. By using selective inhibitors of different signaling molecules downstream from the receptor, we provide evidence that activation of STAT3, via either JAK2 and/or PI3K, through a single (JAK2/PI3K/STAT3 or two convergent cascades (JAK2/STAT3 and PI3K/STAT3, is necessary for nicotine-induced IRAK-M expression. Moreover, down-regulation of this expression by small interfering RNAs specific to the IRAK-M gene significantly reverses the anti-inflammatory effect of nicotine on LPS-induced TNF-α production. Interestingly, macrophages pre-exposed to nicotine exhibit higher IRAK-M levels and reduced TNF-α response to an additional LPS challenge, a behavior reminiscent of the 'endotoxin tolerant' phenotype identified in monocytes either pre-exposed to LPS or from immunocompromised septic patients. Since nicotine is a major component of tobacco smoke and increased IRAK-M expression has been considered one of the molecular determinants for the induction of the tolerant phenotype, our findings showing IRAK-M overexpression could partially explain the known influence of smoking on the onset and progression of inflammatory and infectious diseases.

  7. Microglia and macrophages express tumor necrosis factor receptor p75 following middle cerebral artery occlusion in mice

    DEFF Research Database (Denmark)

    Lambertsen, Kate Lykke; Clausen, Bettina Hjelm; Fenger, Claus

    2007-01-01

    The proinflammatory and potential neurotoxic cytokine tumor necrosis factor (TNF) is produced by activated CNS resident microglia and infiltrating blood-borne macrophages in infarct and peri-infarct areas following induction of focal cerebral ischemia. Here, we investigated the expression of the ...

  8. Triamcinolone acetonide activates an anti-inflammatory and folate receptor-positive macrophage that prevents osteophytosis in vivo

    NARCIS (Netherlands)

    M. Siebelt (Michiel); N. Korthagen (Nicoline); W. Wei (Wu); H.C. Groen (Harald); Y.M. Bastiaansen-Jenniskens (Yvonne); C. Müller (Cristina); J.H. Waarsing (Jan); M. de Jong (Marcel); H.H. Weinans (Harrie)

    2015-01-01

    textabstractIntroduction: Triamcinolone acetonide (TA) is used for osteoarthritis management to reduce pain, and pre-clinical studies have shown that TA limits osteophyte formation. Osteophyte formation is known to be facilitated by synovial macrophage activation. TA injections might influence

  9. CD163-L1 is an endocytic macrophage protein strongly regulated by mediators in the inflammatory response

    DEFF Research Database (Denmark)

    Moeller, Jesper B; Nielsen, Marianne J; Reichhardt, Martin P

    2012-01-01

    CD163-L1 belongs to the group B scavenger receptor cysteine-rich family of proteins, where the CD163-L1 gene arose by duplication of the gene encoding the hemoglobin scavenger receptor CD163 in late evolution. The current data demonstrate that CD163-L1 is highly expressed and colocalizes with CD163...... on large subsets of macrophages, but in contrast to CD163 the expression is low or absent in monocytes and in alveolar macrophages, glia, and Kupffer cells. The expression of CD163-L1 increases when cultured monocytes are M-CSF stimulated to macrophages, and the expression is further increased by the acute......-phase mediator IL-6 and the anti-inflammatory mediator IL-10 but is suppressed by the proinflammatory mediators IL-4, IL-13, TNF-α, and LPS/IFN-γ. Furthermore, we show that CD163-L1 is an endocytic receptor, which internalizes independently of cross-linking through a clathrin-mediated pathway. Two cytoplasmic...

  10. DMPD: TLR9 as a key receptor for the recognition of DNA. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18262306 TLR9 as a key receptor for the recognition of DNA. Kumagai Y, Takeuchi O, ...TLR9 as a key receptor for the recognition of DNA. PubmedID 18262306 Title TLR9 as a key receptor for the recognition

  11. DMPD: The negative regulation of Toll-like receptor and associated pathways. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17621314 The negative regulation of Toll-like receptor and associated pathways. Lan...) Show The negative regulation of Toll-like receptor and associated pathways. PubmedID 17621314 Title The ne...gative regulation of Toll-like receptor and associated pathways. Authors Lang T,

  12. DMPD: Toll-like receptors: novel pharmacological targets for the treatment ofneurological diseases. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17974478 Toll-like receptors: novel pharmacological targets for the treatment ofneu...png) (.svg) (.html) (.csml) Show Toll-like receptors: novel pharmacological targets for the treatment ofneur...ological diseases. PubmedID 17974478 Title Toll-like receptors: novel pharmacological target

  13. DMPD: The role of Toll-like receptors and Nod proteins in bacterial infection. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15476921 The role of Toll-like receptors and Nod proteins in bacterial infection. P...of Toll-like receptors and Nod proteins in bacterial infection. PubmedID 15476921 Title The role of Toll-like receptors and Nod prote...ins in bacterial infection. Authors Philpott DJ, Girardi

  14. DMPD: Proximal effects of Toll-like receptor activation in dendritic cells. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17142025 Proximal effects of Toll-like receptor activation in dendritic cells. Watt...) (.svg) (.html) (.csml) Show Proximal effects of Toll-like receptor activation in dendritic cells. PubmedID... 17142025 Title Proximal effects of Toll-like receptor activation in dendritic ce

  15. DMPD: Innate immunity and toll-like receptors: clinical implications of basic scienceresearch. [Dynamic Macrophage Pathway CSML Database

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    Full Text Available 15069387 Innate immunity and toll-like receptors: clinical implications of basic science...te immunity and toll-like receptors: clinical implications of basic scienceresearch. PubmedID 15069387 Title... Innate immunity and toll-like receptors: clinical implications of basic sciencer

  16. DMPD: Toll-like receptors: paving the path to T cell-driven autoimmunity? [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17888644 Toll-like receptors: paving the path to T cell-driven autoimmunity? Marsla... Toll-like receptors: paving the path to T cell-driven autoimmunity? PubmedID 17888644 Title Toll-like recep...tors: paving the path to T cell-driven autoimmunity? Authors Marsland BJ, Kopf M.

  17. Blood Glutamate Scavenging: Insight into Neuroprotection

    Directory of Open Access Journals (Sweden)

    Alexander Zlotnik

    2012-08-01

    Full Text Available Brain insults are characterized by a multitude of complex processes, of which glutamate release plays a major role. Deleterious excess of glutamate in the brain’s extracellular fluids stimulates glutamate receptors, which in turn lead to cell swelling, apoptosis, and neuronal death. These exacerbate neurological outcome. Approaches aimed at antagonizing the astrocytic and glial glutamate receptors have failed to demonstrate clinical benefit. Alternatively, eliminating excess glutamate from brain interstitial fluids by making use of the naturally occurring brain-to-blood glutamate efflux has been shown to be effective in various animal studies. This is facilitated by gradient driven transport across brain capillary endothelial glutamate transporters. Blood glutamate scavengers enhance this naturally occurring mechanism by reducing the blood glutamate concentration, thus increasing the rate at which excess glutamate is cleared. Blood glutamate scavenging is achieved by several mechanisms including: catalyzation of the enzymatic process involved in glutamate metabolism, redistribution of glutamate into tissue, and acute stress response. Regardless of the mechanism involved, decreased blood glutamate concentration is associated with improved neurological outcome. This review focuses on the physiological, mechanistic and clinical roles of blood glutamate scavenging, particularly in the context of acute and chronic CNS injury. We discuss the details of brain-to-blood glutamate efflux, auto-regulation mechanisms of blood glutamate, natural and exogenous blood glutamate scavenging systems, and redistribution of glutamate. We then propose different applied methodologies to reduce blood and brain glutamate concentrations and discuss the neuroprotective role of blood glutamate scavenging.

  18. Cannabinoid CB2 receptors are involved in the protection of RAW264.7 macrophages against the oxidative stress: an in vitro study

    Directory of Open Access Journals (Sweden)

    Sabrina Giacoppo

    2017-01-01

    Full Text Available Research in the last decades has widely investigated the anti-oxidant properties of natural products as a therapeutic approach for the prevention and the treatment of oxidative-stress related disorders. In this context, several studies were aimed to evaluate the therapeutic potential of phytocannabinoids, the bioactive compounds of Cannabis sativa. Here, we examined the anti-oxidant ability of Cannabigerol (CBG, a non-psychotropic cannabinoid, still little known, into counteracting the hydrogen peroxide (H2O2-induced oxidative stress in murine RAW264.7 macrophages. In addition, we tested selective receptor antagonists for cannabinoid receptors and specifically CB1R (SR141716A and CB2R (AM630 in order to investigate through which CBG may exert its action. Taken together, our in vitro results showed that CBG is able to counteract oxidative stress by activation of CB2 receptors. CB2 antagonist pre-treatment indeed blocked the protective effects of CBG in H2O2 stimulated macrophages, while CB1R was not involved. Specifically, CBG exhibited a potent action in inhibiting oxidative stress, by down-regulation of the main oxidative markers (iNOS, nitrotyrosine and PARP-1, by preventing IκB-α phosphorylation and translocation of the nuclear factor-κB (NF-κB and also via the modulation of MAP kinases pathway. On the other hand, CBG was found to increase anti-oxidant defense of cells by modulating superoxide dismutase-1 (SOD-1 expression and thus inhibiting cell death (results focused on balance between Bax and Bcl-2. Based on its antioxidant activities, CBG may hold great promise as an anti-oxidant agent and therefore used in clinical practice as a new approach in oxidative-stress related disorders.

  19. Mucosa-Associated Lymphoid Tissue Lymphoma Translocation Protein 1 Positively Modulates Matrix Metalloproteinase-9 Production in Alveolar Macrophages upon Toll-Like Receptor 7 Signaling and Influenza Virus Infection

    Directory of Open Access Journals (Sweden)

    Yu-Hsiang Lee

    2017-09-01

    Full Text Available Influenza A virus (IAV infection causes significant morbidity and mortality worldwide. Matrix metalloproteinase-9 (MMP-9 degrades extracellular matrix and is involved in the pathology of influenza. It has been reported that MMP-9 mediates neutrophil migration in IAV infection. Whether alveolar macrophages, the first immune cells that encounter IAV, produce MMP-9, and the mechanism of its regulation have never been investigated. As Toll-like receptor 7 (TLR7 is one of the receptors in innate immune cells that recognize IAV, we used TLR7 agonists and IAV to stimulate alveolar macrophage MH-S cells, primary macrophages, and bone marrow neutrophils. Results showed that MMP-9 expression in macrophages is inducible by TLR7 agonists and IAV, yet, MMP-9 production by neutrophils is not inducible by either one of them. We hypothesized that MMP-9 production in macrophages is mediated through TLR7-NF-κB pathway and used microarray to analyze TLR7 agonist-induced NF-κB-related genes. Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1, a positive regulator of NF-κB, is amongst the top highly induced genes. By use of MALT1 inhibitor (z-VRPR-fmk and alveolar macrophages from MALT1-deficient mice, we found that MMP-9 production is MALT1-dependent. While MALT1 can act as a paracaspase in lymphocytes through degrading various signaling proteins, we discovered that MALT1 functions to reduce a negative regulator of NF-κB, cylindromatosis (CYLD, in alveolar macrophages. IAV-induced MMP-9, TNF, and IL-6 in lungs of MALT1-deficient mice are significantly lower than in wild-type mice after intratracheal infection. MALT1-deficient mice also have less body weight loss and longer survival after infection. Taken together, we demonstrated a novel role of MALT1 in regulating alveolar macrophage MMP-9 production whose presence exacerbates the severity of influenza.

  20. Sodium methyldithiocarbamate inhibits MAP kinase activation through toll-like receptor 4, alters cytokine production by mouse peritoneal macrophages, and suppresses innate immunity.

    Science.gov (United States)

    Pruett, Stephen B; Zheng, Qiang; Schwab, Carlton; Fan, Ruping

    2005-09-01

    Sodium methyldithiocarbamate (SMD; trade name, Metam Sodium) is an abundantly used soil fumigant that can cause adverse health effects in humans, including some immunological manifestations. The mechanisms by which SMD acts, and its targets within the immune system are not fully understood. Initial experiments demonstrated that SMD administered by oral gavage substantially decreased IL-12 production and increased IL-10 production induced by lipopolysaccharide in mice. The present study was conducted to further characterize these effects and to evaluate our working hypothesis that the mechanism for these effects involves alteration in signaling through toll-like receptor 4 and that this would suppress innate immunity to infection. SMD decreased the activation of MAP kinases and AP-1 but not NF-kappaB in peritoneal macrophages. The expression of mRNA for IL-1alpha, IL-1beta, IL-18, IFN-gamma, IL-12 p35, IL-12 p40, and macrophage migration inhibitory factor (MIF) was inhibited by SMD, whereas mRNA for IL-10 was increased. SMD increased the IL-10 concentration in the peritoneal cavity and serum and decreased the concentration of IL-12 p40 in the serum, peritoneal cavity, and intracellularly in peritoneal cells (which are >80% macrophages). Similar effects on LPS-induced cytokine production were observed following dermal administration of SMD. The major breakdown product of SMD, methylisothiocyanate (MITC), caused similar effects on cytokine production at dosages as low as 17 mg/kg, a dosage relevant to human exposure levels associated with agricultural use of SMD. Treatment of mice with SMD decreased survival following challenge with non-pathogenic Escherichia coli within 24-48 h, demonstrating suppression of innate immunity.

  1. Purple perilla extracts with α-asarone enhance cholesterol efflux from oxidized LDL-exposed macrophages.

    Science.gov (United States)

    Park, Sin-Hye; Paek, Ji Hun; Shin, Daekeun; Lee, Jae-Yong; Lim, Soon Sung; Kang, Young-Hee

    2015-04-01

    The cellular accumulation of cholesterol is critical in the development and progression of atherosclerosis. ATP-binding cassette (ABC) transporters play an essential role in mediating the efflux of excess cholesterol. In the current study, we investigated whether purple Perilla frutescens extracts (PPE) at a non-toxic concentration of 1-10 µg/ml stimulate the induction of the ABC transporters, ABCA1 and ABCG1, and cholesterol efflux from lipid-laden J774A.1 murine macrophages exposed to 50 ng/ml oxidized low-density lipoprotein (LDL). Purple perilla, an annual herb in the mint family and its constituents, have been reported to exhibit antioxidant and cytostatic activity, as well as to exert anti-allergic effects. Our results revealed that treatment with oxidized LDL for 24 h led to the accumulation of lipid droplets in the macrophages. PPE suppressed the oxidized LDL-induced foam cell formation by blocking the induction of scavenger receptor B1. However, PPE promoted the induction of the ABC transporters, ABCA1 and ABCG1, and subsequently accelerated cholesterol efflux from the lipid-loaded macrophages. The liver X receptor (LXR) agonist, TO-091317, and the peroxisome proliferator-activated receptor (PPAR) agonist, pioglitazone, increased ABCA1 expression and treatment with 10 µg/ml PPE further enhanced this effect. PPE did not induce LXRα and PPARγ expression per se, but enhanced their expression in the macrophages exposed to oxidized LDL. α-asarone was isolated from PPE and characterized as a major component enhancing the induction of ABCA1 and ABCG1 in macrophages exposed to oxidized LDL. α-asarone, but not β-asarone was effective in attenuating foam cell formation and enhancing cholesterol efflux, revealing an isomeric difference in their activity. The results from the present study demonstrate that PPE promotes cholesterol efflux from macrophages by activating the interaction of PPARγ-LXRα-ABC transporters.

  2. Andrographolide Inhibits Oxidized LDL-Induced Cholesterol Accumulation and Foam Cell Formation in Macrophages.

    Science.gov (United States)

    Lin, Hung-Chih; Lii, Chong-Kuei; Chen, Hui-Chun; Lin, Ai-Hsuan; Yang, Ya-Chen; Chen, Haw-Wen

    2018-01-01

    oxLDL is involved in the pathogenesis of atherosclerotic lesions through cholesterol accumulation in macrophage foam cells. Andrographolide, the bioactive component of Andrographis paniculata, possesses several biological activities such as anti-inflammatory, anti-oxidant, and anticancer functions. Scavenger receptors (SRs), including class A SR (SR-A) and CD36, are responsible for the internalization of oxLDL. In contrast, receptors for reverse cholesterol transport, including ABCA1 and ABCG1, mediate the efflux of cholesterol from macrophage foam cells. Transcription factor liver X receptor [Formula: see text] (LXR[Formula: see text] plays a key role in lipid metabolism and inflammation as well as in the regulation of ABCA1 and ABCG1 expression. Because of the contribution of inflammation to macrophage foam cell formation and the potent anti-inflammatory activity of andrographolide, we hypothesized that andrographolide might inhibit oxLDL-induced macrophage foam cell formation. The results showed that andrographolide reduced oxLDL-induced lipid accumulation in macrophage foam cells. Andrographolide decreased the mRNA and protein expression of CD36 by inducing the degradation of CD36 mRNA; however, andrographolide had no effect on SR-A expression. In contrast, andrographolide increased the mRNA and protein expression of ABCA1 and ABCG1, which were dependent on LXR[Formula: see text]. Andrographolide enhanced LXR[Formula: see text] nuclear translocation and DNA binding activity. Treatment with the LXR[Formula: see text] antagonist GGPP and transfection with LXR[Formula: see text] siRNA reversed the ability of andrographolide to stimulate ABCA1 and ABCG1 protein expression. In conclusion, inhibition of CD36-mediated oxLDL uptake and induction of ABCA1- and ABCG1-dependent cholesterol efflux are two working mechanisms by which andrographolide inhibits macrophage foam cell formation, which suggests that andrographolide could be a potential candidate to prevent

  3. Anti-WASP intrabodies inhibit inflammatory responses induced by Toll-like receptors 3, 7, and 9, in macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Sakuma, Chisato [Animal Immune and Cell Biology Research Unit, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki, 305-8634 (Japan); Sato, Mitsuru, E-mail: mitsuru.sato@affrc.go.jp [Animal Immune and Cell Biology Research Unit, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki, 305-8634 (Japan); Oshima, Takuma [Department of Biological Science and Technology, Graduate School of Faculty of Industrial Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510 (Japan); Takenouchi, Takato [Animal Immune and Cell Biology Research Unit, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki, 305-8634 (Japan); Chiba, Joe [Department of Biological Science and Technology, Graduate School of Faculty of Industrial Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510 (Japan); Kitani, Hiroshi [Animal Immune and Cell Biology Research Unit, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki, 305-8634 (Japan)

    2015-02-27

    Wiskott-Aldrich syndrome protein (WASP) is an adaptor molecule in immune cells. Recently, we showed that the WASP N-terminal domain interacted with the SH3 domain of Bruton's tyrosine kinase (Btk), and that the complex formed by WASP and Btk was important for TLR2 and TLR4 signaling in macrophages. Several other studies have shown that Btk played important roles in modulating innate immune responses through TLRs in immune cells. Here, we evaluated the significance of the interaction between WASP and Btk in TLR3, TLR7, and TLR9 signaling. We established bone marrow–derived macrophage cell lines from transgenic (Tg) mice that expressed intracellular antibodies (intrabodies) that specifically targeted the WASP N-terminal domain. One intrabody comprised the single-chain variable fragment and the other comprised the light-chain variable region single domain of an anti-WASP N-terminal monoclonal antibody. Both intrabodies inhibited the specific interaction between WASP and Btk, which impaired the expression of TNF-α, IL-6, and IL-1β in response to TLR3, TLR7, or TLR9 stimulation. Furthermore, the intrabodies inhibited the phosphorylation of both nuclear factor (NF)-κB and WASP in response to TLR3, TLR7, or TLR9 stimulation, in the Tg bone marrow-derived macrophages. These results suggested that WASP plays important roles in TLR3, TLR7, and TLR9 signaling by associating with Btk in macrophages. - Highlights: • The interaction between WASP and Btk is critical for TLR3, TLR7, and TLR9 signaling. • Anti-WASP intrabodies inhibited several TLR pathways that led to cytokine expression. • Phosphorylation of NF-κB via TLR signaling was inhibited by anti-WASP intrabodies. • WASP phosphorylation via several TLR ligands was inhibited by anti-WASP intrabodies.

  4. Anti-WASP intrabodies inhibit inflammatory responses induced by Toll-like receptors 3, 7, and 9, in macrophages

    International Nuclear Information System (INIS)

    Sakuma, Chisato; Sato, Mitsuru; Oshima, Takuma; Takenouchi, Takato; Chiba, Joe; Kitani, Hiroshi

    2015-01-01

    Wiskott-Aldrich syndrome protein (WASP) is an adaptor molecule in immune cells. Recently, we showed that the WASP N-terminal domain interacted with the SH3 domain of Bruton's tyrosine kinase (Btk), and that the complex formed by WASP and Btk was important for TLR2 and TLR4 signaling in macrophages. Several other studies have shown that Btk played important roles in modulating innate immune responses through TLRs in immune cells. Here, we evaluated the significance of the interaction between WASP and Btk in TLR3, TLR7, and TLR9 signaling. We established bone marrow–derived macrophage cell lines from transgenic (Tg) mice that expressed intracellular antibodies (intrabodies) that specifically targeted the WASP N-terminal domain. One intrabody comprised the single-chain variable fragment and the other comprised the light-chain variable region single domain of an anti-WASP N-terminal monoclonal antibody. Both intrabodies inhibited the specific interaction between WASP and Btk, which impaired the expression of TNF-α, IL-6, and IL-1β in response to TLR3, TLR7, or TLR9 stimulation. Furthermore, the intrabodies inhibited the phosphorylation of both nuclear factor (NF)-κB and WASP in response to TLR3, TLR7, or TLR9 stimulation, in the Tg bone marrow-derived macrophages. These results suggested that WASP plays important roles in TLR3, TLR7, and TLR9 signaling by associating with Btk in macrophages. - Highlights: • The interaction between WASP and Btk is critical for TLR3, TLR7, and TLR9 signaling. • Anti-WASP intrabodies inhibited several TLR pathways that led to cytokine expression. • Phosphorylation of NF-κB via TLR signaling was inhibited by anti-WASP intrabodies. • WASP phosphorylation via several TLR ligands was inhibited by anti-WASP intrabodies

  5. TARM1 Is a Novel Leukocyte Receptor Complex-Encoded ITAM Receptor That Costimulates Proinflammatory Cytokine Secretion by Macrophages and Neutrophils

    DEFF Research Database (Denmark)

    Radjabova, Valeria; Mastroeni, Piero; Skjødt, Karsten

    2015-01-01

    We identified a novel, evolutionarily conserved receptor encoded within the human leukocyte receptor complex and syntenic region of mouse chromosome 7, named T cell-interacting, activating receptor on myeloid cells-1 (TARM1). The transmembrane region of TARM1 contained a conserved arginine residu...

  6. Reduced number and morphofunctional change of alveolar macrophages in MafB gene-targeted mice.

    Directory of Open Access Journals (Sweden)

    Michiko Sato-Nishiwaki

    Full Text Available Alveolar macrophages (AMs play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD. We previously demonstrated that the transcription factor, MafB, increased in the AMs of mice exposed to cigarette smoke, and in those of human patients with COPD. The aim of this study was to evaluate the role of MafB in AMs using newly established transgenic (TG mice that specifically express dominant negative (DN MafB in macrophages under the control of macrophage scavenger receptor (MSR enhancer-promoter. We performed cell differential analyses in bronchoalveolar lavage cells, morphological analyses with electron microscopy, and flow cytometry-based analyses of surface markers and a phagocytic capacity assay in macrophages. AM number in the TG mice was significantly decreased compared with wild-type (WT mice. Morphologically, the high electron density area in the nucleus increased, the shape of pseudopods on the AMs was altered, and actin filament was less localized in the pseudopods of AMs of TG mice, compared with WT mice. The expression of surface markers, F4/80 and CD11b, on peritoneal macrophages in TG mice was reduced compared with WT mice, while those on AMs remained unchanged. Phagocytic capacity was decreased in AMs from TG mice, compared with WT mice. In conclusion, MafB regulates the phenotype of macrophages with respect to the number of alveolar macrophages, the nuclear compartment, cellular shape, surface marker expression, and phagocytic function. MSR-DN MafB TG mice may present a useful model to clarify the precise role of MafB in macrophages.

  7. Arctigenin suppresses receptor activator of nuclear factor κB ligand (RANKL)-mediated osteoclast differentiation in bone marrow-derived macrophages.

