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Sample records for activation regulated chemokine

  1. German cockroach proteases and protease-activated receptor-2 regulate chemokine production and dendritic cell recruitment.

    PubMed

    Day, Scottie B; Ledford, John R; Zhou, Ping; Lewkowich, Ian P; Page, Kristen

    2012-01-01

    We recently showed that serine proteases in German cockroach (GC) feces (frass) decreased experimental asthma through the activation of protease-activated receptor (PAR)-2. Since dendritic cells (DCs) play an important role in the initiation of asthma, we queried the role of GC frass proteases in modulating CCL20 (chemokine C-C motif ligand 20) and granulocyte macrophage colony-stimulating factor (GM-CSF) production, factors that regulate pulmonary DCs. A single exposure to GC frass resulted in a rapid, but transient, increase in GM-CSF and a steady increase in CCL20 in the airways of mice. Instillation of protease-depleted GC frass or instillation of GC frass in PAR-2-deficient mice significantly decreased chemokine release. A specific PAR-2-activating peptide was also sufficient to induce CCL20 production. To directly assess the role of the GC frass protease in chemokine release, we enriched the protease from GC frass and confirmed that the protease was sufficient to induce both GM-CSF and CCL20 production in vivo. Primary airway epithelial cells produced both GM-CSF and CCL20 in a protease- and PAR-2-dependent manner. Finally, we show a decreased percentage of myeloid DCs in the lung following allergen exposure in PAR-2-deficient mice compared to wild-type mice. However, there was no difference in GC frass uptake. Our data indicate that, through the activation of PAR-2, allergen-derived proteases are sufficient to induce CCL20 and GM-CSF production in the airways. This leads to increased recruitment and/or differentiation of myeloid DC populations in the lungs and likely plays an important role in the initiation of allergic airway responses. PMID:21876326

  2. Ras regulates alveolar macrophage formation of CXC chemokines and neutrophil activation in streptococcal M1 protein-induced lung injury.

    PubMed

    Zhang, Songen; Hwaiz, Rundk; Rahman, Milladur; Herwald, Heiko; Thorlacius, Henrik

    2014-06-15

    Streptococcal toxic shock syndrome (STSS) is associated with a high mortality rate. The M1 serotype of Streptococcus pyogenes is most frequently associated with STSS. Herein, we examined the role of Ras signaling in M1 protein-induced lung injury. Male C57BL/6 mice received the Ras inhibitor (farnesylthiosalicylic acid, FTS) prior to M1 protein challenge. Bronchoalveolar fluid and lung tissue were harvested for quantification of neutrophil recruitment, edema and CXC chemokine formation. Neutrophil expression of Mac-1 was quantified by use of flow cytometry. Quantitative RT-PCR was used to determine gene expression of CXC chemokines in alveolar macrophages. Administration of FTS reduced M1 protein-induced neutrophil recruitment, edema formation and tissue damage in the lung. M1 protein challenge increased Mac-1 expression on neutrophils and CXC chemokine levels in the lung. Inhibition of Ras activity decreased M1 protein-induced expression of Mac-1 on neutrophils and secretion of CXC chemokines in the lung. Moreover, FTS abolished M1 protein-provoked gene expression of CXC chemokines in alveolar macrophages. Ras inhibition decreased chemokine-mediated neutrophil migration in vitro. Taken together, our novel findings indicate that Ras signaling is a potent regulator of CXC chemokine formation and neutrophil infiltration in the lung. Thus, inhibition of Ras activity might be a useful way to antagonize streptococcal M1 protein-triggered acute lung injury. PMID:24704370

  3. Thymus and activation-regulated chemokine as a clinical biomarker in atopic dermatitis.

    PubMed

    Kataoka, Yoko

    2014-03-01

    Thymus and activation-regulated chemokine (TARC/CCL17) is a member of the T-helper 2 chemokine family. In Japan, serum TARC level has been commercially measured since 2008. After years of experience, we realized that TARC is an extremely useful clinical biomarker for atopic dermatitis (AD) treatment. Usually, physicians conduct a visual examination to determine whether their treatment has been successful; however, the visual examination results may not always be accurate; in such cases, serum TARC levels should be measured to eliminate any ambiguity regarding the treatment outcome. When the waning and waxing of eczema and fluctuations in the serum TARC levels were considered, we frequently found that AD does not follow a natural course but follows non-regulated inflammatory floating caused by insufficient intermittent topical treatment. Serum TARC is a promising biomarker for remission and can be used for accurately monitoring proactive treatment for long-term control. Abnormally high serum TARC levels indicate accelerated pathogenesis of cutaneous inflammation. Rapid normalization and maintaining normal serum TARC levels using appropriate topical treatment is a reasonable strategy for alleviating inflammation without upregulating cytokine expression. Observing serum TARC levels during early intervention for severe infantile AD is worthwhile to determine initial disease activity and evaluate treatment efficacy. Appropriate control of severe early-onset infantile AD is important for improving prognosis of eczema and for preventing food allergies. Additionally, this biomarker is useful for improving patient adherence. Dermatologists will be able to make great progress in treating AD by adopting biomarkers such as TARC for accurately assessing non-visible subclinical disorders. PMID:24628072

  4. Novel antiviral activity of chemokines

    SciTech Connect

    Nakayama, Takashi; Shirane, Jumi; Hieshima, Kunio; Shibano, Michiko; Watanabe, Masayasu; Jin, Zhe; Nagakubo, Daisuke; Saito, Takuya; Shimomura, Yoshikazu; Yoshie, Osamu . E-mail: o.yoshie@med.kindai.ac.jp

    2006-07-05

    Antimicrobial peptides are a diverse family of small, mostly cationic polypeptides that kill bacteria, fungi and even some enveloped viruses, while chemokines are a group of mostly cationic small proteins that induce directed migration of leukocytes through interactions with a group of seven transmembrane G protein-coupled receptors. Recent studies have shown that antimicrobial peptides and chemokines have substantially overlapping functions. Thus, while some antimicrobial peptides are chemotactic for leukocytes, some chemokines can kill a wide range of bacteria and fungi. Here, we examined a possible direct antiviral activity of chemokines against an enveloped virus HSV-1. Among 22 human chemokines examined, chemokines such as MIP-1{alpha}/CCL3, MIP-1{beta}/CCL4 and RANTES/CCL5 showed a significant direct antiviral activity against HSV-1. It is intriguing that these chemokines are mostly known to be highly expressed by effector CD8{sup +} T cells. The chemokines with a significant anti-HSV-1 activity commonly bound to HSV-1 virions via envelope glycoprotein gB. Electron microscopy revealed that the chemokines with a significant anti-HSV-1 activity were commonly capable of generating pores in the envelope of HSV-1. Thus, some chemokines have a significant direct antiviral activity against HSV-1 in vitro and may have a potential role in host defense against HSV-1 as a direct antiviral agent.

  5. Regulation of skeletal muscle regeneration by CCR2-activating chemokines is directly related to macrophage recruitment

    PubMed Central

    Martinez, Carlo O.; McHale, Matthew J.; Wells, Jason T.; Ochoa, Oscar; Michalek, Joel E.; McManus, Linda M.

    2010-01-01

    Muscle regeneration requires CC chemokine receptor 2 (CCR2) expression on bone marrow-derived cells; macrophages are a prominent CCR2-expressing cell in this process. CCR2−/− mice have severe impairments in angiogenesis, macrophage recruitment, and skeletal muscle regeneration following cardiotoxin (CTX)-induced injury. However, multiple chemokines activate CCR2, including monocyte chemotactic proteins (MCP)-1, -3, and -5. We hypothesized that MCP-1 is the chemokine ligand that mediates the impairments present in CCR2−/− mice. We examined muscle regeneration, capillary density, and cellular recruitment in MCP-1−/− and CCR2−/− mice following injury. Muscle regeneration and adipocyte accumulation, but not capillary density, were significantly impaired in MCP-1−/− compared with wild-type (WT) mice; however, muscle regeneration and adipocyte accumulation impairments were not as severe as observed in CCR2−/− mice. Although tissue levels of MCP-5 were elevated in MCP-1−/− mice compared with WT, the administration of MCP-5 neutralizing antibody did not alter muscle regeneration in MCP-1−/− mice. While neutrophil accumulation after injury was similar in all three mouse strains, macrophage recruitment was highest in WT mice, intermediate in MCP-1−/− mice, and severely impaired in CCR2−/− mice. In conclusion, while the absence of MCP-1 resulted in impaired macrophage recruitment and muscle regeneration, MCP-1−/− mice exhibit an intermediate phenotype compared with CCR2−/− mice. Intermediate macrophage recruitment in MCP-1−/− mice was associated with similar capillary density to WT, suggesting that fewer macrophages may be needed to restore angiogenesis vs. muscle regeneration. Finally, other chemokines, in addition to MCP-1 and MCP-5, may activate CCR2-dependent regenerative processes resulting in an intermediate phenotype in MCP-1−/− mice. PMID:20631294

  6. Regulation of skeletal muscle regeneration by CCR2-activating chemokines is directly related to macrophage recruitment.

    PubMed

    Martinez, Carlo O; McHale, Matthew J; Wells, Jason T; Ochoa, Oscar; Michalek, Joel E; McManus, Linda M; Shireman, Paula K

    2010-09-01

    Muscle regeneration requires CC chemokine receptor 2 (CCR2) expression on bone marrow-derived cells; macrophages are a prominent CCR2-expressing cell in this process. CCR2-/- mice have severe impairments in angiogenesis, macrophage recruitment, and skeletal muscle regeneration following cardiotoxin (CTX)-induced injury. However, multiple chemokines activate CCR2, including monocyte chemotactic proteins (MCP)-1, -3, and -5. We hypothesized that MCP-1 is the chemokine ligand that mediates the impairments present in CCR2-/- mice. We examined muscle regeneration, capillary density, and cellular recruitment in MCP-1-/- and CCR2-/- mice following injury. Muscle regeneration and adipocyte accumulation, but not capillary density, were significantly impaired in MCP-1-/- compared with wild-type (WT) mice; however, muscle regeneration and adipocyte accumulation impairments were not as severe as observed in CCR2-/- mice. Although tissue levels of MCP-5 were elevated in MCP-1-/- mice compared with WT, the administration of MCP-5 neutralizing antibody did not alter muscle regeneration in MCP-1-/- mice. While neutrophil accumulation after injury was similar in all three mouse strains, macrophage recruitment was highest in WT mice, intermediate in MCP-1-/- mice, and severely impaired in CCR2-/- mice. In conclusion, while the absence of MCP-1 resulted in impaired macrophage recruitment and muscle regeneration, MCP-1-/- mice exhibit an intermediate phenotype compared with CCR2-/- mice. Intermediate macrophage recruitment in MCP-1-/- mice was associated with similar capillary density to WT, suggesting that fewer macrophages may be needed to restore angiogenesis vs. muscle regeneration. Finally, other chemokines, in addition to MCP-1 and MCP-5, may activate CCR2-dependent regenerative processes resulting in an intermediate phenotype in MCP-1-/- mice. PMID:20631294

  7. The Early Activation Marker CD69 Regulates the Expression of Chemokines and CD4 T Cell Accumulation in Intestine

    PubMed Central

    Radulovic, Katarina; Rossini, Valerio; Manta, Calin; Holzmann, Karlheinz; Kestler, Hans A.; Niess, Jan Hendrik

    2013-01-01

    Migration of naïve and activated lymphocytes is regulated by the expression of various molecules such as chemokine receptors and ligands. CD69, the early activation marker of C-type lectin domain family, is also shown to regulate the lymphocyte migration by affecting their egress from the thymus and secondary lymphoid organs. Here, we aimed to investigate the role of CD69 in accumulation of CD4 T cells in intestine using murine models of inflammatory bowel disease. We found that genetic deletion of CD69 in mice increases the expression of the chemokines CCL-1, CXCL-10 and CCL-19 in CD4+ T cells and/or CD4− cells. Efficient in vitro migration of CD69-deficient CD4 T cells toward the chemokine stimuli was the result of increased expression and/or affinity of chemokine receptors. In vivo CD69−/− CD4 T cells accumulate in the intestine in higher numbers than B6 CD4 T cells as observed in competitive homing assay, dextran sodium sulphate (DSS)-induced colitis and antigen-specific transfer colitis. In DSS colitis CD69−/− CD4 T cell accumulation in colonic lamina propria (cLP) was associated with increased expression of CCL-1, CXCL-10 and CCL-19 genes. Furthermore, treatment of DSS-administrated CD69−/− mice with the mixture of CCL-1, CXCL-10 and CCL-19 neutralizing Abs significantly decreased the histopathological signs of colitis. Transfer of OT-II×CD69−/− CD45RBhigh CD4 T cells into RAG−/− hosts induced CD4 T cell accumulation in cLP. This study showed CD69 as negative regulator of inflammatory responses in intestine as it decreases the expression of chemotactic receptors and ligands and reduces the accumulation of CD4 T cells in cLP during colitis. PMID:23776480

  8. Chemokine Regulation of Neutrophil Infiltration of Skin Wounds

    PubMed Central

    Su, Yingjun; Richmond, Ann

    2015-01-01

    Significance: Efficient recruitment of neutrophils to an injured skin lesion is an important innate immune response for wound repair. Defects in neutrophil recruitment lead to impaired wound healing. Recent Advances: Chemokines and chemokine receptors are known to regulate neutrophil recruitment. Recent research advances reveal more mechanistic details about the regulation of chemokines and chemokine receptors on neutrophil egress from bone marrow, transmigration into the wound site, spatial navigation toward the necrotic skin tissue, and apoptosis-induced clearance by efferocytosis. Critical Issues: Skin injury triggers local and systemic alterations in the expression of multiple chemotactic molecules and the magnitude of chemokine receptor-mediated signaling. The responses of a number of CXC and CX3C chemokines and their receptors closely associate with the temporal and spatial recruitment of neutrophils to wound sites during the inflammatory phase and promote the clearance of necrotic neutrophils during the transition into the proliferative phase. Functional aberrancy in these chemokines and chemokine receptor systems is recognized as one of the important mechanisms underlying the pathology of impaired wound healing. Future Directions: Future research should aim to investigate the therapeutic modulation of neutrophil activity through the targeting of specific chemokines or chemokine receptors in the early inflammatory phase to improve clinical management of wound healing. PMID:26543677

  9. Jak3 Enables Chemokine-Dependent Actin Cytoskeleton Reorganization by Regulating Cofilin and Rac/Rhoa GTPases Activation

    PubMed Central

    Ambriz-Peña, Xochitl; García-Zepeda, Eduardo Alberto; Meza, Isaura; Soldevila, Gloria

    2014-01-01

    We have previously shown that Jak3 is involved in the signaling pathways of CCR7, CCR9 and CXCR4 in murine T lymphocytes and that Jak3−/− lymphocytes display an intrinsic defect in homing to peripheral lymph nodes. However, the molecular mechanism underlying the defective migration observed in Jak3−/− lymphocytes remains elusive. Here, it is demonstrated for the first time, that Jak3 is required for the actin cytoskeleton reorganization in T lymphocytes responding to chemokines. It was found that Jak3 regulates actin polymerization by controlling cofilin inactivation in response to CCL21 and CXCL12. Interestingly, cofilin inactivation was not precluded in PTX- treated cells despite their impaired actin polymerization. Additionally, Jak3 was required for small GTPases Rac1 and RhoA activation, which are indispensable for acquisition of the migratory cell phenotype and the generation of a functional leading edge and uropod, respectively. This defect correlates with data obtained by time-lapse video-microscopy showing an incompetent uropod formation and impaired motility in Jak3-pharmacologically inhibited T lymphocytes. Our data support a new model in which Jak3 and heterotrimeric G proteins can use independent, but complementary, signaling pathways to regulate actin cytoskeleton dynamics during cell migration in response to chemokines. PMID:24498424

  10. Chemokines and the Signaling Modules Regulating Integrin Affinity

    PubMed Central

    Montresor, Alessio; Toffali, Lara; Constantin, Gabriela; Laudanna, Carlo

    2012-01-01

    Integrin-mediated adhesion is a general concept referring to a series of adhesive phenomena including tethering–rolling, affinity, valency, and binding stabilization altogether controlling cell avidity (adhesiveness) for the substrate. Arrest chemokines modulate each aspect of integrin activation, although integrin affinity regulation has been recognized as the prominent event in rapid leukocyte arrest induced by chemokines. A variety of inside-out and outside-in signaling mechanisms have been related to the process of integrin-mediated adhesion in different cellular models, but only few of them have been clearly contextualized to rapid integrin affinity modulation by arrest chemokines in primary leukocytes. Complex signaling processes triggered by arrest chemokines and controlling leukocyte integrin activation have been described for ras-related rap and for rho-related small GTPases. We summarize the role of rap and rho small GTPases in the regulation of rapid integrin affinity in primary leukocytes and provide a modular view of these pro-adhesive signaling events. A potential, albeit still speculative, mechanism of rho-mediated regulation of cytoskeletal proteins controlling the last step of integrin activation is also discussed. We also discuss data suggesting a functional integration between the rho- and rap-modules of integrin activation. Finally we examine the universality of signaling mechanisms regulating integrin triggering by arrest chemokines. PMID:22654882

  11. The chemokine system -- a major regulator of angiogenesis in health and disease.

    PubMed

    Rosenkilde, Mette M; Schwartz, Thue W

    2004-01-01

    The chemokine system controls leukocyte trafficking during homeostasis as well as during inflammation and is necessary for the linkage between innate and adaptive immunity. Tissue regulation outside the hematopoietic compartment, for instance, angiogenesis, organogenesis and tumor development, growth and metastasis, is another important function of the chemokine system. The chemokine-mediated regulation of angiogenesis is highly sophisticated and fine tuned, and involves pro-angiogenic chemokines, for instance, CXCL8/IL8 interacting with the CXCR2 receptor, and anti-angiogenic (i.e. angiostatic) chemokines, for instance, CXCL10/IP10 interacting with the CXCR3 receptor. Chemokines also regulate angiogenesis in a receptor-independent manner by means of a perturbation of bFGF and VEGF function. The current review focuses on the influence of the chemokine system in angiogenesis. Examples of the delicate angiogenesis regulation by the chemokine system in, for instance, wound healing and of the dysregulation in, for instance, tumor development are provided along with the interesting phenomenon of molecular piracy of host-encoded genes within the chemokine system. This phenomenon is a general strategy to circumvent and exploit the immune system -- and thereby improve survival -- for many viruses. Yet, a certain group of herpesviruses -- the gamma2-herpesviruses -- encode a functional CXCR2 receptor homolog that is activated by angiogenic chemokines and antagonized by angiostatic chemokines, and this particular gene seems to cause the development of a vascular tumor -- Kaposi's sarcoma -- in the host. PMID:15563311

  12. RelB regulation of chemokine expression modulates local inflammation.

    PubMed Central

    Xia, Y.; Pauza, M. E.; Feng, L.; Lo, D.

    1997-01-01

    The resolution of acute inflammation is incompletely understood but presumably requires the elimination of both inflammatory cells and production of inflammatory cytokines. In the case of recruited bone-marrow-derived inflammatory cells such as granulocytes and macrophages, their short life span helps eliminate these cells and the cytokines they produce. By contrast, resident permanent cells such as fibroblasts require other mechanisms to stop the production of chemokines generated in response to inflammatory triggers such as lipopolysaccharide. Here we demonstrate that RelB is an important regulator of chemokine expression in fibroblasts, thereby playing a key role in the resolution of acute inflammation. Activation of normal fibroblasts by lipopolysaccharide induced a transient production of chemokines, closely followed by induction of RelB expression. However, stimulated RelB-/- fibroblasts exhibited dramatic persistent induction of seven chemokines (RANTES, MIP-1 alpha, MIP-1 beta, MIP-2, IP-10, JE/MCP-1, and KC/CINC). The persistent overexpression of chemokines correlated with increased NF- kappa B binding as well as with increased p50, p65/RelA, and I kappa B alpha expression. Transfection of RelB cDNA into RelB-deficient fibroblasts reversed the lipopolysaccharide-induced chemokine overexpression. In vivo, activated RelB-/- fibroblasts dramatically increased recruitment of granulocytes into tissues. In view of the apparent role of RelB in the resolution of acute inflammation in tissues and previous work showing a requirement for RelB in the initiation of immune responses through the differentiation of antigen-presenting cells, RelB may be an important factor regulating the transition from innate to adaptive immunity. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:9250151

  13. The Anti-inflammatory Protein TSG-6 Regulates Chemokine Function by Inhibiting Chemokine/Glycosaminoglycan Interactions*

    PubMed Central

    Dyer, Douglas P.; Salanga, Catherina L.; Johns, Scott C.; Valdambrini, Elena; Fuster, Mark M.; Milner, Caroline M.; Day, Anthony J.; Handel, Tracy M.

    2016-01-01

    TNF-stimulated gene-6 (TSG-6) is a multifunctional protein secreted in response to pro-inflammatory stimuli by a wide range of cells, including neutrophils, monocytes, and endothelial cells. It has been shown to mediate anti-inflammatory and protective effects when administered in disease models, in part, by reducing neutrophil infiltration. Human TSG-6 inhibits neutrophil migration by binding CXCL8 through its Link module (Link_TSG6) and interfering with the presentation of CXCL8 on cell-surface glycosaminoglycans (GAGs), an interaction that is vital for the function of many chemokines. TSG-6 was also found to interact with chemokines CXCL11 and CCL5, suggesting the possibility that it may function as a broad specificity chemokine-binding protein, functionally similar to those encoded by viruses. This study was therefore undertaken to explore the ability of TSG-6 to regulate the function of other chemokines. Herein, we demonstrate that Link_TSG6 binds chemokines from both the CXC and CC families, including CXCL4, CXCL12, CCL2, CCL5, CCL7, CCL19, CCL21, and CCL27. We also show that the Link_TSG6-binding sites on chemokines overlap with chemokine GAG-binding sites, and that the affinities of Link_TSG6 for these chemokines (KD values 1–85 nm) broadly correlate with chemokine-GAG affinities. Link_TSG6 also inhibits chemokine presentation on endothelial cells not only through a direct interaction with chemokines but also by binding and therefore masking the availability of GAGs. Along with previous work, these findings suggest that TSG-6 functions as a pluripotent regulator of chemokines by modulating chemokine/GAG interactions, which may be a major mechanism by which TSG-6 produces its anti-inflammatory effects in vivo. PMID:27044744

  14. The Anti-inflammatory Protein TSG-6 Regulates Chemokine Function by Inhibiting Chemokine/Glycosaminoglycan Interactions.

    PubMed

    Dyer, Douglas P; Salanga, Catherina L; Johns, Scott C; Valdambrini, Elena; Fuster, Mark M; Milner, Caroline M; Day, Anthony J; Handel, Tracy M

    2016-06-10

    TNF-stimulated gene-6 (TSG-6) is a multifunctional protein secreted in response to pro-inflammatory stimuli by a wide range of cells, including neutrophils, monocytes, and endothelial cells. It has been shown to mediate anti-inflammatory and protective effects when administered in disease models, in part, by reducing neutrophil infiltration. Human TSG-6 inhibits neutrophil migration by binding CXCL8 through its Link module (Link_TSG6) and interfering with the presentation of CXCL8 on cell-surface glycosaminoglycans (GAGs), an interaction that is vital for the function of many chemokines. TSG-6 was also found to interact with chemokines CXCL11 and CCL5, suggesting the possibility that it may function as a broad specificity chemokine-binding protein, functionally similar to those encoded by viruses. This study was therefore undertaken to explore the ability of TSG-6 to regulate the function of other chemokines. Herein, we demonstrate that Link_TSG6 binds chemokines from both the CXC and CC families, including CXCL4, CXCL12, CCL2, CCL5, CCL7, CCL19, CCL21, and CCL27. We also show that the Link_TSG6-binding sites on chemokines overlap with chemokine GAG-binding sites, and that the affinities of Link_TSG6 for these chemokines (KD values 1-85 nm) broadly correlate with chemokine-GAG affinities. Link_TSG6 also inhibits chemokine presentation on endothelial cells not only through a direct interaction with chemokines but also by binding and therefore masking the availability of GAGs. Along with previous work, these findings suggest that TSG-6 functions as a pluripotent regulator of chemokines by modulating chemokine/GAG interactions, which may be a major mechanism by which TSG-6 produces its anti-inflammatory effects in vivo. PMID:27044744

  15. Anti-inflammatory actions of herbal formula Gyejibokryeong-hwan regulated by inhibiting chemokine production and STAT1 activation in HaCaT cells.

    PubMed

    Jeong, Soo-Jin; Lim, Hye-Sun; Seo, Chang-Seob; Jin, Seong-Eun; Yoo, Sae-Rom; Lee, Nari; Shin, Hyeun-Kyoo

    2015-01-01

    Gyejibokryeong-hwan (GJBRH; Keishi-bukuryo-gan in Japan and Guizhi Fuling Wan in China) is a traditional herbal formula comprising five medicinal herbs and is used to treat climacteric syndrome. GJBRH has been shown to exhibit biological activity against diabetes, diabetic nephropathy, atherosclerosis, ischemia, and cancer. However, there is no scientific evidence of its activities against skin inflammation, including atopic dermatitis. We used the HaCaT human keratinocyte cell line to investigate the effects of GJBRH on skin inflammation. No significant cytotoxicity was observed in cells treated with GJBRH up to a concentration of 1000 µg/mL. Exposure to the proinflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) significantly increased HaCaT cell production of the following chemokines: macrophage-derived chemokine (MDC)/CCL22; regulated on activation, normal T-cell expressed and secreted (RANTES)/CCL5; and interleukin-8 (IL-8). In contrast, GJBRH significantly reduced the production of MDC, RANTES, and IL-8 compared with control cells simulated with TNF-α and IFN-γ. Consistently, GJBRH suppressed the mRNA expression of MDC, RANTES, and IL-8 in TNF-α and IFN-γ-treated cells. Treatment with GJBRH markedly inhibited phosphorylation of signal transducer and activator of transcription 1 (STAT1) in HaCaT cells stimulated with TNF-α and IFN-γ. Our findings indicate that GJBRH impairs TNF-α and IFN-γ-mediated inflammatory chemokine production and STAT1 phosphorylation in keratinocytes. We suggest that GJBRH may be a potent therapeutic agent for inflammatory skin disorders. PMID:25757924

  16. Transcriptional regulation of chemokine expression in ovarian cancer.

    PubMed

    Singha, Bipradeb; Gatla, Himavanth R; Vancurova, Ivana

    2015-01-01

    The increased expression of pro-inflammatory and pro-angiogenic chemokines contributes to ovarian cancer progression through the induction of tumor cell proliferation, survival, angiogenesis, and metastasis. The substantial potential of these chemokines to facilitate the progression and metastasis of ovarian cancer underscores the need for their stringent transcriptional regulation. In this Review, we highlight the key mechanisms that regulate the transcription of pro-inflammatory chemokines in ovarian cancer cells, and that have important roles in controlling ovarian cancer progression. We further discuss the potential mechanisms underlying the increased chemokine expression in drug resistance, along with our perspective for future studies. PMID:25790431

  17. A20 regulates IL-1-induced tolerant production of CXC chemokines in human mesangial cells via inhibition of MAPK signaling

    PubMed Central

    Luo, Hongbo; Liu, Yuming; Li, Qian; Liao, Lingjuan; Sun, Ruili; Liu, Xueting; Jiang, Manli; Hu, Jinyue

    2015-01-01

    Chemokines and chemokine receptors are involved in the resolution or progression of renal diseases. Locally secreted chemokines mediated leukocyte recruitment during the initiation and amplification phase of renal inflammation. However, the regulation of chemokine induction is not fully understood. In this study, we found that IL-1 induced a significant up-regulation of CXC chemokines CXCL1, 2, and 8 at both mRNA and protein levels in human mesangial cells. The induction of chemokines was tolerant, as the pre-treatment of HMC with IL-1 down-regulated the induction of chemokines induced by IL-1 re-stimulation. IL-1 up-regulated the ubiquintin-editing enzyme A20. A20 over-expression down-regulated IL-1-induced up-regulation of chemokines, and A20 down-regulation reversed chemokine inhibition induced by IL-1 pre-treatment, suggested that A20 played important roles in the tolerant production of chemokines. Unexpectedly, A20 over- expression inhibited the activation of ERK, JNK, and P38, but did not inhibit the activation of NF-κB. In addition, both IL-1 treatment and A20 over-expression induced the degradation of IRAK1, an important adaptor for IL-1R1 signaling, and A20 inhibition by RNA interference partly reversed the degradation of IRAK1. Taken together, IL-1-induced A20 negatively regulated chemokine production, suggesting that A20 may be an important target for the prevention and control of kidney inflammation. PMID:26648169

  18. Tumorigenesis induced by the HHV8-encoded chemokine receptor requires ligand modulation of high constitutive activity.

    PubMed

    Holst, P J; Rosenkilde, M M; Manfra, D; Chen, S C; Wiekowski, M T; Holst, B; Cifire, F; Lipp, M; Schwartz, T W; Lira, S A

    2001-12-01

    ORF74 (or KSHV-vGPCR) is a highly constitutively active G protein-coupled receptor encoded by HHV8 that is regulated both positively and negatively by endogenous chemokines. When expressed in transgenic mice, this chemokine receptor induces an angioproliferative disease closely resembling Kaposi sarcoma (KS). Here we demonstrate that several lines of mice carrying mutated receptors deficient in either constitutive activity or chemokine regulation fail to develop KS-like disease. In addition, animals expressing a receptor that preserves chemokine binding and constitutive activity but that does not respond to agonist stimulation have a much lower incidence of angiogenic lesions and tumors. These results indicate that induction of the KS-like disease in transgenic mice by ORF74 requires not only high constitutive signaling activity but also modulation of this activity by endogenous chemokines. PMID:11748262

  19. Tumorigenesis induced by the HHV8-encoded chemokine receptor requires ligand modulation of high constitutive activity

    PubMed Central

    Holst, Peter J.; Rosenkilde, Mette M.; Manfra, Denise; Chen, Shu-Cheng; Wiekowski, Maria T.; Holst, Birgitte; Cifire, Felix; Lipp, Martin; Schwartz, Thue W.; Lira, Sergio A.

    2001-01-01

    ORF74 (or KSHV-vGPCR) is a highly constitutively active G protein–coupled receptor encoded by HHV8 that is regulated both positively and negatively by endogenous chemokines. When expressed in transgenic mice, this chemokine receptor induces an angioproliferative disease closely resembling Kaposi sarcoma (KS). Here we demonstrate that several lines of mice carrying mutated receptors deficient in either constitutive activity or chemokine regulation fail to develop KS-like disease. In addition, animals expressing a receptor that preserves chemokine binding and constitutive activity but that does not respond to agonist stimulation have a much lower incidence of angiogenic lesions and tumors. These results indicate that induction of the KS-like disease in transgenic mice by ORF74 requires not only high constitutive signaling activity but also modulation of this activity by endogenous chemokines. PMID:11748262

  20. CD26/dipeptidylpeptidase IV-chemokine interactions: double-edged regulation of inflammation and tumor biology.

    PubMed

    Mortier, Anneleen; Gouwy, Mieke; Van Damme, Jo; Proost, Paul; Struyf, Sofie

    2016-06-01

    Post-translational modification of chemokines is an essential regulatory mechanism to enhance or dampen the inflammatory response. CD26/dipeptidylpeptidase IV, ubiquitously expressed in tissues and blood, removes NH2-terminal dipeptides from proteins with a penultimate Pro or Ala. A large number of human chemokines, including CXCL2, CXCL6, CXCL9, CXCL10, CXCL11, CXCL12, CCL3L1, CCL4, CCL5, CCL11, CCL14, and CCL22, are cleaved by CD26; however, the efficiency is clearly influenced by the amino acids surrounding the cleavage site and although not yet proven, potentially affected by the chemokine concentration and interactions with third molecules. NH2-terminal cleavage of chemokines by CD26 has prominent effects on their receptor binding, signaling, and hence, in vitro and in vivo biologic activities. However, rather than having a similar result, the outcome of NH2-terminal truncation is highly diverse. Either no difference in activity or drastic alterations in receptor recognition/specificity and hence, chemotactic activity are observed. Analogously, chemokine-dependent inhibition of HIV infection is enhanced (for CCL3L1 and CCL5) or decreased (for CXCL12) by CD26 cleavage. The occurrence of CD26-processed chemokine isoforms in plasma underscores the importance of the in vitro-observed CD26 cleavages. Through modulation of chemokine activity, CD26 regulates leukocyte/tumor cell migration and progenitor cell release from the bone marrow, as shown by use of mice treated with CD26 inhibitors or CD26 knockout mice. As chemokine processing by CD26 has a significant impact on physiologic and pathologic processes, application of CD26 inhibitors to affect chemokine function is currently explored, e.g., as add-on therapy in viral infection and cancer. PMID:26744452

  1. The crucial role of IL-22 and its receptor in thymus and activation regulated chemokine production and T-cell migration by house dust mite extract.

    PubMed

    Jang, Mirim; Kim, Hyemin; Kim, Yejin; Choi, Jiyea; Jeon, Jane; Hwang, Youngil; Kang, Jae Seung; Lee, Wang Jae

    2016-08-01

    House dust mite (HDM) is known as one of the factors that causes atopic dermatitis (AD). Interleukin (IL)-22 and thymus and activation regulated chemokine (TARC) are related to skin inflammatory disease and highly expressed in AD lesions. However, the effects of HDM on IL-22 production in T cells and on TARC production and IL-22Rα receptor expression in keratinocytes are unknown. To identify the role of HDM in keratinocytes and T cells, we investigated IL-22Rα expression and TARC production in the human keratinocyte cell line HaCaT and IL-22 production in T cells treated with HDM extract as well as their roles in HDM-induced skin inflammation. HDM extract not only increased IL-22Rα expression and TARC production in HaCaT but also enhanced IL-22, tumor necrosis factor (TNF)-α and interferon (IFN)-γ production in T cells. The HDM extract-induced IL-22 from T cells significantly increased the production of IL-1α, IL-6 and TARC in HaCaT cells. In addition, we found that TARC produced in HDM extract-treated HaCaT induced T-cell recruitment. These results suggest that there is a direct involvement of HDM extract-induced IL-22 in TARC production and T-cell migration. Taken together, TARC production in HaCaT through the interaction between IL-22 and IL-22Rα facilitates T-cell migration. These data show one of the reasons for inflammation in the skin lesions of AD patients. PMID:26914146

  2. Antimicrobial Activities of Chemokines: Not Just a Side-Effect?

    PubMed Central

    Wolf, Marlene; Moser, Bernhard

    2012-01-01

    The large family of chemoattractant cytokines (chemokines) embraces multiple, in part unrelated functions that go well beyond chemotaxis. Undoubtedly, the control of immune cell migration (chemotaxis) is the single, unifying response mediated by all chemokines, which involves the sequential engagement of chemokine receptors on migrating target cells. However, numerous additional cellular responses are mediated by some (but not all) chemokines, including angiogenesis, tumor cell growth, T-cell co-stimulation, and control of HIV-1 infection. The recently described antimicrobial activity of several chemokines is of particular interest because antimicrobial peptides are thought to provide an essential first-line defense against invading microbes at the extremely large body surfaces of the skin, lungs, and gastrointestinal-urinary tract. Here we summarize the current knowledge about chemokines with antimicrobial activity and discuss their potential contribution to the control of bacterial infections that may take place at the earliest stage of antimicrobial immunity. In the case of homeostatic chemokines with antimicrobial function, such as CXCL14, we propose an immune surveillance function in healthy epithelial tissues characterized by low-level exposure to environmental microbes. Inflammatory chemokines, i.e., chemokines that are produced in tissue cells in response to microbial antigens (such as pathogen-associated molecular patterns) may be more important in orchestrating the cellular arm in antimicrobial immunity. PMID:22837760

  3. Chemokines and Their Receptors Are Key Players in the Orchestra That Regulates Wound Healing

    PubMed Central

    Martins-Green, Manuela; Petreaca, Melissa; Wang, Lei

    2013-01-01

    Significance Normal wound healing progresses through a series of overlapping phases, all of which are coordinated and regulated by a variety of molecules, including chemokines. Because these regulatory molecules play roles during the various stages of healing, alterations in their presence or function can lead to dysregulation of the wound-healing process, potentially leading to the development of chronic, nonhealing wounds. Recent Advances A discovery that chemokines participate in a variety of disease conditions has propelled the study of these proteins to a level that potentially could lead to new avenues to treat disease. Their small size, exposed termini, and the fact that their only modifications are two disulfide bonds make them excellent targets for manipulation. In addition, because they bind to G-protein-coupled receptors (GPCRs), they are highly amenable to pharmacological modulation. Critical Issues Chemokines are multifunctional, and in many situations, their functions are highly dependent on the microenvironment. Moreover, each specific chemokine can bind to several GPCRs to stimulate the function, and both can function as monomers, homodimers, heterodimers, and even oligomers. Activation of one receptor by any single chemokine can lead to desensitization of other chemokine receptors, or even other GPCRs in the same cell, with implications for how these proteins or their receptors could be used to manipulate function. Future Directions Investment in better understanding of the functions of chemokines and their receptors in a local context can reveal new ways for therapeutic intervention. Understanding how different chemokines can activate the same receptor and vice versa could identify new possibilities for drug development based on their heterotypic interactions. PMID:24587971

  4. Duffy Antigen Receptor for Chemokines Regulates Post-Fracture Inflammation

    PubMed Central

    Rundle, Charles H.; Mohan, Subburaman; Edderkaoui, Bouchra

    2013-01-01

    There is now considerable experimental data to suggest that inflammatory cells collaborate in the healing of skeletal fractures. In terms of mechanisms that contribute to the recruitment of inflammatory cells to the fracture site, chemokines and their receptors have received considerable attention. Our previous findings have shown that Duffy antigen receptor for chemokines (Darc), the non-classical chemokine receptor that does not signal, but rather acts as a scavenger of chemokines that regulate cell migration, is a negative regulator of peak bone density in mice. Furthermore, because Darc is expressed by inflammatory and endothelial cells, we hypothesized that disruption of Darc action will affect post-fracture inflammation and consequently will affect fracture healing. To test this hypothesis, we evaluated fracture healing in mice with targeted disruption of Darc and corresponding wild type (WT) control mice. We found that fracture callus cartilage formation was significantly greater (33%) at 7 days post-surgery in Darc-KO compared to WT mice. The increased cartilage was associated with greater Collagen (Col) II expression at 3 days post-fracture and Col-X at 7 days post-fracture compared to WT mice, suggesting that Darc deficiency led to early fracture cartilage formation and differentiation. We then compared the expression of cytokine and chemokine genes known to be induced during inflammation. Interleukin (Il)-1β, Il-6, and monocyte chemotactic protein 1 were all down regulated in the fractures derived from Darc-KO mice at one day post-fracture, consistent with an altered inflammatory response. Furthermore, the number of macrophages was significantly reduced around the fractures in Darc-KO compared to WT mice. Based on these data, we concluded that Darc plays a role in modulating the early inflammatory response to bone fracture and subsequent cartilage formation. However, the early cartilage formation was not translated with an early bone formation at the

  5. Chemokine (C-X-C Motif) Receptor 4 and Atypical Chemokine Receptor 3 Regulate Vascular α1-Adrenergic Receptor Function

    PubMed Central

    Bach, Harold H; Wong, Yee M; Tripathi, Abhishek; Nevins, Amanda M; Gamelli, Richard L; Volkman, Brian F; Byron, Kenneth L; Majetschak, Matthias

    2014-01-01

    Chemokine (C-X-C motif) receptor (CXCR) 4 and atypical chemokine receptor (ACKR) 3 ligands have been reported to modulate cardiovascular function in various disease models. The underlying mechanisms, however, remain unknown. Thus, it was the aim of the present study to determine how pharmacological modulation of CXCR4 and ACKR3 regulate cardiovascular function. In vivo administration of TC14012, a CXCR4 antagonist and ACKR3 agonist, caused cardiovascular collapse in normal animals. During the cardiovascular stress response to hemorrhagic shock, ubiquitin, a CXCR4 agonist, stabilized blood pressure, whereas coactivation of CXCR4 and ACKR3 with CXC chemokine ligand 12 (CXCL12), or blockade of CXCR4 with AMD3100 showed opposite effects. While CXCR4 and ACKR3 ligands did not affect myocardial function, they selectively altered vascular reactivity upon α1-adrenergic receptor (AR) activation in pressure myography experiments. CXCR4 activation with ubiquitin enhanced α1-AR-mediated vasoconstriction, whereas ACKR3 activation with various natural and synthetic ligands antagonized α1-AR-mediated vasoconstriction. The opposing effects of CXCR4 and ACKR3 activation by CXCL12 could be dissected pharmacologically. CXCR4 and ACKR3 ligands did not affect vasoconstriction upon activation of voltage-operated Ca2+ channels or endothelin receptors. Effects of CXCR4 and ACKR3 agonists on vascular α1-AR responsiveness were independent of the endothelium. These findings suggest that CXCR4 and ACKR3 modulate α1-AR reactivity in vascular smooth muscle and regulate hemodynamics in normal and pathological conditions. Our observations point toward CXCR4 and ACKR3 as new pharmacological targets to control vasoreactivity and blood pressure. PMID:25032954

  6. Tropoelastin regulates chemokine expression in fibroblasts in Costello syndrome

    SciTech Connect

    Tatano, Yutaka; Fujinawa, Reiko; Kozutsumi, Yasunori; Takahashi, Tsutomu; Tsuji, Daisuke; Takeuchi, Naohiro; Tsuta, Kohji; Takada, Goro; Sakuraba, Hitoshi; Itoh, Kohji

    2008-08-08

    Costello syndrome is a multiple congenital anomaly associated with growth and mental retardation, cardiac and skeletal anomalies, and a predisposition to develop neoplasia. Comprehensive expression analysis revealed remarkable up-regulation of several cytokines and chemokines including Gro family proteins, interleukin-1{beta} (IL-1{beta}), IL-8 and MCP-1 but down-regulation of extracellular matrix components including collagens and proteoglycans of skin fibroblasts derived from a Japanese Costello syndrome patient characterized by significantly reduced tropoelastin mRNA, impaired elastogenesis and enhanced cell proliferation. In contrast, decreases in these chemokines and IL-1{beta} expression were observed in Costello fibroblastic cell lines stably expressing the bovine tropoelastin (btEln) gene and in restored elastic fibers. These results strongly suggest that the human TE gene (ELN) transfer could be applicable for the gene therapy of a group of Costello syndrome patients with reduced ELN gene expression.

  7. Analysis of G Protein and β-Arrestin Activation in Chemokine Receptors Signaling.

    PubMed

    Vacchini, Alessandro; Busnelli, Marta; Chini, Bice; Locati, Massimo; Borroni, Elena Monica

    2016-01-01

    Chemokines are key regulators of leukocyte migration and play fundamental roles in immune responses. The chemokine system includes a set of over 40 ligands which engage in a promiscuous fashion a panel of over 25 receptors belonging to a distinct family of 7 transmembrane-domain receptors (7TM) widely expressed on a variety of cells. Although responses evoked by chemokine receptors have long been considered the result of balanced activation of the G protein- and β-arrestin-dependent signaling modules, evidence is accumulating showing that these receptors are capable, as other 7TMs, to activate different signaling modules in a ligand- and cell/tissue-specific manner. This biased signaling, or functional selectivity, confers a hitherto largely uncharacterized level of complexity to the chemokine system and challenges our present understanding of its redundancy. At the same time, it also provides new insights of relevance for chemokine receptors targeting drug development plans. Here, we provide current methods to study biased signaling of chemokine receptors by dissecting G proteins and β-arrestins activation upon chemokine stimulation. PMID:26921957

  8. Regulation of breast cancer metastasis by atypical chemokine receptors.

    PubMed

    Cheng, Xiaoyun; Hung, Mien-Chie

    2009-05-01

    The interaction between chemokines and their G-protein-coupled receptors plays an important role in promoting metastasis of different kinds of human cancers. However, the expression of an atypical chemokine receptor, CCX-CKR, which serves as a decoy receptor to attract chemokines, inhibits the growth and metastasis of breast cancer by sequestration of chemokines. PMID:19383808

  9. Platelet-Derived CCL5 Regulates CXC Chemokine Formation and Neutrophil Recruitment in Acute Experimental Colitis.

    PubMed

    Yu, Changhui; Zhang, Songen; Wang, Yongzhi; Zhang, Su; Luo, Lingtao; Thorlacius, Henrik

    2016-02-01

    Accumulating data suggest that platelets not only regulate thrombosis and haemostasis but also inflammatory processes. Platelets contain numerous potent pro-inflammatory compounds, including the chemokines CCL5 and CXCL4, although their role in acute colitis remains elusive. The aim of this study is to examine the role of platelets and platelet-derived chemokines in acute colitis. Acute colitis is induced in female Balb/c mice by administration of 5% dextran sodium sulfate (DSS) for 5 days. Animals receive a platelet-depleting, anti-CCL5, anti-CXCL4, or a control antibody prior to DSS challenge. Colonic tissue is collected for quantification of myeloperoxidase (MPO) activity, CXCL5, CXCL2, interleukin-6 (IL-6), and CCL5 levels as well as morphological analyses. Platelet depletion reduce tissue damage and clinical disease activity index in DSS-exposed animals. Platelet depletion not only reduces levels of CXCL2 and CXCL5 but also levels of CCL5 in the inflamed colon. Immunoneutralization of CCL5 but not CXCL4 reduces tissue damage, CXC chemokine expression, and neutrophil recruitment in DSS-treated animals. These findings show that platelets play a key role in acute colitis by regulating CXC chemokine generation, neutrophil infiltration, and tissue damage in the colon. Moreover, our results suggest that platelet-derived CCL5 is an important link between platelet activation and neutrophil recruitment in acute colitis. PMID:26089223

  10. Chemokine CXCL16 Regulates Neutrophil and Macrophage Infiltration into Injured Muscle, Promoting Muscle Regeneration

    PubMed Central

    Zhang, Liping; Ran, Limei; Garcia, Gabriela E.; Wang, Xiaonan H.; Han, Shuhua; Du, Jie; Mitch, William E.

    2009-01-01

    Only a few specific chemokines that mediate interactions between inflammatory and satellite cells in muscle regeneration have been identified. The chemokine CXCL16 differs from other chemokines because it has both a transmembrane region and active, soluble chemokine forms. Indeed, we found increased expression of CXCL16 and its receptor, CXCR6, in regenerating myofibers. Muscle regeneration in CXCL16-deficient (CXCL16KO) mice was severely impaired compared with regeneration in wild-type mice. In addition, there was decreased MyoD and myogenin expression in regenerating muscle in CXCL16KO mice, indicating impaired satellite cell proliferation and differentiation. After 1 month, new myofibers in CXCL16KO mice remained significantly smaller than those in muscle of wild-type mice. To understand how CXCL16 regulates muscle regeneration, we examined cells infiltrating injured muscle. There were more infiltrating neutrophils and fewer macrophages in injured muscle of CXCL16KO mice compared with events in wild-type mice. Moreover, absence of CXCL16 led to different expression of cytokines/chemokines in injured muscles: mRNAs of macrophage-inflammatory protein (MIP)-1α, MIP-1β, and MIP-2 were increased, whereas regulated on activation normal T cell expressed and secreted, T-cell activation-3, and monocyte chemoattractant protein-1 mRNAs were lower compared with results in muscles of wild-type mice. Impaired muscle regeneration in CXCL16KO mice also resulted in fibrosis, which was linked to transforming growth factor-β1 expression. Thus, CXCL16 expression is a critical mediator of muscle regeneration, and it suppresses the development of fibrosis. PMID:19893053

  11. Simultaneous Activation of Induced Heterodimerization between CXCR4 Chemokine Receptor and Cannabinoid Receptor 2 (CB2) Reveals a Mechanism for Regulation of Tumor Progression.

    PubMed

    Coke, Christopher J; Scarlett, Kisha A; Chetram, Mahandranauth A; Jones, Kia J; Sandifer, Brittney J; Davis, Ahriea S; Marcus, Adam I; Hinton, Cimona V

    2016-05-01

    The G-protein-coupled chemokine receptor CXCR4 generates signals that lead to cell migration, cell proliferation, and other survival mechanisms that result in the metastatic spread of primary tumor cells to distal organs. Numerous studies have demonstrated that CXCR4 can form homodimers or can heterodimerize with other G-protein-coupled receptors to form receptor complexes that can amplify or decrease the signaling capacity of each individual receptor. Using biophysical and biochemical approaches, we found that CXCR4 can form an induced heterodimer with cannabinoid receptor 2 (CB2) in human breast and prostate cancer cells. Simultaneous, agonist-dependent activation of CXCR4 and CB2 resulted in reduced CXCR4-mediated expression of phosphorylated ERK1/2 and ultimately reduced cancer cell functions such as calcium mobilization and cellular chemotaxis. Given that treatment with cannabinoids has been shown to reduce invasiveness of cancer cells as well as CXCR4-mediated migration of immune cells, it is plausible that CXCR4 signaling can be silenced through a physical heterodimeric association with CB2, thereby inhibiting subsequent functions of CXCR4. Taken together, the data illustrate a mechanism by which the cannabinoid system can negatively modulate CXCR4 receptor function and perhaps tumor progression. PMID:26841863

  12. A Subset of Patients with Acute Myeloid Leukemia Has Leukemia Cells Characterized by Chemokine Responsiveness and Altered Expression of Transcriptional as well as Angiogenic Regulators

    PubMed Central

    Brenner, Annette K.; Reikvam, Håkon; Bruserud, Øystein

    2016-01-01

    Acute myeloid leukemia (AML) is an aggressive and heterogeneous bone marrow malignancy, the only curative treatment being intensive chemotherapy eventually in combination with allogeneic stem cell transplantation. Both the AML and their neighboring stromal cells show constitutive chemokine release, but chemokines seem to function as regulators of AML cell proliferation only for a subset of patients. Chemokine targeting is therefore considered not only for immunosuppression in allotransplanted patients but also as a possible antileukemic strategy in combination with intensive chemotherapy or as part of disease-stabilizing treatment at least for the subset of patients with chemokine-responsive AML cells. In this study, we characterized more in detail the leukemia cell phenotype of the chemokine-responsive patients. We investigated primary AML cells derived from 79 unselected patients. Standardized in vitro suspension cultures were used to investigate AML cell proliferation, and global gene expression profiles were compared for chemokine responders and non-responders identified through the proliferation assays. CCL28-induced growth modulation was used as marker of chemokine responsiveness, and 38 patients were then classified as chemokine-responsive. The effects of exogenous CCL28 (growth inhibition/enhancement/no effect) thus differed among patients and was also dependent on the presence of exogenous hematopoietic growth factors as well as constitutive AML cell cytokine release. The effect of CCR1 inhibition in the presence of chemokine-secreting mesenchymal stem cells also differed among patients. Chemokine-responsive AML cells showed altered expression of genes important for (i) epigenetic transcriptional regulation, particularly lysine acetylation; (ii) helicase activity, especially DExD/H RNA helicases; and (iii) angioregulatory proteins important for integrin binding. Thus, chemokine responsiveness is part of a complex AML cell phenotype with regard to

  13. Focal MMP-2 and MMP-9 activity at the blood-brain barrier promotes chemokine-induced leukocyte migration.

    PubMed

    Song, Jian; Wu, Chuan; Korpos, Eva; Zhang, Xueli; Agrawal, Smriti M; Wang, Ying; Faber, Cornelius; Schäfers, Michael; Körner, Heinrich; Opdenakker, Ghislain; Hallmann, Rupert; Sorokin, Lydia

    2015-02-24

    Although chemokines are sufficient for chemotaxis of various cells, increasing evidence exists for their fine-tuning by selective proteolytic processing. Using a model of immune cell chemotaxis into the CNS (experimental autoimmune encephalomyelitis [EAE]) that permits precise localization of immigrating leukocytes at the blood-brain barrier, we show that, whereas chemokines are required for leukocyte migration into the CNS, additional MMP-2/9 activities specifically at the border of the CNS parenchyma strongly enhance this transmigration process. Cytokines derived from infiltrating leukocytes regulate MMP-2/9 activity at the parenchymal border, which in turn promotes astrocyte secretion of chemokines and differentially modulates the activity of different chemokines at the CNS border, thereby promoting leukocyte migration out of the cuff. Hence, cytokines, chemokines, and cytokine-induced MMP-2/9 activity specifically at the inflammatory border collectively act to accelerate leukocyte chemotaxis across the parenchymal border. PMID:25704809

  14. Regulation of motor function and behavior by atypical chemokine receptor 1.

    PubMed

    Schneider, Erich H; Fowler, Stephen C; Lionakis, Michail S; Swamydas, Muthulekha; Holmes, Gibran; Diaz, Vivian; Munasinghe, Jeeva; Peiper, Stephen C; Gao, Ji-Liang; Murphy, Philip M

    2014-09-01

    Atypical Chemokine Receptor 1 (ACKR1), previously known as Duffy Antigen Receptor for Chemokines, stands out among chemokine receptors for high selective expression on cerebellar Purkinje neurons. Although ACKR1 ligands activate Purkinje cells in vitro, evidence for ACKR1 regulation of brain function in vivo is lacking. Here we demonstrate that Ackr1 (-/-) mice have markedly impaired balance and ataxia on a rotating rod and increased tremor when injected with harmaline, which induces whole-body tremor by activating Purkinje cells. Ackr1 (-/-) mice also exhibited impaired exploratory behavior, increased anxiety-like behavior and frequent episodes of marked hypoactivity under low-stress conditions. Surprisingly, Ackr1 (+/-) had similar behavioral abnormalities, indicating pronounced haploinsufficiency. The behavioral phenotype of Ackr1 (-/-) mice was the opposite of mouse models of cerebellar degeneration, and the defects persisted when Ackr1 was deficient only on non-hematopoietic cells. Together, the results suggest that normal motor function and behavior may partly depend on negative regulation of Purkinje cell activity by Ackr1. PMID:24997773

  15. Atypical chemokine receptors in cancer: friends or foes?

    PubMed

    Massara, Matteo; Bonavita, Ornella; Mantovani, Alberto; Locati, Massimo; Bonecchi, Raffaella

    2016-06-01

    The chemokine system is a fundamental component of cancer-related inflammation involved in all stages of cancer development. It controls not only leukocyte infiltration in primary tumors but also angiogenesis, cancer cell proliferation, and migration to metastatic sites. Atypical chemokine receptors are a new, emerging class of regulators of the chemokine system. They control chemokine bioavailability by scavenging, transporting, or storing chemokines. They can also regulate the activity of canonical chemokine receptors with which they share the ligands by forming heterodimers or by modulating their expression levels or signaling activity. Here, we summarize recent results about the role of these receptors (atypical chemokine receptor 1/Duffy antigen receptor for chemokine, atypical chemokine receptor 2/D6, atypical chemokine receptor 3/CXC-chemokine receptor 7, and atypical chemokine receptor 4/CC-chemokine receptor-like 1) on the tumorigenesis process, indicating that their effects are strictly dependent on the cell type on which they are expressed and on their coexpression with other chemokine receptors. Indeed, atypical chemokine receptors inhibit tumor growth and progression through their activity as negative regulators of chemokine bioavailability, whereas, on the contrary, they can promote tumorigenesis when they regulate the signaling of other chemokine receptors, such as CXC-chemokine receptor 4. Thus, atypical chemokine receptors are key components of the regulatory network of inflammation and immunity in cancer and may have a major effect on anti-inflammatory and immunotherapeutic strategies. PMID:26908826

  16. A silent chemokine receptor regulates steady-state leukocyte homing in vivo.

    PubMed

    Heinzel, Kornelia; Benz, Claudia; Bleul, Conrad C

    2007-05-15

    The location of leukocytes in different microenvironments is intimately connected to their function and, in the case of leukocyte precursors, to the executed differentiation and maturation program. Leukocyte migration within lymphoid organs has been shown to be mediated by constitutively expressed chemokines, but how the bioavailability of these homeostatic chemokines is regulated remains unknown. Here, we report in vivo evidence for the role of a nonsignaling chemokine receptor in the migration of leukocytes under physiological, i.e., noninflammatory, conditions. We have studied the in vivo role of the silent chemokine receptor CCX-CKR1 by both loss- and gain-of-function approaches. CCX-CKR1 binds the constitutively expressed chemokines CC chemokine ligand (CCL)19, CCL21, and CCL25. We find that CCX-CKR1 is involved in the steady-state homing of CD11c(+)MHCII(high) dendritic cells to skin-draining lymph nodes, and it affects the homing of embryonic thymic precursors to the thymic anlage. These observations indicate that the silent chemokine receptor CCX-CKR1, which is exclusively expressed by stroma cells, but not hematopoietic cells themselves, regulates homeostatic leukocyte migration by controlling the availability of chemokines in the extracellular space. This finding adds another level of complexity to our understanding of leukocyte homeostatic migration. PMID:17485674

  17. Functions of the chemokine receptor CXCR4 in the central nervous system and its regulation by μ-opioid receptors.

    PubMed

    Nash, Bradley; Meucci, Olimpia

    2014-01-01

    Activation of the G protein-coupled receptor CXCR4 by its chemokine ligand CXCL12 regulates a number of physiopathological functions in the central nervous system, during development as well as later in life. In addition to the more classical roles of the CXCL12/CXCR4 axis in the recruitment of immune cells or migration and proliferation of neural precursor cells, recent studies suggest that CXCR4 signaling also modulates synaptic function and neuronal survival in the mature brain, through direct and indirect effects on neurons and glia. These effects, which include regulation of glutamate receptors and uptake, and of dendritic spine density, can significantly alter the ability of neurons to face excitotoxic insults. Therefore, they are particularly relevant to neurodegenerative diseases featuring alterations of glutamate neurotransmission, such as HIV-associated neurocognitive disorders. Importantly, CXCR4 signaling can be dysregulated by HIV viral proteins, host HIV-induced factors, and opioids. Potential mechanisms of opioid regulation of CXCR4 include heterologous desensitization, transcriptional regulation and changes in receptor expression levels, opioid-chemokine receptor dimer or heteromer formation, and the newly described modulation by the protein ferritin heavy chain-all leading to inhibition of CXCR4 signaling. After reviewing major effects of chemokines and opioids in the CNS, this chapter discusses chemokine-opioid interactions in neuronal and immune cells, focusing on their potential contribution to HIV-associated neurocognitive disorders. PMID:25175863

  18. Reduced locomotor activity and exploratory behavior in CC chemokine receptor 4 deficient mice.

    PubMed

    Ambrée, Oliver; Klassen, Irene; Förster, Irmgard; Arolt, Volker; Scheu, Stefanie; Alferink, Judith

    2016-11-01

    Chemokines and their receptors are key regulators of immune cell trafficking and activation. Recent findings suggest that they may also play pathophysiological roles in psychiatric diseases like depression and anxiety disorders. The CC chemokine receptor 4 (CCR4) and its two ligands, CCL17 and CCL22, are functionally involved in neuroinflammation as well as anti-infectious and autoimmune responses. However, their influence on behavior remains unknown. Here we characterized the functional role of the CCR4-CCL17 chemokine-receptor axis in the modulation of anxiety-related behavior, locomotor activity, and object exploration and recognition. Additionally, we investigated social exploration of CCR4 and CCL17 knockout mice and wild type (WT) controls. CCR4 knockout (CCR4(-/-)) mice exhibited fewer anxiety-related behaviors in the elevated plus-maze, diminished locomotor activity, exploratory behavior, and social exploration, while their recognition memory was not affected. In contrast, CCL17 deficient mice did not show an altered behavior compared to WT mice regarding locomotor activity, anxiety-related behavior, social exploration, and object recognition memory. In the dark-light and object recognition tests, CCL17(-/-) mice even covered longer distances than WT mice. These data demonstrate a mechanistic or developmental role of CCR4 in the regulation of locomotor and exploratory behaviors, whereas the ligand CCL17 appears not to be involved in the behaviors measured here. Thus, either CCL17 and the alternative ligand CCL22 may be redundant, or CCL22 is the main activator of CCR4 in these processes. Taken together, these findings contribute to the growing evidence regarding the involvement of chemokines and their receptors in the regulation of behavior. PMID:27469058

  19. Up-regulated extracellular matrix components and inflammatory chemokines may impair the regeneration of cholestatic liver

    PubMed Central

    Zhang, Shuai; Li, Tao-Sheng; Soyama, Akihiko; Tanaka, Takayuki; Yan, Chen; Sakai, Yusuke; Hidaka, Masaaki; Kinoshita, Ayaka; Natsuda, Koji; Fujii, Mio; Kugiyama, Tota; Baimakhanov, Zhassulan; Kuroki, Tamotsu; Gu, Weili; Eguchi, Susumu

    2016-01-01

    Although the healthy liver is known to have high regenerative potential, poor liver regeneration under pathological conditions remains a substantial problem. We investigated the key molecules that impair the regeneration of cholestatic liver. C57BL/6 mice were randomly subjected to partial hepatectomy and bile duct ligation (PH+BDL group, n = 16), partial hepatectomy only (PH group, n = 16), or sham operation (Sham group, n = 16). The liver sizes and histological findings were similar in the PH and sham groups 14 days after operation. However, compared with those in the sham group, the livers in mice in the PH+BDL group had a smaller size, a lower cell proliferative activity, and more fibrotic tissue 14 days after the operation, suggesting the insufficient regeneration of the cholestatic liver. Pathway-focused array analysis showed that many genes were up- or down-regulated over 1.5-fold in both PH+BDL and PH groups at 1, 3, 7, and 14 days after treatment. Interestingly, more genes that were functionally related to the extracellular matrix and inflammatory chemokines were found in the PH+BDL group than in the PH group at 7 and 14 days after treatment. Our data suggest that up-regulated extracellular matrix components and inflammatory chemokines may impair the regeneration of cholestatic liver. PMID:27226149

  20. Up-regulated extracellular matrix components and inflammatory chemokines may impair the regeneration of cholestatic liver.

    PubMed

    Zhang, Shuai; Li, Tao-Sheng; Soyama, Akihiko; Tanaka, Takayuki; Yan, Chen; Sakai, Yusuke; Hidaka, Masaaki; Kinoshita, Ayaka; Natsuda, Koji; Fujii, Mio; Kugiyama, Tota; Baimakhanov, Zhassulan; Kuroki, Tamotsu; Gu, Weili; Eguchi, Susumu

    2016-01-01

    Although the healthy liver is known to have high regenerative potential, poor liver regeneration under pathological conditions remains a substantial problem. We investigated the key molecules that impair the regeneration of cholestatic liver. C57BL/6 mice were randomly subjected to partial hepatectomy and bile duct ligation (PH+BDL group, n = 16), partial hepatectomy only (PH group, n = 16), or sham operation (Sham group, n = 16). The liver sizes and histological findings were similar in the PH and sham groups 14 days after operation. However, compared with those in the sham group, the livers in mice in the PH+BDL group had a smaller size, a lower cell proliferative activity, and more fibrotic tissue 14 days after the operation, suggesting the insufficient regeneration of the cholestatic liver. Pathway-focused array analysis showed that many genes were up- or down-regulated over 1.5-fold in both PH+BDL and PH groups at 1, 3, 7, and 14 days after treatment. Interestingly, more genes that were functionally related to the extracellular matrix and inflammatory chemokines were found in the PH+BDL group than in the PH group at 7 and 14 days after treatment. Our data suggest that up-regulated extracellular matrix components and inflammatory chemokines may impair the regeneration of cholestatic liver. PMID:27226149

  1. Polysialylation controls dendritic cell trafficking by regulating chemokine recognition.

    PubMed

    Kiermaier, Eva; Moussion, Christine; Veldkamp, Christopher T; Gerardy-Schahn, Rita; de Vries, Ingrid; Williams, Larry G; Chaffee, Gary R; Phillips, Andrew J; Freiberger, Friedrich; Imre, Richard; Taleski, Deni; Payne, Richard J; Braun, Asolina; Förster, Reinhold; Mechtler, Karl; Mühlenhoff, Martina; Volkman, Brian F; Sixt, Michael

    2016-01-01

    The addition of polysialic acid to N- and/or O-linked glycans, referred to as polysialylation, is a rare posttranslational modification that is mainly known to control the developmental plasticity of the nervous system. Here we show that CCR7, the central chemokine receptor controlling immune cell trafficking to secondary lymphatic organs, carries polysialic acid. This modification is essential for the recognition of the CCR7 ligand CCL21. As a consequence, dendritic cell trafficking is abrogated in polysialyltransferase-deficient mice, manifesting as disturbed lymph node homeostasis and unresponsiveness to inflammatory stimuli. Structure-function analysis of chemokine-receptor interactions reveals that CCL21 adopts an autoinhibited conformation, which is released upon interaction with polysialic acid. Thus, we describe a glycosylation-mediated immune cell trafficking disorder and its mechanistic basis. PMID:26657283

  2. Chemokines derived from soluble fusion proteins expressed in Escherichia coli are biologically active

    SciTech Connect

    Magistrelli, Giovanni; Gueneau, Franck; Muslmani, Machadiya; Ravn, Ulla; Kosco-Vilbois, Marie; Fischer, Nicolas . E-mail: nfischer@novimmune.com

    2005-08-26

    Chemokines are a class of low molecular weight proteins that are involved in leukocytes trafficking. Due to their involvement in recruiting immune cells to sites of inflammation, chemokines, and chemokine receptors have become an attractive class of therapeutic targets. However, when expressed in Escherichia coli chemokines are poorly soluble and accumulate in inclusion bodies. Several purification methods have been described but involve time-consuming refolding, buffer exchange, and purification steps that complicate expression of these proteins. Here, we describe a simple and reliable method to express chemokines as fusions to the protein NusA. The fusion proteins were largely found in the soluble fraction and could be readily purified in a single step. Proteolytic cleavage was used to obtain soluble recombinant chemokines that were found to be very active in a novel in vitro chemotaxis assays. This method could be applied to several {alpha} and {beta} human chemokines, suggesting that it is generally applicable to this class of proteins.

  3. Decidual Cell Regulation of Natural Killer Cell–Recruiting Chemokines

    PubMed Central

    Lockwood, Charles J.; Huang, S. Joseph; Chen, Chie-Pein; Huang, Yingqun; Xu, Jie; Faramarzi, Saeed; Kayisli, Ozlem; Kayisli, Umit; Koopman, Louise; Smedts, Dineke; Buchwalder, Lynn F.; Schatz, Frederick

    2014-01-01

    First trimester human decidua is composed of decidual cells, CD56brightCD16− decidual natural killer (dNK) cells, and macrophages. Decidual cells incubated with NK cell–derived IFN-γ and either macrophage-derived TNF-α or IL-1β synergistically enhanced mRNA and protein expression of IP-10 and I-TAC. Both chemokines recruit CXCR3-expressing NK cells. This synergy required IFN-γ receptor 1 and 2 mediation via JAK/STAT and NFκB signaling pathways. However, synergy was not observed on neutrophil, monocyte, and NK cell–recruiting chemokines. Immunostaining of first trimester decidua localized IP-10, I-TAC, IFN-γR1, and -R2 to vimentin-positive decidual cells versus cytokeratin-positive interstitial trophoblasts. Flow cytometry identified high CXCR3 levels on dNK cells and minority peripheral CD56brightCD16− pNK cells and intermediate CXCR3 levels on the majority of CD56dimCD16+ pNK cells. Incubation of pNK cells with either IP-10 or I-TAC elicited concentration-dependent enhanced CXCR3 levels and migration of both pNK cell subsets that peaked at 10 ng/mL, whereas each chemokine at a concentration of 50 ng/mL inhibited CXCR3 expression and pNK cell migration. Deciduae from women with preeclampsia, a leading cause of maternal and fetal morbidity and mortality, displayed significantly lower dNK cell numbers and higher IP-10 and I-TAC levels versus gestational age–matched controls. Significantly elevated IP-10 levels in first trimester sera from women eventually developing preeclampsia compared with controls, identifying IP-10 as a novel, robust early predictor of preeclampsia. PMID:23973270

  4. Chemokines accentuating protumoral activities in oral cancer microenvironment possess an imperious stratagem for therapeutic resolutions.

    PubMed

    Panda, Swagatika; Padhiary, Subrat Kumar; Routray, Samapika

    2016-09-01

    Chemokines, the chemotactic cytokines have established their role in tumorigenesis and tumor progression. Studies, which explored their role in oral cancer for protumoral activity, point towards targeting chemokines for oral squamous cell carcinoma therapy. The need of the hour is to emphasize/divulge in the activities of chemokine ligands and their receptors in the tumor microenvironment for augmentation of such stratagems. This progressing sentience of chemokines and their receptors has inspired this review which is an endeavour to comprehend their role as an aid in accentuating hallmarks of cancer and targeted therapy. PMID:27531867

  5. Fish chemokines 14, 20 and 25: A comparative statement on computational analysis and mRNA regulation upon pathogenic infection.

    PubMed

    Arockiaraj, Jesu; Bhatt, Prasanth; Kumaresan, Venkatesh; Dhayanithi, Nagarajan Balachandran; Arshad, Aziz; Harikrishnan, Ramasamy; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah

    2015-11-01

    In this study, we reported a molecular characterization of three CC chemokines namely, CsCC-Chem14, CsCC-Chem20 and CsCC-Chem25 which are were identified from the established cDNA library of striped murrel Channa striatus. Multiple sequence alignment of all the three chemokines revealed the presence of gene specific domains and motifs including small cytokine domain, IL8 like domain, receptor binding site and glycosaminoglycan (GAG) binding sites. Three dimensional structures of the chemokines under study showed an important facet on their anti-microbial property. Tissue specific mRNA expression showed that the CsCC-Chem14 is highly expressed in spleen, CsCC-Chem20 in liver and CsCC-Chem25 in trunk kidney. On challenge C. striatus with oomycete fungus Aphanomyces invadans, both CsCC-Chem20 and CsCC-Chem25 showed significant (P < 0.05) up-regulation compared to CsCC-Chem14. The increase in the expression levels of CsCC-Chem20 and CsCC-Chem25 due to infection showed that they are antimicrobial proteins. But considering the CsCC-Chem14 expression, it is found to be a constitutive chemokine and is involved in homeostatic function in spleen of C. striatus. C. striatus challenged with bacteria Aeromonas hydrophila also exhibited different up-regulation pattern in all the three chemokines at various time points. However, extensive studies are required to determine the functional activities of CsCC-Chem14, CsCC-Chem20 and CsCC-Chem25 in vitro and in vivo to gain more knowledge at the molecular and proteomic levels. PMID:26363233

  6. M-sec regulates polarized secretion of inflammatory endothelial chemokines and facilitates CCL2-mediated lymphocyte transendothelial migration.

    PubMed

    Barzilai, Sagi; Blecher-Gonen, Ronnie; Barnett-Itzhaki, Zohar; Zauberman, Ayelet; Lebel-Haziv, Yaeli; Amit, Ido; Alon, Ronen

    2016-06-01

    Activation of endothelial cells by IL-1β triggers the expression of multiple inflammatory cytokines and leukocyte-attracting chemokines. The machineries involved in the secretion of these inducible proteins are poorly understood. With the use of genome-wide transcriptional analysis of inflamed human dermal microvascular endothelial cells, we identified several IL-1β-induced candidate regulators of these machineries and chose to focus our study on TNF-α-induced protein 2 (myeloid-secretory). The silencing of myeloid-secretory did not affect the ability of inflamed endothelial cells to support the adhesion and crawling of effector T lymphocytes. However, the ability of these lymphocytes to complete transendothelial migration across myeloid-secretory-silenced human dermal microvascular endothelial cells was inhibited significantly. These observed effects on lymphocyte transendothelial migration were recovered completely when exogenous promigratory chemokine CXCL12 was overlaid on the endothelial barrier. A polarized secretion assay suggested that the silencing of endothelial myeloid-secretory impairs T effector transendothelial migration by reducing the preferential secretion of endothelial-produced CCL2, a key transendothelial migration-promoting chemokine for these lymphocytes, into the basolateral endothelial compartment. Myeloid-secretory silencing also impaired the preferential secretion of other endothelial-produced inflammatory chemokines, as well as cytokines, such as IL-6 and GM-CSF, into the basolateral endothelial compartment. This is the first evidence of a novel inflammation-inducible machinery that regulates polarized secretion of endothelial CCL2 and other inflammatory chemokines and cytokines into basolateral endothelial compartments and facilitates the ability of endothelial CCL2 to promote T cell transendothelial migration. PMID:26701136

  7. Functions of the Chemokine Receptor CXCR4 in the Central Nervous System and Its Regulation by μ-Opioid Receptors

    PubMed Central

    Nash, Bradley; Meucci, Olimpia

    2015-01-01

    Activation of the G protein-coupled receptor CXCR4 by its chemokine ligand CXCL12 regulates a number of physiopathological functions in the central nervous system, during development as well as later in life. In addition to the more classical roles of the CXCL12/CXCR4 axis in the recruitment of immune cells or migration and proliferation of neural precursor cells, recent studies suggest that CXCR4 signaling also modulates synaptic function and neuronal survival in the mature brain, through direct and indirect effects on neurons and glia. These effects, which include regulation of glutamate receptors and uptake, and of dendritic spine density, can significantly alter the ability of neurons to face excitotoxic insults. Therefore, they are particularly relevant to neurodegenerative diseases featuring alterations of glutamate neurotransmission, such as HIV-associated neurocognitive disorders. Importantly, CXCR4 signaling can be dysregulated by HIV viral proteins, host HIV-induced factors, and opioids. Potential mechanisms of opioid regulation of CXCR4 include heterologous desensitization, transcriptional regulation and changes in receptor expression levels, opioid–chemokine receptor dimer or heteromer formation, and the newly described modulation by the protein ferritin heavy chain—all leading to inhibition of CXCR4 signaling. After reviewing major effects of chemokines and opioids in the CNS, this chapter discusses chemokine–opioid interactions in neuronal and immune cells, focusing on their potential contribution to HIV-associated neurocognitive disorders. PMID:25175863

  8. E-cadherin Is Critical for Collective Sheet Migration and Is Regulated by the Chemokine CXCL12 Protein During Restitution*

    PubMed Central

    Hwang, Soonyean; Zimmerman, Noah P.; Agle, Kimberle A.; Turner, Jerrold R.; Kumar, Suresh N.; Dwinell, Michael B.

    2012-01-01

    Chemokines and other immune mediators enhance epithelial barrier repair. The intestinal barrier is established by highly regulated cell-cell contacts between epithelial cells. The goal of these studies was to define the role for the chemokine CXCL12 in regulating E-cadherin during collective sheet migration during epithelial restitution. Mechanisms regulating E-cadherin were investigated using Caco2BBE and IEC-6 model epithelia. Genetic knockdown confirmed a critical role for E-cadherin in in vitro restitution and in vivo wound repair. During restitution, both CXCL12 and TGF-β1 tightened the monolayer by decreasing the paracellular space between migrating epithelial cells. However, CXCL12 differed from TGF-β1 by stimulating the significant increase in E-cadherin membrane localization during restitution. Chemokine-stimulated relocalization of E-cadherin was paralleled by an increase in barrier integrity of polarized epithelium during restitution. CXCL12 activation of its cognate receptor CXCR4 stimulated E-cadherin localization and monolayer tightening through Rho-associated protein kinase activation and F-actin reorganization. These data demonstrate a key role for E-cadherin in intestinal epithelial restitution. PMID:22549778

  9. Regulation of neuronal ferritin heavy chain, a new player in opiate-induced chemokine dysfunction

    PubMed Central

    Abt, Anna Cook; Meucci, Olimpia

    2013-01-01

    The heavy chain subunit of ferritin (FHC), a ubiquitous protein best known for its iron-sequestering activity as part of the ferritin complex, has recently been described as a novel inhibitor of signaling through the chemokine receptor CXCR4. Levels of FHC as well as its effects on CXCR4 activation increase in cortical neurons exposed to mu-opioid receptor agonists such as morphine, an effect likely specific to neurons. Major actions of CXCR4 signaling in the mature brain include a promotion of neurogenesis, activation of pro-survival signals, and modulation of excitotoxic pathways; thus FHC up-regulation may contribute to the neuronal dysfunction often associated with opiate drug abuse. This review summarizes our knowledge of neuronal CXCR4 function, its regulation by opiates and the role of FHC in this process, and known mechanisms controlling FHC production. We speculate on the mechanism involved in FHC regulation by opiates, and offer FHC as a new target in opioid-induced neuropathology. PMID:21465240

  10. REGULATION OF CONCEPTUS ADHESION BY ENDOMETRIAL CXC CHEMOKINES DURING THE IMPLANTATION PERIOD IN SHEEP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To gain a better understanding of biochemical mechanisms of conceptus adhesion to the maternal endometrium in ruminant ungulates, the present study was performed to clarify roles of chemokines and extracellular matrix (ECM) components in the regulation of ovine blastocyst attachment to the endometri...

  11. Activating Transcription Factor 3-mediated Chemo-intervention with Cancer Chemokines in a Noncanonical Pathway under Endoplasmic Reticulum Stress*

    PubMed Central

    Park, Seong-Hwan; Kim, Juil; Do, Kee Hun; Park, Jiyeon; Oh, Chang Gyu; Choi, Hye Jin; Song, Bo Gyoung; Lee, Seung Joon; Kim, Yong Sik; Moon, Yuseok

    2014-01-01

    The cell-protective features of the endoplasmic reticulum (ER) stress response are chronically activated in vigorously growing malignant tumor cells, which provide cellular growth advantages over the adverse microenvironment including chemotherapy. As an intervention with ER stress responses in the intestinal cancer cells, preventive exposure to flavone apigenin potentiated superinduction of a regulatory transcription factor, activating transcription factor 3 (ATF3), which is also known to be an integral player coordinating ER stress response-related gene expression. ATF3 superinduction was due to increased turnover of ATF3 transcript via stabilization with HuR protein in the cancer cells under ER stress. Moreover, enhanced ATF3 caused inhibitory action against ER stress-induced cancer chemokines that are potent mediators determining the survival and metastatic potential of epithelial cancer cells. Although enhanced ATF3 was a negative regulator of the well known proinflammatory transcription factor NF-κB, blocking of NF-κB signaling did not affect ER stress-induced chemokine expression. Instead, immediately expressed transcription factor early growth response protein 1 (EGR-1) was positively involved in cancer chemokine induction by ER stressors. ER stress-induced EGR-1 and subsequent chemokine production were repressed by ATF3. Mechanistically, ATF3 directly interacted with and recruited HDAC1 protein, which led to epigenetic suppression of EGR-1 expression and subsequent chemokine production. Conclusively, superinduced ATF3 attenuated ER stress-induced cancer chemokine expression by epigenetically interfering with induction of EGR-1, a transcriptional modulator crucial to cancer chemokine production. Thus, these results suggest a potent therapeutic intervention of ER stress response-related cancer-favoring events by ATF3. PMID:25122760

  12. Structural basis for chemokine recognition and activation of a viral G protein-coupled receptor

    SciTech Connect

    Burg, John S.; Ingram, Jessica R.; Venkatakrishnan, A.J.; Jude, Kevin M.; Dukkipati, Abhiram; Feinberg, Evan N.; Angelini, Alessandro; Waghray, Deepa; Dror, Ron O.; Ploegh, Hidde L.; Garcia, K. Christopher

    2015-03-05

    Chemokines are small proteins that function as immune modulators through activation of chemokine G protein-coupled receptors (GPCRs). Several viruses also encode chemokines and chemokine receptors to subvert the host immune response. How protein ligands activate GPCRs remains unknown. We report the crystal structure at 2.9 angstrom resolution of the human cytomegalovirus GPCR US28 in complex with the chemokine domain of human CX3CL1 (fractalkine). The globular body of CX3CL1 is perched on top of the US28 extracellular vestibule, whereas its amino terminus projects into the central core of US28. The transmembrane helices of US28 adopt an active-state-like conformation. Atomic-level simulations suggest that the agonist-independent activity of US28 may be due to an amino acid network evolved in the viral GPCR to destabilize the receptor’s inactive state.

  13. Chemokine Receptors, CXCR1 and CXCR2, Differentially Regulate Exosome Release in Hepatocytes

    PubMed Central

    Nojima, Hiroyuki; Konishi, Takanori; Freeman, Christopher M.; Schuster, Rebecca M.; Japtok, Lukasz; Kleuser, Burkhard; Edwards, Michael J.; Gulbins, Erich; Lentsch, Alex B.

    2016-01-01

    Exosomes are small membrane vesicles released by different cell types, including hepatocytes, that play important roles in intercellular communication. We have previously demonstrated that hepatocyte-derived exosomes contain the synthetic machinery to form sphingosine-1-phosphate (S1P) in target hepatocytes resulting in proliferation and liver regeneration after ischemia/reperfusion (I/R) injury. We also demonstrated that the chemokine receptors, CXCR1 and CXCR2, regulate liver recovery and regeneration after I/R injury. In the current study, we sought to determine if the regulatory effects of CXCR1 and CXCR2 on liver recovery and regeneration might occur via altered release of hepatocyte exosomes. We found that hepatocyte release of exosomes was dependent upon CXCR1 and CXCR2. CXCR1-deficient hepatocytes produced fewer exosomes, whereas CXCR2-deficient hepatocytes produced more exosomes compared to their wild-type controls. In CXCR2-deficient hepatocytes, there was increased activity of neutral sphingomyelinase (Nsm) and intracellular ceramide. CXCR1-deficient hepatocytes had no alterations in Nsm activity or ceramide production. Interestingly, exosomes from CXCR1-deficient hepatocytes had no effect on hepatocyte proliferation, due to a lack of neutral ceramidase and sphingosine kinase. The data demonstrate that CXCR1 and CXCR2 regulate hepatocyte exosome release. The mechanism utilized by CXCR1 remains elusive, but CXCR2 appears to modulate Nsm activity and resultant production of ceramide to control exosome release. CXCR1 is required for packaging of enzymes into exosomes that mediate their hepatocyte proliferative effect. PMID:27551720

  14. Chemokine Receptors, CXCR1 and CXCR2, Differentially Regulate Exosome Release in Hepatocytes.

    PubMed

    Nojima, Hiroyuki; Konishi, Takanori; Freeman, Christopher M; Schuster, Rebecca M; Japtok, Lukasz; Kleuser, Burkhard; Edwards, Michael J; Gulbins, Erich; Lentsch, Alex B

    2016-01-01

    Exosomes are small membrane vesicles released by different cell types, including hepatocytes, that play important roles in intercellular communication. We have previously demonstrated that hepatocyte-derived exosomes contain the synthetic machinery to form sphingosine-1-phosphate (S1P) in target hepatocytes resulting in proliferation and liver regeneration after ischemia/reperfusion (I/R) injury. We also demonstrated that the chemokine receptors, CXCR1 and CXCR2, regulate liver recovery and regeneration after I/R injury. In the current study, we sought to determine if the regulatory effects of CXCR1 and CXCR2 on liver recovery and regeneration might occur via altered release of hepatocyte exosomes. We found that hepatocyte release of exosomes was dependent upon CXCR1 and CXCR2. CXCR1-deficient hepatocytes produced fewer exosomes, whereas CXCR2-deficient hepatocytes produced more exosomes compared to their wild-type controls. In CXCR2-deficient hepatocytes, there was increased activity of neutral sphingomyelinase (Nsm) and intracellular ceramide. CXCR1-deficient hepatocytes had no alterations in Nsm activity or ceramide production. Interestingly, exosomes from CXCR1-deficient hepatocytes had no effect on hepatocyte proliferation, due to a lack of neutral ceramidase and sphingosine kinase. The data demonstrate that CXCR1 and CXCR2 regulate hepatocyte exosome release. The mechanism utilized by CXCR1 remains elusive, but CXCR2 appears to modulate Nsm activity and resultant production of ceramide to control exosome release. CXCR1 is required for packaging of enzymes into exosomes that mediate their hepatocyte proliferative effect. PMID:27551720

  15. Chemokines in tumor development and progression

    SciTech Connect

    Mukaida, Naofumi; Baba, Tomohisa

    2012-01-15

    Chemokines were originally identified as mediators of the inflammatory process and regulators of leukocyte trafficking. Subsequent studies revealed their essential roles in leukocyte physiology and pathology. Moreover, chemokines have profound effects on other types of cells associated with the inflammatory response, such as endothelial cells and fibroblasts. Thus, chemokines are crucial for cancer-related inflammation, which can promote tumor development and progression. Increasing evidence points to the vital effects of several chemokines on the proliferative and invasive properties of tumor cells. The wide range of activities of chemokines in tumorigenesis highlights their roles in tumor development and progression.

