Search PubMed⌕ Search

Biomedical subjects

N Mukaida

Publications and source records attributed to N Mukaida.

At least 163 records · Page 9Linked to original sources
PubMed1993

Prevention of lung reperfusion injury in rabbits by a monoclonal antibody against interleukin-8.

Re-establishing blood flow to ischaemic tissues causes greater injury than that induced during the ischaemic period. This type of tissue injury, reperfusion injury, is involved in frostbite, multiple organ failure after hypovolaemia and in myocardial infarction. Depletion of neutrophils alleviates reperfusion injury, implying a causal role of neutrophil infiltration. Among members of the recently discovered family of chemotactic cytokines (chemokines), interleukin-8 (IL-8) is a major neutrophil chemotactic and activating factor produced by various types of human cells. We investigated its pathophysiological role in a rabbit model of a lung reperfusion injury. Reperfusion of ischaemic lung caused neutrophil infiltration and destruction of pulmonary structure, as well as local production of IL-8. Furthermore, the administration of a neutralizing monoclonal antibody against IL-8 prevented neutrophil infiltration and tissue injury, proving a causal role of locally produced IL-8 in this model.

Animals↗
PubMed1993

Induction of inflammatory cytokines in the pleural effusion of cancer patients after the administration of an immunomodulator, OK-432: role of IL-8 for neutrophil infiltration.

When OK-432, a well-known streptococcal preparation for an anti-tumour drug, was administered into the pleural cavity of patients with malignant pleurisy, a rapid and prominent leukocytosis, predominantly consisting of neutrophils, was observed in the cavity. Neutrophil infiltration usually peaked 6-9 h after OK-432 administration, and levelled down after 24 h. Prior to the neutrophil accumulation, transient but marked elevation of various inflammatory cytokine levels including IL-1 beta, TNF-alpha, IL-8 and G-CSF was observed. In particular, IL-8 levels increased more than 10-fold, while GM-CSF did not change significantly. A good correlation between IL-8 levels and neutrophil chemotactic response was observed particularly during 0-3 h. Specific neutralization or removal of IL-8 by antibody column abrogated half of the neutrophil chemotaxis, while neutralization of C5a removed around 40%. Sequential removal of IL-8 and C5a abrogated totally 80% of chemotaxis, confirming that these two factors are mostly responsible for the neutrophil chemotaxis in the pleural fluids. These results have suggested that rapid neutrophil infiltration induced by OK-432 in vivo is ascribable largely to IL-8 and in part to C5a.

Adult↗
PubMed1993

Expression of recombinant rabbit IL-8 in Escherichia coli and establishment of the essential involvement of IL-8 in recruiting neutrophils into lipopolysaccharide-induced inflammatory site of rabbit skin.

In order to establish the pathophysiological roles of IL-8, rabbit IL-8 was expressed in Escherichia coli and purified to homogeneity by sequential chromatography on heparin agarose, CM-HPLC, and RP-HPLC. The purified recombinant rabbit IL-8 was homogeneous on SDS-PAGE and the ED50 of neutrophil chemotactic activity for rabbit peritoneal neutrophils was 2 ng/ml. The binding of 125I-labeled rabbit IL-8 to rabbit neutrophils was inhibited by unlabeled human IL-8 as well as rabbit IL-8 but not by another leucocyte chemotactic cytokine (chemokine), monocyte chemotactic and activating factor. Scatchard plot analysis of the binding of 125I-labeled rabbit IL-8 to rabbit peritoneal neutrophils revealed that the rabbit neutrophils have two affinity classes of receptors for IL-8 (Kd = 2.3 nM, 4.1 x 10(4) sites/cell; Kd = 18.0 nM, 11.4 x 10(4) sites/cell). It was found that a previously generated mouse anti-human IL-8 mAb, WS-4, inhibited the binding of 125I-labeled rabbit IL-8 to rabbit neutrophils, and blocked neutrophil chemotaxis in vitro in a specific and dose-dependent manner. An ELISA system for rabbit IL-8 was established using this mAb and guinea pig polyclonal antibodies to recombinant rabbit IL-8 to measure the levels of IL-8 in rabbit plasma. Intravenous administration of lipopolysaccharide (LPS) (100 micrograms) in rabbits caused the highest level of IL-8 in blood at around 2 h. Intravenous administration of WS-4 (10 mg) inhibited neutrophil infiltration at the site of LPS injection into the rabbit skin, suggesting that IL-8 is essential in the recruitment of neutrophils at sites of acute inflammation in vivo.

