Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.59 (MIP)
 4,906 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have produced recombinant proteins for a cytokine, L2G25BP (macrophage inflammatory protein-1 alpha) (MIP-1 alpha). By using the recombinant protein (rMIP-1 alpha), receptors for MIP-1 alpha were identified on Con A-stimulated and unstimulated CTLL-R8, a T cell line, and LPS-stimulated RAW 264.7, a macrophage cell line. The 125I-rMIP-1 alpha binds to the receptor in a specific and saturable manner. Scatchard analysis indicated a single class of high affinity receptor, with a Kd of approximately 1.5 x 10(-9) M and approximately 1200 binding sites/Con A-stimulated CTLL-R8 cell and a Kd of 0.9 x 10(-9) M and approximately 380 binding sites/RAW 264.7 cell. 125I-rMIP-1 alpha binding was inhibited by unlabeled rMIP-1 alpha in a dose-dependent manner, but not by IL-1 alpha or IL-2. rMIP-1 alpha inhibited the proliferation of unstimulated CTLL-R8 cells. Rabbit anti-rMIP-1 alpha antibodies blocked the growth-inhibitory effect of the rMIP-1 alpha on CTLL-R8 cells.
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PMID:Identification of cell surface receptors for murine macrophage inflammatory protein-1 alpha. 165 2

Activated macrophages produce a number of proinflammatory cytokines including IL-6, JE, MIP-1 alpha and MIP-1 beta. The induction requirements for production of either IL-6 or the MIP-1 related inflammatory proteins (MIP-1 alpha, MIP-1 beta, and JE) have been analyzed independently using fibroblasts, monocytes, or endothelial cells. However, little is known about the regulation of these cytokines in macrophages. Since activated macrophages produce prostaglandins (PGE2) which may participate in the autoregulation of cytokine production by stimulation of adenylate cyclase and the induction of cAMP-dependent signal pathways, we determined the effects of PGE on the production of IL-6 and MIP-1-related proteins. Murine macrophage cell lines were incubated with PGE1, PGE2, cholera toxin, or dibutyryl cAMP in the presence of absence suboptimal doses of LPS. Pharmacologic agents alone did not induce IL-6 production but incubation of macrophages with combinations of adenylate cyclase stimulators and LPS or dcAMP and LPS led to the dose-dependent enhancement of IL-6 secretion and mRNA expression. In contrast, PGE1 inhibits LPS-induced JE, MIP-1 alpha, and MIP-1 beta mRNA expression and this inhibition is partially dependent on a cAMP-mediated pathway of signal transduction. In previous work we demonstrated that IFN-gamma and PMA do not stimulate the production of IL-6 by macrophages. Here we show that incubation of macrophages with either IFN-gamma or PMA induces the expression of JE, MIP-1 alpha and MIP-1 beta mRNA expression. JE mRNA expression is much more responsive to the stimulatory effects of IFN-gamma than are the MIP-1 genes. Finally, PGE inhibits PMA and IFN-gamma-induced JE and MIP-1-related mRNA expression.
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PMID:Differential regulation of interleukin-6, macrophage inflammatory protein-1, and JE/MCP-1 cytokine expression in macrophage cell lines. 185 Mar 27

Two recently identified and purified murine macrophage inflammatory proteins MIP-1 and MIP-2 were tested in vitro both alone, and in combination with purified recombinant (r) murine (mu) GM-CSF, natural (n)muCSF-1, or rhuman (hu)G-CSF, for effects on mouse marrow CFU-GM, in combination with erythropoietin for effects on mouse marrow BFU-E, and in combination with rhuGM-CSF or rhuG-CSF for effects on human marrow CFU-GM. MIP-1 and MIP-2 did not stimulate, but did enhance by up to threefold, colony formation of mouse CFU-GM co-stimulated by rmuGM-CSF and nmuCSF-1, but not by rhuG-CSF, in the absence or presence of serum. MIP-1 and MIP-2 were maximally active at concentrations greater than or equal to 100 ng/ml and the actions appeared to be initiated during the DNA synthetic portion of the cell cycle. Neither MIP-1 nor MIP-2 at up to 1 microgram/ml had any effect on mouse BFU-E, in the absence or presence of erythropoietin. Both MIP-1 and MIP-2 had direct acting effects on purified mouse CFU-GM. The cloning efficiency of 200 purified cells plated with 50 U muCSF-1 was 82% with and 43% without MIP; the cloning efficiency with 50 U rmuGM-CSF was 65% with and 35% without MIP. MIP effects were not mimicked by bacterial LPS, rhuIL-1 alpha, rhuIL-6, or rmuIL-4, and were neutralized by their respective specific antibodies. MIP-1 and MIP-2 also enhanced endogenously stimulated and rhuGM-CSF-, but not rhuG-CSF-, stimulated colony formation by human marrow CFU-GM. These results demonstrate a new role for MIP-1 and MIP-2 in vitro as myelopoietic enhancing activities for CFU-GM.
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PMID:Myelopoietic enhancing effects of murine macrophage inflammatory proteins 1 and 2 on colony formation in vitro by murine and human bone marrow granulocyte/macrophage progenitor cells. 247 52

