Expression of COX-1, COX-2, and PPAR-γ in the gastric mucosa of children with Helicobacter pylori infection

BACKGROUND Gastric inflammation in patients with Helicobacter pylori infection is considered to be regulated by many kinds of inflammatory and cytoprotective factors. The present study examined the effects of cyclo-oxygenase (COX)-1, -2, and peroxisome proliferator-activated receptor-gamma (PPAR-gamma) on gastric mucosal injury in children with H. pylori infection. METHODS The subjects were 24 children who underwent endoscopy for the evaluation of anemia or gastrointestinal symptoms, and they were divided into two groups: a H. pylori-positive group and -negative group. The numbers of neutrophils in the gastric mucosa of children with and without H. pylori infection and expression of COX-1, -2, and PPAR-gamma were examined, using reverse transcription-polymerase chain reaction. RESULTS The numbers of neutrophils were significantly higher in the H. pylori-positive group than in the H. pylori-negative group. The ratio of COX-1 mRNA to COX-2 mRNA in the H. pylori-positive group was significantly lower than that in the H. pylori-negative group. The ratio of PPAR-gamma m-RNA to beta-actin mRNA was significantly higher in the H. pylori-positive group than the H. pylori-negative group. CONCLUSIONS Enhanced production of COX-2 and PPAR-gamma in the gastric mucosa has cytoprotective and anti-inflammatory effects, although the relationship to the carcinogenic activity of COX-2 and PPAR-gamma should be clarified.