Effect Of Single Nucleotide Polymorphism Of NLRP3 Gene On Gastric Mucosal Inflammation Caused By Hp Infection

Helicobacter pylori?HP?is a pathogen that colonizes in the human gastric mucosa,and it spreads about half the world.The rate of HP infection in China is about 52.2%.Although HP infection rate is high,only a small number of infected individuals develop peptic ulcer or gastric cancer.The clinical results of HP infection are related to different virulence of HP strains,environmental factors and genetic susceptibility of the host.Our previous studies found that 90%of HP strains in China were CagA-positive,and all of them were highly virulent East Asian strains.The different host response to HP infection greatly affects the degree of gastric mucosal inflammation.NLRP3inflammasome plays a key role in innate immunity.It has been found that HP infection can activate the expression of NLRP3 inflammasome,affect the maturation and secretion of downstream inflammatory factor IL-1?,and lead to the occurrence of gastric cancer.Therefore,we suggest that SNPs of NLRP3 gene may affect the degree of gastric mucosal inflammation after HP infection.Objective:The aim of this study was to explore the relationship between HP infection and gastric mucosal inflammation,and to study the main virulence factors vacA gene i and d subtypes of HP in Zhenjiang area and their relationship with gastritis.We also tend to study the influence of HP infection on the expression of NLRP3 and IL-1?mRNA in gastric mucosa,and to explore the correlation between SNPs of NLRP3 and the degree of gastric mucosal inflammation.Methods:1.Select 159 asymptomatic people who underwent gastroscopy and ¹³C breath test at the same time in the Affiliated Hospital of Jiangsu University from January 2014 to December 2017.1.According to ¹³C breath test,they were divided into HP positive group and HP negative group.The differences of chronic inflammation degree and inflammation activity degree of gastric mucosa between the two groups were compared.2.Select 198 patients with gastrointestinal discomfort came to the gastroscopy room of the Affiliated Hospital of Jiangsu University for gastroscopy examination from January2018 to September 2018.According to the rapid urease test,they were divided into HP positive group and HP negative group.The SNPs of NLRP3 gene were detected by Taqman probe method,and the expression of NLRP3 and IL-1?in gastric mucosa was measured by real-time fluorescence quantitative PCR.The differences of chronic inflammation and inflammatory activity of gastric mucosa between the two groups were compared.At the same time,the vacA gene i and d subtypes of HP were detected by PCR in HP positive group.Result:1.The degree of gastric mucosal inflammation and inflammatory activity in HP positive group were significantly higher than those in HP negative group?P<0.001?.2.The expression of NLRP3 and IL-1?mRNA in gastric mucosa of HP positive group was higher than that of HP negative group?P<0.01?.3.The frequencies of CC,CT and TT genotypes of NLRP3 rs4612666?C/T?were 8.6%,83.8%and 7.6%,respectively.There was no significant correlation between the frequencies of CC,CT and TT genotypes and the degree of gastric mucosal inflammation.4.The vacA i and d genotypes of HP strains in Zhenjiang area are mainly i1 and d1.Conclusion:HP infection can improve the degree and activity of gastric mucosal inflammation,which is related to the increased expression of NLRP3 and IL-1?mRNA in gastric mucosa.However,rs4612666 of NLRP3 gene is not associated with HP susceptibility and gastric mucosal inflammation.