Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P80098 (monocyte chemoattractant protein)
 1,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using a rat lung organ culture system, we analyzed the role of monocyte chemoattractant protein 1 (MCP 1) in leukocyte to lung adhesive interactions and monocyte-mediated lung injury. Quantitative leukocyte to lung adhesive interactions were examined using an adaptation of the Woodruff-Stamper frozen section binding assay. Pretreatment of organ cultures with recombinant human tumor necrosis factor (rhTNF alpha) resulted in a protein synthesis-dependent increase in the adhesiveness of lung tissue for peripheral blood monocytes. Adhesion of monocytes to lung tissue was not increased above baseline after 7 hours but increased more than twofold by 24 hours and persisted through 48 hours. Binding of monocyte to lung tissue was further increased when recombinant rat MCP 1 was added to monocyte suspensions immediately before being layered onto lung sections derived from either TNF alpha-treated or untreated organ cultures. Addition of antibody directed against rat CD11b/c resulted in a moderate reduction in monocyte binding. TNF or lipopolysaccharide-induced activation of mononuclear cells in the presence of [3H]leucine-labeled organ cultures resulted in lung injury as assessed by radioisotope release. Mononuclear cell-mediated organ culture injury could be partially inhibited with anti-rat MCP 1 antibody, anti-rat CD11b/c antibody, or antioxidants including catalase and deferoxamine. Anti-MCP 1 and anti-CD11b/c increased the absolute numbers of monocytes that could be retrieved from monocyte-lung co-cultures while catalase and deferoxamine did not. In vitro studies revealed that isolated rat peripheral blood monocytes produce O2- in response to MCP 1. These data provide a functional correlate for recent in vitro studies which suggest that MCP 1 may mediate leukocyte adhesive processes by up-regulating beta 2 integrin expression on monocytes. This study provides evidence that monocytes activated by MCP 1 can damage lung tissue through an oxidant-mediated mechanism. Monocyte chemoattractant protein 1 may participate in the pathogenesis of monocyte-mediated lung injury by modulating inflammatory cell adhesion as well as through monocyte activation.
 ...
PMID:Analysis of monocyte chemoattractant protein 1-mediated lung injury using rat lung organ cultures. 810 96

The CC chemokines regulated on activation normal T expressed and secreted (RANTES) and monocyte chemotactic protein 3 (MCP-3), and the anaphylatoxin C5a, induce activation, degranulation, chemotaxis, and transendothelial migration of eosinophils. Adhesion assays on purified ligands showed differential regulation of beta 1 and beta 2 integrin avidity in eosinophils. Adhesiveness of VLA-4 (alpha 4 beta 1, CD29/CD49d) for vascular cell adhesion molecule 1 or fibronectin was rapidly increased but subsequently reduced by RANTES, MCP-3, or C5a. The deactivation of VLA-4 lead to cell detachment, whereas phorbol 12-myristate 13-acetate induced sustained activation of VLA-4. In contrast, chemoattractants stimulated a prolonged increase in the adhesiveness of Mac-1 (alpha M beta 2, CD11b/CD18) for intercellular adhesion molecule 1. Inhibition by pertussis toxin confirmed signaling via G protein-coupled receptors. Chemoattractants induced transient, while phorbol 12-myristate 13-acetate induced sustained actin polymerization. Disruption of actin filaments by cytochalasins inhibited increases in avidity of VLA-4 but not of Mac-1. Chemoattractants did not upregulate a Mn2+-inducible beta 1 neoepitope defined by the mAb 9EG7, but induced prolonged expression of a Mac-1 activation epitope recognized by the mAb CBRM1/5. This mAb inhibited chemoattractant-stimulated adhesion of eosinophils to intercellular adhesion molecule 1. Thus, regulation of VLA-4 was dependent on the actin cytoskeleton, whereas conformational changes appeared to be crucial for activation of Mac-1. To our knowledge, this is the first demonstration that physiological agonists, such as chemoattractants, can differentially regulate the avidity of a beta 1 and a beta 2 integrin expressed on the same leukocyte.
 ...
PMID:Differential regulation of beta 1 and beta 2 integrin avidity by chemoattractants in eosinophils. 885 87