Amino Acid Sequence↗
PubMed1993

Elevated interleukin-8 levels in the urine of patients with urinary tract infections.

Pyuria is one of the main features of urinary tract infections (UTI). Nevertheless, the mechanism of polymorphonuclear leukocyte (PMN) recruitment into the urine remains to be investigated. We examined whether interleukin-8 (IL-8), a potent neutrophil chemoattractant and activator, was involved in pyuria seen in UTI. Of 113 patients, 112 had elevated levels of IL-8 in their urine (1,078.0 +/- 181.5 pg/ml), regardless of whether they had an upper or lower UTI; this was in contrast to undetectable levels (less than 16 pg/ml) in the urine of all of the 20 normal individuals and 74 control patients without UTI. A concomitant study revealed increases in urine IL-6, but not IL-1 beta, and tumor necrosis factor alpha levels in patients with UTI. In addition to gram-negative bacteria, a wide spectrum of microorganisms was capable of inducing IL-8 production in urine. Local production of IL-8 in the urinary tract was suggested by a urine IL-8 level that was higher than the paired serum IL-8 level. The urine IL-8 level correlated with the number of PMN in the urine, and an average of half of the chemotactic activity in urine from patients with UTI could be abrogated by anti-IL-8 antibody treatment in vitro. Furthermore, urine IL-8 purified from patients was bioactive and showed multiple forms on immunoblotting analysis. This is the first documentation of IL-8 in the urine of patients with UTI, and these results imply that IL-8 is involved in inducing PMN migration into the urinary tract.

Adolescent↗
PubMed1993

Cadmium induces interleukin-8 production in human peripheral blood mononuclear cells with the concomitant generation of superoxide radicals.

Acute or chronic exposure to cadmium (Cd) causes severe organ damages with the infiltration of leukocytes, neutrophils in particular occurring in the acute phase. Interleukin-8 (IL-8), a novel neutrophil chemotactic and activating cytokine, is produced by various types of cells in response to a wide variety of inflammatory stimuli. The administration of an antibody against IL-8 has been shown to inhibit neutrophil infiltration in several animal models, indicating a causal relationship between IL-8 and neutrophil infiltration. Hence, in this study we investigated whether Cd induced IL-8 production in human peripheral blood mononuclear cells (PBMC). Cd, over a wide range of concentrations, did induce human PBMC to produce large amounts of bioactive IL-8, the maximal induction being observed at 10(-4) M. The production was inhibited specifically by a metal chelating agent, ethylenediaminetetraacetic acid (EDTA). Steady level of IL-8 mRNA increased within 30 min after the addition of Cd and reached a maximal level at 2 h, decreasing thereafter. A protein synthesis inhibitor, cycloheximide, failed to inhibit IL-8 mRNA accumulation, indicating that new protein synthesis was not required for IL-8 mRNA induction. Concomitantly with the induction of IL-8, within 10 min Cd generated reactive oxygen intermediates (ROI) in human PBMC. A radical scavenger, N-acetyl-L-cysteine (NAC), inhibited both IL-8 production and the generation of ROI, implying the possible involvement of ROI in IL-8 production. This notion was also supported by our findings that a superoxide generating agent, paraquat, induced IL-8 production in human PBMC and that NAC blocked this paraquat-induced IL-8 production.