Liver and kidney injury following acute or chronic exposure to cadmium is well characterized. While hepatocytes and endothelial cells of the sinusoids are thought to be the primary cellular targets in the liver, ultrastructural changes may vary depending upon the exposure regimen and the time following administration. Since acute and chronic liver disease is often associated with the presence of cytokines, we investigated the role of proinflammatory cytokines in cadmium-induced hepatotoxicity. Supernatants from cultured liver slices obtained from acute or subchronic cadmium-exposed rats and mice were collected and cytokine secretion was examined. In addition, mRNA transcripts for IL-1 alpha, IL-1 beta, IL-6, TNF-alpha, MIP-2, IFN-gamma, and ICAM-1 from livers of treated mice were quantitated by reverse transcription-polymerase chain reaction. Modest increases in secretion of TNF-alpha, IL-1 alpha, and IL-6 were observed in response to cadmium which were enhanced in LPS-primed mice. Additionally, cadmium exposure increased IL-1 alpha, IL-1 beta, TNF-alpha, MIP-2, IL-6, and ICAM-1 mRNA transcripts in the liver. Immunohistochemical analysis revealed that TNF-alpha was associated with nonparenchymal cells in livers of cadmium-treated mice. Cadmium exposure produced a marked increase in plasma hepatocellular enzyme levels (i.e., AST, LDH, SDH), acute phase proteins (i.e., serum amyloid A), and foci formation in the liver, while focal inflammation and serum amyloid A (SAA) secretion, but not plasma enzymes, were further increased in cadmium-exposed mice primed with LPS. SAA secretion and focal inflammation were prevented by pretreatment with antibodies to TNF-alpha, indicating that these pathological manifestations are cytokine dependent. These data indicate that TNF-alpha, released from nonparenchymal cells as well as associated cytokines, are responsible for certain manifestations observed with cadmium-induced hepatotoxicity.
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PMID:Role of tumor necrosis factor-alpha in cadmium-induced hepatotoxicity. 753 60

The mouse KC gene is an alpha-chemokine gene whose transcription is induced in mononuclear phagocytes by LPS. DNA sequences necessary for transcriptional control of KC by LPS were identified in the region flanking the transcription start site. Transient transfection analysis in macrophages using deletion mutants of a 1.5-kb sequence placed in front of the chloramphenicol acetyl transferase (CAT) gene identified an LPS-responsive region between residues -104 and +30. This region contained two kappa B sequence motifs. The first motif (position -70 to -59, kappa beta 1) is highly conserved in all three human GRO genes and in the mouse macrophage inflammatory protein-2 (MIP-2) gene. The second kappa B motif (position -89 to -78, kappa B2) was conserved only between the mouse and the rat KC genes. Consistent with previous reports, the highly conserved kappa B site (kappa B1) was essential for LPS inducibility. Surprisingly, the distal kappa B site (kappa B2) was also necessary for optimal response; mutation of either kappa B site markedly reduced sensitivity to LPS in RAW264.7 cells and to TNF-alpha in NIH 3T3 fibroblasts. Although both kappa B1 and kappa B2 sequences were able to bind members of the Rel homology family, including NF kappa B1 (P50), RelA (65), and c-Rel, the kappa B1 site bound these factors with higher affinity and functioned more effectively than the kappa B2 site in a heterologous promoter. These findings demonstrate that transcriptional control of the KC gene requires cooperation between two kappa B sites and is thus distinct from that of the three human GRO genes and the mouse MIP-2 gene.
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PMID:Two structurally distinct kappa B sequence motifs cooperatively control LPS-induced KC gene transcription in mouse macrophages. 756 Oct 58