    Science.gov (United States)

    Kim, A-Ram; Kim, Hyuk Soon; Lee, Jeong Min; Choi, Jung Ho; Kim, Se Na; Kim, Do Kyun; Kim, Ji Hyung; Mun, Se Hwan; Kim, Jie Wan; Jeon, Hyun Soo; Kim, Young Mi; Choi, Wahn Soo

    2012-05-05

    Osteoclasts, multinucleated bone-resorbing cells, are closely associated with bone diseases such as rheumatoid arthritis and osteoporosis. Osteoclasts are derived from hematopoietic precursor cells, and their differentiation is mediated by two cytokines, including macrophage colony stimulating factor and receptor activator of nuclear factor κB ligand (RANKL). Previous studies have shown that arctigenin exhibits an anti-inflammatory effect. However, the effect of arctigenin on osteoclast differentiation is yet to be elucidated. In this study, we found that arctigenin inhibited RANKL-mediated osteoclast differentiation in bone marrow macrophages in a dose-dependent manner and suppressed RANKL-mediated bone resorption. Additionally, the expression of typical marker proteins, such as NFATc1, c-Fos, TRAF6, c-Src, and cathepsin K, were significantly inhibited. Arctigenin inhibited the phosphorylation of Erk1/2, but not p38 and JNK, in a dose-dependent manner. Arctigenin also dramatically suppressed immunoreceptor tyrosine-based activation motif-mediated costimulatory signaling molecules, including Syk and PLCγ2, and Gab2. Notably, arctigenin inhibited the activation of Syk through RANKL stimulation. Furthermore, arctigenin prevented osteoclast differentiation in the calvarial bone of mice following stimulation with lipopolysaccharide. Our results show that arctigenin inhibits osteoclast differentiation in vitro and in vivo. Therefore, arctigenin may be useful for treating rheumatoid arthritis and osteoporosis. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. DMPD: Toll-like receptor 9 in murine lupus: more friend than foe! [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18241699 Toll-like receptor 9 in murine lupus: more friend than foe! Yu P, Musette ...us: more friend than foe! PubmedID 18241699 Title Toll-like receptor 9 in murine lupus...P, Peng SL. Immunobiology. 2008;213(2):151-7. Epub 2007 Sep 21. (.png) (.svg) (.html) (.csml) Show Toll-like receptor 9 in murine lup

  9. Macrophage immunoregulatory pathways in tuberculosis.

    Science.gov (United States)

    Rajaram, Murugesan V S; Ni, Bin; Dodd, Claire E; Schlesinger, Larry S

    2014-12-01

    Macrophages, the major host cells harboring Mycobacterium tuberculosis (M.tb), are a heterogeneous cell type depending on their tissue of origin and host they are derived from. Significant discord in macrophage responses to M.tb exists due to differences in M.tb strains and the various types of macrophages used to study tuberculosis (TB). This review will summarize current concepts regarding macrophage responses to M.tb infection, while pointing out relevant differences in experimental outcomes due to the use of divergent model systems. A brief description of the lung environment is included since there is increasing evidence that the alveolar macrophage (AM) has immunoregulatory properties that can delay optimal protective host immune responses. In this context, this review focuses on selected macrophage immunoregulatory pattern recognition receptors (PRRs), cytokines, negative regulators of inflammation, lipid mediators and microRNAs (miRNAs). Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. IN VITRO INTERACTION OF INFLUENZA VIRUS A(H1N1pdm09 WITH MONOCYTIC MACROPHAGES: INDIVIDUAL RESPONSES OF TLR7 AND RIG1 RECEPTOR GENES

    Directory of Open Access Journals (Sweden)

    T. M. Sokolova

    2017-01-01

    Full Text Available In vitro differentiation of donor blood monocytes to macrophages (Mph following GM-CSF treatment was accompanied by a significant increase in the levels of gene transcription signaling receptors TLR7 or RIG1. The levels of intracellular viral RNA (M1 gene in Mph remained high upon infection by influenza virus A H1N1pdm (Moscow 2009 for 24-96 hours. The innate immunity reactions caused by influenza virus show individual features: they are decreased in Mph from donor 1 which had initially high level of endosomal TLR7 gene activity, and it increased by influenza virus in MPh from donor 2 who had a very low level of TLR7 gene expression. The influenza H1N1pdm virus weakly stimulated expression of gene RIG1 and production of inflammatory cytokines in Mf in donor 1. The differences may be connected with individual sensitivity of the donors to influenza infection.

  11. Macrophage-specific nanotechnology-driven CD163 overexpression in human macrophages results in an M2 phenotype under inflammatory conditions.

    Science.gov (United States)

    Alvarado-Vazquez, Perla Abigail; Bernal, Laura; Paige, Candler A; Grosick, Rachel L; Moracho Vilrriales, Carolina; Ferreira, David Wilson; Ulecia-Morón, Cristina; Romero-Sandoval, E Alfonso

    2017-08-01

    M1 macrophages release proinflammatory factors during inflammation. They transit to an M2 phenotype and release anti-inflammatory factors to resolve inflammation. An imbalance in the transition from M1 to M2 phenotype in macrophages contributes to the development of persistent inflammation. CD163, a member of the scavenger receptor cysteine-rich family, is an M2 macrophage marker. The functional role of CD163 during the resolution of inflammation is not completely known. We postulate that CD163 contributes to the transition from M1 to M2 phenotype in macrophages. We induced CD163 gene in THP-1 and primary human macrophages using polyethylenimine nanoparticles grafted with a mannose ligand (Man-PEI). This nanoparticle specifically targets cells of monocytic origin via mannose receptors. Cells were challenged with a single or a double stimulation of lipopolysaccharide (LPS). A CD163 or empty plasmid was complexed with Man-PEI nanoparticles for cell transfections. Quantitative RT-PCR, immunocytochemistry, and ELISAs were used for molecular assessments. CD163-overexpressing macrophages displayed reduced levels of tumor necrosis factor-alpha (TNF)-α and monocytes chemoattractant protein (MCP)-1 after a single stimulation with LPS. Following a double stimulation paradigm, CD163-overexpressing macrophages showed an increase of interleukin (IL)-10 and IL-1ra and a reduction of MCP-1. This anti-inflammatory phenotype was partially blocked by an anti-CD163 antibody (effects on IL-10 and IL-1ra). A decrease in the release of TNF-α, IL-1β, and IL-6 was observed in CD163-overexpressing human primary macrophages. The release of IL-6 was blocked by an anti-CD163 antibody in the CD163-overexpressing group. Our data show that the induction of the CD163 gene in human macrophages under inflammatory conditions produces changes in cytokine secretion in favor of an anti-inflammatory phenotype. Targeting macrophages to induce CD163 using cell-directed nanotechnology is an attractive

  12. Macrophage receptor with collagenous structure (MARCO) is a dynamic adhesive molecule that enhances uptake of carbon nanotubes by CHO-K1 Cells

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Seishiro, E-mail: seishiro@nies.go.jp [Environmental Nanotoxicology Project, RCER, National Institute for Environmental Studies (Japan); Fujitani, Yuji; Furuyama, Akiko [Environmental Nanotoxicology Project, RCER, National Institute for Environmental Studies (Japan); Kanno, Sanae [Department of Legal Medicine, St. Marianna School of Medicine (Japan)

    2012-02-15

    The toxicity of carbon nanotubes (CNTs), a highly promising nanomaterial, is similar to that of asbestos because both types of particles have a fibrous shape and are biopersistent. Here, we investigated the characteristics of macrophage receptor with collagenous structure (MARCO), a membrane receptor expressed on macrophages that recognizes environmental or unopsonized particles, and we assessed whether and how MARCO was involved in cellular uptake of multi-walled CNTs (MWCNTs). MARCO-transfected Chinese hamster ovary (CHO-K1) cells took up polystyrene beads irrespective of the particle size (20 nm–1 μm). In the culture of MARCO-transfected CHO-K1 cells dendritic structures were observed on the bottom of culture dishes, and the edges of these dendritic structures were continually renewed as the cell body migrated along the dendritic structures. MWCNTs were first tethered to the dendritic structures and then taken up by the cell body. MWCNTs appeared to be taken up via membrane ruffling like macropinocytosis, rather than phagocytosis. The cytotoxic EC{sub 50} value of MWCNTs in MARCO-transfected CHO-K1 cells was calculated to be 6.1 μg/mL and transmission electron microscopic observation indicated that the toxicity of MWCNTs may be due to the incomplete inclusion of MWCNTs by the membrane structure. -- Highlights: ►Carbon nanotubes (CNTs) were tethered to MARCO in vitro. ►CNTs were taken up rapidly into the cell body via MARCO by membrane ruffling. ►The incomplete inclusion of CNTs by membranes caused cytotoxicity.

  13. PI3K/Akt contributes to increased expression of Toll-like receptor 4 in macrophages exposed to hypoxic stress

    International Nuclear Information System (INIS)

    Kim, So Young; Jeong, Eunshil; Joung, Sun Myung; Lee, Joo Young

    2012-01-01

    Highlights: ► Hypoxic stress-induced TLR4 expression is mediated by PI3K/Akt in macrophages. ► PI3K/Akt regulated HIF-1 activation leading to TLR4 expression. ► p38 mitogen-activated protein kinase was not involved in TLR4 expression by hypoxic stress. ► Sulforaphane suppressed hypoxia-mediated TLR4 expression by inhibiting PI3K/Akt. -- Abstract: Toll-like receptors (TLRs) play critical roles in triggering immune and inflammatory responses by detecting invading microbial pathogens and endogenous danger signals. Increased expression of TLR4 is implicated in aggravated inflammatory symptoms in ischemic tissue injury and chronic diseases. Results from our previous study showed that TLR4 expression was upregulated by hypoxic stress mediated by hypoxia-inducible factor-1 (HIF-1) at a transcriptional level in macrophages. In this study, we further investigated the upstream signaling pathway that contributed to the increase of TLR4 expression by hypoxic stress. Either treatment with pharmacological inhibitors of PI3K and Akt or knockdown of Akt expression by siRNA blocked the increase of TLR4 mRNA and protein levels in macrophages exposed to hypoxia and CoCl 2 . Phosphorylation of Akt by hypoxic stress preceded nuclear accumulation of HIF-1α. A PI3K inhibitor (LY294002) attenuated CoCl 2 -induced nuclear accumulation and transcriptional activation of HIF-1α. In addition, HIF-1α-mediated upregulation of TLR4 expression was blocked by LY294002. Furthermore, sulforaphane suppressed hypoxia- and CoCl 2 -induced upregulation of TLR4 mRNA and protein by inhibiting PI3K/Akt activation and the subsequent nuclear accumulation and transcriptional activation of HIF-1α. However, p38 was not involved in HIF-1α activation and TLR4 expression induced by hypoxic stress in macrophages. Collectively, our results demonstrate that PI3K/Akt contributes to hypoxic stress-induced TLR4 expression at least partly through the regulation of HIF-1 activation. These reveal a novel

  14. PI3K/Akt contributes to increased expression of Toll-like receptor 4 in macrophages exposed to hypoxic stress

    Energy Technology Data Exchange (ETDEWEB)

    Kim, So Young; Jeong, Eunshil; Joung, Sun Myung [School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Lee, Joo Young, E-mail: joolee@catholic.ac.kr [School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); College of Pharmacy, The Catholic University of Korea, Bucheon 420-743 (Korea, Republic of)

    2012-03-16

    Highlights: Black-Right-Pointing-Pointer Hypoxic stress-induced TLR4 expression is mediated by PI3K/Akt in macrophages. Black-Right-Pointing-Pointer PI3K/Akt regulated HIF-1 activation leading to TLR4 expression. Black-Right-Pointing-Pointer p38 mitogen-activated protein kinase was not involved in TLR4 expression by hypoxic stress. Black-Right-Pointing-Pointer Sulforaphane suppressed hypoxia-mediated TLR4 expression by inhibiting PI3K/Akt. -- Abstract: Toll-like receptors (TLRs) play critical roles in triggering immune and inflammatory responses by detecting invading microbial pathogens and endogenous danger signals. Increased expression of TLR4 is implicated in aggravated inflammatory symptoms in ischemic tissue injury and chronic diseases. Results from our previous study showed that TLR4 expression was upregulated by hypoxic stress mediated by hypoxia-inducible factor-1 (HIF-1) at a transcriptional level in macrophages. In this study, we further investigated the upstream signaling pathway that contributed to the increase of TLR4 expression by hypoxic stress. Either treatment with pharmacological inhibitors of PI3K and Akt or knockdown of Akt expression by siRNA blocked the increase of TLR4 mRNA and protein levels in macrophages exposed to hypoxia and CoCl{sub 2}. Phosphorylation of Akt by hypoxic stress preceded nuclear accumulation of HIF-1{alpha}. A PI3K inhibitor (LY294002) attenuated CoCl{sub 2}-induced nuclear accumulation and transcriptional activation of HIF-1{alpha}. In addition, HIF-1{alpha}-mediated upregulation of TLR4 expression was blocked by LY294002. Furthermore, sulforaphane suppressed hypoxia- and CoCl{sub 2}-induced upregulation of TLR4 mRNA and protein by inhibiting PI3K/Akt activation and the subsequent nuclear accumulation and transcriptional activation of HIF-1{alpha}. However, p38 was not involved in HIF-1{alpha} activation and TLR4 expression induced by hypoxic stress in macrophages. Collectively, our results demonstrate that PI3K

  15. DMPD: Structure, function and regulation of the Toll/IL-1 receptor adaptor proteins. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17667936 Structure, function and regulation of the Toll/IL-1 receptor adaptor prote... (.svg) (.html) (.csml) Show Structure, function and regulation of the Toll/IL-1 receptor adaptor proteins. ...PubmedID 17667936 Title Structure, function and regulation of the Toll/IL-1 recep

  16. DMPD: Monocyte CD14: a multifunctional receptor engaged in apoptosis from both sides. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 10380893 Monocyte CD14: a multifunctional receptor engaged in apoptosis from both s...ides. Heidenreich S. J Leukoc Biol. 1999 Jun;65(6):737-43. (.png) (.svg) (.html) (.csml) Show Monocyte CD14: a multifunction...al receptor engaged in apoptosis from both sides. PubmedID 10380893 Title Monocyte CD14: a multifunction

  17. DMPD: Innate recognition of lipopolysaccharide by Toll-like receptor 4-MD-2. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15051069 Innate recognition of lipopolysaccharide by Toll-like receptor 4-MD-2. Miy...ake K. Trends Microbiol. 2004 Apr;12(4):186-92. (.png) (.svg) (.html) (.csml) Show Innate recognition of lip...opolysaccharide by Toll-like receptor 4-MD-2. PubmedID 15051069 Title Innate recognition of lipopolysacchari

  18. DMPD: Toll-like receptor (TLR)-based networks regulate neutrophilic inflammation inrespiratory disease. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18031251 Toll-like receptor (TLR)-based networks regulate neutrophilic inflammation inrespiratory...l) (.csml) Show Toll-like receptor (TLR)-based networks regulate neutrophilic inflammation inrespiratory dis...utrophilic inflammation inrespiratory disease. Authors Sabroe I, Whyte MK. Publication Biochem Soc Trans. 20

  19. DMPD: Signaling to NF-kappaB by Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available l Med. 2007 Nov;13(11):460-9. Epub 2007 Oct 29. (.png) (.svg) (.html) (.csml) Show Signaling to NF-kappaB by Toll-like receptors. Pub...medID 18029230 Title Signaling to NF-kappaB by Toll-like receptors. Authors Kawai T

  20. The effect of albumin on podocytes: The role of the fatty acid moiety and the potential role of CD36 scavenger receptor

    International Nuclear Information System (INIS)

    Pawluczyk, I.Z.A.; Pervez, A.; Ghaderi Najafabadi, M.; Saleem, M.A.; Topham, P.S.

    2014-01-01

    Evidence is emerging that podocytes are able to endocytose proteins such as albumin using kinetics consistent with a receptor-mediated process. To date the role of the fatty acid moiety on albumin uptake kinetics has not been delineated and the receptor responsible for uptake is yet to be identified. Albumin uptake studies were carried out on cultured human podocytes exposed to FITC-labelled human serum albumin either carrying fatty acids (HSA +FA ) or depleted of them (HSA −FA ). Receptor-mediated endocytosis of FITC-HSA +FA over 60 min was 5 times greater than that of FITC-HSA −FA . 24 h exposure of podocytes to albumin up-regulated nephrin expression and induced the activation of caspase-3. These effects were more pronounced in response to HSA −FA. Individually, anti-CD36 antibodies had no effect upon endocytosis of FITC-HSA. However, a cocktail of 2 antibodies reduced uptake by nearly 50%. Albumin endocytosis was enhanced in the presence of the CD36 specific inhibitor sulfo-N-succinimidyl oleate (SSO) while knock-down of CD36 using CD36siRNA had no effect on uptake. These data suggest that receptor-mediated endocytosis of albumin by podocytes is regulated by the fatty acid moiety, although, some of the detrimental effects are induced independently of it. CD36 does not play a direct role in the uptake of albumin. - Highlights: • The fatty acid moiety is essential for receptor mediated endocytosis of albumin. • Fatty acid depleted albumin is more pathogenic to podocytes. • CD36 is not directly involved in albumin uptake by podocytes

  1. Nogo-B Facilitates LPS-Mediated Immune Responses by Up-Regulation of TLR4-Signaling in Macrophage RAW264.7

    Directory of Open Access Journals (Sweden)

    Ying Zhu

    2017-01-01

    Full Text Available Background/Aims: Nogo-B, a member of the reticulon family of proteins, is mainly located in the endoplasmic reticulum (ER. Here, we investigate the function and mechanism of Nogo-B in the regulation of TLR4-associated immune responses in the macrophage cell line of RAW264.7. Methods: Nogo-B was up- and down-regulated through the use of appropriate adenoviral vectors or siRNA, and the effects of Nogo-B on macrophages under liposaccharide (LPS stimulation were evaluated via western blotting, immunofluorescence, enzyme-linked immunosorbent assay (ELISA, flow cytometric analysis, and transwell assay. Results: Our data indicates that the protein of Nogo-B was down-regulated in a time- and dose-dependent manner following LPS administration in the macrophage. Nogo-B overexpression increased the production of inflammatory cytokines (MCP-1, TNF-α, IL-1β, and TGF-β, enhanced macrophage migration activities, activated major histocompatibility complex II (MHC II, and elevated the expression of macrophage scavenger receptor 1(MSR1, all of which suggest that Nogo-B is necessary for immune responses and plays an important role in regulating macrophage recruitment. Mechanistically, Nogo-B may enhance TLR4 expression in macrophage surfaces, activate mitogen-activated protein kinase (MAPK pathways, and initiate inflammatory responses. Conclusion: These findings illustrate the key regulatory functions of Nogo-B in facilitating LPS-mediated immune responses through promoting the phosphorylation of MAP kinase.

  2. Delayed growth of EL4 lymphoma in SR-A-deficient mice is due to upregulation of nitric oxide and interferon-gamma production by tumor-associated macrophages.

    Science.gov (United States)

    Komohara, Yoshihiro; Takemura, Kenichi; Lei, Xiao Feng; Sakashita, Naomi; Harada, Mamoru; Suzuki, Hiroshi; Kodama, Tatsuhiko; Takeya, Motohiro

    2009-11-01

    Class A scavenger receptors (SR-A, CD204) are highly expressed in tumor-associated macrophages (TAM). To investigate the function of SR-A in TAM, wild-type and SR-A-deficient (SR-A(-/-)) mice were injected with EL4 cells. Although these groups of mice did not differ in the numbers of infiltrating macrophages and lymphocytes and in neovascularization, SR-A(-/-) mice had delayed growth of EL4 tumors. Expression of inducible nitric oxide (NO) synthase and interferon (IFN)-gamma mRNA increased significantly in tumor tissues from SR-A(-/-) mice. Engulfment of necrotic EL4 cells induced upregulation of NO and IFN-gamma production by cultured macrophages, and production of NO and IFN-gamma increased in SR-A(-/-) macrophages in vitro. IFN-beta production by cultured macrophages was also elevated in SR-A(-/-) macrophages in vitro. These results suggested that the antitumor activity of macrophages increased in SR-A(-/-) mice because of upregulation of NO and IFN-gamma production. These data indicate an important role of SR-A in regulating TAM function by inhibiting toll-like receptor (TLR)4-IFN-beta signaling.

  3. DMPD: Translational mini-review series on Toll-like receptors: networks regulated byToll-like receptors mediate innate and adaptive immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17223959 Translational mini-review series on Toll-like receptors: networks regulate...ol. 2007 Feb;147(2):199-207. (.png) (.svg) (.html) (.csml) Show Translational mini-review series on Toll-lik... immunity. PubmedID 17223959 Title Translational mini-review series on Toll-like receptors: networks regulat

  4. De Novo Transcriptome Analysis Shows That SAV-3 Infection Upregulates Pattern Recognition Receptors of the Endosomal Toll-Like and RIG-I-Like Receptor Signaling Pathways in Macrophage/Dendritic Like TO-Cells

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    Cheng Xu

    2016-04-01

    Full Text Available A fundamental step in cellular defense mechanisms is the recognition of “danger signals” made of conserved pathogen associated molecular patterns (PAMPs expressed by invading pathogens, by host cell germ line coded pattern recognition receptors (PRRs. In this study, we used RNA-seq and the Kyoto encyclopedia of genes and genomes (KEGG to identify PRRs together with the network pathway of differentially expressed genes (DEGs that recognize salmonid alphavirus subtype 3 (SAV-3 infection in macrophage/dendritic like TO-cells derived from Atlantic salmon (Salmo salar L headkidney leukocytes. Our findings show that recognition of SAV-3 in TO-cells was restricted to endosomal Toll-like receptors (TLRs 3 and 8 together with RIG-I-like receptors (RLRs and not the nucleotide-binding oligomerization domain-like receptors NOD-like receptor (NLRs genes. Among the RLRs, upregulated genes included the retinoic acid inducible gene I (RIG-I, melanoma differentiation association 5 (MDA5 and laboratory of genetics and physiology 2 (LGP2. The study points to possible involvement of the tripartite motif containing 25 (TRIM25 and mitochondrial antiviral signaling protein (MAVS in modulating RIG-I signaling being the first report that links these genes to the RLR pathway in SAV-3 infection in TO-cells. Downstream signaling suggests that both the TLR and RLR pathways use interferon (IFN regulatory factors (IRFs 3 and 7 to produce IFN-a2. The validity of RNA-seq data generated in this study was confirmed by quantitative real time qRT-PCR showing that genes up- or downregulated by RNA-seq were also up- or downregulated by RT-PCR. Overall, this study shows that de novo transcriptome assembly identify key receptors of the TLR and RLR sensors engaged in host pathogen interaction at cellular level. We envisage that data presented here can open a road map for future intervention strategies in SAV infection of salmon.

  5. A Geospatial Scavenger Hunt

    Science.gov (United States)

    Martinez, Adriana E.; Williams, Nikki A.; Metoyer, Sandra K.; Morris, Jennifer N.; Berhane, Stephen A.

    2009-01-01

    With the use of technology such as Global Positioning System (GPS) units and Google Earth for a simple-machine scavenger hunt, you will transform a standard identification activity into an exciting learning experience that motivates students, incorporates practical skills in technology, and enhances students' spatial-thinking skills. In the…

  6. Modulation of cAMP levels by high-fat diet and curcumin and regulatory effects on CD36/FAT scavenger receptor/fatty acids transporter gene expression.

    Science.gov (United States)

    Zingg, Jean-Marc; Hasan, Syeda T; Nakagawa, Kiyotaka; Canepa, Elisa; Ricciarelli, Roberta; Villacorta, Luis; Azzi, Angelo; Meydani, Mohsen

    2017-01-02

    Curcumin, a polyphenol from turmeric (Curcuma longa), reduces inflammation, atherosclerosis, and obesity in several animal studies. In Ldlr -/- mice fed a high-fat diet (HFD), curcumin reduces plasma lipid levels, therefore contributing to a lower accumulation of lipids and to reduced expression of fatty acid transport proteins (CD36/FAT, FABP4/aP2) in peritoneal macrophages. In this study, we analyzed the molecular mechanisms by which curcumin (500, 1000, 1500 mg/kg diet, for 4 months) may influence plasma and tissue lipid levels in Ldlr -/- mice fed an HFD. In liver, HFD significantly suppressed cAMP levels, and curcumin restored almost normal levels. Similar trends were observed in adipose tissues, but not in brain, skeletal muscle, spleen, and kidney. Treatment with curcumin increased phosphorylation of CREB in liver, what may play a role in regulatory effects of curcumin in lipid homeostasis. In cell lines, curcumin increased the level of cAMP, activated the transcription factor CREB and the human CD36 promoter via a sequence containing a consensus CREB response element. Regulatory effects of HFD and Cur on gene expression were observed in liver, less in skeletal muscle and not in brain. Since the cAMP/protein kinase A (PKA)/CREB pathway plays an important role in lipid homeostasis, energy expenditure, and thermogenesis by increasing lipolysis and fatty acid β-oxidation, an increase in cAMP levels induced by curcumin may contribute to its hypolipidemic and anti-atherosclerotic effects. © 2016 BioFactors, 43(1):42-53, 2017. © 2016 International Union of Biochemistry and Molecular Biology.

  7. Protein kinase activity associated with Fcγ/sub 2a/ receptor of a murine macrophage like cell line, P388D1

    International Nuclear Information System (INIS)

    Hirata, Y.; Suzuki, T.

