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)

Biological functions of proteins are influenced by posttranslational modifications such as on/off switching by phosphorylation and modulation by glycosylation. Proteolytic processing regulates cytokine and chemokine activities. In this study, we report that natural posttranslational citrullination or deimination alters the biological activities of the neutrophil chemoattractant and angiogenic cytokine CXCL8/interleukin-8 (IL-8). Citrullination of arginine in position 5 was discovered on 14% of natural leukocyte-derived CXCL8(1-77), generating CXCL8(1-77)Cit(5). Peptidylarginine deiminase (PAD) is known to citrullinate structural proteins, and it may initiate autoimmune diseases. PAD efficiently and site-specifically citrullinated CXCL5, CXCL8, CCL17, CCL26, but not IL-1beta. In comparison with CXCL8(1-77), CXCL8(1-77)Cit(5) had reduced affinity for glycosaminoglycans and induced less CXCR2-dependent calcium signaling and extracellular signal-regulated kinase 1/2 phosphorylation. In contrast to CXCL8(1-77), CXCL8(1-77)Cit(5) was resistant to thrombin- or plasmin-dependent potentiation into CXCL8(6-77). Upon intraperitoneal injection, CXCL8(6-77) was a more potent inducer of neutrophil extravasation compared with CXCL8(1-77). Despite its retained chemotactic activity in vitro, CXCL8(1-77)Cit(5) was unable to attract neutrophils to the peritoneum. Finally, in the rabbit cornea angiogenesis assay, the equally potent CXCL8(1-77) and CXCL8(1-77)Cit(5) were less efficient angiogenic molecules than CXCL8(6-77). This study shows that PAD citrullinates the chemokine CXCL8, and thus may dampen neutrophil extravasation during acute or chronic inflammation.
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PMID:Citrullination of CXCL8 by peptidylarginine deiminase alters receptor usage, prevents proteolysis, and dampens tissue inflammation. 1871 Sep 30

This study was conducted to test the hypothesis that dietary L-arginine supplementation enhances immunity in early weaned piglets. Seventy piglets weaned at 7 days of age were assigned to five groups (14 pigs/group), representing supplementation of 0.0, 0.2, 0.4, 0.6, and 0.8% L-arginine to a milk-based formula. On Day 7 after initiation of treatment, spleen weight in piglets supplemented with 0.2 and 0.8% arginine was heavier and thymus size was larger in piglets supplemented with 0.6% arginine, whereas serum concentration of immunoglobulin (Ig) M was higher but that of IL-8 was lower in piglets supplemented with 0.6 and 0.8% arginine, compared with the control group. Dietary supplementation with 0.8% arginine increased the numbers of white blood cells and granulocytes, and gene expression of interleukin (IL)-8 in spleen. On Day 14, compared with control piglets, granulocyte numbers were greater but lymphocyte numbers were lower in piglets supplemented with 0.2 and 0.4% arginine, whereas splenic expression of IL-8 and tumor necrosis factor-alpha genes was increased in piglets supplemented with 0.8% arginine. Additionally, IgG and IgM concentrations in serum and growth performance were greater in piglets supplemented with 0.4-0.8% arginine, compared with unsupplemented piglets. Collectively, dietary supplementation with 0.4-0.8% L-arginine for 2 weeks enhances both cellular and humoral immunity in piglets by modulating the production of leukocytes, cytokines and antibodies. These results indicate that increasing L-arginine provision is beneficial for optimal immune responses in young pigs and also have important implications for designing the next generation of improved formula for human infants.
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PMID:Dietary L-arginine supplementation enhances the immune status in early-weaned piglets. 1871 73

