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Query: UNIPROT:P80098 (
monocyte chemoattractant protein
)
1,800
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The potential involvement of reactive oxygen species in the expression of genes involved in immune response was examined in mesangial cells. Tumor necrosis factor (TNF-alpha) and aggregated (aggr.) IgG increased mRNA levels for the
monocyte chemoattractant protein
, JE/
MCP-1
, and the colony-stimulating factor, CSF-1. Scavengers for free radicals such as di- and tetra-methylthiourea (DMTU and TMTU) attenuated the increase in mRNA levels in response to TNF-alpha and aggr. IgG. Generation of superoxide anion by xanthine oxidase and hypoxanthine increased mRNA levels of these genes, but exogenous H2O2 did not. Addition of NADPH to activate a membrane-bound NADPH-oxidase generated superoxide and caused a dose-dependent increase in mRNA levels and further enhanced the stimulation by TNF-alpha or aggr. IgG. An inhibitor of NADPH-dependent oxidase 4'-hydroxy-3'-methoxy-acetophenone attenuated the rise in mRNA levels in response to TNF-alpha and aggr. IgG. By nuclear run-on experiments TNF-alpha, aggr. IgG and NADPH increased the transcription rates for JE/
MCP-1
and CSF-1, effects inhibited by TMTU. We conclude that generation of reactive oxygen species, possibly by NADPH-dependent oxidase, are involved in the induction of the JE/
MCP-1
and CSF-1 genes by TNF-alpha and IgG complexes. The concerted expression of leukocyte-directed cytokines represents a general response to tissue injury.
...
PMID:Oxygen radicals as second messengers for expression of the monocyte chemoattractant protein, JE/MCP-1, and the monocyte colony-stimulating factor, CSF-1, in response to tumor necrosis factor-alpha and immunoglobulin G. Evidence for involvement of reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent oxidase. 839 28
The CC chemokine
monocyte chemoattractant protein
-3 (MCP-3) activates human monocytes, lymphocytes, basophils, and eosinophils. MCP-3 has been reported to induce [Ca2+]i changes in cells transfected with the monocyte-selective MCP-1 receptor 2B (CC CKR2B) and competes for 125I-
MCP-1
binding on CC CKR2B, suggesting that it may mediate monocyte responses to MCP-3. However, we now show that MCP-3 is a ligand and potent agonist for the macrophage inflammatory protein-1 alpha (MIP-1 alpha)/regulated on activation, normal T expressed, and secreted protein (RANTES) receptor CC CKR1 (rank order for [Ca2+]i changes = MIP-1 alpha > MCP-3 > RANTES), which is expressed in monocytes > neutrophils > eosinophils. 125I-MCP-3 bound directly to CC CKR1 and CC CKR2B (Ki = 8 and 7 nM, respectively). Binding to CC CKR1 was competed by all CC chemokines tested except
MCP-1
. In contrast, binding to CC CKR2B was competed only by MCP-3 and
MCP-1
. Both
MCP-1
and MCP-3 were equipotent agonists (EC50 = 10 nM for [Ca2+]i changes). Thus, MCP-3 is a functional ligand for both CC CKR1 and CC CKR2B, which otherwise have distinct selectivities for CC chemokines. These data suggest that monocyte responses to MCP-3 could be mediated by both CC CKR2B and CC CKR1, whereas eosinophil responses to MCP-3 could be mediated by CC CKR1.
...
PMID:Monocyte chemoattractant protein-3 is a functional ligand for CC chemokine receptors 1 and 2B. 853 Mar 54
The cDNA encoding human
monocyte chemotactic protein 3
(hMCP-3) was cloned in pHIL-S1, a vector designed for inducible secreted heterologous expression in the methylotrophic yeast Pichia pastoris. After transformation of P. pastoris by electroporation, several clones with the human MCP-3 gene integrated at the alcohol oxidase (AOX-1) locus were isolated. One of these clones (M30) expressed the mature MCP-3 protein with three additional amino acids at its NH2 terminus as a secretion product in the supernatant. The recombinant protein comigrated on SDS-PAGE and cross-reacted immunologically with synthetic hMCP-3. Intermediate-scale production in shake flasks was obtained at expression levels of approximately 1 mg per liter. The recombinant mutant MCP-3 was purified to homogeneity by adsorption on silicic acid, affinity chromatography on heparin-Sepharose, and reversed-phase HPLC. At the amino terminus of the purified recombinant protein, the presence of the additional sequence Arg-Glu-Phe was confirmed by direct protein sequence analysis. The recombinant hMCP-3 mutein was not glycosylated, as evidenced by deglycosylation experiments and by mass spectrometry. In analogy with
MCP-1
, the amino terminus of MCP-3 is crucial for its agonistic effect on receptive cells. At concentrations up to 3.5 micrograms/ml, the recombinant mutein was not active in vitro as a chemotactic factor for monocytes. However, the mutant MCP-3 acted as an MCP-3 receptor antagonist in a competition chemotaxis assay at 100- to 1000-fold excess over the synthetic MCP-3 agonist. It might thus be a useful tool to study antagonism of MCP-3 action in vitro and in disease models of cancer and inflammation.