    1987-01-01

    The properties of protein kinase activity associated with Fc receptor specific for IgG/sub 2a/(Fcγ/sub 2a/R) of a murine macrophage like cell line, P388D 1 , were investigated. IgG/sub 2a/-binding protein isolated from the detergent lysate of P388D 1 cells by affinity chromatography of IgG-Sepharose was found to contain four distinct proteins of M/sub r/ 50,000, 43,000, 37,000, and 17,000, which could be autophosphorylated upon incubation with [γ- 32 P]ATP. The autophosphorylation of Fcγ/sub 2a/ receptor complex ceased when exogenous phosphate acceptors (casein or histone) were added in the reaction mixture. Phosphorylation of casein catalyzed by Fcγ/sub 2a/ receptor complex was dependent on casein concentration, increased with time or temperature, was dependent on the concentration of ATP and Mg 2+ , and was maximum at pH near 8. Casein phosphorylation was significantly inhibited by a high concentration of Mn 2+ or KCl or by a small amount of heparin and was enhanced about 2-fold by protamine. Casein kinase activity associated with Fcγ/sub 2a/ receptor used ATP as substrate with an apparent K/sub m/ of 2 μM as well as GTP with an apparent K/sub m/ of 10 μM. Prior heating (60 0 C for 15 min) or treatment with protease (trypsin or Pronase) of Fcγ/sub 2a/ receptor complex almost totally abolished casein kinase activity. Thin-layer chromatography of a partial acid hydrolysate of the phosphorylated casein showed that the site of phosphorylation is at a seryl residue. These results suggest that Fcγ 2 /sub a/ receptor forms a molecule complex with protein kinase, whose characteristics resemble those of type II casein kinase but are different from those of cyclic nucleotide dependent protein kinase or from those of C protein kinase

  8. Purple perilla extracts allay ER stress in lipid-laden macrophages.

    Directory of Open Access Journals (Sweden)

    Sin-Hye Park

    Full Text Available There is a growing body of evidence that excess lipids, hypoxic stress and other inflammatory signals can stimulate endoplasmic reticulum (ER stress in metabolic diseases. However, the pathophysiological importance and the underlying mechanisms of this phenomenon remain unknown. The current study investigated that 50 ng/ml oxidized LDL promoted unfolded protein response (UPR and ER stress in J774A1 murine macrophages, which was blocked by extracts (PPE of purple Perilla frutescens, a plant of the mint family Lamiaceae. The ER stressor tunicamycin was employed as a positive control. Treating 1-10 µg/ml oxidized LDL for 24 h elicited lipotoxic apoptosis in macrophages with obvious nuclear condensation and DNA fragmentation, which was inhibited by PPE. Tunicamycin and oxidized LDL activated and induced the UPR components of activating transcription factor 6 and ER resident chaperone BiP/Grp78 in temporal manners and such effects were blocked by ≥5 µg/ml PPE. In addition, PPE suppressed the enhanced mRNA transcription and splicing of X-box binding protein 1 (XBP1 by tunicamycin and oxidized LDL. The protein induction and nuclear translocation of XBP1 were deterred in PPE-treated macrophages under ER stress. The induction of ATP-binding cassette transporter A1 (ABCA1, scavenger receptor-B1 (SR-B1 and intracellular adhesion molecule-1 (ICAM-1 was abolished by the ER stressor in activated macrophages. The protein induction of ABCA1 and ICAM1 but not SR-B1 was retrieved by adding 10 µg/ml PPE to cells. These results demonstrate that PPE inhibited lipotoxic apoptosis and demoted the induction and activation of UPR components in macrophages. PPE restored normal proteostasis in activated macrophages oxidized LDL. Therefore, PPE was a potent agent antagonizing macrophage ER stress due to lipotoxic signals associated with atherosclerosis.

  9. Regulation of Human Macrophage M1–M2 Polarization Balance by Hypoxia and the Triggering Receptor Expressed on Myeloid Cells-1

    Directory of Open Access Journals (Sweden)

    Federica Raggi

    2017-09-01

    Full Text Available Macrophages (Mf are a heterogeneous population of tissue-resident professional phagocytes and a major component of the leukocyte infiltrate at sites of inflammation, infection, and tumor growth. They can undergo diverse forms of activation in response to environmental factors, polarizing into specialized functional subsets. A common hallmark of the pathologic environment is represented by hypoxia. The impact of hypoxia on human Mf polarization has not been fully established. The objective of this study was to elucidate the effects of a hypoxic environment reflecting that occurring in vivo in diseased tissues on the ability of human Mf to polarize into classically activated (proinflammatory M1 and alternatively activated (anti-inflammatory M2 subsets. We present data showing that hypoxia hinders Mf polarization toward the M1 phenotype by decreasing the expression of T cell costimulatory molecules and chemokine homing receptors and the production of proinflammatory, Th1-priming cytokines typical of classical activation, while promoting their acquisition of phenotypic and secretory features of alternative activation. Furthermore, we identify the triggering receptor expressed on myeloid cells (TREM-1, a member of the Ig-like immunoregulatory receptor family, as a hypoxia-inducible gene in Mf and demonstrate that its engagement by an agonist Ab reverses the M2-polarizing effect of hypoxia imparting a M1-skewed phenotype to Mf. Finally, we provide evidence that Mf infiltrating the inflamed hypoxic joints of children affected by oligoarticular juvenile idiopatic arthritis express high surface levels of TREM-1 associated with predominant M1 polarization and suggest the potential of this molecule in driving M1 proinflammatory reprogramming in the hypoxic synovial environment.

  10. Regulation of Human Macrophage M1–M2 Polarization Balance by Hypoxia and the Triggering Receptor Expressed on Myeloid Cells-1

    Science.gov (United States)

    Raggi, Federica; Pelassa, Simone; Pierobon, Daniele; Penco, Federica; Gattorno, Marco; Novelli, Francesco; Eva, Alessandra; Varesio, Luigi; Giovarelli, Mirella; Bosco, Maria Carla

    2017-01-01

    Macrophages (Mf) are a heterogeneous population of tissue-resident professional phagocytes and a major component of the leukocyte infiltrate at sites of inflammation, infection, and tumor growth. They can undergo diverse forms of activation in response to environmental factors, polarizing into specialized functional subsets. A common hallmark of the pathologic environment is represented by hypoxia. The impact of hypoxia on human Mf polarization has not been fully established. The objective of this study was to elucidate the effects of a hypoxic environment reflecting that occurring in vivo in diseased tissues on the ability of human Mf to polarize into classically activated (proinflammatory M1) and alternatively activated (anti-inflammatory M2) subsets. We present data showing that hypoxia hinders Mf polarization toward the M1 phenotype by decreasing the expression of T cell costimulatory molecules and chemokine homing receptors and the production of proinflammatory, Th1-priming cytokines typical of classical activation, while promoting their acquisition of phenotypic and secretory features of alternative activation. Furthermore, we identify the triggering receptor expressed on myeloid cells (TREM)-1, a member of the Ig-like immunoregulatory receptor family, as a hypoxia-inducible gene in Mf and demonstrate that its engagement by an agonist Ab reverses the M2-polarizing effect of hypoxia imparting a M1-skewed phenotype to Mf. Finally, we provide evidence that Mf infiltrating the inflamed hypoxic joints of children affected by oligoarticular juvenile idiopatic arthritis express high surface levels of TREM-1 associated with predominant M1 polarization and suggest the potential of this molecule in driving M1 proinflammatory reprogramming in the hypoxic synovial environment. PMID:28936211

  11. P17, an Original Host Defense Peptide from Ant Venom, Promotes Antifungal Activities of Macrophages through the Induction of C-Type Lectin Receptors Dependent on LTB4-Mediated PPARγ Activation

    Directory of Open Access Journals (Sweden)

    Khaddouj Benmoussa

    2017-11-01

    Full Text Available Despite the growing knowledge with regard to the immunomodulatory properties of host defense peptides, their impact on macrophage differentiation and on its associated microbicidal functions is still poorly understood. Here, we demonstrated that the P17, a new cationic antimicrobial peptide from ant venom, induces an alternative phenotype of human monocyte-derived macrophages (h-MDMs. This phenotype is characterized by a C-type lectin receptors (CLRs signature composed of mannose receptor (MR and Dectin-1 expression. Concomitantly, this activation is associated to an inflammatory profile characterized by reactive oxygen species (ROS, interleukin (IL-1β, and TNF-α release. P17-activated h-MDMs exhibit an improved capacity to recognize and to engulf Candida albicans through the overexpression both of MR and Dectin-1. This upregulation requires arachidonic acid (AA mobilization and the activation of peroxisome proliferator-activated receptor gamma (PPARγ nuclear receptor through the leukotriene B4 (LTB4 production. AA/LTB4/PPARγ/Dectin-1-MR signaling pathway is crucial for P17-mediated anti-fungal activity of h-MDMs, as indicated by the fact that the activation of this axis by P17 triggered ROS production and inflammasome-dependent IL-1β release. Moreover, we showed that the increased anti-fungal immune response of h-MDMs by P17 was dependent on intracellular calcium mobilization triggered by the interaction of P17 with pertussis toxin-sensitive G-protein-coupled receptors on h-MDMs. Finally, we also demonstrated that P17-treated mice infected with C. albicans develop less severe gastrointestinal infection related to a higher efficiency of their macrophages to engulf Candida, to produce ROS and IL-1β and to kill the yeasts. Altogether, these results identify P17 as an original activator of the fungicidal response of macrophages that acts upstream PPARγ/CLRs axis and offer new immunomodulatory therapeutic perspectives in the field of

  12. Use of plasma C-reactive protein, procalcitonin, neutrophils,macrophage migration inhibitory factor, soluble urokinase-type plasminogen activator receptor, and soluble triggering receptor expressed on myeloid cells-1 in combination to diagnose infections: a prospective study

    DEFF Research Database (Denmark)

    Kofoed, Kristian; Andersen, Ove; Kronborg, Gitte

    2007-01-01

    the diagnostic characteristics of novel and routinely used biomarkers of sepsis alone and in combination. Methods: This prospective cohort study included patients with systemic inflammatory response syndrome who were suspected of having community-acquired infections. It was conducted in a medical emergency...... department and department of infectious diseases at a university hospital. A multiplex immunoassay measuring soluble urokinase-type plasminogen activator (suPAR) and soluble triggering receptor expressed on myeloid cells (sTREM)-1 and macrophage migration inhibitory factor (MIF) was used in parallel...... with standard measurements of C-reactive protein (CRP), procalcitonin (PCT), and neutrophils. Two composite markers were constructed – one including a linear combination of the three best performing markers and another including all six – and the area under the receiver operating characteristic curve (AUC...

  13. Specific deletion of LDL receptor-related protein on macrophages has skewed in vivo effects on cytokine production by invariant natural killer T cells.

    Directory of Open Access Journals (Sweden)

    Roman Covarrubias

    Full Text Available Expression of molecules involved in lipid homeostasis such as the low density lipoprotein receptor (LDLr on antigen presenting cells (APCs has been shown to enhance invariant natural killer T (iNKT cell function. However, the contribution to iNKT cell activation by other lipoprotein receptors with shared structural and ligand binding properties to the LDLr has not been described. In this study, we investigated whether a structurally related receptor to the LDLr, known as LDL receptor-related protein (LRP, plays a role in iNKT cell activation. We found that, unlike the LDLr which is highly expressed on all immune cells, the LRP was preferentially expressed at high levels on F4/80+ macrophages (MΦ. We also show that CD169+ MΦs, known to present antigen to iNKT cells, exhibited increased expression of LRP compared to CD169- MΦs. To test the contribution of MΦ LRP to iNKT cell activation we used a mouse model of MΦ LRP conditional knockout (LRP-cKO. LRP-cKO MΦs pulsed with glycolipid alpha-galactosylceramide (αGC elicited normal IL-2 secretion by iNKT hybridoma and in vivo challenge of LRP-cKO mice led to normal IFN-γ, but blunted IL-4 response in both serum and intracellular expression by iNKT cells. Flow cytometric analyses show similar levels of MHC class-I like molecule CD1d on LRP-cKO MΦs and normal glycolipid uptake. Survey of the iNKT cell compartment in LRP-cKO mice revealed intact numbers and percentages and no homeostatic disruption as evidenced by the absence of programmed death-1 and Ly-49 surface receptors. Mixed bone marrow chimeras showed that the inability iNKT cells to make IL-4 is cell extrinsic and can be rescued in the presence of wild type APCs. Collectively, these data demonstrate that, although MΦ LRP may not be necessary for IFN-γ responses, it can contribute to iNKT cell activation by enhancing early IL-4 secretion.

  14. Δ8-Tetrahydrocannabinol induces cytotoxicity in macrophage J774-1 cells: Involvement of cannabinoid receptor 2 and p38 MAPK

    International Nuclear Information System (INIS)

    Yamaori, Satoshi; Ishii, Hirosuke; Chiba, Kenzo; Yamamoto, Ikuo; Watanabe, Kazuhito

    2013-01-01

    Tetrahydrocannabinol (THC), a psychoactive component of marijuana, is known to exert cytotoxicity in immune cells. In the present study, we examined the cytotoxicity of Δ 8 -THC in mouse macrophage J774-1 cells and a possible involvement of cannabinoid receptors and stress-responsive mitogen-activated protein kinases (MAPKs) in the cytotoxic process. J774-1 cells were treated with Δ 8 -THC (0–20 μM) for up to 6 h. As measured by the MTT and LDH assays, Δ 8 -THC induced cell death of J774-1 cells in a concentration- and/or exposure time-dependent manner. Δ 8 -THC-induced cell damage was associated with vacuole formation, cell swelling, chromatin condensation, and nuclear fragmentation. The cytotoxic effect of Δ 8 -THC was significantly prevented by a caspase-1 inhibitor Ac-YVAD-cmk but not a caspase-3 inhibitor z-DEVD-fmk. The pretreatment with SR144528, a CB 2 receptor-selective antagonist, effectively suppressed Δ 8 -THC-induced cytotoxicity in J774-1 cells, which exclusively expressed CB 2 receptors as indicated by real-time polymerase chain reaction analysis. In contrast, AM251, a CB 1 receptor-selective antagonist, did not affect the cytotoxicity. Pertussis toxin and α-tocopherol significantly attenuated Δ 8 -THC-induced cytotoxicity suggesting that G i/o protein coupling signal transduction and oxidative stress are responsible for the cytotoxicity. Δ 8 -THC stimulated the phosphorylation of p38 MAPK and c-Jun N-terminal kinase (JNK) in J774-1 cells, which were effectively antagonized by the pretreatment with SR144528. In addition, SB203580, a p38 MARK inhibitor, significantly attenuated the cytotoxic effect of Δ 8 -THC, whereas SP600125, a JNK inhibitor, significantly enhanced the cytotoxicity. These results suggest that the cytotoxicity of Δ 8 -THC to J774-1 cells is exerted mediated through the CB 2 receptor followed by the activation of p38 MAPK

  15. Leptospira surface adhesin (Lsa21) induces Toll like receptor 2 and 4 mediated inflammatory responses in macrophages

    OpenAIRE

    Syed M. Faisal; Vivek P. Varma; M. Subathra; Sarwar Azam; Anil K. Sunkara; Mohd Akif; Mirza. S. Baig; Yung-Fu Chang

    2016-01-01

    Leptospirosis is zoonotic and emerging infectious disease of global importance. Little is understood about Leptospira pathogenesis and host immune response. In the present work we have investigated how Leptospira modulates the host innate immune response mediated by Toll-like receptors (TLRs) via surface exposed proteins. We screened Leptospira outer membrane/surface proteins for their ability to activate/inhibit TLR2/4 signaling in HEK293 cell lines. Of these the 21?kDa Leptospira surface ad...

  16. A concerted kinase interplay identifies PPARgamma as a molecular target of ghrelin signaling in macrophages.

    Directory of Open Access Journals (Sweden)

    Annie Demers

    2009-11-01

    Full Text Available The peroxisome proliferator-activator receptor PPARgamma plays an essential role in vascular biology, modulating macrophage function and atherosclerosis progression. Recently, we have described the beneficial effect of combined activation of the ghrelin/GHS-R1a receptor and the scavenger receptor CD36 to induce macrophage cholesterol release through transcriptional activation of PPARgamma. Although the interplay between CD36 and PPARgamma in atherogenesis is well recognized, the contribution of the ghrelin receptor to regulate PPARgamma remains unknown. Here, we demonstrate that ghrelin triggers PPARgamma activation through a concerted signaling cascade involving Erk1/2 and Akt kinases, resulting in enhanced expression of downstream effectors LXRalpha and ABC sterol transporters in human macrophages. These effects were associated with enhanced PPARgamma phosphorylation independently of the inhibitory conserved serine-84. Src tyrosine kinase Fyn was identified as being recruited to GHS-R1a in response to ghrelin, but failure of activated Fyn to enhance PPARgamma Ser-84 specific phosphorylation relied on the concomitant recruitment of docking protein Dok-1, which prevented optimal activation of the Erk1/2 pathway. Also, substitution of Ser-84 preserved the ghrelin-induced PPARgamma activity and responsiveness to Src inhibition, supporting a mechanism independent of Ser-84 in PPARgamma response to ghrelin. Consistent with this, we found that ghrelin promoted the PI3-K/Akt pathway in a Galphaq-dependent manner, resulting in Akt recruitment to PPARgamma, enhanced PPARgamma phosphorylation and activation independently of Ser-84, and increased expression of LXRalpha and ABCA1/G1. Collectively, these results illustrate a complex interplay involving Fyn/Dok-1/Erk and Galphaq/PI3-K/Akt pathways to transduce in a concerted manner responsiveness of PPARgamma to ghrelin in macrophages.

  17. Apoptotic Cells Induced Signaling for Immune Homeostasis in Macrophages and Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Uriel Trahtemberg

    2017-10-01

    Full Text Available Inefficient and abnormal clearance of apoptotic cells (efferocytosis contributes to systemic autoimmune disease in humans and mice, and inefficient chromosomal DNA degradation by DNAse II leads to systemic polyarthritis and a cytokine storm. By contrast, efficient clearance allows immune homeostasis, generally leads to a non-inflammatory state for both macrophages and dendritic cells (DCs, and contributes to maintenance of peripheral tolerance. As many as 3 × 108 cells undergo apoptosis every hour in our bodies, and one of the primary “eat me” signals expressed by apoptotic cells is phosphatidylserine (PtdSer. Apoptotic cells themselves are major contributors to the “anti-inflammatory” nature of the engulfment process, some by secreting thrombospondin-1 (TSP-1 or adenosine monophosphate and possibly other immune modulating “calm-down” signals that interact with macrophages and DCs. Apoptotic cells also produce “find me” and “tolerate me” signals to attract and immune modulate macrophages and DCs that express specific receptors for some of these signals. Neither macrophages nor DCs are uniform, and each cell type may variably express membrane proteins that function as receptors for PtdSer or for opsonins like complement or opsonins that bind to PtdSer, such as protein S and growth arrest-specific 6. Macrophages and DCs also express scavenger receptors, CD36, and integrins that function via bridging molecules such as TSP-1 or milk fat globule-EGF factor 8 protein and that differentially engage in various multi-ligand interactions between apoptotic cells and phagocytes. In this review, we describe the anti-inflammatory and pro-homeostatic nature of apoptotic cell interaction with the immune system. We do not review some forms of immunogenic cell death. We summarize the known apoptotic cell signaling events in macrophages and DCs that are related to toll-like receptors, nuclear factor kappa B, inflammasome, the lipid

  18. Degradation of tissue-type plasminogen activator by human monocyte- derived macrophages is mediated by the mannose receptor and by the low- density lipoprotein receptor-related protein

    NARCIS (Netherlands)

    Noorman, F.; Braat, E.A.M.; Rijken, D.C.

    1995-01-01

    The balance of tissue-type plasminogen activator (t-PA) production and degradation determines its concentration in blood and tissues. Disturbance of this balance may result in either increased or decreased proteolysis. In the present study, we identified the receptor systems involved in the

  19. Reduced soluble receptor for advanced glycation end-products (sRAGE) scavenger capacity precedes pre-eclampsia in Type 1 diabetes

    Science.gov (United States)

    Yu, Y; Hanssen, KF; Kalyanaraman, V; Chirindel, A; Jenkins, AJ; Nankervis, AJ; Torjesen, PA; Scholz, H; Henriksen, T; Lorentzen, B; Garg, SK; Menard, MK; Hammad, SM; Scardo, JA; Stanley, JR; Wu, M; Basu, A; Aston, CE; Lyons, TJ

    2014-01-01

    Objective Increased advanced glycation end-products (AGEs) and their soluble receptors (sRAGE) have been implicated in the pathogenesis of pre-eclampsia (PE). However, this association has not been elucidated in pregnancies complicated by diabetes. We aimed to investigate the serum levels of these factors in pregnant women with Type 1 diabetes mellitus (T1DM), a condition associated with a four-fold increase in PE. Design Prospective study in women with T1DM at 12.2 ± 1.9, 21.6 ± 1.5 and 31.5 ± 1.7 weeks of gestation [mean ± standard deviation (SD); no overlap] before PE onset. Setting Antenatal clinics. Population Pregnant women with T1DM (n = 118; 26 developed PE) and healthy nondiabetic pregnant controls (n = 21). Methods Maternal serum levels of sRAGE (total circulating pool), Nε-(carboxymethyl)lysine (CML), hydroimidazolone (methylglyoxal-modified proteins) and total AGEs were measured by immunoassays. Main outcome measures Serum sRAGE and AGEs in pregnant women with T1DM who subsequently developed PE (DM PE+) versus those who remained normotensive (DM PE–). Results In DM PE+ versus DM PE–, sRAGE was significantly lower in the first and second trimesters, prior to the clinical manifestation of PE (P diabetes, parity and mean arterial pressure as covariates. Conclusions In the early stages of pregnancy, lower circulating sRAGE levels, and the ratio of sRAGE to AGEs, may be associated with the subsequent development of PE in women with T1DM. PMID:22900949

  20. Precision engineering for PRRSV resistance in pigs: Macrophages from genome edited pigs lacking CD163 SRCR5 domain are fully resistant to both PRRSV genotypes while maintaining biological function.

    Directory of Open Access Journals (Sweden)

    Christine Burkard

    2017-02-01

    Full Text Available Porcine Reproductive and Respiratory Syndrome (PRRS is a panzootic infectious disease of pigs, causing major economic losses to the world-wide pig industry. PRRS manifests differently in pigs of all ages but primarily causes late-term abortions and stillbirths in sows and respiratory disease in piglets. The causative agent of the disease is the positive-strand RNA PRRS virus (PRRSV. PRRSV has a narrow host cell tropism, limited to cells of the monocyte/macrophage lineage. CD163 has been described as a fusion receptor for PRRSV, whereby the scavenger receptor cysteine-rich domain 5 (SRCR5 region was shown to be an interaction site for the virus in vitro. CD163 is expressed at high levels on the surface of macrophages, particularly in the respiratory system. Here we describe the application of CRISPR/Cas9 to pig zygotes, resulting in the generation of pigs with a deletion of Exon 7 of the CD163 gene, encoding SRCR5. Deletion of SRCR5 showed no adverse effects in pigs maintained under standard husbandry conditions with normal growth rates and complete blood counts observed. Pulmonary alveolar macrophages (PAMs and peripheral blood monocytes (PBMCs were isolated from the animals and assessed in vitro. Both PAMs and macrophages obtained from PBMCs by CSF1 stimulation (PMMs show the characteristic differentiation and cell surface marker expression of macrophages of the respective origin. Expression and correct folding of the SRCR5 deletion CD163 on the surface of macrophages and biological activity of the protein as hemoglobin-haptoglobin scavenger was confirmed. Challenge of both PAMs and PMMs with PRRSV genotype 1, subtypes 1, 2, and 3 and PMMs with PRRSV genotype 2 showed complete resistance to viral infections assessed by replication. Confocal microscopy revealed the absence of replication structures in the SRCR5 CD163 deletion macrophages, indicating an inhibition of infection prior to gene expression, i.e. at entry/fusion or unpacking stages.

  1. Macrophage markers in serum and tumor have prognostic impact in American Joint Committee on Cancer stage I/II melanoma

    DEFF Research Database (Denmark)

    Jensen, Trine O.; Schmidt, Henrik; Møller, Holger John

    2009-01-01

    PURPOSE: To evaluate the prognostic role of soluble CD163 (sCD163) in serum and macrophage infiltration in primary melanomas from patients with American Joint Committee on Cancer (AJCC) stage I/II melanoma. The scavenger receptor CD163 is associated with anti-inflammatory macrophages...... melanomas from 190 patients were available for immunohistochemical analyzes of CD163(+) and CD68(+) macrophage infiltration. They were estimated semiquantitatively in three different tumor compartments: tumor nests, tumor stroma, and at the invasive front of the tumor. RESULTS: Serum sCD163 treated......, HR = 1.4; 95% CI, 1.1 to 1.8; P = .003). Melanomas with dense CD163(+) macrophage infiltration in tumor stroma and CD68(+) macrophage infiltration at the invasive front were associated with poor overall survival (CD163, HR = 2.7; 95% CI, 0.8 to 9.3; P = .11; and CD68, HR = 2.8; 95% CI, 1.2 to 6.8; P...

  2. CXC chemokine receptor 3 expression on CD34(+) hematopoietic progenitors from human cord blood induced by granulocyte-macrophage colony-stimulating factor

    DEFF Research Database (Denmark)

    Jinquan, T; Quan, S; Jacobi, H H

    2000-01-01

    -induced CD34(+) progenitor chemotaxis. These chemotactic attracted CD34(+) progenitors are colony-forming units-granulocyte-macrophage. gamma IP-10 and Mig also induced GM-CSF-stimulated CD34(+) progenitor adhesion and aggregation by means of CXCR3, a finding confirmed by the observation that anti-CXCR3 m......Ab blocked these functions of gammaIP-10 and Mig but not of chemokine stromal cell-derived factor 1 alpha. gamma IP-10-induced and Mig-induced up-regulation of integrins (CD49a and CD49b) was found to play a crucial role in adhesion of GM-CSF-stimulated CD34(+) progenitors. Moreover, gamma IP-10 and Mig...... stimulated CXCR3 redistribution and cellular polarization in GM-CSF-stimulated CD34(+) progenitors. These results indicate that CXCR3-gamma IP-10 and CXCR3-Mig receptor-ligand pairs, as well as the effects of GM-CSF on them, may be especially important in the cytokine/chemokine environment...