The regulation of CD4 expression on macrophages and its role in immune cell interactions remain obscure. In contrast with primary lymphocytes, primary macrophages express only low amounts of surface CD4, which is regulated differentially for example by adherence in vitro. We report that addition of LPS for 1-5 days to human blood monocyte tissue culture-derived macrophages (TCDM) down-regulates both surface CD4 expression and total cellular CD4 antigen content as measured by flow cytometry and Western blot analysis. TNF-alpha and IL-1 beta, proinflammatory cytokines which are both induced by LPS, also down-regulate surface and total CD4 expression in TCDM. This down-regulation of CD4 expression by LPS, TNF-alpha, and IL-1 beta occurs at the level of transcription. The decreased macrophage CD4 expression induced by LPS was blocked by MoAbs directed against human TNF-alpha and IL-1 beta, demonstrating that LPS acts on CD4 expression through induction of endogenous TNF-alpha and IL-1 beta. Conversely, neither LPS nor TNF-alpha and IL-1 beta were able to modulate surface CD4 expression on quiescent or phytohaemagglutinin (PHA)-activated lymphocytes. Of other cytokines and growth factors tested, Th2 cytokines (IL-4, IL-10, IL-13), chemokines (MCP-1, MIP-1 alpha, RANTES), and macrophage colony-stimulating factor did not alter CD4 expression in primary macrophages; granulocyte-monocyte colony-stimulating factor and the prototypal Th1 cytokine interferon-gamma (IFN-gamma) modulated surface CD4 expression only after prolonged treatment (5 days). Our results show that LPS, TNF-alpha and IL-1 beta selectively down-regulate CD4 expression in primary human macrophages, and that decreased CD4 expression induced by LPS results from endogenous secretion of TNF-alpha and IL-1 beta by the macrophages.
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PMID:Lipopolysaccharide (LPS) down-regulates CD4 expression in primary human macrophages through induction of endogenous tumour necrosis factor (TNF) and IL-1 beta. 758 2

IL-10 is a pleiotropic cytokine produced by monocytes and T cells that has potent inhibitory effects on monocyte/macrophage function. Because monocytes and macrophages are capable of releasing the C-C chemokine, macrophage inflammatory protein-1 alpha (MIP-1 alpha), which is a potent chemoattractant for activated T cells, we studied the effects of IL-10 on the expression of MIP-1 alpha in these cells. Low levels of MIP-1 alpha were detectable in resting monocytes and macrophages. Both LPS (1 micrograms/ml) and IL-1 beta (10 ng/ml) induced the expression of MIP-1 alpha mRNA and the release of MIP-1 alpha protein from these cells. The addition of exogenous human rIL-10 inhibited induced MIP-1 alpha mRNA expression as well as the release of MIP-1 alpha protein measured after 24 h. This inhibition was significantly higher in monocytes compared with alveolar macrophages. In monocytes, IL-10-induced inhibition of MIP-1 alpha was only partially accounted for by alterations in mRNA stability and was dependent on de novo protein synthesis. In the presence of an anti-human IL-10-neutralizing Ab, the release of MIP-1 alpha induced by LPS and IL-1 beta was further enhanced in monocytes but unchanged in alveolar macrophages. MIP-1 alpha mRNA was also increased in monocytes. There was no detectable release of IL-10 from alveolar macrophages after LPS or IL-1 beta in contrast to modest amounts released from monocytes. Thus, IL-10 is an inhibitor of the induced transcription of MIP-1 alpha mRNA and of the release of MIP-1 alpha protein, with a greater effect on monocytes as compared with alveolar macrophages. IL-10 may indirectly regulate effects on cells such as activated T lymphocytes partly through the inhibition of MIP-1 alpha expression from monocytes and macrophages.
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PMID:Inhibition of macrophage inflammatory protein-1 alpha expression by IL-10. Differential sensitivities in human blood monocytes and alveolar macrophages. 759 2