Previous studies demonstrated that ING4 as a novel member of ING (inhibitor of growth) family has potential effect on tumor inhibition via multiple pathways. However, adenovirus-mediated ING4 expression in inhibition of human tumors has not been reported. To explore its therapeutic effect on human lung carcinoma, we constructed a recombinant adenoviral vector Ad-ING4 expressing the humanized ING4 gene derived from murine ING4 with two amino acid modifications at residue 66 (Arg to Lys) and 156 (Ala to Thr) by site-directed mutagenesis. We demonstrated that Ad-ING4-mediated transfection of A549 human lung carcinoma cells induced cell apoptosis, altered cell cycle with S phase reduction and G2/M phase arrest, suppressed cell invasiveness, and down-regulated IL-6, IL-8, MMP-2, and MMP-9 expression of transfected tumor cells. In athymic mice bearing A549 lung tumors, intratumoral injections of Ad-ING4 suppressed the tumor growth and reduced the tumor microvessel formation. Therefore, Ad-ING4 may be useful in gene therapy of human lung carcinoma.
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PMID:Adenovirus-mediated ING4 expression suppresses lung carcinoma cell growth via induction of cell cycle alteration and apoptosis and inhibition of tumor invasion and angiogenesis. 1878 75

Glutamine (Gln) and arginine (Arg) are conditionally essential amino acids with immunomodulatory properties. The aim of the study was to assess the effects of Gln and Arg alone or in combination on cytokine release by cultured colonic biopsies from patients with active Crohn's disease (CD). Ten consecutive patients [mean (range) age 26 (18-39) y] with active colonic CD (mean CD activity index: 383.7 +/- 129.8) were prospectively included in the study. Eight colonic biopsies were obtained via a colonoscopy and incubated during 18 h with low (physiological) or high (pharmacological) doses of Arg (0.1 or 2 mmol/L designated as Arg(low) or Arg(high), respectively) and Gln (0.6 or 10 mmol/L designated as Gln(low) or Gln(high), respectively). The concentrations of cytokines [interleukin (IL)-4, IL-10, IL-8, IL-6, tumor necrosis factor-alpha (TNFalpha), IL-1beta, interferon-gamma) were assessed by ELISA, and nitric oxide (NO) production was evaluated by Griess assay. Nuclear factor (NF)-kappaB p65 subunit, inhibitor of NFkappaB-alpha, and p38 mitogen-activated protein kinase (MAPK) were assessed by immunoblotting. Arg(high)/Gln(high) decreased the production of TNFalpha, IL-1beta, IL-8, and IL-6 (each P < 0.01). Arg(low)/Gln(high) decreased IL-6 and IL-8 production (both P < 0.01), whereas Arg(high)/Gln(low) did not affect cytokine and NO production. Arg(low)/Gln(high) and Arg(high)/Gln(high) decreased NF-kappaB p65 subunit expression, whereas p38 MAPK was decreased only by Arg(high)/Gln(high). Combined pharmacological doses of Arg and Gln decreased TNFalpha and the main proinflammatory cytokines release in active colonic CD biopsies via NF-kappaB and p38 MAPK pathways. These results could be the basis of prospective studies evaluating the effects of enteral supply of combined Arg and Gln during active CD.
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PMID:Combined glutamine and arginine decrease proinflammatory cytokine production by biopsies from Crohn's patients in association with changes in nuclear factor-kappaB and p38 mitogen-activated protein kinase pathways. 1902 76

The role of estrogen replacement therapy in postmenopausal women remains controversial. The authors hypothesized that contradictory results with estrogen therapy may be explained by estrogen's potent proangiogenic property, which could be protective in women without atherosclerotic disease but in the presence of chronic inflammation, could lead to destabilization of atherosclerotic plaques. The authors thus examined the interaction between 17beta-estradiol (E2) and the inflammatory cytokine tumor necrosis factor alpha (TNFalpha) in an early stage of angiogenesis. Human umbilical endothelial cells were grown to confluence. Migration was assessed with a wound assay and proliferation was assessed with 5-bromo-2'-deoxyuridine (BrDU). Cells were treated with medium alone, TNFalpha at 0.3, 1, or 20 ng/ml, E2 at 20 nM, or the combination of E2 and TNFalpha. The authors used real-time polymerase chain reaction (PCR) to measure changes in expression of the angiogenesis genes angiopoeitin-2 (Ang-2), vacular endothelial growth factor (VEGF)-A and -C, and interleukin (IL)-8. A large dose of TNFalpha (20 ng/ml) inhibited healing at 24 to 48 h and the addition of E2 preserved some healing. E2 by itself doubled migration, with only a minimal effect on proliferation. A low dose of TNFalpha (0.3 ng/ml) had no effect on migration, 1.0 ng/ml moderately increased it, but the addition of E2 to both doses of TNFalpha increased migration. There was no change in migration when cells were pretreated with E2 and given TNFalpha after wounding, whereas pretreatment with TNFalpha followed by E2 significantly increased wound healing. The nitric oxide synthase (NOS) inhibitor N-nitro-l-arginine-methyl ester (l-NAME) completely blocked the E2 effect on migration. TNFalpha (0.3 and 1.0 ng/ml) increased expression of VEGF-C (2.8 +/- 0.1- and 2.5 +/- 0.2-fold, respectively) and IL-8 (32.8 +/- 1.2- and 42.7 +/- 3.6-fold, respectively) mRNA, but E2 had no significant effect on these molecules. E2 increases the angiogenic activity of TNFalpha. This could potentially worsen the stability of complex atherosclerotic plaques and increase cardiovascular events.
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PMID:Interaction of estrogen and tumor necrosis factor alpha in endothelial cell migration and early stage of angiogenesis. 1906 18