Macrophages were elicited by the subcutaneous implantation of ultra high molecular weight polyethylene (UHMWPE) for periods of 2, 7, and 14 days in rats. Exudates of varying volumes were produced that was comprised of granulocytes, monocytes, immature and mature macrophages, and T-lymphocytes. No B-lymphocytes were observed at any time periods. Cell types were identified by their granularity and positivity to the following antibodies: leucocyte common antigen (LCA, pan leucocyte); CD11b/c (macrophage/monocyte); CD5 (T-lymphocyte); CD45RA (B-lymphocyte); HIS48 (granulocyte); ED2 (mature macrophage); and MCP-1 (monocyte chemoattractant protein 1). Monocytes isolated from control rat blood demonstrated a size slightly larger than that of granulocytes but with less granularity. Their size and granularity were followed over increasing time periods. The macrophages elicited by UHMWPE showed a similar pattern, with the exception of an apparently highly granular subpopulation with volumes similar to that of granulocytes but significantly more granular. The granular macrophage subset had a very high degree of ED2 and MCP-1 positivity, and their proportion, compared with other macrophages, was greatest at 2 days. The high MCP-1 expression was accounted for by MCP-1 molecules bound to the surface of a small proportion of macrophages that were activated. It is postulated that this subpopulation was responsible for the synthesis of the MCP-1 and could indicate a mechanism by which monocytes are attracted to the site of an implanted material.
 ...
PMID:Macrophage subpopulation differentiation by stimulation with biomaterials. 940 96

Implanted biomaterials trigger acute and chronic inflammatory responses. The mechanisms involved in such acute inflammatory responses can be arbitrarily divided into phagocyte transmigration, chemotaxis, and adhesion to implant surfaces. We earlier observed that two chemokines-macrophage inflammatory protein 1alpha/monocyte chemoattractant protein 1-and the phagocyte integrin Mac-1 (CD11b/CD18)/surface fibrinogen interaction are, respectively, required for phagocyte chemotaxis and adherence to biomaterial surfaces. However, it is still not clear how the initial transmigration of phagocytes through the endothelial barrier into the area of the implant is triggered. Because implanted biomaterials elicit histaminic responses in the surrounding tissue, and histamine release is known to promote rapid diapedesis of inflammatory cells, we evaluated the possible role of histamine and mast cells in the recruitment of phagocytes to biomaterial implants. Using i.p. and s. c. implantation of polyethylene terephthalate disks in mice we find: (i) Extensive degranulation of mast cells, accompanied by histamine release, occurs adjacent to short-term i.p. implants. (ii) Simultaneous administration of H1 and H2 histamine receptor antagonists (pyrilamine and famotidine, respectively) greatly diminishes recruitment and adhesion of both neutrophils (<20% of control) and monocytes/macrophages (<30% of control) to implants. (iii) Congenitally mast cell-deficient mice also exhibit markedly reduced accumulation of phagocytes on both i.p. and s.c implants. (iv) Finally, mast cell reconstitution of mast cell-deficient mice restores "normal" inflammatory responses to biomaterial implants. We conclude that mast cells and their granular products, especially histamine, are important in recruitment of inflammatory cells to biomaterial implants. Improved knowledge of such responses may permit purposeful modulation of both acute and chronic inflammation affecting implanted biomaterials.
 ...
PMID:Mast cells mediate acute inflammatory responses to implanted biomaterials. 967 66

In 49 acute respiratory distress syndrome (ARDS) patients, the phenotype of alveolar macrophages (AMs) was analyzed by flow cytometry. Bronchoalveolar lavage (BAL) was performed within 24 h after intubation and on days 3-5, 9-12, and 18-21 of mechanical ventilation. The 27E10(high)/CD11b(high)/CD71(low)/ 25F9(low)/HLA DR(low)/RM3/1(low) AM population in the first BAL indicated extensive monocyte influx into the alveolar compartment. There was no evidence of increased local AM proliferation as assessed by nuclear Ki67 staining. Sequential BAL revealed two distinct patient groups. In one, a decrease in 27E10 and CD11b and an increase in CD71, 25F9, HLA DR, and RM3/1 suggested a reduction in monocyte influx and maturation of recruited cells into AMs, whereas the second group displayed sustained monocyte recruitment. In the first BAL from all patients, monocyte chemoattractant protein (MCP)-1 was increased, and AMs displayed elevated MCP-1 gene expression. In sequential BALs, a decrease in MCP-1 coincided with the disappearance of monocyte-like AMs, whereas persistent upregulation of MCP-1 paralleled ongoing monocyte influx. A highly significant correlation between BAL fluid MCP-1 concentration, the predominance of monocyte-like AMs, and the severity of respiratory failure was noted.
 ...
PMID:Phenotypic characterization of alveolar monocyte recruitment in acute respiratory distress syndrome. 1089 99

