[Molecular mechanism of interleukin-8 gene expression].

Evidence is accumulating that interleukin-8 (IL-8), discovered as a potent neutrophil chemotactic factor, plays a crucial role in establishing acute neutrophil-mediated inflammation by exerting various activities against non-leukocytic as well as leukocytic cells. Various types of cells can rapidly produce a large amount of IL-8 upon stimulation with inflammatory stimuli, such as lipopolysaccharide, IL-1, and tumor necrosis factor (TNF). However, IL-8 production is tightly regulated at several levels, particularly at the transcriptional levels to prevent aberrant production.

Molecular analysis of suppression of interleukin-8 production by rebamipide in Helicobacter pylori-stimulated gastric cancer cell lines.

Interleukin-8 (IL-8) may play an important role in Helicobacter pylori infection-associated chronic active gastritis and peptic ulcer disease in human. We have recently reported that a gastric cancer cell line, MKN45, produced a massive amount of IL-8 upon coculture with live H. pylori.

Human T-cell leukemia virus type I Tax transactivates human interleukin 8 gene through acting concurrently on AP-1 and nuclear factor-kappaB-like sites.

The transactivator protein, Tax, from the human T-cell leukemia virus type I (HTLV-I) transactivates both viral and cellular genes. Previously, we had shown that interleukin 8 (IL-8) is constitutively expressed in HTLV-I-infected cells and in cells transiently expressing Tax. We show here that the IL-8 promoter is Tax responsive in Jurkat T cells.

Interleukin-8 (IL-8) and monocyte chemotactic and activating factor (MCAF/MCP-1), chemokines essentially involved in inflammatory and immune reactions.

Leukocyte infiltration is a hallmark of inflammation. Knowledge on molecular mechanisms of leukocyte infiltration has advanced rapidly due to the recent elucidation of structures and functions of adhesion molecules and chemokines. Since the discovery of interleukin-8 (IL-8), a prototype of CXC chemokines, in 1987 and monocyte chemotactic and activating factor/monocyte chemoattractant protein-1 (MCAF/MCP-1), a prototype of chemotactic cytokines (CC) chemokines, in 1989, more than 30 members of chemokines have been identified so far.

Potential involvement of IL-8 in the pathogenesis of human cytomegalovirus infection.

The observations that several types of viruses induced interleukin (IL)-8 production prompted us to investigate the interrelationship between IL-8 and cytomegalovirus (CMV) infection. CMV infection caused IL-8 production in a human monocytic cell line, THP-1, in dose- and time-dependent manners. Moreover, CMV induced IL-8 gene expression by concurrently activating transcription factors, NF-kappaB and AP-1.

Physiologic regulation of postovulatory neutrophil migration into vagina in mice by a C-X-C chemokine(s).

Leukocytes, particularly neutrophils, infiltrate into female genital organs after ovulation in both humans and mice. In mice, a female sexual cycle consists of 5 phases: proestrus, estrus, metestrus-1, metestrus-2, and diestrus. Ovulation occurs at estrus; at metestrus-2, a large number of neutrophils infiltrate into the vaginal epithelium accompanied by an increased neutrophil number in vaginal lavage fluid.

Regulation of placental monocyte chemotactic and activating factor during pregnancy and chorioamnionitis.

A number of placental cytokines participate in the feto-maternal defence mechanism. Monocyte chemotactic and activating factor (MCAF) is one of these chemokines. We investigated the pattern of placental MCAF production, the localization of MCAF-producing cells in the placenta, and alterations in its expression in chorioamnionitis.

Interleukin-8 and monocyte chemotactic protein-1 production by a human glioblastoma cell line, T98G in coculture with monocytes: involvement of monocyte-derived interleukin-1alpha.

We have previously demonstrated that a human glioblastoma cell line, T98G cells, produced high levels of interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1) when stimulated with IL-1 or tumor necrosis factor-alpha (TNF-alpha). In this study, we found that T98G cells are capable of producing large amounts of IL-8 and MCP-1 when cocultured with human peripheral blood monocytes or a monocytic cell line, U937 cells. Since it is possible that both glioblastoma cells and monocytes are capable of producing chemokines, we determined which type of cells actually produced IL-8 and MCP-1, by the fixation of one or the other cell type with 3% paraformaldehyde (PA).

