title: Helicobacter pylori encoding the pathogenicity island activates matrix metalloproteinase 1 in gastric epithelial cells via JNK and ERK.
abstract: Helicobacter pylori colonizes the human gastric epithelium and induces an inflammatory response that is a trigger for gastric carcinogenesis. Matrix metalloproteinases (MMPs) have recently been shown to be up-regulated in gastric epithelial cells infected with H. pylori and might contribute to the pathogenesis of peptic ulcer. The aim of this study was to extend the knowledge about the effect of H. pylori infection on MMP-1 expression by gastric epithelial cells, the kinetics of induction, the pathogenetic properties of the bacterium, and the intracellular signaling pathways required for MMP-1 up-regulation. Expression of MMP-1 was induced more than 10-fold by co-culture of AGS+cells with H. pylori strains carrying the pathogenicity island (PAI). H. pylori strains with mutations in the PAI and a defective type IV secretion system had no effect on MMP-1. Double immunofluorescence revealed strong MMP-1 staining in epithelial cells of gastric biopsies at sites of bacterial attachment. In vitro, MMP-1 is up-regulated by interleukin-1beta and tumor necrosis factor-alpha, but these regulatory mechanisms are not operating in H. pylori infection as shown by inhibitory antibodies. Specific inhibitors of JNK kinase and ERK1/2 kinase were found to suppress the H. pylori-induced MMP-1 expression and activity. AGS cells treated with antisense MMP-1 showed a significantly reduced potential to degrade reconstituted basement membrane. Our results suggest that in gastric epithelial cells, H. pylori up-regulates MMP-1 in a type IV secretion system-dependent manner via JNK and ERK1/2. Induction of MMP-1 is further implicated in complex processes induced by H. pylori, resulting in tissue degradation and remodeling of the gastric mucosa.
authors.affiliation: Institute of Pathology, Department of Gastroenterology, Hepatology and Infectious Diseases, Magdeburg, Germany. sabine.krueger@medizin.uni-magdeburg.de
authors.forename: Sabine
authors.initials: S
authors.lastname: Krueger
authors.forename: Tanja
authors.initials: T
authors.lastname: Hundertmark
authors.forename: Thomas
authors.initials: T
authors.lastname: Kalinski
authors.forename: Ulrich
authors.initials: U
authors.lastname: Peitz
authors.forename: Thomas
authors.initials: T
authors.lastname: Wex
authors.forename: Peter
authors.initials: P
authors.lastname: Malfertheiner
authors.forename: Michael
authors.initials: M
authors.lastname: Naumann
authors.forename: Albert
authors.initials: A
authors.lastname: Roessner
mesh_terms: D004848:Epithelium / Q000201:enzymology / Q000382:microbiology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D044404:Genomic Islands / Q000235:genetics*; D016480:Helicobacter pylori / Q000472:pathogenicity / Q000502:physiology*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D007700:Kinetics; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013270:Stomach / Q000382:microbiology / Q000473:pathology*; D015854:Up-Regulation
chemical_list: D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020781:Matrix Metalloproteinase 1