  3. Study of uptake and endocytosis of gamma rays-irradiated crotoxin by mice peritoneal macrophages

    International Nuclear Information System (INIS)

    Cardi, Bruno Andrade

    1999-01-01

    The purpose was to investigate the uptake and endocytosis of 2000 Gy 60 Co irradiated crotoxin through mouse peritoneal macrophages, correlating with native one and another non related protein, the ovalbumin. Native (CTXN) or 2000 Gy 60 Co γ-rays (dose rate 540 Gy/hour) irradiated crotoxin (CTXI) or ovalbumin processed of same manner (OVAN - OVAI) were offered to mouse peritoneal macrophages and their uptake was evaluated by immunohistochemistry and quantitative in situ ELISA. The involvement of scavenger receptors (ScvR) was evaluated by using blockers drugs (Probuco-PBC or Dextran Sulfate - SD) or with nonspecific blocking using fetal calf serum (FBS). The morphology and viability of macrophages were preserved during the experiments. CTXI showed irradiation-induced aggregates and formation of oxidative changing were observed on this protein after gamma rays treatment. By immunohistochemistry we could observe heavy stained phagocytic vacuole on macrophages incubated with CTXI, as compared with CTXN. Quantitatively by in situ ELISA, the sema pattern was observed, displaying a 2-fold CTXI incorporation. In presence of PBC or SD we could find a significant decrease of CTXI uptake but not of CTXN. However the CTXN uptake was depressed by FBS, not observed with CTXI. OVA, after gamma rays treatment, underwent a high degradation suffering a potent incorporation and metabolism by macrophages, with a major uptake of OVAI in longer incubation (120 minutes). Gamma rays ( 60 Co) produced oxidative changes on CTX molecule, leading to a uptake by ScvR-mice peritoneal macrophages, suggesting that the relation antigen-presenting cells and gamma rays-modified proteins are responsible for the better immune response presented by irradiated antigens. (author)

  4. Macrophages under pressure: the role of macrophage polarization in hypertension.

    Science.gov (United States)

    Harwani, Sailesh C

    2018-01-01

    Hypertension is a multifactorial disease involving the nervous, renal, and cardiovascular systems. Macrophages are the most abundant and ubiquitous immune cells, placing them in a unique position to serve as key mediators between these components. The polarization of macrophages confers vast phenotypic and functional plasticity, allowing them to act as proinflammatory, homeostatic, and anti-inflammatory agents. Key differences between the M1 and M2 phenotypes, the 2 subsets at the extremes of this polarization spectrum, place macrophages at a juncture to mediate many mechanisms involved in the pathogenesis of hypertension. Neuronal and non-neuronal regulation of the immune system, that is, the "neuroimmuno" axis, plays an integral role in the polarization of macrophages. In hypertension, the neuroimmuno axis results in synchronization of macrophage mobilization from immune cell reservoirs and their chemotaxis, via increased expression of chemoattractants, to end organs critical in the development of hypertension. This complicated system is largely coordinated by the dichotomous actions of the autonomic neuronal and non-neuronal activation of cholinergic, adrenergic, and neurohormonal receptors on macrophages, leading to their ability to "switch" between phenotypes at sites of active inflammation. Data from experimental models and human studies are in concordance with each other and support a central role for macrophage polarization in the pathogenesis of hypertension. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Organobasierter Sauerstoff-Scavenger/-Indikator

    OpenAIRE

    Langowski, H.C.; Wanner, T.

    2007-01-01

    WO 2007059901 A1 UPAB: 20070911 NOVELTY - Oxygen scavenger/indicator which contains at least one substance having combined scavenging and indicating functions for oxygen which is capable of absorbing oxygen under the effect of moisture in alkaline conditions, and at least one alkaline compound. The indicator effect is caused by a change in at least one physical property of the substance having combined scavenging and indicating function for oxygen, the change being initiated by the presence o...

  6. Ribosomal Protein S6 Kinase (RSK-2 as a central effector molecule in RON receptor tyrosine kinase mediated epithelial to mesenchymal transition induced by macrophage-stimulating protein

    Directory of Open Access Journals (Sweden)

    Zhang Rui-Wen

    2011-05-01

    Full Text Available Abstract Background Epithelial to mesenchymal transition (EMT occurs during cancer cell invasion and malignant metastasis. Features of EMT include spindle-like cell morphology, loss of epithelial cellular markers and gain of mesenchymal phenotype. Activation of the RON receptor tyrosine kinase by macrophage-stimulating protein (MSP has been implicated in cellular EMT program; however, the major signaling determinant(s responsible for MSP-induced EMT is unknown. Results The study presented here demonstrates that RSK2, a downstream signaling protein of the Ras-Erk1/2 pathway, is the principal molecule that links MSP-activated RON signaling to complete EMT. Using MDCK cells expressing RON as a model, a spindle-shape based screen was conducted, which identifies RSK2 among various intracellular proteins as a potential signaling molecule responsible for MSP-induced EMT. MSP stimulation dissociated RSK2 with Erk1/2 and promoted RSK2 nuclear translocation. MSP strongly induced RSK2 phosphorylation in a dose-dependent manner. These effects relied on RON and Erk1/2 phosphorylation, which is significantly potentiated by transforming growth factor (TGF-β1, an EMT-inducing cytokine. Specific RSK inhibitor SL0101 completely prevented MSP-induced RSK phosphorylation, which results in inhibition of MSP-induced spindle-like morphology and suppression of cell migration associated with EMT. In HT-29 cancer cells that barely express RSK2, forced RSK2 expression results in EMT-like phenotype upon MSP stimulation. Moreover, specific siRNA-mediated silencing of RSK2 but not RSK1 in L3.6pl pancreatic cancer cells significantly inhibited MSP-induced EMT-like phenotype and cell migration. Conclusions MSP-induced RSK2 activation is a critical determinant linking RON signaling to cellular EMT program. Inhibition of RSK2 activity may provide a therapeutic opportunity for blocking RON-mediated cancer cell migration and subsequent invasion.

  7. Identification of the haemoglobin scavenger receptor

    DEFF Research Database (Denmark)

    Kristiansen, M; Graversen, Jonas Heilskov; Jacobsen, C

    2001-01-01

    Intravascular haemolysis is a physiological phenomenon as well as a severe pathological complication when accelerated in various autoimmune, infectious (such as malaria) and inherited (such as sickle cell disease) disorders. Haemoglobin released into plasma is captured by the acute phase protein...

  8. Trichoderma asperelloides Spores Downregulate dectin1/2 and TLR2 Receptors of Mice Macrophages and Decrease Candida parapsilosis Phagocytosis Independent of the M1/M2 Polarization

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    Andréa G. dos Santos

    2017-09-01

    Full Text Available The intensive use of pesticides to control pests in agriculture has promoted several issues relating to environment. As chemical pesticides remain controversial, biocontrol agents originating from fungi could be an alternative. Among them, we highlight biocontrol agents derived from the fungi genus Trichoderma, which have been documented in limiting the growth of other phytopathogenic fungus in the roots and leaves of several plant species. An important member of this genus is Trichoderma asperelloides, whose biocontrol agents have been used to promote plant growth while also treating soil diseases caused by microorganisms in both greenhouses and outdoor crops. To evaluate the safety of fungal biological agents for human health, tests to detect potentially adverse effects, such as allergenicity, toxicity, infectivity and pathogenicity, are crucial. In addition, identifying possible immunomodulating properties of fungal biocontrol agents merits further investigation. Thus, the aim of this study was to evaluate the effects of T. asperelloides spores in the internalization of Candida parapsilosis yeast by mice phagocytes, in order to elucidate the cellular and molecular mechanism of this interaction, as a model to understand possible in vivo effects of this fungus. For this, mice were exposed to a fungal spore suspension through-intraperitoneal injection, euthanized and cells from the peripheral blood and peritoneal cavity were collected for functional, quantitative and phenotypic analysis, throughout analysis of membrane receptors gene expression, phagocytosis ability and cells immunophenotyping M1 (CCR7 and CD86 and M2 (CCR2 and CD206. Our analyses showed that phagocytes exposed to fungal spores had reduced phagocytic capacity, as well as a decrease in the quantity of neutrophils and monocytes in the peripheral blood and peritoneal cavity. Moreover, macrophages exposed to T. asperelloides spores did not display the phenotypic profile M1/M2, and

  9. Depletion of macrophages in CD11b diphtheria toxin receptor mice induces brain inflammation and enhances inflammatory signaling during traumatic brain injury.

    Science.gov (United States)

    Frieler, Ryan A; Nadimpalli, Sameera; Boland, Lauren K; Xie, Angela; Kooistra, Laura J; Song, Jianrui; Chung, Yutein; Cho, Kae W; Lumeng, Carey N; Wang, Michael M; Mortensen, Richard M

    2015-10-22

    Immune cells have important roles during disease and are known to contribute to secondary, inflammation-induced injury after traumatic brain injury. To delineate the functional role of macrophages during traumatic brain injury, we depleted macrophages using transgenic CD11b-DTR mice and subjected them to controlled cortical impact. We found that macrophage depletion had no effect on lesion size assessed by T2-weighted MRI scans 28 days after injury. Macrophage depletion resulted in a robust increase in proinflammatory gene expression in both the ipsilateral and contralateral hemispheres after controlled cortical impact. Interestingly, this sizeable increase in inflammation did not affect lesion development. We also showed that macrophage depletion resulted in increased proinflammatory gene expression in the brain and kidney in the absence of injury. These data demonstrate that depletion of macrophages in CD11b-DTR mice can significantly modulate the inflammatory response during brain injury without affecting lesion formation. These data also reveal a potentially confounding inflammatory effect in CD11b-DTR mice that must be considered when interpreting the effects of macrophage depletion in disease models. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Purinergic signaling during macrophage differentiation results in M2 alternative activated macrophages.

    Science.gov (United States)

    Barberà-Cremades, Maria; Baroja-Mazo, Alberto; Pelegrín, Pablo

    2016-02-01

    Macrophages represent a highly heterogenic cell population of the innate immune system, with important roles in the initiation and resolution of the inflammatory response. Purinergic signaling regulates both M1 and M2 macrophage function at different levels by controlling the secretion of cytokines, phagocytosis, and the production of reactive oxygen species. We found that extracellular nucleotides arrest macrophage differentiation from bone marrow precursors via adenosine and P2 receptors. This results in a mature macrophage with increased expression of M2, but not M1, genes. Similar to adenosine and ATP, macrophage growth arrested with LPS treatment resulted in an increase of the M2-related marker Ym1. Recombinant Ym1 was able to affect macrophage proliferation and could, potentially, be involved in the arrest of macrophage growth during hematopoiesis. © Society for Leukocyte Biology.

  11. Quantitative GPCR and ion channel transcriptomics in primary alveolar macrophages and macrophage surrogates

    Directory of Open Access Journals (Sweden)

    Groot-Kormelink Paul J

    2012-10-01

    Full Text Available Abstract Background Alveolar macrophages are one of the first lines of defence against invading pathogens and play a central role in modulating both the innate and acquired immune systems. By responding to endogenous stimuli within the lung, alveolar macrophages contribute towards the regulation of the local inflammatory microenvironment, the initiation of wound healing and the pathogenesis of viral and bacterial infections. Despite the availability of protocols for isolating primary alveolar macrophages from the lung these cells remain recalcitrant to expansion in-vitro and therefore surrogate cell types, such as monocyte derived macrophages and phorbol ester-differentiated cell lines (e.g. U937, THP-1, HL60 are frequently used to model macrophage function. Methods The availability of high throughput gene expression technologies for accurate quantification of transcript levels enables the re-evaluation of these surrogate cell types for use as cellular models of the alveolar macrophage. Utilising high-throughput TaqMan arrays and focussing on dynamically regulated families of integral membrane proteins, we explore the similarities and differences in G-protein coupled receptor (GPCR and ion channel expression in alveolar macrophages and their widely used surrogates. Results The complete non-sensory GPCR and ion channel transcriptome is described for primary alveolar macrophages and macrophage surrogates. The expression of numerous GPCRs and ion channels whose expression were hitherto not described in human alveolar macrophages are compared across primary macrophages and commonly used macrophage cell models. Several membrane proteins known to have critical roles in regulating macrophage function, including CXCR6, CCR8 and TRPV4, were found to be highly expressed in macrophages but not expressed in PMA-differentiated surrogates. Conclusions The data described in this report provides insight into the appropriate choice of cell models for

  12. Different Effects of the Immunomodulatory Drug GMDP Immobilized onto Aminopropyl Modified and Unmodified Mesoporous Silica Nanoparticles upon Peritoneal Macrophages of Women with Endometriosis

    Directory of Open Access Journals (Sweden)

    Yuliya Antsiferova

    2013-01-01

    Full Text Available The aim of the present work was to compare in vitro the possibility of application of unmodified silica nanoparticles (UMNPs and modified by aminopropyl groups silica nanoparticles (AMNPs for topical delivery of immunomodulatory drug GMDP to the peritoneal macrophages of women with endometriosis. The absence of cytotoxic effect and high cellular uptake was demonstrated for both types of silica nanoparticles. The immobilization of GMDP on the UMNPs led to the suppression of the stimulatory effect of GMDP on the membrane expression of scavenger receptors SR-AI and SR-B, mRNAs expression of NOD2 and RAGE, and synthesis of proteolytic enzyme MMP-9 and its inhibitor TIMP-1. GMDP, immobilized onto AMNPs, enhanced the initially reduced membrane expression of SRs and increased NOD2, RAGE, and MMP-9 mRNAs expression by macrophages. Simultaneously high level of mRNAs expression of factors, preventing undesirable hyperactivation of peritoneal macrophages (SOCS1 and TIMP-1, was observed in macrophages incubated in the presence of GMDP, immobilized onto AMNPs. The effect of AMNPs immobilized GMDP in some cases exceeded the effect of free GMDP. Thus, among the studied types of silica nanoparticles, AMNPs are the most suitable nanoparticles for topical delivery of GMDP to the peritoneal macrophages.

  13. Different effects of the immunomodulatory drug GMDP immobilized onto aminopropyl modified and unmodified mesoporous silica nanoparticles upon peritoneal macrophages of women with endometriosis.

    Science.gov (United States)

    Antsiferova, Yuliya; Sotnikova, Nataliya; Parfenyuk, Elena

    2013-01-01

    The aim of the present work was to compare in vitro the possibility of application of unmodified silica nanoparticles (UMNPs) and modified by aminopropyl groups silica nanoparticles (AMNPs) for topical delivery of immunomodulatory drug GMDP to the peritoneal macrophages of women with endometriosis. The absence of cytotoxic effect and high cellular uptake was demonstrated for both types of silica nanoparticles. The immobilization of GMDP on the UMNPs led to the suppression of the stimulatory effect of GMDP on the membrane expression of scavenger receptors SR-AI and SR-B, mRNAs expression of NOD2 and RAGE, and synthesis of proteolytic enzyme MMP-9 and its inhibitor TIMP-1. GMDP, immobilized onto AMNPs, enhanced the initially reduced membrane expression of SRs and increased NOD2, RAGE, and MMP-9 mRNAs expression by macrophages. Simultaneously high level of mRNAs expression of factors, preventing undesirable hyperactivation of peritoneal macrophages (SOCS1 and TIMP-1), was observed in macrophages incubated in the presence of GMDP, immobilized onto AMNPs. The effect of AMNPs immobilized GMDP in some cases exceeded the effect of free GMDP. Thus, among the studied types of silica nanoparticles, AMNPs are the most suitable nanoparticles for topical delivery of GMDP to the peritoneal macrophages.

  14. Hypervariable region 1 deletion and required adaptive envelope mutations confer decreased dependency on scavenger receptor class B type I and low-density lipoprotein receptor for hepatitis C virus

    DEFF Research Database (Denmark)

    Prentoe, Jannick; Serre, Stéphanie B N; Ramirez, Santseharay

    2014-01-01

    -deleted viruses. Apolipoprotein E (ApoE)-specific HCV neutralization was similar for H77, J6, and S52 viruses with and without HVR1. In conclusion, HVR1 and HVR1-related adaptive envelope mutations appeared to be involved in LDLr and SR-BI dependency, respectively. Also, LDLr served Apo....../S733F), S52(ΔHVR1/A369V), and S52(A369V), but not for J6(ΔHVR1). Low-density lipoprotein receptor (LDLr) dependency was decreased for HVR1-deleted viruses, but not for H77(N476D/S733F) and S52(A369V). Soluble LDLr neutralization revealed strong inhibition of parental HCV but limited effect against HVR1...

  15. Macrophage Liver Kinase B1 Inhibits Foam Cell Formation and Atherosclerosis.

    Science.gov (United States)

    Liu, Zhaoyu; Zhu, Huaiping; Dai, Xiaoyan; Wang, Cheng; Ding, Ye; Song, Ping; Zou, Ming-Hui

    2017-10-13

    LKB1 (liver kinase B1) is a serine/threonine kinase and tumor suppressor, which regulates the homeostasis of hematopoietic cells and immune responses. Macrophages transform into foam cells upon taking-in lipids. No role for LKB1 in foam cell formation has previously been reported. We sought to establish the role of LKB1 in atherosclerotic foam cell formation. LKB1 expression was examined in human carotid atherosclerotic plaques and in western diet-fed atherosclerosis-prone Ldlr -/- and ApoE -/- mice. LKB1 expression was markedly reduced in human plaques when compared with nonatherosclerotic vessels. Consistently, time-dependent reduction of LKB1 levels occurred in atherosclerotic lesions in western diet-fed Ldlr -/- and ApoE -/- mice. Exposure of macrophages to oxidized low-density lipoprotein downregulated LKB1 in vitro. Furthermore, LKB1 deficiency in macrophages significantly increased the expression of SRA (scavenger receptor A), modified low-density lipoprotein uptake and foam cell formation, all of which were abolished by blocking SRA. Further, we found LKB1 phosphorylates SRA resulting in its lysosome degradation. To further investigate the role of macrophage LKB1 in vivo, ApoE -/- LKB1 fl/fl LysM cre and ApoE -/- LKB1 fl/fl mice were fed with western diet for 16 weeks. Compared with ApoE -/- LKB1 fl/fl wild-type control, ApoE -/- LKB1 fl/fl LysM cre mice developed more atherosclerotic lesions in whole aorta and aortic root area, with markedly increased SRA expression in aortic root lesions. We conclude that macrophage LKB1 reduction caused by oxidized low-density lipoprotein promotes foam cell formation and the progression of atherosclerosis. © 2017 American Heart Association, Inc.

  16. Viral Inhibition of Bacterial Phagocytosis by Human Macrophages: Redundant Role of CD36.

    Directory of Open Access Journals (Sweden)

    Grace E Cooper

    Full Text Available Macrophages are essential to maintaining lung homoeostasis and recent work has demonstrated that influenza-infected lung macrophages downregulate their expression of the scavenger receptor CD36. This receptor has also been shown to be involved in phagocytosis of Streptococcus pneumoniae, a primary agent associated with pneumonia secondary to viral infection. The aim of this study was to investigate the role of CD36 in the effects of viral infection on macrophage phagocytic function. Human monocyte-derived macrophages (MDM were exposed to H3N2 X31 influenza virus, M37 respiratory syncytial virus (RSV or UV-irradiated virus. No infection of MDM was seen upon exposure to UV-irradiated virus but incubation with live X31 or M37 resulted in significant levels of viral detection by flow cytometry or RT-PCR respectively. Infection resulted in significantly diminished uptake of S. pneumoniae by MDM and significantly decreased expression of CD36 at both the cell surface and mRNA level. Concurrently, there was a significant increase in IFNβ gene expression in response to infection and we observed a significant decrease in bacterial phagocytosis (p = 0.031 and CD36 gene expression (p = 0.031 by MDM cultured for 24 h in 50IU/ml IFNβ. Knockdown of CD36 by siRNA resulted in decreased phagocytosis, but this was mimicked by transfection reagent alone. When MDM were incubated with CD36 blocking antibodies no effect on phagocytic ability was observed. These data indicate that autologous IFNβ production by virally-infected cells can inhibit bacterial phagocytosis, but that decreased CD36 expression by these cells does not play a major role in this functional deficiency.

  17. Transcriptomic signature of Leishmania infected mice macrophages: a metabolic point of view.

    Directory of Open Access Journals (Sweden)

    Imen Rabhi

    Full Text Available We analyzed the transcriptional signatures of mouse bone marrow-derived macrophages at different times after infection with promastigotes of the protozoan parasite Leishmania major. Ingenuity Pathway Analysis revealed that the macrophage metabolic pathways including carbohydrate and lipid metabolisms were among the most altered pathways at later time points of infection. Indeed, L. major promastiogtes induced increased mRNA levels of the glucose transporter and almost all of the genes associated with glycolysis and lactate dehydrogenase, suggesting a shift to anaerobic glycolysis. On the other hand, L. major promastigotes enhanced the expression of scavenger receptors involved in the uptake of Low-Density Lipoprotein (LDL, inhibited the expression of genes coding for proteins regulating cholesterol efflux, and induced the synthesis of triacylglycerides. These data suggested that Leishmania infection disturbs cholesterol and triglycerides homeostasis and may lead to cholesterol accumulation and foam cell formation. Using Filipin and Bodipy staining, we showed cholesterol and triglycerides accumulation in infected macrophages. Moreover, Bodipy-positive lipid droplets accumulated in close proximity to parasitophorous vacuoles, suggesting that intracellular L. major may take advantage of these organelles as high-energy substrate sources. While the effect of infection on cholesterol accumulation and lipid droplet formation was independent on parasite development, our data indicate that anaerobic glycolysis is actively induced by L. major during the establishment of infection.

  18. Ketamine inhibits tumor necrosis factor-α and interleukin-6 gene expressions in lipopolysaccharide-stimulated macrophages through suppression of toll-like receptor 4-mediated c-Jun N-terminal kinase phosphorylation and activator protein-1 activation

    International Nuclear Information System (INIS)

    Wu, G.-J.; Chen, T.-L.; Ueng, Y.-F.; Chen, R.-M.

    2008-01-01

    Our previous study showed that ketamine, an intravenous anesthetic agent, has anti-inflammatory effects. In this study, we further evaluated the effects of ketamine on the regulation of tumor necrosis factor-α (TNF-α) and interlukin-6 (IL-6) gene expressions and its possible signal-transducing mechanisms in lipopolysaccharide (LPS)-activated macrophages. Exposure of macrophages to 1, 10, and 100 μM ketamine, 100 ng/ml LPS, or a combination of ketamine and LPS for 1, 6, and 24 h was not cytotoxic to macrophages. A concentration of 1000 μM of ketamine alone or in combined treatment with LPS caused significant cell death. Administration of LPS increased cellular TNF-α and IL-6 protein levels in concentration- and time-dependent manners. Meanwhile, treatment with ketamine concentration- and time-dependently alleviated the enhanced effects. LPS induced TNF-α and IL-6 mRNA syntheses. Administration of ketamine at a therapeutic concentration (100 μM) significantly inhibited LPS-induced TNF-α and IL-6 mRNA expressions. Application of toll-like receptor 4 (TLR4) small interfering (si)RNA into macrophages decreased cellular TLR4 levels. Co-treatment of macrophages with ketamine and TLR4 siRNA decreased the LPS-induced TNF-α and IL-6 productions more than alone administration of TLR4 siRNA. LPS stimulated phosphorylation of c-Jun N-terminal kinase and translocation of c-Jun and c-Fos from the cytoplasm to nuclei. However, administration of ketamine significantly decreased LPS-induced activation of c-Jun N-terminal kinase and translocation of c-Jun and c-Fos. LPS increased the binding of nuclear extracts to activator protein-1 consensus DNA oligonucleotides. Administration of ketamine significantly ameliorated LPS-induced DNA binding activity of activator protein-1. Therefore, a clinically relevant concentration of ketamine can inhibit TNF-α and IL-6 gene expressions in LPS-activated macrophages. The suppressive mechanisms occur through suppression of TLR4-mediated

  19. Adipocyte-Macrophage Cross-Talk in Obesity.

    Science.gov (United States)

    Engin, Ayse Basak

    2017-01-01

    Obesity is characterized by the chronic low-grade activation of the innate immune system. In this respect, macrophage-elicited metabolic inflammation and adipocyte-macrophage interaction has a primary importance in obesity. Large amounts of macrophages are accumulated by different mechanisms in obese adipose tissue. Hypertrophic adipocyte-derived chemotactic monocyte chemoattractant protein-1 (MCP-1)/C-C chemokine receptor 2 (CCR2) pathway also promotes more macrophage accumulation into the obese adipose tissue. However, increased local extracellular lipid concentrations is a final mechanism for adipose tissue macrophage accumulation. A paracrine loop involving free fatty acids and tumor necrosis factor-alpha (TNF-alpha) between adipocytes and macrophages establishes a vicious cycle that aggravates inflammatory changes in the adipose tissue. Adipocyte-specific caspase-1 and production of interleukin-1beta (IL-1beta) by macrophages; both adipocyte and macrophage induction by toll like receptor-4 (TLR4) through nuclear factor-kappaB (NF-kappaB) activation; free fatty acid-induced and TLR-mediated activation of c-Jun N-terminal kinase (JNK)-related pro-inflammatory pathways in CD11c+ immune cells; are effective in macrophage accumulation and in the development of adipose tissue inflammation. Old adipocytes are removed by macrophages through trogocytosis or sending an "eat me" signal. The obesity-induced changes in adipose tissue macrophage numbers are mainly due to increases in the triple-positive CD11b+ F4/80+ CD11c+ adipose tissue macrophage subpopulation. The ratio of M1-to-M2 macrophages is increased in obesity. Furthermore, hypoxia along with higher concentrations of free fatty acids exacerbates macrophage-mediated inflammation in obesity. The metabolic status of adipocytes is a major determinant of macrophage inflammatory output. Macrophage/adipocyte fatty-acid-binding proteins act at the interface of metabolic and inflammatory pathways. Both macrophages and

  20. Trastuzumab triggers phagocytic killing of high HER2 cancer cells in vitro and in vivo by interaction with Fcγ receptors on macrophages.

