Helicobacter pylori vacuolating cytotoxin A (VacA) has been considered as an apoptosis-inducing factor. Here, we investigated the mechanism of VacA-induced apoptosis in relation to the defense mechanism and MAP kinases pathway in gastric epithelial cells. AGS cells exposed to enriched VacA extracts affected the level of SOD-1 and villin. We further investigated the role of VacA in those inducti...

Helicobacter pylori infection is common in Alaska. The development of severe H. pylori disease is partially determined by the virulence of the infecting strain. Here we present vacA and cagA genotype data for H. pylori strains isolated from Alaskans and their correlation with clinical disease. We enrolled patients scheduled for esophagogastroduodenoscopy and positive for H. pylori infection. Ga...

In order to better understand pathogenicity of Helicobacter pylori, particularly in the context of its carcinogenic activity, we analysed expression of virulence genes: cagA, virB/D complex (virB4, virB7, virB8, virB9, virB10, virB11, virD4) and vacA in strains of the pathogen originating from persons with gastric diseases. The studies were conducted on 42 strains of H. pylori isolated from pat...

In this study, we describe the ultrastructural changes associated with acid activation of Helicobacter pylori vacuolating cytotoxin (VacA). Purified VacA molecules imaged by deep-etch electron microscopy form approximately 30-nm hexagonal "flowers," each composed of an approximately 15-nm central ring surrounded by six approximately 6-nm globular "petals." Upon exposure to acidic pH, these olig...

One of the major toxins secreted by H. pylori is the Vacuolating cytotoxin A (VacA) named after its ability to induce the formation of "vacuole"-like membrane vesicles in the cytoplasm of gastric cells. VacA has been associated with the disruption of mitochondrial functions, stimulation of apoptosis, blockade of T cell proliferation and promotion of regulatory T cells, thereby making it a promi...

Helicobacter pylori is a gram-negative bacterium that colonizes the stomach of nearly half of the world's population. Genotypic characterization of H. pylori strains involves the analysis of virulence-associated genes, such as vacA, which has multiple alleles. Previous phylogenetic analyses have revealed a connection between modern H. pylori strains and the movement of ancient human populations...

We read with interest the paper by Basiri and colleagues studying the prevalence of vacA d1 and d2 genotypes in the H pylori isolates from patients with gastric adenocarcinoma, peptic ulcer disease and gastritis in East Azerbaijan region, where the incidence of gastric cancer (GC) is high. They found that 43.4% of the isolate carried the d1 allele and 56.6% carried subtype d2. A significant cor...

Helicobacter pylori is a human pathogen responsible for severe gastric diseases such as peptic ulcers, gastric adenocarcinoma, and gastric lymphoma. Vacuolating toxin (VacA) is crucial in facilitating the colonization of the gastric lining by inducing cell apoptosis and immune suppression. VacA inserts into membranes and forms a hexameric, anion-selective pore. Here we present a structural mode...