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Publication
Journal: GLIA
June/11/2008
Abstract
Aicardi-Goutières syndrome (AGS) presents as a severe autosomal recessively inherited neurological brain disease. Clinical and neurological manifestations closely resemble those of congenital viral infection and are generally attributed to a perturbation of innate immunity including a long lasting lymphocytosis and production of interferon-alpha (IFNalpha) in the central nervous system. To clarify the innate immune response evoked in these diseases, we used a 30-mer multiplexed luminex system to measure multiple cytokines and growth factors in the cerebrospinal fluid and serum of patients with AGS and viral meningitis or encephalitis, and febrile controls in whom infection could not be substantiated. In addition to the previously described IFNalpha, both AGS and viral diseases were characterized by expression of CXCL10 and CCL2. In contrast to AGS, viral infection resulted in high levels of IL-6 and CXCL8 in the CNS. Postmortem immunohistochemical staining of brain sections showed that in both AGS and viral CNS infection, astrocytes were responsible for the production of cytokines and not the infiltrating leukocytes. In summary, our data indicate that astrocytes are the predominant cell type responsible for the production of IFNalpha and CXCL10 in AGS. Whereas IFNalpha is assumed to be involved in the neurodegeneration, calcifications and seizures in AGS, CXCL10 may act as the chemoattractant responsible for the influx of activated lymphocytes into the brain. The lack of the inflammatory cytokines IL-6 and CXCL8 in AGS suggest that the neuroinflammatory reaction in this disease is distinct from viral disease.
Publication
Journal: Journal of Immunology
July/18/2010
Abstract
We postulated that CCR2-driven activation of the transcription factor NF-kappaB plays a critical role in dendritic cell (DC) maturation (e.g., migration, costimulation, and IL-12p70 production), necessary for the generation of protective immune responses against the intracellular pathogen Leishmania major. Supporting this notion, we found that CCR2, its ligand CCL2, and NF-kappaB were required for CCL19 production and adequate Langerhans cell (LC) migration both ex vivo and in vivo. Furthermore, a role for CCR2 in upregulating costimulatory molecules was indicated by the reduced expression of CD80, CD86, and CD40 in Ccr2(-/-) bone marrow-derived dendritic cells (BMDCs) compared with wild-type (WT) BMDCs. Four lines of evidence suggested that CCR2 plays a critical role in the induction of protective immunity against L. major by regulating IL-12p70 production and migration of DC populations such as LCs. First, compared with WT, Ccr2(-/-) lymph node cells, splenocytes, BMDCs, and LCs produced lower levels of IL-12p70 following stimulation with LPS/IFN-gamma or L. major. Second, a reduced number of LCs carried L. major from the skin to the draining lymph nodes in Ccr2(-/-) mice compared with WT mice. Third, early treatment with exogenous IL-12 reversed the susceptibility to L. major infection in Ccr2(-/-) mice. Finally, disruption of IL-12p70 in radioresistant cells, such as LCs, but not in BMDCs resulted in the inability to mount a fully protective immune response in bone marrow chimeric mice. Collectively, our data point to an important role for CCR2-driven activation of NF-kappaB in the regulation of DC/LC maturation processes that regulate protective immunity against intracellular pathogens.
Publication
Journal: Journal of Neuroimmunology
July/4/2005
Abstract
Experimental autoimmune encephalomyelitis (EAE) models multiple sclerosis (MS) and is characterized by marked mononuclear cell influx in the brain. Several studies have demonstrated a role for chemokines during EAE. It remains to be determined whether these mediators modulate EAE primarily by mediating leukocyte influx into the CNS or by modifying lymphocyte activation and/or trafficking into lymphoid organs. After induction of EAE with MOG(35-55), leukocyte recruitment peaked on day 14 and correlated with symptom onset, TNF-alpha production and production of CCL2 and CCL5. Levels of CXCL-10 and CCL3 were not different from control animals. Using intravital microscopy, we demonstrated that leukocyte rolling and adhesion also peaked at day 14. Treatment with anti-CCL2 or anti-CCL5 antibodies just prior to the intravital microscopy prevented leukocyte adhesion, but not rolling. Our data suggest that induction of leukocyte adhesion to the brain microvasculature is an important mechanism by which CCL2 and CCL5 participate in the pathophysiology of EAE.
Publication
Journal: Circulation Research
April/21/2015
Abstract
BACKGROUND
Chemokine-controlled arterial leukocyte recruitment is a crucial process in atherosclerosis. Formyl peptide receptor 2 (FPR2) is a chemoattractant receptor that recognizes proinflammatory and proresolving ligands. The contribution of FPR2 and its proresolving ligand annexin A1 to atherosclerotic lesion formation is largely undefined.
OBJECTIVE
Because of the ambivalence of FPR2 ligands, we here investigate the role of FPR2 and its resolving ligand annexin A1 in atherogenesis.
