ABSTRACT
Background/Aims@#Bacteria-derived outer membrane vesicles (OMVs) are commonly associated with various biological activities and functions. Helicobacter pylori-derived OMVs are thought to contribute to pathogenesis. This study aimed to investigate the effects of H. pylori-derived OMVs. @*Methods@#H. pylori strains were isolated from patients with gastritis, gastric ulcer, or gastric cancer using endoscopic biopsy. The U-937, AGS, and MKN-45 cell lines were exposed to H. pylori and H. pylori-derived OMVs. The expression of interleukin 8 (IL-8) messenger RNA (mRNA) was assessed using reverse transcription-polymerase chain reaction (RT-PCR) and real-time RT-PCR, and IL-8 secretion was analyzed using enzyme-linked immunosorbent assay. Nuclear factor kappa B (NF-κB) activation was evaluated by Western blotting. @*Results@#H. pylori and H. pylori-derived OMVs induced the expression of IL-8 mRNA and protein. Importantly, the bacteria induced higher IL-8 mRNA and protein expression than the OMVs. IL-8 expression was induced to different levels in response to H. pylori-derived OMVs from hosts with different gastric diseases. Western blotting revealed the increased phosphorylation and reduced degradation of inhibitor of NF-κB alpha in cells exposed to OMVs. @*Conclusions@#H. pylori-derived OMVs may aid the development of various gastric diseases by inducing IL-8 production and NF-κB activation.
ABSTRACT
Background/Aims@#Bacteria-derived outer membrane vesicles (OMVs) are commonly associated with various biological activities and functions. Helicobacter pylori-derived OMVs are thought to contribute to pathogenesis. This study aimed to investigate the effects of H. pylori-derived OMVs. @*Methods@#H. pylori strains were isolated from patients with gastritis, gastric ulcer, or gastric cancer using endoscopic biopsy. The U-937, AGS, and MKN-45 cell lines were exposed to H. pylori and H. pylori-derived OMVs. The expression of interleukin 8 (IL-8) messenger RNA (mRNA) was assessed using reverse transcription-polymerase chain reaction (RT-PCR) and real-time RT-PCR, and IL-8 secretion was analyzed using enzyme-linked immunosorbent assay. Nuclear factor kappa B (NF-κB) activation was evaluated by Western blotting. @*Results@#H. pylori and H. pylori-derived OMVs induced the expression of IL-8 mRNA and protein. Importantly, the bacteria induced higher IL-8 mRNA and protein expression than the OMVs. IL-8 expression was induced to different levels in response to H. pylori-derived OMVs from hosts with different gastric diseases. Western blotting revealed the increased phosphorylation and reduced degradation of inhibitor of NF-κB alpha in cells exposed to OMVs. @*Conclusions@#H. pylori-derived OMVs may aid the development of various gastric diseases by inducing IL-8 production and NF-κB activation.
ABSTRACT
Sodium picosulfate/magnesium citrate (SPMC) is a widely used oral bowel cleansing agent considered to be relatively safe. However, partially dissolved or undissolved SPMC powder may cause severe injuries of the esophagus and stomach. We report a very rare case of acute gastric injury without esophageal damage caused by the ingestion of undissolved SPMC powder. A 69-year-old man experienced epigastric pain after swallowing SPMC powder without dissolving it in water in preparation for a screening colonoscopy. He realized his mistake immediately and subsequently drank 2 L of water. The esophagogastroduodenoscopy conducted after 12 hours indicated an acute gastric ulceration without injury of the esophagus or duodenum. The endoscopy conducted after 6 weeks of oral proton pump inhibitor treatment showed healing of the gastric injury. This suggested that drinking large amounts of water after ingesting partially dissolved or undissolved SPMC powder can prevent serious esophageal injury, but offers no preventive benefit for acute gastric injury.