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IL-8 Secretion (il-8 + secretion)
Selected AbstractsMacrolide-affected Toll-like receptor 4 expression from Helicobacter pylori -infected monocytes does not modify interleukin-8 productionFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2 2005Joon Yong Park Abstract Macrolide antibiotics have an anti-inflammatory effect by suppressing lipopolysaccharide-induced IL-8 production. IL-8 secretion from monocytes is observed in Helicobacter pylori infection. Although cag gene products are known to induce IL-8 secretion, whether other bacterial substances can initiate the reaction is not determined. In this study, we show that clarithromycin induced down-regulation of Toll-like receptor 4 expression and did not lead to a decrease in IL-8 production and H. pylori lipopolysaccharide. However, Toll-like receptor 4 activation was possibly not the main cause in the induction of inflammation during H. pylori infection. [source] Effect of natural commensal-origin DNA on toll-like receptor 9 (TLR9) signaling cascade, chemokine IL-8 expression, and barrier integritiy of polarized intestinal epithelial cellsINFLAMMATORY BOWEL DISEASES, Issue 3 2010Darab Ghadimi Abstract Background and Aim: The intestinal epithelium is constantly exposed to high levels of genetic material like bacterial DNA. Under normal physiological conditions, the intestinal epithelial monolayer as a formidable dynamic barrier with a high-polarity structure facilitates only a controlled and selective flux on components between the lumen and the underlining mucosa and even is able to facilitate structure-based macromolecules movement. The aim of this study was to test the effect of natural commensal-origin DNA on the TLR9 signaling cascade and the barrier integrity of polarized intestinal epithelial cells (IECs). Methods: Polarized HT-29 and T84 cells were treated with TNF-, in the presence or absence of DNA from Lactobacillus rhamnosus GG (LGG) and Bifidobacterium longum. TLR9 and interleukin-8 (IL-8) mRNA expression was assessed by semiquantitative and TaqMan real-time reverse-transcription polymerase chain reaction. Expression of TLR9 protein, degradation of inhibitor of kappa B alpha (I,B,), and p38 mitogen-activated protein kinase (p38 MAP) phosphorylation were assessed by Western blotting. To further reveal the role of TLR9 signaling, the TLR9 gene was silenced by siRNA. IL-8 secretion was measured by an enzyme-linked immunosorbent assay. Nuclear factor-kappa B (NF-,B) activity was assessed by the electrophoretic mobility shift assay (EMSA) and NF-,B-dependent luciferase reporter gene assays. As an indicator of tight junction formation and monolayer integrity of epithelial cell monolayers, transepithelial electrical resistance (TER) was repetitively monitored. Transmonolayer movement of natural commensal-origin DNA across monolayers was monitored using qRT-PCR and nested PCR based on bacterial 16S rRNA genes. Results: In response to apically applied natural commensal-origin DNA, polarized HT-29 and T84 cells enhanced expression of TLR9 in a specific manner, which was subsequently associated with attenuation of TNF-,-induced NF-,B activation and NF-,B-mediated IL-8 expression. TLR9 silencing abolished this inhibitory effect. Apically applied LGG DNA attenuated TNF-,-enhanced NF-,B activity by reducing I,B, degradation and p38 phosphorylation. LGG DNA did not decrease the TER but rather diminished the TNF-,-induced TER reduction. Translocation of natural commensal-origin DNA into basolateral compartments did not occur under tested conditions. Conclusions: Our study indicates that TLR9 signaling mediates, at least in part, the anti-inflammatory effects of natural commensal-origin DNA on the gut because TLR9 silencing abolished the inhibitory effect of natural commensal-origin DNA on TNF-,-induced IL-8 secretion in polarized IECs. The nature of the TLR9 agonist, the polarity of cells, and the tight junction integrity of IECs has to be taken into account in order to predict the outcome of TLR9 signaling. (Inflamm Bowel Dis 2010) [source] Catalposide, a compound isolated from Catalpa Ovata, attenuates induction of intestinal epithelial proinflammatory gene expression and reduces the severity of trinitrobenzene sulfonic acid-induced colitis in miceINFLAMMATORY BOWEL DISEASES, Issue 5 2004Sang-Wook Kim MD Abstract Certain irinoid-producing plants have been used as herbal anti-inflammatory remedies. Here we evaluated whether catalposide (CATP), a single