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)

Transgenic mice expressing an ANF fusion gene in the liver were used to study renal function before and during an intravenous KCl load. These animals are characterized by a 10- to 20-fold elevation in plasma ANF concentration, and by a reduction in arterial blood pressure by 20-30 mm Hg, compared to nontransgenic littermates. Before the KCl infusion, renal excretions of fluid, sodium, potassium, and chloride were not different from corresponding values in the nontransgenic sibling mice. Glomerular filtration rates were slightly lower in the transgenic animals. During the KCl infusion, diuresis, saluresis, and kaliuresis were found in both groups. However, salt and water excretion, but not potassium excretion, were significantly greater in the transgenic group. In a separate series, plasma aldosterone concentrations were significantly higher in the transgenic, compared to the nontransgenic mice. These data are interpreted as indicating that antinatriuretic mechanisms, including aldosterone-dependent sodium reabsorption in the cortical collecting tubule, can counteract the effect of ANF to inhibit sodium reabsorption in the medullary duct system, thus allowing maintenance of salt balance. Furthermore, a reduced tubular flow rate at the aldosterone-sensitive site would ensure normal potassium excretion despite the elevated mineralocorticoid level. During KCl infusion, the known increase in tubular delivery of salt and water to the duct would allow full expression of the downstream ANF effect, accounting for the relatively greater diuresis and saluresis in the transgenic mice. We conclude that both renal and adrenal actions of ANF can be rendered ineffective by countervailing mechanisms, suggesting an explanation for the apparent lack of biological activity of endogenously elevated plasma NAF in some disease states.
 ...
PMID:Effect of potassium infusion on renal function in ANF-transgenic mice. 128 29

We have investigated the use of oligonucleotide probes for identifying cDNA clones containing the short dAT-rich motifs found in the 3'-untranslated region of cytokine genes. To obtain sufficiently stable duplexes between the octameric probes used to identify genes containing the sequence dTATTTATT and its complement, it was necessary to couple an intercalating agent, an acridine derivative (acr), to the 5'-positions of the probes. The resulting octamers 5'-acr-dAATAAATA and, particularly, 5'-acr-dTATTTATT were successfully used to distinguish the complementary sequences in cDNA from internal, single point mismatched sequences. Southern blot analyses of plasmids containing IL-1 beta and IL-8 gave positive results with the 3' degenerate probe, 5'-acr-dTATTTATTN, clearly showing that the very short probe approach can be used in this type of analysis. Subsequently, in slot blot analyses we found that, even without the degenerate nucleotide, N, plasmids bearing cytokine sequences with at least 7 contiguous matched nucleotides could be unambiguously identified with 5'-acr-dTATTTATT. Unfortunately, because of the ubiquity of these dAT-rich sequences in bacterial DNA, it was not possible to use these probes for direct colony screening. In contrast to the results obtained with DNA, at the RNA level, with IL-1 beta mRNA bound to nitrocellulose, the hybrid formed with 5'-acr-dAATAAATA was very unstable, even in 1M LiCl solution at 2 degrees C; however, in the same salt solution the slightly longer acridine-coupled probes 5'-acr-dAATAAATAGGG and 5'-acr-dAAAGAACAA remained hybridized to their complementary sequences up to about 18 degrees C.
 ...
PMID:Acridine-linked oligonucleotide probes for the short dAT-rich motifs in the 3'-untranslated region of cytokine genes. 189 74