...
PMID:Expression of a human mutant monocyte chemotactic protein 3 in Pichia pastoris and characterization as an MCP-3 receptor antagonist. 859 Mar 7
The differential expression of chemokine receptors may be an important mechanism for the regulation of T cell migration. To test this, we examined the expression and function of the
monocyte chemoattractant protein
(
MCP
)-1 and interleukin (IL)-8 receptors on various population of T cells. Using a simple and reliable transendothelial chemotaxis assay, both
MCP-1
and IL-8 were shown to be chemotactic for subsets of blood T cells, although the relative response varied from donor to donor. To examine receptor expression and correlate it with chemotaxis of T cell subsets, monoclonal antibodies (mAb) to the receptors were produced by immunizing mice either with synthetic peptides (MCP-1 receptor), or with receptor transfectants (IL-8 receptors A and B). A flow cytometric analysis of blood T cells with an anti-MCP-1 receptor mAb revealed low expression on the CD26hi subset and undetectable expression on other T cells. Staining of T cells with anti-Il-8RA and anti-IL-8RB showed much higher levels of expression, but only on a subset of CD3+ cells which were CD8+ and CD56+. That IL-8 and
MCP-1
attracted distinct subsets of T cells was best illustrated using the CD26 marker, since IL-8R+ T cells were CD26-, whereas T cells expressing detectable
MCP
-1R or which responded to
MCP-1
in chemotaxis assays were CD26hi. T cells activated in vitro with anti-CD3 up-regulated expression of the MCP-1 receptor, but not the IL-8 receptors, and were attracted to
MCP-1
much more efficiently than resting T cells. These results show that there is a clear distinction between the IL-8 and
MCP-1
-responsive T cell populations and that chemokine receptor expression on T cells may be regulated with respect to linkage as well as cellular activation.
...
PMID:Expression of monocyte chemoattractant protein-1 and interleukin-8 receptors on subsets of T cells: correlation with transendothelial chemotactic potential. 860 32
Leishmania major promastigotes were found to avoid activation of mouse bone marrow-derived macrophages (BMM0) in vitro for production of cytokines that are typically induced during infection with other intracellular pathogens. Coexposure of BMM0 to the parasite and other microbial stimuli resulted in complete inhibition of interleukin (IL) 12 (p40) mRNA induction and IL-12 release. In contrast, mRNA and protein levels for IL-1(alpha), IL-1(beta), tumor necrosis factor (TNF) alpha, and inducible NO synthase (iNOS) were only partially reduced, and signals for IL-10 and
monocyte chemoattractant protein
(
MCP-1
/JE) were enhanced. The parasite could provide a detectable trigger for TNF-alpha and iNOS in BMM0 primed with interferon (IFN) gamma, but still failed to induce IL-12. Thus IL-12 induction is selectively impaired after infection, whereas activation pathways for other monokine responses remain relatively intact. Selective and complete inhibition of IL-12(p40) induction was observed using BMM0 from either genetically susceptible or resistant mouse strains, as well as IL-10 knockout mice, and was obtained using promastigotes from cutaneous, visceral, and lipophosphoglycan-deficient strains of Leishmania. The impaired production of the major physiological inducer of IFN-gamma is suggested to underlie the relatively prolonged interval of parasite intracellular survival and replication that is typically associate with leishmanial infections, including those producing self-limiting disease.
...