RESULTS
Deletion of FPR2 or its ligand annexin A1 enhances atherosclerotic lesion formation, arterial myeloid cell adhesion, and recruitment. Mechanistically, we identify annexin A1 as an endogenous inhibitor of integrin activation evoked by the chemokines CCL5, CCL2, and CXCL1. Specifically, the annexin A1 fragment Ac2-26 counteracts conformational activation and clustering of integrins on myeloid cells evoked by CCL5, CCL2, and CXCL1 through inhibiting activation of the small GTPase Rap1. In vivo administration of Ac2-26 largely diminishes arterial recruitment of myeloid cells in a FPR2-dependent fashion. This effect is also observed in the presence of selective antagonists to CCR5, CCR2, or CXCR2, whereas Ac2-26 was without effect when all 3 chemokine receptors were antagonized simultaneously. Finally, repeated treatment with Ac2-26 reduces atherosclerotic lesion sizes and lesional macrophage accumulation.
CONCLUSIONS
Instructing the annexin A1-FPR2 axis harbors a novel approach to target arterial leukocyte recruitment. With the ability of Ac2-26 to counteract integrin activation exerted by various chemokines, delivery of Ac2-26 may be superior in inhibition of arterial leukocyte recruitment when compared with blocking individual chemokine receptors.
Publication
Journal: Immunology
September/15/2003
Abstract
Chemokines play an important role in the development of immunity to tuberculosis. Chemokine ligand 2 (CCL2, JE, monocyte chemoattractant protein-1) is thought to be primarily responsible for recruiting monocytes, dendritic cells, natural killer cells and activated T cells, all of which play critical roles in the effective control of tuberculosis infection in mice. We show here that in mice in which the CCL2 gene was disrupted, low-dose aerosol infection with Mycobacterium tuberculosis resulted in fewer macrophages entering the lungs, but only a minor and transient increase in bacterial load in the lungs; these mice were still able to establish a state of chronic disease. Such animals showed similar numbers of activated T cells as wild-type mice, as determined by their expression of the CD44hi CD62lo phenotype, but a transient reduction in cells secreting interferon-gamma. These data indicate that the primary deficiency in mice unable to produce CCL2 is a transient failure to focus antigen-specific T lymphocytes into the infected lung, whereas other elements of the acquired host response are compensated for by different ligands interacting with the chemokine receptor CCR2.
Publication
Journal: Obesity
March/4/2009
Abstract
Infection with Trypanosoma cruzi, the etiologic agent of Chagas disease is accompanied by an intense inflammatory reaction. Our laboratory group has identified adipose tissue as one of the major sites of inflammation during disease progression. Because adipose tissue is composed of many cell types, we were interested in investigating whether the adipocyte per se was a source of inflammatory mediators in this infection. Cultured adipocytes were infected with the Tulahuen strain of T. cruzi for 48-96 h. Immunoblot and quantitative PCR (qPCR) analyses demonstrated an increase in the expression of proinflammatory cytokines and chemokines, including interleukin (IL)-1 beta, interferon-gamma, tumor necrosis factor-alpha, CCL2, CCL5, and CXCL10 as well as an increase in the expression of Toll-like receptors-2 and 9 and activation of the notch pathway. Interestingly, caveolin-1 expression was reduced while cyclin D1 and extracellular signal-regulated kinase (ERK) expression was increased. The expression of PI3kinase and the activation of AKT (phosphorylated AKT) were increased suggesting that infection may induce components of the insulin/IGF-1 receptor cascade. There was an infection-associated decrease in adiponectin and peroxisome proliferator-activated receptor-gamma (PPAR-gamma). These data provide a mechanism for the increase in the inflammatory phenotype that occurs in T. cruzi-infected adipocytes. Overall, these data implicate the adipocyte as an important target of T. cruzi, and one which contributes significantly to the inflammatory response observed in Chagas disease.
Publication
Journal: Journal of Immunology
March/21/2006
Abstract
Saliva of bloodfeeding arthropods has been incriminated in facilitating the establishment of parasite in their host. We report on the leukocyte chemoattractive effect of salivary gland homogenate (SGH) from Lutzomyia longipalpis on saliva-induced inflammation in an air pouch model. SGH (0.5 pair/animal) was inoculated in the air pouch formed in the back of BALB/c or C57BL/6 mice. L. longipalpis SGH induced a significant influx of macrophages in BALB/c but not in C57BL/6 mice. SGH-induced cell recruitment reached a peak at 12 h after inoculation and was higher than that induced by the LPS control. This differential cell recruitment in BALB/c mice was directly correlated to an increase in CCL2/MCP-1 expression in the air pouch lining tissue. In fact, treatment with bindarit, an inhibitor of CCL2/MCP-1 synthesis, and also with a specific anti-MCP-1 mAb resulted in drastic reduction of macrophage recruitment and inhibition of CCL2/MCP-1 expression in the lining tissue. CCL2/MCP-1 production was also seen in vitro when J774 murine macrophages were exposed to L. longipalpis SGH. The SGH effect was abrogated by preincubation with serum containing anti-SGH IgG Abs as well as in mice previously sensitized with L. longipalpis bites. Interestingly, the combination of SGH with Leishmania chagasi induced an increased recruitment of neutrophils and macrophages when compared with L. chagasi alone. Taken together these results suggest that SGH not only induces the recruitment of a greater number of macrophages by enhancing CCL2/MCP-1 production but also synergizes with L. chagasi to recruit more inflammatory cells to the site of inoculation.
