Delayed healing of gastric ulcer is associated with downregulation of connexin 32 in the gastric mucosa

Abstract

Summary Background/Aims Most benign gastric ulcers are healed through suppression of gastric acid by a proton pump inhibitor (PPI). Despite prolonged use of a PPI, some gastric ulcers still do not heal. The primary goal of this study is to investigate the relationship between the expression of connexin 32 (Cx32), a major gap junction protein expressed in the gastric mucosa, and the healing response of gastric ulcers. Methods Patients with endoscopically verified gastric ulcer were treated with a standard dose of PPI for 12 weeks. Histological studies were performed to exclude malignancy. In total, 10 patients having endoscopically verified gastric ulcers with delayed healing at the end of the PPI course were included in this study. The control group consisted of 11 patients with gastric ulcers that healed normally. The expression of Cx32 in the gastric mucosa of the ulcer margin was analyzed by immunoblotting. Results Patients with gastric ulcer showing delayed healing had significantly reduced Cx32 expression in the gastric mucosa compared with the patients in whom the ulcers healed normally (i.e., controls). Age, sex, presence of duodenal ulcers, location and size of gastric ulcer, ulcer staging, Helicobacter pylori infection, use of nonsteroidal anti‐inflammatory drugs (NSAIDs) and aspirin, smoking, and alcohol consumption were similar in both the control and delayed healing groups. H. pylori infection, use of NSAIDs, smoking, and alcohol consumption all had no significant impacts on the expression of Cx32. Age and expression of Cx32 were not correlated. Conclusion Downregulation of Cx32 in the gastric mucosa of the ulcer margin may predict delayed healing in patients with gastric ulcer following acid‐suppression therapy.

Protective Effect of Pomegranate Peels Extracts Against Stomach Peptic-Ulcer Induced By Brexin In Albino Rats

“…The immunohistochemical results of the PCNA indicated proliferations occurring in the gastric tissue following Brexin application. This result agrees with Wang et al (2015). They demonstrated that Pantoprazole showed an increase in immunoreactivity to PCNA whether following prostaglandin application or at treatment with H2 receptor antagonist alone in the gastric tissue.…”

Endoscopic Outcome of non complicated Gastric Ulcer following Standard Medical Treatment in sub-Saharan African Population

“…Differences between this study and Okada et al's study regarding the proportions of patients with healed ulcers are therefore mainly due to differences in sample size and patients' age. Given the high efficacy of PPIs for the treatment of gastric ulcers 4 , it is more likely that differences in the proportions of ulcer healing between this study and literature data 5 are due to the fact this study was underpowered to detect the total healing effect of PPIs in this population.Nevertheless, low expression of connexin 32 on the gastric mucosa of patients included in this study is also a possible explanation to the much lower rate of ulcer healing observed, compared with literature data 5,15 .Systematic research of this marker on patients' gastric mucosa would have been helpful to verify this hypothesis. The fact that a delay of repeat endoscopy > 8 weeks was a predictor of non-healing of the ulcer in this study suggests that when patients came to do repeat endoscopy beyond the 8 th week, it was because they suspected nonhealing of the ulcer due to persistent or worsening symptoms.…”

Petri Net-Based Model of Helicobacter pylori Mediated Disruption of Tight Junction Proteins in Stomach Lining during Gastric Carcinoma

“…The C-terminal of claudin binds to the zonula occludens through their PDZ domains to seal the TJ (Nomme et al, 2015 ). Dysregulation of these proteins along with another gap junction protein CX32 expressed in gastric mucosa has been reported in delayed healing of gastric ulcer thus leading to gastritis or carcinoma (Wang et al, 2015 ). Activation or deactivation of these proteins under various stimuli is studied in this study.…”