During their initial association with plant hosts, pathogenic bacteria interact with plant cell walls. The results of this interaction appear to determine whether bacterial multiplication will take place. With one group of bacterial plant pathogens (e.g. Agrobacterium tumefaciens), attachment to the host surface appears essential for pathogenesis. With another group (e.g. Pseudomonas solanacearum), only those strains that do not attach to the host cell wall are able to multiply in the intercellular spaces. Attachment of many incompatible strains to tobacco mesophyll cell walls leads to a rapid hypersensitive response (HR) and a drastic reduction in bacterial multiplication. Our working hypothesis is that these differences in host response to strains of P. solanacearum are the result of a recognition response in which surface components of both host and pathogen play important roles. Our approach is based on the use of spontaneous or transposon (Tn5)-generated mutants of strains K60 (virulent) and B1 (avirulent) that differ in surface components and in their ability to attach to host cells and to induce the HR. A study of the surface components of bacterial and tobacco cell walls has led to the tentative conclusion that bacterial lipopolysaccharide (LPS) and plant hydroxyproline-rich glycoproteins mediate initial attachment, apparently as a result of charge-charge interaction. This initial attachment is reversed by high salt concentrations during the first 15 min, but not thereafter. Firm attachment appears to depend on hydrophobic interactions mediated by bacterial pili. At the normal ionic strength of intercellular fluids, extracellular polysaccharide (EPS) appears to inhibit only the pili-mediated attachment. Several HR- mutants of strain B1 have been obtained by Tn5 insertion, but they remain avirulent on tobacco. We are examining the EPS, LPS and pili production, and the attachment characteristics of these strains.
 ...
PMID:Surface components involved in bacterial pathogen-plant host recognition. 386 76

Infection-induced malnutrition, the most common form of cytokine-induced malnutrition, results from the actions of proinflammatory cytokines, ie, tumor necrosis factor (TNF) and interleukins 1,6, and 8 (IL-1, IL-6, and IL-8). During acute generalized infections, these cytokines initiate the acute-phase reaction. This reaction is quite stereotyped, and includes fever, malaise, myalgia, headaches, cellular hypermetabolism, and multiple endocrine and enzyme responses. In addition, there is heightened catabolism of muscle proteins and many amino acids; flux of free amino acids into the liver; hepatic synthesis of acute-phase plasma proteins; sequestration of iron and zinc; gluconeo-genesis; insulin resistance; impaired cellular uptake of fatty acids from plasma triglycerides; sizable losses of body nitrogen, potassium, magnesium, phosphate, and zinc; retention of body salt and water; heightened metabolic degradation and/or loss of vitamins; and an activation of the immune system. The pathogenesis of cytokine-induced malnutrition is thus vastly different from the malnutrition caused by uncomplicated starvation. Cytokine-induced malnutrition can have a devastating effect on the immune system and its functions. Although proinflammatory cytokines are found in mucosal fluids, where they contribute to the pathogenesis of inflammatory bowel diseases, it is not known whether cytokines play a role in toxigenic, secretory diarrheas such as cholera, which cause huge losses of body water, electrolytes, and bicarbonate while exhibiting no systemic manifestations of an acute-phase reaction.
 ...
PMID:Herman Award Lecture, 1995: infection-induced malnutrition--from cholera to cytokines. 757 15

These studies were undertaken to investigate the therapeutic mechanism of saturated solutions of KI, used to treat infectious and inflammatory diseases. The addition of 12-50 mM KI to cultured human peripheral blood mononuclear cells resulted in 319-395 mosM final solute concentration and induced interleukin (IL)-8 synthesis. Maximal IL-8 production was seen when 40 mM salt was added (375 mosM) and was equal to IL-8 induced by endotoxin or IL-1 alpha. However, there was no induction of IL-1 alpha, IL-1 beta, or tumor necrosis factor to account for the synthesis of IL-8; the effect of KI was not due to contaminating endotoxins. Hyperosmolar NaCl also induced IL-8 and increased steady-state levels of IL-8 mRNA similar to those induced by IL-1 alpha. IL-8 gene expression was elevated for 96 hr in peripheral blood mononuclear cells incubated with hyperosmolar NaCl. In human THP-1 macrophagic cells, osmotic stimulation with KI, NaI, or NaCl also induced IL-8 production. IL-1 signal transduction includes the phosphorylation of the p38 mitogen-activated protein kinase that is observed following osmotic stress. Using specific blockade of this kinase, a dose-response inhibition of hyperosmolar NaCl-induced IL-8 synthesis was observed, similar to that in cells stimulated with IL-1. Thus, these studies suggest that IL-1 and osmotic shock utilize the same mitogen-activated protein kinase for signal transduction and IL-8 synthesis.
 ...
PMID:Osmotic regulation of cytokine synthesis in vitro. 861 75

