title: Helicobacter pylori CagA protein induces factors involved in the epithelial to mesenchymal transition (EMT) in infected gastric epithelial cells in an EPIYA- phosphorylation-dependent manner.
abstract: As a result of Helicobacter pylori adhesion to gastric epithelial cells, the bacterial effector cytotoxin-associated gene A (CagA) is translocated intracellularly, and after hierarchical tyrosine phosphorylation on multiple EPIYA motifs, de-regulates cellular polarity and contributes to induction of an elongation and scattering phenotype that resembles the epithelial to mesenchymal transition (EMT). Stromelysin-1/matrix metalloproteinase-3 (MMP-3) has been reported to induce a sequence of molecular alterations leading to stable EMT transition and carcinogenesis in epithelial cells. To identify the putative role of CagA protein in MMP-3 induction, we exploited an experimental H. pylori infection system in gastric epithelial cell lines. We utilized isogenic mutants expressing CagA protein with variable numbers of EPIYA and phosphorylation-deficient EPIFA motifs, as well as cagA knockout and translocation-deficient cagE knockout strains. Increased levels of MMP-3 transcriptional activation were demonstrated by quantitative real time-PCR for strains with more than two terminal EPIYA phosphorylation motifs in CagA. MMP-3 expression in total cell lysates and the corresponding culture supernatants was associated with CagA expression and translocation and was dependent on CagA phosphorylation. A CagA EPIYA phosphorylation-dependent increase in gelatinase and caseinolytic activity was also detected in culture supernatants by zymography. A significant increase in the transcriptional activity of the mesenchymal markers Vimentin, Snail and ZEB1 and the stem cell marker CD44 was observed in the case of CagA containing phosphorylation-functional EPIYA motifs. Our data suggest that CagA protein induces EMT through EPIYA phosphorylation-dependent up-regulation of MMP-3. Moreover, no significant increase in EMT and stem cell markers was observed following infection with H. pylori strains that cannot effectively translocate CagA protein.
authors.affiliation: Laboratory of Medical Microbiology, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Ioanna S
authors.initials: IS
authors.lastname: Sougleri
authors.affiliation: Laboratory of Medical Microbiology, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Konstantinos S
authors.initials: KS
authors.lastname: Papadakos
authors.affiliation: Laboratory of Medical Microbiology, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Mairi P
authors.initials: MP
authors.lastname: Zadik
authors.affiliation: Laboratory of Biochemistry, Department of Chemistry, National and Kapodistrian University of Athens, Greece.
authors.forename: Mary
authors.initials: M
authors.lastname: Mavri-Vavagianni
authors.affiliation: Laboratory of Medical Microbiology, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Andreas F
authors.initials: AF
authors.lastname: Mentis
authors.affiliation: Laboratory of Medical Microbiology, Hellenic Pasteur Institute, Athens, Greece.
authors.forename: Dionyssios N
authors.identifier: http://orcid.org/0000-0003-0975-2607
authors.initials: DN
authors.lastname: Sgouras
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000378:metabolism* / Q000382:microbiology; D058750:Epithelial-Mesenchymal Transition; D005753:Gastric Mucosa / Q000378:metabolism* / Q000382:microbiology; D016481:Helicobacter Infections / Q000378:metabolism* / Q000473:pathology; D016480:Helicobacter pylori / Q000472:pathogenicity*; D054884:Host-Pathogen Interactions; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism; D008969:Molecular Sequence Data; D010766:Phosphorylation; D014746:Vimentin / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D018960:Hyaluronan Receptors; C103937:PicB protein, Helicobacter pylori; D014746:Vimentin; C080866:cagA protein, Helicobacter pylori; D019278:Matrix Metalloproteinase 3
keywords: CD44; MMP-9; ZEB1; matrix metalloproteinase; stromelysin-1/MMP-3