The Damage Effect And Mechanism Of H.pylori Isolated From Salted Pork To Human Gastric Epithelial Cell GES-1

PrefaceIt is evidence that H.pylori infection and high-salt diet are thought to have an important role in the development of gastric cancer, but it is not known whether they interact with each other between these two facters when put together as well as the effect of interaction to gastric cancer. Zhuanghe in Liaoning province is a high-risk area of gastric cancer in North China. Salted pork is the traditionary method to storage food in this area. In the previous study we have reported that more than 79.3% individuals in the high-risk area of gastric cancer in Zhuanghe infected with H.pylori; and it has significant association with gastric diseases. H.pylori is strict to the living environment in normal and it is not survival in physical environment. Recently, we have isolated H.pylori from salted pork. But it is not known whether its bionomics change, whether its pathopoesis and virulence change. This study was designed to observe the damage effect of H.pylori isolated from salted pork (X27) or human gastric mucosa (B975) to human gastric epithelial cell (GES-1) and compare the virulence between different derived H.pylori strains. 8-OHdG was examined to clarity the mechanism of DNA damage and malignant transformation.Materials and MethodsH.pylori isolated from salted pork (X27) or human gastric mucosa (B975) was seeded on brain heart infusion agar medium containing 7% sheep blood, cultivated at 37℃, 10% CO₂ incubator with 95% relative humidity. The strains were identified by hematoxylin-eosin (HE) and Warthin-Starry silver, and polymerase chain reaction(PCR). The genetypes of X27 and B975 were cagA⁺vacAs1⁺/m1b⁺. By co-culture of GES-1 cells and H.pylori (X27 and B975), the damage effect of H.pylori to GES-1 cells was observed by morphology and 8-OHdG expression was detected by confocal laser sanning microscopy, PBS as control.Results1. the morphology observation of co-cultured GES-1 cellsUnder inverted phase contrast microscope, the normal GES-1 cells are spindle, polygon, adhering to wall, floating cell is almost never seen. The morphology of cocultured GES-1 cells were changed from spindle to round, the ability of GES-1 cells adhering to wall was decreased. There was no significant between H.pylori X27 and B975.2. the 8-OHdG expression of co-cultured GES-1 cellsUnder confocal laser sanning microscopy, the fluorescence intensity of the expression of 8-OHdG was weak in normal GES-1 cells, but had obvious fluorescence enhancement in H.pylori X27 and B975, which the former was higher than later.3. the 8-OHdG quantitation comparison between H.pylori X27 and B975There was statistical significant in the expression of 8-OHdG in co-cultured GES-1 cells compared with control (p＜0.01); Between H.pylori X27 and B975, the expression of 8-OHdG was higher in the former than the later (p＜0.01).conclusions1. H.pylori isolated from Salted pork or gastric mucosa both have damage effect to human gastric epithelial cell GES-1.2. H.pylori isolated from Salted pork or gastric mucosa both can increase the 8-OHdG expression, which may be one of mechanisms induce DNA oxygen damage by H.pylori.3. Under the same genotype, compared with H.pylori B975, H.pylori X27 has stronger damage effect on human gastric epithelial cell GES-1.