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Query: UNIPROT:P10145 (
IL-8
)
23,849
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Chemokines are a group of structurally related peptides that promote the directed migration of leukocytes in tissue. Mechanisms controlling the retention of chemokines in tissue are not well understood. In this study we present evidence that two different mechanisms control the persistence of the
CXC chemokine
,
IL-8
, in lungs and skin. (125)I-labeled
IL-8
was injected into the airspaces of the lungs and the dermis of the skin and the amount of (125)I-labeled
IL-8
that remained at specified times was measured by scintillation counting. The (125)I-labeled
IL-8
was cleared much more rapidly from skin than lungs, as only 2% of the (125)I-labeled
IL-8
remained in skin at 4 h whereas 50% of the (125)I-labeled
IL-8
remained in lungs at 4 h. Studies in neutropenic rabbits showed that neutrophils shortened the retention of (125)I-labeled
IL-8
in skin but not lungs. A monomeric form of
IL-8
, N-methyl-leucine 25
IL-8
, was not retained as long in lungs as recombinant human
IL-8
, indicating that dimerization of
IL-8
is a mechanism that increases the local concentration and prolongs the retention of (125)I-labeled
IL-8
in lungs. These observations show that the mechanisms that control the retention of
IL-8
in tissue include neutrophil migration and dimerization, and that the importance of these varies in different tissues.
...
PMID:Tissue-specific mechanisms control the retention of IL-8 in lungs and skin. 1190 18
The
CXC chemokine
interleukin-8 (
IL-8
/
CXCL8
) induces rapid mobilization of hematopoietic progenitor cells (HPCs). Previously we showed that mobilization could be prevented completely in mice by pretreatment with neutralizing antibodies against the beta2-integrin LFA-1 (CD11a). In addition, murine HPCs do not express LFA-1, indicating that mobilization requires a population of accessory cells. Here we show that polymorphonuclear cells (PMNs) serve as key regulators in
IL-8
-induced HPC mobilization. The role of PMNs was studied in mice rendered neutropenic by administration of a single injection of antineutrophil antibodies. Absolute neutropenia was observed up to 3-5 days with a rebound neutrophilia at day 7. The
IL-8
-induced mobilizing capacity was reduced significantly during the neutropenic phase, reappeared with recurrence of the PMNs, and was increased proportionally during the neutrophilic phase. In neutropenic mice, the
IL-8
-induced mobilizing capacity was restored by the infusion of purified PMNs but not by infusion of mononuclear cells. Circulating metalloproteinase gelatinase B (MMP-9) levels were detectable only in neutropenic animals treated with PMNs in combination with
IL-8
, showing that in vivo activated PMNs are required for the restoration of mobilization. However,
IL-8
-induced mobilization was not affected in MMP-9-deficient mice, indicating that MMP-9 is not indispensable for mobilization. These data demonstrate that
IL-8
-induced mobilization of HPCs requires the in vivo activation of circulating PMNs.
...
PMID:Neutrophils are indispensable for hematopoietic stem cell mobilization induced by interleukin-8 in mice. 1198 13
Leukocyte infiltration in the liver is one of the most important features of alcoholic liver disease. However, in alcoholic hepatitis, the role of polymorphonuclear neutrophils (PMNs) in liver injury still remains to be fully elucidated. Furthermore, the migration of PMNs and their presence in the liver during alcoholic hepatitis have not been fully investigated. Up-regulation of chemokine secretion and adhesion molecule expression on effector cells (i.e., PMNs) and target cells (i.e., hepatocytes) are important factors in neutrophilic infiltration of the liver. The CXC chemokines--that is, interleukin (IL)-8 (in human beings), cytokine-induced neutrophil chemoattractant (CINC) (in rats), and KC (in mice)--are proneutrophilic agents. They are up-regulated during chronic--that is, several years of--alcohol use in human beings and in up to 30 weeks in experimental models of ethanol intoxication in mice and rats. Up-regulation of these chemokines in the circulation and tissues is also associated with enhanced neutrophilic infiltration in the liver. In the rat, the up-regulation of
CXC chemokine
production is time dependent. For example, after 16 weeks of feeding, up-regulation of
CXC chemokine
is observed, whereas after 32 weeks, CC chemokines are enhanced. Concomitantly, selective migration of PMNs and mononuclear cells is observed. In another model, in which both CXC and CC chemokines were enhanced after chronic ethanol use for 12 weeks in mice, neutrophilic and mononuclear/lymphocytic infiltrations were also seen. This model correlates closely with alcoholic hepatitis in human beings, characterized by increased
IL-8
, RANTES (regulated upon activation, normal T cell expressed and secreted), and macrophage inflammatory protein-1 (MIP-1) and profound increases in neutrophils and lymphocytes in the liver.
