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

Interleukin (IL)-8 elicits neutrophil migration in the early inflammatory response. This action of IL-8 is believed to involve mitogen-activated protein (MAP) kinase p44/42. In the present study, we used specific inhibitors to investigate the role of p44/42 kinase in stimulating neutrophil migration. The IL-8-guided migration through an imitation of inflammatory matrix, a fibrin gel, was impaired by 90% after treatment with 7 microM U0126, a specific inhibitor of the kinase of p44/42 kinase. Superoxide anion generation induced by high concentrations of bacterial signals was not impaired in the absence of functional p44/42. This anion generation could be decoupled from the p44/42 independency by priming the cells, a pretreatment with IL-8. The addition of U0126 inhibited by 60% the priming and subsequent superoxide anion generation triggered by low concentrations of bacterial signals. An impact on the priming effect and migration of neutrophils was found upon blockade (with wortmannin) of a further kinase event that converges on the p44/42 phosphorylation. Wortmannin blocked phosphatidylinositol 3-kinase and secondarily phosphorylation of p44/42 and of the p44/42-related MAP kinase p38. The overlapping functional consequences of a specific blockade of p38 MAP kinase (applying in vivo anti-inflammatory pyridinyl imidazole) further ascribed a migratory role to those signals culminating in p44/42 MAP kinase phosphorylation, and suggests a role in vivo.
 ...
PMID:Role of interleukin-8 phosphorylated kinases in stimulating neutrophil migration through fibrin gels. 1057 11

The organic compounds of diesel exhaust particles (DEP-PAHs) have been shown to favor immunoglobulin production and bronchial hyperresponsiveness and to affect cytokine and chemokine productions. To evaluate if diesel exhaust could act in synergy with a house dust mite allergen (Der p 1), peripheral blood mononuclear cells from allergic patients were exposed to DEP-PAHs, with or without purified Der p 1. DEP-PAHs and Der p 1 separately induced an increase in interleukin (IL)-8, regulated on activation, normal T cells expressed and secreted (RANTES), and tumor necrosis factor-alpha concentrations. Interestingly, a synergy between the two stimuli was also observed. In the case of monocyte chemotactic protein (MCP)-1, DEP-PAHs reduced the release, whereas Der p 1 enhanced it. A simultaneous exposure led to reduced production as compared with allergen exposure alone, but still represented an increase as compared with the control exposure. Mitogen-activated protein (MAP) kinase Erk1/2 antagonist mainly inhibited the release of MCP-1, whereas MAP kinase p38 antagonist mainly suppressed the release of IL-8 and RANTES. Messenger RNA expression correlated with protein measurements. Moreover, supernatants from cells exposed to both DEP-PAHs and Der p 1 had a significant chemotactic activity on neutrophils and eosinophils. These findings suggest that simultaneous exposure of allergic patients to DEPs and allergens could result in high local chemokine levels via MAP kinase pathways activation, increasing the likelihood of reaching a critical threshold leading to the initiation of respiratory allergic symptoms.
 ...
PMID:Synergistic effect of diesel organic extracts and allergen Der p 1 on the release of chemokines by peripheral blood mononuclear cells from allergic subjects: involvement of the map kinase pathway. 1091 93

Epidemiologic and experimental studies suggest that diesel exhaust particles (DEPs) may be related to increasing respiratory mortality and morbidity. We have shown that DEPs augmented the production of inflammatory cytokines by human airway epithelial cells in vitro. To better understand the mechanisms of their proinflammatory activities, we studied the effects of several components extracted from DEPs on interleukin (IL)-8 expression in human bronchial epithelial cell line BEAS-2B and normal human airway epithelial cells obtained from very peripheral airways by an ultrathin bronchoscope. We used several agents active on signal transduction pathways in cytokine expression, such as the protein kinase C inhibitor staurosporin, antioxidant agents including N-acetyl cysteine (NAC) and pyrrolidine dithiocarbamate (PDTC), and p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580. Benzene-extracted components showed effects mimicking DEPs on IL-8 gene expression, release of several cytokines (IL-8; granulocyte macrophage colony-stimulating factor; and regulated on activation, normal T cells expressed and secreted) and nuclear factor (NF)-kappa B activation. We also found that NAC, PDTC, and SB203580 suppressed the activities of DEPs and their benzene extracts, suggesting the roles of oxidants-mediated NF-kappa B activation and p38MAPK pathways. Finally, benzo[a]pyrene, one of the important compounds included in the benzene component, replicated the activities shown by DEPs.
 ...
PMID:Benzene-extracted components are important for the major activity of diesel exhaust particles: effect on interleukin-8 gene expression in human bronchial epithelial cells. 1130 35

