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)

Gastric infection with Helicobacter pylori activates a mucosal inflammatory response by mononuclear cells and neutrophils that includes expression of cytokines interleukin-1 beta (IL-1 beta), IL-6, tumor necrosis factor alpha, and IL-8. In this study, we analyzed the IL-8 response of human gastric cancer cell lines (Kato III, AGS, and MKN28) to H. pylori infection in vitro. IL-8 mRNA expression was detected by reverse transcription-PCR amplification of RNA extracted from epithelial cells after incubation with different H. pylori wild-type and mutant strains, and IL-8 secretion was measured by an enzyme-linked immunosorbent assay. Exposure to viable H. pylori induced IL-8 mRNA and protein synthesis in all three gastric cell lines but not in nongastric epithelial cell lines. Heat-killed H. pylori and a crude cytotoxin preparation did not induce significant IL-8 secretion. IL-8 mRNA peaked between 2 and 4 h postinfection, and IL-8 protein production was maximal 24 h postinfection. Exposure of gastric carcinoma cells to other gastrointestinal bacteria, such as Pseudomonas aeruginosa, Campylobacter jejuni, and Escherichia coli, but not Campylobacter fetus, induced IL-8 synthesis. Wild-type strains that expressed the vacuolating cytotoxin (Tox+) and a cytotoxin-associated gene (cagA) product (CagA+) induced significantly more IL-8 than did CagA- Tox- strains. However, there was no decrease in IL-8 induction by isogenic mutants of CagA-, Tox-, or Cag- Tox- strains or by a mutant lacking the urease subunits. These results indicate that exposure to H. pylori and other gram-negative organisms that do not colonize the gastric mucosa induces IL-8 production by gastric carcinoma cells in vitro. Although the CagA+ Tox+ phenotype of H. pylori is associated with enhanced IL-8 production by gastric cell lines, other bacterial constituents are clearly essential.
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PMID:Interleukin-8 response of gastric epithelial cell lines to Helicobacter pylori stimulation in vitro. 772 72

Gastric infection with Helicobacter pylori is frequently characterized by neutrophil infiltration. The production of the neutrophil-activating peptide (NAP-1/IL-8) and mucosal IgA autoantibodies to IL-8 by human antral biopsies have been examined during short-term in vitro culture. Detectable IL-8 was secreted by 84% of H. pylori-negative patients with normal antral mucosa (range < 0.07-61.5 ng/mg biopsy protein, n = 19). Concentrations in 4 patients with reactive gastritis and 10 with inactive gastritis were not significantly different from subjects with normal mucosa. In H. pylori-positive patients with active gastritis and neutrophil infiltration into the epithelium (n = 17) IL-8 secretion was significantly increased relative to subjects with normal mucosa (P < 0.0001), inactive gastritis (P < 0.001) and reactive gastritis (P < 0.01). IL-8 concentrations in active gastritis were significantly correlated with the extent of epithelial surface degeneration (r = 0.64). IgA autoantibodies were present in 19 patients (13 active, 4 inactive gastritis) and concentrations were significantly correlated with IL-8 production (P < 0.001). Gastric synthesis of IL-8 is likely to be an important factor in regulating mucosal neutrophil infiltration and activation in patients with H. pylori infection. The local production of IgA antibodies to IL-8 may represent a down-regulatory response of the host to limit mucosal damage associated with a chronic bacterial infection.
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PMID:Gastric interleukin-8 and IgA IL-8 autoantibodies in Helicobacter pylori infection. 841 74

Gastric infection by Helicobacter pylori is the most common cause of ulcer disease and gastric cancer. The mechanism of progression from gastritis and inflammation to ulcers and cancer in a fraction of those infected is not definitively known. Significant acidity is unique to the gastric environment and is required for ulcer development. The interplay between gastric acidity and H. pylori pathogenesis is important in progression to advanced disease. The aim of this study was to characterize the impact of acid on gastric epithelial integrity and cytokine release and how H. pylori infection alters these responses. Human gastric epithelial (HGE-20) cells were grown on porous inserts, and survival, barrier function, and cytokine release were studied at various apical pH levels in the presence and absence of H. pylori. With apical acidity, gastric epithelial cells demonstrate increased barrier function, as evidenced by increased transepithelial electrical resistance (TEER) and decreased paracellular permeability. This effect is reduced in the presence of wild-type, but not urease knockout, H. pylori. The epithelial inflammatory response is also modulated by acidity and H. pylori infection. Without H. pylori, epithelial IL-8 release decreases in acid, while IL-6 release increases. In the presence of H. pylori, acidic pH diminishes the magnitude of the previously reported increase in IL-8 and IL-6 release. H. pylori interferes with the gastric epithelial response to acid, contributing to altered barrier function and inflammatory response. H. pylori diminishes acid-induced tightening of cell junctions in a urease-dependent manner, suggesting that local pH elevation promotes barrier compromise and progression to mucosal damage.
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PMID:Helicobacter pylori impedes acid-induced tightening of gastric epithelial junctions. 2398 11