...
PMID:Neutrophilic infiltration in alcoholic hepatitis. 1206 32
Rotavirus is the major etiologic agent of diarrhea in children and the most common cause of severe pediatric gastroenteritis. Rotavirus infection is limited to mature enterocytes that line the villi of the small intestine. Gut epithelial cells, upon infection and cytokine stimulation, are able to produce chemokines, a family of small chemotactic cytokines that regulate the migration and activation of leukocytes. We have previously shown that rotavirus infection of the intestinal epithelial cell line HT-29 induces increased expression of the
CXC chemokine
interleukin- (IL) 8. Mechanisms responsible for the transcriptional regulation of the
IL-8
gene in intestinal epithelial cells during viral infections have not been fully elucidated. Therefore, the purpose of this study was to define the molecular mechanisms of
IL-8
gene expression in HT-29 cells infected with rotavirus. Transient transfection analysis of 5' deletions and mutations of the
IL-8
promoter driving expression of luciferase reporter gene indicates that the activating protein- (AP) 1 and nuclear factor- (NF) kappaB elements are necessary for
IL-8
promoter activation during rotavirus infection. The importance of NF-kappaB activation for
IL-8
gene expression was further demonstrated by the inhibition of rotavirus-induced
IL-8
gene transcription and protein synthesis following blockade of degradation of the NF-kappaB cytoplasmic inhibitor IkappaB-alpha. Rotavirus infection of HT-29-induced IkappaB kinase (IKK) activation and overexpression of a dominant negative mutant of IKK-beta greatly reduced rotavirus-induced
IL-8
promoter activation and NF-kappaB-driven transcription, indicating that IKK is involved in rotavirus-induced
IL-8
gene expression and NF-kappaB activation.
...
PMID:Interleukin-8 gene regulation in intestinal epithelial cells infected with rotavirus: role of viral-induced IkappaB kinase activation. 1209 68
The
CXC chemokine
, CXCL1 (melanoma growth-stimulatory activity/growth-regulated protein alpha), plays a major role in inflammation, angiogenesis, tumorigenesis, and wound healing. Recently, chemokines have been extensively related to cellular transformation, tumor growth, homing, and metastasis. CXCL1 and its mouse homologue MIP-2 have been shown to be involved in the process of tumor formation. When chemokines such as CXCL1 and
CXCL8
(
IL-8
) become disregulated so that they are chronically expressed, tissue damage, angiogenesis, and tumorigenesis can follow. This up-regulation of chemokines has been attributed to constitutive activation of NF-kappaB. The constitutive NF-kappaB activation is an emerging hallmark in various types of tumors including breast, colon, pancreatic, ovarian, as well as melanoma. Previous findings from our laboratory and other laboratories have demonstrated the role of endogenous activation of NF-kappaB in association with enhanced metastatic potential of malignant melanoma cells and suggest that targeting NF-kappaB may have potential therapeutic effects in clinical trials. An important step in this direction would be to delineate the important intracellular pathways and upstream kinases involved in up-regulation of NF-kappaB in melanoma cells. In this review, the signaling pathways involved in the disregulation of NF-kappaB and chemokine expression are discussed.
