The Effect Of Leptin On The Formation Of Gastric Mucosa-associated Lymphoid Tissue After Helicobacter Suis Infection

Objective To investigate the effect of leptin on the formation of gastric mucosa associated lymphoid tissue(MALT)after H.suis infection and its possible mechanism,for gastric MALT formation mechanism after helicobacter infection and the influence of obesity treated related research to provide theoretical basis.Methods Twenty female C57BL/6 wild type mice and twenty leptin-deficient(Ob/Ob)mice were randomly divided into four groups(ten mice per group),which are named as normal uninfected wild type(WT)group,H.suis infected wild type(WT+HS)group,uninfected ob/ob(Ob)group and H.suis infected Ob/Ob(Ob+HS)group.At 12 weeks after infection,the serum and gastric tissue samples were collected from each mouse.The number and size of gastric lymphoid follicles were detected by HE staining and the expression level of leptin in serum was detected by enzyme-linked immunosorbent assay(ELISA).The m RNA expression levels of leptin and its receptor Ob-R,inflammatory cytokine IFN-? and chemokine CXCL13 in the gastric mucosa were detected by real-time PCR.In vitro cultured human B cell lymphoma cell line(Toledo),after the stimulation of leptin at different concentrations and at different times,the cells and supernatant were obtained after centrifugation.Enzyme linked immunosorbent assay was used to determine the relative expression levels of IFN-gamma m RNA in cultured cells in vitro.The dissertation is the concentrated expression of the achievements of the postgraduates' scientific research work.It is the main basis for the postgraduates to apply for doctorate or master's degree.It is also the important literature of the society.In order to further promote the standardization of postgraduate degree thesis and improve the quality of writing,we have prepared the "Graduate University of Qingdao University graduate thesis specification(Trial)" for the graduate degree reference.Results 1.At 12 weeks after infection the expression of H.suis 16 S r RNA was detected in the gastric mucosa of the WT+HS group and the Ob+HS group,and there was no statistically significant difference in the relative bacteria content.There was obvious lymphatic follicular formation in the gastric mucosa of mice in WT+HS group,and the lymphatic follicular formation was not detected in the gastric mucosa of the Ob+HS group.2.The expression levels of leptin in serum in WT+HS group and the expression levels of leptin in gastric mucosa were significantly higher than that in WT group after 12 weeks of infection.The expression of leptin was not detected in the serum and gastric mucosa of the Ob group and Ob+HS group.At the same time,the m RNA expression levels of leptin receptor Ob-R,inflammatory factor IFN-gamma and chemokines CXCL13 in mice gastric mucosa in WT+HS group were also significantly increased compared with that in WT group.However,there was no significant difference in the expression level of the above factors in the gastric mucosa of the Ob group and Ob+HS group,which was significantly lower than that in the WT+HS group.3.Human B cell lymphoma cell line in vitro by different concentration of leptin stimulate and different time after,found that leptin treatment group of medium,the concentration of IFN-gamma and cells of IFN-gamma m RNA expression level was significantly increased,.As the stimulation concentration or stimulation time increased,the expression level of IFN-gamma in the medium was also increased.Conclusion Ob/Ob mice cannot form gastric mucosal lymphoid follicles after H.suis infected,may be associated with leptin secretion defects.Leptin may be involved in the formation of gastric MALT after H.suis infection via the up-regulation of IFN-? in the gastric mucosa.