compound isolated from irinoid-producing plant Catalpa ovata, has a potential for preventing or ameliorating diseases characterized by mucosal inflammation. Preliminary microarray-based gene expression test revealed that CATP, which alone did not significantly affect expression of any of the >8,000 genes analyzed, attenuated the expression of tumor necrosis factor-, (TNF-,)-induced proinflammatory genes including interleukin-8 (IL-8) in human intestinal epithelial HT-29 cells. Down-regulation of IL-8 mRNA accumulation was also reflected by the decreased IL-8 secretion in CATP-treated HT-29 cells. The signal transduction study revealed that CATP significantly attenuates TNF-,-mediated p38 and extracellular signal-regulated kinase (ERK) phosphorylation. Further, CATP reduced NF-,B-mediated transcriptional activation as well as I,-B, degradation. To establish the in vivo relevance of these findings, we examined whether CATP could affect intestinal inflammation in vivo using the mouse model of trinitrobenzene sulfonic acid (TNBS)-induced inflammatory colitis. Intrarectal administration of CATP dramatically reduced the weight loss, colonic damage, and mucosal ulceration that characterize TNBS colitis. Moreover, CATP suppressed the expression of TNF-,, interleukin-1,, and intercellular adhesion molecule-1 along with the inhibition of NF-, B p65 translocation into nucleus in TNBS colitis. Collectively, current results demonstrate that CATP may be an effective agent for the treatment of diseases characterized by mucosal inflammation. [source] Stimulation of epithelial cell matrix metalloproteinase (MMP-2, -9, -13) and interleukin-8 secretion by fusobacteriaMOLECULAR ORAL MICROBIOLOGY, Issue 5 2008U. K. Gursoy Background/aims:, Bacterial pathogens involved in periodontal diseases exert their destructive effects primarily by stimulating the host cells to increase their secretion of proinflammatory cytokines and matrix metalloproteinases (MMPs). This study aimed to determine the epithelial cell matrix metalloproteinase and interleukin-8 (IL-8) secretion upon exposure to fusobacteria. Methods:, Eight different oral and non-oral Fusobacterium strains were incubated with HaCaT epithelial cells. Gelatin zymography and Western blot analysis were performed to detect collagenase 3 (MMP-13), gelatinase A (MMP-2), gelatinase B (MMP-9), and IL-8 secretion by epithelial cells. Results:, All Fusobacterium strains, especially Fusobacterium necrophorum ATCC 25286, Fusobacterium nucleatum ATCC 25586, and Fusobacterium varium ATCC 51644, increased MMP-9 and MMP-13 secretion. Fusobacterium simiae ATCC 33568, and to a lesser extent F. nucleatum and F. necrophorum, increased epithelial MMP-2 secretion. F. nucleatum and F. necrophorum also increased IL-8 secretion. F. varium ATCC 27725, a strain that only weakly stimulated MMP production, strongly increased the IL-8 production, suggesting that their expression is differently regulated. Conclusion:, We conclude that the pathogenic potential of fusobacteria may partly result from their ability to stimulate secretion of MMP-9, MMP-13, and IL-8 from epithelial cells. [source] N -acetyl- L -cysteine inhibits bleomycin-induced interleukin-8 secretion by bronchial epithelial cellsRESPIROLOGY, Issue 4 2000Yasuhiro Gon Objective: Bleomycin (BLM) has proven effective for the treatment of cancers, but the most serious dose-limiting side-effect is the development of pulmonary toxicity. Although the precise mechanism in the pathogenesis of BLM-induced lung injury has not been determined, oxygen radicals and neutrophils are indicated to play a key role in it. Interleukin-8 (IL-8) is thought to be an important mediator of the pathogenesis of acute lung injury. Methodology: The IL-8 production from bronchial epithelial cell line, BEAS-2B cells was measured by enzyme-linked immunosorbent assays for IL-8. Results: The concentrations of IL-8 were reportedly elevated in BLM-induced lung injury, suggesting the involvement of IL-8 in the pathogenesis of BLM-induced lung injury. In the present study, we showed that BLM induced the expression of IL-8 protein and mRNA in BEAS-2B cells, and N -acetyl- L -cysteine (NAC) inhibited IL-8 expression. In addition, the structurally unrelated anti-oxidant, pyrrolidine dithiocarbamate (PDTC) also effectively inhibited BLM-induced IL-8 production. Conclusion: These results suggest that anti-oxidant-sensitive mechanism might be involved in the inhibition of IL-8 secretion by BLM-stimulated bronchial epithelial cells and that