ABSTRACT
Objective To investigate the correlation between Helicobacter pylori (HP) infection-associated gastritis and the ap-optotic genes in gastric mucosa .Methods Forty-five patients with chronic gastritis were registrated in our study from November 2013 to December 2014 .HP infection status in the patients was detected by using urease test and 13C-urea breath test .The degree of gastritis in the gastric mucosa with HP infection was confirmed via histopathology .qRT-PCR was used to measure the mRNA ex-pressions of Bax ,Bak and Bcl-2 in the gastric mucosa with HP infection and matched normal gastric mucosa .Person analysis was used to assess the correlation between the HP infection-associated gastritis and the mRNA expressions of Bax ,Bak and Bcl-2 in the gastric mucosa .Results Forty-five patients with HP infection in antrum and 45 patients (100% ) with chronic antrum gastritis were identified ,including 28 patients (62 .2% ) with light gastritis ,16 patients (35 .6% ) with moderate gastritis ,1 patient (2 .0% ) with severe gastritis .9 patients (20 .0% )with metaplasia ,5 patients(11 .1% ) with low grade intraepithelial neoplasms .The urease tests were negative in the gastric body of 45 patients ,6 patients (13 .3% )were mild chronic gastritis in the body ;Patient with meta-plasia and intrapithelial gastritis was not found .The Bax expression in the HP-infected gastric mucosa was markedly increased when compared with the normal gastric mucosa (P0 .05) .Conclusion HP infec-tion-associated gastritis positively correlated with the expressions of apoptotic genes in gastric mucosa ,suggesting that HP infection might result in increasing the Bax expression and further enhancing the cell apoptosis .
ABSTRACT
Objective To isolate and purify VacA protein secreted by Helicobacter pylori or recombinant VacA , and to investigate the effect of VacA-induced cell vacuolar change and apoptosis .Methods VacA proteins were separated and pu-rified from the culture supernatant of H.pylori ( ATCC26695 ) or from the split products of genetically engineered bacteria (pQE30-VacA-E.coli M15) expressing recombinant VacA.The VacA protein obtained was acidified and then incubated with AGS cells for 24 h at different final concentrations of 5 and 10 ng/ml before the vacuolar change and apoptosis of AGS cells were detected via microscopy and flow cytometry assay , respectively .Results H.pylori-secreted VacA and recombi-nant VacA were successfully separated and purified .The H.pylori-secreted VacA significantly induced the vacuolar change and apoptosis of AGS cells (P<0.01) while the recombinant VacA did not.Conclusion H.pylori-secreted VacA protein can effectively induce cell vacuolar change and apoptosis, but recombinant VacA can not, suggesting that the purified VacA protein secreted by H.pylori can be used to explore VacA-induced pathogenesis.