Systemic exposure to LPS initiates a complex sequence of events resulting in organ-specific leukocyte recruitment and end-organ injury. We hypothesized that macrophage inflammatory protein-1 alpha (MIP-1 alpha), a C-C chemokine with leukocyte chemotactic and activating properties, may play an important role in lung inflammatory cell recruitment, subsequent lung injury, and mortality in endotoxemia. CD-1 mice were challenged with LPS (200 micrograms), resulting in a maximal 3.5-fold increase in neutrophils (polymorphonuclear leukocytes (PMNs)) at 6 h post-LPS, and a 2.6-fold increase in numbers of macrophages (M phi) within lung minces at 24 h. A time-dependent increase in MIP-1 alpha mRNA and protein was detected in lung after LPS treatment, with immunolocalization of MIP-1 alpha to blood and lung M phi, and the subendothelium. The pretreatment of mice with rabbit anti-MIP-1 alpha Ab resulted in a decrease in the influx of PMNs at 6 h, and influx of M phi at 24 h post-LPS challenge, an approximately 65% reduction in LPS-induced lung permeability to Evans blue, and a modest decrease in mortality at 24, but not 48 h post-LPS. Furthermore, passive immunization of mice with anti-MIP-1 alpha serum resulted in a 35% reduction in ICAM-1 mRNA levels within lung homogenates post-LPS. Finally, the pretreatment of animals with sTNFR:Fc (soluble TNF receptor:Ig construct) resulted in a 60% reduction in LPS-induced MIP-1 alpha mRNA expression within lung homogenates at 4 h post-LPS. Our studies indicate that MIP-1 alpha plays an integral role as a mediator of both PMN and M phi recruitment in murine endotoxemia.
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PMID:Macrophage inflammatory protein-1 alpha mediates lung leukocyte recruitment, lung capillary leak, and early mortality in murine endotoxemia. 763 13

The overzealous production of pro-inflammatory cytokines during endotoxemia can result in shock, multiorgan dysfunction, and even death. The extent of tissue injury that occurs in endotoxemia is determined not only by the release of pro-inflammatory cytokines, but also by the expression of endogenous counter-regulatory cytokines, such as IL-10. In this study, we defined the role of endogenously-produced IL-10 in a murine model of endotoxemia. Initial studies indicated that LPS administration to mice i.p. induces a significant time-dependent increase in plasma IL-10. Passive immunization with anti-IL-10 serum before LPS administration resulted in substantial increases in endotoxin-induced lethality. Furthermore, the inhibition of IL-10 bioactivity in vivo resulted in a greater and more sustained increase in plasma TNF and macrophage inflammatory protein-2 (MIP-2) levels, as compared with control animals, which was accompanied by early increases in lung polymorphonuclear leukocyte influx and lung capillary leak. Finally, anti-IL-10-mediated lethality was significantly abrogated by concomitant treatment with anti-MIP-2 serum and/or sTNFR:Fc alone or in combination. These observations indicate that TNF and MIP-2 are important cytokine mediators during endotoxemia, and endogenously produced IL-10 is instrumental in down-regulating the overzealous production of both TNF and MIP-2 that occurs in response to systemic endotoxin exposure.
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PMID:Neutralization of IL-10 increases lethality in endotoxemia. Cooperative effects of macrophage inflammatory protein-2 and tumor necrosis factor. 763 69

The role of macrophage inflammatory protein-1 alpha (MIP-1 alpha) in the pathogenesis of acute lung injury in rats after intrapulmonary deposition of IgG immune complexes or intratracheal administration of LPS has been assessed. Critical to these studies was the cloning and functional expression of rat MIP-1 alpha. The resulting product shared 92% and 90% homology with the known murine sequence at the cDNA level and protein level, respectively. Recombinant rat MIP-1 alpha exhibited dose-dependent chemotactic activity for both rat and human monocytes and neutrophils, which could be blocked by anti-murine MIP-1 alpha Ab. Rat MIP-1 alpha mRNA and protein expression were determined as a function of time in both injury models. A time-dependent increase in MIP-1 alpha mRNA in lung extracts was observed in both models. In the LPS model, MIP-1 alpha protein could also be detected in bronchoalveolar lavage (BAL) fluids by Western blot analysis. Anti-MIP-1 alpha administered at commencement of IgG immune complex- or LPS-induced injury resulted in significant reductions in BAL neutrophils as well as in injury as measured by pulmonary vascular permeability. Under such conditions, in both models TNF-alpha content in BAL fluids was substantially reduced as compared with BAL fluids from positive control animals. These findings suggest that rat MIP-1 alpha plays an important role in the development of lung injury in these neutrophil-dependent models. The role of MIP-1 alpha seems to be related to production of TNF-alpha, which in turn up-regulates vascular adhesion molecules required for neutrophil influx.
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PMID:Role of macrophage inflammatory protein-1 alpha (MIP-1 alpha) in acute lung injury in rats. 772 28


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