Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10145 (IL-8)
 23,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thrombin stimulation of human platelets results in the release of a preformed proteinaceous human eosinophil (Eo)-chemotactic activity. By the use of different high-performance liquid chromatography techniques, two Eo-chemotactic polypeptides (EoCPs), tentatively termed EoCP-1 and EoCP-2, were purified to homogeneity. Upon SDS-PAGE analysis, these chemotaxins showed molecular masses near 8 kD. NH2-terminal amino acid sequence analysis revealed identical sequences for both EoCP-1 and EoCP-2, which are also identical to that of RANTES, a cytokine that structurally belongs to the interleukin 8 superfamily of leukocyte selective attractants, and that is known to be a "memory-type" T lymphocyte-selective attractant. In the major Eo chemotaxin, EoCP-1, the residues 4 and 5, which in EoCP-2 were found to be serine residues, could not be identified. Electrospray mass spectrometry (ESP-MS) of EoCPs revealed for EoCP-2 a molecular mass of 7,862.8 +/- 1.1 daltons, which is 15.8 mass units higher than the calculated value of RANTES, indicating that EoCP-2 is identical to the full-length cytokine, and oxygenation, probably at methionine residue number 64, has taken place. Upon ESP-MS, EoCP-1 showed an average molecular mass of 8,355 +/- 10 daltons, suggesting O-glycosylation at these serine residues. Both natural forms of RANTES showed strong Eo-chemotactic activity (ED50 = 2 nM) with optimal chemotactic migration at concentrations near 10 nM, however, there were no significant migratory responses with human neutrophils. Chemotactic activity of RANTES for human Eos could be confirmed using recombinant material, which has been found to be as active as the natural forms. Since RANTES gene expression has been detected in activated T lymphocytes, and recombinant RANTES was shown to be a "memory" T lymphocyte-selective attractant, it is now tempting to speculate about an important role of RANTES in clinical situations such as allergene-induced late-phase skin reactions in atopic subjects or asthma, where in affected tissues both memory T cells and Eos are characteristic.
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PMID:Cytokine RANTES released by thrombin-stimulated platelets is a potent attractant for human eosinophils. 138 64

We have recently shown that endothelial cell-derived IL-8 inhibits neutrophil adhesion to IL1-beta-activated human umbilical vein endothelial cell monolayers. IL-8 secreted by T lymphocytes or monocytes has been characterized as a promoter of neutrophil degranulation and chemotaxis. The IL-8 isolated from each of these cell types is a mixture of two IL-8 polypeptides, one consisting of 72 amino acids (herein called [ser-IL-8]72) and the other 77 amino acids (an N-terminal extended form herein called [ala-IL-8]77). IL-8 derived from T lymphocytes and monocytes is predominantly [ser-IL-8]72, whereas endothelial-derived IL-8 is highly enriched (greater than 80%) in [ala-IL-8]77. We address the relationship and activities of these two forms of IL-8 using recombinant proteins expressed by both mammalian cells and Escherichia coli. Thrombin was found to efficiently convert [ala-IL-8]77 to [ser-IL-8]72. In contrast, urokinase and tissue-type plasminogen activator were unable to cleave [ala-IL-8]77, and trypsin generated multiple IL-8 cleavage fragments. In competitive binding assays using 125I[ala-IL-8]77 neutrophils exhibited a twofold preference for [ser-IL-8]72 over [ala-IL-8]77. Both forms of IL-8 inhibited neutrophil adhesion to IL-1-beta-activated HUVEC monolayers by up to 90%. However, [ser-IL-8]72 was approximately 10-fold more potent than [ala-IL-8]77 in these assays (ED50 approximately 0.3 nM for [ser-IL-8]72 vs approximately 3 nM for [ala-IL-8]77. Both forms of IL-8 promoted degranulation of cytochalasin B-treated neutrophils [[ser-IL-8]72 (ED50 greater than 10 nM) was two- to three-fold more potent than [ala-IL-8]77], although in this regard they were less active than FMLP. Our data suggest that [ala-IL-8]77 and [ser-IL-8]72 have qualitatively similar and potentially complex biological activities, and that full activation of IL-8 requires cleavage to the [ser-IL-8]72 form. In the case of inflamed endothelial cells this activation could be mediated by thrombin generated in the procoagulant environment associated with these cells.
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PMID:Endothelial and leukocyte forms of IL-8. Conversion by thrombin and interactions with neutrophils. 221 72