The current gold standard for imaging infection is radiolabeled white blood cells. For reasons of safety, simplicity and cost, it would be desirable to have a receptor-specific ligand that could be used for imaging infection and that would allow a differential diagnosis between sterile and septic inflammatory processes. Ligands tested for this purpose include labeled peptides ((99m)Tc-labeled f-Met-Leu-Phe, (123)I-IL-1ra, (99m)Tc-IL-8, (99m)Tc-P483H, (99m)Tc-P1827DS, (99m)Tc-C5a-des-Arg, (99m)Tc-RP517, (11)In-DPC11870-11), human polyclonal antibodies, monoclonal antibodies, antibody fragments, antimicrobial agents (ciprofloxacin, sparfloxacin, ceftizoxime, isoniazid, ethambutol, fluconazole, all labeled with (99m)Tc), antimicrobial peptides and bacteriophages. Radiolabeled antibodies represent a valid alternative to labeled white blood cells under specific conditions and indications. Radiolabeled antibiotics and antimicrobial peptides are promising candidates for an infection-specific radiopharmaceutical. However, at present we still need to investigate many basic aspects to better understand the mechanisms of binding and accumulation of this class of radiopharmaceuticals to bacteria.
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PMID:Receptor binding ligands to image infection. 1907 10

C-reactive protein (CRP) is a risk factor for cardiovascular events and functions to amplify vascular inflammation through promoting endothelial dysfunction. Lectin-like oxidized low-density lipoprotein (oxLDL) receptor-1 (LOX-1) is the primary endothelial receptor for oxLDL, and both its expression and function are associated with vascular inflammation. As a scavenger receptor, LOX-1 is capable of binding to a variety of structurally unrelated ligands. Evidence is provided that demonstrates that CRP can act as a novel ligand for LOX-1. The direct interaction between these two proteins was demonstrated with purified protein in both ELISA and AlphaScreen assays. This interaction could be disrupted with known LOX-1 ligands, such as oxLDL and carrageenan. Moreover, the CRP interaction with cell surface-expressed LOX-1 was confirmed in cell-based immunofluorescent-binding studies. Mutagenesis studies demonstrated that the arginine residues forming the basic spine structure on the LOX-1 ligand-binding interface were dispensable for CRP binding, suggesting a novel ligand-binding mechanism for LOX-1, distinct from that used for oxLDL binding. The treatment of human endothelial cells with CRP led to the activation of proinflammatory genes including IL-8, ICAM-1, and VCAM-1. The inductions of these genes by CRP were LOX-1 dependent, as demonstrated by their attenuation in cells transfected with LOX-1 small-interfering RNA. Our study identifies and characterizes the direct interaction between LOX-1 and CRP and suggests that this interaction may mediate CRP-induced endothelial dysfunction.
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PMID:CRP is a novel ligand for the oxidized LDL receptor LOX-1. 1925 93