Sodium fluoride (NaF) has previously been reported to induce a strong IL-8 response in human epithelial lung cells (A549) via mechanisms that seem to involve the activation of G proteins. In the present study the signal pathways downstream of the G proteins have been examined. NaF induced a weak, but sustained increase in PKC activity. In contrast, the PKC activator TPA induced a relatively strong, but transient effect and augmented the NaF-induced PKC activity. TPA induced a marked IL-8 response compared to NaF. PDB, another PKC activator, was less effective, but augmented the IL-8 response to NaF. Pretreatment with TPA for 20 h, or the PKC inhibitor GF109203X for 1 h, abolished the basal and NaF-induced PKC activities and partially prevented the NaF-induced IL-8 response. Inhibition of the MAP kinase p38 by SB202190 partially reduced the IL-8 response to NaF, whereas a reduction in ERK activity by PD98059 led to an increased response. The NaF-induced IL-8 response was weakly augmented by the PKA stimulator forskolin and the G(i) inhibitor pertussis toxin. The PKA inhibitor H89 seemed to reduce the NaF-induced IL-8 response, but the measured effect was not statistically significant. BAPTA-AM, KN93 and W7, that inhibit Ca(2+)-linked effects, did not affect the IL-8 response. Furthermore, the tyrosine kinase inhibitor genestein, the PI-3 kinase inhibitor wortmannin and phosphatase inhibition were without effects. In conclusion, the data suggest that NaF-induced increase of IL-8 in A549 cells involved PKC- and p38-linked pathways, whereas an ERK-dependent pathway counteracted the response. Tyrosine kinases, Ca(2+)-linked pathways, PI-3 kinase, PKA and phosphatase inhibition seem to play no or minor roles in the fluoride-induced IL-8 response.
 ...
PMID:Mechanisms in fluoride-induced interleukin-8 synthesis in human lung epithelial cells. 1156 78

Interleukin-8 (IL-8) is known to contribute to human cancer progression through its potential function as a mitogenic, angiogenic, or motogenic factor. We found a high level of IL-8 production in SK-N-MC human primitive neuroectodermal tumor cells transfected with the human RET gene (SK-N-MC (RET) cells) in response to glial cell line-derived neurotrophic factor (GDNF) stimulation. IL-8 was also produced at high levels in TT human medullary thyroid carcinoma and TPC-1 human papillary thyroid carcinoma cell lines both of which express activated RET tyrosine kinase. To investigate which signaling pathways are responsible for IL-8 expression, we treated SK-N-MC (RET) cells with several kinase inhibitors before GDNF stimulation. The results showed that a MEK1 inhibitor, PD98059, a p38MAPK inhibitor, SB202190, and a protein kinase C (PKC) inhibitor, Calphostin C, markedly decreased the IL-8 secretion from SK-N-MC (RET) cells at 24 h after GDNF stimulation. In contrast, a phosphatidylinositol 3-kinase (PI3-K) inhibitor, LY294002, increased its secretion. These results thus suggested that IL-8 production by RET tyrosine kinase is regulated by multiple signaling pathways.
 ...
PMID:Activation of RET tyrosine kinase regulates interleukin-8 production by multiple signaling pathways. 1205 17