...
PMID:Role of CXCL1 in tumorigenesis of melanoma. 1210 Dec 57
The transcription factor NF-kappaB is a pivotal intracellular regulator of many inflammatory responses and it has been proposed that it represents a potential therapeutic target. As chemokines are important for the progress of an inflammatory response by the recruitment of immuno-competent cells, the role NF-kappaB plays in TNFalpha- or lipopolysaccharides (LPS)-induced chemokine secretion by human monocyte-derived macrophages was examined. Secretion of the CXC chemokines
IL-8
, GROalpha and ENA-78, induced by TNFalpha, was significantly suppressed by inhibiting NF-kappaB, using overexpression of IkappaBalpha. However, when induced by LPS the expression of these chemokines was unaffected. In contrast, expression of the CC chemokines MIP-1alpha, MCP-1 and RANTES inducedby TNFalpha or LPS was significantly inhibited by the overexpression of IkappaBalpha. Therefore, there appear to be different mechanisms regulating CC and
CXC chemokine
secretion by macrophages, depending on the stimulus and that TNFalpha and LPS can use different signaling mechanisms in macrophages to regulate chemokine synthesis.
...
PMID:TNFalpha-induced macrophage chemokine secretion is more dependent on NF-kappaB expression than lipopolysaccharides-induced macrophage chemokine secretion. 1211 25
The interactions of Neisseria meningitidis with cells of the leptomeninges are pivotal events in the progression of bacterial leptomeningitis. An in vitro model based on the culture of human meningioma cells was used to investigate the role of the leptomeninges in the inflammatory response. Following challenge with meningococci, meningioma cells secreted specifically the proinflammatory cytokine interleukin-6 (IL-6), the
CXC chemokine
IL-8
, the CC chemokines monocyte chemoattractant protein 1 (MCP-1) and regulated-upon-activation, normal-T-cell expressed and secreted protein (RANTES), and the cytokine growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF). A temporal pattern of cytokine production was observed, with early secretion of IL-6,
IL-8
, and MCP-1 followed by later increases in RANTES and GM-CSF levels. IL-6 was induced equally by the interactions of piliated and nonpiliated meningococci, whereas lipopolysaccharide (LPS) had a minimal effect, suggesting that other, possibly secreted, bacterial components were responsible. Induction of
IL-8
and MCP-1 also did not require adherence of bacteria to meningeal cells, but LPS was implicated. In contrast, efficient stimulation of RANTES by intact meningococci required pilus-mediated adherence, which served to deliver increased local concentrations of LPS onto the surface of meningeal cells. Secretion of GM-CSF was induced by pilus-mediated interactions but did not involve LPS. In addition, capsule expression had a specific inhibitory effect on GM-CSF secretion, which was not observed with IL-6,
IL-8
, MCP-1, or RANTES. Thus, the data demonstrate that cells of the leptomeninges are not inert but are active participants in the innate host response during leptomeningitis and that there is a complex relationship between expression of meningococcal components and cytokine induction.
...
PMID:Interaction of Neisseria meningitidis with human meningeal cells induces the secretion of a distinct group of chemotactic, proinflammatory, and growth-factor cytokines. 1211 9
We hypothesized that US28, a cytomegalovirus (CMV) CC chemokine receptor homolog, plays a role in modulating the host antiviral defense. Monocyte chemotaxis was induced by supernatants from fibroblasts infected with a US28 deletion mutant of CMV (CMV Delta US28) due to endogenously produced CC chemokines MCP-1 and RANTES. However, these chemokines were sequestered from the supernatants of CMV-infected cells that did express US28. US28 was also capable of sequestering exogenously added RANTES. Surprisingly, cells infected with CMV Delta US28 transcribed and secreted increased levels
IL-8
, a
CXC chemokine
, when compared to CMV-infected cells. Finally, because chemokines are potent mediators of immune cell migration through the endothelium, we characterized the CC chemokine binding potential of CMV-infected endothelial cells. We propose that US28 functions as a 'chemokine sink' by sequestering endogenously and exogenously produced chemokines and alters the production of the
CXC chemokine
IL-8
, suggesting that CMV could significantly alter the inflammatory milieu surrounding infected cells.