Recent studies have demonstrated that ING4, as a novel member of the ING (inhibitor of growth) family, has a potential effect on tumor inhibition via multiple pathways. However, adenovirus-mediated ING4 expression in the application of gene therapy for pancreatic carcinoma has not been reported. To explore its therapeutic effect on human pancreatic carcinoma, we constructed a recombinant adenoviral vector, Ad-ING4, expressing the green fluorescent protein (GFP) marker gene and the tumor-suppressor gene, humanized ING4 derived from murine ING4 with two amino-acid modifications at residues 66 (Arg to Lys) and 156 (Ala to Thr) by site-directed mutagenesis. We demonstrated that Ad-ING4-mediated transfection of PANC-1 human pancreatic carcinoma cells inhibited cell growth, altered the cell cycle with S-phase reduction and G2/M phase arrest, induced apoptosis, and downregulated interleukin (IL)-6 and IL-8 expression of transfected tumor cells. In athymic mice bearing the PANC-1 human pancreatic tumors, intratumoral injections of Ad-ING4 suppressed the tumor growth, downregulated CD34 expression, and reduced the tumor microvessel formation. Therefore, this study will provide a framework for future clinical application of Ad-ING4 in human pancreatic carcinoma gene therapy.
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PMID:Adenovirus-mediated ING4 expression suppresses pancreatic carcinoma cell growth via induction of cell-cycle alteration, apoptosis, and inhibition of tumor angiogenesis. 1940 49

In this study, an IL-8 homologue has been cloned and identified from a reptile, Chinese soft-shelled turtle for the first time. The full-length cDNA of turtle IL-8 was 1188bp and contained a 312bp open reading frame (ORF) coding for a protein of 104 amino acids. The chemokine CXC domain, which contained Glu-Leu-Arg (ELR) motif and four cysteine residues, was well conserved in turtle IL-8. The 4924bp genomic DNA of turtle IL-8 contained four exons and three introns. Phylogenetic analysis showed that the amino acid sequence of turtle IL-8 clustered together with birds. RT-PCR analysis showed that turtle IL-8 mRNA was constitutively expressed liver, spleen, kidney, heart, blood and intestine tissues of control turtles. Real-time quantitative PCR analysis further indicated that the turtle IL-8 mRNA expression was apparent in various tissues at 8h and up-regulated significantly during 8h-7d after Aeromonas hydrophila infection. The present studies will help us to understand the evolution of IL-8 molecule and the inflammatory response mechanism in reptiles.
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PMID:Molecular characterization and expression profiles in response to bacterial infection of Chinese soft-shelled turtle interleukin-8 (IL-8), the first reptilian chemokine gene. 1942 85

Arginase 1 (ARG1) inhibits T-cell proliferation by degrading extracellular arginine, which results in decreased responsiveness of T cells to CD3/TCR stimulation. In humans, ARG1 is stored in inactive form within granules of polymorphonuclear neutrophils (PMNs) and gets activated on release. We studied the role of PMNs-related ARG1 activity in nonsmall cell lung cancer (NSLC), in which tumor-infiltrating lymphocytes showed reduced proliferation in response to CD3/TCR triggering. Patients with NSCLC had increased ARG1 plasma levels as compared to healthy controls. Furthermore, immunohistochemistry showed that tumor-infiltrating PMNs display reduced intracellular ARG1, in comparison to intravascular or peritumoral PMNs, suggesting a role of tumor microenvironment in ARG1 release. Indeed, supernatants of NSCLC cell lines induced exocytosis of ARG1 from PMNs. All (4/4) NSCLC cell lines and all (7/7) CD14- cell samples from NSCLC expressed interleukin (IL)-8 mRNA, whereas TNFalpha mRNA was expressed by 1 cell line and by 2 tumor specimens. Furthermore, all NSCLC cell lines secreted immunoreactive IL-8, albeit at different levels. IL-8 was as effective as TNFalpha in triggering ARG1 release and the 2 cytokines acted synergistically. Secreted ARG1 was biologically active and catabolized extracellular arginine. The supernatant of IL-8 gene-silenced NSCLC cells did not mediate ARG1 release by PMNs. Altogether these findings demonstrate a role of IL-8 in ARG1 exocytosis by PMNs and indicate that, due at least in part to IL-8 secreted by NSCLC cells, PMNs infiltrating NSCLC release ARG1. This phenomenon could contribute to local immune suppression.
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PMID:IL-8 induces exocytosis of arginase 1 by neutrophil polymorphonuclears in nonsmall cell lung cancer. 1943 Nov 48


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