NAC might be useful for the treatment of BLM-induced lung injury. [source] ORIGINAL ARTICLE: Cellular Interaction Regulates Interleukin-8 Secretion by Granulosa-Lutein Cells and Monocytes/MacrophagesAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 1 2009Anna Po Problem, Peri-ovulatory migration of leukocytes towards the follicle plays an important role during corpus luteum formation. In this study, we examined the secretion of the neutrophil chemoattractant interleukin (IL)-8 by ovarian GL cells and the role of monocytes in IL-8 secretion. Method of study, Granulosa-lutein cells were isolated from the pre-ovulatory follicle. After depletion of contaminating leukocytes, GL cells were co-cultured with the myelo-monocytic cell line THP-1. Intracellular IL-8 accumulation, IL-8 secretion, and chemotactic activity of cell culture media were examined. Results, Intracellular IL-8 was predominantly localized in the endoplasmatic reticulum-Golgi both in GL cells and in THP-1 cells. In co-cultured cells, intracellular IL-8-specific immunofluorescence and IL-8 secretion were increased compared with either GL cells or THP-1 cells that were cultured alone. Conditioned cell culture media from GL cells and THP-1 cells induced directed cell migration by neutrophils. Conclusion, Human GL cells constitutively synthesize IL-8. An increased IL-8 secretion by co-cultured GL cells and THP-1 cells suggest that GL cells and monocytes mutually induce chemokine secretion. An initial interaction between GL cells and ovarian leukocytes may therefore contribute to an increased chemokine release and leukocyte recruitment to the forming corpus luteum. [source] Influence of antiseptic agents on interleukin 8 release and transmigration of polymorphonuclear granulocytes in an in vitro model of peritonitisBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 7 2000W. Sendt Background The effect of antiseptic agents on peritoneal cells is ill defined. The influence of taurolidine (TAU) and polyhexamide (HEX) was investigated in an in vitro model. Methods Human umbilical vein endothelial cells (HUVECs) and human peritoneal mesothelial cells (HPMCs) were laid on collagen-coated filter inserts (HUVECs on the bottom, HPMCs on the top), thus representing a two-chamber peritoneal model. When confluence was reached, HPMCs were stimulated with 0·5 ml tumour necrosis factor (TNF) , 10 ,g ml,1 for 4 h. Afterwards 0·5 ml TAU (1 and 2 per cent) or 0·5 ml HEX (0·1 and 0·2 per cent) solutions were added to the upper compartment. After 1 h polymorphonuclear granulocytes (PMNs) (105 ml,1) were added to the lower compartment. After 2 and 6 h aliquots were taken from both compartments, transmigrated PMNs were counted and interleukin (IL) 8 concentrations were measured. Controls were either TNF-,-stimulated HPMCs or stimulated HPMCs where culture medium had been substituted for TNF-,. Significance of differences was assessed by analysis of variance with Bonferroni corrections. Correlations were calculated by linear regression analysis. Results Stimulation with TNF-, led to a time-dependent increase in PMN transmigration. IL-8 secretion into the apical compartment increased time dependently, resulting in a gradient between the two chambers. After substitution of the stimulus by culture medium, significantly less IL-8 was measured in both compartments. PMN transmigration was almost absent. Addition of HEX resulted in an initial increase in IL-8 levels comparable to TNF controls without further changes. A concentration-dependent decrease in IL-8 gradient was associated with reduced transmigration. The IL-8 gradient between the upper and lower chambers correlated significantly with PMN transmigration (r = 0·8205, P < 0·0001). Conclusion The decrease in IL-8 gradients by HEX and the diminished IL-8 response after addition of TAU may reflect either anti-inflammatory effects or cellular damage. Both antiseptic solutions reduced PMN migration, irrespective of continuous stimulation in this model. © 2000 British Journal of Surgery Society Ltd [source] Changes in IL-8 release and intracellular content in DMSO-differentiated HL-60 cells after treatment with 4-hydroxynonenalCELL BIOCHEMISTRY AND FUNCTION, Issue 5 2008Marina Maggiora Abstract 4-Hydroxynonenal (HNE), a chemotactic aldehyde produced by lipid peroxidation, has been shown to trigger exocytosis in HL-60 cells induced to differentiate toward the granulocytic cell line by DMSO. In this work we studied HNE effects on the intracellular content of IL-8 and its