The evaluation of monocytes recruited into the alveolar space under both physiological and inflammatory conditions is hampered by difficulties in discriminating these cells from resident alveolar macrophages (rAMs). Using the intravenous injected fluorescent dye PKH26, which accumulated in rAMs without labeling blood leukocytes, we developed a technique that permits the identification, isolation, and functional analysis of monocytes recruited into lung alveoli of mice. Alveolar deposition of murine JE, the homologue of human monocyte chemoattractant protein (MCP)-1 (JE/MCP-1), in mice provoked an alveolar influx of monocytes that were recovered by bronchoalveolar lavage and separated from PKH26-stained rAMs by flow cytometry. Alveolar recruited monocytes showed a blood monocytic phenotype as assessed by cell surface expression of F4/80, CD11a, CD11b, CD18, CD49d, and CD62L. In contrast, CD14 was markedly upregulated on alveolar recruited monocytes together with increased tumor necrosis factor-alpha message, discriminating this monocyte population from peripheral blood monocytes and rAMs. Thus monocytes recruited into the alveolar air space of mice in response to JE/MCP-1 keep phenotypic features of blood monocytes but upregulate CD14 and are "primed" for enhanced responsiveness to endotoxin with increased cytokine expression.
 ...
PMID:Monocytes recruited into the alveolar air space of mice show a monocytic phenotype but upregulate CD14. 1113 95

Although the existence of anti-inflammatory alternatively activated macrophages (aamphi) has been accepted widely based on in vitro studies, their in vivo location, phenotype, and function still are debated. Gaucher disease (GD) is caused by a genetic deficiency in the lysosomal enzyme glucocerebrosidase and is characterized by accumulation of glycosphingolipids in so-called Gaucher cells (GCs). By using immunohistochemical analysis, we investigated whether this results in an aamphi phenotype. GCs are macrophage-like cells, expressing acid phosphatase, CD68, CD14, and HLA class II, but not CD11b, CD40, or dendritic cell markers. GCs show infrequent immunoreactivity for mannose receptor GCs did not express proinflammatory cytokines such as tumor necrosis factor alpha and monocyte chemoattractant protein 1, but did express the aamphi markers CD163, CCL18, and interleukin-1 receptor antagonist. Furthermore, CD36 and signal receptor protein alpha, involved in lipid uptake, also were observed on GCs. Thus, GCs represent a distinctive population of myeloid cells that resemble aamphi but differ from previously described in vitro aamphi.
 ...
PMID:Gaucher cells demonstrate a distinct macrophage phenotype and resemble alternatively activated macrophages. 1536 65

Several CXC-chemokines, of which interleukin (IL)-8 is the prototype, are potent neutrophil chemotactic and activating cytokines, inducing the secretion of granule proteins and the generation of reactive oxygen intermediates that may cause tissue damage and amplify inflammatory responses. Here, we investigated whether chemokines play a key role in the inflammatory process following cardiac surgery with cardiopulmonary bypass (CPB) in children. We performed an observational prospective clinical study of 40 pediatric patients before, during, and after open heart surgery with CPB. Plasma levels of chemokines, myeloperoxidase (MPO), and lactoferrin were measured by immunoassays. Cell surface receptors were detected by flow cytometry. Plasma levels of IL-8 were increased after CPB, correlating strongly with a reduction of expression of the CXC-chemokine receptors (CXCR) 1 and 2 on neutrophils indicating in vivo activation of neutrophils by IL-8. Other CXC-chemokines with Glu-Leu-Arg motif showed no correlation with CXCR1 or CXCR2 expression. Two components of neutrophilic granules, MPO and lactoferrin, were strongly elevated postoperatively, and the levels of both were correlated with IL-8. Levels of monocyte chemoattractant protein (MCP)-1 were increased postoperatively, correlating with a reduction of CCR2 expression and an increase of CD11b expression on monocytes, suggesting monocyte activation by MCP-1. The early postoperative course was complicated in patients with an increase of these inflammatory parameters. Impaired cardiovascular function correlated with increased levels of IL-8 and activation of neutrophils and was most prominent in patients with a long time on CPB and in those with cyanotic heart lesions. In conclusion, MCP-1 is involved in the regulation of chemotaxis and function of monocytes during and early after the end of CPB. Activation of neutrophils and down-regulation of CXCR1 and CXCR2 were predominantly caused by IL-8. This activation implies release of components of neutrophilic granules and correlates with the need for inotropic support.
 ...
PMID:CXC-chemokine stimulation of neutrophils correlates with plasma levels of myeloperoxidase and lactoferrin and contributes to clinical outcome after pediatric cardiac surgery. 1554 21

