The Influence Of CagA And Density Of H.pylori On Expression Levels Of INOS And NF-κB In Gastric Mucosa From Patients With H.pylori Infection

Objectives1. To investigate the distribution of H.pylori density, virulent cagA gene among H.pylori associated gastric disease.2. To study the effect of H.pylori density and cagA gene on INOS expression levels in gastric mucosa.3. To study whether NF-KB regulate INOS expression in H.pylori infected gastric mucosa.Methods1. 123 Patients (82 with chronic gastritis; 20 with dysplasia; 21 with gastric cancer) were biopsied under endoscopy for gastric mucosa.2. Rapid urease test , Warthin-Starry silver stains and Urease gene by PCR were used for diagnosing H.pylori infection(including density grade):the positive infection of H.pylori was defined when both of the tests were positive while the negative infection of H.pylori was defined when both of them were negative.3. Hp-cagA gene was determined by PCR .4. INOS and NF-KB were determined by immunohistochemistory. ResultsINOS Protein was localized in the cytoplasm of inflammatory cells filtrating into the lamina propria. The level INOS from cagA+ patients are significantly higher than that cagA" ones(p<0.05), Higher density grade enhanced the expression of INOS ,especially for the cagA+ layer, Hp density have a stronger effects on INOS expression whereas H.pylori density has less effect on INOS level from cagA" layer. NF-KB (p65) was localized in both the nuclear of gastric glandular epithelial cells and lamina propria inflammatory cells. H.pylori promote NF-KB expression in the glandular epithelial but INOS expression is independent on NF-KB in H.pylori associated gastric disease. Conclusions1. The prevalence of cagA is higher with disease severeness while H.pylori density has little correlation with it.2. The infection with H.pylori higher density and cagA+ strains enhanced the INOS level ,esp. in the layer of cagA+, the grade of H.pylori density have more effect on the INOS expression.3. H.pylori activate NF-KB in gastric epithelial cell. But in patients with H.pylori infection, the expression of INOS is independent on NF-KB activation.