Base Sequence↗
PubMed1992

Tumor necrosis factor alpha and interferon gamma synergistically induce interleukin 8 production in a human gastric cancer cell line through acting concurrently on AP-1 and NF-kB-like binding sites of the interleukin 8 gene.

Interleukin 8 (IL-8) is a novel cytokine which possesses neutrophil chemotactic and activating activities in addition to chemotactic activity for basophils and T lymphocytes. It has been shown that IL-8 is produced by a variety of human somatic cells including monocytes/macrophages, dermal fibroblasts, vascular endothelial cells, keratinocytes, mesangeal cells, and several types of tumor cell lines. We have examined here whether or not human gastric cancer cell lines produce IL-8 in vitro. The production of IL-8 protein was detected by enzyme-linked immunosorbent assay in the culture supernatants derived from eight of nine human gastric cancer cell lines stimulated with either interleukin 1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF alpha), or TNF alpha plus interferon gamma (IFN gamma). In some of the gastric cancer cell lines such as MKN 45 and KATO, TNF alpha plus IFN gamma synergistically induced the production of IL-8. In MKN 45 cells, synergistic increase of the steady state level of IL-8 mRNA by TNF alpha plus IFN gamma was not inhibited by cycloheximide treatment. Scatchard analysis revealed that IFN gamma changed neither the number nor the affinity constant of TNF alpha binding sites on a gastric cancer cell line, suggesting that the synergism was a post-receptor event. Furthermore, synergistic induction of chloramphenicol acetyltransferase activity by TNF alpha plus IFN gamma was observed in MKN 45 that were transiently transfected with chimeric chloramphenicol acetyltransferase reporter genes driven by the transcriptional regulatory region of human IL-8 gene. Through the mutation of the regulatory region of the IL-8 gene, both AP-1- and NF-kB-like factor binding elements were presumed to be involved in conferring the responsiveness to TNF alpha plus IFN gamma. Moreover, gel retardation analyses revealed that TNF alpha and IFN gamma synergistically induced the binding of NF-kB like as well as AP-1 like proteins bound to these sites. These results indicated that IFN gamma synergistically enhanced TNF alpha-induced IL-8 production in a human gastric cancer cell line through synergistic activation of transcription factors without up-regulating TNF alpha receptor.

Base Sequence↗
PubMed1992

Simple and high-yield purification of urine protein 1 using immunoaffinity chromatography: evidence for the identity of urine protein 1 and human Clara cell 10-kilodalton protein.

A simple and high-yield purification procedure for urine protein 1 (UP1) using anti-UP1 immunoaffinity chromatography is described. Pure UP1 was obtained in a final yield of 60.2%, and observed as a single electrophoretic band and as a single peak on reversed-phase high-performance liquid chromatography. The N-terminal amino acid residue of UP1 was found to be glutamic acid, contrary to what was reported previously. Furthermore, the N-terminal sequence of UP1 up to 53 amino acids was confirmed to be identical with that of mature human Clara cell 10-kilodalton protein, which inhibits phospholipase A2 activity.

Amino Acid Sequence↗
PubMed1992

A sensitive enzyme-linked immunosorbent assay for human interleukin-8.

In order to quantify human interleukin-8 (IL-8), which is chemotactic for T cells and basophils as well as neutrophils, we developed an enzyme-linked immunosorbent assay (ELISA). Since binding inhibition tests indicated that three monoclonal antibodies (mAbs; BS-1, WS-4, WS-6) blocked the binding of 125I-labelled IL-8 to neutrophils, we tested an ELISA using these mAbs as primary antibodies, rabbit anti-IL-8 Ab as the secondary antibody, and alkaline phosphatase-labelled goat anti-rabbit Ab as the conjugate. Among the three mAbs tested, WS-4 was the most sensitive with a detection limit of 16 pg/ml. Several other cytokines, including monocyte chemotactic and activating factor (MCAF), which is structurally related to IL-8, showed no cross-reactivity in this system, indicating that this ELISA is specific for IL-8. The coefficients of variation for the intra- and interassays were below 10%. Furthermore, this ELISA also detected natural IL-8 (including both 72 and 77 amino acid forms) produced by cultured human cells and cell lines stimulated with IL-1, suggesting that this system will be useful in the detection of natural IL-8 in various body fluids.