Publication
Journal: Laboratory Investigation
July/6/2010
Abstract
Recent studies disclosed that autophagy is induced during and facilitates the process of senescence. Given that biliary epithelial cells (BECs) in damaged small bile ducts in primary biliary cirrhosis (PBC) show senescent features, we examined an involvement of autophagy in the process of biliary epithelial senescence in PBC. We examined immunohistochemically the expression of microtubule-associated proteins-light chain 3beta (LC3), a marker of autophagy, in livers taken from the patients with PBC (n=37) and control livers (n=75). We also examined the co-localization of LC3 with autophagy-related cathepsin D, lysosome-associated membrane protein-1 (LAMP-1), and senescent markers, p16(INK4a) and p21(WAF1/Cip1). We examined the effect of autophagy inhibitor (3-methyladenine) on the induction of cellular senescence and senescence-associated secretion (CCL2 and CX3CL1) in cultured murine BECs. The expression of LC3 was specifically seen in vesicles in BECs in the inflamed and damaged small bile ducts in PBC, when compared with non-inflamed small bile ducts in PBC and in control livers (P<0.01). The expression of LC3 was closely related to the expression of cathepsin D, LAMP-1, and senescent markers. In cultured BECs, oxidative stress, DNA damage, and serum deprivation induced cellular senescence, when compared with control and the inhibition of autophagy significantly decreased the stress-induced cellular senescence (P<0.01). Furthermore, the secretion level of CCL2 and CX3CL1 increased significantly by various stress and suppressed by the inhibition of autophagy (P<0.01). In conclusion, autophagy is specifically seen in the damaged small bile ducts along with cellular senescence in PBC. The inhibition of autophagy suppressed cellular senescence in cultured cells. These findings suggest that autophagy may mediate the process of biliary epithelial senescence and involve in the pathogenesis of bile duct lesions in PBC.
Publication
Journal: Alcoholism: Clinical and Experimental Research
November/26/2015
Abstract
BACKGROUND
Fetal alcohol spectrum disorders (FASD) result from fetal exposure to alcohol and are the leading cause of mental retardation in the United States. There is currently no effective treatment that targets the causes of these disorders. Thus, novel therapies are critically needed to limit the neurodevelopmental and neurodegenerative pathologies associated with FASD.
METHODS
A neonatal mouse FASD model was used to examine the role of the neuroimmune system in ethanol (EtOH)-induced neuropathology. Neonatal C57BL/6 mice were treated with EtOH, with or without pioglitazone, on postnatal days 4 through 9, and tissue was harvested 1 day post treatment. Pioglitazone is a peroxisome proliferator-activated receptor (PPAR)-γ agonist that exhibits anti-inflammatory activity and is neuroprotective. We compared the effects of EtOH with or without pioglitazone on cytokine and chemokine expression and microglial morphology in the hippocampus, cerebellum, and cerebral cortex.
RESULTS
In EtOH-treated animals compared with controls, cytokines interleukin-1β and tumor necrosis factor-α mRNA levels were increased significantly in the hippocampus, cerebellum, and cerebral cortex. Chemokine CCL2 mRNA was increased significantly in the hippocampus and cerebellum. Pioglitazone effectively blocked the EtOH-induced increase in the cytokines and chemokine in all tissues to the level expressed in handled-only and vehicle-treated control animals. EtOH also produced a change in microglial morphology in all brain regions that was indicative of microglial activation, and pioglitazone blocked this EtOH-induced morphological change.
CONCLUSIONS
These studies indicate that EtOH activates microglia to a pro-inflammatory stage and also increases the expression of neuroinflammatory cytokines and chemokines in diverse regions of the developing brain. Further, the anti-inflammatory and neuroprotective PPAR-γ agonist pioglitazone blocked these effects. It is proposed that microglial activation and inflammatory molecules expressed as a result of EtOH treatment during brain development contribute to the sequelae associated with FASD. Thus, pioglitazone and anti-inflammatory pharmaceuticals more broadly have potential as novel therapeutics for FASD.