Alleviation of monocrotaline-induced pulmonary hypertension by antibodies to monocyte chemotactic and activating factor/monocyte chemoattractant protein-1.

Administration of monocrotaline (MCT) causes pulmonary vascular lesions consisting of monocyte/macrophage infiltration in the early phase and medial thickening in pulmonary arteries and arterioles associated with pulmonary hypertension (PH) in the later phase. However, the molecular mechanism of monocyte/macrophage infiltration and its roles remain elusive. Herein, we have evaluated the role of a potent monocyte chemotactic and activating chemokine/monocyte chemoattractant protein-1 (MCAF/MCP-1) in MCT-induced PH in rats.

Activator protein-1 is the preferred transcription factor for cooperative interaction with nuclear factor-kappaB in respiratory syncytial virus-induced interleukin-8 gene expression in airway epithelium.

The role of "oxidant-sensitive" transcription factors activator protein (AP)-1, nuclear factor (NF)-kappaB, and NF-IL6 in respiratory syncytial virus (RSV)-induced interleukin (IL)-8 gene expression in A549 epithelial cells was evaluated. RSV infection resulted in increased binding of each of these transcription factors. Transfection of A549 cells with plasmids containing serial truncations of the 5'-flanking region of the IL-8 gene revealed a positive cooperative effect of the binding sites for AP-1 and NF-kappaB.

Down-regulation of CXCR2 expression on human polymorphonuclear leukocytes by TNF-alpha.

TNF-alpha is implicated in the initiation of cytokine cascades in various inflammatory settings. To assess the interactions of multiple cytokines at the level of inflammatory effector cells, we examined the effects of TNF-alpha on the expression of two IL-8Rs (CXCR1 and CXCR2) on polymorphonuclear leukocytes (PMNs). TNF-alpha decreased the surface expression of CXCR2 in a dose- and time-dependent manner.

Urinary levels of chemokines (MCAF/MCP-1, IL-8) reflect distinct disease activities and phases of human IgA nephropathy.

Leukocytes have been implicated to be involved in the pathogenesis of IgA nephropathy (IgAN). To clarify the precise molecular mechanism of recruitment and activation of leukocytes in the subgroups of IgAN, latent, acute, and chronic types, we studied monocyte chemotactic and activating factor (MCAF/MCP-1) and interleukin (IL)-8 in urines and renal expression of these cytokines. Urinary MCAF levels were significantly higher in chronic type, and were correlated with pathological progressive factors such as mesangial proliferation and interstitial cellular infiltration associated with CD68-positive macrophage.

Enhanced AP-1 and NF-kappaB activities and stability of interleukin 8 (IL-8) transcripts are implicated in IL-8 mRNA superinduction in lung epithelial H292 cells.

Inhibition of protein synthesis may result in superinduction of short-lived transcripts and has been attributed variably to stabilization of transcripts and/or increased gene transcription. Little is known about the kinetics of these processes and relevant transcriptional elements have not been identified. In this study, we describe superinduction of interleukin 8 (IL-8) mRNA, an important inflammatory mediator, in lung epithelial-like H292 cells and identify the underlying molecular mechanisms and their kinetics.

Stimulation of interleukin-8 production by acidic polysaccharides from the root of Panax ginseng.

The root of Panax ginseng C.A. Meyer, is a well-known important Chinese traditional medicine used as a stomachic, tonic, sedative and as an elixir called Ginseng in China and Japan.

Chemokines in the bronchoalveolar lavage fluid of patients with sarcoidosis.

We measured the levels of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) in the bronchoalveolar lavage (BAL) fluids from 27 patients with active pulmonary sarcoidosis and examined the relationship between chemokine levels and some clinical manifestations. The levels of two chemokines were assessed by enzyme-linked immunosorbent assay. There were significant positive correlations between the absolute number of lymphocytes and MCP-1 levels.

Induction of dendritic cell differentiation by granulocyte-macrophage colony-stimulating factor, stem cell factor, and tumor necrosis factor alpha in vitro from lineage phenotypes-negative c-kit+ murine hematopoietic progenitor cells.