  16. Regulation of the psoriatic chemokine CCL20 by E3 ligases Trim32 and Piasy in keratinocytes.

    PubMed

    Liu, Yuangang; Lagowski, James P; Gao, Shangpu; Raymond, James H; White, Clifton R; Kulesz-Martin, Molly F

    2010-05-01

    Psoriasis is an inflammatory skin disorder with aberrant regulation of keratinocytes and immunocytes. Although it is well known that uncontrolled keratinocyte proliferation is largely driven by proinflammatory cytokines from the immunocytes, the functional role of keratinocytes in the regulation of immunocytes is poorly understood. Recently, we found that tripartite motif-containing protein 32 (Trim32), an E3-ubiquitin ligase, is elevated in the epidermal lesions of human psoriasis. We previously showed that Trim32 binds to the protein inhibitor of activated STAT-Y (Piasy) and mediates its degradation through ubiquitination. Interestingly, the Piasy gene is localized in the PSORS6 susceptibility locus on chromosome 19p13, and Piasy negatively regulates the activities of several transcription factors, including NF-kappaB, STAT, and SMADs, that are implicated in the pathogenesis of psoriasis. In this study, we show that Trim32 activates, and Piasy inhibits, keratinocyte production of CC chemokine ligand 20 (CCL20), a psoriatic chemokine essential for recruitment of DCs and T helper (Th)17 cells to the skin. Further, Trim32/Piasy regulation of CCL20 is mediated through Piasy interaction with the RelA/p65 subunit of NF-kappaB. As CCL20 is activated by Th17 cytokines, the upregulation of CCL20 production by Trim32 provides a positive feedback loop of CCL20 and Th17 activation in the self-perpetuating cycle of psoriasis. PMID:20054338

  17. Omega-3 fatty acids inhibit the up-regulation of endothelial chemokines in maintenance hemodialysis patients

    PubMed Central

    Hung, Adriana M.; Booker, Cindy; Ellis, Charles D.; Siew, Edward D.; Graves, Amy J.; Shintani, Ayumi; Abumrad, Naji N.; Himmelfarb, Jonathan; Ikizler, Talat Alp

    2015-01-01

    Background Chronic systemic inflammation is common in patients with chronic kidney disease on dialysis (CKD5D) and has been considered a key mediator of the increased cardiovascular risk in this patient population. In this study, we tested the hypothesis that supplementation of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) will attenuate the systemic inflammatory process in CKD5D patients. Methods The design was a randomized, double-blinded, placebo controlled pilot trial (NCT00655525). Thirty-eight patients were randomly assigned in a 1 : 1 fashion to receive 2.9 g of eicosapentaenoic acid (C20:5, n-3) plus docosahexaenoic acid (C22:6, n-3) versus placebo for 12 weeks. The primary outcome was change in pro-inflammatory chemokines measured by lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs). Secondary outcomes were changes in systemic inflammatory markers. Analysis of covariance was used to compare percent change from baseline to 12 weeks. Results Thirty-one patients completed 12 weeks and three patients completed 6 weeks of the study. Median age was 52 (interquartile range 45, 60) years, 74% were African-American and 79% were male. Supplementation of ω-3 PUFAs effectively decreased the LPS-induced PBMC expression of RANTES (Regulated upon Activation, Normal T cell Expressed and Secreted) and MCP-1 (Monocyte Chemotactic Protein-1; unadjusted P = 0.04 and 0.06; adjusted for demographics P = 0.02 and 0.05, respectively). There was no significant effect of the intervention on serum inflammatory markers (C-reactive protein, interleukin-6 and procalcitonin). Conclusions The results of this pilot study suggest that supplementation of ω-3 PUFAs is beneficial in decreasing the levels of endothelial chemokines, RANTES and MCP-1. Studies of larger sample size and longer duration are required to further evaluate effects of ω-3 PUFAs on systemic markers of inflammation, other metabolic parameters and clinical outcomes, particularly

  18. Up-regulation of chemokine C-C ligand 2 (CCL2) and C-X-C chemokine 8 (CXCL8) expression by monocytes in chronic idiopathic urticaria.

    PubMed

    Santos, J C; de Brito, C A; Futata, E A; Azor, M H; Orii, N M; Maruta, C W; Rivitti, E A; Duarte, A J S; Sato, M N

    2012-01-01

    The disturbed cytokine-chemokine network could play an important role in the onset of diseases with inflammatory processes such as chronic idiopathic urticaria (CIU). Our main objectives were to evaluate the relation between proinflammatory chemokine serum levels from CIU patients and their response to autologous skin test (ASST) and basophil histamine release (BHR). We also aimed to assess the chemokine secretion by peripheral blood mononuclear cells (PBMC) upon polyclonal stimulus and to evaluate chemokine C-C ligand 2/C-X-C chemokine 8 (CCL2/CXCL8) and Toll-like receptor-4 (TLR-4) expression in monocytes. We observed significantly higher serum levels of the CXCL8, CXCL9, CXCL10 and CCL2 in CIU patients compared to the healthy group, regardless of the BHR or ASST response. The basal secretion of CCL2 by PBMC or induced by Staphylococcus aureus enterotoxin A (SEA) was higher in CIU patients than in the control group, as well as for CXCL8 and CCL5 secretions upon phytohaemagglutinin stimulation. Also, up-regulation of CCL2 and CXCL8 mRNA expression was found in monocytes of patients upon SEA stimulation. The findings showed a high responsiveness of monocytes through CCL2/CXCL8 expression, contributing to the creation of a proinflammatory environment in CIU. PMID:22132892

  19. Activation of prostaglandin E2-EP4 signaling reduces chemokine production in adipose tissue.

    PubMed

    Tang, Eva H C; Cai, Yin; Wong, Chi Kin; Rocha, Viviane Z; Sukhova, Galina K; Shimizu, Koichi; Xuan, Ge; Vanhoutte, Paul M; Libby, Peter; Xu, Aimin

    2015-02-01

    Inflammation of adipose tissue induces metabolic derangements associated with obesity. Thus, determining ways to control or inhibit inflammation in adipose tissue is of clinical interest. The present study tested the hypothesis that in mouse adipose tissue, endogenous prostaglandin E2 (PGE2) negatively regulates inflammation via activation of prostaglandin E receptor 4 (EP4). PGE2 (5-500 nM) attenuated lipopolysaccharide-induced mRNA and protein expression of chemokines, including interferon-γ-inducible protein 10 and macrophage-inflammatory protein-1α in mouse adipose tissue. A selective EP4 antagonist (L161,982) reversed, and two structurally different selective EP4 agonists [CAY10580 and CAY10598] mimicked these actions of PGE2. Adipose tissue derived from EP4-deficient mice did not display this response. These findings establish the involvement of EP4 receptors in this anti-inflammatory response. Experiments performed on adipose tissue from high-fat-fed mice demonstrated EP4-dependent attenuation of chemokine production during diet-induced obesity. The anti-inflammatory actions of EP4 became more important on a high-fat diet, in that EP4 activation suppressed a greater variety of chemokines. Furthermore, adipose tissue and systemic inflammation was enhanced in high-fat-fed EP4-deficient mice compared with wild-type littermates, and in high-fat-fed untreated C57BL/6 mice compared with mice treated with EP4 agonist. These findings provide in vivo evidence that PGE2-EP4 signaling limits inflammation. In conclusion, PGE2, via activation of EP4 receptors, functions as an endogenous anti-inflammatory mediator in mouse adipose tissue, and targeting EP4 may mitigate adipose tissue inflammation. PMID:25510249

  20. Hormonal regulation of uterine chemokines and immune cells

    PubMed Central

    Park, Dong-Wook

    2011-01-01

    The ultimate function of the endometrium is to allow the implantation of a blastocyst and to support pregnancy. Cycles of tissue remodeling ensure that the endometrium is in a receptive state during the putative 'implantation window', the few days of each menstrual cycle when an appropriately developed blastocyst may be available to implant in the uterus. A successful pregnancy requires strict temporal regulation of maternal immune function to accommodate a semi-allogeneic embryo. To preparing immunological tolerance at the onset of implantation, tight temporal regulations are required between the immune and endocrine networks. This review will discuss about the action of steroid hormones on the human endometrium and particularly their role in regulating the inflammatory processes associated with endometrial receptivity. PMID:22384440

  1. Chemokine sequestration by atypical chemokine receptors.

    PubMed

    Hansell, C A H; Simpson, C V; Nibbs, R J B

    2006-12-01

    Leucocyte migration is essential for robust immune and inflammatory responses, and plays a critical role in many human diseases. Chemokines, a family of small secreted protein chemoattractants, are of fundamental importance in this process, directing leucocyte trafficking by signalling through heptahelical G-protein-coupled receptors expressed by the migrating cells. However, several mammalian chemokine receptors, including D6 and CCX-CKR (ChemoCentryx chemokine receptor), do not fit existing models of chemokine receptor function, and do not even appear to signal in response to chemokine binding. Instead, these 'atypical' chemokine receptors are biochemically specialized for chemokine sequestration, acting to regulate chemokine bioavailability and thereby influence responses through signalling-competent chemokine receptors. This is of critical importance in vivo, as mice lacking D6 show exaggerated cutaneous inflammatory responses and an increased susceptibility to the development of skin cancer. CCX-CKR, on the other hand, is predicted to modulate homoeostatic lymphocyte and dendritic cell trafficking, key migratory events in acquired immune responses that are directed by CCX-CKR-binding chemokines. Thus studies on 'atypical' chemokine receptors are revealing functional and biochemical diversity within the chemokine receptor family and providing insights into novel mechanisms of chemokine regulation. PMID:17073739

  2. Coordinated Post-Transcriptional Regulation of the Chemokine System: Messages from CCL2

    PubMed Central

    Panganiban, Ronaldo P.; Vonakis, Becky M.; Ishmael, Faoud T.

    2014-01-01

    The molecular cross-talk between epithelium and immune cells in the airway mucosa is a key regulator of homeostatic immune surveillance and is crucially involved in the development of chronic lung inflammatory diseases. The patterns of gene expression that follow the sensitization process occurring in allergic asthma and chronic rhinosinusitis and those present in the neutrophilic response of other chronic inflammatory lung diseases such as chronic obstructive pulmonary disease (COPD) are tightly regulated in their specificity. Studies exploring the global transcript profiles associated with determinants of post-transcriptional gene regulation (PTR) such as RNA-binding proteins (RBP) and microRNAs identified several of these factors as being crucially involved in controlling the expression of chemokines upon airway epithelial cell stimulation with cytokines prototypic of Th1- or Th2-driven responses. These studies also uncovered the participation of these pathways to glucocorticoids' inhibitory effect on the epithelial chemokine network. Unmasking the molecular mechanisms of chemokine PTR may likely uncover novel therapeutic strategies for the blockade of proinflammatory pathways that are pathogenetic for asthma, COPD, and other lung inflammatory diseases. PMID:24697203

  3. Mechanisms regulating cell membrane localization of the chemokine receptor CXCR4 in human hepatocarcinoma cells.

    PubMed

    Cepeda, Edgar B; Dediulia, Tatjana; Fernando, Joan; Bertran, Esther; Egea, Gustavo; Navarro, Estanislao; Fabregat, Isabel

    2015-05-01

    Hepatocellular carcinoma (HCC) cells with a mesenchymal phenotype show an asymmetric subcellular distribution of the chemokine receptor CXCR4, which is required for cell migration and invasion. In this work we examine the mechanisms that regulate the intracellular trafficking of CXCR4 in HCC cells. Results indicate that HCC cells present CXCR4 at the cell surface, but most of this protein is in endomembranes colocalizing with markers of the Golgi apparatus and recycling endosomes. The presence of high protein levels of CXCR4 present at the cell surface correlates with a mesenchymal-like phenotype and a high autocrine activation of the Transforming Growth Factor-beta (TGF-β) pathway. CXCR4 traffics along the Golgi/exocyst/plasma membrane pathway and requires EXOC4 (Sec8) component of the exocyst complex. HCC cells use distinct mechanisms for the CXCR4 internalization such as dynamin-dependent endocytosis and macropinocytosis. Regardless of the endocytic mechanisms, colocalization of CXCR4 and Rab11 is observed, which could be involved not only in receptor recycling but also in its post-Golgi transport. In summary, this work highlights membrane trafficking pathways whose pharmacological targeting could subsequently result in the inactivation of one of the main guiding mechanisms used by metastatic cells to colonize secondary organs and tissues. PMID:25704914

  4. A Dap12-Mediated Pathway Regulates Expression of Cc Chemokine Receptor 7 and Maturation of Human Dendritic Cells

    PubMed Central

    Bouchon, Axel; Hernández-Munain, Cristina; Cella, Marina; Colonna, Marco

    2001-01-01

    Gene targeting of the adaptor molecule DAP12 in mice caused abnormal distribution and impaired antigen presentation capacity of dendritic cells (DCs). However, the DAP12-associated receptors expressed on DCs and their functions have not been identified yet. Here we show that the triggering receptor expressed on myeloid cells-2 (TREM-2) is a cell surface receptor on human monocyte-derived DCs, which is associated with DAP12. TREM-2/DAP12 promotes upregulation of CC chemokine receptor 7, partial DC maturation, and DC survival through activation of protein tyrosine kinases and extracellular signal–regulated kinase. In contrast to Toll-like receptor-mediated signaling, TREM2/DAP12 stimulation is independent of nuclear factor-κB and p38 stress-activated protein kinase. This novel DC activation pathway may regulate DC homeostasis and amplify DC responses to pathogens, explaining the phenotype observed in DAP12-deficient mice. PMID:11602640

  5. Chemokines and the pathophysiology of neuropathic pain

    PubMed Central

    White, Fletcher A.; Jung, Hosung; Miller, Richard J.

    2007-01-01

    Chemokines and chemokine receptors are widely expressed by cells of the immune and nervous systems. This review focuses on our current knowledge concerning the role of chemokines in the pathophysiology of chronic pain syndromes. Injury- or disease-induced changes in the expression of diverse chemokines and their receptors have been demonstrated in the neural and nonneural elements of pain pathways. Under these circumstances, chemokines have been shown to modulate the electrical activity of neurons by multiple regulatory pathways including increases in neurotransmitter release through Ca-dependent mechanisms and transactivation of transient receptor channels. Either of these mechanisms alone, or in combination, may contribute to sustained excitability of primary afferent and secondary neurons within spinal pain pathways. Another manner in which chemokines may influence sustained neuronal excitability may be their ability to function as excitatory neurotransmitters within the peripheral and central nervous system. As is the case for traditional neurotransmitters, injury-induced up-regulated chemokines are found within synaptic vesicles. Chemokines released after depolarization of the cell membrane can then act on other chemokine receptor-bearing neurons, glia, or immune cells. Because up-regulation of chemokines and their receptors may be one of the mechanisms that directly or indirectly contribute to the development and maintenance of chronic pain, these molecules may then represent novel targets for therapeutic intervention in chronic pain states. PMID:18083844

  6. Signal pathways in up-regulation of chemokines by tyrosine kinase MER/NYK in prostate cancer cells.

    PubMed

    Wu, Yi-Mi; Robinson, Dan R; Kung, Hsing-Jien

    2004-10-15

    The AXL/UFO family of tyrosine kinases is characterized by a common N-CAM (neural adhesion molecule)-related extracellular domain and a common ligand, GAS6 (growth arrest-specific protein 6). Family members are prone to transcriptional regulation and carry out diverse functions including the regulation of cell adhesion, migration, phagocytosis, and survival. In this report, we describe a new role of MER/N-CAM-related kinase (NYK), a member of the AXL family of kinases, in the up-regulation of chemokines in prostate cancer cells. We show that NYK has elevated expression in a subset of tumor specimens and prostate cancer cell lines. Activation of NYK in the prostate cancer cell line DU145 does not cause a mitogenic effect; instead, it causes a differentiation phenotype. Microarray analysis revealed that NYK is a strong inducer of endocrine factors including interleukin (IL)-8 and several other angiogenic CXC chemokines as well as bone morphogenic factors. The dramatic increase of IL-8 expression is seen at both transcriptional and posttranscriptional levels. The downstream signals engaged by NYK were characterized, and those responsible for the up-regulation of IL-8 transcription were defined. In contrast to IL-1alpha, NYK-induced up-regulation of IL-8 in DU145 depends on the mitogen-activated protein kinase kinase/extracellular signal-regulated kinase/Jun/Fos pathway, but not phosphoinositide 3'-kinase/nuclear factor-kappaB. These data define a new function of the AXL family of kinases and suggest a potential role of NYK in prostate cancer progression. PMID:15492251

  7. Positive and negative regulation by SLP-76/ADAP and Pyk2 of chemokine-stimulated T-lymphocyte adhesion mediated by integrin α4β1

    PubMed Central

    Dios-Esponera, Ana; Isern de Val, Soledad; Sevilla-Movilla, Silvia; García-Verdugo, Rosa; García-Bernal, David; Arellano-Sánchez, Nohemí; Cabañas, Carlos; Teixidó, Joaquin

    2015-01-01

    Stimulation by chemokines of integrin α4β1–dependent T-lymphocyte adhesion is a crucial step for lymphocyte trafficking. The adaptor Vav1 is required for chemokine-activated T-cell adhesion mediated by α4β1. Conceivably, proteins associating with Vav1 could potentially modulate this adhesion. Correlating with activation by the chemokine CXCL12 of T-lymphocyte attachment to α4β1 ligands, a transient stimulation in the association of Vav1 with SLP-76, Pyk2, and ADAP was observed. Using T-cells depleted for SLP-76, ADAP, or Pyk2, or expressing Pyk2 kinase–inactive forms, we show that SLP-76 and ADAP stimulate chemokine-activated, α4β1-mediated adhesion, whereas Pyk2 opposes T-cell attachment. While CXCL12-promoted generation of high-affinity α4β1 is independent of SLP-76, ADAP, and Pyk2, the strength of α4β1-VCAM-1 interaction and cell spreading on VCAM-1 are targets of regulation by these three proteins. GTPase assays, expression of activated or dominant-negative Rac1, or combined ADAP and Pyk2 silencing indicated that Rac1 activation by CXCL12 is a common mediator response in SLP-76–, ADAP-, and Pyk2-regulated cell adhesion involving α4β1. Our data strongly suggest that chemokine-stimulated associations between Vav1, SLP-76, and ADAP facilitate Rac1 activation and α4β1-mediated adhesion, whereas Pyk2 opposes this adhesion by limiting Rac1 activation. PMID:26202465

  8. Cutting edge: identification of a novel chemokine receptor that binds dendritic cell- and T cell-active chemokines including ELC, SLC, and TECK.

    PubMed

    Gosling, J; Dairaghi, D J; Wang, Y; Hanley, M; Talbot, D; Miao, Z; Schall, T J

    2000-03-15

    Searching for new receptors of dendritic cell- and T cell-active chemokines, we used a combination of techniques to interrogate orphan chemokine receptors. We report here on human CCX CKR, previously represented only by noncontiguous expressed sequence tags homologous to bovine PPR1, a putative gustatory receptor. We employed a two-tiered process of ligand assignment, where immobilized chemokines constructed on stalks (stalkokines) were used as bait for adhesion of cells expressing CCX CKR. These cells adhered to stalkokines representing ELC, a chemokine previously thought to bind only CCR7. Adhesion was abolished in the presence of soluble ELC, SLC (CCR7 ligands), and TECK (a CCR9 ligand). Complete ligand profiles were further determined by radiolabeled ligand binding and competition with >80 chemokines. ELC, SLC, and TECK comprised high affinity ligands (IC50 <15 nM); lower affinity ligands include BLC and vMIP-II (IC50 <150 nM). With its high affinity for CC chemokines and homology to CC receptors, we provisionally designate this new receptor CCR10. PMID:10706668

  9. Association between Gαi2 and ELMO1/Dock180 connects chemokine signalling with Rac activation and metastasis.

    PubMed

    Li, Hongyan; Yang, Lei; Fu, Hui; Yan, Jianshe; Wang, Ying; Guo, Hua; Hao, Xishan; Xu, Xuehua; Jin, Tian; Zhang, Ning

    2013-01-01

    The chemokine CXCL12 and its G-protein-coupled receptor CXCR4 control the migration, invasiveness and metastasis of breast cancer cells. Binding of CXCL12 to CXCR4 triggers activation of heterotrimeric Gi proteins that regulate actin polymerization and migration. However, the pathways linking chemokine G-protein-coupled receptor/Gi signalling to actin polymerization and cancer cell migration are not known. Here we show that CXCL12 stimulation promotes interaction between Gαi2 and ELMO1. Gi signalling and ELMO1 are both required for CXCL12-mediated actin polymerization, migration and invasion of breast cancer cells. CXCL12 triggers a Gαi2-dependent membrane translocation of ELMO1, which associates with Dock180 to activate small G-proteins Rac1 and Rac2. In vivo, ELMO1 expression is associated with lymph node and distant metastasis, and knocking down ELMO1 impairs metastasis to the lung. Our findings indicate that a chemokine-controlled pathway, consisting of Gαi2, ELMO1/Dock180, Rac1 and Rac2, regulates the actin cytoskeleton during breast cancer metastasis. PMID:23591873

  10. The atypical chemokine receptor CCX-CKR regulates metastasis of mammary carcinoma via an effect on EMT.

    PubMed

    Harata-Lee, Yuka; Turvey, Michelle E; Brazzatti, Julie A; Gregor, Carly E; Brown, Michael P; Smyth, Mark J; Comerford, Iain; McColl, Shaun R

    2014-11-01

    Over the last decade, the significance of the homeostatic CC chemokine receptor-7 and its ligands CC chemokine ligand-19 (CCL19) and CCL21, in various types of cancer, particularly mammary carcinoma, has been highlighted. The chemokine receptor CCX-CKR is a high-affinity receptor for these chemokine ligands but rather than inducing classical downstream signalling events promoting migration, it instead sequesters and targets its ligands for degradation, and appears to function as a regulator of the bioavailability of these chemokines in vivo. Therefore, in this study, we tested the hypothesis that local regulation of chemokine levels by CCX-CKR expressed on tumours alters tumour growth and metastasis in vivo. Expression of CCX-CKR on 4T1.2 mouse mammary carcinoma cells inhibited orthotopic tumour growth. However, this effect could not be correlated with chemokine scavenging in vivo and was not mediated by host adaptive immunity. Conversely, expression of CCX-CKR on 4T1.2 cells resulted in enhanced spontaneous metastasis and haematogenous metastasis in vivo. In vitro characterisation of the tumourigenicity of CCX-CKR-expressing 4T1.2 cells suggested accelerated epithelial-mesenchymal transition (EMT) revealed by their more invasive and motile character, lower adherence to the extracellular matrix and to each other, and greater resistance to anoikis. Further analysis of CCX-CKR-expressing 4T1.2 cells also revealed that transforming growth factor (TGF)-β1 expression was increased both at mRNA and protein levels leading to enhanced autocrine phosphorylation of Smad 2/3 in these cells. Together, our data show a novel function for the chemokine receptor CCX-CKR as a regulator of TGF-β1 expression and the EMT in breast cancer cells. PMID:25027038

  11. Regulation of eotaxin-3/CC chemokine ligand 26 expression by T helper type 2 cytokines in human colonic myofibroblasts.

    PubMed

    Takahashi, K; Imaeda, H; Fujimoto, T; Ban, H; Bamba, S; Tsujikawa, T; Sasaki, M; Fujiyama, Y; Andoh, A

    2013-08-01

    Eotaxins induce the trafficking of eosinophils to the sites of inflammation via CC chemokine receptor 3 (CCR3). In this study, we investigated eotaxin-3/CC chemokine ligand 26 (CCL26) expression in the inflamed mucosa of patients with inflammatory bowel disease (IBD), and characterized the molecular mechanisms responsible for eotaxin-3 expression in human colonic myofibroblasts. Eotaxin-3 mRNA and protein expression was evaluated by real time-polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Eotaxin-3 mRNA expression was elevated significantly in the active lesions of ulcerative colitis (UC) patients. Significant elevations were also observed in the active lesions of Crohn's disease (CD) patients, but this was significantly lower than that detected in the active UC lesions. There were no significant increases in the inactive lesions of UC or CD patients. Colonic myofibroblasts were identified as a major source of eotaxin-3 in the colonic mucosa, and interleukin (IL)-4 and IL-13 enhanced eotaxin-3 mRNA and protein expression significantly in these cells. There was a significant positive correlation between mucosal eotaxin-3 and IL-4 mRNA expression in the active lesions of IBD patients. The IL-4- and IL-13-induced eotaxin-3 mRNA expression was regulated by the signal transducer and activator of transcription-6 (STAT-6) and suppressor of cytokine signalling (SOCS)1-mediated pathways. Interferon (IFN)-γ acts as a negative regulator on the IL-4- and IL-13-induced eotaxin-3 expression via STAT-1 activation. Eotaxin-3 expression was elevated specifically in the active lesions of IBD, in particular UC. Eotaxin-3 derived from colonic myofibroblasts may play an important role in the pathophysiology of UC. PMID:23607908

  12. The chemokine receptors ACKR2 and CCR2 reciprocally regulate lymphatic vessel density

    PubMed Central

    Lee, Kit M; Danuser, Renzo; Stein, Jens V; Graham, Delyth; Nibbs, Robert JB; Graham, Gerard J

    2014-01-01

    Macrophages regulate lymphatic vasculature development; however, the molecular mechanisms regulating their recruitment to developing, and adult, lymphatic vascular sites are not known. Here, we report that resting mice deficient for the inflammatory chemokine-scavenging receptor, ACKR2, display increased lymphatic vessel density in a range of tissues under resting and regenerating conditions. This appears not to alter dendritic cell migration to draining lymph nodes but is associated with enhanced fluid drainage from peripheral tissues and thus with a hypotensive phenotype. Examination of embryonic skin revealed that this lymphatic vessel density phenotype is developmentally established. Further studies indicated that macrophages and the inflammatory CC-chemokine CCL2, which is scavenged by ACKR2, are associated with this phenotype. Accordingly, mice deficient for the CCL2 signalling receptor, CCR2, displayed a reciprocal phenotype of reduced lymphatic vessel density. Further examination revealed that proximity of pro-lymphangiogenic macrophages to developing lymphatic vessel surfaces is increased in ACKR2-deficient mice and reduced in CCR2-deficient mice. Therefore, these receptors regulate vessel density by reciprocally modulating pro-lymphangiogenic macrophage recruitment, and proximity, to developing, resting and regenerating lymphatic vessels. PMID:25271254

  13. Delta-Like Ligand 4 Modulates Liver Damage by Down-Regulating Chemokine Expression.

    PubMed

    Shen, Zhe; Liu, Yan; Dewidar, Bedair; Hu, Junhao; Park, Ogyi; Feng, Teng; Xu, Chengfu; Yu, Chaohui; Li, Qi; Meyer, Christoph; Ilkavets, Iryna; Müller, Alexandra; Stump-Guthier, Carolin; Munker, Stefan; Liebe, Roman; Zimmer, Vincent; Lammert, Frank; Mertens, Peter R; Li, Hai; Ten Dijke, Peter; Augustin, Hellmut G; Li, Jun; Gao, Bin; Ebert, Matthias P; Dooley, Steven; Li, Youming; Weng, Hong-Lei

    2016-07-01

    Disrupting Notch signaling ameliorates experimental liver fibrosis. However, the role of individual Notch ligands in liver damage is unknown. We investigated the effects of Delta-like ligand 4 (Dll4) in liver disease. DLL4 expression was measured in 31 human liver tissues by immunohistochemistry. Dll4 function was examined in carbon tetrachloride- and bile duct ligation-challenged mouse models in vivo and evaluated in hepatic stellate cells, hepatocytes, and Kupffer cells in vitro. DLL4 was expressed in patients' Kupffer and liver sinusoidal endothelial cells. Recombinant Dll4 protein (rDll4) ameliorated hepatocyte apoptosis, inflammation, and fibrosis in mice after carbon tetrachloride challenge. In vitro, rDll4 significantly decreased lipopolysaccharide-dependent chemokine expression in both Kupffer and hepatic stellate cells. In bile duct ligation mice, rDll4 induced massive hepatic necrosis, resulting in the death of all animals within 1 week. Inflammatory cell infiltration and chemokine ligand 2 (Ccl2) expression were significantly reduced in rDll4-receiving bile duct ligation mice. Recombinant Ccl2 rescued bile duct ligation mice from rDll4-mediated death. In patients with acute-on-chronic liver failure, DLL4 expression was inversely associated with CCL2 abundance. Mechanistically, Dll4 regulated Ccl2 expression via NF-κB. Taken together, Dll4 modulates liver inflammatory response by down-regulating chemokine expression. rDll4 application results in opposing outcomes in two models of liver damage. Loss of DLL4 may be associated with CCL2-mediated cytokine storm in patients with acute-on-chronic liver failure. PMID:27171900

  14. The Tumor-Promoting Flow of Cells Into, Within and Out of the Tumor Site: Regulation by the Inflammatory Axis of TNFα and Chemokines.

    PubMed

    Ben-Baruch, Adit

    2012-08-01

    Tumors are dynamic organs, in which active processes of cell motility affect disease course by regulating the composition of cells at the tumor site. While sub-populations of tumor-promoting leukocytes are recruited inward and endothelial cell migration stands in the basis of vascular branching throughout the tumor, cancer cells make their way out of the primary site towards specific metastatic sites. This review describes the independent and cross-regulatory roles of inflammatory chemokines and of the inflammatory cytokine tumor necrosis factor α (TNFα) in determining cell motility processes that eventually have profound effects on tumor growth and metastasis. First, the effects of inflammatory chemokines such as CCL2 (MCP-1), CCL5 (RANTES) and CXCL8 (IL-8) are described, regulating the inward flow of leukocyte sub-populations with pro-tumoral activities, such as tumor-associated macrophages (TAM), myeloid-derived suppressor cells (MDSC), tumor-associated neutrophils (TAN), Th17 cells and Tregs. Then, the ability of inflammatory chemokines to induce endothelial cell migration, sprouting and tube formation is discussed, with its implications on tumor angiogenesis. This part is followed by an in depth description of the manners by which TNFα potentiates the above activities of the inflammatory chemokines, alongside with its ability to directly induce migratory processes in the tumor cells thus promoting metastasis. Note worthy is the ability of TNFα to induce in the tumor cells the important process of epithelial-to-mesenchymal transition (EMT). Emphasis is given to the ability of TNFα to establish an inflammatory network with the chemokines, and in parallel to form a cell re-modeling network together with transforming growth factor β (TGFβ). The review concludes by discussing the implications of such networks on disease course, and on the future design of therapeutic measures in cancer. PMID:22190050

  15. Up-regulation of the pro-inflammatory chemokine CXCL16 is a common response of tumor cells to ionizing radiation.

    PubMed

    Matsumura, Satoko; Demaria, Sandra

    2010-04-01

    We recently showed that mouse and human breast carcinoma cells respond to ionizing radiation therapy by up-regulating the expression and release of the pro-inflammatory chemokine CXCL16, which binds to the CXCR6 receptor expressed by activated T cells. Enhanced recruitment of activated T cells to irradiated mouse 4T1 breast tumors was mediated largely by CXCL16 and was correlated with tumor inhibition in mice treated with the combination of local radiation and immunotherapy. In this study, the expression of CXCL16 and its modulation by radiation were analyzed in mouse melanoma B16/F10, fibrosarcoma MC57, colon carcinoma MCA38, and prostate carcinoma TRAMP-C1 cells. Only TRAMP-C1 cells showed detectable expression of CXCL16, although the level was lower than in 4T1 and 67NR breast carcinoma cells. Ionizing radiation up-regulated CXCL16 expression in all cells except B16/F10, but only TRAMP-C1, 67NR and 4T1 cells released the soluble chemokine in significant quantities. The metalloproteinases ADAM10 and ADAM17, which are responsible for cleaving the chemokine domain from the CXCL16 transmembrane form, were expressed in all cells. Overall, our data indicate that up-regulation of CXCL16 is a common response of tumor cells to radiation, and they have important implications for the use of local radiotherapy in combination with immunotherapy. PMID:20334513

  16. Estrogen, SNP-Dependent Chemokine Expression and Selective Estrogen Receptor Modulator Regulation.

    PubMed

    Ho, Ming-Fen; Bongartz, Tim; Liu, Mohan; Kalari, Krishna R; Goss, Paul E; Shepherd, Lois E; Goetz, Matthew P; Kubo, Michiaki; Ingle, James N; Wang, Liewei; Weinshilboum, Richard M

    2016-03-01

    We previously reported, on the basis of a genome-wide association study for aromatase inhibitor-induced musculoskeletal symptoms, that single-nucleotide polymorphisms (SNPs) near the T-cell leukemia/lymphoma 1A (TCL1A) gene were associated with aromatase inhibitor-induced musculoskeletal pain and with estradiol (E2)-induced TCL1A expression. Furthermore, variation in TCL1A expression influenced the downstream expression of proinflammatory cytokines and cytokine receptors. Specifically, the top hit genome-wide association study SNP, rs11849538, created a functional estrogen response element (ERE) that displayed estrogen receptor (ER) binding and increased E2 induction of TCL1A expression only for the variant SNP genotype. In the present study, we pursued mechanisms underlying the E2-SNP-dependent regulation of TCL1A expression and, in parallel, our subsequent observations that SNPs at a distance from EREs can regulate ERα binding and that ER antagonists can reverse phenotypes associated with those SNPs. Specifically, we performed a series of functional genomic studies using a large panel of lymphoblastoid cell lines with dense genomic data that demonstrated that TCL1A SNPs at a distance from EREs can modulate ERα binding and expression of TCL1A as well as the expression of downstream immune mediators. Furthermore, 4-hydroxytamoxifen or fulvestrant could reverse these SNP-genotype effects. Similar results were found for SNPs in the IL17A cytokine and CCR6 chemokine receptor genes. These observations greatly expand our previous results and support the existence of a novel molecular mechanism that contributes to the complex interplay between estrogens and immune systems. They also raise the possibility of the pharmacological manipulation of the expression of proinflammatory cytokines and chemokines in a SNP genotype-dependent fashion. PMID:26866883

  17. Regulation of chemokine receptor by Toll-like receptor 2 is critical to neutrophil migration and resistance to polymicrobial sepsis

    PubMed Central

    Alves-Filho, Jose C.; Freitas, Andressa; Souto, Fabricio O.; Spiller, Fernando; Paula-Neto, Heitor; Silva, Joao S.; Gazzinelli, Ricardo T.; Teixeira, Mauro M.; Ferreira, Sergio H.; Cunha, Fernando Q.

    2009-01-01

    Patients with sepsis have a marked defect in neutrophil migration. Here we identify a key role of Toll-like receptor 2 (TLR2) in the regulation of neutrophil migration and resistance during polymicrobial sepsis. We found that the expression of the chemokine receptor CXCR2 was dramatically down-regulated in circulating neutrophils from WT mice with severe sepsis, which correlates with reduced chemotaxis to CXCL2 in vitro and impaired migration into an infectious focus in vivo. TLR2 deficiency prevented the down-regulation of CXCR2 and failure of neutrophil migration. Moreover, TLR2−/− mice exhibited higher bacterial clearance, lower serum inflammatory cytokines, and improved survival rate during severe sepsis compared with WT mice. In vitro, the TLR2 agonist lipoteichoic acid (LTA) down-regulated CXCR2 expression and markedly inhibited the neutrophil chemotaxis and actin polymerization induced by CXCL2. Moreover, neutrophils activated ex vivo by LTA and adoptively transferred into naïve WT recipient mice displayed a significantly reduced competence to migrate toward thioglycolate-induced peritonitis. Finally, LTA enhanced the expression of G protein–coupled receptor kinases 2 (GRK2) in neutrophils; increased expression of GRK2 was seen in blood neutrophils from WT mice, but not TLR2−/− mice, with severe sepsis. Our findings identify an unexpected detrimental role of TLR2 in polymicrobial sepsis and suggest that inhibition of TLR2 signaling may improve survival from sepsis. PMID:19234125

  18. Chemokines and chemokine receptors in mucosal homeostasis at the intestinal epithelial barrier in inflammatory bowel disease.

    PubMed

    Zimmerman, Noah P; Vongsa, Rebecca A; Wendt, Michael K; Dwinell, Michael B

    2008-07-01

    Chemokines, a large family of small chemoattractive cytokines, and their receptors play an integral role in the regulation of the immune response and homeostasis. The ability of chemokines to attract specific populations of immune cells sets them apart from other chemoattractants. Chemokines produced within the gastrointestinal mucosa are critical players in directing the balance between physiological and pathophysiological inflammation in health, inflammatory bowel disease (IBD), and the progression to colon cancer. In addition to the well-characterized role of chemokines in directed trafficking of immune cells to the gut mucosa, the expression of chemokine receptors on the cells of the epithelium makes them active participants in the chemokine signaling network. Recent findings demonstrate an important role for chemokines and chemokine receptors in epithelial barrier repair and maintenance as well as an intricate involvement in limiting metastasis of colonic carcinoma. Increased recognition of the association between barrier defects and inflammation and the subsequent progression to cancer in IBD thus implicates chemokines as key regulators of mucosal homeostasis and disease pathogenesis. PMID:18452220

  19. Analysis of the antimicrobial activities of a chemokine-derived peptide (CDAP-4) on Pseudomonas aeruginosa

    SciTech Connect

    Martinez-Becerra, Francisco; Dominguez-Ramirez, Lenin; Mendoza-Hernandez, Guillermo; Lopez-Vidal, Yolanda; Soldevila, Gloria . E-mail: garciaze@servidor.unam.mx

    2007-04-06

    Chemokines are key molecules involved in the control of leukocyte trafficking. Recently, a novel function as antimicrobial proteins has been described. CCL13 is the only member of the MCP chemokine subfamily displaying antimicrobial activity. To determine Key residues involved in its antimicrobial activity, CCL13 derived peptides were synthesized and tested against several bacterial strains, including Pseudomonas aeruginosa. One of these peptides, corresponding to the C-terminal region of CCL13 (CDAP-4) displayed good antimicrobial activity. Electron microscopy studies revealed remarkable morphological changes after CDAP-4 treatment. By computer modeling, CDAP-4 in {alpha} helical configuration generated a positive electrostatic potential that extended beyond the surface of the molecule. This feature is similar to other antimicrobial peptides. Altogether, these findings indicate that the antimicrobial activity was displayed by CCL13 resides to some extent at the C-terminal region. Furthermore, CDAP-4 could be considered a good antimicrobial candidate with a potential use against pathogens including P. aeruginosa.

  20. The Role of Chemokines in Acute Liver Injury

    PubMed Central

    Saiman, Yedidya; Friedman, Scott L.

    2012-01-01

    Chemokines are small molecular weight proteins primarily known to drive migration of immune cell populations. In both acute and chronic liver injury, hepatic chemokine expression is induced resulting in inflammatory cell infiltration, angiogenesis, and cell activation and survival. During acute injury, massive parenchymal cell death due to apoptosis and/or necrosis leads to chemokine production by hepatocytes, cholangiocytes, Kupffer cells, hepatic stellate cells, and sinusoidal endothelial cells. The specific chemokine profile expressed during injury is dependent on both the type and course of injury. Hepatotoxicity by acetaminophen for example leads to cellular necrosis and activation of Toll-like receptors while the inciting insult in ischemia reperfusion injury produces reactive oxygen species and subsequent production of pro-inflammatory chemokines. Chemokine expression by these cells generates a chemoattractant gradient promoting infiltration by monocytes/macrophages, NK cells, NKT cells, neutrophils, B cells, and T cells whose activity are highly regulated by the specific chemokine profiles within the liver. Additionally, resident hepatic cells express chemokine receptors both in the normal and injured liver. While the role of these receptors in normal liver has not been well described, during injury, receptor up-regulation, and chemokine engagement leads to cellular survival, proliferation, apoptosis, fibrogenesis, and expression of additional chemokines and growth factors. Hepatic-derived chemokines can therefore function in both paracrine and autocrine fashions further expanding their role in liver disease. More recently it has been appreciated that chemokines can have diverging effects depending on their temporal expression pattern and the type of injury. A better understanding of chemokine/chemokine receptor axes will therefore pave the way for development of novel targeted therapies for the treatment of liver disease. PMID:22723782

  1. S100B protein stimulates microglia migration via RAGE-dependent up-regulation of chemokine expression and release.

    PubMed

    Bianchi, Roberta; Kastrisianaki, Eirini; Giambanco, Ileana; Donato, Rosario

    2011-03-01

    The Ca(2+)-binding protein of the EF-hand type, S100B, is abundantly expressed in and secreted by astrocytes, and release of S100B from damaged astrocytes occurs during the course of acute and chronic brain disorders. Thus, the concept has emerged that S100B might act an unconventional cytokine or a damage-associated molecular pattern protein playing a role in the pathophysiology of neurodegenerative disorders and inflammatory brain diseases. S100B proinflammatory effects require relatively high concentrations of the protein, whereas at physiological concentrations S100B exerts trophic effects on neurons. Most if not all of the extracellular (trophic and toxic) effects of S100B in the brain are mediated by the engagement of RAGE (receptor for advanced glycation end products). We show here that high S100B stimulates murine microglia migration in Boyden chambers via RAGE-dependent activation of Src kinase, Ras, PI3K, MEK/ERK1/2, RhoA/ROCK, Rac1/JNK/AP-1, Rac1/NF-κB, and, to a lesser extent, p38 MAPK. Recruitment of the adaptor protein, diaphanous-1, a member of the formin protein family, is also required for S100B/RAGE-induced migration of microglia. The S100B/RAGE-dependent activation of diaphanous-1/Rac1/JNK/AP-1, Ras/Rac1/NF-κB and Src/Ras/PI3K/RhoA/diaphanous-1 results in the up-regulation of expression of the chemokines, CCL3, CCL5, and CXCL12, whose release and activity are required for S100B to stimulate microglia migration. Lastly, RAGE engagement by S100B in microglia results in up-regulation of the chemokine receptors, CCR1 and CCR5. These results suggests that S100B might participate in the pathophysiology of brain inflammatory disorders via RAGE-dependent regulation of several inflammation-related events including activation and migration of microglia. PMID:21209080

  2. Tumor-associated macrophage or chemokine ligand CCL17 positively regulates the tumorigenesis of hepatocellular carcinoma.

    PubMed

    Zhu, Fangyu; Li, Xiangnan; Chen, Siyu; Zeng, Qiu; Zhao, Yu; Luo, Fang

    2016-02-01

    Alternatively activated macrophages (M2) can secrete chemokines, such as chemokine ligand 17 (CCL17), and are associated with promoting tumorigenesis of hepatocellular carcinoma (HCC). This study aimed at investigating the potential role of M2 and CCL17 in progression of HCC. The levels of CCL17 expression in 90 HCC samples were characterized by tissue microarray and stratified for the postsurgical survival. MHCC97L cells were co-cultured with classically activated M1, M2 or CCL17-silencing M2(ccl17mute) or treated with conditional medium (CM) from these cells or CCL17 in vitro. The wound healing, invasion, viability and apoptosis of MHCC97L cells in vitro and tumor growth in vivo were determined. The stemness of MHCC97L cells was examined by sphere formation, flow cytometry and Western blot. The relative expression levels of epithelial-mesenchymal transition (EMT) factors and the Wnt/β-catenin signaling were determined. Higher levels of intratumoral CCL17 expression were significantly associated with clinical pathological characteristics of HCC and with poorer overall survival rates in HCC patients (P < 0.05). High levels of CCR4 were detected in MHCC97L cells. Treatment with the CM from M2 or with CCL17 significantly enhanced the wound healing process, invasion and proliferation of MHCC97L cells in vitro. Co-implantation MHCC97L cells with M2 significantly promoted the growth of MHCC97L tumors in vivo. Co-culture with M2 or treatment with CCL17 enhanced the stemness, EMT process, the TGF-β1 and Wnt/β-catenin signaling in MHCC97L cells. CCL17 promotes the tumorigenesis of HCC and may be a potential biomarker and target for HCC prognosis and therapy. PMID:26781124

  3. The β-catenin signaling pathway induces aggressive potential in breast cancer by up-regulating the chemokine CCL5.

    PubMed

    Yasuhara, Rika; Irié, Tarou; Suzuki, Kenya; Sawada, Terumasa; Miwa, Noriko; Sasaki, Akiko; Tsunoda, Yuko; Nakamura, Seigo; Mishima, Kenji

    2015-10-15

    β-Catenin signaling plays a pivotal role in the genesis of a variety of malignant tumors, but its role in breast cancer has not been fully elucidated. Here, we examined whether deregulation of β-catenin signaling is related to the aggressive characteristics of certain types of breast cancers. Analysis of cytokine levels in MDA-MB-231 cells overexpressing a constitutively active form of β-catenin (CAβ-catenin) revealed a higher level of CCL5 expression. Cells transfected with CAβ-catenin or stimulated with recombinant CCL5 exhibited increased cell invasion activity and spheroid formation in vitro. Furthermore, CAβ-catenin-transfected MDA-MB-231 cells formed larger tumor masses that contained more Ki-67-positive cells and infiltrating lymphocytes than did the control cells. An inhibitor of CCR5 and a pan-CXCR neutralizing antibody dramatically reduced CAβ-catenin-promoted activities. In addition to CCL5, 6-BIO, a chemical activator of β-catenin, induced cell invasion and spheroid formation in MDA-MB-231 cells. Furthermore, high levels of nuclear β-catenin accumulation were detected in breast cancer in patients with metastasis but not in those without metastasis. Nuclear β-catenin localization is related to increased CCL5 production in breast cancer. These findings suggest that β-catenin expression enhances tumor progression via chemokine production in breast cancers and that β-catenin signaling is a critical regulator of the aggressive traits of breast cancers. PMID:26363360

  4. The chemokine system in diverse forms of macrophage activation and polarization.

    PubMed

    Mantovani, Alberto; Sica, Antonio; Sozzani, Silvano; Allavena, Paola; Vecchi, Annunciata; Locati, Massimo

    2004-12-01

    Plasticity and functional polarization are hallmarks of the mononuclear phagocyte system. Here we review emerging key properties of different forms of macrophage activation and polarization (M1, M2a, M2b, M2c), which represent extremes of a continuum. In particular, recent evidence suggests that differential modulation of the chemokine system integrates polarized macrophages in pathways of resistance to, or promotion of, microbial pathogens and tumors, or immunoregulation, tissue repair and remodeling. PMID:15530839

  5. CC chemokine receptor 10 cell surface presentation in melanocytes is regulated by the novel interaction partner S100A10

    PubMed Central

    Hessner, F.; Dlugos, C. P.; Chehab, T.; Schaefer, C.; Homey, B.; Gerke, V.; Weide, T.; Pavenstädt, H.; Rescher, U.

    2016-01-01

    The superfamily of G-protein-coupled receptors (GPCR) conveys signals in response to various endogenous and exogenous stimuli. Consequently, GPCRs are the most important drug targets. CCR10, the receptor for the chemokines CCL27/CTACK and CCL28/MEC, belongs to the chemokine receptor subfamily of GPCRs and is thought to function in immune responses and tumour progression. However, there is only limited information on the intracellular regulation of CCR10. We find that S100A10, a member of the S100 family of Ca2+ binding proteins, binds directly to the C-terminal cytoplasmic tail of CCR10 and that this interaction regulates the CCR10 cell surface presentation. This identifies S100A10 as a novel interaction partner and regulator of CCR10 that might serve as a target for therapeutic intervention. PMID:26941067

  6. Effects of CXC chemokines on neutrophil activation and sequestration in hepatic vasculature.

    PubMed

    Bajt, M L; Farhood, A; Jaeschke, H

    2001-11-01

    The initiating step of neutrophil-induced cytotoxicity in the liver is the recruitment of these phagocytes into sinusoids. The aim of our study was to compare the efficacy of systemic exposure with individual inflammatory mediators on neutrophil activation and sequestration in the hepatic vasculature of C3Heb/FeJ mice as assessed by flow cytometry and histochemistry, respectively. The CXC chemokine macrophage inflammatory protein-2 (MIP-2; 20 microg/kg) induced a time-dependent upregulation of Mac-1 (318% at 4 h) and shedding of L-selectin (41% at 4 h). MIP-2 treatment caused a temporary increase of sinusoidal neutrophil accumulation at 0.5 h [97 +/- 6 polymorphonuclear leukocytes (PMN)/50 high-power fields (HPF)], which declined to baseline (8 +/- 2) at 4 h. The CXC chemokine KC was largely ineffective in activating neutrophils or recruiting them into the liver. Cytokines (tumor necrosis factor-alpha and interleukin-1alpha) and cobra venom factor substantially increased Mac-1 expression and L-selectin shedding on neutrophils and caused stable sinusoidal neutrophil accumulation (170-220 PMN/50 HPF). Only cytokines induced venular neutrophil margination. Thus CXC chemokines in circulation are less effective than cytokines or complement in activation of neutrophils and their recruitment into the hepatic vasculature in vivo. PMID:11668027

  7. Protein Kinase C-δ (PKCδ) Regulates Proinflammatory Chemokine Expression through Cytosolic Interaction with the NF-κB Subunit p65 in Vascular Smooth Muscle Cells*

    PubMed Central

    Ren, Jun; Wang, Qiwei; Morgan, Stephanie; Si, Yi; Ravichander, Aarthi; Dou, Changlin; Kent, K. Craig; Liu, Bo

    2014-01-01

    Proinflammatory chemokines released by vascular smooth muscle cells (VSMCs) play a critical role in vascular inflammation. Protein kinase C-δ (PKCδ) has been shown to be up-regulated in VSMCs of injured arteries. PKCδ knock-out (Prkcd−/−) mice are resistant to inflammation as well as apoptosis in models of abdominal aortic aneurysm. However, the precise mechanism by which PKCδ modulates inflammation remains incompletely understood. In this study, we identified four inflammatory chemokines (Ccl2/Mcp-1, Ccl7, Cxcl16, and Cx3cl1) of over 45 PKCδ-regulated genes associated with inflammatory response by microarray analysis. Using CCL2 as a prototype, we demonstrated that PKCδ stimulated chemokine expression at the transcriptional level. Inhibition of the NF-κB pathway or siRNA knockdown of subunit p65, but not p50, eliminated the effect of PKCδ on Ccl2 expression. Overexpressing PKCδ followed by incubation with phorbol 12-myristate 13-acetate resulted in an increase in p65 Ser-536 phosphorylation and enhanced DNA binding affinity without affecting IκB degradation or p65 nuclear translocation. Prkcd gene deficiency impaired p65 Ser-536 phosphorylation and DNA binding affinity in response to TNFα. Results from in situ proximity ligation analysis and co-immunoprecipitation performed on cultured VSMCs and aneurysmal aorta demonstrated physical interaction between PKCδ and p65 that took place largely outside the nucleus. Promoting nuclear translocation of PKCδ with peptide ψδRACK diminished Ccl2 production, whereas inhibition of PKCδ translocation with peptide δV1-1 enhanced Ccl2 expression. Together, these results suggest that PKCδ modulates inflammation at least in part through the NF-κB-mediated chemokines. Mechanistically, PKCδ activates NF-κB through an IκB-independent cytosolic interaction, which subsequently leads to enhanced p65 phosphorylation and DNA binding affinity. PMID:24519937

  8. Anti-chemokine activities of ixodid ticks depend on tick species, developmental stage, and duration of feeding.

    PubMed

    Vancová, Iveta; Hajnická, Valeria; Slovák, Mirko; Nuttall, Patricia A

    2010-02-10

    Ixodid ticks require comparatively large bloodmeals for their development and survival. Blood-feeding elicits signaling events in the host leading to wound healing responses (hemostasis, inflammation, and tissue repair) and immunity. Bioactive molecules present in tick saliva sabotage these host responses at several levels. One of them is neutralization of cellular communication by binding of specific saliva molecules to cytokines that have important roles in innate and adaptive immunity. Chemokines are a subset of cytokines having chemotactic activities. We show anti-chemokine activities in salivary gland extracts (SGE) of adult Rhipicephalus appendiculatus ticks against human chemokines CXCL8, CCL2, CCL3, CCL5, and CCL11. At comparable protein concentrations, male Ixodes ricinus SGE showed activity against all the chemokines; SGE of female I. ricinus had comparatively lower levels of activity against all the chemokines but no detectable activity against CCL5 and CCL11. However, when the equivalent of a single pair of salivary glands was tested, male I. ricinus showed little or no activity against CCL3 and CCL5. No fundamental differences in activity were observed against mouse compared with human chemokines. A comparison with previously published data for Dermacentor reticulatus and Amblyomma variegatum indicates that the level of anti-cytokine activity depends on the species, developmental stage (adult or nymph), and amount of SGE used, as well as on the number of days the tick has been feeding. PMID:19836889

  9. Bone marrow mesenchymal stem cells express a restricted set of functionally active chemokine receptors capable of promoting migration to pancreatic islets.

    PubMed

    Sordi, Valeria; Malosio, Maria Luisa; Marchesi, Federica; Mercalli, Alessia; Melzi, Raffaella; Giordano, Tiziana; Belmonte, Nathalie; Ferrari, Giuliana; Leone, Biagio Eugenio; Bertuzzi, Federico; Zerbini, Gianpaolo; Allavena, Paola; Bonifacio, Ezio; Piemonti, Lorenzo

    2005-07-15

    Bone marrow-derived mesenchymal stem cells (BM-MSCs) are stromal cells with the ability to proliferate and differentiate into many tissues. Although they represent powerful tools for several therapeutic settings, mechanisms regulating their migration to peripheral tissues are still unknown. Here, we report chemokine receptor expression on human BM-MSCs and their role in mediating migration to tissues. A minority of BM-MSCs (2% to 25%) expressed a restricted set of chemokine receptors (CXC receptor 4 [CXCR4], CX3C receptor 1 [CX3CR1], CXCR6, CC chemokine receptor 1 [CCR1], CCR7) and, accordingly, showed appreciable chemotactic migration in response to the chemokines CXC ligand 12 (CXCL12), CX3CL1, CXCL16, CC chemokine ligand 3 (CCL3), and CCL19. Using human pancreatic islets as an in vitro model of peripheral tissue, we showed that islet supernatants released factors able to attract BM-MSCs in vitro, and this attraction was principally mediated by CX3CL1 and CXCL12. Moreover, cells with features of BM-MSCs were detected within the pancreatic islets of mice injected with green fluorescent protein (GFP)-positive BM. A population of bona fide MSCs that also expressed CXCR4, CXCR6, CCR1, and CCR7 could be isolated from normal adult human pancreas. This study defines the chemokine receptor repertoire of human BM-MSCs that determines their migratory activity. Modulation of homing capacity may be instrumental for harnessing the therapeutic potential of BM-MSCs. PMID:15784733

  10. Chemokines and chemokine receptors blockers as new drugs for the treatment of chronic obstructive pulmonary disease.

    PubMed

    Caramori, G; Di Stefano, A; Casolari, P; Kirkham, P A; Padovani, A; Chung, K F; Papi, A; Adcock, I M

    2013-01-01

    Chronic obstructive pulmonary disease (COPD) is characterised by an abnormal inflammatory response of the lung to noxious particles or gases. The cellular inflammatory response in COPD is characterised by an increased number of inflammatory cells in the lungs. Although the molecular and cellular mechanisms responsible for the development of COPD are not well understood; several mediators are assumed to regulate the activation and recruitment of these inflammatory cells into the lung of COPD patients particularly those belonging to the chemokine family. Inhibitors or blockers of chemokine and chemokine receptors are therefore of great interest as potential novel therapies for COPD and many are now in clinical development. A high degree of redundancy exists in the chemokine network and inhibition of a single chemokine or receptor may not be sufficient to block the inflammatory response. Despite this, animal studies suggest a strong rationale for inhibiting the chemokine network in COPD. As such, every leading pharmaceutical company maintains a significant interest in developing agents that regulate leukocyte navigation as potential anti-inflammatory drugs. Drugs and antibodies targeting chemokines and their receptors are generally still in early stages of development and the results of clinical trial are awaited with great interest. These agents may not only provide improved management of COPD but also, importantly, indicate proof-of-concept to further clarify the role of chemokines in the pathophysiology of COPD. PMID:24059236

  11. Targeted Intestinal Epithelial Deletion of the Chemokine Receptor CXCR4 Reveals Key Roles for Extracellular-Regulated Kinase-1/2 in Restitution

    PubMed Central

    Zimmerman, Noah P.; Vongsa, Rebecca A.; Faherty, Sheena L.; Salzman, Nita H.; Dwinell, Michael B.

    2011-01-01

    Barrier defects and/or alterations in the ability of the gut epithelium to repair itself are critical etiologic mechanisms of gastrointestinal disease. Our ongoing studies indicate that the chemokine receptor CXCR4 and its cognate ligand CXCL12 regulate intestinal epithelial barrier maturation and restitution in cell culture models. Gene deficient mice lacking CXCR4 expression specifically by the cells of the intestinal epithelium were used to test the hypothesis that CXCR4 regulates mucosal barrier integrity in vivo. Epithelial expression of CXCR4 was assessed by RT-PCR, Southern blot, Western blot and immunohistochemistry. In vivo wounding assays were performed by addition of 3% Dextran Sodium Sulfate in drinking water for 5 days. Intestinal damage and DAI scores were assessed by histological examination. ERK phosphorylation was assessed in vivo by immunoblot and immunofluorescence. CXCR4 knockdown cells were established using a lentiviral approach and ERK phosphorylation was assessed. Consistent with targeted roles in restitution, epithelium from patients with inflammatory bowel disease indicated that CXCR4 and CXCL12 expression was stable throughout the human colonic epithelium. Conditional CXCR4-deficient mice developed normally, with little phenotypic differences in epithelial morphology, proliferation, or migration. Re-epithelialization was absent in CXCR4 conditional knockout mice following acute dextran-sodium sulfate-induced inflammation. In contrast, heterozygous CXCR4 depleted mice displayed significant improvement in epithelial ulcer healing in acute and chronic inflammation. Mucosal injury repair was correlated with extracellular-regulated kinase (ERK)-1/2 activity and localization along the crypt-villus axis, with heterozygous mice characterized by increased ERK1/2 activation. Lentiviral depletion of CXCR4 in IEC6 cells similarly altered ERK1/2 activity and prevented chemokine stimulated migration. Together these data indicate that chemokine

  12. TLR3 activation increases chemokine expression in human fetal airway smooth muscle cells.

    PubMed

    Faksh, Arij; Britt, Rodney D; Vogel, Elizabeth R; Thompson, Michael A; Pandya, Hitesh C; Martin, Richard J; Pabelick, Christina M; Prakash, Y S

    2016-01-15

    Viral infections, such as respiratory syncytial virus and rhinovirus, adversely affect neonatal and pediatric populations, resulting in significant lung morbidity, including acute asthma exacerbation. Studies in adults have demonstrated that human airway smooth muscle (ASM) cells modulate inflammation through their ability to secrete inflammatory cytokines and chemokines. The role of ASM in the developing airway during infection remains undefined. In our study, we used human fetal ASM cells as an in vitro model to examine the effect of Toll-like receptor (TLR) agonists on chemokine secretion. We found that fetal ASM express multiple TLRs, including TLR3 and TLR4, which are implicated in the pathogenesis of respiratory syncytial virus and rhinovirus infection. Cells were treated with TLR agonists, polyinosinic-polycytidylic acid [poly(I:C)] (TLR3 agonist), lipopolysaccharide (TLR4 agonist), or R848 (TLR7/8 agonist), and IL-8 and chemokine (C-C motif) ligand 5 (CCL5) secretion were evaluated. Interestingly, poly(I:C), but neither lipopolysaccharide nor R848, increased IL-8 and chemokine (C-C motif) ligand 5 secretion. Examination of signaling pathways suggested that the poly(I:C) effects in fetal ASM involve TLR and ERK signaling, in addition to another major inflammatory pathway, NF-κB. Moreover, there are variations between fetal and adult ASM with respect to poly(I:C) effects on signaling pathways. Pharmacological inhibition suggested that ERK pathways mediate poly(I:C) effects. Overall, our data show that poly(I:C) initiates activation of proinflammatory pathways in developing ASM, which may contribute to immune responses to infection and exacerbation of asthma. PMID:26589477

  13. CCR2 and CXCR3 agonistic chemokines are differently expressed and regulated in human alveolar epithelial cells type II

    PubMed Central

    Pechkovsky, Dmitri V; Goldmann, Torsten; Ludwig, Corinna; Prasse, Antje; Vollmer, Ekkehard; Müller-Quernheim, Joachim; Zissel, Gernot

    2005-01-01

    The attraction of leukocytes from circulation to inflamed lungs depends on the activation of both the leukocytes and the resident cells within the lung. In this study we determined gene expression and secretion patterns for monocyte chemoattractant protein-1 (MCP-1/CCL2) and T-cell specific CXCR3 agonistic chemokines (Mig/CXCL9, IP-10/CXCL10, and I-TAC/CXCL11) in TNF-α-, IFN-γ-, and IL-1β-stimulated human alveolar epithelial cells type II (AEC-II). AEC-II constitutively expressed high level of CCL2 mRNA in vitro and in situ , and released CCL2 protein in vitro . Treatment of AEC-II with proinflammatory cytokines up-regulated both CCL2 mRNA expression and release of immunoreactive CCL2, whereas IFN-γ had no effect on CCL2 release. In contrast, CXCR3 agonistic chemokines were not detected in freshly isolated AEC-II or in non-stimulated epithelial like cell line A549. IFN-γ, alone or in combination with IL-1β and TNF-α resulted in an increase in CXCL10, CXCL11, and CXCL9 mRNA expression and generation of CXCL10 protein by AEC-II or A549 cells. CXCL10 gene expression and secretion were induced in dose-dependent manner after cytokine-stimulation of AEC-II with an order of potency IFN-γ>>IL-1β ≥ TNF-α. Additionally, we localized the CCL2 and CXCL10 mRNAs in human lung tissue explants by in situ hybridization, and demonstrated the selective effects of cytokines and dexamethasone on CCL2 and CXCL10 expression. These data suggest that the regulation of the CCL2 and CXCL10 expression exhibit significant differences in their mechanisms, and also demonstrate that the alveolar epithelium contributes to the cytokine milieu of the lung, with the ability to respond to locally generated cytokines and to produce potent mediators of the local inflammatory response. PMID:16033640

  14. Chemokines in the cerebrospinal fluid of patients with active and stable relapsing-remitting multiple sclerosis.

    PubMed

    Moreira, M A; Souza, A L S; Lana-Peixoto, M A; Teixeira, M M; Teixeira, A L

    2006-04-01

    Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the human central nervous system. Although its etiology is unknown, the accumulation and activation of mononuclear cells in the central nervous system are crucial to its pathogenesis. Chemokines have been proposed to play a major role in the recruitment and activation of leukocytes in inflammatory sites. They are divided into subfamilies on the basis of the location of conserved cysteine residues. We determined the levels of some CC and CXC chemokines in the cerebrospinal fluid (CSF) of 23 relapsing-remitting MS patients under interferon-ss-1a therapy and 16 control subjects using ELISA. MS patients were categorized as having active or stable disease. CXCL10 was significantly increased in the CSF of active MS patients (mean +/- SEM, 369.5 +/- 69.3 pg/mL) when compared with controls (178.5 +/- 29.1 pg/mL, P < 0.05). CSF levels of CCL2 were significantly lower in active MS (144.7 +/- 14.4 pg/mL) than in controls (237.1 +/- 16.4 pg/mL, P < 0.01). There was no difference in the concentration of CCL2 and CXCL10 between patients with stable MS and controls. CCL5 was not detectable in the CSF of most patients or controls. The qualitative and quantitative differences of chemokines in CSF during relapses of MS suggest that they may be useful as a marker of disease activity and of the mechanisms involved in the pathogenesis of the disease. PMID:16612466

  15. Role of chemokine RANTES in the regulation of perivascular inflammation, T-cell accumulation, and vascular dysfunction in hypertension

    PubMed Central

    Mikolajczyk, Tomasz P.; Nosalski, Ryszard; Szczepaniak, Piotr; Budzyn, Klaudia; Osmenda, Grzegorz; Skiba, Dominik; Sagan, Agnieszka; Wu, Jing; Vinh, Antony; Marvar, Paul J.; Guzik, Bartlomiej; Podolec, Jakub; Drummond, Grant; Lob, Heinrich E.; Harrison, David G.; Guzik, Tomasz J.

    2016-01-01

    Recent studies have emphasized the role of perivascular inflammation in cardiovascular disease. We studied mechanisms of perivascular leukocyte infiltration in angiotensin II (Ang II)-induced hypertension and their links to vascular dysfunction. Chronic Ang II infusion in mice increased immune cell content of T cells (255 ± 130 to 1664 ± 349 cells/mg; P < 0.01), M1 and M2 macrophages, and dendritic cells in perivascular adipose tissue. In particular, the content of T lymphocytes bearing CC chemokine receptor (CCR) 1, CCR3, and CCR5 receptors for RANTES chemokine was increased by Ang II (CCR1, 15.6 ± 1.5% vs. 31 ± 5%; P < 0.01). Hypertension was associated with an increase in perivascular adipose tissue expression of the chemokine RANTES (relative quantification, 1.2 ± 0.2 vs. 3.5 ± 1.1; P < 0.05), which induced T-cell chemotaxis and vascular accumulation of T cells expressing the chemokine receptors CCR1, CCR3, and CCR5. Mechanistically, RANTES−/− knockout protected against vascular leukocyte, and in particular T lymphocyte infiltration (26 ± 5% in wild type Ang II vs. 15 ± 4% in RANTES−/−), which was associated with protection from endothelial dysfunction induced by Ang II. This effect was linked with diminished infiltration of IFN-γ-producing CD8+ and double-negative CD3+CD4−CD8− T cells in perivascular space and reduced vascular oxidative stress while FoxP3+ T-regulatory cells were unaltered. IFN-γ ex vivo caused significant endothelial dysfunction, which was reduced by superoxide anion scavenging. In a human cohort, a significant inverse correlation was observed between circulating RANTES levels as a biomarker and vascular function measured as flow-mediated dilatation (R = −0.3, P < 0.01) or endothelial injury marker von Willebrand factor (R = +0.3; P < 0.01). Thus, chemokine RANTES is important in the regulation of vascular dysfunction through modulation of perivascular inflammation.—Mikolajczyk, T. P., Nosalski, R., Szczepaniak, P

  16. Berberine suppresses migration of MCF-7 breast cancer cells through down-regulation of chemokine receptors

    PubMed Central

    Ahmadiankia, Naghmeh; Moghaddam, Hamid Kalalian; Mishan, Mohammad Amir; Bahrami, Ahmad Reza; Naderi-Meshkin, Hojjat; Bidkhori, Hamid Reza; Moghaddam, Maryam; Mirfeyzi, Seyed Jamal Aldin

    2016-01-01

    Objective(s): Berberine is one of the main alkaloids and it has been proven to have different pharmacological effects including inhibition of cell cycle and progression of apoptosis in various cancerous cells; however, its effects on cancer metastasis are not well known. Cancer cells obtain the ability to change their chemokine system and convert into metastatic cells. In this study, we examined the effect of berberine on breast cancer cell migration and its probable interaction with the chemokine system in cancer cells. Materials and Methods: The MCF-7 breast cancer cell line was cultured, and then, treated with berberine (10, 20, 40 and 80 μg/ml) for 24 hr. MTT assay was used in order to determine the cytotoxic effect of berberine on MCF-7 breast cancer cells. Wound healing assay was applied to determine the inhibitory effect of berberine on cell migration. Moreover, real-time quantitative PCR analysis of selected chemokine receptors was performed to determine the probable molecular mechanism underlying the effect of berberine on breast cancer cell migration. Results: The results of wound healing assay revealed that berberine decreases cell migration. Moreover, we found that the mRNA levels of some chemokine receptors were reduced after berberine treatment, and this may be the underlying mechanism for decreased cell migration. Conclusion: Our results indicate that berberine might be a potential preventive biofactor for human breast cancer metastasis by targeting chemokine receptor genes. PMID:27081456

  17. BMP9 Crosstalk with the Hippo Pathway Regulates Endothelial Cell Matricellular and Chemokine Responses

    PubMed Central

    Young, Kira; Tweedie, Eric; Conley, Barbara; Ames, Jacquelyn; FitzSimons, MaryLynn; Brooks, Peter; Liaw, Lucy; Vary, Calvin P. H.

    2015-01-01

    Endoglin is a type III TGFβ auxiliary receptor that is upregulated in endothelial cells during angiogenesis and, when mutated in humans, results in the vascular disease hereditary hemorrhagic telangiectasia (HHT). Though endoglin has been implicated in cell adhesion, the underlying molecular mechanisms are still poorly understood. Here we show endoglin expression in endothelial cells regulates subcellular localization of zyxin in focal adhesions in response to BMP9. RNA knockdown of endoglin resulted in mislocalization of zyxin and altered formation of focal adhesions. The mechanotransduction role of focal adhesions and their ability to transmit regulatory signals through binding of the extracellular matrix are altered by endoglin deficiency. BMP/TGFβ transcription factors, SMADs, and zyxin have recently been implicated in a newly emerging signaling cascade, the Hippo pathway. The Hippo transcription coactivator, YAP1 (yes-associated protein 1), has been suggested to play a crucial role in mechanotransduction and cell-cell contact. Identification of BMP9-dependent nuclear localization of YAP1 in response to endoglin expression suggests a mechanism of crosstalk between the two pathways. Suppression of endoglin and YAP1 alters BMP9-dependent expression of YAP1 target genes CCN1 (cysteine-rich 61, CYR61) and CCN2 (connective tissue growth factor, CTGF) as well as the chemokine CCL2 (monocyte chemotactic protein 1, MCP-1). These results suggest a coordinate effect of endoglin deficiency on cell matrix remodeling and local inflammatory responses. Identification of a direct link between the Hippo pathway and endoglin may reveal novel mechanisms in the etiology of HHT. PMID:25909848

  18. Chemokine Receptor Type 4 Regulates Migration and Invasion of Trophectoderm Cell in the Human Blastocyst.

    PubMed

    Bao, Siyu; Li, Tianjie; Long, Xiaoyu; Zhang, Jinjuan; Zhao, Hongcui; Ren, Yun; Zhao, Yue; Li, Rong; Tan, Tao; Yu, Yang; Qiao, Jie

    2016-07-01

    Chemokine receptor type 4 (CXCR4) has been suggested to regulate cell migration and invasion in human somatic cells. However, its role in human oocytes and embryos has not been investigated directly. Here we show that CXCR4 mRNA was initially expressed at the 4-cell stage, and its expression gradually increased until the blastocyst stage, whereas its protein was detectable only after the 8-cell stage. In addition, CXCR4 mRNA and protein were expressed in the inner cell mass (ICM) and trophectoderm (TE) cell of the blastocyst. Furthermore, we collected embryos from women whose embryos had undergone successful implantation (SI) and those whose embryos had failed implantation (FI) in their fresh cycles. TE cells from the FI group had reduced CXCR4 mRNA expression relative to those from the SI group but not in the ICM. Through ICM replacement, we constructed mouse blastocysts in which Cxcr4 was specifically knocked down in TE cells to simulate the CXCR4 expression profile of human blastocysts from the FI group. In this case, we found that the implantation rate significantly decreased after transfer of reconstructed embryos. Bioinformatic analysis indicated that CXCR4 can induce cell apoptosis and migration mediated by Rho signaling. This hypothesis was confirmed by invasion and migration experiments, using a human trophoblast cell line. The present study is the first to explore the characteristics of CXCR4 expression using human oocytes and embryos and suggests that CXCR4 is required upstream of TE cell apoptosis and migration. CXCR4 expression is a potential biomarker to predict implantation competence during assisted reproductive technologies. PMID:27146031

  19. Chemokines and angiogenesis in rheumatoid arthritis

    PubMed Central

    Szekanecz, Zoltan; Pakozdi, Angela; Szentpetery, Agnes; Besenyei, Timea; Koch, Alisa E.

    2010-01-01

    In rheumatoid arthritis, chemokines mediate the migration of inflammatory leukocytes into the synovium. Among the four known chemokine families, CXC, CC chemokines and fractalkine seem to be of outstanding importance in this process. Angiogenesis, the formation of new vessels, is also important during the perpetuation of inflammation underlying rheumatoid arthritis. In this review, authors discuss the role of the most important chemokines and chemokine repetors in arthritis-associated neovascularization. The process and regulation of angiogenesis are described in this context as well. Apart from discussing the pathogenic role of chemokines and chemokine receptors in arthritic vessel formation, authors also review the important relevance of chemokines and angiogenesis for therapeutic intervention. PMID:19482623

  20. Chemokine signaling in cancer: Implications on the tumor microenvironment and therapeutic targeting

    PubMed Central

    Hembruff, Stacey L.; Cheng, Nikki

    2010-01-01

    Summary Chemokines are soluble factors shown to play important roles in regulating immune cell recruitment during inflammatory responses and defense against foreign pathogens. De-regulated expression and activity of several chemokine signaling pathways have been implicated in cancer progression, including: CCL2, CCL5, CXCL1 and CXCL12. While studies in the past have focused the role of these chemokine signaling pathways in regulating immune responses, emerging studies show that these molecules regulate diverse cellular processes including angiogenesis, and regulation of epithelial cell growth and survival. New evidence indicates that chemokines are critical for cancer progression and indicate complex and diverse functions in the tumor microenvironment. This review will focus on the contributions of chemokine signaling in regulating cancer microvironment and discuss the utility of targeting or delivering chemokines in cancer therapeutics. PMID:20651940

  1. Chemokine receptor CCR6 expression is regulated by miR-518a-5p in colorectal cancer cells

    PubMed Central

    2014-01-01

    Background Recently, involvement of the chemokine/receptor system CCL20/CCR6 in colorectal cancer (CRC) progression was shown. Here, we analyzed the functional interaction of miRNA-518-5p (miR-518a-5p) with CCR6 and its impact on CCR6 expression in CRC cells. Methods MiR-518a-5p was identified by computer software to potentially interact with CCR6. Hence, functional implications of miR-518a-5p with the 3′UTR of CCR6 were analyzed using the Dual Luciferase Reporter assay system. Confirmation of the predicted target site for miR-518a-5p was achieved by site-directed mutagenesis of the seed sequence in the 3′UTR of CCR6 and subsequent application of the mutated seed sequence in a luciferase assay with miR-518a-5p mimics. Accordingly, two CRC cell lines (Caco-2 and HT-29) were transfected with miR-518a-5p miRNA mimics and gene and protein expression of CCR6 was monitored using qRT PCR and immunocytochemistry, respectively. Results Addition of miR-518a-5p led to significant down-regulation of luciferase activity (P < 0.05), which was significantly reversed in a reporter test system containing the mutated seed sequences in the 3′UTR of CCR6. Following transfection of CRC cell lines with miR-518a-5p mimics and subsequent monitoring of CCR6 expression showed significant down-regulation of CCR6 mRNA and CCR6 protein expression in both CRC cell lines under investigation (P < 0.05). Conclusions We have shown that miR-518a-5p functionally interacts with CCR6 and that transfection of CRC cells with miR-518a-5p leads to significant CCR6 down-regulation. Consequently, CCR6 expression is regulated by miR-518a-5p in CRC cells indicating that regulation of CCR6 expression by miR-518a-5p might be a regulatory mechanism involved in CRC pathogenesis. PMID:24559209

  2. Apigenin suppresses migration and invasion of transformed cells through down-regulation of C-X-C chemokine receptor 4 expression

    SciTech Connect

    Wang, Lei; Kuang, Lisha; Hitron, John Andrew; Son, Young-Ok; Wang, Xin; Budhraja, Amit; Lee, Jeong-Chae; Pratheeshkumar, Poyil; Chen, Gang; Zhang, Zhuo; Luo, Jia; Shi, Xianglin

    2013-10-01

    Environmental exposure to arsenic is known to cause various cancers. There are some potential relationships between cell malignant transformation and C-X-C chemokine receptor type 4 (CXCR4) expressions. Metastasis, one of the major characteristics of malignantly transformed cells, contributes to the high mortality of cells. CXCR4 and its natural chemokine ligand C-X-C motif ligand 12 (CXCL12) play a critical role in metastasis. Therefore, identification of nutritional factors which are able to inhibit CXCR4 is important for protection from environmental arsenic-induced carcinogenesis and for abolishing metastasis of malignantly transformed cells. The present study demonstrates that apigenin (4′,5,7-trihydroxyflavone), a natural dietary flavonoid, suppressed CXCR4 expression in arsenic-transformed Beas-2B cells (B-AsT) and several other types of transformed/cancer cells in a dose- and time-dependent manner. Neither proteasome nor lysosome inhibitor had any effect in reducing the apigenin-induced down-regulation of CXCR4, indicating that apigenin-induced down-regulation of CXCR4 is not due to proteolytic degradation. The down-regulation of CXCR4 is mainly due to the inhibition of nuclear factor κB (NF-κB) transcriptional activity. Apigenin also abolished migration and invasion of transformed cells induced by CXCL12. In a xenograft mouse model, apigenin down-regulated CXCR4 expression and suppressed tumor growth. Taken together, our results show that apigenin is a novel inhibitor of CXCR4 expression. This dietary flavonoid has the potential to suppress migration and invasion of transformed cells and prevent environmental arsenic-induced carcinogenesis. - Highlights: • Apigenin has a potential in preventing environmental arsenic induced carcinogenesis. • Apigenin suppresses CXCR4 in malignant transformed cells in vitro and in vivo. • The down-regulation of CXCR4 is mainly due to inhibition of NF-κB activity.

  3. Human p38{delta} MAP kinase mediates UV irradiation induced up-regulation of the gene expression of chemokine BRAK/CXCL14

    SciTech Connect

    Ozawa, Shigeyuki; Ito, Shin; Kato, Yasumasa; Kubota, Eiro; Hata, Ryu-Ichiro

    2010-06-11

    The mitogen-activated protein kinase (MAPK) family comprises ERK, JNK, p38 and ERK5 (big-MAPK, BMK1). UV irradiation of squamous cell carcinoma cells induced up-regulation of gene expression of chemokine BRAK/CXCL14, stimulated p38 phosphorylation, and down-regulated the phosphorylation of ERK. Human p38 MAPKs exist in 4 isoforms: p38{alpha}, {beta}, {gamma} and {delta}. The UV stimulation of p38 phosphorylation was not inhibited by the presence of SB203580 or PD169316, inhibitors of p38{alpha} and {beta}, suggesting p38 phosphorylation was not dependent on these 2 isoforms and that p38{gamma} and/or {delta} was responsible for the phosphorylation. In fact, inhibition of each of these 4 p38 isoforms by the introduction of short hairpin (sh) RNAs for respective isoforms revealed that only shRNA for p38{delta} attenuated the UV-induced up-regulation of BRAK/CXCL14 gene expression. In addition, over-expression of p38 isoforms in the cells showed the association of p38{delta} with ERK1 and 2, concomitant with down-regulation of ERK phosphorylation. The usage of p38{delta} isoform by UV irradiation is not merely due to the abundance of this p38 isoform in the cells. Because serum deprivation of the cells also induced an increase in BRAK/CXCL14 gene expression, and in this case p38{alpha} and/or {beta} isoform is responsible for up-regulation of BRAK/CXCL14 gene expression. Taken together, the data indicate that the respective stress-dependent action of p38 isoforms is responsible for the up-regulation of the gene expression of the chemokine BRAK/CXCL14.

  4. Chemokines and tissue injury.

    PubMed Central

    Furie, M. B.; Randolph, G. J.

    1995-01-01

    Accumulation of leukocytes at sites of inflammation is essential for host defense, yet secretory products of the white cells may augment injury by damaging surrounding healthy tissues. Members of the chemokine family of chemotactic cytokines play a fundamental role in this process by attracting and stimulating specific subsets of leukocytes. In vitro studies suggest that chemokines participate in at least three phases of leukocyte recruitment. First, they foster tight adhesion of circulating leukocytes to the vascular endothelium by activating leukocytic integrins. Second, because of their chemoattractant properties, chemokines guide leukocytes through the endothelial junctions and underlying tissue to the inflammatory focus. Finally, chemokines activate effector functions of leukocytes, including production of reactive oxygen intermediates and exocytosis of degradative enzymes. Animal studies in which antibodies are used to neutralize the activity of individual members of the chemokine family confirm that these mediators contribute to the development of both acute and chronic inflammatory conditions. A number of mechanisms may operate in vivo to limit the proinflammatory properties of chemokines. Therapies that target chemokines directly or enhance the body's mechanisms for controlling their activity may prove to be reasonable approaches for treatment of inflammatory diseases. PMID:7778669

  5. Phosphatase regulation of macrophage activation.

    PubMed

    Kozicky, Lisa K; Sly, Laura M

    2015-08-01

    Macrophages are innate immune cells that play critical roles in tissue homeostasis and the immune response to invading pathogens or tumor cells. A hallmark of macrophages is their "plasticity," that is, their ability to respond to cues in their local microenvironment and adapt their activation state or phenotype to mount an appropriate response. During the inflammatory response, macrophages may be required to mount a profound anti-bacterial or anti-tumor response, an anti-inflammatory response, an anti-parasitic response, or a wound healing response. To do so, macrophages express cell surface receptors for growth factors, chemokines and cytokines, as well pathogen and danger associated molecular patterns. Downstream of these cell surface receptors, cell signalling cascades are activated and deactivated by reversible and competing activities of lipid and protein kinases and phosphatases. While kinases drive the activation of cell signalling pathways critical for macrophage activation, the strength and duration of the signalling is regulated by phosphatases. Hence, gene knockout mouse models have revealed critical roles for lipid and protein phosphatases in macrophage activation. Herein, we describe our current understanding and the key roles of specific cellular phosphatases in the regulation of the quality of macrophage polarization as well as the quantity of cytokines produced by activated macrophages. PMID:26216598

  6. Up-regulation of CC chemokine ligand 20 and its receptor CCR6 in the lesional skin of early systemic sclerosis.

    PubMed

    Tao, Juan; Li, Lin; Tan, Zhijian; Li, Yan; Yang, Jing; Tian, Fen; Wang, Li; Ren, Yali; Xu, Guangfen; He, Xiaoliang; Shen, Guanxin; Tu, Yating

    2011-01-01

    Mononuclear cell (MNC) infiltrate is one of the earliest pathological changes in systemic sclerosis (SSc) skin. However, little is known about the recruitment of these cells into skin lesions. Recently, the role of chemokines has been suggested in the pathogenesis of SSc. Here we studied the expressions and distributions of CC chemokine CCL20 and its receptor CCR6 in early SSc skin lesions and the difference in CCL20 expressions and ability to recruite MNCs of normal dermal fibroblast (NDF) and scleroderma dermal fibroblast (SSDF). We found that the expressions of CCL20 and its receptor CCR6 were obviously up-regulated in SSc in contrast to normal human skin. mRNA levels were significantly expressed in SSc lesional skins vs normal skin tissues. SSDF displayed increased constitutive expressions of CCL20 mRNA and protein. In addition, Th1 cytokines (TNF-α and IL-1β) remarkably increased the expression of CCL20 in both NDF and SSDF in a dose- and time-dependent manner. Supernatants from SSDF showed stronger chemotactic activity to PBMCs than those from NDF. Thus our findings suggest that CCL20 released from cytokine-activated SSDF plays an important role in the induction of SSc by further recruiting more MNCs to the skin. PMID:21742595

  7. Regulation of the migration and survival of monocyte subsets by chemokine receptors and its relevance to atherosclerosis

    PubMed Central

    Gautier, Emmanuel L.; Jakubzick, Claudia; Randolph, Gwendalyn J.