release in DMSO-differentiated HL-60 cells. Cell incubation at 37°C in the presence of 0.1,µM HNE induced a significant increase of IL-8 release after 30,min; the degree of HNE-induced IL-8 secretion became quite strong after 1,h, whereas the intracellular content showed no statistically significant changes. By contrast, 1,µM HNE induced a low decrease of the chemokine release; however, the used HNE concentrations failed to increase the release of lactate dehydrogenase (LDH), a test used to assay cell viability. The addition of 0.1,µM IL-8 to DMSO-differentiated HL-60 cells induced a strong increase of exocytosis, measured by , -glucuronidase secretion. Exocytosis stimulation by IL-8 was much higher than that given by the aldehyde; the addition of various HNE concentrations to cells incubated in the presence of IL-8 decreased the secretion given by the cytokine alone. However, HNE-induced exocytosis was likely to be a direct action of the aldehyde and was not mediated through the stimulation of IL-8 release since HNE was unable to modify IL-8 secretion during the short time of 10,min used in the exocytosis assay. Copyright © 2008 John Wiley & Sons, Ltd. [source] Expression of a Porphyromonas gingivalis lipid A palmitylacyltransferase in Escherichia coli yields a chimeric lipid A with altered ability to stimulate interleukin-8 secretionCELLULAR MICROBIOLOGY, Issue 1 2006Brian W. Bainbridge Summary In Escherichia coli the gene htrB codes for an acyltransferase that catalyses the incorporation of laurate into lipopolysaccharide (LPS) as a lipid A substituent. We describe the cloning, expression and characterization of a Porphyromonas gingivalis htrB homologue. When the htrB homologue was expressed in wild-type E. coli or a mutant strain deficient in htrB, a chimeric LPS with altered lipid A structure was produced. Compared with wild-type E. coli lipid A, the new lipid A species contained a palmitate (C16) in the position normally occupied by laurate (C12) suggesting that the cloned gene performs the same function as E. coli htrB but preferentially transfers the longer-chain palmitic acid that is known to be present in P. gingivalis LPS. LPS was purified from wild-type E. coli, the E. coli htrB mutant strain and the htrB mutant strain expressing the P. gingivalis acyltransferase. LPS from the palmitate bearing chimeric LPS as well as the htrB mutant exhibited a reduced ability to activate human embryonic kidney 293 (HEK293) cells transfected with TLR4/MD2. LPS from the htrB mutant also had a greatly reduced ability to stimulate interleukin-8 (IL-8) secretion in both endothelial cells and monocytes. In contrast, the activity of LPS from the htrB mutant bacteria expressing the P. gingivalis gene displayed wild-type activity to stimulate IL-8 production from endothelial cells but a reduced ability to stimulate IL-8 secretion from monocytes. The intermediate activation observed in monocytes for the chimeric LPS was similar to the pattern seen in HEK293 cells expressing TLR4/MD2 and CD14. Thus, the presence of a longer-chain fatty acid on E. coli lipid A altered the activity of the LPS in monocytes but not endothelial cell assays and the difference in recognition does not appear to be related to differences in Toll-like receptor utilization. [source] Human mucosa/submucosa interactions during intestinal inflammation: involvement of the enteric nervous system in interleukin-8 secretionCELLULAR MICROBIOLOGY, Issue 12 2005Emmanuelle Tixier Summary Interleukin-8 (IL-8) is a key chemokine upregulated in various forms of intestinal inflammation, especially those induced by bacteria such as Clostridium difficile (C. difficile). Although interactions between different mucosal and submucosal cellular components have been reported, whether such interactions are involved in the regulation of IL-8 secretion during C. difficile infection is unknown. Moreover, whether the enteric nervous system, a major component of the submucosa, is involved in IL-8 secretion during an inflammatory challenge remains to be determined. In order to investigate mucosa/submucosa interactions that regulate IL-8 secretion, we co-cultured human intestinal mucosa and submucosa. In control condition, IL-8 secretion in co-culture was lower than the sum of the IL-8 secretion of both tissue layers cultured alone. Contrastingly, IL-8 secretion increased in co-culture after mucosal challenge with toxin B of C. difficile through an IL-1,-dependent pathway. Moreover, we observed that toxin B of C. difficile increased