Publication
Journal: Science Translational Medicine
November/14/2011
Abstract
Many persistent pain states (pain lasting for hours, days, or longer) are poorly treated because of the limitations of existing therapies. Analgesics such as nonsteroidal anti-inflammatory drugs and opioids often provide incomplete pain relief and prolonged use results in the development of severe side effects. Identification of the key mediators of various types of pain could improve such therapies. Here, we tested the hypothesis that hitherto unrecognized cytokines and chemokines might act as mediators in inflammatory pain. We used ultraviolet B (UVB) irradiation to induce persistent, abnormal sensitivity to pain in humans and rats. The expression of more than 90 different inflammatory mediators was measured in treated skin at the peak of UVB-induced hypersensitivity with custom-made polymerase chain reaction arrays. There was a significant positive correlation in the overall expression profiles between the two species. The expression of several genes [interleukin-1β (IL-1β), IL-6, and cyclooxygenase-2 (COX-2)], previously shown to contribute to pain hypersensitivity, was significantly increased after UVB exposure, and there was dysregulation of several chemokines (CCL2, CCL3, CCL4, CCL7, CCL11, CXCL1, CXCL2, CXCL4, CXCL7, and CXCL8). Among the genes measured, CXCL5 was induced to the greatest extent by UVB treatment in human skin; when injected into the skin of rats, CXCL5 recapitulated the mechanical hypersensitivity caused by UVB irradiation. This hypersensitivity was associated with the infiltration of neutrophils and macrophages into the dermis, and neutralizing the effects of CXCL5 attenuated the abnormal pain-like behavior. Our findings demonstrate that the chemokine CXCL5 is a peripheral mediator of UVB-induced inflammatory pain, likely in humans as well as rats.
Publication
Journal: Journal of Infectious Diseases
June/2/2014
Abstract
BACKGROUND
Mucosal macrophages are involved in the maintenance of epithelial barrier integrity and the elimination of invading pathogens. Although an intestinal barrier defect and microbial translocation are hallmarks of human immunodeficiency virus (HIV) infection, recent data on gut mucosal macrophages in HIV infection are sparse.
METHODS
Treatment-naive and treated HIV-infected patients and healthy controls were studied for frequencies and functional parameters of blood monocytes and macrophages in duodenal mucosa.
RESULTS
We found mucosal enrichment of macrophages in untreated HIV infection associated with reduced monocyte counts in blood and increased monocyte expression of the gut-homing molecule integrin β7. Increased CCR2 density on integrin β7-expressing monocytes and mucosal secretion of CCL2 suggest that CCR2/CCL2-chemotaxis is involved in enhanced trafficking of blood monocytes to the gut. Secretion of macrophage-related proinflammatory molecules interleukin 1β, CCL5, CXCL9, and CXCL10 was increased in the gut mucosa of untreated patients. Moreover, mucosal macrophages of untreated patients showed reduced phagocytic activity.
CONCLUSIONS
These data suggest a role for gut mucosal macrophages in HIV immune pathogenesis: infiltrated macrophages in the intestinal mucosa may promote local inflammation and tissue injury, whereas their low phagocytic activity prevents the efficient elimination of luminal antigens that cross the damaged intestinal barrier.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
June/7/2010
Abstract
Astroglial reactivity associated with increased production of NFkappaB-dependent proinflammatory molecules is an important component of the pathophysiology of chronic neurological disorders such as multiple sclerosis (MS). The use of estrogens as potential anti-inflammatory and neuroprotective drugs is a matter of debate. Using mouse experimental allergic encephalomyelitis (EAE) as a model of chronic neuroinflammation, we report that implants reproducing pregnancy levels of 17beta-estradiol (E2) alleviate ongoing disease and decrease astrocytic production of CCL2, a proinflammatory chemokine that drives the local recruitment of inflammatory myeloid cells. Immunohistochemistry and confocal imaging reveal that, in spinal cord white matter EAE lesions, reactive astrocytes express estrogen receptor (ER)alpha (and to a lesser extent ERbeta) with a preferential nuclear localization, whereas other cells including infiltrated leukocytes express ERs only in their membranes or cytosol. In cultured rodent astrocytes, E2 or an ERalpha agonist, but not an ERbeta agonist, inhibits TNFalpha-induced CCL2 expression at nanomolar concentrations, and the ER antagonist ICI 182,170 blocks this effect. We show that this anti-inflammatory action is not associated with inhibition of NFkappaB nuclear translocation but rather involves direct repression of NFkappaB-dependent transcription. Chromatin immunoprecipitation assays further indicate that estrogen suppresses TNFalpha-induced NFkappaB recruitment to the CCL2 enhancer. These data uncover reactive astrocytes as an important target for nuclear ERalpha inhibitory action on chemokine expression and suggest that targeting astrocytic nuclear NFkappaB activation with estrogen receptor alpha modulators may improve therapies of chronic neurodegenerative disorders involving astroglial neuroinflammation.
