The Effect Of Helicobacter Pylori From Human And Salt Pork On Cell Proliferation Of Mongolian Gerbil Gastric Epithelial Cells

IntroductionHelicobacter pylori infection is an important risk factor of gastric cancer incidence. Currently Mongolia gerbil is thought to be an ideal animal models to study H.pylori pathogenic function.Zhuanghe in Liaoning Province is a high incidence area of gastric cancer in northern China,the local H.pylori detection rate was as high as 79.3%in epidemiological survey,which was significantly higher than the low-incidence areas of gastric cancer.And the local residents had a habit to eat salt pork.Our team cultivated H pylori from the salt pork previous.However,whether the biological characteristics of the survived H.pylori would change in the high-salt environment,and whether the pathogenic effect of H.pylori is changed,and its virulence,the pathogenic mechanism, these are still unclear.In this study,the model of the cultivated H.pylori,which was from salt pork and human gastric mucosa in Zhuanghe high risk of gastric cancer, infected Mongolian gerbils was used,we observed the proliferation of salt pork-derived H.pylori in gastric mucosa of Mongolian gerbils in epithelial cell,and detected PCNA, cyclinD1,p21 expression of different strains infected Mongolian gerbils,compared proliferation differences between salt pork and human-derived H.pylori affected on gastric epithelial cell,in order to further clarify the biological characteristics and its pathogenic mechanism of Helicobacter pylori.Materials and MethodsUsing our team established salt pork-derived H.pylori(X23),as well as human gastric mucosa-derived H.pylori(4854),cultivated for recovery in micro-oxybiontic conditions.Using colony characteristics,morphology staining,PCR,sequencing confirmed that the bacteria was H.pylori.Feeding Mongolian gerbils H.pylori X23 and 4854 by gastric gavage,the Mongolian gerbil animal model infected by H.pylori was established,and we observed the proliferation of salt pork-derived H.pylori in gastric mucosa of Mongolian gerbils in epithelial cell,and detected PCNA,cyclinD1, p21 expression of different strains infected Mongolian gerbils.The statistical software SPSS11.5 was used for statistical analysis.ResultsHelicobacter pylori cultivation and identificationUrease half solid medium was observed to change to red,it meaned urease test was positive.The positive criterion for H.pylori is gram's staining is red observed in optical microscope,or W-S dyeing is dark brown or black bacteria shaped"S"type,bending, gulls,or rods.Helicobacter pylori colonization in the situation from different sources of Mongolian gerbil gastric mucosaStomach tissue of Mongolian gerbils fixed by Formalin solution,forming paraffin slice,HE,W-S nitric acid silver staining observed there was H.pylori colonization in stomach tissue of experimental animals,but there was not H.pylori colonization in the control group.Morphological changes of Mongolian gastric mucosa after Helicobacter pylori infectionThe Mongolian gerbils in H.pylori infected group was dissected in 13^thweek while X23 mucosa was observed erosion,bleeding,and and did not see 4854 group. when Mongolian gerbils was dissected in the 26^thand 52^thweeks,the gastric mucosa was visible obvious bleeding and ulcer disease,inflammation,especially ulcer was happened in gastric antrum,ulcer formed ovoid and edge slightly raised.In the control group,mucosal erosion,bleeding and ulcers was not observed while in the whole process of experiment.After H.pylori infected Mongolian gerbils 13^thweeks later,there was visible lymphoid follicles in distal stomach submucosal and lamina propria by HE staining in X23 group,and had a superficial gastritis.4854 group did not observe abnormal. Infection X23 distal stomach group had obvious atrophy in 26^thweek,4854 group performanced for superficial gastritis.52^thweeks,X23 group infection for severe distal stomach and atrophic gastritis,4854 for hyperplasia,ulcer and superficial gastritis.The normal control group in the experimental process were not found inflammatory cells, gastritis pathological changes.PCNA,cyclinD1 and p21 expression of different Mongolian gerbil gastric mucosa after Helicobacter pylori infectionPCNA-positive cells showed nuclear staining in normal antral mucosa,positive cells were mainly distributed in lamina propria of gastric epithelium glandular,showing zonal distribution,with the formation of cell proliferation,there was hardly no PCNA positive cells existent of cell surface.While H.pylori infected,PCNA-positive cells marked increased compared with the control group,salt pork-derivered and gastric mucosa-derived group increased PCNA expression significantly(P＜0.05);and salt pork-derived gastric mucosa was significantly higher than salt pork-derived group(P＜0.05).CyclinD1 marked cells showed positive nuclear staining,the cytoplasm also expressed,and the positive cells were mainly distributed in the surface epithelium. Compared with the control group,salt pork-derived and human gastric mucosa-derived groups cyclinDl expressed significantly increased(P＜0.05);salt pork-derived gastric mucosa was significantly higher than human gastric mucosa-derived group(P＜0.05). Compared with control group,salt pork-derived and human gastric mucosa-derived group had a significant reduction in p21 expression(P＜0.05);salt pork-derived was significantly lower than gastric mucosa-derived group(P＜0.05).Conclusionsl.Salt pork-derived and human-derived Hp can cause PCNA highly expression in gastric mucosal epithelial cell of the Mongolian gerbil,thus can promote the proliferation of Mongolian gerbils gastric epithelial cells.2.The proliferation of Mongolian gerbil gastric epithelial cell promoted by salt pork-derived and human-derived Hp may be due to cyclinDl up-regulation and p21 down-regulation expression.3.The effect of proliferation promoted by salt pork-derived Hp was higher than that of human-derived Hp.