Situated in secretory granules of cytotoxic cells, granzymes are essential for induction of target cell apoptosis with perforin. However, since cytotoxic cells constitutively secrete a portion of their synthesized granzymes, these proteases could mediate extracellular functions independently of their role in the lytic event. Thrombin has been shown to function as an activation molecule by cleaving its receptor. We hypothesize that granzymes may act similarly. In this report, we show that purified human granzyme A can induce human lung fibroblasts to produce IL6 and IL8. Cytokine induction is abrogated by treating the serine protease with the suicide serine protease inhibitor 3,4-dichloroisocoumarin. Other fibroblast lines as well as epithelial cells produced cytokines in response to granzyme A. Our data suggest that granzyme A can function as an activation molecule with potentially important immunoregulatory functions.
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PMID:Extracellular Activities of Human Granzymes 866 Aug 52

Human erythroid progenitor cells grown in a suspension culture system were used to study possible interactions between different guanine nucleotide-binding protein (G-protein)-coupled receptor-effector systems during normal cell differentiation. Agonist-stimulated adenylyl cyclase was not inhibited by any one of a panel of ligands (ADP, UTP, platelet-activating factor, thrombin, alpha2-adrenoceptor agonists, interleukin 8, lysophosphatidic acid) most of which are known, in other cells, to reduce cAMP formation by a Gi-mediated, pertussis toxin-sensitive mechanism. The first four of these ligands are also known to cause transient changes in intracellular [Ca2+] in erythroid cells. Rather than inhibiting, thrombin (but not ADP, UTP or PAF) specifically caused a fivefold increase in the maximum adenosine- or prostaglandin E1-stimulated cAMP formation, without any shift of the concentration/response curves. Thrombin did not enhance forskolin- and AlF4-stimulated cyclase activity and had only a marginal effect on isoprenaline-dependent stimulation. The effect of thrombin seemed to be unrelated to intracellular Ca2+ release but could be partially mimicked by phorbol ester (PMA)-induced stimulation of protein kinase C (PKC) and was inhibited by staurosporin or by inactivation of PKC after long-term incubation with PMA. The activity of thrombin was restricted to proliferating, colony-forming progenitor cells while proerythroblasts were completely unresponsive. Our results suggest that the interaction of thrombin with Gs-linked receptors requires phosphorylation of a target protein that is different from adenylyl cyclase, Gs or Gi but may be involved in the regulation of receptor desensitization.
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PMID:Crosstalk between thrombin and adenylyl cyclase-stimulating agonists in proliferating human erythroid progenitor cells. 875 Sep 12

Situated in secretory granules of cytotoxic cells, granzymes are essential for induction of target cell apoptosis with perforin. However, since cytotoxic cells constitutively secrete a portion of their synthesized granzymes, these proteases could mediate extracellular functions independently of their role in the lytic event. Thrombin has been shown to function as an activation molecule by cleaving its receptor. We hypothesize that granzymes may act similarly. In this report, we show that purified human granzyme A can induce human lung fibroblasts to produce IL6 and IL8. Cytokine induction is abrogated by treating the serine protease with the suicide serine protease inhibitor 3,4-dichloroisocoumarin. Other fibroblast lines as well as epithelial cells produced cytokines in response to granzyme A. Our data suggest that granzyme A can function as an activation molecule with potentially important immunoregulatory functions.
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PMID:Extracellular activities of human granzymes. I. Granzyme A induces IL6 and IL8 production in fibroblast and epithelial cell lines. 875 61