Publication
Journal: Targeted Oncology
December/8/2015
Abstract
C-C chemokine ligand 2 (CCL2) stimulates tumor growth, metastasis, and angiogenesis. Carlumab, a human IgG1κ anti-CCL2 mAb, has shown antitumor activity in preclinical and clinical trials. We conducted a first-in-human phase 1b study of carlumab with one of four chemotherapy regimens (docetaxel, gemcitabine, paclitaxel + carboplatin, and pegylated liposomal doxorubicin HCl [PLD]). Patients had advanced solid tumors for which ≥1 of these regimens was considered standard of care or for whom no other treatment options existed. Dose-limiting toxicities included one grade 4 febrile neutropenia (docetaxel arm) and one grade 3 neutropenia (gemcitabine arm). Combination treatment with carlumab had no clinically relevant pharmacokinetic effect on docetaxel (n = 15), gemcitabine (n = 12), paclitaxel or carboplatin (n = 12), or PLD (n = 14). Total serum CCL2 concentrations increased post-treatment with carlumab alone, consistent with carlumab-CCL2 binding, and continued increase in the presence of all chemotherapy regimens. Free CCL2 declined immediately post-treatment with carlumab but increased with further chemotherapy administrations in all arms, suggesting that carlumab could sequester CCL2 for only a short time. Neither antibodies against carlumab nor consistent changes in circulating tumor cells (CTCs) or circulating endothelial cells (CECs) enumeration were observed. Three of 19 evaluable patients showed a 30 % decrease from baseline urinary cross-linked N-telopeptide of type I collagen (uNTx). One partial response and 18 (38 %) stable disease responses were observed. The most common drug-related grade ≥3 adverse events were docetaxel arm-neutropenia (6/15) and febrile neutropenia (4/15); gemcitabine arm-neutropenia (2/12); paclitaxel + carboplatin arm-neutropenia, thrombocytopenia (4/12 each), and anemia (2/12); and PLD arm-anemia (3/14) and stomatitis (2/14). Carlumab could be safely administered at 10 or 15 mg/kg in combination with standard-of-care chemotherapy and was well-tolerated, although no long-term suppression of serum CCL2 or significant tumor responses were observed.
Publication
Journal: Journal of Neuroinflammation
September/15/2014
Abstract
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
Together our results indicate that the alternative activation status of macrophages promotes their migratory properties to chemoattractants relevant for neuroinflammatory diseases like MS. Conversely, classically activated, proinflammatory macrophages have reduced migratory properties. Based on our results, we postulate that the activation status of the macrophage influences the capacity of the macrophages to rearrange their cytoskeleton. This is the first step in understanding how modulation of macrophage activation affects macrophage migration in neuroinflammatory diseases like MS.
Publication
Journal: Archives of Pharmacal Research
April/28/2014
Abstract
Chemokines are members of the chemoattractant cytokine family. They play key roles in the trafficking of leukocytes and in the induction of chemotaxis through the activation of G protein-coupled receptor. Considerable interest has been paid to these molecules to elucidate their roles in the unique inflammatory responses elicited in the central nervous system (CNS). Chemokine CCL2 (also known as monocyte chemoattractant protein-1, MCP-1) is one of the vital chemokines that control the migration and infiltration of monocytes/macrophages. CCL2 and its receptor CCR2 have been shown to be induced and involved in various neurodegenerative disorders including Alzheimer's disease, multiple sclerosis, and ischemic brain injury. The present review will focus on the biological and pathophysiological aspects of CCL2 and CCR2 in the CNS and the possible therapeutic approaches for targeting these two proteins to combat neurodegenerative diseases.
Publication
Journal: PLoS ONE
May/28/2015
Abstract
Prior studies suggest that the impaired healing seen in diabetic wounds derives from a state of persistent hyper-inflammation characterized by harmful increases in inflammatory leukocytes including macrophages. However, such studies have focused on wounds at later time points (day 10 or older), and very little attention has been given to the dynamics of macrophage responses in diabetic wounds early after injury. Given the importance of macrophages for the process of healing, we studied the dynamics of macrophage response during early and late phases of healing in diabetic wounds. Here, we report that early after injury, the diabetic wound exhibits a significant delay in macrophage infiltration. The delay in the macrophage response in diabetic wounds results from reduced Chemokine (C-C motif) ligand 2 (CCL2) expression. Importantly, one-time treatment with chemoattractant CCL2 significantly stimulated healing in diabetic wounds by restoring the macrophage response. Our data demonstrate that, rather than a hyper-inflammatory state; the early diabetic wound exhibits a paradoxical and damaging decrease in essential macrophage response. Our studies suggest that the restoration of the proper kinetics of macrophage response may be able to jumpstart subsequent healing stages. CCL2 chemokine-based therapy may be an attractive strategy to promote healing in diabetic wounds.