Antibodies, Monoclonal↗
PubMed1992

Establishment of a sensitive radioimmunoassay for serum thymic factor with a special reference to extraction procedures.

A radioimmunoassay (RIA) for serum thymic factor (facteur thymique serique) was established. This assay could detect less than 0.5 pg of serum thymic factor without the interference by other thymic hormones, including thymopoietin II and thymosin alpha 1. Both zinc-free and zinc-bound serum thymic factor showed a similar standard curve, indicating that this RIA could detect both forms of serum thymic factor in the same way. We observed that two procedures were required prior to the measurement in order to measure serum thymic factor content in plasmas; the first, the extraction procedure to remove substances interfering with the assay nonspecifically; the second, the storage of the sample with ethylenediamine tetraacetic acid disodium salt to inhibit the proteases in the plasma to degrade serum thymic factor. By employing this assay system, we observed that cord blood plasmas contained significantly higher level of serum thymic factor than did adult blood plasmas.

Adult↗
PubMed1992

[Inflammation and pro-inflammatory cytokine].

The main pathological feature of inflammation consists of leukocyte infiltration and exudation of plasma into the lesion in the early stage followed by proliferation of connective tissue including fibroblasts, which leads to the formation of granulation tissue. Systemic manifestations include elevation of body temperature and increase of serum acute phase reactants such as C-reactive protein and serum amyloid A. Most of these reactions are presumed to be caused by mediators which are produced by a various kinds of cells and tissues upon contact with inflammatory stimuli, such as bacteria, helminths, viruses, etc. Recently, it has become known that most of inflammatory stimuli induce the production of large amounts of several cytokines including interleukin 1 (IL-1), IL-6, and tumor necrosis factor (TNF) alpha and that these cytokines exert a wide variety of effects to accelerate inflammation. Hence, these cytokines are called "pro-inflammatory cytokines". These cytokines have overlapping biological functions and induce the production of each other, thus forming a complicated cytokine network. Here, in order to review the roles of these cytokines in the progression of inflammation, the effects on the body temperature, leukocyte infiltration and production of serum acute phase reactants, in particular, will be discussed.

Animals↗
PubMed1992

Molecular analysis of the inhibition of interleukin-8 production by dexamethasone in a human fibrosarcoma cell line.

In order to analyse the effects of glucocorticoids on interleukin-8 (IL-8) production more precisely, we examined the effects of dexamethasone on IL-8 production at the molecular level in a human fibrosarcoma cell line, 8387, which IL-1 induces to express IL-8 messenger RNA (mRNA) and to secrete IL-8. Over a wide dose range, dexamethasone inhibited IL-8 production induced by IL-1 alpha stimulation. Northern blotting analysis showed that dexamethasone also inhibited the IL-8 mRNA accumulation in a similar dose-related manner. Nuclear run-off assay revealed that dexamethasone decreased the transcription of the IL-8 gene and the degree of inhibition of transcription correlated well with the inhibition of IL-8 production, suggesting that the action of glucocorticoids is mainly at the transcriptional level. Furthermore, transfection with chloramphenicol acetyl transferase (CAT) expression vectors inserted with the 5'-deleted IL-8 gene demonstrated that the 5'-flanking region which contains the glucocorticoid response element (GRE) was mainly involved in the dexamethasone-induced repression of the IL-8 gene. These data suggest that the inhibition of the IL-8 gene transcription by glucocorticoids occurs through the interaction of the glucocorticoid receptor complex with GRE in the 5'-flanking region of the IL-8 gene.

Blotting, Northern↗
PubMed1992

[A newly discovered chemotactic factor for neutrophil: interleukin 8].