    Science.gov (United States)

    Shi, Yun; Fan, Xuejun; Deng, Hui; Brezski, Randall J; Rycyzyn, Michael; Jordan, Robert E; Strohl, William R; Zou, Quanming; Zhang, Ningyan; An, Zhiqiang

    2015-05-01

    Trastuzumab has been used for the treatment of HER2-overexpressing breast cancer for more than a decade, but the mechanisms of action for the therapy are still being actively investigated. Ab-dependent cell-mediated cytotoxicity mediated by NK cells is well recognized as one of the key mechanisms of action for trastuzumab, but trastuzumab-mediated Ab-dependent cellular phagocytosis (ADCP) has not been established. In this study, we demonstrate that macrophages, by way of phagocytic engulfment, can mediate ADCP and cancer cell killing in the presence of trastuzumab. Increased infiltration of macrophages in the tumor tissue was associated with enhanced efficacy of trastuzumab whereas depletion of macrophages resulted in reduced antitumor efficacy in mouse xenograft tumor models. Among the four mouse FcγRs, FcγRIV exhibits the strongest binding affinity to trastuzumab. Knockdown of FcγRIV in mouse macrophages reduced cancer cell killing and ADCP activity triggered by trastuzumab. Consistently, an upregulation of FcγRIV expression by IFN-γ triggered an increased ADCP activity by trastuzumab. In an analogous fashion, IFN-γ priming of human macrophages increased the expression of FcγRIII, the ortholog of murine FcγRIV, and increased trastuzumab-mediated cancer cell killing. Thus, in two independent systems, the results indicated that activation of macrophages in combination with trastuzumab can serve as a therapeutic strategy for treating high HER2 breast cancer by boosting ADCP killing of cancer cells. Copyright © 2015 by The American Association of Immunologists, Inc.

  1. Acute exposure to crystalline silica reduces macrophage activation in response to bacterial lipoproteins

    Directory of Open Access Journals (Sweden)

    Gillian Lee Beamer

    2016-02-01

    Full Text Available Numerous studies have examined the relationship between alveolar macrophages (AM and crystalline silica (SiO2 using in vitro and in vivo immunotoxicity models; however, exactly how exposure to SiO2 alters the functionality of AM and the potential consequences for immunity to respiratory pathogens remains largely unknown. Because recognition and clearance of inhaled particulates and microbes is largely mediated by pattern recognition receptors (PRR on the surface of AM, we hypothesized that exposure to SiO2 limits the ability of AM to respond to bacterial challenge by altering PRR expression. Alveolar and bone marrow-derived macrophages downregulate TLR2 expression following acute SiO2 exposure (e.g. 4 hours. Interestingly, these responses were dependent upon interactions between SiO2 and the class A scavenger receptor CD204, but not MARCO. Furthermore, SiO2 exposure decreased uptake of fluorescently labeled Pam2CSK4 and Pam3CSK4, resulting in reduced secretion of IL-1β, but not IL-6. Collectively, our data suggest that SiO2 exposure alters AM phenotype, which in turn affects their ability to uptake and respond to bacterial lipoproteins.

  2. Fluoromica nanoparticle cytotoxicity in macrophages decreases with size and extent of uptake

    Directory of Open Access Journals (Sweden)

    Tee N

    2015-03-01

    Full Text Available Nicolin Tee,1 Yingdong Zhu,2 Gysell M Mortimer,1 Darren J Martin,2 Rodney F Minchin11School of Biomedical Science, University of Queensland, Brisbane, QLD, Australia; 2Australian Institute of Bioengineering and Nanotechnology, University of Queensland, Brisbane, QLD, AustraliaAbstract: Polyurethanes are widely used in biomedical devices such as heart valves, pacemaker leads, catheters, vascular devices, and surgical dressings because of their excellent mechanical properties and good biocompatibility. Layered silicate nanoparticles can significantly increase tensile strength and breaking strain of polyurethanes potentially increasing the life span of biomedical devices that suffer from wear in vivo. However, very little is known about how these nanoparticles interact with proteins and cells and how they might exert unwanted effects. A series of fluoromica nanoparticles ranging in platelet size from 90 to over 600 nm in diameter were generated from the same base material ME100 by high energy milling and differential centrifugation. The cytotoxicity of the resulting particles was dependent on platelet size but in a manner that is opposite to many other types of nanomaterials. For the fluoromicas, the smaller the platelet size, the less toxicity was observed. The small fluoromica nanoparticles (<200 nm were internalized by macrophages via scavenger receptors, which was dependent on the protein corona formed in serum. This internalization was associated with apoptosis in RAW cells but not in dTHP-1 cells. The larger particles were not internalized efficiently but mostly decorated the surface of the cells, causing membrane disruption, even in the presence of 80% serum. This work suggests the smaller fluoromica platelets may be safer for use in humans but their propensity to recognize macrophage scavenger receptors also suggests that they will target the reticulo-endoplasmic system in vivo.Keywords: layered silicates, accumulation, phagocytosis, high

  3. Oxidative burst and nitric oxide responses in carp macrophages induced by zymosan, MacroGard® and selective dectin-1 agonists suggest recognition by multiple pattern recognition receptors

    DEFF Research Database (Denmark)

    Pietretti, D.; Jiménez, Natalia Ivonne Vera; Hoole, D.

    2013-01-01

    phosphatase (SEAP) reporter gene. In addition, dectin-1-specific ligands in mammals i.e. zymosan treated to deplete the TLR-stimulating properties and curdlan, were monitored for their effects on carp macrophages by measuring reactive oxygen and nitrogen radicals production, as well as cytokine gene...

  4. Binding and uptake of {sup 125}iodine-labelled, oxidized low density lipoprotein by macrophages: Comparison of the effects of {alpha}-tocopherol, probucol, pyridoxal-5`-phosphate and magnesium-pyridoxal-5`-phosphate-glutamate

    Energy Technology Data Exchange (ETDEWEB)

    Selmer, D. [Technische Univ. Muenchen, Freising-Weihenstephan (Germany). Lehrstuhl fuer Phytopathologie; Senekowitsch-Schmidtke, R. [Technische Univ. Muenchen (Germany). Nuklearmedizinische Klinik; Schneider, W. [Steigerwald Arzneimittel, Darmstadt (Germany); Elstner, E.F. [Technische Univ. Muenchen, Freising-Weihenstephan (Germany). Lehrstuhl fuer Phytopathologie

    1997-01-01

    Specific and unspecific binding and uptake (internalization) by macrophages of {sup 125}iodine-labelled, copper-oxidized human low density lipoprotein is differently influenced by the anti-oxidants {alpha}-tocopherol ({alpha}-Toc), probucol (Prob), pyridoxal-5`-phosphate (PP) and the magnesium-pyridoxal-5`-phosphate glutamate complex (MPPG). Binding as well as internalization, mediated by the so-called `scavenger receptor` is lower in the presence of MPPG whereas both specific binding and internalization are enhanced. The comparison of the effects in vitro allows a rating of the potentially anti-atherogenic and thus protective effects of the tested substances as follows: MPPG>PP>{alpha}-Toc>Prob. (orig.)

  5. The distribution of macrophages with a M1 or M2 phenotype in relation to prognosis and the molecular characteristics of colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Sofia Edin

    Full Text Available High macrophage infiltration has been correlated to improved survival in colorectal cancer (CRC. Tumor associated macrophages (TAMs play complex roles in tumorigenesis since they are believed to hold both tumor preventing (M1 macrophages and tumor promoting (M2 macrophages activities. Here we have applied an immunohistochemical approach to determine the degree of infiltrating macrophages with a M1 or M2 phenotype in clinical specimens of CRC in relation to prognosis, both in CRC in general but also in subgroups of CRC defined by microsatellite instability (MSI screening status and the CpG island methylator phenotype (CIMP. A total of 485 consecutive CRC specimens were stained for nitric oxide synthase 2 (NOS2 (also denoted iNOS as a marker for the M1 macrophage phenotype and the scavenger receptor CD163 as a marker for the M2 macrophage phenotype. The average infiltration of NOS2 and CD163 expressing macrophages along the invasive tumor front was semi-quantitatively evaluated using a four-graded scale. Two subtypes of macrophages, displaying M1 (NOS2(+ or M2 (CD163(+ phenotypes, were recognized. We observed a significant correlation between the amount of NOS2(+ and CD163(+ cells (P<0.0001. A strong inverse correlation to tumor stage was found for both NOS2 (P<0.0001 and CD163 (P<0.0001 infiltration. Furthermore, patients harbouring tumors highly infiltrated by NOS2(+ cells had a significantly better prognosis than those infiltrated by few NOS2(+ cells, and this was found to be independent of MSI screening status and CIMP status. No significant difference was found on cancer-specific survival in groups of CRC with different NOS2/CD163 ratios. In conclusion, an increased infiltration of macrophages with a M1 phenotype at the tumor front is accompanied by a concomitant increase in macrophages with a M2 phenotype, and in a stage dependent manner correlated to a better prognosis in patients with CRC.

  6. DMPD: Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent pathways inmacrophage activation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17502339 Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent pathways inmacrophage...May 14. (.png) (.svg) (.html) (.csml) Show Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent pathways inmacrophage...T, Toll-like receptor, and ITAM-dependent pathways inmacrophage activation. Authors Hu X, Chen J, Wang L, Iv

  7. DMPD: Toll-like receptors: from the discovery of NFkappaB to new insights intotranscriptional regulations in innate immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16930560 Toll-like receptors: from the discovery of NFkappaB to new insights intotr...2-13. Epub 2006 Aug 22. (.png) (.svg) (.html) (.csml) Show Toll-like receptors: from the discovery of NFkapp...6930560 Title Toll-like receptors: from the discovery of NFkappaB to new insights intotranscriptional regula

  8. DMPD: Toll-like receptors and the host defense against microbial pathogens: bringingspecificity to the innate-immune system. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15075354 Toll-like receptors and the host defense against microbial pathogens: brin...oc Biol. 2004 May;75(5):749-55. Epub 2004 Jan 14. (.png) (.svg) (.html) (.csml) Show Toll-like receptors and the host defense again...immune system. PubmedID 15075354 Title Toll-like receptors and the host defense against microbial pathogens:

  9. Rain scavenging of radioactive particles

    International Nuclear Information System (INIS)

    Williams, A.L.

    1975-01-01

    An assessment is made of the rainout of airborne radioactive particles from a nuclear detonation with emphasis on the microphysical removal processes. For submicron particles the scavenging processes examined are Brownian and turbulent diffusion to cloud droplets. For particles larger than 1 μm radius, nucleation scavenging is examined. For various particle size and radioactivity distributions, it is found that from 27 to 99 percent of the radioactivity is attached to cloud droplets and subject to rapid removal by rain. (U.S.)

  10. Macrophages and Uveitis in Experimental Animal Models

    Directory of Open Access Journals (Sweden)

    Salvador Mérida

    2015-01-01

    Full Text Available Resident and infiltrated macrophages play relevant roles in uveitis as effectors of innate immunity and inductors of acquired immunity. They are major effectors of tissue damage in uveitis and are also considered to be potent antigen-presenting cells. In the last few years, experimental animal models of uveitis have enabled us to enhance our understanding of the leading role of macrophages in eye inflammation processes, including macrophage polarization in experimental autoimmune uveoretinitis and the major role of Toll-like receptor 4 in endotoxin-induced uveitis. This improved knowledge should guide advantageous iterative research to establish mechanisms and possible therapeutic targets for human uveitis resolution.

  11. CD36 Differently Regulates Macrophage Responses to Smooth and Rough Lipopolysaccharide.

    Directory of Open Access Journals (Sweden)

    Rafał Biedroń

    Full Text Available Lipopolysaccharide (LPS is the major pathogen-associated molecular pattern of Gram-negative bacterial infections, and includes smooth (S-LPS and rough (R-LPS chemotypes. Upon activation by LPS through CD14, TLR4/MD-2 heterodimers sequentially induce two waves of intracellular signaling for macrophage activation: the MyD88-dependent pathway from the plasma membrane and, following internalization, the TRIF-dependent pathway from endosomes. We sought to better define the role of scavenger receptors CD36 and CD204/SR-A as accessory LPS receptors that can contribute to pro-inflammatory and microbicidal activation of macrophages. We have found that CD36 differently regulates activation of mouse macrophages by S-LPS versus R-LPS. The ability of CD36 to substitute for CD14 in loading R-LPS, but not S-LPS onto TLR4/MD-2 allows CD14-independent macrophage responses to R-LPS. Conversely, S-LPS, but not R-LPS effectively stimulates CD14 binding to CD36, which favors S-LPS transfer from CD14 onto TLR4/MD-2 under conditions of low CD14 occupancy with S-LPS in serum-free medium. In contrast, in the presence of serum, CD36 reduces S-LPS binding to TLR4/MD-2 and the subsequent MyD88-dependent signaling, by mediating internalization of S-LPS/CD14 complexes. Additionally, CD36 positively regulates activation of TRIF-dependent signaling by both S-LPS and R-LPS, by promoting TLR4/MD-2 endocytosis. In contrast, we have found that SR-A does not function as a S-LPS receptor. Thus, by co-operating with CD14 in both R- and S-LPS loading onto TLR4/MD-2, CD36 can enhance the sensitivity of tissue-resident macrophages in detecting infections by Gram-negative bacteria. However, in later phases, following influx of serum to the infection site, the CD36-mediated negative regulation of MyD88-dependent branch of S-LPS-induced TLR4 signaling might constitute a mechanism to prevent an excessive inflammatory response, while preserving the adjuvant effect of S-LPS for adaptive

  12. Nicotine Impairs Macrophage Control of Mycobacterium tuberculosis.

    Science.gov (United States)

    Bai, Xiyuan; Stitzel, Jerry A; Bai, An; Zambrano, Cristian A; Phillips, Matthew; Marrack, Philippa; Chan, Edward D

    2017-09-01

    Pure nicotine impairs macrophage killing of Mycobacterium tuberculosis (MTB), but it is not known whether the nicotine component in cigarette smoke (CS) plays a role. Moreover, the mechanisms by which nicotine impairs macrophage immunity against MTB have not been explored. To neutralize the effects of nicotine in CS extract, we used a competitive inhibitor to the nicotinic acetylcholine receptor (nAChR)-mecamylamine-as well as macrophages derived from mice with genetic disruption of specific subunits of nAChR. We also determined whether nicotine impaired macrophage autophagy and whether nicotine-exposed T regulatory cells (Tregs) could subvert macrophage anti-MTB immunity. Mecamylamine reduced the CS extract increase in MTB burden by 43%. CS extract increase in MTB was also significantly attenuated in macrophages from mice with genetic disruption of either the α7, β2, or β4 subunit of nAChR. Nicotine inhibited autophagosome formation in MTB-infected THP-1 cells and primary murine alveolar macrophages, as well as increased the intracellular MTB burden. Nicotine increased migration of THP-1 cells, consistent with the increased number of macrophages found in the lungs of smokers. Nicotine induced Tregs to produce transforming growth factor-β. Naive mouse macrophages co-cultured with nicotine-exposed Tregs had significantly greater numbers of viable MTB recovered with increased IL-10 production and urea production, but no difference in secreted nitric oxide as compared with macrophages cocultured with unexposed Tregs. We conclude that nicotine in CS plays an important role in subverting macrophage control of MTB infection.

  13. Precipitation scavenging of aerosol particles

    International Nuclear Information System (INIS)

    Radke, L.F.; Eltgroth, M.W.; Hobbs, P.V.

    1978-01-01

    The paper presents the results of precipitation scavenging measurements of particles in the atmosphere and in plumes which were obtained using an airborne measuring system. Attention is given to the so-called 'Greenfield gap' and collection efficiencies for submicron particles

  14. DMPD: CR3 (CD11b, CD18): a phagocyte and NK cell membrane receptor with multipleligand specificities and functions. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available ) (.html) (.csml) Show CR3 (CD11b, CD18): a phagocyte and NK cell membrane receptor with multipleligand specificities and function...d NK cell membrane receptor with multipleligand specificities and functions. Authors Ross GD, Vetvicka V. Pu...igand specificities and functions. Ross GD, Vetvicka V. Clin Exp Immunol. 1993 May;92(2):181-4. (.png) (.svg...8485905 CR3 (CD11b, CD18): a phagocyte and NK cell membrane receptor with multiplel

  15. Identification of a new adapter protein that may link the common beta subunit of the receptor for granulocyte/macrophage colony-stimulating factor, interleukin (IL)-3, and IL-5 to phosphatidylinositol 3-kinase.

    Science.gov (United States)

    Jücker, M; Feldman, R A

    1995-11-17

    Binding of human granulocyte/macrophage colony-stimulating factor (hGM-CSF) to its receptor induces the rapid activation of phosphatidylinositol-3 kinase (PI 3-kinase). As hGM-CSF receptor (hGMR) does not contain a consensus sequence for binding of PI 3-kinase, hGMR must use a distinct mechanism for its association with and activation of PI 3-kinase. Here, we describe the identification of a tyrosine-phosphorylated protein of 76-85 kDa (p80) that associates with the common beta subunit of hGMR and with the SH2 domains of the p85 subunit of PI 3-kinase in hGM-CSF-stimulated cells. Src/Yes and Lyn were tightly associated with the p80.PI 3-kinase complex, suggesting that p80 and other phosphotyrosyl proteins present in the complex were phosphorylated by Src family kinases. Tyrosine phosphorylation of p80 was only detected in hGM-CSF or human interleukin-3-stimulated cells, suggesting that activation of p80 might be specific for signaling via the common beta subunit. We postulate that p80 functions as an adapter protein that may participate in linking the hGM-CSF receptor to the PI 3-kinase signaling pathway.

  16. The response of macrophages to titanium particles is determined by macrophage polarization.

    Science.gov (United States)

    Pajarinen, Jukka; Kouri, Vesa-Petteri; Jämsen, Eemeli; Li, Tian-Fang; Mandelin, Jami; Konttinen, Yrjö T

    2013-11-01

    Aseptic loosening of total joint replacements is driven by the reaction of macrophages to foreign body particles released from the implant. It was hypothesized that the macrophages' response to these particles is dependent, in addition to particle characteristics and contaminating biomolecules, on the state of macrophage polarization as determined by the local cytokine microenvironment. To test this hypothesis we differentiated M1 and M2 macrophages from human peripheral blood monocytes and compared their responses to titanium particles using genome-wide microarray analysis and a multiplex cytokine assay. In comparison to non-activated M0 macrophages, the overall chemotactic and inflammatory responses to titanium particles were greatly enhanced in M1 macrophages and effectively suppressed in M2 macrophages. In addition, the genome-wide approach revealed several novel, potentially osteolytic, particle-induced mediators, and signaling pathway analysis suggested the involvement of toll-like and nod-like receptor signaling in particle recognition. It is concluded that the magnitude of foreign body reaction caused by titanium particles is dependent on the state of macrophage polarization. Thus, by limiting the action of M1 polarizing factors, e.g. bacterial biofilm formation, in peri-implant tissues and promoting M2 macrophage polarization by biomaterial solutions or pharmacologically, it might be possible to restrict wear-particle-induced inflammation and osteolysis. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  17. Inhibitory effect of Piper betel leaf extracts on copper-mediated LDL oxidation and oxLDL-induced lipid accumulation via inducing reverse cholesterol transport in macrophages.

    Science.gov (United States)

    Ma, Gwo-Chin; Wu, Pei-Fang; Tseng, Hsien-Chun; Chyau, Charng-Cherng; Lu, Hsiu-Chin; Chou, Fen-Pi

    2013-12-15

    Piper betel leaf (PBL) has the biological capabilities of detoxification and can work as an anti-inflammatory agent and an anti-oxidant. In this study, we evaluated the anti-oxidative activity of the extract of Piper betel leaves (PBLs) on the basis of Cu(2+)-mediated oxidation, and its ability to prevent foam cell formation in a model for oxidised low density lipoprotein (oxLDL)-induced lipid accumulation in macrophages. Our data demonstrated that PBLs were able to inhibit LDL oxidation in vitro and are able to reduce the lipid accumulation in macrophages. We showed the underlying mechanisms to be the following: PBLs up-regulated the protein levels of the class A and class B scavenger receptors, the membrane lipid transporter ABCA1, and its upstream regulator Liver X receptor (LXR) in the macrophages exposed to oxLDL. The results suggested that PBLs activated the reverse cholesterol transport mechanism to enhance the metabolism of the oxLDL that could prevent both lipid accumulation and foam cell formation and further minimise the possible damage of vessels caused by the oxLDL. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. DMPD: Adipose tissue as an immunological organ: Toll-like receptors, C1q/TNFs andCTRPs. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17681884 Adipose tissue as an immunological organ: Toll-like receptors, C1q/TNFs an...ng) (.svg) (.html) (.csml) Show Adipose tissue as an immunological organ: Toll-like receptors, C1q/TNFs andC...TRPs. PubmedID 17681884 Title Adipose tissue as an immunological organ: Toll-like

  19. Preferential magnetic nanoparticle uptake by bone marrow derived macrophages sub-populations: effect of surface coating on polarization, toxicity, and in vivo MRI detection

    Energy Technology Data Exchange (ETDEWEB)

    Al Faraj, Achraf, E-mail: aalfaraj@ksu.edu.sa [College of Applied Medical Sciences, King Saud University, Molecular and Cellular Imaging Lab, Department of Radiological Sciences (Saudi Arabia)

    2013-07-15

    Noninvasive imaging of macrophages activity has raised increasing interest for diagnosis of different diseases, which make them attractive vehicles to deliver contrast agents or drugs for diagnostic or therapeutic purposes. In this study, the effect of polyethylene glycol functionalization of magnetic iron oxide nanoparticles and their further surface modification with carboxylic groups on bone marrow-derived M1 and M2 macrophages phenotype, labeling efficiency, uptake mechanism, biocompatibility, and their in vivo MR detection was assessed. An enhanced labeling efficiency was observed for carboxylic surface-modified superparamagnetic iron oxide (SPIO) compared to PEGylated SPIO and to a higher extent to plain SPIO along with a higher uptake by M2 subsets. Magnetic nanoparticles were found located in the periphery of the vesicles dispersed in the cytoplasm in TEM. Investigation of the labeling mechanism by inhibiting different uptake pathways revealed that endocytosis via scavenger receptor A, a process known to be clathrin mediated, plays a central role in the cellular uptake kinetics of both macrophages subpopulations. Biocompatibility evaluation showed no variation in cell viability and mitochondrial membrane potential with a low release of ROS. Flow cytometry and measurement of iNOS and Arginase 1 activity as marker of M1 and M2 macrophages polarization confirmed that magnetic labeling of macrophages subsets did not affect their polarization. In addition, no variation was observed in the biodistribution of magnetic iron oxide-labeled M1 and M2 macrophages subsets when monitored using noninvasive magnetic resonance imaging with a better detection for the enhanced SPIO-PEG-COOH-labeled cells.

  20. Preferential magnetic nanoparticle uptake by bone marrow derived macrophages sub-populations: effect of surface coating on polarization, toxicity, and in vivo MRI detection

    International Nuclear Information System (INIS)

    Al Faraj, Achraf

    2013-01-01

    Noninvasive imaging of macrophages activity has raised increasing interest for diagnosis of different diseases, which make them attractive vehicles to deliver contrast agents or drugs for diagnostic or therapeutic purposes. In this study, the effect of polyethylene glycol functionalization of magnetic iron oxide nanoparticles and their further surface modification with carboxylic groups on bone marrow-derived M1 and M2 macrophages phenotype, labeling efficiency, uptake mechanism, biocompatibility, and their in vivo MR detection was assessed. An enhanced labeling efficiency was observed for carboxylic surface-modified superparamagnetic iron oxide (SPIO) compared to PEGylated SPIO and to a higher extent to plain SPIO along with a higher uptake by M2 subsets. Magnetic nanoparticles were found located in the periphery of the vesicles dispersed in the cytoplasm in TEM. Investigation of the labeling mechanism by inhibiting different uptake pathways revealed that endocytosis via scavenger receptor A, a process known to be clathrin mediated, plays a central role in the cellular uptake kinetics of both macrophages subpopulations. Biocompatibility evaluation showed no variation in cell viability and mitochondrial membrane potential with a low release of ROS. Flow cytometry and measurement of iNOS and Arginase 1 activity as marker of M1 and M2 macrophages polarization confirmed that magnetic labeling of macrophages subsets did not affect their polarization. In addition, no variation was observed in the biodistribution of magnetic iron oxide-labeled M1 and M2 macrophages subsets when monitored using noninvasive magnetic resonance imaging with a better detection for the enhanced SPIO–PEG–COOH-labeled cells

  1. 21 CFR 868.5590 - Scavenging mask.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Scavenging mask. 868.5590 Section 868.5590 Food... DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5590 Scavenging mask. (a) Identification. A scavenging mask is a device positioned over a patient's nose to deliver anesthetic or analgesic gases to the...

  2. Scavenging in the genus Natrix

    Directory of Open Access Journals (Sweden)

    Cesar Ayres

    2012-07-01

    Full Text Available Scavenging is reported as an unusual behaviour of snakes. However, it is likely more common than is supposed. Here I report the use of dead newts as prey source by water snakes of the genus Natrix at a dam in north-western Spain. Juveniles and adults viperine snakes (Natrix maura, and also an adult grass snake (Natrix natrix were found feeding on newt carcasses.

