Helicobacter pylori enhances tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis in human gastric epithelial cells

AIM: To investigate the relations between tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and Helicobacter pylori (H pylon) infection in apoptosis of gastric epithelial cells and to assess the expression of TRAIL on the surface of infiltrating T-cells in Hpylori-infected gastric METHODS: Human gastric epithelial cell lines and primary gastric epithelial cells were co-cultured with H pylori in vitro, then recombinant TRAIL proteins were added to the culture. Apoptosis of gastric epithelial cells was determined by a specific ELISA for cell death. Infiltrating lymphocytes were isolated from Hpyiori-infected gastric mucosa, and expression of TRAIL in T cells was analyzed by flow cytometry.RESULTS: The apoptosis of gastric epithelial cell lines and primary human gastric epithelial cells was mildly increased by interaction with either TRAIL or H pyiorialone. Interestingly,the apoptotic indices were markedly elevated when gastric epithelial cells were incubated with both TRAIL and H pylori(Control vs TRAIL and Hpylori. 0.51±0.06 vs 2.29±0.27,P = 0.018). A soluble TRAIL receptor (DR4-Fc) could specifically block the TRAIL-mediated apoptosis. Further studies demonstrated that infiltrating T-cells in gastric mucosa expressed TRAIL on their surfaces, and the induction of TRAIL sensitivity by H pyloriwas dependent upon direct cell contact of viable bacteria, but not CagA and VacA of H pylori.CONCLUSION: H pylori can sensitize human gastric epithelial cells and enhance susceptibility to TRAIL-mediated apoptosis. Modulation of host cell sensitivity to apoptosis by bacterial interaction adds a new dimension to the immunopathogenesis of H pylori infection.

Endoscopic banding ligation can effectively resect hyperplastic polyps of stomach

AIM: Bleeding and perforation are the major and serious complications associated with endoscopic polypectomy. To develop a safe and effective method to resect hyperplastic polyps of the stomach, we employed rubber bands to strangulate hyperplastic polyps and to determine the possibility of inducing avascular necrosis in these lesions.METHODS: Forty-seven patients with 72 hyperplastic polyps were treated with endoscopic banding ligation (EBL). On 14 days after endoscopic ligation, follow-up endoscopies were performed to assess the outcomes of the strangulated polyps.RESULTS: After being strangulated by the rubber bands,all of the polyps immediately became congested (100 %),and then developed cyanotic changes (100 %) approximately 4 minutes later. On follow-up endoscopy 2 weeks later, all the polyps except one had dropped off. The only one residual polyp shrank with a rubber band in its base, and it also dropped off spontaneously during subsequent follow-up.No complications occurred during or following the ligation procedures.CONCLUSION: Gastric polyps develop avascular necrosis following ligation by rubber bands. Employing suction equipment, EBL can easily capture sessile polyps. It is an easy, safe and effective method to eradicate hyperplastic polyps of the stomach.