PMID:Leishmania promastigotes selectively inhibit interleukin 12 induction in bone marrow-derived macrophages from susceptible and resistant mice. 862 63
Antagonists of multiple chemokines could be more effective than inhibitors of specific chemokines for controlling cell migration and inflammation. To attempt to identify such antagonists we characterized a number of truncated analogs of regulated on activation normal T cell expressed protein (RANTES),
monocyte chemoattractant protein
(
MCP
)-3, and
MCP-1
. On the basis of their ability to compete for binding of their parent chemokines, three analogs were selected for cross-reactivity studies: RANTES (9-68), MCP-3 (10-76), and
MCP-1
(9-76). These analogs bound to THP-1 monocytic cells with dissociation constants that were within 4-6-fold of their native counterparts, but they did not promote detectable chemotaxis of THP-1 cells or enzyme release from purified human monocytes. The RANTES (9-68) analog competed for the binding and inhibited the activities of all three chemokines. In contrast, native RANTES was specific for RANTES binding sites. However, truncation of either
MCP-1
or MCP-3 did not change their respective binding specificity. MCP-3 and MCP-3 (10-76) competed for binding of all three labeled chemokines.
MCP-1
(9-76) competed strongly for binding of labeled
MCP-1
, but only weakly for the other two labeled ligands and inhibited the activities induced by
MCP-1
and MCP-3 but not RANTES. Although RANTES (9-68) and MCP-3 (10-76) inhibited all three chemokines, the RANTES analog was significantly more potent for RANTES-induced activity. The results indicate that NH2-terminal residues partly determine the receptor specificity of RANTES, and deletions within this region permit binding to multiple chemokine receptors. The findings suggest the feasibility of design of high affinity multi-specific CC chemokine antagonists.
...
PMID:RANTES and MCP-3 antagonists bind multiple chemokine receptors. 863 50
Inflammation is a critical feature of atherosclerosis and is characterized in part by the migration of circulating monocytes to the atherosclerotic plaque. These monocytes, together with macrophages, are a source of cytokines, growth factors, proteases, and procoagulants, which contribute to the progression of the atherosclerosis lesion. This study employed a modified Boyden chamber to examine the secretion of monocyte chemotactic activity by cultured rat aortic vascular smooth muscle cells in response to growth factors and cytokines. The induction of monocyte chemotactic activity showed a surprising specificity for platelet-derived growth factor-BB. This activity was blocked by actinomycin D and cycloheximide and thus required de novo transcription and protein synthesis. The ability to stimulate monocyte migration appeared to be solely due to the secretion of the
monocyte chemoattractant protein
JE/
MCP-1
and was completely blocked by antisense oligonucleotides and antibodies to JE/
MCP-1
. The induction of chemotactic activity was also blocked by dexamethasone, an inhibitor of JE mRNA accumulation. This study suggests that the secretion of monocyte chemotactic activity by vascular smooth muscle cells is a highly regulatable and specific event and underscores the importance of JE/
MCP-1
in the inflammatory response of the vessel wall.
...
PMID:Secretion of monocyte chemotactic activity by cultured rat aortic smooth muscle cells in response to PDGF is due predominantly to the induction of JE/MCP-1. 868 55
The chemoattractant cytokines,
MCP-1
(
monocyte chemoattractant protein
) and MIP-1alpha (macrophage inflammatory protein), are recognized by highly homologous but distinct receptors. To identify receptor domains involved in determining ligand specificity, we created a series of chimeric
MCP-1
and RANTES (regulated on activation, normal T cell expressed and secreted)/MIP-1alpha receptors that progressively interchanged the amino terminus and each of the three extracellular loops. Radiolabeled
MCP-1
bound with high affinity to the wild-type MCP-1 receptor, but not to the RANTES/MIP-1alpha receptor (C-C CKR-1). Chimeras that retained the amino-terminal extension of the MCP-1 receptor bound
MCP-1
with high affinity. In contrast, chimeric
MCP-1
receptors, in which the wild-type amino terminus was replaced with the corresponding portion of the RANTES/MIP-1alpha receptor, bound
MCP-1
with low affinity. These data indicate that the amino terminus of the MCP-1 receptor is necessary for high affinity binding of the ligand. Very different results were obtained using the RANTES/MIP-1alpha receptor. Radiolabeled MIP-1alpha bound with high affinity to chimeras that expressed the extracellular loops of the RANTES/MIP-1alpha receptor. In contrast to the MCP-1 receptor, substitution of the wild-type amino-terminal extension had little or no effect on MIP-1alpha binding. For the
MCP-1
, but not the RANTES/MIP-1alpha receptor, the presence of the wild-type amino terminus also significantly lowered the ligand concentration required for maximal signaling. We conclude that the amino-terminal extension of the MCP-1 receptor, but not the RANTES/MIP-1alpha receptor, is critically involved in ligand binding and signal transduction. These data reveal significant functional differences between the two C-C chemokine receptors and suggest a two-step mechanism for activation of the MCP-1 receptor.