  3. DNA Damage Signaling Instructs Polyploid Macrophage Fate in Granulomas

    DEFF Research Database (Denmark)

    Herrtwich, Laura; Nanda, Indrajit; Evangelou, Konstantinos

    2016-01-01

    to a chronic stimulus, though critical for disease outcome, have not been defined. Here, we delineate a macrophage differentiation pathway by which a persistent Toll-like receptor (TLR) 2 signal instructs polyploid macrophage fate by inducing replication stress and activating the DNA damage response. Polyploid...

  4. DMPD: Translational mini-review series on Toll-like receptors: recent advances inunderstanding the role of Toll-like receptors in anti-viral immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17223961 Translational mini-review series on Toll-like receptors: recent advances i...147(2):217-26. (.png) (.svg) (.html) (.csml) Show Translational mini-review series on Toll-like receptors: r...nity. PubmedID 17223961 Title Translational mini-review series on Toll-like receptors: recent advances inund

  5. The innate and adaptive immune response induced by alveolar macrophages exposed to ambient particulate matter

    International Nuclear Information System (INIS)

    Miyata, Ryohei; Eeden, Stephan F. van

    2011-01-01

    Emerging epidemiological evidence suggests that exposure to particulate matter (PM) air pollution increases the risk of cardiovascular events but the exact mechanism by which PM has adverse effects is still unclear. Alveolar macrophages (AM) play a major role in clearing and processing inhaled PM. This comprehensive review of research findings on immunological interactions between AM and PM provides potential pathophysiological pathways that interconnect PM exposure with adverse cardiovascular effects. Coarse particles (10 μm or less, PM 10 ) induce innate immune responses via endotoxin-toll-like receptor (TLR) 4 pathway while fine (2.5 μm or less, PM 2.5 ) and ultrafine particles (0.1 μm or less, UFP) induce via reactive oxygen species generation by transition metals and/or polyaromatic hydrocarbons. The innate immune responses are characterized by activation of transcription factors [nuclear factor (NF)-κB and activator protein-1] and the downstream proinflammatory cytokine [interleukin (IL)-1β, IL-6, and tumor necrosis factor-α] production. In addition to the conventional opsonin-dependent phagocytosis by AM, PM can also be endocytosed by an opsonin-independent pathway via scavenger receptors. Activation of scavenger receptors negatively regulates the TLR4-NF-κB pathway. Internalized particles are subsequently subjected to adaptive immunity involving major histocompatibility complex class II (MHC II) expression, recruitment of costimulatory molecules, and the modulation of the T helper (Th) responses. AM show atypical antigen presenting cell maturation in which phagocytic activity decreases while both MHC II and costimulatory molecules remain unaltered. PM drives AM towards a Th1 profile but secondary responses in a Th1- or Th-2 up-regulated milieu drive the response in favor of a Th2 profile.

  6. The innate and adaptive immune response induced by alveolar macrophages exposed to ambient particulate matter

    Energy Technology Data Exchange (ETDEWEB)

    Miyata, Ryohei; Eeden, Stephan F. van, E-mail: Stephan.vanEeden@hli.ubc.ca

    2011-12-15

    Emerging epidemiological evidence suggests that exposure to particulate matter (PM) air pollution increases the risk of cardiovascular events but the exact mechanism by which PM has adverse effects is still unclear. Alveolar macrophages (AM) play a major role in clearing and processing inhaled PM. This comprehensive review of research findings on immunological interactions between AM and PM provides potential pathophysiological pathways that interconnect PM exposure with adverse cardiovascular effects. Coarse particles (10 {mu}m or less, PM{sub 10}) induce innate immune responses via endotoxin-toll-like receptor (TLR) 4 pathway while fine (2.5 {mu}m or less, PM{sub 2.5}) and ultrafine particles (0.1 {mu}m or less, UFP) induce via reactive oxygen species generation by transition metals and/or polyaromatic hydrocarbons. The innate immune responses are characterized by activation of transcription factors [nuclear factor (NF)-{kappa}B and activator protein-1] and the downstream proinflammatory cytokine [interleukin (IL)-1{beta}, IL-6, and tumor necrosis factor-{alpha}] production. In addition to the conventional opsonin-dependent phagocytosis by AM, PM can also be endocytosed by an opsonin-independent pathway via scavenger receptors. Activation of scavenger receptors negatively regulates the TLR4-NF-{kappa}B pathway. Internalized particles are subsequently subjected to adaptive immunity involving major histocompatibility complex class II (MHC II) expression, recruitment of costimulatory molecules, and the modulation of the T helper (Th) responses. AM show atypical antigen presenting cell maturation in which phagocytic activity decreases while both MHC II and costimulatory molecules remain unaltered. PM drives AM towards a Th1 profile but secondary responses in a Th1- or Th-2 up-regulated milieu drive the response in favor of a Th2 profile.

  7. Botanical polysaccharides: macrophage immunomodulation and therapeutic potential.

    Science.gov (United States)

    Schepetkin, Igor A; Quinn, Mark T

    2006-03-01

    Botanical polysaccharides exhibit a number of beneficial therapeutic properties, and it is thought that the mechanisms involved in these effects are due to the modulation of innate immunity and, more specifically, macrophage function. In this review, we summarize our current state of understanding of the macrophage modulatory effects of botanical polysaccharides isolated from a wide array of different species of flora, including higher plants, mushrooms, lichens and algae. Overall, the primary effect of botanical polysaccharides is to enhance and/or activate macrophage immune responses, leading to immunomodulation, anti-tumor activity, wound-healing and other therapeutic effects. Furthermore, botanical and microbial polysaccharides bind to common surface receptors and induce similar immunomodulatory responses in macrophages, suggesting that evolutionarily conserved polysaccharide structural features are shared between these organisms. Thus, the evaluation of botanical polysaccharides provides a unique opportunity for the discovery of novel therapeutic agents and adjuvants that exhibit beneficial immunomodulatory properties.

  8. DMPD: Critical role of toll-like receptors and nucleotide oligomerisation domain inthe regulation of health and disease. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available and nucleotide oligomerisation domain inthe regulation of health and disease. Pu...bmedID 17535871 Title Critical role of toll-like receptors and nucleotide oligomerisation domain inthe regulation of health...17535871 Critical role of toll-like receptors and nucleotide oligomerisation domain inthe regulation of heal...th and disease. Mitchell JA, Paul-Clark MJ, Clarke GW, McMaster SK, Cartwright N. J

  9. Molecular Mechanisms Modulating the Phenotype of Macrophages and Microglia

    Directory of Open Access Journals (Sweden)

    Stephanie A. Amici

    2017-11-01

    Full Text Available Macrophages and microglia play crucial roles during central nervous system development, homeostasis and acute events such as infection or injury. The diverse functions of tissue macrophages and microglia are mirrored by equally diverse phenotypes. A model of inflammatory/M1 versus a resolution phase/M2 macrophages has been widely used. However, the complexity of macrophage function can only be achieved by the existence of varied, plastic and tridimensional macrophage phenotypes. Understanding how tissue macrophages integrate environmental signals via molecular programs to define pathogen/injury inflammatory responses provides an opportunity to better understand the multilayered nature of macrophages, as well as target and modulate cellular programs to control excessive inflammation. This is particularly important in MS and other neuroinflammatory diseases, where chronic inflammatory macrophage and microglial responses may contribute to pathology. Here, we perform a comprehensive review of our current understanding of how molecular pathways modulate tissue macrophage phenotype, covering both classic pathways and the emerging role of microRNAs, receptor-tyrosine kinases and metabolism in macrophage phenotype. In addition, we discuss pathway parallels in microglia, novel markers helpful in the identification of peripheral macrophages versus microglia and markers linked to their phenotype.

  10. TGF-beta receptor 2 downregulation in tumour-associated stroma worsens prognosis and high-grade tumours show more tumour-associated macrophages and lower TGF-beta1 expression in colon carcinoma: a retrospective study

    International Nuclear Information System (INIS)

    Bacman, David; Merkel, Susanne; Croner, Roland; Papadopoulos, Thomas; Brueckl, Wolfgang; Dimmler, Arno

    2007-01-01

    Histological phenotype and clinical behaviour of malignant tumours are not only dependent on alterations in the epithelial cell compartment, but are affected by their interaction with inflammatory cells and tumour-associated stroma. Studies in animal models have shown influence of tumour-associated macrophages (TAM) on histological grade of differentiation in colon carcinoma. Disruption of transforming growth factor beta (TGF-beta) signalling in tumour cells is related to more aggressive clinical behaviour. Expression data of components of this pathway in tumour-associated stroma is limited. Tissue micro arrays of 310 colon carcinomas from curatively resected patients in UICC stage II and III were established. In a first step we quantified amount of CD68 positive TAMs and expression of components of TGF-beta signalling (TGF-beta1, TGF-beta receptors type 1 and 2, Smad 3 and 4) in tumour and associated stroma. Further we analyzed correlation to histological and clinical parameters (histological grade of differentiation (low-grade (i.e. grade 1 and 2) vs. high-grade (i.e. grade 3 and 4)), lymph node metastasis, distant metastasis, 5 year cancer related survival) using Chi-square or Fisher's exact test, when appropriate, to compare frequencies, Kaplan-Meier method to calculate 5-year rates of distant metastases and cancer-related survival and log rank test to compare the rates of distant metastases and survival. To identify independent prognostic factors Cox regression analysis including lymph node status and grading was performed. High-grade tumours and those with lymph node metastases showed higher rates of TAMs and lower expression of TGF-beta1. Loss of nuclear Smad4 expression in tumor was associated with presence of lymph node metastasis, but no influence on prognosis could be demonstrated. Decrease of both TGF-beta receptors in tumour-associated stroma was associated with increased lymph node metastasis and shorter survival. Stromal TGF-beta receptor 2

  11. TGF-beta receptor 2 downregulation in tumour-associated stroma worsens prognosis and high-grade tumours show more tumour-associated macrophages and lower TGF-beta1 expression in colon carcinoma: a retrospective study

    Directory of Open Access Journals (Sweden)

    Papadopoulos Thomas

    2007-08-01

    Full Text Available Abstract Background Histological phenotype and clinical behaviour of malignant tumours are not only dependent on alterations in the epithelial cell compartment, but are affected by their interaction with inflammatory cells and tumour-associated stroma. Studies in animal models have shown influence of tumour-associated macrophages (TAM on histological grade of differentiation in colon carcinoma. Disruption of transforming growth factor beta (TGF-beta signalling in tumour cells is related to more aggressive clinical behaviour. Expression data of components of this pathway in tumour-associated stroma is limited. Methods Tissue micro arrays of 310 colon carcinomas from curatively resected patients in UICC stage II and III were established. In a first step we quantified amount of CD68 positive TAMs and expression of components of TGF-beta signalling (TGF-beta1, TGF-beta receptors type 1 and 2, Smad 3 and 4 in tumour and associated stroma. Further we analyzed correlation to histological and clinical parameters (histological grade of differentiation (low-grade (i.e. grade 1 and 2 vs. high-grade (i.e. grade 3 and 4, lymph node metastasis, distant metastasis, 5 year cancer related survival using Chi-square or Fisher's exact test, when appropriate, to compare frequencies, Kaplan-Meier method to calculate 5-year rates of distant metastases and cancer-related survival and log rank test to compare the rates of distant metastases and survival. To identify independent prognostic factors Cox regression analysis including lymph node status and grading was performed. Results High-grade tumours and those with lymph node metastases showed higher rates of TAMs and lower expression of TGF-beta1. Loss of nuclear Smad4 expression in tumor was associated with presence of lymph node metastasis, but no influence on prognosis could be demonstrated. Decrease of both TGF-beta receptors in tumour-associated stroma was associated with increased lymph node metastasis and

  12. Candida albicans induces pro-inflammatory and anti-apoptotic signals in macrophages as revealed by quantitative proteomics and phosphoproteomics

    DEFF Research Database (Denmark)

    Reales-Calderón, Jose Antonio; Sylvester, Marc; Strijbis, Karin

    2013-01-01

    Macrophages play a pivotal role in the prevention of Candida albicans infections. Yeast recognition and phagocytosis by macrophages is mediated by Pattern Recognition Receptors (PRRs) that initiate downstream signal transduction cascades by protein phosphorylation and dephosphorylation. We exposed...

  13. Lysophosphatidic acid directly induces macrophage-derived foam cell formation by blocking the expression of SRBI.

    Science.gov (United States)

    Chen, Linmu; Zhang, Jun; Deng, Xiao; Liu, Yan; Yang, Xi; Wu, Qiong; Yu, Chao

    2017-09-23

    The leading cause of morbidity and mortality is the result of cardiovascular disease, mainly atherosclerosis. The formation of macrophage foam cells by ingesting ox-LDL and focal retention in the subendothelial space are the hallmarks of the early atherosclerotic lesion. Lysophosphatidic acid (LPA), which is a low-molecular weight lysophospholipid enriched in oxidized LDL, exerts a range of effects on the cardiovascular system. Previous reports show that LPA increases the uptake of ox-LDL to promote the formation of foam cells. However, as the most active component of ox-LDL, there is no report showing whether LPA directly affects foam cell formation. The aim of this study was to investigate the effects of LPA on foam cell formation, as well as to elucidate the underlying mechanism. Oil red O staining and a Cholesterol/cholesteryl ester quantitation assay were used to evaluate foam cell formation in Raw264.7 macrophage cells. We utilized a Western blot and RT-PCR to investigate the relationship between LPA receptors and lipid transport related proteins. We found that LPA promoted foam cell formation, using 200 μM for 24 h. Meanwhile, the expression of the Scavenger receptor BI (SRBI), which promotes the efflux of free cholesterol, was decreased. Furthermore, the LPA 1/3 receptor antagonist Ki16425 significantly abolished the LPA effects, indicating that LPA 1/3 was involved in the foam cell formation and SRBI expression induced by LPA. Additionally, the LPA-induced foam cell formation was blocked with an AKT inhibitor. Our results suggest that LPA-enhanced foam cell formation is mediated by LPA 1/3 -AKT activation and subsequent SRBI expression. Copyright © 2017. Published by Elsevier Inc.

  14. SR-B1 Is a Silica Receptor that Mediates Canonical Inflammasome Activation

    Directory of Open Access Journals (Sweden)

    Misato Tsugita

    2017-01-01

    Full Text Available The inhalation of silica dust is associated with fibrosis and lung cancer, which are triggered by macrophage inflammatory responses; however, how macrophages recognize silica remains largely unknown. Here, we identify by functional expression cloning the class B scavenger receptor SR-B1 as a silica receptor. Through an extracellular α-helix, both mouse and human SR-B1 specifically recognized amorphous and crystalline silica, but not titanium dioxide nanoparticles, latex nanoparticles, or monosodium urate crystals, although all particles exhibited negative surface potentials. Genetic deletion of SR-B1 and masking of SR-B1 by monoclonal antibodies showed that SR-B1-mediated recognition of silica is associated with caspase-1-mediated inflammatory responses in mouse macrophages and human peripheral blood monocytes. Furthermore, SR-B1 was involved in silica-induced pulmonary inflammation in mice. These results indicate that SR-B1 is a silica receptor associated with canonical inflammasome activation.

  15. Key Role of Toll-Like Receptor 2 in the Inflammatory Response and Major Histocompatibility Complex Class II Downregulation in Brucella abortus-Infected Alveolar Macrophages

    Science.gov (United States)

    Ferrero, Mariana C.; Hielpos, M. Soledad; Carvalho, Natalia B.; Barrionuevo, Paula; Corsetti, Patricia P.; Giambartolomei, Guillermo H.; Oliveira, Sergio C.

    2014-01-01

    Alveolar macrophages (AM) seem to constitute the main cellular target of inhaled brucellae. Here, we show that Brucella abortus invades and replicates in murine AM without inducing cytotoxicity. B. abortus infection induced a statistically significant increase of tumor necrosis factor alpha (TNF-α), CXCL1 or keratinocyte chemoattractant (KC), interleukin-1β (IL-1β), IL-6, and IL-12 in AM from C57BL/6 mice and BALB/c mice, but these responses were generally weaker and/or delayed compared to those elicited in peritoneal macrophages. Studies using knockout mice for TLR2, TLR4, and TLR9 revealed that TNF-α and KC responses were mediated by TLR2 recognition. Brucella infection reduced in a multiplicity of infection-dependent manner the expression of major histocompatibility complex class II (MHC-II) molecules induced by gamma interferon (IFN-γ) in AM. The same phenomenon was induced by incubation with heat-killed B. abortus (HKBA) or the lipidated form of the 19-kDa outer membrane protein of Brucella (L-Omp19), and it was shown to be mediated by TLR2 recognition. In contrast, no significant downregulation of MHC-II was induced by either unlipidated Omp19 or Brucella LPS. In a functional assay, treatment of AM with either L-Omp19 or HKBA reduced the MHC-II-restricted presentation of OVA peptides to specific T cells. One week after intratracheal infection, viable B. abortus was detected in AM from both wild-type and TLR2 KO mice, but CFU counts were higher in the latter. These results suggest that B. abortus survives in AM after inhalatory infection in spite of a certain degree of immune control exerted by the TLR2-mediated inflammatory response. Both the modest nature of the latter and the modulation of MHC-II expression by the bacterium may contribute to such survival. PMID:24478078

  16. To scavenge or not to scavenge: that is the question

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Elzbieta; Brzuszkiewicz, Anna [Synchrotron Radiation Research Section, MCL, National Cancer Institute, Argonne National Laboratory, Argonne, IL 60439 (United States); Dauter, Miroslawa [SAIC-Frederick Inc., Basic Research Program, Argonne National Laboratory, Argonne, IL 60439 (United States); Dauter, Zbigniew, E-mail: dauter@anl.gov [Synchrotron Radiation Research Section, MCL, National Cancer Institute, Argonne National Laboratory, Argonne, IL 60439 (United States); Rosenbaum, Gerd, E-mail: dauter@anl.gov [Department of Biochemistry, University of Georgia, SER-CAT at the APS, Argonne, IL 60439 (United States); Synchrotron Radiation Research Section, MCL, National Cancer Institute, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2009-09-01

    Analysis of a series of diffraction data sets measured from several native as well as nicotinic acid-soaked crystals of trypsin suggests that this potential scavenger does not have any statistically significant effect on the amount of radiation damage incurred in the crystals on X-ray irradiation at 100 K. Analysis of a series of diffraction data sets measured from four native as well as four nicotinic acid-soaked crystals of trypsin at 100 K shows a high variability in radiation-sensitivity among individual crystals for both nicotinic acid-soaked and native crystals. The level of radiation-sensitivity and the extent of its variability is statistically indistinguishable between the two conditions. This suggests that this potential scavenger does not have any statistically significant effect on the amount of radiation damage incurred in the crystals on X-ray irradiation. This is in contrast to previous results [Kauffmann et al. (2006 ▶), Structure, 14, 1099–1105] where only one crystal specimen was used for each condition (native and nicotinic acid-soaked)

  17. DMPD: Signal transduction pathways mediated by the interaction of CpG DNA withToll-like receptor 9. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14751759 Signal transduction pathways mediated by the interaction of CpG DNA withTo...;16(1):17-22. (.png) (.svg) (.html) (.csml) Show Signal transduction pathways mediated by the interaction of... CpG DNA withToll-like receptor 9. PubmedID 14751759 Title Signal transduction pathways media

  18. DMPD: The involvement of the interleukin-1 receptor-associated kinases (IRAKs) incellular signaling networks controlling inflammation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available ncellular signaling networks controlling inflammation. Ringwood L, Li L. Cytokine. 2008 Apr;42(1):1-7. Epub ...ases (IRAKs) incellular signaling networks controlling inflammation. PubmedID 182...49132 Title The involvement of the interleukin-1 receptor-associated kinases (IRAKs) incellular signaling networks controlling

  19. Scavenging and recombination kinetics in radiation chemistry.

    Science.gov (United States)

    Al-Samra, Eyad H; Green, Nicholas J B

    2017-08-02

    This work describes stochastic models developed to study the competition between radical scavenging and recombination for simple model systems typical of radiation chemistry, where the reactive particles are tightly clustered and reactions are assumed fully diffusion limited. Three models are developed: a Monte Carlo random flights model with a periodic boundary condition for scavengers, Monte Carlo simulations in which the scavenging rate is calculated from the Smoluchowski theory for diffusion-limited reactions and a modification of the independent reaction times method where the scavengers close to the spur are explicitly included and the scavengers further away are treated as a continuum. The results indicate that the Smoluchowski theory makes a systematic overestimate of the scavenging rate when such competition is present. A correction for the Smoluchowski rate constant is suggested, an analytical justification is presented and it is tested against the simulations, and shown to be a substantial improvement.

  20. Purinergic signaling to terminate TLR responses in macrophages

    Directory of Open Access Journals (Sweden)

    Kajal eHamidzadeh

    2016-03-01

    Full Text Available Macrophages undergo profound physiological alterations when they encounter pathogen associated molecular patterns (PAMPs. These alterations can result in the elaboration of cytokines and mediators that promote immune responses and contribute to the clearance of pathogens. These innate immune responses by myeloid cells are transient. The termination of these secretory responses is not due to the dilution of stimuli, but rather to the active down-regulation of innate responses induced by the very PAMPs that initiated them. Here we describe a purinergic autoregulatory program whereby TLR-stimulated macrophages control their activation state. In this program, TLR stimulated macrophages undergo metabolic alterations that result in the production of ATP and its release through membrane pannexin channels. This purine nucleotide is rapidly hydrolyzed to adenosine by ectoenzymes on the macrophage surface, CD39 and CD73. Adenosine then signals through the P1 class of seven transmembrane receptors to induce a regulatory state that is characterized by the down-regulation of inflammatory cytokines and the production of anti-inflammatory cytokines and growth factors. This purinergic autoregulatory system mitigates the collateral damage that would be caused by the prolonged activation of macrophages, and rather allows the macrophage to maintain homeostasis. The transient activation of macrophages can be prolonged by treating macrophages with IFN-γ. IFN-γ treated macrophages become less sensitive to the regulatory effects of adenosine, allowing them to sustain macrophage activation for the duration of an adaptive immune response.

  1. Macrophage Phenotype and Function in Different Stages of Atherosclerosis

    Science.gov (United States)

    Tabas, Ira; Bornfeldt, Karin E.

    2016-01-01

    The remarkable plasticity and plethora of biological functions performed by macrophages have enticed scientists to study these cells in relation to atherosclerosis for more than 50 years, and major discoveries continue to be made today. It is now understood that macrophages play important roles in all stages of atherosclerosis, from initiation of lesions and lesion expansion, to necrosis leading to rupture and the clinical manifestations of atherosclerosis, to resolution and regression of atherosclerotic lesions. Lesional macrophages are derived primarily from blood monocytes, although recent research has shown that lesional macrophage-like cells can also be derived from smooth muscle cells. Lesional macrophages take on different phenotypes depending on their environment and which intracellular signaling pathways are activated. Rather than a few distinct populations of macrophages, the phenotype of the lesional macrophage is more complex and likely changes during the different phases of atherosclerosis and with the extent of lipid and cholesterol loading, activation by a plethora of receptors, and metabolic state of the cells. These different phenotypes allow the macrophage to engulf lipids, dead cells, and other substances perceived as danger signals; efflux cholesterol to HDL; proliferate and migrate; undergo apoptosis and death; and secrete a large number of inflammatory and pro-resolving molecules. This review article, part of the Compendium on Atherosclerosis, discusses recent advances in our understanding of lesional macrophage phenotype and function in different stages of atherosclerosis. With the increasing understanding of the roles of lesional macrophages, new research areas and treatment strategies are beginning to emerge. PMID:26892964

  2. Formation of Foamy Macrophages by Tuberculous Pleural Effusions Is Triggered by the Interleukin-10/Signal Transducer and Activator of Transcription 3 Axis through ACAT Upregulation

    Directory of Open Access Journals (Sweden)

    Melanie Genoula

    2018-03-01

    Full Text Available The ability of Mycobacterium tuberculosis (Mtb to persist in its human host relies on numerous immune evasion strategies, such as the deregulation of the lipid metabolism leading to the formation of foamy macrophages (FM. Yet, the specific host factors leading to the foamy phenotype of Mtb-infected macrophages remain unknown. Herein, we aimed to address whether host cytokines contribute to FM formation in the context of Mtb infection. Our approach is based on the use of an acellular fraction of tuberculous pleural effusions (TB-PE as a physiological source of local factors released during Mtb infection. We found that TB-PE induced FM differentiation as observed by the increase in lipid bodies, intracellular cholesterol, and expression of the scavenger receptor CD36, as well as the enzyme acyl CoA:cholesterol acyl transferase (ACAT. Importantly, interleukin-10 (IL-10 depletion from TB-PE prevented the augmentation of all these parameters. Moreover, we observed a positive correlation between the levels of IL-10 and the number of lipid-laden CD14+ cells among the pleural cells in TB patients, demonstrating that FM differentiation occurs within the pleural environment. Downstream of IL-10 signaling, we noticed that the transcription factor signal transducer and activator of transcription 3 was activated by TB-PE, and its chemical inhibition prevented the accumulation of lipid bodies and ACAT expression in macrophages. In terms of the host immune response, TB-PE-treated macrophages displayed immunosuppressive properties and bore higher bacillary loads. Finally, we confirmed our results using bone marrow-derived macrophage from IL-10−/− mice demonstrating that IL-10 deficiency partially prevented foamy phenotype induction after Mtb lipids exposure. In conclusion, our results evidence a role of IL-10 in promoting the differentiation of FM in the context of Mtb infection, contributing to our understanding of how alterations of the host metabolic

  3. Activation of adenosine A3 receptors potentiates stimulatory effects of IL-3, SCF, and GM-CSF on mouse granulocyte-macrophage hematopoietic progenitor cells

    Czech Academy of Sciences Publication Activity Database

    Hofer, Michal; Vacek, Antonín; Pospíšil, Milan; Holá, Jiřina; Štreitová, Denisa; Znojil, V.

