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.
FEBS J
; 283(2): 206-20, 2016 Jan.
Article
em En
| MEDLINE
| ID: mdl-26907789
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.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
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Helicobacter pylori
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Infecções por Helicobacter
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Células Epiteliais
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Transição Epitelial-Mesenquimal
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Mucosa Gástrica
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Antígenos de Bactérias
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article