High-throughput genomic technology identified an association between a single nucleotide polymorphism (SNP), a proline (P387) rather than the predominant alanine (A387) at position 387 in thrombospondin-4 (TSP-4) and premature myocardial infarction. The inflammatory hypothesis of atherosclerosis invokes a prominent role of leukocytes and cytokines in pathogenesis. As the expression of TSP-4 by vascular cells permits its exposure to circulating leukocytes, the interactions of human neutrophils (polymorphonuclear leukocytes [PMNs]) with both TSP-4 variants were investigated. Phorbol 12-myristate 13-acetate (PMA)-stimulated PMNs adhered and migrated well and equally on the TSP-4 variants. Integrin alpha(M)beta2 was identified as the TSP-4 receptor mediating these responses, and the 3 epidermal growth factor (EGF)-like domains of TSP-4 harboring the SNPs interacted with the alpha(M)I-domain. Despite the similarity in these responses, the P387 variant induced more robust tyrosine phosphorylation of the stress-related mitogen-activated protein kinases (MAPKs): p38MAPK and c-Jun NH2-terminal kinase (JNK), as well as signal transducer and activator of transcription-1 (STAT1) and heat shock protein 27 (HSP27) than the A387 variant. Additionally, cells adherent to P387 TSP-4 variant released 4-fold more H2O2 and secreted 2-fold more interleukin 8 (IL-8) as compared with the A387. H2O2 release and p38MAPK activation were totally inhibited by blockade of alpha(M)beta2. Thus, alpha(M)beta2 plays a central role in proinflammatory activities of TSP-4 (P387) and may contribute to the prothrombotic phenotype associated with this variant.
 ...
PMID:Mechanism and effect of thrombospondin-4 polymorphisms on neutrophil function. 1609 85

Tumors actively develop different mechanisms such as immunosuppressive cytokine production to escape from immune control and limit the success of immunotherapy. More and more evidences suggest that chronic inflammation contributes to cancer development and progression. Recently, Toll-like receptors (TLRs), the receptors by which immune cells recognize microbial conserved components such as lipopolysaccharide (LPS) then initiate immune and inflammatory responses, have been found to be expressed by some kinds of tumor cells. However, what is the biological function of TLRs on tumor cells and whether human lung cancer cells can express TLRs remain to be fully understood. In the present study, we demonstrate that TLR4 is expressed on human lung cancer cell lines. TLR4 ligation promotes production of immunosuppressive cytokines TGF-beta, VEGF, proangiogenic chemokine IL-8 by human lung cancer cells. In addition, TLR4 ligation induces resistance of human lung cancer cells to TNF-alpha or TRAIL-induced apoptosis. Furthermore, we show p38MAPK activation is necessary for increased VEGF and IL-8 secretion, NF-kappaB activation contributes to apoptosis resistance of human lung cancer cells induced by LPS. Therefore, we demonstrate that TLR4 expressed on human lung cancer cells is functionally active, and may play important roles in promoting immune escape of human lung cancer cells by inducing immunosuppressive cytokines and apoptosis resistance.
 ...
PMID:TLR4 signaling promotes immune escape of human lung cancer cells by inducing immunosuppressive cytokines and apoptosis resistance. 3244 54

Head and neck squamous cell carcinoma (HNSCC) is one of the most frequently diagnosed cancers. It is believed that tumor production of various immune suppressive mediators contributes to massively impaired immune functions, but the underlying signal transduction pathways are mostly unknown. Phosphorylation levels of MAP (mitogen-activated protein) kinase p38 were analyzed in permanent cell lines as well as in solid tumor tissue of HNSCC using flow cytometry and SDS-PAGE. Cytokine secretion was determined using the Cytometric Bead Array Flex Set system. MAP kinase p38 was shown to be activated in HNSCC by phorbol 12-myristate 13-acetate. Activation of p38 led to decreased cell proliferation and increased secretion of cytokines IL-6 and IL-8 in HNSCC. Our data provide novel insights into the origin of the HNSCC microenvironment. A better understanding of these molecular mechanisms in HNSCC is essential for novel drug development and improvement of the clinical perspective of this tumor type.
 ...
PMID:Increased cytokine secretion in head and neck cancer upon p38 mitogen-activated protein kinase activation. 1798 98