    2009-01-01

    Roč. 58, č. 2 (2009), s. 247-252 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA305/06/0015; GA ČR(CZ) GA305/08/0158 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : hematopoiesis * adenosine A3 receptor agonist * hematopoietic growth factors Subject RIV: BO - Biophysics Impact factor: 1.430, year: 2009

  4. Energy scavenging from environmental vibration.

    Energy Technology Data Exchange (ETDEWEB)

    Galchev, Tzeno (University of Michigan); Apblett, Christopher Alan; Najafi, Khalil (University of Michigan)

    2009-10-01

    The goal of this project is to develop an efficient energy scavenger for converting ambient low-frequency vibrations into electrical power. In order to achieve this a novel inertial micro power generator architecture has been developed that utilizes the bi-stable motion of a mechanical mass to convert a broad range of low-frequency (< 30Hz), and large-deflection (>250 {micro}m) ambient vibrations into high-frequency electrical output energy. The generator incorporates a bi-stable mechanical structure to initiate high-frequency mechanical oscillations in an electromagnetic scavenger. This frequency up-conversion technique enhances the electromechanical coupling and increases the generated power. This architecture is called the Parametric Frequency Increased Generator (PFIG). Three generations of the device have been fabricated. It was first demonstrated using a larger bench-top prototype that had a functional volume of 3.7cm3. It generated a peak power of 558{micro}W and an average power of 39.5{micro}W at an input acceleration of 1g applied at 10 Hz. The performance of this device has still not been matched by any other reported work. It yielded the best power density and efficiency for any scavenger operating from low-frequency (<10Hz) vibrations. A second-generation device was then fabricated. It generated a peak power of 288{micro}W and an average power of 5.8{micro}W from an input acceleration of 9.8m/s{sup 2} at 10Hz. The device operates over a frequency range of 20Hz. The internal volume of the generator is 2.1cm{sup 3} (3.7cm{sup 3} including casing), half of a standard AA battery. Lastly, a piezoelectric version of the PFIG is currently being developed. This device clearly demonstrates one of the key features of the PFIG architecture, namely that it is suitable for MEMS integration, more so than resonant generators, by incorporating a brittle bulk piezoelectric ceramic. This is the first micro-scale piezoelectric generator capable of <10Hz operation. The

  5. 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.

    Directory of Open Access Journals (Sweden)

    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

  6. [In vitro anti-inflammatory and free radical scavenging activities of flavans from Ilex centrochinensis].

    Science.gov (United States)

    Li, Lu-jun; Yu, Li-juan; Li, Yan-ci; Liu, Meng-yuan; Wu, Zheng-zhi

    2015-04-01

    This study was carried out to evaluate the anti-inflammatory and free radical scavenging activities of flavans from flex centrochinensis S. Y. Hu in vitro and their structure-activity relationship. LPS-stimulated RAW 264.7 macrophage was used as inflammatory model. MTT assay for cell availability, Griess reaction for nitric oxide (NO) production, the content of TNF-alpha, IL-1beta, IL-6 and PGE, were detected with ELISA kits; DPPH, superoxide anion and hydroxyl free radicals scavenging activities were also investigated. According to the result, all flavans tested exhibited anti-inflammatory effect in different levels. Among them, compounds 1, 3, 4 and 6 showed potent anti-inflammatory effect through the inhibition of NO, TNF-alpha, IL-lp and IL-6, of which 1 was the most effective inhibitor, however, 2 and 5 were relatively weak or inactive. The order of free radical scavenging activities was similar to that of anti-inflammatory activities. Therefore, these results suggest that 3, 4 and 6, especially of 1, were,in part responsible for the anti-inflammatory and free radical scavenging activity of Ilex centrochinensis. Hydroxyl group at 4'-position of B-ring plays an important role in the anti-inflammatory and free radical scavenging capacities.

  7. Crystallization and preliminary X-ray diffraction studies of the carbohydrate-recognition domain of SIGN-R1, a receptor for microbial polysaccharides and sialylated antibody on splenic marginal zone macrophages

    International Nuclear Information System (INIS)

    Silva-Martin, Noella; Schauer, Joseph D.; Park, Chae Gyu; Hermoso, Juan A.

    2009-01-01

    The carbohydrate-recognition domain of the SIGN-R1 receptor from M. musculus has been crystallized by the hanging-drop vapour-diffusion method. A native data set has been collected to 1.87 Å resolution. SIGN-R1, or CD209b, is a mouse C-type lectin receptor that is expressed at high levels on macrophages in lymphoid tissues, especially within the marginal zone of the spleen. SIGN-R1 can bind and mediate the uptake of various microbial polysaccharides, including dextrans, lipopolysaccharides and pneumococcal capsular polysaccharides. It has been shown that SIGN-R1 mediates the clearance of encapsulated pneumococcus, complement fixation via binding C1q independent of antibody and innate resistance to pneumococcal infection. Recently, SIGN-R1 has also been demonstrated to bind sialylated antibody and mediate its activity to suppress autoimmunity. The carbohydrate-recognition domain (CRD) of SIGN-R1 has been cloned and overexpressed in a soluble secretory form in mammalian Chinese hamster ovary (CHO) cells. The CRD protein of SIGN-R1 was purified from CHO cell-culture supernatant and concentrated for crystallization using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture of 2 M ammonium sulfate in 0.1 M bis-tris pH 5.5. Single crystals, which belonged to the monoclinic space group C2 with unit-cell parameters a = 146.72, b = 92.77, c = 77.06 Å, β = 121.66°, allowed the collection of a full X-ray data set to a maximum resolution of 1.87 Å

  8. Crystallization and preliminary X-ray diffraction studies of the carbohydrate-recognition domain of SIGN-R1, a receptor for microbial polysaccharides and sialylated antibody on splenic marginal zone macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Silva-Martin, Noella [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física ‘Rocasolano’, Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid (Spain); Schauer, Joseph D.; Park, Chae Gyu [Laboratory of Cellular Physiology and Immunology and Chris Browne Center for Immunology and Immune Diseases, The Rockefeller University, 1230 York Avenue, New York, NY 10065 (United States); Hermoso, Juan A., E-mail: xjuan@iqfr.csic.es [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física ‘Rocasolano’, Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid (Spain)

    2009-12-01

    The carbohydrate-recognition domain of the SIGN-R1 receptor from M. musculus has been crystallized by the hanging-drop vapour-diffusion method. A native data set has been collected to 1.87 Å resolution. SIGN-R1, or CD209b, is a mouse C-type lectin receptor that is expressed at high levels on macrophages in lymphoid tissues, especially within the marginal zone of the spleen. SIGN-R1 can bind and mediate the uptake of various microbial polysaccharides, including dextrans, lipopolysaccharides and pneumococcal capsular polysaccharides. It has been shown that SIGN-R1 mediates the clearance of encapsulated pneumococcus, complement fixation via binding C1q independent of antibody and innate resistance to pneumococcal infection. Recently, SIGN-R1 has also been demonstrated to bind sialylated antibody and mediate its activity to suppress autoimmunity. The carbohydrate-recognition domain (CRD) of SIGN-R1 has been cloned and overexpressed in a soluble secretory form in mammalian Chinese hamster ovary (CHO) cells. The CRD protein of SIGN-R1 was purified from CHO cell-culture supernatant and concentrated for crystallization using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture of 2 M ammonium sulfate in 0.1 M bis-tris pH 5.5. Single crystals, which belonged to the monoclinic space group C2 with unit-cell parameters a = 146.72, b = 92.77, c = 77.06 Å, β = 121.66°, allowed the collection of a full X-ray data set to a maximum resolution of 1.87 Å.

  9. Anti-Inflammatory Action of an Antimicrobial Model Peptide That Suppresses the TRIF-Dependent Signaling Pathway via Inhibition of Toll-Like Receptor 4 Endocytosis in Lipopolysaccharide-Stimulated Macrophages.

    Directory of Open Access Journals (Sweden)

    Do-Wan Shim

    Full Text Available Antimicrobial peptides (AMPs, also called host defense peptides, particularly those with amphipathic helical structures, are emerging as target molecules for therapeutic development due to their immunomodulatory properties. Although the antimicrobial activity of AMPs is known to be exerted primarily by permeation of the bacterial membrane, the mechanism underlying its anti-inflammatory activity remains to be elucidated. We report potent anti-inflammatory activity of WALK11.3, an antimicrobial model peptide with an amphipathic helical conformation, in lipopolysaccharide (LPS-stimulated RAW264.7 cells. This peptide inhibited the expression of inflammatory mediators, including nitric oxide, COX-2, IL-1β, IL-6, INF-β, and TNF-α. Although WALK11.3 did not exert a major effect on all downstream signaling in the MyD88-dependent pathway, toll-like receptor 4 (TLR4- mediated pro-inflammatory signals were markedly attenuated in the TRIF-dependent pathway due to inhibition of the phosphorylation of STAT1 by attenuation of IRF3 phosphorylation. WALK11.3 specifically inhibited the endocytosis of TLR4, which is essential for triggering TRIF-mediated signaling in macrophage cells. Hence, we suggest that specific interference with TLR4 endocytosis could be one of the major modes of the anti-inflammatory action of AMPs. Our designed WALK11 peptides, which possess both antimicrobial and anti-inflammatory activities, may be promising molecules for the development of therapies for infectious inflammation.

  10. Study of uptake and endocytosis of gamma rays-irradiated crotoxin by mice peritoneal macrophages; Avaliacao do mecanismo de captacao e endocitose de crotoxina submetida a acao da radiacao, por macrofagos peritoneais de camundongos

    Energy Technology Data Exchange (ETDEWEB)

    Cardi, Bruno Andrade

    1999-07-01

    The purpose was to investigate the uptake and endocytosis of 2000 Gy {sup 60}Co irradiated crotoxin through mouse peritoneal macrophages, correlating with native one and another non related protein, the ovalbumin. Native (CTXN) or 2000 Gy {sup 60} Co {gamma}-rays (dose rate 540 Gy/hour) irradiated crotoxin (CTXI) or ovalbumin processed of same manner (OVAN - OVAI) were offered to mouse peritoneal macrophages and their uptake was evaluated by immunohistochemistry and quantitative in situ ELISA. The involvement of scavenger receptors (ScvR) was evaluated by using blockers drugs (Probuco-PBC or Dextran Sulfate - SD) or with nonspecific blocking using fetal calf serum (FBS). The morphology and viability of macrophages were preserved during the experiments. CTXI showed irradiation-induced aggregates and formation of oxidative changing were observed on this protein after gamma rays treatment. By immunohistochemistry we could observe heavy stained phagocytic vacuole on macrophages incubated with CTXI, as compared with CTXN. Quantitatively by in situ ELISA, the sema pattern was observed, displaying a 2-fold CTXI incorporation. In presence of PBC or SD we could find a significant decrease of CTXI uptake but not of CTXN. However the CTXN uptake was depressed by FBS, not observed with CTXI. OVA, after gamma rays treatment, underwent a high degradation suffering a potent incorporation and metabolism by macrophages, with a major uptake of OVAI in longer incubation (120 minutes). Gamma rays ({sup 60} Co) produced oxidative changes on CTX molecule, leading to a uptake by ScvR-mice peritoneal macrophages, suggesting that the relation antigen-presenting cells and gamma rays-modified proteins are responsible for the better immune response presented by irradiated antigens. (author)

  11. CXCR7 functions as a scavenger for CXCL12 and CXCL11.

    Directory of Open Access Journals (Sweden)

    Ulrike Naumann

    2010-02-01

    Full Text Available CXCR7 (RDC1, the recently discovered second receptor for CXCL12, is phylogenetically closely related to chemokine receptors, but fails to couple to G-proteins and to induce typical chemokine receptor mediated cellular responses. The function of CXCR7 is controversial. Some studies suggest a signaling activity in mammalian cells and zebrafish embryos, while others indicate a decoy activity in fish. Here we investigated the two propositions in human tissues.We provide evidence and mechanistic insight that CXCR7 acts as specific scavenger for CXCL12 and CXCL11 mediating effective ligand internalization and targeting of the chemokine cargo for degradation. Consistently, CXCR7 continuously cycles between the plasma membrane and intracellular compartments in the absence and presence of ligand, both in mammalian cells and in zebrafish. In accordance with the proposed activity as a scavenger receptor CXCR7-dependent chemokine degradation does not become saturated with increasing ligand concentrations. Active CXCL12 sequestration by CXCR7 is demonstrated in adult mouse heart valves and human umbilical vein endothelium.The finding that CXCR7 specifically scavenges CXCL12 suggests a critical function of the receptor in modulating the activity of the ubiquitously expressed CXCR4 in development and tumor formation. Scavenger activity of CXCR7 might also be important for the fine tuning of the mobility of hematopoietic cells in the bone marrow and lymphoid organs.

  12. Americans with Disabilities Act Scavenger Hunt

    Science.gov (United States)

    Ramsey, Ursula

    2018-01-01

    This article describes a scavenger hunt for Business Law students. Specifically, students compete in this scavenger hunt to identify accessible design features on campus to undergird their study of Title III of the Americans with Disabilities Act (ADA). Title III of the ADA prohibits public accommodations from discriminating on the basis of…

  13. Augmented macrophage differentiation and polarization of tumor-associated macrophages towards M1 subtype in listeria-administered tumor-bearing host.

    Science.gov (United States)

    Rai, Rakesh K; Vishvakarma, Naveen K; Mohapatra, Tribhuban M; Singh, Sukh Mahendra

    2012-09-01

    This study investigates the effect of Listeria administration on differentiation of macrophages from precursor bone marrow cells and functional status of tumor-associated macrophages (TAM). Listeria administration not only resulted in an augmented infiltration of tumor by F4/80 macrophages but also repolarized the functional status of TAM displaying features of some M1 macrophage subtype with upregulated phagocytosis and tumoricidal activity accompanied by altered expression of monocarboxylate transporter-1, toll-like receptor-2, surface markers: CD11c, interleukin-2 receptor, CD62L, and secreted molecules: nitric oxide, interleukin (IL)-1, IL-6, tumor necrosis factor-α, and vascular endothelial growth factor. Declined tumor cell survival and modulated repertoire of cytokines: interferon-γ, IL-6, IL-10, and transforming growth factor-β in tumor microenvironment indicated their role in polarization of TAM towards proinflammatory state. Bone marrow cell of Listeria-administered tumor-bearing mice showed augmented survival, declined expression of p53 upregulated modulator of apoptosis with an upregulated differentiation into activation responsive bone marrow-derived macrophages along with altered expression of macrophage-colony stimulating factor, macrophage-colony stimulating factor receptor, and granulocyte macrophage-colony stimulating factor receptor. These findings indicate that Listeria infection is associated with an augmented differentiation of macrophages accompanied by tumoricidal activation of TAM.

  14. Macrophages in synovial inflammation

    Directory of Open Access Journals (Sweden)

    Aisling eKennedy

    2011-10-01

    Full Text Available AbstractSynovial macrophages are one of the resident cell types in synovial tissue and while they remain relatively quiescent in the healthy joint, they become activated in the inflamed joint and, along with infiltrating monocytes/macrophages, regulate secretion of pro-inflammatory cytokines and enzymes involved in driving the inflammatory response and joint destruction. Synovial macrophages are positioned throughout the sub-lining layer and lining layer at the cartilage-pannus junction and mediate articular destruction. Sub-lining macrophages are now also considered as the most reliable biomarker for disease severity and response to therapy in rheumatoid arthritis (RA. There is a growing understanding of the molecular drivers of inflammation and an appreciation that the resolution of inflammation is an active process rather than a passive return to homeostasis, and this has implications for our understanding of the role of macrophages in inflammation. Macrophage phenotype determines the cytokine secretion profile and tissue destruction capabilities of these cells. Whereas inflammatory synovial macrophages have not yet been classified into one phenotype or another it is widely known that TNFα and IL-l, characteristically released by M1 macrophages, are abundant in RA while IL-10 activity, characteristic of M2 macrophages, is somewhat diminished.Here we will briefly review our current understanding of macrophages and macrophage polarisation in RA as well as the elements implicated in controlling polarisation, such as cytokines and transcription factors like NFκB, IRFs and NR4A, and pro-resolving factors, such as LXA4 and other lipid mediators which may promote a non-inflammatory, pro-resolving phenotype and may represent a novel therapeutic paradigm.

  15. Functional modifications of macrophage activity after sublethal irradiation

    International Nuclear Information System (INIS)

    Swartz, R.P.

    1982-01-01

    The modifications of macrophage activity following sublethal irradiation, both in vivo and in vitro, were studied using spreading and C3b-receptor-mediated ingestion assays. Nonelicited peritoneal washout cells were examined for changes in activity and selected population characteristics. The cells from irradiated mice were from a resident peritoneal population and not immigrating cells. The macrophage population showed enhanced activity early with a refractory period (24-48) when the macrophages were unresponsive to stimulation by irradiated lymphocytes. The enhanced activity was inversely dose dependent on macrophage. The lymphocytes showed a regulatory function(s) on the time post irradiation at which they were examined. Early lymphocytes exhibited the ability to enhance the activity of normal macrophages while lymphocytes removed 24 hours post irradiation could suppress the activity of already activated macrophages. The effect(s) of the various lymphocyte populations were reproduced with cell-free supernatants which was indicative of the production of lymphokines. Separation on nylon wool columns indicated that the activity resided primarily in the T-cell population of lymphocytes. In vitro irradiation indicated that stimulation of the lymphocytes is macrophage dependent. Additional work indicated that sublethally irradiated macrophages did not inhibit replication of the coccidian protozoon Toxoplasma gondii although they did show increased phagocytosis. Examination of the serum from whole body irradiated mice showed the presence of a postirradiation substance which enhanced the phagocytosis of normal macrophages. It was not present in the serum of normal mice and was not endotoxin

  16. Multifunctional Receptor Stabilin-1 in Homeostasis and Disease

    Directory of Open Access Journals (Sweden)

    Julia Kzhyshkowska

    2010-01-01

    Full Text Available The multifunctional scavenger receptor stabilin-1 (STAB1, FEEL-1, CLEVER-1, KIAA0246 is expressed on tissue macrophages and sinusoidal endothelial cells in healthy organisms, and its expression on both macrophages and different subtypes of endothelial cells is induced during chronic inflammation and tumor progression. Stabilin-1 is a type-1 transmembrane receptor that mediates endocytic and phagocytic clearance of “unwanted-self” components, intracellular sorting of the endogenously synthesized chitinase-like protein SI-CLP, and transcytosis of the growth hormone family member placental lactogen. The central sorting station for stabilin-1 trafficking seems to be the trans-Golgi network (TGN. Transport of stabilin-1 in the TGN requires interaction with GGA adaptors that bind to the classical DDSLL motif and a novel acidic cluster in its cytoplasmic tail. Degradation of stabilin-1 seems to depend on the interaction with sorting nexin 17. However, the mechanisms keeping stabilin-1 on the cell surface remain to be identified. This issue deserves specific attention due to the growing amount of data indicating that function of stabilin-1 in cell adhesion events is essential for inflammation and metastasis. Taking into consideration the complexity of stabilin-1—mediated processes, investigation of stabilin-1 functions in the animal models, as well as mathematic modeling of intracellular trafficking and extracellular contact, would enable prediction of stabilin-1 behavior in complex biological systems and would open perspectives for therapeutic targeting of stabilin-1 pathways in chronic inflammation and carcinogenesis.

  17. Tumor necrosis factor-α and receptor activator of nuclear factor-κB ligand augment human macrophage foam-cell destruction of extracellular matrix through protease-mediated processes

    DEFF Research Database (Denmark)

    Skjøt-Arkil, Helene; Barascuk, Natasha; Larsen, Lise

    2012-01-01

    By secreting proteases such as cathepsins and matrix metalloproteinases (MMPs), macrophage foam cells may be a major cause of ruptured atherosclerotic plaques. The aims of the present study were to investigate in vitro role of human macrophage foam cells in degrading type I collagen, a major...

  18. Dielectric polymer: scavenging energy from human motion

    Science.gov (United States)

    Jean-Mistral, Claire; Basrour, Skandar; Chaillout, Jean-Jacques

    2008-03-01

    More and more sensors are embedded in human body for medical applications, for sport. The short lifetime of the batteries, available on the market, reveals a real problem of autonomy of these systems. A promising alternative is to scavenge the ambient energy such as the mechanical one. Up to now, few scavenging structures have operating frequencies compatible with ambient one. And, most of the developed structures are rigid and use vibration as mechanical source. For these reasons, we developed a scavenger that operates in a large frequency spectrum from quasi-static to dynamic range. This generator is fully flexible, light and does not hamper the human motion. Thus, we report in this paper an analytical model for dielectric generator with news electrical and mechanical characterization, and the development of an innovating application: scavenging energy from human motion. The generator is located on the knee and design to scavenge 0.1mJ per scavenging cycle at a frequency of 1Hz, enough to supply a low consumption system and with a poling voltage as low as possible to facilitate the power management. Our first prototype is a membrane with an area of 5*3cm and 31µm in thickness which scavenge 0.1mJ under 170V at constant charge Q.

  19. Peroxynitrite scavenging activity of herb extracts.

    Science.gov (United States)

    Choi, Hye Rhi; Choi, Jae Sue; Han, Yong Nam; Bae, Song Ja; Chung, Hae Young

    2002-06-01

    Peroxynitrite (ONOO(-)) is a cytotoxicant with strong oxidizing properties toward various cellular constituents, including sulphydryls, lipids, amino acids and nucleotides and can cause cell death, lipid peroxidation, carcinogenesis and aging. The aim of this study was to characterize ONOO(-) scavenging constituents from herbs. Twenty-eight herbs were screened for their ONOO(-) scavenging activities with the use of a fluorometric method. The potency of scavenging activity following the addition of authentic ONOO(-) was in the following order: witch hazel bark > rosemary > jasmine tea > sage > slippery elm > black walnut leaf > Queen Anne's lace > Linden flower. The extracts exhibited dose-dependent ONOO(-) scavenging activities. We found that witch hazel (Hamamelis virginiana L.) bark showed the strongest effect for scavenging ONOO(-) of the 28 herbs. Hamamelitannin, the major active component of witch hazel bark, was shown to have a strong ability to scavenge ONOO(-). It is suggested that hamamelitannin might be developed as an effective peroxynitrite scavenger for the prevention of ONOO(-) involved diseases. Copyright 2002 John Wiley & Sons, Ltd.

  20. BMP pathway regulation of and by macrophages.

    Directory of Open Access Journals (Sweden)

    Megha Talati

    Full Text Available Pulmonary arterial hypertension (PAH is a disease of progressively increasing pulmonary vascular resistance, associated with mutations of the type 2 receptor for the BMP pathway, BMPR2. The canonical signaling pathway for BMPR2 is through the SMAD family of transcription factors. BMPR2 is expressed in every cell type, but the impact of BMPR2 mutations affecting SMAD signaling, such as Bmpr2delx4+, had only previously been investigated in smooth muscle and endothelium. In the present study, we created a mouse with universal doxycycline-inducible expression of Bmpr2delx4+ in order to determine if broader expression had an impact relevant to the development of PAH. We found that the most obvious phenotype was a dramatic, but patchy, increase in pulmonary inflammation. We crossed these double transgenic mice onto an NF-κB reporter strain, and by luciferase assays on live mice, individual organs and isolated macrophages, we narrowed down the origin of the inflammatory phenotype to constitutive activation of tissue macrophages. Study of bone marrow-derived macrophages from mutant and wild-type mice suggested a baseline difference in differentiation state in Bmpr2 mutants. When activated with LPS, both mutant and wild-type macrophages secrete BMP pathway inhibitors sufficient to suppress BMP pathway activity in smooth muscle cells (SMC treated with conditioned media. Functionally, co-culture with macrophages results in a BMP signaling-dependent increase in scratch closure in cultured SMC. We conclude that SMAD signaling through BMP is responsible, in part, for preventing macrophage activation in both live animals and in cells in culture, and that activated macrophages secrete BMP inhibitors in sufficient quantity to cause paracrine effect on vascular smooth muscle.

  1. [Macrophages in human semen].

    Science.gov (United States)

    Bouvet, Beatriz Reina; Brufman, Adriana Silvia; Paparella, Cecilia Vicenta; Feldman, Rodolfo Nestor; Gatti, Vanda Nora; Solis, Edita Amalia

    2003-11-01

    To investigate the presence of macrophages in human semen samples and the function they carry out in the seminal fluid. Their presence was studied in relation to spermatic morphology, percentage of spermatozoids with native DNA, and presence of antispermatic antibodies. The work was performed with semen samples from 31 unfertile males from 63 couples in which the "female factor" was ruled out as the cause of infertility. Sperm study according to WHO (1992) was carried out in all samples, in addition to: DNA study with acridine orange as fluorocrom, macrophage concentration by neutral red in a Neubauer camera, and detection of antispermatic antibodies with a mixed agglutination test (TAC II) (validated with Mar Screen-Fertility technologies). Sperm morphology was evaluated by Papanicolaou test. 19/31 selected sperm samples (61.3%) showed increased concentration of macrophages, 13 of them (41.9%) with denaturalized DNA, and 8 (25.8%) abnormal morphology. Six samples showed increased macrophage concentration and predominance of native DNA, whereas 11 samples showed increased macrophages and abnormal morphology. Among 18 (58.1%) samples showing antispermatic antibodies 14 (77.7%) had an increased concentration of macrophages. Statistical analysis resulted in a high correlation between macrophage concentration and increased percentage of spermatozoids with denaturalized DNA (p < 0.05). An increased concentration of macrophages is associated with the presence of antispermatic antibodies (p < 0.05). There was not evidence of significant association between concentration of macrophages and percentage of morphologically normal spermatozoids (p < 0.05). We can conclude that macrophages are present in human semen and participate in immunovigilance contributing to improve the seminal quality.

