| Objective: Chronic gastritis(CG)refers to chronic gastric mucosal inflammatory lesions caused by various etiologies.There was no obvious atrophy and intestinal metaplasia in the early stage of the patient,but there were obvious symptoms of abdominal pain and abdominal distension.It is one of the most common persistent and insidious diseases in humans,which seriously affects the work and life of patients.Helicobacter pylori is a microaerophilic gram-negative Helicobacter,cytotoxicity-related gene A antigen(Cag A)as its major virulence factor.The study found that Cag A-positive H.pylori damage to gastric mucosa is more serious.Our previous experimental study found that compared with asymptomatic patients with Hp infection,the positive rate of Cag A in gastric mucosa of patients with functional dyspepsia with Hp infection was significantly higher.This result suggests that Hp infection may affect the symptoms and disease development of patients with chronic gastritis through Cag A.Chronic gastritis is often accompanied by obvious abdominal pain and bloating.Many neurotransmitters and endocrine hormones in the human body may be involved in the regulation of the above symptoms.Clinical studies have found that the expression of 5-hydroxytryptamine(5-HT)and 5-hydroxytryptamine receptor(5-HTR)m RNA in gastric mucosa of patients with chronic gastritis is significantly higher than that of normal patients,of which 5-HTR1,5-HTR3,and5-HTR4 are all involved visceral hyperesthesia regulation.NF-k B(P65)is considered to be an important mediator of pathophysiological changes in the stomach.Studies have found that activation of NF-k B(P65)not only affects the release of cytokines,but may even cause hormonal changes in the body.P65 activation can promote increased 5-HT release in studies with enterophagocytoma.Therefore,the purpose of this study was to investigate the effect of Cag A virulence factor released by H.pylori on the content of 5-HT in blood and the expression of 5-HT receptors related to the regulation of gastrointestinal function by activating the NF-k B(P65)signaling pathway,thereby leading to Gastrointestinal-related symptoms in patients with chronic gastritis.Propose new therapeutic directions and targets for clinical treatment of CG.Methods:(1)HP-infected chronic gastritis patients and healthy controls were recruited,and gastric mucosal tissue was collected under endoscopy;(2)Verification at the tissue level: Immunohistochemical and Western-blot methods were used to detect and compare of Changes in protein expression of 5-HTR1,5-HTR3,5-HTR4,Cag A,p-P65.(3)Verification from the cellular level: The Pc DNA3.1-Cag A eukaryotic expression plasmid and the control group Pc DNA3.1-NC plasmid were transfected into MKN28 and MKN45 gastric cancer cells with liposome 8000,to detect and compare of changes in protein expression of 5-HTR1,5HTR3,5-HTR4 and p-P65 in MKN28,MKN45(NC)gastric cancer cell group and MKN28,MKN45(Cag A)gastric cancer cell group.Results:(1)Immunohistochemical results showed that the expressions of 5-HTR3,5-HTR4 and p-P65 in CG-HP(+)Cag A(+)gastric mucosa were significantly higher than those in normal gastric mucosa,and the difference was statistically significant(P<0.05).(2)Western-blot assay showed that compared with the healthy control group,the protein expressions of 5-HTR3,5-HTR4,Cag A and p-P65 in the gastric mucosa of CG-HP(+)Cag A(+)patients were significantly increased,and the difference was statistically significant(P<0.05).(3)The results of cell experiments showed that the protein expressions of 5-HTR3,5-HTR4 and p-P65 in the MKN28 and MKN45 gastric cancer cell lines Pc DNA3.1-Cag A group were significantly higher than those in the Pc DNA3.1-NC group,among which the Pc DNA3.1-Cag A group had positive expression of flag(Confirmed that Cag A overexpression was successfully constructed).Conclusion: The Cag A virulence factor released by H.pylori may affect the expression of 5-HTR3 and 5-HTR4 related to the regulation of gastrointestinal function by activating the NF-k B(P65)signaling pathway,thereby leading to gastrointestinal symptoms in CG patients. |
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