    2009-01-01

    Monocytes are central mediators in the advance of atherosclerotic plaque, making them a natural therapeutic target for reducing disease burden. Here, we highlight recent advances in our current understanding of monocyte heterogeneity and its relevance to regulation of monocyte accumulation and function within atherosclerotic plaques. Differences that distinguish monocyte subsets include differential expression of chemokine receptors, especially CCR2 and CX3CR1. Ablation of expression of these two receptors (or their ligands) in mice has an additive inhibition on monocyte recruitment to atherosclerotic plaques. Moreover, simultaneously interfering with three key pathways—CCR2, CX3CR1, and CCR5--essentially abolishes atherosclerosis in mice. Here, we discuss how these chemokine receptors act at multiple points on at least one monocyte subset, regulating their mobilization from bone marrow, survival, and/or recruitment to plaques. Finally, we discuss how this knowledge may be useful clinically, emphasizing that CX3CR1 may in particular be a viable target for therapeutic manipulation of monocyte-derived cell fate in cardiovascular disease. PMID:19759373

  8. Chemokines, chemokine receptors and the gastrointestinal system

    PubMed Central

    Miyazaki, Hiroshi; Takabe, Kazuaki; Yeudall, W Andrew

    2013-01-01

    The biological properties of tumor cells are known to be regulated by a multitude of cytokines and growth factors, which include epidermal growth factor receptor agonists and members of the transforming growth factor β family. Furthermore, the recent explosion of research in the field of chemokine function as mediators of tumor progression has led to the possibility that these small, immunomodulatory proteins also play key roles in carcinogenesis and may, therefore, be potential targets for novel therapeutic approaches. In this review, we will summarize recently reported findings in chemokine biology with a focus on the gastrointestinal tract. PMID:23704819

  9. Molecular characterisation and biological activity of a novel CXC chemokine gene in rock bream (Oplegnathus fasciatus).

    PubMed

    Kim, Ju-Won; Kim, Eun-Gyeong; Kim, Do-Hyung; Shim, Sang Hee; Park, Chan-Il

    2013-05-01

    Chemokines are chemoattractant cytokines defined by the presence of four conserved cysteine residues. In mammals, these cytokines can be divided into four subfamilies depending on the arrangement of the first two conserved cysteines in the sequence, and include the CXC(α), CC(β), C(γ), and CX3C(δ) classes. We identified CXC chemokine cDNA, designated RbCXC, isolated using expressed sequence tag analysis of a lipopolysaccharide (LPS)-stimulated rock bream liver cDNA library. The full-length RbCXC cDNA (742 bp) contained an open reading frame of 342 bp encoding 114 amino acids. Results from phylogenetic analysis showed that RbCXC was strictly separated into a distinct clade compared to other known CXC chemokine subgroups. RbCXC was significantly expressed in the trunk kidney, liver, spleen, gill, peripheral blood leukocytes (PBLs), and head kidney. Rock bream PBLs were stimulated with several mitogens, including LPS and polyinosinic-polycytidylic acid (poly I:C), which significantly induced the expression of RbCXC mRNA. RbCXC mRNA expression was examined in several tissues under conditions of bacterial and viral challenge. Experimental challenges revealed that all examined tissues from fish infected with Edwardsiella tarda and red sea bream iridovirus showed significant increases in RbCXC expression compared to the control. In the case of Streptococcus iniae infection, RbCXC mRNA expression was markedly upregulated in the kidney, spleen, and liver. In addition, a maltose binding protein fusion recombinant RbCXC (~53 kDa) was produced in an Escherichia coli expression system and purified. Subsequently, the addition of purified recombinant RbCXC (rRbCXC) to kidney leukocytes was examined to investigate the impact of proliferative and chemotactic activity. The rRbCXC induced significant kidney leukocyte proliferation and attraction at concentrations ranging from 10 to 300 μg/mL, suggesting that it can be utilised as an immune stimulant and/or molecular adjuvant to

  10. Post-translational control of chemokines: a role for decoy receptors?

    PubMed

    Comerford, Iain; Nibbs, Robert J B

    2005-01-31

    It is well-established that chemokines play a critical role in the orchestration of inflammation and immunity. Interactions between chemokines and their receptors are essential for the homing of specific subsets of leukocytes to their functional microenvironments. They also influence other diverse biological processes such as development, leukocyte activation, Th1/Th2 polarisation, tumour metastasis, angiogenesis, and HIV pathogenesis. However, despite their importance, only now are we beginning to understand the complex regulation brought to bear on these molecules. In this review, we discuss a number of these key chemokine regulators that exert their influence once these proteins have been synthesised. We examine (i) chemokine storage, release, and presentation, (ii) protease regulation, (iii) viral manipulation of host chemokines, and (iv) natural mammalian receptor antagonists. Principally, the growing evidence for a role for decoy receptors in the chemokine system is discussed. In particular, the potential decoy function of the 'silent' pro-inflammatory chemokine receptor D6 is described alongside two other candidate decoy receptor molecules, DARC, and CCX-CKR. Dissecting the biological and pathological function of these chemokine controllers will lead to a deeper understanding of chemokine regulation, and may reveal novel strategies to therapeutically modify the chemokine system. PMID:15585320

  11. Chemokine Signaling Specificity: Essential Role for the N-Terminal Domain of Chemokine Receptors†

    PubMed Central

    N. Prado, Gregory; Suetomi, Katsutoshi; Shumate, David; Maxwell, Carrie; Ravindran, Aishwarya; Rajarathnam, Krishna; Navarro, Javier

    2009-01-01

    Chemokine IL-8 (CXCL8) binds to its cognate receptors CXCR1 and CXCR2 to induce inflammatory responses, wound healing, tumorogenesis, and neuronal survival. Here we identify the N-loop residues in IL-8 (H18 and F21) and the receptor N-termini as the major structural determinants regulating the rate of receptor internalization, which in turn controlled the activation profile of ERK1/2, a central component of the receptor/ERK signaling pathway that dictates signal specificity. Our data further support the idea that the chemokine receptor core acts as a plastic scaffold. Thus, the diversity and intensity of inflammatory and noninflammatory responses mediated by chemokine receptors appear to be primarily determined by the initial interaction between the receptor N-terminus and the N-loop of chemokines. PMID:17630697

  12. RTN3 Regulates the Expression Level of Chemokine Receptor CXCR4 and is Required for Migration of Primordial Germ Cells

    PubMed Central

    Li, Haitao; Liang, Rong; Lu, Yanan; Wang, Mengxia; Li, Zandong

    2016-01-01

    CXCR4 is a crucial chemokine receptor that plays key roles in primordial germ cell (PGC) homing. To further characterize the CXCR4-mediated migration of PGCs, we screened CXCR4-interacting proteins using yeast two-hybrid screening. We identified reticulon3 (RTN3), a member of the reticulon family, and considered an apoptotic signal transducer, as able to interact directly with CXCR4. Furthermore, we discovered that the mRNA and protein expression levels of CXCR4 could be regulated by RTN3. We also found that RTN3 altered CXCR4 translocation and localization. Moreover, increasing the signaling of either CXCR4b or RTN3 produced similar PGC mislocalization phenotypes in zebrafish. These results suggested that RTN3 modulates PGC migration through interaction with, and regulation of, CXCR4. PMID:27070582

  13. Teleost Chemokines and Their Receptors

    PubMed Central

    Bird, Steve; Tafalla, Carolina

    2015-01-01

    Chemokines are a superfamily of cytokines that appeared about 650 million years ago, at the emergence of vertebrates, and are responsible for regulating cell migration under both inflammatory and physiological conditions. The first teleost chemokine gene was reported in rainbow trout in 1998. Since then, numerous chemokine genes have been identified in diverse fish species evidencing the great differences that exist among fish and mammalian chemokines, and within the different fish species, as a consequence of extensive intrachromosomal gene duplications and different infectious experiences. Subsequently, it has only been possible to establish clear homologies with mammalian chemokines in the case of some chemokines with well-conserved homeostatic roles, whereas the functionality of other chemokine genes will have to be independently addressed in each species. Despite this, functional studies have only been undertaken for a few of these chemokine genes. In this review, we describe the current state of knowledge of chemokine biology in teleost fish. We have mainly focused on those species for which more research efforts have been made in this subject, specifically zebrafish (Danio rerio), rainbow trout (Oncorhynchus mykiss) and catfish (Ictalurus punctatus), outlining which genes have been identified thus far, highlighting the most important aspects of their expression regulation and addressing any known aspects of their biological role in immunity. Finally, we summarise what is known about the chemokine receptors in teleosts and provide some analysis using recently available data to help characterise them more clearly. PMID:26569324

  14. Macrophages migrate in an activation-dependent manner to chemokines involved in neuroinflammation

    PubMed Central

    2014-01-01

    Background In neuroinflammatory diseases, macrophages can play a dual role in the process of tissue damage, depending on their activation status (M1 / M2). M1 macrophages are considered to exert damaging effects to neurons, whereas M2 macrophages are reported to aid regeneration and repair of neurons. Their migration within the central nervous system may be of critical importance in the final outcome of neurodegeneration in neuroinflammatory diseases e.g. multiple sclerosis (MS). To provide insight into this process, we examined the migratory capacity of human monocyte-derived M1 and M2 polarised macrophages towards chemoattractants, relevant for neuroinflammatory diseases like MS. Methods Primary cultures of human monocyte-derived macrophages were exposed to interferon gamma and lipopolysaccharide (LPS) to evoke proinflammatory (M1) activation or IL-4 to evoke anti-inflammatory (M2) activation. In a TAXIScan assay, migration of M0, M1 and M2 towards chemoattractants was measured and quantified. Furthermore the adhesion capacity and the expression levels of integrins as well as chemokine receptors of M0, M1 and M2 were assessed. Alterations in cell morphology were analysed using fluorescent labelling of the cytoskeleton. Results Significant differences were observed between M1 and M2 macrophages in the migration towards chemoattractants. We show that M2 macrophages migrated over longer distances towards CCL2, CCL5, CXCL10, CXCL12 and C1q compared to non-activated (M0) and M1 macrophages. No differences were observed in the adhesion of M0, M1 and M2 macrophages to multiple matrix components, nor in the expression of integrins and chemokine receptors. Significant changes were observed in the cytoskeleton organization upon stimulation with CCL2, M0, M1 and M2 macrophages adopt a spherical morphology and the cytoskeleton is rapidly rearranged. M0 and M2 macrophages are able to form filopodia, whereas M1 macrophages only adapt a spherical morphology. Conclusions

  15. Chemokine decoy receptors: new players in reproductive immunology.

    PubMed

    Borroni, Elena Monica; Bonecchi, Raffaella; Buracchi, Chiara; Savino, Benedetta; Mantovani, Alberto; Locati, Massimo

    2008-01-01

    Chemokines are multifunctional molecules with roles in leukocyte trafficking and developmental processes. Both fetal and maternal components of the placenta produce chemokines, which control leukocyte trafficking observed in the placenta. Thus, chemokines play roles in the balance between protection of the developing embryo/fetus and tolerance of its hemiallogeneic tissues. Recently, a group of chemokine receptors, which include D6, DARC, and CCX-CKR, have been described as "silent" receptors by virtue of their inability to activate signal transduction events leading to cell chemoattraction. Here we review in vitro and in vivo evidence indicating that chemokine "silent" receptors regulate innate and adaptive immunity behaving as decoy receptors that support internalization and degradation of chemotactic factors, and discuss available information on their potential role in reproductive immunology. PMID:18716935

  16. The expression and role of CXC chemokines in colorectal cancer.

    PubMed

    Verbeke, Hannelien; Struyf, Sofie; Laureys, Geneviève; Van Damme, Jo

    2011-01-01

    Cancer is a life-threatening disease world-wide and colorectal cancer is the second common cause of cancer mortality. The interaction between tumor cells and stromal cells plays a crucial role in tumor initiation and progression and is partially mediated by chemokines. Chemokines predominantly participate in the chemoattraction of leukocytes to inflammatory sites. Nowadays, it is clear that CXC chemokines and their receptors (CXCR) may also modulate tumor behavior by several important mechanisms: regulation of angiogenesis, activation of a tumor-specific immune response by attracting leukocytes, stimulation of tumor cell proliferation and metastasis. Here, we review the expression and complex roles of CXC chemokines (CXCL1 to CXCL16) and their receptors (CXCR1 to CXCR6) in colorectal cancer. Overall, increased expression levels of CXC chemokines correlate with poor prognosis. PMID:22000992

  17. Activation and Recruitment of Regulatory T Cells via Chemokine Receptor Activation in Trichinella spiralis-Infected Mice.

    PubMed

    Ahn, Jeong-Bin; Kang, Shin Ae; Kim, Dong-Hee; Yu, Hak Sun

    2016-04-01

    As most infections by the helminth parasite elicit the recruitment of CD4(+)CD25(+)Foxp3(+) T (Treg) cells, many scientists have suggested that these cells could be used for the treatment of immune-mediated inflammation and associated diseases. In order to investigate the distribution and alteration of activated Treg cells, we compared the expression levels of Treg cell activation markers in the ileum and gastrocnemius tissues 1, 2, and 4 weeks after infection. The number of Treg cells was monitored using GFP-coded Foxp3 transgenic mice. In mice at 1 week after Trichinella spiralis infection, the number of activated Treg cells was higher than in the control group. In mice at 2 weeks after infection, there was a significant increase in the number of cells expressing Foxp3 and CTLA-4 when compared to the control group and mice at 1 week after infection. At 4 weeks after infection, T. spiralis was easily identifiable in nurse cells in mouse muscles. In the intestine, the expression of Gzmb and Klrg1 decreased over time and that of Capg remained unchanged for the first and second week, then decreased in the 4th week. However, in the muscles, the expression of most chemokine genes was increased due to T. spiralis infection, in particular the expression levels of Gzmb, OX40, and CTLA-4 increased until week 4. In addition, increased gene expression of all chemokine receptors in muscle, CXCR3, CCR4, CCR5, CCR9, and CCR10, was observed up until the 4th week. In conclusion, various chemokine receptors showed increased expressions combined with recruitment of Treg cells in the muscle tissue. PMID:27180574

  18. Activation and Recruitment of Regulatory T Cells via Chemokine Receptor Activation in Trichinella spiralis-Infected Mice

    PubMed Central

    Ahn, Jeong-Bin; Kang, Shin Ae; Kim, Dong-Hee; Yu, Hak Sun

    2016-01-01

    As most infections by the helminth parasite elicit the recruitment of CD4+CD25+Foxp3+ T (Treg) cells, many scientists have suggested that these cells could be used for the treatment of immune-mediated inflammation and associated diseases. In order to investigate the distribution and alteration of activated Treg cells, we compared the expression levels of Treg cell activation markers in the ileum and gastrocnemius tissues 1, 2, and 4 weeks after infection. The number of Treg cells was monitored using GFP-coded Foxp3 transgenic mice. In mice at 1 week after Trichinella spiralis infection, the number of activated Treg cells was higher than in the control group. In mice at 2 weeks after infection, there was a significant increase in the number of cells expressing Foxp3 and CTLA-4 when compared to the control group and mice at 1 week after infection. At 4 weeks after infection, T. spiralis was easily identifiable in nurse cells in mouse muscles. In the intestine, the expression of Gzmb and Klrg1 decreased over time and that of Capg remained unchanged for the first and second week, then decreased in the 4th week. However, in the muscles, the expression of most chemokine genes was increased due to T. spiralis infection, in particular the expression levels of Gzmb, OX40, and CTLA-4 increased until week 4. In addition, increased gene expression of all chemokine receptors in muscle, CXCR3, CCR4, CCR5, CCR9, and CCR10, was observed up until the 4th week. In conclusion, various chemokine receptors showed increased expressions combined with recruitment of Treg cells in the muscle tissue. PMID:27180574

  19. Microglial Kv1.3 Channels and P2Y12 Receptors Differentially Regulate Cytokine and Chemokine Release from Brain Slices of Young Adult and Aged Mice

    PubMed Central

    Eder, Claudia

    2015-01-01

    Brain tissue damage following stroke or traumatic brain injury is accompanied by neuroinflammatory processes, while microglia play a central role in causing and regulating neuroinflammation via production of proinflammatory substances, including cytokines and chemokines. Here, we used brain slices, an established in situ brain injury model, from young adult and aged mice to investigate cytokine and chemokine production with particular focus on the role of microglia. Twenty four hours after slice preparation, higher concentrations of proinflammatory cytokines, i.e. TNF-α and IL-6, and chemokines, i.e. CCL2 and CXCL1, were released from brain slices of aged mice than from slices of young adult mice. However, maximal microglial stimulation with LPS for 24 h did not reveal age-dependent differences in the amounts of released cytokines and chemokines. Mechanisms underlying microglial cytokine and chemokine production appear to be similar in young adult and aged mice. Inhibition of microglial Kv1.3 channels with margatoxin reduced release of IL-6, but not release of CCL2 and CXCL1. In contrast, blockade of microglial P2Y12 receptors with PSB0739 inhibited release of CCL2 and CXCL1, whereas release of IL-6 remained unaffected. Cytokine and chemokine production was not reduced by inhibitors of Kir2.1 K+ channels or adenosine receptors. In summary, our data suggest that brain tissue damage-induced production of cytokines and chemokines is age-dependent, and differentially regulated by microglial Kv1.3 channels and P2Y12 receptors. PMID:26011191

  20. Chemokine Involvement in Fetal and Adult Wound Healing

    PubMed Central

    Balaji, Swathi; Watson, Carey L.; Ranjan, Rajeev; King, Alice; Bollyky, Paul L.; Keswani, Sundeep G.

    2015-01-01

    Significance: Fetal wounds heal with a regenerative phenotype that is indistinguishable from surrounding skin with restored skin integrity. Compared to this benchmark, all postnatal wound healing is impaired and characterized by scar formation. The biologic basis of the fetal regenerative phenotype can serve as a roadmap to recapitulating regenerative repair in adult wounds. Reduced leukocyte infiltration, likely mediated, in part, through changes in the chemokine milieu, is a fundamental feature of fetal wound healing. Recent Advances: The contributions of chemokines to wound healing are a topic of active investigation. Recent discoveries have opened the possibility of targeting chemokines therapeutically to treat disease processes and improve healing capability, including the possibility of achieving a scarless phenotype in postnatal wounds. Critical Issues: Successful wound healing is a complex process, in which there is a significant interplay between multiple cell types, signaling molecules, growth factors, and extracellular matrix. Chemokines play a crucial role in this interplay and have been shown to have different effects in various stages of the healing process. Understanding how these chemokines are locally produced and regulated during wound healing and how the chemokine milieu differs in fetal versus postnatal wounds may help us identify ways in which we can target chemokine pathways. Future Directions: Further studies on the role of chemokines and their role in the healing process will greatly advance the potential for using these molecules as therapeutic targets. PMID:26543680

  1. Chemokine-Derived Peptides: Novel Antimicrobial and Antineoplasic Agents.

    PubMed

    Valdivia-Silva, Julio; Medina-Tamayo, Jaciel; Garcia-Zepeda, Eduardo A

    2015-01-01

    Chemokines are a burgeoning family of chemotactic cytokines displaying a broad array of functions such as regulation of homeostatic leukocyte traffic and development, as well as activating the innate immune system. Their role in controlling early and late inflammatory stages is now well recognized. An improper balance either in chemokine synthesis or chemokine receptor expression contributes to various pathological disorders making chemokines and their receptors a useful therapeutic target. Research in this area is progressing rapidly, and development of novel agents based on chemokine/ chemokine receptors antagonist functions are emerging as attractive alternative drugs. Some of these novel agents include generation of chemokine-derived peptides (CDP) with potential agonist and antagonist effects on inflammation, cancer and against bacterial infections. CDP have been generated mainly from N- and C-terminus chemokine sequences with subsequent modifications such as truncations or elongations. In this review, we present a glimpse of the different pharmacological actions reported for CDP and our current understanding regarding the potential use of CDP alone or as part of the novel therapies proposed in the treatment of microbial infections and cancer. PMID:26062132

  2. Chemokine-Derived Peptides: Novel Antimicrobial and Antineoplasic Agents

    PubMed Central

    Valdivia-Silva, Julio; Medina-Tamayo, Jaciel; Garcia-Zepeda, Eduardo A.

    2015-01-01

    Chemokines are a burgeoning family of chemotactic cytokines displaying a broad array of functions such as regulation of homeostatic leukocyte traffic and development, as well as activating the innate immune system. Their role in controlling early and late inflammatory stages is now well recognized. An improper balance either in chemokine synthesis or chemokine receptor expression contributes to various pathological disorders making chemokines and their receptors a useful therapeutic target. Research in this area is progressing rapidly, and development of novel agents based on chemokine/chemokine receptors antagonist functions are emerging as attractive alternative drugs. Some of these novel agents include generation of chemokine-derived peptides (CDP) with potential agonist and antagonist effects on inflammation, cancer and against bacterial infections. CDP have been generated mainly from N- and C-terminus chemokine sequences with subsequent modifications such as truncations or elongations. In this review, we present a glimpse of the different pharmacological actions reported for CDP and our current understanding regarding the potential use of CDP alone or as part of the novel therapies proposed in the treatment of microbial infections and cancer. PMID:26062132

  3. PI3K{gamma} activation by CXCL12 regulates tumor cell adhesion and invasion

    SciTech Connect

    Monterrubio, Maria; Mellado, Mario; Carrera, Ana C.

    2009-10-16

    Tumor dissemination is a complex process, in which certain steps resemble those in leukocyte homing. Specific chemokine/chemokine receptor pairs have important roles in both processes. CXCL12/CXCR4 is the most commonly expressed chemokine/chemokine receptor pair in human cancers, in which it regulates cell adhesion, extravasation, metastatic colonization, angiogenesis, and proliferation. All of these processes require activation of signaling pathways that include G proteins, phosphatidylinositol-3 kinase (PI3K), JAK kinases, Rho GTPases, and focal adhesion-associated proteins. We analyzed these pathways in a human melanoma cell line in response to CXCL12 stimulation, and found that PI3K{gamma} regulates tumor cell adhesion through mechanisms different from those involved in cell invasion. Our data indicate that, following CXCR4 activation after CXCL12 binding, the invasion and adhesion processes are regulated differently by distinct downstream events in these signaling cascades.

  4. Differential expression of three T lymphocyte-activating CXC chemokines by human atheroma-associated cells

    PubMed Central

    Mach, François; Sauty, Alain; Iarossi, Albert S.; Sukhova, Galina K.; Neote, Kuldeep; Libby, Peter; Luster, Andrew D.

    1999-01-01

    Activated T lymphocytes accumulate early in atheroma formation and persist at sites of lesion growth and rupture, suggesting that they may play an important role in the pathogenesis of atherosclerosis. Moreover, atherosclerotic lesions contain the Th1-type cytokine IFN-γ, a potentiator of atherosclerosis. The present study demonstrates the differential expression of the 3 IFN-γ–inducible CXC chemokines — IFN-inducible protein 10 (IP-10), monokine induced by IFN-γ (Mig), and IFN-inducible T-cell α chemoattractant (I-TAC) — by atheroma-associated cells, as well as the expression of their receptor, CXCR3, by all T lymphocytes within human atherosclerotic lesions in situ. Atheroma-associated endothelial cells (ECs), smooth muscle cells (SMCs), and macrophages (MØ) all expressed IP-10, whereas Mig and I-TAC were mainly expressed in ECs and MØ, as detected by double immunofluorescence staining. ECs of microvessels within lesions also expressed abundant I-TAC. In vitro experiments supported these results and showed that IL-1β, TNF-α, and CD40 ligand potentiated IP-10 expression from IFN-γ–stimulated ECs. In addition, nitric oxide (NO) treatment decreased IFN-γ induction of IP-10. Our findings suggest that the differential expression of IP-10, Mig, and I-TAC by atheroma-associated cells plays a role in the recruitment and retention of activated T lymphocytes observed within vascular wall lesions during atherogenesis. PMID:10525042

  5. Elevated autocrine chemokine ligand 18 expression promotes oral cancer cell growth and invasion via Akt activation

    PubMed Central

    Hong, Yun; Wu, Tong; Chen, Xiaobing; Xia, Juan; Cheng, Bin

    2016-01-01

    Chemokine (C-C motif) ligand 18 (CCL18) has been implicated in the pathogenesis and progression of various cancers; however, in oral squamous cell carcinoma (OSCC), the role of CCL18 is unknown. In this study, we found that CCL18 was overexpressed in primary OSCC tissues and was associated with an advanced clinical stage. CCL18 was found in both the cytoplasm and cell membrane of OSCC cells and was predominantly produced by cancer epithelial cells, as opposed to tumor-infiltrating macrophages. In vitro studies indicated that the effects of endogenous CCL18 on OSCC cell growth, migration, and invasion could be blocked by treatment with a neutralizing anti-CCL18 antibody or CCL18 knockdown, while exogenous recombinant CCL18 (rCCL18) rescued those effects. Akt was activated in rCCL18-treated OSCC cells, while LY294002, a pan-PI3K inhibitor, abolished both endogenous and exogenous CCL18-induced OSCC cell invasion. In vivo, LY294002 treatment attenuated rCCL18-induced OSCC cell growth. Our results indicate that CCL18 acts in an autocrine manner via Akt activation to stimulate OSCC cell growth and invasion during OSCC progression. They also provide a potential therapeutic target for the treatment of oral cancer. PMID:26919103

  6. Activated Murine B Lymphocytes and Dendritic Cells Produce a Novel CC Chemokine which Acts Selectively on Activated T Cells

    PubMed Central

    Schaniel, Christoph; Pardali, Evangelia; Sallusto, Federica; Speletas, Mattheos; Ruedl, Christiane; Shimizu, Takeyuki; Seidl, Thomas; Andersson, Jan; Melchers, Fritz; Rolink, Antonius G.; Sideras, Paschalis

    1998-01-01

    Genes were isolated using the suppression subtractive hybridization method by stimulation of pro/pre B cells with anti-CD40 and interleukin (IL)-4 to mature Sμ-Sε–switched cells. One of the strongly upregulated genes encodes a novel murine CC chemokine we have named ABCD-1. The ABCD-1 gene has three exons separated by 1.2- and 2.7-kb introns. It gives rise to a 2.2-kb transcript containing an open reading frame of 276 nucleotides. Two polyadenylation sites are used, giving rise to cDNAs with either 1550 or 1850 bp of 3′ untranslated regions. The open reading frame encodes a 24 amino acid–long leader peptide and a 68 amino acid–long mature protein with a predicted molecular mass of 7.8 kD. ABCD-1 mRNA is found in highest quantities in activated splenic B lymphocytes and dendritic cells. Little chemokine mRNA is present in lung, in unstimulated splenic cells, in thymocytes, and in lymph node cells. No ABCD-1 mRNA is detected in bone marrow, liver, kidney, or brain, in peritoneal exudate cells as well as in the majority of all unstimulated B lineage cells tested. It is also undetectable in Concanavalin A–activated/IL-2–restimulated splenic T cells, and in bone marrow–derived IL-2–induced natural killer cells and IL-3–activated macrophages. Recombinant ABCD-1 revealed a concentration-dependent and specific migration of activated splenic T lymphoblasts in chemotaxis assays. FACS® analyses of migrated cells showed no preferential difference in migration of CD4+ versus CD8+ T cell blasts. Murine as well as human T cells responded to ABCD-1. Freshly isolated cells from bone marrow, thymus, spleen, and lymph node, IL-2–activated NK cells, and LPS-stimulated splenic cells, all did not show any chemotactic response. Thus, ABCD-1 is the first chemokine produced in large amounts by activated B cells and acting selectively on activated T lymphocytes. Therefore, ABCD-1 is expected to play an important role in the collaboration of dendritic cells and B

  7. Chemokine receptor internalization and intracellular trafficking.

    PubMed

    Neel, Nicole F; Schutyser, Evemie; Sai, Jiqing; Fan, Guo-Huang; Richmond, Ann

    2005-12-01

    The internalization and intracellular trafficking of chemokine receptors have important implications for the cellular responses elicited by chemokine receptors. The major pathway by which chemokine receptors internalize is the clathrin-mediated pathway, but some receptors may utilize lipid rafts/caveolae-dependent internalization routes. This review discusses the current knowledge and controversies regarding these two different routes of endocytosis. The functional consequences of internalization and the regulation of chemokine receptor recycling will also be addressed. Modifications of chemokine receptors, such as palmitoylation, ubiquitination, glycosylation, and sulfation, may also impact trafficking, chemotaxis and signaling. Finally, this review will cover the internalization and trafficking of viral and decoy chemokine receptors. PMID:15998596

  8. The Chemokine Receptor CCR1 Is Constitutively Active, Which Leads to G Protein-independent, β-Arrestin-mediated Internalization*

    PubMed Central

    Gilliland, C. Taylor; Salanga, Catherina L.; Kawamura, Tetsuya; Trejo, JoAnn; Handel, Tracy M.

    2013-01-01

    Activation of G protein-coupled receptors by their associated ligands has been extensively studied, and increasing structural information about the molecular mechanisms underlying ligand-dependent receptor activation is beginning to emerge with the recent expansion in GPCR crystal structures. However, some GPCRs are also able to adopt active conformations in the absence of agonist binding that result in the initiation of signal transduction and receptor down-modulation. In this report, we show that the CC-type chemokine receptor 1 (CCR1) exhibits significant constitutive activity leading to a variety of cellular responses. CCR1 expression is sufficient to induce inhibition of cAMP formation, increased F-actin content, and basal migration of human and murine leukocytes. The constitutive activity leads to basal phosphorylation of the receptor, recruitment of β-arrestin-2, and subsequent receptor internalization. CCR1 concurrently engages Gαi and β-arrestin-2 in a multiprotein complex, which may be accommodated by homo-oligomerization or receptor clustering. The data suggest the presence of two functional states for CCR1; whereas receptor coupled to Gαi functions as a canonical GPCR, albeit with high constitutive activity, the CCR1·β-arrestin-2 complex is required for G protein-independent constitutive receptor internalization. The pertussis toxin-insensitive uptake of chemokine by the receptor suggests that the CCR1·β-arrestin-2 complex may be related to a potential scavenging function of the receptor, which may be important for maintenance of chemokine gradients and receptor responsiveness in complex fields of chemokines during inflammation. PMID:24056371

  9. The H3K4me3 Histone Demethylase Fbxl10 Is a Regulator of Chemokine Expression, Cellular Morphology, and the Metabolome of Fibroblasts

    PubMed Central

    Janzer, Andreas; Stamm, Katrin; Becker, Astrid; Zimmer, Andreas; Buettner, Reinhard; Kirfel, Jutta

    2012-01-01

    Fbxl10 (Jhdm1b/Kdm2b) is a conserved and ubiquitously expressed member of the JHDM (JmjC domain-containing histone demethylase) family. Fbxl10 was implicated in the demethylation of H3K4me3 or H3K36me2 thereby removing active chromatin marks and inhibiting gene transcription. Apart from the JmjC domain, Fbxl10 consists of a CxxC domain, a PHD domain, and an Fbox domain. By purifying the JmjC and the PHD domain of Fbxl10 and using different approaches we were able to characterize the properties of these domains in vitro. Our results suggest that Fbxl10 is rather a H3K4me3 than a H3K36me2 histone demethylase. The PHD domain exerts a dual function in binding H3K4me3 and H3K36me2 and exhibiting E3 ubiquitin ligase activity. We generated mouse embryonic fibroblasts stably overexpressing Fbxl10. These cells reveal an increase in cell size but no changes in proliferation, mitosis, or apoptosis. Using a microarray approach we were able to identify potentially new target genes for Fbxl10 including chemokines, the noncoding RNA Xist, and proteins involved in metabolic processes. Additionally, we found that Fbxl10 is recruited to the promoters of Ccl7, Xist, Crabp2, and RipK3. Promoter occupancy by Fbxl10 was accompanied by reduced levels of H3K4me3 but unchanged levels of H3K36me2. Furthermore, knockdown of Fbxl10 using small interfering RNA approaches showed inverse regulation of Fbxl10 target genes. In summary, our data reveal a regulatory role of Fbxl10 in cell morphology, chemokine expression, and the metabolic control of fibroblasts. PMID:22825849

  10. Non-canonical NFκB activation promotes chemokine expression in podocytes

    PubMed Central

    Valiño-Rivas, Lara; Gonzalez-Lafuente, Laura; Sanz, Ana B.; Ruiz-Ortega, Marta; Ortiz, Alberto; Sanchez-Niño, Maria D.

    2016-01-01

    TNF-like weak inducer of apoptosis (TWEAK) receptor Fn14 is expressed by podocytes and Fn14 deficiency protects from experimental proteinuric kidney disease. However, the downstream effectors of TWEAK/Fn14 in podocytes are poorly characterized. We have explored TWEAK activation of non-canonical NFκB signaling in cultured podocytes. In cultured podocytes, TWEAK increased the expression of the chemokines CCL21, CCL19 and RANTES in a time-dependent manner. The inhibitor of canonical NFκB activation parthenolide inhibited the CCL19 and the early RANTES responses, but not the CCL21 or late RANTES responses. In this regard, TWEAK induced non-canonical NFκB activation in podocytes, characterized by NFκB2/p100 processing to NFκB2/p52 and nuclear migration of RelB/p52. Silencing by a specific siRNA of NIK, the upstream kinase of the non-canonical NFκB pathway, prevented CCL21 upregulation but did not modulate CCL19 or RANTES expression in response to TWEAK, thus establishing CCL21 as a non-canonical NFκB target in podocytes. Increased kidney Fn14 and CCL21 expression was also observed in rat proteinuric kidney disease induced by puromycin, and was localized to podocytes. In conclusion, TWEAK activates the non-canonical NFκB pathway in podocytes, leading to upregulation of CCL21 expression. The non-canonical NFκB pathway should be explored as a potential therapeutic target in proteinuric kidney disease. PMID:27353019

  11. Expression of cytokine, chemokine, and adhesion molecules during endothelial cell activation induced by antibodies against dengue virus nonstructural protein 1.

    PubMed

    Lin, Chiou-Feng; Chiu, Shu-Chen; Hsiao, Yu-Ling; Wan, Shu-Wen; Lei, Huan-Yao; Shiau, Ai-Li; Liu, Hsiao-Sheng; Yeh, Trai-Ming; Chen, Shun-Hua; Liu, Ching-Chuan; Lin, Yee-Shin

    2005-01-01

    Vascular dysfunction is a hallmark associated with disease onset in dengue hemorrhagic fever and dengue shock syndrome. In addition to direct viral damage, immune responses to dengue virus (DV) infection may also underlie the pathogenesis of disease. We have proposed a mechanism of molecular mimicry in which Abs directed against DV nonstructural protein 1 (NS1) cross-react with endothelial cells and induce damage. In this study, we demonstrated the inflammatory endothelial cell activation induced by anti-DV NS1 via the transcription factor NF-kappaB-regulated pathway. Protein phosphorylation and NF-kappaB activation were observed after anti-DV NS1 stimulation in a human microvascular endothelial cell line-1. The cytokine and chemokine production, including IL-6, IL-8, and MCP-1, but not RANTES, in endothelial cells increased after treatment with anti-DV NS1 Abs. The expression of IL-6, IL-8, and MCP-1 was blocked by the preabsorption of anti-DV NS1 with DV NS1 or by the inhibition of NF-kappaB activation. Furthermore, the increases in both ICAM-1 expression and the ability of human PBMC to adhere to endothelial cells were also observed, and these effects were inhibited by pretreatment with anti-ICAM-1 or anti-MCP-1 Abs. Therefore, in addition to endothelial cell apoptosis, as previously reported, inflammatory activation occurs in endothelial cells after stimulation by anti-DV NS1 Abs. These results suggest the involvement of anti-DV NS1 Abs in the vasculopathy of DV infection. PMID:15611263

  12. Propolis Ethanol Extract Stimulates Cytokine and Chemokine Production through NF-κB Activation in C2C12 Myoblasts

    PubMed Central

    Washio, Kohei; Kobayashi, Mao; Saito, Natsuko; Amagasa, Misato; Kitamura, Hiroshi

    2015-01-01

    Myoblast activation is a triggering event for muscle remodeling. We assessed the stimulatory effects of propolis, a beehive product, on myoblasts. After an 8 h treatment with 100 μg/mL of Brazilian propolis ethanol extract, expression of various chemokines, including CCL-2 and CCL-5, and cytokines, such as IL-6, increased. This propolis-induced cytokine production appears to depend on NF-κB activation, because the IKK inhibitor BMS-345541 repressed mRNA levels of CCL-2 by ~66%, CCL-5 by ~81%, and IL-6 by ~69% after propolis treatment. Supernatant from propolis-conditioned C2C12 cells upregulated RAW264 macrophage migration. The supernatant also stimulated RAW264 cells to produce angiogenic factors, including VEGF-A and MMP-12. Brazilian green propolis therefore causes myoblasts to secrete cytokines and chemokines, which might contribute to tissue remodeling of skeletal muscle. PMID:26604971

  13. A strategy to discover decoy chemokine ligands with an anti-inflammatory activity

    PubMed Central

    Abboud, Dayana; Daubeuf, François; Do, Quoc Tuan; Utard, Valérie; Villa, Pascal; Haiech, Jacques; Bonnet, Dominique; Hibert, Marcel; Bernard, Philippe; Galzi, Jean-Luc; Frossard, Nelly

    2015-01-01

    Excessive signaling by chemokines has been associated with chronic inflammation or cancer, thus attracting substantial attention as promising therapeutic targets. Inspired by chemokine-clearing molecules shaped by pathogens to escape the immune system, we designed a generic screening assay to discover chemokine neutralizing molecules (neutraligands) and unambiguously distinguish them from molecules that block the receptor (receptor antagonists). This assay, called TRIC-r, combines time-resolved intracellular calcium recordings with pre-incubation of bioactive compounds either with the chemokine or the receptor-expressing cells. We describe here the identification of high affinity neutraligands of CCL17 and CCL22, two chemokines involved in the Th2-type of lung inflammation. The decoy molecules inhibit in vitro CCL17- or CCL22-induced intracellular calcium responses, CCR4 endocytosis and human T cell migration. In vivo, they inhibit inflammation in a murine model of asthma, in particular the recruitment of eosinophils, dendritic cells and CD4+T cells. Altogether, we developed a successful strategy to discover as new class of pharmacological tools to potently control cell chemotaxis in vitro and in vivo. PMID:26442456

  14. Potential combinatorial effects of recombinant atypical chemokine receptors in breast cancer cell invasion: A research perspective.

    PubMed

    Chew, Ai Lan; Tan, Wee Yee; Khoo, Boon Yin

    2013-03-01

    Apart from their major function in the coordination of leukocyte recruitment, chemokines, in cooperation with their receptors, have been implicated in the progression of various diseases including different types of cancer, affecting survival, proliferation and metastasis. A complex network of chemokines and receptors exists in the tumor microenvironment and affects tumor development in various ways where chemokines activate typical signalling pathways by binding to the respective receptors. The identification and characterization of a group of atypical chemokine receptors [D6, Duffy antigen receptor for chemokines (DARC), ChemoCentryx chemokine receptor (CCX-CKR) and CXCR7] which appear to use unique biochemical properties to regulate the biological activities of these chemokines, is useful in the effort to therapeutically manipulate chemokines in a broad spectrum of diseases in which these chemokines play a critical role. The aim of this review was to investigate the combinatorial effect of two reported atypical chemokine receptors, D6 and DARC, on breast cancer cell invasion to understand their role and therapeutic potential in cancer treatment. In this regard, findings of the present review should be confirmed via the construction of recombinant D6 and DARC clones as well as the expression of the respective recombinant proteins using the Pichia pastoris (P. pastoris) expression system is to be performed in a future study in order to support findings of the current review. PMID:24648916

  15. [Interceptors:--"silent" chemokine receptors].

    PubMed

    Grodecka, Magdalena; Waśniowska, Kazimiera

    2007-01-01

    The physiological effect caused by chemokines is regulated by interactions with a group of rodopsin-like G protein-coupled receptors (GPCRs). These receptors share a number of common features: the polypeptide chain is a 7-transmembrane ?-helix (7 TMD motif) and the region involved in G-protein interaction (the DRYLAIV sequence) is located in the second transmembrane loop. So far, 19 chemokine receptors have been identified. Three of them (Duffy glycoprotein, D6, and CCX-CKR proteins), although structurally related to other GPCRs, lack the ability of G-protein signal transduction. Instead, they efficiently internalize their cognate ligands, regulating chemokine levels in various body compartments. These three proteins are suggested to form a distinct chemokine receptor family, designated "interceptors" or "silent" chemokine receptors. PMID:17507871

  16. Differential Estrogen-Regulation of CXCL12 Chemokine Receptors, CXCR4 and CXCR7, Contributes to the Growth Effect of Estrogens in Breast Cancer Cells

    PubMed Central

    Boudot, Antoine; Kerdivel, Gwenneg; Habauzit, Denis; Eeckhoute, Jerome; Le Dily, François; Flouriot, Gilles; Samson, Michel; Pakdel, Farzad

    2011-01-01

    CXCR4 and CXCR7 are the two receptors for the chemokine CXCL12, a key mediator of the growth effect of estrogens (E2) in estrogen receptor (ER)-positive breast cancers. In this study we examined E2-regulation of the CXCL12 axis components and their involvement in the growth of breast cancer cells. CXCR4 and CXCR7 were differentially regulated by E2 which enhanced the expression of both CXCL12 and CXCR4 but repressed the expression of CXCR7. Formaldehyde-associated isolation of regulatory elements (FAIRE) revealed that E2-mediated transcriptional regulation of these genes is linked to the control of the compaction state of chromatin at their promoters. This effect could be accomplished via several distal ER-binding sites in the regions surrounding these genes, all of which are located 20–250 kb from the transcription start site. Furthermore, individual down-regulation of CXCL12, CXCR4 or CXCR7 expression as well as the inhibition of their activity significantly decreases the rate of basal cell growth. In contrast, E2-induced cell growth was differentially affected. Unlike CXCR7, the inhibition of the expression or activity of either CXCL12 or CXCR4 significantly blunted the E2-mediated stimulation of cellular growth. Besides, CXCR7 over-expression increased the basal MCF-7 cell growth rate and decreased the growth effect of E2. These findings indicate that E2 regulation of the CXCL12 signaling axis is important for the E2-mediated growth effect of breast cancer cells. These data also provide support for distinct biological functions of CXCR4 and CXCR7 and suggest that targeting CXCR4 and/or CXCR7 would have distinct molecular effects on ER-positive breast tumors. PMID:21695171

  17. Chemokines and T lymphocyte recruitment to lymph nodes in HIV infection.

    PubMed Central

    Tedla, N.; Palladinetti, P.; Kelly, M.; Kumar, R. K.; DiGirolamo, N.; Chattophadhay, U.; Cooke, B.; Truskett, P.; Dwyer, J.; Wakefield, D.; Lloyd, A.

    1996-01-01

    Recruitment of T lymphocytes to lymph nodes in patients with HIV infection is critical to the pathogenesis of disease. Chemokines are a family of cytokines, which are potent regulators of leukocyte migration. We studied the leukocyte populations and expression of chemokines known to be active upon T cells in lymph nodes of four HIV infected patients and seven control subjects using in situ hybridization, immunohistochemistry, and FACS analysis. The HIV lymph nodes showed CD8+ T lymphocyte accumulation and strongly enhanced chemokine expression, notably for the CD8+ T cell chemoattractant, macrophage inflammatory protein (MIP)-1 alpha. Resident macrophages appeared to be a major cellular source of chemokines in the HIV nodes. RANTES expression was present in both HIV and control lymph nodes, suggesting a physiological role for this chemokine in T lymphocyte recirculation. Chemokines may be important determinants of T lymphocyte accumulation in lymphoid tissue of patients with HIV/AIDS. Images Figure 1 Figure 2 PMID:8623908

  18. Andrographolide inhibits prostate cancer by targeting cell cycle regulators, CXCR3 and CXCR7 chemokine receptors.

    PubMed

    Mir, Hina; Kapur, Neeraj; Singh, Rajesh; Sonpavde, Guru; Lillard, James W; Singh, Shailesh

    2016-01-01

    Despite state of the art cancer diagnostics and therapies offered in clinic, prostate cancer (PCa) remains the second leading cause of cancer-related deaths. Hence, more robust therapeutic/preventive regimes are required to combat this lethal disease. In the current study, we have tested the efficacy of Andrographolide (AG), a bioactive diterpenoid isolated from Andrographis paniculata, against PCa. This natural agent selectively affects PCa cell viability in a dose and time-dependent manner, without affecting primary prostate epithelial cells. Furthermore, AG showed differential effect on cell cycle phases in LNCaP, C4-2b and PC3 cells compared to retinoblastoma protein (RB(-/-)) and CDKN2A lacking DU-145 cells. G2/M transition was blocked in LNCaP, C4-2b and PC3 after AG treatment whereas DU-145 cells failed to transit G1/S phase. This difference was primarily due to differential activation of cell cycle regulators in these cell lines. Levels of cyclin A2 after AG treatment increased in all PCa cells line. Cyclin B1 levels increased in LNCaP and PC3, decreased in C4-2b and showed no difference in DU-145 cells after AG treatment. AG decreased cyclin E2 levels only in PC3 and DU-145 cells. It also altered Rb, H3, Wee1 and CDC2 phosphorylation in PCa cells. Intriguingly, AG reduced cell viability and the ability of PCa cells to migrate via modulating CXCL11 and CXCR3 and CXCR7 expression. The significant impact of AG on cellular and molecular processes involved in PCa progression suggests its potential use as a therapeutic and/or preventive agent for PCa. PMID:27029529

  19. Stability of cytokines, chemokines and soluble activation markers in unprocessed blood stored under different conditions

    PubMed Central

    Aziz, Najib; Detels, Roger; Quint, Joshua J.; Li, Qian; Gjertson, David; Butch, Anthony W.

    2016-01-01

    Background Biomarkers such as cytokines, chemokines, and soluble activation markers can be unstable when processing of blood is delayed. The stability of various biomarkers in serum and plasma was investigated when unprocessed blood samples were stored for up to 24 h at room and refrigerator temperature. Methods Blood was collected from 16 healthy volunteers. Unprocessed serum, EDTA and heparinized blood was stored at room (20–25 °C) and refrigerator temperature (4–8 °C) for 0.5, 2, 4, 6, 8, and 24 h after collection before centrifugation and separation of serum and plasma. Samples were batch tested for various biomarkers using commercially available immunoassays. Statistically significant changes were determined using the generalized estimating equation. Results IFN-γ, sIL-2Rα, sTNF-RII and β2-microglobulin were stable in unprocessed serum, EDTA and heparinized blood samples stored at either room or refrigerator temperature for up to 24 h. IL-6, TNF-α, MIP-1β and RANTES were unstable in heparinized blood at room temperature; TNF-α, and MIP-1β were unstable in unprocessed serum at room temperature; IL-12 was unstable in unprocessed serum at refrigerator temperature; and neopterin was unstable in unprocessed EDTA blood at room temperature. IL-1ra was stable only in unprocessed serum at room temperature. Conclusion All the biomarkers studied, with the exception of IL-1ra, were stable in unprocessed EDTA blood stored at refrigerator temperature for 24 h. This indicates that blood for these biomarkers should be collected in EDTA and if delays in processing are anticipated the unseparated blood should be stored at refrigerator temperature until processing. PMID:27208752

  20. Chemokines and skin diseases.

    PubMed

    Sugaya, Makoto

    2015-04-01

    Chemokines are small molecules that induce chemotaxis and activation of certain subsets of leukocytes. The expression patterns of chemokines and chemokine receptors are specific to certain organs and cells. Therefore, chemokines are important to elucidate the mechanism of organ-specific human diseases. CCL17 expressed by Langerhans cells, blood endothelial cells, and fibroblasts plays a key role in attracting Th2 cells and tumor cells of adult T-cell leukemia/lymphoma and mycosis fungoides/Sézary syndrome into the skin, developing various Th2-type inflammatory skin diseases as well as cutaneous lymphoma. CCL11 and CCL26 expressed by skin-resident cells, such as fibroblasts, blood endothelial cells, and keratinocytes, induce infiltration of CCR3-expressing cells such as Th2 cells and eosinophils. CCL11 may also serve as an autocrine as well as a paracrine in anaplastic large cell lymphoma. CX3CL1 expressed on blood endothelial cells leads to infiltration of CX3CR1(+) immune cells, such as mast cells, neutrophils, and macrophages, playing important roles in wound healing, tumor immunity, and vasculitis. Biologics targeting chemokines and their receptors are promising strategies for various skin diseases that are resistant to the current therapy. PMID:25182982

  1. Epigenetic regulation of human β-defensin 2 and CC chemokine ligand 20 expression in gingival epithelial cells in response to oral bacteria

    PubMed Central

    Yin, L; Chung, W O

    2011-01-01

    Gingival epithelia utilize multiple signaling pathways to regulate innate immune responses to various oral bacteria, but little is understood about how these bacteria alter epithelial epigenetic status. In this study we report that DNA methyltransferase (DNMT1) and histone deacetylase expression were decreased in gingival epithelial cells treated with oral pathogen Porphyromonas gingivalis and nonpathogen Fusobacterium nucleatum. Pretreatment with trichostatin A and sodium butyrate, which increase acetylation of chromatin histones, significantly enhanced the gene expression of antimicrobial proteins human β-defensin 2 (hBD2) and CC chemokine ligand 20 (CCL20) in response to both bacterial challenges. Pretreatment with DNMT inhibitor 5′-azacytidine increased hBD2 and CCL20 expression in response to F. nucleatum, but not to P. gingivalis. Furthermore, we observed a differential pattern of protein levels of H3K4me3, which has been associated with chromatin remodeling and activation of gene transcription, in response to P. gingivalis vs. F. nucleatum. This study provides a new insight into the bacteria-specific innate immune responses via epigenetic regulation. PMID:21248725

  2. Heme oxygenase-1 induction alters chemokine regulation and ameliorates human immunodeficiency virus-type-1 infection in lipopolysaccharide-stimulated macrophages

    SciTech Connect

    Zhou, Zhao-Hua; Kumari, Namita; Nekhai, Sergei; Clouse, Kathleen A.; Wahl, Larry M.; Yamada, Kenneth M.; Dhawan, Subhash

    2013-06-07

    Highlights: •Lipopolysaccharide stimulation of heme oxygenase-1 (HO-1) ameliorated HIV-1 infection of primary human macrophages. •The partial protection by HO-1 against HIV infection was associated with induction of chemokines such as MIP1α and MIP1β. •This mechanism explains lipopolysaccharide-stimulated HO-1-mediated inhibition of HIV-1 infection of macrophages. -- Abstract: We have elucidated a putative mechanism for the host resistance against HIV-1 infection of primary human monocyte-derived macrophages (MDM) stimulated with lipopolysaccharide (LPS). We show that LPS-activated MDM both inhibited HIV-1 entry into the cells and were refractory to post-entry productive viral replication. LPS-treated cells were virtually negative for mature virions as revealed by transmission electron microscopy. LPS activation of MDM markedly enhanced the expression of heme oxygenase-1 (HO-1), a potent inducible cytoprotective enzyme. Increased HO-1 expression was accompanied by elevated production of macrophage inflammatory chemokines (MIP1α and MIP1β) by LPS-activated MDM, significantly decreased surface chemokine receptor-5 (CCR-5) expression, and substantially reduced virus replication. Treatment of cells with HO-1 inhibitor SnPP IX (tin protoporphyrin IX) attenuated the LPS-mediated responses, HIV-1 replication and secretion of MIP1α, MIP1β, and LD78β chemokines with little change in surface CCR-5 expression. These results identify a novel role for HO-1 in the modulation of host immune response against HIV infection of MDM.

  3. Role of chemokines and chemokine receptors in shaping the effector phase of the antitumor immune response.

    PubMed

    Franciszkiewicz, Katarzyna; Boissonnas, Alexandre; Boutet, Marie; Combadière, Christophe; Mami-Chouaib, Fathia

    2012-12-15

    Immune system-mediated eradication of neoplastic cells requires induction of a strong long-lasting antitumor T-cell response. However, generation of tumor-specific effector T cells does not necessarily result in tumor clearance. CTL must first be able to migrate to the tumor site, infiltrate the tumor tissue, and interact with the target to finally trigger effector functions indispensable for tumor destruction. Chemokines are involved in circulation, homing, retention, and activation of immunocompetent cells. Although some of them are known to contribute to tumor growth and metastasis, others are responsible for changes in the tumor microenvironment that lead to extensive infiltration of lymphocytes, resulting in tumor eradication. Given their chemoattractive and activating properties, a role for chemokines in the development of the effector phase of the antitumor immune response has been suggested. Here, we emphasize the role of the chemokine-chemokine receptor network at multiple levels of the T-cell-mediated antitumor immune response. The identification of chemokine-dependent molecular mechanisms implicated in tumor-specific CTL trafficking, retention, and regulation of their in situ effector functions may offer new perspectives for development of innovative immunotherapeutic approaches to cancer treatment. PMID:23222302

  4. Association between preeclampsia and the CXC chemokine family (Review)

    PubMed Central

    LIU, XIJING; DAI, LI; ZHOU, RONG

    2015-01-01

    Preeclampsia is a major cause of maternal and perinatal mortality and morbidity, characterized by gestational hypertension, proteinuria, systemic endothelial cell activation and an exaggerated inflammatory response. The precise cause of preeclampsia is not currently known; however, it is widely accepted that the pathogenesis of preeclampsia involves inadequate trophoblast invasion, leading to generalized endothelial dysfunction and an exaggerated inflammatory response. Chemokines are a superfamily of structurally similar proteins that mediate cell recruitment, angiogenesis, immunity and stem cell trafficking. CXC chemokines are a family of cytokines, unique in their ability to behave in a disparate manner in the regulation of angiogenesis. The CXC chemokine family further divides into two subfamilies; CXC ELR+, which promotes angiogenesis, and CXC ELR-, which inhibits angiogenesis. Furthermore, CXC chemokines are involved in the pathogenesis of various conditions, including malignant tumors, wound repair, chronic inflammation, atherosclerosis and potentially preeclampsia. PMID:26136860

  5. Migration of eosinophils across endothelial cell monolayers: interactions among IL-5, endothelial-activating cytokines, and C-C chemokines.

    PubMed

    Shahabuddin, S; Ponath, P; Schleimer, R P

    2000-04-01

    Eosinophils are the predominant cell type recruited in inflammatory reactions in response to allergen challenge. The mechanisms of selective eosinophil recruitment in allergic reactions are not fully elucidated. In this study, the ability of several C-C chemokines to induce transendothelial migration (TEM) of eosinophils in vitro was assessed. Eotaxin, eotaxin-2, monocyte chemotactic protein (MCP)-4, and RANTES induced eosinophil TEM across unstimulated human umbilical vein endothelial cells (HUVEC) in a concentration-dependent manner with the following rank order of potency: eotaxin approximately eotaxin-2 > MCP-4 approximately RANTES. The maximal response induced by eotaxin or eotaxin-2 exceeded that of RANTES or MCP-4. Preincubation of eosinophils with anti-CCR3 Ab (7B11) completely blocked eosinophil TEM induced by eotaxin, MCP-4, and RANTES. Activation of endothelial cells with IL-1beta or TNF-alpha induced concentration-dependent migration of eosinophils, which was enhanced synergistically in the presence of eotaxin and RANTES. Anti-CCR3 also inhibited eotaxin-induced eosinophil TEM across TNF-alpha-stimulated HUVEC. The ability of eosinophil-active cytokines to potentiate eosinophil TEM was assessed by investigating eotaxin or RANTES-induced eosinophil TEM across resting and IL-1beta-stimulated HUVEC in the presence or absence of IL-5. The results showed synergy between IL-5 and the chemokines but not between IL-5 and the endothelial activator IL-1beta. Our data suggest that eotaxin, eotaxin-2, MCP-4, and RANTES induce eosinophil TEM via CCR3 with varied potency and efficacy. Activation of HUVEC by IL-1beta or TNF-alpha or priming of eosinophils by IL-5 both promote CCR3-dependent migration of eosinophils from the vasculature in conjunction with CCR3-active chemokines. PMID:10725746

  6. Role of chemokine pathways in hepatobiliary cancer.

    PubMed

    Ehling, Josef; Tacke, Frank

    2016-09-01

    Persistent hepatic inflammation resulting from hepatitis B or C virus infections (HBV or HCV, respectively), obesity-associated non-alcoholic steatohepatitis (NASH) or alcohol abuse is a hallmark feature of chronic liver diseases and appears to be an essential prerequisite of hepatocarcinogenesis. The inflammatory processes in the liver are regulated by various chemokines, which orchestrate the interaction between parenchymal liver cells, Kupffer cells (resident macrophages), hepatic stellate cells (HSC), endothelial cells, and infiltrating immune cells. In consequence, these cellular interactions result in the re-modeling of the hepatic microenvironment toward a pro-inflammatory, pro-fibrotic, pro-angiogenic and thus pre-neoplastic milieu. Once developed, liver neoplasms provoke pro- and anti-tumor immune responses that are also critically regulated through differential activation of chemokine pathways. With respect to hepatobiliary cancers, including hepatocellular carcinoma (HCC), gallbladder cancer and cholangiocellular carcinoma (cholangiocarcinoma), together belonging to the highest causes of cancer-related deaths worldwide, this review article will give an overview of chemokine pathways involved in both the establishment of a pro-tumorigenic microenvironment as well as the development and progression of hepatobiliary cancer. Pharmaceutical targeting of chemokine pathways is a promising approach to treat or even prevent hepatobiliary cancer. PMID:26123664

  7. The good and the bad of chemokines/chemokine receptors in melanoma

    PubMed Central

    Richmond, Ann; Yang, Jinming; Su, Yingjun

    2010-01-01

    Summary Chemokine ligand/receptor interactions affect melanoma cell growth, stimulate or inhibit angiogenesis, recruit leukocytes, promote metastasis, and alter the gene expression profile of the melanoma associated fibroblasts. Chemokine/chemokine receptor interactions can protect against tumor development/growth or can stimulate melanoma tumor progression, tumor growth and metastasis. Metastatic melanoma cells express chemokine receptors that play a major role in the specifying the organ site for metastasis, based upon receptor detection of the chemokine gradient elaborated by a specific organ/tissue. A therapeutic approach that utilizes the protective benefit of chemokines involves delivery of angiostatic chemokines or chemokines that stimulate the infiltration of cytotoxic T cells and natural killer T cells into the tumor microenvironment. An alternative approach that tackles the tumorigenic property of chemokines uses chemokine antibodies or chemokine receptor antagonists to target the growth and metastatic properties of these interactions. Based upon our current understanding of the role of chemokine-mediated inflammation in cancer, it is important that we learn to appropriately regulate the chemokine contribution to the tumorigenic `cytokine/chemokine storm', and to metastasis. PMID:19222802

  8. Modulation of Chemokine Responses: Synergy and Cooperativity

    PubMed Central

    Proudfoot, Amanda E. I.; Uguccioni, Mariagrazia

    2016-01-01

    Chemokine biology is mediated by more complex interactions than simple monomolecular ligand–receptor interactions, as chemokines can form higher order quaternary structures, which can also be formed after binding to glycosaminoglycans (GAGs) on endothelial cells, and their receptors are found as dimers and/or oligomers at the cell surface. Due to the complexity of the chemokine binding and signaling system, several mechanisms have been proposed to provide an explanation for the synergy observed between chemokines in leukocyte migration. Pioneering studies on interactions between different chemokines have revealed that they can act as antagonists, or synergize with other chemokines. The synergism can occur at different levels, involving either two chemokine receptors triggered simultaneously or sequentially exposed to their agonists, or the activation of one type of chemokine receptor triggered by chemokine heterocomplexes. In addition to the several chemokines that, by forming a heterocomplex with chemokine receptor agonists, act as enhancers of molecules of the same family, we have recently identified HMGB1, an endogenous damage-associated molecular patterns (DAMPs) molecule, as an enhancer of the activity of CXCL12. It is now evident that synergism between chemokines is crucial at the very early stage of inflammation. In addition, the low-affinity interaction with GAGs has recently been shown to induce cooperativity allowing synergy or inhibition of activity by displacement of other ligands. PMID:27242790

  9. Lactobacillus acidophilus induces cytokine and chemokine production via NF-κB and p38 mitogen-activated protein kinase signaling pathways in intestinal epithelial cells.

    PubMed

    Jiang, Yujun; Lü, Xuena; Man, Chaoxin; Han, Linlin; Shan, Yi; Qu, Xingguang; Liu, Ying; Yang, Shiqin; Xue, Yuqing; Zhang, Yinghua

    2012-04-01

    Intestinal epithelial cells can respond to certain bacteria by producing an array of cytokines and chemokines which are associated with host immune responses. Lactobacillus acidophilus NCFM is a characterized probiotic, originally isolated from human feces. This study aimed to test the ability of L. acidophilus NCFM to stimulate cytokine and chemokine production in intestinal epithelial cells and to elucidate the mechanisms involved in their upregulation. In experiments using intestinal epithelial cell lines and mouse models, we observed that L. acidophilus NCFM could rapidly but transiently upregulate a number of effector genes encoding cytokines and chemokines such as interleukin 1α (IL-1α), IL-1β, CCL2, and CCL20 and that cytokines showed lower expression levels with L. acidophilus NCFM treatment than chemokines. Moreover, L. acidophilus NCFM could activate a pathogen-associated molecular pattern receptor, Toll-like receptor 2 (TLR2), in intestinal epithelial cell lines. The phosphorylation of NF-κB p65 and p38 mitogen-activated protein kinase (MAPK) in intestinal epithelial cell lines was also enhanced by L. acidophilus NCFM. Furthermore, inhibitors of NF-κB (pyrrolidine dithiocarbamate [PDTC]) and p38 MAPK (SB203580) significantly reduced cytokine and chemokine production in the intestinal epithelial cell lines stimulated by L. acidophilus NCFM, suggesting that both NF-κB and p38 MAPK signaling pathways were important for the production of cytokines and chemokines induced by L. acidophilus NCFM. PMID:22357649

  10. DIFFERENTIAL REGULATION OF CXC CHEMOKINES BY ONCOSTATIN M (OSM) IN CARDIAC FIBROBLASTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    OSM is a member of the IL-6 cytokine family and is produced by activated T-cells, monocytes, and neutrophils (PMNs). In an animal model of myocardial ischemia and reperfusion injury, transmigrated PMNs were frequently found in close proximity to peri-venular cardiac fibroblasts (CFs). We sought to d...

  11. Chemokines in the balance: maintenance of homeostasis and protection at CNS barriers

    PubMed Central

    Williams, Jessica L.; Holman, David W.; Klein, Robyn S.

    2014-01-01

    In the adult central nervous system (CNS), chemokines and their receptors are involved in developmental, physiological and pathological processes. Although most lines of investigation focus on their ability to induce the migration of cells, recent studies indicate that chemokines also promote cellular interactions and activate signaling pathways that maintain CNS homeostatic functions. Many homeostatic chemokines are expressed on the vasculature of the blood brain barrier (BBB) including CXCL12, CCL19, CCL20, and CCL21. While endothelial cell expression of these chemokines is known to regulate the entry of leukocytes into the CNS during immunosurveillance, new data indicate that CXCL12 is also involved in diverse cellular activities including adult neurogenesis and neuronal survival, having an opposing role to the homeostatic chemokine, CXCL14, which appears to regulate synaptic inputs to neural precursors. Neuronal expression of CX3CL1, yet another homeostatic chemokine that promotes neuronal survival and communication with microglia, is partly regulated by CXCL12. Regulation of CXCL12 is unique in that it may regulate its own expression levels via binding to its scavenger receptor CXCR7/ACKR3. In this review, we explore the diverse roles of these and other homeostatic chemokines expressed within the CNS, including the possible implications of their dysfunction as a cause of neurologic disease. PMID:24920943

  12. Cancer-associated fibroblasts promote hepatocellular carcinoma metastasis through chemokine-activated hedgehog and TGF-β pathways.

    PubMed

    Liu, Jiao; Chen, Sheng; Wang, Wei; Ning, Bei-Fang; Chen, Fei; Shen, Weifeng; Ding, Jin; Chen, Wansheng; Xie, Wei-Fen; Zhang, Xin

    2016-08-28

    Fibroblasts are rich in the surrounding microenvironment of hepatocellular carcinoma (HCC) because most HCCs occur in fibrotic or cirrhotic livers. However, the role of cancer-associated fibroblasts (CAFs) in HCC metastasis remains obscure. Here, we reported that CAFs promote the migration and invasion of HCC cells in vitro and facilitate the HCC metastasis to the bone, brain and lung in NOD/SCID mice. The RayBio human chemokine antibody array revealed that CAFs secret higher levels of CCL2, CCL5, CCL7 and CXCL16 than peri-tumor fibroblasts. CCL2 and CCL5 increase the migration but not the invasion of HCC cells, while CCL7 and CXCL16 promote both migration and invasion of HCC cells. Moreover, CCL2 and CCL5 stimulate the activation of the hedgehog (Hh) pathway, while CCL7 and CXCL16 enhance the activity of the transforming growth factor-β (TGF-β) pathway in HCC cells. The neutralizing antibodies of chemokines notably attenuate the effect of CAFs on HCC metastasis and compromised the activation of Hh and TGF-β pathways in HCC cells. In summary, CAF-secreted CCL2, CCL5, CCL7 and CXCL16 promote HCC metastasis through the coordinate activation of Hh and TGF-β pathways in HCC cells. PMID:27216982

  13. Inflammatory cytokines regulate secretion of VEGF and chemokines by human conjunctival fibroblasts: Role in dysfunctional tear syndrome.

    PubMed

    Nagineni, Chandrasekharam N; William, Abitha; Cherukuri, Aswini; Samuel, William; Hooks, John J; Detrick, Barbara

    2016-02-01

    Ocular surface inflammation is one of the primary mechanisms associated with dysfunctional tear syndrome (DTS), also known as dry eye disease. DTS, more prevalent in older populations, causes ocular discomfort and visual disturbance due to dryness on the surface layer in the eye. We used human conjunctival fibroblast cultures (HCJVF) to investigate the effects of inflammatory cytokines IFN-γ, TNF-α and IL-1β (ITI) on the secretions of VEGF and chemokines. Our results demonstrate the elevated secretion of angiogenic VEGF molecules by ITI without affecting anti-angiogenic molecules, PEDF, endostatin, thrombospondin and sVEGF-R1. The secretion of interferon-γ inducible chemokines, CXCL9, -10, -11 by HCJVF were significantly enhanced by ITI. Our in vitro study supports previously reported observations of elevated VEGF and chemokines in tear fluids of DTS patients, reiterating the role of inflammatory reactions in DTS. PMID:26615568

  14. Role of Chemokines in Non-Small Cell Lung Cancer: Angiogenesis and Inflammation

    PubMed Central

    Rivas-Fuentes, Selma; Salgado-Aguayo, Alfonso; Pertuz Belloso, Silvana; Gorocica Rosete, Patricia; Alvarado-Vásquez, Noé; Aquino-Jarquin, Guillermo

    2015-01-01

    Non-small cell lung cancer (NSCLC) is one of the most common types of aggressive cancer. The tumor tissue, which shows an active angiogenesis, is composed of neoplastic and stromal cells, and an abundant inflammatory infiltrate. Angiogenesis is important to support tumor growth, while infiltrating cells contribute to the tumor microenvironment through the secretion of growth factors, cytokines and chemokines, important molecules in the progression of the disease. Chemokines are important in development, activation of the immune response, and physiological angiogenesis. Chemokines have emerged as important regulators in the pathophysiology of cancer. These molecules are involved in the angiogenesis/angiostasis balance and in the recruitment of tumor infiltrating hematopoietic cells. In addition, chemokines promote tumor cell survival, as well as the directing and establishment of tumor cells to metastasis sites. The findings summarized here emphasize the central role of chemokines as modulators of tumor angiogenesis and their potential role as therapeutic targets in the inflammatory process of NSCLC angiogenesis. PMID:26316890

  15. Chemokines and chemokine receptors in arthritis

    PubMed Central

    Szekanecz, Zoltan; Vegvari, Aniko; Szabo, Zoltan; Koch, Alisa E.

    2010-01-01

    Chemokines are involved in leukocyte recruitment to inflammatory sites, such as the synovial tissue in rheumatoid arthritis (RA). There is a structural and a functional classification of chemokines. The former includes four groups: CXC, CC, C and CX3C chemokines. Chemokines may also be either inflammatory or homeostatic, however, these functions often overlap. Anti-chemokine and anti-chemokine receptor targeting may be therapeutically used in the future biological therapy of arthritis. Most data in this field have been obtained from animal models of arthritis as only very few human RA trials have been completed. However, it is very likely that various specific chemokine and chemokine receptor antagonists will be developed and administered to RA patients. PMID:20036936

  16. Acidic pH stimulates the production of the angiogenic CXC chemokine, CXCL8 (interleukin-8), in human adult mesenchymal stem cells via the extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, and NF-kappaB pathways.

    PubMed

    Bischoff, David S; Zhu, Jian-Hua; Makhijani, Nalini S; Yamaguchi, Dean T

    2008-07-01

    Blood vessel injury results in limited oxygen tension and diffusion leading to hypoxia, increased anaerobic metabolism, and elevated production of acidic metabolites that cannot be easily removed due to the reduced blood flow. Therefore, an acidic extracellular pH occurs in the local microenvironment of disrupted bone. The potential role of acidic pH and glu-leu-arg (ELR(+)) CXC chemokines in early events in bone repair was studied in human mesenchymal stem cells (hMSCs) treated with medium of decreasing pH (7.4, 7.0, 6.7, and 6.4). The cells showed a reciprocal increase in CXCL8 (interleukin-8, IL-8) mRNA levels as extracellular pH decreased. At pH 6.4, CXCL8 mRNA was induced >60x in comparison to levels at pH 7.4. hMSCs treated with osteogenic medium (OGM) also showed an increase in CXCL8 mRNA with decreasing pH; although, at a lower level than that seen in cells grown in non-OGM. CXCL8 protein was secreted into the medium at all pHs with maximal induction at pH 6.7. Inhibition of the G-protein-coupled receptor alpha, G(alphai), suppressed CXCL8 levels in response to acidic pH; whereas phospholipase C inhibition had no effect on CXCL8. The use of specific mitogen-activated protein kinase (MAPK) signal transduction inhibitors indicated that the pH-dependent increase in CXCL8 mRNA is due to activation of ERK and p38 pathways. The JNK pathway was not involved. NF-kappaB inhibition resulted in a decrease in CXCL8 levels in hMSCs grown in non-OGM. However, OGM-differentiated hMSCs showed an increase in CXCL8 levels when treated with the NF-kappaB inhibitor PDTC, a pyrrolidine derivative of dithiocarbamate. PMID:18275043

  17. Molecular Pharmacology of Chemokine Receptors.

    PubMed

    de Wit, Raymond H; de Munnik, Sabrina M; Leurs, Rob; Vischer, Henry F; Smit, Martine J

    2016-01-01

    Chemokine receptors are involved in various pathologies such as inflammatory diseases, cancer, and HIV infection. Small molecule and antibody-based antagonists have been developed to inhibit chemokine-induced receptor activity. Currently two small molecule inhibitors targeting CXCR4 and CCR5 are on the market for stem cell mobilization and the treatment of HIV infection, respectively. Antibody fragments (e.g., nanobodies) targeting chemokine receptors are primarily orthosteric ligands, competing for the chemokine binding site. This is opposed by most small molecules, which act as allosteric modulators and bind to the receptor at a topographically distinct site as compared to chemokines. Allosteric modulators can be distinguished from orthosteric ligands by unique features, such as a saturable effect and probe dependency. For successful drug development, it is essential to determine pharmacological parameters (i.e., affinity, potency, and efficacy) and the mode of action of potential drugs during early stages of research in order to predict the biological effect of chemokine receptor targeting drugs in the clinic. This chapter explains how the pharmacological profile of chemokine receptor targeting ligands can be determined and quantified using binding and functional experiments. PMID:26921959

  18. Evaluation of the Microbicidal Activity and Cytokines/Chemokines Profile Released by Neutrophils from HTLV-1-Infected Individuals

    PubMed Central

    Bezerra, Caroline A.; Cardoso, Thiago M.; Giudice, Angela; Porto, Aurélia F.; Santos, Silvane B.; Carvalho, Edgar M.; Bacellar, Olívia

    2011-01-01

    Human T cell lymphotropic virus type-1 (HTLV-1) induces activation and spontaneous proliferation of T cells with production of type-1 pro-inflammatory cytokines. It modifies the immune response to other antigens and increases susceptibility to infectious diseases. However, little is known about innate immunity in HTLV-1 infection. HTLV-1-infected individuals have higher spontaneous neutrophil activation than HTLV-1-seronegative individuals, as shown by the nitroblue tetrazolium (NBT) assay. This study was conducted to evaluate neutrophil function in HTLV-1-infected individuals. Participants in the study included 18 HTLV-1-infected individuals and 14 HTLV-1-seronegative controls. We evaluated the ability of neutrophils (PMNs) to control a parasite infection, to produce peroxynitrite, cytokines and chemokines and to express activation markers in cultures when stimulated with LPS or infected with Leishmania. When compared with the control group, there was no difference in the percentage of PMNs infected with Leishmania or in the number of amastigotes/100 PMNs in HTLV-1-infected individuals. The microbicidal activity of the PMNs and the levels of CXCL8 and CCL4 released by these cells did not show a difference between HTLV-1-infected individuals and the control group. In both the HTLV-1 group and the control group, infection with Leishmania or stimulation of PMNs led to cellular activation. These observations suggest that neutrophils from HTLV-1-infected individuals have preserved their ability to become activated and to produce chemokines and peroxynitrite after stimulation and that the susceptibility to infection by intracellular Leishmania amazonensis in HTLV-1-infected individuals does not depend on impairment of neutrophil function. PMID:21595736

  19. Biased agonism at chemokine receptors: obstacles or opportunities for drug discovery?

    PubMed

    Anderson, Caroline A; Solari, Roberto; Pease, James E

    2016-06-01

    Chemokine receptors are typically promiscuous, binding more than one ligand, with the ligands themselves often expressed in different spatial localizations by multiple cell types. This is normally a tightly regulated process; however, in a variety of inflammatory disorders, dysregulation results in the excessive or inappropriate expression of chemokines that drives disease progression. Biased agonism, the phenomenon whereby different ligands of the same receptor are able to preferentially activate one signaling pathway over another, adds another level of complexity to an already complex system. In this minireview, we discuss the concept of biased agonism within the chemokine family and report that targeting single signaling axes downstream of chemokine receptors is not only achievable, but may well present novel opportunities to target chemokine receptors, allowing the fine tuning of receptor responses in the context of allergic inflammation and beyond. PMID:26701135

  20. Chemokine receptor CXCR3 agonist prevents human T-cell migration in a humanized model of arthritic inflammation.

    PubMed

    O'Boyle, Graeme; Fox, Christopher R J; Walden, Hannah R; Willet, Joseph D P; Mavin, Emily R; Hine, Dominic W; Palmer, Jeremy M; Barker, Catriona E; Lamb, Christopher A; Ali, Simi; Kirby, John A

    2012-03-20

    The recruitment of T lymphocytes during diseases such as rheumatoid arthritis is regulated by stimulation of the chemokine receptors expressed by these cells. This study was designed to assess the potential of a CXCR3-specific small-molecule agonist to inhibit the migration of activated human T cells toward multiple chemokines. Further experiments defined the molecular mechanism for this anti-inflammatory activity. Analysis in vitro demonstrated agonist induced internalization of both CXCR3 and other chemokine receptors coexpressed by CXCR3(+) T cells. Unlike chemokine receptor-specific antagonists, the CXCR3 agonist inhibited migration of activated T cells toward the chemokine mixture in synovial fluid from patients with active rheumatoid arthritis. A humanized mouse air-pouch model showed that intravenous treatment with the CXCR3 agonist prevented inflammatory migration of activated human T cells toward this synovial fluid. A potential mechanism for this action was defined by demonstration that the CXCR3 agonist induces receptor cross-phosphorylation within CXCR3-CCR5 heterodimers on the surface of activated T cells. This study shows that generalized chemokine receptor desensitization can be induced by specific stimulation of a single chemokine receptor on the surface of activated human T cells. A humanized mouse model was used to demonstrate that this receptor desensitization inhibits the inflammatory response that is normally produced by the chemokines present in synovial fluid from patients with active rheumatoid arthritis. PMID:22392992

  1. Mechanical stretch inhibits lipopolysaccharide-induced keratinocyte-derived chemokine and tissue factor expression while increasing procoagulant activity in murine lung epithelial cells.

    PubMed

    Sebag, Sara C; Bastarache, Julie A; Ware, Lorraine B

    2013-03-15

    Previous studies have shown that the innate immune stimulant LPS augments mechanical ventilation-induced pulmonary coagulation and inflammation. Whether these effects are mediated by alveolar epithelial cells is unclear. The alveolar epithelium is a key regulator of the innate immune reaction to pathogens and can modulate both intra-alveolar inflammation and coagulation through up-regulation of proinflammatory cytokines and tissue factor (TF), the principal initiator of the extrinsic coagulation pathway. We hypothesized that cyclic mechanical stretch (MS) potentiates LPS-mediated alveolar epithelial cell (MLE-12) expression of the chemokine keratinocyte-derived cytokine (KC) and TF. Contrary to our hypothesis, MS significantly decreased LPS-induced KC and TF mRNA and protein expression. Investigation into potential mechanisms showed that stretch significantly reduced LPS-induced surface expression of TLR4 that was not a result of increased degradation. Decreased cell surface TLR4 expression was concomitant with reduced LPS-mediated NF-κB activation. Immunofluorescence staining showed that cyclic MS markedly altered LPS-induced organization of actin filaments. In contrast to expression, MS significantly increased LPS-induced cell surface TF activity independent of calcium signaling. These findings suggest that cyclic MS of lung epithelial cells down-regulates LPS-mediated inflammatory and procoagulant expression by modulating actin organization and reducing cell surface TLR4 expression and signaling. However, because LPS-induced surface TF activity was enhanced by stretch, these data demonstrate differential pathways regulating TF expression and activity. Ultimately, loss of LPS responsiveness in the epithelium induced by MS could result in increased susceptibility of the lung to bacterial infections in the setting of mechanical ventilation. PMID:23362270

  2. Mechanical Stretch Inhibits Lipopolysaccharide-induced Keratinocyte-derived Chemokine and Tissue Factor Expression While Increasing Procoagulant Activity in Murine Lung Epithelial Cells*

    PubMed Central

    Sebag, Sara C.; Bastarache, Julie A.; Ware, Lorraine B.

    2013-01-01

    Previous studies have shown that the innate immune stimulant LPS augments mechanical ventilation-induced pulmonary coagulation and inflammation. Whether these effects are mediated by alveolar epithelial cells is unclear. The alveolar epithelium is a key regulator of the innate immune reaction to pathogens and can modulate both intra-alveolar inflammation and coagulation through up-regulation of proinflammatory cytokines and tissue factor (TF), the principal initiator of the extrinsic coagulation pathway. We hypothesized that cyclic mechanical stretch (MS) potentiates LPS-mediated alveolar epithelial cell (MLE-12) expression of the chemokine keratinocyte-derived cytokine (KC) and TF. Contrary to our hypothesis, MS significantly decreased LPS-induced KC and TF mRNA and protein expression. Investigation into potential mechanisms showed that stretch significantly reduced LPS-induced surface expression of TLR4 that was not a result of increased degradation. Decreased cell surface TLR4 expression was concomitant with reduced LPS-mediated NF-κB activation. Immunofluorescence staining showed that cyclic MS markedly altered LPS-induced organization of actin filaments. In contrast to expression, MS significantly increased LPS-induced cell surface TF activity independent of calcium signaling. These findings suggest that cyclic MS of lung epithelial cells down-regulates LPS-mediated inflammatory and procoagulant expression by modulating actin organization and reducing cell surface TLR4 expression and signaling. However, because LPS-induced surface TF activity was enhanced by stretch, these data demonstrate differential pathways regulating TF expression and activity. Ultimately, loss of LPS responsiveness in the epithelium induced by MS could result in increased susceptibility of the lung to bacterial infections in the setting of mechanical ventilation. PMID:23362270

  3. The sweet spot: how GAGs help chemokines guide migrating cells.

    PubMed

    Monneau, Yoan; Arenzana-Seisdedos, Fernando; Lortat-Jacob, Hugues

    2016-06-01

    Glycosaminoglycans are polysaccharides that occur both at the cell surface and within extracellular matrices. Through their ability to bind to a large array of proteins, almost 500 of which have been identified to date, including most chemokines, these molecules regulate key biologic processes at the cell-tissue interface. To do so, glycosaminoglycans can provide scaffolds to ensure that proteins mediating specific functions will be presented at the correct site and time and can also directly contribute to biologic activities or signaling processes. The binding of chemokines to glycosaminoglycans, which, at the biochemical level, has been mostly studied using heparin, has traditionally been thought of as a mechanism for maintaining haptotactic gradients within tissues along which cells can migrate directionally. Many aspects of chemokine-glycosaminoglycan interactions, however, also suggest that the formation of these complexes could serve additional purposes that go well beyond a simple immobilization process. In addition, progress in glycobiology has revealed that glycosaminoglycan structures, in term of length, sulfation, and epimerization pattern, are specific for cell, tissue, and developmental stage. Glycosaminoglycan regulation and glycosaminoglycan diversity, which cannot be replicated using heparin, thus suggests that these molecules may fine-tune the immune response by selectively recruiting specific chemokines to cell surfaces. In this context, the aim of the present text is to review the chemokine-glycosaminoglycan complexes described to date and provide a critical analysis of the tools, molecules, and strategies that can be used to structurally and functionally investigate the formation of these complexes. PMID:26701132

  4. Chemokines and the microenvironment in neuroectodermal tumor-host interaction

    PubMed Central

    Somasundaram, Rajasekharan; Herlyn, Dorothee

    2009-01-01

    Chemokines and chemokine receptors play an important role in immune homeostasis and surveillance. Altered or defective expression of chemokines and/or chemokine receptors could lead to a disease state including autoimmune disorder or cancer. Tumors from glioblastoma, melanoma, and neuroblastoma secrete high levels of chemokines that can promote tumor growth and progression or induce stromal cells present in the tumor microenvironment to produce cytokines or chemokines which, in turn, can regulate angiogenesis, tumor growth, and metastasis. On the other hand, chemokines secreted by tumor or stromal cells can also attract leukocytes such as dendritic cells, macrophages, neutrophils, and lymphocytes which may downmodulate tumor growth. New therapies that are aimed at limiting tumor growth and progression by attracting immune effector cells to the tumor site with chemokines may hold the key to the successful treatment of cancer, although this approach may be hampered by possible tumor growth-stimulating effects of chemokines. PMID:19049876

  5. Transcription factor RUNX2 up-regulates chemokine receptor CXCR4 to promote invasive and metastatic potentials of human gastric cancer

    PubMed Central

    Guo, Zheng-Jun; Yang, Lang; Qian, Feng; Wang, Yan-Xia; Yu, Xi; Ji, Cheng-Dong; Cui, Wei; Xiang, Dong-Fang; Zhang, Xia; Zhang, Peng; Wang, Ji Ming; Cui, You-Hong; Bian, Xiu-Wu

    2016-01-01

    Runt-related transcription factor 2 (RUNX2) is a regulator of embryogenesis and development, but has also been implicated in the progression of certain human cancer. This study aimed to elucidate the role of RUNX2 in the invasive and metastatic potentials of human gastric cancer (GC) and the underlying mechanisms. We found that the levels of RUNX2 expression in gastric cancer tissues were correlated with the differentiation degrees, invasion depth and lymph node metastasis. COX regression analysis indicated that RUNX2 was an independent prognostic indicator for GC patients. RUNX2 significantly increased the migration and invasion ability of GC cells in vitro and enhanced the invasion and metastatic potential of GC cells in an orthotopic GC model of nude mice. Mechanistically, RUNX2 directly bound to the promoter region of the gene coding for the chemokine receptor CXCR4 to enhance its transcription. CXCR4 knockdown or treatment with AMD3100, a CXCR4 inhibitor, attenuated RUNX2-promoted invasion and metastasis. These results demonstrate that RUNX2 promotes the invasion and metastasis of human GC by transcriptionally up-regulating the chemokine receptor CXCR4. Therefore, the RUNX2-CXCR4 axis is a potential therapeutic target for GC. PMID:27007162

  6. Prostaglandin I2 Suppresses Proinflammatory Chemokine Expression, CD4 T Cell Activation, and STAT6-Independent Allergic Lung Inflammation.