A potent peptide chemotactic factor for leukocytes has been purified from lipopolysaccharide (LPS)-stimulated human peripheral blood mononuclear cell culture supernatant, followed by its cDNA cloning and its expression in Escherichia coli. This factor was named interleukin-8 (IL-8) since it is produced by various kinds of cells in response to inflammatory stimuli including LPS, IL-1 and tumor necrosis factor (TNF) and has pleiotropic effects on T lymphocytes and basophils as well as neutrophils. The receptors for IL-8 contain seven transmembrane domains as revealed by cDNA cloning, suggesting that they are a member of superfamily of G-protein-coupled receptors. The transcription of IL-8 gene is presumed to be regulated by the action of two kinds of transcription factors, NF-kappa B and NF-IL6, both of which are supposed to be involved in the activation of acute phase reactant genes, suggesting that the activation of IL-8 gene is a good model for elucidating the molecular mechanism of the transcription of these genes. In various kinds of diseases in which neutrophilia or neutrophil infiltration is found, the increase of IL-8 level in body fluids is often observed. The clarification of the role of IL-8 in the process of these inflammatory diseases will lead to the development of a novel kind of anti-inflammatory or immunomodulating agents.

Amino Acid Sequence↗
PubMed1991

Hepatitis B virus X protein transactivates human interleukin-8 gene through acting on nuclear factor kB and CCAAT/enhancer-binding protein-like cis-elements.

Interleukin-8 (IL-8) is a newly described leukocyte chemotactic and activating cytokine that belongs to the novel family of inflammatory cytokines whose genes locate on human chromosome 4, q12-21 region. The production of IL-8 is usually not constitutive and can be induced rapidly and abundantly in different cell types by a variety of stimuli such as lipopolysaccharide, interleukin-1, tumor necrosis factor-alpha as well as a tumor promotor phorbol myristate acetate. We report here that in addition to these stimuli the IL-8 gene can also be induced by the protein X of the hepatitis B virus (HBV-X) as evidenced by the enhanced IL-8 mRNA expression and IL-8 production observed in HBV-X-transfected cells. Furthermore, using several deletion mutants of the 5'-flanking regulatory region of the human IL-8 gene linked to the chloramphenicol acetyl transferase gene as a reporter, we have established here that both nuclear factor kB and CCAAT/enhancer-binding protein-like cis-elements located at -94 to -71 base pairs of IL-8 gene are essential and sufficient for the induction of the IL-8 gene by HBV-X. The same elements have been identified recently by us to be interleukin-1-, tumor necrosis factor-alpha-, and phorbol myristate acetate-responsive elements on the IL-8 gene. This suggests the existence of a common pathway for these inflammatory cytokines and HBV-X to activate the IL-8 gene. These observations might be relevant to the pathogenesis of inflammation in viral hepatitis.

Base Sequence↗
PubMed1991

Dexamethasone inhibits the induction of monocyte chemotactic-activating factor production by IL-1 or tumor necrosis factor.

Recently purified and molecularly cloned monocyte chemotactic and activating factor (MCAF) may play a major role in recruiting and activating monocytes in the inflammatory process. We examined the effects of a potent anti-inflammatory agent, dexamethasone (DXS), on the production of this factor. Over a wide range of concentrations (10(-5) to 10(-8) M), DXS inhibited the production of MCAF at the mRNA and protein level in a human fibrosarcoma cell line, which was stimulated with either IL-1 or TNF-alpha. We examined the turn-over of synthesized MCAF mRNA that showed DXS decreased the stability of MCAF mRNA. Furthermore, the addition of actinomycin D and cycloheximide abolished this effect of DXS, indicating that de novo mRNA and protein synthesis were required for this process. In addition, a nuclear run-off analysis revealed that DXS also inhibited the transcription of IL-1- or TNF-activated MCAF genes. Therefore, both the destabilization of MCAF mRNA and the inhibition of transcription of the gene contribute to the decrease in the MCAF mRNA steady state level by DXS.

Chemokine CCL2↗