Helicobacter pylori VacA induces multiple effects on susceptible cells, including vacuolation, mitochondrial damage, inhibition of cell growth, and enhanced cyclooxygenase-2 expression. To assess the ability of H. pylori to modulate the production of inflammatory mediators, we examined the mechanisms by which VacA enhanced IL-8 production by promonocytic U937 cells, which demonstrated the greatest VacA-induced IL-8 release of the cells tested. Inhibitors of p38 MAPK (SB203580), ERK1/2 (PD98059), IkappaBalpha ((E)-3-(4-methylphenylsulfonyl)-2-propenenitrile), Ca(2+) entry (SKF96365), and intracellular Ca(2+) channels (dantrolene) blocked VacA-induced IL-8 production. Furthermore, an intracellular Ca(2+) chelator (BAPTA-AM), which inhibited VacA-activated p38 MAPK, caused a dose-dependent reduction in VacA-induced IL-8 secretion by U937 cells, implying a role for intracellular Ca(2+) in mediating activation of MAPK and the canonical NF-kappaB pathway. VacA stimulated translocation of NF-kappaBp65 to the nucleus, consistent with enhancement of IL-8 expression by activation of the NF-kappaB pathway. In addition, small interfering RNA of activating transcription factor (ATF)-2 or CREB, which is a p38MAPK substrate and binds to the AP-1 site of the IL-8 promoter, inhibited VacA-induced IL-8 production. VacA activated an IL-8 promoter containing an NF-IL-6 site, but not a mutated AP-1 or NF-kappaB site, suggesting direct involvement of the ATF-2/CREB binding region or NF-kappaB-binding regions in VacA-induced IL-8 promoter activation. Thus, in U937 cells, VacA directly increases IL-8 production by activation of the p38 MAPK via intracellular Ca(2+) release, leading to activation of the transcription factors, ATF-2, CREB, and NF-kappaB.
 ...
PMID:Molecular characterization of Helicobacter pylori VacA induction of IL-8 in U937 cells reveals a prominent role for p38MAPK in activating transcription factor-2, cAMP response element binding protein, and NF-kappaB activation. 1835 27

The purpose of this study was to identify the Pseudomonas aeruginosa-activated signaling pathway leading to interleukin (IL)-8 gene expression and protein synthesis by human conjunctival epithelium. IL-8 protein and mRNA were determined by enzyme-linked immunosorbent assay and reverse transcription-PCR, respectively. Activation of MAPKs and NF-kappaB was analyzed by Western blotting using phosphospecific antibodies. We used transfection with wild-type or mutated IL-8 promoters and cotransfection with transcription factor overexpressing plasmids or small interfering RNAs. Electrophoretic mobility shift assay and chromatin immunoprecipitation (ChIP) were performed for in vitro and in vivo protein-DNA binding studies, respectively. P. aeruginosa increased IL-8 expression at the transcriptional level by phosphorylating CCAAT/enhancer-binding protein beta (C/EBPbeta) via p38MAPK and activating NF-kappaB. The simultaneous involvement of RelA and C/EBPbeta and the integrity of the corresponding consensus sites were required, whereas c-Jun was involved only in basal IL-8 expression. Re-ChIP experiments showed that RelA and C/EBPbeta act together at the IL-8 promoter level upon P. aeruginosa infection. Taken together, our results suggest that P. aeruginosa induces IL-8 promoter expression and protein production in conjunctival epithelial cells by activating RelA and C/EBPbeta and by promoting the cooperative binding of these transcription factors to the IL-8 promoter that in turn activates transcription.
 ...
PMID:Pseudomonas aeruginosa induces interleukin-8 (IL-8) gene expression in human conjunctiva through the recruitment of both RelA and CCAAT/enhancer-binding protein beta to the IL-8 promoter. 1906 95


1 2 3 4 5 6 7 Next >>