...
PMID:The amino-terminal extracellular domain of the MCP-1 receptor, but not the RANTES/MIP-1alpha receptor, confers chemokine selectivity. Evidence for a two-step mechanism for MCP-1 receptor activation. 870 81
The present study compares the activity of TCA3 with other beta-chemokines (macrophage inflammatory protein (MIP)-1 alpha, MIP-1 beta, and
monocyte chemoattractant protein
(
MCP
)-1) on rat vascular smooth muscle cells. TCA3, MIP-1 alpha, and
MCP-1
(but not MIP-1 beta) treatment stimulates chemotaxis of vascular smooth muscle cells. TCA3-mediated chemotactic responses are sensitive to treatment with pertussis toxin, suggesting that G alpha-i proteins are involved in TCA3 signaling of smooth muscle. In addition, TCA3, MIP-1 alpha, and
MCP-1
increase vascular smooth muscle cell adhesiveness to type III collagen. In contrast, stimulation with TCA3, but not other beta-chemokines, induces proliferation of vascular smooth muscle cells. TCA3 receptors were identified on rat vascular smooth muscle cells by direct binding of radiolabeled ligand. TCA3 binds to this receptor with high affinity (3 nM). Rat vascular smooth muscle cells display approximately 75,000 binding sites/cell. Competitive inhibition studies indicated that murine MIP-1 alpha, murine
MCP-1
, and human RANTES are weak partial competitors of TCA3 binding, demonstrating the existence of a unique receptor for TCA3. Murine MIP-1 beta, which fails to stimulate any biologic functions in vascular smooth muscle cells, also does not inhibit TCA3 binding. The combined data demonstrate that TCA3 and other beta-chemokines can modulate vascular smooth muscle cell function.
...
PMID:Beta-chemokine TCA3 binds to and activates rat vascular smooth muscle cells. 875 39
Leukocyte emigration possibly requires dynamic regulation of integrin adhesiveness for endothelial and extracellular matrix ligands. Adhesion assays on purified vascular cell adhension molecule (VCAM)-1, fibronectin, and fibronectin fragments revealed distinct kinetic patterns for the regulation of very late antigen (VLA)-4 (alpha 4 beta 1) and VLA-5 (alpha 5 beta 1) avidity by the CC chemokines monocyte inflammatory protein (MIP)-1 alpha, RANTES (regulated on activation, normal T expressed and secreted), or
monocyte chemoattractant protein
(
MCP
)-1 in monocytes. CC chemokines induced early activation and subsequent deactivation of VLA-4, whereas upregulation of VLA-5 avidity occurred later and persisted. Controlled detachment assays in shear flow suggested that adhesive strength of VLA-4 for VCAM-1 or the 40-kD fragment of fibronectin (FN40) is more rapidly increased and subsequently reduced by
MCP-1
than by MIP-1 alpha, and confirmed late and sustained activation of the adhesive strength of VLA-5 for the 120-kD fragment of fibronectin (FN120). Mn2+ or the stimulating beta 1 mAb TS2/16 strongly and stably enhanced monocyte binding to VCAM-1 or fibronectin, and locked beta 1 integrins in a high avidity state, which was not further modulated by CC chemokines. Mn2+ and mAb TS2/16 inhibited CC chemokine-induced transendothelial migration, particularly chemotaxis across stimulated endothelium that involved VLA-4 and VCAM-1. VLA-4 on Jurkat cells is of constitutively high avidity and interfered with migration across barriers expressing VCAM-1. Low but not high site densities of VCAM-1 or FN40 promoted, while FN120 impaired, beta 1 integrin-dependent monocyte chemotaxis to
MCP-1
across filters coated with these substrates. Thus, we show that CC chemokines can differentially and selectively regulate avidity of integrins sharing common beta subunits. Transient activation and deactivation of VLA-4 may serve to facilitate transendothelial diapedesis, whereas late and prolonged activation of VLA-5 may mediate subsequent interactions with the basement membrane and extracellular matrix.
...
PMID:Sequential regulation of alpha 4 beta 1 and alpha 5 beta 1 integrin avidity by CC chemokines in monocytes: implications for transendothelial chemotaxis. 876 27
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