Granzymes, serine proteases located in the granules of cytotoxic T cel ls and NK cells, are essential for induction of target cell apoptosis. However, since cytotoxic cells constitutively secrete a portion of their synthesized granzymes, these proteases could mediate extracellular functions independent of their role in the lytic event. Thrombin, another serine protease, can induce cytokine production in a number of different cell types. In this study, we test the hypothesis that granzymes, like thrombin, can regulate cell-mediated immunity by inducing the production of different cytokines. We show that granzyme A (GA) stimulates IL-6, IL-8, and TNF-alpha production by human PBMC and purified monocytes. In contrast, monocytes exposed to thrombin had enhanced IL-8 production with no induction of IL-6 or TNF-alpha production. However, monocytes exposed to either GA or thrombin had enhanced phagocytic activity. The enzymatic activity of GA and thrombin was required for the induction of cytokine production and for the enhancement of phagocytic activity. The induction of different cytokine profiles by GA vs thrombin suggested that GA activates monocytes via a receptor that was different from the thrombin receptor. This conclusion was strengthened by the fact that GA was incapable of inducing Ca2+ mobilization in insect cells transfected with the thrombin receptor. These results suggest that enzymatically active GA mediates important immunoregulatory functions through signaling pathways that does not involve thrombin receptor activation.
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PMID:Extracellular activities of human granzyme A. Monocyte activation by granzyme A versus alpha-thrombin. 878 23

In addition to its role in coagulation, thrombin is involved in the inflammatory process by inducing vessel neutrophilic infiltration. Thrombin induces endothelial P-selectin expression and platelet activating factor release, which participate to induce early neutrophil adhesion and activation. We employed HUVEC and now show that thrombin induces the production of the chemokine IL-8 in a time- and dose-dependent fashion. Similarly, thrombin induced E-selectin expression on HUVEC. Both IL-8 secretion and E-selectin expression were preceded by an increase in steady state levels of the respective mRNAs. Thrombin action on HUVEC was inhibited by the specific thrombin inhibitor, hirudin. In addition, these effects of thrombin on HUVEC were mimicked by the 14-amino acid thrombin receptor agonist peptide, which triggers the native thrombin receptor in a similar fashion to thrombin itself. Although IL-1 and TNF-alpha also induce IL-8 and E-selectin, the thrombin effects in these experiments were not mediated by those cytokines, since neither IL-1 receptor antagonist nor anti-TNF-alpha Ab inhibited the effects of thrombin. Furthermore, IL-1alpha, IL-1beta, and TNF-alpha were not detected in the supernatants of thrombin-activated HUVEC. Although intracellular IL-1alpha was found in thrombin-activated HUVEC, antisense IL-1alpha had no inhibitory effect on IL-8 secretion. These results demonstrate that in addition to short term endothelial activation, thrombin also functions as a long acting proinflammatory agent by inducing endothelial synthesis of the mediators required for neutrophils activation and extravazation during inflammation.
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PMID:Thrombin induces endothelial type II activation in vitro: IL-1 and TNF-alpha-independent IL-8 secretion and E-selectin expression. 916 65

During vascular injury, such as observed in atherosclerosis, restenosis, vasculitides, transplantation, or sepsis, vascular smooth muscle cells (SMC) can be exposed to platelets or platelet products. Under these conditions proliferation or cytokine production of SMC stimulated by platelets or platelet products may contribute to regulation of vascular pathogenesis. Thus, we investigated interleukin-6 (IL-6) and IL-8 production as well as proliferation of SMC in response to platelets or platelet lysates. Platelets not already preactivated by thrombin induced IL-6 (10- to 50-fold) or IL-8 production of unstimulated SMC in a cell number dependent fashion. Preactivation of platelets with thrombin potently increased the platelet-mediated IL-6 (50- to 1,000-fold) and IL-8 production of SMC. Hirudin specifically inhibited the activation of platelets with thrombin. Isolated platelets cultured in the absence of SMC did not contain detectable IL-6 or IL-8. Prestimulation (4 hours) of SMC with pathophysiologically relevant substances (lipopolysaccharide [LPS], tumor necrosis factor-alpha [TNF-alpha], or IL-1alpha) further increased the platelet-induced cytokine production. The platelet-derived SMC stimulatory activity was IL-1, since IL-1 receptor antagonist (IL-1-Ra) inhibited the platelet-induced cytokine production of SMC. Anti-platelet-derived growth factor (PDGF)-antibody did not further reduce this activity. Thrombin itself stimulated expression of IL-6 and IL-8 to some degree and induced IL-6 production of SMC synergistically with IL-1. Platelets also induced proliferation of SMC, however, anti-PDGF antibodies, rather than IL-1-Ra blocked this response. These data show that platelet-derived IL-1 stimulates cytokine production of vascular smooth muscle cells, indicating that platelet-derived IL-1 may contribute to regulation of local pathogenesis in the vessel wall by activation of the cytokine regulatory network.
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PMID:Platelet-derived interleukin-1 induces cytokine production, but not proliferation of human vascular smooth muscle cells. 941 77