Publication
Journal: Journal of Immunology
May/25/2011
Abstract
Chemokines play critical roles in inflammation by recruiting inflammatory cells to injury sites. In this study, we found that UDP induced expression of chemokines CCL2 (MCP-1) and CCL3 (MIP-1α) in microglia, astrocytes, and slice cultures by activation of P2Y(6). Interestingly, CCL2 was more highly expressed than CCL3. However, CCL2 synthesis kinetics in response to UDP differed in microglia and astrocytes; microglia rapidly produced small amounts of CCL2, whereas astrocytes continuously synthesized large amounts of CCL2, resulting in a high ultimate level of the chemokine. UDP-induced chemokine expression was reduced in the presence of a specific antagonist of P2Y(6) (MRS2578) or small interfering RNA directed against the P2Y(6) gene. Inhibition of phospholipase C and calcium increase, downstream signaling pathways of Gq-coupled P2Y(6), reduced UDP-induced chemokine expression. UDP activated two calcium-activated transcription factors, NFATc1 and c2. Furthermore, inhibitors of calcineurin (a phosphatase activating NFAT) and NFAT reduced UDP-induced chemokine synthesis. We also found, using a transmigration assay, that UDP-treated astrocytes recruited monocytes. These results suggest that UDP induces chemokine expression in microglia and astrocytes of the injured brain by activation of P2Y(6) receptors.
Publication
Journal: Clinical and Experimental Immunology
June/17/2007
Abstract
To investigate the molecular effects of the periodontopathogens Fusobacterium nucleatum (FN) and Porphyromonas gingivalis (PG) on the oral epithelium, the H400 oral epithelial cell line was cultured in the presence of non-viable bacteria. Following confirmation of the presence of transcripts for the bacterial pattern recognition receptors in H400 cells, Toll-like receptors -2, -4 and -9, and components of the NF-kappaB signalling pathway, immunocytochemical analyses were performed showing that NF-kappaB was activated within 1 h of exposure to both periodontopathogens. A significantly greater number of NF-kappaB nuclear translocations were apparent following H400 cell exposure to FN as compared with PG. Gene expression analyses indicated that transcripts known to be regulated by the NF-kappaB pathway, including cytokines/chemokines TNF-alpha, IL-1beta, IL-8, MCP-1/<em>CCL2</em> and GM-CSF, were up-regulated following 4 and 24 h of exposure to both periodontopathogens. In addition, H400 periodontopathogen exposure resulted in differential regulation of transcripts for several cytokeratin gene family members. Consistent with the immunocytochemical data, microarray results indicated that FN induced a greater number of gene expression changes than PG following 24 h of exposure, 609 and 409 genes, respectively. Ninety-one genes were commonly differentially expressed by both periodontopathogens and represented biological processes commonly associated with periodontitis. Gene expression analyses by reserve transcriptase-polymerase chain reaction (RT-PCR) of molecules identified from the microarray data sets, including Heme oxygenase-1, lysyl oxidase, SOD2, <em>CCL2</em>0 and calprotectin components, confirmed their differential expression profiles induced by the two periodontopathogens. FN and PG have clearly different molecular effects on oral epithelial cells, potentially highlighting the importance of the composition of the plaque biofilm in periodontitis pathogenesis.
Publication
Journal: Journal of Urology
May/19/2008
Abstract
OBJECTIVE
The chronic pelvic pain syndrome is characterized by pelvic pain, voiding symptoms and varying degrees of inflammation within expressed prostatic secretions. We evaluated the chemokines monocyte chemoattractant protein 1 (CCL2) and macrophage inflammatory protein-1alpha (CCL3) in expressed prostatic secretions to identify marker increases associated with inflammatory (IIIA) and noninflammatory (IIIB) chronic pelvic pain syndrome. In addition, chemokine levels were correlated with clinical pain as determined by the National Institutes of Health chronic prostatitis symptom index.
METHODS
Expressed prostatic secretions were collected by digital rectal examination, and evaluated by enzyme linked immunosorbent assays for monocyte chemoattractant protein 1 and macrophage inflammatory protein-1alpha in 154 patients including controls (13), those with benign prostatic hyperplasia (54), chronic pelvic pain syndrome IIIA (37) and IIIB (50). Monocyte chemoattractant protein 1 and macrophage inflammatory protein-1alpha levels were compared between IIIA, IIIB and the control subgroups, and correlated against the chronic prostatitis symptom index and pain subscore using a Spearman test.
RESULTS
Mean levels of monocyte chemoattractant protein 1 in the control, inflammatory benign prostatic hyperplasia, noninflammatory benign prostatic hyperplasia, inflammatory chronic pelvic pain syndrome and noninflammatory chronic pelvic pain syndrome were 599.4, 886.0, 1,636.5, 3,261.2 and 2,272.7 pg/ml, respectively. Mean levels of macrophage inflammatory protein-1alpha in the control, inflammatory benign prostatic hyperplasia, noninflammatory benign prostatic hyperplasia, IIIA chronic pelvic pain syndrome and IIIB chronic pelvic pain syndrome were 140.1, 299.4, 238.7, 1,057.8 and 978.4 pg/ml, respectively. For each cytokine both chronic pelvic pain syndrome subtypes had statistically higher levels than the control group and patients with benign prostatic hyperplasia (p = 0.0002). Receiver operating curves using monocyte chemoattractant protein 1 levels greater than 704 pg/ml and macrophage inflammatory protein-1alpha greater than 146 pg/ml identified patients with chronic pelvic pain syndrome with an accuracy of 90% from control patients. Macrophage inflammatory protein-1alpha levels (p = 0.0007) correlated with the pain subscore of the chronic prostatitis symptom index while monocyte chemoattractant protein 1 (p = 0.71) did not.
