| Objectives1. To observe the effect of Helicobacter pylori infection on the expression and phosphorylation of ?-Catenin in human gastric mucosal epithelial cells.2. To clarify the effect of Cag A protein on the expression and phosphorylation of ?-Catenin in human gastric mucosal epithelial cells.3. To investigate the molecular mechanism of the increase of ?-Catenin expression in gastric mucosal epithelial cells induced by Cag A protein.Methods1. 80 cases of gastric antrum mucosa biopsy specimens were colelected, and the pathological changes were observed;2. Immunohistochemical staining was used to detecte the HP infection status in gastric mucosa: All the gastric mucosal specimens were in 6mm thickness. After dewaxing and hydration, the sections were stained with HP specific antibody to determ the HP infection status in gastric epithelial cells. According to HP infection, all specimens were divided into HP positive group and HP negative group.3. PCR amplification was applied to amplify Cag A gene in HP positive gastric mucosa. 6-8 sections of all HP positive gastric mucosa specimens were collected into the EP tube. Total DNA were extracted from the paraffin embedded tissues by using the Qiagen kit. This DNA were used as a template, the Cag A gene was amplified by Cag A specific primers. PCR products were analysed by agarose gel electrophoresis.HP positive gastric mucosa was further divided into Cag A positive group and Cag A negative group.4. Immunohistochemical staining was used to observe the expression and distribution of?-Catenin. inepithelial cells of gastric mucosa. Both the expression of ?-Cateninand ?-Cateninin gastrical mucasal epithelial cells were analyzed by using semi quantitative and quantitative methods. The effect of HP,with different Cag A, on the ?-Catenin expression, distribution and phosphorylation in the gastric mucosa epithelial cells were analyzed5. Cell culture and gene transfection experiments were performed to investigate the mechanism of increased expression of?-Cateningastric mucosal epithelial cellsResults1. HP infection induced the expression of ?-Catenin in human gastric mucosal epithelial cells.2. HP infection induced theincreasedexpression of?-Catenin in gastric mucosal epithelial cells was associated with the status of the Cag A gene. Infection with Cag A positive HP cause decresed phosphorylation of?-Catenin in gastric mucosa.3. Cag A protein inhibits the activity of PAR1b/MARK2 kinase, which leads to the decrease of phosphorylation of ?-Catenin.Conclusions1. Helicobacter pylori infection inducesincreased expression of ?-Catenin in human gastric mucosal epithelial cells.2. The increased expression of ?-Catenin in gastric mucosal epithelial cells induced by HP infection was closely related to the state of Cag A gene. Cag A protein inhibited the phosphorylation of ?-Catenin in gastric mucosal epithelial cells.3. CagA protein inhibits the activity of PAR1b/MARK2 kinase, which leads to the decrease of phosphorylation of ?-Catenin. |
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