    PubMed

    Zhou, Weisong; Zhang, Jian; Goleniewska, Kasia; Dulek, Daniel E; Toki, Shinji; Newcomb, Dawn C; Cephus, Jacqueline Y; Collins, Robert D; Wu, Pingsheng; Boothby, Mark R; Peebles, R Stokes

    2016-09-01

    Allergic airway diseases are immune disorders associated with heightened type 2 immune responses and IL-5 and IL-13 production at the site of inflammation. We have previously reported that cyclooxygenase (COX) inhibition by indomethacin augmented allergic airway inflammation in a STAT6-independent manner. However, the key COX product(s) responsible for restraining indomethacin-mediated STAT6-independent allergic inflammation is unknown. In this study, using the mouse model of OVA-induced allergic airway inflammation, we identified that PGI2 receptor (IP) signaling was critical for indomethacin-induced, STAT6-independent proallergic effects. We demonstrated that IP deficiency increased inflammatory cell infiltration, eosinophilia, and IL-5 and IL-13 expression in the lung in a STAT6-independent manner. The augmented STAT6-independent allergic inflammation correlated with enhanced primary immune responses to allergic sensitization and elevated production of multiple inflammatory chemokines (CCL11, CCL17, CCL22, and CXCL12) in the lung after allergen challenge. We also showed that the PGI2 analogue cicaprost inhibited CD4 T cell proliferation and IL-5 and IL-13 expression in vitro, and IP deficiency diminished the stimulatory effect of indomethacin on STAT6-independent IL-5 and IL-13 responses in vivo. The inhibitory effects of PGI2 and the IP signaling pathway on CD4 T cell activation, inflammatory chemokine production, and allergic sensitization and airway inflammation suggest that PGI2 and its analogue iloprost, both Food and Drug Administration-approved drugs, may be useful in treating allergic diseases and asthma. In addition, inhibiting PGI2 signaling by drugs that either block PGI2 production or restrain IP signaling may augment STAT6-independent pathways of allergic inflammation. PMID:27456482

  7. Decidual cell regulation of natural killer cell-recruiting chemokines: implications for the pathogenesis and prediction of preeclampsia.

    PubMed

    Lockwood, Charles J; Huang, S Joseph; Chen, Chie-Pein; Huang, Yingqun; Xu, Jie; Faramarzi, Saeed; Kayisli, Ozlem; Kayisli, Umit; Koopman, Louise; Smedts, Dineke; Buchwalder, Lynn F; Schatz, Frederick

    2013-09-01

    First trimester human decidua is composed of decidual cells, CD56(bright)CD16(-) decidual natural killer (dNK) cells, and macrophages. Decidual cells incubated with NK cell-derived IFN-γ and either macrophage-derived TNF-α or IL-1β synergistically enhanced mRNA and protein expression of IP-10 and I-TAC. Both chemokines recruit CXCR3-expressing NK cells. This synergy required IFN-γ receptor 1 and 2 mediation via JAK/STAT and NFκB signaling pathways. However, synergy was not observed on neutrophil, monocyte, and NK cell-recruiting chemokines. Immunostaining of first trimester decidua localized IP-10, I-TAC, IFN-γR1, and -R2 to vimentin-positive decidual cells versus cytokeratin-positive interstitial trophoblasts. Flow cytometry identified high CXCR3 levels on dNK cells and minority peripheral CD56(bright)CD16(-) pNK cells and intermediate CXCR3 levels on the majority of CD56(dim)CD16(+) pNK cells. Incubation of pNK cells with either IP-10 or I-TAC elicited concentration-dependent enhanced CXCR3 levels and migration of both pNK cell subsets that peaked at 10 ng/mL, whereas each chemokine at a concentration of 50 ng/mL inhibited CXCR3 expression and pNK cell migration. Deciduae from women with preeclampsia, a leading cause of maternal and fetal morbidity and mortality, displayed significantly lower dNK cell numbers and higher IP-10 and I-TAC levels versus gestational age-matched controls. Significantly elevated IP-10 levels in first trimester sera from women eventually developing preeclampsia compared with controls, identifying IP-10 as a novel, robust early predictor of preeclampsia. PMID:23973270

  8. Peroxisome proliferator-activated receptor {alpha} agonists modulate Th1 and Th2 chemokine secretion in normal thyrocytes and Graves' disease

    SciTech Connect

    Antonelli, Alessandro; Ferrari, Silvia Martina; Frascerra, Silvia; Corrado, Alda; Pupilli, Cinzia; Bernini, Giampaolo; Benvenga, Salvatore; Ferrannini, Ele; Fallahi, Poupak

    2011-07-01

    Until now, no data are present about the effect of peroxisome proliferator-activated receptor (PPAR){alpha} activation on the prototype Th1 [chemokine (C-X-C motif) ligand (CXCL)10] (CXCL10) and Th2 [chemokine (C-C motif) ligand 2] (CCL2) chemokines secretion in thyroid cells. The role of PPAR{alpha} and PPAR{gamma} activation on CXCL10 and CCL2 secretion was tested in Graves' disease (GD) and control primary thyrocytes stimulated with interferon (IFN){gamma} and tumor necrosis factor (TNF){alpha}. IFN{gamma} stimulated both CXCL10 and CCL2 secretion in primary GD and control thyrocytes. TNF{alpha} alone stimulated CCL2 secretion, while had no effect on CXCL10. The combination of IFN{gamma} and TNF{alpha} had a synergistic effect both on CXCL10 and CCL2 chemokines in GD thyrocytes at levels comparable to those of controls. PPAR{alpha} activators inhibited the secretion of both chemokines (stimulated with IFN{gamma} and TNF{alpha}) at a level higher (for CXCL10, about 60-72%) than PPAR{gamma} agonists (about 25-35%), which were confirmed to inhibit CXCL10, but not CCL2. Our data show that CCL2 is modulated by IFN{gamma} and TNF{alpha} in GD and normal thyrocytes. Furthermore we first show that PPAR{alpha} activators inhibit the secretion of CXCL10 and CCL2 in thyrocytes, suggesting that PPAR{alpha} may be involved in the modulation of the immune response in the thyroid.

  9. Utility of CSF Cytokine/Chemokines as Markers of Active Intrathecal Inflammation: Comparison of Demyelinating, Anti-NMDAR and Enteroviral Encephalitis

    PubMed Central

    Kothur, Kavitha; Wienholt, Louise; Mohammad, Shekeeb S.; Tantsis, Esther M.; Pillai, Sekhar; Britton, Philip N.; Jones, Cheryl A.; Angiti, Rajeshwar R.; Barnes, Elizabeth H.; Schlub, Timothy; Bandodkar, Sushil; Brilot, Fabienne; Dale, Russell C.

    2016-01-01

    Background Despite the discovery of CSF and serum diagnostic autoantibodies in autoimmune encephalitis, there are still very limited CSF biomarkers for diagnostic and monitoring purposes in children with inflammatory or autoimmune brain disease. The cause of encephalitis is unknown in up to a third of encephalitis cohorts, and it is important to differentiate infective from autoimmune encephalitis given the therapeutic implications. Aim To study CSF cytokines and chemokines as diagnostic biomarkers of active neuroinflammation, and assess their role in differentiating demyelinating, autoimmune, and viral encephalitis. Methods We measured and compared 32 cytokine/chemokines using multiplex immunoassay and APRIL and BAFF using ELISA in CSF collected prior to commencing treatment from paediatric patients with confirmed acute disseminated encephalomyelitis (ADEM, n = 16), anti-NMDAR encephalitis (anti-NMDAR E, n = 11), and enteroviral encephalitis (EVE, n = 16). We generated normative data using CSF from 20 non-inflammatory neurological controls. The sensitivity of CSF cytokine/chemokines to diagnose encephalitis cases was calculated using 95th centile of control values as cut off. We correlated CSF cytokine/chemokines with disease severity and follow up outcome based on modified Rankin scale. One-way hierarchical correlational cluster analysis of molecules was performed in different encephalitis and outcome groups. Results In descending order, CSF TNF-α, IL-10, IFN-α, IL-6, CXCL13 and CXCL10 had the best sensitivity (>79.1%) when all encephalitis patients were included. The combination of IL-6 and IFN-α was most predictive of inflammation on multiple logistic regression with area under the ROC curve 0.99 (CI 0.97–1.00). There were no differences in CSF cytokine concentrations between EVE and anti-NMDAR E, whereas ADEM showed more pronounced elevation of Th17 related (IL-17, IL-21) and Th2 (IL-4, CCL17) related cytokine/chemokines. Unlike EVE, heat map analysis

  10. ROLE OF CHEMOKINES IN TUMOR GROWTH

    PubMed Central

    Raman, Dayanidhi; Baugher, Paige J.; Thu, Yee Mon; Richmond, Ann

    2007-01-01

    Chemokines play a paramount role in the tumor progression. Chronic inflammation promotes tumor formation. Both tumor cells and stromal cells elaborate chemokines and cytokines. These act either by autocrine or paracrine mechanisms to sustain tumor cell growth, induce angiogenesis and facilitate evasion of immune surveillance through immunoediting. The chemokine receptor CXCR2 and its ligands promote tumor angiogenesis and leukocyte infiltration into the tumor microenvironment. In harsh acidic and hypoxic microenvironmental conditions tumor cells up-regulate their expression of CXCR4, which equips them to migrate up a gradient of CXCL12 elaborated by carcinoma associated fibroblasts (CAFs) to a normoxic microenvironment. The CXCL12-CXCR4 axis facilitates metastasis to distant organs and the CCL21-CCR7 chemokine ligand-receptor pair favors metastasis to lymph nodes. These two chemokine ligand-receptor systems are common key mediators of tumor cell metastasis for several malignancies and as such provide key targets for chemotherapy. In this paper, the role of specific chemokines/chemokine receptor interactions in tumor progression, growth and metastasis and the role of chemokine/chemokine receptor interactions in the stromal compartment as related to angiogenesis, metastasis, and immune response to the tumor are reviewed. PMID:17629396

  11. Increased expression of chemokines in patients with Wegener's granulomatosis – modulating effects of methylprednisolone in vitro

    PubMed Central

    Torheim, E A; Yndestad, A; Bjerkeli, V; Halvorsen, B; Aukrust, P; Frøland, S S

    2005-01-01

    Chemokines, a group of cytokines that attracts and activates leucocyte subpopulations in inflamed tissue, have been associated with the pathogenesis of a number of inflammatory diseases, and some recent reports have suggested their involvement in Wegener's granulomatosis (WG). To elucidate further the possible role of chemokines in WG we examined serum levels of several CC- and CXC-chemokines in WG patients and assessed the ability of corticosteroids to modulate the expression of these mediators in vitro. Our main findings were: (i) WG patients (n = 14) had elevated serum levels of several inflammatory chemokines [i.e. regulated upon activation normal T cell expressed and secreted (RANTES), monocyte chemoattractant protein (MCP)-1 and interleukin (IL)-8] compared to healthy controls (n = 9), as assessed by enzyme immunoassays (EIAs); (ii) by using EIAs and real-time reverse transcription-polymerase chain reaction (RT-PCR), we demonstrated the ability of methylprednisolone (MP) to down-regulate both the spontaneous and the staphylococcal enterotoxin B (SEB)-induced release of chemokines from peripheral blood mononuclear cells (PBMC) in vitro in both WG patients and controls, possibly involving both transcriptional and post-transcriptional mechanisms; and (iii) the ability of MP to attenuate chemokine secretion was less pronounced in WG patients than in controls, particularly with regard to inhibition of spontaneous release. Our findings suggest a role for chemokines in the pathogenesis of WG. The diminished MP-mediated suppression of chemokines in PBMC from WG patients suggests that more specific modulators of chemokine levels should be investigated in this disorder. PMID:15807865

  12. Chemokine Receptor Oligomerization and Allostery

    PubMed Central

    Stephens, Bryan; Handel, Tracy M.

    2014-01-01

    Oligomerization of chemokine receptors has been reported to influence many aspects of receptor function through allosteric communication between receptor protomers. Allosteric interactions within chemokine receptor hetero-oligomers have been shown to cause negative cooperativity in the binding of chemokines and to inhibit receptor activation in the case of some receptor pairs. Other receptor pairs can cause enhanced signaling and even activate entirely new, hetero-oligomer-specific signaling complexes and responses downstream of receptor activation. Many mechanisms contribute to these effects including direct allosteric coupling between the receptors, G protein mediated allostery, G protein stealing, ligand sequestration and recruitment of new intracellular proteins by exposing unique binding interfaces on the oligomerized receptors. These effects present both challenges as well as exciting opportunities for drug discovery. One of the most difficult challenges will involve determining if and when hetero-oligomers versus homo-oligomers are involved in specific disease states. PMID:23415099

  13. The Tandem PH Domain-Containing Protein 2 (TAPP2) Regulates Chemokine-Induced Cytoskeletal Reorganization and Malignant B Cell Migration

    PubMed Central

    Li, Hongzhao; Hou, Sen; Wu, Xun; Nandagopal, Saravanan; Lin, Francis; Kung, Sam; Marshall, Aaron James

    2013-01-01

    The intracellular signaling processes controlling malignant B cell migration and tissue localization remain largely undefined. Tandem PH domain-containing proteins TAPP1 and TAPP2 are adaptor proteins that specifically bind to phosphatidylinositol-3,4-bisphosphate, or PI(3,4)P2, a product of phosphoinositide 3-kinases (PI3K). While PI3K enzymes have a number of functions in cell biology, including cell migration, the functions of PI(3,4)P2 and its binding proteins are not well understood. Previously we found that TAPP2 is highly expressed in primary leukemic B cells that have strong migratory capacity. Here we find that SDF-1-dependent migration of human malignant B cells requires both PI3K signaling and TAPP2. Migration in a transwell assay is significantly impaired by pan-PI3K and isoform-selective PI3K inhibitors, or by TAPP2 shRNA knockdown (KD). Strikingly, TAPP2 KD in combination with PI3K inhibitor treatment nearly abolished the migration response, suggesting that TAPP2 may contribute some functions independent of the PI3K pathway. In microfluidic chamber cell tracking assays, TAPP2 KD cells show reduction in percentage of migrating cells, migration velocity and directionality. TAPP2 KD led to alterations in chemokine-induced rearrangement of the actin cytoskeleton and failure to form polarized morphology. TAPP2 co-localized with the stable F-actin-binding protein utrophin, with both molecules reciprocally localizing against F-actin accumulated at the leading edge upon SDF-1 stimulation. In TAPP2 KD cells, Rac was over-activated and localized to multiple membrane protrusions, suggesting that TAPP2 may act in concert with utrophin and stable F-actin to spatially restrict Rac activation and reduce formation of multiple membrane protrusions. TAPP2 function in cell migration is also apparent in the more complex context of B cell migration into stromal cell layers – a process that is only partially dependent on PI3K and SDF-1. In summary, this study identified

  14. Site-specific chemokine expression regulates central nervous system inflammation and determines clinical phenotype in autoimmune encephalomyelitis.

    PubMed

    Stoolman, Joshua S; Duncker, Patrick C; Huber, Amanda K; Segal, Benjamin M

    2014-07-15

    The adoptive transfer of myelin-reactive T cells into wild-type hosts results in spinal cord inflammation and ascending paralysis, referred to as conventional experimental autoimmune encephalomyelitis (EAE), as opposed to brainstem inflammation and ataxia, which characterize disease in IFN-γRKO hosts (atypical EAE). In this article, we show that atypical EAE correlates with preferential upregulation of CXCL2 in the brainstem, and is driven by CXCR2-dependent recruitment of neutrophils. In contrast, conventional EAE is associated with upregulation of CCL2 in the spinal cord, and is driven by recruitment of monocytes via a partially CCR2-dependent pathway. This study illustrates how regional differences in chemokine expression within a target organ shape the spatial pattern and composition of autoimmune infiltrates, leading to disparate clinical outcomes. PMID:24928987

  15. Entamoeba lysyl-tRNA Synthetase Contains a Cytokine-Like Domain with Chemokine Activity towards Human Endothelial Cells

    PubMed Central

    Han, Jung Min; Kim, Sunghoon; Celada, Antonio; Ribas de Pouplana, Lluís

    2011-01-01

    Immunological pressure encountered by protozoan parasites drives the selection of strategies to modulate or avoid the immune responses of their hosts. Here we show that the parasite Entamoeba histolytica has evolved a chemokine that mimics the sequence, structure, and function of the human cytokine HsEMAPII (Homo sapiens endothelial monocyte activating polypeptide II). This Entamoeba EMAPII-like polypeptide (EELP) is translated as a domain attached to two different aminoacyl-tRNA synthetases (aaRS) that are overexpressed when parasites are exposed to inflammatory signals. EELP is dispensable for the tRNA aminoacylation activity of the enzymes that harbor it, and it is cleaved from them by Entamoeba proteases to generate a standalone cytokine. Isolated EELP acts as a chemoattractant for human cells, but its cell specificity is different from that of HsEMAPII. We show that cell specificity differences between HsEMAPII and EELP can be swapped by site directed mutagenesis of only two residues in the cytokines' signal sequence. Thus, Entamoeba has evolved a functional mimic of an aaRS-associated human cytokine with modified cell specificity. PMID:22140588

  16. Detection and Quantification of Citrullinated Chemokines

    PubMed Central

    Moelants, Eva A. V.; Van Damme, Jo; Proost, Paul

    2011-01-01

    Background Posttranslational deimination or citrullination by peptidylarginine deiminases (PAD) regulates the biological function of proteins and may be involved in the development of autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. This posttranslational modification of arginine was recently discovered on inflammatory chemokines including CXCL8 and CXCL10, and significantly reduced their biological activity. To evaluate the importance of these modified chemokines in patients, methods for the detection and quantification of citrullinated chemokines are needed. Since citrullination only results in an increase of the protein mass with one mass unit and the loss of one positive charge, selective biochemical detection is difficult. Therefore, we developed an antibody-based method to specifically detect and quantify citrullination on a protein of interest. Methodology/Principal Findings First, the citrullinated proteins were chemically modified with antipyrine and 2,3-butanedione at low pH. Such selectively modified citrullines were subsequently detected and quantified by specific antibodies raised against a modified citrulline-containing peptide. The specificity of this two-step procedure was validated for citrullinated CXCL8 ([Cit5]CXCL8). Specific detection of [Cit5]CXCL8 concentrations between 1 and 50 ng/ml was possible, also in complex samples containing an excess of contaminating proteins. This novel detection method was used to evaluate the effect of lipopolysaccharide (LPS) on the citrullination of inflammatory chemokines induced in peripheral blood mononuclear cells (PBMCs) and granulocytes. LPS had no significant effect on the induction of CXCL8 citrullination in human PBMCs and granulocytes. However, granulocytes, known to contain PAD, were essential for the production of significant amounts of [Cit5]CXCL8. Conclusion/Significance The newly developed antibody-based method to specifically detect and quantify chemically modified

  17. Splicing Regulation of Pro-Inflammatory Cytokines and Chemokines: At the Interface of the Neuroendocrine and Immune Systems.

    PubMed

    Shakola, Felitsiya; Suri, Parul; Ruggiu, Matteo

    2015-01-01

    Alternative splicing plays a key role in posttranscriptional regulation of gene expression, allowing a single gene to encode multiple protein isoforms. As such, alternative splicing amplifies the coding capacity of the genome enormously, generates protein diversity, and alters protein function. More than 90% of human genes undergo alternative splicing, and alternative splicing is especially prevalent in the nervous and immune systems, tissues where cells need to react swiftly and adapt to changes in the environment through carefully regulated mechanisms of cell differentiation, migration, targeting, and activation. Given its prevalence and complexity, this highly regulated mode of gene expression is prone to be affected by disease. In the following review, we look at how alternative splicing of signaling molecules—cytokines and their receptors—changes in different pathological conditions, from chronic inflammation to neurologic disorders, providing means of functional interaction between the immune and neuroendocrine systems. Switches in alternative splicing patterns can be very dynamic and can produce signaling molecules with distinct or antagonistic functions and localization to different subcellular compartments. This newly discovered link expands our understanding of the biology of immune and neuroendocrine cells, and has the potential to open new windows of opportunity for treatment of neurodegenerative disorders. PMID:26371053

  18. Splicing Regulation of Pro-Inflammatory Cytokines and Chemokines: At the Interface of the Neuroendocrine and Immune Systems

    PubMed Central

    Shakola, Felitsiya; Suri, Parul; Ruggiu, Matteo

    2015-01-01

    Alternative splicing plays a key role in posttranscriptional regulation of gene expression, allowing a single gene to encode multiple protein isoforms. As such, alternative splicing amplifies the coding capacity of the genome enormously, generates protein diversity, and alters protein function. More than 90% of human genes undergo alternative splicing, and alternative splicing is especially prevalent in the nervous and immune systems, tissues where cells need to react swiftly and adapt to changes in the environment through carefully regulated mechanisms of cell differentiation, migration, targeting, and activation. Given its prevalence and complexity, this highly regulated mode of gene expression is prone to be affected by disease. In the following review, we look at how alternative splicing of signaling molecules—cytokines and their receptors—changes in different pathological conditions, from chronic inflammation to neurologic disorders, providing means of functional interaction between the immune and neuroendocrine systems. Switches in alternative splicing patterns can be very dynamic and can produce signaling molecules with distinct or antagonistic functions and localization to different subcellular compartments. This newly discovered link expands our understanding of the biology of immune and neuroendocrine cells, and has the potential to open new windows of opportunity for treatment of neurodegenerative disorders. PMID:26371053

  19. Factors regulating microglia activation

    PubMed Central

    Kierdorf, Katrin; Prinz, Marco

    2013-01-01

    Microglia are resident macrophages of the central nervous system (CNS) that display high functional similarities to other tissue macrophages. However, it is especially important to create and maintain an intact tissue homeostasis to support the neuronal cells, which are very sensitive even to minor changes in their environment. The transition from the “resting” but surveying microglial phenotype to an activated stage is tightly regulated by several intrinsic (e.g., Runx-1, Irf8, and Pu.1) and extrinsic factors (e.g., CD200, CX3CR1, and TREM2). Under physiological conditions, minor changes of those factors are sufficient to cause fatal dysregulation of microglial cell homeostasis and result in severe CNS pathologies. In this review, we discuss recent achievements that gave new insights into mechanisms that ensure microglia quiescence. PMID:23630462

  20. CXC-chemokine regulation and neutrophil trafficking in hepatic ischemia-reperfusion injury in P-selectin/ICAM-1 deficient mice

    PubMed Central

    Monson, Keith M; Dowlatshahi, Shadi; Crockett, Elahé T

    2007-01-01

    to be critical for neutrophil infiltration and I/R injury in the liver, they may regulate CXC-chemokine production. Blockage of these adhesion molecules may improve survival and remote organ injury that often accompanies liver I/R injury, through chemokine regulation. PMID:17524141

  1. A myriad of functions and complex regulation of the CCR7/CCL19/CCL21 chemokine axis in the adaptive immune system.

    PubMed

    Comerford, Iain; Harata-Lee, Yuka; Bunting, Mark D; Gregor, Carly; Kara, Ervin E; McColl, Shaun R

    2013-06-01

    The chemokine receptor CCR7 and its ligands CCL19 and CCL21 control a diverse array of migratory events in adaptive immune function. Most prominently, CCR7 promotes homing of T cells and DCs to T cell areas of lymphoid tissues where T cell priming occurs. However, CCR7 and its ligands also contribute to a multitude of adaptive immune functions including thymocyte development, secondary lymphoid organogenesis, high affinity antibody responses, regulatory and memory T cell function, and lymphocyte egress from tissues. In this survey, we summarise the role of CCR7 in adaptive immunity and describe recent progress in understanding how this axis is regulated. In particular we highlight CCX-CKR, which scavenges both CCR7 ligands, and discuss its emerging significance in the immune system. PMID:23587803

  2. Chemokines and Chemokine Receptors in Lymphoid Tissue Dynamics.

    PubMed

    Schulz, Olga; Hammerschmidt, Swantje I; Moschovakis, G Leandros; Förster, Reinhold

    2016-05-20

    The continuous migration of immune cells between lymphoid and nonlymphoid organs is a key feature of the immune system, facilitating the distribution of effector cells within nearly all compartments of the body. Furthermore, reaching their correct position within primary, secondary, or tertiary lymphoid organs is a prerequisite to ensure immune cells' unimpaired differentiation, maturation, and selection, as well as their activation or functional silencing. The superfamilies of chemokines and chemokine receptors are of major importance in guiding immune cells to and within lymphoid and nonlymphoid tissues. In this review we focus on the role of the chemokine system in the migration dynamics of immune cells within lymphoid organs at the steady state and on how these dynamics are affected by infectious and inflammatory processes. PMID:26907216

  3. CCL19 is a specific ligand of the constitutively recycling atypical human chemokine receptor CRAM-B.

    PubMed

    Leick, Marion; Catusse, Julie; Follo, Marie; Nibbs, Robert J; Hartmann, Tanja N; Veelken, Hendrik; Burger, Meike

    2010-04-01

    The human chemokine receptor CRAM (chemokine receptor on activated macrophages), encoded by the gene CCRL2, is a new candidate for the atypical chemokine receptor family that includes the receptors DARC, D6 and chemocentryx chemokine receptor (CCX-CKR). CRAM is maturation-stage-dependently expressed on human B lymphocytes and its surface expression is up-regulated upon short-term CCL5 exposure. Here, we demonstrate that the homeostatic chemokine CCL19 is a specific ligand for CRAM. In radioactive labelling studies CCL19 bound to CRAM-expressing cells with an affinity similar to the described binding of its other receptor CCR7. In contrast to the known CCL19/CCR7 ligand/receptor pair, CRAM stimulation by CCL19 did not result in typical chemokine-receptor-dependent cellular activation like calcium mobilization or migration. Instead, we demonstrate that CRAM is constitutively recycling via clathrin-coated pits and able to internalize CCL19 as well as anti-CRAM antibodies. As this absence of classical chemokine receptor responses and the recycling and internalization features are characteristic for non-classical chemokine receptors, we suggest that CRAM is the newest member of this group. As CCL19 is known to be critically involved in lymphocyte and dendritic cell trafficking, CCL19-binding competition by CRAM might be involved in modulating these processes. PMID:20002784

  4. Chemokines and immunity

    PubMed Central

    Palomino, Diana Carolina Torres; Marti, Luciana Cavalheiro

    2015-01-01

    Chemokines are a large family of small cytokines and generally have low molecular weight ranging from 7 to 15kDa. Chemokines and their receptors are able to control the migration and residence of all immune cells. Some chemokines are considered pro-inflammatory, and their release can be induced during an immune response at a site of infection, while others are considered homeostatic and are involved in controlling of cells migration during tissue development or maintenance. The physiologic importance of this family of mediators is resulting from their specificity − members of the chemokine family induce recruitment of well-defined leukocyte subsets. There are two major chemokine sub-families based upon cysteine residues position: CXC and CC. As a general rule, members of the CXC chemokines are chemotactic for neutrophils, and CC chemokines are chemotactic for monocytes and sub-set of lymphocytes, although there are some exceptions. This review discusses the potential role of chemokines in inflammation focusing on the two best-characterized chemokines: monocyte chemoattractant protein-1, a CC chemokine, and interleukin-8, a member of the CXC chemokine sub-family. PMID:26466066

  5. Up-regulation of Interferon-inducible protein 16 contributes to psoriasis by modulating chemokine production in keratinocytes

    PubMed Central

    Cao, Tianyu; Shao, Shuai; Li, Bing; Jin, Liang; Lei, Jie; Qiao, Hongjiang; Wang, Gang

    2016-01-01

    Psoriasis is a common chronic inflammatory skin disease characterized by epidermal hyperplasia and dermal inflammation. Keratinocyte activation is known to play a critical role in psoriasis, but the underlying mechanism remains unclear. Interferon-inducible protein 16 (IFI16), an innate immune system sensor, is reported to affect keratinocyte function. We therefore hypothesized that IFI16 promotes psoriasis by modulating keratinocyte activation. In the present study, we cinfirmed that IFI16 was overexpressed in epidermal keratinocytes of psoriasis patients. In addition, psoriasis-related cytokines, including IFN-γ, TNF-α, IL-17 and IL-22, induced IFI16 up-regulation in keratinocytes via activation of STAT3 signaling. We also observed that IFI16 activated the TBK1-NF-κB signaling, leading to the production of CXCL10 and CCL20. Importantly, knocking down p204, which is reported as the mouse orthologous of human IFI16, inhibited epidermal hyperplasia in mice with imiquimod-induced psoriasiform dermatitis. These findings indicate that IFI16 plays a critical role in the pathogenesis of psoriasis and may be a potential therapeutic target. PMID:27137868

  6. Role of chemokines and their receptors in viral persistence and liver damage during chronic hepatitis C virus infection.

    PubMed

    Larrubia, Juan R; Benito-Martínez, Selma; Calvino, Miryam; Sanz-de-Villalobos, Eduardo; Parra-Cid, Trinidad

    2008-12-21

    Chemokines produced in the liver during hepatitis C virus (HCV) infection induce migration of activated T cells from the periphery to infected parenchyma. The milieu of chemokines secreted by infected hepatocytes is predominantly associated with the T-helper cell/Tc1 T cell (Th1/Tc1) response. These chemokines consist of CCL3 (macrophage inflammatory protein-1 alpha; MIP-1 alpha), CCL4 (MIP-1 beta), CCL5 (regulated on activation normal T cell expressed and secreted; RANTES), CXCL10 (interferon-gamma-inducible protein-10; IP-10), CXCL11 (interferon-inducible T-cell alpha chemoattractant; I-TAC), and CXCL9 (monokine induced by interferon gamma; Mig) and they recruit T cells expressing either CCR5 or CXCR3 chemokine receptors. Intrahepatic and peripheral blood levels of these chemokines are increased during chronic hepatitis C. The interaction between chemokines and their receptors is essential in recruiting HCV-specific T cells to control the infection. When the adaptive immune response fails in this task, non-specific T cells without the capacity to control the infection are also recruited to the liver, and these are ultimately responsible for the persistent hepatic damage. The modulation of chemokine receptor expression and chemokine secretion could be a viral escape mechanism to avoid specific T cell migration to the liver during the early phase of infection, and to maintain liver viability during the chronic phase, by impairing non-specific T cell migration. Some chemokines and their receptors correlate with liver damage, and CXCL10 (IP-10) and CXCR3 levels have shown a clinical utility as predictors of treatment response outcome. The regulation of chemokines and their receptors could be a future potential therapeutic target to decrease liver inflammation and to increase specific T cell migration to the infected liver. PMID:19084927

  7. Semi-synthesis of chemokines.

    PubMed

    Beck-Sickinger, Annette G; Panitz, Nydia

    2014-10-01

    Protein ligation allows the introduction of a wide range of modifications into proteins that are not accessible by mutagenesis. This includes non-proteinogenic amino acids and even backbone modification. This review summarizes recent reports on modified chemokine variants by ligation technologies and includes the development of the first protein with a full secondary structure motif exchanged by a helix that exclusively consists of β-amino acids. Furthermore the first protein activatable by light by rearrangement of a depsi-peptide bond is described. Combining different ligation methods, immobilization and specific release of chemokines were achieved, which is of major importance for the gradient forming activity of chemokines. Examples are shown for CXCL8 (interleukin 8, IL-8) and CXCL12 (stromal derived factor 1, SDF 1) including their chemical and structural characterization as well as the most frequently used assays. PMID:25299571

  8. Aquaporin 5 increases keratinocyte-derived chemokine expression and NF-κB activity through ERK activation.

    PubMed

    Sakamoto, Yuima; Hisatsune, Akinori; Katsuki, Hiroshi; Horie, Ichiro; Isohama, Yoichiro

    2014-06-13

    Aquaporin-5 (AQP5) is a water-selective channel protein that is expressed in submucosal glands and alveolar epithelial cells in the lungs. Recent studies have revealed that AQPs regulate not only water metabolism, but also some cellular functions such as cell growth and migration. Here, we report the role of AQP5 in inflammatory responses. In MLE-12 cells, knockdown of AQP5 using siRNA (10-50 nM) attenuated TNF-α-induced expression of keratinocyte chemoattractant (KC) mRNA and protein. Conversely, in NIH-3T3 cells, overexpression of AQP5 increased KC expression, NF-κB activation, and ERK phosphorylation. The AQP5-induced increase of KC expression was diminished by treatment with ERK inhibitors. Taken together, we propose a new function of AQP5 as an inflammatory signal potentiator, which may be mediated by increased activation of ERK and NF-κB. PMID:24747567

  9. Touch of Chemokines

    PubMed Central

    Blanchet, Xavier; Langer, Marcella; Weber, Christian; Koenen, Rory R.; von Hundelshausen, Philipp

    2012-01-01

    Chemoattractant cytokines or chemokines constitute a family of structurally related proteins found in vertebrates, bacteria, or viruses. So far, 48 chemokine genes have been identified in humans, which bind to around 20 chemokine receptors. These receptors belong to the seven transmembrane G-protein-coupled receptor family. Chemokines and their receptors were originally studied for their role in cellular trafficking of leukocytes during inflammation and immune surveillance. It is now known that they exert different functions under physiological conditions such as homeostasis, development, tissue repair, and angiogenesis but also under pathological disorders including tumorigenesis, cancer metastasis, inflammatory, and autoimmune diseases. Physicochemical properties of chemokines and chemokine receptors confer the ability to homo- and hetero-oligomerize. Many efforts are currently performed in establishing new therapeutically compounds able to target the chemokine/chemokine receptor system. In this review, we are interested in the role of chemokines in inflammatory disease and leukocyte trafficking with a focus on vascular inflammatory diseases, the operating synergism, and the emerging therapeutic approaches of chemokines. PMID:22807925

  10. Thromboxane A2 Regulates CXCL1 and CXCL8 Chemokine Expression in the Nasal Mucosa–Derived Fibroblasts of Chronic Rhinosinusitis Patients

    PubMed Central

    Tsai, Yih-Jeng; Hao, Sheng-Po; Chen, Chih-Li; Wu, Wen-Bin

    2016-01-01

    Background Chronic rhinosinusitis without nasal polyps (CRSsNP) is a common chronic disease and the etiology remains unclear. Thromboxane A2 (TXA2) participates in platelet aggregation and tissue inflammation. In this study, the CXCL1/8 chemokine and TXA2-TP receptor expression in the CRSsNP mucosa was investigated. Experimental Approach Immunohistochemistry, chemokine release assay by ELISA, RT-PCR, Real-time PCR, Western blotting, pharmacological and siRNA knockdown analysis were applied in the CRSsNP tissue specimen and cultured nasal mucosa-derived fibroblasts. Results The immunohistochemistry results indicated that CXCL1 and CXCL8 were highly expressed in the CRSsNP mucosa compared with the controls; however, the TP receptors were expressed in both mucosa. Therefore, U46619 and IBOP, a TXA2 analog and TP agonist, were used to explore the role of TP activation in CXCL1/8 expression; both of these induced CXCL1/8 mRNA and protein expression in CRSsNP mucosa-derived fibroblasts. U46619 phosphorylated PI-3K, cyclic AMP (cAMP)/PKA, PKC, and cAMP response element (CREB). Activation of cAMP/PKA, PKC, and CREB was the major pathway for cxcl1/8 gene transcription. Pharmacological and siRNA knockdown analyses revealed that activation of cAMP/PKA and PKCμ/PKD pathways were required for CREB phosphorylation and PKA/C crosstalked with the PI-3K pathway. Conclusion and Implications Our study provides the first evidence for abundant TP receptor and CXCL1/8 expression in human CRSsNP mucosa and for TXA2 stimulation inducing CXCL1/8 expression in nasal fibroblasts primarily through TP receptor, cAMP/PKA, PKCμ/PKD, and CREB-related pathways. PMID:27351369

  11. Kinin B2 receptor regulates chemokines CCL2 and CCL5 expression and modulates leukocyte recruitment and pathology in experimental autoimmune encephalomyelitis (EAE) in mice

    PubMed Central

    Dos Santos, Adriana C; Roffê, Ester; Arantes, Rosa ME; Juliano, Luiz; Pesquero, Jorge L; Pesquero, João B; Bader, Michael; Teixeira, Mauro M; Carvalho-Tavares, Juliana

    2008-01-01

    Background Kinins are important mediators of inflammation and act through stimulation of two receptor subtypes, B1 and B2. Leukocyte infiltration contributes to the pathogenesis of autoimmune inflammation in the central nervous system (CNS), occurring not only in multiple sclerosis (MS) but also in experimental autoimmune encephalomyelitis (EAE). We have previously shown that the chemokines CCL2 and CCL5 play an important role in the adhesion of leukocytes to the brain microcirculation in EAE. The aim of the present study was to evaluate the relevance of B2 receptors to leukocyte-endothelium interactions in the cerebral microcirculation, and its participation in CNS inflammation in the experimental model of myelin-oligodendrocyte-glycoprotein (MOG)35–55-induced EAE in mice. Methods In order to evaluate the role of B2 receptor in the cerebral microvasculature we used wild-type (WT) and kinin B2 receptor knockout (B2-/-) mice subjected to MOG35–55-induced EAE. Intravital microscopy was used to investigate leukocyte recruitment on pial matter vessels in B2-/- and WT EAE mice. Histological documentation of inflammatory infiltrates in brain and spinal cords was correlated with intravital findings. The expression of CCL5 and CCL2 in cerebral tissue was assessed by ELISA. Results Clinical parameters of disease were reduced in B2-/- mice in comparison to wild type EAE mice. At day 14 after EAE induction, there was a significant decrease in the number of adherent leukocytes, a reduction of cerebral CCL5 and CCL2 expressions, and smaller inflammatory and degenerative changes in B2-/- mice when compared to WT. Conclusion Our results suggest that B2 receptors have two major effects in the control of EAE severity: (i) B2 regulates the expression of chemokines, including CCL2 and CCL5, and (ii) B2 modulates leukocyte recruitment and inflammatory lesions in the CNS. PMID:18986535

  12. Gene expression profiles in the bovine corpus luteum (CL) during the estrous cycle and pregnancy: possible roles of chemokines in regulating CL function during pregnancy.

    PubMed

    Sakumoto, Ryosuke; Hayashi, Ken-Go; Hosoe, Misa; Iga, Kosuke; Kizaki, Keiichiro; Okuda, Kiyoshi

    2015-01-01

    To determine functional differences between the corpus luteum (CL) of the estrous cycle and pregnancy in cows, gene expression profiles were compared using a 15 K bovine oligo DNA microarray. In the pregnant CL at days 20-25, 40-45 and 150-160, the expressions of 138, 265 and 455 genes differed by a factor of > 2-fold (P < 0.05) from their expressions in the cyclic CL (days 10-12 of the estrous cycle). Messenger RNA expressions of chemokines (eotaxin, lymphotactin and ENA-78) and their receptors (CCR3, XCR1 and CXCR2) were validated by quantitative real-time PCR. Transcripts of eotaxin were more abundant in the CL at days 40-45 and 150-160 of pregnancy than in the cyclic CL (P < 0.01). In contrast, the mRNA expressions of lymphotactin, ENA-78 and XCR1 were lower in the CL of pregnancy (P < 0.05). Messenger RNAs of CCR3 and CXCR2 were similarly detected both in the cyclic and pregnant CL. Tissue protein levels of eotaxin were significantly higher in the CL at days 150-160 of pregnancy than in the CL at other stages, whereas the lymphotactin protein levels in the CL at days 20-25 of pregnancy were lower (P < 0.05). Immunohistochemical staining showed that CCR3 was expressed in the luteal cells and that XCR1 was expressed in both the luteal cells and endothelial cells. Collectively, the different gene expression profiles may contribute to functional differences between the cyclic and pregnant CL, and chemokines including eotaxin and lymphotactin may regulate CL function during pregnancy in cows. PMID:25382605

  13. The Role of Chemokines in Breast Cancer Pathology and Its Possible Use as Therapeutic Targets

    PubMed Central

    Palacios-Arreola, M. Isabel; Nava-Castro, Karen E.; Castro, Julieta I.; García-Zepeda, Eduardo; Carrero, Julio C.; Morales-Montor, Jorge

    2014-01-01

    Chemokines are small proteins that primarily regulate the traffic of leukocytes under homeostatic conditions and during specific immune responses. The chemokine-chemokine receptor system comprises almost 50 chemokines and approximately 20 chemokine receptors; thus, there is no unique ligand for each receptor and the binding of different chemokines to the same receptor might have disparate effects. Complicating the system further, these effects depend on the cellular milieu. In cancer, although chemokines are associated primarily with the generation of a protumoral microenvironment and organ-directed metastasis, they also mediate other phenomena related to disease progression, such as angiogenesis and even chemoresistance. Therefore, the chemokine system is becoming a target in cancer therapeutics. We review the emerging data and correlations between chemokines/chemokine receptors and breast cancer, their implications in cancer progression, and possible therapeutic strategies that exploit the chemokine system. PMID:25165728

  14. Rainbow trout CK9, a CCL25-like ancient chemokine that attracts and regulates B cells and macrophages, the main antigen presenting cells in fish

    PubMed Central

    Aquilino, Carolina; Granja, Aitor G.; Castro, Rosario; Wang, Tiehui; Abos, Beatriz; Parra, David; Secombes, Christopher J.; Tafalla, Carolina

    2016-01-01

    CK9 is a rainbow trout (Oncorhynchus mykiss) CC chemokine phylogenetically related to mammalian CCL25. Although CK9 is known to be transcriptionally regulated in response to inflammation particularly in mucosal tissues, its functionality has never been revealed. In the current work, we have demonstrated that CK9 is chemoattractant for antigen presenting cells (APCs) expressing major histocompatibility complex class II (MHC II) on the cell surface. Among these APCs, CK9 has a strong chemotactic capacity for both B cells (IgM+ and IgT+) and macrophages. Along with its chemotactic capacities, CK9 modulated the MHC II turnover of B lymphocytes and up-regulated the phagocytic capacity of both IgM+ cells and macrophages. Although CK9 had no lymphoproliferative effects, it increased the survival of IgT+ lymphocytes. Furthermore, we have established that the chemoattractant capacity of CK9 is strongly increased after pre-incubation of leukocytes with a T-independent antigen, whereas B cell receptor (BCR) cross-linking strongly abrogated their capacity to migrate to CK9, indicating that CK9 preferentially attracts B cells at the steady state or under BCR-independent stimulation. These results point to CK9 being a key regulator of B lymphocyte trafficking in rainbow trout, able to modulate innate functions of teleost B lymphocytes and macrophages. PMID:27003360

  15. Chemokine receptors in cancer metastasis and cancer cell-derived chemokines in host immune response.

    PubMed

    Koizumi, Keiichi; Hojo, Shozo; Akashi, Takuya; Yasumoto, Kazuo; Saiki, Ikuo

    2007-11-01

    The chemotactic cytokines called chemokines are a superfamily of small secreted cytokines that were initially characterized through their ability to prompt the migration of leukocytes. Attention has been focused on the chemokine receptors expressed on cancer cells because cancer cell migration and metastasis show similarities to leukocyte trafficking. CXC chemokine receptor 4 (CXCR4) was first investigated as a chemokine receptor that is associated with lung metastasis of breast cancers. Recently, CXCR4 was reported to be a key molecule in the formation of peritoneal carcinomatosis in gastric cancer. In the present review, we highlight current knowledge about the role of CXCR4 in cancer metastases. In contrast to chemokine receptors expressed on cancer cells, little is known about the roles of cancer cell-derived chemokines. Cancer tissue consists of both cancer cells and various stromal cells, and leukocytes that infiltrate into cancer are of particular importance in cancer progression. Although colorectal cancer invasion is regulated by the chemokine CCL9-induced infiltration of immature myeloid cells into cancer, high-level expression of cancer cell-derived chemokine CXCL16 increases infiltrating CD8(+) and CD4(+) T cells into cancer tissues, and correlates with a good prognosis. We discuss the conflicting biological effects of cancer cell-derived chemokines on cancer progression, using CCL9 and CXCL16 as examples. PMID:17894551

  16. Mitochondrial-derived oxidants and quartz activation of chemokine gene expression.

    PubMed

    Driscoll, K E; Howard, B W; Carter, J M; Janssen, Y M; Mossman, B T; Isfort, R J

    2001-01-01

    Macrophage inflammatory protein 2 (MIP-2) is a chemotactic cytokine which mediates neutrophil recruitment in the lung and other tissues. Pneumotoxic particles such as quartz increase MIP-2 expression in rat lung and rat alveolar type II epithelial cells. Deletion mutant analysis of the rat MIP-2 promoter demonstrated quartz-induction depended on a single NFkappaB consensus binding site. Quartz activation of NFkappaB and MIP-2 gene expression in RLE-6TN cells was inhibited by anti-oxidants suggesting the responses were dependent on oxidative stress. Consistent with anti-oxidant effects, quartz was demonstrated to increase RLE-6TN cell production of hydrogen peroxide. Rotenone treatment of RLE-6TN cells attenuated hydrogen peroxide production, NFkappaB activation and MIP-2 gene expression induced by quartz indicating that mitochondria-derived oxidants were contributing to these responses. Collectively, these findings indicate that quartz and crocidolite induction of MIP-2 gene expression in rat alveolar type II cells results from stimulation of an intracellular signaling pathway involving increased generation of hydrogen peroxide by mitochondria and subsequent activation of NFkappaB. PMID:11764986

  17. Sulfated and Glucuronated trans-Resveratrol Metabolites Regulate Chemokines and Sirtuin-1 Expression in U-937 Macrophages.

    PubMed

    Schueller, Katharina; Pignitter, Marc; Somoza, Veronika

    2015-07-29

    The natural anti-inflammatory compound resveratrol (RES) is metabolized upon ingestion. After dietary-scale doses, plasma concentrations of sulfated and glucuronated metabolites in humans exceed those of RES. The aim of this in vitro study was to assess the effect of physiological concentrations (1 μM) of the most abundant RES metabolites (RES-3-O-sulfate, R3S; RES-disulfates, RdS; RES-3-O-glucuronide, R3G; RES-4'-O-glucuronide, R4G) on genes and proteins involved in immune cell chemotaxis and inflammation (IL-8, MIP-1b, MCP-1, CCR1, CCR2, CXCR2, SIRT1) in a cell model of lipopolysaccharide (LPS)-activated U-937 macrophages. Levels of MCP-1 mRNA were comparably decreased after 3 h of treatment with R3S and RdS by -24.7 ± 5.51 and -28.7 ± 19.2%, respectively. LPS-induced MCP-1 protein release was reduced after 3 h of treatment by R3S (-20.8 ± 13.9%) and RdS (-25.7 ± 8.29%). After a 9 h treatment, RdS also inhibited IL-8 and MIP-1b protein release by -22.9 ± 3.57 and -20.1 ± 7.00%, respectively. Glucuronides showed differential effects after 6 h of treatment, with R4G up-regulating mRNA of MIP-1b (24.5 ± 14.8%) and R3G and R4G down-regulating CXCR2 surface protein compared to cells treated with LPS alone, by -5.33 ± 4.18 and -15.2 ± 5.99%, respectively. On the contrary, R3G and R4G up-regulated SIRT1 mRNA by 22.7 ± 17.9 and 22.8 ± 16.9%, respectively, in LPS-stimulated U-937 macrophages, showing anti-inflammatory properties. In conclusion, sulfated RES metabolites show an interesting beneficial potential for attenuating inflammatory immune processes. PMID:26111115

  18. Chemokine Expression in Melanoma Metastases Associated with CD8+ T-Cell Recruitment

    PubMed Central

    Harlin, Helena; Meng, Yuru; Peterson, Amy C.; Zha, Yuanyuan; Tretiakova, Maria; Slingluff, Craig; McKee, Mark; Gajewski, Thomas F.

    2013-01-01

    Despite the frequent detection of circulating tumor antigen–specific T cells, either spontaneously or following active immunization or adoptive transfer, immune-mediated cancer regression occurs only in the minority of patients. One theoretical rate-limiting step is whether effector T cells successfully migrate into metastatic tumor sites. Affymetrix gene expression profiling done on a series of metastatic melanoma biopsies revealed a major segregation of samples based on the presence or absence of T-cell-associated transcripts. The presence of lymphocytes correlated with the expression of defined chemokine genes. A subset of six chemokines (CCL2, CCL3, CCL4, CCL5, CXCL9, and CXCL10) was confirmed by protein array and/or quantitative reverse transcription-PCR to be preferentially expressed in tumors that contained T cells. Corresponding chemokine receptors were found to be up-regulated on human CD8+ effector T cells, and transwell migration assays confirmed the ability of each of these chemokines to promote migration of CD8+ effector cells in vitro. Screening by chemokine protein array identified a subset of melanoma cell lines that produced a similar broad array of chemokines. These melanoma cells more effectively recruited human CD8+ effector T cells when implanted as xenografts in nonobese diabetic/severe combined immunodeficient mice in vivo. Chemokine blockade with specific antibodies inhibited migration of CD8+ T cells. Our results suggest that lack of critical chemokines in a subset of melanoma metastases may limit the migration of activated T cells, which in turn could limit the effectiveness of antitumor immunity. PMID:19293190

  19. Constitutive and inflammatory induction of alpha and beta chemokines in human first trimester forebrain astrocytes and neurons.

    PubMed

    Bakhiet, Moiz; Mousa, Alyaa; Seiger, Ake; Andersson, Jan

    2002-05-01

    Chemokine effects on leukocyte infiltration into the central nervous system (CNS) are key events in the inflammatory processes of neuroimmunologic and neuroinfectious diseases. Because, chemokines may play important roles in proliferation and differentiation of brain cells and in the initiation and progression of CNS inflammatory disorders, we analyzed constitutive and inflammatory-induced expression of alpha and beta chemokines in human first trimester forebrain cells. Constitutive induction of IL-8, MIP-1alpha, MIP-1beta, MCP-1 and regulated on activation, normal T-cell expressed, and secreted (Rantes) was detected in cryostat sections of embryonic forebrains in an age-dependent manner. Dissociated cell cultures were studied for spontaneous chemokine induction and after stimulation with the trypanosome lymphocyte triggering factor (TLTF), a novel trypanokine secreted by African trypanosomes that triggers a complex of immune responses. LPS and variant surface glycoprotein (VSG) were used as controls. In cultures, unstimulated cells expressed minimal chemokine levels except for Rantes. In response to TLTF and LPS, but not VSG, all chemokines were highly induced at the mRNA and protein levels in a dose- and age-dependent manner. Combined assays (in situ hybridization and immunohistochemistry) revealed that astrocytes and neurons are major sources for chemokines. These results illustrate the ability of resident brain cells to constitutively express chemokine genes, which may suggest an important role for chemokines during brain development. Furthermore, TLTF-induced chemokine expression in astrocytes and neurons indicate the capacity of TLTF to provoke neuroinflammation in the brain, which may have important therapeutic implications for the neurological manifestations of African trypanosomiasis. PMID:12009570

  20. The cyclophilin-binding agent Sanglifehrin A is a dendritic cell chemokine and migration inhibitor.

    PubMed

    Immecke, Sabrina N; Baal, Nelli; Wilhelm, Jochen; Bechtel, Juliane; Knoche, Angela; Bein, Gregor; Hackstein, Holger

    2011-01-01

    Sanglifehrin A (SFA) is a cyclophilin-binding immunosuppressant but the immunobiology of action is poorly understood. We and others have reported that SFA inhibits IL-12 production and antigen uptake in dendritic cells (DC) and exhibits lower activity against lymphocytes. Here we show that SFA suppresses DC chemokine production and migration. Gene expression analysis and subsequent protein level confirmation revealed that SFA suppressed CCL5, CCL17, CCL19, CXCL9 and CXCL10 expression in human monocyte-derived DC (moDC). A systems biology analysis, Onto Express, confirmed that SFA interferes with chemokine-chemokine receptor gene expression with the highest impact. Direct comparison with the related agent cyclosporine A (CsA) and dexamethasone indicated that SFA uniquely suppresses moDC chemokine expression. Competitive experiments with a 100-fold molar excess of CsA and with N-Methyl-Val-4-cyclosporin, representing a nonimmunosuppressive derivative of CsA indicated chemokine suppression through a cyclophilin-A independent pathway. Functional assays confirmed reduced migration of CD4+ Tcells and moDCs to supernatant of SFA-exposed moDCs. Vice versa, SFA-exposed moDC exhibited reduced migration against CCL19. Moreover, SFA suppressed expression of the ectoenzyme CD38 that was reported to regulate DC migration and cytokine production. These results identify SFA as a DC chemokine and migration inhibitor and provide novel insight into the immunobiology of SFA. PMID:21483789

  1. The Cyclophilin-Binding Agent Sanglifehrin A Is a Dendritic Cell Chemokine and Migration Inhibitor

    PubMed Central

    Immecke, Sabrina N.; Baal, Nelli; Wilhelm, Jochen; Bechtel, Juliane; Knoche, Angela; Bein, Gregor; Hackstein, Holger

    2011-01-01

    Sanglifehrin A (SFA) is a cyclophilin-binding immunosuppressant but the immunobiology of action is poorly understood. We and others have reported that SFA inhibits IL-12 production and antigen uptake in dendritic cells (DC) and exhibits lower activity against lymphocytes. Here we show that SFA suppresses DC chemokine production and migration. Gene expression analysis and subsequent protein level confirmation revealed that SFA suppressed CCL5, CCL17, CCL19, CXCL9 and CXCL10 expression in human monocyte-derived DC (moDC). A systems biology analysis, Onto Express, confirmed that SFA interferes with chemokine-chemokine receptor gene expression with the highest impact. Direct comparison with the related agent cyclosporine A (CsA) and dexamethasone indicated that SFA uniquely suppresses moDC chemokine expression. Competitive experiments with a 100-fold molar excess of CsA and with N-Methyl-Val-4-cyclosporin, representing a nonimmunosuppressive derivative of CsA indicated chemokine suppression through a cyclophilin-A independent pathway. Functional assays confirmed reduced migration of CD4+ Tcells and moDCs to supernatant of SFA-exposed moDCs. Vice versa, SFA-exposed moDC exhibited reduced migration against CCL19. Moreover, SFA suppressed expression of the ectoenzyme CD38 that was reported to regulate DC migration and cytokine production. These results identify SFA as a DC chemokine and migration inhibitor and provide novel insight into the immunobiology of SFA. PMID:21483789

  2. Chemokines and their receptors in Atherosclerosis.

    PubMed

    van der Vorst, Emiel P C; Döring, Yvonne; Weber, Christian

    2015-09-01

    Atherosclerosis, a chronic inflammatory disease of the medium- and large-sized arteries, is the main underlying cause of cardiovascular diseases (CVDs) most often leading to a myocardial infarction or stroke. However, atherosclerosis can also develop without this clinical manifestation. The pathophysiology of atherosclerosis is very complex and consists of many cells and molecules interacting with each other. Over the last years, chemokines (small 8-12 kDa cytokines with chemotactic properties) have been identified as key players in atherogenesis. However, this remains a very active and dynamic field of research. Here, we will give an overview of the current knowledge about the involvement of chemokines in all phases of atherosclerotic lesion development. Furthermore, we will focus on two chemokines that recently have been associated with atherogenesis, CXCL12, and macrophage migration inhibitory factor (MIF). Both chemokines play a crucial role in leukocyte recruitment and arrest, a critical step in atherosclerosis development. MIF has shown to be a more pro-inflammatory and thus pro-atherogenic chemokine, instead CXCL12 seems to have a more protective function. However, results about this protective role are still quite debatable. Future research will further elucidate the precise role of these chemokines in atherosclerosis and determine the potential of chemokine-based therapies. PMID:26175090

  3. Human herpesvirus 8-encoded chemokine vCCL2/vMIP-II is an agonist of the atypical chemokine receptor ACKR3/CXCR7.

    PubMed

    Szpakowska, Martyna; Dupuis, Nadine; Baragli, Alessandra; Counson, Manuel; Hanson, Julien; Piette, Jacques; Chevigné, Andy

    2016-08-15

    The atypical chemokine receptor CXCR7/ACKR3 binds two endogenous chemokines, CXCL12 and CXCL11, and is upregulated in many cancers or following infection by several cancer-inducing viruses, including HHV-8. ACKR3 is a ligand-scavenging receptor and does not activate the canonical G protein pathways but was proposed to trigger β-arrestin-dependent signaling. Here, we identified the human herpesvirus 8-encoded CC chemokine vCCL2/vMIP-II as a third high-affinity ligand for ACKR3. vCCL2 acted as partial ACKR3 agonist, inducing β-arrestin recruitment to the receptor, subsequent reduction of its surface levels and its delivery to endosomes. In addition, ACKR3 reduced vCCL2-triggered MAP kinase and PI3K/Akt signaling through other chemokine receptors. Our data suggest that ACKR3 acts as a scavenger receptor for vCCL2, regulating its availability and activity toward human receptors, thereby likely controlling its function in HHV-8 infection. Our study provides new insights into the complex crosstalk between viral chemokines and host receptors as well as into the biology of ACKR3, this atypical and still enigmatic receptor. PMID:27238288

  4. Extensive expansion and diversification of the chemokine gene family in zebrafish: Identification of a novel chemokine subfamily CX

    PubMed Central

    Nomiyama, Hisayuki; Hieshima, Kunio; Osada, Naoki; Kato-Unoki, Yoko; Otsuka-Ono, Kaori; Takegawa, Sumio; Izawa, Toshiaki; Yoshizawa, Akio; Kikuchi, Yutaka; Tanase, Sumio; Miura, Retsu; Kusuda, Jun; Nakao, Miki; Yoshie, Osamu

    2008-01-01

    Background The chemokine family plays important roles in cell migration and activation. In humans, at least 44 members are known. Based on the arrangement of the four conserved cysteine residues, chemokines are now classified into four subfamilies, CXC, CC, XC and CX3C. Given that zebrafish is an important experimental model and teleost fishes constitute an evolutionarily diverse group that forms half the vertebrate species, it would be useful to compare the zebrafish chemokine system with those of mammals. Prior to this study, however, only incomplete lists of the zebrafish chemokine genes were reported. Results We systematically searched chemokine genes in the zebrafish genome and EST databases, and identified more than 100 chemokine genes. These genes were CXC, CC and XC subfamily members, while no CX3C gene was identified. We also searched chemokine genes in pufferfish fugu and Tetraodon, and found only 18 chemokine genes in each species. The majority of the identified chemokine genes are unique to zebrafish or teleost fishes. However, several groups of chemokines are moderately similar to human chemokines, and some chemokines are orthologous to human homeostatic chemokines CXCL12 and CXCL14. Zebrafish also possesses a novel species-specific subfamily consisting of five members, which we term the CX subfamily. The CX chemokines lack one of the two N-terminus conserved cysteine residues but retain the third and the fourth ones. (Note that the XC subfamily only retains the second and fourth of the signature cysteines residues.) Phylogenetic analysis and genome organization of the chemokine genes showed that successive tandem duplication events generated the CX genes from the CC subfamily. Recombinant CXL-chr24a, one of the CX subfamily members on chromosome 24, showed marked chemotactic activity for carp leukocytes. The mRNA was expressed mainly during a certain period of the embryogenesis, suggesting its role in the zebrafish development. Conclusion The

  5. A CCL chemokine-derived peptide (CDIP-2) exerts anti-inflammatory activity via CCR1, CCR2 and CCR3 chemokine receptors: Implications as a potential therapeutic treatment of asthma.

    PubMed

    Méndez-Enríquez, E; Medina-Tamayo, J; Soldevila, G; Fortoul, T I; Anton, B; Flores-Romo, L; García-Zepeda, E A

    2014-05-01

    Allergic asthma is a chronic inflammatory disease characterized by the accumulation of eosinophils, Th2 cells and mononuclear cells in the airways, leading to changes in lung architecture and subsequently reduced respiratory function. We have previously demonstrated that CDIP-2, a chemokine derived peptide, reduced in vitro chemotaxis and decreased cellular infiltration in a murine model of allergic airway inflammation. However, the mechanisms involved in this process have not been identified yet. Now, we found that CDIP-2 reduces chemokine-mediated functions via interactions with CCR1, CCR2 and CCR3. Moreover, using bone marrow-derived eosinophils, we demonstrated that CDIP-2 modifies the calcium fluxes induced by CCL11 and down-modulated CCR3 expression. Finally, CDIP-2 treatment in a murine model of OVA-induced allergic airway inflammation reduced leukocyte recruitment and decreases production of cytokines. These data suggest that chemokine-derived peptides represent new therapeutic tools to generate more effective antiinflammatory drugs. PMID:24560857

  6. Regulation of inflammasome activation.

    PubMed

    Man, Si Ming; Kanneganti, Thirumala-Devi

    2015-05-01

    Inflammasome biology is one of the most exciting and rapidly growing areas in immunology. Over the past 10 years, inflammasomes have been recognized for their roles in the host defense against invading pathogens and in the development of cancer, auto-inflammatory, metabolic, and neurodegenerative diseases. Assembly of an inflammasome complex requires cytosolic sensing of pathogen-associated molecular patterns or danger-associated molecular patterns by a nucleotide-binding domain and leucine-rich repeat receptor (NLR) or absent in melanoma 2 (AIM2)-like receptors (ALR). NLRs and ALRs engage caspase-1, in most cases requiring the adapter protein apoptosis-associated speck-like protein containing a CARD (ASC), to catalyze proteolytic cleavage of pro-interleukin-1β (pro-IL-1β) and pro-IL-18 and drive pyroptosis. Recent studies indicate that caspase-8, caspase-11, IL-1R-associated kinases (IRAK), and receptor-interacting protein (RIP) kinases contribute to inflammasome functions. In addition, post-translational modifications, including ubiquitination, deubiquitination, phosphorylation, and degradation control almost every aspect of inflammasome activities. Genetic studies indicate that mutations in NLRP1, NLRP3, NLRC4, and AIM2 are linked with the development of auto-inflammatory diseases, enterocolitis, and cancer. Overall, these findings transform our understanding of the basic biology and clinical relevance of inflammasomes. In this review, we provide an overview of the latest development of inflammasome research and discuss how inflammasome activities govern health and disease. PMID:25879280

  7. Regulation of inflammasome activation

    PubMed Central

    Man, Si Ming; Kanneganti, Thirumala-Devi

    2015-01-01

    Summary Inflammasome biology is one of the most exciting and rapidly growing areas in immunology. Over the past 10 years, inflammasomes have been recognized for their roles in the host defense against invading pathogens and in the development of cancer, autoinflammatory, metabolic, and neurodegenerative diseases. Assembly of an inflammasome complex requires cytosolic sensing of pathogen-associated molecular patterns or danger-associated molecular patterns by a nucleotide-binding domain and leucine-rich repeat receptor (NLR) or absent in melanoma 2-like receptor (ALR). NLRs and ALRs engage caspase-1, in most cases requiring the adapter protein apoptosis-associated speck-like protein containing a CARD (ASC), to catalyze proteolytic cleavage of pro-interleukin-1β (pro-IL-1β) and pro-IL-18 and drive pyroptosis. Recent studies indicate that caspase-8, caspase-11, IL-1R–associated kinases (IRAK), and receptor-interacting protein (RIP) kinases contribute to inflammasome functions. In addition, post-translational modifications, including ubiquitination, deubiquitination, phosphorylation, and degradation, control almost every aspect of inflammasome activities. Genetic studies indicate that mutations in NLRP1, NLRP3, NLRC4, and AIM2 are linked to the development of autoinflammatory diseases, enterocolitis, and cancer. Overall, these findings transform our understanding of the basic biology and clinical relevance of inflammasomes. In this review, we provide an overview of the latest development of inflammasome research and discuss how inflammasome activities govern health and disease. PMID:25879280

  8. Role of Tertiary Lymphoid Structures (TLS) in Anti-Tumor Immunity: Potential Tumor-Induced Cytokines/Chemokines that Regulate TLS Formation in Epithelial-Derived Cancers

    PubMed Central

    Pimenta, Erica M.; Barnes, Betsy J.

    2014-01-01

    Following the successes of monoclonal antibody immunotherapies (trastuzumab (Herceptin®) and rituximab (Rituxan®)) and the first approved cancer vaccine, Provenge® (sipuleucel-T), investigations into the immune system and how it can be modified by a tumor has become an exciting and promising new field of cancer research. Dozens of clinical trials for new antibodies, cancer and adjuvant vaccines, and autologous T and dendritic cell transfers are ongoing in hopes of identifying ways to re-awaken the immune system and force an anti-tumor response. To date, however, few consistent, reproducible, or clinically-relevant effects have been shown using vaccine or autologous cell transfers due in part to the fact that the immunosuppressive mechanisms of the tumor have not been overcome. Much of the research focus has been on re-activating or priming cytotoxic T cells to recognize tumor, in some cases completely disregarding the potential roles that B cells play in immune surveillance or how a solid tumor should be treated to maximize immunogenicity. Here, we will summarize what is currently known about the induction or evasion of humoral immunity via tumor-induced cytokine/chemokine expression and how formation of tertiary lymphoid structures (TLS) within the tumor microenvironment may be used to enhance immunotherapy response. PMID:24762633

  9. RAPID HETEROLOGOUS DESENSITIZATION OF ANTINOCICEPTIVE ACTIVITY BETWEEN MU OR DELTA OPIOID RECEPTORS AND CHEMOKINE RECEPTORS IN RATS

    PubMed Central

    Chen, Xiaohong; Geller, Ellen B.; Rogers, Thomas J.; Adler, Martin W.

    2007-01-01

    Previous studies have shown pretreatment with chemokines CCL5/RANTES (100 ng) or CXCL12/SDF-1alpha (100 ng) injected into the periaqueductal grey (PAG) region of the brain, 30 minutes (min) before the mu opioid agonist DAMGO (400 ng), blocked the antinociception induced by DAMGO in the in vivo cold water tail-flick (CWT) antinociceptive test in rats. In the present experiments, we tested whether the action of other agonists at mu and delta opioid receptors is blocked when CCL5/RANTES or CXCL12/SDF-1alpha is administered into the PAG 30 min before, or co-administered with, opioid agonists in the CWT assay. The results showed that (1) CXCL12/SDF-1alpha (100 ng, PAG) or CCL5/RANTES (100 ng, PAG), given 30 min before the opioid agonist morphine, or selective delta opioid receptor agonist DPDPE, blocked the antinociceptive effect of these drugs; (2) CXCL12/SDF-1alpha (100 ng, PAG) or CCL5/RANTES (100 ng, PAG), injected at the same time as DAMGO or DPDPE, significantly reduced the antinociceptive effect induced by these drugs. These results demonstrate that the heterologous desensitization is rapid between the mu or delta opioid receptors and either CCL5/RANTES receptor CCR5 or CXCL12/SDF-1alpha receptor CXCR4 in vivo, but the effect is greater if the chemokine is administered before the opioid. PMID:17049756

  10. Benzopyrene promotes lung cancer A549 cell migration and invasion through up-regulating cytokine IL8 and chemokines CCL2 and CCL3 expression.

    PubMed

    Zhang, Jin; Chang, Li; Jin, Hanyu; Xia, Yaoxiong; Wang, Li; He, Wenjie; Li, Wenhui; Chen, Hong

    2016-08-01

    Tobacco-sourced carcinogen including benzopyrene (B[a]P) in lung cancer metastasis has not been fully reported. In this study, lung carcinoma A549 cell line was used to investigate the potential roles of tobacco-sourced B[a]P on cell metastasis and invasion and to assess its underlying mechanism. Effects of tobacco-sourced carcinogen on A549 cell proliferation, metastasis, and invasion were analyzed using MTT assay, Transwell assay, and scratch method, respectively. The effects of tobacco-sourced carcinogen on cytokines and chemokines secretion were detected using enzyme-linked immunosorbent assay. Moreover, correlation between inflammatory factor expression and cancer cell migration and invasion was assessed using siRNA-mediated gene silencing. Data showed that both B[a]P and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone either at high or low dose performed no significant difference on A549 cell proliferation with time increasing. 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone performed no significant difference on A549 cell migration and invasion while B[a]P significantly increased A549 cell migration and invasion compared to the control group (P < 0.05). Consequently, except for IL-6, IL-8, CCL-2, and CCL-3, secretions were significantly increased by B[a]P treatment compared to the control (P < 0.05). Furthermore, when CCL-2 and CCL-3 were silenced, the migrated and invasive A549 cells were significantly decreased compared to the control, respectively (P < 0.05), while silenced IL-8 drastically decreased the migrated and invasive cells compared to the control (P < 0.01). Taken together, this study illustrated that there may be significant correlation between smoking and lung cancer metastasis. B[a]P maybe an excellent contributor for lung cancer metastasis through up-regulating IL-8, CCL-2, and CCL-3 expression. PMID:27075927

  11. Characterization and expression analysis of an interferon-γ2 induced chemokine receptor CXCR3 in common carp (Cyprinus carpio L.).

    PubMed

    Chadzinska, M; Golbach, L; Pijanowski, L; Scheer, M; Verburg-van Kemenade, B M L

    2014-11-01

    Chemokine and chemokine receptor signalling pairs play a crucial role in regulation of cell migration, morphogenesis, and cell activation. Expressed in mammals on activated T and NK cells, chemokine receptor CXCR3 binds interferon-γ inducible chemokines CXCL9-11 and CCL21. Here we sequenced the carp CXCR3 chemokine receptor and showed its relationship to CXCR3a receptors found in other teleosts. We found high expression of the CXCR3 gene in most of the organs and tissues of the immune system and in immune-related tissues such as gills and gut, corroborating a predominantly immune-related function. The very high expression in gill and gut moreover indicates a role for CXCR3 in cell recruitment during infection. High in vivo expression of CXCR3 at later stages of inflammation, as well as its in vitro sensitivity to IFN-γ2 stimulation indicate that in carp, CXCR3 is involved in macrophage-mediated responses. Moreover, as expression of the CXCR3 and CXCb genes coincides in the focus of inflammation and as both the CXCb chemokines and the CXCR3 receptor are significantly up-regulated upon IFN-γ stimulation it is hypothesized that CXCb chemokines may be putative ligands for CXCR3. PMID:25036761

  12. Molecular regulation of osteoclast activity.

    PubMed

    Bruzzaniti, Angela; Baron, Roland

    2006-06-01

    Osteoclasts are multinucleated cells derived from hematopoietic precursors that are primarily responsible for the degradation of mineralized bone during bone development, homeostasis and repair. In various skeletal disorders such as osteoporosis, hypercalcemia of malignancy, tumor metastases and Paget's disease, bone resorption by osteoclasts exceeds bone formation by osteoblasts leading to decreased bone mass, skeletal fragility and bone fracture. The overall rate of osteoclastic bone resorption is regulated either at the level of differentiation of osteoclasts from their monocytic/macrophage precursor pool or through the regulation of key functional proteins whose specific activities in the mature osteoclast control its attachment, migration and resorption. Thus, reducing osteoclast numbers and/or decreasing the bone resorbing activity of osteoclasts are two common therapeutic approaches for the treatment of hyper-resorptive skeletal diseases. In this review, several of the key functional players involved in the regulation of osteoclast activity will be discussed. PMID:16951988

  13. Chemokine production by human vascular smooth muscle cells: modulation by IL-13

    PubMed Central

    Jordan, Nicola J; Watson, Malcolm L; Williams, Robert J; Roach, Alan G; Yoshimura, Teizo; Westwick, John

    1997-01-01

    The production of chemokines by vascular smooth muscle cells (SMC) is implicated in the pathogenesis of atherosclerosis, although the factors regulating chemokine production by these cells are incompletely characterized. We describe the differential stimulation of interleukin-(IL)-8, monocyte chemoattractant protein (MCP)-1 and regulated on activation normal T-cell expressed and secreted (RANTES) synthesis following treatment of human vascular SMC with IL-1α or tumour necrosis factor α (TNFα). Under basal conditions, cultured SMC release very low amounts of IL-8, MCP-1 and RANTES as assessed by specific ELISA. Concentration-response studies with IL-1α or TNFα revealed that each stimulus induced a similar amount of MCP-1. In contrast approximately three fold more IL-8 was induced by IL-1α than by TNFα whereas significant RANTES production was induced only by TNFα. These findings point to a divergence in the regulation of synthesis of the different chemokines in response to IL-1α or TNFα stimulation. The T-cell derived cytokines IL-10 and IL-13 were also found to have differential effects on chemokine production by SMC. IL-13, but not IL-10, significantly enhanced IL-8 and MCP-1 release in response to IL-1α or TNFα. This increase in chemokine release appeared to be accounted for by increased mRNA expression. These findings provide support for the concept that smooth muscle cells can have an active role in a local immune response via the production of chemokines which can be selectively modulated by T-cell derived cytokines. PMID:9375973

  14. The biochemistry and biology of the atypical chemokine receptors.

    PubMed

    Graham, G J; Locati, M; Mantovani, A; Rot, A; Thelen, M

    2012-07-30

    A subset of chemokine receptors, initially called "silent" on the basis of their apparent failure to activate conventional signalling events, has recently attracted growing interest due to their ability to internalize, degrade, or transport ligands and thus modify gradients and create functional chemokine patterns in tissues. These receptors recognize distinct and complementary sets of ligands with high affinity, are strategically expressed in different cellular contexts, and lack structural determinants supporting Gα(i) activation, a key signalling event in cell migration. This is in keeping with the hypothesis that they have evolved to fulfil fundamentally different functions to the classical signalling chemokine receptors. Based on these considerations, these receptors (D6, Duffy antigen receptor for chemokines (DARC), CCX-CKR1 and CXCR7) are now collectively considered as an emerging class of 'atypical' chemokine receptors. In this article, we review the biochemistry and biology of this emerging chemokine receptor subfamily. PMID:22698181

  15. Chemokine binding proteins: An immunomodulatory strategy going viral.

    PubMed

    González-Motos, Víctor; Kropp, Kai A; Viejo-Borbolla, Abel

    2016-08-01

    Chemokines are chemotactic cytokines whose main function is to direct cell migration. The chemokine network is highly complex and its deregulation is linked to several diseases including immunopathology, cancer and chronic pain. Chemokines also play essential roles in the antiviral immune response. Viruses have therefore developed several counter strategies to modulate chemokine activity. One of these is the expression of type I transmembrane or secreted proteins with the ability to bind chemokines and modulate their activity. These proteins, termed viral chemokine binding proteins (vCKBP), do not share sequence homology with host proteins and are immunomodulatory in vivo. In this review we describe the discovery and characterization of vCKBP, explain their role in the context of infection in vivo and discuss relevant novel findings. PMID:26987612

  16. Mechanisms and implications of air pollution particle associations with chemokines

    SciTech Connect

    Seagrave, JeanClare

    2008-11-01

    Inflammation induced by inhalation of air pollutant particles has been implicated as a mechanism for the adverse health effects associated with exposure to air pollution. The inflammatory response is associated with upregulation of various pro-inflammatory cytokines and chemokines. We have previously shown that diesel exhaust particles (DEP), a significant constituent of air pollution particulate matter in many urban areas, bind and concentrate IL-8, an important human neutrophil-attracting chemokine, and that the chemokine remains biologically active. In this report, we examine possible mechanisms of this association and the effects on clearance of the chemokine. The binding appears to be the result of ionic interactions between negatively charged particles and positively charged chemokine molecules, possibly combined with intercalation into small pores in the particles. The association is not limited to diesel exhaust particles and IL-8: several other particle types also adsorb the chemokine and several other cytokines are adsorbed onto the diesel particles. However, there are wide ranges in the effectiveness of various particle types and various cytokines. Finally, male Fisher 344 rats were intratracheally instilled with chemokine alone or combined with diesel exhaust or silica particles under isofluorane anesthesia. In contrast to silica particles, which do not bind the chemokine, the presence of diesel exhaust particles, which bind the chemokine, prolonged the retention of the chemokine.

  17. CXC and CC Chemokines as Angiogenic Modulators in Nonhaematological Tumors

    PubMed Central

    Bracarda, Sergio; Nabissi, Massimo; Massari, Francesco; Bria, Emilio; Tortora, Giampaolo; Santoni, Giorgio; Cascinu, Stefano

    2014-01-01

    Chemokines are a superfamily of structurally homologous heparin-binding proteins that includes potent inducers and inhibitors of angiogenesis. The imbalance between angiogenic and angiostatic chemokine activities can lead to abnormalities, such as chronic inflammation, dysplastic transformation, and even tumor development and spreading. In this review, we summarize the current literature regarding the role of chemokines as modulators of tumor angiogenesis and their potential role as therapeutic targets in patients with nonhaematological tumors. PMID:24971349

  18. Profiling Heparin-Chemokine Interactions Using Synthetic Tools

    PubMed Central

    de Paz, Jose L.; Moseman, E. Ashley; Noti, Christian; Polito, Laura; von Andrian, Ulrich H.; Seeberger, Peter H.