The physiological roles of glial cell line-derived neurotrophic factor (GDNF) expressed in the microglia/macrophages of the injured spinal cord have not yet been clarified. mRNA expression of chemokines, including monocyte chemoattractant protein (MCP)-1, was evoked within 1 hr after transection of the spinal cord, and GDNF mRNA expression was similarly up-regulated. Immunohistochemical analysis showed that GDNF was coexpressed with MCP-1 in the CD11b-positive cells. Therefore, we examined further the effects of GDNF on cultured rat peritoneal macrophages. GDNF enhanced the phagocytic activity of the macrophages via GFRalpha-1, glycosylphosphatidylinositol-anchored specific binding site of GDNF, in a c-Ret-independent manner. The influence of autocrine and/or paracrine GDNF synthesis was evaluated by performing activation experiments using macrophages cultured from heterozygous (+/-) GDNF gene-deficient mice or wild-type (+/+) mice. There were no morphological differences dependent on genetic types or stimulators. However, the GDNF mRNA level, but not the MCP-1 or GFRalpha-1 mRNA level, was substantially lower in the mutant macrophages than in the +/+ cells irrespective of stimulation with MCP-1 or lipopolysaccharide (LPS). The phagocytic activity enhanced by MCP-1 or LPS was significantly lower in the mutant cells (+/-) than in the +/+ ones, demonstrating the involvement of endogenous GDNF in the activation processes of macrophages in vitro and suggesting that not only neuroprotective function but also activation of macrophages is effected by the GDNF produced after a spinal cord injury.
 ...
PMID:Involvement of glial cell line-derived neurotrophic factor in activation processes of rodent macrophages. 1563 9

Increased central nervous system (CNS) levels of monocyte chemoattractant protein 1 [CC chemokine ligand 2 (CCL2) in the systematic nomenclature] have been reported in chronic neurological diseases such as human immunodeficiency virus type 1-associated dementia, amyotrophic lateral sclerosis, and multiple sclerosis. However, a pathogenic role for CCL2 has not been confirmed, and there is no established model for the effects of chronic CCL2 expression on resident and recruited CNS cells. We report that aged (>6 months) transgenic (tg) mice expressing CCL2 under the control of the human glial fibrillary acidic protein promoter (huGFAP-CCL2hi tg+ mice) manifested encephalopathy with mild perivascular leukocyte infiltration, impaired blood brain barrier function, and increased CD45-immunoreactive microglia, which had morphologic features of activation. huGFAP-CCL2hi tg+ mice lacking CC chemokine receptor 2 (CCR2) were normal, showing that chemokine action via CCR2 was required. Studies of cortical slice preparations using video confocal microscopy showed that microglia in the CNS of huGFAP-CCL2hi tg+ mice were defective in expressing amoeboid morphology. Treatment with mutant CCL2 peptides, a receptor antagonist and an obligate monomer, also suppressed morphological transformation in this assay, indicating a critical role for CCL2 in microglial activation and suggesting that chronic CCL2 exposure desensitized CCR2 on microglia, which in the CNS of huGFAP-CCL2hi tg+ mice, did not up-regulate cell-surface expression of major histocompatibility complex class II, CD11b, CD11c, or CD40, in contrast to recruited perivascular macrophages that expressed enhanced levels of these markers. These results indicate that huGFAP-CCL2hi tg+ mice provide a useful model to study how chronic CNS expression of CCL2 alters microglial function and CNS physiology.
 ...
PMID:Chronic expression of monocyte chemoattractant protein-1 in the central nervous system causes delayed encephalopathy and impaired microglial function in mice. 1585 90


1 2 3 4 Next >>