IL-8 dimers have been observed in NMR and X-ray structures of the protein. We have engineered IL-8 monomers by mutations of residues throughout the dimer interface, which introduce hindrance determinants to dimerization. These IL-8 variants are shown by NMR to have wild-type monomer folding, but by ultracentrifugation to have a range of dimerization constants from microM to mM, as compared with a dimerization constant of about 10 microM for wild-type IL-8, under physiological salt and temperature conditions. The monomeric variants of IL-8 bind the erythrocyte chemokine receptor DARC, as well as the neutrophil IL-8 receptors CXCR1 and CXCR2 with affinities similar to that of wild-type IL-8. In addition, the monomeric variants were shown to have agonist activity, with similar potency to wild-type, in both Ca(2+)-flux assays on CXCR1 and CXCR2 transfected cells, and in chemotaxis assays on neutrophils. Thus, these variants confirm that monomeric IL-8 is functionally equivalent to wild-type in vitro assays. We have also investigated the effects of various solution conditions upon IL-8 dimer formation using analytical ultracentrifugation. At salt concentrations, temperatures, and pH conditions lower than physiological, the dimerization affinity of IL-8 is greatly enhanced. This suggests that, under some conditions, IL-8 dimer formation may occur at concentrations of IL-8 considerably lower than 10 microM, with consequences in vivo that are yet to be determined.
 ...
PMID:Monomeric variants of IL-8: effects of side chain substitutions and solution conditions upon dimer formation. 907 Apr 42

Recently, some investigators have observed elevated concentrations of chloride in the airway surface fluid (ASF) overlying respiratory epithelia from cystic fibrosis (CF) patients compared with ASF overlying non-CF epithelia. Others have shown that this elevated ASF salt concentration can inactivate human beta-defensin-1, an antimicrobial peptide secreted by respiratory epithelia. This could impair the primary epithelial defense against bacteria in the CF airway, thereby forcing a greater reliance on polymorphonuclear leukocyte (PMN)-mediated defenses. Pseudomonas aeruginosa (Psa) flourishes in the CF airway despite the presence of abundant PMN. We therefore investigated whether elevated ASF chloride concentration in CF might also compromise PMN function. We employed a cell-culture model in which halide concentrations and osmolarity were varied independently. We examined the effects of chloride concentration on three aspects of PMN function: recruitment of PMN to the airway (production of interleukin-8 [IL-8]), PMN antimicrobial activity (killing of Psa), and PMN clearance from the airways (apoptosis and lysis). We found that exposure to elevated chloride concentration increased PMN synthesis of IL-8, decreased PMN killing of Psa, and accelerated PMN apoptosis and lysis. In CF airways, elevated chloride therefore could contribute to the increased number of PMN recruited into the airways, the increased survival of Psa, and the increased quantity of toxic mediators released by PMN into the airways. These effects of elevated chloride on PMN function may provide another causal link between loss of cystic fibrosis transmembrane conductance regulator function and CF lung disease.
 ...
PMID:The effect of chloride concentration on human neutrophil functions: potential relevance to cystic fibrosis. 976 62