    2009-01-01

    Glycosaminoglycans (GAGs), such as heparin or heparan sulfate, are required for the in vivo function of chemokines. Chemokines play a crucial role in the recruitment of leukocyte subsets to sites of inflammation and lymphocytes trafficking. GAG-chemokine interactions mediate cell migration and determine which leukocyte subsets enter tissues. Identifying the exact GAC sequences that bind to particular chemokines is key to understand chemokine function at the molecular level and develop strategies to interfere with chemokine-mediated processes. Here, we characterize the heparin binding profiles of eight chemokines (CCL21, IL-8, CXCL12, CXCL13, CCL19, CCL25, CCL28, and CXCL16) by employing heparin microarrays containing a small library of synthetic heparin oligosaccharides. The chemokines differ significantly in their interactions with heparin oligosaccharides: While some chemokines, (e.g., CCL21) strongly bind to a hexasaccharide containing the GlcNSO3(6-OSO3)-IdoA(2-OSO3) repeating unit, CCL19 does not bind and CXCL12 binds only weakly. The carbohydrate microarray binding results were validated by surface plasmon resonance experiments. In vitro chemotaxis assays revealed that dendrimers coated with the fully sulfated heparin hexasaccharide inhibit lymphocyte migration toward CCL21. Migration toward CXCL12 or CCL19 was not affected. These in vitro homing assays indicate that multivalent synthetic heparin dendrimers inhibit the migration of lymphocytes toward certain chemokine gradients by blocking the formation of a chemokine concentration gradient on GAG endothelial chains. These findings are in agreement with preliminary in vivo measurements of circulating lymphocytes. The results presented here contribute to the understanding of GAG-chemokine interactions, a first step toward the design of novel drugs that modulate chemokine activity. PMID:18030990

  19. Chemokine-dependent T cell migration requires aquaporin-3–mediated hydrogen peroxide uptake

    PubMed Central

    Chikuma, Shunsuke; Sugiyama, Yoshinori; Kabashima, Kenji; Verkman, Alan S.; Inoue, Shintaro; Miyachi, Yoshiki

    2012-01-01

    Chemokine-dependent trafficking is indispensable for the effector function of antigen-experienced T cells during immune responses. In this study, we report that the water/glycerol channel aquaporin-3 (AQP3) is expressed on T cells and regulates their trafficking in cutaneous immune reactions. T cell migration toward chemokines is dependent on AQP3-mediated hydrogen peroxide (H2O2) uptake but not the canonical water/glycerol transport. AQP3-mediated H2O2 transport is essential for the activation of the Rho family GTPase Cdc42 and the subsequent actin dynamics. Coincidentally, AQP3-deficient mice are defective in the development of hapten-induced contact hypersensitivity, which is attributed to the impaired trafficking of antigen-primed T cells to the hapten-challenged skin. We therefore suggest that AQP3-mediated H2O2 uptake is required for chemokine-dependent T cell migration in sufficient immune response. PMID:22927550

  20. Acoustic sensing of the initial adhesion of chemokine-stimulated cancer cells.

    PubMed

    Wei, Xiao-Lan; Zhang, Jing; Zhao, Na

    2013-11-01

    Chemokines together with their receptors play important roles in tumor metastasis. Intracellular signals stimulated by chemokines regulate the initial adhesion of cancer cells, which controls the subsequent cell spreading and migration. Until now, the nature of initial cell adhesion has been understood very poorly, since conventional assays are static and could not provide dynamic information. In order to address this issue, we adopt an acoustic sensor, quartz crystal microbalance (QCM), to monitor the attachment of chemokine-stimulated cancer cells in real-time. As a model, the chemokine CXCL12 was used to stimulate three human breast cancer cell lines expressing different levels of its receptor CXCR4, which triggers intracellular signaling pathways that activate integrins across cell membrane. Interaction between cellular integrins and adhesion molecules (CAMs) pre-coated on sensor surfaces were in situ monitored by QCM of which the frequency was sensitive to the mechanical connection of cells to the sensor surface. The ratio of frequency shift under stimulation to that without stimulation indicated the number and strength of integrin-CAM binding stimulated by the chemokine. The cell-surface binding was found to be enhanced by CXCL12, which depends on the CAM type and levels of chemokine and receptor, and was significantly inhibited by a blocker of the chemokine pathway. The binding of integrin with intercellular adhesion molecule was also found to be strong and in good correlated with the chemotactic indexes obtained by the classical Boyden chamber assay. This research suggests that acoustic sensing of initial cell adhesion could provide a dynamic insight into cell interfacial phenomena. PMID:23911626

  1. Neurotactin, a membrane-anchored chemokine upregulated in brain inflammation.

    PubMed

    Pan, Y; Lloyd, C; Zhou, H; Dolich, S; Deeds, J; Gonzalo, J A; Vath, J; Gosselin, M; Ma, J; Dussault, B; Woolf, E; Alperin, G; Culpepper, J; Gutierrez-Ramos, J C; Gearing, D

    1997-06-01

    Chemokines are small secreted proteins that stimulate the directional migration of leukocytes and mediate inflammation. During screening of a murine choroid plexus complementary DNA library, we identified a new chemokine, designated neurotactin. Unlike other chemokines, neurotactin has a unique cysteine pattern, Cys-X-X-X-Cys, and is predicted to be a type 1 membrane protein. Full-length recombinant neurotactin is localized on the surface of transfected 293 cells. Recombinant neurotactin containing the chemokine domain is chemotactic for neutrophils both in vitro and in vivo. Neurotactin messenger RNA is predominantly expressed in normal murine brain and its protein expression in activated brain microglia is upregulated in mice with experimental autoimmune encephalomyelitis, as well as in mice treated with lipopolysaccharide. Distinct from all other chemokine genes, the neurotactin gene is localized to human chromosome 16q. Consequently we propose that neurotactin represents a new delta-chemokine family and that it may play a role in brain inflammation processes. PMID:9177350

  2. The Retinoic Acid Receptor-α mediates human T-cell activation and Th2 cytokine and chemokine production

    PubMed Central

    Dawson, Harry D; Collins, Gary; Pyle, Robert; Key, Michael; Taub, Dennis D

    2008-01-01

    Background We have recently demonstrated that all-trans-retinoic acid (ATRA) and 9-cis-retinoic acid (9-cis RA) promote IL-4, IL-5 and IL-13 synthesis, while decreasing IFN-γ and TNF-α expression by activated human T cells and reduces the synthesis of IL-12p70 from accessory cells. Here, we have demonstrated that the observed effects using ATRA and 9-cis RA are shared with the clinically useful RAR ligand, 13-cis retinoic acid (13-cis RA), and the retinoic acid receptor-α (RAR-α)-selective agonist, AM580 but not with the RAR-β/γ ligand, 4-hydroxyphenylretinamide (4-HPR). Results The increase in type 2 cytokine production by these retinoids correlated with the expression of the T cell activation markers, CD69 and CD38. The RAR-α-selective agonist, AM580 recapitulated all of the T cell activation and type 2 cytokine-inducing effects of ATRA and 9-cis-RA, while the RAR-α-selective antagonist, RO 41–5253, inhibited these effects. Conclusion These results strongly support a role for RAR-α engagement in the regulation of genes and proteins involved with human T cell activation and type 2 cytokine production. PMID:18416830

  3. The chemokine-like factor 1 induces asthmatic pathological change by activating nuclear factor-κB signaling pathway.

    PubMed

    Li, Gang; Li, Guang-yan; Wang, Zhen-zhen; Ji, Hai-jie; Wang, Dong-mei; Hu, Jin-feng; Yuan, Yu-he; Liu, Gang; Chen, Nai-hong

    2014-05-01

    CKLF1, which exhibits chemotactic activities on a wide spectrum of leukocytes, is up-regulated during the progress of asthma. It plays a vital role in the pathogenesis of pulmonary disease. Here, we report that CKLF1 has the capability to activate the NF-κB signaling pathway leading to the pathological change in the lung. The HEK293-CCR4 cell line, which expressed CCR4 stably, was established and screened. Western blot analysis was performed to determine the expression of NF-κB in HEK293-CCR4 and A549 cells following the C27 (10μg/ml) added in each well at different times. These results showed that C27 (10μg/ml) time-dependently induced the accumulation of NF-κB in the nucleus of HEK293-CCR4 and A549 cells. In addition, CKLF1 plasmid (100μg) injection and electroporation led to the asthmatic change in the lung in mice as shown by HE and PAS staining. Furthermore, it was confirmed that CKLF1 significantly up-regulated the p-IκB expression, decreased the IκB expression, and suppressed the NF-κB expression in the cytoplasm of pulmonary tissue in vivo study. Intriguingly, an enhanced nuclear accumulation of NF-κB was observed in the lung of pCDI-CKLF1 electroporated mice, compared to that in the sham group. Therefore, the NF-κB signaling pathway was involved in the asthmatic change induced by CKLF1, among which CCR4 might play a crucial role. PMID:24583145

  4. Chemokines and Chemokine Receptors in the Development of Lupus Nephritis

    PubMed Central

    2016-01-01

    Lupus nephritis (LN) is a major cause of morbidity and mortality in the patients with systemic lupus erythematosus (SLE), an autoimmune disease with damage to multiple organs. Leukocyte recruitment into the inflamed kidney is a critical step to promote LN progression, and the chemokine/chemokine receptor system is necessary for leukocyte recruitment. In this review, we summarize recent studies on the roles of chemokines and chemokine receptors in the development of LN and discuss the potential and hurdles of developing novel, chemokine-based drugs to treat LN. PMID:27403037

  5. Chemokines and Chemokine Receptors in the Development of Lupus Nephritis.

    PubMed

    Liao, Xiaofeng; Pirapakaran, Tharshikha; Luo, Xin M

    2016-01-01

    Lupus nephritis (LN) is a major cause of morbidity and mortality in the patients with systemic lupus erythematosus (SLE), an autoimmune disease with damage to multiple organs. Leukocyte recruitment into the inflamed kidney is a critical step to promote LN progression, and the chemokine/chemokine receptor system is necessary for leukocyte recruitment. In this review, we summarize recent studies on the roles of chemokines and chemokine receptors in the development of LN and discuss the potential and hurdles of developing novel, chemokine-based drugs to treat LN. PMID:27403037

  6. Epac Activation Regulates Human Mesenchymal Stem Cells Migration and Adhesion.

    PubMed

    Yu, Jiao-Le; Deng, Ruixia; Chung, Sookja K; Chan, Godfrey Chi-Fung

    2016-04-01

    How to enhance the homing of human mesenchymal stem cells (hMSCs) to the target tissues remains a clinical challenge nowadays. To overcome this barrier, the mechanism responsible for the hMSCs migration and engraftment has to be defined. Currently, the exact mechanism involved in migration and adhesion of hMSCs remains unknown. Exchange protein directly activated by cAMP (Epac), a novel protein discovered in cAMP signaling pathway, may have a potential role in regulating cells adhesion and migration by triggering the downstream Rap family signaling cascades. However, the exact role of Epac in cells homing is elusive. Our study evaluated the role of Epac in the homing of hMSCs. We confirmed that hMSCs expressed functional Epac and its activation enhanced the migration and adhesion of hMSCs significantly. The Epac activation was further found to be contributed directly to the chemotactic responses induced by stromal cell derived factor-1 (SDF-1) which is a known chemokine in regulating hMSCs homing. These findings suggested Epac is connected to the SDF-1 signaling cascades. In conclusion, our study revealed that Epac plays a role in hMSCs homing by promoting adhesion and migration. Appropriate manipulation of Epac may enhance the homing of hMSCs and facilitate their future clinical applications. Stem Cells 2016;34:948-959. PMID:26727165

  7. Systemic chemokine levels, coronary heart disease, and ischemic stroke events

    PubMed Central

    Canouï-Poitrine, F.; Luc, G.; Mallat, Z.; Machez, E.; Bingham, A.; Ferrieres, J.; Ruidavets, J.-B.; Montaye, M.; Yarnell, J.; Haas, B.; Arveiler, D.; Morange, P.; Kee, F.; Evans, A.; Amouyel, P.; Ducimetiere, P.

    2011-01-01

    Objectives: To quantify the association between systemic levels of the chemokine regulated on activation normal T-cell expressed and secreted (RANTES/CCL5), interferon-γ-inducible protein-10 (IP-10/CXCL10), monocyte chemoattractant protein-1 (MCP-1/CCL2), and eotaxin-1 (CCL11) with future coronary heart disease (CHD) and ischemic stroke events and to assess their usefulness for CHD and ischemic stroke risk prediction in the PRIME Study. Methods: After 10 years of follow-up of 9,771 men, 2 nested case-control studies were built including 621 first CHD events and 1,242 matched controls and 95 first ischemic stroke events and 190 matched controls. Standardized hazard ratios (HRs) for each log-transformed chemokine were estimated by conditional logistic regression. Results: None of the 4 chemokines were independent predictors of CHD, either with respect to stable angina or to acute coronary syndrome. Conversely, RANTES (HR = 1.70; 95% confidence interval [CI] 1.05–2.74), IP-10 (HR = 1.53; 95% CI 1.06–2.20), and eotaxin-1 (HR = 1.59; 95% CI 1.02–2.46), but not MCP-1 (HR = 0.99; 95% CI 0.68–1.46), were associated with ischemic stroke independently of traditional cardiovascular risk factors, hs-CRP, and fibrinogen. When the first 3 chemokines were included in the same multivariate model, RANTES and IP-10 remained predictive of ischemic stroke. Their addition to a traditional risk factor model predicting ischemic stroke substantially improved the C-statistic from 0.6756 to 0.7425 (p = 0.004). Conclusions: In asymptomatic men, higher systemic levels of RANTES and IP-10 are independent predictors of ischemic stroke but not of CHD events. RANTES and IP-10 may improve the accuracy of ischemic stroke risk prediction over traditional risk factors. PMID:21849651

  8. Airway epithelial cell PPARγ modulates cigarette smoke-induced chemokine expression and emphysema susceptibility in mice.

    PubMed

    Solleti, Siva Kumar; Simon, Dawn M; Srisuma, Sorachai; Arikan, Meltem C; Bhattacharya, Soumyaroop; Rangasamy, Tirumalai; Bijli, Kaiser M; Rahman, Arshad; Crossno, Joseph T; Shapiro, Steven D; Mariani, Thomas J

    2015-08-01

    Chronic obstructive pulmonary disease (COPD) is a highly prevalent, chronic inflammatory lung disease with limited existing therapeutic options. While modulation of peroxisome proliferator-activating receptor (PPAR)-γ activity can modify inflammatory responses in several models of lung injury, the relevance of the PPARG pathway in COPD pathogenesis has not been previously explored. Mice lacking Pparg specifically in airway epithelial cells displayed increased susceptibility to chronic cigarette smoke (CS)-induced emphysema, with excessive macrophage accumulation associated with increased expression of chemokines, Ccl5, Cxcl10, and Cxcl15. Conversely, treatment of mice with a pharmacological PPARγ activator attenuated Cxcl10 and Cxcl15 expression and macrophage accumulation in response to CS. In vitro, CS increased lung epithelial cell chemokine expression in a PPARγ activation-dependent fashion. The ability of PPARγ to regulate CS-induced chemokine expression in vitro was not specifically associated with peroxisome proliferator response element (PPRE)-mediated transactivation activity but was correlated with PPARγ-mediated transrepression of NF-κB activity. Pharmacological or genetic activation of PPARγ activity abrogated CS-dependent induction of NF-κB activity. Regulation of NF-κB activity involved direct PPARγ-NF-κB interaction and PPARγ-mediated effects on IKK activation, IκBα degradation, and nuclear translocation of p65. Our data indicate that PPARG represents a disease-relevant pathophysiological and pharmacological target in COPD. Its activation state likely contributes to NF-κB-dependent, CS-induced chemokine-mediated regulation of inflammatory cell accumulation. PMID:26024894

  9. Targeting of TGF-β-activated protein kinase 1 inhibits chemokine (C-C motif) receptor 7 expression, tumor growth and metastasis in breast cancer

    PubMed Central

    Hung, Wen-Chun; Hou, Ming-Feng

    2015-01-01

    TGF-β-activated protein kinase 1 (TAK1) is a critical mediator in inflammation, immune response and cancer development. Our previous study demonstrated that activation of TAK1 increases the expression of chemokine (C-C motif) receptor 7 (CCR7) and promotes lymphatic invasion ability of breast cancer cells. However, the expression and association of activated TAK1 and CCR7 in breast tumor tissues is unknown and the therapeutic effect by targeting TAK1 is also unclear. We showed that activated TAK1 (as indicated by phospho-TAK1) and its binding protein TAB1 are strongly expressed in breast tumor tissues (77% and 74% respectively). In addition, increase of phospho-TAK1 or TAB1 is strongly associated with over-expression of CCR7. TAK1 inhibitor 5Z-7-Oxozeaenol (5Z-O) inhibited TAK1 activity, suppressed downstream signaling pathways including p38, IκB kinase (IKK) and c-Jun N-terminal kinase (JNK) and reduced CCR7 expression in metastatic MDA-MB-231 cells. In addition, 5Z-O repressed NF-κB- and c-JUN-mediated transcription of CCR7 gene. Knockdown of TAB1 attenuated CCR7 expression and tumor growth in an orthotopic animal study. More importantly, lymphatic invasion and lung metastasis were suppressed. Collectively, our results demonstrate that constitutive activation of TAK1 is frequently found in human breast cancer and this kinase is a potential therapeutic target for this cancer. PMID:25557171

  10. The N-terminal Region of the Atypical Chemokine Receptor ACKR2 Is a Key Determinant of Ligand Binding*

    PubMed Central

    Hewit, Kay D.; Fraser, Alasdair; Nibbs, Robert J. B.; Graham, Gerard J.

    2014-01-01

    The atypical chemokine receptor, ACKR2 is a pivotal regulator of chemokine-driven inflammatory responses and works by binding, internalizing, and degrading inflammatory CC-chemokines. ACKR2 displays promiscuity of ligand binding and is capable of interacting with up to 14 different inflammatory CC-chemokines. Despite its prominent biological role, little is known about the structure/function relationship within ACKR2, which regulates ligand binding. Here we demonstrate that a conserved tyrosine motif at the N terminus of ACKR2 is essential for ligand binding, internalization, and scavenging. In addition we demonstrate that sulfation of this motif contributes to ligand internalization. Furthermore, a peptide derived from this region is capable of binding inflammatory chemokines and inhibits their interaction with their cognate signaling receptors. Importantly, the peptide is only active in the sulfated form, further confirming the importance of the sulfated tyrosines for function. Finally, we demonstrate that the bacterial protease, staphopain A, can cleave the N terminus of ACKR2 and suppress its ligand internalization activity. Overall, these results shed new light on the nature of the structural motifs in ACKR2 that are responsible for ligand binding. The study also highlights ACKR2-derived N-terminal peptides as being of potential therapeutic significance. PMID:24644289

  11. Production of Recombinant Chemokines and Validation of Refolding.

    PubMed

    Veldkamp, Christopher T; Koplinski, Chad A; Jensen, Davin R; Peterson, Francis C; Smits, Kaitlin M; Smith, Brittney L; Johnson, Scott K; Lettieri, Christina; Buchholz, Wallace G; Solheim, Joyce C; Volkman, Brian F

    2016-01-01

    The diverse roles of chemokines in normal immune function and many human diseases have motivated numerous investigations into the structure and function of this family of proteins. Recombinant chemokines are often used to study how chemokines coordinate the trafficking of immune cells in various biological contexts. A reliable source of biologically active protein is vital for any in vitro or in vivo functional analysis. In this chapter, we describe a general method for the production of recombinant chemokines and robust techniques for efficient refolding that ensure consistently high biological activity. Considerations for initiating development of protocols consistent with Current Good Manufacturing Practices (cGMPs) to produce biologically active chemokines suitable for use in clinical trials are also discussed. PMID:26921961

  12. Chemokines in health and disease

    PubMed Central

    Raman, Dayanidhi; Sobolik-Delmaire, Tammy; Richmond, Ann

    2011-01-01

    Chemokines and their receptors play a key role in development and homeostasis as well as in the pathogenesis of tumors and autoimmune diseases. Chemokines are involved in the implantation of the early conceptus, the migration of subsets of cells during embryonic development, and the overall growth of the embryo. Chemokines also have an important role in the development and maintenance of innate and adaptive immunity. In addition, they play a significant role in wound healing and angiogenesis. When the physiological role of chemokines is subverted or chronically amplified, disease often follows. Chemokines are involved in the pathobiology of chronic inflammation, tumorigenesis and metastasis, as well as autoimmune diseases. This article reviews the role of chemokines and their receptors in normal and disease processes and the potential for using chemokine antagonists for appropriate targeted therapy. PMID:21223965

  13. Gating function of isoleucine-116 in TM-3 (position III:16/3.40) for the activity state of the CC-chemokine receptor 5 (CCR5)

    PubMed Central

    Steen, A; Sparre-Ulrich, A H; Thiele, S; Guo, D; Frimurer, T M; Rosenkilde, M M

    2014-01-01

    Background and Purpose A conserved amino acid within a protein family indicates a significance of the residue. In the centre of transmembrane helix (TM)-5, position V:13/5.47, an aromatic amino acid is conserved among class A 7TM receptors. However, in 37% of chemokine receptors – a subgroup of 7TM receptors – it is a leucine indicating an altered function. Here, we describe the significance of this position and its possible interaction with TM-3 for CCR5 activity. Experimental Approach The effects of [L203F]-CCR5 in TM-5 (position V:13/5.47), [I116A]-CCR5 in TM-3 (III:16/3.40) and [L203F;G286F]-CCR5 (V:13/5.47;VII:09/7.42) were determined in G-protein-and β-arrestin-coupled signalling. Computational modelling monitored changes in amino acid conformation. Key Results [L203F]-CCR5 increased the basal level of G-protein coupling (20–70% of Emax) and β-arrestin recruitment (50% of Emax) with a threefold increase in agonist potency. In silico, [I116A]-CCR5 switched χ1-angle in [L203F]-CCR5. Furthermore, [I116A]-CCR5 was constitutively active to a similar degree as [L203F]-CCR5. Tyr244 in TM-6 (VI:09/6.44) moved towards TM-5 in silico, consistent with its previously shown function for CCR5 activation. On [L203F;G286F]-CCR5 the antagonist aplaviroc was converted to a superagonist. Conclusions and Implications The results imply that an aromatic amino acid in the centre of TM-5 controls the level of receptor activity. Furthermore, Ile116 acts as a gate for the movement of Tyr244 towards TM-5 in the active state, a mechanism proposed previously for the β2-adrenoceptor. The results provide an understanding of chemokine receptor function and thereby information for the development of biased and non-biased antagonists and inverse agonists. PMID:24328926

  14. Actions of Thyroid Hormone Analogues on Chemokines

    PubMed Central

    Glinsky, Gennadi V.

    2016-01-01

    The extracellular domain of plasma membrane integrin αvβ3 contains a receptor for thyroid hormone (L-thyroxine, T4; 3,5,3′-triiodo-L-thyronine, T3); this receptor also binds tetraiodothyroacetic acid (tetrac), a derivative of T4. Tetrac inhibits the binding of T4 and T3 to the integrin. Fractalkine (CX3CL1) is a chemokine relevant to inflammatory processes in the CNS that are microglia-dependent but also important to normal brain development. Expression of the CX3CL1 gene is downregulated by tetrac, suggesting that T4 and T3 may stimulate fractalkine expression. Independently of its specific receptor (CX3CR1), fractalkine binds to αvβ3 at a site proximal to the thyroid hormone-tetrac receptor and changes the physical state of the integrin. Tetrac also affects expression of the genes for other CNS-relevant chemokines, including CCL20, CCL26, CXCL2, CXCL3, and CXCL10. The chemokine products of these genes are important to vascularity of the brain, particularly of the choroid plexus, to inflammatory processes in the CNS and, in certain cases, to neuroprotection. Thyroid hormones are known to contribute to regulation of each of these CNS functions. We propose that actions of thyroid hormone and hormone analogues on chemokine gene expression contribute to regulation of inflammatory processes in brain and of brain blood vessel formation and maintenance. PMID:27493972

  15. Actions of Thyroid Hormone Analogues on Chemokines.

    PubMed

    Davis, Paul J; Glinsky, Gennadi V; Lin, Hung-Yun; Mousa, Shaker A

    2016-01-01

    The extracellular domain of plasma membrane integrin αvβ3 contains a receptor for thyroid hormone (L-thyroxine, T4; 3,5,3'-triiodo-L-thyronine, T3); this receptor also binds tetraiodothyroacetic acid (tetrac), a derivative of T4. Tetrac inhibits the binding of T4 and T3 to the integrin. Fractalkine (CX3CL1) is a chemokine relevant to inflammatory processes in the CNS that are microglia-dependent but also important to normal brain development. Expression of the CX3CL1 gene is downregulated by tetrac, suggesting that T4 and T3 may stimulate fractalkine expression. Independently of its specific receptor (CX3CR1), fractalkine binds to αvβ3 at a site proximal to the thyroid hormone-tetrac receptor and changes the physical state of the integrin. Tetrac also affects expression of the genes for other CNS-relevant chemokines, including CCL20, CCL26, CXCL2, CXCL3, and CXCL10. The chemokine products of these genes are important to vascularity of the brain, particularly of the choroid plexus, to inflammatory processes in the CNS and, in certain cases, to neuroprotection. Thyroid hormones are known to contribute to regulation of each of these CNS functions. We propose that actions of thyroid hormone and hormone analogues on chemokine gene expression contribute to regulation of inflammatory processes in brain and of brain blood vessel formation and maintenance. PMID:27493972

  16. 6-shogaol, an active constituent of dietary ginger, impairs cancer development and lung metastasis by inhibiting the secretion of CC-chemokine ligand 2 (CCL2) in tumor-associated dendritic cells.

    PubMed

    Hsu, Ya-Ling; Hung, Jen-Yu; Tsai, Ying-Ming; Tsai, Eing-Mei; Huang, Ming-Shyan; Hou, Ming-Feng; Kuo, Po-Lin

    2015-02-18

    This study has two novel findings: it is not only the first to demonstrate that tumor-associated dendritic cells (TADCs) facilitate lung and breast cancer metastasis in vitro and in vivo by secreting inflammatory mediator CC-chemokine ligand 2 (CCL2), but it is also the first to reveal that 6-shogaol can decrease cancer development and progression by inhibiting the production of TADC-derived CCL2. Human lung cancer A549 and breast cancer MDA-MB-231 cells increase TADCs to express high levels of CCL2, which increase cancer stem cell features, migration, and invasion, as well as immunosuppressive tumor-associated macrophage infiltration. 6-Shogaol decreases cancer-induced up-regulation of CCL2 in TADCs, preventing the enhancing effects of TADCs on tumorigenesis and metastatic properties in A549 and MDA-MB-231 cells. A549 and MDA-MB-231 cells enhance CCL2 expression by increasing the phosphorylation of signal transducer and activator of transcription 3 (STAT3), and the activation of STAT3 induced by A549 and MDA-MB-231 is completely inhibited by 6-shogaol. 6-Shogaol also decreases the metastasis of lung and breast cancers in mice. 6-Shogaol exerts significant anticancer effects on lung and breast cells in vitro and in vivo by targeting the CCL2 secreted by TADCs. Thus, 6-shogaol may have the potential of being an efficacious immunotherapeutic agent for cancers. PMID:25621970

  17. Activation of p38 Mitogen-Activated Protein Kinase Promotes Peritoneal Fibrosis by Regulating Fibrocytes

    PubMed Central

    Kokubo, Satoshi; Sakai, Norihiko; Furuichi, Kengo; Toyama, Tadashi; Kitajima, Shinji; Okumura, Toshiya; Matsushima, Kouji; Kaneko, Shuichi; Wada, Takashi

    2012-01-01

    ♦ Background: Peritoneal fibrosis is a serious complication of long-term peritoneal dialysis, and yet the precise pathogenic mechanisms of peritoneal fibrosis remain unknown. Fibrocytes participate in tissue fibrosis and express chemokine receptors that are necessary for migration. The p38 mitogen-activated protein kinase (MAPK) pathway regulates the production of chemokines and has been demonstrated to contribute to the pathogenesis of various fibrotic conditions. Accordingly, we used an experimental mouse model of peritoneal fibrosis to examine the dependency of fibrocytes on p38MAPK signaling. ♦ Methods: Peritoneal fibrosis was induced in mice by the injection of 0.1% chlorhexidine gluconate (CG) into the abdominal cavity. Mice were treated with FR167653, a specific inhibitor of p38MAPK, and immunohistochemical studies were performed to detect fibrocytes and cells positive for phosphorylated p38MAPK. The involvement of p38MAPK in the activation of fibrocytes also was also investigated in vitro. ♦ Results: Fibrocytes infiltrated peritoneum in response to CG, and that response was accompanied by progressive peritoneal fibrosis. The phosphorylation of p38MAPK, as defined by CD45+ spindle-shaped cells, was detected both in peritoneal mesothelial cells and in fibrocytes. The level of peritoneal expression of CCL2, a chemoattractant for fibrocytes, was upregulated by CG injection, and treatment with FR167653 reduced the number of cells positive for phosphorylated p38MAPK, the peritoneal expression of CCL2, and the extent of peritoneal fibrosis. Pretreatment with FR167653 inhibited the expression of procollagen type I α1 induced by transforming growth factor-β1. ♦ Conclusions: Our results suggest that p38MAPK signaling contributes to peritoneal fibrosis by regulating fibrocyte function. PMID:21719683

  18. Association of MIF, but not type I interferon-induced chemokines, with increased disease activity in Asian patients with systemic lupus erythematosus

    PubMed Central

    Connelly, K. L.; Kandane-Rathnayake, R.; Hoi, A.; Nikpour, Mandana; Morand, E. F.

    2016-01-01

    Ethnicity is a key factor impacting on disease severity in SLE, but molecular mechanisms of these associations are unknown. Type I IFN and MIF have each been associated with SLE pathogenesis. We investigated whether increased SLE severity in Asian patients is associated with either MIF or Type I IFN. SLE patients (n = 151) had prospective recording of disease variables. Serum MIF, and a validated composite score of three Type I IFN-inducible chemokines (IFNCK:CCL2, CXCL10, CCL19) were measured. Associations of MIF and IFNCK score with disease activity were assessed, with persistent active disease (PAD) used as a marker of high disease activity over a median 2.6 years follow up. In univariable analysis, MIF, IFNCK score and Asian ethnicity were significantly associated with PAD. Asian ethnicity was associated with higher MIF but not IFNCK score. In multivariable logistic regression analysis, MIF (OR3.62 (95% CI 1.14,11.5), p = 0.03) and Asian ethnicity (OR3.00 (95% CI 1.39,6.46), p < 0.01) but not IFNCK were significantly associated with PAD. These results potentially support an effect of MIF, but not Type I IFN, in heightened SLE disease severity in Asian SLE. The associations of MIF and Asian ethnicity with PAD are at least partly independent. PMID:27453287

  19. 1,25-dihydroxyvitamin D3 Protects against Macrophage-Induced Activation of NFκB and MAPK Signalling and Chemokine Release in Human Adipocytes

    PubMed Central

    Ding, Cherlyn; Wilding, John P. H.; Bing, Chen

    2013-01-01

    Increased accumulation of macrophages in adipose tissue in obesity is linked to low-grade chronic inflammation, and associated with features of metabolic syndrome. Vitamin D3 may have immunoregulatory effects and reduce adipose tissue inflammation, although the molecular mechanisms remain to be established. This study investigated the effects of vitamin D3 on macrophage-elicited inflammatory responses in cultured human adipocytes, particularly the signalling pathways involved. Macrophage-conditioned (MC) medium (25% with adipocyte maintenance media) markedly inhibited protein expression of the nuclear factor-κB (NFκB) subunit inhibitor κBα (IκBα) (71%, P<0.001) and increased NFκB p65 (1.5-fold, P = 0.026) compared with controls. Treatment with 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) abolished macrophage-induced activation of NFκB signalling by increasing IκBα expression (2.7-fold, P = 0.005) and reducing NFκB p65 phosphorylation (68%; P<0.001). The mitogen-activated protein kinase (MAPK) signalling was activated by MC medium, which was also blunted by 1,25(OH)2D3 with a downregulation of phosphorylated p38 MAPK (32%, P = 0.005) and phosphorylated Erk1/2 (49%, P = 0.001). Furthermore, MC medium (12.5% or 25%) dose-dependently upregulated secretion of key proinflammatory chemokines/cytokines (22-368-fold; all P<0.001) and this was significantly decreased by 1,25(OH)2D3: IL-8 (61% and 31%, P<0.001), MCP-1 (37%, P<0.001 and 36%, P = 0.002), RANTES (78% and 62%, P<0.001) and IL-6 (29%, P<0.001 and 34%, P = 0.019). Monocyte migration-elicited by adipocytes treated with 1,25(OH)2D3 was also reduced (up to 25%, P<0.001). In conclusion, vitamin D3 could be anti-inflammatory in adipose tissue, decreasing macrophage-induced release of chemokines and cytokines by adipocytes and the chemotaxis of monocytes. Our data suggests these effects are mediated by inhibition of the NFκB and MAPK signalling pathways. PMID:23637889

  20. Molecular Basis of Glycosaminoglycan Heparin Binding to the Chemokine CXCL1 Dimer*

    PubMed Central

    Poluri, Krishna Mohan; Joseph, Prem Raj B.; Sawant, Kirti V.; Rajarathnam, Krishna

    2013-01-01

    Glycosaminoglycan (GAG)-bound and soluble chemokine gradients in the vasculature and extracellular matrix mediate neutrophil recruitment to the site of microbial infection and sterile injury in the host tissue. However, the molecular principles by which chemokine-GAG interactions orchestrate these gradients are poorly understood. This, in part, can be directly attributed to the complex interrelationship between the chemokine monomer-dimer equilibrium and binding geometry and affinities that are also intimately linked to GAG length. To address some of this missing knowledge, we have characterized the structural basis of heparin binding to the murine CXCL1 dimer. CXCL1 is a neutrophil-activating chemokine and exists as both monomers and dimers (Kd = 36 μm). To avoid interference from monomer-GAG interactions, we designed a trapped dimer (dCXCL1) by introducing a disulfide bridge across the dimer interface. We characterized the binding of GAG heparin octasaccharide to dCXCL1 using solution NMR spectroscopy. Our studies show that octasaccharide binds orthogonally to the interhelical axis and spans the dimer interface and that heparin binding enhances the structural integrity of the C-terminal helical residues and stability of the dimer. We generated a quadruple mutant (H20A/K22A/K62A/K66A) on the basis of the binding data and observed that this mutant failed to bind heparin octasaccharide, validating our structural model. We propose that the stability enhancement of dimers upon GAG binding regulates in vivo neutrophil trafficking by increasing the lifetime of “active” chemokines, and that this structural knowledge could be exploited for designing inhibitors that disrupt chemokine-GAG interactions and neutrophil homing to the target tissue. PMID:23864653

  1. Atlantic cod (Gadus morhua) CC chemokines: Diversity and expression analysis.

    PubMed

    Borza, Tudor; Stone, Cynthia; Rise, Matthew L; Bowman, Sharen; Johnson, Stewart C

    2010-08-01

    Chemokines are a large, diverse group of small cytokines that can be classified into several families, including the CC chemokines that are characterized by two adjacent cysteines near their amino terminus. CC chemokines play a pivotal role in host defense mechanisms by inducing leukocyte chemotaxis under physiological and inflammatory conditions. Analysis of CC chemokines from teleost fishes indicates that the number of CC chemokine genes and their tissue expression patterns vary largely in this group of vertebrates. Here we describe 32 distinct CC chemokine sequences from Atlantic cod (Gadus morhua) identified by analysis of approximately 206,000 ESTs. Phylogenetic analysis of Atlantic cod CC chemokines placed these sequences in seven clusters, most likely resulting from species-specific gene duplications, and two unique sequences; 12 of these CC chemokines, including at least one member of each cluster, were analyzed by QPCR using four immune-related tissues (head kidney, liver, spleen and blood) obtained from unstimulated, polyriboinosinic polyribocytidylic acid (pIC)-stimulated and formalin-killed atypical Aeromonas salmonicida-stimulated individuals. EST abundance and QPCR analysis indicate that the expression of closely related CC chemokines GmSCYA101 and GmSCYA102, GmSCYA108 and GmSCYA109 or GmSCYA122 and GmSCYA124 can be highly tissue-specific despite substantial sequence identity. Stimulation with the viral mimic pIC or formalin-killed atypical A. salmonicida resulted in increased expression of most of the CC chemokines, indicating that they can be regarded as either inducible (inflammatory) or dual-function rather than constitutive (homeostatic). Tissue specificity, and the level of induction, varied broadly; for example, GmSCYA123 was at least 4-fold up-regulated by both inducers in all tissues analyzed, whereas pIC increased the expression of GmSCYA124 in liver over 1500 times. PMID:20381521

  2. Differential Chemokine Signature between Human Preadipocytes and Adipocytes

    PubMed Central

    Ignacio, Rosa Mistica C.; Gibbs, Carla R.; Lee, Eun-Sook

    2016-01-01

    Obesity is characterized as an accumulation of adipose tissue mass represented by chronic, low-grade inflammation. Obesity-derived inflammation involves chemokines as important regulators contributing to the pathophysiology of obesity-related diseases such as cardiovascular disease, diabetes and some cancers. The obesity-driven chemokine network is poorly understood. Here, we identified the profiles of chemokine signature between human preadipocytes and adipocytes, using PCR arrays and qRT-PCR. Both preadipocytes and adipocytes showed absent or low levels in chemokine receptors in spite of some changes. On the other hand, the chemokine levels of CCL2, CCL7-8, CCL11, CXCL1-3, CXCL6 and CXCL10-11 were dominantly expressed in preadipocytes compared to adipocytes. Interestingly, CXCL14 was the most dominant chemokine expressed in adipocytes compared to preadipocytes. Moreover, there is significantly higher protein level of CXCL14 in conditioned media from adipocytes. In addition, we analyzed the data of the chemokine signatures in adipocytes obtained from healthy lean and obese postmenopausal women based on Gene Expression Omnibus (GEO) dataset. Adipocytes from obese individuals had significantly higher levels in chemokine signature as follows: CCL2, CCL13, CCL18-19, CCL23, CCL26, CXCL1, CXCL3 and CXCL14, as compared to those from lean ones. Also, among the chemokine networks, CXCL14 appeared to be the highest levels in adipocytes from both lean and obese women. Taken together, these results identify CXCL14 as an important chemokine induced during adipogenesis, requiring further research elucidating its potential therapeutic benefits in obesity. PMID:27340388

  3. Differential Chemokine Signature between Human Preadipocytes and Adipocytes.

    PubMed

    Ignacio, Rosa Mistica C; Gibbs, Carla R; Lee, Eun-Sook; Son, Deok-Soo

    2016-06-01

    Obesity is characterized as an accumulation of adipose tissue mass represented by chronic, low-grade inflammation. Obesity-derived inflammation involves chemokines as important regulators contributing to the pathophysiology of obesity-related diseases such as cardiovascular disease, diabetes and some cancers. The obesity-driven chemokine network is poorly understood. Here, we identified the profiles of chemokine signature between human preadipocytes and adipocytes, using PCR arrays and qRT-PCR. Both preadipocytes and adipocytes showed absent or low levels in chemokine receptors in spite of some changes. On the other hand, the chemokine levels of CCL2, CCL7-8, CCL11, CXCL1-3, CXCL6 and CXCL10-11 were dominantly expressed in preadipocytes compared to adipocytes. Interestingly, CXCL14 was the most dominant chemokine expressed in adipocytes compared to preadipocytes. Moreover, there is significantly higher protein level of CXCL14 in conditioned media from adipocytes. In addition, we analyzed the data of the chemokine signatures in adipocytes obtained from healthy lean and obese postmenopausal women based on Gene Expression Omnibus (GEO) dataset. Adipocytes from obese individuals had significantly higher levels in chemokine signature as follows: CCL2, CCL13, CCL18-19, CCL23, CCL26, CXCL1, CXCL3 and CXCL14, as compared to those from lean ones. Also, among the chemokine networks, CXCL14 appeared to be the highest levels in adipocytes from both lean and obese women. Taken together, these results identify CXCL14 as an important chemokine induced during adipogenesis, requiring further research elucidating its potential therapeutic benefits in obesity. PMID:27340388

  4. Therapeutic potential of chemokine signal inhibition for metastatic breast cancer

    PubMed Central

    Kitamura, Takanori; Pollard, Jeffrey W.

    2015-01-01

    Metastatic breast cancer is incurable by current therapies including chemotherapy and immunotherapy. Accumulating evidence indicates that tumor-infiltrating macrophages promote establishment of the lethal metastatic foci and contribute to therapeutic resistance. Recent studies suggest that the accumulation of these macrophages is regulated by a chemokine network established in the tumor microenvironment. In this perspective paper, we elaborate on the chemokine signals that can attract monocytes/macrophages to the site of metastasis, and discuss whether inhibition of these chemokine signals can represent a new therapeutic strategy for metastatic breast cancer. PMID:26275794

  5. Chemokine-guided cell migration and motility in zebrafish development

    PubMed Central

    Bussmann, Jeroen; Raz, Erez

    2015-01-01

    Chemokines are vertebrate-specific, structurally related proteins that function primarily in controlling cell movements by activating specific 7-transmembrane receptors. Chemokines play critical roles in a large number of biological processes and are also involved in a range of pathological conditions. For these reasons, chemokines are at the focus of studies in developmental biology and of clinically oriented research aimed at controlling cancer, inflammation, and immunological diseases. The small size of the zebrafish embryos, their rapid external development, and optical properties as well as the large number of eggs and the fast expansion in genetic tools available make this model an extremely useful one for studying the function of chemokines and chemokine receptors in an in vivo setting. Here, we review the findings relevant to the role that chemokines play in the context of directed single-cell migration, primarily in neutrophils and germ cells, and compare it to the collective cell migration of the zebrafish lateral line. We present the current knowledge concerning the formation of the chemokine gradient, its interpretation within the cell, and the molecular mechanisms underlying the cellular response to chemokine signals during directed migration. PMID:25762592

  6. Chemokine Detection Using Receptors Immobilized on an SPR Sensor Surface.

    PubMed

    Rodríguez-Frade, José Miguel; Martínez-Muñoz, Laura; Villares, Ricardo; Cascio, Graciela; Lucas, Pilar; Gomariz, Rosa P; Mellado, Mario

    2016-01-01

    Chemokines and their receptors take part in many physiological and pathological processes, and their dysregulated expression is linked to chronic inflammatory and autoimmune diseases, immunodeficiencies, and cancer. The chemokine receptors, members of the G protein-coupled receptor family, are integral membrane proteins, with seven-transmembrane domains that bind the chemokines and transmit signals through GTP-binding proteins. Many assays used to study the structure, conformation, or activation mechanism of these receptors are based on ligand-binding measurement, as are techniques to detect new agonists and antagonists that modulate chemokine function. Such methods require labeling of the chemokine and/or its receptor, which can alter their binding characteristics. Surface plasmon resonance (SPR) is a powerful technique for analysis of the interaction between immobilized receptors and ligands in solution, in real time, and without labeling. SPR measurements nonetheless require expression and purification steps that can alter the conformation, stability, and function of the chemokine and/or the chemokine receptor. In this review, we focus on distinct methods to immobilize chemokine receptors on the surface of an optical biosensor. We expose the advantages and disadvantages of different protocols used and describe in detail the method to retain viral particles as receptor carriers that can be used for SPR determinations. PMID:26921939

  7. Chemokines, costimulatory molecules and fusion proteins for the immunotherapy of solid tumors

    PubMed Central

    Lechner, Melissa G; Russell, Sarah M; Bass, Rikki S; Epstein, Alan L

    2011-01-01

    In this article, the role of chemokines and costimulatory molecules in the immunotherapy of experimental murine solid tumors and immunotherapy used in ongoing clinical trials are presented. Chemokine networks regulate physiologic cell migration that may be disrupted to inhibit antitumor immune responses or coopted to promote tumor growth and metastasis in cancer. Recent studies highlight the potential use of chemokines in cancer immunotherapy to improve innate and adaptive cell interactions and to recruit immune effector cells into the tumor microenvironment. Another critical component of antitumor immune responses is antigen priming and activation of effector cells. Reciprocal expression and binding of costimulatory molecules and their ligands by antigen-presenting cells and naive lymphocytes ensures robust expansion, activity and survival of tumor-specific effector cells in vivo. Immunotherapy approaches using agonist antibodies or fusion proteins of immunomodulatory molecules significantly inhibit tumor growth and boost cell-mediated immunity. To localize immune stimulation to the tumor site, a series of fusion proteins consisting of a tumor-targeting monoclonal antibody directed against tumor necrosis and chemokines or costimulatory molecules were generated and tested in tumor-bearing mice. While several of these reagents were initially shown to have therapeutic value, combination therapies with methods to delete suppressor cells had the greatest effect on tumor growth. In conclusion, a key conclusion that has emerged from these studies is that successful immunotherapy will require both advanced methods of immunostimulation and the removal of immunosuppression in the host. PMID:22053884

  8. A novel chemokine receptor for SDF-1 and I-TAC involved in cell survival, cell adhesion, and tumor development

    PubMed Central

    Burns, Jennifer M.; Summers, Bretton C.; Wang, Yu; Melikian, Anita; Berahovich, Rob; Miao, Zhenhua; Penfold, Mark E. T.; Sunshine, Mary Jean; Littman, Dan R.; Kuo, Calvin J.; Wei, Kevin; McMaster, Brian E.; Wright, Kim; Howard, Maureen C.; Schall, Thomas J.

    2006-01-01

    The chemokine stromal cell–derived factor (SDF-1; also known as chemokine ligand 12 [CXCL12]) regulates many essential biological processes, including cardiac and neuronal development, stem cell motility, neovascularization, angiogenesis, apoptosis, and tumorigenesis. It is generally believed that SDF-1 mediates these many disparate processes via a single cell surface receptor known as chemokine receptor 4 (CXCR4). This paper characterizes an alternate receptor, CXCR7, which binds with high affinity to SDF-1 and to a second chemokine, interferon-inducible T cell α chemoattractant (I-TAC; also known as CXCL11). Membrane-associated CXCR7 is expressed on many tumor cell lines, on activated endothelial cells, and on fetal liver cells, but on few other cell types. Unlike many other chemokine receptors, ligand activation of CXCR7 does not cause Ca2+ mobilization or cell migration. However, expression of CXCR7 provides cells with a growth and survival advantage and increased adhesion properties. Consistent with a role for CXCR7 in cell survival and adhesion, a specific, high affinity small molecule antagonist to CXCR7 impedes in vivo tumor growth in animal models, validating this new receptor as a target for development of novel cancer therapeutics. PMID:16940167

  9. Expression Profiles of Circulating Cytokines, Chemokines and Immune Cells in Patients With Hepatitis B Virus Infection

    PubMed Central

    Lian, Jian-Qi; Yang, Xiao-Fei; Zhao, Rong-Rong; Zhao, Yan-Yan; Li, Yu; Zhang, Ye; Huang, Chang-Xing

    2014-01-01

    Background: Immune cells and molecules play a vital role in initiating, maintaining, regulating immunological homeostasis and inflammation in many pathological and physiological processes; however, the changes on expressions and functions of these cells and molecules in hepatitis B virus (HBV) infection have not been elucidated well. Objectives: The current study aimed to determine the expression pattern of different cytokines, chemokines, immune cells in HBV infection and their association with disease progression. Patients and Methods: Sixty-nine patients with chronic HBV infection were enrolled. Five immune cell subsets and 46 cytokines and chemokines were analyzed by flow cytometry and Luminex 200. Results: In comparison to healthy individuals and asymptomatic HBV carriers, expression of CXCL9, CXCL10, CXCL11, and IL-10 were elevated in patients with chronic active HBV and had positive correlation with ALT levels. In contrast, G-CSF, MCP-3, and IFN-γ levels were significantly decreased in patients with chronic active HBV infection in contrast to carriers and healthy individuals; however, these down regulations did not show any correlation with either virological findings or liver inflammation. Although the proportion of CD4+ CD25 high regulatory T cells (Tregs) was higher in patients with HBV infection than in healthy controls, no correlations were found between Tregs and other cytokines or chemokines. Conclusions: CXCR3-associated chemokines might contribute to liver inflammation in chronic hepatitis B, while MCP-3 and G-CSF were inhibited by HBV infection. Host immune response was suppressed as manifested by an increase in CD4+ CD25high Tregs and IL-10 as well as a decrease in IFN-γ. Exploiting the expression pattern of cytokine and chemokine may help to develop a better understanding of chronic HBV infection pathogenesis. PMID:24976843

  10. Chemokines in cancer related inflammation

    SciTech Connect

    Allavena, Paola; Germano, Giovanni; Marchesi, Federica; Mantovani, Alberto

    2011-03-10

    Chemokines are key players of the cancer-related inflammation. Chemokine ligands and receptors are downstream of genetic events that cause neoplastic transformation and are abundantly expressed in chronic inflammatory conditions which predispose to cancer. Components of the chemokine system affect multiple pathways of tumor progression including: leukocyte recruitment, neo-angiogenesis, tumor cell proliferation and survival, invasion and metastasis. Evidence in pre-clinical and clinical settings suggests that the chemokine system represents a valuable target for the development of innovative therapeutic strategies.

  11. Cytokine/Chemokine Responses in Activated CD4+ and CD8+ T Cells Isolated from Peripheral Blood, Bone Marrow, and Axillary Lymph Nodes during Acute Simian Immunodeficiency Virus Infection

    PubMed Central

    Kenway-Lynch, Carys S.; Das, Arpita; Lackner, Andrew A.

    2014-01-01

    ABSTRACT Understanding the cytokine/chemokine networks in CD4+ and CD8+ T cells during the acute phase of infection is crucial to design therapies for the control of early human immunodeficiency virus (HIV)/simian immunodeficiency virus (SIV) replication. Here, we measured early changes in CD4+ and CD8+ T cells in the peripheral blood (PB), bone marrow (BM), and axillary lymph node (ALN) tissue of rhesus macaques infected with SIVMAC251. At 21 days after infection, all tissues showed a statistically significant loss of CD4+ T cells along with immune activation of CD8+ T cells in PB and ALN tissue. Twenty-eight different cytokines/chemokines were quantified in either anti-CD3/28 antibody- or staphylococcal enterotoxin B-stimulated single-positive CD4+ and CD8+ T cells. PB CD4+ T cells produced predominantly interleukin-2 (IL-2), whereas CD4+ and CD8+ T-cell subsets in tissues produced β-chemokines both before and 21 days after SIV infection. Tissues generally exhibited massive upregulation of many cytokines/chemokines following infection, possibly in an attempt to mitigate the loss of CD4+ T cells. There was no evidence of a T-helper 1 (TH1)-to-TH2 shift in CD4+ T cells or a T-cytotoxic 1 (TC1)-to-TC2 cytokine shift in CD8+ T cells in PB, BM, and ALN T-cell subsets during the acute phase of SIV infection. Despite the upregulation of several important effector cytokines/chemokines (IL-2, IL-12, IL-17, gamma interferon, granulocyte-macrophage colony-stimulating factor) by CD4+ and CD8+ T cells, upregulation of β-chemokines (CCL2 and CCL22), basic fibroblast growth factor (FGF-basic), hepatocyte growth factor (HGF), and migration inhibition factor (MIF) may provide a poor prognosis either by inducing increased virus replication or by other unknown mechanisms. Therefore, drugs targeting β-chemokines (CCL2 and CCL22), FGF-basic, HGF, or MIF might be important for developing effective vaccines and therapeutics against HIV. IMPORTANCE Human immunodeficiency virus (HIV

  12. Chemokine interaction with synergy-inducing molecules: fine tuning modulation of cell trafficking.

    PubMed

    Cecchinato, Valentina; D'Agostino, Gianluca; Raeli, Lorenzo; Uguccioni, Mariagrazia

    2016-06-01

    Directed migration and arrest of leukocytes during homeostasis, inflammation, and tumor development is mediated by the chemokine system, which governs leukocyte migration and activities. Although we understand well the effects of different chemokines one by one, much less was known about the potential consequences of the concomitant expression of multiple chemokines or of their interaction with inflammatory molecules on leukocyte migration and functions. In the past 10 yr, several studies revealed the existence of additional features of chemokines: they can antagonize chemokine receptors or synergize with other chemokines, also by forming heterocomplexes. Moreover, recent data show that not only chemokines but also the alarmin high-mobility group box 1 can for a complex with CXCL12, enhancing its potency on CXCR4. The molecular mechanism underlying the effect of the heterocomplex has been partially elucidated, whereas its structure is a matter of current investigations. The present review discusses the current knowledge and relevance of the functions of heterocomplexes formed between chemokines or between the chemokine CXCL12 and the alarmin high-mobility group box 1. These studies highlight the importance of taking into account, when approaching innovative therapies targeting the chemokine system, also the fact that some chemokines and molecules released in inflammation, can considerably affect the activity of chemokine receptor agonists. PMID:26715684

  13. Cytokine and chemokine expression profiles in response to Mycobacterium tuberculosis stimulation are altered in HIV-infected compared to HIV-uninfected subjects with active tuberculosis.

    PubMed

    Waruk, Jillian L M; Machuki, Zipporah; Mesa, Christine; Juno, Jennifer A; Anzala, Omu; Sharma, Meenu; Ball, T Blake; Oyugi, Julius; Kiazyk, Sandra

    2015-09-01

    Mycobacterium tuberculosis (Mtb) infects nearly 2 million people annually and is the most common cause of death in HIV-infected individuals. Tuberculosis (TB) diagnostics cater to HIV-uninfected individuals in non-endemic countries, are expensive, slow, and lack sensitivity for those most affected. Patterns of soluble immune markers from Mtb-stimulated immune cells are not well defined in HIV co-infection. We assessed immune differences between HIV-infected and HIV-uninfected individuals with active TB utilizing IFNγ-based QuantiFERON®-TB Gold In-Tube (QFT) testing in Nairobi, Kenya. Excess QFT supernatants were used to measure cytokine and chemokine responses by a 17-plex bead array. Mtb/HIV co-infected participants were significantly less likely to be QFT+ (47.2% versus 84.2% in the HIV-uninfected group), and demonstrated lower expression of all cytokines except for IFNα2. Receiver operator characteristic analyses identified IL-1α as a potential marker of co-infection. Among HIV-infected individuals, CD4+ T cell count correlated weakly with the expression of several analytes. Co-expression analysis highlighted differences in immune profiles between the groups. These data suggest that there is a unique and detectable Mtb-specific immune response in co-infection. A better understanding of Mtb immunology can translate into much needed immunodiagnostics with enhanced sensitivity in HIV-infected individuals, facilitating their opportunity to obtain live-saving treatment. PMID:26073895

  14. Chemokine genetic polymorphism in human health and disease.

    PubMed

    Qidwai, Tabish

    2016-08-01

    Chemokine receptor-ligand interaction regulates transmigration of lymphocytes and monocytes from circulation to the inflammatory sites. CC chemokine receptors, chemokine receptor 2(CCR2) and 5 (CCR5) are important in recruitment of immune cells as well as non-immune cells under pathological condition. CCR2, CCR5 and their ligands (CCL2 and CCL5) are major contributor to the autoimmune and inflammatory diseases and cancer. Currently studies are being done to explore genetic variations in chemokine genes and their involvement in diseases that could make clear disease severity and deaths. Conflicting results of studies in different populations and diseases promoted to investigate chemokines genetic polymorphisms in miscellaneous diseases. This study is aimed to evaluate the influence of chemokines genetic polymorphisms in pathogenesis and outcome of prevalent non infectious diseases. Present study demonstrates the likely role played by genetic variations in drug response and evolution. Moreover this study highlights chemokine as therapeutic target and diagnostic biomarker in pathological condition. PMID:27262929

  15. Upregulation of chemokine receptor CCR10 is essential for glioma proliferation, invasion and patient survival

    PubMed Central

    Chen, Lingchao; Liu, Xing; Zhang, Hai-Yan; Du, Wenzong; Qin, Zhiyong; Yao, Yu; Mao, Ying; Zhou, Liangfu

    2014-01-01

    Human gliomas are characterized by their invasion of normal brain structures irrespective of their grade of malignancy. Tumor cell invasion share many similarities with leukocyte trafficking, which is critically regulated by chemokines and their receptors. Here we report that the chemokine receptor CCR10 is highly expressed in human glioblastoma compared with control brain tissue. In vitro, signaling through CCL27-CCR10 mediates activation of p-Akt, and subsequently induces proliferation and invasive responses. Cell proliferation and invasion promoted by CCL27 were blocked by inhibition of p-Akt or CCR10. In vivo, down-regulation of CCR10 significantly impairs growth of glioma. Clinically, High CCR10 expression in GBM correlated with p-Akt, shorter overall survival and progression-free survival (P < 0.05). Together, these findings suggest that elevated CCR10 is a critical molecular event associated with gliomagenesis. PMID:25149529

  16. Negative feedback between prostaglandin and alpha- and beta-chemokine synthesis in human microglial cells and astrocytes.

    PubMed

    Janabi, N; Hau, I; Tardieu, M

    1999-02-01

    The understanding of immune surveillance and inflammation regulation in cerebral tissue is essential in the therapy of neuroimmunological disorders. We demonstrate here that primary human glial cells were able to produce alpha- and beta-chemokines (IL-8 > growth related protein alpha (GROalpha) > RANTES > microphage inflammatory protein (MIP)-1alpha and MIP-1beta) in parallel to PGs (PGE2 and PGF2alpha) after proinflammatory cytokine stimulation: TNF-alpha + IL-1beta induced all except RANTES, which was induced by TNF-alpha + IFN-gamma. Purified cultures of astrocytes and microglia were also induced by the same combination of cytokines, to produce all these mediators except MIP-1alpha and MIP-1beta, which were produced predominantly by astrocytes. The inhibition of PG production by indomethacin led to a 37-60% increase in RANTES, MIP-1alpha, and MIP-1beta but not in GROalpha and IL-8 secretion. In contrast, inhibition of IL-8 and GRO activities using neutralizing Abs resulted in a specific 6-fold increase in PGE2 but not in PGF2alpha production by stimulated microglial cells and astrocytes, whereas Abs to beta-chemokines had no effect. Thus, the production of PGs in human glial cells down-regulates their beta-chemokine secretion, whereas alpha-chemokine production in these cells controls PG secretion level. These data suggest that under inflammatory conditions, the intraparenchymal production of PGs could control chemotactic gradient of beta-chemokines for an appropriate effector cell recruitment or activation. Conversely, the elevated intracerebral alpha-chemokine levels could reduce PG secretion, preventing the exacerbation of inflammation and neurotoxicity. PMID:9973432

  17. A beginner's guide to chemokines.

    PubMed

    Vinader, Victoria; Afarinkia, Kamyar

    2012-05-01

    This review provides an overview of chemokines and their receptors, with an emphasis on general features and nomenclature along with a short summary of their properties and functions. It is intended as an introduction to the subject and a reference point for those wishing to learn key facts about chemokines and their role in biology. PMID:22571610

  18. PARC/CCL18 Is a Plasma CC Chemokine with Increased Levels in Childhood Acute Lymphoblastic Leukemia

    PubMed Central

    Struyf, Sofie; Schutyser, Evemie; Gouwy, Mieke; Gijsbers, Klara; Proost, Paul; Benoit, Yves; Opdenakker, Ghislain; Van Damme, Jo; Laureys, Geneviève

    2003-01-01

    Chemokines play an important role in leukocyte mobilization, hematopoiesis, and angiogenesis. Tissue-specific expression of particular chemokines also influences tumor growth and metastasis. Here, the CC chemokine pulmonary and activation-regulated chemokine (PARC)/CCL18 was measured in pediatric patients with acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML). Surprisingly, PARC immunoreactivity was consistently detected in plasma from healthy donors. After purification to homogeneity, the presence of intact PARC (1–69) and processed PARC (1–68) in normal human plasma was confirmed by sequence and mass spectrometry analysis. Furthermore, PARC serum levels were significantly increased in children with T-ALL and prepreB-ALL compared to control serum samples, whereas serum levels in AML and preB-ALL patients were not significantly different from controls. In contrast, the hemofiltrate CC chemokine-1 (HCC-1)/CCL14 was not found to be a biomarker in any of these patients’ strata, whereas the cytokine interleukin-6 (IL-6) was significantly decreased in AML and prepreB-ALL. Stimulated leukocytic cell lines or lymphoblasts from patients produced IL-8/CXCL8 or macrophage inflammatory protein-1α (MIP-1α/CCL3) but not PARC, not even after IL-4 or IL-10 treatment. However, PARC was produced by superantigen or IL-4 stimulated monocytes co-cultured with lymphocytes or lymphoblastic cells. Serum PARC levels thus constitute a novel leukemia marker, possibly reflecting tumor/host cell interactions in the circulation. PMID:14578205

  19. Role of Chemokine Network in the Development and Progression of Ovarian Cancer: A Potential Novel Pharmacological Target

    PubMed Central

    Barbieri, Federica; Bajetto, Adriana; Florio, Tullio

    2010-01-01

    Ovarian cancer is the most common type of gynecologic malignancy. Despite advances in surgery and chemotherapy, the survival rate is still low since most ovarian cancers relapse and become drug-resistant. Chemokines are small chemoattractant peptides mainly involved in the immune responses. More recently, chemokines were also demonstrated to regulate extra-immunological functions. It was shown that the chemokine network plays crucial functions in the tumorigenesis in several tissues. In particular the imbalanced or aberrant expression of CXCL12 and its receptor CXCR4 strongly affects cancer cell proliferation, recruitment of immunosuppressive cells, neovascularization, and metastasization. In the last years, several molecules able to target CXCR4 or CXCL12 have been developed to interfere with tumor growth, including pharmacological inhibitors, antagonists, and specific antibodies. This chemokine ligand/receptor pair was also proposed to represent an innovative therapeutic target for the treatment of ovarian cancer. Thus, a thorough understanding of ovarian cancer biology, and how chemokines may control these different biological activities might lead to the development of more effective therapies. This paper will focus on the current biology of CXCL12/CXCR4 axis in the context of understanding their potential role in ovarian cancer development. PMID:20049170

  20. Chemokines and diabetic wound healing.

    PubMed

    Ochoa, Oscar; Torres, Francis M; Shireman, Paula K

    2007-01-01

    Chemokines are critical for white blood cell recruitment to injured tissues and play an important role in normal wound healing processes. In contrast, impaired wound healing in diabetic patients is accompanied by decreased early inflammatory cell infiltration but persistence of neutrophils and macrophages in the chronic, nonhealing wounds. These changes in inflammatory cell recruitment occur in conjunction with alterations in chemokine and growth factor expression. In addition to leukocyte trafficking, many different cell types, including endothelial cells, fibroblasts, and keratinocytes, produce and respond to chemokines, and these interactions are altered in diabetic wounds. Thus, the chemokine system may have both direct and inflammatory-mediated effects on many different aspects of diabetic wound healing. The potential roles of chemokines and inflammatory or immune cells in nonhealing diabetic wounds, including impairments in growth factor expression, angiogenesis, extracellular matrix formation, and reepithelialization, are examined. PMID:18053419

  1. Nitric Oxide Donors Suppress Chemokine Production by Keratinocytes in Vitro and in Vivo

    PubMed Central

    Giustizieri, Maria Laura; Albanesi, Cristina; Scarponi, Claudia; De Pità, Ornella; Girolomoni, Giampiero

    2002-01-01

    Nitric oxide (NO) is involved in the modulation of inflammatory responses. In psoriatic skin, NO is highly produced by epidermal keratinocytes in response to interferon-γ and tumor necrosis factor-α. In this study, we investigated whether the NO donors, S-nitrosoglutathione (GS-NO) and NOR-1, could regulate chemokine production by human keratinocytes activated with interferon-γ and tumor necrosis factor-α. In addition, we studied the effects of the topical application of a GS-NO ointment on chemokine expression in lesional psoriatic skin. NO donors diminished in a dose-dependent manner and at both mRNA and protein levels the IP-10, RANTES, and MCP-1 expression in keratinocytes cultured from healthy patients and psoriatic patients. In contrast, constitutive and induced interleukin-8 production was unchanged. GS-NO-treated psoriatic skin showed reduction of IP-10, RANTES, and MCP-1, but not interleukin-8 expression by keratinocytes. Moreover, the number of CD14+ and CD3+ cells infiltrating the epidermis and papillary dermis diminished significantly. NO donors also down-regulated ICAM-1 protein expression without affecting mRNA accumulation in vitro, and suppressed keratinocyte ICAM-1 in vivo. Finally, NO donors inhibited nuclear factor-κB and STAT-1, but not AP-1 activities in transiently transfected keratinocytes. These results define NO donors as negative regulators of chemokine production by keratinocytes. PMID:12368213

  2. Methemoglobin-induced signaling and chemokine responses in human alveolar epithelial cells

    PubMed Central

    Mumby, Sharon; Ramakrishnan, Latha; Evans, Timothy W.; Griffiths, Mark J. D.

    2013-01-01

    Diffuse alveolar hemorrhage is characterized by the presence of red blood cells and free hemoglobin in the alveoli and complicates a number of serious medical and surgical lung conditions including the pulmonary vasculitides and acute respiratory distress syndrome. In this study we investigated the hypothesis that exposure of human alveolar epithelial cells to hemoglobin and its breakdown products regulates chemokine release via iron- and oxidant-mediated activation of the transcription factor NF-κB. Methemoglobin alone stimulated the release of IL-8 and MCP-1 from A549 cells via activation of the NF-κB pathway; additionally, IL-8 required ERK activation and MCP-1 required JNK activation. Neither antioxidants nor iron chelators and knockdown of ferritin heavy and light chains affected these responses, indicating that iron and reactive oxygen species are not involved in the response of alveolar epithelial cells to methemoglobin. Incubation of primary cultures of human alveolar type 2 cells with methemoglobin resulted in a similar pattern of chemokine release and signaling pathway activation. In summary, we have shown for the first time that methemoglobin induced chemokine release from human lung epithelial cells independent of iron- and redox-mediated signaling involving the activation of the NF-κB and MAPK pathways. Decompartmentalization of hemoglobin may be a significant proinflammatory stimulus in a variety of lung diseases. PMID:24142518

  3. Resistin-Like Molecule–α Regulates IL-13–Induced Chemokine Production but Not Allergen-Induced Airway Responses

    PubMed Central

    Munitz, Ariel; Cole, Eric T.; Karo-Atar, Danielle; Finkelman, Fred D.

    2012-01-01

    Resistin-like molecule α (Relm-α) is one of the most up-regulated gene products in allergen- and parasite-associated Th2 responses. Localized to alternatively activated macrophages, Relm-α was shown to exert an anti-inflammatory effect in parasite-induced Th2 responses, but its role in experimental asthma remains unexplored. Here, we analyzed the cellular source, the IL-4 receptors required to stimulate Relm-α production, and the role of Relm-α after experimental asthma induction by IL-4, IL-13, or multiple experimental regimes, including ovalbumin and Aspergillus fumigatus immunization. We demonstrate that Relm-α was secreted into the airway lumen, dependent on both the IL-13 receptor–α1 chain and likely the Type I IL-4 receptor, and differentially localized to epithelial cells and myeloid cells, depending on the specific cytokine or aeroallergen trigger. Studies performed with Retnla gene–targeted mice demonstrate that Relm-α was largely redundant in terms of inducing the infiltration of Th2 cytokines, mucus, and inflammatory cells into the lung. These results mirror the dispensable role that other alternatively activated macrophage products (such as arginase 1) have in allergen-induced experimental asthma and contrast with their role in the setting of parasitic infections. Taken together, our findings demonstrate the distinct utilization of IL-4/IL-13 receptors for the induction of Relm-α in the lungs. The differential regulation of Relm-α expression is likely determined by the relative expression levels of IL-4, IL-13, and their corresponding receptors, which are differentially expressed by divergent cells (i.e., epithelial cells and macrophages.) Finally, we identify a largely redundant functional role for Relm-α in acute experimental models of allergen-associated Th2 immune responses. PMID:22246861

  4. The fine balance of chemokines during disease: trafficking, inflammation and homeostasis

    PubMed Central

    Cardona, Sandra M.; Garcia, Jenny A.; Cardona, Astrid E.

    2014-01-01

    Summary The action of chemokines (or ‘chemotactic cytokines’) is recognized as an integral part of inflammatory and regulatory processes. Leukocyte mobilization during physiological conditions, trafficking of various cell types during pathological conditions, cell activation and angiogenesis are among the target functions exerted by chemokines upon signaling via their specific receptors. Current research is focused in analyzing changes in chemokine/chemokine receptor patterns during various diseases with the aim to modulate pathological trafficking of cells, or to attract particular cell types to specific tissues. This review focuses on defining the role(s) of certain chemokine ligands and receptors in inflammatory neurological conditions such as multiple sclerosis. In addition, the role(s) of chemokines in neurodegenerative conditions such as Alzheimer’s disease and Parkinson’s disease are also described, as well as the contribution of chemokines to the pathogenesis of cancer, diabetes and cardiovascular disease. PMID:23625489

  5. Chemokines as Cancer Vaccine Adjuvants

    PubMed Central

    Bobanga, Iuliana D.; Petrosiute, Agne; Huang, Alex Y.

    2013-01-01

    We are witnessing a new era of immune-mediated cancer therapies and vaccine development. As the field of cancer vaccines advances into clinical trials, overcoming low immunogenicity is a limiting step in achieving full success of this therapeutic approach. Recent discoveries in the many biological roles of chemokines in tumor immunology allow their exploitation in enhancing recruitment of antigen presenting cells (APCs) and effector cells to appropriate anatomical sites. This knowledge, combined with advances in gene therapy and virology, allows researchers to employ chemokines as potential vaccine adjuvants. This review will focus on recent murine and human studies that use chemokines as therapeutic anti-cancer vaccine adjuvants. PMID:24967094

  6. The chemokine receptor CCR2 is not required for successful initiation of labor in mice.

    PubMed

    Menzies, Fiona M; Khan, Abdul H; Higgins, Claire A; Nelson, Scott M; Nibbs, Robert J B

    2012-04-01

    Chemokine-driven neutrophil and monocyte recruitment into the uterus and cervix has been proposed to initiate labor. Chemokines that bind CXCR2 direct neutrophil migration and are induced during labor in humans. The chemokine CCL2, induced in the uterus by endocrine and mechanical signals, has been proposed to drive CCR2-dependent monocyte homing to the uterus to contribute to the initiation of labor. However, no direct evidence indicates that chemokines or their receptors play indispensable roles in labor-associated inflammation, and the impact of leukocyte infiltration on labor is unclear. Here, we have quantified expression of the principal monocyte- and neutrophil-attracting chemokines in the uteri of term pregnant (Day 18) and laboring wild-type mice. None of the neutrophil attractants we assayed were up-regulated with labor. Strikingly, however, Ccl2 was markedly increased, and this was concomitant with increased expression of Ccr2, the myeloid marker Itgam (also known as Cd11b), the monocyte/macrophage marker Emr1 (also known as F4/80). Moreover, in CCR2-deficient mice, this labor-associated increase in Itgam and Emr1 was not seen, consistent with the monocyte-trafficking defects that exist in these animals. Nonetheless, laboring CCR2-deficient and wild-type uteri showed similarly enhanced expression of the myometrial activation markers Gja1 and Oxtr (commonly known as connexin 43 and oxytocin receptor, respectively), and CCR2-deficient mice had gestation lengths, litter sizes, and fetal and placental weights no different from those of their wild-type counterparts. Thus, whereas labor is associated with an inflammatory response in gestational tissues, CCR2-dependent leukocyte recruitment into the mouse uterus is dispensable for the initiation of successful labor. PMID:22278981

  7. Natural killer cells produce T cell-recruiting chemokines in response to antibody-coated tumor cells.

    PubMed

    Roda, Julie M; Parihar, Robin; Magro, Cynthia; Nuovo, Gerard J; Tridandapani, Susheela; Carson, William E

    2006-01-01

    In the current report, we have examined the ability of natural killer (NK) cells to produce T cell-recruiting chemokines following dual stimulation with interleukin (IL)-2 or IL-12 and human breast cancer cells coated with an antitumor antibody (trastuzumab). NK cells stimulated in this manner secreted an array of T cell-recruiting chemotactic factors, including IL-8, macrophage-derived chemokine, macrophage inflammatory protein 1alpha (MIP-1alpha), monocyte chemoattractant protein 1, and regulated on activation, normal T-cell expressed and secreted (RANTES), whereas stimulation of NK cells with either agent alone had minimal effect. Furthermore, these factors were functional for T-cell chemotaxis as culture supernatants derived from costimulated NK cells induced migration of both naïve and activated T cells in an in vitro chemotaxis assay. T-cell migration was significantly reduced when neutralizing antibodies to IL-8, MIP-1alpha, or RANTES were added to culture supernatants before their use in the chemotaxis assay. In addition, coadministration of trastuzumab-coated tumor cells and IL-12 to mice led to enhanced serum MIP-1alpha. As a clinical correlate, we examined the chemokine content of serum samples from breast cancer patients enrolled on a phase I trial of trastuzumab and IL-12, and found elevated levels of IL-8, RANTES, IFN-gamma inducible protein 10, monokine induced by IFN-gamma, and MIP-1alpha, specifically in those patients that experienced a clinical benefit. Sera from these patients exhibited the ability to direct T-cell migration in a chemotaxis assay, and neutralization of chemokines abrogated this effect. These data are the first to show chemokine production by NK cells, specifically in response to stimulation with antibody-coated tumor cells, and suggest a potential role for NK cell-derived chemokines in patients receiving therapeutic monoclonal antibodies. PMID:16397268

  8. The effect of HIV coinfection, HAART and TB treatment on cytokine/chemokine responses to Mycobacterium tuberculosis (Mtb) antigens in active TB patients and latently Mtb infected individuals.

    PubMed

    Kassa, Desta; de Jager, Wilco; Gebremichael, Gebremedhin; Alemayehu, Yodit; Ran, Leonie; Fransen, Justin; Wolday, Dawit; Messele, Tsehaynesh; Tegbaru, Belete; Ottenhoff, Tom H M; van Baarle, Debbie

    2016-01-01

    Identification of Mtb specific induced cytokine/chemokine host biomarkers could assist in developing novel diagnostic, prognostic and therapeutic tools for TB. Levels of IFN-γ, IL-2, IL-17, IL-10, IP-10 and MIP-1α were measured in supernatants of whole blood stimulated with Mtb specific fusion protein ESAT-6/CFP-10 using xMAP technology. The study groups were HIV positive TB patients (HIV(+)TB(+)), HIV negative TB patients (HIV(-)TB(+)), HIV positive tuberculin skin test positive (TST+) (HIV(+)TST(+)), HIV negative TST+ (HIV(-)TST(+)), and HIV(-)TST(-) individuals. Compared to HIV(-)TST(-), latent TB infection led to increased levels of IP-10, IFN-γ and IL-17, while levels of IL-2 and IP-10 were increased with active TB. Levels of IFN-γ, IL-17, MIP-1α, and IL-10 were increased in HIV(-)TST(+) individuals compared to HIV(-)TB(+) patients. HIV coinfection decreased the level of IFN-γ, IL-17, IP-10 and IL-2. After six months (M6) of anti-TB treatment (ATT) in HIV(-)TB(+) patients, IFN-γ, IL-10, and MIP-1α levels normalized. After M6 and M18 of ATT plus HAART in HIV(+)TB(+) patients, levels of MIP-1α and IL-10 normalized, while this was not the case for IFN-γ, IL-2, IL-17, and IP-10 levels. In HIV(+)TST(+) patients on HAART, levels of IFN-γ, IL-17, IL-10 and MIP-1α normalized, while no change in the levels of IL-2 and IP-10 were observed. In conclusion, the simultaneous measurement of IFN-γ, IL-17 and IP-10 may assist in diagnosing LTBI; IL-2 and IP-10 may assist in diagnosing active TB; while IFN-γ, IL-17, MIP-1α, and IL-10 levels could help to discriminate LTBI and active TB. In addition, IL-10 and MIP-1α levels could help to monitor responses to TB treatment and HAART. PMID:26631832

  9. Human Mas-Related G Protein-Coupled Receptors-X1 Induce Chemokine Receptor 2 Expression in Rat Dorsal Root Ganglia Neurons and Release of Chemokine Ligand 2 from the Human LAD-2 Mast Cell Line

    PubMed Central

    Solinski, Hans Jürgen; Petermann, Franziska; Rothe, Kathrin; Boekhoff, Ingrid; Gudermann, Thomas; Breit, Andreas

    2013-01-01

    Primate-specific Mas-related G protein-coupled receptors-X1 (MRGPR-X1) are highly enriched in dorsal root ganglia (DRG) neurons and induce acute pain. Herein, we analyzed effects of MRGPR-X1 on serum response factors (SRF) or nuclear factors of activated T cells (NFAT), which control expression of various markers of chronic pain. Using HEK293, DRG neuron-derived F11 cells and cultured rat DRG neurons recombinantly expressing human MRGPR-X1, we found activation of a SRF reporter gene construct and induction of the early growth response protein-1 via extracellular signal-regulated kinases-1/2 known to play a significant role in the development of inflammatory pain. Furthermore, we observed MRGPR-X1-induced up-regulation of the chemokine receptor 2 (CCR2) via NFAT, which is considered as a key event in the onset of neuropathic pain and, so far, has not yet been described for any endogenous neuropeptide. Up-regulation of CCR2 is often associated with increased release of its endogenous agonist chemokine ligand 2 (CCL2). We also found MRGPR-X1-promoted release of CCL2 in a human connective tissue mast cell line endogenously expressing MRGPR-X1. Thus, we provide first evidence to suggest that MRGPR-X1 induce expression of chronic pain markers in DRG neurons and propose a so far unidentified signaling circuit that enhances chemokine signaling by acting on two distinct yet functionally co-operating cell types. Given the important role of chemokine signaling in pain chronification, we propose that interruption of this signaling circuit might be a promising new strategy to alleviate chemokine-promoted pain. PMID:23505557

  10. Chemokines in Cancer Development and Progression and Their Potential as Targeting Molecules for Cancer Treatment

    PubMed Central

    Mukaida, Naofumi; Sasaki, So-ichiro; Baba, Tomohisa

    2014-01-01

    Chemokines were initially identified as bioactive substances, which control the trafficking of inflammatory cells including granulocytes and monocytes/macrophages. Moreover, chemokines have profound impacts on other types of cells associated with inflammatory responses, such as endothelial cells and fibroblasts. These observations would implicate chemokines as master regulators in various inflammatory responses. Subsequent studies have further revealed that chemokines can regulate the movement of a wide variety of immune cells including lymphocytes, natural killer cells, and dendritic cells in both physiological and pathological conditions. These features endow chemokines with crucial roles in immune responses. Furthermore, increasing evidence points to the vital effects of several chemokines on the proliferative and invasive properties of cancer cells. It is widely acknowledged that cancer develops and progresses to invade and metastasize in continuous interaction with noncancerous cells present in cancer tissues, such as macrophages, lymphocytes, fibroblasts, and endothelial cells. The capacity of chemokines to regulate both cancerous and noncancerous cells highlights their crucial roles in cancer development and progression. Here, we will discuss the roles of chemokines in carcinogenesis and the possibility of chemokine targeting therapy for the treatment of cancer. PMID:24966464

  11. Emerging Concepts and Approaches for Chemokine-Receptor Drug Discovery

    PubMed Central

    O’Hayre, Morgan; Salanga, Catherina L.; Handel, Tracy M.; Hamel, Damon J.

    2010-01-01

    Importance of the field Chemokine receptors are G protein-coupled receptors (GPCRs) most noted for their role in cell migration. However, inappropriate utilization or regulation of these receptors is implicated in many inflammatory diseases, cancer and HIV, making them important drug targets. Areas covered in this review Allostery, oligomerization, and ligand bias are presented as they pertain to chemokine receptors and their associated pathologies. Specific examples of each are described from the recent literature and their implications are discussed in terms of drug discovery efforts targeting chemokine receptors. What the reader will gain Insight into the expanding view of the multitude of pharmacological variables that need to be considered or that may be exploited in chemokine receptor drug discovery. Take home message Since 2007, two drugs targeting chemokine receptors have been approved by the FDA, Maraviroc for preventing HIV infection and Mozobil™ for hematopoietic stem cell mobilization. While these successes permit optimism for chemokine receptors as drug targets, only recently has the complexity of this system begun to be appreciated. The concepts of allosteric inhibitors, biased ligands and functional selectivity raise the possibility that drugs with precisely-defined properties can be developed. Other complexities such as receptor oligomerization and tissue-specific functional states of receptors also offer opportunities for increased target and response specificity, although it will be more challenging to translate these ideas into approved therapeutics compared to traditional approaches. PMID:21132095

  12. The histone deacetylase inhibitor suberoylanilide hydroxamic acid induces apoptosis, down-regulates the CXCR4 chemokine receptor and impairs migration of chronic lymphocytic leukemia cells

    PubMed Central

    Stamatopoulos, Basile; Meuleman, Nathalie; De Bruyn, Cécile; Delforge, Alain; Bron, Dominique; Lagneaux, Laurence

    2010-01-01

    Background Chronic lymphocytic leukemia is a neoplastic disorder that arises largely as a result of defective apoptosis leading to chemoresistance. Stromal cell-derived factor-1 and its receptor, CXCR4, have been shown to play an important role in chronic lymphocytic leukemia cell trafficking and survival. Design and Methods Since histone acetylation is involved in the modulation of gene expression, we evaluated the effects of suberoylanilide hydroxamic acid, a histone deacetylase inhibitor, on chronic lymphocytic leukemia cells and in particular on cell survival, CXCR4 expression, migration, and drug sensitization. Results Here, we showed that treatment with suberoylanilide hydroxamic acid (20 μM) for 48 hours induced a decrease in chronic lymphocytic leukemia cell viability via apoptosis (n=20, P=0.0032). Using specific caspase inhibitors, we demonstrated the participation of caspases-3, -6 and -8, suggesting an activation of the extrinsic pathway. Additionally, suberoylanilide hydroxamic acid significantly decreased CXCR4 mRNA (n=10, P=0.0010) and protein expression (n=40, P<0.0001). As a result, chronic lymphocytic leukemia cell migration in response to stromal cell-derived factor-1 (n=23, P<0.0001) or through bone marrow stromal cells was dramatically impaired. Consequently, suberoylanilide hydroxamic acid reduced the protective effect of the microenvironment and thus sensitized chronic lymphocytic leukemia cells to chemotherapy such as fludarabine. Conclusions In conclusion, suberoylanilide hydroxamic acid induces apoptosis in chronic lymphocytic leukemia cells via the extrinsic pathway and down-regulates CXCR4 expression leading to decreased cell migration. Suberoylanilide hydroxamic acid in combination with other drugs represents a promising therapeutic approach to inhibiting migration, chronic lymphocytic leukemia cell survival and potentially overcoming drug resistance. PMID:20145270

  13. Long non‑coding RNA‑GAS5 acts as a tumor suppressor in bladder transitional cell carcinoma via regulation of chemokine (C‑C motif) ligand 1 expression.

    PubMed

    Cao, Qifeng; Wang, Ning; Qi, Juan; Gu, Zhengqin; Shen, Haibo

    2016-01-01

    Long non‑coding RNAs (lncRNAs) have important roles in diverse biological processes, including transcriptional regulation, cell growth and tumorigenesis. The present study aimed to investigate whether lncRNA‑growth arrest‑specific (GAS)5 regulated bladder cancer progression via regulation of chemokine (C‑C) ligand (CCL)1 expression. The viability of BLX bladder cancer cells was detected using a Cell Counting kit‑8 assay, and cell apoptosis was assessed by annexin V‑propidium iodide double‑staining. The expression levels of specific genes and proteins were analyzed by reverse transcription‑quantitative polymerase chain reaction and western blotting, respectively. In addition, cells were transfected with small interfering (si)RNAs or recombinant GAS5 in order to silence or overexpress GAS5, respectively. The results of the present study demonstrated that knockdown of GAS5 expression promoted bladder cancer cell proliferation, whereas overexpression of GAS5 suppressed cell proliferation. Furthermore, knockdown of GAS5 resulted in an increased percentage of cells in S and G2 phase, and a decreased percentage of cells in G1 phase. In addition, the present study performed a hierarchical cluster analysis of differentially expressed lncRNAs in bladder cancer cells and detected that CCL1 overexpression resulted in an upregulation of GAS5, which may improve the ability of cells to regulate a stress response in vitro. Furthermore, knockdown of GAS5 expression increased the mRNA and protein expression of CCL1 in bladder cancer cells. Gain‑of‑function and loss‑of‑function studies demonstrated that GAS5 was able to inhibit bladder cancer cell proliferation, at least in part, by suppressing the expression of CCL1. The results of the present study demonstrated that GAS5 was able to suppress bladder cancer cell proliferation, at least partially, by suppressing the expression of CCL1. The results of the present study may provide a basis for developing novel

  14. Long non-coding RNA-GAS5 acts as a tumor suppressor in bladder transitional cell carcinoma via regulation of chemokine (C-C motif) ligand 1 expression

    PubMed Central

    CAO, QIFENG; WANG, NING; QI, JUAN; GU, ZHENGQIN; SHEN, HAIBO

    2016-01-01

    Long non-coding RNAs (lncRNAs) have important roles in diverse biological processes, including transcriptional regulation, cell growth and tumorigenesis. The present study aimed to investigate whether lncRNA-growth arrest-specific (GAS)5 regulated bladder cancer progression via regulation of chemokine (C-C) ligand (CCL)1 expression. The viability of BLX bladder cancer cells was detected using a Cell Counting kit-8 assay, and cell apoptosis was assessed by annexin V-propidium iodide double-staining. The expression levels of specific genes and proteins were analyzed by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. In addition, cells were transfected with small interfering (si)RNAs or recombinant GAS5 in order to silence or overexpress GAS5, respectively. The results of the present study demonstrated that knockdown of GAS5 expression promoted bladder cancer cell proliferation, whereas overexpression of GAS5 suppressed cell proliferation. Furthermore, knockdown of GAS5 resulted in an increased percentage of cells in S and G2 phase, and a decreased percentage of cells in G1 phase. In addition, the present study performed a hierarchical cluster analysis of differentially expressed lncRNAs in bladder cancer cells and detected that CCL1 overexpression resulted in an upregulation of GAS5, which may improve the ability of cells to regulate a stress response in vitro. Furthermore, knockdown of GAS5 expression increased the mRNA and protein expression of CCL1 in bladder cancer cells. Gain-of-function and loss-of-function studies demonstrated that GAS5 was able to inhibit bladder cancer cell proliferation, at least in part, by suppressing the expression of CCL1. The results of the present study demonstrated that GAS5 was able to suppress bladder cancer cell proliferation, at least partially, by suppressing the expression of CCL1. The results of the present study may provide a basis for developing novel effective treatment

  15. (+)-Nootkatone inhibits tumor necrosis factor α/interferon γ-induced production of chemokines in HaCaT cells.