CONCLUSIONS
Monocyte chemoattractant protein 1 and macrophage inflammatory protein-1alpha within the prostatic fluid in both chronic pelvic pain syndrome subtypes provide candidate future biomarkers for chronic pelvic pain syndrome. In addition, macrophage inflammatory protein-1alpha increase in expressed prostatic secretions provides a new marker for clinical pain in chronic pelvic pain syndrome patients. Given these findings prostatic dysfunction likely has a role in the pathophysiology of this syndrome. These chemokines may serve as effective diagnostic markers and modulators against the chemokines could provide an attractive treatment strategy in individuals with chronic pelvic pain syndrome.
Publication
Journal: Arthritis research & therapy
September/8/2009
Abstract
BACKGROUND
The high-affinity receptor for IgG Fcgamma/CD64 is critical for the development of lupus nephritis (LN). Cross-linking Fc receptor on recruited monocytes by IgG-containing immune complexes is a key step in immune-complex-mediated nephritis in systemic lupus erythematosus (SLE). The goal of this study was to determine whether expression of Fc receptor (FcgammaR) I on circulating monocytes is associated with systemic inflammation and renal disease in SLE patients.
METHODS
We studied 205 SLE patients (132 with LN and 73 without LN) along with 74 healthy control individuals. Surface expression of CD14 (monocytes), FcgammaRI/CD64, FcgammaRII/CD32, and FcgammaRIII/CD16 was evaluated by flow cytometry. Monocyte function was assessed by determining the migratory capacity and the ability to produce CCL2 (monocyte chemotractic protein 1). High-sensitivity C-reactive protein, C3 and C4 were measured by nephelometry.
RESULTS
There was little difference in the expression of FcgammaRIII/CD16 or FcgammaRIII/CD32 on circulating monocytes between patients with SLE and control individuals. In contrast, FcgammaRI/CD64 expression was significantly higher in SLE patients and even higher in patients with LN. FcgammaRI/CD64 expression was positively associated with serum creatinine and indicators of systemic inflammation. Monocytes from patients with high FcgammaRI/CD64 expression also exhibited increased chemotaxis and capacity to produce monocyte chemotractic protein 1.
CONCLUSIONS
Increased FcgammaRI/CD64 expression on circulating monocytes parallels systemic inflammation and renal disease in SLE patients. We propose that circulating monocytes activated by immune complexes and/or proinflammatory mediators upregulate surface expression of FcgammaRI/CD64 in SLE. The enhanced chemotactic and inflammatory potential of the activated monocytes may participate in a vicious cycle of immune cell recruitment and renal injury in SLE.
Publication
Journal: Molecular Vision
July/8/2012
Abstract
OBJECTIVE
To compare the aqueous humor levels of proinflammatory and angiogenic factors of diabetic patients with and without retinopathy.
METHODS
Aqueous humor was collected at the start of cataract surgery from diabetic subjects and non-diabetic controls. The presence and severity of diabetic retinopathy were graded with fundus examination. Levels of 22 different inflammatory and angiogenic cytokines and chemokines were compared.
RESULTS
Aqueous humor samples from 47 diabetic patients (20 without retinopathy, 27 with retinopathy) and 24 non-diabetic controls were included. Interleukin (IL)-2, IL-10, IL-12, interferon-alpha (IFN-α), and tumor necrosis factor (TNF)-α were measurable in significantly fewer diabetic samples, and where measurable, were at lower levels than in non-diabetic controls. IL-6 was measurable in significantly more diabetic samples, and the median levels were significantly higher in the eyes with retinopathy than the eyes without retinopathy and the non-diabetic eyes. The vascular endothelial growth factor (VEGF) level was significantly higher in the diabetic eyes with and without retinopathy compared to the non-diabetic controls. The IL-6 level positively correlated with the monocyte chemotactic protein-1 (CCL2) and interleukin-8 (CXCL8) levels and negatively with the TNF-α level. The VEGF level negatively correlated with the IL-12 and TNF-α levels.
CONCLUSIONS
The aqueous humor cytokine profile of diabetic patients without retinopathy was similar to that of patients with diabetic retinopathy. These cytokines may be useful biomarkers for early detection and prognosis of diabetic retinopathy. Compared to diabetic patients without retinopathy, only the IL-6 and VEGF levels were significantly higher in diabetic patients with retinopathy.
Publication
Journal: British Journal of Pharmacology
October/31/2011
Abstract
OBJECTIVE
The effects of metformin, an antidiabetic agent that improves insulin sensitivity, on endothelial function have not been fully elucidated. This study was designed to assess the effect of metformin on impaired endothelial function, oxidative stress, inflammation and advanced glycation end products formation in type 2 diabetes mellitus.