To elucidate the capacity of murine early hematopoietic progenitor cells (HPCs) to differentiate into dendritic cells (DCs), lineage phenotypes (Lin)-c-kit+ HPCs were highly purified from either wild-type or tumor necrosis factor (TNF) receptor p55 (TNF-Rp55)-deficient mice. Upon culture with granulocyte-macrophage colony-stimulating factor (GM-CSF) and stem cell factor (SCF) for 14 days, wild-type mouse Lin-c-kit+ HPCs did not exhibit characteristic features of DC such as sheet-like projections and veil processes. Moreover, these cells expressed a marginal level of DC markers such as DEC-205, CD86, and barely supported allogenic MLR.

Effect of thromboxane A2 antagonists on bronchial hyperresponsiveness induced immediately after interleukin-8 inhalation in guinea-pigs.

1. Although repeated intranasal administration of interleukin-8 (IL-8) causes bronchial hyperresponsiveness (BHR) mediated via thromboxane A2 (TXA2) and airway neutrophil accumulation in guinea-pigs, the acute effect of inhaled IL-8 is unclear. We performed this study to clarify the acute effect of IL-8 on bronchial responsiveness and the role of TXA2.

Pivotal role of interleukin-8 in the acute respiratory distress syndrome and cerebral reperfusion injury.

Neutrophil recruitment is one of the hallmarks of acute inflammation. A potent neutrophil chemotactic and activating factor, interleukin-8 (IL-8), has been demonstrated to be elevated in body fluids in various human diseases and experimental animal models. Recent investigations on animal disease models using blocking antibodies to IL-8 have revealed the essential involvement of IL-8 in acute inflammation.

Enhanced mobilization of hematopoietic progenitor cells by mouse MIP-2 and granulocyte colony-stimulating factor in mice.

Human interleukin-8 (IL-8) induces a rapid mobilization of hematopoietic progenitor cells (HPCs) into peripheral blood in mice and primates. Because an exact homologue of human IL-8 does not exist in mice, a chemokine, macrophage inflammatory protein-2 (MIP-2), is supposed to substitute the function of IL-8 in mice. Hence, we investigated the capacity of mouse MIP-2 to induce HPC mobilization in mice.

Attenuation of monosodium urate crystal-induced arthritis in rabbits by a neutralizing antibody against interleukin-8.

Accumulating evidence implicates interleukin-8 (IL-8) as an essential mediator in neutrophil-mediated acute inflammation. Neutrophils have also been shown to have a crucial role in the pathogenesis of acute gouty arthritis. Thus, we investigate the pathophysiological role of IL-8 in an experimental model of acute gout, monosodium urate (MSU) crystal-induced arthritis in rabbits.

The alpha chemokine, interleukin 8, inhibits the antiviral action of interferon alpha.

Interferon (IFN) exhibits a potent antiviral activity in vitro and plays a major role in the early defense against viruses. Like IFN, the proinflammatory chemokine, interleukin (IL)-8, is induced by viruses and appears in circulation during viral infections. In an in vitro cytopathic effect assay for IFN, we found that IL-8 can inhibit IFN-alpha activity in a dose-dependent manner.

Identification of tumor-specific paclitaxel (Taxol)-responsive regulatory elements in the interleukin-8 promoter.

Paclitaxel (Taxol) is a novel chemotherapeutic drug that is effective against breast and ovarian cancers. Although the primary target of paclitaxel is microtubules, its efficacy exceeds that of conventional microtubule-disrupting agents, suggesting that it may have additional cellular effects. Previously, we demonstrated that paclitaxel can induce interleukin-8 (IL-8) gene expression at the transcriptional level in subsets of human ovarian cancer lines.

Prevention of cerebral edema and infarct in cerebral reperfusion injury by an antibody to interleukin-8.

Reperfusion after a transient ischemia is a frequently encountered clinical condition that often causes greater tissue damage than persistent ischemia itself. Reperfusion to rabbit brain, after a transient focal ischemia, induced neutrophil infiltration and aggregation--neither of which were observed in rabbit brain rendered ischemic alone for the same time interval--thereby leading to severe brain edema and infarct. Brain tissue levels of interleukin-8 (IL-8), a potent neutrophil chemotactic cytokine (chemokine), increased significantly at 6 hours after reperfusion, but without a noticeable elevation of plasma IL-8 levels.