...
PMID:The expression of the cytomegalovirus chemokine receptor homolog US28 sequesters biologically active CC chemokines and alters IL-8 production. 1220 Jan 12
Nuclear translocation of beta-catenin and its association with Tcf/Lef factors are key steps in transduction of the Wnt signal, which is aberrantly activated in a variety of human cancers. In a search for new beta-catenin-Tcf target genes, we analyzed beta-catenin-induced alterations of gene expression in primary human hepatocytes, after transduction of either dominant stable beta-catenin or its truncated, transactivation-deficient counterpart by means of a lentiviral vector. cDNA microarray analysis revealed a limited set of up-regulated genes, including known Wnt targets such as matrilysin and keratin-1. In this screen, we identified the
CXC chemokine
interleukin 8
(
IL-8
) as a direct target of beta-catenin-Tcf4.
IL-8
is constitutively expressed in various cancers, and it has been implicated in tumor progression through its mitogenic, motogenic, and angiogenic activities. The
IL-8
promoter contains a unique consensus Tcf/Lef site that is critical for
IL-8
activation by beta-catenin. We show here that the p300 coactivator was required for efficient transactivation of beta-catenin on this promoter. Ectopic expression of beta-catenin in hepatoma cells promoted
IL-8
secretion, which stimulated endothelial cell migration. These data define
IL-8
as a Wnt target and suggest that
IL-8
induction by beta-catenin might be implicated in developmental and tumorigenic processes.
...
PMID:Transcriptional activation of interleukin-8 by beta-catenin-Tcf4. 1220 Apr 48
Members of the cytomegalovirus (CMV) subfamily of betaherpesviruses infecting primates and rodents encode divergent proteins with sequence characteristics and activities of chemokines, a class of small, secreted proteins that control leukocyte migration and trafficking behavior. Human CMV genes UL146 and UL147 encode proteins with sequence characteristics of CXC chemokines, whereas, murine CMV encodes a CC chemokine homolog (MCK-2). Human CMV UL146 encodes a neutrophil-attracting chemokine denoted viral
CXC chemokine
-1 (vCXCL1) that is as potent as host
IL-8
and functions via the CXCR2 receptor, one of two human
IL-8
receptors. Murine CMV MCK-2 is composed of a chemokine domain derived from open reading frame (ORF) m131 (and denoted MCK-1) as well as a domain derived from m129 that does not have sequence similarity to any known class of proteins. A synthetic version of murine CMV m131 (MCK-1) protein carries out many of the activities of a positive-acting chemokine, including transient release of intracellular calcium stores and cell adhesion of peritoneal macrophage populations. In the context of the viral genome and infection of the mouse host, the m131-m129 (MCK-2) gene product confers increased inflammation, higher levels of viremia, and higher titers of virus in salivary glands, consistent with a role in promoting dissemination by attracting an important mononuclear leukocyte population. Other characterized primate CMVs, but not other primate betaherpesviruses, encode gene products similar to human UL146 and UL147. Other characterized rodent CMVs encode a gene product similar to the murine CMV chemokine homolog, although not as a spliced gene product. Thus chemokines, like viral proteins that downmodulate MHC class I expression or have sequence homology to host MHC class I proteins, have evolved in primate and rodent CMVs to carry out an analogous set of immunomodulatory functions during infection of the host even though they arise from distinct origins.
...
PMID:Fatal attraction: cytomegalovirus-encoded chemokine homologs. 1222 12
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