Thrombin is the central bioregulatory enzyme in hemostasis and is generated in vascular beds in which inflammatory responses are ongoing. In this study, we examined the effect of thrombin, both alone and in combination with TNF, on gene expression in porcine aortic endothelial cells (EC). Thrombin (1-10 U/ml) induced increased mRNA levels of E-selectin, monocyte chemoattractant protein-1, IL-8, plasminogen activator inhibitor-1, and IkappaB-alpha. These effects were mimicked by a thrombin receptor-activating peptide; preincubation of thrombin with hirudin blocked the induction of mRNA, suggesting that the increased gene expression was due to thrombin-specific activity. Because these genes are known to contain nuclear-factor-kappaB (NF-kappaB)-binding elements in their promoter region, we next examined the ability of thrombin to activate this transcription factor. As detected by electrophoretic mobility shift assay, thrombin (10 U/ml) or thrombin receptor-activating peptide (100 microM) stimulated increased NF-kappaB-binding activity. Supershift analysis revealed that these complexes were comprised principally of the RelA (p65) and NF-kappaB1 (p50) Rel family members. Thrombin alone did not substantively increase protein levels of E-selectin despite the increase in E-selectin mRNA levels. However, thrombin (3-10 U/ml) stimulated a 10-fold enhancement in the ability of TNF (0.3-1.0 ng/ml) to induce E-selectin surface expression. Similar potentiation of TNF-induced NF-kappaB activity and E-selectin transcription by thrombin was observed in experiments utilizing luciferase reporter constructs expressed in bovine aortic EC. The ability of thrombin to potentiate TNF-induced EC activation thus provides an important mechanism by which products of the coagulation cascade may enhance cytokine-mediated inflammatory responses.
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PMID:Thrombin activates nuclear factor-kappaB and potentiates endothelial cell activation by TNF. 954 5

We have previously shown that an anticoagulant could attenuate inflammation in animal models of sepsis with disseminated intravascular coagulation (DIC) and that coagulation activation of human whole blood ex vivo results in a proinflammatory cytokine response. The current studies were performed to better understand mechanisms for the blood cell cytokine response and extend the investigation of such a response to endothelial cells as likely contributors to a vascular inflammatory response. Utilizing cell separation techniques, it was determined that the whole blood IL-8 response to coagulation activation or thrombin, specifically, was mediated by CD14+ monocytes. Moreover, thrombin was observed to stimulate both IL-8 and IL-6 production in cultured mononuclear cells. Analyses of the effects of coagulation activation and thrombin were extended to cultured human endothelial cells, and a similar cytokine response was observed. Thrombin catalytic activity appeared essential, since hirudin reduced thrombin-stimulated proinflammatory cytokine production in cultured monocytes and endothelial cells and prothrombin only weakly mimicked the thrombin response. The endothelial cell IL-8 and IL-6 response to thrombin could be mimicked by the thrombin receptor agonist peptide (TRAP), implicating a functional role of the classic thrombin receptor. Altogether, the results facilitate a better understanding of potential proinflammatory vascular responses to coagulation activation.
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PMID:Potential mechanisms for a proinflammatory vascular cytokine response to coagulation activation. 959 Feb 65


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