  2. Macrophages recognize size and shape of their targets.

    Directory of Open Access Journals (Sweden)

    Nishit Doshi

    2010-04-01

    Full Text Available Recognition by macrophages is a key process in generating immune response against invading pathogens. Previous studies have focused on recognition of pathogens through surface receptors present on the macrophage's surface. Here, using polymeric particles of different geometries that represent the size and shape range of a variety of bacteria, the importance of target geometry in recognition was investigated. The studies reported here reveal that attachment of particles of different geometries to macrophages exhibits a strong dependence on size and shape. For all sizes and shapes studied, particles possessing the longest dimension in the range of 2-3 microm exhibited highest attachment. This also happens to be the size range of most commonly found bacteria in nature. The surface features of macrophages, in particular the membrane ruffles, might play an important role in this geometry-based target recognition by macrophages. These findings have significant implications in understanding the pathogenicity of bacteria and in designing drug delivery carriers.

  3. Therapeutic potential of regulatory macrophages generated from peritoneal dialysate in adriamycin nephropathy.

    Science.gov (United States)

    Cao, Qi; Wang, Yiping; Wang, Changqi; Wang, Xin M; Lee, Vincent W S; Zheng, Guoping; Zhao, Ye; Alexander, Stephen I; Harris, David C H

    2018-04-01

    Cell therapy using macrophages requires large amounts of cells, which are difficult to collect from patients. Patients undergoing peritoneal dialysis (PD) discard huge numbers of peritoneal macrophages in dialysate daily. Macrophages can be modulated to become regulatory macrophages, which have shown great promise as a therapeutic strategy in experimental kidney disease and human kidney transplantation. This study aimed to examine the potential of using peritoneal macrophages (PMs) from peritoneal dialysate to treat kidney disease. Monocytes/macrophages accounted for >40% of total peritoneal leukocytes in both patients and mice undergoing PD. PMs from patients and mice undergoing PD were more mature than peripheral monocytes/macrophages, as shown by low expression of C-C motif chemokine receptor 2 (CCR2) and morphological changes during in vitro culture. PMs from patients and mice undergoing PD displayed normal macrophage function and could be modulated into a regulatory (M2) phenotype. In vivo, adoptive transfer of peritoneal M2 macrophages derived from PD mice effectively protected against kidney injury in mice with adriamycin nephropathy (AN). Importantly, the transfused peritoneal M2 macrophages maintained their M2 phenotype in kidney of AN mice. In conclusion, PMs derived from patients and mice undergoing PD exhibited conventional macrophage features. Peritoneal M2 macrophages derived from PD mice are able to reduce kidney injury in AN, suggesting that peritoneal macrophages from patients undergoing PD may have the potential for clinical therapeutic application.

  4. Impact of gene variants on sex-specific regulation of human Scavenger receptor class B type 1 (SR-BI expression in liver and association with lipid levels in a population-based study

    Directory of Open Access Journals (Sweden)

    Barrett-Connor Elizabeth

    2010-01-01

    Full Text Available Abstract Background Several studies have noted that genetic variants of SCARB1, a lipoprotein receptor involved in reverse cholesterol transport, are associated with serum lipid levels in a sex-dependent fashion. However, the mechanism underlying this gene by sex interaction has not been explored. Methods We utilized both epidemiological and molecular methods to study how estrogen and gene variants interact to influence SCARB1 expression and lipid levels. Interaction between 35 SCARB1 haplotype-tagged polymorphisms and endogenous estradiol levels was assessed in 498 postmenopausal Caucasian women from the population-based Rancho Bernardo Study. We further examined associated variants with overall and SCARB1 splice variant (SR-BI and SR-BII expression in 91 human liver tissues using quantitative real-time PCR. Results Several variants on a haplotype block spanning intron 11 to intron 12 of SCARB1 showed significant gene by estradiol interaction affecting serum lipid levels, the strongest for rs838895 with HDL-cholesterol (p = 9.2 × 10-4 and triglycerides (p = 1.3 × 10-3 and the triglyceride:HDL cholesterol ratio (p = 2.7 × 10-4. These same variants were associated with expression of the SR-BI isoform in a sex-specific fashion, with the strongest association found among liver tissue from 52 young women Conclusions Estrogen and SCARB1 genotype may act synergistically to regulate expression of SCARB1 isoforms and impact serum levels of HDL cholesterol and triglycerides. This work highlights the importance of considering sex-dependent effects of gene variants on serum lipid levels.

  5. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

    Full Text Available Se trata de un estudio etnográfico, que tuvo lo objetivo de interpretar el sistema de conocimiento y del significado atribuidos a la sangre referente a la transfusión sanguínea por los donadores y receptores de un banco de sangre. Para la colecta de las informaciones se observaron los participantes y la entrevista etnográfica se realizó el análisis de dominio, taxonómicos y temáticos. Los dominios culturales fueron: la sangre es vida: fuente de vida y alimento valioso; creencias religiosas: fuentes simbólicas de apoyos; donación sanguínea: un gesto colaborador que exige cuidarse, gratifica y trae felicidad; donación sanguínea: fuente simbólica de inseguridad; estar enfermo es una condición para realizar transfusión sanguínea; transfusión sanguínea: esperanza de vida; Creencias populares: transfusión sanguínea como riesgo para la salud; donadores de sangre: personas benditas; donar y recibir sangre: como significado de felicidad. Temática: “líquido precioso que origina, sostiene, modifica la vida, provoca miedo e inseguridad”.

  6. Targeting Dexamethasone to Macrophages in a Porcine Endotoxemic Model

    DEFF Research Database (Denmark)

    Granfeldt, Asger; Hvas, Christine Lodberg; Graversen, Jonas Heilskov

    2013-01-01

    -8 minutes. CONCLUSION: Targeted delivery of dexamethasone to macrophages using a humanized CD163 antibody as carrier exhibits anti-inflammatory effects comparable with 50 times higher concentrations of free dexamethasone and does not inhibit endogenous cortisol production. This antibody-drug complex showing......OBJECTIVES: Macrophages are important cells in immunity and the main producers of pro-inflammatory cytokines. The main objective was to evaluate if specific delivery of glucocorticoid to the macrophage receptor CD163 is superior to systemic glucocorticoid therapy in dampening the cytokine response...

  7. Mapping of monoclonal antibody- and receptor-binding domains on human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) using a surface plasmon resonance-based biosensor.

    Science.gov (United States)

    Laricchia-Robbio, L; Liedberg, B; Platou-Vikinge, T; Rovero, P; Beffy, P; Revoltella, R P

    1996-10-01

    An automated surface plasmon resonance (SPR)-based biosensor system has been used for mapping antibody and receptor-binding regions on the recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) molecule. A rabbit antimouse IgG1-Fc antibody (RAM.Fc) was coupled to an extended carboxymethylated-hydrogel matrix attached to a gold surface in order to capture an anti-rhGM-CSF monoclonal antibody (MAb) injected over the sensing layer. rhGM-CSF was subsequently injected and allowed to bind to this antibody. Multisite binding assays were then performed, by flowing sequentially other antibodies and peptides over the surface, and the capacity of the latter to interact with the entrapped rhGM-CSF in a multimolecular complex was monitored in real time with SPR. Eleven MAb (all IgG1K), were analyzed: respectively, four antipeptide MAb raised against three distinct epitopes of the cytokine (two clones against residues 14-24, that includes part of the first alpha-helix toward the N-terminal region; one clone against peptide 30-41, an intrahelical loop; and one clone against residues 79-91, including part of the third alpha-helix) and seven antiprotein MAbs raised against the entire rhGM-CSF, whose target native epitopes are still undetermined. In addition, the binding capacity to rhGM-CSF of a synthetic peptide, corresponding to residues 238-254 of the extracellular human GM-CSF receptor alpha-chain, endowed with rhGM-CSF binding activity, was tested. The results from experiments performed with the biosensor were compared with those obtained by a sandwich enzyme-linked immunosorbent assay (ELISA), using the same reagents. The features of the biosensor technology (fully automated, measure in real time, sharpened yes/no response, less background disturbances, no need for washing step or labeling of the reagent) offered several advantages in these studies of MAb immunoreactivity and epitope mapping, giving a much better resolution and enabling more distinct

  8. Role of antioxidant scavenging enzymes and extracellular ...

    African Journals Online (AJOL)

    ChithrashreeGS

    2012-08-23

    Aug 23, 2012 ... peroxidase are two important antioxidant scavenging enzymes involved in ... Catalase was assayed using the method of Beers and Sizer. (1951) with .... yeast dextrose calcium carbonate agar (YDC) medium. Catalase and ...

  9. Flavonoids as scavengers of nitric oxide radical.

    NARCIS (Netherlands)

    van Acker, S.A.B.E.; Tromp, M.N.J.L.; Haenen, G.R.M.M.; van der Vijgh, W.J.F.; Bast, A.

    1995-01-01

    Flavonoids are a group of naturally occurring compounds used, e.g., in the treatment of vascular endothelial damage. They are known to be excellent scavengers of oxygen free radicals. Since the nitric oxide radical (

  10. Agomelatine, a MT1/MT2 melatonergic receptor agonist with serotonin 5-HT2C receptor antagonistic properties, suppresses Prevotella intermedia lipopolysaccharide-induced production of proinflammatory mediators in murine macrophages.

    Science.gov (United States)

    Hyeon, Jin-Yi; Choi, Eun-Young; Choe, So-Hui; Park, Hae Ryoun; Choi, Jeom-Il; Choi, In Soon; Kim, Sung-Jo

    2017-10-01

    This study was performed in an attempt to examine the influence of agomelatine in mitigating the generation of proinflammatory mediators in RAW264.7 murine macrophages exposed to lipopolysaccharide (LPS) obtained from Prevotella intermedia, a gram-negative anaerobic bacterium that is related with various types of periodontal diseases, and the molecular mechanisms behind its effects. LPS from P. intermedia strain ATCC 25611 was prepared employing the conventional phenol-water procedure. Conditioned culture media were analyzed for the levels of nitric oxide (NO), interleukin-1β (IL-1β) and IL-6. Real-time PCR analysis was carried out to determine the mRNA levels of inducible NO synthase (iNOS), IL-1β, IL-6 and SOCS1. Protein expression levels were evaluated by immunoblot test. NF-κB-dependent SEAP reporter assay was performed using a reporter cell line. DNA-binding activities of NF-κB subunits were analyzed utilizing the ELISA-based kits. Agomelatine was found to down-regulate significantly the generation of iNOS-derived NO, IL-1β and IL-6 as well as the expression of their mRNAs in cells activated with P. intermedia LPS. Agomelatine decreased NF-κB-dependent SEAP release caused by P. intermedia LPS. Agomelatine did not inhibit NF-κB transcription induced by LPS at the level of IκB-α degradation. Instead, LPS-induced nuclear translocation and DNA binding of NF-κB p50 subunit was blocked by agomelatine. P. intermedia LPS-elicited activation of STAT1 and STAT3 was reduced notably by co-treatment with agomelatine. Agomelatine showed a tendency to enhance mRNA level of SOCS1 in LPS-activated cells as well. Agomelatine merits further evaluation to reveal its usefulness on the host modulation of periodontal disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Daintain/AIF-1 Plays Roles in Coronary Heart Disease via Affecting the Blood Composition and Promoting Macrophage Uptake and Foam Cell Formation

    Directory of Open Access Journals (Sweden)

    Junhan Wang

    2013-07-01

    Full Text Available Background: Daintain/AIF-1 is an inflammatory polypeptide factor/allograft inflammatory factor 1 derived from macrophages. It is characterized in APOE-/- mice as a novel inflammatory factor associated with atherosclerosis. The purpose of this study was to characterize its function in human atherosclerosis. Methods: Immunohistochemistry was used to identify the expression of daintain/AIF-1 in vessel segments within and far from atherosclerotic plaques; High-performance liquid chromatography (HPLC was used to display the effects of daintain/AIF-1 on C-reactive protein (CRP, oxidative capacity and superoxide dismutase (SOD in vivo; Oil Red O Staining was used to show the effects of daintain/AIF-1 on uptake of oxidized low density lipoprotein (ox-LDL into U937 cells, a macrophage line; Western Blot was used to test scavenger receptor A (SRA expression. Results: A high density of daintain/AIF-1 was observed in the tunica intima and media of coronary artery with atherosclerotic plaque, and fewer daintain/AIF-1 in the vessels without atherosclerotic plaque; Daintain/AIF-1 injected intravenously into BALB/c mice boosted oxidative capacity, significantly impaired SOD activities and augmented the CRP level in blood. According to the oil red O test, daintain/AIF-1 profoundly facilitated the uptake of ox-LDL in U937 macrophages and formation of foam cells in the endothelium. We also found that the molecular mechanisms are effective by promoting overexpression of SRA on macrophages. Conclusion: These findings implicate that the inflammatory factor daintain/AIF-1 is closely associated with atherogenesis, and could be further characterized as a novel risk factor for atherosclerosis

  12. Dual prognostic significance of tumour-associated macrophages in human pancreatic adenocarcinoma treated or untreated with chemotherapy.

    Science.gov (United States)

    Di Caro, Giuseppe; Cortese, Nina; Castino, Giovanni Francesco; Grizzi, Fabio; Gavazzi, Francesca; Ridolfi, Cristina; Capretti, Giovanni; Mineri, Rossana; Todoric, Jelena; Zerbi, Alessandro; Allavena, Paola; Mantovani, Alberto; Marchesi, Federica

    2016-10-01

    Tumour-associated macrophages (TAMs) play key roles in tumour progression. Recent evidence suggests that TAMs critically modulate the efficacy of anticancer therapies, raising the prospect of their targeting in human cancer. In a large retrospective cohort study involving 110 patients with pancreatic ductal adenocarcinoma (PDAC), we assessed the density of CD68-TAM immune reactive area (%IRA) at the tumour-stroma interface and addressed their prognostic relevance in relation to postsurgical adjuvant chemotherapy (CTX). In vitro, we dissected the synergism of CTX and TAMs. In human PDAC, TAMs predominantly exhibited an immunoregulatory profile, characterised by expression of scavenger receptors (CD206, CD163) and production of interleukin 10 (IL-10). Surprisingly, while the density of TAMs associated to worse prognosis and distant metastasis, CTX restrained their protumour prognostic significance. High density of TAMs at the tumour-stroma interface positively dictated prognostic responsiveness to CTX independently of T-cell density. Accordingly, in vitro, gemcitabine-treated macrophages became tumoricidal, activating a cytotoxic gene expression programme, inhibiting their protumoural effect and switching to an antitumour phenotype. In patients with human PDAC, neoadjuvant CTX was associated to a decreased density of CD206(+) and IL-10(+) TAMs at the tumour-stroma interface. Overall, our data highlight TAMs as critical determinants of prognostic responsiveness to CTX and provide clinical and in vitro evidence that CTX overall directly re-educates TAMs to restrain tumour progression. These results suggest that the quantification of TAMs could be exploited to select patients more likely to respond to CTX and provide the basis for novel strategies aimed at re-educating macrophages in the context of CTX. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  13. Macrophages are critical effectors of antibody therapies for cancer.

    Science.gov (United States)

    Weiskopf, Kipp; Weissman, Irving L

    2015-01-01

    Macrophages are innate immune cells that derive from circulating monocytes, reside in all tissues, and participate in many states of pathology. Macrophages play a dichotomous role in cancer, where they promote tumor growth but also serve as critical immune effectors of therapeutic antibodies. Macrophages express all classes of Fcγ receptors, and they have immense potential to destroy tumors via the process of antibody-dependent phagocytosis. A number of studies have demonstrated that macrophage phagocytosis is a major mechanism of action of many antibodies approved to treat cancer. Consequently, a number of approaches to augment macrophage responses to therapeutic antibodies are under investigation, including the exploration of new targets and development of antibodies with enhanced functions. For example, the interaction of CD47 with signal-regulatory protein α (SIRPα) serves as a myeloid-specific immune checkpoint that limits the response of macrophages to antibody therapies, and CD47-blocking agents overcome this barrier to augment phagocytosis. The response of macrophages to antibody therapies can also be enhanced with engineered Fc variants, bispecific antibodies, or antibody-drug conjugates. Macrophages have demonstrated success as effectors of cancer immunotherapy, and further investigation will unlock their full potential for the benefit of patients.

  14. Nonantibiotic macrolides restore airway macrophage phagocytic function with potential anti-inflammatory effects in chronic lung diseases.

    Science.gov (United States)

    Hodge, Sandra; Tran, Hai B; Hamon, Rhys; Roscioli, Eugene; Hodge, Greg; Jersmann, Hubertus; Ween, Miranda; Reynolds, Paul N; Yeung, Arthur; Treiberg, Jennifer; Wilbert, Sibylle

    2017-05-01

    We reported defective efferocytosis associated with cigarette smoking and/or airway inflammation in chronic lung diseases, including chronic obstructive pulmonary disease, severe asthma, and childhood bronchiectasis. We also showed defects in phagocytosis of nontypeable Haemophilus influenzae (NTHi), a common colonizer of the lower airway in these diseases. These defects could be substantially overcome with low-dose azithromycin; however, chronic use may induce bacterial resistance. The aim of the present study was therefore to investigate two novel macrolides-2'-desoxy-9-(S)-erythromycylamine (GS-459755) and azithromycin-based 2'-desoxy molecule (GS-560660)-with significantly diminished antibiotic activity against Staphylococcus aureus , Streptococcus pneumonia , Moraxella catarrhalis , and H. influenzae We tested their effects on efferocytosis, phagocytosis of NTHi, cell viability, receptors involved in recognition of apoptotic cells and/or NTHi (flow cytometry), secreted and cleaved intracellular IL-1β (cytometric bead array, immunofluorescence/confocal microscopy), and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) using primary alveolar macrophages and THP-1 macrophages ± 10% cigarette smoke extract. Dose-response experiments showed optimal prophagocytic effects of GS-459755 and GS-560660 at concentrations of 0.5-1 µg/ml compared with our findings with azithromycin. Both macrolides significantly improved phagocytosis of apoptotic cells and NTHi (e.g., increases in efferocytosis and phagocytosis of NTHi: GS-459755, 23 and 22.5%, P = 0.043; GS-560660, 23.5 and 22%, P = 0.043, respectively). Macrophage viability remained >85% following 24 h exposure to either macrolide at concentrations up to 20 µg/ml. Secreted and intracellular-cleaved IL-1β was decreased with both macrolides with no significant changes in recognition molecules c-mer proto-oncogene tyrosine kinase; scavenger receptor class A, member 1; Toll

  15. Functional analysis and molecular dynamics simulation of LOX-1 K167N polymorphism reveal alteration of receptor activity.

    Directory of Open Access Journals (Sweden)

    Silvia Biocca

    Full Text Available The human lectin-like oxidized low density lipoprotein receptor 1 LOX-1, encoded by the ORL1 gene, is the major scavenger receptor for oxidized low density lipoprotein in endothelial cells. Here we report on the functional effects of a coding SNP, c.501G>C, which produces a single amino acid change (K>N at codon 167. Our study was aimed at elucidating whether the c.501G>C polymorphism changes the binding affinity of LOX-1 receptor altering its function. The presence of p.K167N mutation reduces ox-LDL binding and uptake. Ox-LDL activated extracellular signal-regulated kinases 1 and 2 (ERK 1/2 is inhibited. Furthermore, ox-LDL induced biosynthesis of LOX-1 receptors is dependent on the p.K167N variation. In human macrophages, derived from c.501G>C heterozygous individuals, the ox-LDL induced LOX-1 46 kDa band is markedly lower than in induced macrophages derived from c.501G>C controls. Investigation of p.K167N mutation through molecular dynamics simulation and electrostatic analysis suggests that the ox-LDL binding may be attributed to the coupling between the electrostatic potential distribution and the asymmetric flexibility of the basic spine residues. The N/N-LOX-1 mutant has either interrupted electrostatic potential and asymmetric fluctuations of the basic spine arginines.

  16. Differential trafficking of oxidized LDL and oxidized LDL immune complexes in macrophages: impact on oxidative stress.

    Directory of Open Access Journals (Sweden)

    Mohammed M Al Gadban

    2010-09-01

    Full Text Available Oxidized low-density lipoproteins (oxLDL and oxLDL-containing immune complexes (oxLDL-IC contribute to formation of lipid-laden macrophages (foam cells. It has been shown that oxLDL-IC are considerably more efficient than oxLDL in induction of foam cell formation, inflammatory cytokines secretion, and cell survival promotion. Whereas oxLDL is taken up by several scavenger receptors, oxLDL-IC are predominantly internalized through the FCgamma receptor I (FCgamma RI. This study examined differences in intracellular trafficking of lipid and apolipoprotein moieties of oxLDL and oxLDL-IC and the impact on oxidative stress.Fluorescently labeled lipid and protein moieties of oxLDL co-localized within endosomal and lysosomal compartments in U937 human monocytic cells. In contrast, the lipid moiety of oxLDL-IC was detected in the endosomal compartment, whereas its apolipoprotein moiety advanced to the lysosomal compartment. Cells treated with oxLDL-IC prior to oxLDL demonstrated co-localization of internalized lipid moieties from both oxLDL and oxLDL-IC in the endosomal compartment. This sequential treatment likely inhibited oxLDL lipid moieties from trafficking to the lysosomal compartment. In RAW 264.7 macrophages, oxLDL-IC but not oxLDL induced GFP-tagged heat shock protein 70 (HSP70 and HSP70B', which co-localized with the lipid moiety of oxLDL-IC in the endosomal compartment. This suggests that HSP70 family members might prevent the degradation of the internalized lipid moiety of oxLDL-IC by delaying its advancement to the lysosome. The data also showed that mitochondrial membrane potential was decreased and generation of reactive oxygen and nitrogen species was increased in U937 cell treated with oxLDL compared to oxLDL-IC.Findings suggest that lipid and apolipoprotein moieties of oxLDL-IC traffic to separate cellular compartments, and that HSP70/70B' might sequester the lipid moiety of oxLDL-IC in the endosomal compartment. This mechanism could

  17. Evaluation of antitumor, immunomodulatory and free radical scavenging effects of a new herbal prescription seaweed complex preparation

    Science.gov (United States)

    Liu, Xin; Shao, Changlun; Kong, Wenwen; Fang, Yuchun; Wang, Changyun

    2013-09-01

    Seaweed Complex Preparation (SCP) is a clinical traditional Chinese medicine preparation which is composed of seven traditional Chinese herbs, and it has been used for treatment of lung cancer, liver cancer and digestive cancer. However, little information is available about the pharmacodynamic basis. The antitumor, immunomodulatory and free radical scavenging effects of SCP were evaluated in this study. Transplanted tumor in vivo method was used to determine the antitumor effect. The effects on splenocyte proliferation and phagocytosis of macrophages in tumor-bearing mice were measured by the MTT method and the phagocytizing cock red blood cell (CRBC) method respectively. The scavenging activities of SCP on DPPH and hydroxyl radicals in vitro were investigated. It was found that the medium-dose and high-dose of SCP could significantly inhibit the growth of transplanted hepatic tumor of murine hepatocarcinoma cell line H22, and promote proliferation of splenocytes and phagocytosis of macrophages. SCP possessed noticeable scavenging activities on DPPH and hydroxyl radicals. The antitumor effects of SCP might be achieved by improving immune system and scavenging free radicals, which is in accordance with the viewpoint of traditional Chinese medicine in promoting the body resistance and eliminating pathogenic factors for cancer treatment.

  18. The elusive antifibrotic macrophage

    Directory of Open Access Journals (Sweden)

    Adhyatmika eAdhyatmika

    2015-11-01

    Full Text Available Fibrotic diseases, especially of the liver, the cardiovascular system, the kidneys, and the lungs account for approximately 45% of deaths in Western societies. Fibrosis is a serious complication associated with aging and/or chronic inflammation or injury and cannot be treated effectively yet. It is characterized by excessive deposition of extracellular matrix (ECM proteins by myofibroblasts and impaired degradation by macrophages. This ultimately destroys the normal structure of an organ, which leads to loss of function. Most efforts to develop drugs have focused on inhibiting ECM production by myofibroblasts and have not yielded many effective drugs yet. Another option is to stimulate the cells that are responsible for degradation and uptake of excess ECM, i.e. antifibrotic macrophages. However, macrophages are plastic cells that have many faces in fibrosis, including profibrotic behaviour stimulating ECM production. This can be dependent on their origin, as the different organs have tissue-resident macrophages with different origins and a various influx of incoming monocytes in steady-state conditions and during fibrosis. To be able to pharmacologically stimulate the right kind of behaviour in fibrosis, a thorough characterization of antifibrotic macrophages is necessary, as well as an understanding of the signals they need to degrade ECM. In this review we will summarize the current state of the art regarding the antifibrotic macrophage phenotype and the signals that stimulate its behaviour.

  19. Essential Role of DAP12 Signaling in Macrophage Programming into a Fusion-Compete