    PubMed

    Choi, Hyeon-Jae; Lee, Jin-Hwee; Jung, Yi-Sook

    2014-05-01

    Chemokines are important mediators of cell migration, and thymus and activation-regulated chemokine (TARC/CCL17) and macrophage-derived chemokine (MDC/CCL22) are well-known typical inflammatory chemokines involved in atopic dermatitis (AD). (+)-Nootkatone is the major component of Cyperus rotundus. (+)-Nootkatone has antiallergic, anti-inflammatory, and antiplatelet activities. The purpose of this study was to investigate the effect of (+)-nootkatone on tumor necrosis factor α (TNF-α)/interferon γ (IFN-γ)-induced expression of Th2 chemokines in HaCaT cells. We found that (+)-nootkatone inhibited the TNF-α/IFN-γ-induced expression of TARC/CCL17 and MDC/CCL22 mRNA in HaCaT cells. It also significantly inhibited TNF-α/IFN-γ-induced activation of nuclear factor kappa B (NF-κB), p38 mitogen-activated protein kinase (MAPK), and protein kinase Cζ (PKCζ). Furthermore, we showed that PKCζ and p38 MAPK contributed to the inhibition of TNF-α/IFN-γ-induced TARC/CCL17 and MDC/CCL22 expression by blocking IκBα degradation in HaCaT cells. Taken together, these results suggest that (+)-nootkatone may suppress TNF-α/IFN-γ-induced TARC/CCL17 and MDC/CCL22 expression in HaCaT cells by inhibiting of PKCζ and p38 MAPK signaling pathways that lead to activation of NF-κB. We propose that (+)-nootkatone may be a useful therapeutic candidate for inflammatory skin diseases such as AD. PMID:24704449

  16. Akt-mTORC1 signaling regulates Acly to integrate metabolic input to control of macrophage activation

    PubMed Central

    Covarrubias, Anthony J; Aksoylar, Halil Ibrahim; Yu, Jiujiu; Snyder, Nathaniel W; Worth, Andrew J; Iyer, Shankar S; Wang, Jiawei; Ben-Sahra, Issam; Byles, Vanessa; Polynne-Stapornkul, Tiffany; Espinosa, Erika C; Lamming, Dudley; Manning, Brendan D; Zhang, Yijing; Blair, Ian A; Horng, Tiffany

    2016-01-01

    Macrophage activation/polarization to distinct functional states is critically supported by metabolic shifts. How polarizing signals coordinate metabolic and functional reprogramming, and the potential implications for control of macrophage activation, remains poorly understood. Here we show that IL-4 signaling co-opts the Akt-mTORC1 pathway to regulate Acly, a key enzyme in Ac-CoA synthesis, leading to increased histone acetylation and M2 gene induction. Only a subset of M2 genes is controlled in this way, including those regulating cellular proliferation and chemokine production. Moreover, metabolic signals impinge on the Akt-mTORC1 axis for such control of M2 activation. We propose that Akt-mTORC1 signaling calibrates metabolic state to energetically demanding aspects of M2 activation, which may define a new role for metabolism in supporting macrophage activation. DOI: http://dx.doi.org/10.7554/eLife.11612.001 PMID:26894960

  17. Transmembrane chemokines act as receptors in a novel mechanism termed inverse signaling

    PubMed Central

    Hattermann, Kirsten; Gebhardt, Henrike; Krossa, Sebastian; Ludwig, Andreas; Lucius, Ralph

    2016-01-01

    The transmembrane chemokines CX3CL1/fractalkine and CXCL16 are widely expressed in different types of tumors, often without an appropriate expression of their classical receptors. We observed that receptor-negative cancer cells could be stimulated by the soluble chemokines. Searching for alternative receptors we detected that all cells expressing or transfected with transmembrane chemokine ligands bound the soluble chemokines with high affinity and responded by phosphorylation of intracellular kinases, enhanced proliferation and anti-apoptosis. This activity requires the intracellular domain and apparently the dimerization of the transmembrane chemokine ligand. Thus, shed soluble chemokines can generate auto- or paracrine signals by binding and activating their transmembrane forms. We term this novel mechanism “inverse signaling”. We suppose that inverse signaling is an autocrine feedback and fine-tuning system in the communication between cells that in tumors supports stabilization and proliferation. DOI: http://dx.doi.org/10.7554/eLife.10820.001 PMID:26796342

  18. Experimental design of complement component 5a-induced acute lung injury (C5a-ALI): a role of CC-chemokine receptor type 5 during immune activation by anaphylatoxin

    PubMed Central

    Russkamp, Norman F.; Ruemmler, Robert; Roewe, Julian; Moore, Bethany B.; Ward, Peter A.; Bosmann, Markus

    2015-01-01

    Excessive activation of the complement system is detrimental in acute inflammatory disorders. In this study, we analyzed the role of complement-derived anaphylatoxins in the pathogenesis of experimental acute lung injury/acute respiratory distress syndrome (ALI/ARDS) in C57BL/6J mice. Intratracheal administration of recombinant mouse complement component (C5a) caused alveolar inflammation with abundant recruitment of Ly6-G+CD11b+ leukocytes to the alveolar spaces and severe alveolar-capillary barrier dysfunction (C5a-ALI; EC50[C5a] = 20 ng/g body weight). Equimolar concentrations of C3a or desarginated C5a (C5adesArg) did not induce alveolar inflammation. The severity of C5a-ALI was aggravated in C5-deficient mice. Depletion of Ly6-G+ cells and use of C5aR1−/− bone marrow chimeras suggested an essential role of C5aR1+ hematopoietic cells in C5a-ALI. Blockade of PI3K/Akt and MEK1/2 kinase pathways completely abrogated lung injury. The mechanistic description is that C5a altered the alveolar cytokine milieu and caused significant release of CC-chemokines. Mice with genetic deficiency of CC-chemokine receptor (CCR) type 5, the common receptor of chemokine (C-C motif) ligand (CCL) 3, CCL4, and CCL5, displayed reduced lung damage. Moreover, treatment with a CCR5 antagonist, maraviroc, was protective against C5a-ALI. In summary, our results suggest that the detrimental effects of C5a in this model are partly mediated through CCR5 activation downstream of C5aR1, which may be evaluated for potential therapeutic exploitation in ALI/ARDS.—Russkamp, N. F., Ruemmler, R., Roewe, J., Moore, B. B., Ward, P. A., Bosmann, M. Experimental design of complement component 5a-induced acute lung injury (C5a-ALI): a role of CC-chemokine receptor type 5 during immune activation by anaphylatoxin. PMID:25999468

  19. Glutathione protects chemokine-scavenging and antioxidative defense functions in human RBCs.

    PubMed

    Dumaswala, U J; Zhuo, L; Mahajan, S; Nair, P N; Shertzer, H G; Dibello, P; Jacobsen, D W

    2001-04-01

    Oxidant stress, in vivo or in vitro, is known to induce oxidative changes in human red blood cells (RBCs). Our objective was to examine the effect of augmenting RBC glutathione (GSH) synthesis on 1) degenerative protein loss and 2) RBC chemokine- and free radical-scavenging functions in the oxidatively stressed human RBCs by using banked RBCs as a model. Packed RBCs were stored up to 84 days at 1-6 degrees C in Adsol or in the experimental additive solution (Adsol fortified with glutamine, glycine, and N-acetyl-L-cysteine). Supplementing the conventional additive with GSH precursor amino acids improved RBC GSH synthesis and maintenance. The rise in RBC gamma-glutamylcysteine ligase activity was directly proportional to the GSH content and inversely proportional to extracellular homocysteine concentration, methemoglobin formation, and losses of the RBC proteins band 3, band 4.1, band 4.2, glyceraldehyde-3-phosphate dehydrogenase, and Duffy antigen (P < 0.01). Reduced loss of Duffy antigen correlated well with a decrease in chemokine RANTES (regulated upon activation, normal T-cell expressed, and secreted) concentration. We conclude that the concomitant loss of GSH and proteins in oxidatively stressed RBCs can compromise RBC scavenging function. Upregulating GSH synthesis can protect RBC scavenging (free radical and chemokine) function. These results have implications not only in a transfusion setting but also in conditions like diabetes and sickle cell anemia, in which RBCs are subjected to chronic/acute oxidant stresses. PMID:11245604

  20. Kinetic mRNA Profiling in a Rat Model of Left-Ventricular Hypertrophy Reveals Early Expression of Chemokines and Their Receptors

    PubMed Central

    Nemska, Simona; Monassier, Laurent; Gassmann, Max; Frossard, Nelly; Tavakoli, Reza

    2016-01-01

    Left-ventricular hypertrophy (LVH), a risk factor for heart failure and death, is characterized by cardiomyocyte hypertrophy, interstitial cell proliferation, and leukocyte infiltration. Chemokines interacting with G protein-coupled chemokine receptors may play a role in LVH development by promoting recruitment of activated leukocytes or modulating left-ventricular remodeling. Using a pressure overload-induced kinetic model of LVH in rats, we examined during 14 days the expression over time of chemokine and chemokine receptor mRNAs in left ventricles from aortic-banded vs sham-operated animals. Two phases were clearly distinguished: an inflammatory phase (D3-D5) with overexpression of inflammatory genes such as il-1ß, tnfa, nlrp3, and the rela subunit of nf-kb, and a hypertrophic phase (D7-D14) where anp overexpression was accompanied by a heart weight/body weight ratio that increased by more than 20% at D14. No cardiac dysfunction was detectable by echocardiography at the latter time point. Of the 36 chemokines and 20 chemokine receptors analyzed by a Taqman Low Density Array panel, we identified at D3 (the early inflammatory phase) overexpression of mRNAs for the monocyte chemotactic proteins CCL2 (12-fold increase), CCL7 (7-fold increase), and CCL12 (3-fold increase), for the macrophage inflammatory proteins CCL3 (4-fold increase), CCL4 (2-fold increase), and CCL9 (2-fold increase), for their receptors CCR2 (4-fold increase), CCR1 (3-fold increase), and CCR5 (3-fold increase), and for CXCL1 (8-fold increase) and CXCL16 (2-fold increase). During the hypertrophic phase mRNA expression of chemokines and receptors returned to the baseline levels observed at D0. Hence, this first exhaustive study of chemokine and chemokine receptor mRNA expression kinetics reports early expression of monocyte/macrophage-related chemokines and their receptors during the development of LVH in rats, followed by regulation of inflammation as LVH progresses. PMID:27525724

  1. Gene profile of chemokines on hepatic stellate cells of schistosome-infected mice and antifibrotic roles of CXCL9/10 on liver non-parenchymal cells.

    PubMed

    Liang, Yue-jin; Luo, Jie; Lu, Qiao; Zhou, Ying; Wu, Hai-wei; Zheng, Dan; Ren, Yong-ya; Sun, Ke-yi; Wang, Yong; Zhang, Zhao-song

    2012-01-01

    Hepatic stellate cells (HSCs) play a key role in the development of liver fibrosis caused by schistosomiasis. Chemokines were widely expressed and involved in cellular activation, proliferation and migration in inflammatory and infectious diseases. However, little is known about the expressions of chemokines on HSCs in the schistosoma infection. In addition, the roles of chemokines in pathogenesis of liver fibrosis are not totally clear. In our study, we used microarray to analyze the temporal gene expressions of primary HSCs isolated from mice with both acute and chronic schistosomiasis. Our microarray data showed that most of the chemokines expressed on HSCs were upregulated at 3 weeks post-infection (p.i) when the egg granulomatous response was not obviously evoked in the liver. However, some of them like CXCL9, CXCL10 and CXCL11 were subsequently decreased at 6 weeks p.i when the granulomatous response reached the peak. In the chronic stage, most of the differentially expressed chemokines maintained persistent high-abundances. Furthermore, several chemokines including CCR2, CCR5, CCR7, CXCR3, CXCR4, CCL2, CCL5, CCL21, CXCL9 and CXCL10 were expressed by HCSs and the abundances of them were changed following the praziquantel treatment in the chronic stage, indicating that chemokines were possibly necessary for the persistence of the chronic stage. In vitro experiments, hepatic non-parenchymal cells, primary HSCs and human HSCs line LX-2 were stimulated by chemokines. The results showed that CXCL9 and CXCL10, but not CXCL11 or CXCL4, significantly inhibited the gene expressions of Col1α1, Col3α1 and α-SMA, indicating the potential anti-fibrosis effect of CXCL9 and CXCL10 in schistosomiasis. More interestingly, soluble egg antigen (SEA) of Schistosoma japonicum was able to inhibit transcriptional expressions of some chemokines by LX-2 cells, suggesting that SEA was capable of regulating the expression pattern of chemokine family and modulating the hepatic immune

  2. The Possible Diagnostic and Prognostic Use of Systemic Chemokine Profiles in Clinical Medicine—The Experience in Acute Myeloid Leukemia from Disease Development and Diagnosis via Conventional Chemotherapy to Allogeneic Stem Cell Transplantation

    PubMed Central

    Reikvam, Håkon; Fredly, Hanne; Kittang, Astrid Olsnes; Bruserud, Øystein

    2013-01-01

    Chemokines are important regulators of many different biological processes, including (i) inflammation with activation and local recruitment of immunocompetent cells; (ii) angiogenesis as a part of inflammation or carcinogenesis; and (iii) as a bridge between the coagulation system and inflammation/immune activation. The systemic levels of various chemokines may therefore reflect local disease processes, and such variations may thereby be used in the routine clinical handling of patients. The experience from patients with myeloproliferative diseases, and especially patients with acute myeloid leukemia (AML), suggests that systemic plasma/serum cytokine profiles can be useful, both as a diagnostic tool and for prognostication of patients. However, cytokines/chemokines are released by a wide range of cells and are involved in a wide range of biological processes; the altered levels may therefore mainly reflect the strength and nature of the biological processes, and the optimal clinical use of chemokine/cytokine analyses may therefore require combination with organ-specific biomarkers. Chemokine levels are also altered by clinical procedures, therapeutic interventions and the general status of the patients. A careful standardization of sample collection is therefore important, and the interpretation of the observations will require that the overall clinical context is considered. Despite these limitations, we conclude that analysis of systemic chemokine/cytokine profiles can reflect important clinical characteristics and, therefore, is an important scientific tool that can be used as a part of future clinical studies to identify clinically relevant biomarkers. PMID:23430540

  3. Selected CC and CXC chemokines in children with atopic asthma

    PubMed Central

    Machura, Edyta; Mazur, Bogdan; Chrobak, Ewelina; Ziora, Katarzyna; Ziora, Dariusz; Kasperska-Zajac, Alicja

    2016-01-01

    Introduction There are only limited data on CC and CXC chemokines regulation in children with asthma. Aim We compared the serum profile of selected CC and CXC chemokines in patients with atopic asthma and healthy children. Material and methods Serum concentration of CC chemokines RANTES, MCP-1, and CXC chemokines IP-10, MIG, IL-8, RANTES was measured using cytometric bead array in 44 children with atopic asthma and 17 healthy subjects. Results The concentration of RANTES was significantly higher and the MIG level was lower in all children with asthma as compared to their control counterparts. We observed increased RANTES and decreased MIG levels also in patients with stable asthma when compared with children in the control group. The IP-10 concentration was similar between the whole asthma group and healthy controls, while significantly increased levels of this chemokine in acute asthma have been observed when compared to stable asthma. For MCP-1 and IL-8, the serum concentration was similar in all compared groups. The MIG concentration correlated positively with IP-10, IL-8, and CRP levels and negatively with the eosinophil count. A negative correlation between the IP-10 and eosinophil count and a negative correlation between FEV1 and IP-10 were found. Conclusions An increased serum RANTES level in children with asthma may result in enhancement of Th2 lymphocyte recruitment into the airway. A decreased expression of Th1 chemokine MIG in children with stable asthma may contribute to a diminished antagonizing effect on Th2 cytokine production and hence intensify Th2 predominance. An increased IP-10 level in children during an asthma attack suggest that this chemokine is a serological marker of disease exacerbation. PMID:27279817

  4. Calcitonin Gene-related Peptide Inhibits Chemokine Production by Human Dermal Microvascular Endothelial Cells

    PubMed Central

    Huang, Jing; Stohl, Lori L.; Zhou, Xi; Ding, Wanhong; Granstein, Richard D.

    2011-01-01

    This study examined whether the sensory neuropeptide calcitonin gene-related peptide (CGRP) inhibits release of chemokines by dermal microvascular endothelial cells. Dermal blood vessels are associated with nerves containing CGRP, suggesting that CGRP-containing nerves may regulate cutaneous inflammation through effects on vessels. We examined CGRP effects on stimulated chemokine production by a human dermal microvascular endothelial cell line (HMEC-1) and primary human dermal microvascular endothelial cells (pHDMECs). HMEC-1 cells and pHDMECs expressed mRNA for components of the CGRP and adrenomedullin receptors and CGRP inhibited LPS-induced production of the chemokines CXCL8, CCL2, and CXCL1 by both HMEC-1 cells and pHDMECs. The receptor activity-modifying protein (RAMP)1/calcitonin receptor-like receptor (CL)-specific antagonists CGRP8-37 and BIBN4096BS, blocked this effect of CGRP in a dose-dependent manner. CGRP prevented LPS-induced IκBα degradation and NF-κB binding to the promoters of CXCL1, CXCL8 and CCL2 in HMEC-1 cells and Bay 11-7085, an inhibitor of NF-κB activation, suppressed LPS-induced production of CXCL1, CXCL8 and CCL2. Thus, the NF-κB pathway appears to be involved in CGRP-mediated suppression of chemokine production. Accordingly, CGRP treatment of LPS-stimulated HMEC-1 cells inhibited their ability to chemoattract human neutrophils and mononuclear cells. Elucidation of this pathway may suggest new avenues for therapeutic manipulation of cutaneous inflammation. PMID:21334428

  5. Biased and G Protein-Independent Signaling of Chemokine Receptors

    PubMed Central

    Steen, Anne; Larsen, Olav; Thiele, Stefanie; Rosenkilde, Mette M.

    2014-01-01

    Biased signaling or functional selectivity occurs when a 7TM-receptor preferentially activates one of several available pathways. It can be divided into three distinct forms: ligand bias, receptor bias, and tissue or cell bias, where it is mediated by different ligands (on the same receptor), different receptors (with the same ligand), or different tissues or cells (for the same ligand–receptor pair). Most often biased signaling is differentiated into G protein-dependent and β-arrestin-dependent signaling. Yet, it may also cover signaling differences within these groups. Moreover, it may not be absolute, i.e., full versus no activation. Here we discuss biased signaling in the chemokine system, including the structural basis for biased signaling in chemokine receptors, as well as in class A 7TM receptors in general. This includes overall helical movements and the contributions of micro-switches based on recently published 7TM crystals and molecular dynamics studies. All three forms of biased signaling are abundant in the chemokine system. This challenges our understanding of “classic” redundancy inevitably ascribed to this system, where multiple chemokines bind to the same receptor and where a single chemokine may bind to several receptors – in both cases with the same functional outcome. The ubiquitous biased signaling confers a hitherto unknown specificity to the chemokine system with a complex interaction pattern that is better described as promiscuous with context-defined roles and different functional outcomes in a ligand-, receptor-, or cell/tissue-defined manner. As the low number of successful drug development plans implies, there are great difficulties in targeting chemokine receptors; in particular with regard to receptor antagonists as anti-inflammatory drugs. Un-defined and putative non-selective targeting of the complete cellular signaling system could be the underlying cause of lack of success. Therefore, biased ligands could be the solution

  6. New paradigms in chemokine receptor signal transduction: Moving beyond the two-site model.

    PubMed

    Kleist, Andrew B; Getschman, Anthony E; Ziarek, Joshua J; Nevins, Amanda M; Gauthier, Pierre-Arnaud; Chevigné, Andy; Szpakowska, Martyna; Volkman, Brian F

    2016-08-15

    Chemokine receptor (CKR) signaling forms the basis of essential immune cellular functions, and dysregulated CKR signaling underpins numerous disease processes of the immune system and beyond. CKRs, which belong to the seven transmembrane domain receptor (7TMR) superfamily, initiate signaling upon binding of endogenous, secreted chemokine ligands. Chemokine-CKR interactions are traditionally described by a two-step/two-site mechanism, in which the CKR N-terminus recognizes the chemokine globular core (i.e. site 1 interaction), followed by activation when the unstructured chemokine N-terminus is inserted into the receptor TM bundle (i.e. site 2 interaction). Several recent studies challenge the structural independence of sites 1 and 2 by demonstrating physical and allosteric links between these supposedly separate sites. Others contest the functional independence of these sites, identifying nuanced roles for site 1 and other interactions in CKR activation. These developments emerge within a rapidly changing landscape in which CKR signaling is influenced by receptor PTMs, chemokine and CKR dimerization, and endogenous non-chemokine ligands. Simultaneous advances in the structural and functional characterization of 7TMR biased signaling have altered how we understand promiscuous chemokine-CKR interactions. In this review, we explore new paradigms in CKR signal transduction by considering studies that depict a more intricate architecture governing the consequences of chemokine-CKR interactions. PMID:27106080

  7. Expression of Chemokine Receptors on Peripheral Blood T Cells in Children with Chronic Kidney Disease

    PubMed Central

    Szczepańska, Maria; Sędek, Łukasz; Makulska, Irena; Szprynger, Krystyna; Mazur, Bogdan; Zwolińska, Danuta; Karpe, Jacek; Ziora, Katarzyna; Szczepański, Tomasz

    2015-01-01

    Chemokine receptors play a role in leukocyte recruitment, activation, and maintaining effector functions and regulate adaptive immune response and angiogenesis. The study aimed at flow cytometric analysis of T cell subsets with selected surface chemokine receptors (CCR4, CCR5, CCR7, CXCR3, and CXCR4) or receptor combination in peripheral blood of children with chronic kidney disease (CKD) on hemodialysis (HD). The percentage of T lymphocytes with CD8 and combined CD28,CCR7 expression was higher in HD children. The percentage of T lymphocytes expressing CCR7, CD28,CCR7, and CXCR4,CD8 was increased in children on conservative treatment. Total number (tn) of CXCR4+ cells was reduced in children on hemodialysis. The tn of T CXCR3+ cells was lower in children on conservative treatment. During HD the percentage of T CD4+ cells was higher and of T CXCR3+ lymphocytes was lower after HD session as compared to 15 min of session duration. During HD tn of T cells with expression of CCR4, CCR5, CCR7, CXCR3, and CXCR4 was constant. The alteration of chemokine receptors expression in children with CKD occurs early in the development. Diminished expression of CXCR3, CXCR4 on T cells in patients with CKD on HD might result in impaired inflammatory response. Increased CCR7+ T cell percentage could be responsible for the alteration of migration of cells into secondary lymphatic organs. PMID:25866451

  8. Altered release of chemokines by phagocytes from fibromyalgia patients: a pilot study.

    PubMed

    García, Juan José; Carvajal-Gil, Julián; Guerrero-Bonmatty, Rafael

    2016-01-01

    Fibromyalgia (FM) is a syndrome characterized by widespread chronic pain and is associated with elevated systemic inflammatory biomarkers, and an elevated innate cellular response. The aim of this study was to determine if fibromyalgia patients have altered ability to release pro-inflammatory chemokines by isolated neutrophils and monocytes. The study participants were women diagnosed with FM (n = 6) and a control group of healthy women (HW) (n = 6). Supernatant concentrations of eotaxin (CCL11), human macrophage-derived chemokine (MDC) (CCL22) and growth regulated-oncogene (GRO-α) (CXCL1) released by both monocytes and neutrophils either resting or stimulated by LPS were determined by ELISA and compared between the FM and HW groups. Both resting and activated monocytes from FM patients released more eotaxin, MDC and GRO-α than those from HW. However, there were no significant differences in the release of chemokines from neutrophils of FM patients and the ones from healthy women. In conclusion, monocytes from women with FM are deregulated, releasing higher amounts of eotaxin, MDC and GRO-α than healthy individuals. This fact does not occur in neutrophils from women with FM. PMID:26341115

  9. High-dose hydrocortisone reduces expression of the pro-inflammatory chemokines CXCL8 and CXCL10 in SARS coronavirus-infected intestinal cells.

    PubMed

    Cinatl, Jindrich; Michaelis, Martin; Morgenstern, Birgit; Doerr, Hans Wilhelm

    2005-02-01

    Clinical observations and our high-density oligonucleotide microarray results demonstrated increased expression of proinflammatory chemokines after SARS-CoV infection. Here, we investigated the influence of SARS-CoV infection on CXCL8 (interleukin 8) and CXCL10 (interferon-gamma-inducible protein 10) in human intestinal epithelial (Caco2) cells. RT-PCR and ELISA showed time-dependent up-regulation of both chemokines after SARS-CoV infection. Electric mobility shift assay revealed increased DNA binding activity of the cellular transcription factors activator protein 1 (AP-1) and nuclear factor (B (NF-kappaB) in SARS-CoV infected cells. High hydrocortisone concentrations (> or =50 microg/ml) completely prevented increased DNA binding activity of AP-1 and NF-kappaB and inhibited up-regulation of CXCL8 and CXCL10, but did not reduce chemokine expression to basal levels. Ribavirin that does not inhibit SARS-CoV replication in Vero cells inhibited SARS-CoV replication in Caco2 cells at therapeutical concentrations. Hydrocortisone neither influenced SARS-CoV titres alone nor in combination with ribavirin. Our results show that corticosteroids may be of limited benefit in the suppression of chemokine production by SARS-CoV-infected cells. PMID:15647850

  10. CCRL2 regulates M1/M2 polarization during EAE recovery phase.

    PubMed

    Mazzon, Cristina; Zanotti, Lucia; Wang, Li; Del Prete, Annalisa; Fontana, Elena; Salvi, Valentina; Poliani, Pietro Luigi; Sozzani, Silvano

    2016-06-01

    Chemokine (CC motif) receptor-like 2 is a 7-transmembrane protein related to the family of the atypical chemokine receptors, which are proteins devoid of chemotactic activity and involved in the control of inflammation. Experimental autoimmune encephalitis is an autoimmune disorder that replicates the inflammatory aspects of multiple sclerosis. Chemokine (CC motif) receptor-like 2-deficient mice developed exacerbated, nonresolving disease with protracted inflammatory response and increased demyelination. The increased severity of the disease was associated with higher levels of microglia/macrophage activation markers and imbalanced M1/M2 polarization. Thus, chemokine (CC motif) receptor-like 2 is involved in the downregulation of central nervous system-associated experimental autoimmune encephalitis inflammation in the recovery phase of the disease. Therefore chemokine (CC motif) receptor-like 2 should be considered to be a molecule involved in the regulation of the inflammatory response associated with multiple sclerosis. PMID:26744451

  11. The host response to the probiotic Escherichia coli strain Nissle 1917: Specific up-regulation of the proinflammatory chemokine MCP-1

    PubMed Central

    Ukena, Sya N; Westendorf, Astrid M; Hansen, Wiebke; Rohde, Manfred; Geffers, Robert; Coldewey, Sina; Suerbaum, Sebastian; Buer, Jan; Gunzer, Florian

    2005-01-01

    Background The use of live microorganisms to influence positively the course of intestinal disorders such as infectious diarrhea or chronic inflammatory conditions has recently gained increasing interest as a therapeutic alternative. In vitro and in vivo investigations have demonstrated that probiotic-host eukaryotic cell interactions evoke a large number of responses potentially responsible for the effects of probiotics. The aim of this study was to improve our understanding of the E. coli Nissle 1917-host interaction by analyzing the gene expression pattern initiated by this probiotic in human intestinal epithelial cells. Methods Gene expression profiles of Caco-2 cells treated with E. coli Nissle 1917 were analyzed with microarrays. A second human intestinal cell line and also pieces of small intestine from BALB/c mice were used to confirm regulatory data of selected genes by real-time RT-PCR and cytometric bead array (CBA) to detect secretion of corresponding proteins. Results Whole genome expression analysis revealed 126 genes specifically regulated after treatment of confluent Caco-2 cells with E. coli Nissle 1917. Among others, expression of genes encoding the proinflammatory molecules monocyte chemoattractant protein-1 ligand 2 (MCP-1), macrophage inflammatory protein-2 alpha (MIP-2α) and macrophage inflammatory protein-2 beta (MIP-2β) was increased up to 10 fold. Caco-2 cells cocultured with E. coli Nissle 1917 also secreted high amounts of MCP-1 protein. Elevated levels of MCP-1 and MIP-2α mRNA could be confirmed with Lovo cells. MCP-1 gene expression was also up-regulated in mouse intestinal tissue. Conclusion Thus, probiotic E. coli Nissle 1917 specifically upregulates expression of proinflammatory genes and proteins in human and mouse intestinal epithelial cells. PMID:16351713

  12. International Union of Pharmacology. LXXXIX. Update on the Extended Family of Chemokine Receptors and Introducing a New Nomenclature for Atypical Chemokine Receptors

    PubMed Central

    Bachelerie, Francoise; Ben-Baruch, Adit; Burkhardt, Amanda M.; Combadiere, Christophe; Farber, Joshua M.; Graham, Gerard J.; Horuk, Richard; Sparre-Ulrich, Alexander Hovard; Locati, Massimo; Luster, Andrew D.; Mantovani, Alberto; Matsushima, Kouji; Nibbs, Robert; Nomiyama, Hisayuki; Power, Christine A.; Proudfoot, Amanda E. I.; Rosenkilde, Mette M.; Rot, Antal; Sozzani, Silvano; Thelen, Marcus; Yoshie, Osamu; Zlotnik, Albert

    2014-01-01

    Sixteen years ago, the Nomenclature Committee of the International Union of Pharmacology approved a system for naming human seven-transmembrane (7TM) G protein-coupled chemokine receptors, the large family of leukocyte chemoattractant receptors that regulates immune system development and function, in large part by mediating leukocyte trafficking. This was announced in Pharmacological Reviews in a major overview of the first decade of research in this field [Murphy PM, Baggiolini M, Charo IF, Hébert CA, Horuk R, Matsushima K, Miller LH, Oppenheim JJ, and Power CA (2000) Pharmacol Rev 52:145–176]. Since then, several new receptors have been discovered, and major advances have been made for the others in many areas, including structural biology, signal transduction mechanisms, biology, and pharmacology. New and diverse roles have been identified in infection, immunity, inflammation, development, cancer, and other areas. The first two drugs acting at chemokine receptors have been approved by the U.S. Food and Drug Administration (FDA), maraviroc targeting CCR5 in human immunodeficiency virus (HIV)/AIDS, and plerixafor targeting CXCR4 for stem cell mobilization for transplantation in cancer, and other candidates are now undergoing pivotal clinical trials for diverse disease indications. In addition, a subfamily of atypical chemokine receptors has emerged that may signal through arrestins instead of G proteins to act as chemokine scavengers, and many microbial and invertebrate G protein-coupled chemokine receptors and soluble chemokine-binding proteins have been described. Here, we review this extended family of chemokine receptors and chemokine-binding proteins at the basic, translational, and clinical levels, including an update on drug development. We also introduce a new nomenclature for atypical chemokine receptors with the stem ACKR (atypical chemokine receptor) approved by the Nomenclature Committee of the International Union of Pharmacology and the Human

  13. Virus-encoded chemokine receptors--putative novel antiviral drug targets.

    PubMed

    Rosenkilde, Mette M

    2005-01-01

    Large DNA viruses, in particular herpes- and poxviruses, have evolved proteins that serve as mimics or decoys for endogenous proteins in the host. The chemokines and their receptors serve key functions in both innate and adaptive immunity through control of leukocyte trafficking, and have as such a paramount role in the antiviral immune responses. It is therefore not surprising that viruses have found ways to exploit and subvert the chemokine system by means of molecular mimicry. By ancient acts of molecular piracy and by induction and suppression of endogenous genes, viruses have utilized chemokines and their receptors to serve a variety of roles in viral life-cycle. This review focuses on the pharmacology of virus-encoded chemokine receptors, yet also the family of virus-encoded chemokines and chemokine-binding proteins will be touched upon. Key properties of the virus-encoded receptors, compared to their closest endogenous homologs, are interactions with a wider range of chemokines, which can act as agonists, antagonists and inverse agonists, and the exploitation of many signal transduction pathways. High constitutive activity is another key property of some--but not all--of these receptors. The chemokine receptors belong to the superfamily of G-protein coupled 7TM receptors that per se are excellent drug targets. At present, non-peptide antagonists have been developed against many chemokine receptors. The potentials of the virus-encoded chemokine receptors as drug targets--ie. as novel antiviral strategies--will be highlighted here together with the potentials of the virus-encoded chemokines and chemokine-binding proteins as novel anti-inflammatory biopharmaceutical strategies. PMID:15617722

  14. Dogs immunized with LBSap vaccine displayed high levels of IL-12 and IL-10 cytokines and CCL4, CCL5 and CXCL8 chemokines in the dermis.

    PubMed

    Vitoriano-Souza, Juliana; Moreira, Nádia das Dores; Menezes-Souza, Daniel; Roatt, Bruno Mendes; de Oliveira Aguiar-Soares, Rodrigo Dian; Siqueira-Mathias, Fernando Augusto; de Oliveira Cardoso, Jamille Mirelle; Giunchetti, Rodolfo Cordeiro; de Sá, Renata Guerra; Corrêa-Oliveira, Rodrigo; Carneiro, Cláudia Martins; Reis, Alexandre Barbosa

    2013-12-01

    The complex interplay between cytokines and chemokines regulates innate and adaptive immune responses against pathogens; specifically, cytokine and chemokine expression drives activation of immune effector cells and their recruitment to tissue infection sites. Herein, we inoculated dogs with Leishmania braziliensis antigens plus saponin (the LBSap vaccine), as well as with the vaccine components, and then used real-time PCR to evaluate the kinetics of dermal expression of mRNAs of cytokines (IL-12, IFN-γ, TNF-α, IL-4, IL-13, TGF-β and IL-10) and chemokines (CCL2, CCL4, CCL5, CCL21 and CXCL8) 1, 12, 24 and 48 h after inoculation. We also evaluated the correlation between cytokine and chemokine expression and dermal cellularity. The LBSap vaccine induced high levels of IL-12 and IL-10 expression at 12 and 24 h, respectively. Furthermore, we observed positive correlations between IL-12 and IL-13 expression, IFN-γ and IL-13 expression, and IL-13 and TGF-β expression, suggesting that a mixed cytokine microenvironment developed after immunization with the vaccine. Inoculation with the saponin adjuvant alone induced a chemokine and cytokine expression profile similar to that observed in the LBSap group. CCL4 and CXCL8 chemokine expression was up regulated by the LBSap vaccine. CCL5 expression was initially highest in the LBSap group, but at 48 h, expression was highest in the LB group. Information about the kinetics of the immune response to this vaccine gained using this dog model will help to elucidate the mechanisms of and factors involved in a protective response against Leishmania infection and will aid in establishing rational approaches for the development of vaccines against canine visceral leishmaniasis. PMID:23911411

  15. Transglutaminase 2 Regulates the GTPase-activating Activity of Bcr*

    PubMed Central

    Yi, Sun-Ju; Groffen, John; Heisterkamp, Nora

    2009-01-01

    Transglutaminase 2 (TG2) is a multifunctional protein that has been implicated in numerous pathologies including that of neurodegeneration and celiac disease, but the molecular interactions that mediate its diverse activities are largely unknown. Bcr and the closely related Abr negatively regulate the small G-protein Rac: loss of their combined function in vivo results in increased reactivity of innate immune cells. Bcr and Abr are GTPase-activating proteins that catalyze the hydrolysis of the GTP bound to Rac. However, how the Bcr and Abr GTPase-activating activity is regulated is not precisely understood. We here report a novel mechanism of regulation through direct protein-protein interaction with TG2. TG2 bound to the Rac-binding pocket in the GTPase-activating domains of Bcr and Abr, blocked Bcr activity and, through this mechanism, increased levels of active GTP-bound Rac and EGF-stimulated membrane ruffling. TG2 exists in at least two different conformations. Interestingly, experiments using TG2 mutants showed that Bcr exhibits preferential binding to the non-compacted conformation of TG2, in which its catalytic domain is exposed, but transamidation is not needed for the interaction. Thus, TG2 regulates levels of cellular GTP-bound Rac and actin cytoskeletal reorganization through a new mechanism involving direct inhibition of Bcr GTPase-activating activity. PMID:19840940

  16. Inflammatory reaction after traumatic brain injury: Therapeutic potential of targeting cell-cell communication by chemokines

    PubMed Central

    Gyoneva, Stefka; Ransohoff, Richard M.

    2015-01-01

    Traumatic brain injury (TBI) affects millions of people worldwide every year. The primary impact initiates the secretion of pro- and anti-inflammatory factors, subsequent recruitment of peripheral immune cells and activation of brain-resident microglia and astrocytes. Chemokines are major mediators of peripheral blood cell recruitment to damaged tissue, including the TBI brain. Here we review the involvement of specific chemokine pathways in TBI pathology and attempts to modulate these pathways for therapeutic purposes. We focus on chemokine (C-C motif) ligand 2/chemokine (C-C motif) receptor 2 (CCL2/CCR2) and chemokine (C-X-C motif) ligand 12/chemokine (C-X-C motif) receptor 4 (CXCL12/CXCR4). Recent micro-array and multiplex expression profiling have also implicated CXCL10 and CCL5 in TBI pathology. Chemokine (C-X3-C motif) ligand 1/ chemokine (C-X3-C motif) receptor 1 (CX3CL1/CX3CR1) signaling in the context of TBI is also discussed. Current literature suggests that modulating chemokine signaling, especially CCL2/CCR2, may be beneficial in TBI treatment. PMID:25979813

  17. 50 CFR 665.964 - Regulated activities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Regulated activities. 665.964 Section 665.964 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC Rose Atoll Marine...

  18. 50 CFR 665.964 - Regulated activities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Regulated activities. 665.964 Section 665.964 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC Rose Atoll Marine...

  19. Regulation of ROCK activity in cancer.

    PubMed

    Morgan-Fisher, Marie; Wewer, Ulla M; Yoneda, Atsuko

    2013-03-01

    Cancer-associated changes in cellular behavior, such as modified cell-cell contact, increased migratory potential, and generation of cellular force, all require alteration of the cytoskeleton. Two homologous mammalian serine/threonine kinases, Rho-associated protein kinases (ROCK I and II), are key regulators of the actin cytoskeleton acting downstream of the small GTPase Rho. ROCK is associated with cancer progression, and ROCK protein expression is elevated in several types of cancer. ROCKs exist in a closed, inactive conformation under quiescent conditions, which is changed to an open, active conformation by the direct binding of guanosine triphosphate (GTP)-loaded Rho. In recent years, a number of ROCK isoform-specific binding partners have been found to modulate the kinase activity through direct interactions with the catalytic domain or via altered cellular localization of the kinases. Thus, these findings demonstrate additional modes to regulate ROCK activity. This review describes the molecular mechanisms of ROCK activity regulation in cancer, with emphasis on ROCK isoform-specific regulation and interaction partners, and discusses the potential of ROCKs as therapeutic targets in cancer. PMID:23204112

  20. Regulation of brain aromatase activity in rats

    SciTech Connect

    Roselli, C.E.; Ellinwood, W.E.; Resko, J.A.

    1984-01-01

    The distribution and regulation of aromatase activity in the adult rat brain with a sensitive in vitro assay that measures the amount of /sup 3/H/sub 2/O formed during the conversion of (1 beta-/sup 3/H)androstenedione to estrone. The rate of aromatase activity in the hypothalamus-preoptic area (HPOA) was linear with time up to 1 h, and with tissue concentrations up to 5 mgeq/200 microliters incubation mixture. The enzyme demonstrated a pH optimum of 7.4 and an apparent Michaelis-Menten constant (Km) of 0.04 microns. The greatest amount of aromatase activity was found in amygdala and HPOA from intact male rats. The hippocampus, midbrain tegmentum, cerebral cortex, cerebellum, and anterior pituitary all contained negligible enzymatic activity. Castration produced a significant decrease in aromatase activity in the HPOA, but not in the amygdala or cerebral cortex. The HPOAs of male rats contained significantly greater aromatase activity than the HPOAs of female rats. In females, this enzyme activity did not change during the estrous cycle or after ovariectomy. Administration of testosterone to gonadectomized male and female rats significantly enhanced HPOA aromatase activities to levels approximating those found in HPOA from intact males. Therefore, the results suggest that testosterone, or one of its metabolites, is a major steroidal regulator of HPOA aromatase activity in rats.

  1. Molecular cloning and characterization of chemokine-like factor 1 (CKLF1), a novel human cytokine with unique structure and potential chemotactic activity.

    PubMed Central

    Han, W; Lou, Y; Tang, J; Zhang, Y; Chen, Y; Li, Y; Gu, W; Huang, J; Gui, L; Tang, Y; Li, F; Song, Q; Di, C; Wang, L; Shi, Q; Sun, R; Xia, D; Rui, M; Tang, J; Ma, D

    2001-01-01

    Cytokines are small proteins that have an essential role in the immune and inflammatory responses. The repertoire of cytokines is becoming diverse and expanding. Here we report the identification and characterization of a novel cytokine designated as chemokine-like factor 1 (CKLF1). The full-length cDNA of CKLF1 is 530 bp long and a single open reading frame encoding 99 amino acid residues. CKLF1 bears no significant similarity to any other known cytokine in its amino acid sequence. Expression of CKLF1 can be partly inhibited by interleukin 10 in PHA-stimulated U937 cells. Recombinant CKLF1 is a potent chemoattractant for neutrophils, monocytes and lymphocytes; moreover, it can stimulate the proliferation of murine skeletal muscle cells. These results suggest that CKLF1 might have important roles in inflammation and in the regeneration of skeletal muscle. PMID:11415443

  2. Differential expression of chemokines, chemokine receptors and proteinases by foreign body giant cells (FBGCs) and osteoclasts.

    PubMed

    Khan, Usman A; Hashimi, Saeed M; Khan, Shershah; Quan, Jingjing; Bakr, Mahmoud M; Forwood, Mark R; Morrison, Nigel M

    2014-07-01

    Osteoclasts and foreign body giant cells (FBGCs) are both derived from the fusion of macropahges. These cells are seen in close proximity during foreign body reactions, therefore it was assumed that they might interact with each other. The aim was to identify important genes that are expressed by osteoclasts and FBGCs which can be used to understand peri-implantitis and predict the relationship of these cells during foreign body reactions. Bone marrow macrophages (BMM) were treated with receptor activator of nuclear factor kappa B ligand (RANKL) to produce osteoclasts. Quantitative PCR (qPCR) was used to identify the genes that were expressed by osteoclasts and FBGCs compared to macrophage controls. TRAP staining was used to visualise the cells while gelatine zymography and western blots were used for protein expression. Tartrate-resistant acid phosphatase (TRAP), matrix metallo proteinase 9 (MMP9), nuclear factor of activated T cells 1 (NFATc1), cathepsin K (CTSK) and RANK were significantly lower in FBGCs compared to osteoclasts. Inflammation specific chemokines such as monocyte chemotactic protein (MCP1 also called CCL2), macrophage inflammatory protein 1 alpha (MIP1α), MIP1β and MIP1γ, and their receptors CCR1, CCR3 and CCR5, were highly expressed by FBGCs. FBGCs were negative for osteoclast specific markers (RANK, NFATc1, CTSK). FBGCs expressed chemokines such as CCL2, 3, 5 and 9 while osteoclasts expressed the receptors for these chemokines i.e. CCR1, 2 and 3. Our findings show that osteoclast specific genes are not expressed by FBGCs and that FBGCs interact with osteoclasts during foreign body reaction through chemokines. PMID:24500983

  3. Regulating the regulators: modulators of transcription factor activity.

    PubMed

    Everett, Logan; Hansen, Matthew; Hannenhalli, Sridhar

    2010-01-01

    Gene transcription is largely regulated by DNA-binding transcription factors (TFs). However, the TF activity itself is modulated via, among other things, post-translational modifications (PTMs) by specific modification enzymes in response to cellular stimuli. TF-PTMs thus serve as "molecular switchboards" that map upstream signaling events to the downstream transcriptional events. An important long-term goal is to obtain a genome-wide map of "regulatory triplets" consisting of a TF, target gene, and a modulator gene that specifically modulates the regulation of the target gene by the TF. A variety of genome-wide data sets can be exploited by computational methods to obtain a rough map of regulatory triplets, which can guide directed experiments. However, a prerequisite to developing such computational tools is a systematic catalog of known instances of regulatory triplets. We first describe PTM-Switchboard, a recent database that stores triplets of genes such that the ability of one gene (the TF) to regulate a target gene is dependent on one or more PTMs catalyzed by a third gene, the modifying enzyme. We also review current computational approaches to infer regulatory triplets from genome-wide data sets and conclude with a discussion of potential future research. PTM-Switchboard is accessible at http://cagr.pcbi.upenn.edu/PTMswitchboard / PMID:20827600

  4. Chemokines in tumor progression and metastasis.

    PubMed

    Sarvaiya, Purvaba J; Guo, Donna; Ulasov, Ilya; Gabikian, Patrik; Lesniak, Maciej S

    2013-12-01

    Chemokines play a vital role in tumor progression and metastasis. Chemokines are involved in the growth of many cancers including breast cancer, ovarian cancer, pancreatic cancer, melanoma, lung cancer, gastric cancer, acute lymphoblastic leukemia, colon cancer, non-small lung cancer, non-hodgkin's lymphoma, etc. The expression of chemokines and their receptors is altered in many malignancies and leads to aberrant chemokine receptor signaling. This review focuses on the role of chemokines in key processes that facilitate tumor progression including proliferation, senescence, angiogenesis, epithelial mesenchymal transition, immune evasion and metastasis. PMID:24259307

  5. Chemokines in tumor progression and metastasis

    PubMed Central

    Sarvaiya, Purvaba J.; Guo, Donna; Ulasov, Ilya; Gabikian, Patrik; Lesniak, Maciej S.

    2013-01-01

    Chemokines play a vital role in tumor progression and metastasis. Chemokines are involved in the growth of many cancers including breast cancer, ovarian cancer, pancreatic cancer, melanoma, lung cancer, gastric cancer, acute lymphoblastic leukemia, colon cancer, non-small lung cancer and non-hodgkin's lymphoma among many others. The expression of chemokines and their receptors is altered in many malignancies and leads to aberrant chemokine receptor signaling. This review focuses on the role of chemokines in key processes that facilitate tumor progression including proliferation, senescence, angiogenesis, epithelial mesenchymal transition, immune evasion and metastasis. PMID:24259307

  6. Atypical Chemokine Receptors and Their Roles in the Resolution of the Inflammatory Response

    PubMed Central

    Bonecchi, Raffaella; Graham, Gerard J.

    2016-01-01

    Chemokines and their receptors are key mediators of the inflammatory process regulating leukocyte extravasation and directional migration into inflamed and infected tissues. The control of chemokine availability within inflamed tissues is necessary to attain a resolving environment and when this fails chronic inflammation ensues. Accordingly, vertebrates have adopted a number of mechanisms for removing chemokines from inflamed sites to help precipitate resolution. Over the past 15 years, it has become apparent that essential players in this process are the members of the atypical chemokine receptor (ACKR) family. Broadly speaking, this family is expressed on stromal cell types and scavenges chemokines to either limit their spatial availability or to remove them from in vivo sites. Here, we provide a brief review of these ACKRs and discuss their involvement in the resolution of inflammatory responses and the therapeutic implications of our current knowledge. PMID:27375622

  7. Chemokines and their receptors in the allergic airway inflammatory process.

    PubMed

    Velazquez, Juan Raymundo; Teran, Luis Manuel

    2011-08-01

    The development of the allergic airway disease conveys several cell types, such as T-cells, eosinophils, mast cells, and dendritic cells, which act in a special and temporal synchronization. Cellular mobilization and its complex interactions are coordinated by a broad range of bioactive mediators known as chemokines. These molecules are an increasing family of small proteins with common structural motifs and play an important role in the recruitment and cell activation of both leukocytes and resident cells at the allergic inflammatory site via their receptors. Trafficking and recruitment of cell populations with specific chemokines receptors assure the presence of reactive allergen-specific T-cells in the lung, and therefore the establishment of an allergic inflammatory process. Different approaches directed against chemokines receptors have been developed during the last decades with promising therapeutic results in the treatment of asthma. In this review we explore the role of the chemokines and chemokine receptors in allergy and asthma and discuss their potential as targets for therapy. PMID:20352527

  8. Involvement of the nuclear factor-κB signaling pathway in the regulation of CXC chemokine receptor-4 expression in neuroblastoma cells induced by tumor necrosis factor-α

    PubMed Central

    ZHI, YUNLAI; LU, HONGTING; DUAN, YUHE; SUN, WEISHENG; GUAN, GE; DONG, QIAN; YANG, CHUANMIN

    2015-01-01

    Metastasis is a hallmark of malignant neuroblastoma and is the main reason for therapeutic failure and recurrence of the tumor. The CXC chemokine receptor-4 (CXCR4), a Gi protein-coupled receptor for the ligand CXCL12/stromal cell-derived factor-1α (SDF-1α), is expressed in various types of tumor. This receptor mediates the homing of tumor cells to specific organs that express the ligand, CXCL12, for this receptor and plays an important role in tumor growth, invasion, metastasis and angiogenesis. In the present study, the inflammatory cytokine, tumor necrosis factor-α (TNF-α) upregulated CXCR4 expression in neuroblastoma cells and increased migration to the CXCR4 ligand SDF-1α. In addition, this effect was dependent upon NF-κB transcriptional activity, as blocking the NF-κB pathway with pyrrolidinedithiocarbamic acid ammonium salt suppressed TNF-α-induced upregulation of CXCR4 expression and reduced the migration towards the CXCR4 ligand, SDF-1α. Treating neuroblastoma cells with TNF-α resulted in the activation of nuclear factor-kappa B (NF-κB) and subsequently, the translocation of NF-κB from the cytoplasm to the nucleus. Using immunohistochemistry, NF-κB and CXCR4 were significantly correlated with each other (P=0.0052, Fisher’s exact test) in a cohort of neuroblastoma samples (n=80). The present study indicates that the inflammatory cytokine, TNF-α, partially functions through the NF-κB signaling pathway to upregulate CXCR4 expression to foster neuroblastoma cell metastasis. These findings indicate that effective inhibition of neuroblastoma metastasis should be directed against the inflammatory cytokine-induced NF-κB/CXCR4/SDF-1α signaling pathway. PMID:25503960

  9. (+)-Nootkatone inhibits tumor necrosis factor α/interferon γ-induced production of chemokines in HaCaT cells

    SciTech Connect

    Choi, Hyeon-Jae; Lee, Jin-Hwee; Jung, Yi-Sook

    2014-05-02

    Highlights: • (+)-Nootkatone inhibits TNF-α/IFN-γ-induced TARC and MDC expression in HaCaT cells. • PKCζ, p38 MAPK, or NF-κB mediate TNF-α/IFN-γ-induced TARC and MDC expression. • (+)-Nootkatone inhibits TNF-α/IFN-γ-induced activation of PKCζ, p38 MAPK, or NF-κB. • (+)-Nootkatone suppresses chemokine expression by inhibiting of PKCζ and p38 pathways. - Abstract: Chemokines are important mediators of cell migration, and thymus and activation-regulated chemokine (TARC/CCL17) and macrophage-derived chemokine (MDC/CCL22) are well-known typical inflammatory chemokines involved in atopic dermatitis (AD). (+)-Nootkatone is the major component of Cyperus rotundus. (+)-Nootkatone has antiallergic, anti-inflammatory, and antiplatelet activities. The purpose of this study was to investigate the effect of (+)-nootkatone on tumor necrosis factor α (TNF-α)/interferon γ (IFN-γ)-induced expression of Th2 chemokines in HaCaT cells. We found that (+)-nootkatone inhibited the TNF-α/IFN-γ-induced expression of TARC/CCL17 and MDC/CCL22 mRNA in HaCaT cells. It also significantly inhibited TNF-α/IFN-γ-induced activation of nuclear factor kappa B (NF-κB), p38 mitogen-activated protein kinase (MAPK), and protein kinase Cζ (PKCζ). Furthermore, we showed that PKCζ and p38 MAPK contributed to the inhibition of TNF-α/IFN-γ-induced TARC/CCL17 and MDC/CCL22 expression by blocking IκBα degradation in HaCaT cells. Taken together, these results suggest that (+)-nootkatone may suppress TNF-α/IFN-γ-induced TARC/CCL17 and MDC/CCL22 expression in HaCaT cells by inhibiting of PKCζ and p38 MAPK signaling pathways that lead to activation of NF-κB. We propose that (+)-nootkatone may be a useful therapeutic candidate for inflammatory skin diseases such as AD.

  10. Structure of mouse IP-10, a chemokine

    SciTech Connect

    Jabeen, Talat; Leonard, Philip; Jamaluddin, Haryati; Acharya, K. Ravi

    2008-06-01

    The structure of mouse IP-10 shows a novel tetrameric association. Interferon-γ-inducible protein (IP-10) belongs to the CXC class of chemokines and plays a significant role in the pathophysiology of various immune and inflammatory responses. It is also a potent angiostatic factor with antifibrotic properties. The biological activities of IP-10 are exerted by interactions with the G-protein-coupled receptor CXCR3 expressed on Th1 lymphocytes. IP-10 thus forms an attractive target for structure-based rational drug design of anti-inflammatory molecules. The crystal structure of mouse IP-10 has been determined and reveals a novel tetrameric association. In the tetramer, two conventional CXC chemokine dimers are associated through their N-terminal regions to form a 12-stranded elongated β-sheet of ∼90 Å in length. This association differs significantly from the previously studied tetramers of human IP-10, platelet factor 4 and neutrophil-activating peptide-2. In addition, heparin- and receptor-binding residues were mapped on the surface of IP-10 tetramer. Two heparin-binding sites were observed on the surface and were present at the interface of each of the two β-sheet dimers. The structure supports the formation of higher order oligomers of IP-10, as observed in recent in vivo studies with mouse IP-10, which will have functional relevance.

  11. Structure of mouse IP-10, a chemokine.

    PubMed

    Jabeen, Talat; Leonard, Philip; Jamaluddin, Haryati; Acharya, K Ravi

    2008-06-01

    Interferon-gamma-inducible protein (IP-10) belongs to the CXC class of chemokines and plays a significant role in the pathophysiology of various immune and inflammatory responses. It is also a potent angiostatic factor with antifibrotic properties. The biological activities of IP-10 are exerted by interactions with the G-protein-coupled receptor CXCR3 expressed on Th1 lymphocytes. IP-10 thus forms an attractive target for structure-based rational drug design of anti-inflammatory molecules. The crystal structure of mouse IP-10 has been determined and reveals a novel tetrameric association. In the tetramer, two conventional CXC chemokine dimers are associated through their N-terminal regions to form a 12-stranded elongated beta-sheet of approximately 90 A in length. This association differs significantly from the previously studied tetramers of human IP-10, platelet factor 4 and neutrophil-activating peptide-2. In addition, heparin- and receptor-binding residues were mapped on the surface of IP-10 tetramer. Two heparin-binding sites were observed on the surface and were present at the interface of each of the two beta-sheet dimers. The structure supports the formation of higher order oligomers of IP-10, as observed in recent in vivo studies with mouse IP-10, which will have functional relevance. PMID:18560148

  12. Structural basis of the herpesvirus M3-chemokine interaction.

    PubMed

    Alcami, Antonio

    2003-05-01

    Viruses have been fighting the immune systems of their hosts for millions of years and have evolved evasion strategies to ensure their survival. Viruses can teach us efficient mechanisms to control the immune system, and this information can be used to design new strategies of immune modulation that we might apply to diminish immunopathological responses that cause human diseases. Large DNA viruses, such as poxviruses and herpesviruses, encode proteins that are secreted from infected cells, bind cytokines and neutralize their activity. A subgroup of these viral proteins binds chemokines, a complex family of cytokines that control the recruitment of cells to sites of infection and inflammation. One of the major unresolved questions in the field was to understand how these viral secreted proteins bind chemokines with high affinity, despite having no amino acid sequence similarity to the host chemokine receptors, which are seven-transmembrane-domain proteins that cannot be engineered as soluble proteins. PMID:12781515

  13. The protein phosphatase inhibitor calyculin A stimulates chemokine production by human synovial cells.

    PubMed Central

    Jordan, N J; Watson, M L; Westwick, J

    1995-01-01

    Cultured human synovial fibroblasts express mRNA for the chemotactic cytokines (chemokines) interleukin-8 (IL-8), monocyte chemotactic protein 1 (MCP-1) and regulated upon activation normal T-cell expressed and presumably secreted (RANTES), when stimulated with IL-1 or tumour necrosis factor alpha (TNF alpha). Calyculin A, a potent type 1/2A protein serine/threonine phosphatase inhibitor, was used to examine the role of protein phosphatases in the regulation of chemokine gene expression. Calyculin A (1 nM) mimicked IL-1 by inducing IL-8 and MCP-1 mRNA expression in synovial cells. IL-8 mRNA was induced over a similar time period (1-6 h) in response to IL-1 or calyculin A, whereas MCP-1 mRNA was induced more rapidly (1-2 h) by calyculin A than by IL-1 (4-6 h). Expression of RANTES mRNA occurred in response to TNF alpha, but could not be induced by stimulation with calyculin A alone. These results suggest that inhibition of protein phosphatase type 1/2A may have a differential role in the regulation of the expression of each of the chemokine genes. Synovial fibroblasts also secreted IL-8 and IL-6 peptide when stimulated with either IL-1/TNF alpha or calyculin A. The amount of IL-8 and IL-6 peptide produced in response to calyculin A was significantly increased above that produced by untreated synovial cells, though it was much less than the amount induced by IL-1 or TNF alpha. Calyculin A also acted synergistically with IL-1 or TNF alpha to cause a 2-fold potentiation of IL-1- or TNF alpha-induced IL-8 mRNA and peptide and RANTES mRNA expression. These results suggest that although inhibition of a protein phosphatase may be able to regulate the magnitude of IL-1-induced chemokine gene expression, the IL-1 signal transduction pathway involves components in addition to phosphatase inhibition, possibly including the activation of a protein kinase, the action of which may be opposed by a protein phosphatase inhibited by calyculin A. Images Figure 1 Figure 2 Figure 3

  14. Src regulates the activity of SIRT2

    SciTech Connect

    Choi, You Hee; Kim, Hangun; Lee, Sung Ho; Jin, Yun-Hye; Lee, Kwang Youl

    2014-07-25

    Highlights: • Src decreases the protein levels of Sirt2. • Src inhibitor and knockdown of Src increase the protein levels of Sirt2. • Src interacts with and phosphorylates Sirt2. • Src regulate the activity of Sirt2. - Abstract: SIRT2 is a mammalian member of the Sirtuin family of NAD{sup +}-dependent protein deacetylases. The tyrosine kinase Src is involved in a variety of cellular signaling pathways, leading to the induction of DNA synthesis, cell proliferation, and cytoskeletal reorganization. The function of SIRT2 is modulated by post-translational modifications; however, the precise molecular signaling mechanism of SIRT2 through interactions with c-Src has not yet been established. In this study, we investigated the potential regulation of SIRT2 function by c-Src. We found that the protein levels of SIRT2 were decreased by c-Src, and subsequently rescued by the addition of a Src specific inhibitor, SU6656, or by siRNA-mediated knockdown of c-Src. The c-Src interacts with and phosphorylates SIRT2 at Tyr104. c-Src also showed the ability to regulate the deacetylation activity of SIRT2. Investigation on the phosphorylation of SIRT2 suggested that this was the method of c-Src-mediated SIRT2 regulation.

  15. Chemokine CXCL1 mediated neutrophil recruitment: Role of glycosaminoglycan interactions.

    PubMed

    Sawant, Kirti V; Poluri, Krishna Mohan; Dutta, Amit K; Sepuru, Krishna Mohan; Troshkina, Anna; Garofalo, Roberto P; Rajarathnam, Krishna

    2016-01-01

    The chemokine CXCL1/MGSA plays a pivotal role in the host immune response by recruiting and activating neutrophils for microbial killing at the tissue site. CXCL1 exists reversibly as monomers and dimers, and mediates its function by binding glycosaminoglycans (GAG) and CXCR2 receptor. We recently showed that both monomers and dimers are potent CXCR2 agonists, the dimer is the high-affinity GAG ligand, lysine and arginine residues located in two non-overlapping domains mediate GAG interactions, and there is extensive overlap between GAG and receptor-binding domains. To understand how these structural properties influence in vivo function, we characterized peritoneal neutrophil recruitment of a trapped monomer and trapped dimer and a panel of WT lysine/arginine to alanine mutants. Monomers and dimers were active, but WT was more active indicating synergistic interactions promote recruitment. Mutants from both domains showed reduced GAG heparin binding affinities and reduced neutrophil recruitment, providing compelling evidence that both GAG-binding domains mediate in vivo trafficking. Further, mutant of a residue that is involved in both GAG binding and receptor signaling showed the highest reduction in recruitment. We conclude that GAG interactions and receptor activity of CXCL1 monomers and dimers are fine-tuned to regulate neutrophil trafficking for successful resolution of tissue injury. PMID:27625115

  16. Chemokine gene variants in schizophrenia.

    PubMed

    Dasdemir, Selcuk; Kucukali, Cem Ismail; Bireller, Elif Sinem; Tuzun, Erdem; Cakmakoglu, Bedia

    2016-08-01

    Background Chemokines are known to play a major role in driving inflammation and immune responses in several neuroinflammatory diseases, including multiple sclerosis, Alzheimer's disease and Parkinson's disease. Inflammation has also been implicated in the pathogenesis of schizophrenia. Aim We aimed to investigate a potential link between chemokines and schizophrenia and analyze the role of MCP-1-A2518G, SDF-1-3'A, CCR5-delta32, CCR5-A55029G, CXCR4-C138T and CCR2-V64I gene polymorphisms in the Turkish population. Methods Genotyping was conducted by PCR-RFLP based on 140 patients and 123 unrelated healthy controls to show the relation between chemokine gene variants and schizophrenia risk. Results Frequencies of CCR5-A55029G A genotypes and CCR5-A55029G AG genotypes were found higher in patients than the controls and even also CCR2-V64I WT: CCR5-A55029G A and CCR2-V64I 64I: CCR5-A55029G A haplotypes significantly associated according to Bonferroni correction. However, no significant association was found for any of the other polymorphisms with the risk of schizophrenia. Conclusions Our findings suggest that CCR5-A55029G polymorphisms and CCR2-V64I WT: CCR5-A55029G A and CCR2-V64I 64I: CCR5-A55029G A haplotypes might have association with schizophrenia pathogenesis. PMID:26906930

  17. THE ROLE OF TRPM2 IN HYDROGEN PEROXIDE-INDUCED EXPRESSION OF INFLAMMATORY CYTOKINE AND CHEMOKINE IN RAT TRIGEMINAL GANGLIA

    PubMed Central

    CHUNG, M.-K.; ASGAR, J.; LEE, J.; SHIM, M. S.; DUMLER, C.; RO, J. Y.

    2016-01-01

    Trigeminal ganglia (TG) contain neuronal cell bodies surrounded by satellite glial cells. Although peripheral injury is well known to induce changes in gene expression within sensory ganglia, detailed mechanisms whereby peripheral injury leads to gene expression within sensory ganglia are not completely understood. Reactive oxygen species (ROS) are an important modulator of hyperalgesia, but the role of ROS generated within sensory ganglia is unclear. Since ROS are known to affect transcription processes, ROS generated within sensory ganglia could directly influence gene expression and induce cellular changes at the soma level. In this study, we hypothesized that peripheral inflammation leads to cytokine and chemokine production and ROS generation within TG and that transient receptor potential melastatin (TRPM2), a well known oxidative sensor, contributes to ROS-induced gene regulation within TG. The masseter injection of complete Freund’s adjuvant (CFA) resulted in a significantly elevated level of ROS within TG of the inflamed side with a concurrent increase in cytokine expression in TG. Treatment of TG cultures with H2O2 significantly up-regulated mRNA and protein levels of cytokine/chemokine such as interleukin 6 (IL-6) and chemokine (C-X-C motif) ligand 2 (CXCL2). TRPM2 was expressed in both neurons and nonneuronal cells in TG, and pretreatment of TG cultures with 2-aminoethoxydiphenyl borate (2-APB), an inhibitor of TRPM2, or siRNA against TRPM2 attenuated H2O2-induced up-regulation of IL-6 and CXCL2. These results suggested that activation of TRPM2 could play an important role in the modulation of cytokine/chemokine expression within TG under oxidative stress and that such changes may contribute to amplification of nociceptive signals leading to pathological pain conditions. PMID:25849615

  18. Indole-3-carbinol and 3’, 3’-diindolylmethane modulate androgen effect up-regulation on C-C chemokine ligand 2 and monocyte attraction to prostate cancer cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inflammation has a role in prostate tumorigenesis. Recruitment of inflammatory monocytes to the tumor site is mediated by C-C chemokine ligand 2 (CCL2) through binding to its receptor CCR2. We hypothesized that androgen could modulate CCL2 expression in hormone-responsive prostate cancer cells, and ...

  19. Regulators of Slc4 bicarbonate transporter activity

    PubMed Central

    Thornell, Ian M.; Bevensee, Mark O.

    2015-01-01

    The Slc4 family of transporters is comprised of anion exchangers (AE1-4), Na+-coupled bicarbonate transporters (NCBTs) including electrogenic Na/bicarbonate cotransporters (NBCe1 and NBCe2), electroneutral Na/bicarbonate cotransporters (NBCn1 and NBCn2), and the electroneutral Na-driven Cl-bicarbonate exchanger (NDCBE), as well as a borate transporter (BTR1). These transporters regulate intracellular pH (pHi) and contribute to steady-state pHi, but are also involved in other physiological processes including CO2 carriage by red blood cells and solute secretion/reabsorption across epithelia. Acid-base transporters function as either acid extruders or acid loaders, with the Slc4 proteins moving HCO−3 either into or out of cells. According to results from both molecular and functional studies, multiple Slc4 proteins and/or associated splice variants with similar expected effects on pHi are often found in the same tissue or cell. Such apparent redundancy is likely to be physiologically important. In addition to regulating pHi, a HCO−3 transporter contributes to a cell's ability to fine tune the intracellular regulation of the cotransported/exchanged ion(s) (e.g., Na+ or Cl−). In addition, functionally similar transporters or splice variants with different regulatory profiles will optimize pH physiology and solute transport under various conditions or within subcellular domains. Such optimization will depend on activated signaling pathways and transporter expression profiles. In this review, we will summarize and discuss both well-known and more recently identified regulators of the Slc4 proteins. Some of these regulators include traditional second messengers, lipids, binding proteins, autoregulatory domains, and less conventional regulators. The material presented will provide insight into the diversity and physiological significance of multiple members within the Slc4 gene family. PMID:26124722

  20. Team Regulation, Regulation of Social Activities or Co-Regulation: Different Labels for Effective Regulation of Learning in CSCL

    ERIC Educational Resources Information Center

    Saab, Nadira

    2012-01-01

    Computer-supported collaborative learning (CSCL) is an approach to learning in which learners can actively and collaboratively construct knowledge by means of interaction and joint problem solving. Regulation of learning is especially important in the domain of CSCL. Next to the regulation of task performance, the interaction between learners who…

  1. Activities and regulation of peptidoglycan synthases

    PubMed Central

    Egan, Alexander J. F.; Biboy, Jacob; van't Veer, Inge; Breukink, Eefjan; Vollmer, Waldemar

    2015-01-01

    Peptidoglycan (PG) is an essential component in the cell wall of nearly all bacteria, forming a continuous, mesh-like structure, called the sacculus, around the cytoplasmic membrane to protect the cell from bursting by its turgor. Although PG synthases, the penicillin-binding proteins (PBPs), have been studied for 70 years, useful in vitro assays for measuring their activities were established only recently, and these provided the first insights into the regulation of these enzymes. Here, we review the current knowledge on the glycosyltransferase and transpeptidase activities of PG synthases. We provide new data showing that the bifunctional PBP1A and PBP1B from Escherichia coli are active upon reconstitution into the membrane environment of proteoliposomes, and that these enzymes also exhibit DD-carboxypeptidase activity in certain conditions. Both novel features are relevant for their functioning within the cell. We also review recent data on the impact of protein–protein interactions and other factors on the activities of PBPs. As an example, we demonstrate a synergistic effect of multiple protein–protein interactions on the glycosyltransferase activity of PBP1B, by its cognate lipoprotein activator LpoB and the essential cell division protein FtsN. PMID:26370943

  2. Molecular mechanisms regulating NLRP3 inflammasome activation

    PubMed Central

    Jo, Eun-Kyeong; Kim, Jin Kyung; Shin, Dong-Min; Sasakawa, Chihiro

    2016-01-01

    Inflammasomes are multi-protein signaling complexes that trigger the activation of inflammatory caspases and the maturation of interleukin-1β. Among various inflammasome complexes, the NLRP3 inflammasome is best characterized and has been linked with various human autoinflammatory and autoimmune diseases. Thus, the NLRP3 inflammasome may be a promising target for anti-inflammatory therapies. In this review, we summarize the current understanding of the mechanisms by which the NLRP3 inflammasome is activated in the cytosol. We also describe the binding partners of NLRP3 inflammasome complexes activating or inhibiting the inflammasome assembly. Our knowledge of the mechanisms regulating NLRP3 inflammasome signaling and how these influence inflammatory responses offers further insight into potential therapeutic strategies to treat inflammatory diseases associated with dysregulation of the NLRP3 inflammasome. PMID:26549800

  3. Overview and potential unifying themes of the atypical chemokine receptor family.

    PubMed

    Vacchini, Alessandro; Locati, Massimo; Borroni, Elena Monica

    2016-06-01

    Chemokines modulate immune responses through their ability to orchestrate the migration of target cells. Chemokines directly induce cell migration through a distinct set of 7 transmembrane domain G protein-coupled receptors but are also recognized by a small subfamily of atypical chemokine receptors, characterized by their inability to support chemotactic activity. Atypical chemokine receptors are now emerging as crucial regulatory components of chemokine networks in a wide range of physiologic and pathologic contexts. Although a new nomenclature has been approved recently to reflect their functional distinction from their conventional counterparts, a systematic view of this subfamily is still missing. This review discusses their biochemical and immunologic properties to identify potential unifying themes in this emerging family. PMID:26740381

  4. Regulation of Trichophyton rubrum proteolytic activity.

    PubMed Central

    Apodaca, G; McKerrow, J H

    1989-01-01

    Trichophyton rubrum is the most common dermatophyte of humans and normally colonizes the superficial layers of the epidermis (stratum corneum). Several proteinases with a possible role in the metabolism of host proteins have been purified from this fungus. The regulation of these enzymes and their role in fungal metabolism were studied at the biochemical level. General proteolytic (azocollytic) activity was repressed when log-phase cultures of T. rubrum were grown in a minimal medium that contained readily metabolized sources of carbon, nitrogen, sulfur, and phosphorus. When either carbon, nitrogen, or sulfur was deleted from this minimal medium, azocollytic activity was derepressed. In all cases a high-molecular-weight activity (Mr, greater than 200,000) was expressed. A 71,000-Mr proteinase was observed in nitrogen-depleted cultures, and proteolytic species of Mr 124,000 and 27,000 were secreted in sulfur-depleted cultures. The addition of either inorganic (MgSO4, Na2SO3, NaS2O3) or organic (methionine, cysteine) sulfur to the sulfur-depleted medium repressed the expression of azocollytic activity. In contrast, keratinolytic activity was not repressed by carbon, nitrogen, or sulfur but instead was induced when a protein source was included in the minimal medium. Stationary-phase cultures of T. rubrum secreted all proteolytic activities constitutively. Unlike log-phase cultures, the stationary-phase cultures secreted azocollytic, elastinolytic, and keratinolytic activity in minimal medium. These activities fell in the carbon-, nitrogen-, and phosphorous-depleted media but remained high in sulfur-depleted medium. The following model is proposed for the regulation of T. rubrum proteolytic activity. In the initial stages of infection, T. rubrum grows logarithmically. In this state, proteolytic activity is derepressed whenever carbon, nitrogen, or sulfur is lacking in the fungal milieu. The general proteinases produced would act on the nonkeratinous proteins in the

  5. Magnetoreception Regulates Male Courtship Activity in Drosophila

    PubMed Central

    Wu, Chia-Lin; Fu, Tsai-Feng; Chiang, Meng-Hsuan; Chang, Yu-Wei; Her, Jim-Long; Wu, Tony

    2016-01-01

    The possible neurological and biophysical effects of magnetic fields on animals is an area of active study. Here, we report that courtship activity of male Drosophila increases in a magnetic field and that this effect is regulated by the blue light-dependent photoreceptor cryptochrome (CRY). Naïve male flies exhibited significantly increased courtship activities when they were exposed to a ≥ 20-Gauss static magnetic field, compared with their behavior in the natural environment (0 Gauss). CRY-deficient flies, cryb and crym, did not show an increased courtship index in a magnetic field. RNAi-mediated knockdown of cry in cry-GAL4-positive neurons disrupted the increased male courtship activity in a magnetic field. Genetically expressing cry under the control of cry-GAL4 in the CRY-deficient flies restored the increase in male courtship index that occurred in a magnetic field. Interestingly, artificially activating cry-GAL4-expressing neurons, which include large ventral lateral neurons and small ventral lateral neurons, via expression of thermosensitive cation channel dTrpA1, also increased the male courtship index. This enhancement was abolished by the addition of the cry-GAL80 transgene. Our results highlight the phenomenon of increased male courtship activity caused by a magnetic field through CRY-dependent magnetic sensation in CRY expression neurons in Drosophila. PMID:27195955

  6. Regulation of pokemon 1 activity by sumoylation.

    PubMed

    Roh, Hee-Eun; Lee, Min-Nyung; Jeon, Bu-Nam; Choi, Won-Il; Kim, Yoo-Jin; Yu, Mi-Young; Hur, Man-Wook

    2007-01-01

    Pokemon 1 is a proto-oncogenic transcriptional regulator that contains a POZ domain at the N-terminus and four Kruppel-like zinc fingers at the C-terminus. Pokemon 1 plays an important role in adipogenesis, osteogenesis, oncogenesis, and transcription of NF-kB responsive genes. Recent reports have shown that biological activities of transcription factors are regulated by sumolylation. We investigated whether Pokemon 1 is post-translationally modified by sumoylation and whether the modification affects Pokemon 1's transcriptional properties. We found that Pokemon 1 is sumoylated in vitro and in vivo. Upon careful analysis of the amino acid sequence of Pokemon 1, we found ten potential sumoylation sites located at lysines 61, 354, 371, 379, 383, 396, 486, 487, 536 and 539. We mutated each of these amino acids into arginine and tested whether the mutation could affect the transcriptional properties of Pokemon 1 on the Pokemon 1 responsive genes, such as ADH5/FDH and pG5-FRE-Luc. Wild-type Pokemon 1 potently represses transcription of ADH5/FDH. Most of the mutants, however, were weaker transcription repressors and repressed transcription 1.3-3.3 fold less effective. Although potential sumoylation sites were located close to the DNA binding domain or the nuclear localization sequence, the mutations did not alter nuclear localization or DNA binding activity. In addition, on the pG5-FRE-Luc test promoter construct, ectopic SUMO-1 repressed transcription in the presence of Pokemon 1. The sumoylation target lysine residue at amino acid 61, which is located in the middle of the POZ-domain, is important because K61R mutation resulted in a much weaker molecular interaction with corepressors. Our data suggest that Pokemon 1's activity as a transcription factor may involve sumoylation, and that sumoylation might be important in the regulation of transcription by Pokemon 1. PMID:17595526

  7. Constitutive ß-Catenin Signaling by the Viral Chemokine Receptor US28

    PubMed Central

    de Munnik, Sabrina; Schreiber, Andreas; Maussang, David; Vischer, Henry; Verkaar, Folkert; Leurs, Rob; Siderius, Marco; Smit, Martine J.

    2012-01-01

    Chronic activation of Wnt/ß-catenin signaling is found in a variety of human malignancies including melanoma, colorectal and hepatocellular carcinomas. Interestingly, expression of the HCMV-encoded chemokine receptor US28 in intestinal epithelial cells promotes intestinal neoplasia in transgenic mice, which is associated with increased nuclear accumulation of ß-catenin. In this study we show that this viral receptor constitutively activates ß-catenin and enhances ß-catenin-dependent transcription. Our data illustrate that this viral receptor does not activate ß-catenin via the classical Wnt/Frizzled signaling pathway. Analysis of US28 mediated signaling indicates the involvement of the Rho-Rho kinase (ROCK) pathway in the activation of ß-catenin. Moreover, cells infected with HCMV show significant increases in ß-catenin stabilization and signaling, which is mediated to a large extent by expression of US28. The modulation of the ß-catenin signal transduction pathway by a viral chemokine receptor provides alternative regulation of this pathway, with potential relevance for the development of colon cancer and virus-associated diseases. PMID:23145028

  8. Anti-infective peptide IDR-1002 augments monocyte chemotaxis towards CCR5 chemokines.

    PubMed

    Madera, Laurence; Hancock, Robert E W

    2015-08-28

    Innate defense regulator (IDR) peptides are a class of immunomodulators which enhance and modulate host innate immune responses against microbial pathogens. While IDR-mediated protection against a range of bacterial pathogens is dependent on enhanced monocyte recruitment to the site of infection, the mechanisms through which they increase monocyte trafficking remain unclear. In this study, anti-infective peptide IDR-1002 was shown to enhance monocyte chemotaxis towards chemokines CCL3 and CCL5. This enhancement correlated with the selective upregulation of CCR5 surface expression by peptide-treated monocytes. It was found that IDR-1002 enhancement of monocyte chemotaxis was fully dependent on CCR5 function. Furthermore, IDR-1002 enhanced chemokine-induced monocyte p38 MAPK phosphorylation in a CCR5-dependent fashion. Overall, these results indicate that peptide IDR-1002 can selectively influence monocyte recruitment by host chemokines through the regulation of chemokine receptors. PMID:26168734

  9. C-Terminal Engineering of CXCL12 and CCL5 Chemokines: Functional Characterization by Electrophysiological Recordings

    PubMed Central

    Petit-Hartlein, Isabelle; Sadir, Rabia; Revilloud, Jean; Caro, Lydia; Vivaudou, Michel; Fieschi, Franck; Moreau, Christophe; Vivès, Corinne

    2014-01-01

    Chemokines are chemotactic cytokines comprised of 70–100 amino acids. The chemokines CXCL12 and CCL5 are the endogenous ligands of the CXCR4 and CCR5 G protein-coupled receptors that are also HIV co-receptors. Biochemical, structural and functional studies of receptors are ligand-consuming and the cost of commercial chemokines hinders their use in such studies. Here, we describe methods for the expression, refolding, purification, and functional characterization of CXCL12 and CCL5 constructs incorporating C-terminal epitope tags. The model tags used were hexahistidines and Strep-Tag for affinity purification, and the double lanthanoid binding tag for fluorescence imaging and crystal structure resolution. The ability of modified and purified chemokines to bind and activate CXCR4 and CCR5 receptors was tested in Xenopus oocytes expressing the receptors, together with a Kir3 G-protein activated K+ channel that served as a reporter of receptor activation. Results demonstrate that tags greatly influence the biochemical properties of the recombinant chemokines. Besides, despite the absence of any evidence for CXCL12 or CCL5 C-terminus involvement in receptor binding and activation, we demonstrated unpredictable effects of tag insertion on the ligand apparent affinity and efficacy or on the ligand dissociation. These tagged chemokines should constitute useful tools for the selective purification of properly-folded chemokines receptors and the study of their native quaternary structures. PMID:24498095

  10. Chemokines as Therapeutic Targets to Improve Healing Efficiency of Chronic Wounds

    PubMed Central

    Satish, Latha

    2015-01-01

    Significance: Impaired wound healing leading to chronic wounds is an important clinical problem that needs immediate attention to develop new effective therapies. Members of the chemokine family seem to be attractive and amenable to stimulate the healing process in chronic wounds. Targeting specific chemokines and/or their receptors has the potential to modify chronic inflammation to acute inflammation, which will hasten the healing process. Recent Advances: Over the years, expression levels of various chemokines and their receptors have been identified as key players in the inflammatory phase of wound healing. In addition, they contribute to regulating other phases of wound healing making them key targets for novel therapies. Understanding the signaling pathways of these chemokines will provide valuable clues for modulating their function to enhance the wound healing process. Critical Issues: Inflammation, an important first-stage process in wound healing, is dysregulated in chronic wounds; emerging studies show that chemokines play a crucial role in regulating inflammation. The knowledge gained so far is still limited in understanding the enormous complexity of the chemokine network during inflammation not just in chronic wounds but also in acute (normal) wounds. A much better understanding of the individual chemokines will pave the way for better targets and therapies to improve the healing efficiency of chronic wounds. Future Directions: Effective understanding of the interaction of chemokines and their receptors during chronic wound healing would facilitate the design of novel therapeutic drugs. Development of chemokine-based drugs targeting specific inflammatory cells will be invaluable in the treatment of chronic wounds, in which inflammation plays a major role. PMID:26543679

  11. Role of Conserved Disulfide Bridges and Aromatic Residues in Extracellular Loop 2 of Chemokine Receptor CCR8 for Chemokine and Small Molecule Binding.