METHODS
Goto-Kakizaki (GK) rats, an animal model of nonobese type 2 diabetes, fed with normal and high-fat diet during 4 months were treated with metformin for 4 weeks before evaluation. Systemic oxidative stress, endothelial function, insulin resistance, nitric oxide (NO) bioavailability, glycation and vascular oxidative stress were determined in the aortic rings of the different groups. A pro-inflammatory biomarker the chemokine CCL2 (monocyte chemoattractant protein-1) was also evaluated.
RESULTS
High-fat fed GK rats with hyperlipidaemia showed increased vascular and systemic oxidative stress and impaired endothelial-dependent vasodilatation. Metformin treatment significantly improved glycation, oxidative stress, CCL2 levels, NO bioavailability and insulin resistance and normalized endothelial function in aorta.
CONCLUSIONS
Metformin restores endothelial function and significantly improves NO bioavailability, glycation and oxidative stress in normal and high-fat fed GK rats. This supports the concept of the central role of metformin as a first-line therapeutic to treat diabetic patients in order to protect against endothelial dysfunction associated with type 2 diabetes mellitus.
Publication
Journal: PLoS ONE
August/26/2012
Abstract
The recognition of pathogen-derived structures by C-type lectins and the chemotactic activity mediated by the CCL2/CCR2 axis are critical steps in determining the host immune response to fungi. The present study was designed to investigate whether the presence of single nucleotide polymorphisms (SNPs) within DC-SIGN, Dectin-1, Dectin-2, CCL2 and CCR2 genes influence the risk of developing Invasive Pulmonary Aspergillosis (IPA). Twenty-seven SNPs were selected using a hybrid functional/tagging approach and genotyped in 182 haematological patients, fifty-seven of them diagnosed with proven or probable IPA according to the 2008 EORTC/MSG criteria. Association analysis revealed that carriers of the Dectin-1(rs3901533 T/T) and Dectin-1(rs7309123 G/G) genotypes and DC-SIGN(rs4804800 G), DC-SIGN(rs11465384 T), DC-SIGN(7248637 A) and DC-SIGN(7252229 C) alleles had a significantly increased risk of IPA infection (OR = 5.59 95%CI 1.37-22.77; OR = 4.91 95%CI 1.52-15.89; OR = 2.75 95%CI 1.27-5.95; OR = 2.70 95%CI 1.24-5.90; OR = 2.39 95%CI 1.09-5.22 and OR = 2.05 95%CI 1.00-4.22, respectively). There was also a significantly increased frequency of galactomannan positivity among patients carrying the Dectin-1(rs3901533_T) allele and Dectin-1(rs7309123_G/G) genotype. In addition, healthy individuals with this latter genotype showed a significantly decreased level of Dectin-1 mRNA expression compared to C-allele carriers, suggesting a role of the Dectin-1(rs7309123) polymorphism in determining the levels of Dectin-1 and, consequently, the level of susceptibility to IPA infection. SNP-SNP interaction (epistasis) analysis revealed significant interactions models including SNPs in Dectin-1, Dectin-2, CCL2 and CCR2 genes, with synergistic genetic effects. Although these results need to be further validated in larger cohorts, they suggest that Dectin-1, DC-SIGN, Dectin-2, CCL2 and CCR2 genetic variants influence the risk of IPA infection and might be useful in developing a risk-adapted prophylaxis.
Publication
Journal: Immunology
January/21/2008
Abstract
Interleukin-31 (IL-31) is a novel T-helper-lymphocyte-derived cytokine that plays an important role in allergic skin inflammation and atopic dermatitis. It has recently been implicated in bronchial inflammation. We investigated the functions and mechanisms of IL-31-induced activation of human bronchial epithelial cells. The gene and protein expressions of candidate cytokines/chemokines from IL-31-stimulated human bronchial epithelial BEAS-2B cells were first quantified by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The activity of different mitogen-activated protein kinases (MAPKs) in IL-31-stimulated BEAS-2B cells was assessed by Western blot. The IL-31 could significantly elevate the gene and protein expressions of epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1/CCL2) of BEAS-2B cells in both time-dependently and dose-dependently. Combination of IL-31 with either IL-4 or IL-13 further enhanced VEGF and CCL2 production while IL-31 could synergistically augment the release of EGF, VEGF, CCL2, IL-6 and IL-8 in cocultures of BEAS-2B cells and eosinophils. In addition, IL-31 could activate p38 MAPK, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) of BEAS-2B cells. Selective inhibitors of p38 MAPK (SB203580), ERK (PD98059), and JNK (SP600125) could differentially inhibit the production of EGF, VEGF and CCL2, thereby suggesting a role for MAPKs in IL-31 functions. In conclusion, the activation of MAPKs can be crucial for IL-31-mediated activation of bronchial epithelial cells, thereby providing an immunological role for IL-31 in bronchial inflammation, at least partly, via epithelial EGF, VEGF and CCL2 production.
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