Nacystelyn (NAL), a recently developed lysine salt of N-acetyl-L-cytokine (NAC) has mucolytic and antioxidant properties. In this study, we investigated the effect of NAL upon oxidant-mediated interleukin (IL)-8 release and the activation of the redox-sensitive transcription factors AP-1, NF-kappaB, and C/EBP in a human alveolar epithelial cell line (A549). NAL (5 mM) enhanced intracellular glutathione (GSH) after 4 h and abolished H(2)O(2)-induced IL-8 release from A549 cells. This was associated with inhibition of NF-kappaB and C/EBP DNA-binding, measured by the Electrophoretic Mobility Shift Assay (EMSA). NAL also abolished the transcriptional activation of IL-8 in an IL-8-chloramphenicol acetyl transferase (CAT) reporter system, transfected into A549 cells. Supernatants obtained from H(2)O(2)-treated A549 cells induced chemotaxis of polymorphonuclear neutrophils, which could be inhibited by co-incubation with NAL. These data indicate that NAL may be used to modulate pro-inflammatory process by inhibiting cytokine release in the lungs and thus has therapeutic potential in inflammatory lung diseases.
 ...
PMID:Nacystelyn inhibits oxidant-mediated interleukin-8 expression and NF-kappaB nuclear binding in alveolar epithelial cells. 1195 50

Limited scientific studies suggest that myrrh (Commiphora molmol) has antibacterial and anti-inflammatory activities. This study determined myrrh oil (MO) cytotoxicity to human gingival fibroblasts and epithelial cells and its effect, measured by ELISA, on interleukin (IL)-1beta-stimulated IL-6 and IL-8 production. Cell viability and cytotoxicity were determined by metabolic reduction of a tetrazolium salt to a formazan dye (MTT assay) and by release of lactate dehydrogenase (LDH) from membrane damaged (LDH release assay) cells, respectively. Based on the MTT assay, 24- and 48-h exposures to </=0.001% MO had little effect on fibroblast and epithelial cell (24-h only) viability. At 48 h, 0.0005-0.001% MO decreased epithelial cell viability 30-50%. After 24 and 48 h, MO, at >/=0.005%, maximally decreased viability of all cell lines. In the LDH release assay, exposure to </=0.0001% MO caused <10% cytotoxicity to all cells. At 24 h, >/=0.0025% MO caused maximal cytotoxicity; </=0.001% MO caused 10-70% cytotoxicity. At longer exposure times, epithelial cells were more susceptible to cytotoxic effects of MO. There was little or no detectable IL-1beta-stimulated production of IL-6 or IL-8 by cells exposed to >/=0.0025% MO, probably reflective of loss of viability. At subtoxic MO levels (0.00001-0.001%), there was a significant reduction of IL-1beta-stimulated IL-6 and IL-8 production by fibroblasts, but not by epithelial cells.
 ...
PMID:In vitro cytotoxic and anti-inflammatory effects of myrrh oil on human gingival fibroblasts and epithelial cells. 1278 Dec 9

Carbocysteine lysine salt monohydrate (SCMC-Lys) is a well-known mucoactive drug whose therapeutic efficacy is commonly related to the ability of SCMC-Lys to replace fucomucins by sialomucins. The aim of this study was to determine if SCMC-Lys could exert an anti-oxidant action by scavenging reactive oxygen intermediates (ROIs). Our results show that SCMC-Lys proved effective as a selective scavenger of hypochlorous acid (HOCl) and hydroxyl radical (OH.), this effect being related to the reactivity of the SCMC tioether group. The scavenger activity of SCMC-Lys was observed in free cellular system as well as in activated human polymorphonuclear neutrophils (PMNs). SCMC-Lys scavenger activity on HOCl was paralleled by a powerful protection from HOCl-mediated inactivation of alpha1-antitripsin (alpha1-AT) inhibitor, the main serum protease inhibitor. Production of interleukin-(IL-)8, a major mediator of PMN recruitment in inflammatory diseases, is known to be mediated by intracellular OH. SCMC-Lys significantly reduced IL-8 production on stimulated human peripheral blood mononuclear cells (PBMCs) in the same range of concentrations affecting OH. activity. It is concluded that SCMC-Lys could exert, in addition to its mucoactive capacity, an anti-oxidant action, thus contributing to the therapeutic efficacy of SCMC-Lys.
 ...
PMID:Carbocysteine lysine salt monohydrate (SCMC-LYS) is a selective scavenger of reactive oxygen intermediates (ROIs). 1279 10


1 2 3 4 5 6 Next >>