    PubMed

    Barington, Line; Rummel, Pia C; Lückmann, Michael; Pihl, Heidi; Larsen, Olav; Daugvilaite, Viktorija; Johnsen, Anders H; Frimurer, Thomas M; Karlshøj, Stefanie; Rosenkilde, Mette M

    2016-07-29

    Chemokine receptors play important roles in the immune system and are linked to several human diseases. The initial contact of chemokines with their receptors depends on highly specified extracellular receptor features. Here we investigate the importance of conserved extracellular disulfide bridges and aromatic residues in extracellular loop 2 (ECL-2) for ligand binding and activation in the chemokine receptor CCR8. We used inositol 1,4,5-trisphosphate accumulation and radioligand binding experiments to determine the impact of receptor mutagenesis on both chemokine and small molecule agonist and antagonist binding and action in CCR8. We find that the seven-transmembrane (TM) receptor conserved disulfide bridge (7TM bridge) linking transmembrane helix III (TMIII) and ECL-2 is crucial for chemokine and small molecule action, whereas the chemokine receptor conserved disulfide bridge between the N terminus and TMVII is needed only for chemokines. Furthermore, we find that two distinct aromatic residues in ECL-2, Tyr(184) (Cys + 1) and Tyr(187) (Cys + 4), are crucial for binding of the CC chemokines CCL1 (agonist) and MC148 (antagonist), respectively, but not for small molecule binding. Finally, using in silico modeling, we predict an aromatic cluster of interaction partners for Tyr(187) in TMIV (Phe(171)) and TMV (Trp(194)). We show in vitro that these residues are crucial for the binding and action of MC148, thus supporting their participation in an aromatic cluster with Tyr(187) This aromatic cluster appears to be present in a large number of CC chemokine receptors and thereby could play a more general role to be exploited in future drug development targeting these receptors. PMID:27226537

  12. Regulation of Aicda expression and AID activity.

    PubMed

    Zan, Hong; Casali, Paolo

    2013-03-01

    Activation-induced cytidine deaminase (AID) is expressed in a B cell differentiation stage-specific fashion and is essential for immunoglobulin (Ig) gene class switch DNA recombination (CSR) and somatic hypermutation (SHM). CSR and SHM play a central role in the maturation of antibody and autoantibody responses. AID displays a mutagenic activity by catalyzing targeted deamination of deoxycytidine (dC) residues in DNA resulting in dU:dG mismatches, which are processed into point-mutations in SHM or double-strand breaks (DSBs) in CSR. Although AID specifically targets the Ig gene loci (IgH, Igκ and Igλ), it can also home into a wide array of non-Ig genes in B-and non-B-cell backgrounds. Aberrant expression of AID is associated with multiple diseases such as allergy, inflammation, autoimmunity and cancer. In autoimmune systemic lupus erythematosus, dysregulated AID expression underpins increased CSR, SHM and autoantibody production. As a potent mutator, AID is under stringent transcriptional, post-transcriptional and post-translational regulation. AID is also regulated in its targeting and enzymatic function. In resting naïve or memory B cells, AID transcripts and protein are undetectable. These, however, are readily and significantly up-regulated in B cells induced to undergo CSR and/or SHM. Transcription factors, such as HoxC4 and NF-κB, which are up-regulated in a B cell lineage-and/or differentiation stage-specific manner, regulate the induction of AID. HoxC4 induces AID expression by directly binding to the AID gene promoter through an evolutionarily conserved 5'-ATTT-3' motif. HoxC4 is induced by the same stimuli that induce AID and CSR. It is further up-regulated by estrogen through three estrogen responsive elements in its promoter region. The targeting of AID to switch (S) regions is mediated by 14-3-3 adaptor proteins, which specifically bind to 5'-AGCT-3' repeats that are exist at high frequency in S region cores. Like HoxC4, 14-3-3 adaptors are induced

  13. NF-κB Repressing Factor Inhibits Chemokine Synthesis by Peripheral Blood Mononuclear Cells and Alveolar Macrophages in Active Pulmonary Tuberculosis

    PubMed Central

    Huang, Kuo-Hsiung; Wang, Chun-Hua; Lee, Kang-Yun; Lin, Shu-Min

    2013-01-01

    NF-κB repressing factor (NRF) is a transcriptional silencer implicated in the basal silencing of specific NF-κB targeting genes, including iNOS, IFN-β and IL-8/CXCL8. IP-10/CXCL10 and IL-8/CXCL8 are involved in neutrophil and lymphocyte recruitment against M. tuberculosis (MTb) and disease progression of pulmonary tuberculosis (TB). Alveolar macrophages (AM) and peripheral blood mononuclear cells (PBMC) were used to study the regulatory role of NRF in pulmonary TB. AM and PBMC were purified from 19 TB patients and 15 normal subjects. To study the underlying mechanism, PBMC were exposed to heated TB bacilli. The regulation role of NRF in IP-10/CXCL10 and IL-8/CXCL8 was determined by NRF knock-down or over-expression. NRF binding capabilities in promoter sites were measured by chromatin immunoprecipitation (ChIP) assay. The levels of IP-10/CXCL10, IL-8/CXCL8 and NRF were significantly higher in AM and PBMC in patients with active TB. NRF played an inhibitory role in IP-10/CXCL10 and IL-8/CXCL8 inductions. We delineate the role of NRF in pulmonary TB, which inhibits the expressions of IP-10/CXCL10 and IL-8/CXCL8 in AM and PBMC of patients with high bacterial load. NRF may serve as an endogenous repressor to prevent robust increase in IP-10/CXCL10 and IL-8/CXCL8 when TB bacterial load is high. PMID:24223729

  14. Proinflammatory chemokines during Candida albicans keratitis.

    PubMed

    Yuan, Xiaoyong; Hua, Xia; Wilhelmus, Kirk R

    2010-03-01

    Chemotactic cytokines mediate the recruitment of leukocytes into infected tissues. This study investigated the profile of chemokines during experimental Candida albicans keratitis and determined the effects of chemokine inhibition on leukocyte infiltration and fungal growth during murine keratomycosis. Scarified corneas of BALB/c mice were topically inoculated with C. albicans and monitored daily over one week for fungal keratitis. After a gene microarray for murine chemokines compared infected corneas to controls, real-time reverse transcription polymerase chain reaction (RT-PCR) and immunostaining assessed chemokine expression in infected and mock-inoculated corneas. An anti-chemokine antibody was then administered subconjunctivally and evaluated for effects on clinical severity, corneal inflammation, fungal recovery, and cytokine expression. Of 33 chemokine genes examined by microarray, 6 CC chemokines and 6 CXC chemokines were significantly (P<0.05) upregulated more than two-fold. Chemokine (CC-motif) ligand 3 (CCL3) was upregulated 108-fold (P=0.03) by real-time RT-PCR within one day after fungal inoculation and remained increased 28-fold (P=0.02) at one week, and its in situ expression increased in the epithelium and stroma of infected corneas. Compared to the control antibody-treated group, eyes treated with anti-CCL3 antibody showed reduced clinical severity (P<0.05), less corneal neovascularization (P=0.02), and fewer inflammatory cells infiltrating corneal tissue, but the amount of recoverable fungi was not significantly (P=0.4) affected. Anti-CCL3 treatment significantly (P=0.01) reduced the expression of tumor necrosis factor and interleukin-1beta in infected corneas. These results indicate that chemokines, especially the CC chemokine CCL3, play important roles in the acute inflammatory response to C. albicans corneal infection. PMID:20005222

  15. Enhancement of Chemokine Function as an Immunomodulatory Strategy Employed by Human Herpesviruses

    PubMed Central

    Viejo-Borbolla, Abel; Martinez-Martín, Nadia; Nel, Hendrik J.; Rueda, Patricia; Martín, Rocío; Blanco, Soledad; Arenzana-Seisdedos, Fernando; Thelen, Marcus; Fallon, Padraic G.; Alcamí, Antonio

    2012-01-01

    Herpes simplex virus (HSV) types 1 and 2 are highly prevalent human neurotropic pathogens that cause a variety of diseases, including lethal encephalitis. The relationship between HSV and the host immune system is one of the main determinants of the infection outcome. Chemokines play relevant roles in antiviral response and immunopathology, but the modulation of chemokine function by HSV is not well understood. We have addressed the modulation of chemokine function mediated by HSV. By using surface plasmon resonance and crosslinking assays we show that secreted glycoprotein G (SgG) from both HSV-1 and HSV-2 binds chemokines with high affinity. Chemokine binding activity was also observed in the supernatant of HSV-2 infected cells and in the plasma membrane of cells infected with HSV-1 wild type but not with a gG deficient HSV-1 mutant. Cell-binding and competition experiments indicate that the interaction takes place through the glycosaminoglycan-binding domain of the chemokine. The functional relevance of the interaction was determined both in vitro, by performing transwell assays, time-lapse microscopy, and signal transduction experiments; and in vivo, using the air pouch model of inflammation. Interestingly, and in contrast to what has been observed for previously described viral chemokine binding proteins, HSV SgGs do not inhibit chemokine function. On the contrary, HSV SgGs enhance chemotaxis both in vitro and in vivo through increasing directionality, potency and receptor signaling. This is the first report, to our knowledge, of a viral chemokine binding protein from a human pathogen that increases chemokine function and points towards a previously undescribed strategy of immune modulation mediated by viruses. PMID:22319442

  16. Chemokine gene expression in the brains of mice with lymphocytic choriomeningitis.

    PubMed Central

    Asensio, V C; Campbell, I L

    1997-01-01

    Chemokines are pivotal in the trafficking of leukocytes. In the present study, we examined the expression of multiple chemokine genes during the course of lymphocytic choriomeningitis (LCM) in mice. In noninfected mice, no detectable chemokine gene expression was found in the brain; however, by day 3 postinfection, the induction of a number of chemokine mRNAs was observed as follows (in order from the greatest to the least): cytokine responsive gene-2 or interferon-inducible 10-kDa protein (Crg-2/IP-10), RANTES, monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1 (MIP-1beta), and MCP-3. At day 6 postinfection, the expression of these chemokine mRNAs was increased, and low expression of lymphotactin, C10, MIP-2, and MIP-1alpha mRNAs was detectable. Transcript for T-cell activation-3 was not detectable in the brain at any time following LCM virus (LCMV) infection. With some exceptions, a pattern of chemokine gene expression similar to that in the brain was observed in the peripheral organs of LCMV-infected mice. Mice that lacked expression of gamma interferon developed LCM and had a qualitatively similar but quantitatively reduced cerebral chemokine gene expression profile. In contrast, little or no chemokine gene expression was detectable in the brains of LCMV-infected athymic mice which did not develop LCM. Expression of Crg-2/IP-10 RNA was localized to predominantly resident cells of the central nervous system (CNS) and overlapped with sites of viral infection and immune cell infiltration. These findings demonstrate the expression of a number of chemokine genes in the brains of mice infected with LCMV. The pattern of chemokine gene expression in LCM may profoundly influence the characteristic phenotype and response of leukocytes in the brain and contribute to the immunopathogenesis of this fatal CNS infection. PMID:9311871

  17. Comparative study of CXC chemokines modulation in brown trout (Salmo trutta) following infection with a bacterial or viral pathogen.

    PubMed

    Gorgoglione, Bartolomeo; Zahran, Eman; Taylor, Nick G H; Feist, Stephen W; Zou, Jun; Secombes, Christopher J

    2016-03-01

    Chemokine modulation in response to pathogens still needs to be fully characterised in fish, in view of the recently described novel chemokines present. This paper reports the first comparative study of CXC chemokine genes transcription in salmonids (brown trout), with a particular focus on the fish specific CXC chemokines (CXCL_F). Adopting new primer sets, optimised to specifically target mRNA, a RT-qPCR gene screening was carried out. Constitutive gene expression was assessed first in six tissues from SPF brown trout. Transcription modulation was next investigated in kidney and spleen during septicaemic infection induced by a RNA virus (Viral Haemorrhagic Septicaemia virus, genotype Ia) or by a Gram negative bacterium (Yersinia ruckeri, ser. O1/biot. 2). From each target organ specific pathogen burden, measured detecting VHSV-glycoprotein or Y. ruckeri 16S rRNA, and IFN-γ gene expression were analysed for their correlation to chemokine transcription. Both pathogens modulated CXC chemokine gene transcript levels, with marked up-regulation seen in some cases, and with both temporal and tissue specific effects apparent. For example, Y. ruckeri strongly induced chemokine transcription in spleen within 24h, whilst VHS generally induced the largest increases at 3d.p.i. in both tissues. This study gives clues to the role of the novel CXC chemokines, in comparison to the other known CXC chemokines in salmonids. PMID:26866873

  18. Identification of Chemokines Associated with the Recruitment of Decidual Leukocytes in Human Labour: Potential Novel Targets for Preterm Labour

    PubMed Central

    Hamilton, Sarah A.; Tower, Clare L.; Jones, Rebecca L.

    2013-01-01

    study provides compelling evidence that chemokines regulate decidual leukocyte recruitment during labour. The 6 chemokines identified represent potential novel therapeutic targets to block PTL. PMID:23451115

  19. The Maternal Cytokine and Chemokine Profile of Naturally Conceived Gestations Is Mainly Preserved during In Vitro Fertilization and Egg Donation Pregnancies.

    PubMed

    Martínez-Varea, Alicia; Pellicer, Begoña; Serra, Vicente; Hervás-Marín, David; Martínez-Romero, Alicia; Bellver, José; Perales-Marín, Alfredo; Pellicer, Antonio

    2015-01-01

    This prospective longitudinal study aimed at comparing maternal immune response among naturally conceived (NC; n = 25), in vitro fertilization (IVF; n = 25), and egg donation (ED; n = 25) pregnancies. The main outcome measures were, firstly, to follow up plasma levels of interleukin (IL) 1 beta, IL2, IL4, IL5, IL6, IL8, IL10, IL17, interferon gamma, tumor necrosis factor-alpha (TNFα), transforming growth factor-beta (TGFβ), regulated upon activation normal T-cell expressed and secreted (RANTES), stromal cell-derived factor 1 alpha (SDF1α), and decidual granulocyte-macrophage colony-stimulating factor (GM-CSF) during the three trimesters of pregnancy during the three trimesters of pregnancy; secondly, to evaluate if the cytokine and chemokine pattern of ED pregnant women differs from that of those with autologous oocytes and, thirdly, to assess if women with preeclampsia show different cytokine and chemokine profile throughout pregnancy versus women with uneventful pregnancies. Pregnant women in the three study groups displayed similar cytokine and chemokine pattern throughout pregnancy. The levels of all quantified cytokines and chemokines, except RANTES, TNFα, IL8, TGFβ, and SDF1α, rose in the second trimester compared with the first, and these higher values remained in the third trimester. ED pregnancies showed lower SDF1α levels in the third trimester compared with NC and IVF pregnancies. Patients who developed preeclampsia displayed higher SDF1α plasma levels in the third trimester. PMID:26346343

  20. Chemokines, macrophage inflammatory protein-2 and stromal cell-derived factor-1α, suppress amyloid β-induced neurotoxicity

    PubMed Central

    Raman, Dayanidhi; Milatovic, Snjezana-Zaja; Milatovic, Dejan; Splittgerber, Ryan; Fan, Guo-Huang; Richmond, Ann

    2011-01-01

    Alzheimer’s disease (AD) is characterized by a progressive cognitive decline and accumulation of neurotoxic oligomeric peptides amyloid-β (Aβ). Although the molecular events are not entirely known, it has become evident that inflammation, environmental and other risk factors may play a causal, disruptive and/or protective role in the development of AD. The present study investigated the ability of the chemokines, macrophage inflammatory protein-2 (MIP-2) and stromal cell-derived factor-1α (SDF-1α), the respective ligands for chemokine receptors CXCR2 and CXCR4, to suppress Aβ-induced neurotoxicity in vitro and in vivo. Pretreatment with MIP-2 or SDF-1α significantly protected neurons from Aβ-induced dendritic regression and apoptosis in vitro through activation of Akt, ERK1/2 and maintenance of metalloproteinase ADAM17 especially with SDF-1α. Intra-cerebroventricular (ICV) injection of Aβ led to reduction in dendritic length and spine density of pyramidal neurons in the CA1 area of the hippocampus and increased oxidative damage 24 h following the exposure. The Aβ-induced morphometric changes of neurons and increase in biomarkers of oxidative damage, F2-isoprostanes, was significantly inhibited by pretreatment with the chemokines MIP-2 or SDF-1α. Additionally, MIP-2 or SDF-1α was able to suppress the aberrant mislocalization of p21-activated kinase (PAK), one of the proteins involved in the maintenance of dendritic spines. Furthermore, MIP-2 also protected neurons against Aβ neurotoxicity in CXCR2−/− mice, potentially through observed up regulation of CXCR1 mRNA. Understanding the neuroprotective potential of chemokines is crucial in defining the role for their employment during the early stages of neurodegeneration. PMID:21704645

  1. Endoglin regulates cyclooxygenase-2 expression and activity.

    PubMed

    Jerkic, Mirjana; Rivas-Elena, Juan V; Santibanez, Juan F; Prieto, Marta; Rodríguez-Barbero, Alicia; Perez-Barriocanal, Fernando; Pericacho, Miguel; Arévalo, Miguel; Vary, Calvin P H; Letarte, Michelle; Bernabeu, Carmelo; López-Novoa, Jose M

    2006-08-01

    The endoglin heterozygous (Eng(+/-)) mouse, which serves as a model of hereditary hemorrhagic telangiectasia (HHT), was shown to express reduced levels of endothelial NO synthase (eNOS) with impaired activity. Because of intricate changes in vasomotor function in the Eng(+/-) mice and the potential interactions between the NO- and prostaglandin-producing pathways, we assessed the expression and function of cyclooxygenase (COX) isoforms. A specific upregulation of COX-2 in the vascular endothelium and increased urinary excretion of prostaglandin E(2) were observed in the Eng(+/-) mice. Specific COX-2 inhibition with parecoxib transiently increased arterial pressure in Eng(+/-) but not in Eng(+/+) mice. Transfection of endoglin in L6E9 myoblasts, shown previously to stimulate eNOS expression, led to downregulation of COX-2 with no change in COX-1. In addition, COX-2 promoter activity and protein levels were inversely correlated with endoglin levels, in doxycyclin-inducible endothelial cells. Chronic NO synthesis inhibition with N(omega)-nitro-l-arginine methyl ester induced a marked increase in COX-2 only in the normal Eng(+/+) mice. N(omega)-nitro-l-arginine methyl ester also increased COX-2 expression and promoter activity in doxycyclin-inducible endoglin expressing endothelial cells, but not in control cells. The level of COX-2 expression following transforming growth factor-beta1 treatment was less in endoglin than in mock transfected L6E9 myoblasts and was higher in human endothelial cells silenced for endoglin expression. Our results indicate that endoglin is involved in the regulation of COX-2 activity. Furthermore, reduced endoglin levels and associated impaired NO production may be responsible, at least in part, for augmented COX-2 expression and activity in the Eng(+/-) mice. PMID:16840721

  2. Structural Basis for Plexin Activation and Regulation.

    PubMed

    Kong, Youxin; Janssen, Bert J C; Malinauskas, Tomas; Vangoor, Vamshidhar R; Coles, Charlotte H; Kaufmann, Rainer; Ni, Tao; Gilbert, Robert J C; Padilla-Parra, Sergi; Pasterkamp, R Jeroen; Jones, E Yvonne

    2016-08-01

    Class A plexins (PlxnAs) act as semaphorin receptors and control diverse aspects of nervous system development and plasticity, ranging from axon guidance and neuron migration to synaptic organization. PlxnA signaling requires cytoplasmic domain dimerization, but extracellular regulation and activation mechanisms remain unclear. Here we present crystal structures of PlxnA (PlxnA1, PlxnA2, and PlxnA4) full ectodomains. Domains 1-9 form a ring-like conformation from which the C-terminal domain 10 points away. All our PlxnA ectodomain structures show autoinhibitory, intermolecular "head-to-stalk" (domain 1 to domain 4-5) interactions, which are confirmed by biophysical assays, live cell fluorescence microscopy, and cell-based and neuronal growth cone collapse assays. This work reveals a 2-fold role of the PlxnA ectodomains: imposing a pre-signaling autoinhibitory separation for the cytoplasmic domains via intermolecular head-to-stalk interactions and supporting dimerization-based PlxnA activation upon ligand binding. More generally, our data identify a novel molecular mechanism for preventing premature activation of axon guidance receptors. PMID:27397516

  3. Deficiency for the Chemokine Monocyte Chemoattractant Protein-1 Aggravates Tubular Damage after Renal Ischemia/Reperfusion Injury

    PubMed Central

    Stroo, Ingrid; Claessen, Nike; Teske, Gwendoline J. D.; Butter, Loes M.; Florquin, Sandrine; Leemans, Jaklien C.

    2015-01-01

    Temporal expression of chemokines is a crucial factor in the regulation of renal ischemia/reperfusion (I/R) injury and repair. Beside their role in the migration and activation of inflammatory cells to sites of injury, chemokines are also involved in other processes such as angiogenesis, development and migration of stem cells. In the present study we investigated the role of the chemokine MCP-1 (monocyte chemoattractant protein-1 or CCL2), the main chemoattractant for monocytes, during renal I/R injury. MCP-1 expression peaks several days after inducing renal I/R injury coinciding with macrophage accumulation. However, MCP-1 deficient mice had a significant decreased survival and increased renal damage within the first two days, i.e. the acute inflammatory response, after renal I/R injury with no evidence of altered macrophage accumulation. Kidneys and primary tubular epithelial cells from MCP-1 deficient mice showed increased apoptosis after ischemia. Taken together, MCP-1 protects the kidney during the acute inflammatory response following renal I/R injury. PMID:25875776

  4. Cytokines and chemokines as biomarkers of ethanol-induced neuroinflammation and anxiety-related behavior: role of TLR4 and TLR2.

    PubMed

    Pascual, María; Baliño, Pablo; Aragón, Carlos M G; Guerri, Consuelo

    2015-02-01

    Recent evidence supports the influence of neuroimmune system activation on behavior. We have demonstrated that ethanol activates the innate immune system by stimulating toll-like receptor 4 (TLR4) signaling in glial cells, which triggers the release of inflammatory mediators and causes neuroinflammation. The present study aimed to evaluate whether the ethanol-induced up-regulation of cytokines and chemokines is associated with anxiety-related behavior, 24 h after ethanol removal, and if TLR4 or TLR2 is involved in these effects. We used WT, TLR4-KO and TLR2-KO mice treated with alcohol for 5 months to show that chronic ethanol consumption increases the levels of cytokines (IL-1β, IL-17, TNF-α) and chemokines (MCP-1, MIP-1α, CX3CL1) in the striatum and serum (MCP-1, MIP-1α, CX3CL1) of WT mice. Alcohol deprivation for 24 h induces IFN-γ levels in the striatum and maintains high levels of some cytokines (IL-1β, IL-17) and chemokines (MIP-1α, CX3CL1) in this brain region. The latter events were associated with an increase in anxiogenic-related behavior, as evaluated by the dark and light box and the elevated plus maze tests. Notably, mice lacking TLR4 or TLR2 receptors are largely protected against ethanol-induced cytokine and chemokine release, and behavioral associated effects during alcohol abstinence. These data support the role of TLR4 and TLR2 responses in neuroinflammation and in anxiogenic-related behavior effects during ethanol deprivation, and also provide evidence that chemokines and cytokines can be biomarkers of ethanol-induced neuroimmune response. PMID:25446779

  5. Langerhans cell histiocytosis: a cytokine/chemokine-mediated disorder?

    PubMed

    Garabedian, Lara; Struyf, Sofie; Opdenakker, Ghislain; Sozzani, Silvano; Van Damme, Jo; Laureys, Geneviève

    2011-09-01

    Langerhans cell histiocytosis (LCH) is a rare disorder characterized by an abnormal accumulation and/or proliferation of cells with a Langerhans cell phenotype. Although no clear cause of LCH has been identified, it has been postulated that LCH might be the consequence of an immune dysregulation, causing Langerhans cells to migrate to and accumulate at various sites. Production of cytokines and chemokines is a central feature of immune regulation. Cytokines are abundantly present within LCH lesions. We review here the potential role of cytokines and chemokines in the pathogenesis of LCH. The type, distribution, and number of different cytokines released within lesions can provide clues to the possible aetiology of LCH and, ultimately, might offer therapeutic possibilities using recombinant cytokines or antagonists for this disorder. PMID:22001902

  6. The chemokine receptor CCX-CKR mediates effective scavenging of CCL19 in vitro.

    PubMed

    Comerford, Iain; Milasta, Sandra; Morrow, Valerie; Milligan, Graeme; Nibbs, Robert

    2006-07-01

    The chemokines CCL19, CCL21 and CCL25, by signalling through the receptors CCR7 or CCR9, play critical roles in leukocyte homing. They also bind another heptahelical surface protein, CCX-CKR. CCX-CKR cannot couple to typical chemokine receptor signalling pathways or mediate chemotaxis, and its function remains unclear. We have proposed that it controls chemokine bioavailability. Here, using transfected HEK293 cells, we have shown that both CCX-CKR and CCR7 mediate rapid CCL19 internalisation upon initial chemokine exposure. However, internalised CCL19 was more efficiently retained and degraded after uptake via CCX-CKR. More importantly, CCR7 rapidly became refractory for CCL19 uptake, but the sequestration activity of CCX-CKR was enhanced. These properties endowed CCX-CKR with an impressive ability to mediate progressive sequestration and degradation of large quantities of CCL19, and conversely, prevented CCR7-expressing cells from extensively altering their chemokine environment. These differences may be linked to the routes of endocytosis used by these receptors. CCX-CKR, unlike CCR7, was not critically dependent on beta-arrestins or clathrin-coated pits. However, over-expression of caveolin-1, which stabilises caveolae, blocked CCL19 uptake by CCX-CKR while having no impact on other chemokine receptors, including CCR7. These data predict that CCX-CKR scavenges extracellular chemokines in vivo to modify responses through CCR7. PMID:16791897

  7. Use of Resonance Energy Transfer Techniques for In Vivo Detection of Chemokine Receptor Oligomerization.

    PubMed

    Martínez-Muñoz, Laura; Rodríguez-Frade, José Miguel; Mellado, Mario

    2016-01-01

    Since the first reports on chemokine function, much information has been generated on the implications of these molecules in numerous physiological and pathological processes, as well as on the signaling events activated through their binding to receptors. As is the case for other G protein-coupled receptors, chemokine receptors are not isolated entities that are activated following ligand binding; rather, they are found as dimers and/or higher order oligomers at the cell surface, even in the absence of ligands. These complexes form platforms that can be modified by receptor expression and ligand levels, indicating that they are dynamic structures. The analysis of the conformations adopted by these receptors at the membrane and their dynamics is thus crucial for a complete understanding of the function of the chemokines. We focus here on the methodology insights of new techniques, such as those based on resonance energy transfer for the analysis of chemokine receptor conformations in living cells. PMID:27271913

  8. Substance P primes lipoteichoic acid- and Pam3CysSerLys4-mediated activation of human mast cells by up-regulating Toll-like receptor 2.

    PubMed

    Tancowny, Brian P; Karpov, Victor; Schleimer, Robert P; Kulka, Marianna

    2010-10-01

    Substance P (SP) is a neuropeptide with neuroimmunoregulatory activity that may play a role in susceptibility to infection. Human mast cells, which are important in innate immune responses, were analysed for their responses to pathogen-associated molecules via Toll-like receptors (TLRs) in the presence of SP. Human cultured mast cells (LAD2) were activated by SP and TLR ligands including lipopolysaccharide (LPS), Pam3CysSerLys4 (Pam3CSK4) and lipoteichoic acid (LTA), and mast cell leukotriene and chemokine production was assessed by enzyme-linked immunosorbent assay (ELISA) and gene expression by quantitative PCR (qPCR). Mast cell degranulation was determined using a β-hexosaminidase (β-hex) assay. SP treatment of LAD2 up-regulated mRNA for TLR2, TLR4, TLR8 and TLR9 while anti-immunoglobulin E (IgE) stimulation up-regulated expression of TLR4 only. Flow cytometry and western blot confirmed up-regulation of TLR2 and TLR8. Pretreatment of LAD2 with SP followed by stimulation with Pam3CSK4 or LTA increased production of leukotriene C4 (LTC(4) ) and interleukin (IL)-8 compared with treatment with Pam3CSK4 or LTA alone (>2-fold; P<0·01). SP alone activated 5-lipoxygenase (5-LO) nuclear translocation but also augmented Pam3CSK4 and LTA-mediated 5-LO translocation. Pam3CSK4, LPS and LTA did not induce LAD2 degranulation. SP primed LTA and Pam3CSK4-mediated activation of JNK, p38 and extracellular-signal-regulated kinase (ERK) and activated the nuclear translocation of c-Jun, nuclear factor (NF)-κB, activating transcription factor 2 (ATF-2) and cyclic-AMP-responsive element binding protein (CREB) transcription factors. Pretreatment with SP followed by LTA stimulation synergistically induced production of chemokine (C-X-C motif) ligand 8 (CXCL8)/IL-8, chemokine (C-C motif) ligand 2 (CCL2)/monocyte chemotactic protein 1 (MCP-1), tumour necrosis factor (TNF) and IL-6 protein. SP primes TLR2-mediated activation of human mast cells by up-regulating TLR expression and

  9. Cyfip1 Regulates Presynaptic Activity during Development

    PubMed Central

    Hsiao, Kuangfu; Harony-Nicolas, Hala; Buxbaum, Joseph D.

    2016-01-01

    Copy number variations encompassing the gene encoding Cyfip1 have been associated with a variety of human diseases, including autism and schizophrenia. Here we show that juvenile mice hemizygous for Cyfip1 have altered presynaptic function, enhanced protein translation, and increased levels of F-actin. In developing hippocampus, reduced Cyfip1 levels serve to decrease paired pulse facilitation and increase miniature EPSC frequency without a change in amplitude. Higher-resolution examination shows these changes to be caused primarily by an increase in presynaptic terminal size and enhanced vesicle release probability. Short hairpin-mediated knockdown of Cyfip1 coupled with expression of mutant Cyfip1 proteins indicates that the presynaptic alterations are caused by dysregulation of the WAVE regulatory complex. Such dysregulation occurs downstream of Rac1 as acute exposure to Rac1 inhibitors rescues presynaptic responses in culture and in hippocampal slices. The data serve to highlight an early and essential role for Cyfip1 in the generation of normally functioning synapses and suggest a means by which changes in Cyfip1 levels could impact the generation of neural networks and contribute to abnormal and maladaptive behaviors. SIGNIFICANCE STATEMENT Several developmental brain disorders have been associated with gene duplications and deletions that serve to increase or decrease levels of encoded proteins. Cyfip1 is one such protein, but the role it plays in brain development is poorly understood. We asked whether decreased Cyfip1 levels altered the function of developing synapses. The data show that synapses with reduced Cyfip1 are larger and release neurotransmitter more rapidly. These effects are due to Cyfip1's role in actin polymerization and are reversed by expression of a Cyfip1 mutant protein retaining actin regulatory function or by inhibiting Rac1. Thus, Cyfip1 has a more prominent early role regulating presynaptic activity during a stage of development when

  10. Activity and Regulation of Archaeal DNA Alkyltransferase

    PubMed Central

    Perugino, Giuseppe; Vettone, Antonella; Illiano, Giuseppina; Valenti, Anna; Ferrara, Maria C.; Rossi, Mosè; Ciaramella, Maria

    2012-01-01

    Agents that form methylation adducts in DNA are highly mutagenic and carcinogenic, and organisms have evolved specialized cellular pathways devoted to their repair, including DNA alkyltransferases. These are proteins conserved in eucarya, bacteria and archaea, acting by a unique reaction mechanism, which leads to direct repair of DNA alkylation damage and irreversible protein alkylation. The alkylated form of DNA alkyltransferases is inactive, and in eukaryotes, it is rapidly directed to degradation. We report here in vitro and in vivo studies on the DNA alkyltransferase from the thermophilic archaeon Sulfolobus solfataricus (SsOGT). The development of a novel, simple, and sensitive fluorescence-based assay allowed a careful characterization of the SsOGT biochemical and DNA binding activities. In addition, transcriptional and post-translational regulation of SsOGT by DNA damage was studied. We show that although the gene transcription is induced by alkylating agent treatment, the protein is degraded in vivo by an alkylation-dependent mechanism. These experiments suggest a striking conservation, from archaea to humans, of this important pathway safeguarding genome stability. PMID:22167184

  11. 76 FR 12364 - Agency Information Collection Activities: Bonded Warehouse Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-07

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Bonded Warehouse... Bonded Warehouse Regulations. This request for comment is being made pursuant to the Paperwork Reduction... concerning the following information collection: Title: Bonded Warehouse Regulations. OMB Number:...

  12. Chemokines, macrophage inflammatory protein-2 and stromal cell-derived factor-1{alpha}, suppress amyloid {beta}-induced neurotoxicity

    SciTech Connect

    Raman, Dayanidhi; Milatovic, Snjezana-Zaja; Milatovic, Dejan; Fan, Guo-Huang; Richmond, Ann

    2011-11-15

    Alzheimer's disease (AD) is characterized by a progressive cognitive decline and accumulation of neurotoxic oligomeric peptides amyloid-{beta} (A{beta}). Although the molecular events are not entirely known, it has become evident that inflammation, environmental and other risk factors may play a causal, disruptive and/or protective role in the development of AD. The present study investigated the ability of the chemokines, macrophage inflammatory protein-2 (MIP-2) and stromal cell-derived factor-1{alpha} (SDF-1{alpha}), the respective ligands for chemokine receptors CXCR2 and CXCR4, to suppress A{beta}-induced neurotoxicity in vitro and in vivo. Pretreatment with MIP-2 or SDF-1{alpha} significantly protected neurons from A{beta}-induced dendritic regression and apoptosis in vitro through activation of Akt, ERK1/2 and maintenance of metalloproteinase ADAM17 especially with SDF-1{alpha}. Intra-cerebroventricular (ICV) injection of A{beta} led to reduction in dendritic length and spine density of pyramidal neurons in the CA1 area of the hippocampus and increased oxidative damage 24 h following the exposure. The A{beta}-induced morphometric changes of neurons and increase in biomarkers of oxidative damage, F{sub 2}-isoprostanes, were significantly inhibited by pretreatment with the chemokines MIP-2 or SDF-1{alpha}. Additionally, MIP-2 or SDF-1{alpha} was able to suppress the aberrant mislocalization of p21-activated kinase (PAK), one of the proteins involved in the maintenance of dendritic spines. Furthermore, MIP-2 also protected neurons against A{beta} neurotoxicity in CXCR2-/- mice, potentially through observed up regulation of CXCR1 mRNA. Understanding the neuroprotective potential of chemokines is crucial in defining the role for their employment during the early stages of neurodegeneration. -- Research highlights: Black-Right-Pointing-Pointer Neuroprotective ability of the chemokines MIP2 and CXCL12 against A{beta} toxicity. Black-Right-Pointing-Pointer MIP-2 or

  13. Vesicular Trafficking and Signaling for Cytokine and Chemokine Secretion in Mast Cells

    PubMed Central

    Blank, Ulrich; Madera-Salcedo, Iris Karina; Danelli, Luca; Claver, Julien; Tiwari, Neeraj; Sánchez-Miranda, Elizabeth; Vázquez-Victorio, Genaro; Ramírez-Valadez, Karla Alina; Macias-Silva, Marina; González-Espinosa, Claudia

    2014-01-01

    Upon activation mast cells (MCs) secrete numerous inflammatory compounds stored in their cytoplasmic secretory granules by a process called anaphylactic degranulation, which is responsible for type I hypersensitivity responses. Prestored mediators include histamine and MC proteases but also some cytokines and growth factors making them available within minutes for a maximal biological effect. Degranulation is followed by the de novo synthesis of lipid mediators such as prostaglandins and leukotrienes as well as a vast array of cytokines, chemokines, and growth factors, which are responsible for late phase inflammatory responses. While lipid mediators diffuse freely out of the cell through lipid bilayers, both anaphylactic degranulation and secretion of cytokines, chemokines, and growth factors depends on highly regulated vesicular trafficking steps that occur along the secretory pathway starting with the translocation of proteins to the endoplasmic reticulum. Vesicular trafficking in MCs also intersects with endocytic routes, notably to form specialized cytoplasmic granules called secretory lysosomes. Some of the mediators like histamine reach granules via specific vesicular monoamine transporters directly from the cytoplasm. In this review, we try to summarize the available data on granule biogenesis and signaling events that coordinate the complex steps that lead to the release of the inflammatory mediators from the various vesicular carriers in MCs. PMID:25295038

  14. The chemokine receptor CCR7 promotes mammary tumorigenesis through amplification of stem-like cells.

    PubMed

    Boyle, S T; Ingman, W V; Poltavets, V; Faulkner, J W; Whitfield, R J; McColl, S R; Kochetkova, M

    2016-01-01

    The chemokine receptor CCR7 is widely implicated in breast cancer pathobiology. Although recent reports correlated high CCR7 levels with more advanced tumor grade and poor prognosis, limited in vivo data are available regarding its specific function in mammary gland neoplasia and the underlying mechanisms involved. To address these questions we generated a bigenic mouse model of breast cancer combined with CCR7 deletion, which revealed that CCR7 ablation results in a considerable delay in tumor onset as well as significantly reduced tumor burden. Importantly, CCR7 was found to exert its function by regulating mammary cancer stem-like cells in both murine and human tumors. In vivo experiments showed that loss of CCR7 activity either through deletion or pharmacological antagonism significantly decreased functional pools of stem-like cells in mouse primary mammary tumors, providing a mechanistic explanation for the tumor-promoting role of this chemokine receptor. These data characterize the oncogenic properties of CCR7 in mammary epithelial neoplasia and point to a new route for therapeutic intervention to target evasive cancer stem cells. PMID:25772241

  15. Involvement of the chemokine-like receptor GPR33 in innate immunity⋆

    PubMed Central

    Bohnekamp, Jens; Böselt, Iris; Saalbach, Anja; Tönjes, Anke; Kovacs, Peter; Biebermann, Heike; Manvelyan, Hovhannes M.; Polte, Tobias; Gasperikova, Daniela; Lkhagvasuren, Sodnomtsogt; Baier, Leslie; Stumvoll, Michael; Römpler, Holger; Schöneberg, Torsten

    2010-01-01

    Chemokine receptors control leukocyte chemotaxis and cell-cell communication but have also been associated with pathogen entry. GPR33, an orphan member of the chemokine-like receptor family, is a pseudogene in most humans. After the appearance of GPR33 in first mammalian genomes, this receptor underwent independent pseudogenization in humans, other hominoids and some rodent species. It was speculated that a likely cause of GPR33 inactivation was its interplay with a rodent–hominoid-specific pathogen. Simultaneous pseudogenization in several unrelated species within the last 1 million years (myr) caused by neutral drift appears to be very unlikely suggesting selection on the GPR33 null-allele. Although there are no signatures of recent selection on human GPR33 we found a significant increase in the pseudogene allele frequency in European populations when compared with African and Asian populations. Because its role in the immune system was still hypothetical expression analysis revealed that GPR33 is highly expressed in dendritic cells (DC). Murine GPR33 expression is regulated by the activity of toll-like receptors (TLR) and AP-1/NF-κB signaling pathways in cell culture and in vivo. Our data indicate an important role of GPR33 function in innate immunity which became dispensable during human evolution most likely due to past or balancing selection. PMID:20399748

  16. Pancreatic adenocarcinoma upregulated factor promotes metastasis by regulating TLR/CXCR4 activation

    PubMed Central

    Park, HD; Lee, Y; Oh, YK; Jung, JG; Park, YW; Myung, K; Kim, K-H; Koh, SS; Lim, D-S

    2012-01-01

    Pancreatic adenocarcinoma upregulated factor (PAUF) is overproduced in certain types of cancer. However, little is known of the tumorigenic function of PAUF. In this study, we report the X-ray crystal structure of PAUF and reveal that PAUF is a mammalian lectin normally found in plant lectins. We also identify PAUF as an endogenous ligand of Toll-like receptor 2 (TLR2) and TLR4 by screening extracellular domain receptor pools.We further confirmed the specificity of the PAUF–TLR2 interaction. PAUF induces extracellular signal-regulated kinase (ERK) phosphorylation and activates the IKK-β-mediated TPL2/MEK/ERK signaling pathway through TLR2. In agreement with the result of TLR2-mediated ERK activation by PAUF, PAUF induces increased expression of the protumorigenic cytokines RANTES and MIF in THP-1 cells. However, PAUF does not fully activate Iκ-B-α signaling pathways in THP-1 cells, and fails to translocate the p65 subunit of the nuclear factor-κB (NF-κB) complex into the nucleus, resulting in no NF-κB activation. Surprisingly, we found that PAUF also associated with the CXC chemokine receptor (CXCR4)–TLR2 complex and inhibited CXCR4-dependent, TLR2-mediated NF-κB activation. Together, these findings suggest that the new cancer-associated ligand, PAUF, may activate TLR-mediated ERK signaling to produce the protumorigenic cytokines, but inhibits TLR-mediated NF-κB signaling, thereby facilitating tumor growth and escape from innate immune surveillance. PMID:20802527

  17. Involvement of chemokine receptors in breast cancer metastasis

    NASA Astrophysics Data System (ADS)

    Müller, Anja; Homey, Bernhard; Soto, Hortensia; Ge, Nianfeng; Catron, Daniel; Buchanan, Matthew E.; McClanahan, Terri; Murphy, Erin; Yuan, Wei; Wagner, Stephan N.; Barrera, Jose Luis; Mohar, Alejandro; Verástegui, Emma; Zlotnik, Albert

    2001-03-01

    Breast cancer is characterized by a distinct metastatic pattern involving the regional lymph nodes, bone marrow, lung and liver. Tumour cell migration and metastasis share many similarities with leukocyte trafficking, which is critically regulated by chemokines and their receptors. Here we report that the chemokine receptors CXCR4 and CCR7 are highly expressed in human breast cancer cells, malignant breast tumours and metastases. Their respective ligands CXCL12/SDF-1α and CCL21/6Ckine exhibit peak levels of expression in organs representing the first destinations of breast cancer metastasis. In breast cancer cells, signalling through CXCR4 or CCR7 mediates actin polymerization and pseudopodia formation, and subsequently induces chemotactic and invasive responses. In vivo, neutralizing the interactions of CXCL12/CXCR4 significantly impairs metastasis of breast cancer cells to regional lymph nodes and lung. Malignant melanoma, which has a similar metastatic pattern as breast cancer but also a high incidence of skin metastases, shows high expression levels of CCR10 in addition to CXCR4 and CCR7. Our findings indicate that chemokines and their receptors have a critical role in determining the metastatic destination of tumour cells.

  18. Binding of HCV E2 to CD81 induces RANTES secretion and internalization of CC chemokine receptor 5.

    PubMed

    Nattermann, J; Nischalke, H D; Feldmann, G; Ahlenstiel, G; Sauerbruch, T; Spengler, U

    2004-11-01

    Hepatitis C virus (HCV) infection has been shown to be associated with reduced expression of the CC chemokine receptor (CCR) 5, and reduced responsiveness of lymphocytes to chemokines. However, the mechanism by which HCV alters CCR5 expression remains unclear. Here, we investigated whether altered CCR5 expression in hepatitis C results from interactions of CD81 with the HCV E2 protein. Peripheral blood mononuclear cells (PBMC) from HCV-negative individuals were prepared by Ficoll density gradient separation. PBMC subpopulations (CD4+, CD8+ lymphocytes, CD19+ B cells, natural killer (NK) cells and monocyte-derived dendritic cells) were isolated and stimulated with immobilized HCV E2, and changes in CCR5 expression and CC-chemokine secretion were determined. Migration assays were performed using a 5-microm nitrocellulose filter microchamber system according to the manufacturer's recommendations. Exposure of PBMC to HCV E2 induced a dose-dependent release of regulated on activation normal T-cell-expressed and secreted (RANTES), down-regulation of CCR5 expression and intracellular accumulation of CCR5. This effect was blocked by preincubation of PBMC with anti-CD81. RANTES release following exposure to HCV E2 was mainly attributable to CD8+ cells. After exposure to HCV E2 markedly fewer CD8-positive lymphocytes were attracted by RANTES when compared with CD8+ cells that were studied in the absence of HCV E2. Our results suggest that interaction of HCV E2 with CD81 leads to increased RANTES secretion by CD8+ lymphocytes which induces down-regulation of CCR5 surface via receptor internalization resulting in altered lymphocyte migration. PMID:15500552

  19. A Chemokine Receptor, CXCR4, Which Is Regulated by Hypoxia-Inducible Factor 2α, Is Crucial for Functional Endothelial Progenitor Cells Migration to Ischemic Tissue and Wound Repair

    PubMed Central

    Tu, Tran Cam; Nagano, Masumi; Yamashita, Toshiharu; Hamada, Hiromi; Ohneda, Kinuko; Kimura, Kenichi

    2016-01-01

    Endothelial progenitor cells (EPCs) have the ability to form new blood vessels and protect ischemic tissues from damage. We previously reported that EPCs with low activity of aldehyde dehydrogenase (Alde-Low EPCs) possess the greater ability to treat ischemic tissues compared with Alde-High EPCs. The expression level of the hypoxia-inducible factors (HIFs), HIF-1α and HIF-2α, was found to be greater in Alde-Low EPCs than in Alde-High EPCs. However, the precise role of the HIF factors in the regulation of EPC activity remains obscure. In this study, we demonstrate a critical role of HIF-2α and its target gene CXCR4 for controlling the migratory activity of EPC to ischemic tissue. We found that coculture of Alde-High EPCs with microvesicles derived from Alde-Low EPCs improved their ability to repair an ischemic skin flap, and the expression of CXCR4 and its ligand SDF1 was significantly increased following the coculture. In Alde-Low EPCs, the expression of CXCR4 was suppressed by short hairpin RNA (shRNA)-mediated HIF-2α, but not HIF-1α downregulation. Chromatin immunoprecipitation assays showed that HIF-2α, but not HIF-1α, binds to the promoter region of CXCR4 gene. The CXCR4 shRNA treatment in Alde-Low EPCs almost completely abrogated their migratory activity to ischemic tissues, whereas the reduction of vascular endothelial growth factor (VEGF) showed much less effect. The CXCR4 overexpression in Alde-High EPCs resulted in a partial, but significant improvement in their repairing ability in an ischemic skin flap. Collectively, these findings indicate that the CXCR4/SDF-1 axis, which is specifically regulated by HIF-2α, plays a crucial role in the regulation of EPC migration to ischemic tissues. PMID:26620723

  20. A Chemokine Receptor, CXCR4, Which Is Regulated by Hypoxia-Inducible Factor 2α, Is Crucial for Functional Endothelial Progenitor Cells Migration to Ischemic Tissue and Wound Repair.

    PubMed

    Tu, Tran Cam; Nagano, Masumi; Yamashita, Toshiharu; Hamada, Hiromi; Ohneda, Kinuko; Kimura, Kenichi; Ohneda, Osamu

    2016-02-01

    Endothelial progenitor cells (EPCs) have the ability to form new blood vessels and protect ischemic tissues from damage. We previously reported that EPCs with low activity of aldehyde dehydrogenase (Alde-Low EPCs) possess the greater ability to treat ischemic tissues compared with Alde-High EPCs. The expression level of the hypoxia-inducible factors (HIFs), HIF-1α and HIF-2α, was found to be greater in Alde-Low EPCs than in Alde-High EPCs. However, the precise role of the HIF factors in the regulation of EPC activity remains obscure. In this study, we demonstrate a critical role of HIF-2α and its target gene CXCR4 for controlling the migratory activity of EPC to ischemic tissue. We found that coculture of Alde-High EPCs with microvesicles derived from Alde-Low EPCs improved their ability to repair an ischemic skin flap, and the expression of CXCR4 and its ligand SDF1 was significantly increased following the coculture. In Alde-Low EPCs, the expression of CXCR4 was suppressed by short hairpin RNA (shRNA)-mediated HIF-2α, but not HIF-1α downregulation. Chromatin immunoprecipitation assays showed that HIF-2α, but not HIF-1α, binds to the promoter region of CXCR4 gene. The CXCR4 shRNA treatment in Alde-Low EPCs almost completely abrogated their migratory activity to ischemic tissues, whereas the reduction of vascular endothelial growth factor (VEGF) showed much less effect. The CXCR4 overexpression in Alde-High EPCs resulted in a partial, but significant improvement in their repairing ability in an ischemic skin flap. Collectively, these findings indicate that the CXCR4/SDF-1 axis, which is specifically regulated by HIF-2α, plays a crucial role in the regulation of EPC migration to ischemic tissues. PMID:26620723

  1. The atypical chemokine receptor CCX-CKR scavenges homeostatic chemokines in circulation and tissues and suppresses Th17 responses.

    PubMed

    Comerford, Iain; Nibbs, Robert J B; Litchfield, Wendel; Bunting, Mark; Harata-Lee, Yuka; Haylock-Jacobs, Sarah; Forrow, Steve; Korner, Heinrich; McColl, Shaun R

    2010-11-18

    Our previous in vitro studies led to proposals that the atypical chemokine receptor CCX-CKR is a scavenger of CCR7 ligand homeostatic chemokines. In the present study, we generated CCX-CKR(-/-) mice and confirm this scavenger function in vivo. Compared with wild-type mice, CCX-CKR(-/-) have a 5-fold increase in the level of CCL21 protein in blood, and 2- to 3-fold increases in CCL19 and CCL21 in peripheral lymph nodes. The effect of these protein increases on immunity was investigated after immunization with MOG(35-55) peptide emulsified in complete Freund adjuvant (CFA). The subsequent characteristic paralysis develops with enhanced kinetics and severity in CCX-CKR(-/-) versus wild-type mice. Despite this effect, antigen-specific immune responses in the draining lymph nodes are diminished in CCX-CKR(-/-) mice. Instead, the earlier onset of disease is associated with enhanced T-cell priming in the CCX-CKR(-/-) spleen and a skewing of CD4(+) T-cell responses toward Th17 rather than Th1. This observation correlates with increased expression of IL-23 in the CCX-CKR(-/-) spleen and increased CCL21 levels in the central nervous system postimmunization. The early onset of disease in CCX-CKR(-/-) mice is reversed by systemic administration of neutralizing anti-CCL21 antibodies. Thus, by regulating homeostatic chemokine bioavailability, CCX-CKR influences the localization, kinetics, and nature of adaptive immune responses in vivo. PMID:20562329

  2. Interference with Glycosaminoglycan-Chemokine Interactions with a Probe to Alter Leukocyte Recruitment and Inflammation In Vivo

    PubMed Central

    Li, Sandra; Pettersson, Ulrika S.; Hoorelbeke, Bart; Kolaczkowska, Elzbieta; Schelfhout, Katrien; Martens, Erik; Kubes, Paul; Van Damme, Jo; Phillipson, Mia; Opdenakker, Ghislain

    2014-01-01

    In vivo leukocyte recruitment is not fully understood and may result from interactions of chemokines with glycosaminoglycans/GAGs. We previously showed that chlorite-oxidized oxyamylose/COAM binds the neutrophil chemokine GCP-2/CXCL6. Here, mouse chemokine binding by COAM was studied systematically and binding affinities of chemokines to COAM versus GAGs were compared. COAM and heparan sulphate bound the mouse CXC chemokines KC/CXCL1, MIP-2/CXCL2, IP-10/CXCL10 and I-TAC/CXCL11 and the CC chemokine RANTES/CCL5 with affinities in the nanomolar range, whereas no binding interactions were observed for mouse MCP-1/CCL2, MIP-1α/CCL3 and MIP-1β/CCL4. The affinities of COAM-interacting chemokines were similar to or higher than those observed for heparan sulphate. Although COAM did not display chemotactic activity by itself, its co-administration with mouse GCP-2/CXCL6 and MIP-2/CXCL2 or its binding of endogenous chemokines resulted in fast and cooperative peritoneal neutrophil recruitment and in extravasation into the cremaster muscle in vivo. These local GAG mimetic features by COAM within tissues superseded systemic effects and were sufficient and applicable to reduce LPS-induced liver-specific neutrophil recruitment and activation. COAM mimics glycosaminoglycans and is a nontoxic probe for the study of leukocyte recruitment and inflammation in vivo. PMID:25093679

  3. Interference with glycosaminoglycan-chemokine interactions with a probe to alter leukocyte recruitment and inflammation in vivo.

    PubMed

    Li, Sandra; Pettersson, Ulrika S; Hoorelbeke, Bart; Kolaczkowska, Elzbieta; Schelfhout, Katrien; Martens, Erik; Kubes, Paul; Van Damme, Jo; Phillipson, Mia; Opdenakker, Ghislain

    2014-01-01

    In vivo leukocyte recruitment is not fully understood and may result from interactions of chemokines with glycosaminoglycans/GAGs. We previously showed that chlorite-oxidized oxyamylose/COAM binds the neutrophil chemokine GCP-2/CXCL6. Here, mouse chemokine binding by COAM was studied systematically and binding affinities of chemokines to COAM versus GAGs were compared. COAM and heparan sulphate bound the mouse CXC chemokines KC/CXCL1, MIP-2/CXCL2, IP-10/CXCL10 and I-TAC/CXCL11 and the CC chemokine RANTES/CCL5 with affinities in the nanomolar range, whereas no binding interactions were observed for mouse MCP-1/CCL2, MIP-1α/CCL3 and MIP-1β/CCL4. The affinities of COAM-interacting chemokines were similar to or higher than those observed for heparan sulphate. Although COAM did not display chemotactic activity by itself, its co-administration with mouse GCP-2/CXCL6 and MIP-2/CXCL2 or its binding of endogenous chemokines resulted in fast and cooperative peritoneal neutrophil recruitment and in extravasation into the cremaster muscle in vivo. These local GAG mimetic features by COAM within tissues superseded systemic effects and were sufficient and applicable to reduce LPS-induced liver-specific neutrophil recruitment and activation. COAM mimics glycosaminoglycans and is a nontoxic probe for the study of leukocyte recruitment and inflammation in vivo. PMID:25093679

  4. Heterologous Quaternary Structure of CXCL12 and its Relationship to the CC Chemokine Family

    SciTech Connect

    Murphy, J.; Yuan, H; Kong, Y; Xiong, Y; Lolis, E

    2010-01-01

    X-ray crystallographic studies reveal that CXCL12 is able to form multiple dimer types, a traditional CXC dimer and a 'CC-like' form. Phylogenetic analysis of all known human chemokines demonstrates CXCL12 is more closely related to the CC chemokine class than other CXC chemokines. These observations indicate that CXCL12 contains genomic and structural elements characteristic of both CXC and CC chemokines.Chemokines are members of a superfamily of proteins involved in the migration of cells to the proper anatomical position during embryonic development or in response to infection or stress during an immune response. There are two major (CC and CXC) and two minor (CX3C and XC) families based on the sequence around the first conserved cysteine. The topology of all structures is essentially identical with a flexible N-terminal region of 3-8 amino acids, a 10-20 residue N-terminal loop, a short 3{sub 10}-helix, three {beta}-strands, and a {alpha}-helix. The major consequence of the subtle difference between the families occurs at the oligomeric level. Monomers of the CC, CXC, and CX3C families form dimers in a family-specific manner. The XCL1 chemokine is a monomer that can interconvert between two folded states. All chemokines activate GPCRs according to family-specificity, however there are a few examples of chemokines crossing the family boundary to function as antagonists. A two-stage mechanism for chemokine activation of GPCRs has been proposed. The N-terminal region of the receptor interacts with the chemokine, followed by receptor activation by the chemokine N-terminal region. Monomeric chemokines have been demonstrated to be the active form for receptor function. There are numerous examples of both chemokines and their receptors forming dimers. While family-specific dimerization may be an attractive explanation for why specific chemokines only activate GPCRs within their own family, the role of dimers in the function of chemokines has not been resolved. Given

  5. Chemokines CCL2, 3, 14 stimulate macrophage bone marrow homing, proliferation, and polarization in multiple myeloma

    PubMed Central

    Wang, Qiang; Qian, Jianfei; Lu, Yong; Zhang, Mingjun; Bi, Enguang; Yang, Maojie; Reu, Frederic; Yi, Qing; Cai, Zhen

    2015-01-01

    We previously showed that macrophages (MΦs) infiltrate the bone marrow (BM) of patients with myeloma and may play a role in drug resistance. This study analyzed chemokines expressed by myeloma BM that are responsible for recruiting monocytes to the tumor bed. We found that chemokines CCL3, CCL14, and CCL2 were highly expressed by myeloma and BM cells, and the levels of CCL14 and CCL3 in myeloma BM positively correlated with the percentage of BM-infiltrating MΦs. In vitro, these chemokines were responsible for chemoattracting human monocytes to tumor sites and in vivo for MΦ infiltration into myeloma-bearing BM in the 5TGM1 mouse model. Surprisingly, we also found that these chemokines stimulated MΦ in vitro proliferation induced by myeloma cells and in vivo in a human myeloma xenograft SCID mouse model. The chemokines also activated normal MΦ polarization and differentiation into myeloma-associated MΦs. Western blot analysis revealed that these chemokines promoted growth and survival signaling in MΦs via activating the PI3K/Akt and ERK MAPK pathways and c-myc expression. Thus, this study provides novel insight into the mechanism of MΦ infiltration of BM and also potential targets for improving the efficacy of chemotherapy in myeloma. PMID:26155942

  6. Interferons Induce CXCR3-cognate Chemokine Production by Human Metastatic Melanoma

    PubMed Central

    Dengel, Lynn T.; Norrod, Allison G.; Gregory, Briana L.; Clancy-Thompson, Eleanor; Burdick, Marie D.; Strieter, Robert M.; Slingluff, Craig L.; Mullins, David W.

    2010-01-01

    Immune-mediated cancer regression requires tumor infiltration by Ag-specific effector T cells, but lymphocytes are commonly sparse in melanoma metastases. Activated T cells express CXCR3, whose cognate chemokines are CXCL9/MIG, CXCL10/IP-10 and CXCL11/I-TAC. Little is known about expression of these chemokines in lymph node (LN) metastases of melanoma. We evaluated whether metastatic melanoma induces these CXCR3-cognate chemokines in human LN-derived tissues. Also, because these chemokines can be induced by interferon (IFN), we evaluated whether type I or II IFNs (IFN-α or IFN-γ, respectively) can modulate chemokine expression in an in vitro model of the human tumor microenvironment. Production of CXCL9-11 by melanoma-infiltrated nodes (MIN) was no different than tumor-free nodes (TFN); both produced less chemokine than activated LN (sentinel immunized nodes, SIN). These data suggest melanoma infiltration into LN neither induces nor reduces CXCL9-11. Stimulation with IFN-α or IFN-γ increased production of CXCL10-11 from MIN, but not TFN or SIN. IFN-γ also increased production of CXCL9 in MIN. In IFN-treated SIN, CD14+ cells were the primary source of CXCL9-11, whereas melanoma cells were the source of chemokine in MIN. Melanoma cells in MIN express IFN receptors. Consistent with these observations, multiple human melanoma lines expressed IFN receptors and produced CXCL9-11 in response to IFN treatment. Thus, melanoma infiltration of LN is insufficient to induce the production of CXCL9-11, but melanoma may be a significant source of IFN-induced chemokines. Collectively, these data suggest that IFN-α or IFN-γ may act in the tumor microenvironment to increase the chemotactic gradient for CXCR3+ T cells. PMID:20948440

  7. Systemic and Local CC Chemokines Production in a Murine Model of Listeria monocytogenes Infection

    PubMed Central

    Bubonja, Marina; Wraber, Branka; Brumini, Gordana; Gobin, Ivana; Veljkovic, Danijela; Abram, Maja

    2006-01-01

    Repeated intragastric inoculation of Listeria monocytogenes into BALB/c mice resulted in prolonged bacteraemia and severe hepatic infection. Bacteria could also be isolated from the brain tissue of all experimental mice. During the inflammatory process, chemokine concentrations typically increased at the local site in comparison to the systemic level. The liver-to-serum ratio was more pronounced in the case of macrophage inflammatory protein 1α (MIP-1α), suggesting its role in the inflammatory response in the liver. The ratio of brain-to-serum concentration of monocyte chemoattractant protein 1 (MCP-1) remained the same as in the control animals, while it was lower in the infected mice, both in the case MIP-1α and in the case of regulated on activation, normal T cell expressed and secreted (RANTES). This is in correlation with slight inflammatory infiltrates found in the brain tissue early in infection. PMID:16951491

  8. Carnosol and Related Substances Modulate Chemokine and Cytokine Production in Macrophages and Chondrocytes.

    PubMed

    Schwager, Joseph; Richard, Nathalie; Fowler, Ann; Seifert, Nicole; Raederstorff, Daniel

    2016-01-01

    Phenolic diterpenes present in Rosmarinus officinalis and Salvia officinalis have anti-inflammatory and chemoprotective effects. We investigated the in vitro effects of carnosol (CL), carnosic acid (CA), carnosic acid-12-methylether (CAME), 20-deoxocarnosol and abieta-8,11,13-triene-11,12,20-triol (ABTT) in murine macrophages (RAW264.7 cells) and human chondrocytes. The substances concentration-dependently reduced nitric oxide (NO) and prostaglandin E₂ (PGE₂) production in LPS-stimulated macrophages (i.e., acute inflammation). They significantly blunted gene expression levels of iNOS, cytokines/interleukins (IL-1α, IL-6) and chemokines including CCL5/RANTES, CXCL10/IP-10. The substances modulated the expression of catabolic and anabolic genes in chondrosarcoma cell line SW1353 and in primary human chondrocytes that were stimulated by IL-1β (i.e., chronic inflammation In SW1353, catabolic genes like MMP-13 and ADAMTS-4 that contribute to cartilage erosion were down-regulated, while expression of anabolic genes including Col2A1 and aggrecan were shifted towards pre-pathophysiological homeostasis. CL had the strongest overall effect on inflammatory mediators, as well as on macrophage and chondrocyte gene expression. Conversely, CAME mainly affected catabolic gene expression, whereas ABTT had a more selectively altered interleukin and chemokine gene exprssion. CL inhibited the IL-1β induced nuclear translocation of NF-κBp65, suggesting that it primarily regulated via the NF-κB signalling pathway. Collectively, CL had the strongest effects on inflammatory mediators and chondrocyte gene expression. The data show that the phenolic diterpenes altered activity pattern of genes that regulate acute and chronic inflammatory processes. Since the substances affected catabolic and anabolic gene expression in cartilage cells in vitro, they may beneficially act on the aetiology of osteoarthritis. PMID:27070563

  9. The atypical chemokine receptor D6 contributes to the development of experimental colitis1

    PubMed Central

    Bordon, Yvonne; Hansell, Chris A. H.; Sester, David P; Clarke, Mairi; Mowat, Allan McI.; Nibbs, Robert J. B.

    2009-01-01

    Pro-inflammatory CC chemokines control leukocyte recruitment and function during inflammation by engaging chemokine receptors expressed on circulating leukocytes. The D6 chemokine receptor can bind several of these chemokines but appears unable to couple to signal transduction pathways or direct cell migration. Instead, D6 has been proposed to act as a chemokine scavenger, removing pro-inflammatory chemokines to dampen leukocyte responses. In this report, we have examined the role of D6 in the colon using the dextran sodium sulphate-induced model of colitis. We show that D6 is expressed in the resting colon, predominantly by stromal cells and B cells, and is up-regulated during colitis. Unexpectedly, D6-deficient mice showed reduced susceptibility to colitis and had less pronounced clinical symptoms associated with this model. D6 deletion had no impact on the level of pro-inflammatory CC chemokines released from cultured colon explants, or on the balance of leukocyte subsets recruited to the inflamed colon. However, late in colitis, inflamed D6-deficient colons showed enhanced production of several pro-inflammatory cytokines, including IFNγ and IL-17A, and there was a marked increase in IL-17A-secreting γδ T cells in the lamina propria. Moreover, antibody-mediated neutralisation of IL-17A worsened the clinical symptoms of colitis at these later stages of the response in D6-deficient, but not wild-type, mice. Thus, D6 can contribute to the development of colitis by regulating IL-17A secretion by γδ T cells in the inflamed colon. PMID:19342683

  10. Chemokines and the inflammatory response following cardiopulmonary bypass--a new target for therapeutic intervention?--A review.

    PubMed

    Ben-Abraham, Ron; Weinbroum, Avi A; Dekel, Benjamin; Paret, Gideon

    2003-10-01

    This 10-year Medline search of English-language articles describing experimental and clinical studies on chemokines, cardiopulmonary bypass (CPB) and systemic or multiorgan failure revealed that chemokines are significantly involved in the pathogenesis of post-CPB syndrome. The post-CPB inflammatory response depends upon recruitment and activation of inflammatory cells. Leucocyte recruitment is a well-orchestrated process that involves several protein families, including pro-inflammatory cytokines, adhesion molecules and chemokines. Current anti-inflammatory therapies mostly act on the cells that have already been recruited. A more efficient therapy might be the prevention of excessive recruitment of particular leucocyte populations by antagonizing chemokine receptors which might act upstream of the current anti-inflammatory agents. The chemokines, which are a cytokine subfamily of chemotactic cytokines, participate in recognizing, recruiting, removing and repairing inflammation. As chemokines target specific leucocyte subsets, antagonism of a single chemokine ligand or receptor would be expected to have a circumscribed effect, thereby endowing the antagonist with a limited side-effect profile. Chemokines should be considered as possible targets for therapeutic intervention. PMID:14535901

  11. Pharmacological modulation of chemokine receptor function

    PubMed Central

    Scholten, DJ; Canals, M; Maussang, D; Roumen, L; Smit, MJ; Wijtmans, M; de Graaf, C; Vischer, HF; Leurs, R

    2012-01-01

    G protein-coupled chemokine receptors and their peptidergic ligands are interesting therapeutic targets due to their involvement in various immune-related diseases, including rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease, chronic obstructive pulmonary disease, HIV-1 infection and cancer. To tackle these diseases, a lot of effort has been focused on discovery and development of small-molecule chemokine receptor antagonists. This has been rewarded by the market approval of two novel chemokine receptor inhibitors, AMD3100 (CXCR4) and Maraviroc (CCR5) for stem cell mobilization and treatment of HIV-1 infection respectively. The recent GPCR crystal structures together with mutagenesis and pharmacological studies have aided in understanding how small-molecule ligands interact with chemokine receptors. Many of these ligands display behaviour deviating from simple competition and do not interact with the chemokine binding site, providing evidence for an allosteric mode of action. This review aims to give an overview of the evidence supporting modulation of this intriguing receptor family by a range of ligands, including small molecules, peptides and antibodies. Moreover, the computer-assisted modelling of chemokine receptor–ligand interactions is discussed in view of GPCR crystal structures. Finally, the implications of concepts such as functional selectivity and chemokine receptor dimerization are considered. LINKED ARTICLES This article is part of a themed section on the Molecular Pharmacology of G Protein-Coupled Receptors (GPCRs). To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-6. To view the 2010 themed section on the same topic visit http://onlinelibrary.wiley.com/doi/10.1111/bph.2010.159.issue-5/issuetoc PMID:21699506

  12. Local Chemokine Paralysis, a Novel Pathogenic Mechanism for Porphyromonas gingivalis

    PubMed Central

    Darveau, Richard P.; Belton, Carol M.; Reife, Robert A.; Lamont, Richard J.

    1998-01-01

    Periodontitis, which is widespread in the adult population, is a persistent bacterial infection associated with Porphyromonas gingivalis. Gingival epithelial cells are among the first cells encountered by both P. gingivalis and commensal oral bacteria. The chemokine interleukin 8 (IL-8), a potent chemoattractant and activator of polymorphonuclear leukocytes, was secreted by gingival epithelial cells in response to components of the normal oral flora. In contrast, P. gingivalis was found to strongly inhibit IL-8 accumulation from gingival epithelial cells. Inhibition was associated with a decrease in mRNA for IL-8. Antagonism of IL-8 accumulation did not occur in KB cells, an epithelial cell line that does not support high levels of intracellular invasion by P. gingivalis. Furthermore, a noninvasive mutant of P. gingivalis was unable to antagonize IL-8 accumulation. Invasion-dependent destruction of the gingival IL-8 chemokine gradient at sites of P. gingivalis colonization (local chemokine paralysis) will severely impair mucosal defense and represents a novel mechanism for bacterial colonization of host tissue. PMID:9529095

  13. Dynamics and thermodynamic properties of CXCL7 chemokine.

    PubMed

    Herring, Charles A; Singer, Christopher M; Ermakova, Elena A; Khairutdinov, Bulat I; Zuev, Yuriy F; Jacobs, Donald J; Nesmelova, Irina V

    2015-11-01

    Chemokines form a family of signaling proteins mainly responsible for directing the traffic of leukocytes, where their biological activity can be modulated by their oligomerization state. We characterize the dynamics and thermodynamic stability of monomer and homodimer structures of CXCL7, one of the most abundant platelet chemokines, using experimental methods that include circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy, and computational methods that include the anisotropic network model (ANM), molecular dynamics (MD) simulations and the distance constraint model (DCM). A consistent picture emerges for the effects of dimerization and Cys5-Cys31 and Cys7-Cys47 disulfide bonds formation. The presence of disulfide bonds is not critical for maintaining structural stability in the monomer or dimer, but the monomer is destabilized more than the dimer upon removal of disulfide bonds. Disulfide bonds play a key role in shaping the characteristics of native state dynamics. The combined analysis shows that upon dimerization flexibly correlated motions are induced between the 30s and 50s loop within each monomer and across the dimer interface. Interestingly, the greatest gain in flexibility upon dimerization occurs when both disulfide bonds are present, and the homodimer is least stable relative to its two monomers. These results suggest that the highly conserved disulfide bonds in chemokines facilitate a structural mechanism that is tuned to optimally distinguish functional characteristics between monomer and dimer. PMID:26297927

  14. Chemokine Function in Periodontal Disease and Oral Cavity Cancer

    PubMed Central

    Sahingur, Sinem Esra; Yeudall, W. Andrew

    2015-01-01

    The chemotactic cytokines, or chemokines, comprise a superfamily of polypeptides with a wide range of activities that include recruitment of immune cells to sites of infection and inflammation, as well as stimulation of cell proliferation. As such, they function as antimicrobial molecules and play a central role in host defenses against pathogen challenge. However, their ability to recruit leukocytes and potentiate or prolong the inflammatory response may have profound implications for the progression of oral diseases such as chronic periodontitis, where tissue destruction may be widespread. Moreover, it is increasingly recognized that chronic inflammation is a key component of tumor progression. Interaction between cancer cells and their microenvironment is mediated in large part by secreted factors such as chemokines, and serves to enhance the malignant phenotype in oral and other cancers. In this article, we will outline the biological and biochemical mechanisms of chemokine action in host–microbiome interactions in periodontal disease and in oral cancer, and how these may overlap and contribute to pathogenesis. PMID:25999952

  15. Inhibition of zymosan-induced cytokine and chemokine expression in human corneal fibroblasts by triptolide

    PubMed Central

    Liu, Yang; Li, Jing; Liu, Ye; Wang, Ping; Jia, Hui

    2016-01-01

    AIM To investigate the effects of triptolide on proinflammatory cytokine and chemokine expression induced by the fungal component zymosan in cultured human corneal fibroblasts (HCFs). METHODS HCFs were cultured in the absence or presence of zymosan or triptolide. The release of interleukin (IL)-6, IL-8, and monocyte chemoattractant protein-1 (MCP-1) into culture supernatants was measured with enzyme-linked immunosorbent assays. The cellular abundance of the mRNAs for these proteins was determined by reverse transcription and real-time polymerase chain reaction analysis. The phosphorylation of mitogen-activated protein kinases (MAPKs) and the endogenous nuclear factor-κB (NF-κB) inhibitor IκB-α was examined by immunoblot analysis. The release of lactate dehydrogenase (LDH) activity from HCFs was measured with a colorimetric assay. RESULTS Triptolide inhibited the zymosan-induced release of IL-6, IL-8, and MCP-1 from HCFs in a concentration- and time-dependent manner. It also inhibited the zymosan-induced up-regulation of IL-6, IL-8, and MCP-1 mRNA abundance in these cells. Furthermore, triptolide attenuated zymosan-induced phosphorylation of the MAPKs extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK), and p38 as well as the phosphorylation and degradation of IκB-α. Triptolide did not exhibit cytotoxicity for HCFs. CONCLUSION Triptolide inhibited proinflammatory cytokine and chemokine production by HCFs exposed to zymosan, with this action likely being mediated by suppression of MAPK and NF-κB signaling pathways. This compound might thus be expected to limit the infiltration of inflammatory cells into the cornea associated with fungal infection. PMID:26949603

  16. Structural biology. Crystal structure of the chemokine receptor CXCR4 in complex with a viral chemokine.

    PubMed

    Qin, Ling; Kufareva, Irina; Holden, Lauren G; Wang, Chong; Zheng, Yi; Zhao, Chunxia; Fenalti, Gustavo; Wu, Huixian; Han, Gye Won; Cherezov, Vadim; Abagyan, Ruben; Stevens, Raymond C; Handel, Tracy M

    2015-03-01

    Chemokines and their receptors control cell migration during development, immune system responses, and in numerous diseases, including inflammation and cancer. The structural basis of receptor:chemokine recognition has been a long-standing unanswered question due to the challenges of structure determination for membrane protein complexes. Here, we report the crystal structure of the chemokine receptor CXCR4 in complex with the viral chemokine antagonist vMIP-II at 3.1 angstrom resolution. The structure revealed a 1:1 stoichiometry and a more extensive binding interface than anticipated from the paradigmatic two-site model. The structure helped rationalize a large body of mutagenesis data and together with modeling provided insights into CXCR4 interactions with its endogenous ligand CXCL12, its ability to recognize diverse ligands, and the specificity of CC and CXC receptors for their respective chemokines. PMID:25612609

  17. Significance of chemokine and chemokine receptors in head and neck squamous cell carcinoma: A critical review.

    PubMed

    da Silva, Janine Mayra; Soave, Danilo Figueiredo; Moreira Dos Santos, Tálita Pollyanna; Batista, Aline Carvalho; Russo, Remo Castro; Teixeira, Mauro Martins; Silva, Tarcília Aparecida da

    2016-05-01

    Chemokines are small chemotactic proteins that coordinate circulation of immune/inflammatory cells throughout body compartments. Because of this property chemokines and their cell surface receptors are implicated in several physiological and pathological conditions, including cancer. These molecules are expressed by neoplastic or stromal cells and have effects at tumor primary site (e.g. stimulating angiogenesis and tumor cells motility) and lymph nodes (creating a gradient to direct migration of neoplastic cells). In this article we review the current knowledge about the function(s) of chemokines and receptors in squamous cell carcinoma from the oral cavity and head and neck region. Accumulating evidence suggests some chemokine(s) and receptor(s) as potential targets in adjuvant therapies for these malignancies. PMID:27086481

  18. The {beta}-chemokines CCL2 and CCL7 are two novel differentiation factors for midbrain dopaminergic precursors and neurons

    SciTech Connect

    Edman, Linda C.; Mira, Helena; Arenas, Ernest

    2008-06-10

    {beta}-chemokines are secreted factors that regulate diverse functions in the adult brain, such as neuro-immune responses and neurotransmission, but their function in the developing brain is largely unknown. We recently found that the orphan nuclear receptor, Nurr1, up regulates CCL2 and CCL7 in neural stem cells, suggesting a possible function of {beta}-chemokines in midbrain development. Here we report that two {beta}-chemokines, CCL2 and CCL7, and two of their receptors, CCR1 and CCR2, are expressed and developmentally regulated in the ventral midbrain (VM). Moreover, we found that the expression of CCL7 was down regulated in the Nurr1 knockout mice, linking CCL7 to dopamine (DA) neuron development. When the function of CCL2 and CCL7 was examined, we found that they selectively enhanced the differentiation of Nurr1+ precursors into DA neurons, but not their survival or progenitor proliferation in primary precursor cultures. Moreover, both CCL2 and CCL7 promoted neuritogenesis in midbrain DA neuron cultures. Thus, our results show for the first time a function of {beta}-chemokines in the developing brain and identify {beta}-chemokines as novel class of pro-differentiation factors for midbrain DA neurons. These data also suggest that {beta}-chemokines may become useful tools to enhance the differentiation of DA cell preparations for cell replacement therapy and drug discovery in Parkinson's disease (PD)

  19. Elevated expression of the chemokine CCL18 in chronic rhinosinusitis with nasal polyps

    PubMed Central

    Peterson, Sarah; Poposki, Julie A.; Nagarkar, Deepti R.; Chustz, Regina T.; Peters, Anju T.; Suh, Lydia A.; Carter, Roderick; Norton, James; Harris, Kathleen E.; Grammer, Leslie C.; Tan, Bruce K.; Chandra, Rakesh K.; Conley, David B.; Kern, Robert C.; Schleimer, Robert P.; Kato, Atsushi

    2011-01-01

    Background Chronic rhinosinusitis with nasal polyps (CRSwNP) is associated with Th2-dominant inflammation including eosinophilia, in contrast to non-polypoid CRS (CRSsNP). Chemokine CCL18/PARC (pulmonary and activation regulated chemokine) is known to recruit naïve T cells, B cells, and immature dendritic cells, as well as activate fibroblasts. CCL18is thought to be involved in Th2-related inflammatory diseases including asthma and atopic dermatitis. Objectives The objective of this study was to investigate the expression of CCL18 in patients with CRS. Methods Using nasal polyp tissue (NP) and uncinate tissue (UT) from controls and patients with CRS, we examined the expression of CCL18 mRNA by real-time PCR and measured CCL18 protein by ELISA, western blot and immunofluorescence. Results Compared to UT tissue in control subjects, CCL18 mRNA was significantly increased in NP (p<0.001) and UT (p<0.05) from patients with CRSwNP but not in UT from patients with CRSsNP. Similarly, CCL18 protein was elevated in NP and UT from CRSwNP and levels were even higher in Samter’s triad patients. Immunohistochemical analysis revealed CCL18 expression in inflammatory cells and CCL18+ cells were significantly increased in NP. Immunofluorescence data showed co-localization of CCL18 in CD68+/CD163+/macrophage mannose receptor+ M2 macrophages and tryptase+ mast cells in NP. Levels of CCL18 correlated with markers of M2 macrophages but not with tryptase, suggesting that M2 macrophages are a major CCL18-producing cells in NP. Conclusion Overproduction of CCL18 might contribute to the pathogenesis of CRSwNP through its known activities, which include recruitment of lymphocytes and dendritic cells, activation of fibroblasts, and initiation of local inflammation. PMID:21943944

  20. Mechanisms of specificity in neuronal activity-regulated gene transcription

    PubMed Central

    Lyons, Michelle R.; West, Anne E.

    2011-01-01

    The brain is a highly adaptable organ that is capable of converting sensory information into changes in neuronal function. This plasticity allows behavior to be accommodated to the environment, providing an important evolutionary advantage. Neurons convert environmental stimuli into long-lasting changes in their physiology in part through the synaptic activity-regulated transcription of new gene products. Since the neurotransmitter-dependent regulation of Fos transcription was first discovered nearly 25 years ago, a wealth of studies have enriched our understanding of the molecular pathways that mediate activity-regulated changes in gene transcription. These findings show that a broad range of signaling pathways and transcriptional regulators can be engaged by neuronal activity to sculpt complex programs of stimulus-regulated gene transcription. However, the shear scope of the transcriptional pathways engaged by neuronal activity raises the question of how specificity in the nature of the transcriptional response is achieved in order to encode physiologically relevant responses to divergent stimuli. Here we summarize the general paradigms by which neuronal activity regulates transcription while focusing on the molecular mechanisms that confer differential stimulus-, cell-type-, and developmental-specificity upon activity-regulated programs of neuronal gene transcription. In addition, we preview some of the new technologies that will advance our future understanding of the mechanisms and consequences of activity-regulated gene transcription in the brain. PMID:21620929

  1. Chemokines and chemokine receptors as novel therapeutic targets in rheumatoid arthritis (RA): inhibitory effects of traditional Chinese medicinal components.

    PubMed

    Chen, Xin; Oppenheim, Joost J; Howard, O M Zack

    2004-10-01

    Chemokines belong to a large family of inflammatory cytokines responsible for migration and accumulation of leukocytes at inflammatory sites. Over the past decade, accumulating evidence indicated a crucial role for chemokines and chemokine receptors in the pathophysiology of rheumatoid arthritis (RA). RA is a chronic autoimmune disease in which the synovial tissue is heavily infiltrated by leukocytes. Chemokines play an important role in the infiltration, localization, retention of infiltrating leukocytes and generation of ectopic germinal centers in the inflamed synovium. Recent evidence also suggests that identification of inhibitors directly targeting chemokines or their receptors may provide a novel therapeutic strategy in RA. Traditional Chinese medicines (TCMs) have a long history in the treatment of inflammatory joint disease. The basis for the clinical benefits of TCM remains largely unclear. Our studies have led to the identification of numerous novel chemokine/chemokine receptor inhibitors present in anti-inflammatory TCMs. All of these inhibitors were previously reported by other researchers to have anti-arthritic effect, which may be attributable, at least in part, to their inhibitory effect on chemokine and/or chemokine receptor. Therefore, identification of agents capable of targeting chemokine/chemokine receptor interactions has suggested a mechanism of action for several TCM components and provided a means of identifying additional anti-RA TCM. Thus, this approach may lead to the discovery of new inhibitors of chemokines or chemokine receptors that can be used to treat diseases associated with inappropriately overactive chemokine mediated inflammatory reactions. PMID:16285892

  2. Antimicrobial Effects of Interferon-Inducible CXC Chemokines against Bacillus anthracis Spores and Bacilli▿

    PubMed Central

    Crawford, Matthew A.; Zhu, Yinghua; Green, Candace S.; Burdick, Marie D.; Sanz, Patrick; Alem, Farhang; O'Brien, Alison D.; Mehrad, Borna; Strieter, Robert M.; Hughes, Molly A.

    2009-01-01

    Based on previous studies showing that host chemokines exert antimicrobial activities against bacteria, we sought to determine whether the interferon-inducible Glu-Leu-Arg-negative CXC chemokines CXCL9, CXCL10, and CXCL11 exhibit antimicrobial activities against Bacillus anthracis. In vitro analysis demonstrated that all three CXC chemokines exerted direct antimicrobial effects against B. anthracis spores and bacilli including marked reductions in spore and bacillus viability as determined using a fluorometric assay of bacterial viability and CFU determinations. Electron microscopy studies revealed that CXCL10-treated spores failed to undergo germination as judged by an absence of cytological changes in spore structure that occur during the process of germination. Immunogold labeling of CXCL10-treated spores demonstrated that the chemokine was located internal to the exosporium in association primarily with the spore coat and its interface with the cortex. To begin examining the potential biological relevance of chemokine-mediated antimicrobial activity, we used a murine model of inhalational anthrax. Upon spore challenge, the lungs of C57BL/6 mice (resistant to inhalational B. anthracis infection) had significantly higher levels of CXCL9, CXCL10, and CXCL11 than did the lungs of A/J mice (highly susceptible to infection). Increased CXC chemokine levels were associated with significantly reduced levels of spore germination within the lungs as determined by in vivo imaging. Taken together, our data demonstrate a novel antimicrobial role for host chemokines against B. anthracis that provides unique insight into host defense against inhalational anthrax; these data also support the notion for an innovative approach in treating B. anthracis infection as well as infections caused by other spore-forming organisms. PMID:19179419

  3. Structural Basis of Chemokine Sequestration by a Tick Chemokine Binding Protein: The Crystal Structure of the Complex between Evasin-1 and CCL3

    PubMed Central

    Dias, João M.; Losberger, Christophe; Déruaz, Maud; Power, Christine A.; Proudfoot, Amanda E. I.; Shaw, Jeffrey P.

    2009-01-01

    Background Chemokines are a subset of cytokines responsible for controlling the cellular migration of inflammatory cells through interaction with seven transmembrane G protein-coupled receptors. The blocking of a chemokine-receptor interaction results in a reduced inflammatory response, and represents a possible anti-inflammatory strategy, a strategy that is already employed by some virus and parasites. Anti-chemokine activity has been described in the extracts of tick salivary glands, and we have recently described the cloning and characterization of such chemokine binding proteins from the salivary glands, which we have named Evasins. Methodology/Principal Findings We have solved the structure of Evasin-1, a very small and highly selective chemokine-binding protein, by x-ray crystallography and report that the structure is novel, with no obvious similarity to the previously described structures of viral chemokine binding proteins. Moreover it does not possess a known fold. We have also solved the structure of the complex of Evasin-1 and its high affinity ligand, CCL3. The complex is a 1∶1 heterodimer in which the N-terminal region of CCL3 forms numerous contacts with Evasin-1, including prominent π-π interactions between residues Trp89 and Phe14 of the binding protein and Phe29 and Phe13 of the chemokine. Conclusions/Significance However, these interactions do not appear to be crucial for the selectivity of the binding protein, since these residues are found in CCL5, which is not a ligand for Evasin-1. The selectivity of the interaction would appear to lie in the N-terminal residues of the chemokine, which form the “address” whereas the hydrophobic interactions in the rest of the complex would serve primarily to stabilize the complex. A thorough understanding of the binding mode of this small protein, and its other family members, could be very informative in the design of potent neutralizing molecules of pro-inflammatory mediators of the immune system

  4. Matrix metalloproteinases and chemokines in the gingival crevicular fluid during orthodontic tooth movement.

    PubMed

    Capelli, Jonas; Kantarci, Alpdogan; Haffajee, Anne; Teles, Ricardo Palmier; Fidel, Rivail; Figueredo, Carlos Marcelo

    2011-12-01

    Matrix metalloproteinases (MMPs) and monocyte chemoattractants are key modulators of the biological mechanisms triggered in the periodontium by mechanical forces. The gingival crevicular fluid (GCF) provides a non-invasive method to assess longitudinally the release of inflammatory mediators during orthodontic tooth movement. The goal of this study was to examine the GCF levels of MMP-3, MMP-9, and MMP-13 and of the chemokines macrophage inflammatory protein (MIP)-1β, monocyte chemoattractant protein (MCP)-1, and regulated on activation normal T cells expressed and secreted (RANTES) at different time points during orthodontic tooth movement. Fourteen subjects (three males and 11 females, 18.8 ± 4.8 years of age; range from 12 to 28 years) had their maxillary canines retracted. Thirty-second GCF samples were collected from the tension and pressure sides 7 days prior to the activation of the orthodontic appliance, on the day of activation, and after 1 and 24 hours, and 14, 21, and 80 days of constant force application. The volume of GCF was measured and samples analysed using a multiplexed bead immunoassay for the content of the six target molecules. Differences in the mean GFC volumes and mean level for each analyte over time were assessed using the Friedman test, and differences between the tension and pressure sides at each time point with the Mann-Whitney test. The mean levels of the three MMPs changed significantly over time but only at the compression side (P < 0.05, Friedman test). The GCF levels of the three chemokines were not affected by the application of mechanical stress. The levels of MMPs in GCF at the pressure side are modulated by the application of orthodontic force. PMID:21389074

  5. Cysteine Cathepsin Activity Regulation by Glycosaminoglycans

    PubMed Central

    Lenarčič, Brigita

    2014-01-01

    Cysteine cathepsins are a group of enzymes normally found in the endolysosomes where they are primarily involved in intracellular protein turnover but also have a critical role in MHC II-mediated antigen processing and presentation. However, in a number of pathologies cysteine cathepsins were found to be heavily upregulated and secreted into extracellular milieu, where they were found to degrade a number of extracellular proteins. A major role in modulating cathepsin activities play glycosaminoglycans, which were found not only to facilitate their autocatalytic activation including at neutral pH, but also to critically modulate their activities such as in the case of the collagenolytic activity of cathepsin K. The interaction between cathepsins and glycosaminoglycans will be discussed in more detail. PMID:25587532

  6. Chemokine CCL17 induced by hypoxia promotes the proliferation of cervical cancer cell

    PubMed Central

    Liu, Li-Bing; Xie, Feng; Chang, Kai-Kai; Shang, Wen-Qing; Meng, Yu-Han; Yu, Jia-Jun; Li, Hui; Sun, Qian; Yuan, Min-Min; Jin, Li-Ping; Li, Da-Jin; Li, Ming-Qing

    2015-01-01

    Cervical cancer is often associated with hypoxia and many kinds of chemokines. But the relationship and role of hypoxia and Chemokine (C-C motif) ligand 17 (CCL17) in cervical cancer are still unknown. Here, we found that CCL17 was high expressed in cervical cancer. HeLa and SiHa cells could secrete CCL17 in a time-dependent manner. Hypoxia increased expression of CCL17 receptor (CCR4) on HeLa and SiHa cells. Treatment with recombination human CCL17 (rhCCL17) led to an elevation of cell proliferation in HeLa and SiHa cells in a dose-dependent manner. In contrast, blocking CCL17 with anti-human CCL17 neutralizing antibody (α-CCL17) played an oppose effect. However, rhCCL17 had no effect on apoptosis in cervical cancer cells. Further analysis showed that hypoxia promoted the proliferation of HeLa and SiHa cells, and these effects could be reversed by α-CCL17. Stimulation with the inhibitor for c-Jun N-terminal kinase (JNK) or signal transducers and activator of transcription 5 (STAT5) signal pathway not only directly decreased the proliferation of HeLa and SiHa cells, but also abrogated the stimulatory effect of rhCCL17 on the proliferation of HeLa and SiHa cells. These results suggest that a high level of CCL17 in cervical cancer lesions is an important regulator in the proliferation of cervical cancer cells through JNK and STAT5 signaling pathways. In this process, hypoxia magnifies this effect by up-regulating CCR4 expression and strengthening the interaction of CCL17/CCR4. PMID:26693060

  7. [Regulation of peptide hydrolase activity in psoriasis].