IL-8 immunoreactivity in submucosal enteric neurones in co-culture and in intact preparations of mucosa/submucosa, through an IL-1,-dependent pathway. IL-1, also increased IL-8 secretion and IL-8 mRNA expression in human neuronal cell lines (NT2-N and SH-SY5Y), through p38 and ERK1/2 MAP kinase-dependent pathways. Our results demonstrate that mucosa/submucosa interactions regulate IL-8 secretion during inflammatory processes in human through IL-1,-dependent pathways. Finally we observed that human submucosal neurones synthesize IL-8, whose production in neurones is induced by IL-1, via MAPK-dependent pathways. [source] Role of EHEC O157:H7 virulence factors in the activation of intestinal epithelial cell NF-,B and MAP kinase pathways and the upregulated expression of interleukin 8CELLULAR MICROBIOLOGY, Issue 10 2002M. Cecilia Berin Summary Enterohaemorrhagic Escherichia coli O157:H7 (EHEC) is a gastrointestinal pathogen that is generally non-invasive for intestinal epithelial cells, yet causes acute intestinal inflammation, diarrhoea, haemorrhagic colitis and haemolytic uraemic syndrome. To study signal transduction pathways activated in human intestinal epithelial cells by EHEC, we took advantage of EHEC O157:H7 and isogenic mutants deficient in the major EHEC virulence factors, intimin (eae,) and Shiga toxin (stx,). Infection with wild-type EHEC activated p38 and ERK MAP kinases and the nuclear translocation of the transcription factor NF-,B. Downstream, this was accompanied by increased expression of mRNA and protein for the neutrophil chemoattractant IL-8. Isogenic eae, and stx, mutants also activated p38 and ERK MAP kinases, and NF-,B and stimulated increases in IL-8 protein secretion similar to those of wild-type EHEC. Further, inhibition of either p38, ERK or NF-,B activation abrogated the IL-8 response induced by wild-type EHEC and the mutants. Epithelial cell MAP kinase and NF-,B pathways leading to IL-8 secretion were also activated by isolated EHEC H7 flagellin, which was active when added to either the apical or basolateral surface of polarized human intestinal epithelial cells. We conclude that EHEC interacting with intestinal epithelial cells activates intracellular signalling pathways and an epithelial cell proinflammatory response independent of either Shiga toxin or intimin, two of the major known virulence factors of EHEC. The activation of proinflammatory signals in human colon epithelial cells in response to this non-invasive pathogen appears to depend to a significant extent on H7 flagellin. [source] Anti-inflammatory properties of heat shock protein 70 and butyrate on Salmonella -induced interleukin-8 secretion in enterocyte-like Caco-2 cellsCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 1 2005J. J. Malago Summary Intestinal epithelial cells secrete the chemokine interleukin (IL)-8 in the course of inflammation. Because heat shock proteins (Hsps) and butyrate confer protection to enterocytes, we investigated whether they modulate Salmonella enterica serovar Enteritidis (S. serovar Enteritidis)-induced secretion of IL-8 in enterocyte-like Caco-2 cells. Caco-2 cells incubated with or without butyrate (0,20 m M, 48 h) were infected with S. serovar Enteritidis after (1 h at 42°C, 6 h at 37°C) or without prior heat shock (37°C). Levels of Hsp70 production and IL-8 secretion were analysed using immunostaining of Western blots and enzyme-linked immunosorbent assay (ELISA), respectively. The cells secreted IL-8 in response to S. serovar Enteritidis and produced Hsp70 after heat shock or incubation with butyrate. The IL-8 secretion was inhibited by heat shock and butyrate concentrations as low as 0·2 m M for crypt-like and 1 m M for villous-like cells. In a dose-dependent manner, higher butyrate concentrations enhanced IL-8 secretion to maximal levels followed by a gradual but stable decline. This decline was associated with increasing production of Hsp70 and was more vivid in crypt-like cells. In addition, the higher concentrations abolished the heat shock inhibitory effect. Instead, they promoted the IL-8 production in heat-shocked cells even in the absence of S. serovar Enteritidis. We conclude that heat shock and low concentrations of butyrate inhibit IL-8 production by Caco-2 cells exposed to S. serovar Enteritidis. Higher butyrate concentrations stimulate the chemokine production and override the inhibitory effect of the heat shock. The IL-8 down-regulation could in part be mediated via production of Hsp70. [source] | |||||||||||||