The Effection Of Helicobacter Pylori Infection On The Expression Of NADPH Oxidase DUOX2 And NOX2 In Human Gastric Mucosa

Objective: To further reveal the pathogenesis of gastric disease by studying the effection of Helicobacter pylori(Hp) infection on the expression levels of DUOX2 and NOX2 mRNA and protein in gastic mucosal.Methods: Two hundred gastric mucosa samples were collected from patients who have done gastroscopes in the First Affiliated Hospital of Henan University of Science and Technology from August, 2013 to February, 2014, 113 cases were male and 87 females, age 16 to 86 years old, and mean 52.3. Hp infection was determined by rapid urease testing(RUT). The CagA and Vac A antibodies in serum of Hp(+) patients was assayed by ELISA. The expression of DUOX2 and NOX2 m RNA was measured by RT-PCR, and the expression of DUOX2 and NOX2 protein was evaluated by the method of immunohistochemical and Western blot.Results:1. RUT results showed that 111 cases were Hp(+)(69 male, 42 female), and 89 cases were Hp(-)(44 male, 45 female).2. RT-PCR results showed that DUOX2 mRNA expression level was significantly lower in the Hp(+) patients’ gastric mucosa than that in the Hp(-) group(P=0.02). DUOX2 m RNA expression was lower in Hp Cag A+/Vac A+ and higher in Hp CagA-/VacA-(both P<0.05). On the contrary, the gastric mucosa NOX2 m RNA level in Hp(+) group was significantly higher than that in Hp(-) group(P<0.05). But the expression of NOX2 mRNA in the gastric mucosa was no difference among different strains of Hp.3. The results of immunohistochemistry showed that DUOX2 protein was expressed in the gastric mucosa of all 200 cases which was consistent with its mRNA level. DUOX2 was significantly lower expressed in Hp(+) group than in Hp(-) group(P<0.05) DUOX2 protein expression was lower in CagA+ or Vac A+ group than Cag A-/VacA- group,and it was the lowest in the group of Cag A+/Vac A+(all P<0.05). NOX2 was expressed in inflammatory cells of gastric mucosas, and the expression of NOX2 protein in Hp(+) was higher than that of Hp(-)(P<0.05), but it had no distinction in different strains of Hp.4. Western Blot results showed that gastric mucosal DUOX2 protein expression in Hp(+) group was lower than Hp(-) group, which was 2.2 times higher than the former(P<0.05).Conclusions:1. The expression of DUOX2 was reduced in gastric mucosa with Hp infected. NOX2 was expression in inflammatory cells and was increased in patients who infected with Hp. It showed Hp infection affect the expression of DUOX2 and NOX2 in the epithelial cell of gastric mucosa.2. Hp infection might suppress the expression of DUOX2. The stronger virulence was, the more inhibition effect was. In contrast to, Hp infection increased the expression of NOX2, but the expression of NOX2 was independent of Hp virulence.3. Both of DUOX2 and NOX2 played important roles in gastric mucosal diseases which were induced by Hp infection.