    PubMed

    Suworow, A P

    1990-01-01

    Clinico-biological examination of 154 patients with psoriasis resulted in data showing high activity of endo- and exopeptidases in efflorescences of that dermatosis. This was accompanied by depressed activity of trypsin inhibitor. At the same time magnesium deficiency, polysaccharide decrease and leucocyte increase were stated to be in the focus of skin damage. That character of interrelation, which play an important role in the pathogenesis of this widespread skin disease, is demonstrated. PMID:2257941

  8. Dietary methanol regulates human gene activity.

    PubMed

    Shindyapina, Anastasia V; Petrunia, Igor V; Komarova, Tatiana V; Sheshukova, Ekaterina V; Kosorukov, Vyacheslav S; Kiryanov, Gleb I; Dorokhov, Yuri L

    2014-01-01

    Methanol (MeOH) is considered to be a poison in humans because of the alcohol dehydrogenase (ADH)-mediated conversion of MeOH to formaldehyde (FA), which is toxic. Our recent genome-wide analysis of the mouse brain demonstrated that an increase in endogenous MeOH after ADH inhibition led to a significant increase in the plasma MeOH concentration and a modification of mRNA synthesis. These findings suggest endogenous MeOH involvement in homeostasis regulation by controlling mRNA levels. Here, we demonstrate directly that study volunteers displayed increasing concentrations of MeOH and FA in their blood plasma when consuming citrus pectin, ethanol and red wine. A microarray analysis of white blood cells (WBC) from volunteers after pectin intake showed various responses for 30 significantly differentially regulated mRNAs, most of which were somehow involved in the pathogenesis of Alzheimer's disease (AD). There was also a decreased synthesis of hemoglobin mRNA, HBA and HBB, the presence of which in WBC RNA was not a result of red blood cells contamination because erythrocyte-specific marker genes were not significantly expressed. A qRT-PCR analysis of volunteer WBCs after pectin and red wine intake confirmed the complicated relationship between the plasma MeOH content and the mRNA accumulation of both genes that were previously identified, namely, GAPDH and SNX27, and genes revealed in this study, including MME, SORL1, DDIT4, HBA and HBB. We hypothesized that human plasma MeOH has an impact on the WBC mRNA levels of genes involved in cell signaling. PMID:25033451

  9. Endogenous Methanol Regulates Mammalian Gene Activity

    PubMed Central

    Komarova, Tatiana V.; Petrunia, Igor V.; Shindyapina, Anastasia V.; Silachev, Denis N.; Sheshukova, Ekaterina V.; Kiryanov, Gleb I.; Dorokhov, Yuri L.

    2014-01-01

    We recently showed that methanol emitted by wounded plants might function as a signaling molecule for plant-to-plant and plant-to-animal communications. In mammals, methanol is considered a poison because the enzyme alcohol dehydrogenase (ADH) converts methanol into toxic formaldehyde. However, the detection of methanol in the blood and exhaled air of healthy volunteers suggests that methanol may be a chemical with specific functions rather than a metabolic waste product. Using a genome-wide analysis of the mouse brain, we demonstrated that an increase in blood methanol concentration led to a change in the accumulation of mRNAs from genes primarily involved in detoxification processes and regulation of the alcohol/aldehyde dehydrogenases gene cluster. To test the role of ADH in the maintenance of low methanol concentration in the plasma, we used the specific ADH inhibitor 4-methylpyrazole (4-MP) and showed that intraperitoneal administration of 4-MP resulted in a significant increase in the plasma methanol, ethanol and formaldehyde concentrations. Removal of the intestine significantly decreased the rate of methanol addition to the plasma and suggested that the gut flora may be involved in the endogenous production of methanol. ADH in the liver was identified as the main enzyme for metabolizing methanol because an increase in the methanol and ethanol contents in the liver homogenate was observed after 4-MP administration into the portal vein. Liver mRNA quantification showed changes in the accumulation of mRNAs from genes involved in cell signalling and detoxification processes. We hypothesized that endogenous methanol acts as a regulator of homeostasis by controlling the mRNA synthesis. PMID:24587296

  10. Dietary Methanol Regulates Human Gene Activity

    PubMed Central

    Komarova, Tatiana V.; Sheshukova, Ekaterina V.; Kosorukov, Vyacheslav S.; Kiryanov, Gleb I.; Dorokhov, Yuri L.

    2014-01-01

    Methanol (MeOH) is considered to be a poison in humans because of the alcohol dehydrogenase (ADH)-mediated conversion of MeOH to formaldehyde (FA), which is toxic. Our recent genome-wide analysis of the mouse brain demonstrated that an increase in endogenous MeOH after ADH inhibition led to a significant increase in the plasma MeOH concentration and a modification of mRNA synthesis. These findings suggest endogenous MeOH involvement in homeostasis regulation by controlling mRNA levels. Here, we demonstrate directly that study volunteers displayed increasing concentrations of MeOH and FA in their blood plasma when consuming citrus pectin, ethanol and red wine. A microarray analysis of white blood cells (WBC) from volunteers after pectin intake showed various responses for 30 significantly differentially regulated mRNAs, most of which were somehow involved in the pathogenesis of Alzheimer's disease (AD). There was also a decreased synthesis of hemoglobin mRNA, HBA and HBB, the presence of which in WBC RNA was not a result of red blood cells contamination because erythrocyte-specific marker genes were not significantly expressed. A qRT-PCR analysis of volunteer WBCs after pectin and red wine intake confirmed the complicated relationship between the plasma MeOH content and the mRNA accumulation of both genes that were previously identified, namely, GAPDH and SNX27, and genes revealed in this study, including MME, SORL1, DDIT4, HBA and HBB. We hypothesized that human plasma MeOH has an impact on the WBC mRNA levels of genes involved in cell signaling. PMID:25033451

  11. Solution structure of the complex between poxvirus-encoded CC chemokine inhibitor vCCI and human MIP-1β

    SciTech Connect

    Zhang, Li; DeRider, Michele; McCornack, Milissa A.; Jao, Chris; Isern, Nancy G.; Ness, Traci; Moyer, Richard; Liwang, Patricia J.

    2006-09-19

    Chemokines (chemotactic cytokines) comprise a large family of proteins that recruit and activate leukocytes, giving chemokines a major role in both the immune response and inflammation-related diseases. The poxvirus-encoded viral CC chemokine inhibitor (vCCI) binds to many CC chemokines with high affinity, acting as a potent inhibitor of chemokine action. We have used heteronuclear multidimensional NMR to determine the first structure of an orthopoxvirus vCCI in complex with a human CC chemokine MIP-1β. vCCI binds to the chemokine with 1:1 stoichiometry, using residues from its β-sheet II to interact with the a surface of MIP-1β that includes the N-terminus, the following residues in the so-called N-loop20’s region, and the 40’s loop. This structure reveals a general strategy of vCCI for selective chemokine binding, as vCCI appears to interact most stronglyinteracts most directly with residues that are conserved among a subset of CC chemokines, but are not conservednot among the other chemokine subfamilies. This structure reveals a general strategy of vCCI for selective chemokine binding. Chemokines play critical roles in the immune system, causing chemotaxis of a variety of cells to sites of infection and inflammation, as well as mediating cell homing and immune system development 1(Baggiolini 2001). To date, about 50 chemokines have been identified, and these small proteins (7-14 kDa) are believed to function by binding with endothelial or matrix glycosaminoglycans to form a concentration gradient that is then sensed by high affinity, 7-transmembrane domain G-protein coupled chemokine receptors on the surface of immune cells surface. The chemokine system is critical for host defense in healthy individuals, butand can also lead to diseases including asthma, arthritis, and atherosclerosis in the case of malfunction, often due to inappropriate inflammation and subsequent tissue damage 2(Gerard and Rollins 2001). There are four subfamilies of chemokines, CC

  12. The integrative roles of chemokines at the maternal-fetal interface in early pregnancy.

    PubMed

    Du, Mei-Rong; Wang, Song-Cun; Li, Da-Jin

    2014-09-01

    Embryos express paternal antigens that are foreign to the mother, but the mother provides a special immune milieu at the fetal-maternal interface to permit rather than reject the embryo growth in the uterus until parturition by establishing precise crosstalk between the mother and the fetus. There are unanswered questions in the maintenance of pregnancy, including the poorly understood phenomenon of maternal tolerance to the allogeneic conceptus, and the remarkable biological roles of placental trophoblasts that invade the uterine wall. Chemokines are multifunctional molecules initially described as having a role in leukocyte trafficking and later found to participate in developmental processes such as differentiation and directed migration. It is increasingly evident that the gestational uterine microenvironment is characterized, at least in part, by the differential expression and secretion of chemokines that induce selective trafficking of leukocyte subsets to the maternal-fetal interface and regulate multiple events that are closely associated with normal pregnancy. Here, we review the expression and function of chemokines and their receptors at the maternal-fetal interface, with a special focus on chemokine as a key component in trophoblast invasiveness and placental angiogenesis, recruitment and instruction of immune cells so as to form a fetus-supporting milieu during pregnancy. The chemokine network is also involved in pregnancy complications. PMID:25109684

  13. The integrative roles of chemokines at the maternal–fetal interface in early pregnancy

    PubMed Central

    Du, Mei-Rong; Wang, Song-Cun; Li, Da-Jin

    2014-01-01

    Embryos express paternal antigens that are foreign to the mother, but the mother provides a special immune milieu at the fetal–maternal interface to permit rather than reject the embryo growth in the uterus until parturition by establishing precise crosstalk between the mother and the fetus. There are unanswered questions in the maintenance of pregnancy, including the poorly understood phenomenon of maternal tolerance to the allogeneic conceptus, and the remarkable biological roles of placental trophoblasts that invade the uterine wall. Chemokines are multifunctional molecules initially described as having a role in leukocyte trafficking and later found to participate in developmental processes such as differentiation and directed migration. It is increasingly evident that the gestational uterine microenvironment is characterized, at least in part, by the differential expression and secretion of chemokines that induce selective trafficking of leukocyte subsets to the maternal–fetal interface and regulate multiple events that are closely associated with normal pregnancy. Here, we review the expression and function of chemokines and their receptors at the maternal–fetal interface, with a special focus on chemokine as a key component in trophoblast invasiveness and placental angiogenesis, recruitment and instruction of immune cells so as to form a fetus-supporting milieu during pregnancy. The chemokine network is also involved in pregnancy complications. PMID:25109684

  14. "Chemokine receptors as therapeutic targets: Why aren't there more drugs?".

    PubMed

    Solari, Roberto; Pease, James E; Begg, Malcolm

    2015-01-01

    Chemokines are a family of around 40 small proteins, which are secreted by a variety of cells, including structural cell types and leukocytes of the immune system. Chemokines bind to their specific 7-transmembrane G protein-coupled receptors (GPCRs) and induce a variety of downstream signals which notably modulate polymerization of the actin cytoskeleton and thus drive cellular motility. Excessive or inappropriate release of chemokines is observed in many inflammatory diseases and so there has been a great effort in industry to target chemokine receptors. The large family of GPCRs regulate many physiological cellular processes and they have proved to be highly amenable to pharmacological intervention with small chemicals. Consequently GPCRs make attractive targets for drug discovery and indeed a large number of successful current therapeutics are either agonists or antagonists of GPCRs. The apparent lack of success with chemokine receptors has been frustrating and in this paper we discuss potential reasons for previous failures and also why there is considerable cause for optimism. PMID:25016087

  15. 15 CFR 922.102 - Prohibited or otherwise regulated activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 3 2011-01-01 2011-01-01 false Prohibited or otherwise regulated activities. 922.102 Section 922.102 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT NATIONAL...

  16. Physical Activity and Self-Regulation Strategy Use in Adolescents

    ERIC Educational Resources Information Center

    Matthews, James; Moran, Aidan

    2011-01-01

    Objective: To examine the degree to which the use of selected theoretically derived self-regulation strategies (eg, goal setting) could predict adolescents' self-reported leisure-time physical activity behavior. Method: Two hundred thirty-three (M age = 15.88) high school students completed measures assessing their self-regulation strategy use and…

  17. 15 CFR 922.152 - Prohibited or otherwise regulated activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 3 2011-01-01 2011-01-01 false Prohibited or otherwise regulated activities. 922.152 Section 922.152 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT NATIONAL...

  18. The Equine Herpesvirus 2 E1 Open Reading Frame Encodes a Functional Chemokine Receptor

    PubMed Central

    Camarda, Grazia; Spinetti, Gaia; Bernardini, Giovanni; Mair, Catherine; Davis-Poynter, Nick; Capogrossi, Maurizio C.; Napolitano, Monica

    1999-01-01

    Several herpesviruses contain open reading frames (ORFs) that encode potential homologs of eucaryotic genes. Equine herpesvirus 2 (EHV-2) is a gammaherpesvirus related to other lymphotropic herpesviruses such as herpesvirus saimiri and Epstein-Barr virus. The E1 ORF of EHV-2, a G protein-coupled receptor homolog, shows 31 to 47% amino acid identity with known CC chemokine receptors. To investigate whether E1 may encode a functional receptor, we cloned the E1 ORF and expressed it in stably transfected cell lines. We report here the identification of the CC chemokine eotaxin as a functional ligand for the EHV-2 E1 receptor. Chemokines are likely to play a role in the regulation of immune functions in equine hosts during EHV-2 infection and, via interaction with E1, may affect viral replication and/or escape from immune responses. PMID:10559296

  19. Delayed functional expression of neuronal chemokine receptors following focal nerve demyelination in the rat: a mechanism for the development of chronic sensitization of peripheral nociceptors

    PubMed Central

    Bhangoo, Sonia; Ren, Dongjun; Miller, Richard J; Henry, Kenneth J; Lineswala, Jayana; Hamdouchi, Chafiq; Li, Baolin; Monahan, Patrick E; Chan, David M; Ripsch, Matthew S; White, Fletcher A

    2007-01-01

    Background Animal and clinical studies have revealed that focal peripheral nerve axon demyelination is accompanied by nociceptive pain behavior. C-C and C-X-C chemokines and their receptors have been strongly implicated in demyelinating polyneuropathies and persistent pain syndromes. Herein, we studied the degree to which chronic nociceptive pain behavior is correlated with the neuronal expression of chemokines and their receptors following unilateral lysophosphatidylcholine (LPC)-induced focal demyelination of the sciatic nerve in rats. Results Focal nerve demyelination increased behavioral reflex responsiveness to mechanical stimuli between postoperative day (POD) 3 and POD28 in both the hindpaw ipsilateral and contralateral to the nerve injury. This behavior was accompanied by a bilateral increase in the numbers of primary sensory neurons expressing the chemokine receptors CCR2, CCR5, and CXCR4 by POD14, with no change in the pattern of CXCR3 expression. Significant increases in the numbers of neurons expressing the chemokines monocyte chemoattractant protein-1 (MCP-1/CCL2), Regulated on Activation, Normal T Expressed and Secreted (RANTES/CCL5) and interferon γ-inducing protein-10 (IP-10/CXCL10) were also evident following nerve injury, although neuronal expression pattern of stromal cell derived factor-1α (SDF1/CXCL12) did not change. Functional studies demonstrated that acutely dissociated sensory neurons derived from LPC-injured animals responded with increased [Ca2+]i following exposure to MCP-1, IP-10, SDF1 and RANTES on POD 14 and 28, but these responses were largely absent by POD35. On days 14 and 28, rats received either saline or a CCR2 receptor antagonist isomer (CCR2 RA-[R]) or its inactive enantiomer (CCR2 RA-[S]) by intraperitoneal (i.p.) injection. CCR2 RA-[R] treatment of nerve-injured rats produced stereospecific bilateral reversal of tactile hyperalgesia. Conclusion These results suggest that the presence of chemokine signaling by both injured

  20. THE CHEMOKINE CX3CL1/FRACTALKINE INTERFERES WITH THE ANTINOCICEPTIVE EFFECT INDUCED BY OPIOID AGONISTS IN THE PERIAQUEDUCTAL GREY OF RATS

    PubMed Central

    Chen, Xiaohong; Geller, Ellen B.; Rogers, Thomas J.; Adler, Martin W.

    2007-01-01

    We have reported that there is heterologous interaction between the mu, delta or kappa opioid receptors and the receptors for the chemokines CCL5/RANTES or CXCL12/SDF-1 in the regulation of antinociception in rats. CX3CL1/fractalkine, a chemokine that exclusively binds to CX3CR1, has been found to affect morphine analgesia and tolerance in the spinal cord. The purpose of the present study was to see if the interaction between the chemokine CX3CL1/fractalkine receptor and mu, delta or kappa opioid receptors occurs in the periaqueductal grey (PAG) of adult male S-D rats. The cold-water tail-flick (CWT) test was used to measure antinociception. The results showed that intra-PAG injection of 100 ng CX3CL1/fractalkine 30 min before administration of 400 ng DAMGO, 100 ng DPDPE or 20 μg dynorphin significantly reduced the antinociception induced by each of these peptides. These results demonstrate that activation of the CX3CL1 receptor diminishes the effect of mu, delta and kappa opioid agonists on their receptors in the PAG of rats. PMID:17459345

  1. The Intricate Expression of CC Chemokines in Glial Tumors: Evidence for Involvement of CCL2 and CCL5 but Not CCL11.

    PubMed

    Moogooei, Mozhgan; Shamaei, Masoud; Khorramdelazad, Hossein; Fattahpour, Shirin; Seyedmehdi, Seyed Mohammad; Moogooei, Maryam; Hassanshahi, Gholamhossein; Kalantari Khandani, Behjat

    2015-12-01

    Chemokines are biologically active peptides involved in the pathogenesis of various pathologies including brain malignancies. They are amongst primitive regulators of the development of immune responses against malignant glial tumors. The present study aimed to examine the expression of CC chemokines in anaplastic astrocytoma and glioblastoma multiform patients at both mRNA and protein levels. Blood specimens in parallel with stereotactic biopsy specimens were obtained from 123 patients suffering from glial tumors and 100 healthy participants as a control. The serum levels of CCL2, CCL5, and CCL11 were measured by ELISA and stereotactic samples subjected to western and northern blotting methods for protein and mRNA, respectively. Demographic characteristics were also collected by a researcher-designed questionnaire. Results of the present study indicated that, however,CCL2 and CCL5 are elevated in serum and tumor tissues of patients suffering from a glial tumor at both mRNA and protein levels, the CCL11 was almost undetectable. According to the findings of the present investigation, it could presumably be reasonable to conclude that chemokines are good predictive molecules for expecting disease severity, metastasis, and response to treatment. PMID:26749234

  2. Renalase regulates peripheral and central dopaminergic activities

    PubMed Central

    Serrão, Maria Paula; Soares-Silva, Isabel; Fernandes-Cerqueira, Cátia; Simões-Silva, Liliana; Pinho, Maria João; Remião, Fernando; Sampaio-Maia, Benedita; Desir, Gary V.; Pestana, Manuel

    2014-01-01

    Renalase is a recently identified FAD/NADH-dependent amine oxidase mainly expressed in kidney that is secreted into blood and urine where it was suggested to metabolize catecholamines. The present study evaluated central and peripheral dopaminergic activities in the renalase knockout (KO) mouse model and examined the changes induced by recombinant renalase (RR) administration on plasma and urine catecholamine levels. Compared with wild-type (WT) mice, KO mice presented increased plasma levels of epinephrine (Epi), norepinephrine (NE), and dopamine (DA) that were accompanied by increases in the urinary excretion of Epi, NE, DA. In addition, the KO mice presented an increase in urinary DA-to-l-3,4-dihydroxyphenylalanine (l-DOPA) ratios without changes in renal tubular aromatic-l-amino acid decarboxylase (AADC) activity. By contrast, the in vivo administration of RR (1.5 mg/kg sc) to KO mice was accompanied by significant decreases in plasma levels of Epi, DA, and l-DOPA as well as in urinary excretion of Epi, DA, and DA-to-l-DOPA ratios notwithstanding the accompanied increase in renal AADC activity. In addition, the increase in renal DA output observed in renalase KO mice was accompanied by an increase in the expression of the L-type amino acid transporter like (LAT) 1 that is reversed by the administration of RR in these animals. These results suggest that the overexpression of LAT1 in the renal cortex of the renalase KO mice might contribute to the enhanced l-DOPA availability/uptake and consequently to the activation of the renal dopaminergic system in the presence of renalase deficiency. PMID:25411385

  3. Elevated Urinary T Helper 1 Chemokine Levels in Newly Diagnosed Hypertensive Obese Children

    PubMed Central

    Övünç Hacıhamdioğlu, Duygu; Zeybek, Cengiz; Gök, Faysal; Pekel, Aysel; Muşabak, Uğur

    2015-01-01

    Objective: Increasing evidence suggests that T helper (Th) cells play a significant role in the pathogenesis of hypertension. The aim of this study was to evaluate the effect of obesity and anti-hypertensive treatment on urinary Th1 chemokines. Methods: The study groups consisted of three types of patients: hypertensive obese, healthy, and non-hypertensive obese. Pre-treatment and post-treatment samples of the hypertensive obese group and one sample from the other two groups were evaluated for urinary chemokine: regulated on activation, normal T cell expressed and secreted (RANTES), interferon-gamma-inducible protein 10 (IP10), and monokine induced by interferon-gamma (MIG). In the hypertensive obese group, urine microalbumin: creatinine ratio was examined before and after treatment. We recommended lifestyle changes to all patients. Captopril was started in those who could not be controlled with lifestyle changes and those who had stage 2 hypertension. Results: Twenty-four hypertensive obese (mean age 13.1), 27 healthy (mean age 11.2) and 22 non-hypertensive obese (mean age 11.5) children were investigated. The pre-treatment urine albumin: creatinine ratio was positively correlated with pre-treatment MIG levels (r=0.41, p<0.05). RANTES was significantly higher in the pre-treatment hypertensive and non-hypertensive obese group than in the controls. The urinary IP10 and MIG levels were higher in the pre-treatment hypertensive obese group than in the non-hypertensive obese. Comparison of the pre- and post-treatment values indicated significant decreases in RANTES, IP10, and MIG levels in the hypertensive obese group (p<0.05). Conclusion: Th1 cells could be activated in obese hypertensive children before the onset of clinical indicators of target organ damage. Urinary RANTES seemed to be affected by both hypertension and obesity, and urinary IP10 and MIG seemed to be affected predominantly by hypertension. PMID:26831550

  4. Expression of chemokine decoy receptors and their ligands at the porcine maternal-fetal interface.

    PubMed

    Wessels, Jocelyn M; Linton, Nicola F; van den Heuvel, Marianne J; Cnossen, Sonya A; Edwards, Andrew K; Croy, Barbara Anne; Tayade, Chandrakant

    2011-02-01

    Successful pregnancy requires coordinated maternal-fetal cross-talk to establish vascular connections that support conceptus growth. In pigs, two waves of spontaneous fetal loss occur and 30-40% of conceptuses are lost before parturition. Previous studies associated these losses with decreased angiogenic and increased inflammatory cytokines. Chemokines, a sub-category of cytokines, and decoy receptors control leukocyte trafficking, angiogenesis and development. The availability of chemokines is regulated by three non-signalling decoy receptors: chemokine decoy receptor (D6), Duffy antigen receptor for chemokines (DARC) and Chemocentryx decoy receptor (CCX CKR). We hypothesized that the expression of these receptors and their chemokine ligands regulate the porcine pregnancy success or failure. Here, we describe for the first time the transcription and translation of all three decoy receptors and several chemokine ligands in endometrium and trophoblast associated with healthy and arresting conceptuses at gestation day (gd) 20 and gd50. Among decoy receptors, transcripts for DARC were significantly reduced in endometrium, whereas that for CCX CKR were significantly increased in endometrium and trophoblast at gd50 arresting compared with healthy sites. However, western blot analysis revealed no differences in decoy receptor expression between healthy and arresting tissues. Transcripts for decoy receptor ligands CCL2, CCL3, CCL4, CCL5, CCL11, CCL19, CCL21, CXCL2 and CXCL8 were stable between healthy and arresting littermates. Quantification by SearchLight chemiluminescent protein array confirmed ligand expression at the protein level. These data indicate that decoy receptors and ligands are expressed at the porcine maternal-fetal interface and dysregulation of decoy receptor (DARC and CCX CKR) transcripts occurs at sites of fetal arrest. PMID:20680026

  5. p21-activated kinase 2 regulates HSPC cytoskeleton, migration, and homing via CDC42 activation and interaction with β-Pix.

    PubMed

    Reddy, Pavankumar N G; Radu, Maria; Xu, Ke; Wood, Jenna; Harris, Chad E; Chernoff, Jonathan; Williams, David A

    2016-04-21

    Cytoskeletal remodeling of hematopoietic stem and progenitor cells (HSPCs) is essential for homing to the bone marrow (BM). The Ras-related C3 botulinum toxin substrate (Rac)/cell division control protein 42 homolog (CDC42) effector p21-activated kinase (Pak2) has been implicated in HSPC homing and engraftment. However, the molecular pathways mediating Pak2 functions in HSPCs are unknown. Here, we demonstrate that both Pak2 kinase activity and its interaction with the PAK-interacting exchange factor-β (β-Pix) are required to reconstitute defective ITALIC! Pak2 (ITALIC! Δ/Δ)HSPC homing to the BM. Pak2 serine/threonine kinase activity is required for stromal-derived factor-1 (SDF1α) chemokine-induced HSPC directional migration, whereas Pak2 interaction with β-Pix is required to regulate the velocity of HSPC migration and precise F-actin assembly. Lack of SDF1α-induced filopodia and associated abnormal cell protrusions seen in ITALIC! Pak2 (ITALIC! Δ/Δ)HSPCs were rescued by wild-type (WT) Pak2 but not by a Pak2-kinase dead mutant (KD). Expression of a β-Pix interaction-defective mutant of Pak2 rescued filopodia formation but led to abnormal F-actin bundles. Although CDC42 has previously been considered an upstream regulator of Pak2, we found a paradoxical decrease in baseline activation of CDC42 in ITALIC! Pak2 (ITALIC! Δ/Δ)HSPCs, which was rescued by expression of Pak2-WT but not by Pak2-KD; defective homing of ITALIC! Pak2-deleted HSPCs was rescued by constitutive active CDC42. These data demonstrate that both Pak2 kinase activity and its interaction with β-Pix are essential for HSPC filopodia formation, cytoskeletal integrity, and homing via activation of CDC42. Taken together, we provide mechanistic insights into the role of Pak2 in HSPC migration and homing. PMID:26932803

  6. Structure-function analysis of the extracellular domains of the Duffy antigen/receptor for chemokines: characterization of antibody and chemokine binding sites.

    PubMed

    Tournamille, Christophe; Filipe, Anne; Wasniowska, Kazimiera; Gane, Pierre; Lisowska, Elwira; Cartron, Jean-Pierre; Colin, Yves; Le Van Kim, Caroline

    2003-09-01

    The Duffy antigen/receptor for chemokines (DARC), a seven-transmembrane glycoprotein carrying the Duffy (Fy) blood group, acts as a widely expressed promiscuous chemokine receptor. In a structure-function study, we analysed the binding of chemokines and anti-Fy monoclonal antibodies (mAbs) to K562 cells expressing 39 mutant forms of DARC with alanine substitutions spread out on the four extracellular domains (ECDs). Using synthetic peptides, we defined previously the Fy6 epitope (22-FEDVW-26), and we characterized the Fya epitope as the linear sequence 41-YGANLE-46. In agreement with these results, mutations of F22-E23, V25 and Y41, G42, N44, L45 on ECD1 abolished the binding of anti-Fy6 and anti-Fya mAbs to K562 cells respectively, Anti-Fy3 binding was abolished by D58-D59 (ECD1), R124 (ECD2), D263 and D283 (ECD4) substitutions. Mutations of C51 (ECD1), C129 (ECD2), C195 (ECD3) and C276 (ECD4 severely reduced anti-Fy3 and CXC-chemokine ligand 8 (CXCL-8) binding. CXCL-8 binding was also abrogated by mutations of F22-E23, P50 (ECD1) and D263, R267, D283 (ECD4). These results defined the Fya epitope and suggested that (1) two disulphide bridges are involved in the creation of an active chemokine binding pocket; (2) a limited number of amino acids in ECDs 1-4 participate in CXCL-8 binding; and (3) Fy3 is a conformation-dependent epitope involving all ECDs. We also showed that N-glycosylation of DARC occurred on N16SS and did not influence antibody and chemokine binding. PMID:12956774

  7. Emerging importance of chemokine receptor CXCR3 and its ligands in cardiovascular diseases.

    PubMed

    Altara, Raffaele; Manca, Marco; Brandão, Rita D; Zeidan, Asad; Booz, George W; Zouein, Fouad A

    2016-04-01

    The CXC chemokines, CXCL4, -9, -10, -11, CXCL4L1, and the CC chemokine CCL21, activate CXC chemokine receptor 3 (CXCR3), a cell-surface G protein-coupled receptor expressed mainly by Th1 cells, cytotoxic T (Tc) cells and NK cells that have a key role in immunity and inflammation. However, CXCR3 is also expressed by vascular smooth muscle and endothelial cells, and appears to be important in controlling physiological vascular function. In the last decade, evidence from pre-clinical and clinical studies has revealed the participation of CXCR3 and its ligands in multiple cardiovascular diseases (CVDs) of different aetiologies including atherosclerosis, hypertension, cardiac hypertrophy and heart failure, as well as in heart transplant rejection and transplant coronary artery disease (CAD). CXCR3 ligands have also proven to be valid biomarkers for the development of heart failure and left ventricular dysfunction, suggesting an underlining pathophysiological relation between levels of these chemokines and the development of adverse cardiac remodelling. The observation that several of the above-mentioned chemokines exert biological actions independent of CXCR3 provides both opportunities and challenges for developing effective drug strategies. In this review, we provide evidence to support our contention that CXCR3 and its ligands actively participate in the development and progression of CVDs, and may additionally have utility as diagnostic and prognostic biomarkers. PMID:26888559

  8. Clinical utilization of chemokines to combat cancer: the double-edged sword

    PubMed Central

    Dell’Agnola, Chiara; Biragyn, Arya

    2008-01-01

    Chemokines are a small group of related chemoattractant peptides that play an essential role in the homeostatic maintenance of the immune system. They control the recruitment of cells needed for the induction and activation of innate and adaptive immune responses. However, tumors also utilize chemokines to actively progress and evade immunosurveillance. In fact, chemokines are involved directly or indirectly in almost every aspect of tumorigenesis. They mediate survival and metastatic spread of tumors, promote new blood vessel formation (neovascularization) and induce an immunosuppressive microenvironment via recruitment of immunosuppressive cells. As a result, a number of therapeutic strategies have been proposed to target almost every step of the chemokine/chemokine receptor involvement in tumors. Yet, despite occasional success stories, most of them appear to be ineffective or impractical, presumably due to ‘nonspecific’ harm of cells needed for the elimination of tumor escapees and maintenance of immunological memory. The strategy would only be effective if it also promoted antitumor adaptive immune responses capable of combating a residual disease and tumor relapse. PMID:17408375

  9. Basic Research on Virus-Induced Asthma Exacerbation: Inhibition of Inflammatory Chemokine Expression by Fluticasone Propionate

    PubMed Central

    Matsukura, Satoshi; Kurokawa, Masatsugu; Homma, Tetsuya; Watanabe, Shin; Suzuki, Shintaro; Ieki, Koushi; Takeuchi, Hiroko; Notomi, Kyoko; Schleimer, Robert P.; Kawaguchi, Mio; Kokubu, Fumio

    2016-01-01

    Background Viral infection can exacerbate asthma by inducing the accumulation of inflammatory cells in the airway. We have previously reported that double-stranded RNA (dsRNA), a viral product and ligand of the Toll-like receptor-3 (TLR3), activates the transcription factors NF-κB and IRF-3 and upregulates the expression of inflammatory chemokines in airway epithelial cells. Here, we examined the effects of the glucocorticoid fluticasone propionate (FP) on the expression of the inflammatory chemokines CCL5, CXCL8 and CXCL10. Methods The airway epithelial cell line BEAS-2B was used for this study. Expression of CCL5, CXCL8 and CXCL10 mRNA and protein was quantified by real-time PCR and ELISA assay, respectively. To examine the association of FP with the physiology of chemokine production, we included several methods. Nuclear translocation of transcription factors was determined by performing Western blot analysis. Histone deacetylase (HDAC) activity in nuclear extracts was measured using a colorimetric assay. Stability of the chemokine mRNAs was examined in cells incubated with actinomycin D. The activities of the CCL5 promoter and the transcription factors NF-κB and IRF-3 were assessed using luciferase reporter assays. Results Treatment of BEAS-2B cells with FP significantly and dose-dependently (10−9 to 10−6 M) inhibited dsRNA-induced expression of CCL5, CXCL8 and CXCL10 protein and mRNA, but did not affect mRNA stability. FP also significantly inhibited dsRNA-stimulated CCL5 promoter activity. However, FP had no effect on the activity of HDAC or the nuclear translocation of NF-κB and IRF-3. Conclusions FP inhibits the dsRNA-stimulated expression of inflammatory chemokines in airway epithelial cells. FP may act by inhibiting chemokine transcription through an as yet Unidentified mechanism. PMID:23711858

  10. Kinase active Misshapen regulates Notch signaling in Drosophila melanogaster.

    PubMed

    Mishra, Abhinava K; Sachan, Nalani; Mutsuddi, Mousumi; Mukherjee, Ashim

    2015-11-15

    Notch signaling pathway represents a principal cellular communication system that plays a pivotal role during development of metazoans. Drosophila misshapen (msn) encodes a protein kinase, which is related to the budding yeast Ste20p (sterile 20 protein) kinase. In a genetic screen, using candidate gene approach to identify novel kinases involved in Notch signaling, we identified msn as a novel regulator of Notch signaling. Data presented here suggest that overexpression of kinase active form of Msn exhibits phenotypes similar to Notch loss-of-function condition and msn genetically interacts with components of Notch signaling pathway. Kinase active form of Msn associates with Notch receptor and regulate its signaling activity. We further show that kinase active Misshapen leads to accumulation of membrane-tethered form of Notch. Moreover, activated Msn also depletes Armadillo and DE-Cadherin from adherens junctions. Thus, this study provides a yet unknown mode of regulation of Notch signaling by Misshapen. PMID:26431585

  11. Chemokine/chemokine receptor pair CCL20/CCR6 in human colorectal malignancy: An overview

    PubMed Central

    Frick, Vilma Oliveira; Rubie, Claudia; Keilholz, Ulrich; Ghadjar, Pirus

    2016-01-01

    Chemokines belong to a superfamily of small, cytokine-like proteins, which induce multiple physiological functions, particularly cytoskeletal rearrangement and compartment-specific migration through their interaction with G-protein-coupled receptors. Chemokines and their receptors have been widely acknowledged as essential and selective mediators in leukocyte migration in inflammatory response. It is now established that the chemokine/chemokine receptor system is also used by cancer cells to direct lymphatic and haematogenous spreading and additionally has an impact on the site of metastatic growth of different tumours. In recent years an increasing number of studies have drawn attention to CC-chemokine cysteine motif chemokine ligand 20 (CCL20) and its physiological sole receptor CCR6 to play a role in the onset, development and metastatic spread of various gastrointestinal cancer entities. Among various cancer types CCR6 was also demonstrated to be significantly overexpressed in colorectal cancer (CRC) and stimulation by its physiological ligand CCL20 has been reported to promote CRC cell proliferation and migration in vitro. Further, the CCL20/CCR6 system apparently plays a role in the organ-selective liver metastasis of CRC. Here we review the literature on expression patterns of CCL20 and CCR6 and their physiological interactions as well as the currently presumed role of CCL20 and CCR6 in the formation of CRC and the development of liver metastasis, providing a potential basis for novel treatment strategies. PMID:26811629

  12. Ragweed-allergic subjects have decreased serum levels of chemokines CCL2, CCL3, CCL4 and CCL5 out of the pollen season

    PubMed Central

    Kostova, Zhivka; Batsalova, Tsvetelina; Moten, Dzhemal; Teneva, Ivanka

    2016-01-01

    CC-chemokines are important mediators of the allergic responses and regulate the cell trafficking. The aim of this study was to examine the serum levels of CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β and CCL5/RANTES, and to determine whether there are differences between ragweed-allergic subjects and healthy individuals out of the pollen season. Peripheral blood samples were collected from 24 subjects allergic to ragweed pollen and 12 healthy controls. Serum concentrations of chemokines/cytokines were measured by an enzyme-linked immunosorbent assay. We observed significantly decreased concentrations of CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β and CCL5/RANTES in the sera of ragweed-allergic patients compared to the healthy individuals (32.2 vs. 106.4 pg/ml, 89.5 vs. 135.7 pg/ml, 63.4 vs. 119.2 pg/ml and 11.2 vs. 18.1 ng/ml, respectively, p < 0.01). In contrast to the CC-chemokines, the serum levels of IL-8/CXCL8 showed a significant increase (p < 0.05) in the allergic group compared to the non-allergic subjects. Interleukin 4 levels were similar in both groups. In the sera of allergic patients, we have also detected significantly elevated levels of ragweed-specific IgE and IgG. However, decreased serum concentrations of the four CC-chemokines and elevated levels of IL-8/CXCL8 can be used as biomarkers for more accurate evaluation of the allergic status of patients with pollen allergy out of the season, to study the mechanisms for activation/inhibition of the subclinical allergic responses and for development of therapeutic strategies. PMID:26862308

  13. Ragweed-allergic subjects have decreased serum levels of chemokines CCL2, CCL3, CCL4 and CCL5 out of the pollen season.

    PubMed

    Kostova, Zhivka; Batsalova, Tsvetelina; Moten, Dzhemal; Teneva, Ivanka; Dzhambazov, Balik

    2015-01-01

    CC-chemokines are important mediators of the allergic responses and regulate the cell trafficking. The aim of this study was to examine the serum levels of CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β and CCL5/RANTES, and to determine whether there are differences between ragweed-allergic subjects and healthy individuals out of the pollen season. Peripheral blood samples were collected from 24 subjects allergic to ragweed pollen and 12 healthy controls. Serum concentrations of chemokines/cytokines were measured by an enzyme-linked immunosorbent assay. We observed significantly decreased concentrations of CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β and CCL5/RANTES in the sera of ragweed-allergic patients compared to the healthy individuals (32.2 vs. 106.4 pg/ml, 89.5 vs. 135.7 pg/ml, 63.4 vs. 119.2 pg/ml and 11.2 vs. 18.1 ng/ml, respectively, p < 0.01). In contrast to the CC-chemokines, the serum levels of IL-8/CXCL8 showed a significant increase (p < 0.05) in the allergic group compared to the non-allergic subjects. Interleukin 4 levels were similar in both groups. In the sera of allergic patients, we have also detected significantly elevated levels of ragweed-specific IgE and IgG. However, decreased serum concentrations of the four CC-chemokines and elevated levels of IL-8/CXCL8 can be used as biomarkers for more accurate evaluation of the allergic status of patients with pollen allergy out of the season, to study the mechanisms for activation/inhibition of the subclinical allergic responses and for development of therapeutic strategies. PMID:26862308

  14. Suppression of silent information regulator 1 activity in noncancerous tissues of hepatocellular carcinoma: Possible association with non-B non-C hepatitis pathogenesis

    PubMed Central

    Konishi, Hideyuki; Shirabe, Ken; Nakagawara, Hidekazu; Harimoto, Norifumi; Yamashita, Yo-Ichi; Ikegami, Toru; Yoshizumi, Tomoharu; Soejima, Yuji; Oda, Yoshinao; Maehara, Yoshihiko

    2015-01-01

    Silent information regulator 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylase. In mice, mSirt1 deficiency causes the onset of fatty liver via regulation of the hepatic nutrient metabolism pathway. In this study, we demonstrate SIRT1 expression, activity and NAD+ regulation using noncancerous liver tissue specimens from hepatocellular carcinoma patients with non-B non-C (NBNC) hepatitis. SIRT1 expression levels were higher in NBNC patients than in healthy donors, while SIRT1 histone H3K9 deacetylation activity was suppressed in NBNC patients. In the liver of hepatitis patients, decreased NAD+ amounts and its regulatory enzyme nicotinamide phosphoribosyltransferase expression levels were observed, and this led to inhibition of SIRT1 activity. SIRT1 expression was associated with HIF1 protein accumulation in both the NBNC liver and liver cancer cell lines. These results may indicate that the NBNC hepatitis liver is exposed to hypoxic conditions. In HepG2 cells, hypoxia induced inflammatory chemokines, such as CXCL10 and MCP-1. These inductions were suppressed in rich NAD+ condition, and by SIRT1 activator treatment. In conclusion, hepatic SIRT1 activity was repressed in NBNC patients, and normalization of NAD+ amounts and activation of SIRT1 could improve the inflammatory condition in the liver of NBNC hepatitis patients. PMID:25736100

  15. Transferring the C-terminus of the chemokine CCL21 to CCL19 confers enhanced heparin binding.

    PubMed

    Barmore, Austin J; Castex, Sally M; Gouletas, Brittany A; Griffith, Alex J; Metz, Slater W; Muelder, Nicolas G; Populin, Michael J; Sackett, David M; Schuster, Abigail M; Veldkamp, Christopher T

    2016-09-01

    Chemokines direct the migration of cells during various immune processes and are involved in many disease states. For example, CCL19 and CCL21, through activation of the CCR7 receptor, recruit dendritic cells and naïve T-cells to the secondary lymphoid organs aiding in balancing immune response and tolerance. However, CCL19 and CCL21 can also direct the metastasis of CCR7 expressing cancers. Chemokine binding to glycosaminoglycans, such as heparin, is as important to chemokine function as receptor activation. CCL21 is unique in that it contains an extended C-terminus not found in other chemokines like CCL19. Deletion of this extended C-terminus reduces CCL21's affinity for heparin and transferring the CCL21 C-terminus to CCL19 enhances heparin binding mainly through non-specific, electrostatic interactions. PMID:27338641

  16. Constitutive secretion of chemokines by cultured human trabecular meshwork cells.

    PubMed

    Shifera, Amde Selassie; Trivedi, Sheetal; Chau, Phuonglan; Bonnemaison, Lucia H; Iguchi, Rumiko; Alvarado, Jorge A

    2010-07-01

    Trabecular meshwork endothelial (TME) cells secrete a number of factors, such as enzymes and cytokines, which modulate the functions of the cells and the extracellular matrix of the conventional aqueous outflow pathway. TME cells usually secrete these factors in response to stimuli such as mechanical stretching, laser irradiation and pro-inflammatory cytokines. Here, we report that cultured human TME cells isolated from two non-glaucomatous individuals secrete significant quantities of the chemotactic cytokines IL8, CXCL6 and MCP1 in the absence of any stimulation. The secretion of these chemokines was augmented by treatment with the pro-inflammatory cytokines TNFalpha and IL1beta. By way of comparison, there was little or very low production of the three chemokines by human non-pigmented ciliary epithelial cells in the absence of stimulation. Our findings provide support to our recent observations that monocytes, presumably under the influence of chemotactic signals, circulate through the trabecular meshwork in the normal state and also that cytokines regulate the permeability of Schlemm's canal endothelial cells. In addition, the fact that normal TME cells constitutively secrete chemotactic cytokines strengthens the notion that cytokines play a key role in the homeostasis of the outflow of the aqueous humor and, possibly, in the pathogenesis of glaucoma. PMID:20403352

  17. Absence of canonical active chromatin marks in developmentally regulated genes

    PubMed Central

    Ruiz-Romero, Marina; Corominas, Montserrat; Guigó, Roderic

    2015-01-01

    The interplay of active and repressive histone modifications is assumed to play a key role in the regulation of gene expression. In contrast to this generally accepted view, we show that transcription of genes temporally regulated during fly and worm development occurs in the absence of canonically active histone modifications. Conversely, strong chromatin marking is related to transcriptional and post-transcriptional stability, an association that we also observe in mammals. Our results support a model in which chromatin marking is associated to stable production of RNA, while unmarked chromatin would permit rapid gene activation and de-activation during development. In this case, regulation by transcription factors would play a comparatively more important regulatory role. PMID:26280901

  18. Cytokine and Chemokine Profile in Amicrobial Pustulosis of the Folds: Evidence for Autoinflammation.

    PubMed

    Marzano, Angelo V; Tavecchio, Simona; Berti, Emilio; Gelmetti, Carlo; Cugno, Massimo

    2015-12-01

    Autoinflammation has recently been suggested in the pathogenesis of neutrophilic dermatoses but systematic studies on their cytokine profile are lacking. Notably, amicrobial pustulosis of the folds (APF), classified among neutrophilic dermatoses, has been studied only in small case series. In our University Hospital, we conducted an observational study on 15 APF patients, analyzing their clinical and laboratory features with a follow-up of 9 months to 20 years. Skin cytokine pattern of 9 of them was compared to that of 6 normal controls. In all patients, primary lesions were pustules symmetrically involving the skin folds and anogenital region with a chronic-relapsing course and responding to corticosteroids. Dapsone, cyclosporine, and tumor necrosis factor blockers were effective in refractory cases. In skin samples, the expressions of interleukin (IL)-1β, pivotal cytokine in autoinflammation, and its receptors I and II were significantly higher in APF (P = 0.005, 0.018, and 0.034, respectively) than in controls. Chemokines responsible for neutrophil recruitment such as IL-8 (P = 0.003), CXCL 1/2/3 (C-X-C motif ligand 1/2/3) (P = 0.010), CXCL 16 (P = 0.045), and RANTES (regulated on activation, normal T cell expressed and secreted) (P = 0.034) were overexpressed. Molecules involved in tissue damage like matrix metalloproteinase-2 (MMP-2) (P = 0.010) and MMP-9 (P = 0.003) were increased. APF is a pustular neutrophilic dermatosis with a typical distribution in all patients. The disorder may coexist with an underlying autoimmune/dysimmune disease but is often associated only with a few autoantibodies without a clear autoimmunity. The overexpression of cytokines/chemokines and molecules amplifying the inflammatory network supports the view that APF has an important autoinflammatory component. PMID:26683967

  19. When human immunodeficiency virus meets chemokines and microglia: neuroprotection or neurodegeneration?

    PubMed

    Mocchetti, Italo; Campbell, Lee A; Harry, G Jean; Avdoshina, Valeriya

    2013-03-01

    Chemokines are chemotactic cytokines that were originally discovered as promoters of leukocyte proliferation and mobility. In recent years, however, evidence has demonstrated constitutive expression of chemokines and chemokine receptors in a variety of cells in the central and peripheral nervous system and has proposed a role for chemokines in neurodegenerative diseases characterized by inflammation and microglia proliferation. In addition, chemokine receptors, and in particular CXCR4 and CCR5, mediate human immunodeficiency virus type 1 (HIV) infection of immunocompetent cells as well as microglia. Subsequently, HIV, through a variety of mechanisms, promotes synapto-dendritic alterations and neuronal loss that ultimately lead to motor and cognitive impairments. These events are accompanied by microglia activation. Nevertheless, a microglia-mediated mechanism of neuronal degeneration alone cannot fully explain some of the pathological features of HIV infected brain such as synaptic simplification. In this article, we present evidence that some of the microglia responses to HIV are beneficial and neuroprotective. These include the ability of microglia to release anti-inflammatory cytokines, to remove dying cells and to promote axonal sprouting. PMID:22527632

  20. Expression of Chemokine XCL2 and CX3CL1 in Lung Cancer

    PubMed Central

    Zhou, Bing; Xu, Heyun; Ni, Kewei; Ni, Xuming; Shen, Jian

    2016-01-01

    Background Chemokines are a family of small proteins secreted by cells with chemotactic activity, and they play important roles in cell adhesion. However, the expression of chemokine XCL2 and CX3CL1 in lung cancers in different pathological stages remains unclear. Material/Methods XCL2 and CX3CL1 expression in lung cancers and adjacent non-cancerous tissues was detected by quantitative PCR and ELISA. The relative expression of both chemokines in lung cancers in different pathological stages was compared by immunohistochemical assay. Results The relative expression level of XCL2 and CX3CL1 in lung cancer was significantly higher compared with adjacent normal tissues (P<0.001). The expression level of both chemokines was significantly increased with higher pathological stages, as indicated by immunohistochemical assay (P<0.05 or P <0.001). Their expression level in cancers with higher numbers of metastatic lymph nodes was also significantly increased compared with cancers with lower numbers of metastatic lymph nodes (P<0.05 or P<0.001). Conclusions The expression of XCL2 and CX3CL1 increases with increasing degree of malignancy, indicating that both chemokines might be important targets in gene therapy for lung cancer. PMID:27156946

  1. Purification and biochemical characterization of the D6 chemokine receptor.

    PubMed Central

    Blackburn, Paul E; Simpson, Clare V; Nibbs, Robert J B; O'Hara, Maureen; Booth, Rhona; Poulos, Jemma; Isaacs, Neil W; Graham, Gerard J

    2004-01-01

    There is much interest in chemokine receptors as therapeutic targets in diseases such as AIDS, autoimmune and inflammatory disorders, and cancer. Hampering such studies is the lack of accurate three-dimensional structural models of these molecules. The CC-chemokine receptor D6 is expressed at exceptionally high levels in heterologous transfectants. Here we report the purification and biochemical characterization of milligram quantities of D6 protein from relatively small cultures of transfected mammalian cells. Importantly, purified D6 retains full functional activity, shown by displaceable binding of 125I-labelled MIP-1beta (macrophage inflammatory protein-1beta) and by complete binding of the receptor to a MIP-1alpha affinity column. In addition, we show that D6 is decorated on the N-terminus by N-linked glycosylation. Mutational analysis reveals that this glycosylation is dispensable for ligand binding and high expression in transfected cells. Metabolic labelling has revealed the receptor to also be sulphated and phosphorylated. Phosphorylation is ligand independent and is not enhanced by ligand binding and internalization, suggesting similarities with the viral chemokine receptor homologue US28. Like US28, an analysis of the full cellular complement of D6 in transfected cells indicates that >80% is found associated with intracellular vesicular structures. This may account for the high quantities of D6 that can be synthesized in these cells. These unusual properties of D6, and the biochemical characterization described here, leads the way towards work aimed at generating the three-dimensional structure of this seven-transmembrane-spanning receptor. PMID:14723600

  2. Chromatin Remodeling Inactivates Activity Genes and Regulates Neural Coding

    PubMed Central

    Hill, Kelly K.; Hemberg, Martin; Reddy, Naveen C.; Cho, Ha Y.; Guthrie, Arden N.; Oldenborg, Anna; Heiney, Shane A.; Ohmae, Shogo; Medina, Javier F.; Holy, Timothy E.; Bonni, Azad

    2016-01-01

    Activity-dependent transcription influences neuronal connectivity, but the roles and mechanisms of inactivation of activity-dependent genes have remained poorly understood. Genome-wide analyses in the mouse cerebellum revealed that the nucleosome remodeling and deacetylase (NuRD) complex deposits the histone variant H2A.z at promoters of activity-dependent genes, thereby triggering their inactivation. Purification of translating mRNAs from synchronously developing granule neurons (Sync-TRAP) showed that conditional knockout of the core NuRD subunit Chd4 impairs inactivation of activity-dependent genes when neurons undergo dendrite pruning. Chd4 knockout or expression of NuRD-regulated activity genes impairs dendrite pruning. Imaging of behaving mice revealed hyperresponsivity of granule neurons to sensorimotor stimuli upon Chd4 knockout. Our findings define an epigenetic mechanism that inactivates activity-dependent transcription and regulates dendrite patterning and sensorimotor encoding in the brain. PMID:27418512

  3. Interferon-Inducible CXC Chemokines Directly Contribute to Host Defense against Inhalational Anthrax in a Murine Model of Infection

    PubMed Central

    Crawford, Matthew A.; Burdick, Marie D.; Glomski, Ian J.; Boyer, Anne E.; Barr, John R.; Mehrad, Borna; Strieter, Robert M.; Hughes, Molly A.

    2010-01-01

    Chemokines have been found to exert direct, defensin-like antimicrobial activity in vitro, suggesting that, in addition to orchestrating cellular accumulation and activation, chemokines may contribute directly to the innate host response against infection. No observations have been made, however, demonstrating direct chemokine-mediated promotion of host defense in vivo. Here, we show that the murine interferon-inducible CXC chemokines CXCL9, CXCL10, and CXCL11 each exert direct antimicrobial effects in vitro against Bacillus anthracis Sterne strain spores and bacilli including disruptions in spore germination and marked reductions in spore and bacilli viability as assessed using CFU determination and a fluorometric assay of metabolic activity. Similar chemokine-mediated antimicrobial activity was also observed against fully virulent Ames strain spores and encapsulated bacilli. Moreover, antibody-mediated neutralization of these CXC chemokines in vivo was found to significantly increase host susceptibility to pulmonary B. anthracis infection in a murine model of inhalational anthrax with disease progression characterized by systemic bacterial dissemination, toxemia, and host death. Neutralization of the shared chemokine receptor CXCR3, responsible for mediating cellular recruitment in response to CXCL9, CXCL10, and CXCL11, was not found to increase host susceptibility to inhalational anthrax. Taken together, our data demonstrate a novel, receptor-independent antimicrobial role for the interferon-inducible CXC chemokines in pulmonary innate immunity in vivo. These data also support an immunomodulatory approach for effectively treating and/or preventing pulmonary B. anthracis infection, as well as infections caused by pathogenic and potentially, multi-drug resistant bacteria including other spore-forming organisms. PMID:21124994

  4. Developmental regulation of aromatase activity in the rat hypothalamus

    SciTech Connect

    Lephart, E.D.

    1989-01-01

    The brain of all mammalian species studied thus far contain an enzymatic activity (aromatase) that catalyzes the conversion of androgens to estrogens. The activity is highest during prenatal development and contributes to the establishment of sex differences which determine adult gonadotropin secretion patterns and reproductive behavior. The studies presented in this dissertation represent a systematic effort to elucidate the mechanism(s) that control the initiation of and contribute to maintaining rat hypothalamic aromatase activity during pre- and postnatal development. Aromatase enzyme activity was measured by the {sup 3}H{sub 2}O release assay or by traditional estrogen product isolation. Brain aromatase mRNA was detected by hybridization to a cDNA encoding rat aromatase cytochrome P-450. In both males and females the time of puberty was associated with a decline in hypothalamic aromatase activity. This decline may represent a factor underlying the peri-pubertal decrease in the sensitivity to gonadal steroid feedback that accompanies completion of puberty. The results also indicate that androgens regulate brain aromatase levels during both the prepubertal and peri-pubertal stages of sexual development and that this regulation is transiently lost in young adults. Utilizing a hypothalamic organotypic culture system, aromatase activity in vitro was maintained for as long as two days. The results of studies of a variety of hormonal and metabolic regulators suggest that prenatal aromatase activity is regulated by factor(s) that function independently from the classical cyclic AMP and protein kinase C trans-membrane signaling pathways.

  5. Effect of a topical steroid on gene expressions for chemokines in mice with contact hypersensitivity.

    PubMed

    Mitsui, Gaku; Hirano, Takeo; Niwano, Yoshimi; Mitsui, Kazutaka; Ohara, Osamu; Yanagihara, Satoshi; Kato, Masatoshi

    2004-01-01

    Effects of a topical corticosteroid drug, diflucortolone valerate, on the mRNA expressions for four CC- and four CXC-chemokines, which have been reported to be associated with recruitment of different kinds of proinflammatory and inflammatory cells, were investigated by RT-PCR in mice with 2,4,6-trinitrochlorobenzene (TNCB)-induced contact hypersensitivity (CHS) response. All of the eight gene expressions were clearly up-regulated in the lesion site of the CHS response up to 24 h post-challenge of TNCB at which ear swelling response reached a peak, so that heavy infiltration of inflammatory cells consisting mainly of mononuclear cells and neutrophils was likely induced by these chemokines. Topical treatment with diflucortolone valerate suppressed completely the infiltrates as well as the ear swelling response. In addition, the up-regulation of gene expressions for these eight chemokines were suppressed by the treatment, indicating that the corticosteroid drug attenuates the expression of chemokine genes essential for orientating nonspecific skin response to hapten-specific CHS response through the recruitment of inflammatory cells from the circulation into the tissue site. PMID:14975360

  6. IQGAP1 promotes CXCR4 chemokine receptor function and trafficking via EEA-1+ endosomes

    PubMed Central

    Bamidele, Adebowale O.; Kremer, Kimberly N.; Hirsova, Petra; Clift, Ian C.; Gores, Gregory J.; Billadeau, Daniel D.

    2015-01-01

    IQ motif–containing GTPase-activating protein 1 (IQGAP1) is a cytoskeleton-interacting scaffold protein. CXCR4 is a chemokine receptor that binds stromal cell–derived factor-1 (SDF-1; also known as CXCL12). Both IQGAP1 and CXCR4 are overexpressed in cancer cell types, yet it was unclear whether these molecules functionally interact. Here, we show that depleting IQGAP1 in Jurkat T leukemic cells reduced CXCR4 expression, disrupted trafficking of endocytosed CXCR4 via EEA-1+ endosomes, and decreased efficiency of CXCR4 recycling. SDF-1–induced cell migration and activation of extracellular signal-regulated kinases 1 and 2 (ERK) MAPK were strongly inhibited, even when forced overexpression restored CXCR4 levels. Similar results were seen in KMBC and HEK293 cells. Exploring the mechanism, we found that SDF-1 treatment induced IQGAP1 binding to α-tubulin and localization to CXCR4-containing endosomes and that CXCR4-containing EEA-1+ endosomes were abnormally located distal from the microtubule (MT)-organizing center (MTOC) in IQGAP1-deficient cells. Thus, IQGAP1 critically mediates CXCR4 cell surface expression and signaling, evidently by regulating EEA-1+ endosome interactions with MTs during CXCR4 trafficking and recycling. IQGAP1 may similarly promote CXCR4 functions in other cancer cell types. PMID:26195666

  7. Analysis of Chemokine Receptor Trafficking by Site-Specific Biotinylation

    PubMed Central

    Liebick, Marcel; Schläger, Christian; Oppermann, Martin

    2016-01-01

    Chemokine receptors undergo internalization and desensitization in response to ligand activation. Internalized receptors are either preferentially directed towards recycling pathways (e.g. CCR5) or sorted for proteasomal degradation (e.g. CXCR4). Here we describe a method for the analysis of receptor internalization and recycling based on specific Bir A-mediated biotinylation of an acceptor peptide coupled to the receptor, which allows a more detailed analysis of receptor trafficking compared to classical antibody-based detection methods. Studies on constitutive internalization of the chemokine receptors CXCR4 (12.1% ± 0.99% receptor internalization/h) and CCR5 (13.7% ± 0.68%/h) reveals modulation of these processes by inverse (TAK779; 10.9% ± 0.95%/h) or partial agonists (Met-CCL5; 15.6% ± 0.5%/h). These results suggest an actively driven internalization process. We also demonstrate the advantages of specific biotinylation compared to classical antibody detection during agonist-induced receptor internalization, which may be used for immunofluorescence analysis as well. Site-specific biotinylation may be applicable to studies on trafficking of transmembrane proteins, in general. PMID:27310579

  8. Heparanase augments inflammatory chemokine production from colorectal carcinoma cell lines.

    PubMed

    Tsunekawa, Naoki; Higashi, Nobuaki; Kogane, Yusuke; Waki, Michihiko; Shida, Hiroaki; Nishimura, Yoshio; Adachi, Hayamitsu; Nakajima, Motowo; Irimura, Tatsuro

    2016-01-22

    To explore possible roles of heparanase in cancer-host crosstalk, we examined whether heparanase influences expression of inflammatory chemokines in colorectal cancer cells. Murine colorectal carcinoma cells incubated with heparanase upregulated MCP-1, KC, and RANTES genes and released MCP-1 and KC proteins. Heparanase-dependent production of IL-8 was detected in two human colorectal carcinoma cell lines. Addition of a heparanase inhibitor Heparastatin (SF4) did not influence MCP-1 production, while both latent and mature forms of heparanase augmented MCP-1 release, suggesting that heparanase catalytic activity was dispensable for MCP-1 production. In contrast, addition of heparin to the medium suppressed MCP-1 release in a dose-dependent manner. Similarly, targeted suppression of Ext1 by RNAi significantly suppressed cell surface expression of heparan sulfate and MCP-1 production in colon 26 cells. Taken together, it is concluded that colon 26 cells transduce the heparanase-mediated signal through heparan sulfate binding. We propose a novel function for heparanase independent of its endoglycosidase activity, namely as a stimulant for chemokine production. PMID:26713365

  9. Bacterial differentiation via gradual activation of global regulators.

    PubMed

    Kovács, Ákos T

    2016-02-01

    Bacteria have evolved to adapt to various conditions and respond to certain stress conditions. The ability to sense and efficiently reply to these environmental effects involve versatile array of sensors and global or specific regulators. Interestingly, modulation of the levels of active global regulators enables bacteria to respond to diverse signals via a single central transcriptional regulator and to activate or repress certain differentiation pathways at a spatio-temporal manner. The Gram-positive Bacillus subtilis is an ideal bacterium to study how membrane bound and cytoplasmic sensor kinases affect the level of phosphorylated global regulator, Spo0A which in response activates genes related to sliding, biofilm formation, and sporulation. In addition, other global regulators, including the two-component system DegS-DegU, modulate overlapping and complementary genes in B. subtilis related to surface colonization and biofilm formation. The intertwinement of global regulatory systems also allows the accurate modulation of differentiation pathways. Studies in the last decade enable us to get a deeper insight into the role of global regulators on the smooth transition of developmental processes in B. subtilis. PMID:26458398

  10. Molecular cloning, characterization and expression analysis of a CC chemokine gene from miiuy croaker (Miichthys miiuy).

    PubMed

    Cheng, Yuanzhi; Sun, Yuena; Shi, Ge; Wang, Rixin; Xu, Tianjun

    2012-12-01

    Chemokines are a family of structurally related chemotactic cytokines that regulate the migration of leukocytes, under both physiological and inflammatory conditions. A partial cDNA of CC chemokine gene designed as Mimi-CC3 was isolated from miiuy croaker (Miichthys miiuy) spleen cDNA library. Unknown 3' part of the cDNA was amplified by 3'-RACE. The complete cDNA of Mimi-CC3 contains an 89-nt 5'-UTR, a 303-nt open reading frame and a 441-nt 3'-UTR. Three exons and two introns were identified in Mimi-CC3. The deduced Mimi-CC3 protein sequences contain a 22 amino acids signal peptide and a 78 amino acids mature polypeptide, which possesses the typical arrangement of four cysteines as found in other known CC chemokines. It shares low amino acid sequence identities with most other fish and mammalian CC chemokines (less than 54.1 %), but shares very high identities with large yellow croaker CC chemokine (94.6 %). Phylogenetic analysis showed that Mimi-CC3 gene may have an orthologous relationship with mammalian/amphibian CCL25 gene. Tissue expression distributed analysis showed that Mimi-CC3 gene was constitutively expressed in all nine tissues examined, although at different levels. Upon stimulated with Vibrio anguillarum, the time-course analysis using a real-time PCR showed that Mimi-CC3 transcript in kidney and liver was obviously up-regulated and reached the peak levels, followed by a recovery. Mimi-CC3 expression in kidney was more strongly increased than in liver. However, down-regulation was observed in spleen. These results indicated that Mimi-CC3 plays important roles in miiuy croaker immune response as well as in homeostatic mechanisms. PMID:22736236

  11. Expression of cytokines, chemokines and other effector molecules in two prototypic autoinflammatory skin diseases, pyoderma gangrenosum and Sweet's syndrome

    PubMed Central

    Marzano, A V; Fanoni, D; Antiga, E; Quaglino, P; Caproni, M; Crosti, C; Meroni, P L; Cugno, M

    2014-01-01

    Pyoderma gangrenosum (PG) and Sweet's syndrome (SS) are two inflammatory skin diseases presenting with painful ulcers and erythematous plaques, respectively; both disorders have a debilitating clinical behaviour and PG is potentially life-threatening. Recently, PG and SS have been included among the autoinflammatory diseases, which are characterized by recurrent episodes of sterile inflammation, without circulating autoantibodies and autoreactive T cells. However, an autoinflammatory pattern clearly supporting this inclusion has never been demonstrated. We studied 16 patients with PG, six with SS and six controls, evaluating, using a sandwich-based protein antibody array method, the expression profile of inflammatory effector molecules in PG, SS and normal skin. The expressions of interleukin (IL)-1 beta and its receptor I were significantly higher in PG (P = 0·0001 for both) and SS (P = 0·004–0·040) than in controls. In PG, chemokines such as IL-8 (P = 0·0001), chemokine (C-X-C motif) ligand (CXCL) 1/2/3 (P = 0·002), CXCL 16 (P = 0·003) and regulated upon activation normal T cell expressed and secreted (RANTES) (P = 0·005) were over-expressed. In SS, IL-8 (P = 0·018), CXCL 1/2/3 (P = 0·006) and CXCL 16 (P = 0·036) but not RANTES were over-expressed, suggesting that chemokine-mediated signals are lower than in PG. Fas/Fas ligand and CD40/CD40 ligand systems were over-expressed in PG (P = 0·0001 for Fas, P = 0·009 for Fas ligand, P = 0·012 for CD40, P = 0·0001 for CD40 ligand), contributing to tissue damage and inflammation, while their role seems to be less significant in SS. Over-expression of cytokines/chemokines and molecules amplifying the inflammatory network supports the view that PG and SS are autoinflammatory diseases. The differences in expression profile of inflammatory effectors between these two disorders may explain the stronger local aggressiveness in PG than SS. PMID:24903614

  12. Epigenetic regulator Lid maintains germline stem cells through regulating JAK-STAT signaling pathway activity

    PubMed Central

    Tarayrah, Lama; Li, Yuping; Gan, Qiang; Chen, Xin

    2015-01-01

    ABSTRACT Signaling pathways and epigenetic mechanisms have both been shown to play essential roles in regulating stem cell activity. While the role of either mechanism in this regulation is well established in multiple stem cell lineages, how the two mechanisms interact to regulate stem cell activity is not as well understood. Here we report that in the Drosophila testis, an H3K4me3-specific histone demethylase encoded by little imaginal discs (lid) maintains germline stem cell (GSC) mitotic index and prevents GSC premature differentiation. Lid is required in germ cells for proper expression of the Stat92E transcription factor, the downstream effector of the Janus kinase signal transducer and activator of transcription (JAK-STAT) signaling pathway. Our findings support a germ cell autonomous role for the JAK-STAT pathway in maintaining GSCs and place Lid as an upstream regulator of this pathway. Our study provides new insights into the biological functions of a histone demethylase in vivo and sheds light on the interaction between epigenetic mechanisms and signaling pathways in regulating stem cell activities. PMID:26490676

  13. Targeting chemokine pathways in esophageal adenocarcinoma

    PubMed Central

    Shrivastava, Makardhwaj S; Hussain, Zulfiqar; Giricz, Orsolya; Shenoy, Niraj; Polineni, Rahul; Maitra, Anirban; Verma, Amit

    2014-01-01

    Esophageal adenocarcinoma (EAC) is one of the fastest growing malignancies in the US and needs newer therapeutic and diagnostic strategies. Chronic inflammation plays a role in the pathogenesis of EAC and contributes to the dysplastic conversion of normal esophageal epithelium to Barrett's esophagus and frank adenocarcinoma. Chemokines play important roles in mediating inflammation and recent evidence implicates these ligands and their receptors in the development and spread of various tumors. We demonstrated that the chemokines IL8, CXCL1 and CXCL3 are significantly overexpressed during esophageal carcinogenesis and accompanied by amplification and demethylation of the chr4q21 gene locus. We also demonstrated that IL8 levels can be detected in serum of patients with EAC and can serve as potential biomarkers. We now demonstrate that inhibition of IL8 receptor, CXCR2, leads to decreased invasiveness of esophageal adenocarcinoma derived cells without affecting cellular proliferation. Taken together, these studies reveal the important roles that chemokines play in development of esophageal cancer and demonstrate that these pathways can serve as potential therapeutic targets. PMID:25485576

  14. 34 CFR 110.2 - To what programs or activities do these regulations apply?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... labor-management joint apprenticeship training program, except any program or activity receiving Federal... regulations apply? (a) These regulations apply to any program or activity receiving Federal...

  15. 34 CFR 110.2 - To what programs or activities do these regulations apply?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... labor-management joint apprenticeship training program, except any program or activity receiving Federal... regulations apply? (a) These regulations apply to any program or activity receiving Federal...

  16. 34 CFR 110.2 - To what programs or activities do these regulations apply?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... labor-management joint apprenticeship training program, except any program or activity receiving Federal... regulations apply? (a) These regulations apply to any program or activity receiving Federal...

  17. 34 CFR 110.2 - To what programs or activities do these regulations apply?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... labor-management joint apprenticeship training program, except any program or activity receiving Federal... regulations apply? (a) These regulations apply to any program or activity receiving Federal...

  18. 34 CFR 110.2 - To what programs or activities do these regulations apply?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... labor-management joint apprenticeship training program, except any program or activity receiving Federal... regulations apply? (a) These regulations apply to any program or activity receiving Federal...

  19. Ikkepsilon regulates viral-induced interferon regulatory factor-3 activation via a redox-sensitive pathway

    SciTech Connect

    Indukuri, Hemalatha; Castro, Shawn M.; Liao, S.-M.; Feeney, Lee Ann; Dorsch, Marion; Coyle, Anthony J.; Garofalo, Roberto P.; Brasier, Allan R.; Casola, Antonella . E-mail: ancasola@utmb.edu

    2006-09-15

    Respiratory syncytial virus (RSV)-induced chemokine gene expression occurs through the activation of a subset of transcription factors, including Interferon Regulatory Factor (IRF)-3. In this study, we have investigated the signaling pathway leading to RSV-induced IRF-3 activation and whether it is mediated by intracellular reactive oxygen species (ROS) generation. Our results show that RSV infection induces expression and catalytic activity of IKK{epsilon}, a noncanonical IKK-like kinase. Expression of a kinase-inactive IKK{epsilon} blocks RSV-induced IRF-3 serine phosphorylation, nuclear translocation and DNA-binding, leading to inhibition of RANTES gene transcription, mRNA expression and protein synthesis. Treatment of alveolar epithelial cells with antioxidants or with NAD(P)H oxidase inhibitors abrogates RSV-induced chemokine secretion, IRF-3 phosphorylation and IKK{epsilon} induction, indicating that ROS generation plays a fundamental role in the signaling pathway leading to IRF-3 activation, therefore, identifying a novel molecular target for the development of strategies aimed to modify the inflammatory response associated with RSV infection of the lung.

  20. Minimal regulation of platelet activity by PECAM-1.

    PubMed

    Dhanjal, Tarvinder S; Ross, Ewan A; Auger, Jocelyn M; McCarty, Owen J T; Hughes, Craig E; Senis, Yotis A; Buckley, Chris D; Watson, Steve P

    2007-02-01

    PECAM-1 is a member of the superfamily of immunoglobulins (Ig) and is expressed on platelets at moderate level. PECAM-1 has been reported to have contrasting effects on platelet activation by the collagen receptor GPVI and the integrin, alphaIIbbeta3, even though both receptors signal through Src-kinase regulation of PLCgamma2. The present study compares the role of PECAM-1 on platelet activation by these two receptors and by the lectin receptor, CLEC-2, which also signals via PLCgamma2. Studies using PECAM-1 knockout-mice and cross-linking of PECAM-1 using specific antibodies demonstrated a minor inhibitory role on platelet responses to the above three receptors and also under some conditions to the G-protein agonist thrombin. The degree of inhibition was considerably less than that produced by PGI2, which elevates cAMP. There was no significant difference in thrombus formation on collagen in PECAM-1-/- platelets relative to litter-matched controls. The very weak inhibitory effect of PECAM-1 on platelet activation relative to that of PGI2 indicate that the Ig-receptor is not a major regulator of platelet activation. PECAM-1 has been reported to have contrasting effects on platelet activation. The present study demonstrates a very mild or negligible effect on platelet activation in response to stimulation by a variety of agonists, thereby questioning the physiological role of the immunoglobulin receptor as a major regulator of platelet activation. PMID:17365855

  1. Platelet activating factor: regulation by mast cells and aspirin.

    PubMed

    Denburg, J A; Williams, D B; Kinlough-Rathbone, R L; Cazenave, J P; Bienenstock, J

    1984-02-01

    We have investigated some aspects of the regulation of production of rat platelet activating factor (PAF)2 in vitro. Suspensions of unseparated (PLC1), mast cell-depleted (PLC2), or mast cell (MC)-enriched rat peritoneal lavage cells (PLC) were analyzed for PAF content by extraction at alkaline pH. PAF activity extracted from PLC1 varied inversely with viable cell concentration: at 1 X 10(6) cells/ml, 32 +/- 9.3 PAF units, decreasing to 11.2 +/- 9.5 units at 10 X 10(6) cells/ml, and no activity at higher concentrations. Incubation of PLC1 in Tyrode's buffer or acetylsalicylic acid (ASA), but not salicylate, resulted in a time-dependent loss of PAF activity. Mean PAF activity of PLC2 was similar to that in PLC1, while no PAF activity was extractable from MC. Co-incubation with MC extracts inhibited PAF activity of PLC1 extracts in a dose-dependent fashion. Ultracentrifugation of PAF-containing samples led to a loss of all PAF activity in PLC1 extracts, suggesting the association of PAF activity with subcellular components. PAF appears to be derived from a non-MC population of rat PLC, is not extractable from rat PLC in the presence of ASA and is inhibited by MC extracts. These studies suggest that ASA regulates PAF availability unrelated to its effect on cyclooxygenase and that MC membrane products directly inhibit PAF activity from rat PLC. PMID:6711391

  2. Intracerebroventricular injection of adiponectin regulates locomotor activity in rats.

    PubMed

    Miyatake, Yumiko; Shiuchi, Tetsuya; Ueta, Tomoyo; Taniguchi, Yasuko; Futami, Akari; Sato, Fukiko; Kitamura, Tadahiro; Tsutsumi, Rie; Harada, Nagakatsu; Nakaya, Yutaka; Sakaue, Hiroshi

    2015-01-01

    Enhancing exercise motivation is the best way to prevent obesity and diabetes. In this study, we examined whether adiponectin affects locomotion activity in Wister and Spontaneously-Running Tokushima-Shikoku (SPORTS) rats using two types of behavioral assays: home cage and wheel running activity. SPORTS rats were established from an original line from Wister strain that had shown high level of wheel running activity in our laboratory. Injection of adiponectin into the lateral ventricle of Wister rats and SPORTS rats decreased home cage activity, but no change was observed in the food intake and oxygen consumption. This result indicates the possibility that adiponectin can reduce non-exercise activity thermogenesis (NEAT) and physical activity via the central nervous system. In contrast, injection of adiponectin did not change wheel running activity in SPORTS rats. We produced hypothalamus-destructed model rat using monosodium glutamate (MSG) to elucidate the regulation site of adiponectin. Injection of adiponectin into MSG-treated SPORTS rats did not change amount of home cage activity and food intake, suggesting that adiponectin action on home cage activity was in the hypothalamic area. These results suggest that adiponectin regulates locomotion activity through mediobasal hypothalamus. PMID:26399348

  3. Enhanced Levels of Chemokines and Their Receptors in the Colon of Microscopic Colitis Patients Indicate Mixed Immune Cell Recruitment

    PubMed Central

    Günaltay, Sezin; Bohr, Johan; Hultgren, Olof

    2015-01-01

    Microscopic colitis (MC), comprising collagenous colitis (CC) and lymphocytic colitis (LC), is a common cause of chronic diarrhea. Various immune cell infiltrations in the epithelium and lamina propria are seen in MC immunopathology. We compared gene and protein expressions of different immune cell attracting chemokines and their receptors in colon biopsies from MC patients in active disease or histopathological remission (CC/LC-HR) with controls, using qRT-PCR and Luminex, respectively. CC and LC patients with active disease demonstrated a mixed chemokine profile with significantly enhanced gene and/or protein expressions of the chemokines CCL2, CCL3, CCL4, CCL5, CCL7, CCL22, CXCL8, CXCL9, CXCL10, CXCL11, and CX3CL1 and the receptors CCR2, CCR3, CCR4, CXCR1, CXCR2, and CX3CR1. Enhanced chemokine/chemokine receptor gene and protein levels in LC-HR patients were similar to LC patients, whereas CC-HR patients demonstrated almost normalized levels. These findings expand the current understanding of the involvement of various immune cells in MC immunopathology and endorse chemokines as potential diagnostic markers as well as therapeutic candidates. Moreover, this study further supports the hypothesis that CC and LC are two different entities due to differences in their immunoregulatory responses. PMID:25948880

  4. CXCL1/MGSA Is a Novel Glycosaminoglycan (GAG)-binding Chemokine: STRUCTURAL EVIDENCE FOR TWO DISTINCT NON-OVERLAPPING BINDING DOMAINS.

    PubMed

    Sepuru, Krishna Mohan; Rajarathnam, Krishna

    2016-02-19

    In humans, the chemokine CXCL1/MGSA (hCXCL1) plays fundamental and diverse roles in pathophysiology, from microbial killing to cancer progression, by orchestrating the directed migration of immune and non-immune cells. Cellular trafficking is highly regulated and requires concentration gradients that are achieved by interactions with sulfated glycosaminoglycans (GAGs). However, very little is known regarding the structural basis underlying hCXCL1-GAG interactions. We addressed this by characterizing the binding of GAG heparin oligosaccharides to hCXCL1 using NMR spectroscopy. Binding experiments under conditions at which hCXCL1 exists as monomers and dimers indicate that the dimer is the high-affinity GAG ligand. NMR experiments and modeling studies indicate that lysine and arginine residues mediate binding and that they are located in two non-overlapping domains. One domain, consisting of N-loop and C-helical residues (defined as α-domain) has also been identified previously as the GAG-binding domain for the related chemokine CXCL8/IL-8. The second domain, consisting of residues from the N terminus, 40s turn, and third β-strand (defined as β-domain) is novel. Eliminating β-domain binding by mutagenesis does not perturb α-domain binding, indicating two independent GAG-binding sites. It is known that N-loop and N-terminal residues mediate receptor activation, and we show that these residues are also involved in extensive GAG interactions. We also show that the GAG-bound hCXCL1 completely occlude receptor binding. We conclude that hCXCL1-GAG interactions provide stringent control over regulating chemokine levels and receptor accessibility and activation, and that chemotactic gradients mediate cellular trafficking to the target site. PMID:26721883

  5. Active Inference, homeostatic regulation and adaptive behavioural control

    PubMed Central

    Pezzulo, Giovanni; Rigoli, Francesco; Friston, Karl

    2015-01-01

    We review a theory of homeostatic regulation and adaptive behavioural control within the Active Inference framework. Our aim is to connect two research streams that are usually considered independently; namely, Active Inference and associative learning theories of animal behaviour. The former uses a probabilistic (Bayesian) formulation of perception and action, while the latter calls on multiple (Pavlovian, habitual, goal-directed) processes for homeostatic and behavioural control. We offer a synthesis these classical processes and cast them as successive hierarchical contextualisations of sensorimotor constructs, using the generative models that underpin Active Inference. This dissolves any apparent mechanistic distinction between the optimization processes that mediate classical control or learning. Furthermore, we generalize the scope of Active Inference by emphasizing interoceptive inference and homeostatic regulation. The ensuing homeostatic (or allostatic) perspective provides an intuitive explanation for how priors act as drives or goals to enslave action, and emphasises the embodied nature of inference. PMID:26365173

  6. Active Inference, homeostatic regulation and adaptive behavioural control.

    PubMed

    Pezzulo, Giovanni; Rigoli, Francesco; Friston, Karl

    2015-11-01

    We review a theory of homeostatic regulation and adaptive behavioural control within the Active Inference framework. Our aim is to connect two research streams that are usually considered independently; namely, Active Inference and associative learning theories of animal behaviour. The former uses a probabilistic (Bayesian) formulation of perception and action, while the latter calls on multiple (Pavlovian, habitual, goal-directed) processes for homeostatic and behavioural control. We offer a synthesis these classical processes and cast them as successive hierarchical contextualisations of sensorimotor constructs, using the generative models that underpin Active Inference. This dissolves any apparent mechanistic distinction between the optimization processes that mediate classical control or learning. Furthermore, we generalize the scope of Active Inference by emphasizing interoceptive inference and homeostatic regulation. The ensuing homeostatic (or allostatic) perspective provides an intuitive explanation for how priors act as drives or goals to enslave action, and emphasises the embodied nature of inference. PMID:26365173

  7. Regulation of the extracellular ligand binding activity of integrins.

    PubMed

    Fernandez, C; Clark, K; Burrows, L; Schofield, N R; Humphries, M J

    1998-07-01

    Integrins are a large heterodimeric family of cell surface adhesion receptors that bind extracellular matrix and cell surface ligands. The extracellular ligand binding activity of integrins is a dynamic and highly regulated event involving the induction of conformational changes within the integrin structure. The adhesive properties of integrins can be controlled by altering the activation state of the integrin, either through conformational change or receptor clustering, using mechanisms that are regulated by intracellular proteins. In this review, we will discuss what is currently known about integrin structure and the ligand binding sites present within the receptor. In addition, the mechanisms by which the ligand binding event is regulated through conformational change will be addressed, and the potential role of intracellular cytoplasmic proteins will be discussed. PMID:9637803

  8. Liver X receptor regulates rheumatoid arthritis fibroblast-like synoviocyte invasiveness, matrix metalloproteinase 2 activation, interleukin-6 and CXCL10.

    PubMed

    Laragione, Teresina; Gulko, Pércio S

    2012-01-01

    Fibroblast-like synoviocyte (FLS) invasiveness correlates with articular damage in rheumatoid arthritis (RA), yet little is known about its regulat